xref: /linux/drivers/ata/libata-core.c (revision a1e58bbdc969c3fe60addca7f2729779d22a83c1)
1 /*
2  *  libata-core.c - helper library for ATA
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
9  *  Copyright 2003-2004 Jeff Garzik
10  *
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2, or (at your option)
15  *  any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; see the file COPYING.  If not, write to
24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  *  Standards documents from:
34  *	http://www.t13.org (ATA standards, PCI DMA IDE spec)
35  *	http://www.t10.org (SCSI MMC - for ATAPI MMC)
36  *	http://www.sata-io.org (SATA)
37  *	http://www.compactflash.org (CF)
38  *	http://www.qic.org (QIC157 - Tape and DSC)
39  *	http://www.ce-ata.org (CE-ATA: not supported)
40  *
41  */
42 
43 #include <linux/kernel.h>
44 #include <linux/module.h>
45 #include <linux/pci.h>
46 #include <linux/init.h>
47 #include <linux/list.h>
48 #include <linux/mm.h>
49 #include <linux/highmem.h>
50 #include <linux/spinlock.h>
51 #include <linux/blkdev.h>
52 #include <linux/delay.h>
53 #include <linux/timer.h>
54 #include <linux/interrupt.h>
55 #include <linux/completion.h>
56 #include <linux/suspend.h>
57 #include <linux/workqueue.h>
58 #include <linux/jiffies.h>
59 #include <linux/scatterlist.h>
60 #include <linux/io.h>
61 #include <scsi/scsi.h>
62 #include <scsi/scsi_cmnd.h>
63 #include <scsi/scsi_host.h>
64 #include <linux/libata.h>
65 #include <asm/semaphore.h>
66 #include <asm/byteorder.h>
67 #include <linux/cdrom.h>
68 
69 #include "libata.h"
70 
71 
72 /* debounce timing parameters in msecs { interval, duration, timeout } */
73 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
74 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
75 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
76 
77 static unsigned int ata_dev_init_params(struct ata_device *dev,
78 					u16 heads, u16 sectors);
79 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
80 static unsigned int ata_dev_set_feature(struct ata_device *dev,
81 					u8 enable, u8 feature);
82 static void ata_dev_xfermask(struct ata_device *dev);
83 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
84 
85 unsigned int ata_print_id = 1;
86 static struct workqueue_struct *ata_wq;
87 
88 struct workqueue_struct *ata_aux_wq;
89 
90 struct ata_force_param {
91 	const char	*name;
92 	unsigned int	cbl;
93 	int		spd_limit;
94 	unsigned long	xfer_mask;
95 	unsigned int	horkage_on;
96 	unsigned int	horkage_off;
97 };
98 
99 struct ata_force_ent {
100 	int			port;
101 	int			device;
102 	struct ata_force_param	param;
103 };
104 
105 static struct ata_force_ent *ata_force_tbl;
106 static int ata_force_tbl_size;
107 
108 static char ata_force_param_buf[PAGE_SIZE] __initdata;
109 /* param_buf is thrown away after initialization, disallow read */
110 module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0);
111 MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/kernel-parameters.txt for details)");
112 
113 int atapi_enabled = 1;
114 module_param(atapi_enabled, int, 0444);
115 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
116 
117 static int atapi_dmadir = 0;
118 module_param(atapi_dmadir, int, 0444);
119 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
120 
121 int atapi_passthru16 = 1;
122 module_param(atapi_passthru16, int, 0444);
123 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices; on by default (0=off, 1=on)");
124 
125 int libata_fua = 0;
126 module_param_named(fua, libata_fua, int, 0444);
127 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
128 
129 static int ata_ignore_hpa;
130 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
131 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
132 
133 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
134 module_param_named(dma, libata_dma_mask, int, 0444);
135 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
136 
137 static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
138 module_param(ata_probe_timeout, int, 0444);
139 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
140 
141 int libata_noacpi = 0;
142 module_param_named(noacpi, libata_noacpi, int, 0444);
143 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
144 
145 int libata_allow_tpm = 0;
146 module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
147 MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands");
148 
149 MODULE_AUTHOR("Jeff Garzik");
150 MODULE_DESCRIPTION("Library module for ATA devices");
151 MODULE_LICENSE("GPL");
152 MODULE_VERSION(DRV_VERSION);
153 
154 
155 /**
156  *	ata_force_cbl - force cable type according to libata.force
157  *	@ap: ATA port of interest
158  *
159  *	Force cable type according to libata.force and whine about it.
160  *	The last entry which has matching port number is used, so it
161  *	can be specified as part of device force parameters.  For
162  *	example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
163  *	same effect.
164  *
165  *	LOCKING:
166  *	EH context.
167  */
168 void ata_force_cbl(struct ata_port *ap)
169 {
170 	int i;
171 
172 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
173 		const struct ata_force_ent *fe = &ata_force_tbl[i];
174 
175 		if (fe->port != -1 && fe->port != ap->print_id)
176 			continue;
177 
178 		if (fe->param.cbl == ATA_CBL_NONE)
179 			continue;
180 
181 		ap->cbl = fe->param.cbl;
182 		ata_port_printk(ap, KERN_NOTICE,
183 				"FORCE: cable set to %s\n", fe->param.name);
184 		return;
185 	}
186 }
187 
188 /**
189  *	ata_force_spd_limit - force SATA spd limit according to libata.force
190  *	@link: ATA link of interest
191  *
192  *	Force SATA spd limit according to libata.force and whine about
193  *	it.  When only the port part is specified (e.g. 1:), the limit
194  *	applies to all links connected to both the host link and all
195  *	fan-out ports connected via PMP.  If the device part is
196  *	specified as 0 (e.g. 1.00:), it specifies the first fan-out
197  *	link not the host link.  Device number 15 always points to the
198  *	host link whether PMP is attached or not.
199  *
200  *	LOCKING:
201  *	EH context.
202  */
203 static void ata_force_spd_limit(struct ata_link *link)
204 {
205 	int linkno, i;
206 
207 	if (ata_is_host_link(link))
208 		linkno = 15;
209 	else
210 		linkno = link->pmp;
211 
212 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
213 		const struct ata_force_ent *fe = &ata_force_tbl[i];
214 
215 		if (fe->port != -1 && fe->port != link->ap->print_id)
216 			continue;
217 
218 		if (fe->device != -1 && fe->device != linkno)
219 			continue;
220 
221 		if (!fe->param.spd_limit)
222 			continue;
223 
224 		link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
225 		ata_link_printk(link, KERN_NOTICE,
226 			"FORCE: PHY spd limit set to %s\n", fe->param.name);
227 		return;
228 	}
229 }
230 
231 /**
232  *	ata_force_xfermask - force xfermask according to libata.force
233  *	@dev: ATA device of interest
234  *
235  *	Force xfer_mask according to libata.force and whine about it.
236  *	For consistency with link selection, device number 15 selects
237  *	the first device connected to the host link.
238  *
239  *	LOCKING:
240  *	EH context.
241  */
242 static void ata_force_xfermask(struct ata_device *dev)
243 {
244 	int devno = dev->link->pmp + dev->devno;
245 	int alt_devno = devno;
246 	int i;
247 
248 	/* allow n.15 for the first device attached to host port */
249 	if (ata_is_host_link(dev->link) && devno == 0)
250 		alt_devno = 15;
251 
252 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
253 		const struct ata_force_ent *fe = &ata_force_tbl[i];
254 		unsigned long pio_mask, mwdma_mask, udma_mask;
255 
256 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
257 			continue;
258 
259 		if (fe->device != -1 && fe->device != devno &&
260 		    fe->device != alt_devno)
261 			continue;
262 
263 		if (!fe->param.xfer_mask)
264 			continue;
265 
266 		ata_unpack_xfermask(fe->param.xfer_mask,
267 				    &pio_mask, &mwdma_mask, &udma_mask);
268 		if (udma_mask)
269 			dev->udma_mask = udma_mask;
270 		else if (mwdma_mask) {
271 			dev->udma_mask = 0;
272 			dev->mwdma_mask = mwdma_mask;
273 		} else {
274 			dev->udma_mask = 0;
275 			dev->mwdma_mask = 0;
276 			dev->pio_mask = pio_mask;
277 		}
278 
279 		ata_dev_printk(dev, KERN_NOTICE,
280 			"FORCE: xfer_mask set to %s\n", fe->param.name);
281 		return;
282 	}
283 }
284 
285 /**
286  *	ata_force_horkage - force horkage according to libata.force
287  *	@dev: ATA device of interest
288  *
289  *	Force horkage according to libata.force and whine about it.
290  *	For consistency with link selection, device number 15 selects
291  *	the first device connected to the host link.
292  *
293  *	LOCKING:
294  *	EH context.
295  */
296 static void ata_force_horkage(struct ata_device *dev)
297 {
298 	int devno = dev->link->pmp + dev->devno;
299 	int alt_devno = devno;
300 	int i;
301 
302 	/* allow n.15 for the first device attached to host port */
303 	if (ata_is_host_link(dev->link) && devno == 0)
304 		alt_devno = 15;
305 
306 	for (i = 0; i < ata_force_tbl_size; i++) {
307 		const struct ata_force_ent *fe = &ata_force_tbl[i];
308 
309 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
310 			continue;
311 
312 		if (fe->device != -1 && fe->device != devno &&
313 		    fe->device != alt_devno)
314 			continue;
315 
316 		if (!(~dev->horkage & fe->param.horkage_on) &&
317 		    !(dev->horkage & fe->param.horkage_off))
318 			continue;
319 
320 		dev->horkage |= fe->param.horkage_on;
321 		dev->horkage &= ~fe->param.horkage_off;
322 
323 		ata_dev_printk(dev, KERN_NOTICE,
324 			"FORCE: horkage modified (%s)\n", fe->param.name);
325 	}
326 }
327 
328 /**
329  *	atapi_cmd_type - Determine ATAPI command type from SCSI opcode
330  *	@opcode: SCSI opcode
331  *
332  *	Determine ATAPI command type from @opcode.
333  *
334  *	LOCKING:
335  *	None.
336  *
337  *	RETURNS:
338  *	ATAPI_{READ|WRITE|READ_CD|PASS_THRU|MISC}
339  */
340 int atapi_cmd_type(u8 opcode)
341 {
342 	switch (opcode) {
343 	case GPCMD_READ_10:
344 	case GPCMD_READ_12:
345 		return ATAPI_READ;
346 
347 	case GPCMD_WRITE_10:
348 	case GPCMD_WRITE_12:
349 	case GPCMD_WRITE_AND_VERIFY_10:
350 		return ATAPI_WRITE;
351 
352 	case GPCMD_READ_CD:
353 	case GPCMD_READ_CD_MSF:
354 		return ATAPI_READ_CD;
355 
356 	case ATA_16:
357 	case ATA_12:
358 		if (atapi_passthru16)
359 			return ATAPI_PASS_THRU;
360 		/* fall thru */
361 	default:
362 		return ATAPI_MISC;
363 	}
364 }
365 
366 /**
367  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
368  *	@tf: Taskfile to convert
369  *	@pmp: Port multiplier port
370  *	@is_cmd: This FIS is for command
371  *	@fis: Buffer into which data will output
372  *
373  *	Converts a standard ATA taskfile to a Serial ATA
374  *	FIS structure (Register - Host to Device).
375  *
376  *	LOCKING:
377  *	Inherited from caller.
378  */
379 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
380 {
381 	fis[0] = 0x27;			/* Register - Host to Device FIS */
382 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
383 	if (is_cmd)
384 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
385 
386 	fis[2] = tf->command;
387 	fis[3] = tf->feature;
388 
389 	fis[4] = tf->lbal;
390 	fis[5] = tf->lbam;
391 	fis[6] = tf->lbah;
392 	fis[7] = tf->device;
393 
394 	fis[8] = tf->hob_lbal;
395 	fis[9] = tf->hob_lbam;
396 	fis[10] = tf->hob_lbah;
397 	fis[11] = tf->hob_feature;
398 
399 	fis[12] = tf->nsect;
400 	fis[13] = tf->hob_nsect;
401 	fis[14] = 0;
402 	fis[15] = tf->ctl;
403 
404 	fis[16] = 0;
405 	fis[17] = 0;
406 	fis[18] = 0;
407 	fis[19] = 0;
408 }
409 
410 /**
411  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
412  *	@fis: Buffer from which data will be input
413  *	@tf: Taskfile to output
414  *
415  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
416  *
417  *	LOCKING:
418  *	Inherited from caller.
419  */
420 
421 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
422 {
423 	tf->command	= fis[2];	/* status */
424 	tf->feature	= fis[3];	/* error */
425 
426 	tf->lbal	= fis[4];
427 	tf->lbam	= fis[5];
428 	tf->lbah	= fis[6];
429 	tf->device	= fis[7];
430 
431 	tf->hob_lbal	= fis[8];
432 	tf->hob_lbam	= fis[9];
433 	tf->hob_lbah	= fis[10];
434 
435 	tf->nsect	= fis[12];
436 	tf->hob_nsect	= fis[13];
437 }
438 
439 static const u8 ata_rw_cmds[] = {
440 	/* pio multi */
441 	ATA_CMD_READ_MULTI,
442 	ATA_CMD_WRITE_MULTI,
443 	ATA_CMD_READ_MULTI_EXT,
444 	ATA_CMD_WRITE_MULTI_EXT,
445 	0,
446 	0,
447 	0,
448 	ATA_CMD_WRITE_MULTI_FUA_EXT,
449 	/* pio */
450 	ATA_CMD_PIO_READ,
451 	ATA_CMD_PIO_WRITE,
452 	ATA_CMD_PIO_READ_EXT,
453 	ATA_CMD_PIO_WRITE_EXT,
454 	0,
455 	0,
456 	0,
457 	0,
458 	/* dma */
459 	ATA_CMD_READ,
460 	ATA_CMD_WRITE,
461 	ATA_CMD_READ_EXT,
462 	ATA_CMD_WRITE_EXT,
463 	0,
464 	0,
465 	0,
466 	ATA_CMD_WRITE_FUA_EXT
467 };
468 
469 /**
470  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
471  *	@tf: command to examine and configure
472  *	@dev: device tf belongs to
473  *
474  *	Examine the device configuration and tf->flags to calculate
475  *	the proper read/write commands and protocol to use.
476  *
477  *	LOCKING:
478  *	caller.
479  */
480 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
481 {
482 	u8 cmd;
483 
484 	int index, fua, lba48, write;
485 
486 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
487 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
488 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
489 
490 	if (dev->flags & ATA_DFLAG_PIO) {
491 		tf->protocol = ATA_PROT_PIO;
492 		index = dev->multi_count ? 0 : 8;
493 	} else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
494 		/* Unable to use DMA due to host limitation */
495 		tf->protocol = ATA_PROT_PIO;
496 		index = dev->multi_count ? 0 : 8;
497 	} else {
498 		tf->protocol = ATA_PROT_DMA;
499 		index = 16;
500 	}
501 
502 	cmd = ata_rw_cmds[index + fua + lba48 + write];
503 	if (cmd) {
504 		tf->command = cmd;
505 		return 0;
506 	}
507 	return -1;
508 }
509 
510 /**
511  *	ata_tf_read_block - Read block address from ATA taskfile
512  *	@tf: ATA taskfile of interest
513  *	@dev: ATA device @tf belongs to
514  *
515  *	LOCKING:
516  *	None.
517  *
518  *	Read block address from @tf.  This function can handle all
519  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
520  *	flags select the address format to use.
521  *
522  *	RETURNS:
523  *	Block address read from @tf.
524  */
525 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
526 {
527 	u64 block = 0;
528 
529 	if (tf->flags & ATA_TFLAG_LBA) {
530 		if (tf->flags & ATA_TFLAG_LBA48) {
531 			block |= (u64)tf->hob_lbah << 40;
532 			block |= (u64)tf->hob_lbam << 32;
533 			block |= tf->hob_lbal << 24;
534 		} else
535 			block |= (tf->device & 0xf) << 24;
536 
537 		block |= tf->lbah << 16;
538 		block |= tf->lbam << 8;
539 		block |= tf->lbal;
540 	} else {
541 		u32 cyl, head, sect;
542 
543 		cyl = tf->lbam | (tf->lbah << 8);
544 		head = tf->device & 0xf;
545 		sect = tf->lbal;
546 
547 		block = (cyl * dev->heads + head) * dev->sectors + sect;
548 	}
549 
550 	return block;
551 }
552 
553 /**
554  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
555  *	@tf: Target ATA taskfile
556  *	@dev: ATA device @tf belongs to
557  *	@block: Block address
558  *	@n_block: Number of blocks
559  *	@tf_flags: RW/FUA etc...
560  *	@tag: tag
561  *
562  *	LOCKING:
563  *	None.
564  *
565  *	Build ATA taskfile @tf for read/write request described by
566  *	@block, @n_block, @tf_flags and @tag on @dev.
567  *
568  *	RETURNS:
569  *
570  *	0 on success, -ERANGE if the request is too large for @dev,
571  *	-EINVAL if the request is invalid.
572  */
573 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
574 		    u64 block, u32 n_block, unsigned int tf_flags,
575 		    unsigned int tag)
576 {
577 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
578 	tf->flags |= tf_flags;
579 
580 	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
581 		/* yay, NCQ */
582 		if (!lba_48_ok(block, n_block))
583 			return -ERANGE;
584 
585 		tf->protocol = ATA_PROT_NCQ;
586 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
587 
588 		if (tf->flags & ATA_TFLAG_WRITE)
589 			tf->command = ATA_CMD_FPDMA_WRITE;
590 		else
591 			tf->command = ATA_CMD_FPDMA_READ;
592 
593 		tf->nsect = tag << 3;
594 		tf->hob_feature = (n_block >> 8) & 0xff;
595 		tf->feature = n_block & 0xff;
596 
597 		tf->hob_lbah = (block >> 40) & 0xff;
598 		tf->hob_lbam = (block >> 32) & 0xff;
599 		tf->hob_lbal = (block >> 24) & 0xff;
600 		tf->lbah = (block >> 16) & 0xff;
601 		tf->lbam = (block >> 8) & 0xff;
602 		tf->lbal = block & 0xff;
603 
604 		tf->device = 1 << 6;
605 		if (tf->flags & ATA_TFLAG_FUA)
606 			tf->device |= 1 << 7;
607 	} else if (dev->flags & ATA_DFLAG_LBA) {
608 		tf->flags |= ATA_TFLAG_LBA;
609 
610 		if (lba_28_ok(block, n_block)) {
611 			/* use LBA28 */
612 			tf->device |= (block >> 24) & 0xf;
613 		} else if (lba_48_ok(block, n_block)) {
614 			if (!(dev->flags & ATA_DFLAG_LBA48))
615 				return -ERANGE;
616 
617 			/* use LBA48 */
618 			tf->flags |= ATA_TFLAG_LBA48;
619 
620 			tf->hob_nsect = (n_block >> 8) & 0xff;
621 
622 			tf->hob_lbah = (block >> 40) & 0xff;
623 			tf->hob_lbam = (block >> 32) & 0xff;
624 			tf->hob_lbal = (block >> 24) & 0xff;
625 		} else
626 			/* request too large even for LBA48 */
627 			return -ERANGE;
628 
629 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
630 			return -EINVAL;
631 
632 		tf->nsect = n_block & 0xff;
633 
634 		tf->lbah = (block >> 16) & 0xff;
635 		tf->lbam = (block >> 8) & 0xff;
636 		tf->lbal = block & 0xff;
637 
638 		tf->device |= ATA_LBA;
639 	} else {
640 		/* CHS */
641 		u32 sect, head, cyl, track;
642 
643 		/* The request -may- be too large for CHS addressing. */
644 		if (!lba_28_ok(block, n_block))
645 			return -ERANGE;
646 
647 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
648 			return -EINVAL;
649 
650 		/* Convert LBA to CHS */
651 		track = (u32)block / dev->sectors;
652 		cyl   = track / dev->heads;
653 		head  = track % dev->heads;
654 		sect  = (u32)block % dev->sectors + 1;
655 
656 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
657 			(u32)block, track, cyl, head, sect);
658 
659 		/* Check whether the converted CHS can fit.
660 		   Cylinder: 0-65535
661 		   Head: 0-15
662 		   Sector: 1-255*/
663 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
664 			return -ERANGE;
665 
666 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
667 		tf->lbal = sect;
668 		tf->lbam = cyl;
669 		tf->lbah = cyl >> 8;
670 		tf->device |= head;
671 	}
672 
673 	return 0;
674 }
675 
676 /**
677  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
678  *	@pio_mask: pio_mask
679  *	@mwdma_mask: mwdma_mask
680  *	@udma_mask: udma_mask
681  *
682  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
683  *	unsigned int xfer_mask.
684  *
685  *	LOCKING:
686  *	None.
687  *
688  *	RETURNS:
689  *	Packed xfer_mask.
690  */
691 unsigned long ata_pack_xfermask(unsigned long pio_mask,
692 				unsigned long mwdma_mask,
693 				unsigned long udma_mask)
694 {
695 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
696 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
697 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
698 }
699 
700 /**
701  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
702  *	@xfer_mask: xfer_mask to unpack
703  *	@pio_mask: resulting pio_mask
704  *	@mwdma_mask: resulting mwdma_mask
705  *	@udma_mask: resulting udma_mask
706  *
707  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
708  *	Any NULL distination masks will be ignored.
709  */
710 void ata_unpack_xfermask(unsigned long xfer_mask, unsigned long *pio_mask,
711 			 unsigned long *mwdma_mask, unsigned long *udma_mask)
712 {
713 	if (pio_mask)
714 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
715 	if (mwdma_mask)
716 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
717 	if (udma_mask)
718 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
719 }
720 
721 static const struct ata_xfer_ent {
722 	int shift, bits;
723 	u8 base;
724 } ata_xfer_tbl[] = {
725 	{ ATA_SHIFT_PIO, ATA_NR_PIO_MODES, XFER_PIO_0 },
726 	{ ATA_SHIFT_MWDMA, ATA_NR_MWDMA_MODES, XFER_MW_DMA_0 },
727 	{ ATA_SHIFT_UDMA, ATA_NR_UDMA_MODES, XFER_UDMA_0 },
728 	{ -1, },
729 };
730 
731 /**
732  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
733  *	@xfer_mask: xfer_mask of interest
734  *
735  *	Return matching XFER_* value for @xfer_mask.  Only the highest
736  *	bit of @xfer_mask is considered.
737  *
738  *	LOCKING:
739  *	None.
740  *
741  *	RETURNS:
742  *	Matching XFER_* value, 0xff if no match found.
743  */
744 u8 ata_xfer_mask2mode(unsigned long xfer_mask)
745 {
746 	int highbit = fls(xfer_mask) - 1;
747 	const struct ata_xfer_ent *ent;
748 
749 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
750 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
751 			return ent->base + highbit - ent->shift;
752 	return 0xff;
753 }
754 
755 /**
756  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
757  *	@xfer_mode: XFER_* of interest
758  *
759  *	Return matching xfer_mask for @xfer_mode.
760  *
761  *	LOCKING:
762  *	None.
763  *
764  *	RETURNS:
765  *	Matching xfer_mask, 0 if no match found.
766  */
767 unsigned long ata_xfer_mode2mask(u8 xfer_mode)
768 {
769 	const struct ata_xfer_ent *ent;
770 
771 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
772 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
773 			return ((2 << (ent->shift + xfer_mode - ent->base)) - 1)
774 				& ~((1 << ent->shift) - 1);
775 	return 0;
776 }
777 
778 /**
779  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
780  *	@xfer_mode: XFER_* of interest
781  *
782  *	Return matching xfer_shift for @xfer_mode.
783  *
784  *	LOCKING:
785  *	None.
786  *
787  *	RETURNS:
788  *	Matching xfer_shift, -1 if no match found.
789  */
790 int ata_xfer_mode2shift(unsigned long xfer_mode)
791 {
792 	const struct ata_xfer_ent *ent;
793 
794 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
795 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
796 			return ent->shift;
797 	return -1;
798 }
799 
800 /**
801  *	ata_mode_string - convert xfer_mask to string
802  *	@xfer_mask: mask of bits supported; only highest bit counts.
803  *
804  *	Determine string which represents the highest speed
805  *	(highest bit in @modemask).
806  *
807  *	LOCKING:
808  *	None.
809  *
810  *	RETURNS:
811  *	Constant C string representing highest speed listed in
812  *	@mode_mask, or the constant C string "<n/a>".
813  */
814 const char *ata_mode_string(unsigned long xfer_mask)
815 {
816 	static const char * const xfer_mode_str[] = {
817 		"PIO0",
818 		"PIO1",
819 		"PIO2",
820 		"PIO3",
821 		"PIO4",
822 		"PIO5",
823 		"PIO6",
824 		"MWDMA0",
825 		"MWDMA1",
826 		"MWDMA2",
827 		"MWDMA3",
828 		"MWDMA4",
829 		"UDMA/16",
830 		"UDMA/25",
831 		"UDMA/33",
832 		"UDMA/44",
833 		"UDMA/66",
834 		"UDMA/100",
835 		"UDMA/133",
836 		"UDMA7",
837 	};
838 	int highbit;
839 
840 	highbit = fls(xfer_mask) - 1;
841 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
842 		return xfer_mode_str[highbit];
843 	return "<n/a>";
844 }
845 
846 static const char *sata_spd_string(unsigned int spd)
847 {
848 	static const char * const spd_str[] = {
849 		"1.5 Gbps",
850 		"3.0 Gbps",
851 	};
852 
853 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
854 		return "<unknown>";
855 	return spd_str[spd - 1];
856 }
857 
858 void ata_dev_disable(struct ata_device *dev)
859 {
860 	if (ata_dev_enabled(dev)) {
861 		if (ata_msg_drv(dev->link->ap))
862 			ata_dev_printk(dev, KERN_WARNING, "disabled\n");
863 		ata_acpi_on_disable(dev);
864 		ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
865 					     ATA_DNXFER_QUIET);
866 		dev->class++;
867 	}
868 }
869 
870 static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
871 {
872 	struct ata_link *link = dev->link;
873 	struct ata_port *ap = link->ap;
874 	u32 scontrol;
875 	unsigned int err_mask;
876 	int rc;
877 
878 	/*
879 	 * disallow DIPM for drivers which haven't set
880 	 * ATA_FLAG_IPM.  This is because when DIPM is enabled,
881 	 * phy ready will be set in the interrupt status on
882 	 * state changes, which will cause some drivers to
883 	 * think there are errors - additionally drivers will
884 	 * need to disable hot plug.
885 	 */
886 	if (!(ap->flags & ATA_FLAG_IPM) || !ata_dev_enabled(dev)) {
887 		ap->pm_policy = NOT_AVAILABLE;
888 		return -EINVAL;
889 	}
890 
891 	/*
892 	 * For DIPM, we will only enable it for the
893 	 * min_power setting.
894 	 *
895 	 * Why?  Because Disks are too stupid to know that
896 	 * If the host rejects a request to go to SLUMBER
897 	 * they should retry at PARTIAL, and instead it
898 	 * just would give up.  So, for medium_power to
899 	 * work at all, we need to only allow HIPM.
900 	 */
901 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
902 	if (rc)
903 		return rc;
904 
905 	switch (policy) {
906 	case MIN_POWER:
907 		/* no restrictions on IPM transitions */
908 		scontrol &= ~(0x3 << 8);
909 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
910 		if (rc)
911 			return rc;
912 
913 		/* enable DIPM */
914 		if (dev->flags & ATA_DFLAG_DIPM)
915 			err_mask = ata_dev_set_feature(dev,
916 					SETFEATURES_SATA_ENABLE, SATA_DIPM);
917 		break;
918 	case MEDIUM_POWER:
919 		/* allow IPM to PARTIAL */
920 		scontrol &= ~(0x1 << 8);
921 		scontrol |= (0x2 << 8);
922 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
923 		if (rc)
924 			return rc;
925 
926 		/*
927 		 * we don't have to disable DIPM since IPM flags
928 		 * disallow transitions to SLUMBER, which effectively
929 		 * disable DIPM if it does not support PARTIAL
930 		 */
931 		break;
932 	case NOT_AVAILABLE:
933 	case MAX_PERFORMANCE:
934 		/* disable all IPM transitions */
935 		scontrol |= (0x3 << 8);
936 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
937 		if (rc)
938 			return rc;
939 
940 		/*
941 		 * we don't have to disable DIPM since IPM flags
942 		 * disallow all transitions which effectively
943 		 * disable DIPM anyway.
944 		 */
945 		break;
946 	}
947 
948 	/* FIXME: handle SET FEATURES failure */
949 	(void) err_mask;
950 
951 	return 0;
952 }
953 
954 /**
955  *	ata_dev_enable_pm - enable SATA interface power management
956  *	@dev:  device to enable power management
957  *	@policy: the link power management policy
958  *
959  *	Enable SATA Interface power management.  This will enable
960  *	Device Interface Power Management (DIPM) for min_power
961  * 	policy, and then call driver specific callbacks for
962  *	enabling Host Initiated Power management.
963  *
964  *	Locking: Caller.
965  *	Returns: -EINVAL if IPM is not supported, 0 otherwise.
966  */
967 void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy)
968 {
969 	int rc = 0;
970 	struct ata_port *ap = dev->link->ap;
971 
972 	/* set HIPM first, then DIPM */
973 	if (ap->ops->enable_pm)
974 		rc = ap->ops->enable_pm(ap, policy);
975 	if (rc)
976 		goto enable_pm_out;
977 	rc = ata_dev_set_dipm(dev, policy);
978 
979 enable_pm_out:
980 	if (rc)
981 		ap->pm_policy = MAX_PERFORMANCE;
982 	else
983 		ap->pm_policy = policy;
984 	return /* rc */;	/* hopefully we can use 'rc' eventually */
985 }
986 
987 #ifdef CONFIG_PM
988 /**
989  *	ata_dev_disable_pm - disable SATA interface power management
990  *	@dev: device to disable power management
991  *
992  *	Disable SATA Interface power management.  This will disable
993  *	Device Interface Power Management (DIPM) without changing
994  * 	policy,  call driver specific callbacks for disabling Host
995  * 	Initiated Power management.
996  *
997  *	Locking: Caller.
998  *	Returns: void
999  */
1000 static void ata_dev_disable_pm(struct ata_device *dev)
1001 {
1002 	struct ata_port *ap = dev->link->ap;
1003 
1004 	ata_dev_set_dipm(dev, MAX_PERFORMANCE);
1005 	if (ap->ops->disable_pm)
1006 		ap->ops->disable_pm(ap);
1007 }
1008 #endif	/* CONFIG_PM */
1009 
1010 void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
1011 {
1012 	ap->pm_policy = policy;
1013 	ap->link.eh_info.action |= ATA_EH_LPM;
1014 	ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
1015 	ata_port_schedule_eh(ap);
1016 }
1017 
1018 #ifdef CONFIG_PM
1019 static void ata_lpm_enable(struct ata_host *host)
1020 {
1021 	struct ata_link *link;
1022 	struct ata_port *ap;
1023 	struct ata_device *dev;
1024 	int i;
1025 
1026 	for (i = 0; i < host->n_ports; i++) {
1027 		ap = host->ports[i];
1028 		ata_port_for_each_link(link, ap) {
1029 			ata_link_for_each_dev(dev, link)
1030 				ata_dev_disable_pm(dev);
1031 		}
1032 	}
1033 }
1034 
1035 static void ata_lpm_disable(struct ata_host *host)
1036 {
1037 	int i;
1038 
1039 	for (i = 0; i < host->n_ports; i++) {
1040 		struct ata_port *ap = host->ports[i];
1041 		ata_lpm_schedule(ap, ap->pm_policy);
1042 	}
1043 }
1044 #endif	/* CONFIG_PM */
1045 
1046 
1047 /**
1048  *	ata_devchk - PATA device presence detection
1049  *	@ap: ATA channel to examine
1050  *	@device: Device to examine (starting at zero)
1051  *
1052  *	This technique was originally described in
1053  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
1054  *	later found its way into the ATA/ATAPI spec.
1055  *
1056  *	Write a pattern to the ATA shadow registers,
1057  *	and if a device is present, it will respond by
1058  *	correctly storing and echoing back the
1059  *	ATA shadow register contents.
1060  *
1061  *	LOCKING:
1062  *	caller.
1063  */
1064 
1065 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
1066 {
1067 	struct ata_ioports *ioaddr = &ap->ioaddr;
1068 	u8 nsect, lbal;
1069 
1070 	ap->ops->dev_select(ap, device);
1071 
1072 	iowrite8(0x55, ioaddr->nsect_addr);
1073 	iowrite8(0xaa, ioaddr->lbal_addr);
1074 
1075 	iowrite8(0xaa, ioaddr->nsect_addr);
1076 	iowrite8(0x55, ioaddr->lbal_addr);
1077 
1078 	iowrite8(0x55, ioaddr->nsect_addr);
1079 	iowrite8(0xaa, ioaddr->lbal_addr);
1080 
1081 	nsect = ioread8(ioaddr->nsect_addr);
1082 	lbal = ioread8(ioaddr->lbal_addr);
1083 
1084 	if ((nsect == 0x55) && (lbal == 0xaa))
1085 		return 1;	/* we found a device */
1086 
1087 	return 0;		/* nothing found */
1088 }
1089 
1090 /**
1091  *	ata_dev_classify - determine device type based on ATA-spec signature
1092  *	@tf: ATA taskfile register set for device to be identified
1093  *
1094  *	Determine from taskfile register contents whether a device is
1095  *	ATA or ATAPI, as per "Signature and persistence" section
1096  *	of ATA/PI spec (volume 1, sect 5.14).
