xref: /linux/drivers/ata/libata-core.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
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  */
34 
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/pci.h>
38 #include <linux/init.h>
39 #include <linux/list.h>
40 #include <linux/mm.h>
41 #include <linux/highmem.h>
42 #include <linux/spinlock.h>
43 #include <linux/blkdev.h>
44 #include <linux/delay.h>
45 #include <linux/timer.h>
46 #include <linux/interrupt.h>
47 #include <linux/completion.h>
48 #include <linux/suspend.h>
49 #include <linux/workqueue.h>
50 #include <linux/jiffies.h>
51 #include <linux/scatterlist.h>
52 #include <scsi/scsi.h>
53 #include <scsi/scsi_cmnd.h>
54 #include <scsi/scsi_host.h>
55 #include <linux/libata.h>
56 #include <asm/io.h>
57 #include <asm/semaphore.h>
58 #include <asm/byteorder.h>
59 
60 #include "libata.h"
61 
62 /* debounce timing parameters in msecs { interval, duration, timeout } */
63 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
64 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
65 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
66 
67 static unsigned int ata_dev_init_params(struct ata_device *dev,
68 					u16 heads, u16 sectors);
69 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
70 static void ata_dev_xfermask(struct ata_device *dev);
71 
72 static unsigned int ata_unique_id = 1;
73 static struct workqueue_struct *ata_wq;
74 
75 struct workqueue_struct *ata_aux_wq;
76 
77 int atapi_enabled = 1;
78 module_param(atapi_enabled, int, 0444);
79 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
80 
81 int atapi_dmadir = 0;
82 module_param(atapi_dmadir, int, 0444);
83 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
84 
85 int libata_fua = 0;
86 module_param_named(fua, libata_fua, int, 0444);
87 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
88 
89 static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
90 module_param(ata_probe_timeout, int, 0444);
91 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
92 
93 MODULE_AUTHOR("Jeff Garzik");
94 MODULE_DESCRIPTION("Library module for ATA devices");
95 MODULE_LICENSE("GPL");
96 MODULE_VERSION(DRV_VERSION);
97 
98 
99 /**
100  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
101  *	@tf: Taskfile to convert
102  *	@fis: Buffer into which data will output
103  *	@pmp: Port multiplier port
104  *
105  *	Converts a standard ATA taskfile to a Serial ATA
106  *	FIS structure (Register - Host to Device).
107  *
108  *	LOCKING:
109  *	Inherited from caller.
110  */
111 
112 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 *fis, u8 pmp)
113 {
114 	fis[0] = 0x27;	/* Register - Host to Device FIS */
115 	fis[1] = (pmp & 0xf) | (1 << 7); /* Port multiplier number,
116 					    bit 7 indicates Command FIS */
117 	fis[2] = tf->command;
118 	fis[3] = tf->feature;
119 
120 	fis[4] = tf->lbal;
121 	fis[5] = tf->lbam;
122 	fis[6] = tf->lbah;
123 	fis[7] = tf->device;
124 
125 	fis[8] = tf->hob_lbal;
126 	fis[9] = tf->hob_lbam;
127 	fis[10] = tf->hob_lbah;
128 	fis[11] = tf->hob_feature;
129 
130 	fis[12] = tf->nsect;
131 	fis[13] = tf->hob_nsect;
132 	fis[14] = 0;
133 	fis[15] = tf->ctl;
134 
135 	fis[16] = 0;
136 	fis[17] = 0;
137 	fis[18] = 0;
138 	fis[19] = 0;
139 }
140 
141 /**
142  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
143  *	@fis: Buffer from which data will be input
144  *	@tf: Taskfile to output
145  *
146  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
147  *
148  *	LOCKING:
149  *	Inherited from caller.
