xref: /linux/drivers/ata/libata-core.c (revision 40efcb05f213180b7cc8fd8d963377305f236c28)
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 int atapi_enabled = 1;
91 module_param(atapi_enabled, int, 0444);
92 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
93 
94 int atapi_dmadir = 0;
95 module_param(atapi_dmadir, int, 0444);
96 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
97 
98 int atapi_passthru16 = 1;
99 module_param(atapi_passthru16, int, 0444);
100 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices; on by default (0=off, 1=on)");
101 
102 int libata_fua = 0;
103 module_param_named(fua, libata_fua, int, 0444);
104 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
105 
106 static int ata_ignore_hpa;
107 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
108 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
109 
110 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
111 module_param_named(dma, libata_dma_mask, int, 0444);
112 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
113 
114 static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
115 module_param(ata_probe_timeout, int, 0444);
116 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
117 
118 int libata_noacpi = 0;
119 module_param_named(noacpi, libata_noacpi, int, 0444);
120 MODULE_PARM_DESC(noacpi, "Disables the use of ACPI in probe/suspend/resume when set");
121 
122 MODULE_AUTHOR("Jeff Garzik");
123 MODULE_DESCRIPTION("Library module for ATA devices");
124 MODULE_LICENSE("GPL");
125 MODULE_VERSION(DRV_VERSION);
126 
127 
128 /**
129  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
130  *	@tf: Taskfile to convert
131  *	@pmp: Port multiplier port
132  *	@is_cmd: This FIS is for command
133  *	@fis: Buffer into which data will output
134  *
135  *	Converts a standard ATA taskfile to a Serial ATA
136  *	FIS structure (Register - Host to Device).
137  *
138  *	LOCKING:
139  *	Inherited from caller.
140  */
141 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
142 {
143 	fis[0] = 0x27;			/* Register - Host to Device FIS */
144 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
145 	if (is_cmd)
146 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
147 
148 	fis[2] = tf->command;
149 	fis[3] = tf->feature;
150 
151 	fis[4] = tf->lbal;
152 	fis[5] = tf->lbam;
153 	fis[6] = tf->lbah;
154 	fis[7] = tf->device;
155 
156 	fis[8] = tf->hob_lbal;
157 	fis[9] = tf->hob_lbam;
158 	fis[10] = tf->hob_lbah;
159 	fis[11] = tf->hob_feature;
160 
161 	fis[12] = tf->nsect;
162 	fis[13] = tf->hob_nsect;
163 	fis[14] = 0;
164 	fis[15] = tf->ctl;
165 
166 	fis[16] = 0;
167 	fis[17] = 0;
168 	fis[18] = 0;
169 	fis[19] = 0;
170 }
171 
172 /**
173  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
174  *	@fis: Buffer from which data will be input
175  *	@tf: Taskfile to output
176  *
177  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
178  *
179  *	LOCKING:
180  *	Inherited from caller.
181  */
182 
183 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
184 {
185 	tf->command	= fis[2];	/* status */
186 	tf->feature	= fis[3];	/* error */
187 
188 	tf->lbal	= fis[4];
189 	tf->lbam	= fis[5];
190 	tf->lbah	= fis[6];
191 	tf->device	= fis[7];
192 
193 	tf->hob_lbal	= fis[8];
194 	tf->hob_lbam	= fis[9];
195 	tf->hob_lbah	= fis[10];
196 
197 	tf->nsect	= fis[12];
198 	tf->hob_nsect	= fis[13];
199 }
200 
201 static const u8 ata_rw_cmds[] = {
202 	/* pio multi */
203 	ATA_CMD_READ_MULTI,
204 	ATA_CMD_WRITE_MULTI,
205 	ATA_CMD_READ_MULTI_EXT,
206 	ATA_CMD_WRITE_MULTI_EXT,
207 	0,
208 	0,
209 	0,
210 	ATA_CMD_WRITE_MULTI_FUA_EXT,
211 	/* pio */
212 	ATA_CMD_PIO_READ,
213 	ATA_CMD_PIO_WRITE,
214 	ATA_CMD_PIO_READ_EXT,
215 	ATA_CMD_PIO_WRITE_EXT,
216 	0,
217 	0,
218 	0,
219 	0,
220 	/* dma */
221 	ATA_CMD_READ,
222 	ATA_CMD_WRITE,
223 	ATA_CMD_READ_EXT,
224 	ATA_CMD_WRITE_EXT,
225 	0,
226 	0,
227 	0,
228 	ATA_CMD_WRITE_FUA_EXT
229 };
230 
231 /**
232  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
233  *	@tf: command to examine and configure
234  *	@dev: device tf belongs to
235  *
236  *	Examine the device configuration and tf->flags to calculate
237  *	the proper read/write commands and protocol to use.
238  *
239  *	LOCKING:
240  *	caller.
241  */
242 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
243 {
244 	u8 cmd;
245 
246 	int index, fua, lba48, write;
247 
248 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
249 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
250 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
251 
252 	if (dev->flags & ATA_DFLAG_PIO) {
253 		tf->protocol = ATA_PROT_PIO;
254 		index = dev->multi_count ? 0 : 8;
255 	} else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
256 		/* Unable to use DMA due to host limitation */
257 		tf->protocol = ATA_PROT_PIO;
258 		index = dev->multi_count ? 0 : 8;
259 	} else {
260 		tf->protocol = ATA_PROT_DMA;
261 		index = 16;
262 	}
263 
264 	cmd = ata_rw_cmds[index + fua + lba48 + write];
265 	if (cmd) {
266 		tf->command = cmd;
267 		return 0;
268 	}
269 	return -1;
270 }
271 
272 /**
273  *	ata_tf_read_block - Read block address from ATA taskfile
274  *	@tf: ATA taskfile of interest
275  *	@dev: ATA device @tf belongs to
276  *
277  *	LOCKING:
278  *	None.
279  *
280  *	Read block address from @tf.  This function can handle all
281  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
282  *	flags select the address format to use.
283  *
284  *	RETURNS:
285  *	Block address read from @tf.
286  */
287 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
288 {
289 	u64 block = 0;
290 
291 	if (tf->flags & ATA_TFLAG_LBA) {
292 		if (tf->flags & ATA_TFLAG_LBA48) {
293 			block |= (u64)tf->hob_lbah << 40;
294 			block |= (u64)tf->hob_lbam << 32;
295 			block |= tf->hob_lbal << 24;
296 		} else
297 			block |= (tf->device & 0xf) << 24;
298 
299 		block |= tf->lbah << 16;
300 		block |= tf->lbam << 8;
301 		block |= tf->lbal;
302 	} else {
303 		u32 cyl, head, sect;
304 
305 		cyl = tf->lbam | (tf->lbah << 8);
306 		head = tf->device & 0xf;
307 		sect = tf->lbal;
308 
309 		block = (cyl * dev->heads + head) * dev->sectors + sect;
310 	}
311 
312 	return block;
313 }
314 
315 /**
316  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
317  *	@tf: Target ATA taskfile
318  *	@dev: ATA device @tf belongs to
319  *	@block: Block address
320  *	@n_block: Number of blocks
321  *	@tf_flags: RW/FUA etc...
322  *	@tag: tag
323  *
324  *	LOCKING:
325  *	None.
326  *
327  *	Build ATA taskfile @tf for read/write request described by
328  *	@block, @n_block, @tf_flags and @tag on @dev.
329  *
330  *	RETURNS:
331  *
332  *	0 on success, -ERANGE if the request is too large for @dev,
333  *	-EINVAL if the request is invalid.
334  */
335 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
336 		    u64 block, u32 n_block, unsigned int tf_flags,
337 		    unsigned int tag)
338 {
339 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
340 	tf->flags |= tf_flags;
341 
342 	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
343 		/* yay, NCQ */
344 		if (!lba_48_ok(block, n_block))
345 			return -ERANGE;
346 
347 		tf->protocol = ATA_PROT_NCQ;
348 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
349 
350 		if (tf->flags & ATA_TFLAG_WRITE)
351 			tf->command = ATA_CMD_FPDMA_WRITE;
352 		else
353 			tf->command = ATA_CMD_FPDMA_READ;
354 
355 		tf->nsect = tag << 3;
356 		tf->hob_feature = (n_block >> 8) & 0xff;
357 		tf->feature = n_block & 0xff;
358 
359 		tf->hob_lbah = (block >> 40) & 0xff;
360 		tf->hob_lbam = (block >> 32) & 0xff;
361 		tf->hob_lbal = (block >> 24) & 0xff;
362 		tf->lbah = (block >> 16) & 0xff;
363 		tf->lbam = (block >> 8) & 0xff;
364 		tf->lbal = block & 0xff;
365 
366 		tf->device = 1 << 6;
367 		if (tf->flags & ATA_TFLAG_FUA)
368 			tf->device |= 1 << 7;
369 	} else if (dev->flags & ATA_DFLAG_LBA) {
370 		tf->flags |= ATA_TFLAG_LBA;
371 
372 		if (lba_28_ok(block, n_block)) {
373 			/* use LBA28 */
374 			tf->device |= (block >> 24) & 0xf;
375 		} else if (lba_48_ok(block, n_block)) {
376 			if (!(dev->flags & ATA_DFLAG_LBA48))
377 				return -ERANGE;
378 
379 			/* use LBA48 */
380 			tf->flags |= ATA_TFLAG_LBA48;
381 
382 			tf->hob_nsect = (n_block >> 8) & 0xff;
383 
384 			tf->hob_lbah = (block >> 40) & 0xff;
385 			tf->hob_lbam = (block >> 32) & 0xff;
386 			tf->hob_lbal = (block >> 24) & 0xff;
387 		} else
388 			/* request too large even for LBA48 */
389 			return -ERANGE;
390 
391 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
392 			return -EINVAL;
393 
394 		tf->nsect = n_block & 0xff;
395 
396 		tf->lbah = (block >> 16) & 0xff;
397 		tf->lbam = (block >> 8) & 0xff;
398 		tf->lbal = block & 0xff;
399 
400 		tf->device |= ATA_LBA;
401 	} else {
402 		/* CHS */
403 		u32 sect, head, cyl, track;
404 
405 		/* The request -may- be too large for CHS addressing. */
406 		if (!lba_28_ok(block, n_block))
407 			return -ERANGE;
408 
409 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
410 			return -EINVAL;
411 
412 		/* Convert LBA to CHS */
413 		track = (u32)block / dev->sectors;
414 		cyl   = track / dev->heads;
415 		head  = track % dev->heads;
416 		sect  = (u32)block % dev->sectors + 1;
417 
418 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
419 			(u32)block, track, cyl, head, sect);
420 
421 		/* Check whether the converted CHS can fit.
422 		   Cylinder: 0-65535
423 		   Head: 0-15
424 		   Sector: 1-255*/
425 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
426 			return -ERANGE;
427 
428 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
429 		tf->lbal = sect;
430 		tf->lbam = cyl;
431 		tf->lbah = cyl >> 8;
432 		tf->device |= head;
433 	}
434 
435 	return 0;
436 }
437 
438 /**
439  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
440  *	@pio_mask: pio_mask
441  *	@mwdma_mask: mwdma_mask
442  *	@udma_mask: udma_mask
443  *
444  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
445  *	unsigned int xfer_mask.
446  *
447  *	LOCKING:
448  *	None.
449  *
450  *	RETURNS:
451  *	Packed xfer_mask.
452  */
453 static unsigned int ata_pack_xfermask(unsigned int pio_mask,
454 				      unsigned int mwdma_mask,
455 				      unsigned int udma_mask)
456 {
457 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
458 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
459 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
460 }
461 
462 /**
463  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
464  *	@xfer_mask: xfer_mask to unpack
465  *	@pio_mask: resulting pio_mask
466  *	@mwdma_mask: resulting mwdma_mask
467  *	@udma_mask: resulting udma_mask
468  *
469  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
470  *	Any NULL distination masks will be ignored.
471  */
472 static void ata_unpack_xfermask(unsigned int xfer_mask,
473 				unsigned int *pio_mask,
474 				unsigned int *mwdma_mask,
475 				unsigned int *udma_mask)
476 {
477 	if (pio_mask)
478 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
479 	if (mwdma_mask)
480 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
481 	if (udma_mask)
482 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
483 }
484 
485 static const struct ata_xfer_ent {
486 	int shift, bits;
487 	u8 base;
488 } ata_xfer_tbl[] = {
489 	{ ATA_SHIFT_PIO, ATA_BITS_PIO, XFER_PIO_0 },
490 	{ ATA_SHIFT_MWDMA, ATA_BITS_MWDMA, XFER_MW_DMA_0 },
491 	{ ATA_SHIFT_UDMA, ATA_BITS_UDMA, XFER_UDMA_0 },
492 	{ -1, },
493 };
494 
495 /**
496  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
497  *	@xfer_mask: xfer_mask of interest
498  *
499  *	Return matching XFER_* value for @xfer_mask.  Only the highest
500  *	bit of @xfer_mask is considered.
501  *
502  *	LOCKING:
503  *	None.
504  *
505  *	RETURNS:
506  *	Matching XFER_* value, 0 if no match found.
507  */
508 static u8 ata_xfer_mask2mode(unsigned int xfer_mask)
509 {
510 	int highbit = fls(xfer_mask) - 1;
511 	const struct ata_xfer_ent *ent;
512 
513 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
514 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
515 			return ent->base + highbit - ent->shift;
516 	return 0;
517 }
518 
519 /**
520  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
521  *	@xfer_mode: XFER_* of interest
522  *
523  *	Return matching xfer_mask for @xfer_mode.
524  *
525  *	LOCKING:
526  *	None.
527  *
528  *	RETURNS:
529  *	Matching xfer_mask, 0 if no match found.
530  */
531 static unsigned int ata_xfer_mode2mask(u8 xfer_mode)
532 {
533 	const struct ata_xfer_ent *ent;
534 
535 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
536 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
537 			return 1 << (ent->shift + xfer_mode - ent->base);
538 	return 0;
539 }
540 
541 /**
542  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
543  *	@xfer_mode: XFER_* of interest
544  *
545  *	Return matching xfer_shift for @xfer_mode.
546  *
547  *	LOCKING:
548  *	None.
549  *
550  *	RETURNS:
551  *	Matching xfer_shift, -1 if no match found.
552  */
553 static int ata_xfer_mode2shift(unsigned int xfer_mode)
554 {
555 	const struct ata_xfer_ent *ent;
556 
557 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
558 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
559 			return ent->shift;
560 	return -1;
561 }
562 
563 /**
564  *	ata_mode_string - convert xfer_mask to string
565  *	@xfer_mask: mask of bits supported; only highest bit counts.
566  *
567  *	Determine string which represents the highest speed
568  *	(highest bit in @modemask).
569  *
570  *	LOCKING:
571  *	None.
572  *
573  *	RETURNS:
574  *	Constant C string representing highest speed listed in
575  *	@mode_mask, or the constant C string "<n/a>".
576  */
577 static const char *ata_mode_string(unsigned int xfer_mask)
578 {
579 	static const char * const xfer_mode_str[] = {
580 		"PIO0",
581 		"PIO1",
582 		"PIO2",
583 		"PIO3",
584 		"PIO4",
585 		"PIO5",
586 		"PIO6",
587 		"MWDMA0",
588 		"MWDMA1",
589 		"MWDMA2",
590 		"MWDMA3",
591 		"MWDMA4",
592 		"UDMA/16",
593 		"UDMA/25",
594 		"UDMA/33",
595 		"UDMA/44",
596 		"UDMA/66",
597 		"UDMA/100",
598 		"UDMA/133",
599 		"UDMA7",
600 	};
601 	int highbit;
602 
603 	highbit = fls(xfer_mask) - 1;
604 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
605 		return xfer_mode_str[highbit];
606 	return "<n/a>";
607 }
608 
609 static const char *sata_spd_string(unsigned int spd)
610 {
611 	static const char * const spd_str[] = {
612 		"1.5 Gbps",
613 		"3.0 Gbps",
614 	};
615 
616 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
617 		return "<unknown>";
618 	return spd_str[spd - 1];
619 }
620 
621 void ata_dev_disable(struct ata_device *dev)
622 {
623 	if (ata_dev_enabled(dev)) {
624 		if (ata_msg_drv(dev->link->ap))
625 			ata_dev_printk(dev, KERN_WARNING, "disabled\n");
626 		ata_acpi_on_disable(dev);
627 		ata_down_xfermask_limit(dev, ATA_DNXFER_FORCE_PIO0 |
628 					     ATA_DNXFER_QUIET);
629 		dev->class++;
630 	}
631 }
632 
633 static int ata_dev_set_dipm(struct ata_device *dev, enum link_pm policy)
634 {
635 	struct ata_link *link = dev->link;
636 	struct ata_port *ap = link->ap;
637 	u32 scontrol;
638 	unsigned int err_mask;
639 	int rc;
640 
641 	/*
642 	 * disallow DIPM for drivers which haven't set
643 	 * ATA_FLAG_IPM.  This is because when DIPM is enabled,
644 	 * phy ready will be set in the interrupt status on
645 	 * state changes, which will cause some drivers to
646 	 * think there are errors - additionally drivers will
647 	 * need to disable hot plug.
648 	 */
649 	if (!(ap->flags & ATA_FLAG_IPM) || !ata_dev_enabled(dev)) {
650 		ap->pm_policy = NOT_AVAILABLE;
651 		return -EINVAL;
652 	}
653 
654 	/*
655 	 * For DIPM, we will only enable it for the
656 	 * min_power setting.
657 	 *
658 	 * Why?  Because Disks are too stupid to know that
659 	 * If the host rejects a request to go to SLUMBER
660 	 * they should retry at PARTIAL, and instead it
661 	 * just would give up.  So, for medium_power to
662 	 * work at all, we need to only allow HIPM.
663 	 */
664 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
665 	if (rc)
666 		return rc;
667 
668 	switch (policy) {
669 	case MIN_POWER:
670 		/* no restrictions on IPM transitions */
671 		scontrol &= ~(0x3 << 8);
672 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
673 		if (rc)
674 			return rc;
675 
676 		/* enable DIPM */
677 		if (dev->flags & ATA_DFLAG_DIPM)
678 			err_mask = ata_dev_set_feature(dev,
679 					SETFEATURES_SATA_ENABLE, SATA_DIPM);
680 		break;
681 	case MEDIUM_POWER:
682 		/* allow IPM to PARTIAL */
683 		scontrol &= ~(0x1 << 8);
684 		scontrol |= (0x2 << 8);
685 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
686 		if (rc)
687 			return rc;
688 
689 		/*
690 		 * we don't have to disable DIPM since IPM flags
691 		 * disallow transitions to SLUMBER, which effectively
692 		 * disable DIPM if it does not support PARTIAL
693 		 */
694 		break;
695 	case NOT_AVAILABLE:
696 	case MAX_PERFORMANCE:
697 		/* disable all IPM transitions */
698 		scontrol |= (0x3 << 8);
699 		rc = sata_scr_write(link, SCR_CONTROL, scontrol);
700 		if (rc)
701 			return rc;
702 
703 		/*
704 		 * we don't have to disable DIPM since IPM flags
705 		 * disallow all transitions which effectively
706 		 * disable DIPM anyway.
707 		 */
708 		break;
709 	}
710 
711 	/* FIXME: handle SET FEATURES failure */
712 	(void) err_mask;
713 
714 	return 0;
715 }
716 
717 /**
718  *	ata_dev_enable_pm - enable SATA interface power management
719  *	@dev:  device to enable power management
720  *	@policy: the link power management policy
721  *
722  *	Enable SATA Interface power management.  This will enable
723  *	Device Interface Power Management (DIPM) for min_power
724  * 	policy, and then call driver specific callbacks for
725  *	enabling Host Initiated Power management.
726  *
727  *	Locking: Caller.
728  *	Returns: -EINVAL if IPM is not supported, 0 otherwise.
729  */
730 void ata_dev_enable_pm(struct ata_device *dev, enum link_pm policy)
731 {
732 	int rc = 0;
733 	struct ata_port *ap = dev->link->ap;
734 
735 	/* set HIPM first, then DIPM */
736 	if (ap->ops->enable_pm)
737 		rc = ap->ops->enable_pm(ap, policy);
738 	if (rc)
739 		goto enable_pm_out;
740 	rc = ata_dev_set_dipm(dev, policy);
741 
742 enable_pm_out:
743 	if (rc)
744 		ap->pm_policy = MAX_PERFORMANCE;
745 	else
746 		ap->pm_policy = policy;
747 	return /* rc */;	/* hopefully we can use 'rc' eventually */
748 }
749 
750 #ifdef CONFIG_PM
751 /**
752  *	ata_dev_disable_pm - disable SATA interface power management
753  *	@dev: device to disable power management
754  *
755  *	Disable SATA Interface power management.  This will disable
756  *	Device Interface Power Management (DIPM) without changing
757  * 	policy,  call driver specific callbacks for disabling Host
758  * 	Initiated Power management.
759  *
760  *	Locking: Caller.
761  *	Returns: void
762  */
763 static void ata_dev_disable_pm(struct ata_device *dev)
764 {
765 	struct ata_port *ap = dev->link->ap;
766 
767 	ata_dev_set_dipm(dev, MAX_PERFORMANCE);
768 	if (ap->ops->disable_pm)
769 		ap->ops->disable_pm(ap);
770 }
771 #endif	/* CONFIG_PM */
772 
773 void ata_lpm_schedule(struct ata_port *ap, enum link_pm policy)
774 {
775 	ap->pm_policy = policy;
776 	ap->link.eh_info.action |= ATA_EHI_LPM;
777 	ap->link.eh_info.flags |= ATA_EHI_NO_AUTOPSY;
778 	ata_port_schedule_eh(ap);
779 }
780 
781 #ifdef CONFIG_PM
782 static void ata_lpm_enable(struct ata_host *host)
783 {
784 	struct ata_link *link;
785 	struct ata_port *ap;
786 	struct ata_device *dev;
787 	int i;
788 
789 	for (i = 0; i < host->n_ports; i++) {
790 		ap = host->ports[i];
791 		ata_port_for_each_link(link, ap) {
792 			ata_link_for_each_dev(dev, link)
793 				ata_dev_disable_pm(dev);
794 		}
795 	}
796 }
797 
798 static void ata_lpm_disable(struct ata_host *host)
799 {
800 	int i;
801 
802 	for (i = 0; i < host->n_ports; i++) {
803 		struct ata_port *ap = host->ports[i];
804 		ata_lpm_schedule(ap, ap->pm_policy);
805 	}
806 }
807 #endif	/* CONFIG_PM */
808 
809 
810 /**
811  *	ata_devchk - PATA device presence detection
812  *	@ap: ATA channel to examine
813  *	@device: Device to examine (starting at zero)
814  *
815  *	This technique was originally described in
816  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
817  *	later found its way into the ATA/ATAPI spec.
818  *
819  *	Write a pattern to the ATA shadow registers,
820  *	and if a device is present, it will respond by
821  *	correctly storing and echoing back the
822  *	ATA shadow register contents.
823  *
824  *	LOCKING:
825  *	caller.
826  */
827 
828 static unsigned int ata_devchk(struct ata_port *ap, unsigned int device)
829 {
830 	struct ata_ioports *ioaddr = &ap->ioaddr;
831 	u8 nsect, lbal;
832 
833 	ap->ops->dev_select(ap, device);
834 
835 	iowrite8(0x55, ioaddr->nsect_addr);
836 	iowrite8(0xaa, ioaddr->lbal_addr);
837 
838 	iowrite8(0xaa, ioaddr->nsect_addr);
839 	iowrite8(0x55, ioaddr->lbal_addr);
840 
841 	iowrite8(0x55, ioaddr->nsect_addr);
842 	iowrite8(0xaa, ioaddr->lbal_addr);
843 
844 	nsect = ioread8(ioaddr->nsect_addr);
845 	lbal = ioread8(ioaddr->lbal_addr);
846 
847 	if ((nsect == 0x55) && (lbal == 0xaa))
848 		return 1;	/* we found a device */
849 
850 	return 0;		/* nothing found */
851 }
852 
853 /**
854  *	ata_dev_classify - determine device type based on ATA-spec signature
855  *	@tf: ATA taskfile register set for device to be identified
856  *
857  *	Determine from taskfile register contents whether a device is
858  *	ATA or ATAPI, as per "Signature and persistence" section
859  *	of ATA/PI spec (volume 1, sect 5.14).
860  *
861  *	LOCKING:
862  *	None.
863  *
864  *	RETURNS:
865  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP or
866  *	%ATA_DEV_UNKNOWN the event of failure.
867  */
868 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
869 {
870 	/* Apple's open source Darwin code hints that some devices only
871 	 * put a proper signature into the LBA mid/high registers,
872 	 * So, we only check those.  It's sufficient for uniqueness.
873 	 *
874 	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
875 	 * signatures for ATA and ATAPI devices attached on SerialATA,
876 	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
877 	 * spec has never mentioned about using different signatures
878 	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
879 	 * Multiplier specification began to use 0x69/0x96 to identify
880 	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
881 	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
882 	 * 0x69/0x96 shortly and described them as reserved for
883 	 * SerialATA.
884 	 *
885 	 * We follow the current spec and consider that 0x69/0x96
886 	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
887 	 */
888 	if ((tf->lbam == 0) && (tf->lbah == 0)) {
889 		DPRINTK("found ATA device by sig\n");
890 		return ATA_DEV_ATA;
891 	}
892 
893 	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
894 		DPRINTK("found ATAPI device by sig\n");
895 		return ATA_DEV_ATAPI;
896 	}
897 
898 	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
899 		DPRINTK("found PMP device by sig\n");
900 		return ATA_DEV_PMP;
901 	}
902 
903 	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
904 		printk(KERN_INFO "ata: SEMB device ignored\n");
905 		return ATA_DEV_SEMB_UNSUP; /* not yet */
906 	}
907 
908 	DPRINTK("unknown device\n");
909 	return ATA_DEV_UNKNOWN;
910 }
911 
912 /**
913  *	ata_dev_try_classify - Parse returned ATA device signature
914  *	@dev: ATA device to classify (starting at zero)
915  *	@present: device seems present
916  *	@r_err: Value of error register on completion
917  *
918  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
919  *	an ATA/ATAPI-defined set of values is placed in the ATA
920  *	shadow registers, indicating the results of device detection
921  *	and diagnostics.
922  *
923  *	Select the ATA device, and read the values from the ATA shadow
924  *	registers.  Then parse according to the Error register value,
925  *	and the spec-defined values examined by ata_dev_classify().
926  *
927  *	LOCKING:
928  *	caller.
929  *
930  *	RETURNS:
931  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
932  */
933 unsigned int ata_dev_try_classify(struct ata_device *dev, int present,
934 				  u8 *r_err)
935 {
936 	struct ata_port *ap = dev->link->ap;
937 	struct ata_taskfile tf;
938 	unsigned int class;
939 	u8 err;
940 
941 	ap->ops->dev_select(ap, dev->devno);
942 
943 	memset(&tf, 0, sizeof(tf));
944 
945 	ap->ops->tf_read(ap, &tf);
946 	err = tf.feature;
947 	if (r_err)
948 		*r_err = err;
949 
950 	/* see if device passed diags: if master then continue and warn later */
951 	if (err == 0 && dev->devno == 0)
952 		/* diagnostic fail : do nothing _YET_ */
953 		dev->horkage |= ATA_HORKAGE_DIAGNOSTIC;
954 	else if (err == 1)
955 		/* do nothing */ ;
956 	else if ((dev->devno == 0) && (err == 0x81))
957 		/* do nothing */ ;
958 	else
959 		return ATA_DEV_NONE;
960 
961 	/* determine if device is ATA or ATAPI */
962 	class = ata_dev_classify(&tf);
963 
964 	if (class == ATA_DEV_UNKNOWN) {
965 		/* If the device failed diagnostic, it's likely to
966 		 * have reported incorrect device signature too.
967 		 * Assume ATA device if the device seems present but
968 		 * device signature is invalid with diagnostic
969 		 * failure.
970 		 */
971 		if (present && (dev->horkage & ATA_HORKAGE_DIAGNOSTIC))
972 			class = ATA_DEV_ATA;
973 		else
974 			class = ATA_DEV_NONE;
975 	} else if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
976 		class = ATA_DEV_NONE;
977 
978 	return class;
979 }
980 
981 /**
982  *	ata_id_string - Convert IDENTIFY DEVICE page into string
983  *	@id: IDENTIFY DEVICE results we will examine
984  *	@s: string into which data is output
985  *	@ofs: offset into identify device page
986  *	@len: length of string to return. must be an even number.
987  *
988  *	The strings in the IDENTIFY DEVICE page are broken up into
989  *	16-bit chunks.  Run through the string, and output each
990  *	8-bit chunk linearly, regardless of platform.
991  *
992  *	LOCKING:
993  *	caller.
994  */
995 
996 void ata_id_string(const u16 *id, unsigned char *s,
997 		   unsigned int ofs, unsigned int len)
998 {
999 	unsigned int c;
1000 
1001 	while (len > 0) {
1002 		c = id[ofs] >> 8;
1003 		*s = c;
1004 		s++;
1005 
1006 		c = id[ofs] & 0xff;
1007 		*s = c;
1008 		s++;
1009 
1010 		ofs++;
1011 		len -= 2;
1012 	}
1013 }
1014 
1015 /**
1016  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
1017  *	@id: IDENTIFY DEVICE results we will examine
1018  *	@s: string into which data is output
1019  *	@ofs: offset into identify device page
1020  *	@len: length of string to return. must be an odd number.
1021  *
1022  *	This function is identical to ata_id_string except that it
1023  *	trims trailing spaces and terminates the resulting string with
1024  *	null.  @len must be actual maximum length (even number) + 1.
1025  *
1026  *	LOCKING:
1027  *	caller.
1028  */
1029 void ata_id_c_string(const u16 *id, unsigned char *s,
1030 		     unsigned int ofs, unsigned int len)
1031 {
1032 	unsigned char *p;
1033 
1034 	WARN_ON(!(len & 1));
1035 
1036 	ata_id_string(id, s, ofs, len - 1);
1037 
1038 	p = s + strnlen(s, len - 1);
1039 	while (p > s && p[-1] == ' ')
1040 		p--;
1041 	*p = '\0';
1042 }
1043 
1044 static u64 ata_id_n_sectors(const u16 *id)
1045 {
1046 	if (ata_id_has_lba(id)) {
1047 		if (ata_id_has_lba48(id))
1048 			return ata_id_u64(id, 100);
1049 		else
1050 			return ata_id_u32(id, 60);
1051 	} else {
1052 		if (ata_id_current_chs_valid(id))
1053 			return ata_id_u32(id, 57);
1054 		else
1055 			return id[1] * id[3] * id[6];
1056 	}
1057 }
1058 
1059 static u64 ata_tf_to_lba48(struct ata_taskfile *tf)
1060 {
1061 	u64 sectors = 0;
1062 
1063 	sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
1064 	sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
1065 	sectors |= (tf->hob_lbal & 0xff) << 24;
1066 	sectors |= (tf->lbah & 0xff) << 16;
1067 	sectors |= (tf->lbam & 0xff) << 8;
1068 	sectors |= (tf->lbal & 0xff);
1069 
1070 	return ++sectors;
1071 }
1072 
1073 static u64 ata_tf_to_lba(struct ata_taskfile *tf)
1074 {
1075 	u64 sectors = 0;
1076 
1077 	sectors |= (tf->device & 0x0f) << 24;
1078 	sectors |= (tf->lbah & 0xff) << 16;
1079 	sectors |= (tf->lbam & 0xff) << 8;
1080 	sectors |= (tf->lbal & 0xff);
1081 
1082 	return ++sectors;
1083 }
1084 
1085 /**
1086  *	ata_read_native_max_address - Read native max address
1087  *	@dev: target device
1088  *	@max_sectors: out parameter for the result native max address
1089  *
1090  *	Perform an LBA48 or LBA28 native size query upon the device in
1091  *	question.
1092  *
1093  *	RETURNS:
1094  *	0 on success, -EACCES if command is aborted by the drive.
1095  *	-EIO on other errors.