1097  *
1098  *	LOCKING:
1099  *	None.
1100  *
1101  *	RETURNS:
1102  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP or
1103  *	%ATA_DEV_UNKNOWN the event of failure.
1104  */
1105 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
1106 {
1107 	/* Apple's open source Darwin code hints that some devices only
1108 	 * put a proper signature into the LBA mid/high registers,
1109 	 * So, we only check those.  It's sufficient for uniqueness.
1110 	 *
1111 	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
1112 	 * signatures for ATA and ATAPI devices attached on SerialATA,
1113 	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
1114 	 * spec has never mentioned about using different signatures
1115 	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
1116 	 * Multiplier specification began to use 0x69/0x96 to identify
1117 	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
1118 	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
1119 	 * 0x69/0x96 shortly and described them as reserved for
1120 	 * SerialATA.
1121 	 *
1122 	 * We follow the current spec and consider that 0x69/0x96
1123 	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
1124 	 */
1125 	if ((tf->lbam == 0) && (tf->lbah == 0)) {
1126 		DPRINTK("found ATA device by sig\n");
1127 		return ATA_DEV_ATA;
1128 	}
1129 
1130 	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
1131 		DPRINTK("found ATAPI device by sig\n");
1132 		return ATA_DEV_ATAPI;
1133 	}
1134 
1135 	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
1136 		DPRINTK("found PMP device by sig\n");
1137 		return ATA_DEV_PMP;
1138 	}
1139 
1140 	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
1141 		printk(KERN_INFO "ata: SEMB device ignored\n");
1142 		return ATA_DEV_SEMB_UNSUP; /* not yet */
1143 	}
1144 
1145 	DPRINTK("unknown device\n");
1146 	return ATA_DEV_UNKNOWN;
1147 }
1148 
1149 /**
1150  *	ata_dev_try_classify - Parse returned ATA device signature
1151  *	@dev: ATA device to classify (starting at zero)
1152  *	@present: device seems present
1153  *	@r_err: Value of error register on completion
1154  *
1155  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
1156  *	an ATA/ATAPI-defined set of values is placed in the ATA
1157  *	shadow registers, indicating the results of device detection
1158  *	and diagnostics.
1159  *
1160  *	Select the ATA device, and read the values from the ATA shadow
1161  *	registers.  Then parse according to the Error register value,
1162  *	and the spec-defined values examined by ata_dev_classify().
1163  *
1164  *	LOCKING:
1165  *	caller.
1166  *
1167  *	RETURNS:
1168  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
1169  */
1170 unsigned int ata_dev_try_classify(struct ata_device *dev, int present,
1171 				  u8 *r_err)
1172 {
1173 	struct ata_port *ap = dev->link->ap;
1174 	struct ata_taskfile tf;
1175 	unsigned int class;
1176 	u8 err;
1177 
1178 	ap->ops->dev_select(ap, dev->devno);
1179 
1180 	memset(&tf, 0, sizeof(tf));
1181 
1182 	ap->ops->tf_read(ap, &tf);
1183 	err = tf.feature;
1184 	if (r_err)
1185 		*r_err = err;
1186 
1187 	/* see if device passed diags: continue and warn later */
1188 	if (err == 0)
1189 		/* diagnostic fail : do nothing _YET_ */
1190 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
1191 	else if (err == 1)
1192 		/* do nothing */ ;
1193 	else if ((dev->devno == 0) && (err == 0x81))
1194 		/* do nothing */ ;
1195 	else
1196 		return ATA_DEV_NONE;
1197 
1198 	/* determine if device is ATA or ATAPI */
1199 	class = ata_dev_classify(&tf);
1200 
1201 	if (class == ATA_DEV_UNKNOWN) {
1202 		/* If the device failed diagnostic, it's likely to
1203 		 * have reported incorrect device signature too.
1204 		 * Assume ATA device if the device seems present but
1205 		 * device signature is invalid with diagnostic
1206 		 * failure.
1207 		 */
1208 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
1209 			class = ATA_DEV_ATA;
1210 		else
1211 			class = ATA_DEV_NONE;
1212 	} else if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
1213 		class = ATA_DEV_NONE;
1214 
1215 	return class;
1216 }
1217 
1218 /**
1219  *	ata_id_string - Convert IDENTIFY DEVICE page into string
1220  *	@id: IDENTIFY DEVICE results we will examine
1221  *	@s: string into which data is output
1222  *	@ofs: offset into identify device page
1223  *	@len: length of string to return. must be an even number.
1224  *
1225  *	The strings in the IDENTIFY DEVICE page are broken up into
1226  *	16-bit chunks.  Run through the string, and output each
1227  *	8-bit chunk linearly, regardless of platform.
1228  *
1229  *	LOCKING:
1230  *	caller.
1231  */
1232 
1233 void ata_id_string(const u16 *id, unsigned char *s,
1234 		   unsigned int ofs, unsigned int len)
1235 {
1236 	unsigned int c;
1237 
1238 	while (len > 0) {
1239 		c = id[ofs] >> 8;
1240 		*s = c;
1241 		s++;
1242 
1243 		c = id[ofs] & 0xff;
1244 		*s = c;
1245 		s++;
1246 
1247 		ofs++;
1248 		len -= 2;
1249 	}
1250 }
1251 
1252 /**
1253  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
1254  *	@id: IDENTIFY DEVICE results we will examine
1255  *	@s: string into which data is output
1256  *	@ofs: offset into identify device page
1257  *	@len: length of string to return. must be an odd number.
1258  *
1259  *	This function is identical to ata_id_string except that it
1260  *	trims trailing spaces and terminates the resulting string with
1261  *	null.  @len must be actual maximum length (even number) + 1.
1262  *
1263  *	LOCKING:
1264  *	caller.
1265  */
1266 void ata_id_c_string(const u16 *id, unsigned char *s,
1267 		     unsigned int ofs, unsigned int len)
1268 {
1269 	unsigned char *p;
1270 
1271 	WARN_ON(!(len & 1));
1272 
1273 	ata_id_string(id, s, ofs, len - 1);
1274 
1275 	p = s + strnlen(s, len - 1);
1276 	while (p > s && p[-1] == ' ')
1277 		p--;
1278 	*p = '\0';
1279 }
1280 
1281 static u64 ata_id_n_sectors(const u16 *id)
1282 {
1283 	if (ata_id_has_lba(id)) {
1284 		if (ata_id_has_lba48(id))
1285 			return ata_id_u64(id, 100);
1286 		else
1287 			return ata_id_u32(id, 60);
1288 	} else {
1289 		if (ata_id_current_chs_valid(id))
1290 			return ata_id_u32(id, 57);
1291 		else
1292 			return id[1] * id[3] * id[6];
1293 	}
1294 }
1295 
1296 static u64 ata_tf_to_lba48(struct ata_taskfile *tf)
1297 {
1298 	u64 sectors = 0;
1299 
1300 	sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
1301 	sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
1302 	sectors |= (tf->hob_lbal & 0xff) << 24;
1303 	sectors |= (tf->lbah & 0xff) << 16;
1304 	sectors |= (tf->lbam & 0xff) << 8;
1305 	sectors |= (tf->lbal & 0xff);
1306 
1307 	return ++sectors;
1308 }
1309 
1310 static u64 ata_tf_to_lba(struct ata_taskfile *tf)
1311 {
1312 	u64 sectors = 0;
1313 
1314 	sectors |= (tf->device & 0x0f) << 24;
1315 	sectors |= (tf->lbah & 0xff) << 16;
1316 	sectors |= (tf->lbam & 0xff) << 8;
1317 	sectors |= (tf->lbal & 0xff);
1318 
1319 	return ++sectors;
1320 }
1321 
1322 /**
1323  *	ata_read_native_max_address - Read native max address
1324  *	@dev: target device
1325  *	@max_sectors: out parameter for the result native max address
1326  *
1327  *	Perform an LBA48 or LBA28 native size query upon the device in
1328  *	question.
1329  *
1330  *	RETURNS:
1331  *	0 on success, -EACCES if command is aborted by the drive.
1332  *	-EIO on other errors.
1333  */
1334 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
1335 {
1336 	unsigned int err_mask;
1337 	struct ata_taskfile tf;
1338 	int lba48 = ata_id_has_lba48(dev->id);
1339 
1340 	ata_tf_init(dev, &tf);
1341 
1342 	/* always clear all address registers */
1343 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1344 
1345 	if (lba48) {
1346 		tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
1347 		tf.flags |= ATA_TFLAG_LBA48;
1348 	} else
1349 		tf.command = ATA_CMD_READ_NATIVE_MAX;
1350 
1351 	tf.protocol |= ATA_PROT_NODATA;
1352 	tf.device |= ATA_LBA;
1353 
1354 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1355 	if (err_mask) {
1356 		ata_dev_printk(dev, KERN_WARNING, "failed to read native "
1357 			       "max address (err_mask=0x%x)\n", err_mask);
1358 		if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
1359 			return -EACCES;
1360 		return -EIO;
1361 	}
1362 
1363 	if (lba48)
1364 		*max_sectors = ata_tf_to_lba48(&tf);
1365 	else
1366 		*max_sectors = ata_tf_to_lba(&tf);
1367 	if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
1368 		(*max_sectors)--;
1369 	return 0;
1370 }
1371 
1372 /**
1373  *	ata_set_max_sectors - Set max sectors
1374  *	@dev: target device
1375  *	@new_sectors: new max sectors value to set for the device
1376  *
1377  *	Set max sectors of @dev to @new_sectors.
1378  *
1379  *	RETURNS:
1380  *	0 on success, -EACCES if command is aborted or denied (due to
1381  *	previous non-volatile SET_MAX) by the drive.  -EIO on other
1382  *	errors.
1383  */
1384 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
1385 {
1386 	unsigned int err_mask;
1387 	struct ata_taskfile tf;
1388 	int lba48 = ata_id_has_lba48(dev->id);
1389 
1390 	new_sectors--;
1391 
1392 	ata_tf_init(dev, &tf);
1393 
1394 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1395 
1396 	if (lba48) {
1397 		tf.command = ATA_CMD_SET_MAX_EXT;
1398 		tf.flags |= ATA_TFLAG_LBA48;
1399 
1400 		tf.hob_lbal = (new_sectors >> 24) & 0xff;
1401 		tf.hob_lbam = (new_sectors >> 32) & 0xff;
1402 		tf.hob_lbah = (new_sectors >> 40) & 0xff;
1403 	} else {
1404 		tf.command = ATA_CMD_SET_MAX;
1405 
1406 		tf.device |= (new_sectors >> 24) & 0xf;
1407 	}
1408 
1409 	tf.protocol |= ATA_PROT_NODATA;
1410 	tf.device |= ATA_LBA;
1411 
1412 	tf.lbal = (new_sectors >> 0) & 0xff;
1413 	tf.lbam = (new_sectors >> 8) & 0xff;
1414 	tf.lbah = (new_sectors >> 16) & 0xff;
1415 
1416 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1417 	if (err_mask) {
1418 		ata_dev_printk(dev, KERN_WARNING, "failed to set "
1419 			       "max address (err_mask=0x%x)\n", err_mask);
1420 		if (err_mask == AC_ERR_DEV &&
1421 		    (tf.feature & (ATA_ABORTED | ATA_IDNF)))
1422 			return -EACCES;
1423 		return -EIO;
1424 	}
1425 
1426 	return 0;
1427 }
1428 
1429 /**
1430  *	ata_hpa_resize		-	Resize a device with an HPA set
1431  *	@dev: Device to resize
1432  *
1433  *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
1434  *	it if required to the full size of the media. The caller must check
1435  *	the drive has the HPA feature set enabled.
1436  *
1437  *	RETURNS:
1438  *	0 on success, -errno on failure.
1439  */
1440 static int ata_hpa_resize(struct ata_device *dev)
1441 {
1442 	struct ata_eh_context *ehc = &dev->link->eh_context;
1443 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1444 	u64 sectors = ata_id_n_sectors(dev->id);
1445 	u64 native_sectors;
1446 	int rc;
1447 
1448 	/* do we need to do it? */
1449 	if (dev->class != ATA_DEV_ATA ||
1450 	    !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
1451 	    (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
1452 		return 0;
1453 
1454 	/* read native max address */
1455 	rc = ata_read_native_max_address(dev, &native_sectors);
1456 	if (rc) {
1457 		/* If device aborted the command or HPA isn't going to
1458 		 * be unlocked, skip HPA resizing.
1459 		 */
1460 		if (rc == -EACCES || !ata_ignore_hpa) {
1461 			ata_dev_printk(dev, KERN_WARNING, "HPA support seems "
1462 				       "broken, skipping HPA handling\n");
1463 			dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1464 
1465 			/* we can continue if device aborted the command */
1466 			if (rc == -EACCES)
1467 				rc = 0;
1468 		}
1469 
1470 		return rc;
1471 	}
1472 
1473 	/* nothing to do? */
1474 	if (native_sectors <= sectors || !ata_ignore_hpa) {
1475 		if (!print_info || native_sectors == sectors)
1476 			return 0;
1477 
1478 		if (native_sectors > sectors)
1479 			ata_dev_printk(dev, KERN_INFO,
1480 				"HPA detected: current %llu, native %llu\n",
1481 				(unsigned long long)sectors,
1482 				(unsigned long long)native_sectors);
1483 		else if (native_sectors < sectors)
1484 			ata_dev_printk(dev, KERN_WARNING,
1485 				"native sectors (%llu) is smaller than "
1486 				"sectors (%llu)\n",
1487 				(unsigned long long)native_sectors,
1488 				(unsigned long long)sectors);
1489 		return 0;
1490 	}
1491 
1492 	/* let's unlock HPA */
1493 	rc = ata_set_max_sectors(dev, native_sectors);
1494 	if (rc == -EACCES) {
1495 		/* if device aborted the command, skip HPA resizing */
1496 		ata_dev_printk(dev, KERN_WARNING, "device aborted resize "
1497 			       "(%llu -> %llu), skipping HPA handling\n",
1498 			       (unsigned long long)sectors,
1499 			       (unsigned long long)native_sectors);
1500 		dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1501 		return 0;
1502 	} else if (rc)
1503 		return rc;
1504 
1505 	/* re-read IDENTIFY data */
1506 	rc = ata_dev_reread_id(dev, 0);
1507 	if (rc) {
1508 		ata_dev_printk(dev, KERN_ERR, "failed to re-read IDENTIFY "
1509 			       "data after HPA resizing\n");
1510 		return rc;
1511 	}
1512 
1513 	if (print_info) {
1514 		u64 new_sectors = ata_id_n_sectors(dev->id);
1515 		ata_dev_printk(dev, KERN_INFO,
1516 			"HPA unlocked: %llu -> %llu, native %llu\n",
1517 			(unsigned long long)sectors,
1518 			(unsigned long long)new_sectors,
1519 			(unsigned long long)native_sectors);
1520 	}
1521 
1522 	return 0;
1523 }
1524 
1525 /**
1526  *	ata_noop_dev_select - Select device 0/1 on ATA bus
1527  *	@ap: ATA channel to manipulate
1528  *	@device: ATA device (numbered from zero) to select
1529  *
1530  *	This function performs no actual function.
1531  *
1532  *	May be used as the dev_select() entry in ata_port_operations.
1533  *
1534  *	LOCKING:
1535  *	caller.
1536  */
1537 void ata_noop_dev_select(struct ata_port *ap, unsigned int device)
1538 {
1539 }
1540 
1541 
1542 /**
1543  *	ata_std_dev_select - Select device 0/1 on ATA bus
1544  *	@ap: ATA channel to manipulate
1545  *	@device: ATA device (numbered from zero) to select
1546  *
1547  *	Use the method defined in the ATA specification to
1548  *	make either device 0, or device 1, active on the
1549  *	ATA channel.  Works with both PIO and MMIO.
1550  *
1551  *	May be used as the dev_select() entry in ata_port_operations.
1552  *
1553  *	LOCKING:
1554  *	caller.
1555  */
1556 
1557 void ata_std_dev_select(struct ata_port *ap, unsigned int device)
1558 {
1559 	u8 tmp;
1560 
1561 	if (device == 0)
1562 		tmp = ATA_DEVICE_OBS;
1563 	else
1564 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
1565 
1566 	iowrite8(tmp, ap->ioaddr.device_addr);
1567 	ata_pause(ap);		/* needed; also flushes, for mmio */
1568 }
1569 
1570 /**
1571  *	ata_dev_select - Select device 0/1 on ATA bus
1572  *	@ap: ATA channel to manipulate
1573  *	@device: ATA device (numbered from zero) to select
1574  *	@wait: non-zero to wait for Status register BSY bit to clear
1575  *	@can_sleep: non-zero if context allows sleeping
1576  *
1577  *	Use the method defined in the ATA specification to
1578  *	make either device 0, or device 1, active on the
1579  *	ATA channel.
1580  *
1581  *	This is a high-level version of ata_std_dev_select(),
1582  *	which additionally provides the services of inserting
1583  *	the proper pauses and status polling, where needed.
1584  *
1585  *	LOCKING:
1586  *	caller.
1587  */
1588 
1589 void ata_dev_select(struct ata_port *ap, unsigned int device,
1590 			   unsigned int wait, unsigned int can_sleep)
1591 {
1592 	if (ata_msg_probe(ap))
1593 		ata_port_printk(ap, KERN_INFO, "ata_dev_select: ENTER, "
1594 				"device %u, wait %u\n", device, wait);
1595 
1596 	if (wait)
1597 		ata_wait_idle(ap);
1598 
1599 	ap->ops->dev_select(ap, device);
1600 
1601 	if (wait) {
1602 		if (can_sleep && ap->link.device[device].class == ATA_DEV_ATAPI)
1603 			msleep(150);
1604 		ata_wait_idle(ap);
1605 	}
1606 }
1607 
1608 /**
1609  *	ata_dump_id - IDENTIFY DEVICE info debugging output
1610  *	@id: IDENTIFY DEVICE page to dump
1611  *
1612  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
1613  *	page.
1614  *
1615  *	LOCKING:
1616  *	caller.
1617  */
1618 
1619 static inline void ata_dump_id(const u16 *id)
1620 {
1621 	DPRINTK("49==0x%04x  "
1622 		"53==0x%04x  "
1623 		"63==0x%04x  "
1624 		"64==0x%04x  "
1625 		"75==0x%04x  \n",
1626 		id[49],
1627 		id[53],
1628 		id[63],
1629 		id[64],
1630 		id[75]);
1631 	DPRINTK("80==0x%04x  "
1632 		"81==0x%04x  "
1633 		"82==0x%04x  "
1634 		"83==0x%04x  "
1635 		"84==0x%04x  \n",
1636 		id[80],
1637 		id[81],
1638 		id[82],
1639 		id[83],
1640 		id[84]);
1641 	DPRINTK("88==0x%04x  "
1642 		"93==0x%04x\n",
1643 		id[88],
1644 		id[93]);
1645 }
1646 
1647 /**
1648  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1649  *	@id: IDENTIFY data to compute xfer mask from
1650  *
1651  *	Compute the xfermask for this device. This is not as trivial
1652  *	as it seems if we must consider early devices correctly.
1653  *
1654  *	FIXME: pre IDE drive timing (do we care ?).
1655  *
1656  *	LOCKING:
1657  *	None.
1658  *
1659  *	RETURNS:
1660  *	Computed xfermask
1661  */
1662 unsigned long ata_id_xfermask(const u16 *id)
1663 {
1664 	unsigned long pio_mask, mwdma_mask, udma_mask;
1665 
1666 	/* Usual case. Word 53 indicates word 64 is valid */
1667 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1668 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1669 		pio_mask <<= 3;
1670 		pio_mask |= 0x7;
1671 	} else {
1672 		/* If word 64 isn't valid then Word 51 high byte holds
1673 		 * the PIO timing number for the maximum. Turn it into
1674 		 * a mask.
1675 		 */
1676 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1677 		if (mode < 5)	/* Valid PIO range */
1678 			pio_mask = (2 << mode) - 1;
1679 		else
1680 			pio_mask = 1;
1681 
1682 		/* But wait.. there's more. Design your standards by
1683 		 * committee and you too can get a free iordy field to
1684 		 * process. However its the speeds not the modes that
1685 		 * are supported... Note drivers using the timing API
1686 		 * will get this right anyway
1687 		 */
1688 	}
1689 
1690 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1691 
1692 	if (ata_id_is_cfa(id)) {
1693 		/*
1694 		 *	Process compact flash extended modes
1695 		 */
1696 		int pio = id[163] & 0x7;
1697 		int dma = (id[163] >> 3) & 7;
1698 
1699 		if (pio)
1700 			pio_mask |= (1 << 5);
1701 		if (pio > 1)
1702 			pio_mask |= (1 << 6);
1703 		if (dma)
1704 			mwdma_mask |= (1 << 3);
1705 		if (dma > 1)
1706 			mwdma_mask |= (1 << 4);
1707 	}
1708 
1709 	udma_mask = 0;
1710 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1711 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1712 
1713 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1714 }
1715 
1716 /**
1717  *	ata_pio_queue_task - Queue port_task
1718  *	@ap: The ata_port to queue port_task for
1719  *	@fn: workqueue function to be scheduled
1720  *	@data: data for @fn to use
1721  *	@delay: delay time for workqueue function
1722  *
1723  *	Schedule @fn(@data) for execution after @delay jiffies using
1724  *	port_task.  There is one port_task per port and it's the
1725  *	user(low level driver)'s responsibility to make sure that only
1726  *	one task is active at any given time.
1727  *
1728  *	libata core layer takes care of synchronization between
1729  *	port_task and EH.  ata_pio_queue_task() may be ignored for EH
1730  *	synchronization.
1731  *
1732  *	LOCKING:
1733  *	Inherited from caller.
1734  */
1735 static void ata_pio_queue_task(struct ata_port *ap, void *data,
1736 			       unsigned long delay)
1737 {
1738 	ap->port_task_data = data;
1739 
1740 	/* may fail if ata_port_flush_task() in progress */
1741 	queue_delayed_work(ata_wq, &ap->port_task, delay);
1742 }
1743 
1744 /**
1745  *	ata_port_flush_task - Flush port_task
1746  *	@ap: The ata_port to flush port_task for
1747  *
1748  *	After this function completes, port_task is guranteed not to
1749  *	be running or scheduled.
1750  *
1751  *	LOCKING:
1752  *	Kernel thread context (may sleep)
1753  */
1754 void ata_port_flush_task(struct ata_port *ap)
1755 {
1756 	DPRINTK("ENTER\n");
1757 
1758 	cancel_rearming_delayed_work(&ap->port_task);
1759 
1760 	if (ata_msg_ctl(ap))
1761 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __func__);
1762 }
1763 
1764 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1765 {
1766 	struct completion *waiting = qc->private_data;
1767 
1768 	complete(waiting);
1769 }
1770 
1771 /**
1772  *	ata_exec_internal_sg - execute libata internal command
1773  *	@dev: Device to which the command is sent
1774  *	@tf: Taskfile registers for the command and the result
1775  *	@cdb: CDB for packet command
1776  *	@dma_dir: Data tranfer direction of the command
1777  *	@sgl: sg list for the data buffer of the command
1778  *	@n_elem: Number of sg entries
1779  *	@timeout: Timeout in msecs (0 for default)
1780  *
1781  *	Executes libata internal command with timeout.  @tf contains
1782  *	command on entry and result on return.  Timeout and error
1783  *	conditions are reported via return value.  No recovery action
1784  *	is taken after a command times out.  It's caller's duty to
1785  *	clean up after timeout.
1786  *
1787  *	LOCKING:
1788  *	None.  Should be called with kernel context, might sleep.
1789  *
1790  *	RETURNS:
1791  *	Zero on success, AC_ERR_* mask on failure
1792  */
1793 unsigned ata_exec_internal_sg(struct ata_device *dev,
1794 			      struct ata_taskfile *tf, const u8 *cdb,
1795 			      int dma_dir, struct scatterlist *sgl,
1796 			      unsigned int n_elem, unsigned long timeout)
1797 {
1798 	struct ata_link *link = dev->link;
1799 	struct ata_port *ap = link->ap;
1800 	u8 command = tf->command;
1801 	struct ata_queued_cmd *qc;
1802 	unsigned int tag, preempted_tag;
1803 	u32 preempted_sactive, preempted_qc_active;
1804 	int preempted_nr_active_links;
1805 	DECLARE_COMPLETION_ONSTACK(wait);
1806 	unsigned long flags;
1807 	unsigned int err_mask;
1808 	int rc;
1809 
1810 	spin_lock_irqsave(ap->lock, flags);
1811 
1812 	/* no internal command while frozen */
1813 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1814 		spin_unlock_irqrestore(ap->lock, flags);
1815 		return AC_ERR_SYSTEM;
1816 	}
1817 
1818 	/* initialize internal qc */
1819 
1820 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1821 	 * drivers choke if any other tag is given.  This breaks
1822 	 * ata_tag_internal() test for those drivers.  Don't use new
1823 	 * EH stuff without converting to it.
1824 	 */
1825 	if (ap->ops->error_handler)
1826 		tag = ATA_TAG_INTERNAL;
1827 	else
1828 		tag = 0;
1829 
1830 	if (test_and_set_bit(tag, &ap->qc_allocated))
1831 		BUG();
1832 	qc = __ata_qc_from_tag(ap, tag);
1833 
1834 	qc->tag = tag;
1835 	qc->scsicmd = NULL;
1836 	qc->ap = ap;
1837 	qc->dev = dev;
1838 	ata_qc_reinit(qc);
1839 
1840 	preempted_tag = link->active_tag;
1841 	preempted_sactive = link->sactive;
1842 	preempted_qc_active = ap->qc_active;
1843 	preempted_nr_active_links = ap->nr_active_links;
1844 	link->active_tag = ATA_TAG_POISON;
1845 	link->sactive = 0;
1846 	ap->qc_active = 0;
1847 	ap->nr_active_links = 0;
1848 
1849 	/* prepare & issue qc */
1850 	qc->tf = *tf;
1851 	if (cdb)
1852 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1853 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1854 	qc->dma_dir = dma_dir;
1855 	if (dma_dir != DMA_NONE) {
1856 		unsigned int i, buflen = 0;
1857 		struct scatterlist *sg;
1858 
1859 		for_each_sg(sgl, sg, n_elem, i)
1860 			buflen += sg->length;
1861 
1862 		ata_sg_init(qc, sgl, n_elem);
1863 		qc->nbytes = buflen;
1864 	}
1865 
1866 	qc->private_data = &wait;
1867 	qc->complete_fn = ata_qc_complete_internal;
1868 
1869 	ata_qc_issue(qc);
1870 
1871 	spin_unlock_irqrestore(ap->lock, flags);
1872 
1873 	if (!timeout)
1874 		timeout = ata_probe_timeout * 1000 / HZ;
1875 
1876 	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
1877 
1878 	ata_port_flush_task(ap);
1879 
1880 	if (!rc) {
1881 		spin_lock_irqsave(ap->lock, flags);
1882 
1883 		/* We're racing with irq here.  If we lose, the
1884 		 * following test prevents us from completing the qc
1885 		 * twice.  If we win, the port is frozen and will be
1886 		 * cleaned up by ->post_internal_cmd().
1887 		 */
1888 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1889 			qc->err_mask |= AC_ERR_TIMEOUT;
1890 
1891 			if (ap->ops->error_handler)
1892 				ata_port_freeze(ap);
1893 			else
1894 				ata_qc_complete(qc);
1895 
1896 			if (ata_msg_warn(ap))
1897 				ata_dev_printk(dev, KERN_WARNING,
1898 					"qc timeout (cmd 0x%x)\n", command);
1899 		}
1900 
1901 		spin_unlock_irqrestore(ap->lock, flags);
1902 	}
1903 
1904 	/* do post_internal_cmd */
1905 	if (ap->ops->post_internal_cmd)
1906 		ap->ops->post_internal_cmd(qc);
1907 
1908 	/* perform minimal error analysis */
1909 	if (qc->flags & ATA_QCFLAG_FAILED) {
1910 		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
1911 			qc->err_mask |= AC_ERR_DEV;
1912 
1913 		if (!qc->err_mask)
1914 			qc->err_mask |= AC_ERR_OTHER;
1915 
1916 		if (qc->err_mask & ~AC_ERR_OTHER)
1917 			qc->err_mask &= ~AC_ERR_OTHER;
1918 	}
1919 
1920 	/* finish up */
1921 	spin_lock_irqsave(ap->lock, flags);
1922 
1923 	*tf = qc->result_tf;
1924 	err_mask = qc->err_mask;
1925 
1926 	ata_qc_free(qc);
1927 	link->active_tag = preempted_tag;
1928 	link->sactive = preempted_sactive;
1929 	ap->qc_active = preempted_qc_active;
1930 	ap->nr_active_links = preempted_nr_active_links;
1931 
1932 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1933 	 * Until those drivers are fixed, we detect the condition
1934 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1935 	 * port.
1936 	 *
1937 	 * Note that this doesn't change any behavior as internal
1938 	 * command failure results in disabling the device in the
1939 	 * higher layer for LLDDs without new reset/EH callbacks.
1940 	 *
1941 	 * Kill the following code as soon as those drivers are fixed.
1942 	 */
1943 	if (ap->flags & ATA_FLAG_DISABLED) {
1944 		err_mask |= AC_ERR_SYSTEM;
1945 		ata_port_probe(ap);
1946 	}
1947 
1948 	spin_unlock_irqrestore(ap->lock, flags);
1949 
1950 	return err_mask;
1951 }
1952 
1953 /**
1954  *	ata_exec_internal - execute libata internal command
1955  *	@dev: Device to which the command is sent
1956  *	@tf: Taskfile registers for the command and the result
1957  *	@cdb: CDB for packet command
1958  *	@dma_dir: Data tranfer direction of the command
1959  *	@buf: Data buffer of the command
1960  *	@buflen: Length of data buffer
1961  *	@timeout: Timeout in msecs (0 for default)
1962  *
1963  *	Wrapper around ata_exec_internal_sg() which takes simple
1964  *	buffer instead of sg list.
1965  *
1966  *	LOCKING:
1967  *	None.  Should be called with kernel context, might sleep.
1968  *
1969  *	RETURNS:
1970  *	Zero on success, AC_ERR_* mask on failure
1971  */
1972 unsigned ata_exec_internal(struct ata_device *dev,
1973 			   struct ata_taskfile *tf, const u8 *cdb,
1974 			   int dma_dir, void *buf, unsigned int buflen,
1975 			   unsigned long timeout)
1976 {
1977 	struct scatterlist *psg = NULL, sg;
1978 	unsigned int n_elem = 0;
1979 
1980 	if (dma_dir != DMA_NONE) {
1981 		WARN_ON(!buf);
1982 		sg_init_one(&sg, buf, buflen);
1983 		psg = &sg;
1984 		n_elem++;
1985 	}
1986 
1987 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
1988 				    timeout);
1989 }
1990 
1991 /**
1992  *	ata_do_simple_cmd - execute simple internal command
1993  *	@dev: Device to which the command is sent
1994  *	@cmd: Opcode to execute
1995  *
1996  *	Execute a 'simple' command, that only consists of the opcode
1997  *	'cmd' itself, without filling any other registers
1998  *
1999  *	LOCKING:
2000  *	Kernel thread context (may sleep).
2001  *
2002  *	RETURNS:
2003  *	Zero on success, AC_ERR_* mask on failure
2004  */
2005 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
2006 {
2007 	struct ata_taskfile tf;
2008 
2009 	ata_tf_init(dev, &tf);
2010 
2011 	tf.command = cmd;
2012 	tf.flags |= ATA_TFLAG_DEVICE;
2013 	tf.protocol = ATA_PROT_NODATA;
2014 
2015 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
2016 }
2017 
2018 /**
2019  *	ata_pio_need_iordy	-	check if iordy needed
2020  *	@adev: ATA device
2021  *
2022  *	Check if the current speed of the device requires IORDY. Used
2023  *	by various controllers for chip configuration.
2024  */
2025 
2026 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
2027 {
2028 	/* Controller doesn't support  IORDY. Probably a pointless check
2029 	   as the caller should know this */
2030 	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
2031 		return 0;
2032 	/* PIO3 and higher it is mandatory */
2033 	if (adev->pio_mode > XFER_PIO_2)
2034 		return 1;
2035 	/* We turn it on when possible */
2036 	if (ata_id_has_iordy(adev->id))
2037 		return 1;
2038 	return 0;
2039 }
2040 
2041 /**
2042  *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
2043  *	@adev: ATA device
2044  *
2045  *	Compute the highest mode possible if we are not using iordy. Return
2046  *	-1 if no iordy mode is available.