150  */
151 
152 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
153 {
154 	tf->command	= fis[2];	/* status */
155 	tf->feature	= fis[3];	/* error */
156 
157 	tf->lbal	= fis[4];
158 	tf->lbam	= fis[5];
159 	tf->lbah	= fis[6];
160 	tf->device	= fis[7];
161 
162 	tf->hob_lbal	= fis[8];
163 	tf->hob_lbam	= fis[9];
164 	tf->hob_lbah	= fis[10];
165 
166 	tf->nsect	= fis[12];
167 	tf->hob_nsect	= fis[13];
168 }
169 
170 static const u8 ata_rw_cmds[] = {
171 	/* pio multi */
172 	ATA_CMD_READ_MULTI,
173 	ATA_CMD_WRITE_MULTI,
174 	ATA_CMD_READ_MULTI_EXT,
175 	ATA_CMD_WRITE_MULTI_EXT,
176 	0,
177 	0,
178 	0,
179 	ATA_CMD_WRITE_MULTI_FUA_EXT,
180 	/* pio */
181 	ATA_CMD_PIO_READ,
182 	ATA_CMD_PIO_WRITE,
183 	ATA_CMD_PIO_READ_EXT,
184 	ATA_CMD_PIO_WRITE_EXT,
185 	0,
186 	0,
187 	0,
188 	0,
189 	/* dma */
190 	ATA_CMD_READ,
191 	ATA_CMD_WRITE,
192 	ATA_CMD_READ_EXT,
193 	ATA_CMD_WRITE_EXT,
194 	0,
195 	0,
196 	0,
197 	ATA_CMD_WRITE_FUA_EXT
198 };
199 
200 /**
201  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
202  *	@tf: command to examine and configure
203  *	@dev: device tf belongs to
204  *
205  *	Examine the device configuration and tf->flags to calculate
206  *	the proper read/write commands and protocol to use.
207  *
208  *	LOCKING:
209  *	caller.
210  */
211 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
212 {
213 	u8 cmd;
214 
215 	int index, fua, lba48, write;
216 
217 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
218 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
219 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
220 
221 	if (dev->flags & ATA_DFLAG_PIO) {
222 		tf->protocol = ATA_PROT_PIO;
223 		index = dev->multi_count ? 0 : 8;
224 	} else if (lba48 && (dev->ap->flags & ATA_FLAG_PIO_LBA48)) {
225 		/* Unable to use DMA due to host limitation */
226 		tf->protocol = ATA_PROT_PIO;
227 		index = dev->multi_count ? 0 : 8;
228 	} else {
229 		tf->protocol = ATA_PROT_DMA;
230 		index = 16;
231 	}
232 
233 	cmd = ata_rw_cmds[index + fua + lba48 + write];
234 	if (cmd) {
235 		tf->command = cmd;
236 		return 0;
237 	}
238 	return -1;
239 }
240 
241 /**
242  *	ata_tf_read_block - Read block address from ATA taskfile
243  *	@tf: ATA taskfile of interest
244  *	@dev: ATA device @tf belongs to
245  *
246  *	LOCKING:
247  *	None.
248  *
249  *	Read block address from @tf.  This function can handle all
250  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
251  *	flags select the address format to use.
252  *
253  *	RETURNS:
254  *	Block address read from @tf.
255  */
256 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
257 {
258 	u64 block = 0;
259 
260 	if (tf->flags & ATA_TFLAG_LBA) {
261 		if (tf->flags & ATA_TFLAG_LBA48) {
262 			block |= (u64)tf->hob_lbah << 40;
263 			block |= (u64)tf->hob_lbam << 32;
264 			block |= tf->hob_lbal << 24;
265 		} else
266 			block |= (tf->device & 0xf) << 24;
267 
268 		block |= tf->lbah << 16;
269 		block |= tf->lbam << 8;
270 		block |= tf->lbal;
271 	} else {
272 		u32 cyl, head, sect;
273 
274 		cyl = tf->lbam | (tf->lbah << 8);
275 		head = tf->device & 0xf;
276 		sect = tf->lbal;
277 
278 		block = (cyl * dev->heads + head) * dev->sectors + sect;
279 	}
280 
281 	return block;
282 }
283 
284 /**
285  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
286  *	@tf: Target ATA taskfile
287  *	@dev: ATA device @tf belongs to
288  *	@block: Block address
289  *	@n_block: Number of blocks
290  *	@tf_flags: RW/FUA etc...
291  *	@tag: tag
292  *
293  *	LOCKING:
294  *	None.
295  *
296  *	Build ATA taskfile @tf for read/write request described by
297  *	@block, @n_block, @tf_flags and @tag on @dev.
298  *
299  *	RETURNS:
300  *
301  *	0 on success, -ERANGE if the request is too large for @dev,
302  *	-EINVAL if the request is invalid.