1096  */
1097 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
1098 {
1099 	unsigned int err_mask;
1100 	struct ata_taskfile tf;
1101 	int lba48 = ata_id_has_lba48(dev->id);
1102 
1103 	ata_tf_init(dev, &tf);
1104 
1105 	/* always clear all address registers */
1106 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1107 
1108 	if (lba48) {
1109 		tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
1110 		tf.flags |= ATA_TFLAG_LBA48;
1111 	} else
1112 		tf.command = ATA_CMD_READ_NATIVE_MAX;
1113 
1114 	tf.protocol |= ATA_PROT_NODATA;
1115 	tf.device |= ATA_LBA;
1116 
1117 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1118 	if (err_mask) {
1119 		ata_dev_printk(dev, KERN_WARNING, "failed to read native "
1120 			       "max address (err_mask=0x%x)\n", err_mask);
1121 		if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
1122 			return -EACCES;
1123 		return -EIO;
1124 	}
1125 
1126 	if (lba48)
1127 		*max_sectors = ata_tf_to_lba48(&tf);
1128 	else
1129 		*max_sectors = ata_tf_to_lba(&tf);
1130 	if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
1131 		(*max_sectors)--;
1132 	return 0;
1133 }
1134 
1135 /**
1136  *	ata_set_max_sectors - Set max sectors
1137  *	@dev: target device
1138  *	@new_sectors: new max sectors value to set for the device
1139  *
1140  *	Set max sectors of @dev to @new_sectors.
1141  *
1142  *	RETURNS:
1143  *	0 on success, -EACCES if command is aborted or denied (due to
1144  *	previous non-volatile SET_MAX) by the drive.  -EIO on other
1145  *	errors.
1146  */
1147 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
1148 {
1149 	unsigned int err_mask;
1150 	struct ata_taskfile tf;
1151 	int lba48 = ata_id_has_lba48(dev->id);
1152 
1153 	new_sectors--;
1154 
1155 	ata_tf_init(dev, &tf);
1156 
1157 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1158 
1159 	if (lba48) {
1160 		tf.command = ATA_CMD_SET_MAX_EXT;
1161 		tf.flags |= ATA_TFLAG_LBA48;
1162 
1163 		tf.hob_lbal = (new_sectors >> 24) & 0xff;
1164 		tf.hob_lbam = (new_sectors >> 32) & 0xff;
1165 		tf.hob_lbah = (new_sectors >> 40) & 0xff;
1166 	} else {
1167 		tf.command = ATA_CMD_SET_MAX;
1168 
1169 		tf.device |= (new_sectors >> 24) & 0xf;
1170 	}
1171 
1172 	tf.protocol |= ATA_PROT_NODATA;
1173 	tf.device |= ATA_LBA;
1174 
1175 	tf.lbal = (new_sectors >> 0) & 0xff;
1176 	tf.lbam = (new_sectors >> 8) & 0xff;
1177 	tf.lbah = (new_sectors >> 16) & 0xff;
1178 
1179 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1180 	if (err_mask) {
1181 		ata_dev_printk(dev, KERN_WARNING, "failed to set "
1182 			       "max address (err_mask=0x%x)\n", err_mask);
1183 		if (err_mask == AC_ERR_DEV &&
1184 		    (tf.feature & (ATA_ABORTED | ATA_IDNF)))
1185 			return -EACCES;
1186 		return -EIO;
1187 	}
1188 
1189 	return 0;
1190 }
1191 
1192 /**
1193  *	ata_hpa_resize		-	Resize a device with an HPA set
1194  *	@dev: Device to resize
1195  *
1196  *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
1197  *	it if required to the full size of the media. The caller must check
1198  *	the drive has the HPA feature set enabled.
1199  *
1200  *	RETURNS:
1201  *	0 on success, -errno on failure.
1202  */
1203 static int ata_hpa_resize(struct ata_device *dev)
1204 {
1205 	struct ata_eh_context *ehc = &dev->link->eh_context;
1206 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1207 	u64 sectors = ata_id_n_sectors(dev->id);
1208 	u64 native_sectors;
1209 	int rc;
1210 
1211 	/* do we need to do it? */
1212 	if (dev->class != ATA_DEV_ATA ||
1213 	    !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
1214 	    (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
1215 		return 0;
1216 
1217 	/* read native max address */
1218 	rc = ata_read_native_max_address(dev, &native_sectors);
1219 	if (rc) {
1220 		/* If HPA isn't going to be unlocked, skip HPA
1221 		 * resizing from the next try.
1222 		 */
1223 		if (!ata_ignore_hpa) {
1224 			ata_dev_printk(dev, KERN_WARNING, "HPA support seems "
1225 				       "broken, will skip HPA handling\n");
1226 			dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1227 
1228 			/* we can continue if device aborted the command */
1229 			if (rc == -EACCES)
1230 				rc = 0;
1231 		}
1232 
1233 		return rc;
1234 	}
1235 
1236 	/* nothing to do? */
1237 	if (native_sectors <= sectors || !ata_ignore_hpa) {
1238 		if (!print_info || native_sectors == sectors)
1239 			return 0;
1240 
1241 		if (native_sectors > sectors)
1242 			ata_dev_printk(dev, KERN_INFO,
1243 				"HPA detected: current %llu, native %llu\n",
1244 				(unsigned long long)sectors,
1245 				(unsigned long long)native_sectors);
1246 		else if (native_sectors < sectors)
1247 			ata_dev_printk(dev, KERN_WARNING,
1248 				"native sectors (%llu) is smaller than "
1249 				"sectors (%llu)\n",
1250 				(unsigned long long)native_sectors,
1251 				(unsigned long long)sectors);
1252 		return 0;
1253 	}
1254 
1255 	/* let's unlock HPA */
1256 	rc = ata_set_max_sectors(dev, native_sectors);
1257 	if (rc == -EACCES) {
1258 		/* if device aborted the command, skip HPA resizing */
1259 		ata_dev_printk(dev, KERN_WARNING, "device aborted resize "
1260 			       "(%llu -> %llu), skipping HPA handling\n",
1261 			       (unsigned long long)sectors,
1262 			       (unsigned long long)native_sectors);
1263 		dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1264 		return 0;
1265 	} else if (rc)
1266 		return rc;
1267 
1268 	/* re-read IDENTIFY data */
1269 	rc = ata_dev_reread_id(dev, 0);
1270 	if (rc) {
1271 		ata_dev_printk(dev, KERN_ERR, "failed to re-read IDENTIFY "
1272 			       "data after HPA resizing\n");
1273 		return rc;
1274 	}
1275 
1276 	if (print_info) {
1277 		u64 new_sectors = ata_id_n_sectors(dev->id);
1278 		ata_dev_printk(dev, KERN_INFO,
1279 			"HPA unlocked: %llu -> %llu, native %llu\n",
1280 			(unsigned long long)sectors,
1281 			(unsigned long long)new_sectors,
1282 			(unsigned long long)native_sectors);
1283 	}
1284 
1285 	return 0;
1286 }
1287 
1288 /**
1289  *	ata_id_to_dma_mode	-	Identify DMA mode from id block
1290  *	@dev: device to identify
1291  *	@unknown: mode to assume if we cannot tell
1292  *
1293  *	Set up the timing values for the device based upon the identify
1294  *	reported values for the DMA mode. This function is used by drivers
1295  *	which rely upon firmware configured modes, but wish to report the
1296  *	mode correctly when possible.
1297  *
1298  *	In addition we emit similarly formatted messages to the default
1299  *	ata_dev_set_mode handler, in order to provide consistency of
1300  *	presentation.
1301  */
1302 
1303 void ata_id_to_dma_mode(struct ata_device *dev, u8 unknown)
1304 {
1305 	unsigned int mask;
1306 	u8 mode;
1307 
1308 	/* Pack the DMA modes */
1309 	mask = ((dev->id[63] >> 8) << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA;
1310 	if (dev->id[53] & 0x04)
1311 		mask |= ((dev->id[88] >> 8) << ATA_SHIFT_UDMA) & ATA_MASK_UDMA;
1312 
1313 	/* Select the mode in use */
1314 	mode = ata_xfer_mask2mode(mask);
1315 
1316 	if (mode != 0) {
1317 		ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
1318 		       ata_mode_string(mask));
1319 	} else {
1320 		/* SWDMA perhaps ? */
1321 		mode = unknown;
1322 		ata_dev_printk(dev, KERN_INFO, "configured for DMA\n");
1323 	}
1324 
1325 	/* Configure the device reporting */
1326 	dev->xfer_mode = mode;
1327 	dev->xfer_shift = ata_xfer_mode2shift(mode);
1328 }
1329 
1330 /**
1331  *	ata_noop_dev_select - Select device 0/1 on ATA bus
1332  *	@ap: ATA channel to manipulate
1333  *	@device: ATA device (numbered from zero) to select
1334  *
1335  *	This function performs no actual function.
1336  *
1337  *	May be used as the dev_select() entry in ata_port_operations.
1338  *
1339  *	LOCKING:
1340  *	caller.
1341  */
1342 void ata_noop_dev_select(struct ata_port *ap, unsigned int device)
1343 {
1344 }
1345 
1346 
1347 /**
1348  *	ata_std_dev_select - Select device 0/1 on ATA bus
1349  *	@ap: ATA channel to manipulate
1350  *	@device: ATA device (numbered from zero) to select
1351  *
1352  *	Use the method defined in the ATA specification to
1353  *	make either device 0, or device 1, active on the
1354  *	ATA channel.  Works with both PIO and MMIO.
1355  *
1356  *	May be used as the dev_select() entry in ata_port_operations.
1357  *
1358  *	LOCKING:
1359  *	caller.
1360  */
1361 
1362 void ata_std_dev_select(struct ata_port *ap, unsigned int device)
1363 {
1364 	u8 tmp;
1365 
1366 	if (device == 0)
1367 		tmp = ATA_DEVICE_OBS;
1368 	else
1369 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
1370 
1371 	iowrite8(tmp, ap->ioaddr.device_addr);
1372 	ata_pause(ap);		/* needed; also flushes, for mmio */
1373 }
1374 
1375 /**
1376  *	ata_dev_select - Select device 0/1 on ATA bus
1377  *	@ap: ATA channel to manipulate
1378  *	@device: ATA device (numbered from zero) to select
1379  *	@wait: non-zero to wait for Status register BSY bit to clear
1380  *	@can_sleep: non-zero if context allows sleeping
1381  *
1382  *	Use the method defined in the ATA specification to
1383  *	make either device 0, or device 1, active on the
1384  *	ATA channel.
1385  *
1386  *	This is a high-level version of ata_std_dev_select(),
1387  *	which additionally provides the services of inserting
1388  *	the proper pauses and status polling, where needed.
1389  *
1390  *	LOCKING:
1391  *	caller.
1392  */
1393 
1394 void ata_dev_select(struct ata_port *ap, unsigned int device,
1395 			   unsigned int wait, unsigned int can_sleep)
1396 {
1397 	if (ata_msg_probe(ap))
1398 		ata_port_printk(ap, KERN_INFO, "ata_dev_select: ENTER, "
1399 				"device %u, wait %u\n", device, wait);
1400 
1401 	if (wait)
1402 		ata_wait_idle(ap);
1403 
1404 	ap->ops->dev_select(ap, device);
1405 
1406 	if (wait) {
1407 		if (can_sleep && ap->link.device[device].class == ATA_DEV_ATAPI)
1408 			msleep(150);
1409 		ata_wait_idle(ap);
1410 	}
1411 }
1412 
1413 /**
1414  *	ata_dump_id - IDENTIFY DEVICE info debugging output
1415  *	@id: IDENTIFY DEVICE page to dump
1416  *
1417  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
1418  *	page.
1419  *
1420  *	LOCKING:
1421  *	caller.
1422  */
1423 
1424 static inline void ata_dump_id(const u16 *id)
1425 {
1426 	DPRINTK("49==0x%04x  "
1427 		"53==0x%04x  "
1428 		"63==0x%04x  "
1429 		"64==0x%04x  "
1430 		"75==0x%04x  \n",
1431 		id[49],
1432 		id[53],
1433 		id[63],
1434 		id[64],
1435 		id[75]);
1436 	DPRINTK("80==0x%04x  "
1437 		"81==0x%04x  "
1438 		"82==0x%04x  "
1439 		"83==0x%04x  "
1440 		"84==0x%04x  \n",
1441 		id[80],
1442 		id[81],
1443 		id[82],
1444 		id[83],
1445 		id[84]);
1446 	DPRINTK("88==0x%04x  "
1447 		"93==0x%04x\n",
1448 		id[88],
1449 		id[93]);
1450 }
1451 
1452 /**
1453  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1454  *	@id: IDENTIFY data to compute xfer mask from
1455  *
1456  *	Compute the xfermask for this device. This is not as trivial
1457  *	as it seems if we must consider early devices correctly.
1458  *
1459  *	FIXME: pre IDE drive timing (do we care ?).
1460  *
1461  *	LOCKING:
1462  *	None.
1463  *
1464  *	RETURNS:
1465  *	Computed xfermask
1466  */
1467 static unsigned int ata_id_xfermask(const u16 *id)
1468 {
1469 	unsigned int pio_mask, mwdma_mask, udma_mask;
1470 
1471 	/* Usual case. Word 53 indicates word 64 is valid */
1472 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1473 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1474 		pio_mask <<= 3;
1475 		pio_mask |= 0x7;
1476 	} else {
1477 		/* If word 64 isn't valid then Word 51 high byte holds
1478 		 * the PIO timing number for the maximum. Turn it into
1479 		 * a mask.
1480 		 */
1481 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1482 		if (mode < 5)	/* Valid PIO range */
1483 			pio_mask = (2 << mode) - 1;
1484 		else
1485 			pio_mask = 1;
1486 
1487 		/* But wait.. there's more. Design your standards by
1488 		 * committee and you too can get a free iordy field to
1489 		 * process. However its the speeds not the modes that
1490 		 * are supported... Note drivers using the timing API
1491 		 * will get this right anyway
1492 		 */
1493 	}
1494 
1495 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1496 
1497 	if (ata_id_is_cfa(id)) {
1498 		/*
1499 		 *	Process compact flash extended modes
1500 		 */
1501 		int pio = id[163] & 0x7;
1502 		int dma = (id[163] >> 3) & 7;
1503 
1504 		if (pio)
1505 			pio_mask |= (1 << 5);
1506 		if (pio > 1)
1507 			pio_mask |= (1 << 6);
1508 		if (dma)
1509 			mwdma_mask |= (1 << 3);
1510 		if (dma > 1)
1511 			mwdma_mask |= (1 << 4);
1512 	}
1513 
1514 	udma_mask = 0;
1515 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1516 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1517 
1518 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1519 }
1520 
1521 /**
1522  *	ata_port_queue_task - Queue port_task
1523  *	@ap: The ata_port to queue port_task for
1524  *	@fn: workqueue function to be scheduled
1525  *	@data: data for @fn to use
1526  *	@delay: delay time for workqueue function
1527  *
1528  *	Schedule @fn(@data) for execution after @delay jiffies using
1529  *	port_task.  There is one port_task per port and it's the
1530  *	user(low level driver)'s responsibility to make sure that only
1531  *	one task is active at any given time.
1532  *
1533  *	libata core layer takes care of synchronization between
1534  *	port_task and EH.  ata_port_queue_task() may be ignored for EH
1535  *	synchronization.
1536  *
1537  *	LOCKING:
1538  *	Inherited from caller.
1539  */
1540 void ata_port_queue_task(struct ata_port *ap, work_func_t fn, void *data,
1541 			 unsigned long delay)
1542 {
1543 	PREPARE_DELAYED_WORK(&ap->port_task, fn);
1544 	ap->port_task_data = data;
1545 
1546 	/* may fail if ata_port_flush_task() in progress */
1547 	queue_delayed_work(ata_wq, &ap->port_task, delay);
1548 }
1549 
1550 /**
1551  *	ata_port_flush_task - Flush port_task
1552  *	@ap: The ata_port to flush port_task for
1553  *
1554  *	After this function completes, port_task is guranteed not to
1555  *	be running or scheduled.
1556  *
1557  *	LOCKING:
1558  *	Kernel thread context (may sleep)
1559  */
1560 void ata_port_flush_task(struct ata_port *ap)
1561 {
1562 	DPRINTK("ENTER\n");
1563 
1564 	cancel_rearming_delayed_work(&ap->port_task);
1565 
1566 	if (ata_msg_ctl(ap))
1567 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __FUNCTION__);
1568 }
1569 
1570 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1571 {
1572 	struct completion *waiting = qc->private_data;
1573 
1574 	complete(waiting);
1575 }
1576 
1577 /**
1578  *	ata_exec_internal_sg - execute libata internal command
1579  *	@dev: Device to which the command is sent
1580  *	@tf: Taskfile registers for the command and the result
1581  *	@cdb: CDB for packet command
1582  *	@dma_dir: Data tranfer direction of the command
1583  *	@sgl: sg list for the data buffer of the command
1584  *	@n_elem: Number of sg entries
1585  *	@timeout: Timeout in msecs (0 for default)
1586  *
1587  *	Executes libata internal command with timeout.  @tf contains
1588  *	command on entry and result on return.  Timeout and error
1589  *	conditions are reported via return value.  No recovery action
1590  *	is taken after a command times out.  It's caller's duty to
1591  *	clean up after timeout.
1592  *
1593  *	LOCKING:
1594  *	None.  Should be called with kernel context, might sleep.
1595  *
1596  *	RETURNS:
1597  *	Zero on success, AC_ERR_* mask on failure
1598  */
1599 unsigned ata_exec_internal_sg(struct ata_device *dev,
1600 			      struct ata_taskfile *tf, const u8 *cdb,
1601 			      int dma_dir, struct scatterlist *sgl,
1602 			      unsigned int n_elem, unsigned long timeout)
1603 {
1604 	struct ata_link *link = dev->link;
1605 	struct ata_port *ap = link->ap;
1606 	u8 command = tf->command;
1607 	struct ata_queued_cmd *qc;
1608 	unsigned int tag, preempted_tag;
1609 	u32 preempted_sactive, preempted_qc_active;
1610 	int preempted_nr_active_links;
1611 	DECLARE_COMPLETION_ONSTACK(wait);
1612 	unsigned long flags;
1613 	unsigned int err_mask;
1614 	int rc;
1615 
1616 	spin_lock_irqsave(ap->lock, flags);
1617 
1618 	/* no internal command while frozen */
1619 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1620 		spin_unlock_irqrestore(ap->lock, flags);
1621 		return AC_ERR_SYSTEM;
1622 	}
1623 
1624 	/* initialize internal qc */
1625 
1626 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1627 	 * drivers choke if any other tag is given.  This breaks
1628 	 * ata_tag_internal() test for those drivers.  Don't use new
1629 	 * EH stuff without converting to it.
1630 	 */
1631 	if (ap->ops->error_handler)
1632 		tag = ATA_TAG_INTERNAL;
1633 	else
1634 		tag = 0;
1635 
1636 	if (test_and_set_bit(tag, &ap->qc_allocated))
1637 		BUG();
1638 	qc = __ata_qc_from_tag(ap, tag);
1639 
1640 	qc->tag = tag;
1641 	qc->scsicmd = NULL;
1642 	qc->ap = ap;
1643 	qc->dev = dev;
1644 	ata_qc_reinit(qc);
1645 
1646 	preempted_tag = link->active_tag;
1647 	preempted_sactive = link->sactive;
1648 	preempted_qc_active = ap->qc_active;
1649 	preempted_nr_active_links = ap->nr_active_links;
1650 	link->active_tag = ATA_TAG_POISON;
1651 	link->sactive = 0;
1652 	ap->qc_active = 0;
1653 	ap->nr_active_links = 0;
1654 
1655 	/* prepare & issue qc */
1656 	qc->tf = *tf;
1657 	if (cdb)
1658 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1659 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1660 	qc->dma_dir = dma_dir;
1661 	if (dma_dir != DMA_NONE) {
1662 		unsigned int i, buflen = 0;
1663 		struct scatterlist *sg;
1664 
1665 		for_each_sg(sgl, sg, n_elem, i)
1666 			buflen += sg->length;
1667 
1668 		ata_sg_init(qc, sgl, n_elem);
1669 		qc->nbytes = buflen;
1670 	}
1671 
1672 	qc->private_data = &wait;
1673 	qc->complete_fn = ata_qc_complete_internal;
1674 
1675 	ata_qc_issue(qc);
1676 
1677 	spin_unlock_irqrestore(ap->lock, flags);
1678 
1679 	if (!timeout)
1680 		timeout = ata_probe_timeout * 1000 / HZ;
1681 
1682 	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
1683 
1684 	ata_port_flush_task(ap);
1685 
1686 	if (!rc) {
1687 		spin_lock_irqsave(ap->lock, flags);
1688 
1689 		/* We're racing with irq here.  If we lose, the
1690 		 * following test prevents us from completing the qc
1691 		 * twice.  If we win, the port is frozen and will be
1692 		 * cleaned up by ->post_internal_cmd().
1693 		 */
1694 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1695 			qc->err_mask |= AC_ERR_TIMEOUT;
1696 
1697 			if (ap->ops->error_handler)
1698 				ata_port_freeze(ap);
1699 			else
1700 				ata_qc_complete(qc);
1701 
1702 			if (ata_msg_warn(ap))
1703 				ata_dev_printk(dev, KERN_WARNING,
1704 					"qc timeout (cmd 0x%x)\n", command);
1705 		}
1706 
1707 		spin_unlock_irqrestore(ap->lock, flags);
1708 	}
1709 
1710 	/* do post_internal_cmd */
1711 	if (ap->ops->post_internal_cmd)
1712 		ap->ops->post_internal_cmd(qc);
1713 
1714 	/* perform minimal error analysis */
1715 	if (qc->flags & ATA_QCFLAG_FAILED) {
1716 		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
1717 			qc->err_mask |= AC_ERR_DEV;
1718 
1719 		if (!qc->err_mask)
1720 			qc->err_mask |= AC_ERR_OTHER;
1721 
1722 		if (qc->err_mask & ~AC_ERR_OTHER)
1723 			qc->err_mask &= ~AC_ERR_OTHER;
1724 	}
1725 
1726 	/* finish up */
1727 	spin_lock_irqsave(ap->lock, flags);
1728 
1729 	*tf = qc->result_tf;
1730 	err_mask = qc->err_mask;
1731 
1732 	ata_qc_free(qc);
1733 	link->active_tag = preempted_tag;
1734 	link->sactive = preempted_sactive;
1735 	ap->qc_active = preempted_qc_active;
1736 	ap->nr_active_links = preempted_nr_active_links;
1737 
1738 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1739 	 * Until those drivers are fixed, we detect the condition
1740 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1741 	 * port.
1742 	 *
1743 	 * Note that this doesn't change any behavior as internal
1744 	 * command failure results in disabling the device in the
1745 	 * higher layer for LLDDs without new reset/EH callbacks.
1746 	 *
1747 	 * Kill the following code as soon as those drivers are fixed.
1748 	 */
1749 	if (ap->flags & ATA_FLAG_DISABLED) {
1750 		err_mask |= AC_ERR_SYSTEM;
1751 		ata_port_probe(ap);
1752 	}
1753 
1754 	spin_unlock_irqrestore(ap->lock, flags);
1755 
1756 	return err_mask;
1757 }
1758 
1759 /**
1760  *	ata_exec_internal - execute libata internal command
1761  *	@dev: Device to which the command is sent
1762  *	@tf: Taskfile registers for the command and the result
1763  *	@cdb: CDB for packet command
1764  *	@dma_dir: Data tranfer direction of the command
1765  *	@buf: Data buffer of the command
1766  *	@buflen: Length of data buffer
1767  *	@timeout: Timeout in msecs (0 for default)
1768  *
1769  *	Wrapper around ata_exec_internal_sg() which takes simple
1770  *	buffer instead of sg list.
1771  *
1772  *	LOCKING:
1773  *	None.  Should be called with kernel context, might sleep.
1774  *
1775  *	RETURNS:
1776  *	Zero on success, AC_ERR_* mask on failure
1777  */
1778 unsigned ata_exec_internal(struct ata_device *dev,
1779 			   struct ata_taskfile *tf, const u8 *cdb,
1780 			   int dma_dir, void *buf, unsigned int buflen,
1781 			   unsigned long timeout)
1782 {
1783 	struct scatterlist *psg = NULL, sg;
1784 	unsigned int n_elem = 0;
1785 
1786 	if (dma_dir != DMA_NONE) {
1787 		WARN_ON(!buf);
1788 		sg_init_one(&sg, buf, buflen);
1789 		psg = &sg;
1790 		n_elem++;
1791 	}
1792 
1793 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
1794 				    timeout);
1795 }
1796 
1797 /**
1798  *	ata_do_simple_cmd - execute simple internal command
1799  *	@dev: Device to which the command is sent
1800  *	@cmd: Opcode to execute
1801  *
1802  *	Execute a 'simple' command, that only consists of the opcode
1803  *	'cmd' itself, without filling any other registers
1804  *
1805  *	LOCKING:
1806  *	Kernel thread context (may sleep).
1807  *
1808  *	RETURNS:
1809  *	Zero on success, AC_ERR_* mask on failure
1810  */
1811 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
1812 {
1813 	struct ata_taskfile tf;
1814 
1815 	ata_tf_init(dev, &tf);
1816 
1817 	tf.command = cmd;
1818 	tf.flags |= ATA_TFLAG_DEVICE;
1819 	tf.protocol = ATA_PROT_NODATA;
1820 
1821 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1822 }
1823 
1824 /**
1825  *	ata_pio_need_iordy	-	check if iordy needed
1826  *	@adev: ATA device
1827  *
1828  *	Check if the current speed of the device requires IORDY. Used
1829  *	by various controllers for chip configuration.
1830  */
1831 
1832 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1833 {
1834 	/* Controller doesn't support  IORDY. Probably a pointless check
1835 	   as the caller should know this */
1836 	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
1837 		return 0;
1838 	/* PIO3 and higher it is mandatory */
1839 	if (adev->pio_mode > XFER_PIO_2)
1840 		return 1;
1841 	/* We turn it on when possible */
1842 	if (ata_id_has_iordy(adev->id))
1843 		return 1;
1844 	return 0;
1845 }
1846 
1847 /**
1848  *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
1849  *	@adev: ATA device
1850  *
1851  *	Compute the highest mode possible if we are not using iordy. Return
1852  *	-1 if no iordy mode is available.
1853  */
1854 
1855 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
1856 {
1857 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1858 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1859 		u16 pio = adev->id[ATA_ID_EIDE_PIO];
1860 		/* Is the speed faster than the drive allows non IORDY ? */
1861 		if (pio) {
1862 			/* This is cycle times not frequency - watch the logic! */
1863 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1864 				return 3 << ATA_SHIFT_PIO;
1865 			return 7 << ATA_SHIFT_PIO;
1866 		}
1867 	}
1868 	return 3 << ATA_SHIFT_PIO;
1869 }
1870 
1871 /**
1872  *	ata_dev_read_id - Read ID data from the specified device
1873  *	@dev: target device
1874  *	@p_class: pointer to class of the target device (may be changed)
1875  *	@flags: ATA_READID_* flags
1876  *	@id: buffer to read IDENTIFY data into
1877  *
1878  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1879  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1880  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1881  *	for pre-ATA4 drives.
1882  *
1883  *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
1884  *	now we abort if we hit that case.
1885  *
1886  *	LOCKING:
1887  *	Kernel thread context (may sleep)
1888  *
1889  *	RETURNS:
1890  *	0 on success, -errno otherwise.
1891  */
1892 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1893 		    unsigned int flags, u16 *id)
1894 {
1895 	struct ata_port *ap = dev->link->ap;
1896 	unsigned int class = *p_class;
1897 	struct ata_taskfile tf;
1898 	unsigned int err_mask = 0;
1899 	const char *reason;
1900 	int may_fallback = 1, tried_spinup = 0;
1901 	int rc;
1902 
1903 	if (ata_msg_ctl(ap))
1904 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __FUNCTION__);
1905 
1906 	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
1907  retry:
1908 	ata_tf_init(dev, &tf);
1909 
1910 	switch (class) {
1911 	case ATA_DEV_ATA:
1912 		tf.command = ATA_CMD_ID_ATA;
1913 		break;
1914 	case ATA_DEV_ATAPI:
1915 		tf.command = ATA_CMD_ID_ATAPI;
1916 		break;
1917 	default:
1918 		rc = -ENODEV;
1919 		reason = "unsupported class";
1920 		goto err_out;
1921 	}
1922 
1923 	tf.protocol = ATA_PROT_PIO;
1924 
1925 	/* Some devices choke if TF registers contain garbage.  Make
1926 	 * sure those are properly initialized.
1927 	 */
1928 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1929 
1930 	/* Device presence detection is unreliable on some
1931 	 * controllers.  Always poll IDENTIFY if available.
1932 	 */
1933 	tf.flags |= ATA_TFLAG_POLLING;
1934 
1935 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1936 				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
1937 	if (err_mask) {
1938 		if (err_mask & AC_ERR_NODEV_HINT) {
1939 			DPRINTK("ata%u.%d: NODEV after polling detection\n",
1940 				ap->print_id, dev->devno);
1941 			return -ENOENT;
1942 		}
1943 
1944 		/* Device or controller might have reported the wrong
1945 		 * device class.  Give a shot at the other IDENTIFY if
1946 		 * the current one is aborted by the device.
1947 		 */
1948 		if (may_fallback &&
1949 		    (err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
1950 			may_fallback = 0;
1951 
1952 			if (class == ATA_DEV_ATA)
1953 				class = ATA_DEV_ATAPI;
1954 			else
1955 				class = ATA_DEV_ATA;
1956 			goto retry;
1957 		}
1958 
1959 		rc = -EIO;
1960 		reason = "I/O error";
1961 		goto err_out;
1962 	}
1963 
1964 	/* Falling back doesn't make sense if ID data was read
1965 	 * successfully at least once.
1966 	 */
1967 	may_fallback = 0;
1968 
1969 	swap_buf_le16(id, ATA_ID_WORDS);
1970 
1971 	/* sanity check */
1972 	rc = -EINVAL;
1973 	reason = "device reports invalid type";
1974 
1975 	if (class == ATA_DEV_ATA) {
1976 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
1977 			goto err_out;
1978 	} else {
1979 		if (ata_id_is_ata(id))
1980 			goto err_out;
1981 	}
1982 
1983 	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
1984 		tried_spinup = 1;
1985 		/*
1986 		 * Drive powered-up in standby mode, and requires a specific
1987 		 * SET_FEATURES spin-up subcommand before it will accept
1988 		 * anything other than the original IDENTIFY command.
1989 		 */
1990 		err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
1991 		if (err_mask && id[2] != 0x738c) {
1992 			rc = -EIO;
1993 			reason = "SPINUP failed";
1994 			goto err_out;
1995 		}
1996 		/*
1997 		 * If the drive initially returned incomplete IDENTIFY info,
1998 		 * we now must reissue the IDENTIFY command.
1999 		 */
2000 		if (id[2] == 0x37c8)
2001 			goto retry;
2002 	}
2003 
2004 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
2005 		/*
2006 		 * The exact sequence expected by certain pre-ATA4 drives is:
2007 		 * SRST RESET
2008 		 * IDENTIFY (optional in early ATA)
2009 		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
2010 		 * anything else..
2011 		 * Some drives were very specific about that exact sequence.
2012 		 *
2013 		 * Note that ATA4 says lba is mandatory so the second check
2014 		 * shoud never trigger.
2015 		 */
2016 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
2017 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
2018 			if (err_mask) {
2019 				rc = -EIO;
2020 				reason = "INIT_DEV_PARAMS failed";
2021 				goto err_out;
2022 			}
2023 
2024 			/* current CHS translation info (id[53-58]) might be
2025 			 * changed. reread the identify device info.