2047  */
2048 
2049 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
2050 {
2051 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
2052 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
2053 		u16 pio = adev->id[ATA_ID_EIDE_PIO];
2054 		/* Is the speed faster than the drive allows non IORDY ? */
2055 		if (pio) {
2056 			/* This is cycle times not frequency - watch the logic! */
2057 			if (pio > 240)	/* PIO2 is 240nS per cycle */
2058 				return 3 << ATA_SHIFT_PIO;
2059 			return 7 << ATA_SHIFT_PIO;
2060 		}
2061 	}
2062 	return 3 << ATA_SHIFT_PIO;
2063 }
2064 
2065 /**
2066  *	ata_dev_read_id - Read ID data from the specified device
2067  *	@dev: target device
2068  *	@p_class: pointer to class of the target device (may be changed)
2069  *	@flags: ATA_READID_* flags
2070  *	@id: buffer to read IDENTIFY data into
2071  *
2072  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
2073  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
2074  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
2075  *	for pre-ATA4 drives.
2076  *
2077  *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
2078  *	now we abort if we hit that case.
2079  *
2080  *	LOCKING:
2081  *	Kernel thread context (may sleep)
2082  *
2083  *	RETURNS:
2084  *	0 on success, -errno otherwise.
2085  */
2086 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
2087 		    unsigned int flags, u16 *id)
2088 {
2089 	struct ata_port *ap = dev->link->ap;
2090 	unsigned int class = *p_class;
2091 	struct ata_taskfile tf;
2092 	unsigned int err_mask = 0;
2093 	const char *reason;
2094 	int may_fallback = 1, tried_spinup = 0;
2095 	int rc;
2096 
2097 	if (ata_msg_ctl(ap))
2098 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __func__);
2099 
2100 	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
2101  retry:
2102 	ata_tf_init(dev, &tf);
2103 
2104 	switch (class) {
2105 	case ATA_DEV_ATA:
2106 		tf.command = ATA_CMD_ID_ATA;
2107 		break;
2108 	case ATA_DEV_ATAPI:
2109 		tf.command = ATA_CMD_ID_ATAPI;
2110 		break;
2111 	default:
2112 		rc = -ENODEV;
2113 		reason = "unsupported class";
2114 		goto err_out;
2115 	}
2116 
2117 	tf.protocol = ATA_PROT_PIO;
2118 
2119 	/* Some devices choke if TF registers contain garbage.  Make
2120 	 * sure those are properly initialized.
2121 	 */
2122 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
2123 
2124 	/* Device presence detection is unreliable on some
2125 	 * controllers.  Always poll IDENTIFY if available.
2126 	 */
2127 	tf.flags |= ATA_TFLAG_POLLING;
2128 
2129 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
2130 				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
2131 	if (err_mask) {
2132 		if (err_mask & AC_ERR_NODEV_HINT) {
2133 			ata_dev_printk(dev, KERN_DEBUG,
2134 				       "NODEV after polling detection\n");
2135 			return -ENOENT;
2136 		}
2137 
2138 		if ((err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
2139 			/* Device or controller might have reported
2140 			 * the wrong device class.  Give a shot at the
2141 			 * other IDENTIFY if the current one is
2142 			 * aborted by the device.
2143 			 */
2144 			if (may_fallback) {
2145 				may_fallback = 0;
2146 
2147 				if (class == ATA_DEV_ATA)
2148 					class = ATA_DEV_ATAPI;
2149 				else
2150 					class = ATA_DEV_ATA;
2151 				goto retry;
2152 			}
2153 
2154 			/* Control reaches here iff the device aborted
2155 			 * both flavors of IDENTIFYs which happens
2156 			 * sometimes with phantom devices.
2157 			 */
2158 			ata_dev_printk(dev, KERN_DEBUG,
2159 				       "both IDENTIFYs aborted, assuming NODEV\n");
2160 			return -ENOENT;
2161 		}
2162 
2163 		rc = -EIO;
2164 		reason = "I/O error";
2165 		goto err_out;
2166 	}
2167 
2168 	/* Falling back doesn't make sense if ID data was read
2169 	 * successfully at least once.
2170 	 */
2171 	may_fallback = 0;
2172 
2173 	swap_buf_le16(id, ATA_ID_WORDS);
2174 
2175 	/* sanity check */
2176 	rc = -EINVAL;
2177 	reason = "device reports invalid type";
2178 
2179 	if (class == ATA_DEV_ATA) {
2180 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
2181 			goto err_out;
2182 	} else {
2183 		if (ata_id_is_ata(id))
2184 			goto err_out;
2185 	}
2186 
2187 	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
2188 		tried_spinup = 1;
2189 		/*
2190 		 * Drive powered-up in standby mode, and requires a specific
2191 		 * SET_FEATURES spin-up subcommand before it will accept
2192 		 * anything other than the original IDENTIFY command.
2193 		 */
2194 		err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
2195 		if (err_mask && id[2] != 0x738c) {
2196 			rc = -EIO;
2197 			reason = "SPINUP failed";
2198 			goto err_out;
2199 		}
2200 		/*
2201 		 * If the drive initially returned incomplete IDENTIFY info,
2202 		 * we now must reissue the IDENTIFY command.
2203 		 */
2204 		if (id[2] == 0x37c8)
2205 			goto retry;
2206 	}
2207 
2208 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
2209 		/*
2210 		 * The exact sequence expected by certain pre-ATA4 drives is:
2211 		 * SRST RESET
2212 		 * IDENTIFY (optional in early ATA)
2213 		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
2214 		 * anything else..
2215 		 * Some drives were very specific about that exact sequence.
2216 		 *
2217 		 * Note that ATA4 says lba is mandatory so the second check
2218 		 * shoud never trigger.
2219 		 */
2220 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
2221 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
2222 			if (err_mask) {
2223 				rc = -EIO;
2224 				reason = "INIT_DEV_PARAMS failed";
2225 				goto err_out;
2226 			}
2227 
2228 			/* current CHS translation info (id[53-58]) might be
2229 			 * changed. reread the identify device info.
2230 			 */
2231 			flags &= ~ATA_READID_POSTRESET;
2232 			goto retry;
2233 		}
2234 	}
2235 
2236 	*p_class = class;
2237 
2238 	return 0;
2239 
2240  err_out:
2241 	if (ata_msg_warn(ap))
2242 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
2243 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
2244 	return rc;
2245 }
2246 
2247 static inline u8 ata_dev_knobble(struct ata_device *dev)
2248 {
2249 	struct ata_port *ap = dev->link->ap;
2250 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
2251 }
2252 
2253 static void ata_dev_config_ncq(struct ata_device *dev,
2254 			       char *desc, size_t desc_sz)
2255 {
2256 	struct ata_port *ap = dev->link->ap;
2257 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
2258 
2259 	if (!ata_id_has_ncq(dev->id)) {
2260 		desc[0] = '\0';
2261 		return;
2262 	}
2263 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
2264 		snprintf(desc, desc_sz, "NCQ (not used)");
2265 		return;
2266 	}
2267 	if (ap->flags & ATA_FLAG_NCQ) {
2268 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
2269 		dev->flags |= ATA_DFLAG_NCQ;
2270 	}
2271 
2272 	if (hdepth >= ddepth)
2273 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
2274 	else
2275 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
2276 }
2277 
2278 /**
2279  *	ata_dev_configure - Configure the specified ATA/ATAPI device
2280  *	@dev: Target device to configure
2281  *
2282  *	Configure @dev according to @dev->id.  Generic and low-level
2283  *	driver specific fixups are also applied.
2284  *
2285  *	LOCKING:
2286  *	Kernel thread context (may sleep)
2287  *
2288  *	RETURNS:
2289  *	0 on success, -errno otherwise
2290  */
2291 int ata_dev_configure(struct ata_device *dev)
2292 {
2293 	struct ata_port *ap = dev->link->ap;
2294 	struct ata_eh_context *ehc = &dev->link->eh_context;
2295 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
2296 	const u16 *id = dev->id;
2297 	unsigned long xfer_mask;
2298 	char revbuf[7];		/* XYZ-99\0 */
2299 	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
2300 	char modelbuf[ATA_ID_PROD_LEN+1];
2301 	int rc;
2302 
2303 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
2304 		ata_dev_printk(dev, KERN_INFO, "%s: ENTER/EXIT -- nodev\n",
2305 			       __func__);
2306 		return 0;
2307 	}
2308 
2309 	if (ata_msg_probe(ap))
2310 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __func__);
2311 
2312 	/* set horkage */
2313 	dev->horkage |= ata_dev_blacklisted(dev);
2314 	ata_force_horkage(dev);
2315 
2316 	/* let ACPI work its magic */
2317 	rc = ata_acpi_on_devcfg(dev);
2318 	if (rc)
2319 		return rc;
2320 
2321 	/* massage HPA, do it early as it might change IDENTIFY data */
2322 	rc = ata_hpa_resize(dev);
2323 	if (rc)
2324 		return rc;
2325 
2326 	/* print device capabilities */
2327 	if (ata_msg_probe(ap))
2328 		ata_dev_printk(dev, KERN_DEBUG,
2329 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
2330 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
2331 			       __func__,
2332 			       id[49], id[82], id[83], id[84],
2333 			       id[85], id[86], id[87], id[88]);
2334 
2335 	/* initialize to-be-configured parameters */
2336 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
2337 	dev->max_sectors = 0;
2338 	dev->cdb_len = 0;
2339 	dev->n_sectors = 0;
2340 	dev->cylinders = 0;
2341 	dev->heads = 0;
2342 	dev->sectors = 0;
2343 
2344 	/*
2345 	 * common ATA, ATAPI feature tests
2346 	 */
2347 
2348 	/* find max transfer mode; for printk only */
2349 	xfer_mask = ata_id_xfermask(id);
2350 
2351 	if (ata_msg_probe(ap))
2352 		ata_dump_id(id);
2353 
2354 	/* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
2355 	ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
2356 			sizeof(fwrevbuf));
2357 
2358 	ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
2359 			sizeof(modelbuf));
2360 
2361 	/* ATA-specific feature tests */
2362 	if (dev->class == ATA_DEV_ATA) {
2363 		if (ata_id_is_cfa(id)) {
2364 			if (id[162] & 1) /* CPRM may make this media unusable */
2365 				ata_dev_printk(dev, KERN_WARNING,
2366 					       "supports DRM functions and may "
2367 					       "not be fully accessable.\n");
2368 			snprintf(revbuf, 7, "CFA");
2369 		} else {
2370 			snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
2371 			/* Warn the user if the device has TPM extensions */
2372 			if (ata_id_has_tpm(id))
2373 				ata_dev_printk(dev, KERN_WARNING,
2374 					       "supports DRM functions and may "
2375 					       "not be fully accessable.\n");
2376 		}
2377 
2378 		dev->n_sectors = ata_id_n_sectors(id);
2379 
2380 		if (dev->id[59] & 0x100)
2381 			dev->multi_count = dev->id[59] & 0xff;
2382 
2383 		if (ata_id_has_lba(id)) {
2384 			const char *lba_desc;
2385 			char ncq_desc[20];
2386 
2387 			lba_desc = "LBA";
2388 			dev->flags |= ATA_DFLAG_LBA;
2389 			if (ata_id_has_lba48(id)) {
2390 				dev->flags |= ATA_DFLAG_LBA48;
2391 				lba_desc = "LBA48";
2392 
2393 				if (dev->n_sectors >= (1UL << 28) &&
2394 				    ata_id_has_flush_ext(id))
2395 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
2396 			}
2397 
2398 			/* config NCQ */
2399 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
2400 
2401 			/* print device info to dmesg */
2402 			if (ata_msg_drv(ap) && print_info) {
2403 				ata_dev_printk(dev, KERN_INFO,
2404 					"%s: %s, %s, max %s\n",
2405 					revbuf, modelbuf, fwrevbuf,
2406 					ata_mode_string(xfer_mask));
2407 				ata_dev_printk(dev, KERN_INFO,
2408 					"%Lu sectors, multi %u: %s %s\n",
2409 					(unsigned long long)dev->n_sectors,
2410 					dev->multi_count, lba_desc, ncq_desc);
2411 			}
2412 		} else {
2413 			/* CHS */
2414 
2415 			/* Default translation */
2416 			dev->cylinders	= id[1];
2417 			dev->heads	= id[3];
2418 			dev->sectors	= id[6];
2419 
2420 			if (ata_id_current_chs_valid(id)) {
2421 				/* Current CHS translation is valid. */
2422 				dev->cylinders = id[54];
2423 				dev->heads     = id[55];
2424 				dev->sectors   = id[56];
2425 			}
2426 
2427 			/* print device info to dmesg */
2428 			if (ata_msg_drv(ap) && print_info) {
2429 				ata_dev_printk(dev, KERN_INFO,
2430 					"%s: %s, %s, max %s\n",
2431 					revbuf,	modelbuf, fwrevbuf,
2432 					ata_mode_string(xfer_mask));
2433 				ata_dev_printk(dev, KERN_INFO,
2434 					"%Lu sectors, multi %u, CHS %u/%u/%u\n",
2435 					(unsigned long long)dev->n_sectors,
2436 					dev->multi_count, dev->cylinders,
2437 					dev->heads, dev->sectors);
2438 			}
2439 		}
2440 
2441 		dev->cdb_len = 16;
2442 	}
2443 
2444 	/* ATAPI-specific feature tests */
2445 	else if (dev->class == ATA_DEV_ATAPI) {
2446 		const char *cdb_intr_string = "";
2447 		const char *atapi_an_string = "";
2448 		const char *dma_dir_string = "";
2449 		u32 sntf;
2450 
2451 		rc = atapi_cdb_len(id);
2452 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
2453 			if (ata_msg_warn(ap))
2454 				ata_dev_printk(dev, KERN_WARNING,
2455 					       "unsupported CDB len\n");
2456 			rc = -EINVAL;
2457 			goto err_out_nosup;
2458 		}
2459 		dev->cdb_len = (unsigned int) rc;
2460 
2461 		/* Enable ATAPI AN if both the host and device have
2462 		 * the support.  If PMP is attached, SNTF is required
2463 		 * to enable ATAPI AN to discern between PHY status
2464 		 * changed notifications and ATAPI ANs.
2465 		 */
2466 		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
2467 		    (!ap->nr_pmp_links ||
2468 		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
2469 			unsigned int err_mask;
2470 
2471 			/* issue SET feature command to turn this on */
2472 			err_mask = ata_dev_set_feature(dev,
2473 					SETFEATURES_SATA_ENABLE, SATA_AN);
2474 			if (err_mask)
2475 				ata_dev_printk(dev, KERN_ERR,
2476 					"failed to enable ATAPI AN "
2477 					"(err_mask=0x%x)\n", err_mask);
2478 			else {
2479 				dev->flags |= ATA_DFLAG_AN;
2480 				atapi_an_string = ", ATAPI AN";
2481 			}
2482 		}
2483 
2484 		if (ata_id_cdb_intr(dev->id)) {
2485 			dev->flags |= ATA_DFLAG_CDB_INTR;
2486 			cdb_intr_string = ", CDB intr";
2487 		}
2488 
2489 		if (atapi_dmadir || atapi_id_dmadir(dev->id)) {
2490 			dev->flags |= ATA_DFLAG_DMADIR;
2491 			dma_dir_string = ", DMADIR";
2492 		}
2493 
2494 		/* print device info to dmesg */
2495 		if (ata_msg_drv(ap) && print_info)
2496 			ata_dev_printk(dev, KERN_INFO,
2497 				       "ATAPI: %s, %s, max %s%s%s%s\n",
2498 				       modelbuf, fwrevbuf,
2499 				       ata_mode_string(xfer_mask),
2500 				       cdb_intr_string, atapi_an_string,
2501 				       dma_dir_string);
2502 	}
2503 
2504 	/* determine max_sectors */
2505 	dev->max_sectors = ATA_MAX_SECTORS;
2506 	if (dev->flags & ATA_DFLAG_LBA48)
2507 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2508 
2509 	if (!(dev->horkage & ATA_HORKAGE_IPM)) {
2510 		if (ata_id_has_hipm(dev->id))
2511 			dev->flags |= ATA_DFLAG_HIPM;
2512 		if (ata_id_has_dipm(dev->id))
2513 			dev->flags |= ATA_DFLAG_DIPM;
2514 	}
2515 
2516 	/* Limit PATA drive on SATA cable bridge transfers to udma5,
2517 	   200 sectors */
2518 	if (ata_dev_knobble(dev)) {
2519 		if (ata_msg_drv(ap) && print_info)
2520 			ata_dev_printk(dev, KERN_INFO,
2521 				       "applying bridge limits\n");
2522 		dev->udma_mask &= ATA_UDMA5;
2523 		dev->max_sectors = ATA_MAX_SECTORS;
2524 	}
2525 
2526 	if ((dev->class == ATA_DEV_ATAPI) &&
2527 	    (atapi_command_packet_set(id) == TYPE_TAPE)) {
2528 		dev->max_sectors = ATA_MAX_SECTORS_TAPE;
2529 		dev->horkage |= ATA_HORKAGE_STUCK_ERR;
2530 	}
2531 
2532 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
2533 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
2534 					 dev->max_sectors);
2535 
2536 	if (ata_dev_blacklisted(dev) & ATA_HORKAGE_IPM) {
2537 		dev->horkage |= ATA_HORKAGE_IPM;
2538 
2539 		/* reset link pm_policy for this port to no pm */
2540 		ap->pm_policy = MAX_PERFORMANCE;
2541 	}
2542 
2543 	if (ap->ops->dev_config)
2544 		ap->ops->dev_config(dev);
2545 
2546 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
2547 		/* Let the user know. We don't want to disallow opens for
2548 		   rescue purposes, or in case the vendor is just a blithering
2549 		   idiot. Do this after the dev_config call as some controllers
2550 		   with buggy firmware may want to avoid reporting false device
2551 		   bugs */
2552 
2553 		if (print_info) {
2554 			ata_dev_printk(dev, KERN_WARNING,
2555 "Drive reports diagnostics failure. This may indicate a drive\n");
2556 			ata_dev_printk(dev, KERN_WARNING,
2557 "fault or invalid emulation. Contact drive vendor for information.\n");
2558 		}
2559 	}
2560 
2561 	if (ata_msg_probe(ap))
2562 		ata_dev_printk(dev, KERN_DEBUG, "%s: EXIT, drv_stat = 0x%x\n",
2563 			__func__, ata_chk_status(ap));
2564 	return 0;
2565 
2566 err_out_nosup:
2567 	if (ata_msg_probe(ap))
2568 		ata_dev_printk(dev, KERN_DEBUG,
2569 			       "%s: EXIT, err\n", __func__);
2570 	return rc;
2571 }
2572 
2573 /**
2574  *	ata_cable_40wire	-	return 40 wire cable type
2575  *	@ap: port
2576  *
2577  *	Helper method for drivers which want to hardwire 40 wire cable
2578  *	detection.
2579  */
2580 
2581 int ata_cable_40wire(struct ata_port *ap)
2582 {
2583 	return ATA_CBL_PATA40;
2584 }
2585 
2586 /**
2587  *	ata_cable_80wire	-	return 80 wire cable type
2588  *	@ap: port
2589  *
2590  *	Helper method for drivers which want to hardwire 80 wire cable
2591  *	detection.
2592  */
2593 
2594 int ata_cable_80wire(struct ata_port *ap)
2595 {
2596 	return ATA_CBL_PATA80;
2597 }
2598 
2599 /**
2600  *	ata_cable_unknown	-	return unknown PATA cable.
2601  *	@ap: port
2602  *
2603  *	Helper method for drivers which have no PATA cable detection.
2604  */
2605 
2606 int ata_cable_unknown(struct ata_port *ap)
2607 {
2608 	return ATA_CBL_PATA_UNK;
2609 }
2610 
2611 /**
2612  *	ata_cable_ignore	-	return ignored PATA cable.
2613  *	@ap: port
2614  *
2615  *	Helper method for drivers which don't use cable type to limit
2616  *	transfer mode.
2617  */
2618 int ata_cable_ignore(struct ata_port *ap)
2619 {
2620 	return ATA_CBL_PATA_IGN;
2621 }
2622 
2623 /**
2624  *	ata_cable_sata	-	return SATA cable type
2625  *	@ap: port
2626  *
2627  *	Helper method for drivers which have SATA cables
2628  */
2629 
2630 int ata_cable_sata(struct ata_port *ap)
2631 {
2632 	return ATA_CBL_SATA;
2633 }
2634 
2635 /**
2636  *	ata_bus_probe - Reset and probe ATA bus
2637  *	@ap: Bus to probe
2638  *
2639  *	Master ATA bus probing function.  Initiates a hardware-dependent
2640  *	bus reset, then attempts to identify any devices found on
2641  *	the bus.
2642  *
2643  *	LOCKING:
2644  *	PCI/etc. bus probe sem.
2645  *
2646  *	RETURNS:
2647  *	Zero on success, negative errno otherwise.
2648  */
2649 
2650 int ata_bus_probe(struct ata_port *ap)
2651 {
2652 	unsigned int classes[ATA_MAX_DEVICES];
2653 	int tries[ATA_MAX_DEVICES];
2654 	int rc;
2655 	struct ata_device *dev;
2656 
2657 	ata_port_probe(ap);
2658 
2659 	ata_link_for_each_dev(dev, &ap->link)
2660 		tries[dev->devno] = ATA_PROBE_MAX_TRIES;
2661 
2662  retry:
2663 	ata_link_for_each_dev(dev, &ap->link) {
2664 		/* If we issue an SRST then an ATA drive (not ATAPI)
2665 		 * may change configuration and be in PIO0 timing. If
2666 		 * we do a hard reset (or are coming from power on)
2667 		 * this is true for ATA or ATAPI. Until we've set a
2668 		 * suitable controller mode we should not touch the
2669 		 * bus as we may be talking too fast.
2670 		 */
2671 		dev->pio_mode = XFER_PIO_0;
2672 
2673 		/* If the controller has a pio mode setup function
2674 		 * then use it to set the chipset to rights. Don't
2675 		 * touch the DMA setup as that will be dealt with when
2676 		 * configuring devices.
2677 		 */
2678 		if (ap->ops->set_piomode)
2679 			ap->ops->set_piomode(ap, dev);
2680 	}
2681 
2682 	/* reset and determine device classes */
2683 	ap->ops->phy_reset(ap);
2684 
2685 	ata_link_for_each_dev(dev, &ap->link) {
2686 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
2687 		    dev->class != ATA_DEV_UNKNOWN)
2688 			classes[dev->devno] = dev->class;
2689 		else
2690 			classes[dev->devno] = ATA_DEV_NONE;
2691 
2692 		dev->class = ATA_DEV_UNKNOWN;
2693 	}
2694 
2695 	ata_port_probe(ap);
2696 
2697 	/* read IDENTIFY page and configure devices. We have to do the identify
2698 	   specific sequence bass-ackwards so that PDIAG- is released by
2699 	   the slave device */
2700 
2701 	ata_link_for_each_dev_reverse(dev, &ap->link) {
2702 		if (tries[dev->devno])
2703 			dev->class = classes[dev->devno];
2704 
2705 		if (!ata_dev_enabled(dev))
2706 			continue;
2707 
2708 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
2709 				     dev->id);
2710 		if (rc)
2711 			goto fail;
2712 	}
2713 
2714 	/* Now ask for the cable type as PDIAG- should have been released */
2715 	if (ap->ops->cable_detect)
2716 		ap->cbl = ap->ops->cable_detect(ap);
2717 
2718 	/* We may have SATA bridge glue hiding here irrespective of the
2719 	   reported cable types and sensed types */
2720 	ata_link_for_each_dev(dev, &ap->link) {
2721 		if (!ata_dev_enabled(dev))
2722 			continue;
2723 		/* SATA drives indicate we have a bridge. We don't know which
2724 		   end of the link the bridge is which is a problem */
2725 		if (ata_id_is_sata(dev->id))
2726 			ap->cbl = ATA_CBL_SATA;
2727 	}
2728 
2729 	/* After the identify sequence we can now set up the devices. We do
2730 	   this in the normal order so that the user doesn't get confused */
2731 
2732 	ata_link_for_each_dev(dev, &ap->link) {
2733 		if (!ata_dev_enabled(dev))
2734 			continue;
2735 
2736 		ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
2737 		rc = ata_dev_configure(dev);
2738 		ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
2739 		if (rc)
2740 			goto fail;
2741 	}
2742 
2743 	/* configure transfer mode */
2744 	rc = ata_set_mode(&ap->link, &dev);
2745 	if (rc)
2746 		goto fail;
2747 
2748 	ata_link_for_each_dev(dev, &ap->link)
2749 		if (ata_dev_enabled(dev))
2750 			return 0;
2751 
2752 	/* no device present, disable port */
2753 	ata_port_disable(ap);
2754 	return -ENODEV;
2755 
2756  fail:
2757 	tries[dev->devno]--;
2758 
2759 	switch (rc) {
2760 	case -EINVAL:
2761 		/* eeek, something went very wrong, give up */
2762 		tries[dev->devno] = 0;
2763 		break;
2764 
2765 	case -ENODEV:
2766 		/* give it just one more chance */
2767 		tries[dev->devno] = min(tries[dev->devno], 1);
2768 	case -EIO:
2769 		if (tries[dev->devno] == 1) {
2770 			/* This is the last chance, better to slow
2771 			 * down than lose it.
2772 			 */
2773 			sata_down_spd_limit(&ap->link);
2774 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2775 		}
2776 	}
2777 
2778 	if (!tries[dev->devno])
2779 		ata_dev_disable(dev);
2780 
2781 	goto retry;
2782 }
2783 
2784 /**
2785  *	ata_port_probe - Mark port as enabled
2786  *	@ap: Port for which we indicate enablement
2787  *
2788  *	Modify @ap data structure such that the system
2789  *	thinks that the entire port is enabled.
2790  *
2791  *	LOCKING: host lock, or some other form of
2792  *	serialization.
2793  */
2794 
2795 void ata_port_probe(struct ata_port *ap)
2796 {
2797 	ap->flags &= ~ATA_FLAG_DISABLED;
2798 }
2799 
2800 /**
2801  *	sata_print_link_status - Print SATA link status
2802  *	@link: SATA link to printk link status about
2803  *
2804  *	This function prints link speed and status of a SATA link.
2805  *
2806  *	LOCKING:
2807  *	None.
2808  */
2809 void sata_print_link_status(struct ata_link *link)
2810 {
2811 	u32 sstatus, scontrol, tmp;
2812 
2813 	if (sata_scr_read(link, SCR_STATUS, &sstatus))
2814 		return;
2815 	sata_scr_read(link, SCR_CONTROL, &scontrol);
2816 
2817 	if (ata_link_online(link)) {
2818 		tmp = (sstatus >> 4) & 0xf;
2819 		ata_link_printk(link, KERN_INFO,
2820 				"SATA link up %s (SStatus %X SControl %X)\n",
2821 				sata_spd_string(tmp), sstatus, scontrol);
2822 	} else {
2823 		ata_link_printk(link, KERN_INFO,
2824 				"SATA link down (SStatus %X SControl %X)\n",
2825 				sstatus, scontrol);
2826 	}
2827 }
2828 
2829 /**
2830  *	ata_dev_pair		-	return other device on cable
2831  *	@adev: device
2832  *
2833  *	Obtain the other device on the same cable, or if none is
2834  *	present NULL is returned
2835  */
2836 
2837 struct ata_device *ata_dev_pair(struct ata_device *adev)
2838 {
2839 	struct ata_link *link = adev->link;
2840 	struct ata_device *pair = &link->device[1 - adev->devno];
2841 	if (!ata_dev_enabled(pair))
2842 		return NULL;
2843 	return pair;
2844 }
2845 
2846 /**
2847  *	ata_port_disable - Disable port.
2848  *	@ap: Port to be disabled.
2849  *
2850  *	Modify @ap data structure such that the system
2851  *	thinks that the entire port is disabled, and should
2852  *	never attempt to probe or communicate with devices
2853  *	on this port.
2854  *
2855  *	LOCKING: host lock, or some other form of
2856  *	serialization.
2857  */
2858 
2859 void ata_port_disable(struct ata_port *ap)
2860 {
2861 	ap->link.device[0].class = ATA_DEV_NONE;
2862 	ap->link.device[1].class = ATA_DEV_NONE;
2863 	ap->flags |= ATA_FLAG_DISABLED;
2864 }
2865 
2866 /**
2867  *	sata_down_spd_limit - adjust SATA spd limit downward
2868  *	@link: Link to adjust SATA spd limit for
2869  *
2870  *	Adjust SATA spd limit of @link downward.  Note that this
2871  *	function only adjusts the limit.  The change must be applied
2872  *	using sata_set_spd().
2873  *
2874  *	LOCKING:
2875  *	Inherited from caller.
2876  *
2877  *	RETURNS:
2878  *	0 on success, negative errno on failure
2879  */
2880 int sata_down_spd_limit(struct ata_link *link)
2881 {
2882 	u32 sstatus, spd, mask;
2883 	int rc, highbit;
2884 
2885 	if (!sata_scr_valid(link))
2886 		return -EOPNOTSUPP;
2887 
2888 	/* If SCR can be read, use it to determine the current SPD.
2889 	 * If not, use cached value in link->sata_spd.
2890 	 */
2891 	rc = sata_scr_read(link, SCR_STATUS, &sstatus);
2892 	if (rc == 0)
2893 		spd = (sstatus >> 4) & 0xf;
2894 	else
2895 		spd = link->sata_spd;
2896 
2897 	mask = link->sata_spd_limit;
2898 	if (mask <= 1)
2899 		return -EINVAL;
2900 
2901 	/* unconditionally mask off the highest bit */
2902 	highbit = fls(mask) - 1;
2903 	mask &= ~(1 << highbit);
2904 
2905 	/* Mask off all speeds higher than or equal to the current
2906 	 * one.  Force 1.5Gbps if current SPD is not available.
2907 	 */
2908 	if (spd > 1)
2909 		mask &= (1 << (spd - 1)) - 1;
2910 	else
2911 		mask &= 1;
2912 
2913 	/* were we already at the bottom? */
2914 	if (!mask)
2915 		return -EINVAL;
2916 
2917 	link->sata_spd_limit = mask;
2918 
2919 	ata_link_printk(link, KERN_WARNING, "limiting SATA link speed to %s\n",
2920 			sata_spd_string(fls(mask)));
2921 
2922 	return 0;
2923 }
2924 
2925 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
2926 {
2927 	struct ata_link *host_link = &link->ap->link;
2928 	u32 limit, target, spd;
2929 
2930 	limit = link->sata_spd_limit;
2931 
2932 	/* Don't configure downstream link faster than upstream link.
2933 	 * It doesn't speed up anything and some PMPs choke on such
2934 	 * configuration.
2935 	 */
2936 	if (!ata_is_host_link(link) && host_link->sata_spd)
2937 		limit &= (1 << host_link->sata_spd) - 1;
2938 
2939 	if (limit == UINT_MAX)
2940 		target = 0;
2941 	else
2942 		target = fls(limit);
2943 
2944 	spd = (*scontrol >> 4) & 0xf;
2945 	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
2946 
2947 	return spd != target;
2948 }
2949 
2950 /**
2951  *	sata_set_spd_needed - is SATA spd configuration needed
2952  *	@link: Link in question
2953  *
2954  *	Test whether the spd limit in SControl matches
2955  *	@link->sata_spd_limit.  This function is used to determine
2956  *	whether hardreset is necessary to apply SATA spd
2957  *	configuration.
2958  *
2959  *	LOCKING:
2960  *	Inherited from caller.
2961  *
2962  *	RETURNS:
2963  *	1 if SATA spd configuration is needed, 0 otherwise.
2964  */
2965 int sata_set_spd_needed(struct ata_link *link)
2966 {
2967 	u32 scontrol;
2968 
2969 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
2970 		return 1;
2971 
2972 	return __sata_set_spd_needed(link, &scontrol);
2973 }
2974 
2975 /**
2976  *	sata_set_spd - set SATA spd according to spd limit
2977  *	@link: Link to set SATA spd for
2978  *
2979  *	Set SATA spd of @link according to sata_spd_limit.
2980  *
2981  *	LOCKING:
2982  *	Inherited from caller.
2983  *
2984  *	RETURNS:
2985  *	0 if spd doesn't need to be changed, 1 if spd has been
2986  *	changed.  Negative errno if SCR registers are inaccessible.
2987  */
2988 int sata_set_spd(struct ata_link *link)
2989 {
2990 	u32 scontrol;
2991 	int rc;
2992 
2993 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
2994 		return rc;
2995 
2996 	if (!__sata_set_spd_needed(link, &scontrol))
2997 		return 0;
2998 
2999 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3000 		return rc;
3001 
3002 	return 1;
3003 }
3004 
3005 /*
3006  * This mode timing computation functionality is ported over from
3007  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
3008  */
3009 /*
3010  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
3011  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
3012  * for UDMA6, which is currently supported only by Maxtor drives.