303  */
304 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
305 		    u64 block, u32 n_block, unsigned int tf_flags,
306 		    unsigned int tag)
307 {
308 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
309 	tf->flags |= tf_flags;
310 
311 	if ((dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ_OFF |
312 			   ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ &&
313 	    likely(tag != ATA_TAG_INTERNAL)) {
314 		/* yay, NCQ */
315 		if (!lba_48_ok(block, n_block))
316 			return -ERANGE;
317 
318 		tf->protocol = ATA_PROT_NCQ;
319 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
320 
321 		if (tf->flags & ATA_TFLAG_WRITE)
322 			tf->command = ATA_CMD_FPDMA_WRITE;
323 		else
324 			tf->command = ATA_CMD_FPDMA_READ;
325 
326 		tf->nsect = tag << 3;
327 		tf->hob_feature = (n_block >> 8) & 0xff;
328 		tf->feature = n_block & 0xff;
329 
330 		tf->hob_lbah = (block >> 40) & 0xff;
331 		tf->hob_lbam = (block >> 32) & 0xff;
332 		tf->hob_lbal = (block >> 24) & 0xff;
333 		tf->lbah = (block >> 16) & 0xff;
334 		tf->lbam = (block >> 8) & 0xff;
335 		tf->lbal = block & 0xff;
336 
337 		tf->device = 1 << 6;
338 		if (tf->flags & ATA_TFLAG_FUA)
339 			tf->device |= 1 << 7;
340 	} else if (dev->flags & ATA_DFLAG_LBA) {
341 		tf->flags |= ATA_TFLAG_LBA;
342 
343 		if (lba_28_ok(block, n_block)) {
344 			/* use LBA28 */
345 			tf->device |= (block >> 24) & 0xf;
346 		} else if (lba_48_ok(block, n_block)) {
347 			if (!(dev->flags & ATA_DFLAG_LBA48))
348 				return -ERANGE;
349 
350 			/* use LBA48 */
351 			tf->flags |= ATA_TFLAG_LBA48;
352 
353 			tf->hob_nsect = (n_block >> 8) & 0xff;
354 
355 			tf->hob_lbah = (block >> 40) & 0xff;
356 			tf->hob_lbam = (block >> 32) & 0xff;
357 			tf->hob_lbal = (block >> 24) & 0xff;
358 		} else
359 			/* request too large even for LBA48 */
360 			return -ERANGE;
361 
362 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
363 			return -EINVAL;
364 
365 		tf->nsect = n_block & 0xff;
366 
367 		tf->lbah = (block >> 16) & 0xff;
368 		tf->lbam = (block >> 8) & 0xff;
369 		tf->lbal = block & 0xff;
370 
371 		tf->device |= ATA_LBA;
372 	} else {
373 		/* CHS */
374 		u32 sect, head, cyl, track;
375 
376 		/* The request -may- be too large for CHS addressing. */
377 		if (!lba_28_ok(block, n_block))
378 			return -ERANGE;
379 
380 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
381 			return -EINVAL;
382 
383 		/* Convert LBA to CHS */
384 		track = (u32)block / dev->sectors;
385 		cyl   = track / dev->heads;
386 		head  = track % dev->heads;
387 		sect  = (u32)block % dev->sectors + 1;
388 
389 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
390 			(u32)block, track, cyl, head, sect);
391 
392 		/* Check whether the converted CHS can fit.
393 		   Cylinder: 0-65535
394 		   Head: 0-15
395 		   Sector: 1-255*/
396 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
397 			return -ERANGE;
398 
399 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
400 		tf->lbal = sect;
401 		tf->lbam = cyl;
402 		tf->lbah = cyl >> 8;
403 		tf->device |= head;
404 	}
405 
406 	return 0;
407 }
408 
409 /**
410  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
411  *	@pio_mask: pio_mask
412  *	@mwdma_mask: mwdma_mask
413  *	@udma_mask: udma_mask
414  *
415  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
416  *	unsigned int xfer_mask.
417  *
418  *	LOCKING:
419  *	None.
420  *
421  *	RETURNS:
422  *	Packed xfer_mask.
423  */
424 static unsigned int ata_pack_xfermask(unsigned int pio_mask,
425 				      unsigned int mwdma_mask,
426 				      unsigned int udma_mask)
427 {
428 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
429 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
430 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
431 }
432 
433 /**
434  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
435  *	@xfer_mask: xfer_mask to unpack
436  *	@pio_mask: resulting pio_mask
437  *	@mwdma_mask: resulting mwdma_mask
438  *	@udma_mask: resulting udma_mask
439  *
440  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
441  *	Any NULL distination masks will be ignored.