2026 			 */
2027 			flags &= ~ATA_READID_POSTRESET;
2028 			goto retry;
2029 		}
2030 	}
2031 
2032 	*p_class = class;
2033 
2034 	return 0;
2035 
2036  err_out:
2037 	if (ata_msg_warn(ap))
2038 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
2039 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
2040 	return rc;
2041 }
2042 
2043 static inline u8 ata_dev_knobble(struct ata_device *dev)
2044 {
2045 	struct ata_port *ap = dev->link->ap;
2046 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
2047 }
2048 
2049 static void ata_dev_config_ncq(struct ata_device *dev,
2050 			       char *desc, size_t desc_sz)
2051 {
2052 	struct ata_port *ap = dev->link->ap;
2053 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
2054 
2055 	if (!ata_id_has_ncq(dev->id)) {
2056 		desc[0] = '\0';
2057 		return;
2058 	}
2059 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
2060 		snprintf(desc, desc_sz, "NCQ (not used)");
2061 		return;
2062 	}
2063 	if (ap->flags & ATA_FLAG_NCQ) {
2064 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
2065 		dev->flags |= ATA_DFLAG_NCQ;
2066 	}
2067 
2068 	if (hdepth >= ddepth)
2069 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
2070 	else
2071 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
2072 }
2073 
2074 /**
2075  *	ata_dev_configure - Configure the specified ATA/ATAPI device
2076  *	@dev: Target device to configure
2077  *
2078  *	Configure @dev according to @dev->id.  Generic and low-level
2079  *	driver specific fixups are also applied.
2080  *
2081  *	LOCKING:
2082  *	Kernel thread context (may sleep)
2083  *
2084  *	RETURNS:
2085  *	0 on success, -errno otherwise
2086  */
2087 int ata_dev_configure(struct ata_device *dev)
2088 {
2089 	struct ata_port *ap = dev->link->ap;
2090 	struct ata_eh_context *ehc = &dev->link->eh_context;
2091 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
2092 	const u16 *id = dev->id;
2093 	unsigned int xfer_mask;
2094 	char revbuf[7];		/* XYZ-99\0 */
2095 	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
2096 	char modelbuf[ATA_ID_PROD_LEN+1];
2097 	int rc;
2098 
2099 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
2100 		ata_dev_printk(dev, KERN_INFO, "%s: ENTER/EXIT -- nodev\n",
2101 			       __FUNCTION__);
2102 		return 0;
2103 	}
2104 
2105 	if (ata_msg_probe(ap))
2106 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER\n", __FUNCTION__);
2107 
2108 	/* set horkage */
2109 	dev->horkage |= ata_dev_blacklisted(dev);
2110 
2111 	/* let ACPI work its magic */
2112 	rc = ata_acpi_on_devcfg(dev);
2113 	if (rc)
2114 		return rc;
2115 
2116 	/* massage HPA, do it early as it might change IDENTIFY data */
2117 	rc = ata_hpa_resize(dev);
2118 	if (rc)
2119 		return rc;
2120 
2121 	/* print device capabilities */
2122 	if (ata_msg_probe(ap))
2123 		ata_dev_printk(dev, KERN_DEBUG,
2124 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
2125 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
2126 			       __FUNCTION__,
2127 			       id[49], id[82], id[83], id[84],
2128 			       id[85], id[86], id[87], id[88]);
2129 
2130 	/* initialize to-be-configured parameters */
2131 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
2132 	dev->max_sectors = 0;
2133 	dev->cdb_len = 0;
2134 	dev->n_sectors = 0;
2135 	dev->cylinders = 0;
2136 	dev->heads = 0;
2137 	dev->sectors = 0;
2138 
2139 	/*
2140 	 * common ATA, ATAPI feature tests
2141 	 */
2142 
2143 	/* find max transfer mode; for printk only */
2144 	xfer_mask = ata_id_xfermask(id);
2145 
2146 	if (ata_msg_probe(ap))
2147 		ata_dump_id(id);
2148 
2149 	/* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
2150 	ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
2151 			sizeof(fwrevbuf));
2152 
2153 	ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
2154 			sizeof(modelbuf));
2155 
2156 	/* ATA-specific feature tests */
2157 	if (dev->class == ATA_DEV_ATA) {
2158 		if (ata_id_is_cfa(id)) {
2159 			if (id[162] & 1) /* CPRM may make this media unusable */
2160 				ata_dev_printk(dev, KERN_WARNING,
2161 					       "supports DRM functions and may "
2162 					       "not be fully accessable.\n");
2163 			snprintf(revbuf, 7, "CFA");
2164 		} else
2165 			snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
2166 
2167 		dev->n_sectors = ata_id_n_sectors(id);
2168 
2169 		if (dev->id[59] & 0x100)
2170 			dev->multi_count = dev->id[59] & 0xff;
2171 
2172 		if (ata_id_has_lba(id)) {
2173 			const char *lba_desc;
2174 			char ncq_desc[20];
2175 
2176 			lba_desc = "LBA";
2177 			dev->flags |= ATA_DFLAG_LBA;
2178 			if (ata_id_has_lba48(id)) {
2179 				dev->flags |= ATA_DFLAG_LBA48;
2180 				lba_desc = "LBA48";
2181 
2182 				if (dev->n_sectors >= (1UL << 28) &&
2183 				    ata_id_has_flush_ext(id))
2184 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
2185 			}
2186 
2187 			/* config NCQ */
2188 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
2189 
2190 			/* print device info to dmesg */
2191 			if (ata_msg_drv(ap) && print_info) {
2192 				ata_dev_printk(dev, KERN_INFO,
2193 					"%s: %s, %s, max %s\n",
2194 					revbuf, modelbuf, fwrevbuf,
2195 					ata_mode_string(xfer_mask));
2196 				ata_dev_printk(dev, KERN_INFO,
2197 					"%Lu sectors, multi %u: %s %s\n",
2198 					(unsigned long long)dev->n_sectors,
2199 					dev->multi_count, lba_desc, ncq_desc);
2200 			}
2201 		} else {
2202 			/* CHS */
2203 
2204 			/* Default translation */
2205 			dev->cylinders	= id[1];
2206 			dev->heads	= id[3];
2207 			dev->sectors	= id[6];
2208 
2209 			if (ata_id_current_chs_valid(id)) {
2210 				/* Current CHS translation is valid. */
2211 				dev->cylinders = id[54];
2212 				dev->heads     = id[55];
2213 				dev->sectors   = id[56];
2214 			}
2215 
2216 			/* print device info to dmesg */
2217 			if (ata_msg_drv(ap) && print_info) {
2218 				ata_dev_printk(dev, KERN_INFO,
2219 					"%s: %s, %s, max %s\n",
2220 					revbuf,	modelbuf, fwrevbuf,
2221 					ata_mode_string(xfer_mask));
2222 				ata_dev_printk(dev, KERN_INFO,
2223 					"%Lu sectors, multi %u, CHS %u/%u/%u\n",
2224 					(unsigned long long)dev->n_sectors,
2225 					dev->multi_count, dev->cylinders,
2226 					dev->heads, dev->sectors);
2227 			}
2228 		}
2229 
2230 		dev->cdb_len = 16;
2231 	}
2232 
2233 	/* ATAPI-specific feature tests */
2234 	else if (dev->class == ATA_DEV_ATAPI) {
2235 		const char *cdb_intr_string = "";
2236 		const char *atapi_an_string = "";
2237 		u32 sntf;
2238 
2239 		rc = atapi_cdb_len(id);
2240 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
2241 			if (ata_msg_warn(ap))
2242 				ata_dev_printk(dev, KERN_WARNING,
2243 					       "unsupported CDB len\n");
2244 			rc = -EINVAL;
2245 			goto err_out_nosup;
2246 		}
2247 		dev->cdb_len = (unsigned int) rc;
2248 
2249 		/* Enable ATAPI AN if both the host and device have
2250 		 * the support.  If PMP is attached, SNTF is required
2251 		 * to enable ATAPI AN to discern between PHY status
2252 		 * changed notifications and ATAPI ANs.
2253 		 */
2254 		if ((ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
2255 		    (!ap->nr_pmp_links ||
2256 		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
2257 			unsigned int err_mask;
2258 
2259 			/* issue SET feature command to turn this on */
2260 			err_mask = ata_dev_set_feature(dev,
2261 					SETFEATURES_SATA_ENABLE, SATA_AN);
2262 			if (err_mask)
2263 				ata_dev_printk(dev, KERN_ERR,
2264 					"failed to enable ATAPI AN "
2265 					"(err_mask=0x%x)\n", err_mask);
2266 			else {
2267 				dev->flags |= ATA_DFLAG_AN;
2268 				atapi_an_string = ", ATAPI AN";
2269 			}
2270 		}
2271 
2272 		if (ata_id_cdb_intr(dev->id)) {
2273 			dev->flags |= ATA_DFLAG_CDB_INTR;
2274 			cdb_intr_string = ", CDB intr";
2275 		}
2276 
2277 		/* print device info to dmesg */
2278 		if (ata_msg_drv(ap) && print_info)
2279 			ata_dev_printk(dev, KERN_INFO,
2280 				       "ATAPI: %s, %s, max %s%s%s\n",
2281 				       modelbuf, fwrevbuf,
2282 				       ata_mode_string(xfer_mask),
2283 				       cdb_intr_string, atapi_an_string);
2284 	}
2285 
2286 	/* determine max_sectors */
2287 	dev->max_sectors = ATA_MAX_SECTORS;
2288 	if (dev->flags & ATA_DFLAG_LBA48)
2289 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2290 
2291 	if (!(dev->horkage & ATA_HORKAGE_IPM)) {
2292 		if (ata_id_has_hipm(dev->id))
2293 			dev->flags |= ATA_DFLAG_HIPM;
2294 		if (ata_id_has_dipm(dev->id))
2295 			dev->flags |= ATA_DFLAG_DIPM;
2296 	}
2297 
2298 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
2299 		/* Let the user know. We don't want to disallow opens for
2300 		   rescue purposes, or in case the vendor is just a blithering
2301 		   idiot */
2302 		if (print_info) {
2303 			ata_dev_printk(dev, KERN_WARNING,
2304 "Drive reports diagnostics failure. This may indicate a drive\n");
2305 			ata_dev_printk(dev, KERN_WARNING,
2306 "fault or invalid emulation. Contact drive vendor for information.\n");
2307 		}
2308 	}
2309 
2310 	/* limit bridge transfers to udma5, 200 sectors */
2311 	if (ata_dev_knobble(dev)) {
2312 		if (ata_msg_drv(ap) && print_info)
2313 			ata_dev_printk(dev, KERN_INFO,
2314 				       "applying bridge limits\n");
2315 		dev->udma_mask &= ATA_UDMA5;
2316 		dev->max_sectors = ATA_MAX_SECTORS;
2317 	}
2318 
2319 	if ((dev->class == ATA_DEV_ATAPI) &&
2320 	    (atapi_command_packet_set(id) == TYPE_TAPE)) {
2321 		dev->max_sectors = ATA_MAX_SECTORS_TAPE;
2322 		dev->horkage |= ATA_HORKAGE_STUCK_ERR;
2323 	}
2324 
2325 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
2326 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
2327 					 dev->max_sectors);
2328 
2329 	if (ata_dev_blacklisted(dev) & ATA_HORKAGE_IPM) {
2330 		dev->horkage |= ATA_HORKAGE_IPM;
2331 
2332 		/* reset link pm_policy for this port to no pm */
2333 		ap->pm_policy = MAX_PERFORMANCE;
2334 	}
2335 
2336 	if (ap->ops->dev_config)
2337 		ap->ops->dev_config(dev);
2338 
2339 	if (ata_msg_probe(ap))
2340 		ata_dev_printk(dev, KERN_DEBUG, "%s: EXIT, drv_stat = 0x%x\n",
2341 			__FUNCTION__, ata_chk_status(ap));
2342 	return 0;
2343 
2344 err_out_nosup:
2345 	if (ata_msg_probe(ap))
2346 		ata_dev_printk(dev, KERN_DEBUG,
2347 			       "%s: EXIT, err\n", __FUNCTION__);
2348 	return rc;
2349 }
2350 
2351 /**
2352  *	ata_cable_40wire	-	return 40 wire cable type
2353  *	@ap: port
2354  *
2355  *	Helper method for drivers which want to hardwire 40 wire cable
2356  *	detection.
2357  */
2358 
2359 int ata_cable_40wire(struct ata_port *ap)
2360 {
2361 	return ATA_CBL_PATA40;
2362 }
2363 
2364 /**
2365  *	ata_cable_80wire	-	return 80 wire cable type
2366  *	@ap: port
2367  *
2368  *	Helper method for drivers which want to hardwire 80 wire cable
2369  *	detection.
2370  */
2371 
2372 int ata_cable_80wire(struct ata_port *ap)
2373 {
2374 	return ATA_CBL_PATA80;
2375 }
2376 
2377 /**
2378  *	ata_cable_unknown	-	return unknown PATA cable.
2379  *	@ap: port
2380  *
2381  *	Helper method for drivers which have no PATA cable detection.
2382  */
2383 
2384 int ata_cable_unknown(struct ata_port *ap)
2385 {
2386 	return ATA_CBL_PATA_UNK;
2387 }
2388 
2389 /**
2390  *	ata_cable_sata	-	return SATA cable type
2391  *	@ap: port
2392  *
2393  *	Helper method for drivers which have SATA cables
2394  */
2395 
2396 int ata_cable_sata(struct ata_port *ap)
2397 {
2398 	return ATA_CBL_SATA;
2399 }
2400 
2401 /**
2402  *	ata_bus_probe - Reset and probe ATA bus
2403  *	@ap: Bus to probe
2404  *
2405  *	Master ATA bus probing function.  Initiates a hardware-dependent
2406  *	bus reset, then attempts to identify any devices found on
2407  *	the bus.
2408  *
2409  *	LOCKING:
2410  *	PCI/etc. bus probe sem.
2411  *
2412  *	RETURNS:
2413  *	Zero on success, negative errno otherwise.
2414  */
2415 
2416 int ata_bus_probe(struct ata_port *ap)
2417 {
2418 	unsigned int classes[ATA_MAX_DEVICES];
2419 	int tries[ATA_MAX_DEVICES];
2420 	int rc;
2421 	struct ata_device *dev;
2422 
2423 	ata_port_probe(ap);
2424 
2425 	ata_link_for_each_dev(dev, &ap->link)
2426 		tries[dev->devno] = ATA_PROBE_MAX_TRIES;
2427 
2428  retry:
2429 	ata_link_for_each_dev(dev, &ap->link) {
2430 		/* If we issue an SRST then an ATA drive (not ATAPI)
2431 		 * may change configuration and be in PIO0 timing. If
2432 		 * we do a hard reset (or are coming from power on)
2433 		 * this is true for ATA or ATAPI. Until we've set a
2434 		 * suitable controller mode we should not touch the
2435 		 * bus as we may be talking too fast.
2436 		 */
2437 		dev->pio_mode = XFER_PIO_0;
2438 
2439 		/* If the controller has a pio mode setup function
2440 		 * then use it to set the chipset to rights. Don't
2441 		 * touch the DMA setup as that will be dealt with when
2442 		 * configuring devices.
2443 		 */
2444 		if (ap->ops->set_piomode)
2445 			ap->ops->set_piomode(ap, dev);
2446 	}
2447 
2448 	/* reset and determine device classes */
2449 	ap->ops->phy_reset(ap);
2450 
2451 	ata_link_for_each_dev(dev, &ap->link) {
2452 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
2453 		    dev->class != ATA_DEV_UNKNOWN)
2454 			classes[dev->devno] = dev->class;
2455 		else
2456 			classes[dev->devno] = ATA_DEV_NONE;
2457 
2458 		dev->class = ATA_DEV_UNKNOWN;
2459 	}
2460 
2461 	ata_port_probe(ap);
2462 
2463 	/* read IDENTIFY page and configure devices. We have to do the identify
2464 	   specific sequence bass-ackwards so that PDIAG- is released by
2465 	   the slave device */
2466 
2467 	ata_link_for_each_dev(dev, &ap->link) {
2468 		if (tries[dev->devno])
2469 			dev->class = classes[dev->devno];
2470 
2471 		if (!ata_dev_enabled(dev))
2472 			continue;
2473 
2474 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
2475 				     dev->id);
2476 		if (rc)
2477 			goto fail;
2478 	}
2479 
2480 	/* Now ask for the cable type as PDIAG- should have been released */
2481 	if (ap->ops->cable_detect)
2482 		ap->cbl = ap->ops->cable_detect(ap);
2483 
2484 	/* We may have SATA bridge glue hiding here irrespective of the
2485 	   reported cable types and sensed types */
2486 	ata_link_for_each_dev(dev, &ap->link) {
2487 		if (!ata_dev_enabled(dev))
2488 			continue;
2489 		/* SATA drives indicate we have a bridge. We don't know which
2490 		   end of the link the bridge is which is a problem */
2491 		if (ata_id_is_sata(dev->id))
2492 			ap->cbl = ATA_CBL_SATA;
2493 	}
2494 
2495 	/* After the identify sequence we can now set up the devices. We do
2496 	   this in the normal order so that the user doesn't get confused */
2497 
2498 	ata_link_for_each_dev(dev, &ap->link) {
2499 		if (!ata_dev_enabled(dev))
2500 			continue;
2501 
2502 		ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
2503 		rc = ata_dev_configure(dev);
2504 		ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
2505 		if (rc)
2506 			goto fail;
2507 	}
2508 
2509 	/* configure transfer mode */
2510 	rc = ata_set_mode(&ap->link, &dev);
2511 	if (rc)
2512 		goto fail;
2513 
2514 	ata_link_for_each_dev(dev, &ap->link)
2515 		if (ata_dev_enabled(dev))
2516 			return 0;
2517 
2518 	/* no device present, disable port */
2519 	ata_port_disable(ap);
2520 	return -ENODEV;
2521 
2522  fail:
2523 	tries[dev->devno]--;
2524 
2525 	switch (rc) {
2526 	case -EINVAL:
2527 		/* eeek, something went very wrong, give up */
2528 		tries[dev->devno] = 0;
2529 		break;
2530 
2531 	case -ENODEV:
2532 		/* give it just one more chance */
2533 		tries[dev->devno] = min(tries[dev->devno], 1);
2534 	case -EIO:
2535 		if (tries[dev->devno] == 1) {
2536 			/* This is the last chance, better to slow
2537 			 * down than lose it.
2538 			 */
2539 			sata_down_spd_limit(&ap->link);
2540 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2541 		}
2542 	}
2543 
2544 	if (!tries[dev->devno])
2545 		ata_dev_disable(dev);
2546 
2547 	goto retry;
2548 }
2549 
2550 /**
2551  *	ata_port_probe - Mark port as enabled
2552  *	@ap: Port for which we indicate enablement
2553  *
2554  *	Modify @ap data structure such that the system
2555  *	thinks that the entire port is enabled.
2556  *
2557  *	LOCKING: host lock, or some other form of
2558  *	serialization.
2559  */
2560 
2561 void ata_port_probe(struct ata_port *ap)
2562 {
2563 	ap->flags &= ~ATA_FLAG_DISABLED;
2564 }
2565 
2566 /**
2567  *	sata_print_link_status - Print SATA link status
2568  *	@link: SATA link to printk link status about
2569  *
2570  *	This function prints link speed and status of a SATA link.
2571  *
2572  *	LOCKING:
2573  *	None.
2574  */
2575 void sata_print_link_status(struct ata_link *link)
2576 {
2577 	u32 sstatus, scontrol, tmp;
2578 
2579 	if (sata_scr_read(link, SCR_STATUS, &sstatus))
2580 		return;
2581 	sata_scr_read(link, SCR_CONTROL, &scontrol);
2582 
2583 	if (ata_link_online(link)) {
2584 		tmp = (sstatus >> 4) & 0xf;
2585 		ata_link_printk(link, KERN_INFO,
2586 				"SATA link up %s (SStatus %X SControl %X)\n",
2587 				sata_spd_string(tmp), sstatus, scontrol);
2588 	} else {
2589 		ata_link_printk(link, KERN_INFO,
2590 				"SATA link down (SStatus %X SControl %X)\n",
2591 				sstatus, scontrol);
2592 	}
2593 }
2594 
2595 /**
2596  *	ata_dev_pair		-	return other device on cable
2597  *	@adev: device
2598  *
2599  *	Obtain the other device on the same cable, or if none is
2600  *	present NULL is returned
2601  */
2602 
2603 struct ata_device *ata_dev_pair(struct ata_device *adev)
2604 {
2605 	struct ata_link *link = adev->link;
2606 	struct ata_device *pair = &link->device[1 - adev->devno];
2607 	if (!ata_dev_enabled(pair))
2608 		return NULL;
2609 	return pair;
2610 }
2611 
2612 /**
2613  *	ata_port_disable - Disable port.
2614  *	@ap: Port to be disabled.
2615  *
2616  *	Modify @ap data structure such that the system
2617  *	thinks that the entire port is disabled, and should
2618  *	never attempt to probe or communicate with devices
2619  *	on this port.
2620  *
2621  *	LOCKING: host lock, or some other form of
2622  *	serialization.
2623  */
2624 
2625 void ata_port_disable(struct ata_port *ap)
2626 {
2627 	ap->link.device[0].class = ATA_DEV_NONE;
2628 	ap->link.device[1].class = ATA_DEV_NONE;
2629 	ap->flags |= ATA_FLAG_DISABLED;
2630 }
2631 
2632 /**
2633  *	sata_down_spd_limit - adjust SATA spd limit downward
2634  *	@link: Link to adjust SATA spd limit for
2635  *
2636  *	Adjust SATA spd limit of @link downward.  Note that this
2637  *	function only adjusts the limit.  The change must be applied
2638  *	using sata_set_spd().
2639  *
2640  *	LOCKING:
2641  *	Inherited from caller.
2642  *
2643  *	RETURNS:
2644  *	0 on success, negative errno on failure
2645  */
2646 int sata_down_spd_limit(struct ata_link *link)
2647 {
2648 	u32 sstatus, spd, mask;
2649 	int rc, highbit;
2650 
2651 	if (!sata_scr_valid(link))
2652 		return -EOPNOTSUPP;
2653 
2654 	/* If SCR can be read, use it to determine the current SPD.
2655 	 * If not, use cached value in link->sata_spd.
2656 	 */
2657 	rc = sata_scr_read(link, SCR_STATUS, &sstatus);
2658 	if (rc == 0)
2659 		spd = (sstatus >> 4) & 0xf;
2660 	else
2661 		spd = link->sata_spd;
2662 
2663 	mask = link->sata_spd_limit;
2664 	if (mask <= 1)
2665 		return -EINVAL;
2666 
2667 	/* unconditionally mask off the highest bit */
2668 	highbit = fls(mask) - 1;
2669 	mask &= ~(1 << highbit);
2670 
2671 	/* Mask off all speeds higher than or equal to the current
2672 	 * one.  Force 1.5Gbps if current SPD is not available.
2673 	 */
2674 	if (spd > 1)
2675 		mask &= (1 << (spd - 1)) - 1;
2676 	else
2677 		mask &= 1;
2678 
2679 	/* were we already at the bottom? */
2680 	if (!mask)
2681 		return -EINVAL;
2682 
2683 	link->sata_spd_limit = mask;
2684 
2685 	ata_link_printk(link, KERN_WARNING, "limiting SATA link speed to %s\n",
2686 			sata_spd_string(fls(mask)));
2687 
2688 	return 0;
2689 }
2690 
2691 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
2692 {
2693 	struct ata_link *host_link = &link->ap->link;
2694 	u32 limit, target, spd;
2695 
2696 	limit = link->sata_spd_limit;
2697 
2698 	/* Don't configure downstream link faster than upstream link.
2699 	 * It doesn't speed up anything and some PMPs choke on such
2700 	 * configuration.
2701 	 */
2702 	if (!ata_is_host_link(link) && host_link->sata_spd)
2703 		limit &= (1 << host_link->sata_spd) - 1;
2704 
2705 	if (limit == UINT_MAX)
2706 		target = 0;
2707 	else
2708 		target = fls(limit);
2709 
2710 	spd = (*scontrol >> 4) & 0xf;
2711 	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
2712 
2713 	return spd != target;
2714 }
2715 
2716 /**
2717  *	sata_set_spd_needed - is SATA spd configuration needed
2718  *	@link: Link in question
2719  *
2720  *	Test whether the spd limit in SControl matches
2721  *	@link->sata_spd_limit.  This function is used to determine
2722  *	whether hardreset is necessary to apply SATA spd
2723  *	configuration.
2724  *
2725  *	LOCKING:
2726  *	Inherited from caller.
2727  *
2728  *	RETURNS:
2729  *	1 if SATA spd configuration is needed, 0 otherwise.
2730  */
2731 int sata_set_spd_needed(struct ata_link *link)
2732 {
2733 	u32 scontrol;
2734 
2735 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
2736 		return 1;
2737 
2738 	return __sata_set_spd_needed(link, &scontrol);
2739 }
2740 
2741 /**
2742  *	sata_set_spd - set SATA spd according to spd limit
2743  *	@link: Link to set SATA spd for
2744  *
2745  *	Set SATA spd of @link according to sata_spd_limit.
2746  *
2747  *	LOCKING:
2748  *	Inherited from caller.
2749  *
2750  *	RETURNS:
2751  *	0 if spd doesn't need to be changed, 1 if spd has been
2752  *	changed.  Negative errno if SCR registers are inaccessible.
2753  */
2754 int sata_set_spd(struct ata_link *link)
2755 {
2756 	u32 scontrol;
2757 	int rc;
2758 
2759 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
2760 		return rc;
2761 
2762 	if (!__sata_set_spd_needed(link, &scontrol))
2763 		return 0;
2764 
2765 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
2766 		return rc;
2767 
2768 	return 1;
2769 }
2770 
2771 /*
2772  * This mode timing computation functionality is ported over from
2773  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2774  */
2775 /*
2776  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2777  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2778  * for UDMA6, which is currently supported only by Maxtor drives.
2779  *
2780  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2781  */
2782 
2783 static const struct ata_timing ata_timing[] = {
2784 
2785 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
2786 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
2787 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
2788 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
2789 
2790 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
2791 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
2792 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
2793 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
2794 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
2795 
2796 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
2797 
2798 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
2799 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
2800 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
2801 
2802 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
2803 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
2804 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
2805 
2806 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
2807 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
2808 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
2809 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
2810 
2811 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
2812 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
2813 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
2814 
2815 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
2816 
2817 	{ 0xFF }
2818 };
2819 
2820 #define ENOUGH(v, unit)		(((v)-1)/(unit)+1)
2821 #define EZ(v, unit)		((v)?ENOUGH(v, unit):0)
2822 
2823 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2824 {
2825 	q->setup   = EZ(t->setup   * 1000,  T);
2826 	q->act8b   = EZ(t->act8b   * 1000,  T);
2827 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
2828 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
2829 	q->active  = EZ(t->active  * 1000,  T);
2830 	q->recover = EZ(t->recover * 1000,  T);
2831 	q->cycle   = EZ(t->cycle   * 1000,  T);
2832 	q->udma    = EZ(t->udma    * 1000, UT);
2833 }
2834 
2835 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2836 		      struct ata_timing *m, unsigned int what)
2837 {
2838 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2839 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2840 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2841 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2842 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
2843 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
2844 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
2845 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
2846 }
2847 
2848 static const struct ata_timing *ata_timing_find_mode(unsigned short speed)
2849 {
2850 	const struct ata_timing *t;
2851 
2852 	for (t = ata_timing; t->mode != speed; t++)
2853 		if (t->mode == 0xFF)
2854 			return NULL;
2855 	return t;
2856 }
2857 
2858 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
2859 		       struct ata_timing *t, int T, int UT)
2860 {
2861 	const struct ata_timing *s;
2862 	struct ata_timing p;
2863 
2864 	/*
2865 	 * Find the mode.
2866 	 */
2867 
2868 	if (!(s = ata_timing_find_mode(speed)))
2869 		return -EINVAL;
2870 
2871 	memcpy(t, s, sizeof(*s));
2872 
2873 	/*
2874 	 * If the drive is an EIDE drive, it can tell us it needs extended
2875 	 * PIO/MW_DMA cycle timing.
2876 	 */
2877 
2878 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
2879 		memset(&p, 0, sizeof(p));
2880 		if (speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
2881 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
2882 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
2883 		} else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
2884 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
2885 		}
2886 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
2887 	}
2888 
2889 	/*
2890 	 * Convert the timing to bus clock counts.
2891 	 */
2892 
2893 	ata_timing_quantize(t, t, T, UT);
2894 
2895 	/*
2896 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
2897 	 * S.M.A.R.T * and some other commands. We have to ensure that the
2898 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
2899 	 */
2900 
2901 	if (speed > XFER_PIO_6) {
2902 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
2903 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
2904 	}
2905 
2906 	/*
2907 	 * Lengthen active & recovery time so that cycle time is correct.
2908 	 */
2909 
2910 	if (t->act8b + t->rec8b < t->cyc8b) {
2911 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
2912 		t->rec8b = t->cyc8b - t->act8b;
2913 	}
2914 
2915 	if (t->active + t->recover < t->cycle) {
2916 		t->active += (t->cycle - (t->active + t->recover)) / 2;
2917 		t->recover = t->cycle - t->active;
2918 	}
2919 
2920 	/* In a few cases quantisation may produce enough errors to
2921 	   leave t->cycle too low for the sum of active and recovery
2922 	   if so we must correct this */
2923 	if (t->active + t->recover > t->cycle)
2924 		t->cycle = t->active + t->recover;
2925 
2926 	return 0;
2927 }
2928 
2929 /**
2930  *	ata_down_xfermask_limit - adjust dev xfer masks downward
2931  *	@dev: Device to adjust xfer masks
2932  *	@sel: ATA_DNXFER_* selector
2933  *
2934  *	Adjust xfer masks of @dev downward.  Note that this function
2935  *	does not apply the change.  Invoking ata_set_mode() afterwards
2936  *	will apply the limit.
2937  *
2938  *	LOCKING:
2939  *	Inherited from caller.
2940  *
2941  *	RETURNS:
2942  *	0 on success, negative errno on failure
2943  */
2944 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
2945 {
2946 	char buf[32];
2947 	unsigned int orig_mask, xfer_mask;
2948 	unsigned int pio_mask, mwdma_mask, udma_mask;
2949 	int quiet, highbit;
2950 
2951 	quiet = !!(sel & ATA_DNXFER_QUIET);
2952 	sel &= ~ATA_DNXFER_QUIET;
2953 
2954 	xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
2955 						  dev->mwdma_mask,
2956 						  dev->udma_mask);
2957 	ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
2958 
2959 	switch (sel) {
2960 	case ATA_DNXFER_PIO:
2961 		highbit = fls(pio_mask) - 1;
2962 		pio_mask &= ~(1 << highbit);
2963 		break;
2964 
2965 	case ATA_DNXFER_DMA:
2966 		if (udma_mask) {
2967 			highbit = fls(udma_mask) - 1;
2968 			udma_mask &= ~(1 << highbit);
2969 			if (!udma_mask)
2970 				return -ENOENT;
2971 		} else if (mwdma_mask) {
2972 			highbit = fls(mwdma_mask) - 1;
2973 			mwdma_mask &= ~(1 << highbit);
2974 			if (!mwdma_mask)
2975 				return -ENOENT;
2976 		}
2977 		break;
2978 
2979 	case ATA_DNXFER_40C:
2980 		udma_mask &= ATA_UDMA_MASK_40C;
2981 		break;
2982 
2983 	case ATA_DNXFER_FORCE_PIO0:
2984 		pio_mask &= 1;
2985 	case ATA_DNXFER_FORCE_PIO:
2986 		mwdma_mask = 0;
2987 		udma_mask = 0;
2988 		break;
2989 
2990 	default:
2991 		BUG();
2992 	}
2993 
2994 	xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
2995 
2996 	if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
2997 		return -ENOENT;
2998 
2999 	if (!quiet) {
3000 		if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
3001 			snprintf(buf, sizeof(buf), "%s:%s",
3002 				 ata_mode_string(xfer_mask),
3003 				 ata_mode_string(xfer_mask & ATA_MASK_PIO));
3004 		else
3005 			snprintf(buf, sizeof(buf), "%s",
3006 				 ata_mode_string(xfer_mask));
3007 
3008 		ata_dev_printk(dev, KERN_WARNING,
3009 			       "limiting speed to %s\n", buf);
3010 	}
3011 
3012 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
3013 			    &dev->udma_mask);
3014 
3015 	return 0;
3016 }
3017 
3018 static int ata_dev_set_mode(struct ata_device *dev)
3019 {
3020 	struct ata_eh_context *ehc = &dev->link->eh_context;
3021 	unsigned int err_mask;
3022 	int rc;
3023 
3024 	dev->flags &= ~ATA_DFLAG_PIO;
3025 	if (dev->xfer_shift == ATA_SHIFT_PIO)
3026 		dev->flags |= ATA_DFLAG_PIO;
3027 
3028 	err_mask = ata_dev_set_xfermode(dev);
3029 
3030 	/* Old CFA may refuse this command, which is just fine */
3031 	if (dev->xfer_shift == ATA_SHIFT_PIO && ata_id_is_cfa(dev->id))
3032 		err_mask &= ~AC_ERR_DEV;
3033 
3034 	/* Some very old devices and some bad newer ones fail any kind of
3035 	   SET_XFERMODE request but support PIO0-2 timings and no IORDY */
3036 	if (dev->xfer_shift == ATA_SHIFT_PIO && !ata_id_has_iordy(dev->id) &&
3037 			dev->pio_mode <= XFER_PIO_2)
3038 		err_mask &= ~AC_ERR_DEV;
3039 
3040 	/* Early MWDMA devices do DMA but don't allow DMA mode setting.