3013  *
3014  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
3015  */
3016 
3017 static const struct ata_timing ata_timing[] = {
3018 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
3019 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
3020 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
3021 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
3022 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
3023 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
3024 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
3025 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
3026 
3027 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
3028 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
3029 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
3030 
3031 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
3032 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
3033 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
3034 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
3035 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
3036 
3037 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
3038 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
3039 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
3040 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
3041 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
3042 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
3043 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
3044 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
3045 
3046 	{ 0xFF }
3047 };
3048 
3049 #define ENOUGH(v, unit)		(((v)-1)/(unit)+1)
3050 #define EZ(v, unit)		((v)?ENOUGH(v, unit):0)
3051 
3052 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
3053 {
3054 	q->setup   = EZ(t->setup   * 1000,  T);
3055 	q->act8b   = EZ(t->act8b   * 1000,  T);
3056 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
3057 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
3058 	q->active  = EZ(t->active  * 1000,  T);
3059 	q->recover = EZ(t->recover * 1000,  T);
3060 	q->cycle   = EZ(t->cycle   * 1000,  T);
3061 	q->udma    = EZ(t->udma    * 1000, UT);
3062 }
3063 
3064 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
3065 		      struct ata_timing *m, unsigned int what)
3066 {
3067 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
3068 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
3069 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
3070 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
3071 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
3072 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
3073 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
3074 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
3075 }
3076 
3077 const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
3078 {
3079 	const struct ata_timing *t = ata_timing;
3080 
3081 	while (xfer_mode > t->mode)
3082 		t++;
3083 
3084 	if (xfer_mode == t->mode)
3085 		return t;
3086 	return NULL;
3087 }
3088 
3089 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
3090 		       struct ata_timing *t, int T, int UT)
3091 {
3092 	const struct ata_timing *s;
3093 	struct ata_timing p;
3094 
3095 	/*
3096 	 * Find the mode.
3097 	 */
3098 
3099 	if (!(s = ata_timing_find_mode(speed)))
3100 		return -EINVAL;
3101 
3102 	memcpy(t, s, sizeof(*s));
3103 
3104 	/*
3105 	 * If the drive is an EIDE drive, it can tell us it needs extended
3106 	 * PIO/MW_DMA cycle timing.
3107 	 */
3108 
3109 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
3110 		memset(&p, 0, sizeof(p));
3111 		if (speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
3112 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
3113 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
3114 		} else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
3115 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
3116 		}
3117 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
3118 	}
3119 
3120 	/*
3121 	 * Convert the timing to bus clock counts.
3122 	 */
3123 
3124 	ata_timing_quantize(t, t, T, UT);
3125 
3126 	/*
3127 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
3128 	 * S.M.A.R.T * and some other commands. We have to ensure that the
3129 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
3130 	 */
3131 
3132 	if (speed > XFER_PIO_6) {
3133 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
3134 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
3135 	}
3136 
3137 	/*
3138 	 * Lengthen active & recovery time so that cycle time is correct.
3139 	 */
3140 
3141 	if (t->act8b + t->rec8b < t->cyc8b) {
3142 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
3143 		t->rec8b = t->cyc8b - t->act8b;
3144 	}
3145 
3146 	if (t->active + t->recover < t->cycle) {
3147 		t->active += (t->cycle - (t->active + t->recover)) / 2;
3148 		t->recover = t->cycle - t->active;
3149 	}
3150 
3151 	/* In a few cases quantisation may produce enough errors to
3152 	   leave t->cycle too low for the sum of active and recovery
3153 	   if so we must correct this */
3154 	if (t->active + t->recover > t->cycle)
3155 		t->cycle = t->active + t->recover;
3156 
3157 	return 0;
3158 }
3159 
3160 /**
3161  *	ata_timing_cycle2mode - find xfer mode for the specified cycle duration
3162  *	@xfer_shift: ATA_SHIFT_* value for transfer type to examine.
3163  *	@cycle: cycle duration in ns
3164  *
3165  *	Return matching xfer mode for @cycle.  The returned mode is of
3166  *	the transfer type specified by @xfer_shift.  If @cycle is too
3167  *	slow for @xfer_shift, 0xff is returned.  If @cycle is faster
3168  *	than the fastest known mode, the fasted mode is returned.
3169  *
3170  *	LOCKING:
3171  *	None.
3172  *
3173  *	RETURNS:
3174  *	Matching xfer_mode, 0xff if no match found.
3175  */
3176 u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
3177 {
3178 	u8 base_mode = 0xff, last_mode = 0xff;
3179 	const struct ata_xfer_ent *ent;
3180 	const struct ata_timing *t;
3181 
3182 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
3183 		if (ent->shift == xfer_shift)
3184 			base_mode = ent->base;
3185 
3186 	for (t = ata_timing_find_mode(base_mode);
3187 	     t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
3188 		unsigned short this_cycle;
3189 
3190 		switch (xfer_shift) {
3191 		case ATA_SHIFT_PIO:
3192 		case ATA_SHIFT_MWDMA:
3193 			this_cycle = t->cycle;
3194 			break;
3195 		case ATA_SHIFT_UDMA:
3196 			this_cycle = t->udma;
3197 			break;
3198 		default:
3199 			return 0xff;
3200 		}
3201 
3202 		if (cycle > this_cycle)
3203 			break;
3204 
3205 		last_mode = t->mode;
3206 	}
3207 
3208 	return last_mode;
3209 }
3210 
3211 /**
3212  *	ata_down_xfermask_limit - adjust dev xfer masks downward
3213  *	@dev: Device to adjust xfer masks
3214  *	@sel: ATA_DNXFER_* selector
3215  *
3216  *	Adjust xfer masks of @dev downward.  Note that this function
3217  *	does not apply the change.  Invoking ata_set_mode() afterwards
3218  *	will apply the limit.
3219  *
3220  *	LOCKING:
3221  *	Inherited from caller.
3222  *
3223  *	RETURNS:
3224  *	0 on success, negative errno on failure
3225  */
3226 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
3227 {
3228 	char buf[32];
3229 	unsigned long orig_mask, xfer_mask;
3230 	unsigned long pio_mask, mwdma_mask, udma_mask;
3231 	int quiet, highbit;
3232 
3233 	quiet = !!(sel & ATA_DNXFER_QUIET);
3234 	sel &= ~ATA_DNXFER_QUIET;
3235 
3236 	xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
3237 						  dev->mwdma_mask,
3238 						  dev->udma_mask);
3239 	ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
3240 
3241 	switch (sel) {
3242 	case ATA_DNXFER_PIO:
3243 		highbit = fls(pio_mask) - 1;
3244 		pio_mask &= ~(1 << highbit);
3245 		break;
3246 
3247 	case ATA_DNXFER_DMA:
3248 		if (udma_mask) {
3249 			highbit = fls(udma_mask) - 1;
3250 			udma_mask &= ~(1 << highbit);
3251 			if (!udma_mask)
3252 				return -ENOENT;
3253 		} else if (mwdma_mask) {
3254 			highbit = fls(mwdma_mask) - 1;
3255 			mwdma_mask &= ~(1 << highbit);
3256 			if (!mwdma_mask)
3257 				return -ENOENT;
3258 		}
3259 		break;
3260 
3261 	case ATA_DNXFER_40C:
3262 		udma_mask &= ATA_UDMA_MASK_40C;
3263 		break;
3264 
3265 	case ATA_DNXFER_FORCE_PIO0:
3266 		pio_mask &= 1;
3267 	case ATA_DNXFER_FORCE_PIO:
3268 		mwdma_mask = 0;
3269 		udma_mask = 0;
3270 		break;
3271 
3272 	default:
3273 		BUG();
3274 	}
3275 
3276 	xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
3277 
3278 	if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
3279 		return -ENOENT;
3280 
3281 	if (!quiet) {
3282 		if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
3283 			snprintf(buf, sizeof(buf), "%s:%s",
3284 				 ata_mode_string(xfer_mask),
3285 				 ata_mode_string(xfer_mask & ATA_MASK_PIO));
3286 		else
3287 			snprintf(buf, sizeof(buf), "%s",
3288 				 ata_mode_string(xfer_mask));
3289 
3290 		ata_dev_printk(dev, KERN_WARNING,
3291 			       "limiting speed to %s\n", buf);
3292 	}
3293 
3294 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
3295 			    &dev->udma_mask);
3296 
3297 	return 0;
3298 }
3299 
3300 static int ata_dev_set_mode(struct ata_device *dev)
3301 {
3302 	struct ata_eh_context *ehc = &dev->link->eh_context;
3303 	const char *dev_err_whine = "";
3304 	int ign_dev_err = 0;
3305 	unsigned int err_mask;
3306 	int rc;
3307 
3308 	dev->flags &= ~ATA_DFLAG_PIO;
3309 	if (dev->xfer_shift == ATA_SHIFT_PIO)
3310 		dev->flags |= ATA_DFLAG_PIO;
3311 
3312 	err_mask = ata_dev_set_xfermode(dev);
3313 
3314 	if (err_mask & ~AC_ERR_DEV)
3315 		goto fail;
3316 
3317 	/* revalidate */
3318 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
3319 	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
3320 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
3321 	if (rc)
3322 		return rc;
3323 
3324 	/* Old CFA may refuse this command, which is just fine */
3325 	if (dev->xfer_shift == ATA_SHIFT_PIO && ata_id_is_cfa(dev->id))
3326 		ign_dev_err = 1;
3327 
3328 	/* Some very old devices and some bad newer ones fail any kind of
3329 	   SET_XFERMODE request but support PIO0-2 timings and no IORDY */
3330 	if (dev->xfer_shift == ATA_SHIFT_PIO && !ata_id_has_iordy(dev->id) &&
3331 			dev->pio_mode <= XFER_PIO_2)
3332 		ign_dev_err = 1;
3333 
3334 	/* Early MWDMA devices do DMA but don't allow DMA mode setting.
3335 	   Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
3336 	if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
3337 	    dev->dma_mode == XFER_MW_DMA_0 &&
3338 	    (dev->id[63] >> 8) & 1)
3339 		ign_dev_err = 1;
3340 
3341 	/* if the device is actually configured correctly, ignore dev err */
3342 	if (dev->xfer_mode == ata_xfer_mask2mode(ata_id_xfermask(dev->id)))
3343 		ign_dev_err = 1;
3344 
3345 	if (err_mask & AC_ERR_DEV) {
3346 		if (!ign_dev_err)
3347 			goto fail;
3348 		else
3349 			dev_err_whine = " (device error ignored)";
3350 	}
3351 
3352 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
3353 		dev->xfer_shift, (int)dev->xfer_mode);
3354 
3355 	ata_dev_printk(dev, KERN_INFO, "configured for %s%s\n",
3356 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)),
3357 		       dev_err_whine);
3358 
3359 	return 0;
3360 
3361  fail:
3362 	ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
3363 		       "(err_mask=0x%x)\n", err_mask);
3364 	return -EIO;
3365 }
3366 
3367 /**
3368  *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
3369  *	@link: link on which timings will be programmed
3370  *	@r_failed_dev: out parameter for failed device
3371  *
3372  *	Standard implementation of the function used to tune and set
3373  *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3374  *	ata_dev_set_mode() fails, pointer to the failing device is
3375  *	returned in @r_failed_dev.
3376  *
3377  *	LOCKING:
3378  *	PCI/etc. bus probe sem.
3379  *
3380  *	RETURNS:
3381  *	0 on success, negative errno otherwise
3382  */
3383 
3384 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3385 {
3386 	struct ata_port *ap = link->ap;
3387 	struct ata_device *dev;
3388 	int rc = 0, used_dma = 0, found = 0;
3389 
3390 	/* step 1: calculate xfer_mask */
3391 	ata_link_for_each_dev(dev, link) {
3392 		unsigned long pio_mask, dma_mask;
3393 		unsigned int mode_mask;
3394 
3395 		if (!ata_dev_enabled(dev))
3396 			continue;
3397 
3398 		mode_mask = ATA_DMA_MASK_ATA;
3399 		if (dev->class == ATA_DEV_ATAPI)
3400 			mode_mask = ATA_DMA_MASK_ATAPI;
3401 		else if (ata_id_is_cfa(dev->id))
3402 			mode_mask = ATA_DMA_MASK_CFA;
3403 
3404 		ata_dev_xfermask(dev);
3405 		ata_force_xfermask(dev);
3406 
3407 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
3408 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3409 
3410 		if (libata_dma_mask & mode_mask)
3411 			dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3412 		else
3413 			dma_mask = 0;
3414 
3415 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
3416 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
3417 
3418 		found = 1;
3419 		if (dev->dma_mode != 0xff)
3420 			used_dma = 1;
3421 	}
3422 	if (!found)
3423 		goto out;
3424 
3425 	/* step 2: always set host PIO timings */
3426 	ata_link_for_each_dev(dev, link) {
3427 		if (!ata_dev_enabled(dev))
3428 			continue;
3429 
3430 		if (dev->pio_mode == 0xff) {
3431 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
3432 			rc = -EINVAL;
3433 			goto out;
3434 		}
3435 
3436 		dev->xfer_mode = dev->pio_mode;
3437 		dev->xfer_shift = ATA_SHIFT_PIO;
3438 		if (ap->ops->set_piomode)
3439 			ap->ops->set_piomode(ap, dev);
3440 	}
3441 
3442 	/* step 3: set host DMA timings */
3443 	ata_link_for_each_dev(dev, link) {
3444 		if (!ata_dev_enabled(dev) || dev->dma_mode == 0xff)
3445 			continue;
3446 
3447 		dev->xfer_mode = dev->dma_mode;
3448 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
3449 		if (ap->ops->set_dmamode)
3450 			ap->ops->set_dmamode(ap, dev);
3451 	}
3452 
3453 	/* step 4: update devices' xfer mode */
3454 	ata_link_for_each_dev(dev, link) {
3455 		/* don't update suspended devices' xfer mode */
3456 		if (!ata_dev_enabled(dev))
3457 			continue;
3458 
3459 		rc = ata_dev_set_mode(dev);
3460 		if (rc)
3461 			goto out;
3462 	}
3463 
3464 	/* Record simplex status. If we selected DMA then the other
3465 	 * host channels are not permitted to do so.
3466 	 */
3467 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
3468 		ap->host->simplex_claimed = ap;
3469 
3470  out:
3471 	if (rc)
3472 		*r_failed_dev = dev;
3473 	return rc;
3474 }
3475 
3476 /**
3477  *	ata_tf_to_host - issue ATA taskfile to host controller
3478  *	@ap: port to which command is being issued
3479  *	@tf: ATA taskfile register set
3480  *
3481  *	Issues ATA taskfile register set to ATA host controller,
3482  *	with proper synchronization with interrupt handler and
3483  *	other threads.
3484  *
3485  *	LOCKING:
3486  *	spin_lock_irqsave(host lock)
3487  */
3488 
3489 static inline void ata_tf_to_host(struct ata_port *ap,
3490 				  const struct ata_taskfile *tf)
3491 {
3492 	ap->ops->tf_load(ap, tf);
3493 	ap->ops->exec_command(ap, tf);
3494 }
3495 
3496 /**
3497  *	ata_busy_sleep - sleep until BSY clears, or timeout
3498  *	@ap: port containing status register to be polled
3499  *	@tmout_pat: impatience timeout
3500  *	@tmout: overall timeout
3501  *
3502  *	Sleep until ATA Status register bit BSY clears,
3503  *	or a timeout occurs.
3504  *
3505  *	LOCKING:
3506  *	Kernel thread context (may sleep).
3507  *
3508  *	RETURNS:
3509  *	0 on success, -errno otherwise.
3510  */
3511 int ata_busy_sleep(struct ata_port *ap,
3512 		   unsigned long tmout_pat, unsigned long tmout)
3513 {
3514 	unsigned long timer_start, timeout;
3515 	u8 status;
3516 
3517 	status = ata_busy_wait(ap, ATA_BUSY, 300);
3518 	timer_start = jiffies;
3519 	timeout = timer_start + tmout_pat;
3520 	while (status != 0xff && (status & ATA_BUSY) &&
3521 	       time_before(jiffies, timeout)) {
3522 		msleep(50);
3523 		status = ata_busy_wait(ap, ATA_BUSY, 3);
3524 	}
3525 
3526 	if (status != 0xff && (status & ATA_BUSY))
3527 		ata_port_printk(ap, KERN_WARNING,
3528 				"port is slow to respond, please be patient "
3529 				"(Status 0x%x)\n", status);
3530 
3531 	timeout = timer_start + tmout;
3532 	while (status != 0xff && (status & ATA_BUSY) &&
3533 	       time_before(jiffies, timeout)) {
3534 		msleep(50);
3535 		status = ata_chk_status(ap);
3536 	}
3537 
3538 	if (status == 0xff)
3539 		return -ENODEV;
3540 
3541 	if (status & ATA_BUSY) {
3542 		ata_port_printk(ap, KERN_ERR, "port failed to respond "
3543 				"(%lu secs, Status 0x%x)\n",
3544 				tmout / HZ, status);
3545 		return -EBUSY;
3546 	}
3547 
3548 	return 0;
3549 }
3550 
3551 /**
3552  *	ata_wait_after_reset - wait before checking status after reset
3553  *	@ap: port containing status register to be polled
3554  *	@deadline: deadline jiffies for the operation
3555  *
3556  *	After reset, we need to pause a while before reading status.
3557  *	Also, certain combination of controller and device report 0xff
3558  *	for some duration (e.g. until SATA PHY is up and running)
3559  *	which is interpreted as empty port in ATA world.  This
3560  *	function also waits for such devices to get out of 0xff
3561  *	status.
3562  *
3563  *	LOCKING:
3564  *	Kernel thread context (may sleep).
3565  */
3566 void ata_wait_after_reset(struct ata_port *ap, unsigned long deadline)
3567 {
3568 	unsigned long until = jiffies + ATA_TMOUT_FF_WAIT;
3569 
3570 	if (time_before(until, deadline))
3571 		deadline = until;
3572 
3573 	/* Spec mandates ">= 2ms" before checking status.  We wait
3574 	 * 150ms, because that was the magic delay used for ATAPI
3575 	 * devices in Hale Landis's ATADRVR, for the period of time
3576 	 * between when the ATA command register is written, and then
3577 	 * status is checked.  Because waiting for "a while" before
3578 	 * checking status is fine, post SRST, we perform this magic
3579 	 * delay here as well.
3580 	 *
3581 	 * Old drivers/ide uses the 2mS rule and then waits for ready.
3582 	 */
3583 	msleep(150);
3584 
3585 	/* Wait for 0xff to clear.  Some SATA devices take a long time
3586 	 * to clear 0xff after reset.  For example, HHD424020F7SV00
3587 	 * iVDR needs >= 800ms while.  Quantum GoVault needs even more
3588 	 * than that.
3589 	 *
3590 	 * Note that some PATA controllers (pata_ali) explode if
3591 	 * status register is read more than once when there's no
3592 	 * device attached.
3593 	 */
3594 	if (ap->flags & ATA_FLAG_SATA) {
3595 		while (1) {
3596 			u8 status = ata_chk_status(ap);
3597 
3598 			if (status != 0xff || time_after(jiffies, deadline))
3599 				return;
3600 
3601 			msleep(50);
3602 		}
3603 	}
3604 }
3605 
3606 /**
3607  *	ata_wait_ready - sleep until BSY clears, or timeout
3608  *	@ap: port containing status register to be polled
3609  *	@deadline: deadline jiffies for the operation
3610  *
3611  *	Sleep until ATA Status register bit BSY clears, or timeout
3612  *	occurs.
3613  *
3614  *	LOCKING:
3615  *	Kernel thread context (may sleep).
3616  *
3617  *	RETURNS:
3618  *	0 on success, -errno otherwise.
3619  */
3620 int ata_wait_ready(struct ata_port *ap, unsigned long deadline)
3621 {
3622 	unsigned long start = jiffies;
3623 	int warned = 0;
3624 
3625 	while (1) {
3626 		u8 status = ata_chk_status(ap);
3627 		unsigned long now = jiffies;
3628 
3629 		if (!(status & ATA_BUSY))
3630 			return 0;
3631 		if (!ata_link_online(&ap->link) && status == 0xff)
3632 			return -ENODEV;
3633 		if (time_after(now, deadline))
3634 			return -EBUSY;
3635 
3636 		if (!warned && time_after(now, start + 5 * HZ) &&
3637 		    (deadline - now > 3 * HZ)) {
3638 			ata_port_printk(ap, KERN_WARNING,
3639 				"port is slow to respond, please be patient "
3640 				"(Status 0x%x)\n", status);
3641 			warned = 1;
3642 		}
3643 
3644 		msleep(50);
3645 	}
3646 }
3647 
3648 static int ata_bus_post_reset(struct ata_port *ap, unsigned int devmask,
3649 			      unsigned long deadline)
3650 {
3651 	struct ata_ioports *ioaddr = &ap->ioaddr;
3652 	unsigned int dev0 = devmask & (1 << 0);
3653 	unsigned int dev1 = devmask & (1 << 1);
3654 	int rc, ret = 0;
3655 
3656 	/* if device 0 was found in ata_devchk, wait for its
3657 	 * BSY bit to clear
3658 	 */
3659 	if (dev0) {
3660 		rc = ata_wait_ready(ap, deadline);
3661 		if (rc) {
3662 			if (rc != -ENODEV)
3663 				return rc;
3664 			ret = rc;
3665 		}
3666 	}
3667 
3668 	/* if device 1 was found in ata_devchk, wait for register
3669 	 * access briefly, then wait for BSY to clear.
3670 	 */
3671 	if (dev1) {
3672 		int i;
3673 
3674 		ap->ops->dev_select(ap, 1);
3675 
3676 		/* Wait for register access.  Some ATAPI devices fail
3677 		 * to set nsect/lbal after reset, so don't waste too
3678 		 * much time on it.  We're gonna wait for !BSY anyway.
3679 		 */
3680 		for (i = 0; i < 2; i++) {
3681 			u8 nsect, lbal;
3682 
3683 			nsect = ioread8(ioaddr->nsect_addr);
3684 			lbal = ioread8(ioaddr->lbal_addr);
3685 			if ((nsect == 1) && (lbal == 1))
3686 				break;
3687 			msleep(50);	/* give drive a breather */
3688 		}
3689 
3690 		rc = ata_wait_ready(ap, deadline);
3691 		if (rc) {
3692 			if (rc != -ENODEV)
3693 				return rc;
3694 			ret = rc;
3695 		}
3696 	}
3697 
3698 	/* is all this really necessary? */
3699 	ap->ops->dev_select(ap, 0);
3700 	if (dev1)
3701 		ap->ops->dev_select(ap, 1);
3702 	if (dev0)
3703 		ap->ops->dev_select(ap, 0);
3704 
3705 	return ret;
3706 }
3707 
3708 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
3709 			     unsigned long deadline)
3710 {
3711 	struct ata_ioports *ioaddr = &ap->ioaddr;
3712 
3713 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
3714 
3715 	/* software reset.  causes dev0 to be selected */
3716 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3717 	udelay(20);	/* FIXME: flush */
3718 	iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
3719 	udelay(20);	/* FIXME: flush */
3720 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3721 
3722 	/* wait a while before checking status */
3723 	ata_wait_after_reset(ap, deadline);
3724 
3725 	/* Before we perform post reset processing we want to see if
3726 	 * the bus shows 0xFF because the odd clown forgets the D7
3727 	 * pulldown resistor.
3728 	 */
3729 	if (ata_chk_status(ap) == 0xFF)
3730 		return -ENODEV;
3731 
3732 	return ata_bus_post_reset(ap, devmask, deadline);
3733 }
3734 
3735 /**
3736  *	ata_bus_reset - reset host port and associated ATA channel
3737  *	@ap: port to reset
3738  *
3739  *	This is typically the first time we actually start issuing
3740  *	commands to the ATA channel.  We wait for BSY to clear, then
3741  *	issue EXECUTE DEVICE DIAGNOSTIC command, polling for its
3742  *	result.  Determine what devices, if any, are on the channel
3743  *	by looking at the device 0/1 error register.  Look at the signature
3744  *	stored in each device's taskfile registers, to determine if
3745  *	the device is ATA or ATAPI.
3746  *
3747  *	LOCKING:
3748  *	PCI/etc. bus probe sem.
3749  *	Obtains host lock.
3750  *
3751  *	SIDE EFFECTS:
3752  *	Sets ATA_FLAG_DISABLED if bus reset fails.
3753  */
3754 
3755 void ata_bus_reset(struct ata_port *ap)
3756 {
3757 	struct ata_device *device = ap->link.device;
3758 	struct ata_ioports *ioaddr = &ap->ioaddr;
3759 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
3760 	u8 err;
3761 	unsigned int dev0, dev1 = 0, devmask = 0;
3762 	int rc;
3763 
3764 	DPRINTK("ENTER, host %u, port %u\n", ap->print_id, ap->port_no);
3765 
3766 	/* determine if device 0/1 are present */
3767 	if (ap->flags & ATA_FLAG_SATA_RESET)
3768 		dev0 = 1;
3769 	else {
3770 		dev0 = ata_devchk(ap, 0);
3771 		if (slave_possible)
3772 			dev1 = ata_devchk(ap, 1);
3773 	}
3774 
3775 	if (dev0)
3776 		devmask |= (1 << 0);
3777 	if (dev1)
3778 		devmask |= (1 << 1);
3779 
3780 	/* select device 0 again */
3781 	ap->ops->dev_select(ap, 0);
3782 
3783 	/* issue bus reset */
3784 	if (ap->flags & ATA_FLAG_SRST) {
3785 		rc = ata_bus_softreset(ap, devmask, jiffies + 40 * HZ);
3786 		if (rc && rc != -ENODEV)
3787 			goto err_out;
3788 	}
3789 
3790 	/*
3791 	 * determine by signature whether we have ATA or ATAPI devices
3792 	 */
3793 	device[0].class = ata_dev_try_classify(&device[0], dev0, &err);
3794 	if ((slave_possible) && (err != 0x81))
3795 		device[1].class = ata_dev_try_classify(&device[1], dev1, &err);
3796 
3797 	/* is double-select really necessary? */
3798 	if (device[1].class != ATA_DEV_NONE)
3799 		ap->ops->dev_select(ap, 1);
3800 	if (device[0].class != ATA_DEV_NONE)
3801 		ap->ops->dev_select(ap, 0);
3802 
3803 	/* if no devices were detected, disable this port */
3804 	if ((device[0].class == ATA_DEV_NONE) &&
3805 	    (device[1].class == ATA_DEV_NONE))
3806 		goto err_out;
3807 
3808 	if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
3809 		/* set up device control for ATA_FLAG_SATA_RESET */
3810 		iowrite8(ap->ctl, ioaddr->ctl_addr);
3811 	}
3812 
3813 	DPRINTK("EXIT\n");
3814 	return;
3815 
3816 err_out:
3817 	ata_port_printk(ap, KERN_ERR, "disabling port\n");
3818 	ata_port_disable(ap);
3819 
3820 	DPRINTK("EXIT\n");
3821 }
3822 
3823 /**
3824  *	sata_link_debounce - debounce SATA phy status
3825  *	@link: ATA link to debounce SATA phy status for
3826  *	@params: timing parameters { interval, duratinon, timeout } in msec
3827  *	@deadline: deadline jiffies for the operation
3828  *
3829 *	Make sure SStatus of @link reaches stable state, determined by
3830  *	holding the same value where DET is not 1 for @duration polled
3831  *	every @interval, before @timeout.  Timeout constraints the
3832  *	beginning of the stable state.  Because DET gets stuck at 1 on
3833  *	some controllers after hot unplugging, this functions waits
3834  *	until timeout then returns 0 if DET is stable at 1.
3835  *
3836  *	@timeout is further limited by @deadline.  The sooner of the
3837  *	two is used.
3838  *
3839  *	LOCKING:
3840  *	Kernel thread context (may sleep)
3841  *
3842  *	RETURNS:
3843  *	0 on success, -errno on failure.
3844  */
3845 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
3846 		       unsigned long deadline)
3847 {
3848 	unsigned long interval_msec = params[0];
3849 	unsigned long duration = msecs_to_jiffies(params[1]);
3850 	unsigned long last_jiffies, t;
3851 	u32 last, cur;
3852 	int rc;
3853 
3854 	t = jiffies + msecs_to_jiffies(params[2]);
3855 	if (time_before(t, deadline))
3856 		deadline = t;
3857 
3858 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3859 		return rc;
3860 	cur &= 0xf;
3861 
3862 	last = cur;
3863 	last_jiffies = jiffies;
3864 
3865 	while (1) {
3866 		msleep(interval_msec);
3867 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3868 			return rc;
3869 		cur &= 0xf;
3870 
3871 		/* DET stable? */
3872 		if (cur == last) {
3873 			if (cur == 1 && time_before(jiffies, deadline))
3874 				continue;
3875 			if (time_after(jiffies, last_jiffies + duration))
3876 				return 0;
3877 			continue;
3878 		}
3879 
3880 		/* unstable, start over */
3881 		last = cur;
3882 		last_jiffies = jiffies;
3883 
3884 		/* Check deadline.  If debouncing failed, return
3885 		 * -EPIPE to tell upper layer to lower link speed.
3886 		 */
3887 		if (time_after(jiffies, deadline))
3888 			return -EPIPE;
3889 	}
3890 }
3891 
3892 /**
3893  *	sata_link_resume - resume SATA link
3894  *	@link: ATA link to resume SATA
3895  *	@params: timing parameters { interval, duratinon, timeout } in msec
3896  *	@deadline: deadline jiffies for the operation
3897  *
3898  *	Resume SATA phy @link and debounce it.
3899  *
3900  *	LOCKING:
3901  *	Kernel thread context (may sleep)
3902  *
3903  *	RETURNS:
3904  *	0 on success, -errno on failure.
3905  */
3906 int sata_link_resume(struct ata_link *link, const unsigned long *params,
3907 		     unsigned long deadline)
3908 {
3909 	u32 scontrol;
3910 	int rc;
3911 
3912 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3913 		return rc;
3914 
3915 	scontrol = (scontrol & 0x0f0) | 0x300;
3916 
3917 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3918 		return rc;
3919 
3920 	/* Some PHYs react badly if SStatus is pounded immediately
3921 	 * after resuming.  Delay 200ms before debouncing.
3922 	 */
3923 	msleep(200);
3924 
3925 	return sata_link_debounce(link, params, deadline);
3926 }
3927 
3928 /**
3929  *	ata_std_prereset - prepare for reset
3930  *	@link: ATA link to be reset
3931  *	@deadline: deadline jiffies for the operation
3932  *
3933  *	@link is about to be reset.  Initialize it.  Failure from
3934  *	prereset makes libata abort whole reset sequence and give up
3935  *	that port, so prereset should be best-effort.  It does its
3936  *	best to prepare for reset sequence but if things go wrong, it
3937  *	should just whine, not fail.
3938  *
3939  *	LOCKING:
3940  *	Kernel thread context (may sleep)
3941  *
3942  *	RETURNS:
3943  *	0 on success, -errno otherwise.
3944  */
3945 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
3946 {
3947 	struct ata_port *ap = link->ap;
3948 	struct ata_eh_context *ehc = &link->eh_context;
3949 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
3950 	int rc;
3951 
3952 	/* handle link resume */
3953 	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
3954 	    (link->flags & ATA_LFLAG_HRST_TO_RESUME))
3955 		ehc->i.action |= ATA_EH_HARDRESET;
3956 
3957 	/* Some PMPs don't work with only SRST, force hardreset if PMP
3958 	 * is supported.
3959 	 */
3960 	if (ap->flags & ATA_FLAG_PMP)
3961 		ehc->i.action |= ATA_EH_HARDRESET;
3962 
3963 	/* if we're about to do hardreset, nothing more to do */
3964 	if (ehc->i.action & ATA_EH_HARDRESET)
3965 		return 0;
3966 
3967 	/* if SATA, resume link */
3968 	if (ap->flags & ATA_FLAG_SATA) {
3969 		rc = sata_link_resume(link, timing, deadline);
3970 		/* whine about phy resume failure but proceed */
3971 		if (rc && rc != -EOPNOTSUPP)
3972 			ata_link_printk(link, KERN_WARNING, "failed to resume "
3973 					"link for reset (errno=%d)\n", rc);
3974 	}
3975 
3976 	/* Wait for !BSY if the controller can wait for the first D2H
3977 	 * Reg FIS and we don't know that no device is attached.
3978 	 */
3979 	if (!(link->flags & ATA_LFLAG_SKIP_D2H_BSY) && !ata_link_offline(link)) {
3980 		rc = ata_wait_ready(ap, deadline);
3981 		if (rc && rc != -ENODEV) {
3982 			ata_link_printk(link, KERN_WARNING, "device not ready "
3983 					"(errno=%d), forcing hardreset\n", rc);
3984 			ehc->i.action |= ATA_EH_HARDRESET;
3985 		}
3986 	}
3987 
3988 	return 0;
3989 }
3990 
3991 /**
3992  *	ata_std_softreset - reset host port via ATA SRST
3993  *	@link: ATA link to reset
3994  *	@classes: resulting classes of attached devices
3995  *	@deadline: deadline jiffies for the operation
3996  *
3997  *	Reset host port using ATA SRST.
3998  *
3999  *	LOCKING:
4000  *	Kernel thread context (may sleep)
4001  *
4002  *	RETURNS:
4003  *	0 on success, -errno otherwise.