442  */
443 static void ata_unpack_xfermask(unsigned int xfer_mask,
444 				unsigned int *pio_mask,
445 				unsigned int *mwdma_mask,
446 				unsigned int *udma_mask)
447 {
448 	if (pio_mask)
449 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
450 	if (mwdma_mask)
451 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
452 	if (udma_mask)
453 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
454 }
455 
456 static const struct ata_xfer_ent {
457 	int shift, bits;
458 	u8 base;
459 } ata_xfer_tbl[] = {
460 	{ ATA_SHIFT_PIO, ATA_BITS_PIO, XFER_PIO_0 },
461 	{ ATA_SHIFT_MWDMA, ATA_BITS_MWDMA, XFER_MW_DMA_0 },
462 	{ ATA_SHIFT_UDMA, ATA_BITS_UDMA, XFER_UDMA_0 },
463 	{ -1, },
464 };
465 
466 /**
467  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
468  *	@xfer_mask: xfer_mask of interest
469  *
470  *	Return matching XFER_* value for @xfer_mask.  Only the highest
471  *	bit of @xfer_mask is considered.
472  *
473  *	LOCKING:
474  *	None.
475  *
476  *	RETURNS:
477  *	Matching XFER_* value, 0 if no match found.
478  */
479 static u8 ata_xfer_mask2mode(unsigned int xfer_mask)
480 {
481 	int highbit = fls(xfer_mask) - 1;
482 	const struct ata_xfer_ent *ent;
483 
484 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
485 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
486 			return ent->base + highbit - ent->shift;
487 	return 0;
488 }
489 
490 /**
491  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
492  *	@xfer_mode: XFER_* of interest
493  *
494  *	Return matching xfer_mask for @xfer_mode.
495  *
496  *	LOCKING:
497  *	None.
498  *
499  *	RETURNS:
500  *	Matching xfer_mask, 0 if no match found.
501  */
502 static unsigned int ata_xfer_mode2mask(u8 xfer_mode)
503 {
504 	const struct ata_xfer_ent *ent;
505 
506 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
507 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
508 			return 1 << (ent->shift + xfer_mode - ent->base);
509 	return 0;
510 }
511 
512 /**
513  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
514  *	@xfer_mode: XFER_* of interest
515  *
516  *	Return matching xfer_shift for @xfer_mode.
517  *
518  *	LOCKING:
519  *	None.
520  *
521  *	RETURNS:
522  *	Matching xfer_shift, -1 if no match found.
523  */
524 static int ata_xfer_mode2shift(unsigned int xfer_mode)
525 {
526 	const struct ata_xfer_ent *ent;
527 
528 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
529 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
530 			return ent->shift;
531 	return -1;
532 }
533 
534 /**
535  *	ata_mode_string - convert xfer_mask to string
536  *	@xfer_mask: mask of bits supported; only highest bit counts.
537  *
538  *	Determine string which represents the highest speed
539  *	(highest bit in @modemask).
540  *
541  *	LOCKING:
542  *	None.
543  *
544  *	RETURNS:
545  *	Constant C string representing highest speed listed in
546  *	@mode_mask, or the constant C string "<n/a>".
547  */
548 static const char *ata_mode_string(unsigned int xfer_mask)
549 {
550 	static const char * const xfer_mode_str[] = {
551 		"PIO0",
552 		"PIO1",
553 		"PIO2",
554 		"PIO3",
555 		"PIO4",
556 		"PIO5",
557 		"PIO6",
558 		"MWDMA0",
559 		"MWDMA1",
560 		"MWDMA2",
561 		"MWDMA3",
562 		"MWDMA4",
563 		"UDMA/16",
564 		"UDMA/25",
565 		"UDMA/33",
566 		"UDMA/44",
567 		"UDMA/66",
568 		"UDMA/100",
569 		"UDMA/133",
570 		"UDMA7",
571 	};
572 	int highbit;
573 
574 	highbit = fls(xfer_mask) - 1;
575 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
576 		return xfer_mode_str[highbit];
577 	return "<n/a>";
578 }
579 
580 static const char *sata_spd_string(unsigned int spd)
581 {
582 	static const char * const spd_str[] = {
583 		"1.5 Gbps",
584 		"3.0 Gbps",
585 	};
586 
587 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
588 		return "<unknown>";
589 	return spd_str[spd - 1];
590 }
591 
592 void ata_dev_disable(struct ata_device *dev)
593 {
594 	if (ata_dev_enabled(dev) && ata_msg_drv(dev->ap)) {
595 		ata_dev_printk(dev, KERN_WARNING, "disabled\n");
596 		dev->class++;
597 	}
598 }
599 
600 /**
601  *	ata_pio_devchk - PATA device presence detection
602  *	@ap: ATA channel to examine
603  *	@device: Device to examine (starting at zero)
604  *
605  *	This technique was originally described in
606  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
607  *	later found its way into the ATA/ATAPI spec.