3041 	   Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
3042 	if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
3043 	    dev->dma_mode == XFER_MW_DMA_0 &&
3044 	    (dev->id[63] >> 8) & 1)
3045 		err_mask &= ~AC_ERR_DEV;
3046 
3047 	if (err_mask) {
3048 		ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
3049 			       "(err_mask=0x%x)\n", err_mask);
3050 		return -EIO;
3051 	}
3052 
3053 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
3054 	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
3055 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
3056 	if (rc)
3057 		return rc;
3058 
3059 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
3060 		dev->xfer_shift, (int)dev->xfer_mode);
3061 
3062 	ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
3063 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)));
3064 	return 0;
3065 }
3066 
3067 /**
3068  *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
3069  *	@link: link on which timings will be programmed
3070  *	@r_failed_dev: out paramter for failed device
3071  *
3072  *	Standard implementation of the function used to tune and set
3073  *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3074  *	ata_dev_set_mode() fails, pointer to the failing device is
3075  *	returned in @r_failed_dev.
3076  *
3077  *	LOCKING:
3078  *	PCI/etc. bus probe sem.
3079  *
3080  *	RETURNS:
3081  *	0 on success, negative errno otherwise
3082  */
3083 
3084 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3085 {
3086 	struct ata_port *ap = link->ap;
3087 	struct ata_device *dev;
3088 	int rc = 0, used_dma = 0, found = 0;
3089 
3090 	/* step 1: calculate xfer_mask */
3091 	ata_link_for_each_dev(dev, link) {
3092 		unsigned int pio_mask, dma_mask;
3093 		unsigned int mode_mask;
3094 
3095 		if (!ata_dev_enabled(dev))
3096 			continue;
3097 
3098 		mode_mask = ATA_DMA_MASK_ATA;
3099 		if (dev->class == ATA_DEV_ATAPI)
3100 			mode_mask = ATA_DMA_MASK_ATAPI;
3101 		else if (ata_id_is_cfa(dev->id))
3102 			mode_mask = ATA_DMA_MASK_CFA;
3103 
3104 		ata_dev_xfermask(dev);
3105 
3106 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
3107 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3108 
3109 		if (libata_dma_mask & mode_mask)
3110 			dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
3111 		else
3112 			dma_mask = 0;
3113 
3114 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
3115 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
3116 
3117 		found = 1;
3118 		if (dev->dma_mode)
3119 			used_dma = 1;
3120 	}
3121 	if (!found)
3122 		goto out;
3123 
3124 	/* step 2: always set host PIO timings */
3125 	ata_link_for_each_dev(dev, link) {
3126 		if (!ata_dev_enabled(dev))
3127 			continue;
3128 
3129 		if (!dev->pio_mode) {
3130 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
3131 			rc = -EINVAL;
3132 			goto out;
3133 		}
3134 
3135 		dev->xfer_mode = dev->pio_mode;
3136 		dev->xfer_shift = ATA_SHIFT_PIO;
3137 		if (ap->ops->set_piomode)
3138 			ap->ops->set_piomode(ap, dev);
3139 	}
3140 
3141 	/* step 3: set host DMA timings */
3142 	ata_link_for_each_dev(dev, link) {
3143 		if (!ata_dev_enabled(dev) || !dev->dma_mode)
3144 			continue;
3145 
3146 		dev->xfer_mode = dev->dma_mode;
3147 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
3148 		if (ap->ops->set_dmamode)
3149 			ap->ops->set_dmamode(ap, dev);
3150 	}
3151 
3152 	/* step 4: update devices' xfer mode */
3153 	ata_link_for_each_dev(dev, link) {
3154 		/* don't update suspended devices' xfer mode */
3155 		if (!ata_dev_enabled(dev))
3156 			continue;
3157 
3158 		rc = ata_dev_set_mode(dev);
3159 		if (rc)
3160 			goto out;
3161 	}
3162 
3163 	/* Record simplex status. If we selected DMA then the other
3164 	 * host channels are not permitted to do so.
3165 	 */
3166 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
3167 		ap->host->simplex_claimed = ap;
3168 
3169  out:
3170 	if (rc)
3171 		*r_failed_dev = dev;
3172 	return rc;
3173 }
3174 
3175 /**
3176  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
3177  *	@link: link on which timings will be programmed
3178  *	@r_failed_dev: out paramter for failed device
3179  *
3180  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3181  *	ata_set_mode() fails, pointer to the failing device is
3182  *	returned in @r_failed_dev.
3183  *
3184  *	LOCKING:
3185  *	PCI/etc. bus probe sem.
3186  *
3187  *	RETURNS:
3188  *	0 on success, negative errno otherwise
3189  */
3190 int ata_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3191 {
3192 	struct ata_port *ap = link->ap;
3193 
3194 	/* has private set_mode? */
3195 	if (ap->ops->set_mode)
3196 		return ap->ops->set_mode(link, r_failed_dev);
3197 	return ata_do_set_mode(link, r_failed_dev);
3198 }
3199 
3200 /**
3201  *	ata_tf_to_host - issue ATA taskfile to host controller
3202  *	@ap: port to which command is being issued
3203  *	@tf: ATA taskfile register set
3204  *
3205  *	Issues ATA taskfile register set to ATA host controller,
3206  *	with proper synchronization with interrupt handler and
3207  *	other threads.
3208  *
3209  *	LOCKING:
3210  *	spin_lock_irqsave(host lock)
3211  */
3212 
3213 static inline void ata_tf_to_host(struct ata_port *ap,
3214 				  const struct ata_taskfile *tf)
3215 {
3216 	ap->ops->tf_load(ap, tf);
3217 	ap->ops->exec_command(ap, tf);
3218 }
3219 
3220 /**
3221  *	ata_busy_sleep - sleep until BSY clears, or timeout
3222  *	@ap: port containing status register to be polled
3223  *	@tmout_pat: impatience timeout
3224  *	@tmout: overall timeout
3225  *
3226  *	Sleep until ATA Status register bit BSY clears,
3227  *	or a timeout occurs.
3228  *
3229  *	LOCKING:
3230  *	Kernel thread context (may sleep).
3231  *
3232  *	RETURNS:
3233  *	0 on success, -errno otherwise.
3234  */
3235 int ata_busy_sleep(struct ata_port *ap,
3236 		   unsigned long tmout_pat, unsigned long tmout)
3237 {
3238 	unsigned long timer_start, timeout;
3239 	u8 status;
3240 
3241 	status = ata_busy_wait(ap, ATA_BUSY, 300);
3242 	timer_start = jiffies;
3243 	timeout = timer_start + tmout_pat;
3244 	while (status != 0xff && (status & ATA_BUSY) &&
3245 	       time_before(jiffies, timeout)) {
3246 		msleep(50);
3247 		status = ata_busy_wait(ap, ATA_BUSY, 3);
3248 	}
3249 
3250 	if (status != 0xff && (status & ATA_BUSY))
3251 		ata_port_printk(ap, KERN_WARNING,
3252 				"port is slow to respond, please be patient "
3253 				"(Status 0x%x)\n", status);
3254 
3255 	timeout = timer_start + tmout;
3256 	while (status != 0xff && (status & ATA_BUSY) &&
3257 	       time_before(jiffies, timeout)) {
3258 		msleep(50);
3259 		status = ata_chk_status(ap);
3260 	}
3261 
3262 	if (status == 0xff)
3263 		return -ENODEV;
3264 
3265 	if (status & ATA_BUSY) {
3266 		ata_port_printk(ap, KERN_ERR, "port failed to respond "
3267 				"(%lu secs, Status 0x%x)\n",
3268 				tmout / HZ, status);
3269 		return -EBUSY;
3270 	}
3271 
3272 	return 0;
3273 }
3274 
3275 /**
3276  *	ata_wait_after_reset - wait before checking status after reset
3277  *	@ap: port containing status register to be polled
3278  *	@deadline: deadline jiffies for the operation
3279  *
3280  *	After reset, we need to pause a while before reading status.
3281  *	Also, certain combination of controller and device report 0xff
3282  *	for some duration (e.g. until SATA PHY is up and running)
3283  *	which is interpreted as empty port in ATA world.  This
3284  *	function also waits for such devices to get out of 0xff
3285  *	status.
3286  *
3287  *	LOCKING:
3288  *	Kernel thread context (may sleep).
3289  */
3290 void ata_wait_after_reset(struct ata_port *ap, unsigned long deadline)
3291 {
3292 	unsigned long until = jiffies + ATA_TMOUT_FF_WAIT;
3293 
3294 	if (time_before(until, deadline))
3295 		deadline = until;
3296 
3297 	/* Spec mandates ">= 2ms" before checking status.  We wait
3298 	 * 150ms, because that was the magic delay used for ATAPI
3299 	 * devices in Hale Landis's ATADRVR, for the period of time
3300 	 * between when the ATA command register is written, and then
3301 	 * status is checked.  Because waiting for "a while" before
3302 	 * checking status is fine, post SRST, we perform this magic
3303 	 * delay here as well.
3304 	 *
3305 	 * Old drivers/ide uses the 2mS rule and then waits for ready.
3306 	 */
3307 	msleep(150);
3308 
3309 	/* Wait for 0xff to clear.  Some SATA devices take a long time
3310 	 * to clear 0xff after reset.  For example, HHD424020F7SV00
3311 	 * iVDR needs >= 800ms while.  Quantum GoVault needs even more
3312 	 * than that.
3313 	 *
3314 	 * Note that some PATA controllers (pata_ali) explode if
3315 	 * status register is read more than once when there's no
3316 	 * device attached.
3317 	 */
3318 	if (ap->flags & ATA_FLAG_SATA) {
3319 		while (1) {
3320 			u8 status = ata_chk_status(ap);
3321 
3322 			if (status != 0xff || time_after(jiffies, deadline))
3323 				return;
3324 
3325 			msleep(50);
3326 		}
3327 	}
3328 }
3329 
3330 /**
3331  *	ata_wait_ready - sleep until BSY clears, or timeout
3332  *	@ap: port containing status register to be polled
3333  *	@deadline: deadline jiffies for the operation
3334  *
3335  *	Sleep until ATA Status register bit BSY clears, or timeout
3336  *	occurs.
3337  *
3338  *	LOCKING:
3339  *	Kernel thread context (may sleep).
3340  *
3341  *	RETURNS:
3342  *	0 on success, -errno otherwise.
3343  */
3344 int ata_wait_ready(struct ata_port *ap, unsigned long deadline)
3345 {
3346 	unsigned long start = jiffies;
3347 	int warned = 0;
3348 
3349 	while (1) {
3350 		u8 status = ata_chk_status(ap);
3351 		unsigned long now = jiffies;
3352 
3353 		if (!(status & ATA_BUSY))
3354 			return 0;
3355 		if (!ata_link_online(&ap->link) && status == 0xff)
3356 			return -ENODEV;
3357 		if (time_after(now, deadline))
3358 			return -EBUSY;
3359 
3360 		if (!warned && time_after(now, start + 5 * HZ) &&
3361 		    (deadline - now > 3 * HZ)) {
3362 			ata_port_printk(ap, KERN_WARNING,
3363 				"port is slow to respond, please be patient "
3364 				"(Status 0x%x)\n", status);
3365 			warned = 1;
3366 		}
3367 
3368 		msleep(50);
3369 	}
3370 }
3371 
3372 static int ata_bus_post_reset(struct ata_port *ap, unsigned int devmask,
3373 			      unsigned long deadline)
3374 {
3375 	struct ata_ioports *ioaddr = &ap->ioaddr;
3376 	unsigned int dev0 = devmask & (1 << 0);
3377 	unsigned int dev1 = devmask & (1 << 1);
3378 	int rc, ret = 0;
3379 
3380 	/* if device 0 was found in ata_devchk, wait for its
3381 	 * BSY bit to clear
3382 	 */
3383 	if (dev0) {
3384 		rc = ata_wait_ready(ap, deadline);
3385 		if (rc) {
3386 			if (rc != -ENODEV)
3387 				return rc;
3388 			ret = rc;
3389 		}
3390 	}
3391 
3392 	/* if device 1 was found in ata_devchk, wait for register
3393 	 * access briefly, then wait for BSY to clear.
3394 	 */
3395 	if (dev1) {
3396 		int i;
3397 
3398 		ap->ops->dev_select(ap, 1);
3399 
3400 		/* Wait for register access.  Some ATAPI devices fail
3401 		 * to set nsect/lbal after reset, so don't waste too
3402 		 * much time on it.  We're gonna wait for !BSY anyway.
3403 		 */
3404 		for (i = 0; i < 2; i++) {
3405 			u8 nsect, lbal;
3406 
3407 			nsect = ioread8(ioaddr->nsect_addr);
3408 			lbal = ioread8(ioaddr->lbal_addr);
3409 			if ((nsect == 1) && (lbal == 1))
3410 				break;
3411 			msleep(50);	/* give drive a breather */
3412 		}
3413 
3414 		rc = ata_wait_ready(ap, deadline);
3415 		if (rc) {
3416 			if (rc != -ENODEV)
3417 				return rc;
3418 			ret = rc;
3419 		}
3420 	}
3421 
3422 	/* is all this really necessary? */
3423 	ap->ops->dev_select(ap, 0);
3424 	if (dev1)
3425 		ap->ops->dev_select(ap, 1);
3426 	if (dev0)
3427 		ap->ops->dev_select(ap, 0);
3428 
3429 	return ret;
3430 }
3431 
3432 static int ata_bus_softreset(struct ata_port *ap, unsigned int devmask,
3433 			     unsigned long deadline)
3434 {
3435 	struct ata_ioports *ioaddr = &ap->ioaddr;
3436 
3437 	DPRINTK("ata%u: bus reset via SRST\n", ap->print_id);
3438 
3439 	/* software reset.  causes dev0 to be selected */
3440 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3441 	udelay(20);	/* FIXME: flush */
3442 	iowrite8(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
3443 	udelay(20);	/* FIXME: flush */
3444 	iowrite8(ap->ctl, ioaddr->ctl_addr);
3445 
3446 	/* wait a while before checking status */
3447 	ata_wait_after_reset(ap, deadline);
3448 
3449 	/* Before we perform post reset processing we want to see if
3450 	 * the bus shows 0xFF because the odd clown forgets the D7
3451 	 * pulldown resistor.
3452 	 */
3453 	if (ata_chk_status(ap) == 0xFF)
3454 		return -ENODEV;
3455 
3456 	return ata_bus_post_reset(ap, devmask, deadline);
3457 }
3458 
3459 /**
3460  *	ata_bus_reset - reset host port and associated ATA channel
3461  *	@ap: port to reset
3462  *
3463  *	This is typically the first time we actually start issuing
3464  *	commands to the ATA channel.  We wait for BSY to clear, then
3465  *	issue EXECUTE DEVICE DIAGNOSTIC command, polling for its
3466  *	result.  Determine what devices, if any, are on the channel
3467  *	by looking at the device 0/1 error register.  Look at the signature
3468  *	stored in each device's taskfile registers, to determine if
3469  *	the device is ATA or ATAPI.
3470  *
3471  *	LOCKING:
3472  *	PCI/etc. bus probe sem.
3473  *	Obtains host lock.
3474  *
3475  *	SIDE EFFECTS:
3476  *	Sets ATA_FLAG_DISABLED if bus reset fails.
3477  */
3478 
3479 void ata_bus_reset(struct ata_port *ap)
3480 {
3481 	struct ata_device *device = ap->link.device;
3482 	struct ata_ioports *ioaddr = &ap->ioaddr;
3483 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
3484 	u8 err;
3485 	unsigned int dev0, dev1 = 0, devmask = 0;
3486 	int rc;
3487 
3488 	DPRINTK("ENTER, host %u, port %u\n", ap->print_id, ap->port_no);
3489 
3490 	/* determine if device 0/1 are present */
3491 	if (ap->flags & ATA_FLAG_SATA_RESET)
3492 		dev0 = 1;
3493 	else {
3494 		dev0 = ata_devchk(ap, 0);
3495 		if (slave_possible)
3496 			dev1 = ata_devchk(ap, 1);
3497 	}
3498 
3499 	if (dev0)
3500 		devmask |= (1 << 0);
3501 	if (dev1)
3502 		devmask |= (1 << 1);
3503 
3504 	/* select device 0 again */
3505 	ap->ops->dev_select(ap, 0);
3506 
3507 	/* issue bus reset */
3508 	if (ap->flags & ATA_FLAG_SRST) {
3509 		rc = ata_bus_softreset(ap, devmask, jiffies + 40 * HZ);
3510 		if (rc && rc != -ENODEV)
3511 			goto err_out;
3512 	}
3513 
3514 	/*
3515 	 * determine by signature whether we have ATA or ATAPI devices
3516 	 */
3517 	device[0].class = ata_dev_try_classify(&device[0], dev0, &err);
3518 	if ((slave_possible) && (err != 0x81))
3519 		device[1].class = ata_dev_try_classify(&device[1], dev1, &err);
3520 
3521 	/* is double-select really necessary? */
3522 	if (device[1].class != ATA_DEV_NONE)
3523 		ap->ops->dev_select(ap, 1);
3524 	if (device[0].class != ATA_DEV_NONE)
3525 		ap->ops->dev_select(ap, 0);
3526 
3527 	/* if no devices were detected, disable this port */
3528 	if ((device[0].class == ATA_DEV_NONE) &&
3529 	    (device[1].class == ATA_DEV_NONE))
3530 		goto err_out;
3531 
3532 	if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
3533 		/* set up device control for ATA_FLAG_SATA_RESET */
3534 		iowrite8(ap->ctl, ioaddr->ctl_addr);
3535 	}
3536 
3537 	DPRINTK("EXIT\n");
3538 	return;
3539 
3540 err_out:
3541 	ata_port_printk(ap, KERN_ERR, "disabling port\n");
3542 	ata_port_disable(ap);
3543 
3544 	DPRINTK("EXIT\n");
3545 }
3546 
3547 /**
3548  *	sata_link_debounce - debounce SATA phy status
3549  *	@link: ATA link to debounce SATA phy status for
3550  *	@params: timing parameters { interval, duratinon, timeout } in msec
3551  *	@deadline: deadline jiffies for the operation
3552  *
3553 *	Make sure SStatus of @link reaches stable state, determined by
3554  *	holding the same value where DET is not 1 for @duration polled
3555  *	every @interval, before @timeout.  Timeout constraints the
3556  *	beginning of the stable state.  Because DET gets stuck at 1 on
3557  *	some controllers after hot unplugging, this functions waits
3558  *	until timeout then returns 0 if DET is stable at 1.
3559  *
3560  *	@timeout is further limited by @deadline.  The sooner of the
3561  *	two is used.
3562  *
3563  *	LOCKING:
3564  *	Kernel thread context (may sleep)
3565  *
3566  *	RETURNS:
3567  *	0 on success, -errno on failure.
3568  */
3569 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
3570 		       unsigned long deadline)
3571 {
3572 	unsigned long interval_msec = params[0];
3573 	unsigned long duration = msecs_to_jiffies(params[1]);
3574 	unsigned long last_jiffies, t;
3575 	u32 last, cur;
3576 	int rc;
3577 
3578 	t = jiffies + msecs_to_jiffies(params[2]);
3579 	if (time_before(t, deadline))
3580 		deadline = t;
3581 
3582 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3583 		return rc;
3584 	cur &= 0xf;
3585 
3586 	last = cur;
3587 	last_jiffies = jiffies;
3588 
3589 	while (1) {
3590 		msleep(interval_msec);
3591 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3592 			return rc;
3593 		cur &= 0xf;
3594 
3595 		/* DET stable? */
3596 		if (cur == last) {
3597 			if (cur == 1 && time_before(jiffies, deadline))
3598 				continue;
3599 			if (time_after(jiffies, last_jiffies + duration))
3600 				return 0;
3601 			continue;
3602 		}
3603 
3604 		/* unstable, start over */
3605 		last = cur;
3606 		last_jiffies = jiffies;
3607 
3608 		/* Check deadline.  If debouncing failed, return
3609 		 * -EPIPE to tell upper layer to lower link speed.
3610 		 */
3611 		if (time_after(jiffies, deadline))
3612 			return -EPIPE;
3613 	}
3614 }
3615 
3616 /**
3617  *	sata_link_resume - resume SATA link
3618  *	@link: ATA link to resume SATA
3619  *	@params: timing parameters { interval, duratinon, timeout } in msec
3620  *	@deadline: deadline jiffies for the operation
3621  *
3622  *	Resume SATA phy @link and debounce it.
3623  *
3624  *	LOCKING:
3625  *	Kernel thread context (may sleep)
3626  *
3627  *	RETURNS:
3628  *	0 on success, -errno on failure.
3629  */
3630 int sata_link_resume(struct ata_link *link, const unsigned long *params,
3631 		     unsigned long deadline)
3632 {
3633 	u32 scontrol;
3634 	int rc;
3635 
3636 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3637 		return rc;
3638 
3639 	scontrol = (scontrol & 0x0f0) | 0x300;
3640 
3641 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3642 		return rc;
3643 
3644 	/* Some PHYs react badly if SStatus is pounded immediately
3645 	 * after resuming.  Delay 200ms before debouncing.
3646 	 */
3647 	msleep(200);
3648 
3649 	return sata_link_debounce(link, params, deadline);
3650 }
3651 
3652 /**
3653  *	ata_std_prereset - prepare for reset
3654  *	@link: ATA link to be reset
3655  *	@deadline: deadline jiffies for the operation
3656  *
3657  *	@link is about to be reset.  Initialize it.  Failure from
3658  *	prereset makes libata abort whole reset sequence and give up
3659  *	that port, so prereset should be best-effort.  It does its
3660  *	best to prepare for reset sequence but if things go wrong, it
3661  *	should just whine, not fail.
3662  *
3663  *	LOCKING:
3664  *	Kernel thread context (may sleep)
3665  *
3666  *	RETURNS:
3667  *	0 on success, -errno otherwise.
3668  */
3669 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
3670 {
3671 	struct ata_port *ap = link->ap;
3672 	struct ata_eh_context *ehc = &link->eh_context;
3673 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
3674 	int rc;
3675 
3676 	/* handle link resume */
3677 	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
3678 	    (link->flags & ATA_LFLAG_HRST_TO_RESUME))
3679 		ehc->i.action |= ATA_EH_HARDRESET;
3680 
3681 	/* Some PMPs don't work with only SRST, force hardreset if PMP
3682 	 * is supported.
3683 	 */
3684 	if (ap->flags & ATA_FLAG_PMP)
3685 		ehc->i.action |= ATA_EH_HARDRESET;
3686 
3687 	/* if we're about to do hardreset, nothing more to do */
3688 	if (ehc->i.action & ATA_EH_HARDRESET)
3689 		return 0;
3690 
3691 	/* if SATA, resume link */
3692 	if (ap->flags & ATA_FLAG_SATA) {
3693 		rc = sata_link_resume(link, timing, deadline);
3694 		/* whine about phy resume failure but proceed */
3695 		if (rc && rc != -EOPNOTSUPP)
3696 			ata_link_printk(link, KERN_WARNING, "failed to resume "
3697 					"link for reset (errno=%d)\n", rc);
3698 	}
3699 
3700 	/* Wait for !BSY if the controller can wait for the first D2H
3701 	 * Reg FIS and we don't know that no device is attached.
3702 	 */
3703 	if (!(link->flags & ATA_LFLAG_SKIP_D2H_BSY) && !ata_link_offline(link)) {
3704 		rc = ata_wait_ready(ap, deadline);
3705 		if (rc && rc != -ENODEV) {
3706 			ata_link_printk(link, KERN_WARNING, "device not ready "
3707 					"(errno=%d), forcing hardreset\n", rc);
3708 			ehc->i.action |= ATA_EH_HARDRESET;
3709 		}
3710 	}
3711 
3712 	return 0;
3713 }
3714 
3715 /**
3716  *	ata_std_softreset - reset host port via ATA SRST
3717  *	@link: ATA link to reset
3718  *	@classes: resulting classes of attached devices
3719  *	@deadline: deadline jiffies for the operation
3720  *
3721  *	Reset host port using ATA SRST.
3722  *
3723  *	LOCKING:
3724  *	Kernel thread context (may sleep)
3725  *
3726  *	RETURNS:
3727  *	0 on success, -errno otherwise.
3728  */
3729 int ata_std_softreset(struct ata_link *link, unsigned int *classes,
3730 		      unsigned long deadline)
3731 {
3732 	struct ata_port *ap = link->ap;
3733 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
3734 	unsigned int devmask = 0;
3735 	int rc;
3736 	u8 err;
3737 
3738 	DPRINTK("ENTER\n");
3739 
3740 	if (ata_link_offline(link)) {
3741 		classes[0] = ATA_DEV_NONE;
3742 		goto out;
3743 	}
3744 
3745 	/* determine if device 0/1 are present */
3746 	if (ata_devchk(ap, 0))
3747 		devmask |= (1 << 0);
3748 	if (slave_possible && ata_devchk(ap, 1))
3749 		devmask |= (1 << 1);
3750 
3751 	/* select device 0 again */
3752 	ap->ops->dev_select(ap, 0);
3753 
3754 	/* issue bus reset */
3755 	DPRINTK("about to softreset, devmask=%x\n", devmask);
3756 	rc = ata_bus_softreset(ap, devmask, deadline);
3757 	/* if link is occupied, -ENODEV too is an error */
3758 	if (rc && (rc != -ENODEV || sata_scr_valid(link))) {
3759 		ata_link_printk(link, KERN_ERR, "SRST failed (errno=%d)\n", rc);
3760 		return rc;
3761 	}
3762 
3763 	/* determine by signature whether we have ATA or ATAPI devices */
3764 	classes[0] = ata_dev_try_classify(&link->device[0],
3765 					  devmask & (1 << 0), &err);
3766 	if (slave_possible && err != 0x81)
3767 		classes[1] = ata_dev_try_classify(&link->device[1],
3768 						  devmask & (1 << 1), &err);
3769 
3770  out:
3771 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
3772 	return 0;
3773 }
3774 
3775 /**
3776  *	sata_link_hardreset - reset link via SATA phy reset
3777  *	@link: link to reset
3778  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3779  *	@deadline: deadline jiffies for the operation
3780  *
3781  *	SATA phy-reset @link using DET bits of SControl register.
3782  *
3783  *	LOCKING:
3784  *	Kernel thread context (may sleep)
3785  *
3786  *	RETURNS:
3787  *	0 on success, -errno otherwise.
3788  */
3789 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
3790 			unsigned long deadline)
3791 {
3792 	u32 scontrol;
3793 	int rc;
3794 
3795 	DPRINTK("ENTER\n");
3796 
3797 	if (sata_set_spd_needed(link)) {
3798 		/* SATA spec says nothing about how to reconfigure
3799 		 * spd.  To be on the safe side, turn off phy during
3800 		 * reconfiguration.  This works for at least ICH7 AHCI
3801 		 * and Sil3124.
3802 		 */
3803 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3804 			goto out;
3805 
3806 		scontrol = (scontrol & 0x0f0) | 0x304;
3807 
3808 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3809 			goto out;
3810 
3811 		sata_set_spd(link);
3812 	}
3813 
3814 	/* issue phy wake/reset */
3815 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3816 		goto out;
3817 
3818 	scontrol = (scontrol & 0x0f0) | 0x301;
3819 
3820 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
3821 		goto out;
3822 
3823 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3824 	 * 10.4.2 says at least 1 ms.
3825 	 */
3826 	msleep(1);
3827 
3828 	/* bring link back */
3829 	rc = sata_link_resume(link, timing, deadline);
3830  out:
3831 	DPRINTK("EXIT, rc=%d\n", rc);
3832 	return rc;
3833 }
3834 
3835 /**
3836  *	sata_std_hardreset - reset host port via SATA phy reset
3837  *	@link: link to reset
3838  *	@class: resulting class of attached device
3839  *	@deadline: deadline jiffies for the operation
3840  *
3841  *	SATA phy-reset host port using DET bits of SControl register,
3842  *	wait for !BSY and classify the attached device.
3843  *
3844  *	LOCKING:
3845  *	Kernel thread context (may sleep)
3846  *
3847  *	RETURNS:
3848  *	0 on success, -errno otherwise.
3849  */
3850 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
3851 		       unsigned long deadline)
3852 {
3853 	struct ata_port *ap = link->ap;
3854 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
3855 	int rc;
3856 
3857 	DPRINTK("ENTER\n");
3858 
3859 	/* do hardreset */
3860 	rc = sata_link_hardreset(link, timing, deadline);
3861 	if (rc) {
3862 		ata_link_printk(link, KERN_ERR,
3863 				"COMRESET failed (errno=%d)\n", rc);
3864 		return rc;
3865 	}
3866 
3867 	/* TODO: phy layer with polling, timeouts, etc. */
3868 	if (ata_link_offline(link)) {
3869 		*class = ATA_DEV_NONE;
3870 		DPRINTK("EXIT, link offline\n");
3871 		return 0;
3872 	}
3873 
3874 	/* wait a while before checking status */
3875 	ata_wait_after_reset(ap, deadline);
3876 
3877 	/* If PMP is supported, we have to do follow-up SRST.  Note
3878 	 * that some PMPs don't send D2H Reg FIS after hardreset at
3879 	 * all if the first port is empty.  Wait for it just for a
3880 	 * second and request follow-up SRST.
3881 	 */
3882 	if (ap->flags & ATA_FLAG_PMP) {
3883 		ata_wait_ready(ap, jiffies + HZ);
3884 		return -EAGAIN;
3885 	}
3886 
3887 	rc = ata_wait_ready(ap, deadline);
3888 	/* link occupied, -ENODEV too is an error */
3889 	if (rc) {
3890 		ata_link_printk(link, KERN_ERR,
3891 				"COMRESET failed (errno=%d)\n", rc);
3892 		return rc;
3893 	}
3894 
3895 	ap->ops->dev_select(ap, 0);	/* probably unnecessary */
3896 
3897 	*class = ata_dev_try_classify(link->device, 1, NULL);
3898 
3899 	DPRINTK("EXIT, class=%u\n", *class);
3900 	return 0;
3901 }
3902 
3903 /**
3904  *	ata_std_postreset - standard postreset callback
3905  *	@link: the target ata_link
3906  *	@classes: classes of attached devices
3907  *
3908  *	This function is invoked after a successful reset.  Note that
3909  *	the device might have been reset more than once using
3910  *	different reset methods before postreset is invoked.