4004  */
4005 int ata_std_softreset(struct ata_link *link, unsigned int *classes,
4006 		      unsigned long deadline)
4007 {
4008 	struct ata_port *ap = link->ap;
4009 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
4010 	unsigned int devmask = 0;
4011 	int rc;
4012 	u8 err;
4013 
4014 	DPRINTK("ENTER\n");
4015 
4016 	if (ata_link_offline(link)) {
4017 		classes[0] = ATA_DEV_NONE;
4018 		goto out;
4019 	}
4020 
4021 	/* determine if device 0/1 are present */
4022 	if (ata_devchk(ap, 0))
4023 		devmask |= (1 << 0);
4024 	if (slave_possible && ata_devchk(ap, 1))
4025 		devmask |= (1 << 1);
4026 
4027 	/* select device 0 again */
4028 	ap->ops->dev_select(ap, 0);
4029 
4030 	/* issue bus reset */
4031 	DPRINTK("about to softreset, devmask=%x\n", devmask);
4032 	rc = ata_bus_softreset(ap, devmask, deadline);
4033 	/* if link is occupied, -ENODEV too is an error */
4034 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
4035 		ata_link_printk(link, KERN_ERR, "SRST failed (errno=%d)\n", rc);
4036 		return rc;
4037 	}
4038 
4039 	/* determine by signature whether we have ATA or ATAPI devices */
4040 	classes[0] = ata_dev_try_classify(&link->device[0],
4041 					  devmask & (1 << 0), &err);
4042 	if (slave_possible && err != 0x81)
4043 		classes[1] = ata_dev_try_classify(&link->device[1],
4044 						  devmask & (1 << 1), &err);
4045 
4046  out:
4047 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
4048 	return 0;
4049 }
4050 
4051 /**
4052  *	sata_link_hardreset - reset link via SATA phy reset
4053  *	@link: link to reset
4054  *	@timing: timing parameters { interval, duratinon, timeout } in msec
4055  *	@deadline: deadline jiffies for the operation
4056  *
4057  *	SATA phy-reset @link using DET bits of SControl register.
4058  *
4059  *	LOCKING:
4060  *	Kernel thread context (may sleep)
4061  *
4062  *	RETURNS:
4063  *	0 on success, -errno otherwise.
4064  */
4065 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
4066 			unsigned long deadline)
4067 {
4068 	u32 scontrol;
4069 	int rc;
4070 
4071 	DPRINTK("ENTER\n");
4072 
4073 	if (sata_set_spd_needed(link)) {
4074 		/* SATA spec says nothing about how to reconfigure
4075 		 * spd.  To be on the safe side, turn off phy during
4076 		 * reconfiguration.  This works for at least ICH7 AHCI
4077 		 * and Sil3124.
4078 		 */
4079 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
4080 			goto out;
4081 
4082 		scontrol = (scontrol & 0x0f0) | 0x304;
4083 
4084 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
4085 			goto out;
4086 
4087 		sata_set_spd(link);
4088 	}
4089 
4090 	/* issue phy wake/reset */
4091 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
4092 		goto out;
4093 
4094 	scontrol = (scontrol & 0x0f0) | 0x301;
4095 
4096 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
4097 		goto out;
4098 
4099 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
4100 	 * 10.4.2 says at least 1 ms.
4101 	 */
4102 	msleep(1);
4103 
4104 	/* bring link back */
4105 	rc = sata_link_resume(link, timing, deadline);
4106  out:
4107 	DPRINTK("EXIT, rc=%d\n", rc);
4108 	return rc;
4109 }
4110 
4111 /**
4112  *	sata_std_hardreset - reset host port via SATA phy reset
4113  *	@link: link to reset
4114  *	@class: resulting class of attached device
4115  *	@deadline: deadline jiffies for the operation
4116  *
4117  *	SATA phy-reset host port using DET bits of SControl register,
4118  *	wait for !BSY and classify the attached device.
4119  *
4120  *	LOCKING:
4121  *	Kernel thread context (may sleep)
4122  *
4123  *	RETURNS:
4124  *	0 on success, -errno otherwise.
4125  */
4126 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
4127 		       unsigned long deadline)
4128 {
4129 	struct ata_port *ap = link->ap;
4130 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
4131 	int rc;
4132 
4133 	DPRINTK("ENTER\n");
4134 
4135 	/* do hardreset */
4136 	rc = sata_link_hardreset(link, timing, deadline);
4137 	if (rc) {
4138 		ata_link_printk(link, KERN_ERR,
4139 				"COMRESET failed (errno=%d)\n", rc);
4140 		return rc;
4141 	}
4142 
4143 	/* TODO: phy layer with polling, timeouts, etc. */
4144 	if (ata_link_offline(link)) {
4145 		*class = ATA_DEV_NONE;
4146 		DPRINTK("EXIT, link offline\n");
4147 		return 0;
4148 	}
4149 
4150 	/* wait a while before checking status */
4151 	ata_wait_after_reset(ap, deadline);
4152 
4153 	/* If PMP is supported, we have to do follow-up SRST.  Note
4154 	 * that some PMPs don't send D2H Reg FIS after hardreset at
4155 	 * all if the first port is empty.  Wait for it just for a
4156 	 * second and request follow-up SRST.
4157 	 */
4158 	if (ap->flags & ATA_FLAG_PMP) {
4159 		ata_wait_ready(ap, jiffies + HZ);
4160 		return -EAGAIN;
4161 	}
4162 
4163 	rc = ata_wait_ready(ap, deadline);
4164 	/* link occupied, -ENODEV too is an error */
4165 	if (rc) {
4166 		ata_link_printk(link, KERN_ERR,
4167 				"COMRESET failed (errno=%d)\n", rc);
4168 		return rc;
4169 	}
4170 
4171 	ap->ops->dev_select(ap, 0);	/* probably unnecessary */
4172 
4173 	*class = ata_dev_try_classify(link->device, 1, NULL);
4174 
4175 	DPRINTK("EXIT, class=%u\n", *class);
4176 	return 0;
4177 }
4178 
4179 /**
4180  *	ata_std_postreset - standard postreset callback
4181  *	@link: the target ata_link
4182  *	@classes: classes of attached devices
4183  *
4184  *	This function is invoked after a successful reset.  Note that
4185  *	the device might have been reset more than once using
4186  *	different reset methods before postreset is invoked.
4187  *
4188  *	LOCKING:
4189  *	Kernel thread context (may sleep)
4190  */
4191 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
4192 {
4193 	struct ata_port *ap = link->ap;
4194 	u32 serror;
4195 
4196 	DPRINTK("ENTER\n");
4197 
4198 	/* print link status */
4199 	sata_print_link_status(link);
4200 
4201 	/* clear SError */
4202 	if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
4203 		sata_scr_write(link, SCR_ERROR, serror);
4204 	link->eh_info.serror = 0;
4205 
4206 	/* is double-select really necessary? */
4207 	if (classes[0] != ATA_DEV_NONE)
4208 		ap->ops->dev_select(ap, 1);
4209 	if (classes[1] != ATA_DEV_NONE)
4210 		ap->ops->dev_select(ap, 0);
4211 
4212 	/* bail out if no device is present */
4213 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
4214 		DPRINTK("EXIT, no device\n");
4215 		return;
4216 	}
4217 
4218 	/* set up device control */
4219 	if (ap->ioaddr.ctl_addr)
4220 		iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
4221 
4222 	DPRINTK("EXIT\n");
4223 }
4224 
4225 /**
4226  *	ata_dev_same_device - Determine whether new ID matches configured device
4227  *	@dev: device to compare against
4228  *	@new_class: class of the new device
4229  *	@new_id: IDENTIFY page of the new device
4230  *
4231  *	Compare @new_class and @new_id against @dev and determine
4232  *	whether @dev is the device indicated by @new_class and
4233  *	@new_id.
4234  *
4235  *	LOCKING:
4236  *	None.
4237  *
4238  *	RETURNS:
4239  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
4240  */
4241 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
4242 			       const u16 *new_id)
4243 {
4244 	const u16 *old_id = dev->id;
4245 	unsigned char model[2][ATA_ID_PROD_LEN + 1];
4246 	unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
4247 
4248 	if (dev->class != new_class) {
4249 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
4250 			       dev->class, new_class);
4251 		return 0;
4252 	}
4253 
4254 	ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
4255 	ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
4256 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
4257 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
4258 
4259 	if (strcmp(model[0], model[1])) {
4260 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
4261 			       "'%s' != '%s'\n", model[0], model[1]);
4262 		return 0;
4263 	}
4264 
4265 	if (strcmp(serial[0], serial[1])) {
4266 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
4267 			       "'%s' != '%s'\n", serial[0], serial[1]);
4268 		return 0;
4269 	}
4270 
4271 	return 1;
4272 }
4273 
4274 /**
4275  *	ata_dev_reread_id - Re-read IDENTIFY data
4276  *	@dev: target ATA device
4277  *	@readid_flags: read ID flags
4278  *
4279  *	Re-read IDENTIFY page and make sure @dev is still attached to
4280  *	the port.
4281  *
4282  *	LOCKING:
4283  *	Kernel thread context (may sleep)
4284  *
4285  *	RETURNS:
4286  *	0 on success, negative errno otherwise
4287  */
4288 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
4289 {
4290 	unsigned int class = dev->class;
4291 	u16 *id = (void *)dev->link->ap->sector_buf;
4292 	int rc;
4293 
4294 	/* read ID data */
4295 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
4296 	if (rc)
4297 		return rc;
4298 
4299 	/* is the device still there? */
4300 	if (!ata_dev_same_device(dev, class, id))
4301 		return -ENODEV;
4302 
4303 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
4304 	return 0;
4305 }
4306 
4307 /**
4308  *	ata_dev_revalidate - Revalidate ATA device
4309  *	@dev: device to revalidate
4310  *	@new_class: new class code
4311  *	@readid_flags: read ID flags
4312  *
4313  *	Re-read IDENTIFY page, make sure @dev is still attached to the
4314  *	port and reconfigure it according to the new IDENTIFY page.
4315  *
4316  *	LOCKING:
4317  *	Kernel thread context (may sleep)
4318  *
4319  *	RETURNS:
4320  *	0 on success, negative errno otherwise
4321  */
4322 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
4323 		       unsigned int readid_flags)
4324 {
4325 	u64 n_sectors = dev->n_sectors;
4326 	int rc;
4327 
4328 	if (!ata_dev_enabled(dev))
4329 		return -ENODEV;
4330 
4331 	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
4332 	if (ata_class_enabled(new_class) &&
4333 	    new_class != ATA_DEV_ATA && new_class != ATA_DEV_ATAPI) {
4334 		ata_dev_printk(dev, KERN_INFO, "class mismatch %u != %u\n",
4335 			       dev->class, new_class);
4336 		rc = -ENODEV;
4337 		goto fail;
4338 	}
4339 
4340 	/* re-read ID */
4341 	rc = ata_dev_reread_id(dev, readid_flags);
4342 	if (rc)
4343 		goto fail;
4344 
4345 	/* configure device according to the new ID */
4346 	rc = ata_dev_configure(dev);
4347 	if (rc)
4348 		goto fail;
4349 
4350 	/* verify n_sectors hasn't changed */
4351 	if (dev->class == ATA_DEV_ATA && n_sectors &&
4352 	    dev->n_sectors != n_sectors) {
4353 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
4354 			       "%llu != %llu\n",
4355 			       (unsigned long long)n_sectors,
4356 			       (unsigned long long)dev->n_sectors);
4357 
4358 		/* restore original n_sectors */
4359 		dev->n_sectors = n_sectors;
4360 
4361 		rc = -ENODEV;
4362 		goto fail;
4363 	}
4364 
4365 	return 0;
4366 
4367  fail:
4368 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
4369 	return rc;
4370 }
4371 
4372 struct ata_blacklist_entry {
4373 	const char *model_num;
4374 	const char *model_rev;
4375 	unsigned long horkage;
4376 };
4377 
4378 static const struct ata_blacklist_entry ata_device_blacklist [] = {
4379 	/* Devices with DMA related problems under Linux */
4380 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
4381 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
4382 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
4383 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
4384 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
4385 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
4386 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
4387 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
4388 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
4389 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
4390 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
4391 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
4392 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
4393 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
4394 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
4395 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
4396 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
4397 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
4398 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
4399 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
4400 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
4401 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
4402 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
4403 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
4404 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
4405 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
4406 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
4407 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
4408 	{ "SAMSUNG CD-ROM SN-124", "N001",	ATA_HORKAGE_NODMA },
4409 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
4410 	/* Odd clown on sil3726/4726 PMPs */
4411 	{ "Config  Disk",	NULL,		ATA_HORKAGE_NODMA |
4412 						ATA_HORKAGE_SKIP_PM },
4413 
4414 	/* Weird ATAPI devices */
4415 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
4416 
4417 	/* Devices we expect to fail diagnostics */
4418 
4419 	/* Devices where NCQ should be avoided */
4420 	/* NCQ is slow */
4421 	{ "WDC WD740ADFD-00",	NULL,		ATA_HORKAGE_NONCQ },
4422 	{ "WDC WD740ADFD-00NLR1", NULL,		ATA_HORKAGE_NONCQ, },
4423 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
4424 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
4425 	/* NCQ is broken */
4426 	{ "Maxtor *",		"BANC*",	ATA_HORKAGE_NONCQ },
4427 	{ "Maxtor 7V300F0",	"VA111630",	ATA_HORKAGE_NONCQ },
4428 	{ "ST380817AS",		"3.42",		ATA_HORKAGE_NONCQ },
4429 	{ "ST3160023AS",	"3.42",		ATA_HORKAGE_NONCQ },
4430 
4431 	/* Blacklist entries taken from Silicon Image 3124/3132
4432 	   Windows driver .inf file - also several Linux problem reports */
4433 	{ "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
4434 	{ "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
4435 	{ "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },
4436 
4437 	/* devices which puke on READ_NATIVE_MAX */
4438 	{ "HDS724040KLSA80",	"KFAOA20N",	ATA_HORKAGE_BROKEN_HPA, },
4439 	{ "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
4440 	{ "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
4441 	{ "MAXTOR 6L080L4",	"A93.0500",	ATA_HORKAGE_BROKEN_HPA },
4442 
4443 	/* Devices which report 1 sector over size HPA */
4444 	{ "ST340823A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4445 	{ "ST320413A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4446 	{ "ST310211A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4447 
4448 	/* Devices which get the IVB wrong */
4449 	{ "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB, },
4450 	{ "TSSTcorp CDDVDW SH-S202J", "SB00",	  ATA_HORKAGE_IVB, },
4451 	{ "TSSTcorp CDDVDW SH-S202J", "SB01",	  ATA_HORKAGE_IVB, },
4452 	{ "TSSTcorp CDDVDW SH-S202N", "SB00",	  ATA_HORKAGE_IVB, },
4453 	{ "TSSTcorp CDDVDW SH-S202N", "SB01",	  ATA_HORKAGE_IVB, },
4454 
4455 	/* End Marker */
4456 	{ }
4457 };
4458 
4459 static int strn_pattern_cmp(const char *patt, const char *name, int wildchar)
4460 {
4461 	const char *p;
4462 	int len;
4463 
4464 	/*
4465 	 * check for trailing wildcard: *\0
4466 	 */
4467 	p = strchr(patt, wildchar);
4468 	if (p && ((*(p + 1)) == 0))
4469 		len = p - patt;
4470 	else {
4471 		len = strlen(name);
4472 		if (!len) {
4473 			if (!*patt)
4474 				return 0;
4475 			return -1;
4476 		}
4477 	}
4478 
4479 	return strncmp(patt, name, len);
4480 }
4481 
4482 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
4483 {
4484 	unsigned char model_num[ATA_ID_PROD_LEN + 1];
4485 	unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
4486 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
4487 
4488 	ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
4489 	ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
4490 
4491 	while (ad->model_num) {
4492 		if (!strn_pattern_cmp(ad->model_num, model_num, '*')) {
4493 			if (ad->model_rev == NULL)
4494 				return ad->horkage;
4495 			if (!strn_pattern_cmp(ad->model_rev, model_rev, '*'))
4496 				return ad->horkage;
4497 		}
4498 		ad++;
4499 	}
4500 	return 0;
4501 }
4502 
4503 static int ata_dma_blacklisted(const struct ata_device *dev)
4504 {
4505 	/* We don't support polling DMA.
4506 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
4507 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
4508 	 */
4509 	if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
4510 	    (dev->flags & ATA_DFLAG_CDB_INTR))
4511 		return 1;
4512 	return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
4513 }
4514 
4515 /**
4516  *	ata_is_40wire		-	check drive side detection
4517  *	@dev: device
4518  *
4519  *	Perform drive side detection decoding, allowing for device vendors
4520  *	who can't follow the documentation.
4521  */
4522 
4523 static int ata_is_40wire(struct ata_device *dev)
4524 {
4525 	if (dev->horkage & ATA_HORKAGE_IVB)
4526 		return ata_drive_40wire_relaxed(dev->id);
4527 	return ata_drive_40wire(dev->id);
4528 }
4529 
4530 /**
4531  *	ata_dev_xfermask - Compute supported xfermask of the given device
4532  *	@dev: Device to compute xfermask for
4533  *
4534  *	Compute supported xfermask of @dev and store it in
4535  *	dev->*_mask.  This function is responsible for applying all
4536  *	known limits including host controller limits, device
4537  *	blacklist, etc...
4538  *
4539  *	LOCKING:
4540  *	None.
4541  */
4542 static void ata_dev_xfermask(struct ata_device *dev)
4543 {
4544 	struct ata_link *link = dev->link;
4545 	struct ata_port *ap = link->ap;
4546 	struct ata_host *host = ap->host;
4547 	unsigned long xfer_mask;
4548 
4549 	/* controller modes available */
4550 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
4551 				      ap->mwdma_mask, ap->udma_mask);
4552 
4553 	/* drive modes available */
4554 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
4555 				       dev->mwdma_mask, dev->udma_mask);
4556 	xfer_mask &= ata_id_xfermask(dev->id);
4557 
4558 	/*
4559 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
4560 	 *	cable
4561 	 */
4562 	if (ata_dev_pair(dev)) {
4563 		/* No PIO5 or PIO6 */
4564 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
4565 		/* No MWDMA3 or MWDMA 4 */
4566 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
4567 	}
4568 
4569 	if (ata_dma_blacklisted(dev)) {
4570 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4571 		ata_dev_printk(dev, KERN_WARNING,
4572 			       "device is on DMA blacklist, disabling DMA\n");
4573 	}
4574 
4575 	if ((host->flags & ATA_HOST_SIMPLEX) &&
4576 	    host->simplex_claimed && host->simplex_claimed != ap) {
4577 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4578 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
4579 			       "other device, disabling DMA\n");
4580 	}
4581 
4582 	if (ap->flags & ATA_FLAG_NO_IORDY)
4583 		xfer_mask &= ata_pio_mask_no_iordy(dev);
4584 
4585 	if (ap->ops->mode_filter)
4586 		xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
4587 
4588 	/* Apply cable rule here.  Don't apply it early because when
4589 	 * we handle hot plug the cable type can itself change.
4590 	 * Check this last so that we know if the transfer rate was
4591 	 * solely limited by the cable.
4592 	 * Unknown or 80 wire cables reported host side are checked
4593 	 * drive side as well. Cases where we know a 40wire cable
4594 	 * is used safely for 80 are not checked here.
4595 	 */
4596 	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
4597 		/* UDMA/44 or higher would be available */
4598 		if ((ap->cbl == ATA_CBL_PATA40) ||
4599 		    (ata_is_40wire(dev) &&
4600 		    (ap->cbl == ATA_CBL_PATA_UNK ||
4601 		     ap->cbl == ATA_CBL_PATA80))) {
4602 			ata_dev_printk(dev, KERN_WARNING,
4603 				 "limited to UDMA/33 due to 40-wire cable\n");
4604 			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
4605 		}
4606 
4607 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
4608 			    &dev->mwdma_mask, &dev->udma_mask);
4609 }
4610 
4611 /**
4612  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
4613  *	@dev: Device to which command will be sent
4614  *
4615  *	Issue SET FEATURES - XFER MODE command to device @dev
4616  *	on port @ap.
4617  *
4618  *	LOCKING:
4619  *	PCI/etc. bus probe sem.
4620  *
4621  *	RETURNS:
4622  *	0 on success, AC_ERR_* mask otherwise.
4623  */
4624 
4625 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
4626 {
4627 	struct ata_taskfile tf;
4628 	unsigned int err_mask;
4629 
4630 	/* set up set-features taskfile */
4631 	DPRINTK("set features - xfer mode\n");
4632 
4633 	/* Some controllers and ATAPI devices show flaky interrupt
4634 	 * behavior after setting xfer mode.  Use polling instead.
4635 	 */
4636 	ata_tf_init(dev, &tf);
4637 	tf.command = ATA_CMD_SET_FEATURES;
4638 	tf.feature = SETFEATURES_XFER;
4639 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
4640 	tf.protocol = ATA_PROT_NODATA;
4641 	/* If we are using IORDY we must send the mode setting command */
4642 	if (ata_pio_need_iordy(dev))
4643 		tf.nsect = dev->xfer_mode;
4644 	/* If the device has IORDY and the controller does not - turn it off */
4645  	else if (ata_id_has_iordy(dev->id))
4646 		tf.nsect = 0x01;
4647 	else /* In the ancient relic department - skip all of this */
4648 		return 0;
4649 
4650 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4651 
4652 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4653 	return err_mask;
4654 }
4655 /**
4656  *	ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
4657  *	@dev: Device to which command will be sent
4658  *	@enable: Whether to enable or disable the feature
4659  *	@feature: The sector count represents the feature to set
4660  *
4661  *	Issue SET FEATURES - SATA FEATURES command to device @dev
4662  *	on port @ap with sector count
4663  *
4664  *	LOCKING:
4665  *	PCI/etc. bus probe sem.
4666  *
4667  *	RETURNS:
4668  *	0 on success, AC_ERR_* mask otherwise.
4669  */
4670 static unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable,
4671 					u8 feature)
4672 {
4673 	struct ata_taskfile tf;
4674 	unsigned int err_mask;
4675 
4676 	/* set up set-features taskfile */
4677 	DPRINTK("set features - SATA features\n");
4678 
4679 	ata_tf_init(dev, &tf);
4680 	tf.command = ATA_CMD_SET_FEATURES;
4681 	tf.feature = enable;
4682 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4683 	tf.protocol = ATA_PROT_NODATA;
4684 	tf.nsect = feature;
4685 
4686 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4687 
4688 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4689 	return err_mask;
4690 }
4691 
4692 /**
4693  *	ata_dev_init_params - Issue INIT DEV PARAMS command
4694  *	@dev: Device to which command will be sent
4695  *	@heads: Number of heads (taskfile parameter)
4696  *	@sectors: Number of sectors (taskfile parameter)
4697  *
4698  *	LOCKING:
4699  *	Kernel thread context (may sleep)
4700  *
4701  *	RETURNS:
4702  *	0 on success, AC_ERR_* mask otherwise.
4703  */
4704 static unsigned int ata_dev_init_params(struct ata_device *dev,
4705 					u16 heads, u16 sectors)
4706 {
4707 	struct ata_taskfile tf;
4708 	unsigned int err_mask;
4709 
4710 	/* Number of sectors per track 1-255. Number of heads 1-16 */
4711 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
4712 		return AC_ERR_INVALID;
4713 
4714 	/* set up init dev params taskfile */
4715 	DPRINTK("init dev params \n");
4716 
4717 	ata_tf_init(dev, &tf);
4718 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
4719 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4720 	tf.protocol = ATA_PROT_NODATA;
4721 	tf.nsect = sectors;
4722 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
4723 
4724 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4725 	/* A clean abort indicates an original or just out of spec drive
4726 	   and we should continue as we issue the setup based on the
4727 	   drive reported working geometry */
4728 	if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
4729 		err_mask = 0;
4730 
4731 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4732 	return err_mask;
4733 }
4734 
4735 /**
4736  *	ata_sg_clean - Unmap DMA memory associated with command
4737  *	@qc: Command containing DMA memory to be released
4738  *
4739  *	Unmap all mapped DMA memory associated with this command.
4740  *
4741  *	LOCKING:
4742  *	spin_lock_irqsave(host lock)
4743  */
4744 void ata_sg_clean(struct ata_queued_cmd *qc)
4745 {
4746 	struct ata_port *ap = qc->ap;
4747 	struct scatterlist *sg = qc->sg;
4748 	int dir = qc->dma_dir;
4749 
4750 	WARN_ON(sg == NULL);
4751 
4752 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
4753 
4754 	if (qc->n_elem)
4755 		dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
4756 
4757 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4758 	qc->sg = NULL;
4759 }
4760 
4761 /**
4762  *	ata_fill_sg - Fill PCI IDE PRD table
4763  *	@qc: Metadata associated with taskfile to be transferred
4764  *
4765  *	Fill PCI IDE PRD (scatter-gather) table with segments
4766  *	associated with the current disk command.
4767  *
4768  *	LOCKING:
4769  *	spin_lock_irqsave(host lock)
4770  *
4771  */
4772 static void ata_fill_sg(struct ata_queued_cmd *qc)
4773 {
4774 	struct ata_port *ap = qc->ap;
4775 	struct scatterlist *sg;
4776 	unsigned int si, pi;
4777 
4778 	pi = 0;
4779 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
4780 		u32 addr, offset;
4781 		u32 sg_len, len;
4782 
4783 		/* determine if physical DMA addr spans 64K boundary.
4784 		 * Note h/w doesn't support 64-bit, so we unconditionally
4785 		 * truncate dma_addr_t to u32.
4786 		 */
4787 		addr = (u32) sg_dma_address(sg);
4788 		sg_len = sg_dma_len(sg);
4789 
4790 		while (sg_len) {
4791 			offset = addr & 0xffff;
4792 			len = sg_len;
4793 			if ((offset + sg_len) > 0x10000)
4794 				len = 0x10000 - offset;
4795 
4796 			ap->prd[pi].addr = cpu_to_le32(addr);
4797 			ap->prd[pi].flags_len = cpu_to_le32(len & 0xffff);
4798 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
4799 
4800 			pi++;
4801 			sg_len -= len;
4802 			addr += len;
4803 		}
4804 	}
4805 
4806 	ap->prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4807 }
4808 
4809 /**
4810  *	ata_fill_sg_dumb - Fill PCI IDE PRD table
4811  *	@qc: Metadata associated with taskfile to be transferred
4812  *
4813  *	Fill PCI IDE PRD (scatter-gather) table with segments
4814  *	associated with the current disk command. Perform the fill
4815  *	so that we avoid writing any length 64K records for
4816  *	controllers that don't follow the spec.
4817  *
4818  *	LOCKING:
4819  *	spin_lock_irqsave(host lock)
4820  *
4821  */
4822 static void ata_fill_sg_dumb(struct ata_queued_cmd *qc)
4823 {
4824 	struct ata_port *ap = qc->ap;
4825 	struct scatterlist *sg;
4826 	unsigned int si, pi;
4827 
4828 	pi = 0;
4829 	for_each_sg(qc->sg, sg, qc->n_elem, si) {
4830 		u32 addr, offset;
4831 		u32 sg_len, len, blen;
4832 
4833 		/* determine if physical DMA addr spans 64K boundary.
4834 		 * Note h/w doesn't support 64-bit, so we unconditionally
4835 		 * truncate dma_addr_t to u32.
4836 		 */
4837 		addr = (u32) sg_dma_address(sg);
4838 		sg_len = sg_dma_len(sg);
4839 
4840 		while (sg_len) {
4841 			offset = addr & 0xffff;
4842 			len = sg_len;
4843 			if ((offset + sg_len) > 0x10000)
4844 				len = 0x10000 - offset;
4845 
4846 			blen = len & 0xffff;
4847 			ap->prd[pi].addr = cpu_to_le32(addr);
4848 			if (blen == 0) {
4849 			   /* Some PATA chipsets like the CS5530 can't
4850 			      cope with 0x0000 meaning 64K as the spec says */
4851 				ap->prd[pi].flags_len = cpu_to_le32(0x8000);
4852 				blen = 0x8000;
4853 				ap->prd[++pi].addr = cpu_to_le32(addr + 0x8000);
4854 			}
4855 			ap->prd[pi].flags_len = cpu_to_le32(blen);
4856 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", pi, addr, len);
4857 
4858 			pi++;
4859 			sg_len -= len;
4860 			addr += len;
4861 		}
4862 	}
4863 
4864 	ap->prd[pi - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4865 }
4866 
4867 /**
4868  *	ata_check_atapi_dma - Check whether ATAPI DMA can be supported
4869  *	@qc: Metadata associated with taskfile to check
4870  *
4871  *	Allow low-level driver to filter ATA PACKET commands, returning
4872  *	a status indicating whether or not it is OK to use DMA for the
4873  *	supplied PACKET command.
4874  *
4875  *	LOCKING:
4876  *	spin_lock_irqsave(host lock)
4877  *
4878  *	RETURNS: 0 when ATAPI DMA can be used
4879  *               nonzero otherwise
4880  */
4881 int ata_check_atapi_dma(struct ata_queued_cmd *qc)
4882 {
4883 	struct ata_port *ap = qc->ap;
4884 
4885 	/* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
4886 	 * few ATAPI devices choke on such DMA requests.
4887 	 */
4888 	if (unlikely(qc->nbytes & 15))
4889 		return 1;
4890 
4891 	if (ap->ops->check_atapi_dma)
4892 		return ap->ops->check_atapi_dma(qc);
4893 
4894 	return 0;
4895 }
4896 
4897 /**
4898  *	ata_std_qc_defer - Check whether a qc needs to be deferred
4899  *	@qc: ATA command in question
4900  *
4901  *	Non-NCQ commands cannot run with any other command, NCQ or
4902  *	not.  As upper layer only knows the queue depth, we are
4903  *	responsible for maintaining exclusion.  This function checks
4904  *	whether a new command @qc can be issued.
4905  *
4906  *	LOCKING:
4907  *	spin_lock_irqsave(host lock)
4908  *
4909  *	RETURNS:
4910  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
4911  */
4912 int ata_std_qc_defer(struct ata_queued_cmd *qc)
4913 {
4914 	struct ata_link *link = qc->dev->link;
4915 
4916 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4917 		if (!ata_tag_valid(link->active_tag))
4918 			return 0;
4919 	} else {
4920 		if (!ata_tag_valid(link->active_tag) && !link->sactive)
4921 			return 0;
4922 	}
4923 
4924 	return ATA_DEFER_LINK;
4925 }
4926 
4927 /**
4928  *	ata_qc_prep - Prepare taskfile for submission
4929  *	@qc: Metadata associated with taskfile to be prepared
4930  *
4931  *	Prepare ATA taskfile for submission.
4932  *
4933  *	LOCKING:
4934  *	spin_lock_irqsave(host lock)
4935  */
4936 void ata_qc_prep(struct ata_queued_cmd *qc)
4937 {
4938 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4939 		return;
4940 
4941 	ata_fill_sg(qc);
4942 }
4943 
4944 /**
4945  *	ata_dumb_qc_prep - Prepare taskfile for submission
4946  *	@qc: Metadata associated with taskfile to be prepared
4947  *
4948  *	Prepare ATA taskfile for submission.
4949  *
4950  *	LOCKING:
4951  *	spin_lock_irqsave(host lock)
4952  */
4953 void ata_dumb_qc_prep(struct ata_queued_cmd *qc)
4954 {
4955 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4956 		return;
4957 
4958 	ata_fill_sg_dumb(qc);
4959 }
4960 
4961 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
4962 
4963 /**
4964  *	ata_sg_init - Associate command with scatter-gather table.
4965  *	@qc: Command to be associated
4966  *	@sg: Scatter-gather table.
4967  *	@n_elem: Number of elements in s/g table.
4968  *
4969  *	Initialize the data-related elements of queued_cmd @qc
4970  *	to point to a scatter-gather table @sg, containing @n_elem
4971  *	elements.
4972  *
4973  *	LOCKING:
4974  *	spin_lock_irqsave(host lock)
4975  */
4976 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
4977 		 unsigned int n_elem)
4978 {
4979 	qc->sg = sg;
4980 	qc->n_elem = n_elem;
4981 	qc->cursg = qc->sg;
4982 }
4983 
4984 /**
4985  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
4986  *	@qc: Command with scatter-gather table to be mapped.
4987  *
4988  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
4989  *
4990  *	LOCKING:
4991  *	spin_lock_irqsave(host lock)
4992  *
4993  *	RETURNS:
4994  *	Zero on success, negative on error.
4995  *
4996  */
4997 static int ata_sg_setup(struct ata_queued_cmd *qc)
4998 {
4999 	struct ata_port *ap = qc->ap;
5000 	unsigned int n_elem;
5001 
5002 	VPRINTK("ENTER, ata%u\n", ap->print_id);
5003 
5004 	n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
5005 	if (n_elem < 1)
5006 		return -1;
5007 
5008 	DPRINTK("%d sg elements mapped\n", n_elem);
5009 
5010 	qc->n_elem = n_elem;
5011 	qc->flags |= ATA_QCFLAG_DMAMAP;
5012 
5013 	return 0;
5014 }
5015 
5016 /**
5017  *	swap_buf_le16 - swap halves of 16-bit words in place
5018  *	@buf:  Buffer to swap
5019  *	@buf_words:  Number of 16-bit words in buffer.