608  *
609  *	Write a pattern to the ATA shadow registers,
610  *	and if a device is present, it will respond by
611  *	correctly storing and echoing back the
612  *	ATA shadow register contents.
613  *
614  *	LOCKING:
615  *	caller.
616  */
617 
618 static unsigned int ata_pio_devchk(struct ata_port *ap,
619 				   unsigned int device)
620 {
621 	struct ata_ioports *ioaddr = &ap->ioaddr;
622 	u8 nsect, lbal;
623 
624 	ap->ops->dev_select(ap, device);
625 
626 	outb(0x55, ioaddr->nsect_addr);
627 	outb(0xaa, ioaddr->lbal_addr);
628 
629 	outb(0xaa, ioaddr->nsect_addr);
630 	outb(0x55, ioaddr->lbal_addr);
631 
632 	outb(0x55, ioaddr->nsect_addr);
633 	outb(0xaa, ioaddr->lbal_addr);
634 
635 	nsect = inb(ioaddr->nsect_addr);
636 	lbal = inb(ioaddr->lbal_addr);
637 
638 	if ((nsect == 0x55) && (lbal == 0xaa))
639 		return 1;	/* we found a device */
640 
641 	return 0;		/* nothing found */
642 }
643 
644 /**
645  *	ata_mmio_devchk - PATA device presence detection
646  *	@ap: ATA channel to examine
647  *	@device: Device to examine (starting at zero)
648  *
649  *	This technique was originally described in
650  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
651  *	later found its way into the ATA/ATAPI spec.
652  *
653  *	Write a pattern to the ATA shadow registers,
654  *	and if a device is present, it will respond by
655  *	correctly storing and echoing back the
656  *	ATA shadow register contents.
657  *
658  *	LOCKING:
659  *	caller.
660  */
661 
662 static unsigned int ata_mmio_devchk(struct ata_port *ap,
663 				    unsigned int device)
664 {
665 	struct ata_ioports *ioaddr = &ap->ioaddr;
666 	u8 nsect, lbal;
667 
668 	ap->ops->dev_select(ap, device);
669 
670 	writeb(0x55, (void __iomem *) ioaddr->nsect_addr);
671 	writeb(0xaa, (void __iomem *) ioaddr->lbal_addr);
672 
673 	writeb(0xaa, (void __iomem *) ioaddr->nsect_addr);
674 	writeb(0x55, (void __iomem *) ioaddr->lbal_addr);
675 
676 	writeb(0x55, (void __iomem *) ioaddr->nsect_addr);
677 	writeb(0xaa, (void __iomem *) ioaddr->lbal_addr);
678 
679 	nsect = readb((void __iomem *) ioaddr->nsect_addr);
680 	lbal = readb((void __iomem *) ioaddr->lbal_addr);
681 
682 	if ((nsect == 0x55) && (lbal == 0xaa))
683 		return 1;	/* we found a device */
684 
685 	return 0;		/* nothing found */
686 }
687 
688 /**
689  *	ata_devchk - PATA device presence detection
690  *	@ap: ATA channel to examine
691  *	@device: Device to examine (starting at zero)
692  *
693  *	Dispatch ATA device presence detection, depending
694  *	on whether we are using PIO or MMIO to talk to the
695  *	ATA shadow registers.
696  *
697  *	LOCKING:
698  *	caller.
699  */
700 
701 static unsigned int ata_devchk(struct ata_port *ap,
702 				    unsigned int device)
703 {
704 	if (ap->flags & ATA_FLAG_MMIO)
705 		return ata_mmio_devchk(ap, device);
706 	return ata_pio_devchk(ap, device);
707 }
708 
709 /**
710  *	ata_dev_classify - determine device type based on ATA-spec signature
711  *	@tf: ATA taskfile register set for device to be identified
712  *
713  *	Determine from taskfile register contents whether a device is
714  *	ATA or ATAPI, as per "Signature and persistence" section
715  *	of ATA/PI spec (volume 1, sect 5.14).
716  *
717  *	LOCKING:
718  *	None.
719  *
720  *	RETURNS:
721  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, or %ATA_DEV_UNKNOWN
722  *	the event of failure.