3911  *
3912  *	LOCKING:
3913  *	Kernel thread context (may sleep)
3914  */
3915 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
3916 {
3917 	struct ata_port *ap = link->ap;
3918 	u32 serror;
3919 
3920 	DPRINTK("ENTER\n");
3921 
3922 	/* print link status */
3923 	sata_print_link_status(link);
3924 
3925 	/* clear SError */
3926 	if (sata_scr_read(link, SCR_ERROR, &serror) == 0)
3927 		sata_scr_write(link, SCR_ERROR, serror);
3928 	link->eh_info.serror = 0;
3929 
3930 	/* is double-select really necessary? */
3931 	if (classes[0] != ATA_DEV_NONE)
3932 		ap->ops->dev_select(ap, 1);
3933 	if (classes[1] != ATA_DEV_NONE)
3934 		ap->ops->dev_select(ap, 0);
3935 
3936 	/* bail out if no device is present */
3937 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
3938 		DPRINTK("EXIT, no device\n");
3939 		return;
3940 	}
3941 
3942 	/* set up device control */
3943 	if (ap->ioaddr.ctl_addr)
3944 		iowrite8(ap->ctl, ap->ioaddr.ctl_addr);
3945 
3946 	DPRINTK("EXIT\n");
3947 }
3948 
3949 /**
3950  *	ata_dev_same_device - Determine whether new ID matches configured device
3951  *	@dev: device to compare against
3952  *	@new_class: class of the new device
3953  *	@new_id: IDENTIFY page of the new device
3954  *
3955  *	Compare @new_class and @new_id against @dev and determine
3956  *	whether @dev is the device indicated by @new_class and
3957  *	@new_id.
3958  *
3959  *	LOCKING:
3960  *	None.
3961  *
3962  *	RETURNS:
3963  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3964  */
3965 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3966 			       const u16 *new_id)
3967 {
3968 	const u16 *old_id = dev->id;
3969 	unsigned char model[2][ATA_ID_PROD_LEN + 1];
3970 	unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
3971 
3972 	if (dev->class != new_class) {
3973 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
3974 			       dev->class, new_class);
3975 		return 0;
3976 	}
3977 
3978 	ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
3979 	ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
3980 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
3981 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
3982 
3983 	if (strcmp(model[0], model[1])) {
3984 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
3985 			       "'%s' != '%s'\n", model[0], model[1]);
3986 		return 0;
3987 	}
3988 
3989 	if (strcmp(serial[0], serial[1])) {
3990 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
3991 			       "'%s' != '%s'\n", serial[0], serial[1]);
3992 		return 0;
3993 	}
3994 
3995 	return 1;
3996 }
3997 
3998 /**
3999  *	ata_dev_reread_id - Re-read IDENTIFY data
4000  *	@dev: target ATA device
4001  *	@readid_flags: read ID flags
4002  *
4003  *	Re-read IDENTIFY page and make sure @dev is still attached to
4004  *	the port.
4005  *
4006  *	LOCKING:
4007  *	Kernel thread context (may sleep)
4008  *
4009  *	RETURNS:
4010  *	0 on success, negative errno otherwise
4011  */
4012 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
4013 {
4014 	unsigned int class = dev->class;
4015 	u16 *id = (void *)dev->link->ap->sector_buf;
4016 	int rc;
4017 
4018 	/* read ID data */
4019 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
4020 	if (rc)
4021 		return rc;
4022 
4023 	/* is the device still there? */
4024 	if (!ata_dev_same_device(dev, class, id))
4025 		return -ENODEV;
4026 
4027 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
4028 	return 0;
4029 }
4030 
4031 /**
4032  *	ata_dev_revalidate - Revalidate ATA device
4033  *	@dev: device to revalidate
4034  *	@new_class: new class code
4035  *	@readid_flags: read ID flags
4036  *
4037  *	Re-read IDENTIFY page, make sure @dev is still attached to the
4038  *	port and reconfigure it according to the new IDENTIFY page.
4039  *
4040  *	LOCKING:
4041  *	Kernel thread context (may sleep)
4042  *
4043  *	RETURNS:
4044  *	0 on success, negative errno otherwise
4045  */
4046 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
4047 		       unsigned int readid_flags)
4048 {
4049 	u64 n_sectors = dev->n_sectors;
4050 	int rc;
4051 
4052 	if (!ata_dev_enabled(dev))
4053 		return -ENODEV;
4054 
4055 	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
4056 	if (ata_class_enabled(new_class) &&
4057 	    new_class != ATA_DEV_ATA && new_class != ATA_DEV_ATAPI) {
4058 		ata_dev_printk(dev, KERN_INFO, "class mismatch %u != %u\n",
4059 			       dev->class, new_class);
4060 		rc = -ENODEV;
4061 		goto fail;
4062 	}
4063 
4064 	/* re-read ID */
4065 	rc = ata_dev_reread_id(dev, readid_flags);
4066 	if (rc)
4067 		goto fail;
4068 
4069 	/* configure device according to the new ID */
4070 	rc = ata_dev_configure(dev);
4071 	if (rc)
4072 		goto fail;
4073 
4074 	/* verify n_sectors hasn't changed */
4075 	if (dev->class == ATA_DEV_ATA && n_sectors &&
4076 	    dev->n_sectors != n_sectors) {
4077 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
4078 			       "%llu != %llu\n",
4079 			       (unsigned long long)n_sectors,
4080 			       (unsigned long long)dev->n_sectors);
4081 
4082 		/* restore original n_sectors */
4083 		dev->n_sectors = n_sectors;
4084 
4085 		rc = -ENODEV;
4086 		goto fail;
4087 	}
4088 
4089 	return 0;
4090 
4091  fail:
4092 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
4093 	return rc;
4094 }
4095 
4096 struct ata_blacklist_entry {
4097 	const char *model_num;
4098 	const char *model_rev;
4099 	unsigned long horkage;
4100 };
4101 
4102 static const struct ata_blacklist_entry ata_device_blacklist [] = {
4103 	/* Devices with DMA related problems under Linux */
4104 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
4105 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
4106 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
4107 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
4108 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
4109 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
4110 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
4111 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
4112 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
4113 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
4114 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
4115 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
4116 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
4117 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
4118 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
4119 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
4120 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
4121 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
4122 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
4123 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
4124 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
4125 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
4126 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
4127 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
4128 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
4129 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
4130 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
4131 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
4132 	{ "SAMSUNG CD-ROM SN-124", "N001",	ATA_HORKAGE_NODMA },
4133 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
4134 	/* Odd clown on sil3726/4726 PMPs */
4135 	{ "Config  Disk",	NULL,		ATA_HORKAGE_NODMA |
4136 						ATA_HORKAGE_SKIP_PM },
4137 
4138 	/* Weird ATAPI devices */
4139 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
4140 
4141 	/* Devices we expect to fail diagnostics */
4142 
4143 	/* Devices where NCQ should be avoided */
4144 	/* NCQ is slow */
4145 	{ "WDC WD740ADFD-00",	NULL,		ATA_HORKAGE_NONCQ },
4146 	{ "WDC WD740ADFD-00NLR1", NULL,		ATA_HORKAGE_NONCQ, },
4147 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
4148 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
4149 	/* NCQ is broken */
4150 	{ "Maxtor *",		"BANC*",	ATA_HORKAGE_NONCQ },
4151 	{ "Maxtor 7V300F0",	"VA111630",	ATA_HORKAGE_NONCQ },
4152 	{ "HITACHI HDS7250SASUN500G*", NULL,    ATA_HORKAGE_NONCQ },
4153 	{ "HITACHI HDS7225SBSUN250G*", NULL,    ATA_HORKAGE_NONCQ },
4154 	{ "ST380817AS",		"3.42",		ATA_HORKAGE_NONCQ },
4155 	{ "ST3160023AS",	"3.42",		ATA_HORKAGE_NONCQ },
4156 
4157 	/* Blacklist entries taken from Silicon Image 3124/3132
4158 	   Windows driver .inf file - also several Linux problem reports */
4159 	{ "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
4160 	{ "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
4161 	{ "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },
4162 
4163 	/* devices which puke on READ_NATIVE_MAX */
4164 	{ "HDS724040KLSA80",	"KFAOA20N",	ATA_HORKAGE_BROKEN_HPA, },
4165 	{ "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
4166 	{ "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
4167 	{ "MAXTOR 6L080L4",	"A93.0500",	ATA_HORKAGE_BROKEN_HPA },
4168 
4169 	/* Devices which report 1 sector over size HPA */
4170 	{ "ST340823A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4171 	{ "ST320413A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4172 
4173 	/* Devices which get the IVB wrong */
4174 	{ "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB, },
4175 	{ "TSSTcorp CDDVDW SH-S202J", "SB00",	  ATA_HORKAGE_IVB, },
4176 	{ "TSSTcorp CDDVDW SH-S202J", "SB01",	  ATA_HORKAGE_IVB, },
4177 	{ "TSSTcorp CDDVDW SH-S202N", "SB00",	  ATA_HORKAGE_IVB, },
4178 	{ "TSSTcorp CDDVDW SH-S202N", "SB01",	  ATA_HORKAGE_IVB, },
4179 
4180 	/* End Marker */
4181 	{ }
4182 };
4183 
4184 static int strn_pattern_cmp(const char *patt, const char *name, int wildchar)
4185 {
4186 	const char *p;
4187 	int len;
4188 
4189 	/*
4190 	 * check for trailing wildcard: *\0
4191 	 */
4192 	p = strchr(patt, wildchar);
4193 	if (p && ((*(p + 1)) == 0))
4194 		len = p - patt;
4195 	else {
4196 		len = strlen(name);
4197 		if (!len) {
4198 			if (!*patt)
4199 				return 0;
4200 			return -1;
4201 		}
4202 	}
4203 
4204 	return strncmp(patt, name, len);
4205 }
4206 
4207 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
4208 {
4209 	unsigned char model_num[ATA_ID_PROD_LEN + 1];
4210 	unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
4211 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
4212 
4213 	ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
4214 	ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
4215 
4216 	while (ad->model_num) {
4217 		if (!strn_pattern_cmp(ad->model_num, model_num, '*')) {
4218 			if (ad->model_rev == NULL)
4219 				return ad->horkage;
4220 			if (!strn_pattern_cmp(ad->model_rev, model_rev, '*'))
4221 				return ad->horkage;
4222 		}
4223 		ad++;
4224 	}
4225 	return 0;
4226 }
4227 
4228 static int ata_dma_blacklisted(const struct ata_device *dev)
4229 {
4230 	/* We don't support polling DMA.
4231 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
4232 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
4233 	 */
4234 	if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
4235 	    (dev->flags & ATA_DFLAG_CDB_INTR))
4236 		return 1;
4237 	return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
4238 }
4239 
4240 /**
4241  *	ata_is_40wire		-	check drive side detection
4242  *	@dev: device
4243  *
4244  *	Perform drive side detection decoding, allowing for device vendors
4245  *	who can't follow the documentation.
4246  */
4247 
4248 static int ata_is_40wire(struct ata_device *dev)
4249 {
4250 	if (dev->horkage & ATA_HORKAGE_IVB)
4251 		return ata_drive_40wire_relaxed(dev->id);
4252 	return ata_drive_40wire(dev->id);
4253 }
4254 
4255 /**
4256  *	ata_dev_xfermask - Compute supported xfermask of the given device
4257  *	@dev: Device to compute xfermask for
4258  *
4259  *	Compute supported xfermask of @dev and store it in
4260  *	dev->*_mask.  This function is responsible for applying all
4261  *	known limits including host controller limits, device
4262  *	blacklist, etc...
4263  *
4264  *	LOCKING:
4265  *	None.
4266  */
4267 static void ata_dev_xfermask(struct ata_device *dev)
4268 {
4269 	struct ata_link *link = dev->link;
4270 	struct ata_port *ap = link->ap;
4271 	struct ata_host *host = ap->host;
4272 	unsigned long xfer_mask;
4273 
4274 	/* controller modes available */
4275 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
4276 				      ap->mwdma_mask, ap->udma_mask);
4277 
4278 	/* drive modes available */
4279 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
4280 				       dev->mwdma_mask, dev->udma_mask);
4281 	xfer_mask &= ata_id_xfermask(dev->id);
4282 
4283 	/*
4284 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
4285 	 *	cable
4286 	 */
4287 	if (ata_dev_pair(dev)) {
4288 		/* No PIO5 or PIO6 */
4289 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
4290 		/* No MWDMA3 or MWDMA 4 */
4291 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
4292 	}
4293 
4294 	if (ata_dma_blacklisted(dev)) {
4295 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4296 		ata_dev_printk(dev, KERN_WARNING,
4297 			       "device is on DMA blacklist, disabling DMA\n");
4298 	}
4299 
4300 	if ((host->flags & ATA_HOST_SIMPLEX) &&
4301 	    host->simplex_claimed && host->simplex_claimed != ap) {
4302 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4303 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
4304 			       "other device, disabling DMA\n");
4305 	}
4306 
4307 	if (ap->flags & ATA_FLAG_NO_IORDY)
4308 		xfer_mask &= ata_pio_mask_no_iordy(dev);
4309 
4310 	if (ap->ops->mode_filter)
4311 		xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
4312 
4313 	/* Apply cable rule here.  Don't apply it early because when
4314 	 * we handle hot plug the cable type can itself change.
4315 	 * Check this last so that we know if the transfer rate was
4316 	 * solely limited by the cable.
4317 	 * Unknown or 80 wire cables reported host side are checked
4318 	 * drive side as well. Cases where we know a 40wire cable
4319 	 * is used safely for 80 are not checked here.
4320 	 */
4321 	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
4322 		/* UDMA/44 or higher would be available */
4323 		if ((ap->cbl == ATA_CBL_PATA40) ||
4324 		    (ata_is_40wire(dev) &&
4325 		    (ap->cbl == ATA_CBL_PATA_UNK ||
4326 		     ap->cbl == ATA_CBL_PATA80))) {
4327 			ata_dev_printk(dev, KERN_WARNING,
4328 				 "limited to UDMA/33 due to 40-wire cable\n");
4329 			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
4330 		}
4331 
4332 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
4333 			    &dev->mwdma_mask, &dev->udma_mask);
4334 }
4335 
4336 /**
4337  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
4338  *	@dev: Device to which command will be sent
4339  *
4340  *	Issue SET FEATURES - XFER MODE command to device @dev
4341  *	on port @ap.
4342  *
4343  *	LOCKING:
4344  *	PCI/etc. bus probe sem.
4345  *
4346  *	RETURNS:
4347  *	0 on success, AC_ERR_* mask otherwise.
4348  */
4349 
4350 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
4351 {
4352 	struct ata_taskfile tf;
4353 	unsigned int err_mask;
4354 
4355 	/* set up set-features taskfile */
4356 	DPRINTK("set features - xfer mode\n");
4357 
4358 	/* Some controllers and ATAPI devices show flaky interrupt
4359 	 * behavior after setting xfer mode.  Use polling instead.
4360 	 */
4361 	ata_tf_init(dev, &tf);
4362 	tf.command = ATA_CMD_SET_FEATURES;
4363 	tf.feature = SETFEATURES_XFER;
4364 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
4365 	tf.protocol = ATA_PROT_NODATA;
4366 	tf.nsect = dev->xfer_mode;
4367 
4368 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4369 
4370 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4371 	return err_mask;
4372 }
4373 /**
4374  *	ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
4375  *	@dev: Device to which command will be sent
4376  *	@enable: Whether to enable or disable the feature
4377  *	@feature: The sector count represents the feature to set
4378  *
4379  *	Issue SET FEATURES - SATA FEATURES command to device @dev
4380  *	on port @ap with sector count
4381  *
4382  *	LOCKING:
4383  *	PCI/etc. bus probe sem.
4384  *
4385  *	RETURNS:
4386  *	0 on success, AC_ERR_* mask otherwise.
4387  */
4388 static unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable,
4389 					u8 feature)
4390 {
4391 	struct ata_taskfile tf;
4392 	unsigned int err_mask;
4393 
4394 	/* set up set-features taskfile */
4395 	DPRINTK("set features - SATA features\n");
4396 
4397 	ata_tf_init(dev, &tf);
4398 	tf.command = ATA_CMD_SET_FEATURES;
4399 	tf.feature = enable;
4400 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4401 	tf.protocol = ATA_PROT_NODATA;
4402 	tf.nsect = feature;
4403 
4404 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4405 
4406 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4407 	return err_mask;
4408 }
4409 
4410 /**
4411  *	ata_dev_init_params - Issue INIT DEV PARAMS command
4412  *	@dev: Device to which command will be sent
4413  *	@heads: Number of heads (taskfile parameter)
4414  *	@sectors: Number of sectors (taskfile parameter)
4415  *
4416  *	LOCKING:
4417  *	Kernel thread context (may sleep)
4418  *
4419  *	RETURNS:
4420  *	0 on success, AC_ERR_* mask otherwise.
4421  */
4422 static unsigned int ata_dev_init_params(struct ata_device *dev,
4423 					u16 heads, u16 sectors)
4424 {
4425 	struct ata_taskfile tf;
4426 	unsigned int err_mask;
4427 
4428 	/* Number of sectors per track 1-255. Number of heads 1-16 */
4429 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
4430 		return AC_ERR_INVALID;
4431 
4432 	/* set up init dev params taskfile */
4433 	DPRINTK("init dev params \n");
4434 
4435 	ata_tf_init(dev, &tf);
4436 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
4437 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4438 	tf.protocol = ATA_PROT_NODATA;
4439 	tf.nsect = sectors;
4440 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
4441 
4442 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4443 	/* A clean abort indicates an original or just out of spec drive
4444 	   and we should continue as we issue the setup based on the
4445 	   drive reported working geometry */
4446 	if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
4447 		err_mask = 0;
4448 
4449 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4450 	return err_mask;
4451 }
4452 
4453 /**
4454  *	ata_sg_clean - Unmap DMA memory associated with command
4455  *	@qc: Command containing DMA memory to be released
4456  *
4457  *	Unmap all mapped DMA memory associated with this command.
4458  *
4459  *	LOCKING:
4460  *	spin_lock_irqsave(host lock)
4461  */
4462 void ata_sg_clean(struct ata_queued_cmd *qc)
4463 {
4464 	struct ata_port *ap = qc->ap;
4465 	struct scatterlist *sg = qc->__sg;
4466 	int dir = qc->dma_dir;
4467 	void *pad_buf = NULL;
4468 
4469 	WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
4470 	WARN_ON(sg == NULL);
4471 
4472 	if (qc->flags & ATA_QCFLAG_SINGLE)
4473 		WARN_ON(qc->n_elem > 1);
4474 
4475 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
4476 
4477 	/* if we padded the buffer out to 32-bit bound, and data
4478 	 * xfer direction is from-device, we must copy from the
4479 	 * pad buffer back into the supplied buffer
4480 	 */
4481 	if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
4482 		pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4483 
4484 	if (qc->flags & ATA_QCFLAG_SG) {
4485 		if (qc->n_elem)
4486 			dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
4487 		/* restore last sg */
4488 		sg_last(sg, qc->orig_n_elem)->length += qc->pad_len;
4489 		if (pad_buf) {
4490 			struct scatterlist *psg = &qc->pad_sgent;
4491 			void *addr = kmap_atomic(sg_page(psg), KM_IRQ0);
4492 			memcpy(addr + psg->offset, pad_buf, qc->pad_len);
4493 			kunmap_atomic(addr, KM_IRQ0);
4494 		}
4495 	} else {
4496 		if (qc->n_elem)
4497 			dma_unmap_single(ap->dev,
4498 				sg_dma_address(&sg[0]), sg_dma_len(&sg[0]),
4499 				dir);
4500 		/* restore sg */
4501 		sg->length += qc->pad_len;
4502 		if (pad_buf)
4503 			memcpy(qc->buf_virt + sg->length - qc->pad_len,
4504 			       pad_buf, qc->pad_len);
4505 	}
4506 
4507 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4508 	qc->__sg = NULL;
4509 }
4510 
4511 /**
4512  *	ata_fill_sg - Fill PCI IDE PRD table
4513  *	@qc: Metadata associated with taskfile to be transferred
4514  *
4515  *	Fill PCI IDE PRD (scatter-gather) table with segments
4516  *	associated with the current disk command.
4517  *
4518  *	LOCKING:
4519  *	spin_lock_irqsave(host lock)
4520  *
4521  */
4522 static void ata_fill_sg(struct ata_queued_cmd *qc)
4523 {
4524 	struct ata_port *ap = qc->ap;
4525 	struct scatterlist *sg;
4526 	unsigned int idx;
4527 
4528 	WARN_ON(qc->__sg == NULL);
4529 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
4530 
4531 	idx = 0;
4532 	ata_for_each_sg(sg, qc) {
4533 		u32 addr, offset;
4534 		u32 sg_len, len;
4535 
4536 		/* determine if physical DMA addr spans 64K boundary.
4537 		 * Note h/w doesn't support 64-bit, so we unconditionally
4538 		 * truncate dma_addr_t to u32.
4539 		 */
4540 		addr = (u32) sg_dma_address(sg);
4541 		sg_len = sg_dma_len(sg);
4542 
4543 		while (sg_len) {
4544 			offset = addr & 0xffff;
4545 			len = sg_len;
4546 			if ((offset + sg_len) > 0x10000)
4547 				len = 0x10000 - offset;
4548 
4549 			ap->prd[idx].addr = cpu_to_le32(addr);
4550 			ap->prd[idx].flags_len = cpu_to_le32(len & 0xffff);
4551 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
4552 
4553 			idx++;
4554 			sg_len -= len;
4555 			addr += len;
4556 		}
4557 	}
4558 
4559 	if (idx)
4560 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4561 }
4562 
4563 /**
4564  *	ata_fill_sg_dumb - Fill PCI IDE PRD table
4565  *	@qc: Metadata associated with taskfile to be transferred
4566  *
4567  *	Fill PCI IDE PRD (scatter-gather) table with segments
4568  *	associated with the current disk command. Perform the fill
4569  *	so that we avoid writing any length 64K records for
4570  *	controllers that don't follow the spec.
4571  *
4572  *	LOCKING:
4573  *	spin_lock_irqsave(host lock)
4574  *
4575  */
4576 static void ata_fill_sg_dumb(struct ata_queued_cmd *qc)
4577 {
4578 	struct ata_port *ap = qc->ap;
4579 	struct scatterlist *sg;
4580 	unsigned int idx;
4581 
4582 	WARN_ON(qc->__sg == NULL);
4583 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
4584 
4585 	idx = 0;
4586 	ata_for_each_sg(sg, qc) {
4587 		u32 addr, offset;
4588 		u32 sg_len, len, blen;
4589 
4590 		/* determine if physical DMA addr spans 64K boundary.
4591 		 * Note h/w doesn't support 64-bit, so we unconditionally
4592 		 * truncate dma_addr_t to u32.
4593 		 */
4594 		addr = (u32) sg_dma_address(sg);
4595 		sg_len = sg_dma_len(sg);
4596 
4597 		while (sg_len) {
4598 			offset = addr & 0xffff;
4599 			len = sg_len;
4600 			if ((offset + sg_len) > 0x10000)
4601 				len = 0x10000 - offset;
4602 
4603 			blen = len & 0xffff;
4604 			ap->prd[idx].addr = cpu_to_le32(addr);
4605 			if (blen == 0) {
4606 			   /* Some PATA chipsets like the CS5530 can't
4607 			      cope with 0x0000 meaning 64K as the spec says */
4608 				ap->prd[idx].flags_len = cpu_to_le32(0x8000);
4609 				blen = 0x8000;
4610 				ap->prd[++idx].addr = cpu_to_le32(addr + 0x8000);
4611 			}
4612 			ap->prd[idx].flags_len = cpu_to_le32(blen);
4613 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
4614 
4615 			idx++;
4616 			sg_len -= len;
4617 			addr += len;
4618 		}
4619 	}
4620 
4621 	if (idx)
4622 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
4623 }
4624 
4625 /**
4626  *	ata_check_atapi_dma - Check whether ATAPI DMA can be supported
4627  *	@qc: Metadata associated with taskfile to check
4628  *
4629  *	Allow low-level driver to filter ATA PACKET commands, returning
4630  *	a status indicating whether or not it is OK to use DMA for the
4631  *	supplied PACKET command.
4632  *
4633  *	LOCKING:
4634  *	spin_lock_irqsave(host lock)
4635  *
4636  *	RETURNS: 0 when ATAPI DMA can be used
4637  *               nonzero otherwise
4638  */
4639 int ata_check_atapi_dma(struct ata_queued_cmd *qc)
4640 {
4641 	struct ata_port *ap = qc->ap;
4642 
4643 	/* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
4644 	 * few ATAPI devices choke on such DMA requests.
4645 	 */
4646 	if (unlikely(qc->nbytes & 15))
4647 		return 1;
4648 
4649 	if (ap->ops->check_atapi_dma)
4650 		return ap->ops->check_atapi_dma(qc);
4651 
4652 	return 0;
4653 }
4654 
4655 /**
4656  *	atapi_qc_may_overflow - Check whether data transfer may overflow
4657  *	@qc: ATA command in question
4658  *
4659  *	ATAPI commands which transfer variable length data to host
4660  *	might overflow due to application error or hardare bug.  This
4661  *	function checks whether overflow should be drained and ignored
4662  *	for @qc.
4663  *
4664  *	LOCKING:
4665  *	None.
4666  *
4667  *	RETURNS:
4668  *	1 if @qc may overflow; otherwise, 0.
4669  */
4670 static int atapi_qc_may_overflow(struct ata_queued_cmd *qc)
4671 {
4672 	if (qc->tf.protocol != ATA_PROT_ATAPI &&
4673 	    qc->tf.protocol != ATA_PROT_ATAPI_DMA)
4674 		return 0;
4675 
4676 	if (qc->tf.flags & ATA_TFLAG_WRITE)
4677 		return 0;
4678 
4679 	switch (qc->cdb[0]) {
4680 	case READ_10:
4681 	case READ_12:
4682 	case WRITE_10:
4683 	case WRITE_12:
4684 	case GPCMD_READ_CD:
4685 	case GPCMD_READ_CD_MSF:
4686 		return 0;
4687 	}
4688 
4689 	return 1;
4690 }
4691 
4692 /**
4693  *	ata_std_qc_defer - Check whether a qc needs to be deferred
4694  *	@qc: ATA command in question
4695  *
4696  *	Non-NCQ commands cannot run with any other command, NCQ or
4697  *	not.  As upper layer only knows the queue depth, we are
4698  *	responsible for maintaining exclusion.  This function checks
4699  *	whether a new command @qc can be issued.
4700  *
4701  *	LOCKING:
4702  *	spin_lock_irqsave(host lock)
4703  *
4704  *	RETURNS:
4705  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
4706  */
4707 int ata_std_qc_defer(struct ata_queued_cmd *qc)
4708 {
4709 	struct ata_link *link = qc->dev->link;
4710 
4711 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4712 		if (!ata_tag_valid(link->active_tag))
4713 			return 0;
4714 	} else {
4715 		if (!ata_tag_valid(link->active_tag) && !link->sactive)
4716 			return 0;
4717 	}
4718 
4719 	return ATA_DEFER_LINK;
4720 }
4721 
4722 /**
4723  *	ata_qc_prep - Prepare taskfile for submission
4724  *	@qc: Metadata associated with taskfile to be prepared
4725  *
4726  *	Prepare ATA taskfile for submission.
4727  *
4728  *	LOCKING:
4729  *	spin_lock_irqsave(host lock)
4730  */
4731 void ata_qc_prep(struct ata_queued_cmd *qc)
4732 {
4733 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4734 		return;
4735 
4736 	ata_fill_sg(qc);
4737 }
4738 
4739 /**
4740  *	ata_dumb_qc_prep - Prepare taskfile for submission
4741  *	@qc: Metadata associated with taskfile to be prepared
4742  *
4743  *	Prepare ATA taskfile for submission.
4744  *
4745  *	LOCKING:
4746  *	spin_lock_irqsave(host lock)
4747  */
4748 void ata_dumb_qc_prep(struct ata_queued_cmd *qc)
4749 {
4750 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
4751 		return;
4752 
4753 	ata_fill_sg_dumb(qc);
4754 }
4755 
4756 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
4757 
4758 /**
4759  *	ata_sg_init_one - Associate command with memory buffer
4760  *	@qc: Command to be associated
4761  *	@buf: Memory buffer
4762  *	@buflen: Length of memory buffer, in bytes.
4763  *
4764  *	Initialize the data-related elements of queued_cmd @qc
4765  *	to point to a single memory buffer, @buf of byte length @buflen.
4766  *
4767  *	LOCKING:
4768  *	spin_lock_irqsave(host lock)
4769  */
4770 
4771 void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
4772 {
4773 	qc->flags |= ATA_QCFLAG_SINGLE;
4774 
4775 	qc->__sg = &qc->sgent;
4776 	qc->n_elem = 1;
4777 	qc->orig_n_elem = 1;
4778 	qc->buf_virt = buf;
4779 	qc->nbytes = buflen;
4780 	qc->cursg = qc->__sg;
4781 
4782 	sg_init_one(&qc->sgent, buf, buflen);
4783 }
4784 
4785 /**
4786  *	ata_sg_init - Associate command with scatter-gather table.
4787  *	@qc: Command to be associated
4788  *	@sg: Scatter-gather table.
4789  *	@n_elem: Number of elements in s/g table.
4790  *
4791  *	Initialize the data-related elements of queued_cmd @qc
4792  *	to point to a scatter-gather table @sg, containing @n_elem
4793  *	elements.
4794  *
4795  *	LOCKING:
4796  *	spin_lock_irqsave(host lock)
4797  */
4798 
4799 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
4800 		 unsigned int n_elem)
4801 {
4802 	qc->flags |= ATA_QCFLAG_SG;
4803 	qc->__sg = sg;
4804 	qc->n_elem = n_elem;
4805 	qc->orig_n_elem = n_elem;
4806 	qc->cursg = qc->__sg;
4807 }
4808 
4809 /**
4810  *	ata_sg_setup_one - DMA-map the memory buffer associated with a command.
4811  *	@qc: Command with memory buffer to be mapped.
4812  *
4813  *	DMA-map the memory buffer associated with queued_cmd @qc.
4814  *
4815  *	LOCKING:
4816  *	spin_lock_irqsave(host lock)
4817  *
4818  *	RETURNS:
4819  *	Zero on success, negative on error.
4820  */
4821 
4822 static int ata_sg_setup_one(struct ata_queued_cmd *qc)
4823 {
4824 	struct ata_port *ap = qc->ap;
4825 	int dir = qc->dma_dir;
4826 	struct scatterlist *sg = qc->__sg;
4827 	dma_addr_t dma_address;
4828 	int trim_sg = 0;
4829 
4830 	/* we must lengthen transfers to end on a 32-bit boundary */
4831 	qc->pad_len = sg->length & 3;
4832 	if (qc->pad_len) {
4833 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4834 		struct scatterlist *psg = &qc->pad_sgent;
4835 
4836 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
4837 
4838 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
4839 
4840 		if (qc->tf.flags & ATA_TFLAG_WRITE)
4841 			memcpy(pad_buf, qc->buf_virt + sg->length - qc->pad_len,
4842 			       qc->pad_len);
4843 
4844 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
4845 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
4846 		/* trim sg */
4847 		sg->length -= qc->pad_len;
4848 		if (sg->length == 0)
4849 			trim_sg = 1;
4850 
4851 		DPRINTK("padding done, sg->length=%u pad_len=%u\n",
4852 			sg->length, qc->pad_len);
4853 	}
4854 
4855 	if (trim_sg) {
4856 		qc->n_elem--;
4857 		goto skip_map;
4858 	}
4859 
4860 	dma_address = dma_map_single(ap->dev, qc->buf_virt,
4861 				     sg->length, dir);
4862 	if (dma_mapping_error(dma_address)) {
4863 		/* restore sg */
4864 		sg->length += qc->pad_len;
4865 		return -1;
4866 	}
4867 
4868 	sg_dma_address(sg) = dma_address;
4869 	sg_dma_len(sg) = sg->length;
4870 
4871 skip_map:
4872 	DPRINTK("mapped buffer of %d bytes for %s\n", sg_dma_len(sg),
4873 		qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4874 
4875 	return 0;
4876 }
4877 
4878 /**
4879  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
4880  *	@qc: Command with scatter-gather table to be mapped.
4881  *
4882  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
4883  *
4884  *	LOCKING:
4885  *	spin_lock_irqsave(host lock)
4886  *
4887  *	RETURNS:
4888  *	Zero on success, negative on error.