5020  *
5021  *	Swap halves of 16-bit words if needed to convert from
5022  *	little-endian byte order to native cpu byte order, or
5023  *	vice-versa.
5024  *
5025  *	LOCKING:
5026  *	Inherited from caller.
5027  */
5028 void swap_buf_le16(u16 *buf, unsigned int buf_words)
5029 {
5030 #ifdef __BIG_ENDIAN
5031 	unsigned int i;
5032 
5033 	for (i = 0; i < buf_words; i++)
5034 		buf[i] = le16_to_cpu(buf[i]);
5035 #endif /* __BIG_ENDIAN */
5036 }
5037 
5038 /**
5039  *	ata_data_xfer - Transfer data by PIO
5040  *	@dev: device to target
5041  *	@buf: data buffer
5042  *	@buflen: buffer length
5043  *	@rw: read/write
5044  *
5045  *	Transfer data from/to the device data register by PIO.
5046  *
5047  *	LOCKING:
5048  *	Inherited from caller.
5049  *
5050  *	RETURNS:
5051  *	Bytes consumed.
5052  */
5053 unsigned int ata_data_xfer(struct ata_device *dev, unsigned char *buf,
5054 			   unsigned int buflen, int rw)
5055 {
5056 	struct ata_port *ap = dev->link->ap;
5057 	void __iomem *data_addr = ap->ioaddr.data_addr;
5058 	unsigned int words = buflen >> 1;
5059 
5060 	/* Transfer multiple of 2 bytes */
5061 	if (rw == READ)
5062 		ioread16_rep(data_addr, buf, words);
5063 	else
5064 		iowrite16_rep(data_addr, buf, words);
5065 
5066 	/* Transfer trailing 1 byte, if any. */
5067 	if (unlikely(buflen & 0x01)) {
5068 		__le16 align_buf[1] = { 0 };
5069 		unsigned char *trailing_buf = buf + buflen - 1;
5070 
5071 		if (rw == READ) {
5072 			align_buf[0] = cpu_to_le16(ioread16(data_addr));
5073 			memcpy(trailing_buf, align_buf, 1);
5074 		} else {
5075 			memcpy(align_buf, trailing_buf, 1);
5076 			iowrite16(le16_to_cpu(align_buf[0]), data_addr);
5077 		}
5078 		words++;
5079 	}
5080 
5081 	return words << 1;
5082 }
5083 
5084 /**
5085  *	ata_data_xfer_noirq - Transfer data by PIO
5086  *	@dev: device to target
5087  *	@buf: data buffer
5088  *	@buflen: buffer length
5089  *	@rw: read/write
5090  *
5091  *	Transfer data from/to the device data register by PIO. Do the
5092  *	transfer with interrupts disabled.
5093  *
5094  *	LOCKING:
5095  *	Inherited from caller.
5096  *
5097  *	RETURNS:
5098  *	Bytes consumed.
5099  */
5100 unsigned int ata_data_xfer_noirq(struct ata_device *dev, unsigned char *buf,
5101 				 unsigned int buflen, int rw)
5102 {
5103 	unsigned long flags;
5104 	unsigned int consumed;
5105 
5106 	local_irq_save(flags);
5107 	consumed = ata_data_xfer(dev, buf, buflen, rw);
5108 	local_irq_restore(flags);
5109 
5110 	return consumed;
5111 }
5112 
5113 
5114 /**
5115  *	ata_pio_sector - Transfer a sector of data.
5116  *	@qc: Command on going
5117  *
5118  *	Transfer qc->sect_size bytes of data from/to the ATA device.
5119  *
5120  *	LOCKING:
5121  *	Inherited from caller.
5122  */
5123 
5124 static void ata_pio_sector(struct ata_queued_cmd *qc)
5125 {
5126 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
5127 	struct ata_port *ap = qc->ap;
5128 	struct page *page;
5129 	unsigned int offset;
5130 	unsigned char *buf;
5131 
5132 	if (qc->curbytes == qc->nbytes - qc->sect_size)
5133 		ap->hsm_task_state = HSM_ST_LAST;
5134 
5135 	page = sg_page(qc->cursg);
5136 	offset = qc->cursg->offset + qc->cursg_ofs;
5137 
5138 	/* get the current page and offset */
5139 	page = nth_page(page, (offset >> PAGE_SHIFT));
5140 	offset %= PAGE_SIZE;
5141 
5142 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
5143 
5144 	if (PageHighMem(page)) {
5145 		unsigned long flags;
5146 
5147 		/* FIXME: use a bounce buffer */
5148 		local_irq_save(flags);
5149 		buf = kmap_atomic(page, KM_IRQ0);
5150 
5151 		/* do the actual data transfer */
5152 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
5153 
5154 		kunmap_atomic(buf, KM_IRQ0);
5155 		local_irq_restore(flags);
5156 	} else {
5157 		buf = page_address(page);
5158 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
5159 	}
5160 
5161 	qc->curbytes += qc->sect_size;
5162 	qc->cursg_ofs += qc->sect_size;
5163 
5164 	if (qc->cursg_ofs == qc->cursg->length) {
5165 		qc->cursg = sg_next(qc->cursg);
5166 		qc->cursg_ofs = 0;
5167 	}
5168 }
5169 
5170 /**
5171  *	ata_pio_sectors - Transfer one or many sectors.
5172  *	@qc: Command on going
5173  *
5174  *	Transfer one or many sectors of data from/to the
5175  *	ATA device for the DRQ request.
5176  *
5177  *	LOCKING:
5178  *	Inherited from caller.
5179  */
5180 
5181 static void ata_pio_sectors(struct ata_queued_cmd *qc)
5182 {
5183 	if (is_multi_taskfile(&qc->tf)) {
5184 		/* READ/WRITE MULTIPLE */
5185 		unsigned int nsect;
5186 
5187 		WARN_ON(qc->dev->multi_count == 0);
5188 
5189 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
5190 			    qc->dev->multi_count);
5191 		while (nsect--)
5192 			ata_pio_sector(qc);
5193 	} else
5194 		ata_pio_sector(qc);
5195 
5196 	ata_altstatus(qc->ap); /* flush */
5197 }
5198 
5199 /**
5200  *	atapi_send_cdb - Write CDB bytes to hardware
5201  *	@ap: Port to which ATAPI device is attached.
5202  *	@qc: Taskfile currently active
5203  *
5204  *	When device has indicated its readiness to accept
5205  *	a CDB, this function is called.  Send the CDB.
5206  *
5207  *	LOCKING:
5208  *	caller.
5209  */
5210 
5211 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
5212 {
5213 	/* send SCSI cdb */
5214 	DPRINTK("send cdb\n");
5215 	WARN_ON(qc->dev->cdb_len < 12);
5216 
5217 	ap->ops->data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
5218 	ata_altstatus(ap); /* flush */
5219 
5220 	switch (qc->tf.protocol) {
5221 	case ATAPI_PROT_PIO:
5222 		ap->hsm_task_state = HSM_ST;
5223 		break;
5224 	case ATAPI_PROT_NODATA:
5225 		ap->hsm_task_state = HSM_ST_LAST;
5226 		break;
5227 	case ATAPI_PROT_DMA:
5228 		ap->hsm_task_state = HSM_ST_LAST;
5229 		/* initiate bmdma */
5230 		ap->ops->bmdma_start(qc);
5231 		break;
5232 	}
5233 }
5234 
5235 /**
5236  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
5237  *	@qc: Command on going
5238  *	@bytes: number of bytes
5239  *
5240  *	Transfer Transfer data from/to the ATAPI device.
5241  *
5242  *	LOCKING:
5243  *	Inherited from caller.
5244  *
5245  */
5246 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
5247 {
5248 	int rw = (qc->tf.flags & ATA_TFLAG_WRITE) ? WRITE : READ;
5249 	struct ata_port *ap = qc->ap;
5250 	struct ata_device *dev = qc->dev;
5251 	struct ata_eh_info *ehi = &dev->link->eh_info;
5252 	struct scatterlist *sg;
5253 	struct page *page;
5254 	unsigned char *buf;
5255 	unsigned int offset, count, consumed;
5256 
5257 next_sg:
5258 	sg = qc->cursg;
5259 	if (unlikely(!sg)) {
5260 		ata_ehi_push_desc(ehi, "unexpected or too much trailing data "
5261 				  "buf=%u cur=%u bytes=%u",
5262 				  qc->nbytes, qc->curbytes, bytes);
5263 		return -1;
5264 	}
5265 
5266 	page = sg_page(sg);
5267 	offset = sg->offset + qc->cursg_ofs;
5268 
5269 	/* get the current page and offset */
5270 	page = nth_page(page, (offset >> PAGE_SHIFT));
5271 	offset %= PAGE_SIZE;
5272 
5273 	/* don't overrun current sg */
5274 	count = min(sg->length - qc->cursg_ofs, bytes);
5275 
5276 	/* don't cross page boundaries */
5277 	count = min(count, (unsigned int)PAGE_SIZE - offset);
5278 
5279 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
5280 
5281 	if (PageHighMem(page)) {
5282 		unsigned long flags;
5283 
5284 		/* FIXME: use bounce buffer */
5285 		local_irq_save(flags);
5286 		buf = kmap_atomic(page, KM_IRQ0);
5287 
5288 		/* do the actual data transfer */
5289 		consumed = ap->ops->data_xfer(dev,  buf + offset, count, rw);
5290 
5291 		kunmap_atomic(buf, KM_IRQ0);
5292 		local_irq_restore(flags);
5293 	} else {
5294 		buf = page_address(page);
5295 		consumed = ap->ops->data_xfer(dev,  buf + offset, count, rw);
5296 	}
5297 
5298 	bytes -= min(bytes, consumed);
5299 	qc->curbytes += count;
5300 	qc->cursg_ofs += count;
5301 
5302 	if (qc->cursg_ofs == sg->length) {
5303 		qc->cursg = sg_next(qc->cursg);
5304 		qc->cursg_ofs = 0;
5305 	}
5306 
5307 	/* consumed can be larger than count only for the last transfer */
5308 	WARN_ON(qc->cursg && count != consumed);
5309 
5310 	if (bytes)
5311 		goto next_sg;
5312 	return 0;
5313 }
5314 
5315 /**
5316  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
5317  *	@qc: Command on going
5318  *
5319  *	Transfer Transfer data from/to the ATAPI device.
5320  *
5321  *	LOCKING:
5322  *	Inherited from caller.
5323  */
5324 
5325 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
5326 {
5327 	struct ata_port *ap = qc->ap;
5328 	struct ata_device *dev = qc->dev;
5329 	struct ata_eh_info *ehi = &dev->link->eh_info;
5330 	unsigned int ireason, bc_lo, bc_hi, bytes;
5331 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
5332 
5333 	/* Abuse qc->result_tf for temp storage of intermediate TF
5334 	 * here to save some kernel stack usage.
5335 	 * For normal completion, qc->result_tf is not relevant. For
5336 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
5337 	 * So, the correctness of qc->result_tf is not affected.
5338 	 */
5339 	ap->ops->tf_read(ap, &qc->result_tf);
5340 	ireason = qc->result_tf.nsect;
5341 	bc_lo = qc->result_tf.lbam;
5342 	bc_hi = qc->result_tf.lbah;
5343 	bytes = (bc_hi << 8) | bc_lo;
5344 
5345 	/* shall be cleared to zero, indicating xfer of data */
5346 	if (unlikely(ireason & (1 << 0)))
5347 		goto atapi_check;
5348 
5349 	/* make sure transfer direction matches expected */
5350 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
5351 	if (unlikely(do_write != i_write))
5352 		goto atapi_check;
5353 
5354 	if (unlikely(!bytes))
5355 		goto atapi_check;
5356 
5357 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
5358 
5359 	if (unlikely(__atapi_pio_bytes(qc, bytes)))
5360 		goto err_out;
5361 	ata_altstatus(ap); /* flush */
5362 
5363 	return;
5364 
5365  atapi_check:
5366 	ata_ehi_push_desc(ehi, "ATAPI check failed (ireason=0x%x bytes=%u)",
5367 			  ireason, bytes);
5368  err_out:
5369 	qc->err_mask |= AC_ERR_HSM;
5370 	ap->hsm_task_state = HSM_ST_ERR;
5371 }
5372 
5373 /**
5374  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
5375  *	@ap: the target ata_port
5376  *	@qc: qc on going
5377  *
5378  *	RETURNS:
5379  *	1 if ok in workqueue, 0 otherwise.
5380  */
5381 
5382 static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
5383 {
5384 	if (qc->tf.flags & ATA_TFLAG_POLLING)
5385 		return 1;
5386 
5387 	if (ap->hsm_task_state == HSM_ST_FIRST) {
5388 		if (qc->tf.protocol == ATA_PROT_PIO &&
5389 		    (qc->tf.flags & ATA_TFLAG_WRITE))
5390 		    return 1;
5391 
5392 		if (ata_is_atapi(qc->tf.protocol) &&
5393 		    !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5394 			return 1;
5395 	}
5396 
5397 	return 0;
5398 }
5399 
5400 /**
5401  *	ata_hsm_qc_complete - finish a qc running on standard HSM
5402  *	@qc: Command to complete
5403  *	@in_wq: 1 if called from workqueue, 0 otherwise
5404  *
5405  *	Finish @qc which is running on standard HSM.
5406  *
5407  *	LOCKING:
5408  *	If @in_wq is zero, spin_lock_irqsave(host lock).
5409  *	Otherwise, none on entry and grabs host lock.
5410  */
5411 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
5412 {
5413 	struct ata_port *ap = qc->ap;
5414 	unsigned long flags;
5415 
5416 	if (ap->ops->error_handler) {
5417 		if (in_wq) {
5418 			spin_lock_irqsave(ap->lock, flags);
5419 
5420 			/* EH might have kicked in while host lock is
5421 			 * released.
5422 			 */
5423 			qc = ata_qc_from_tag(ap, qc->tag);
5424 			if (qc) {
5425 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
5426 					ap->ops->irq_on(ap);
5427 					ata_qc_complete(qc);
5428 				} else
5429 					ata_port_freeze(ap);
5430 			}
5431 
5432 			spin_unlock_irqrestore(ap->lock, flags);
5433 		} else {
5434 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
5435 				ata_qc_complete(qc);
5436 			else
5437 				ata_port_freeze(ap);
5438 		}
5439 	} else {
5440 		if (in_wq) {
5441 			spin_lock_irqsave(ap->lock, flags);
5442 			ap->ops->irq_on(ap);
5443 			ata_qc_complete(qc);
5444 			spin_unlock_irqrestore(ap->lock, flags);
5445 		} else
5446 			ata_qc_complete(qc);
5447 	}
5448 }
5449 
5450 /**
5451  *	ata_hsm_move - move the HSM to the next state.
5452  *	@ap: the target ata_port
5453  *	@qc: qc on going
5454  *	@status: current device status
5455  *	@in_wq: 1 if called from workqueue, 0 otherwise
5456  *
5457  *	RETURNS:
5458  *	1 when poll next status needed, 0 otherwise.
5459  */
5460 int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
5461 		 u8 status, int in_wq)
5462 {
5463 	unsigned long flags = 0;
5464 	int poll_next;
5465 
5466 	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
5467 
5468 	/* Make sure ata_qc_issue_prot() does not throw things
5469 	 * like DMA polling into the workqueue. Notice that
5470 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
5471 	 */
5472 	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
5473 
5474 fsm_start:
5475 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
5476 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
5477 
5478 	switch (ap->hsm_task_state) {
5479 	case HSM_ST_FIRST:
5480 		/* Send first data block or PACKET CDB */
5481 
5482 		/* If polling, we will stay in the work queue after
5483 		 * sending the data. Otherwise, interrupt handler
5484 		 * takes over after sending the data.
5485 		 */
5486 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
5487 
5488 		/* check device status */
5489 		if (unlikely((status & ATA_DRQ) == 0)) {
5490 			/* handle BSY=0, DRQ=0 as error */
5491 			if (likely(status & (ATA_ERR | ATA_DF)))
5492 				/* device stops HSM for abort/error */
5493 				qc->err_mask |= AC_ERR_DEV;
5494 			else
5495 				/* HSM violation. Let EH handle this */
5496 				qc->err_mask |= AC_ERR_HSM;
5497 
5498 			ap->hsm_task_state = HSM_ST_ERR;
5499 			goto fsm_start;
5500 		}
5501 
5502 		/* Device should not ask for data transfer (DRQ=1)
5503 		 * when it finds something wrong.
5504 		 * We ignore DRQ here and stop the HSM by
5505 		 * changing hsm_task_state to HSM_ST_ERR and
5506 		 * let the EH abort the command or reset the device.
5507 		 */
5508 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
5509 			/* Some ATAPI tape drives forget to clear the ERR bit
5510 			 * when doing the next command (mostly request sense).
5511 			 * We ignore ERR here to workaround and proceed sending
5512 			 * the CDB.
5513 			 */
5514 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
5515 				ata_port_printk(ap, KERN_WARNING,
5516 						"DRQ=1 with device error, "
5517 						"dev_stat 0x%X\n", status);
5518 				qc->err_mask |= AC_ERR_HSM;
5519 				ap->hsm_task_state = HSM_ST_ERR;
5520 				goto fsm_start;
5521 			}
5522 		}
5523 
5524 		/* Send the CDB (atapi) or the first data block (ata pio out).
5525 		 * During the state transition, interrupt handler shouldn't
5526 		 * be invoked before the data transfer is complete and
5527 		 * hsm_task_state is changed. Hence, the following locking.
5528 		 */
5529 		if (in_wq)
5530 			spin_lock_irqsave(ap->lock, flags);
5531 
5532 		if (qc->tf.protocol == ATA_PROT_PIO) {
5533 			/* PIO data out protocol.
5534 			 * send first data block.
5535 			 */
5536 
5537 			/* ata_pio_sectors() might change the state
5538 			 * to HSM_ST_LAST. so, the state is changed here
5539 			 * before ata_pio_sectors().
5540 			 */
5541 			ap->hsm_task_state = HSM_ST;
5542 			ata_pio_sectors(qc);
5543 		} else
5544 			/* send CDB */
5545 			atapi_send_cdb(ap, qc);
5546 
5547 		if (in_wq)
5548 			spin_unlock_irqrestore(ap->lock, flags);
5549 
5550 		/* if polling, ata_pio_task() handles the rest.
5551 		 * otherwise, interrupt handler takes over from here.
5552 		 */
5553 		break;
5554 
5555 	case HSM_ST:
5556 		/* complete command or read/write the data register */
5557 		if (qc->tf.protocol == ATAPI_PROT_PIO) {
5558 			/* ATAPI PIO protocol */
5559 			if ((status & ATA_DRQ) == 0) {
5560 				/* No more data to transfer or device error.
5561 				 * Device error will be tagged in HSM_ST_LAST.
5562 				 */
5563 				ap->hsm_task_state = HSM_ST_LAST;
5564 				goto fsm_start;
5565 			}
5566 
5567 			/* Device should not ask for data transfer (DRQ=1)
5568 			 * when it finds something wrong.
5569 			 * We ignore DRQ here and stop the HSM by
5570 			 * changing hsm_task_state to HSM_ST_ERR and
5571 			 * let the EH abort the command or reset the device.
5572 			 */
5573 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5574 				ata_port_printk(ap, KERN_WARNING, "DRQ=1 with "
5575 						"device error, dev_stat 0x%X\n",
5576 						status);
5577 				qc->err_mask |= AC_ERR_HSM;
5578 				ap->hsm_task_state = HSM_ST_ERR;
5579 				goto fsm_start;
5580 			}
5581 
5582 			atapi_pio_bytes(qc);
5583 
5584 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
5585 				/* bad ireason reported by device */
5586 				goto fsm_start;
5587 
5588 		} else {
5589 			/* ATA PIO protocol */
5590 			if (unlikely((status & ATA_DRQ) == 0)) {
5591 				/* handle BSY=0, DRQ=0 as error */
5592 				if (likely(status & (ATA_ERR | ATA_DF)))
5593 					/* device stops HSM for abort/error */
5594 					qc->err_mask |= AC_ERR_DEV;
5595 				else
5596 					/* HSM violation. Let EH handle this.
5597 					 * Phantom devices also trigger this
5598 					 * condition.  Mark hint.
5599 					 */
5600 					qc->err_mask |= AC_ERR_HSM |
5601 							AC_ERR_NODEV_HINT;
5602 
5603 				ap->hsm_task_state = HSM_ST_ERR;
5604 				goto fsm_start;
5605 			}
5606 
5607 			/* For PIO reads, some devices may ask for
5608 			 * data transfer (DRQ=1) alone with ERR=1.
5609 			 * We respect DRQ here and transfer one
5610 			 * block of junk data before changing the
5611 			 * hsm_task_state to HSM_ST_ERR.
5612 			 *
5613 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
5614 			 * sense since the data block has been
5615 			 * transferred to the device.
5616 			 */
5617 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5618 				/* data might be corrputed */
5619 				qc->err_mask |= AC_ERR_DEV;
5620 
5621 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
5622 					ata_pio_sectors(qc);
5623 					status = ata_wait_idle(ap);
5624 				}
5625 
5626 				if (status & (ATA_BUSY | ATA_DRQ))
5627 					qc->err_mask |= AC_ERR_HSM;
5628 
5629 				/* ata_pio_sectors() might change the
5630 				 * state to HSM_ST_LAST. so, the state
5631 				 * is changed after ata_pio_sectors().
5632 				 */
5633 				ap->hsm_task_state = HSM_ST_ERR;
5634 				goto fsm_start;
5635 			}
5636 
5637 			ata_pio_sectors(qc);
5638 
5639 			if (ap->hsm_task_state == HSM_ST_LAST &&
5640 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
5641 				/* all data read */
5642 				status = ata_wait_idle(ap);
5643 				goto fsm_start;
5644 			}
5645 		}
5646 
5647 		poll_next = 1;
5648 		break;
5649 
5650 	case HSM_ST_LAST:
5651 		if (unlikely(!ata_ok(status))) {
5652 			qc->err_mask |= __ac_err_mask(status);
5653 			ap->hsm_task_state = HSM_ST_ERR;
5654 			goto fsm_start;
5655 		}
5656 
5657 		/* no more data to transfer */
5658 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
5659 			ap->print_id, qc->dev->devno, status);
5660 
5661 		WARN_ON(qc->err_mask);
5662 
5663 		ap->hsm_task_state = HSM_ST_IDLE;
5664 
5665 		/* complete taskfile transaction */
5666 		ata_hsm_qc_complete(qc, in_wq);
5667 
5668 		poll_next = 0;
5669 		break;
5670 
5671 	case HSM_ST_ERR:
5672 		/* make sure qc->err_mask is available to
5673 		 * know what's wrong and recover
5674 		 */
5675 		WARN_ON(qc->err_mask == 0);
5676 
5677 		ap->hsm_task_state = HSM_ST_IDLE;
5678 
5679 		/* complete taskfile transaction */
5680 		ata_hsm_qc_complete(qc, in_wq);
5681 
5682 		poll_next = 0;
5683 		break;
5684 	default:
5685 		poll_next = 0;
5686 		BUG();
5687 	}
5688 
5689 	return poll_next;
5690 }
5691 
5692 static void ata_pio_task(struct work_struct *work)
5693 {
5694 	struct ata_port *ap =
5695 		container_of(work, struct ata_port, port_task.work);
5696 	struct ata_queued_cmd *qc = ap->port_task_data;
5697 	u8 status;
5698 	int poll_next;
5699 
5700 fsm_start:
5701 	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
5702 
5703 	/*
5704 	 * This is purely heuristic.  This is a fast path.
5705 	 * Sometimes when we enter, BSY will be cleared in
5706 	 * a chk-status or two.  If not, the drive is probably seeking
5707 	 * or something.  Snooze for a couple msecs, then
5708 	 * chk-status again.  If still busy, queue delayed work.
5709 	 */
5710 	status = ata_busy_wait(ap, ATA_BUSY, 5);
5711 	if (status & ATA_BUSY) {
5712 		msleep(2);
5713 		status = ata_busy_wait(ap, ATA_BUSY, 10);
5714 		if (status & ATA_BUSY) {
5715 			ata_pio_queue_task(ap, qc, ATA_SHORT_PAUSE);
5716 			return;
5717 		}
5718 	}
5719 
5720 	/* move the HSM */
5721 	poll_next = ata_hsm_move(ap, qc, status, 1);
5722 
5723 	/* another command or interrupt handler
5724 	 * may be running at this point.
5725 	 */
5726 	if (poll_next)
5727 		goto fsm_start;
5728 }
5729 
5730 /**
5731  *	ata_qc_new - Request an available ATA command, for queueing
5732  *	@ap: Port associated with device @dev
5733  *	@dev: Device from whom we request an available command structure
5734  *
5735  *	LOCKING:
5736  *	None.
5737  */
5738 
5739 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
5740 {
5741 	struct ata_queued_cmd *qc = NULL;
5742 	unsigned int i;
5743 
5744 	/* no command while frozen */
5745 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
5746 		return NULL;
5747 
5748 	/* the last tag is reserved for internal command. */
5749 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
5750 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
5751 			qc = __ata_qc_from_tag(ap, i);
5752 			break;
5753 		}
5754 
5755 	if (qc)
5756 		qc->tag = i;
5757 
5758 	return qc;
5759 }
5760 
5761 /**
5762  *	ata_qc_new_init - Request an available ATA command, and initialize it
5763  *	@dev: Device from whom we request an available command structure
5764  *
5765  *	LOCKING:
5766  *	None.
5767  */
5768 
5769 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
5770 {
5771 	struct ata_port *ap = dev->link->ap;
5772 	struct ata_queued_cmd *qc;
5773 
5774 	qc = ata_qc_new(ap);
5775 	if (qc) {
5776 		qc->scsicmd = NULL;
5777 		qc->ap = ap;
5778 		qc->dev = dev;
5779 
5780 		ata_qc_reinit(qc);
5781 	}
5782 
5783 	return qc;
5784 }
5785 
5786 /**
5787  *	ata_qc_free - free unused ata_queued_cmd
5788  *	@qc: Command to complete
5789  *
5790  *	Designed to free unused ata_queued_cmd object
5791  *	in case something prevents using it.
5792  *
5793  *	LOCKING:
5794  *	spin_lock_irqsave(host lock)
5795  */
5796 void ata_qc_free(struct ata_queued_cmd *qc)
5797 {
5798 	struct ata_port *ap = qc->ap;
5799 	unsigned int tag;
5800 
5801 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5802 
5803 	qc->flags = 0;
5804 	tag = qc->tag;
5805 	if (likely(ata_tag_valid(tag))) {
5806 		qc->tag = ATA_TAG_POISON;
5807 		clear_bit(tag, &ap->qc_allocated);
5808 	}
5809 }
5810 
5811 void __ata_qc_complete(struct ata_queued_cmd *qc)
5812 {
5813 	struct ata_port *ap = qc->ap;
5814 	struct ata_link *link = qc->dev->link;
5815 
5816 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5817 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
5818 
5819 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
5820 		ata_sg_clean(qc);
5821 
5822 	/* command should be marked inactive atomically with qc completion */
5823 	if (qc->tf.protocol == ATA_PROT_NCQ) {
5824 		link->sactive &= ~(1 << qc->tag);
5825 		if (!link->sactive)
5826 			ap->nr_active_links--;
5827 	} else {
5828 		link->active_tag = ATA_TAG_POISON;
5829 		ap->nr_active_links--;
5830 	}
5831 
5832 	/* clear exclusive status */
5833 	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
5834 		     ap->excl_link == link))
5835 		ap->excl_link = NULL;
5836 
5837 	/* atapi: mark qc as inactive to prevent the interrupt handler
5838 	 * from completing the command twice later, before the error handler
5839 	 * is called. (when rc != 0 and atapi request sense is needed)
5840 	 */
5841 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
5842 	ap->qc_active &= ~(1 << qc->tag);
5843 
5844 	/* call completion callback */
5845 	qc->complete_fn(qc);
5846 }
5847 
5848 static void fill_result_tf(struct ata_queued_cmd *qc)
5849 {
5850 	struct ata_port *ap = qc->ap;
5851 
5852 	qc->result_tf.flags = qc->tf.flags;
5853 	ap->ops->tf_read(ap, &qc->result_tf);
5854 }
5855 
5856 static void ata_verify_xfer(struct ata_queued_cmd *qc)
5857 {
5858 	struct ata_device *dev = qc->dev;
5859 
5860 	if (ata_tag_internal(qc->tag))
5861 		return;
5862 
5863 	if (ata_is_nodata(qc->tf.protocol))
5864 		return;
5865 
5866 	if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
5867 		return;
5868 
5869 	dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
5870 }
5871 
5872 /**
5873  *	ata_qc_complete - Complete an active ATA command
5874  *	@qc: Command to complete
5875  *	@err_mask: ATA Status register contents
5876  *
5877  *	Indicate to the mid and upper layers that an ATA
5878  *	command has completed, with either an ok or not-ok status.
5879  *
5880  *	LOCKING:
5881  *	spin_lock_irqsave(host lock)
5882  */
5883 void ata_qc_complete(struct ata_queued_cmd *qc)
5884 {
5885 	struct ata_port *ap = qc->ap;
5886 
5887 	/* XXX: New EH and old EH use different mechanisms to
5888 	 * synchronize EH with regular execution path.
5889 	 *
5890 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
5891 	 * Normal execution path is responsible for not accessing a
5892 	 * failed qc.  libata core enforces the rule by returning NULL
5893 	 * from ata_qc_from_tag() for failed qcs.
5894 	 *
5895 	 * Old EH depends on ata_qc_complete() nullifying completion
5896 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
5897 	 * not synchronize with interrupt handler.  Only PIO task is
5898 	 * taken care of.
5899 	 */
5900 	if (ap->ops->error_handler) {
5901 		struct ata_device *dev = qc->dev;
5902 		struct ata_eh_info *ehi = &dev->link->eh_info;
5903 
5904 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
5905 
5906 		if (unlikely(qc->err_mask))
5907 			qc->flags |= ATA_QCFLAG_FAILED;
5908 
5909 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
5910 			if (!ata_tag_internal(qc->tag)) {
5911 				/* always fill result TF for failed qc */
5912 				fill_result_tf(qc);
5913 				ata_qc_schedule_eh(qc);
5914 				return;
5915 			}
5916 		}
5917 
5918 		/* read result TF if requested */
5919 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
5920 			fill_result_tf(qc);
5921 
5922 		/* Some commands need post-processing after successful
5923 		 * completion.
5924 		 */
5925 		switch (qc->tf.command) {
5926 		case ATA_CMD_SET_FEATURES:
5927 			if (qc->tf.feature != SETFEATURES_WC_ON &&
5928 			    qc->tf.feature != SETFEATURES_WC_OFF)
5929 				break;
5930 			/* fall through */
5931 		case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
5932 		case ATA_CMD_SET_MULTI: /* multi_count changed */
5933 			/* revalidate device */
5934 			ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
5935 			ata_port_schedule_eh(ap);
5936 			break;
5937 
5938 		case ATA_CMD_SLEEP:
5939 			dev->flags |= ATA_DFLAG_SLEEPING;
5940 			break;
5941 		}
5942 
5943 		if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
5944 			ata_verify_xfer(qc);
5945 
5946 		__ata_qc_complete(qc);
5947 	} else {
5948 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
5949 			return;
5950 
5951 		/* read result TF if failed or requested */
5952 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
5953 			fill_result_tf(qc);
5954 
5955 		__ata_qc_complete(qc);
5956 	}
5957 }
5958 
5959 /**
5960  *	ata_qc_complete_multiple - Complete multiple qcs successfully
5961  *	@ap: port in question
5962  *	@qc_active: new qc_active mask
5963  *	@finish_qc: LLDD callback invoked before completing a qc
5964  *
5965  *	Complete in-flight commands.  This functions is meant to be
5966  *	called from low-level driver's interrupt routine to complete
5967  *	requests normally.  ap->qc_active and @qc_active is compared
5968  *	and commands are completed accordingly.
5969  *
5970  *	LOCKING:
5971  *	spin_lock_irqsave(host lock)
5972  *
5973  *	RETURNS:
5974  *	Number of completed commands on success, -errno otherwise.
5975  */
5976 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
5977 			     void (*finish_qc)(struct ata_queued_cmd *))
5978 {
5979 	int nr_done = 0;
5980 	u32 done_mask;
5981 	int i;
5982 
5983 	done_mask = ap->qc_active ^ qc_active;
5984 
5985 	if (unlikely(done_mask & qc_active)) {
5986 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
5987 				"(%08x->%08x)\n", ap->qc_active, qc_active);
5988 		return -EINVAL;
5989 	}
5990 
5991 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
5992 		struct ata_queued_cmd *qc;
5993 
5994 		if (!(done_mask & (1 << i)))
5995 			continue;
5996 
5997 		if ((qc = ata_qc_from_tag(ap, i))) {
5998 			if (finish_qc)
5999 				finish_qc(qc);
6000 			ata_qc_complete(qc);
6001 			nr_done++;
6002 		}
6003 	}
6004 
6005 	return nr_done;
6006 }
6007 
6008 /**
6009  *	ata_qc_issue - issue taskfile to device
6010  *	@qc: command to issue to device
6011  *
6012  *	Prepare an ATA command to submission to device.
6013  *	This includes mapping the data into a DMA-able
6014  *	area, filling in the S/G table, and finally
6015  *	writing the taskfile to hardware, starting the command.
6016  *
6017  *	LOCKING:
6018  *	spin_lock_irqsave(host lock)
6019  */
6020 void ata_qc_issue(struct ata_queued_cmd *qc)
6021 {
6022 	struct ata_port *ap = qc->ap;
6023 	struct ata_link *link = qc->dev->link;
6024 	u8 prot = qc->tf.protocol;
6025 
6026 	/* Make sure only one non-NCQ command is outstanding.  The
6027 	 * check is skipped for old EH because it reuses active qc to
6028 	 * request ATAPI sense.
6029 	 */
6030 	WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
6031 
6032 	if (ata_is_ncq(prot)) {
6033 		WARN_ON(link->sactive & (1 << qc->tag));
6034 
6035 		if (!link->sactive)
6036 			ap->nr_active_links++;
6037 		link->sactive |= 1 << qc->tag;
6038 	} else {
6039 		WARN_ON(link->sactive);
6040 
6041 		ap->nr_active_links++;
6042 		link->active_tag = qc->tag;
6043 	}
6044 
6045 	qc->flags |= ATA_QCFLAG_ACTIVE;
6046 	ap->qc_active |= 1 << qc->tag;
6047 
6048 	/* We guarantee to LLDs that they will have at least one
6049 	 * non-zero sg if the command is a data command.
6050 	 */
6051 	BUG_ON(ata_is_data(prot) && (!qc->sg || !qc->n_elem || !qc->nbytes));
6052 
6053 	if (ata_is_dma(prot) || (ata_is_pio(prot) &&
6054 				 (ap->flags & ATA_FLAG_PIO_DMA)))
6055 		if (ata_sg_setup(qc))
6056 			goto sg_err;
6057 
6058 	/* if device is sleeping, schedule softreset and abort the link */
6059 	if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
6060 		link->eh_info.action |= ATA_EH_SOFTRESET;
6061 		ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
6062 		ata_link_abort(link);
6063 		return;
6064 	}
6065 
6066 	ap->ops->qc_prep(qc);
6067 
6068 	qc->err_mask |= ap->ops->qc_issue(qc);
6069 	if (unlikely(qc->err_mask))
6070 		goto err;
6071 	return;
6072 
6073 sg_err:
6074 	qc->err_mask |= AC_ERR_SYSTEM;
6075 err:
6076 	ata_qc_complete(qc);
6077 }
6078 
6079 /**
6080  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
6081  *	@qc: command to issue to device
6082  *
6083  *	Using various libata functions and hooks, this function
6084  *	starts an ATA command.  ATA commands are grouped into
6085  *	classes called "protocols", and issuing each type of protocol
6086  *	is slightly different.
6087  *
6088  *	May be used as the qc_issue() entry in ata_port_operations.
6089  *
6090  *	LOCKING:
6091  *	spin_lock_irqsave(host lock)
6092  *
6093  *	RETURNS:
6094  *	Zero on success, AC_ERR_* mask on failure
6095  */
6096 
6097 unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
6098 {
6099 	struct ata_port *ap = qc->ap;
6100 
6101 	/* Use polling pio if the LLD doesn't handle
6102 	 * interrupt driven pio and atapi CDB interrupt.
6103 	 */
6104 	if (ap->flags & ATA_FLAG_PIO_POLLING) {
6105 		switch (qc->tf.protocol) {
6106 		case ATA_PROT_PIO:
6107 		case ATA_PROT_NODATA:
6108 		case ATAPI_PROT_PIO:
6109 		case ATAPI_PROT_NODATA:
6110 			qc->tf.flags |= ATA_TFLAG_POLLING;
6111 			break;
6112 		case ATAPI_PROT_DMA:
6113 			if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
6114 				/* see ata_dma_blacklisted() */
6115 				BUG();
6116 			break;
6117 		default:
6118 			break;
6119 		}
6120 	}
6121 
6122 	/* select the device */
6123 	ata_dev_select(ap, qc->dev->devno, 1, 0);
6124 
6125 	/* start the command */
6126 	switch (qc->tf.protocol) {
6127 	case ATA_PROT_NODATA:
6128 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6129 			ata_qc_set_polling(qc);
6130 
6131 		ata_tf_to_host(ap, &qc->tf);
6132 		ap->hsm_task_state = HSM_ST_LAST;
6133 
6134 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6135 			ata_pio_queue_task(ap, qc, 0);
6136 
6137 		break;
6138 
6139 	case ATA_PROT_DMA:
6140 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
6141 
6142 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
6143 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
6144 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
6145 		ap->hsm_task_state = HSM_ST_LAST;
6146 		break;
6147 
6148 	case ATA_PROT_PIO:
6149 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6150 			ata_qc_set_polling(qc);
6151 
6152 		ata_tf_to_host(ap, &qc->tf);
6153 
6154 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
6155 			/* PIO data out protocol */
6156 			ap->hsm_task_state = HSM_ST_FIRST;
6157 			ata_pio_queue_task(ap, qc, 0);
6158 
6159 			/* always send first data block using
6160 			 * the ata_pio_task() codepath.
6161 			 */
6162 		} else {
6163 			/* PIO data in protocol */
6164 			ap->hsm_task_state = HSM_ST;
6165 
6166 			if (qc->tf.flags & ATA_TFLAG_POLLING)
6167 				ata_pio_queue_task(ap, qc, 0);
6168 
6169 			/* if polling, ata_pio_task() handles the rest.
6170 			 * otherwise, interrupt handler takes over from here.
6171 			 */
6172 		}
6173 
6174 		break;
6175 
6176 	case ATAPI_PROT_PIO:
6177 	case ATAPI_PROT_NODATA:
6178 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6179 			ata_qc_set_polling(qc);
6180 
6181 		ata_tf_to_host(ap, &qc->tf);
6182 
6183 		ap->hsm_task_state = HSM_ST_FIRST;
6184 
6185 		/* send cdb by polling if no cdb interrupt */
6186 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
6187 		    (qc->tf.flags & ATA_TFLAG_POLLING))
6188 			ata_pio_queue_task(ap, qc, 0);
6189 		break;
6190 
6191 	case ATAPI_PROT_DMA:
6192 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
6193 
6194 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
6195 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
6196 		ap->hsm_task_state = HSM_ST_FIRST;
6197 
6198 		/* send cdb by polling if no cdb interrupt */
6199 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
6200 			ata_pio_queue_task(ap, qc, 0);
6201 		break;
6202 
6203 	default:
6204 		WARN_ON(1);
6205 		return AC_ERR_SYSTEM;
6206 	}
6207 
6208 	return 0;
6209 }
6210 
6211 /**
6212  *	ata_host_intr - Handle host interrupt for given (port, task)
6213  *	@ap: Port on which interrupt arrived (possibly...)
6214  *	@qc: Taskfile currently active in engine
6215  *
6216  *	Handle host interrupt for given queued command.  Currently,
6217  *	only DMA interrupts are handled.  All other commands are
6218  *	handled via polling with interrupts disabled (nIEN bit).
6219  *
6220  *	LOCKING:
6221  *	spin_lock_irqsave(host lock)
6222  *
6223  *	RETURNS:
6224  *	One if interrupt was handled, zero if not (shared irq).
6225  */
6226 
6227 inline unsigned int ata_host_intr(struct ata_port *ap,
6228 				  struct ata_queued_cmd *qc)
6229 {
6230 	struct ata_eh_info *ehi = &ap->link.eh_info;
6231 	u8 status, host_stat = 0;
6232 
6233 	VPRINTK("ata%u: protocol %d task_state %d\n",
6234 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
6235 
6236 	/* Check whether we are expecting interrupt in this state */
6237 	switch (ap->hsm_task_state) {
6238 	case HSM_ST_FIRST:
6239 		/* Some pre-ATAPI-4 devices assert INTRQ
6240 		 * at this state when ready to receive CDB.
6241 		 */
6242 
6243 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
6244 		 * The flag was turned on only for atapi devices.  No
6245 		 * need to check ata_is_atapi(qc->tf.protocol) again.
6246 		 */
6247 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
6248 			goto idle_irq;
6249 		break;
6250 	case HSM_ST_LAST:
6251 		if (qc->tf.protocol == ATA_PROT_DMA ||
6252 		    qc->tf.protocol == ATAPI_PROT_DMA) {
6253 			/* check status of DMA engine */
6254 			host_stat = ap->ops->bmdma_status(ap);
6255 			VPRINTK("ata%u: host_stat 0x%X\n",
6256 				ap->print_id, host_stat);
6257 
6258 			/* if it's not our irq... */
6259 			if (!(host_stat & ATA_DMA_INTR))
6260 				goto idle_irq;
6261 
6262 			/* before we do anything else, clear DMA-Start bit */
6263 			ap->ops->bmdma_stop(qc);
6264 
6265 			if (unlikely(host_stat & ATA_DMA_ERR)) {
6266 				/* error when transfering data to/from memory */
6267 				qc->err_mask |= AC_ERR_HOST_BUS;
6268 				ap->hsm_task_state = HSM_ST_ERR;
6269 			}
6270 		}
6271 		break;
6272 	case HSM_ST:
6273 		break;
6274 	default:
6275 		goto idle_irq;
6276 	}
6277 
6278 	/* check altstatus */
6279 	status = ata_altstatus(ap);
6280 	if (status & ATA_BUSY)
6281 		goto idle_irq;
6282 
6283 	/* check main status, clearing INTRQ */
6284 	status = ata_chk_status(ap);
6285 	if (unlikely(status & ATA_BUSY))
6286 		goto idle_irq;
6287 
6288 	/* ack bmdma irq events */
6289 	ap->ops->irq_clear(ap);
6290 
6291 	ata_hsm_move(ap, qc, status, 0);
6292 
6293 	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
6294 				       qc->tf.protocol == ATAPI_PROT_DMA))
6295 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
6296 
6297 	return 1;	/* irq handled */
6298 
6299 idle_irq:
6300 	ap->stats.idle_irq++;
6301 
6302 #ifdef ATA_IRQ_TRAP
6303 	if ((ap->stats.idle_irq % 1000) == 0) {
6304 		ata_chk_status(ap);
6305 		ap->ops->irq_clear(ap);
6306 		ata_port_printk(ap, KERN_WARNING, "irq trap\n");
6307 		return 1;
6308 	}
6309 #endif
6310 	return 0;	/* irq not handled */
6311 }
6312 
6313 /**
6314  *	ata_interrupt - Default ATA host interrupt handler
6315  *	@irq: irq line (unused)
6316  *	@dev_instance: pointer to our ata_host information structure
6317  *
6318  *	Default interrupt handler for PCI IDE devices.  Calls
6319  *	ata_host_intr() for each port that is not disabled.
6320  *
6321  *	LOCKING:
6322  *	Obtains host lock during operation.
6323  *
6324  *	RETURNS:
6325  *	IRQ_NONE or IRQ_HANDLED.
6326  */
6327 
6328 irqreturn_t ata_interrupt(int irq, void *dev_instance)
6329 {
6330 	struct ata_host *host = dev_instance;
6331 	unsigned int i;
6332 	unsigned int handled = 0;
6333 	unsigned long flags;
6334 
6335 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
6336 	spin_lock_irqsave(&host->lock, flags);
6337 
6338 	for (i = 0; i < host->n_ports; i++) {
6339 		struct ata_port *ap;
6340 
6341 		ap = host->ports[i];
6342 		if (ap &&
6343 		    !(ap->flags & ATA_FLAG_DISABLED)) {
6344 			struct ata_queued_cmd *qc;
6345 
6346 			qc = ata_qc_from_tag(ap, ap->link.active_tag);
6347 			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
6348 			    (qc->flags & ATA_QCFLAG_ACTIVE))
6349 				handled |= ata_host_intr(ap, qc);
6350 		}
6351 	}
6352 
6353 	spin_unlock_irqrestore(&host->lock, flags);
6354 
6355 	return IRQ_RETVAL(handled);
6356 }
6357 
6358 /**
6359  *	sata_scr_valid - test whether SCRs are accessible
6360  *	@link: ATA link to test SCR accessibility for
6361  *
6362  *	Test whether SCRs are accessible for @link.
6363  *
6364  *	LOCKING:
6365  *	None.
6366  *
6367  *	RETURNS:
6368  *	1 if SCRs are accessible, 0 otherwise.
6369  */
6370 int sata_scr_valid(struct ata_link *link)
6371 {
6372 	struct ata_port *ap = link->ap;
6373 
6374 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
6375 }
6376 
6377 /**
6378  *	sata_scr_read - read SCR register of the specified port
6379  *	@link: ATA link to read SCR for
6380  *	@reg: SCR to read
6381  *	@val: Place to store read value
6382  *
6383  *	Read SCR register @reg of @link into *@val.  This function is
6384  *	guaranteed to succeed if @link is ap->link, the cable type of
6385  *	the port is SATA and the port implements ->scr_read.
6386  *
6387  *	LOCKING:
6388  *	None if @link is ap->link.  Kernel thread context otherwise.
6389  *
6390  *	RETURNS:
6391  *	0 on success, negative errno on failure.
6392  */
6393 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
6394 {
6395 	if (ata_is_host_link(link)) {
6396 		struct ata_port *ap = link->ap;
6397 
6398 		if (sata_scr_valid(link))
6399 			return ap->ops->scr_read(ap, reg, val);
6400 		return -EOPNOTSUPP;
6401 	}
6402 
6403 	return sata_pmp_scr_read(link, reg, val);
6404 }
6405 
6406 /**
6407  *	sata_scr_write - write SCR register of the specified port
6408  *	@link: ATA link to write SCR for
6409  *	@reg: SCR to write
6410  *	@val: value to write
6411  *
6412  *	Write @val to SCR register @reg of @link.  This function is
6413  *	guaranteed to succeed if @link is ap->link, the cable type of
6414  *	the port is SATA and the port implements ->scr_read.
6415  *
6416  *	LOCKING:
6417  *	None if @link is ap->link.  Kernel thread context otherwise.
6418  *
6419  *	RETURNS:
6420  *	0 on success, negative errno on failure.
6421  */
6422 int sata_scr_write(struct ata_link *link, int reg, u32 val)
6423 {
6424 	if (ata_is_host_link(link)) {
6425 		struct ata_port *ap = link->ap;
6426 
6427 		if (sata_scr_valid(link))
6428 			return ap->ops->scr_write(ap, reg, val);
6429 		return -EOPNOTSUPP;
6430 	}
6431 
6432 	return sata_pmp_scr_write(link, reg, val);
6433 }
6434 
6435 /**
6436  *	sata_scr_write_flush - write SCR register of the specified port and flush
6437  *	@link: ATA link to write SCR for
6438  *	@reg: SCR to write
6439  *	@val: value to write
6440  *
6441  *	This function is identical to sata_scr_write() except that this
6442  *	function performs flush after writing to the register.
6443  *
6444  *	LOCKING:
6445  *	None if @link is ap->link.  Kernel thread context otherwise.
6446  *
6447  *	RETURNS:
6448  *	0 on success, negative errno on failure.
6449  */
6450 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
6451 {
6452 	if (ata_is_host_link(link)) {
6453 		struct ata_port *ap = link->ap;
6454 		int rc;
6455 
6456 		if (sata_scr_valid(link)) {
6457 			rc = ap->ops->scr_write(ap, reg, val);
6458 			if (rc == 0)
6459 				rc = ap->ops->scr_read(ap, reg, &val);
6460 			return rc;
6461 		}
6462 		return -EOPNOTSUPP;
6463 	}
6464 
6465 	return sata_pmp_scr_write(link, reg, val);
6466 }
6467 
6468 /**
6469  *	ata_link_online - test whether the given link is online
6470  *	@link: ATA link to test
6471  *
6472  *	Test whether @link is online.  Note that this function returns
6473  *	0 if online status of @link cannot be obtained, so
6474  *	ata_link_online(link) != !ata_link_offline(link).
6475  *
6476  *	LOCKING:
6477  *	None.
6478  *
6479  *	RETURNS:
6480  *	1 if the port online status is available and online.
6481  */
6482 int ata_link_online(struct ata_link *link)
6483 {
6484 	u32 sstatus;
6485 
6486 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6487 	    (sstatus & 0xf) == 0x3)
6488 		return 1;
6489 	return 0;
6490 }
6491 
6492 /**
6493  *	ata_link_offline - test whether the given link is offline
6494  *	@link: ATA link to test
6495  *
6496  *	Test whether @link is offline.  Note that this function
6497  *	returns 0 if offline status of @link cannot be obtained, so
6498  *	ata_link_online(link) != !ata_link_offline(link).
6499  *
6500  *	LOCKING:
6501  *	None.
6502  *
6503  *	RETURNS:
6504  *	1 if the port offline status is available and offline.
6505  */
6506 int ata_link_offline(struct ata_link *link)
6507 {
6508 	u32 sstatus;
6509 
6510 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6511 	    (sstatus & 0xf) != 0x3)
6512 		return 1;
6513 	return 0;
6514 }
6515 
6516 int ata_flush_cache(struct ata_device *dev)
6517 {
6518 	unsigned int err_mask;
6519 	u8 cmd;
6520 
6521 	if (!ata_try_flush_cache(dev))
6522 		return 0;
6523 
6524 	if (dev->flags & ATA_DFLAG_FLUSH_EXT)
6525 		cmd = ATA_CMD_FLUSH_EXT;
6526 	else
6527 		cmd = ATA_CMD_FLUSH;
6528 
6529 	/* This is wrong. On a failed flush we get back the LBA of the lost
6530 	   sector and we should (assuming it wasn't aborted as unknown) issue
6531 	   a further flush command to continue the writeback until it
6532 	   does not error */
6533 	err_mask = ata_do_simple_cmd(dev, cmd);
6534 	if (err_mask) {
6535 		ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
6536 		return -EIO;
6537 	}
6538 
6539 	return 0;
6540 }
6541 
6542 #ifdef CONFIG_PM
6543 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
6544 			       unsigned int action, unsigned int ehi_flags,
6545 			       int wait)
6546 {
6547 	unsigned long flags;
6548 	int i, rc;
6549 
6550 	for (i = 0; i < host->n_ports; i++) {
6551 		struct ata_port *ap = host->ports[i];
6552 		struct ata_link *link;
6553 
6554 		/* Previous resume operation might still be in
6555 		 * progress.  Wait for PM_PENDING to clear.
6556 		 */
6557 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
6558 			ata_port_wait_eh(ap);
6559 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6560 		}
6561 
6562 		/* request PM ops to EH */
6563 		spin_lock_irqsave(ap->lock, flags);
6564 
6565 		ap->pm_mesg = mesg;
6566 		if (wait) {
6567 			rc = 0;
6568 			ap->pm_result = &rc;
6569 		}
6570 
6571 		ap->pflags |= ATA_PFLAG_PM_PENDING;
6572 		__ata_port_for_each_link(link, ap) {
6573 			link->eh_info.action |= action;
6574 			link->eh_info.flags |= ehi_flags;
6575 		}
6576 
6577 		ata_port_schedule_eh(ap);
6578 
6579 		spin_unlock_irqrestore(ap->lock, flags);
6580 
6581 		/* wait and check result */
6582 		if (wait) {
6583 			ata_port_wait_eh(ap);
6584 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6585 			if (rc)
6586 				return rc;
6587 		}
6588 	}
6589 
6590 	return 0;
6591 }
6592 
6593 /**
6594  *	ata_host_suspend - suspend host
6595  *	@host: host to suspend
6596  *	@mesg: PM message
6597  *
6598  *	Suspend @host.  Actual operation is performed by EH.  This
6599  *	function requests EH to perform PM operations and waits for EH
6600  *	to finish.
6601  *
6602  *	LOCKING:
6603  *	Kernel thread context (may sleep).
6604  *
6605  *	RETURNS:
6606  *	0 on success, -errno on failure.
6607  */
6608 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
6609 {
6610 	int rc;
6611 
6612 	/*
6613 	 * disable link pm on all ports before requesting
6614 	 * any pm activity
6615 	 */
6616 	ata_lpm_enable(host);
6617 
6618 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
6619 	if (rc == 0)
6620 		host->dev->power.power_state = mesg;
6621 	return rc;
6622 }
6623 
6624 /**
6625  *	ata_host_resume - resume host
6626  *	@host: host to resume
6627  *
6628  *	Resume @host.  Actual operation is performed by EH.  This
6629  *	function requests EH to perform PM operations and returns.
6630  *	Note that all resume operations are performed parallely.
6631  *
6632  *	LOCKING:
6633  *	Kernel thread context (may sleep).
6634  */
6635 void ata_host_resume(struct ata_host *host)
6636 {
6637 	ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
6638 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
6639 	host->dev->power.power_state = PMSG_ON;
6640 
6641 	/* reenable link pm */
6642 	ata_lpm_disable(host);
6643 }
6644 #endif
6645 
6646 /**
6647  *	ata_port_start - Set port up for dma.
6648  *	@ap: Port to initialize
6649  *
6650  *	Called just after data structures for each port are
6651  *	initialized.  Allocates space for PRD table.
6652  *
6653  *	May be used as the port_start() entry in ata_port_operations.
6654  *
6655  *	LOCKING:
6656  *	Inherited from caller.
6657  */
6658 int ata_port_start(struct ata_port *ap)
6659 {
6660 	struct device *dev = ap->dev;
6661 
6662 	ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma,
6663 				      GFP_KERNEL);
6664 	if (!ap->prd)
6665 		return -ENOMEM;
6666 
6667 	return 0;
6668 }
6669 
6670 /**
6671  *	ata_dev_init - Initialize an ata_device structure
6672  *	@dev: Device structure to initialize
6673  *
6674  *	Initialize @dev in preparation for probing.
6675  *
6676  *	LOCKING:
6677  *	Inherited from caller.
6678  */
6679 void ata_dev_init(struct ata_device *dev)
6680 {
6681 	struct ata_link *link = dev->link;
6682 	struct ata_port *ap = link->ap;
6683 	unsigned long flags;
6684 
6685 	/* SATA spd limit is bound to the first device */
6686 	link->sata_spd_limit = link->hw_sata_spd_limit;
6687 	link->sata_spd = 0;
6688 
6689 	/* High bits of dev->flags are used to record warm plug
6690 	 * requests which occur asynchronously.  Synchronize using
6691 	 * host lock.
6692 	 */
6693 	spin_lock_irqsave(ap->lock, flags);
6694 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
6695 	dev->horkage = 0;
6696 	spin_unlock_irqrestore(ap->lock, flags);
6697 
6698 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
6699 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
6700 	dev->pio_mask = UINT_MAX;
6701 	dev->mwdma_mask = UINT_MAX;
6702 	dev->udma_mask = UINT_MAX;
6703 }
6704 
6705 /**
6706  *	ata_link_init - Initialize an ata_link structure
6707  *	@ap: ATA port link is attached to
6708  *	@link: Link structure to initialize
6709  *	@pmp: Port multiplier port number
6710  *
6711  *	Initialize @link.
6712  *
6713  *	LOCKING:
6714  *	Kernel thread context (may sleep)
6715  */
6716 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
6717 {
6718 	int i;
6719 
6720 	/* clear everything except for devices */
6721 	memset(link, 0, offsetof(struct ata_link, device[0]));
6722 
6723 	link->ap = ap;
6724 	link->pmp = pmp;
6725 	link->active_tag = ATA_TAG_POISON;
6726 	link->hw_sata_spd_limit = UINT_MAX;
6727 
6728 	/* can't use iterator, ap isn't initialized yet */
6729 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
6730 		struct ata_device *dev = &link->device[i];
6731 
6732 		dev->link = link;
6733 		dev->devno = dev - link->device;
6734 		ata_dev_init(dev);
6735 	}
6736 }
6737 
6738 /**
6739  *	sata_link_init_spd - Initialize link->sata_spd_limit
6740  *	@link: Link to configure sata_spd_limit for
6741  *
6742  *	Initialize @link->[hw_]sata_spd_limit to the currently
6743  *	configured value.
6744  *
6745  *	LOCKING:
6746  *	Kernel thread context (may sleep).
6747  *
6748  *	RETURNS:
6749  *	0 on success, -errno on failure.
6750  */
6751 int sata_link_init_spd(struct ata_link *link)
6752 {
6753 	u32 scontrol;
6754 	u8 spd;
6755 	int rc;
6756 
6757 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
6758 	if (rc)
6759 		return rc;
6760 
6761 	spd = (scontrol >> 4) & 0xf;
6762 	if (spd)
6763 		link->hw_sata_spd_limit &= (1 << spd) - 1;
6764 
6765 	ata_force_spd_limit(link);
6766 
6767 	link->sata_spd_limit = link->hw_sata_spd_limit;
6768 
6769 	return 0;
6770 }
6771 
6772 /**
6773  *	ata_port_alloc - allocate and initialize basic ATA port resources
6774  *	@host: ATA host this allocated port belongs to
6775  *
6776  *	Allocate and initialize basic ATA port resources.
6777  *
6778  *	RETURNS:
6779  *	Allocate ATA port on success, NULL on failure.
6780  *
6781  *	LOCKING:
6782  *	Inherited from calling layer (may sleep).
6783  */
6784 struct ata_port *ata_port_alloc(struct ata_host *host)
6785 {
6786 	struct ata_port *ap;
6787 
6788 	DPRINTK("ENTER\n");
6789 
6790 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
6791 	if (!ap)
6792 		return NULL;
6793 
6794 	ap->pflags |= ATA_PFLAG_INITIALIZING;
6795 	ap->lock = &host->lock;
6796 	ap->flags = ATA_FLAG_DISABLED;
6797 	ap->print_id = -1;
6798 	ap->ctl = ATA_DEVCTL_OBS;
6799 	ap->host = host;
6800 	ap->dev = host->dev;
6801 	ap->last_ctl = 0xFF;
6802 
6803 #if defined(ATA_VERBOSE_DEBUG)
6804 	/* turn on all debugging levels */
6805 	ap->msg_enable = 0x00FF;
6806 #elif defined(ATA_DEBUG)
6807 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
6808 #else
6809 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
6810 #endif
6811 
6812 	INIT_DELAYED_WORK(&ap->port_task, ata_pio_task);
6813 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
6814 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
6815 	INIT_LIST_HEAD(&ap->eh_done_q);
6816 	init_waitqueue_head(&ap->eh_wait_q);
6817 	init_timer_deferrable(&ap->fastdrain_timer);
6818 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
6819 	ap->fastdrain_timer.data = (unsigned long)ap;
6820 
6821 	ap->cbl = ATA_CBL_NONE;
6822 
6823 	ata_link_init(ap, &ap->link, 0);
6824 
6825 #ifdef ATA_IRQ_TRAP
6826 	ap->stats.unhandled_irq = 1;
6827 	ap->stats.idle_irq = 1;
6828 #endif
6829 	return ap;
6830 }
6831 
6832 static void ata_host_release(struct device *gendev, void *res)
6833 {
6834 	struct ata_host *host = dev_get_drvdata(gendev);
6835 	int i;
6836 
6837 	for (i = 0; i < host->n_ports; i++) {
6838 		struct ata_port *ap = host->ports[i];
6839 
6840 		if (!ap)
6841 			continue;
6842 
6843 		if (ap->scsi_host)
6844 			scsi_host_put(ap->scsi_host);
6845 
6846 		kfree(ap->pmp_link);
6847 		kfree(ap);
6848 		host->ports[i] = NULL;
6849 	}
6850 
6851 	dev_set_drvdata(gendev, NULL);
6852 }
6853 
6854 /**
6855  *	ata_host_alloc - allocate and init basic ATA host resources
6856  *	@dev: generic device this host is associated with
6857  *	@max_ports: maximum number of ATA ports associated with this host
6858  *
6859  *	Allocate and initialize basic ATA host resources.  LLD calls
6860  *	this function to allocate a host, initializes it fully and
6861  *	attaches it using ata_host_register().
6862  *
6863  *	@max_ports ports are allocated and host->n_ports is
6864  *	initialized to @max_ports.  The caller is allowed to decrease
6865  *	host->n_ports before calling ata_host_register().  The unused
6866  *	ports will be automatically freed on registration.
6867  *
6868  *	RETURNS:
6869  *	Allocate ATA host on success, NULL on failure.
6870  *
6871  *	LOCKING:
6872  *	Inherited from calling layer (may sleep).
6873  */
6874 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
6875 {
6876 	struct ata_host *host;
6877 	size_t sz;
6878 	int i;
6879 
6880 	DPRINTK("ENTER\n");
6881 
6882 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
6883 		return NULL;
6884 
6885 	/* alloc a container for our list of ATA ports (buses) */
6886 	sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
6887 	/* alloc a container for our list of ATA ports (buses) */
6888 	host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
6889 	if (!host)
6890 		goto err_out;
6891 
6892 	devres_add(dev, host);
6893 	dev_set_drvdata(dev, host);
6894 
6895 	spin_lock_init(&host->lock);
6896 	host->dev = dev;
6897 	host->n_ports = max_ports;
6898 
6899 	/* allocate ports bound to this host */
6900 	for (i = 0; i < max_ports; i++) {
6901 		struct ata_port *ap;
6902 
6903 		ap = ata_port_alloc(host);
6904 		if (!ap)
6905 			goto err_out;
6906 
6907 		ap->port_no = i;
6908 		host->ports[i] = ap;
6909 	}
6910 
6911 	devres_remove_group(dev, NULL);
6912 	return host;
6913 
6914  err_out:
6915 	devres_release_group(dev, NULL);
6916 	return NULL;
6917 }
6918 
6919 /**
6920  *	ata_host_alloc_pinfo - alloc host and init with port_info array
6921  *	@dev: generic device this host is associated with
6922  *	@ppi: array of ATA port_info to initialize host with
6923  *	@n_ports: number of ATA ports attached to this host
6924  *
6925  *	Allocate ATA host and initialize with info from @ppi.  If NULL
6926  *	terminated, @ppi may contain fewer entries than @n_ports.  The
6927  *	last entry will be used for the remaining ports.
6928  *
6929  *	RETURNS:
6930  *	Allocate ATA host on success, NULL on failure.
6931  *
6932  *	LOCKING:
6933  *	Inherited from calling layer (may sleep).
6934  */
6935 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
6936 				      const struct ata_port_info * const * ppi,
6937 				      int n_ports)
6938 {
6939 	const struct ata_port_info *pi;
6940 	struct ata_host *host;
6941 	int i, j;
6942 
6943 	host = ata_host_alloc(dev, n_ports);
6944 	if (!host)
6945 		return NULL;
6946 
6947 	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
6948 		struct ata_port *ap = host->ports[i];
6949 
6950 		if (ppi[j])
6951 			pi = ppi[j++];
6952 
6953 		ap->pio_mask = pi->pio_mask;
6954 		ap->mwdma_mask = pi->mwdma_mask;
6955 		ap->udma_mask = pi->udma_mask;
6956 		ap->flags |= pi->flags;
6957 		ap->link.flags |= pi->link_flags;
6958 		ap->ops = pi->port_ops;
6959 
6960 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
6961 			host->ops = pi->port_ops;
6962 		if (!host->private_data && pi->private_data)
6963 			host->private_data = pi->private_data;
6964 	}
6965 
6966 	return host;
6967 }
6968 
6969 static void ata_host_stop(struct device *gendev, void *res)
6970 {
6971 	struct ata_host *host = dev_get_drvdata(gendev);
6972 	int i;
6973 
6974 	WARN_ON(!(host->flags & ATA_HOST_STARTED));
6975 
6976 	for (i = 0; i < host->n_ports; i++) {
6977 		struct ata_port *ap = host->ports[i];
6978 
6979 		if (ap->ops->port_stop)
6980 			ap->ops->port_stop(ap);
6981 	}
6982 
6983 	if (host->ops->host_stop)
6984 		host->ops->host_stop(host);
6985 }
6986 
6987 /**
6988  *	ata_host_start - start and freeze ports of an ATA host
6989  *	@host: ATA host to start ports for
6990  *
6991  *	Start and then freeze ports of @host.  Started status is
6992  *	recorded in host->flags, so this function can be called
6993  *	multiple times.  Ports are guaranteed to get started only
6994  *	once.  If host->ops isn't initialized yet, its set to the
6995  *	first non-dummy port ops.
6996  *
6997  *	LOCKING:
6998  *	Inherited from calling layer (may sleep).
6999  *
7000  *	RETURNS:
7001  *	0 if all ports are started successfully, -errno otherwise.