4889  *
4890  */
4891 
4892 static int ata_sg_setup(struct ata_queued_cmd *qc)
4893 {
4894 	struct ata_port *ap = qc->ap;
4895 	struct scatterlist *sg = qc->__sg;
4896 	struct scatterlist *lsg = sg_last(qc->__sg, qc->n_elem);
4897 	int n_elem, pre_n_elem, dir, trim_sg = 0;
4898 
4899 	VPRINTK("ENTER, ata%u\n", ap->print_id);
4900 	WARN_ON(!(qc->flags & ATA_QCFLAG_SG));
4901 
4902 	/* we must lengthen transfers to end on a 32-bit boundary */
4903 	qc->pad_len = lsg->length & 3;
4904 	if (qc->pad_len) {
4905 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
4906 		struct scatterlist *psg = &qc->pad_sgent;
4907 		unsigned int offset;
4908 
4909 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
4910 
4911 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
4912 
4913 		/*
4914 		 * psg->page/offset are used to copy to-be-written
4915 		 * data in this function or read data in ata_sg_clean.
4916 		 */
4917 		offset = lsg->offset + lsg->length - qc->pad_len;
4918 		sg_init_table(psg, 1);
4919 		sg_set_page(psg, nth_page(sg_page(lsg), offset >> PAGE_SHIFT),
4920 				qc->pad_len, offset_in_page(offset));
4921 
4922 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
4923 			void *addr = kmap_atomic(sg_page(psg), KM_IRQ0);
4924 			memcpy(pad_buf, addr + psg->offset, qc->pad_len);
4925 			kunmap_atomic(addr, KM_IRQ0);
4926 		}
4927 
4928 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
4929 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
4930 		/* trim last sg */
4931 		lsg->length -= qc->pad_len;
4932 		if (lsg->length == 0)
4933 			trim_sg = 1;
4934 
4935 		DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
4936 			qc->n_elem - 1, lsg->length, qc->pad_len);
4937 	}
4938 
4939 	pre_n_elem = qc->n_elem;
4940 	if (trim_sg && pre_n_elem)
4941 		pre_n_elem--;
4942 
4943 	if (!pre_n_elem) {
4944 		n_elem = 0;
4945 		goto skip_map;
4946 	}
4947 
4948 	dir = qc->dma_dir;
4949 	n_elem = dma_map_sg(ap->dev, sg, pre_n_elem, dir);
4950 	if (n_elem < 1) {
4951 		/* restore last sg */
4952 		lsg->length += qc->pad_len;
4953 		return -1;
4954 	}
4955 
4956 	DPRINTK("%d sg elements mapped\n", n_elem);
4957 
4958 skip_map:
4959 	qc->n_elem = n_elem;
4960 
4961 	return 0;
4962 }
4963 
4964 /**
4965  *	swap_buf_le16 - swap halves of 16-bit words in place
4966  *	@buf:  Buffer to swap
4967  *	@buf_words:  Number of 16-bit words in buffer.
4968  *
4969  *	Swap halves of 16-bit words if needed to convert from
4970  *	little-endian byte order to native cpu byte order, or
4971  *	vice-versa.
4972  *
4973  *	LOCKING:
4974  *	Inherited from caller.
4975  */
4976 void swap_buf_le16(u16 *buf, unsigned int buf_words)
4977 {
4978 #ifdef __BIG_ENDIAN
4979 	unsigned int i;
4980 
4981 	for (i = 0; i < buf_words; i++)
4982 		buf[i] = le16_to_cpu(buf[i]);
4983 #endif /* __BIG_ENDIAN */
4984 }
4985 
4986 /**
4987  *	ata_data_xfer - Transfer data by PIO
4988  *	@adev: device to target
4989  *	@buf: data buffer
4990  *	@buflen: buffer length
4991  *	@write_data: read/write
4992  *
4993  *	Transfer data from/to the device data register by PIO.
4994  *
4995  *	LOCKING:
4996  *	Inherited from caller.
4997  */
4998 void ata_data_xfer(struct ata_device *adev, unsigned char *buf,
4999 		   unsigned int buflen, int write_data)
5000 {
5001 	struct ata_port *ap = adev->link->ap;
5002 	unsigned int words = buflen >> 1;
5003 
5004 	/* Transfer multiple of 2 bytes */
5005 	if (write_data)
5006 		iowrite16_rep(ap->ioaddr.data_addr, buf, words);
5007 	else
5008 		ioread16_rep(ap->ioaddr.data_addr, buf, words);
5009 
5010 	/* Transfer trailing 1 byte, if any. */
5011 	if (unlikely(buflen & 0x01)) {
5012 		u16 align_buf[1] = { 0 };
5013 		unsigned char *trailing_buf = buf + buflen - 1;
5014 
5015 		if (write_data) {
5016 			memcpy(align_buf, trailing_buf, 1);
5017 			iowrite16(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
5018 		} else {
5019 			align_buf[0] = cpu_to_le16(ioread16(ap->ioaddr.data_addr));
5020 			memcpy(trailing_buf, align_buf, 1);
5021 		}
5022 	}
5023 }
5024 
5025 /**
5026  *	ata_data_xfer_noirq - Transfer data by PIO
5027  *	@adev: device to target
5028  *	@buf: data buffer
5029  *	@buflen: buffer length
5030  *	@write_data: read/write
5031  *
5032  *	Transfer data from/to the device data register by PIO. Do the
5033  *	transfer with interrupts disabled.
5034  *
5035  *	LOCKING:
5036  *	Inherited from caller.
5037  */
5038 void ata_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
5039 			 unsigned int buflen, int write_data)
5040 {
5041 	unsigned long flags;
5042 	local_irq_save(flags);
5043 	ata_data_xfer(adev, buf, buflen, write_data);
5044 	local_irq_restore(flags);
5045 }
5046 
5047 
5048 /**
5049  *	ata_pio_sector - Transfer a sector of data.
5050  *	@qc: Command on going
5051  *
5052  *	Transfer qc->sect_size bytes of data from/to the ATA device.
5053  *
5054  *	LOCKING:
5055  *	Inherited from caller.
5056  */
5057 
5058 static void ata_pio_sector(struct ata_queued_cmd *qc)
5059 {
5060 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
5061 	struct ata_port *ap = qc->ap;
5062 	struct page *page;
5063 	unsigned int offset;
5064 	unsigned char *buf;
5065 
5066 	if (qc->curbytes == qc->nbytes - qc->sect_size)
5067 		ap->hsm_task_state = HSM_ST_LAST;
5068 
5069 	page = sg_page(qc->cursg);
5070 	offset = qc->cursg->offset + qc->cursg_ofs;
5071 
5072 	/* get the current page and offset */
5073 	page = nth_page(page, (offset >> PAGE_SHIFT));
5074 	offset %= PAGE_SIZE;
5075 
5076 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
5077 
5078 	if (PageHighMem(page)) {
5079 		unsigned long flags;
5080 
5081 		/* FIXME: use a bounce buffer */
5082 		local_irq_save(flags);
5083 		buf = kmap_atomic(page, KM_IRQ0);
5084 
5085 		/* do the actual data transfer */
5086 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
5087 
5088 		kunmap_atomic(buf, KM_IRQ0);
5089 		local_irq_restore(flags);
5090 	} else {
5091 		buf = page_address(page);
5092 		ap->ops->data_xfer(qc->dev, buf + offset, qc->sect_size, do_write);
5093 	}
5094 
5095 	qc->curbytes += qc->sect_size;
5096 	qc->cursg_ofs += qc->sect_size;
5097 
5098 	if (qc->cursg_ofs == qc->cursg->length) {
5099 		qc->cursg = sg_next(qc->cursg);
5100 		qc->cursg_ofs = 0;
5101 	}
5102 }
5103 
5104 /**
5105  *	ata_pio_sectors - Transfer one or many sectors.
5106  *	@qc: Command on going
5107  *
5108  *	Transfer one or many sectors of data from/to the
5109  *	ATA device for the DRQ request.
5110  *
5111  *	LOCKING:
5112  *	Inherited from caller.
5113  */
5114 
5115 static void ata_pio_sectors(struct ata_queued_cmd *qc)
5116 {
5117 	if (is_multi_taskfile(&qc->tf)) {
5118 		/* READ/WRITE MULTIPLE */
5119 		unsigned int nsect;
5120 
5121 		WARN_ON(qc->dev->multi_count == 0);
5122 
5123 		nsect = min((qc->nbytes - qc->curbytes) / qc->sect_size,
5124 			    qc->dev->multi_count);
5125 		while (nsect--)
5126 			ata_pio_sector(qc);
5127 	} else
5128 		ata_pio_sector(qc);
5129 
5130 	ata_altstatus(qc->ap); /* flush */
5131 }
5132 
5133 /**
5134  *	atapi_send_cdb - Write CDB bytes to hardware
5135  *	@ap: Port to which ATAPI device is attached.
5136  *	@qc: Taskfile currently active
5137  *
5138  *	When device has indicated its readiness to accept
5139  *	a CDB, this function is called.  Send the CDB.
5140  *
5141  *	LOCKING:
5142  *	caller.
5143  */
5144 
5145 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
5146 {
5147 	/* send SCSI cdb */
5148 	DPRINTK("send cdb\n");
5149 	WARN_ON(qc->dev->cdb_len < 12);
5150 
5151 	ap->ops->data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
5152 	ata_altstatus(ap); /* flush */
5153 
5154 	switch (qc->tf.protocol) {
5155 	case ATA_PROT_ATAPI:
5156 		ap->hsm_task_state = HSM_ST;
5157 		break;
5158 	case ATA_PROT_ATAPI_NODATA:
5159 		ap->hsm_task_state = HSM_ST_LAST;
5160 		break;
5161 	case ATA_PROT_ATAPI_DMA:
5162 		ap->hsm_task_state = HSM_ST_LAST;
5163 		/* initiate bmdma */
5164 		ap->ops->bmdma_start(qc);
5165 		break;
5166 	}
5167 }
5168 
5169 /**
5170  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
5171  *	@qc: Command on going
5172  *	@bytes: number of bytes
5173  *
5174  *	Transfer Transfer data from/to the ATAPI device.
5175  *
5176  *	LOCKING:
5177  *	Inherited from caller.
5178  *
5179  */
5180 static int __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
5181 {
5182 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
5183 	struct ata_port *ap = qc->ap;
5184 	struct ata_eh_info *ehi = &qc->dev->link->eh_info;
5185 	struct scatterlist *sg;
5186 	struct page *page;
5187 	unsigned char *buf;
5188 	unsigned int offset, count;
5189 
5190 next_sg:
5191 	sg = qc->cursg;
5192 	if (unlikely(!sg)) {
5193 		/*
5194 		 * The end of qc->sg is reached and the device expects
5195 		 * more data to transfer. In order not to overrun qc->sg
5196 		 * and fulfill length specified in the byte count register,
5197 		 *    - for read case, discard trailing data from the device
5198 		 *    - for write case, padding zero data to the device
5199 		 */
5200 		u16 pad_buf[1] = { 0 };
5201 		unsigned int i;
5202 
5203 		if (bytes > qc->curbytes - qc->nbytes + ATAPI_MAX_DRAIN) {
5204 			ata_ehi_push_desc(ehi, "too much trailing data "
5205 					  "buf=%u cur=%u bytes=%u",
5206 					  qc->nbytes, qc->curbytes, bytes);
5207 			return -1;
5208 		}
5209 
5210 		 /* overflow is exptected for misc ATAPI commands */
5211 		if (bytes && !atapi_qc_may_overflow(qc))
5212 			ata_dev_printk(qc->dev, KERN_WARNING, "ATAPI %u bytes "
5213 				       "trailing data (cdb=%02x nbytes=%u)\n",
5214 				       bytes, qc->cdb[0], qc->nbytes);
5215 
5216 		for (i = 0; i < (bytes + 1) / 2; i++)
5217 			ap->ops->data_xfer(qc->dev, (unsigned char *)pad_buf, 2, do_write);
5218 
5219 		qc->curbytes += bytes;
5220 
5221 		return 0;
5222 	}
5223 
5224 	page = sg_page(sg);
5225 	offset = sg->offset + qc->cursg_ofs;
5226 
5227 	/* get the current page and offset */
5228 	page = nth_page(page, (offset >> PAGE_SHIFT));
5229 	offset %= PAGE_SIZE;
5230 
5231 	/* don't overrun current sg */
5232 	count = min(sg->length - qc->cursg_ofs, bytes);
5233 
5234 	/* don't cross page boundaries */
5235 	count = min(count, (unsigned int)PAGE_SIZE - offset);
5236 
5237 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
5238 
5239 	if (PageHighMem(page)) {
5240 		unsigned long flags;
5241 
5242 		/* FIXME: use bounce buffer */
5243 		local_irq_save(flags);
5244 		buf = kmap_atomic(page, KM_IRQ0);
5245 
5246 		/* do the actual data transfer */
5247 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
5248 
5249 		kunmap_atomic(buf, KM_IRQ0);
5250 		local_irq_restore(flags);
5251 	} else {
5252 		buf = page_address(page);
5253 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
5254 	}
5255 
5256 	bytes -= count;
5257 	if ((count & 1) && bytes)
5258 		bytes--;
5259 	qc->curbytes += count;
5260 	qc->cursg_ofs += count;
5261 
5262 	if (qc->cursg_ofs == sg->length) {
5263 		qc->cursg = sg_next(qc->cursg);
5264 		qc->cursg_ofs = 0;
5265 	}
5266 
5267 	if (bytes)
5268 		goto next_sg;
5269 
5270 	return 0;
5271 }
5272 
5273 /**
5274  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
5275  *	@qc: Command on going
5276  *
5277  *	Transfer Transfer data from/to the ATAPI device.
5278  *
5279  *	LOCKING:
5280  *	Inherited from caller.
5281  */
5282 
5283 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
5284 {
5285 	struct ata_port *ap = qc->ap;
5286 	struct ata_device *dev = qc->dev;
5287 	unsigned int ireason, bc_lo, bc_hi, bytes;
5288 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
5289 
5290 	/* Abuse qc->result_tf for temp storage of intermediate TF
5291 	 * here to save some kernel stack usage.
5292 	 * For normal completion, qc->result_tf is not relevant. For
5293 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
5294 	 * So, the correctness of qc->result_tf is not affected.
5295 	 */
5296 	ap->ops->tf_read(ap, &qc->result_tf);
5297 	ireason = qc->result_tf.nsect;
5298 	bc_lo = qc->result_tf.lbam;
5299 	bc_hi = qc->result_tf.lbah;
5300 	bytes = (bc_hi << 8) | bc_lo;
5301 
5302 	/* shall be cleared to zero, indicating xfer of data */
5303 	if (ireason & (1 << 0))
5304 		goto err_out;
5305 
5306 	/* make sure transfer direction matches expected */
5307 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
5308 	if (do_write != i_write)
5309 		goto err_out;
5310 
5311 	VPRINTK("ata%u: xfering %d bytes\n", ap->print_id, bytes);
5312 
5313 	if (__atapi_pio_bytes(qc, bytes))
5314 		goto err_out;
5315 	ata_altstatus(ap); /* flush */
5316 
5317 	return;
5318 
5319 err_out:
5320 	ata_dev_printk(dev, KERN_INFO, "ATAPI check failed\n");
5321 	qc->err_mask |= AC_ERR_HSM;
5322 	ap->hsm_task_state = HSM_ST_ERR;
5323 }
5324 
5325 /**
5326  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
5327  *	@ap: the target ata_port
5328  *	@qc: qc on going
5329  *
5330  *	RETURNS:
5331  *	1 if ok in workqueue, 0 otherwise.
5332  */
5333 
5334 static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
5335 {
5336 	if (qc->tf.flags & ATA_TFLAG_POLLING)
5337 		return 1;
5338 
5339 	if (ap->hsm_task_state == HSM_ST_FIRST) {
5340 		if (qc->tf.protocol == ATA_PROT_PIO &&
5341 		    (qc->tf.flags & ATA_TFLAG_WRITE))
5342 		    return 1;
5343 
5344 		if (is_atapi_taskfile(&qc->tf) &&
5345 		    !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5346 			return 1;
5347 	}
5348 
5349 	return 0;
5350 }
5351 
5352 /**
5353  *	ata_hsm_qc_complete - finish a qc running on standard HSM
5354  *	@qc: Command to complete
5355  *	@in_wq: 1 if called from workqueue, 0 otherwise
5356  *
5357  *	Finish @qc which is running on standard HSM.
5358  *
5359  *	LOCKING:
5360  *	If @in_wq is zero, spin_lock_irqsave(host lock).
5361  *	Otherwise, none on entry and grabs host lock.
5362  */
5363 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
5364 {
5365 	struct ata_port *ap = qc->ap;
5366 	unsigned long flags;
5367 
5368 	if (ap->ops->error_handler) {
5369 		if (in_wq) {
5370 			spin_lock_irqsave(ap->lock, flags);
5371 
5372 			/* EH might have kicked in while host lock is
5373 			 * released.
5374 			 */
5375 			qc = ata_qc_from_tag(ap, qc->tag);
5376 			if (qc) {
5377 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
5378 					ap->ops->irq_on(ap);
5379 					ata_qc_complete(qc);
5380 				} else
5381 					ata_port_freeze(ap);
5382 			}
5383 
5384 			spin_unlock_irqrestore(ap->lock, flags);
5385 		} else {
5386 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
5387 				ata_qc_complete(qc);
5388 			else
5389 				ata_port_freeze(ap);
5390 		}
5391 	} else {
5392 		if (in_wq) {
5393 			spin_lock_irqsave(ap->lock, flags);
5394 			ap->ops->irq_on(ap);
5395 			ata_qc_complete(qc);
5396 			spin_unlock_irqrestore(ap->lock, flags);
5397 		} else
5398 			ata_qc_complete(qc);
5399 	}
5400 }
5401 
5402 /**
5403  *	ata_hsm_move - move the HSM to the next state.
5404  *	@ap: the target ata_port
5405  *	@qc: qc on going
5406  *	@status: current device status
5407  *	@in_wq: 1 if called from workqueue, 0 otherwise
5408  *
5409  *	RETURNS:
5410  *	1 when poll next status needed, 0 otherwise.
5411  */
5412 int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
5413 		 u8 status, int in_wq)
5414 {
5415 	unsigned long flags = 0;
5416 	int poll_next;
5417 
5418 	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
5419 
5420 	/* Make sure ata_qc_issue_prot() does not throw things
5421 	 * like DMA polling into the workqueue. Notice that
5422 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
5423 	 */
5424 	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
5425 
5426 fsm_start:
5427 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
5428 		ap->print_id, qc->tf.protocol, ap->hsm_task_state, status);
5429 
5430 	switch (ap->hsm_task_state) {
5431 	case HSM_ST_FIRST:
5432 		/* Send first data block or PACKET CDB */
5433 
5434 		/* If polling, we will stay in the work queue after
5435 		 * sending the data. Otherwise, interrupt handler
5436 		 * takes over after sending the data.
5437 		 */
5438 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
5439 
5440 		/* check device status */
5441 		if (unlikely((status & ATA_DRQ) == 0)) {
5442 			/* handle BSY=0, DRQ=0 as error */
5443 			if (likely(status & (ATA_ERR | ATA_DF)))
5444 				/* device stops HSM for abort/error */
5445 				qc->err_mask |= AC_ERR_DEV;
5446 			else
5447 				/* HSM violation. Let EH handle this */
5448 				qc->err_mask |= AC_ERR_HSM;
5449 
5450 			ap->hsm_task_state = HSM_ST_ERR;
5451 			goto fsm_start;
5452 		}
5453 
5454 		/* Device should not ask for data transfer (DRQ=1)
5455 		 * when it finds something wrong.
5456 		 * We ignore DRQ here and stop the HSM by
5457 		 * changing hsm_task_state to HSM_ST_ERR and
5458 		 * let the EH abort the command or reset the device.
5459 		 */
5460 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
5461 			/* Some ATAPI tape drives forget to clear the ERR bit
5462 			 * when doing the next command (mostly request sense).
5463 			 * We ignore ERR here to workaround and proceed sending
5464 			 * the CDB.
5465 			 */
5466 			if (!(qc->dev->horkage & ATA_HORKAGE_STUCK_ERR)) {
5467 				ata_port_printk(ap, KERN_WARNING,
5468 						"DRQ=1 with device error, "
5469 						"dev_stat 0x%X\n", status);
5470 				qc->err_mask |= AC_ERR_HSM;
5471 				ap->hsm_task_state = HSM_ST_ERR;
5472 				goto fsm_start;
5473 			}
5474 		}
5475 
5476 		/* Send the CDB (atapi) or the first data block (ata pio out).
5477 		 * During the state transition, interrupt handler shouldn't
5478 		 * be invoked before the data transfer is complete and
5479 		 * hsm_task_state is changed. Hence, the following locking.
5480 		 */
5481 		if (in_wq)
5482 			spin_lock_irqsave(ap->lock, flags);
5483 
5484 		if (qc->tf.protocol == ATA_PROT_PIO) {
5485 			/* PIO data out protocol.
5486 			 * send first data block.
5487 			 */
5488 
5489 			/* ata_pio_sectors() might change the state
5490 			 * to HSM_ST_LAST. so, the state is changed here
5491 			 * before ata_pio_sectors().
5492 			 */
5493 			ap->hsm_task_state = HSM_ST;
5494 			ata_pio_sectors(qc);
5495 		} else
5496 			/* send CDB */
5497 			atapi_send_cdb(ap, qc);
5498 
5499 		if (in_wq)
5500 			spin_unlock_irqrestore(ap->lock, flags);
5501 
5502 		/* if polling, ata_pio_task() handles the rest.
5503 		 * otherwise, interrupt handler takes over from here.
5504 		 */
5505 		break;
5506 
5507 	case HSM_ST:
5508 		/* complete command or read/write the data register */
5509 		if (qc->tf.protocol == ATA_PROT_ATAPI) {
5510 			/* ATAPI PIO protocol */
5511 			if ((status & ATA_DRQ) == 0) {
5512 				/* No more data to transfer or device error.
5513 				 * Device error will be tagged in HSM_ST_LAST.
5514 				 */
5515 				ap->hsm_task_state = HSM_ST_LAST;
5516 				goto fsm_start;
5517 			}
5518 
5519 			/* Device should not ask for data transfer (DRQ=1)
5520 			 * when it finds something wrong.
5521 			 * We ignore DRQ here and stop the HSM by
5522 			 * changing hsm_task_state to HSM_ST_ERR and
5523 			 * let the EH abort the command or reset the device.
5524 			 */
5525 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5526 				ata_port_printk(ap, KERN_WARNING, "DRQ=1 with "
5527 						"device error, dev_stat 0x%X\n",
5528 						status);
5529 				qc->err_mask |= AC_ERR_HSM;
5530 				ap->hsm_task_state = HSM_ST_ERR;
5531 				goto fsm_start;
5532 			}
5533 
5534 			atapi_pio_bytes(qc);
5535 
5536 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
5537 				/* bad ireason reported by device */
5538 				goto fsm_start;
5539 
5540 		} else {
5541 			/* ATA PIO protocol */
5542 			if (unlikely((status & ATA_DRQ) == 0)) {
5543 				/* handle BSY=0, DRQ=0 as error */
5544 				if (likely(status & (ATA_ERR | ATA_DF)))
5545 					/* device stops HSM for abort/error */
5546 					qc->err_mask |= AC_ERR_DEV;
5547 				else
5548 					/* HSM violation. Let EH handle this.
5549 					 * Phantom devices also trigger this
5550 					 * condition.  Mark hint.
5551 					 */
5552 					qc->err_mask |= AC_ERR_HSM |
5553 							AC_ERR_NODEV_HINT;
5554 
5555 				ap->hsm_task_state = HSM_ST_ERR;
5556 				goto fsm_start;
5557 			}
5558 
5559 			/* For PIO reads, some devices may ask for
5560 			 * data transfer (DRQ=1) alone with ERR=1.
5561 			 * We respect DRQ here and transfer one
5562 			 * block of junk data before changing the
5563 			 * hsm_task_state to HSM_ST_ERR.
5564 			 *
5565 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
5566 			 * sense since the data block has been
5567 			 * transferred to the device.
5568 			 */
5569 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
5570 				/* data might be corrputed */
5571 				qc->err_mask |= AC_ERR_DEV;
5572 
5573 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
5574 					ata_pio_sectors(qc);
5575 					status = ata_wait_idle(ap);
5576 				}
5577 
5578 				if (status & (ATA_BUSY | ATA_DRQ))
5579 					qc->err_mask |= AC_ERR_HSM;
5580 
5581 				/* ata_pio_sectors() might change the
5582 				 * state to HSM_ST_LAST. so, the state
5583 				 * is changed after ata_pio_sectors().
5584 				 */
5585 				ap->hsm_task_state = HSM_ST_ERR;
5586 				goto fsm_start;
5587 			}
5588 
5589 			ata_pio_sectors(qc);
5590 
5591 			if (ap->hsm_task_state == HSM_ST_LAST &&
5592 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
5593 				/* all data read */
5594 				status = ata_wait_idle(ap);
5595 				goto fsm_start;
5596 			}
5597 		}
5598 
5599 		poll_next = 1;
5600 		break;
5601 
5602 	case HSM_ST_LAST:
5603 		if (unlikely(!ata_ok(status))) {
5604 			qc->err_mask |= __ac_err_mask(status);
5605 			ap->hsm_task_state = HSM_ST_ERR;
5606 			goto fsm_start;
5607 		}
5608 
5609 		/* no more data to transfer */
5610 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
5611 			ap->print_id, qc->dev->devno, status);
5612 
5613 		WARN_ON(qc->err_mask);
5614 
5615 		ap->hsm_task_state = HSM_ST_IDLE;
5616 
5617 		/* complete taskfile transaction */
5618 		ata_hsm_qc_complete(qc, in_wq);
5619 
5620 		poll_next = 0;
5621 		break;
5622 
5623 	case HSM_ST_ERR:
5624 		/* make sure qc->err_mask is available to
5625 		 * know what's wrong and recover
5626 		 */
5627 		WARN_ON(qc->err_mask == 0);
5628 
5629 		ap->hsm_task_state = HSM_ST_IDLE;
5630 
5631 		/* complete taskfile transaction */
5632 		ata_hsm_qc_complete(qc, in_wq);
5633 
5634 		poll_next = 0;
5635 		break;
5636 	default:
5637 		poll_next = 0;
5638 		BUG();
5639 	}
5640 
5641 	return poll_next;
5642 }
5643 
5644 static void ata_pio_task(struct work_struct *work)
5645 {
5646 	struct ata_port *ap =
5647 		container_of(work, struct ata_port, port_task.work);
5648 	struct ata_queued_cmd *qc = ap->port_task_data;
5649 	u8 status;
5650 	int poll_next;
5651 
5652 fsm_start:
5653 	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
5654 
5655 	/*
5656 	 * This is purely heuristic.  This is a fast path.
5657 	 * Sometimes when we enter, BSY will be cleared in
5658 	 * a chk-status or two.  If not, the drive is probably seeking
5659 	 * or something.  Snooze for a couple msecs, then
5660 	 * chk-status again.  If still busy, queue delayed work.
5661 	 */
5662 	status = ata_busy_wait(ap, ATA_BUSY, 5);
5663 	if (status & ATA_BUSY) {
5664 		msleep(2);
5665 		status = ata_busy_wait(ap, ATA_BUSY, 10);
5666 		if (status & ATA_BUSY) {
5667 			ata_port_queue_task(ap, ata_pio_task, qc, ATA_SHORT_PAUSE);
5668 			return;
5669 		}
5670 	}
5671 
5672 	/* move the HSM */
5673 	poll_next = ata_hsm_move(ap, qc, status, 1);
5674 
5675 	/* another command or interrupt handler
5676 	 * may be running at this point.
5677 	 */
5678 	if (poll_next)
5679 		goto fsm_start;
5680 }
5681 
5682 /**
5683  *	ata_qc_new - Request an available ATA command, for queueing
5684  *	@ap: Port associated with device @dev
5685  *	@dev: Device from whom we request an available command structure
5686  *
5687  *	LOCKING:
5688  *	None.
5689  */
5690 
5691 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
5692 {
5693 	struct ata_queued_cmd *qc = NULL;
5694 	unsigned int i;
5695 
5696 	/* no command while frozen */
5697 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
5698 		return NULL;
5699 
5700 	/* the last tag is reserved for internal command. */
5701 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
5702 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
5703 			qc = __ata_qc_from_tag(ap, i);
5704 			break;
5705 		}
5706 
5707 	if (qc)
5708 		qc->tag = i;
5709 
5710 	return qc;
5711 }
5712 
5713 /**
5714  *	ata_qc_new_init - Request an available ATA command, and initialize it
5715  *	@dev: Device from whom we request an available command structure
5716  *
5717  *	LOCKING:
5718  *	None.
5719  */
5720 
5721 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
5722 {
5723 	struct ata_port *ap = dev->link->ap;
5724 	struct ata_queued_cmd *qc;
5725 
5726 	qc = ata_qc_new(ap);
5727 	if (qc) {
5728 		qc->scsicmd = NULL;
5729 		qc->ap = ap;
5730 		qc->dev = dev;
5731 
5732 		ata_qc_reinit(qc);
5733 	}
5734 
5735 	return qc;
5736 }
5737 
5738 /**
5739  *	ata_qc_free - free unused ata_queued_cmd
5740  *	@qc: Command to complete
5741  *
5742  *	Designed to free unused ata_queued_cmd object
5743  *	in case something prevents using it.
5744  *
5745  *	LOCKING:
5746  *	spin_lock_irqsave(host lock)
5747  */
5748 void ata_qc_free(struct ata_queued_cmd *qc)
5749 {
5750 	struct ata_port *ap = qc->ap;
5751 	unsigned int tag;
5752 
5753 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5754 
5755 	qc->flags = 0;
5756 	tag = qc->tag;
5757 	if (likely(ata_tag_valid(tag))) {
5758 		qc->tag = ATA_TAG_POISON;
5759 		clear_bit(tag, &ap->qc_allocated);
5760 	}
5761 }
5762 
5763 void __ata_qc_complete(struct ata_queued_cmd *qc)
5764 {
5765 	struct ata_port *ap = qc->ap;
5766 	struct ata_link *link = qc->dev->link;
5767 
5768 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
5769 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
5770 
5771 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
5772 		ata_sg_clean(qc);
5773 
5774 	/* command should be marked inactive atomically with qc completion */
5775 	if (qc->tf.protocol == ATA_PROT_NCQ) {
5776 		link->sactive &= ~(1 << qc->tag);
5777 		if (!link->sactive)
5778 			ap->nr_active_links--;
5779 	} else {
5780 		link->active_tag = ATA_TAG_POISON;
5781 		ap->nr_active_links--;
5782 	}
5783 
5784 	/* clear exclusive status */
5785 	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
5786 		     ap->excl_link == link))
5787 		ap->excl_link = NULL;
5788 
5789 	/* atapi: mark qc as inactive to prevent the interrupt handler
5790 	 * from completing the command twice later, before the error handler
5791 	 * is called. (when rc != 0 and atapi request sense is needed)
5792 	 */
5793 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
5794 	ap->qc_active &= ~(1 << qc->tag);
5795 
5796 	/* call completion callback */
5797 	qc->complete_fn(qc);
5798 }
5799 
5800 static void fill_result_tf(struct ata_queued_cmd *qc)
5801 {
5802 	struct ata_port *ap = qc->ap;
5803 
5804 	qc->result_tf.flags = qc->tf.flags;
5805 	ap->ops->tf_read(ap, &qc->result_tf);
5806 }
5807 
5808 /**
5809  *	ata_qc_complete - Complete an active ATA command
5810  *	@qc: Command to complete
5811  *	@err_mask: ATA Status register contents
5812  *
5813  *	Indicate to the mid and upper layers that an ATA
5814  *	command has completed, with either an ok or not-ok status.
5815  *
5816  *	LOCKING:
5817  *	spin_lock_irqsave(host lock)
5818  */
5819 void ata_qc_complete(struct ata_queued_cmd *qc)
5820 {
5821 	struct ata_port *ap = qc->ap;
5822 
5823 	/* XXX: New EH and old EH use different mechanisms to
5824 	 * synchronize EH with regular execution path.
5825 	 *
5826 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
5827 	 * Normal execution path is responsible for not accessing a
5828 	 * failed qc.  libata core enforces the rule by returning NULL
5829 	 * from ata_qc_from_tag() for failed qcs.