7002  */
7003 int ata_host_start(struct ata_host *host)
7004 {
7005 	int have_stop = 0;
7006 	void *start_dr = NULL;
7007 	int i, rc;
7008 
7009 	if (host->flags & ATA_HOST_STARTED)
7010 		return 0;
7011 
7012 	for (i = 0; i < host->n_ports; i++) {
7013 		struct ata_port *ap = host->ports[i];
7014 
7015 		if (!host->ops && !ata_port_is_dummy(ap))
7016 			host->ops = ap->ops;
7017 
7018 		if (ap->ops->port_stop)
7019 			have_stop = 1;
7020 	}
7021 
7022 	if (host->ops->host_stop)
7023 		have_stop = 1;
7024 
7025 	if (have_stop) {
7026 		start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
7027 		if (!start_dr)
7028 			return -ENOMEM;
7029 	}
7030 
7031 	for (i = 0; i < host->n_ports; i++) {
7032 		struct ata_port *ap = host->ports[i];
7033 
7034 		if (ap->ops->port_start) {
7035 			rc = ap->ops->port_start(ap);
7036 			if (rc) {
7037 				if (rc != -ENODEV)
7038 					dev_printk(KERN_ERR, host->dev,
7039 						"failed to start port %d "
7040 						"(errno=%d)\n", i, rc);
7041 				goto err_out;
7042 			}
7043 		}
7044 		ata_eh_freeze_port(ap);
7045 	}
7046 
7047 	if (start_dr)
7048 		devres_add(host->dev, start_dr);
7049 	host->flags |= ATA_HOST_STARTED;
7050 	return 0;
7051 
7052  err_out:
7053 	while (--i >= 0) {
7054 		struct ata_port *ap = host->ports[i];
7055 
7056 		if (ap->ops->port_stop)
7057 			ap->ops->port_stop(ap);
7058 	}
7059 	devres_free(start_dr);
7060 	return rc;
7061 }
7062 
7063 /**
7064  *	ata_sas_host_init - Initialize a host struct
7065  *	@host:	host to initialize
7066  *	@dev:	device host is attached to
7067  *	@flags:	host flags
7068  *	@ops:	port_ops
7069  *
7070  *	LOCKING:
7071  *	PCI/etc. bus probe sem.
7072  *
7073  */
7074 /* KILLME - the only user left is ipr */
7075 void ata_host_init(struct ata_host *host, struct device *dev,
7076 		   unsigned long flags, const struct ata_port_operations *ops)
7077 {
7078 	spin_lock_init(&host->lock);
7079 	host->dev = dev;
7080 	host->flags = flags;
7081 	host->ops = ops;
7082 }
7083 
7084 /**
7085  *	ata_host_register - register initialized ATA host
7086  *	@host: ATA host to register
7087  *	@sht: template for SCSI host
7088  *
7089  *	Register initialized ATA host.  @host is allocated using
7090  *	ata_host_alloc() and fully initialized by LLD.  This function
7091  *	starts ports, registers @host with ATA and SCSI layers and
7092  *	probe registered devices.
7093  *
7094  *	LOCKING:
7095  *	Inherited from calling layer (may sleep).
7096  *
7097  *	RETURNS:
7098  *	0 on success, -errno otherwise.
7099  */
7100 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
7101 {
7102 	int i, rc;
7103 
7104 	/* host must have been started */
7105 	if (!(host->flags & ATA_HOST_STARTED)) {
7106 		dev_printk(KERN_ERR, host->dev,
7107 			   "BUG: trying to register unstarted host\n");
7108 		WARN_ON(1);
7109 		return -EINVAL;
7110 	}
7111 
7112 	/* Blow away unused ports.  This happens when LLD can't
7113 	 * determine the exact number of ports to allocate at
7114 	 * allocation time.
7115 	 */
7116 	for (i = host->n_ports; host->ports[i]; i++)
7117 		kfree(host->ports[i]);
7118 
7119 	/* give ports names and add SCSI hosts */
7120 	for (i = 0; i < host->n_ports; i++)
7121 		host->ports[i]->print_id = ata_print_id++;
7122 
7123 	rc = ata_scsi_add_hosts(host, sht);
7124 	if (rc)
7125 		return rc;
7126 
7127 	/* associate with ACPI nodes */
7128 	ata_acpi_associate(host);
7129 
7130 	/* set cable, sata_spd_limit and report */
7131 	for (i = 0; i < host->n_ports; i++) {
7132 		struct ata_port *ap = host->ports[i];
7133 		unsigned long xfer_mask;
7134 
7135 		/* set SATA cable type if still unset */
7136 		if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
7137 			ap->cbl = ATA_CBL_SATA;
7138 
7139 		/* init sata_spd_limit to the current value */
7140 		sata_link_init_spd(&ap->link);
7141 
7142 		/* print per-port info to dmesg */
7143 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
7144 					      ap->udma_mask);
7145 
7146 		if (!ata_port_is_dummy(ap)) {
7147 			ata_port_printk(ap, KERN_INFO,
7148 					"%cATA max %s %s\n",
7149 					(ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
7150 					ata_mode_string(xfer_mask),
7151 					ap->link.eh_info.desc);
7152 			ata_ehi_clear_desc(&ap->link.eh_info);
7153 		} else
7154 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
7155 	}
7156 
7157 	/* perform each probe synchronously */
7158 	DPRINTK("probe begin\n");
7159 	for (i = 0; i < host->n_ports; i++) {
7160 		struct ata_port *ap = host->ports[i];
7161 
7162 		/* probe */
7163 		if (ap->ops->error_handler) {
7164 			struct ata_eh_info *ehi = &ap->link.eh_info;
7165 			unsigned long flags;
7166 
7167 			ata_port_probe(ap);
7168 
7169 			/* kick EH for boot probing */
7170 			spin_lock_irqsave(ap->lock, flags);
7171 
7172 			ehi->probe_mask =
7173 				(1 << ata_link_max_devices(&ap->link)) - 1;
7174 			ehi->action |= ATA_EH_SOFTRESET;
7175 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
7176 
7177 			ap->pflags &= ~ATA_PFLAG_INITIALIZING;
7178 			ap->pflags |= ATA_PFLAG_LOADING;
7179 			ata_port_schedule_eh(ap);
7180 
7181 			spin_unlock_irqrestore(ap->lock, flags);
7182 
7183 			/* wait for EH to finish */
7184 			ata_port_wait_eh(ap);
7185 		} else {
7186 			DPRINTK("ata%u: bus probe begin\n", ap->print_id);
7187 			rc = ata_bus_probe(ap);
7188 			DPRINTK("ata%u: bus probe end\n", ap->print_id);
7189 
7190 			if (rc) {
7191 				/* FIXME: do something useful here?
7192 				 * Current libata behavior will
7193 				 * tear down everything when
7194 				 * the module is removed
7195 				 * or the h/w is unplugged.
7196 				 */
7197 			}
7198 		}
7199 	}
7200 
7201 	/* probes are done, now scan each port's disk(s) */
7202 	DPRINTK("host probe begin\n");
7203 	for (i = 0; i < host->n_ports; i++) {
7204 		struct ata_port *ap = host->ports[i];
7205 
7206 		ata_scsi_scan_host(ap, 1);
7207 		ata_lpm_schedule(ap, ap->pm_policy);
7208 	}
7209 
7210 	return 0;
7211 }
7212 
7213 /**
7214  *	ata_host_activate - start host, request IRQ and register it
7215  *	@host: target ATA host
7216  *	@irq: IRQ to request
7217  *	@irq_handler: irq_handler used when requesting IRQ
7218  *	@irq_flags: irq_flags used when requesting IRQ
7219  *	@sht: scsi_host_template to use when registering the host
7220  *
7221  *	After allocating an ATA host and initializing it, most libata
7222  *	LLDs perform three steps to activate the host - start host,
7223  *	request IRQ and register it.  This helper takes necessasry
7224  *	arguments and performs the three steps in one go.
7225  *
7226  *	An invalid IRQ skips the IRQ registration and expects the host to
7227  *	have set polling mode on the port. In this case, @irq_handler
7228  *	should be NULL.
7229  *
7230  *	LOCKING:
7231  *	Inherited from calling layer (may sleep).
7232  *
7233  *	RETURNS:
7234  *	0 on success, -errno otherwise.
7235  */
7236 int ata_host_activate(struct ata_host *host, int irq,
7237 		      irq_handler_t irq_handler, unsigned long irq_flags,
7238 		      struct scsi_host_template *sht)
7239 {
7240 	int i, rc;
7241 
7242 	rc = ata_host_start(host);
7243 	if (rc)
7244 		return rc;
7245 
7246 	/* Special case for polling mode */
7247 	if (!irq) {
7248 		WARN_ON(irq_handler);
7249 		return ata_host_register(host, sht);
7250 	}
7251 
7252 	rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
7253 			      dev_driver_string(host->dev), host);
7254 	if (rc)
7255 		return rc;
7256 
7257 	for (i = 0; i < host->n_ports; i++)
7258 		ata_port_desc(host->ports[i], "irq %d", irq);
7259 
7260 	rc = ata_host_register(host, sht);
7261 	/* if failed, just free the IRQ and leave ports alone */
7262 	if (rc)
7263 		devm_free_irq(host->dev, irq, host);
7264 
7265 	return rc;
7266 }
7267 
7268 /**
7269  *	ata_port_detach - Detach ATA port in prepration of device removal
7270  *	@ap: ATA port to be detached
7271  *
7272  *	Detach all ATA devices and the associated SCSI devices of @ap;
7273  *	then, remove the associated SCSI host.  @ap is guaranteed to
7274  *	be quiescent on return from this function.
7275  *
7276  *	LOCKING:
7277  *	Kernel thread context (may sleep).
7278  */
7279 static void ata_port_detach(struct ata_port *ap)
7280 {
7281 	unsigned long flags;
7282 	struct ata_link *link;
7283 	struct ata_device *dev;
7284 
7285 	if (!ap->ops->error_handler)
7286 		goto skip_eh;
7287 
7288 	/* tell EH we're leaving & flush EH */
7289 	spin_lock_irqsave(ap->lock, flags);
7290 	ap->pflags |= ATA_PFLAG_UNLOADING;
7291 	spin_unlock_irqrestore(ap->lock, flags);
7292 
7293 	ata_port_wait_eh(ap);
7294 
7295 	/* EH is now guaranteed to see UNLOADING - EH context belongs
7296 	 * to us.  Disable all existing devices.
7297 	 */
7298 	ata_port_for_each_link(link, ap) {
7299 		ata_link_for_each_dev(dev, link)
7300 			ata_dev_disable(dev);
7301 	}
7302 
7303 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
7304 	 * will be skipped and retrials will be terminated with bad
7305 	 * target.
7306 	 */
7307 	spin_lock_irqsave(ap->lock, flags);
7308 	ata_port_freeze(ap);	/* won't be thawed */
7309 	spin_unlock_irqrestore(ap->lock, flags);
7310 
7311 	ata_port_wait_eh(ap);
7312 	cancel_rearming_delayed_work(&ap->hotplug_task);
7313 
7314  skip_eh:
7315 	/* remove the associated SCSI host */
7316 	scsi_remove_host(ap->scsi_host);
7317 }
7318 
7319 /**
7320  *	ata_host_detach - Detach all ports of an ATA host
7321  *	@host: Host to detach
7322  *
7323  *	Detach all ports of @host.
7324  *
7325  *	LOCKING:
7326  *	Kernel thread context (may sleep).
7327  */
7328 void ata_host_detach(struct ata_host *host)
7329 {
7330 	int i;
7331 
7332 	for (i = 0; i < host->n_ports; i++)
7333 		ata_port_detach(host->ports[i]);
7334 
7335 	/* the host is dead now, dissociate ACPI */
7336 	ata_acpi_dissociate(host);
7337 }
7338 
7339 /**
7340  *	ata_std_ports - initialize ioaddr with standard port offsets.
7341  *	@ioaddr: IO address structure to be initialized
7342  *
7343  *	Utility function which initializes data_addr, error_addr,
7344  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
7345  *	device_addr, status_addr, and command_addr to standard offsets
7346  *	relative to cmd_addr.
7347  *
7348  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
7349  */
7350 
7351 void ata_std_ports(struct ata_ioports *ioaddr)
7352 {
7353 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
7354 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
7355 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
7356 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
7357 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
7358 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
7359 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
7360 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
7361 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
7362 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
7363 }
7364 
7365 
7366 #ifdef CONFIG_PCI
7367 
7368 /**
7369  *	ata_pci_remove_one - PCI layer callback for device removal
7370  *	@pdev: PCI device that was removed
7371  *
7372  *	PCI layer indicates to libata via this hook that hot-unplug or
7373  *	module unload event has occurred.  Detach all ports.  Resource
7374  *	release is handled via devres.
7375  *
7376  *	LOCKING:
7377  *	Inherited from PCI layer (may sleep).
7378  */
7379 void ata_pci_remove_one(struct pci_dev *pdev)
7380 {
7381 	struct device *dev = &pdev->dev;
7382 	struct ata_host *host = dev_get_drvdata(dev);
7383 
7384 	ata_host_detach(host);
7385 }
7386 
7387 /* move to PCI subsystem */
7388 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
7389 {
7390 	unsigned long tmp = 0;
7391 
7392 	switch (bits->width) {
7393 	case 1: {
7394 		u8 tmp8 = 0;
7395 		pci_read_config_byte(pdev, bits->reg, &tmp8);
7396 		tmp = tmp8;
7397 		break;
7398 	}
7399 	case 2: {
7400 		u16 tmp16 = 0;
7401 		pci_read_config_word(pdev, bits->reg, &tmp16);
7402 		tmp = tmp16;
7403 		break;
7404 	}
7405 	case 4: {
7406 		u32 tmp32 = 0;
7407 		pci_read_config_dword(pdev, bits->reg, &tmp32);
7408 		tmp = tmp32;
7409 		break;
7410 	}
7411 
7412 	default:
7413 		return -EINVAL;
7414 	}
7415 
7416 	tmp &= bits->mask;
7417 
7418 	return (tmp == bits->val) ? 1 : 0;
7419 }
7420 
7421 #ifdef CONFIG_PM
7422 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
7423 {
7424 	pci_save_state(pdev);
7425 	pci_disable_device(pdev);
7426 
7427 	if (mesg.event & PM_EVENT_SLEEP)
7428 		pci_set_power_state(pdev, PCI_D3hot);
7429 }
7430 
7431 int ata_pci_device_do_resume(struct pci_dev *pdev)
7432 {
7433 	int rc;
7434 
7435 	pci_set_power_state(pdev, PCI_D0);
7436 	pci_restore_state(pdev);
7437 
7438 	rc = pcim_enable_device(pdev);
7439 	if (rc) {
7440 		dev_printk(KERN_ERR, &pdev->dev,
7441 			   "failed to enable device after resume (%d)\n", rc);
7442 		return rc;
7443 	}
7444 
7445 	pci_set_master(pdev);
7446 	return 0;
7447 }
7448 
7449 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
7450 {
7451 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7452 	int rc = 0;
7453 
7454 	rc = ata_host_suspend(host, mesg);
7455 	if (rc)
7456 		return rc;
7457 
7458 	ata_pci_device_do_suspend(pdev, mesg);
7459 
7460 	return 0;
7461 }
7462 
7463 int ata_pci_device_resume(struct pci_dev *pdev)
7464 {
7465 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7466 	int rc;
7467 
7468 	rc = ata_pci_device_do_resume(pdev);
7469 	if (rc == 0)
7470 		ata_host_resume(host);
7471 	return rc;
7472 }
7473 #endif /* CONFIG_PM */
7474 
7475 #endif /* CONFIG_PCI */
7476 
7477 static int __init ata_parse_force_one(char **cur,
7478 				      struct ata_force_ent *force_ent,
7479 				      const char **reason)
7480 {
7481 	/* FIXME: Currently, there's no way to tag init const data and
7482 	 * using __initdata causes build failure on some versions of
7483 	 * gcc.  Once __initdataconst is implemented, add const to the
7484 	 * following structure.
7485 	 */
7486 	static struct ata_force_param force_tbl[] __initdata = {
7487 		{ "40c",	.cbl		= ATA_CBL_PATA40 },
7488 		{ "80c",	.cbl		= ATA_CBL_PATA80 },
7489 		{ "short40c",	.cbl		= ATA_CBL_PATA40_SHORT },
7490 		{ "unk",	.cbl		= ATA_CBL_PATA_UNK },
7491 		{ "ign",	.cbl		= ATA_CBL_PATA_IGN },
7492 		{ "sata",	.cbl		= ATA_CBL_SATA },
7493 		{ "1.5Gbps",	.spd_limit	= 1 },
7494 		{ "3.0Gbps",	.spd_limit	= 2 },
7495 		{ "noncq",	.horkage_on	= ATA_HORKAGE_NONCQ },
7496 		{ "ncq",	.horkage_off	= ATA_HORKAGE_NONCQ },
7497 		{ "pio0",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 0) },
7498 		{ "pio1",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 1) },
7499 		{ "pio2",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 2) },
7500 		{ "pio3",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 3) },
7501 		{ "pio4",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 4) },
7502 		{ "pio5",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 5) },
7503 		{ "pio6",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 6) },
7504 		{ "mwdma0",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 0) },
7505 		{ "mwdma1",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 1) },
7506 		{ "mwdma2",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 2) },
7507 		{ "mwdma3",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 3) },
7508 		{ "mwdma4",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 4) },
7509 		{ "udma0",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
7510 		{ "udma16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
7511 		{ "udma/16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
7512 		{ "udma1",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
7513 		{ "udma25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
7514 		{ "udma/25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
7515 		{ "udma2",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
7516 		{ "udma33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
7517 		{ "udma/33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
7518 		{ "udma3",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
7519 		{ "udma44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
7520 		{ "udma/44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
7521 		{ "udma4",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
7522 		{ "udma66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
7523 		{ "udma/66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
7524 		{ "udma5",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
7525 		{ "udma100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
7526 		{ "udma/100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
7527 		{ "udma6",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
7528 		{ "udma133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
7529 		{ "udma/133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
7530 		{ "udma7",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 7) },
7531 	};
7532 	char *start = *cur, *p = *cur;
7533 	char *id, *val, *endp;
7534 	const struct ata_force_param *match_fp = NULL;
7535 	int nr_matches = 0, i;
7536 
7537 	/* find where this param ends and update *cur */
7538 	while (*p != '\0' && *p != ',')
7539 		p++;
7540 
7541 	if (*p == '\0')
7542 		*cur = p;
7543 	else
7544 		*cur = p + 1;
7545 
7546 	*p = '\0';
7547 
7548 	/* parse */
7549 	p = strchr(start, ':');
7550 	if (!p) {
7551 		val = strstrip(start);
7552 		goto parse_val;
7553 	}
7554 	*p = '\0';
7555 
7556 	id = strstrip(start);
7557 	val = strstrip(p + 1);
7558 
7559 	/* parse id */
7560 	p = strchr(id, '.');
7561 	if (p) {
7562 		*p++ = '\0';
7563 		force_ent->device = simple_strtoul(p, &endp, 10);
7564 		if (p == endp || *endp != '\0') {
7565 			*reason = "invalid device";
7566 			return -EINVAL;
7567 		}
7568 	}
7569 
7570 	force_ent->port = simple_strtoul(id, &endp, 10);
7571 	if (p == endp || *endp != '\0') {
7572 		*reason = "invalid port/link";
7573 		return -EINVAL;
7574 	}
7575 
7576  parse_val:
7577 	/* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
7578 	for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
7579 		const struct ata_force_param *fp = &force_tbl[i];
7580 
7581 		if (strncasecmp(val, fp->name, strlen(val)))
7582 			continue;
7583 
7584 		nr_matches++;
7585 		match_fp = fp;
7586 
7587 		if (strcasecmp(val, fp->name) == 0) {
7588 			nr_matches = 1;
7589 			break;
7590 		}
7591 	}
7592 
7593 	if (!nr_matches) {
7594 		*reason = "unknown value";
7595 		return -EINVAL;
7596 	}
7597 	if (nr_matches > 1) {
7598 		*reason = "ambigious value";
7599 		return -EINVAL;
7600 	}
7601 
7602 	force_ent->param = *match_fp;
7603 
7604 	return 0;
7605 }
7606 
7607 static void __init ata_parse_force_param(void)
7608 {
7609 	int idx = 0, size = 1;
7610 	int last_port = -1, last_device = -1;
7611 	char *p, *cur, *next;
7612 
7613 	/* calculate maximum number of params and allocate force_tbl */
7614 	for (p = ata_force_param_buf; *p; p++)
7615 		if (*p == ',')
7616 			size++;
7617 
7618 	ata_force_tbl = kzalloc(sizeof(ata_force_tbl[0]) * size, GFP_KERNEL);
7619 	if (!ata_force_tbl) {
7620 		printk(KERN_WARNING "ata: failed to extend force table, "
7621 		       "libata.force ignored\n");
7622 		return;
7623 	}
7624 
7625 	/* parse and populate the table */
7626 	for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
7627 		const char *reason = "";
7628 		struct ata_force_ent te = { .port = -1, .device = -1 };
7629 
7630 		next = cur;
7631 		if (ata_parse_force_one(&next, &te, &reason)) {
7632 			printk(KERN_WARNING "ata: failed to parse force "
7633 			       "parameter \"%s\" (%s)\n",
7634 			       cur, reason);
7635 			continue;
7636 		}
7637 
7638 		if (te.port == -1) {
7639 			te.port = last_port;
7640 			te.device = last_device;
7641 		}
7642 
7643 		ata_force_tbl[idx++] = te;
7644 
7645 		last_port = te.port;
7646 		last_device = te.device;
7647 	}
7648 
7649 	ata_force_tbl_size = idx;
7650 }
7651 
7652 static int __init ata_init(void)
7653 {
7654 	ata_probe_timeout *= HZ;
7655 
7656 	ata_parse_force_param();
7657 
7658 	ata_wq = create_workqueue("ata");
7659 	if (!ata_wq)
7660 		return -ENOMEM;
7661 
7662 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
7663 	if (!ata_aux_wq) {
7664 		destroy_workqueue(ata_wq);
7665 		return -ENOMEM;
7666 	}
7667 
7668 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
7669 	return 0;
7670 }
7671 
7672 static void __exit ata_exit(void)
7673 {
7674 	kfree(ata_force_tbl);
7675 	destroy_workqueue(ata_wq);
7676 	destroy_workqueue(ata_aux_wq);
7677 }
7678 
7679 subsys_initcall(ata_init);
7680 module_exit(ata_exit);
7681 
7682 static unsigned long ratelimit_time;
7683 static DEFINE_SPINLOCK(ata_ratelimit_lock);
7684 
7685 int ata_ratelimit(void)
7686 {
7687 	int rc;
7688 	unsigned long flags;
7689 
7690 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
7691 
7692 	if (time_after(jiffies, ratelimit_time)) {
7693 		rc = 1;
7694 		ratelimit_time = jiffies + (HZ/5);
7695 	} else
7696 		rc = 0;
7697 
7698 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
7699 
7700 	return rc;
7701 }
7702 
7703 /**
7704  *	ata_wait_register - wait until register value changes
7705  *	@reg: IO-mapped register
7706  *	@mask: Mask to apply to read register value
7707  *	@val: Wait condition
7708  *	@interval_msec: polling interval in milliseconds
7709  *	@timeout_msec: timeout in milliseconds
7710  *
7711  *	Waiting for some bits of register to change is a common
7712  *	operation for ATA controllers.  This function reads 32bit LE
7713  *	IO-mapped register @reg and tests for the following condition.
7714  *
7715  *	(*@reg & mask) != val
7716  *
7717  *	If the condition is met, it returns; otherwise, the process is
7718  *	repeated after @interval_msec until timeout.
7719  *
7720  *	LOCKING:
7721  *	Kernel thread context (may sleep)
7722  *
7723  *	RETURNS:
7724  *	The final register value.
7725  */
7726 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
7727 		      unsigned long interval_msec,
7728 		      unsigned long timeout_msec)
7729 {
7730 	unsigned long timeout;
7731 	u32 tmp;
7732 
7733 	tmp = ioread32(reg);
7734 
7735 	/* Calculate timeout _after_ the first read to make sure
7736 	 * preceding writes reach the controller before starting to
7737 	 * eat away the timeout.
7738 	 */
7739 	timeout = jiffies + (timeout_msec * HZ) / 1000;
7740 
7741 	while ((tmp & mask) == val && time_before(jiffies, timeout)) {
7742 		msleep(interval_msec);
7743 		tmp = ioread32(reg);
7744 	}
7745 
7746 	return tmp;
7747 }
7748 
7749 /*
7750  * Dummy port_ops
7751  */
7752 static void ata_dummy_noret(struct ata_port *ap)	{ }
7753 static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
7754 static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
7755 
7756 static u8 ata_dummy_check_status(struct ata_port *ap)
7757 {
7758 	return ATA_DRDY;
7759 }
7760 
7761 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
7762 {
7763 	return AC_ERR_SYSTEM;
7764 }
7765 
7766 const struct ata_port_operations ata_dummy_port_ops = {
7767 	.check_status		= ata_dummy_check_status,
7768 	.check_altstatus	= ata_dummy_check_status,
7769 	.dev_select		= ata_noop_dev_select,
7770 	.qc_prep		= ata_noop_qc_prep,
7771 	.qc_issue		= ata_dummy_qc_issue,
7772 	.freeze			= ata_dummy_noret,
7773 	.thaw			= ata_dummy_noret,
7774 	.error_handler		= ata_dummy_noret,
7775 	.post_internal_cmd	= ata_dummy_qc_noret,
7776 	.irq_clear		= ata_dummy_noret,
7777 	.port_start		= ata_dummy_ret0,
7778 	.port_stop		= ata_dummy_noret,
7779 };
7780 
7781 const struct ata_port_info ata_dummy_port_info = {
7782 	.port_ops		= &ata_dummy_port_ops,
7783 };
7784 
7785 /*
7786  * libata is essentially a library of internal helper functions for
7787  * low-level ATA host controller drivers.  As such, the API/ABI is
7788  * likely to change as new drivers are added and updated.
7789  * Do not depend on ABI/API stability.
7790  */
7791 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
7792 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
7793 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
7794 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
7795 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
7796 EXPORT_SYMBOL_GPL(ata_std_bios_param);
7797 EXPORT_SYMBOL_GPL(ata_std_ports);
7798 EXPORT_SYMBOL_GPL(ata_host_init);
7799 EXPORT_SYMBOL_GPL(ata_host_alloc);
7800 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
7801 EXPORT_SYMBOL_GPL(ata_host_start);
7802 EXPORT_SYMBOL_GPL(ata_host_register);
7803 EXPORT_SYMBOL_GPL(ata_host_activate);
7804 EXPORT_SYMBOL_GPL(ata_host_detach);
7805 EXPORT_SYMBOL_GPL(ata_sg_init);
7806 EXPORT_SYMBOL_GPL(ata_hsm_move);
7807 EXPORT_SYMBOL_GPL(ata_qc_complete);
7808 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
7809 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
7810 EXPORT_SYMBOL_GPL(ata_tf_load);
7811 EXPORT_SYMBOL_GPL(ata_tf_read);
7812 EXPORT_SYMBOL_GPL(ata_noop_dev_select);
7813 EXPORT_SYMBOL_GPL(ata_std_dev_select);
7814 EXPORT_SYMBOL_GPL(sata_print_link_status);
7815 EXPORT_SYMBOL_GPL(atapi_cmd_type);
7816 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
7817 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
7818 EXPORT_SYMBOL_GPL(ata_pack_xfermask);
7819 EXPORT_SYMBOL_GPL(ata_unpack_xfermask);
7820 EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
7821 EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
7822 EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
7823 EXPORT_SYMBOL_GPL(ata_mode_string);
7824 EXPORT_SYMBOL_GPL(ata_id_xfermask);
7825 EXPORT_SYMBOL_GPL(ata_check_status);
7826 EXPORT_SYMBOL_GPL(ata_altstatus);
7827 EXPORT_SYMBOL_GPL(ata_exec_command);
7828 EXPORT_SYMBOL_GPL(ata_port_start);
7829 EXPORT_SYMBOL_GPL(ata_sff_port_start);
7830 EXPORT_SYMBOL_GPL(ata_interrupt);
7831 EXPORT_SYMBOL_GPL(ata_do_set_mode);
7832 EXPORT_SYMBOL_GPL(ata_data_xfer);
7833 EXPORT_SYMBOL_GPL(ata_data_xfer_noirq);
7834 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
7835 EXPORT_SYMBOL_GPL(ata_qc_prep);
7836 EXPORT_SYMBOL_GPL(ata_dumb_qc_prep);
7837 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
7838 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
7839 EXPORT_SYMBOL_GPL(ata_bmdma_start);
7840 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
7841 EXPORT_SYMBOL_GPL(ata_bmdma_status);
7842 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
7843 EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
7844 EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
7845 EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
7846 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
7847 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
7848 EXPORT_SYMBOL_GPL(ata_port_probe);
7849 EXPORT_SYMBOL_GPL(ata_dev_disable);
7850 EXPORT_SYMBOL_GPL(sata_set_spd);
7851 EXPORT_SYMBOL_GPL(sata_link_debounce);
7852 EXPORT_SYMBOL_GPL(sata_link_resume);
7853 EXPORT_SYMBOL_GPL(ata_bus_reset);
7854 EXPORT_SYMBOL_GPL(ata_std_prereset);
7855 EXPORT_SYMBOL_GPL(ata_std_softreset);
7856 EXPORT_SYMBOL_GPL(sata_link_hardreset);
7857 EXPORT_SYMBOL_GPL(sata_std_hardreset);
7858 EXPORT_SYMBOL_GPL(ata_std_postreset);
7859 EXPORT_SYMBOL_GPL(ata_dev_classify);
7860 EXPORT_SYMBOL_GPL(ata_dev_pair);
7861 EXPORT_SYMBOL_GPL(ata_port_disable);
7862 EXPORT_SYMBOL_GPL(ata_ratelimit);
7863 EXPORT_SYMBOL_GPL(ata_wait_register);
7864 EXPORT_SYMBOL_GPL(ata_busy_sleep);
7865 EXPORT_SYMBOL_GPL(ata_wait_after_reset);
7866 EXPORT_SYMBOL_GPL(ata_wait_ready);
7867 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
7868 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
7869 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
7870 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
7871 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
7872 EXPORT_SYMBOL_GPL(ata_host_intr);
7873 EXPORT_SYMBOL_GPL(sata_scr_valid);
7874 EXPORT_SYMBOL_GPL(sata_scr_read);
7875 EXPORT_SYMBOL_GPL(sata_scr_write);
7876 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
7877 EXPORT_SYMBOL_GPL(ata_link_online);
7878 EXPORT_SYMBOL_GPL(ata_link_offline);
7879 #ifdef CONFIG_PM
7880 EXPORT_SYMBOL_GPL(ata_host_suspend);
7881 EXPORT_SYMBOL_GPL(ata_host_resume);
7882 #endif /* CONFIG_PM */
7883 EXPORT_SYMBOL_GPL(ata_id_string);
7884 EXPORT_SYMBOL_GPL(ata_id_c_string);
7885 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
7886 
7887 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
7888 EXPORT_SYMBOL_GPL(ata_timing_find_mode);
7889 EXPORT_SYMBOL_GPL(ata_timing_compute);
7890 EXPORT_SYMBOL_GPL(ata_timing_merge);
7891 EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);
7892 
7893 #ifdef CONFIG_PCI
7894 EXPORT_SYMBOL_GPL(pci_test_config_bits);
7895 EXPORT_SYMBOL_GPL(ata_pci_init_sff_host);
7896 EXPORT_SYMBOL_GPL(ata_pci_init_bmdma);
7897 EXPORT_SYMBOL_GPL(ata_pci_prepare_sff_host);
7898 EXPORT_SYMBOL_GPL(ata_pci_activate_sff_host);
7899 EXPORT_SYMBOL_GPL(ata_pci_init_one);
7900 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
7901 #ifdef CONFIG_PM
7902 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
7903 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
7904 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
7905 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
7906 #endif /* CONFIG_PM */
7907 EXPORT_SYMBOL_GPL(ata_pci_default_filter);
7908 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
7909 #endif /* CONFIG_PCI */
7910 
7911 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
7912 EXPORT_SYMBOL_GPL(sata_pmp_std_prereset);
7913 EXPORT_SYMBOL_GPL(sata_pmp_std_hardreset);
7914 EXPORT_SYMBOL_GPL(sata_pmp_std_postreset);
7915 EXPORT_SYMBOL_GPL(sata_pmp_do_eh);
7916 
7917 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
7918 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
7919 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
7920 EXPORT_SYMBOL_GPL(ata_port_desc);
7921 #ifdef CONFIG_PCI
7922 EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
7923 #endif /* CONFIG_PCI */
7924 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
7925 EXPORT_SYMBOL_GPL(ata_link_abort);
7926 EXPORT_SYMBOL_GPL(ata_port_abort);
7927 EXPORT_SYMBOL_GPL(ata_port_freeze);
7928 EXPORT_SYMBOL_GPL(sata_async_notification);
7929 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
7930 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
7931 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
7932 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
7933 EXPORT_SYMBOL_GPL(ata_do_eh);
7934 EXPORT_SYMBOL_GPL(ata_irq_on);
7935 EXPORT_SYMBOL_GPL(ata_dev_try_classify);
7936 
7937 EXPORT_SYMBOL_GPL(ata_cable_40wire);
7938 EXPORT_SYMBOL_GPL(ata_cable_80wire);
7939 EXPORT_SYMBOL_GPL(ata_cable_unknown);
7940 EXPORT_SYMBOL_GPL(ata_cable_ignore);
7941 EXPORT_SYMBOL_GPL(ata_cable_sata);
7942