5830 	 *
5831 	 * Old EH depends on ata_qc_complete() nullifying completion
5832 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
5833 	 * not synchronize with interrupt handler.  Only PIO task is
5834 	 * taken care of.
5835 	 */
5836 	if (ap->ops->error_handler) {
5837 		struct ata_device *dev = qc->dev;
5838 		struct ata_eh_info *ehi = &dev->link->eh_info;
5839 
5840 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
5841 
5842 		if (unlikely(qc->err_mask))
5843 			qc->flags |= ATA_QCFLAG_FAILED;
5844 
5845 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
5846 			if (!ata_tag_internal(qc->tag)) {
5847 				/* always fill result TF for failed qc */
5848 				fill_result_tf(qc);
5849 				ata_qc_schedule_eh(qc);
5850 				return;
5851 			}
5852 		}
5853 
5854 		/* read result TF if requested */
5855 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
5856 			fill_result_tf(qc);
5857 
5858 		/* Some commands need post-processing after successful
5859 		 * completion.
5860 		 */
5861 		switch (qc->tf.command) {
5862 		case ATA_CMD_SET_FEATURES:
5863 			if (qc->tf.feature != SETFEATURES_WC_ON &&
5864 			    qc->tf.feature != SETFEATURES_WC_OFF)
5865 				break;
5866 			/* fall through */
5867 		case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
5868 		case ATA_CMD_SET_MULTI: /* multi_count changed */
5869 			/* revalidate device */
5870 			ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
5871 			ata_port_schedule_eh(ap);
5872 			break;
5873 
5874 		case ATA_CMD_SLEEP:
5875 			dev->flags |= ATA_DFLAG_SLEEPING;
5876 			break;
5877 		}
5878 
5879 		__ata_qc_complete(qc);
5880 	} else {
5881 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
5882 			return;
5883 
5884 		/* read result TF if failed or requested */
5885 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
5886 			fill_result_tf(qc);
5887 
5888 		__ata_qc_complete(qc);
5889 	}
5890 }
5891 
5892 /**
5893  *	ata_qc_complete_multiple - Complete multiple qcs successfully
5894  *	@ap: port in question
5895  *	@qc_active: new qc_active mask
5896  *	@finish_qc: LLDD callback invoked before completing a qc
5897  *
5898  *	Complete in-flight commands.  This functions is meant to be
5899  *	called from low-level driver's interrupt routine to complete
5900  *	requests normally.  ap->qc_active and @qc_active is compared
5901  *	and commands are completed accordingly.
5902  *
5903  *	LOCKING:
5904  *	spin_lock_irqsave(host lock)
5905  *
5906  *	RETURNS:
5907  *	Number of completed commands on success, -errno otherwise.
5908  */
5909 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
5910 			     void (*finish_qc)(struct ata_queued_cmd *))
5911 {
5912 	int nr_done = 0;
5913 	u32 done_mask;
5914 	int i;
5915 
5916 	done_mask = ap->qc_active ^ qc_active;
5917 
5918 	if (unlikely(done_mask & qc_active)) {
5919 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
5920 				"(%08x->%08x)\n", ap->qc_active, qc_active);
5921 		return -EINVAL;
5922 	}
5923 
5924 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
5925 		struct ata_queued_cmd *qc;
5926 
5927 		if (!(done_mask & (1 << i)))
5928 			continue;
5929 
5930 		if ((qc = ata_qc_from_tag(ap, i))) {
5931 			if (finish_qc)
5932 				finish_qc(qc);
5933 			ata_qc_complete(qc);
5934 			nr_done++;
5935 		}
5936 	}
5937 
5938 	return nr_done;
5939 }
5940 
5941 static inline int ata_should_dma_map(struct ata_queued_cmd *qc)
5942 {
5943 	struct ata_port *ap = qc->ap;
5944 
5945 	switch (qc->tf.protocol) {
5946 	case ATA_PROT_NCQ:
5947 	case ATA_PROT_DMA:
5948 	case ATA_PROT_ATAPI_DMA:
5949 		return 1;
5950 
5951 	case ATA_PROT_ATAPI:
5952 	case ATA_PROT_PIO:
5953 		if (ap->flags & ATA_FLAG_PIO_DMA)
5954 			return 1;
5955 
5956 		/* fall through */
5957 
5958 	default:
5959 		return 0;
5960 	}
5961 
5962 	/* never reached */
5963 }
5964 
5965 /**
5966  *	ata_qc_issue - issue taskfile to device
5967  *	@qc: command to issue to device
5968  *
5969  *	Prepare an ATA command to submission to device.
5970  *	This includes mapping the data into a DMA-able
5971  *	area, filling in the S/G table, and finally
5972  *	writing the taskfile to hardware, starting the command.
5973  *
5974  *	LOCKING:
5975  *	spin_lock_irqsave(host lock)
5976  */
5977 void ata_qc_issue(struct ata_queued_cmd *qc)
5978 {
5979 	struct ata_port *ap = qc->ap;
5980 	struct ata_link *link = qc->dev->link;
5981 
5982 	/* Make sure only one non-NCQ command is outstanding.  The
5983 	 * check is skipped for old EH because it reuses active qc to
5984 	 * request ATAPI sense.
5985 	 */
5986 	WARN_ON(ap->ops->error_handler && ata_tag_valid(link->active_tag));
5987 
5988 	if (qc->tf.protocol == ATA_PROT_NCQ) {
5989 		WARN_ON(link->sactive & (1 << qc->tag));
5990 
5991 		if (!link->sactive)
5992 			ap->nr_active_links++;
5993 		link->sactive |= 1 << qc->tag;
5994 	} else {
5995 		WARN_ON(link->sactive);
5996 
5997 		ap->nr_active_links++;
5998 		link->active_tag = qc->tag;
5999 	}
6000 
6001 	qc->flags |= ATA_QCFLAG_ACTIVE;
6002 	ap->qc_active |= 1 << qc->tag;
6003 
6004 	if (ata_should_dma_map(qc)) {
6005 		if (qc->flags & ATA_QCFLAG_SG) {
6006 			if (ata_sg_setup(qc))
6007 				goto sg_err;
6008 		} else if (qc->flags & ATA_QCFLAG_SINGLE) {
6009 			if (ata_sg_setup_one(qc))
6010 				goto sg_err;
6011 		}
6012 	} else {
6013 		qc->flags &= ~ATA_QCFLAG_DMAMAP;
6014 	}
6015 
6016 	/* if device is sleeping, schedule softreset and abort the link */
6017 	if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
6018 		link->eh_info.action |= ATA_EH_SOFTRESET;
6019 		ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
6020 		ata_link_abort(link);
6021 		return;
6022 	}
6023 
6024 	ap->ops->qc_prep(qc);
6025 
6026 	qc->err_mask |= ap->ops->qc_issue(qc);
6027 	if (unlikely(qc->err_mask))
6028 		goto err;
6029 	return;
6030 
6031 sg_err:
6032 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
6033 	qc->err_mask |= AC_ERR_SYSTEM;
6034 err:
6035 	ata_qc_complete(qc);
6036 }
6037 
6038 /**
6039  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
6040  *	@qc: command to issue to device
6041  *
6042  *	Using various libata functions and hooks, this function
6043  *	starts an ATA command.  ATA commands are grouped into
6044  *	classes called "protocols", and issuing each type of protocol
6045  *	is slightly different.
6046  *
6047  *	May be used as the qc_issue() entry in ata_port_operations.
6048  *
6049  *	LOCKING:
6050  *	spin_lock_irqsave(host lock)
6051  *
6052  *	RETURNS:
6053  *	Zero on success, AC_ERR_* mask on failure
6054  */
6055 
6056 unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
6057 {
6058 	struct ata_port *ap = qc->ap;
6059 
6060 	/* Use polling pio if the LLD doesn't handle
6061 	 * interrupt driven pio and atapi CDB interrupt.
6062 	 */
6063 	if (ap->flags & ATA_FLAG_PIO_POLLING) {
6064 		switch (qc->tf.protocol) {
6065 		case ATA_PROT_PIO:
6066 		case ATA_PROT_NODATA:
6067 		case ATA_PROT_ATAPI:
6068 		case ATA_PROT_ATAPI_NODATA:
6069 			qc->tf.flags |= ATA_TFLAG_POLLING;
6070 			break;
6071 		case ATA_PROT_ATAPI_DMA:
6072 			if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
6073 				/* see ata_dma_blacklisted() */
6074 				BUG();
6075 			break;
6076 		default:
6077 			break;
6078 		}
6079 	}
6080 
6081 	/* select the device */
6082 	ata_dev_select(ap, qc->dev->devno, 1, 0);
6083 
6084 	/* start the command */
6085 	switch (qc->tf.protocol) {
6086 	case ATA_PROT_NODATA:
6087 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6088 			ata_qc_set_polling(qc);
6089 
6090 		ata_tf_to_host(ap, &qc->tf);
6091 		ap->hsm_task_state = HSM_ST_LAST;
6092 
6093 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6094 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
6095 
6096 		break;
6097 
6098 	case ATA_PROT_DMA:
6099 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
6100 
6101 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
6102 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
6103 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
6104 		ap->hsm_task_state = HSM_ST_LAST;
6105 		break;
6106 
6107 	case ATA_PROT_PIO:
6108 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6109 			ata_qc_set_polling(qc);
6110 
6111 		ata_tf_to_host(ap, &qc->tf);
6112 
6113 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
6114 			/* PIO data out protocol */
6115 			ap->hsm_task_state = HSM_ST_FIRST;
6116 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
6117 
6118 			/* always send first data block using
6119 			 * the ata_pio_task() codepath.
6120 			 */
6121 		} else {
6122 			/* PIO data in protocol */
6123 			ap->hsm_task_state = HSM_ST;
6124 
6125 			if (qc->tf.flags & ATA_TFLAG_POLLING)
6126 				ata_port_queue_task(ap, ata_pio_task, qc, 0);
6127 
6128 			/* if polling, ata_pio_task() handles the rest.
6129 			 * otherwise, interrupt handler takes over from here.
6130 			 */
6131 		}
6132 
6133 		break;
6134 
6135 	case ATA_PROT_ATAPI:
6136 	case ATA_PROT_ATAPI_NODATA:
6137 		if (qc->tf.flags & ATA_TFLAG_POLLING)
6138 			ata_qc_set_polling(qc);
6139 
6140 		ata_tf_to_host(ap, &qc->tf);
6141 
6142 		ap->hsm_task_state = HSM_ST_FIRST;
6143 
6144 		/* send cdb by polling if no cdb interrupt */
6145 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
6146 		    (qc->tf.flags & ATA_TFLAG_POLLING))
6147 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
6148 		break;
6149 
6150 	case ATA_PROT_ATAPI_DMA:
6151 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
6152 
6153 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
6154 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
6155 		ap->hsm_task_state = HSM_ST_FIRST;
6156 
6157 		/* send cdb by polling if no cdb interrupt */
6158 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
6159 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
6160 		break;
6161 
6162 	default:
6163 		WARN_ON(1);
6164 		return AC_ERR_SYSTEM;
6165 	}
6166 
6167 	return 0;
6168 }
6169 
6170 /**
6171  *	ata_host_intr - Handle host interrupt for given (port, task)
6172  *	@ap: Port on which interrupt arrived (possibly...)
6173  *	@qc: Taskfile currently active in engine
6174  *
6175  *	Handle host interrupt for given queued command.  Currently,
6176  *	only DMA interrupts are handled.  All other commands are
6177  *	handled via polling with interrupts disabled (nIEN bit).
6178  *
6179  *	LOCKING:
6180  *	spin_lock_irqsave(host lock)
6181  *
6182  *	RETURNS:
6183  *	One if interrupt was handled, zero if not (shared irq).
6184  */
6185 
6186 inline unsigned int ata_host_intr(struct ata_port *ap,
6187 				  struct ata_queued_cmd *qc)
6188 {
6189 	struct ata_eh_info *ehi = &ap->link.eh_info;
6190 	u8 status, host_stat = 0;
6191 
6192 	VPRINTK("ata%u: protocol %d task_state %d\n",
6193 		ap->print_id, qc->tf.protocol, ap->hsm_task_state);
6194 
6195 	/* Check whether we are expecting interrupt in this state */
6196 	switch (ap->hsm_task_state) {
6197 	case HSM_ST_FIRST:
6198 		/* Some pre-ATAPI-4 devices assert INTRQ
6199 		 * at this state when ready to receive CDB.
6200 		 */
6201 
6202 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
6203 		 * The flag was turned on only for atapi devices.
6204 		 * No need to check is_atapi_taskfile(&qc->tf) again.
6205 		 */
6206 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
6207 			goto idle_irq;
6208 		break;
6209 	case HSM_ST_LAST:
6210 		if (qc->tf.protocol == ATA_PROT_DMA ||
6211 		    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
6212 			/* check status of DMA engine */
6213 			host_stat = ap->ops->bmdma_status(ap);
6214 			VPRINTK("ata%u: host_stat 0x%X\n",
6215 				ap->print_id, host_stat);
6216 
6217 			/* if it's not our irq... */
6218 			if (!(host_stat & ATA_DMA_INTR))
6219 				goto idle_irq;
6220 
6221 			/* before we do anything else, clear DMA-Start bit */
6222 			ap->ops->bmdma_stop(qc);
6223 
6224 			if (unlikely(host_stat & ATA_DMA_ERR)) {
6225 				/* error when transfering data to/from memory */
6226 				qc->err_mask |= AC_ERR_HOST_BUS;
6227 				ap->hsm_task_state = HSM_ST_ERR;
6228 			}
6229 		}
6230 		break;
6231 	case HSM_ST:
6232 		break;
6233 	default:
6234 		goto idle_irq;
6235 	}
6236 
6237 	/* check altstatus */
6238 	status = ata_altstatus(ap);
6239 	if (status & ATA_BUSY)
6240 		goto idle_irq;
6241 
6242 	/* check main status, clearing INTRQ */
6243 	status = ata_chk_status(ap);
6244 	if (unlikely(status & ATA_BUSY))
6245 		goto idle_irq;
6246 
6247 	/* ack bmdma irq events */
6248 	ap->ops->irq_clear(ap);
6249 
6250 	ata_hsm_move(ap, qc, status, 0);
6251 
6252 	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
6253 				       qc->tf.protocol == ATA_PROT_ATAPI_DMA))
6254 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
6255 
6256 	return 1;	/* irq handled */
6257 
6258 idle_irq:
6259 	ap->stats.idle_irq++;
6260 
6261 #ifdef ATA_IRQ_TRAP
6262 	if ((ap->stats.idle_irq % 1000) == 0) {
6263 		ata_chk_status(ap);
6264 		ap->ops->irq_clear(ap);
6265 		ata_port_printk(ap, KERN_WARNING, "irq trap\n");
6266 		return 1;
6267 	}
6268 #endif
6269 	return 0;	/* irq not handled */
6270 }
6271 
6272 /**
6273  *	ata_interrupt - Default ATA host interrupt handler
6274  *	@irq: irq line (unused)
6275  *	@dev_instance: pointer to our ata_host information structure
6276  *
6277  *	Default interrupt handler for PCI IDE devices.  Calls
6278  *	ata_host_intr() for each port that is not disabled.
6279  *
6280  *	LOCKING:
6281  *	Obtains host lock during operation.
6282  *
6283  *	RETURNS:
6284  *	IRQ_NONE or IRQ_HANDLED.
6285  */
6286 
6287 irqreturn_t ata_interrupt(int irq, void *dev_instance)
6288 {
6289 	struct ata_host *host = dev_instance;
6290 	unsigned int i;
6291 	unsigned int handled = 0;
6292 	unsigned long flags;
6293 
6294 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
6295 	spin_lock_irqsave(&host->lock, flags);
6296 
6297 	for (i = 0; i < host->n_ports; i++) {
6298 		struct ata_port *ap;
6299 
6300 		ap = host->ports[i];
6301 		if (ap &&
6302 		    !(ap->flags & ATA_FLAG_DISABLED)) {
6303 			struct ata_queued_cmd *qc;
6304 
6305 			qc = ata_qc_from_tag(ap, ap->link.active_tag);
6306 			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
6307 			    (qc->flags & ATA_QCFLAG_ACTIVE))
6308 				handled |= ata_host_intr(ap, qc);
6309 		}
6310 	}
6311 
6312 	spin_unlock_irqrestore(&host->lock, flags);
6313 
6314 	return IRQ_RETVAL(handled);
6315 }
6316 
6317 /**
6318  *	sata_scr_valid - test whether SCRs are accessible
6319  *	@link: ATA link to test SCR accessibility for
6320  *
6321  *	Test whether SCRs are accessible for @link.
6322  *
6323  *	LOCKING:
6324  *	None.
6325  *
6326  *	RETURNS:
6327  *	1 if SCRs are accessible, 0 otherwise.
6328  */
6329 int sata_scr_valid(struct ata_link *link)
6330 {
6331 	struct ata_port *ap = link->ap;
6332 
6333 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
6334 }
6335 
6336 /**
6337  *	sata_scr_read - read SCR register of the specified port
6338  *	@link: ATA link to read SCR for
6339  *	@reg: SCR to read
6340  *	@val: Place to store read value
6341  *
6342  *	Read SCR register @reg of @link into *@val.  This function is
6343  *	guaranteed to succeed if @link is ap->link, the cable type of
6344  *	the port is SATA and the port implements ->scr_read.
6345  *
6346  *	LOCKING:
6347  *	None if @link is ap->link.  Kernel thread context otherwise.
6348  *
6349  *	RETURNS:
6350  *	0 on success, negative errno on failure.
6351  */
6352 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
6353 {
6354 	if (ata_is_host_link(link)) {
6355 		struct ata_port *ap = link->ap;
6356 
6357 		if (sata_scr_valid(link))
6358 			return ap->ops->scr_read(ap, reg, val);
6359 		return -EOPNOTSUPP;
6360 	}
6361 
6362 	return sata_pmp_scr_read(link, reg, val);
6363 }
6364 
6365 /**
6366  *	sata_scr_write - write SCR register of the specified port
6367  *	@link: ATA link to write SCR for
6368  *	@reg: SCR to write
6369  *	@val: value to write
6370  *
6371  *	Write @val to SCR register @reg of @link.  This function is
6372  *	guaranteed to succeed if @link is ap->link, the cable type of
6373  *	the port is SATA and the port implements ->scr_read.
6374  *
6375  *	LOCKING:
6376  *	None if @link is ap->link.  Kernel thread context otherwise.
6377  *
6378  *	RETURNS:
6379  *	0 on success, negative errno on failure.
6380  */
6381 int sata_scr_write(struct ata_link *link, int reg, u32 val)
6382 {
6383 	if (ata_is_host_link(link)) {
6384 		struct ata_port *ap = link->ap;
6385 
6386 		if (sata_scr_valid(link))
6387 			return ap->ops->scr_write(ap, reg, val);
6388 		return -EOPNOTSUPP;
6389 	}
6390 
6391 	return sata_pmp_scr_write(link, reg, val);
6392 }
6393 
6394 /**
6395  *	sata_scr_write_flush - write SCR register of the specified port and flush
6396  *	@link: ATA link to write SCR for
6397  *	@reg: SCR to write
6398  *	@val: value to write
6399  *
6400  *	This function is identical to sata_scr_write() except that this
6401  *	function performs flush after writing to the register.
6402  *
6403  *	LOCKING:
6404  *	None if @link is ap->link.  Kernel thread context otherwise.
6405  *
6406  *	RETURNS:
6407  *	0 on success, negative errno on failure.
6408  */
6409 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
6410 {
6411 	if (ata_is_host_link(link)) {
6412 		struct ata_port *ap = link->ap;
6413 		int rc;
6414 
6415 		if (sata_scr_valid(link)) {
6416 			rc = ap->ops->scr_write(ap, reg, val);
6417 			if (rc == 0)
6418 				rc = ap->ops->scr_read(ap, reg, &val);
6419 			return rc;
6420 		}
6421 		return -EOPNOTSUPP;
6422 	}
6423 
6424 	return sata_pmp_scr_write(link, reg, val);
6425 }
6426 
6427 /**
6428  *	ata_link_online - test whether the given link is online
6429  *	@link: ATA link to test
6430  *
6431  *	Test whether @link is online.  Note that this function returns
6432  *	0 if online status of @link cannot be obtained, so
6433  *	ata_link_online(link) != !ata_link_offline(link).
6434  *
6435  *	LOCKING:
6436  *	None.
6437  *
6438  *	RETURNS:
6439  *	1 if the port online status is available and online.
6440  */
6441 int ata_link_online(struct ata_link *link)
6442 {
6443 	u32 sstatus;
6444 
6445 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6446 	    (sstatus & 0xf) == 0x3)
6447 		return 1;
6448 	return 0;
6449 }
6450 
6451 /**
6452  *	ata_link_offline - test whether the given link is offline
6453  *	@link: ATA link to test
6454  *
6455  *	Test whether @link is offline.  Note that this function
6456  *	returns 0 if offline status of @link cannot be obtained, so
6457  *	ata_link_online(link) != !ata_link_offline(link).
6458  *
6459  *	LOCKING:
6460  *	None.
6461  *
6462  *	RETURNS:
6463  *	1 if the port offline status is available and offline.
6464  */
6465 int ata_link_offline(struct ata_link *link)
6466 {
6467 	u32 sstatus;
6468 
6469 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
6470 	    (sstatus & 0xf) != 0x3)
6471 		return 1;
6472 	return 0;
6473 }
6474 
6475 int ata_flush_cache(struct ata_device *dev)
6476 {
6477 	unsigned int err_mask;
6478 	u8 cmd;
6479 
6480 	if (!ata_try_flush_cache(dev))
6481 		return 0;
6482 
6483 	if (dev->flags & ATA_DFLAG_FLUSH_EXT)
6484 		cmd = ATA_CMD_FLUSH_EXT;
6485 	else
6486 		cmd = ATA_CMD_FLUSH;
6487 
6488 	/* This is wrong. On a failed flush we get back the LBA of the lost
6489 	   sector and we should (assuming it wasn't aborted as unknown) issue
6490 	   a further flush command to continue the writeback until it
6491 	   does not error */
6492 	err_mask = ata_do_simple_cmd(dev, cmd);
6493 	if (err_mask) {
6494 		ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
6495 		return -EIO;
6496 	}
6497 
6498 	return 0;
6499 }
6500 
6501 #ifdef CONFIG_PM
6502 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
6503 			       unsigned int action, unsigned int ehi_flags,
6504 			       int wait)
6505 {
6506 	unsigned long flags;
6507 	int i, rc;
6508 
6509 	for (i = 0; i < host->n_ports; i++) {
6510 		struct ata_port *ap = host->ports[i];
6511 		struct ata_link *link;
6512 
6513 		/* Previous resume operation might still be in
6514 		 * progress.  Wait for PM_PENDING to clear.
6515 		 */
6516 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
6517 			ata_port_wait_eh(ap);
6518 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6519 		}
6520 
6521 		/* request PM ops to EH */
6522 		spin_lock_irqsave(ap->lock, flags);
6523 
6524 		ap->pm_mesg = mesg;
6525 		if (wait) {
6526 			rc = 0;
6527 			ap->pm_result = &rc;
6528 		}
6529 
6530 		ap->pflags |= ATA_PFLAG_PM_PENDING;
6531 		__ata_port_for_each_link(link, ap) {
6532 			link->eh_info.action |= action;
6533 			link->eh_info.flags |= ehi_flags;
6534 		}
6535 
6536 		ata_port_schedule_eh(ap);
6537 
6538 		spin_unlock_irqrestore(ap->lock, flags);
6539 
6540 		/* wait and check result */
6541 		if (wait) {
6542 			ata_port_wait_eh(ap);
6543 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
6544 			if (rc)
6545 				return rc;
6546 		}
6547 	}
6548 
6549 	return 0;
6550 }
6551 
6552 /**
6553  *	ata_host_suspend - suspend host
6554  *	@host: host to suspend
6555  *	@mesg: PM message
6556  *
6557  *	Suspend @host.  Actual operation is performed by EH.  This
6558  *	function requests EH to perform PM operations and waits for EH
6559  *	to finish.
6560  *
6561  *	LOCKING:
6562  *	Kernel thread context (may sleep).
6563  *
6564  *	RETURNS:
6565  *	0 on success, -errno on failure.
6566  */
6567 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
6568 {
6569 	int rc;
6570 
6571 	/*
6572 	 * disable link pm on all ports before requesting
6573 	 * any pm activity
6574 	 */
6575 	ata_lpm_enable(host);
6576 
6577 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
6578 	if (rc == 0)
6579 		host->dev->power.power_state = mesg;
6580 	return rc;
6581 }
6582 
6583 /**
6584  *	ata_host_resume - resume host
6585  *	@host: host to resume
6586  *
6587  *	Resume @host.  Actual operation is performed by EH.  This
6588  *	function requests EH to perform PM operations and returns.
6589  *	Note that all resume operations are performed parallely.
6590  *
6591  *	LOCKING:
6592  *	Kernel thread context (may sleep).
6593  */
6594 void ata_host_resume(struct ata_host *host)
6595 {
6596 	ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
6597 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
6598 	host->dev->power.power_state = PMSG_ON;
6599 
6600 	/* reenable link pm */
6601 	ata_lpm_disable(host);
6602 }
6603 #endif
6604 
6605 /**
6606  *	ata_port_start - Set port up for dma.
6607  *	@ap: Port to initialize
6608  *
6609  *	Called just after data structures for each port are
6610  *	initialized.  Allocates space for PRD table.
6611  *
6612  *	May be used as the port_start() entry in ata_port_operations.
6613  *
6614  *	LOCKING:
6615  *	Inherited from caller.
6616  */
6617 int ata_port_start(struct ata_port *ap)
6618 {
6619 	struct device *dev = ap->dev;
6620 	int rc;
6621 
6622 	ap->prd = dmam_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma,
6623 				      GFP_KERNEL);
6624 	if (!ap->prd)
6625 		return -ENOMEM;
6626 
6627 	rc = ata_pad_alloc(ap, dev);
6628 	if (rc)
6629 		return rc;
6630 
6631 	DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd,
6632 		(unsigned long long)ap->prd_dma);
6633 	return 0;
6634 }
6635 
6636 /**
6637  *	ata_dev_init - Initialize an ata_device structure
6638  *	@dev: Device structure to initialize
6639  *
6640  *	Initialize @dev in preparation for probing.
6641  *
6642  *	LOCKING:
6643  *	Inherited from caller.
6644  */
6645 void ata_dev_init(struct ata_device *dev)
6646 {
6647 	struct ata_link *link = dev->link;
6648 	struct ata_port *ap = link->ap;
6649 	unsigned long flags;
6650 
6651 	/* SATA spd limit is bound to the first device */
6652 	link->sata_spd_limit = link->hw_sata_spd_limit;
6653 	link->sata_spd = 0;
6654 
6655 	/* High bits of dev->flags are used to record warm plug
6656 	 * requests which occur asynchronously.  Synchronize using
6657 	 * host lock.
6658 	 */
6659 	spin_lock_irqsave(ap->lock, flags);
6660 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
6661 	dev->horkage = 0;
6662 	spin_unlock_irqrestore(ap->lock, flags);
6663 
6664 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
6665 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
6666 	dev->pio_mask = UINT_MAX;
6667 	dev->mwdma_mask = UINT_MAX;
6668 	dev->udma_mask = UINT_MAX;
6669 }
6670 
6671 /**
6672  *	ata_link_init - Initialize an ata_link structure
6673  *	@ap: ATA port link is attached to
6674  *	@link: Link structure to initialize
6675  *	@pmp: Port multiplier port number
6676  *
6677  *	Initialize @link.
6678  *
6679  *	LOCKING:
6680  *	Kernel thread context (may sleep)
6681  */
6682 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
6683 {
6684 	int i;
6685 
6686 	/* clear everything except for devices */
6687 	memset(link, 0, offsetof(struct ata_link, device[0]));
6688 
6689 	link->ap = ap;
6690 	link->pmp = pmp;
6691 	link->active_tag = ATA_TAG_POISON;
6692 	link->hw_sata_spd_limit = UINT_MAX;
6693 
6694 	/* can't use iterator, ap isn't initialized yet */
6695 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
6696 		struct ata_device *dev = &link->device[i];
6697 
6698 		dev->link = link;
6699 		dev->devno = dev - link->device;
6700 		ata_dev_init(dev);
6701 	}
6702 }
6703 
6704 /**
6705  *	sata_link_init_spd - Initialize link->sata_spd_limit
6706  *	@link: Link to configure sata_spd_limit for
6707  *
6708  *	Initialize @link->[hw_]sata_spd_limit to the currently
6709  *	configured value.
6710  *
6711  *	LOCKING:
6712  *	Kernel thread context (may sleep).
6713  *
6714  *	RETURNS:
6715  *	0 on success, -errno on failure.
6716  */
6717 int sata_link_init_spd(struct ata_link *link)
6718 {
6719 	u32 scontrol, spd;
6720 	int rc;
6721 
6722 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
6723 	if (rc)
6724 		return rc;
6725 
6726 	spd = (scontrol >> 4) & 0xf;
6727 	if (spd)
6728 		link->hw_sata_spd_limit &= (1 << spd) - 1;
6729 
6730 	link->sata_spd_limit = link->hw_sata_spd_limit;
6731 
6732 	return 0;
6733 }
6734 
6735 /**
6736  *	ata_port_alloc - allocate and initialize basic ATA port resources
6737  *	@host: ATA host this allocated port belongs to
6738  *
6739  *	Allocate and initialize basic ATA port resources.
6740  *
6741  *	RETURNS:
6742  *	Allocate ATA port on success, NULL on failure.
6743  *
6744  *	LOCKING:
6745  *	Inherited from calling layer (may sleep).
6746  */
6747 struct ata_port *ata_port_alloc(struct ata_host *host)
6748 {
6749 	struct ata_port *ap;
6750 
6751 	DPRINTK("ENTER\n");
6752 
6753 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
6754 	if (!ap)
6755 		return NULL;
6756 
6757 	ap->pflags |= ATA_PFLAG_INITIALIZING;
6758 	ap->lock = &host->lock;
6759 	ap->flags = ATA_FLAG_DISABLED;
6760 	ap->print_id = -1;
6761 	ap->ctl = ATA_DEVCTL_OBS;
6762 	ap->host = host;
6763 	ap->dev = host->dev;
6764 	ap->last_ctl = 0xFF;
6765 
6766 #if defined(ATA_VERBOSE_DEBUG)
6767 	/* turn on all debugging levels */
6768 	ap->msg_enable = 0x00FF;
6769 #elif defined(ATA_DEBUG)
6770 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
6771 #else
6772 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
6773 #endif
6774 
6775 	INIT_DELAYED_WORK(&ap->port_task, NULL);
6776 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
6777 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
6778 	INIT_LIST_HEAD(&ap->eh_done_q);
6779 	init_waitqueue_head(&ap->eh_wait_q);
6780 	init_timer_deferrable(&ap->fastdrain_timer);
6781 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
6782 	ap->fastdrain_timer.data = (unsigned long)ap;
6783 
6784 	ap->cbl = ATA_CBL_NONE;
6785 
6786 	ata_link_init(ap, &ap->link, 0);
6787 
6788 #ifdef ATA_IRQ_TRAP
6789 	ap->stats.unhandled_irq = 1;
6790 	ap->stats.idle_irq = 1;
6791 #endif
6792 	return ap;
6793 }
6794 
6795 static void ata_host_release(struct device *gendev, void *res)
6796 {
6797 	struct ata_host *host = dev_get_drvdata(gendev);
6798 	int i;
6799 
6800 	for (i = 0; i < host->n_ports; i++) {
6801 		struct ata_port *ap = host->ports[i];
6802 
6803 		if (!ap)
6804 			continue;
6805 
6806 		if (ap->scsi_host)
6807 			scsi_host_put(ap->scsi_host);
6808 
6809 		kfree(ap->pmp_link);
6810 		kfree(ap);
6811 		host->ports[i] = NULL;
6812 	}
6813 
6814 	dev_set_drvdata(gendev, NULL);
6815 }
6816 
6817 /**
6818  *	ata_host_alloc - allocate and init basic ATA host resources
6819  *	@dev: generic device this host is associated with
6820  *	@max_ports: maximum number of ATA ports associated with this host
6821  *
6822  *	Allocate and initialize basic ATA host resources.  LLD calls
6823  *	this function to allocate a host, initializes it fully and
6824  *	attaches it using ata_host_register().
6825  *
6826  *	@max_ports ports are allocated and host->n_ports is
6827  *	initialized to @max_ports.  The caller is allowed to decrease
6828  *	host->n_ports before calling ata_host_register().  The unused
6829  *	ports will be automatically freed on registration.
6830  *
6831  *	RETURNS:
6832  *	Allocate ATA host on success, NULL on failure.
6833  *
6834  *	LOCKING:
6835  *	Inherited from calling layer (may sleep).
6836  */
6837 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
6838 {
6839 	struct ata_host *host;
6840 	size_t sz;
6841 	int i;
6842 
6843 	DPRINTK("ENTER\n");
6844 
6845 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
6846 		return NULL;
6847 
6848 	/* alloc a container for our list of ATA ports (buses) */
6849 	sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
6850 	/* alloc a container for our list of ATA ports (buses) */
6851 	host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
6852 	if (!host)
6853 		goto err_out;
6854 
6855 	devres_add(dev, host);
6856 	dev_set_drvdata(dev, host);
6857 
6858 	spin_lock_init(&host->lock);
6859 	host->dev = dev;
6860 	host->n_ports = max_ports;
6861 
6862 	/* allocate ports bound to this host */
6863 	for (i = 0; i < max_ports; i++) {
6864 		struct ata_port *ap;
6865 
6866 		ap = ata_port_alloc(host);
6867 		if (!ap)
6868 			goto err_out;
6869 
6870 		ap->port_no = i;
6871 		host->ports[i] = ap;
6872 	}
6873 
6874 	devres_remove_group(dev, NULL);
6875 	return host;
6876 
6877  err_out:
6878 	devres_release_group(dev, NULL);
6879 	return NULL;
6880 }
6881 
6882 /**
6883  *	ata_host_alloc_pinfo - alloc host and init with port_info array
6884  *	@dev: generic device this host is associated with
6885  *	@ppi: array of ATA port_info to initialize host with
6886  *	@n_ports: number of ATA ports attached to this host
6887  *
6888  *	Allocate ATA host and initialize with info from @ppi.  If NULL
6889  *	terminated, @ppi may contain fewer entries than @n_ports.  The
6890  *	last entry will be used for the remaining ports.
6891  *
6892  *	RETURNS:
6893  *	Allocate ATA host on success, NULL on failure.
6894  *
6895  *	LOCKING:
6896  *	Inherited from calling layer (may sleep).
6897  */
6898 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
6899 				      const struct ata_port_info * const * ppi,
6900 				      int n_ports)
6901 {
6902 	const struct ata_port_info *pi;
6903 	struct ata_host *host;
6904 	int i, j;
6905 
6906 	host = ata_host_alloc(dev, n_ports);
6907 	if (!host)
6908 		return NULL;
6909 
6910 	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
6911 		struct ata_port *ap = host->ports[i];
6912 
6913 		if (ppi[j])
6914 			pi = ppi[j++];
6915 
6916 		ap->pio_mask = pi->pio_mask;
6917 		ap->mwdma_mask = pi->mwdma_mask;
6918 		ap->udma_mask = pi->udma_mask;
6919 		ap->flags |= pi->flags;
6920 		ap->link.flags |= pi->link_flags;
6921 		ap->ops = pi->port_ops;
6922 
6923 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
6924 			host->ops = pi->port_ops;
6925 		if (!host->private_data && pi->private_data)
6926 			host->private_data = pi->private_data;
6927 	}
6928 
6929 	return host;
6930 }
6931 
6932 static void ata_host_stop(struct device *gendev, void *res)
6933 {
6934 	struct ata_host *host = dev_get_drvdata(gendev);
6935 	int i;
6936 
6937 	WARN_ON(!(host->flags & ATA_HOST_STARTED));
6938 
6939 	for (i = 0; i < host->n_ports; i++) {
6940 		struct ata_port *ap = host->ports[i];
6941 
6942 		if (ap->ops->port_stop)
6943 			ap->ops->port_stop(ap);
6944 	}
6945 
6946 	if (host->ops->host_stop)
6947 		host->ops->host_stop(host);
6948 }
6949 
6950 /**
6951  *	ata_host_start - start and freeze ports of an ATA host
6952  *	@host: ATA host to start ports for
6953  *
6954  *	Start and then freeze ports of @host.  Started status is
6955  *	recorded in host->flags, so this function can be called
6956  *	multiple times.  Ports are guaranteed to get started only
6957  *	once.  If host->ops isn't initialized yet, its set to the
6958  *	first non-dummy port ops.
6959  *
6960  *	LOCKING:
6961  *	Inherited from calling layer (may sleep).
6962  *
6963  *	RETURNS:
6964  *	0 if all ports are started successfully, -errno otherwise.
6965  */
6966 int ata_host_start(struct ata_host *host)
6967 {
6968 	int have_stop = 0;
6969 	void *start_dr = NULL;
6970 	int i, rc;
6971 
6972 	if (host->flags & ATA_HOST_STARTED)
6973 		return 0;
6974 
6975 	for (i = 0; i < host->n_ports; i++) {
6976 		struct ata_port *ap = host->ports[i];
6977 
6978 		if (!host->ops && !ata_port_is_dummy(ap))
6979 			host->ops = ap->ops;
6980 
6981 		if (ap->ops->port_stop)
6982 			have_stop = 1;
6983 	}
6984 
6985 	if (host->ops->host_stop)
6986 		have_stop = 1;
6987 
6988 	if (have_stop) {
6989 		start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
6990 		if (!start_dr)
6991 			return -ENOMEM;
6992 	}
6993 
6994 	for (i = 0; i < host->n_ports; i++) {
6995 		struct ata_port *ap = host->ports[i];
6996 
6997 		if (ap->ops->port_start) {
6998 			rc = ap->ops->port_start(ap);
6999 			if (rc) {
7000 				if (rc != -ENODEV)
7001 					dev_printk(KERN_ERR, host->dev,
7002 						"failed to start port %d "
7003 						"(errno=%d)\n", i, rc);
7004 				goto err_out;
7005 			}
7006 		}
7007 		ata_eh_freeze_port(ap);
7008 	}
7009 
7010 	if (start_dr)
7011 		devres_add(host->dev, start_dr);
7012 	host->flags |= ATA_HOST_STARTED;
7013 	return 0;
7014 
7015  err_out:
7016 	while (--i >= 0) {
7017 		struct ata_port *ap = host->ports[i];
7018 
7019 		if (ap->ops->port_stop)
7020 			ap->ops->port_stop(ap);
7021 	}
7022 	devres_free(start_dr);
7023 	return rc;
7024 }
7025 
7026 /**
7027  *	ata_sas_host_init - Initialize a host struct
7028  *	@host:	host to initialize
7029  *	@dev:	device host is attached to
7030  *	@flags:	host flags
7031  *	@ops:	port_ops
7032  *
7033  *	LOCKING:
7034  *	PCI/etc. bus probe sem.
7035  *
7036  */
7037 /* KILLME - the only user left is ipr */
7038 void ata_host_init(struct ata_host *host, struct device *dev,
7039 		   unsigned long flags, const struct ata_port_operations *ops)
7040 {
7041 	spin_lock_init(&host->lock);
7042 	host->dev = dev;
7043 	host->flags = flags;
7044 	host->ops = ops;
7045 }
7046 
7047 /**
7048  *	ata_host_register - register initialized ATA host
7049  *	@host: ATA host to register
7050  *	@sht: template for SCSI host
7051  *
7052  *	Register initialized ATA host.  @host is allocated using
7053  *	ata_host_alloc() and fully initialized by LLD.  This function
7054  *	starts ports, registers @host with ATA and SCSI layers and
7055  *	probe registered devices.
7056  *
7057  *	LOCKING:
7058  *	Inherited from calling layer (may sleep).
7059  *
7060  *	RETURNS:
7061  *	0 on success, -errno otherwise.
7062  */
7063 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
7064 {
7065 	int i, rc;
7066 
7067 	/* host must have been started */
7068 	if (!(host->flags & ATA_HOST_STARTED)) {
7069 		dev_printk(KERN_ERR, host->dev,
7070 			   "BUG: trying to register unstarted host\n");
7071 		WARN_ON(1);
7072 		return -EINVAL;
7073 	}
7074 
7075 	/* Blow away unused ports.  This happens when LLD can't
7076 	 * determine the exact number of ports to allocate at
7077 	 * allocation time.
7078 	 */
7079 	for (i = host->n_ports; host->ports[i]; i++)
7080 		kfree(host->ports[i]);
7081 
7082 	/* give ports names and add SCSI hosts */
7083 	for (i = 0; i < host->n_ports; i++)
7084 		host->ports[i]->print_id = ata_print_id++;
7085 
7086 	rc = ata_scsi_add_hosts(host, sht);
7087 	if (rc)
7088 		return rc;
7089 
7090 	/* associate with ACPI nodes */
7091 	ata_acpi_associate(host);
7092 
7093 	/* set cable, sata_spd_limit and report */
7094 	for (i = 0; i < host->n_ports; i++) {
7095 		struct ata_port *ap = host->ports[i];
7096 		unsigned long xfer_mask;
7097 
7098 		/* set SATA cable type if still unset */
7099 		if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
7100 			ap->cbl = ATA_CBL_SATA;
7101 
7102 		/* init sata_spd_limit to the current value */
7103 		sata_link_init_spd(&ap->link);
7104 
7105 		/* print per-port info to dmesg */
7106 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
7107 					      ap->udma_mask);
7108 
7109 		if (!ata_port_is_dummy(ap)) {
7110 			ata_port_printk(ap, KERN_INFO,
7111 					"%cATA max %s %s\n",
7112 					(ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
7113 					ata_mode_string(xfer_mask),
7114 					ap->link.eh_info.desc);
7115 			ata_ehi_clear_desc(&ap->link.eh_info);
7116 		} else
7117 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
7118 	}
7119 
7120 	/* perform each probe synchronously */
7121 	DPRINTK("probe begin\n");
7122 	for (i = 0; i < host->n_ports; i++) {
7123 		struct ata_port *ap = host->ports[i];
7124 		int rc;
7125 
7126 		/* probe */
7127 		if (ap->ops->error_handler) {
7128 			struct ata_eh_info *ehi = &ap->link.eh_info;
7129 			unsigned long flags;
7130 
7131 			ata_port_probe(ap);
7132 
7133 			/* kick EH for boot probing */
7134 			spin_lock_irqsave(ap->lock, flags);
7135 
7136 			ehi->probe_mask =
7137 				(1 << ata_link_max_devices(&ap->link)) - 1;
7138 			ehi->action |= ATA_EH_SOFTRESET;
7139 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
7140 
7141 			ap->pflags &= ~ATA_PFLAG_INITIALIZING;
7142 			ap->pflags |= ATA_PFLAG_LOADING;
7143 			ata_port_schedule_eh(ap);
7144 
7145 			spin_unlock_irqrestore(ap->lock, flags);
7146 
7147 			/* wait for EH to finish */
7148 			ata_port_wait_eh(ap);
7149 		} else {
7150 			DPRINTK("ata%u: bus probe begin\n", ap->print_id);
7151 			rc = ata_bus_probe(ap);
7152 			DPRINTK("ata%u: bus probe end\n", ap->print_id);
7153 
7154 			if (rc) {
7155 				/* FIXME: do something useful here?
7156 				 * Current libata behavior will
7157 				 * tear down everything when
7158 				 * the module is removed
7159 				 * or the h/w is unplugged.
7160 				 */
7161 			}
7162 		}
7163 	}
7164 
7165 	/* probes are done, now scan each port's disk(s) */
7166 	DPRINTK("host probe begin\n");
7167 	for (i = 0; i < host->n_ports; i++) {
7168 		struct ata_port *ap = host->ports[i];
7169 
7170 		ata_scsi_scan_host(ap, 1);
7171 		ata_lpm_schedule(ap, ap->pm_policy);
7172 	}
7173 
7174 	return 0;
7175 }
7176 
7177 /**
7178  *	ata_host_activate - start host, request IRQ and register it
7179  *	@host: target ATA host
7180  *	@irq: IRQ to request
7181  *	@irq_handler: irq_handler used when requesting IRQ
7182  *	@irq_flags: irq_flags used when requesting IRQ
7183  *	@sht: scsi_host_template to use when registering the host
7184  *
7185  *	After allocating an ATA host and initializing it, most libata
7186  *	LLDs perform three steps to activate the host - start host,
7187  *	request IRQ and register it.  This helper takes necessasry
7188  *	arguments and performs the three steps in one go.
7189  *
7190  *	An invalid IRQ skips the IRQ registration and expects the host to
7191  *	have set polling mode on the port. In this case, @irq_handler
7192  *	should be NULL.
7193  *
7194  *	LOCKING:
7195  *	Inherited from calling layer (may sleep).
7196  *
7197  *	RETURNS:
7198  *	0 on success, -errno otherwise.
7199  */
7200 int ata_host_activate(struct ata_host *host, int irq,
7201 		      irq_handler_t irq_handler, unsigned long irq_flags,
7202 		      struct scsi_host_template *sht)
7203 {
7204 	int i, rc;
7205 
7206 	rc = ata_host_start(host);
7207 	if (rc)
7208 		return rc;
7209 
7210 	/* Special case for polling mode */
7211 	if (!irq) {
7212 		WARN_ON(irq_handler);
7213 		return ata_host_register(host, sht);
7214 	}
7215 
7216 	rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
7217 			      dev_driver_string(host->dev), host);
7218 	if (rc)
7219 		return rc;
7220 
7221 	for (i = 0; i < host->n_ports; i++)
7222 		ata_port_desc(host->ports[i], "irq %d", irq);
7223 
7224 	rc = ata_host_register(host, sht);
7225 	/* if failed, just free the IRQ and leave ports alone */
7226 	if (rc)
7227 		devm_free_irq(host->dev, irq, host);
7228 
7229 	return rc;
7230 }
7231 
7232 /**
7233  *	ata_port_detach - Detach ATA port in prepration of device removal
7234  *	@ap: ATA port to be detached
7235  *
7236  *	Detach all ATA devices and the associated SCSI devices of @ap;
7237  *	then, remove the associated SCSI host.  @ap is guaranteed to
7238  *	be quiescent on return from this function.
7239  *
7240  *	LOCKING:
7241  *	Kernel thread context (may sleep).
7242  */
7243 static void ata_port_detach(struct ata_port *ap)
7244 {
7245 	unsigned long flags;
7246 	struct ata_link *link;
7247 	struct ata_device *dev;
7248 
7249 	if (!ap->ops->error_handler)
7250 		goto skip_eh;
7251 
7252 	/* tell EH we're leaving & flush EH */
7253 	spin_lock_irqsave(ap->lock, flags);
7254 	ap->pflags |= ATA_PFLAG_UNLOADING;
7255 	spin_unlock_irqrestore(ap->lock, flags);
7256 
7257 	ata_port_wait_eh(ap);
7258 
7259 	/* EH is now guaranteed to see UNLOADING - EH context belongs
7260 	 * to us.  Disable all existing devices.
7261 	 */
7262 	ata_port_for_each_link(link, ap) {
7263 		ata_link_for_each_dev(dev, link)
7264 			ata_dev_disable(dev);
7265 	}
7266 
7267 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
7268 	 * will be skipped and retrials will be terminated with bad
7269 	 * target.
7270 	 */
7271 	spin_lock_irqsave(ap->lock, flags);
7272 	ata_port_freeze(ap);	/* won't be thawed */
7273 	spin_unlock_irqrestore(ap->lock, flags);
7274 
7275 	ata_port_wait_eh(ap);
7276 	cancel_rearming_delayed_work(&ap->hotplug_task);
7277 
7278  skip_eh:
7279 	/* remove the associated SCSI host */
7280 	scsi_remove_host(ap->scsi_host);
7281 }
7282 
7283 /**
7284  *	ata_host_detach - Detach all ports of an ATA host
7285  *	@host: Host to detach
7286  *
7287  *	Detach all ports of @host.
7288  *
7289  *	LOCKING:
7290  *	Kernel thread context (may sleep).
7291  */
7292 void ata_host_detach(struct ata_host *host)
7293 {
7294 	int i;
7295 
7296 	for (i = 0; i < host->n_ports; i++)
7297 		ata_port_detach(host->ports[i]);
7298 
7299 	/* the host is dead now, dissociate ACPI */
7300 	ata_acpi_dissociate(host);
7301 }
7302 
7303 /**
7304  *	ata_std_ports - initialize ioaddr with standard port offsets.
7305  *	@ioaddr: IO address structure to be initialized
7306  *
7307  *	Utility function which initializes data_addr, error_addr,
7308  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
7309  *	device_addr, status_addr, and command_addr to standard offsets
7310  *	relative to cmd_addr.
7311  *
7312  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
7313  */
7314 
7315 void ata_std_ports(struct ata_ioports *ioaddr)
7316 {
7317 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
7318 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
7319 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
7320 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
7321 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
7322 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
7323 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
7324 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
7325 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
7326 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
7327 }
7328 
7329 
7330 #ifdef CONFIG_PCI
7331 
7332 /**
7333  *	ata_pci_remove_one - PCI layer callback for device removal
7334  *	@pdev: PCI device that was removed
7335  *
7336  *	PCI layer indicates to libata via this hook that hot-unplug or
7337  *	module unload event has occurred.  Detach all ports.  Resource
7338  *	release is handled via devres.
7339  *
7340  *	LOCKING:
7341  *	Inherited from PCI layer (may sleep).
7342  */
7343 void ata_pci_remove_one(struct pci_dev *pdev)
7344 {
7345 	struct device *dev = &pdev->dev;
7346 	struct ata_host *host = dev_get_drvdata(dev);
7347 
7348 	ata_host_detach(host);
7349 }
7350 
7351 /* move to PCI subsystem */
7352 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
7353 {
7354 	unsigned long tmp = 0;
7355 
7356 	switch (bits->width) {
7357 	case 1: {
7358 		u8 tmp8 = 0;
7359 		pci_read_config_byte(pdev, bits->reg, &tmp8);
7360 		tmp = tmp8;
7361 		break;
7362 	}
7363 	case 2: {
7364 		u16 tmp16 = 0;
7365 		pci_read_config_word(pdev, bits->reg, &tmp16);
7366 		tmp = tmp16;
7367 		break;
7368 	}
7369 	case 4: {
7370 		u32 tmp32 = 0;
7371 		pci_read_config_dword(pdev, bits->reg, &tmp32);
7372 		tmp = tmp32;
7373 		break;
7374 	}
7375 
7376 	default:
7377 		return -EINVAL;
7378 	}
7379 
7380 	tmp &= bits->mask;
7381 
7382 	return (tmp == bits->val) ? 1 : 0;
7383 }
7384 
7385 #ifdef CONFIG_PM
7386 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
7387 {
7388 	pci_save_state(pdev);
7389 	pci_disable_device(pdev);
7390 
7391 	if (mesg.event == PM_EVENT_SUSPEND)
7392 		pci_set_power_state(pdev, PCI_D3hot);
7393 }
7394 
7395 int ata_pci_device_do_resume(struct pci_dev *pdev)
7396 {
7397 	int rc;
7398 
7399 	pci_set_power_state(pdev, PCI_D0);
7400 	pci_restore_state(pdev);
7401 
7402 	rc = pcim_enable_device(pdev);
7403 	if (rc) {
7404 		dev_printk(KERN_ERR, &pdev->dev,
7405 			   "failed to enable device after resume (%d)\n", rc);
7406 		return rc;
7407 	}
7408 
7409 	pci_set_master(pdev);
7410 	return 0;
7411 }
7412 
7413 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
7414 {
7415 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7416 	int rc = 0;
7417 
7418 	rc = ata_host_suspend(host, mesg);
7419 	if (rc)
7420 		return rc;
7421 
7422 	ata_pci_device_do_suspend(pdev, mesg);
7423 
7424 	return 0;
7425 }
7426 
7427 int ata_pci_device_resume(struct pci_dev *pdev)
7428 {
7429 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
7430 	int rc;
7431 
7432 	rc = ata_pci_device_do_resume(pdev);
7433 	if (rc == 0)
7434 		ata_host_resume(host);
7435 	return rc;
7436 }
7437 #endif /* CONFIG_PM */
7438 
7439 #endif /* CONFIG_PCI */
7440 
7441 
7442 static int __init ata_init(void)
7443 {
7444 	ata_probe_timeout *= HZ;
7445 	ata_wq = create_workqueue("ata");
7446 	if (!ata_wq)
7447 		return -ENOMEM;
7448 
7449 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
7450 	if (!ata_aux_wq) {
7451 		destroy_workqueue(ata_wq);
7452 		return -ENOMEM;
7453 	}
7454 
7455 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
7456 	return 0;
7457 }
7458 
7459 static void __exit ata_exit(void)
7460 {
7461 	destroy_workqueue(ata_wq);
7462 	destroy_workqueue(ata_aux_wq);
7463 }
7464 
7465 subsys_initcall(ata_init);
7466 module_exit(ata_exit);
7467 
7468 static unsigned long ratelimit_time;
7469 static DEFINE_SPINLOCK(ata_ratelimit_lock);
7470 
7471 int ata_ratelimit(void)
7472 {
7473 	int rc;
7474 	unsigned long flags;
7475 
7476 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
7477 
7478 	if (time_after(jiffies, ratelimit_time)) {
7479 		rc = 1;
7480 		ratelimit_time = jiffies + (HZ/5);
7481 	} else
7482 		rc = 0;
7483 
7484 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
7485 
7486 	return rc;
7487 }
7488 
7489 /**
7490  *	ata_wait_register - wait until register value changes
7491  *	@reg: IO-mapped register
7492  *	@mask: Mask to apply to read register value
7493  *	@val: Wait condition
7494  *	@interval_msec: polling interval in milliseconds
7495  *	@timeout_msec: timeout in milliseconds
7496  *
7497  *	Waiting for some bits of register to change is a common
7498  *	operation for ATA controllers.  This function reads 32bit LE
7499  *	IO-mapped register @reg and tests for the following condition.
7500  *
7501  *	(*@reg & mask) != val
7502  *
7503  *	If the condition is met, it returns; otherwise, the process is
7504  *	repeated after @interval_msec until timeout.
7505  *
7506  *	LOCKING:
7507  *	Kernel thread context (may sleep)
7508  *
7509  *	RETURNS:
7510  *	The final register value.
7511  */
7512 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
7513 		      unsigned long interval_msec,
7514 		      unsigned long timeout_msec)
7515 {
7516 	unsigned long timeout;
7517 	u32 tmp;
7518 
7519 	tmp = ioread32(reg);
7520 
7521 	/* Calculate timeout _after_ the first read to make sure
7522 	 * preceding writes reach the controller before starting to
7523 	 * eat away the timeout.
7524 	 */
7525 	timeout = jiffies + (timeout_msec * HZ) / 1000;
7526 
7527 	while ((tmp & mask) == val && time_before(jiffies, timeout)) {
7528 		msleep(interval_msec);
7529 		tmp = ioread32(reg);
7530 	}
7531 
7532 	return tmp;
7533 }
7534 
7535 /*
7536  * Dummy port_ops
7537  */
7538 static void ata_dummy_noret(struct ata_port *ap)	{ }
7539 static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
7540 static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
7541 
7542 static u8 ata_dummy_check_status(struct ata_port *ap)
7543 {
7544 	return ATA_DRDY;
7545 }
7546 
7547 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
7548 {
7549 	return AC_ERR_SYSTEM;
7550 }
7551 
7552 const struct ata_port_operations ata_dummy_port_ops = {
7553 	.check_status		= ata_dummy_check_status,
7554 	.check_altstatus	= ata_dummy_check_status,
7555 	.dev_select		= ata_noop_dev_select,
7556 	.qc_prep		= ata_noop_qc_prep,
7557 	.qc_issue		= ata_dummy_qc_issue,
7558 	.freeze			= ata_dummy_noret,
7559 	.thaw			= ata_dummy_noret,
7560 	.error_handler		= ata_dummy_noret,
7561 	.post_internal_cmd	= ata_dummy_qc_noret,
7562 	.irq_clear		= ata_dummy_noret,
7563 	.port_start		= ata_dummy_ret0,
7564 	.port_stop		= ata_dummy_noret,
7565 };
7566 
7567 const struct ata_port_info ata_dummy_port_info = {
7568 	.port_ops		= &ata_dummy_port_ops,
7569 };
7570 
7571 /*
7572  * libata is essentially a library of internal helper functions for
7573  * low-level ATA host controller drivers.  As such, the API/ABI is
7574  * likely to change as new drivers are added and updated.
7575  * Do not depend on ABI/API stability.
7576  */
7577 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
7578 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
7579 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
7580 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
7581 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
7582 EXPORT_SYMBOL_GPL(ata_std_bios_param);
7583 EXPORT_SYMBOL_GPL(ata_std_ports);
7584 EXPORT_SYMBOL_GPL(ata_host_init);
7585 EXPORT_SYMBOL_GPL(ata_host_alloc);
7586 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
7587 EXPORT_SYMBOL_GPL(ata_host_start);
7588 EXPORT_SYMBOL_GPL(ata_host_register);
7589 EXPORT_SYMBOL_GPL(ata_host_activate);
7590 EXPORT_SYMBOL_GPL(ata_host_detach);
7591 EXPORT_SYMBOL_GPL(ata_sg_init);
7592 EXPORT_SYMBOL_GPL(ata_sg_init_one);
7593 EXPORT_SYMBOL_GPL(ata_hsm_move);
7594 EXPORT_SYMBOL_GPL(ata_qc_complete);
7595 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
7596 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
7597 EXPORT_SYMBOL_GPL(ata_tf_load);
7598 EXPORT_SYMBOL_GPL(ata_tf_read);
7599 EXPORT_SYMBOL_GPL(ata_noop_dev_select);
7600 EXPORT_SYMBOL_GPL(ata_std_dev_select);
7601 EXPORT_SYMBOL_GPL(sata_print_link_status);
7602 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
7603 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
7604 EXPORT_SYMBOL_GPL(ata_check_status);
7605 EXPORT_SYMBOL_GPL(ata_altstatus);
7606 EXPORT_SYMBOL_GPL(ata_exec_command);
7607 EXPORT_SYMBOL_GPL(ata_port_start);
7608 EXPORT_SYMBOL_GPL(ata_sff_port_start);
7609 EXPORT_SYMBOL_GPL(ata_interrupt);
7610 EXPORT_SYMBOL_GPL(ata_do_set_mode);
7611 EXPORT_SYMBOL_GPL(ata_data_xfer);
7612 EXPORT_SYMBOL_GPL(ata_data_xfer_noirq);
7613 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
7614 EXPORT_SYMBOL_GPL(ata_qc_prep);
7615 EXPORT_SYMBOL_GPL(ata_dumb_qc_prep);
7616 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
7617 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
7618 EXPORT_SYMBOL_GPL(ata_bmdma_start);
7619 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
7620 EXPORT_SYMBOL_GPL(ata_bmdma_status);
7621 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
7622 EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
7623 EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
7624 EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
7625 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
7626 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
7627 EXPORT_SYMBOL_GPL(ata_port_probe);
7628 EXPORT_SYMBOL_GPL(ata_dev_disable);
7629 EXPORT_SYMBOL_GPL(sata_set_spd);
7630 EXPORT_SYMBOL_GPL(sata_link_debounce);
7631 EXPORT_SYMBOL_GPL(sata_link_resume);
7632 EXPORT_SYMBOL_GPL(ata_bus_reset);
7633 EXPORT_SYMBOL_GPL(ata_std_prereset);
7634 EXPORT_SYMBOL_GPL(ata_std_softreset);
7635 EXPORT_SYMBOL_GPL(sata_link_hardreset);
7636 EXPORT_SYMBOL_GPL(sata_std_hardreset);
7637 EXPORT_SYMBOL_GPL(ata_std_postreset);
7638 EXPORT_SYMBOL_GPL(ata_dev_classify);
7639 EXPORT_SYMBOL_GPL(ata_dev_pair);
7640 EXPORT_SYMBOL_GPL(ata_port_disable);
7641 EXPORT_SYMBOL_GPL(ata_ratelimit);
7642 EXPORT_SYMBOL_GPL(ata_wait_register);
7643 EXPORT_SYMBOL_GPL(ata_busy_sleep);
7644 EXPORT_SYMBOL_GPL(ata_wait_after_reset);
7645 EXPORT_SYMBOL_GPL(ata_wait_ready);
7646 EXPORT_SYMBOL_GPL(ata_port_queue_task);
7647 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
7648 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
7649 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
7650 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
7651 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
7652 EXPORT_SYMBOL_GPL(ata_host_intr);
7653 EXPORT_SYMBOL_GPL(sata_scr_valid);
7654 EXPORT_SYMBOL_GPL(sata_scr_read);
7655 EXPORT_SYMBOL_GPL(sata_scr_write);
7656 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
7657 EXPORT_SYMBOL_GPL(ata_link_online);
7658 EXPORT_SYMBOL_GPL(ata_link_offline);
7659 #ifdef CONFIG_PM
7660 EXPORT_SYMBOL_GPL(ata_host_suspend);
7661 EXPORT_SYMBOL_GPL(ata_host_resume);
7662 #endif /* CONFIG_PM */
7663 EXPORT_SYMBOL_GPL(ata_id_string);
7664 EXPORT_SYMBOL_GPL(ata_id_c_string);
7665 EXPORT_SYMBOL_GPL(ata_id_to_dma_mode);
7666 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
7667 
7668 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
7669 EXPORT_SYMBOL_GPL(ata_timing_compute);
7670 EXPORT_SYMBOL_GPL(ata_timing_merge);
7671 
7672 #ifdef CONFIG_PCI
7673 EXPORT_SYMBOL_GPL(pci_test_config_bits);
7674 EXPORT_SYMBOL_GPL(ata_pci_init_sff_host);
7675 EXPORT_SYMBOL_GPL(ata_pci_init_bmdma);
7676 EXPORT_SYMBOL_GPL(ata_pci_prepare_sff_host);
7677 EXPORT_SYMBOL_GPL(ata_pci_init_one);
7678 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
7679 #ifdef CONFIG_PM
7680 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
7681 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
7682 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
7683 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
7684 #endif /* CONFIG_PM */
7685 EXPORT_SYMBOL_GPL(ata_pci_default_filter);
7686 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
7687 #endif /* CONFIG_PCI */
7688 
7689 EXPORT_SYMBOL_GPL(sata_pmp_qc_defer_cmd_switch);
7690 EXPORT_SYMBOL_GPL(sata_pmp_std_prereset);
7691 EXPORT_SYMBOL_GPL(sata_pmp_std_hardreset);
7692 EXPORT_SYMBOL_GPL(sata_pmp_std_postreset);
7693 EXPORT_SYMBOL_GPL(sata_pmp_do_eh);
7694 
7695 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
7696 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
7697 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
7698 EXPORT_SYMBOL_GPL(ata_port_desc);
7699 #ifdef CONFIG_PCI
7700 EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
7701 #endif /* CONFIG_PCI */
7702 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
7703 EXPORT_SYMBOL_GPL(ata_link_abort);
7704 EXPORT_SYMBOL_GPL(ata_port_abort);
7705 EXPORT_SYMBOL_GPL(ata_port_freeze);
7706 EXPORT_SYMBOL_GPL(sata_async_notification);
7707 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
7708 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
7709 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
7710 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
7711 EXPORT_SYMBOL_GPL(ata_do_eh);
7712 EXPORT_SYMBOL_GPL(ata_irq_on);
7713 EXPORT_SYMBOL_GPL(ata_dev_try_classify);
7714 
7715 EXPORT_SYMBOL_GPL(ata_cable_40wire);
7716 EXPORT_SYMBOL_GPL(ata_cable_80wire);
7717 EXPORT_SYMBOL_GPL(ata_cable_unknown);
7718 EXPORT_SYMBOL_GPL(ata_cable_sata);
7719