723  */
724 
725 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
726 {
727 	/* Apple's open source Darwin code hints that some devices only
728 	 * put a proper signature into the LBA mid/high registers,
729 	 * So, we only check those.  It's sufficient for uniqueness.
730 	 */
731 
732 	if (((tf->lbam == 0) && (tf->lbah == 0)) ||
733 	    ((tf->lbam == 0x3c) && (tf->lbah == 0xc3))) {
734 		DPRINTK("found ATA device by sig\n");
735 		return ATA_DEV_ATA;
736 	}
737 
738 	if (((tf->lbam == 0x14) && (tf->lbah == 0xeb)) ||
739 	    ((tf->lbam == 0x69) && (tf->lbah == 0x96))) {
740 		DPRINTK("found ATAPI device by sig\n");
741 		return ATA_DEV_ATAPI;
742 	}
743 
744 	DPRINTK("unknown device\n");
745 	return ATA_DEV_UNKNOWN;
746 }
747 
748 /**
749  *	ata_dev_try_classify - Parse returned ATA device signature
750  *	@ap: ATA channel to examine
751  *	@device: Device to examine (starting at zero)
752  *	@r_err: Value of error register on completion
753  *
754  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
755  *	an ATA/ATAPI-defined set of values is placed in the ATA
756  *	shadow registers, indicating the results of device detection
757  *	and diagnostics.
758  *
759  *	Select the ATA device, and read the values from the ATA shadow
760  *	registers.  Then parse according to the Error register value,
761  *	and the spec-defined values examined by ata_dev_classify().
762  *
763  *	LOCKING:
764  *	caller.
765  *
766  *	RETURNS:
767  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
768  */
769 
770 static unsigned int
771 ata_dev_try_classify(struct ata_port *ap, unsigned int device, u8 *r_err)
772 {
773 	struct ata_taskfile tf;
774 	unsigned int class;
775 	u8 err;
776 
777 	ap->ops->dev_select(ap, device);
778 
779 	memset(&tf, 0, sizeof(tf));
780 
781 	ap->ops->tf_read(ap, &tf);
782 	err = tf.feature;
783 	if (r_err)
784 		*r_err = err;
785 
786 	/* see if device passed diags: if master then continue and warn later */
787 	if (err == 0 && device == 0)
788 		/* diagnostic fail : do nothing _YET_ */
789 		ap->device[device].horkage |= ATA_HORKAGE_DIAGNOSTIC;
790 	else if (err == 1)
791 		/* do nothing */ ;
792 	else if ((device == 0) && (err == 0x81))
793 		/* do nothing */ ;
794 	else
795 		return ATA_DEV_NONE;
796 
797 	/* determine if device is ATA or ATAPI */
798 	class = ata_dev_classify(&tf);
799 
800 	if (class == ATA_DEV_UNKNOWN)
801 		return ATA_DEV_NONE;
802 	if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
803 		return ATA_DEV_NONE;
804 	return class;
805 }
806 
807 /**
808  *	ata_id_string - Convert IDENTIFY DEVICE page into string
809  *	@id: IDENTIFY DEVICE results we will examine
810  *	@s: string into which data is output
811  *	@ofs: offset into identify device page
812  *	@len: length of string to return. must be an even number.
813  *
814  *	The strings in the IDENTIFY DEVICE page are broken up into
815  *	16-bit chunks.  Run through the string, and output each
816  *	8-bit chunk linearly, regardless of platform.
817  *
818  *	LOCKING:
819  *	caller.
820  */
821 
822 void ata_id_string(const u16 *id, unsigned char *s,
823 		   unsigned int ofs, unsigned int len)
824 {
825 	unsigned int c;
826 
827 	while (len > 0) {
828 		c = id[ofs] >> 8;
829 		*s = c;
830 		s++;
831 
832 		c = id[ofs] & 0xff;
833 		*s = c;
834 		s++;
835 
836 		ofs++;
837 		len -= 2;
838 	}
839 }
840 
841 /**
842  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
843  *	@id: IDENTIFY DEVICE results we will examine
844  *	@s: string into which data is output
845  *	@ofs: offset into identify device page
846  *	@len: length of string to return. must be an odd number.
847  *
848  *	This function is identical to ata_id_string except that it
849  *	trims trailing spaces and terminates the resulting string with
850  *	null.  @len must be actual maximum length (even number) + 1.
851  *
852  *	LOCKING:
853  *	caller.
854  */
855 void ata_id_c_string(const u16 *id, unsigned char *s,
856 		     unsigned int ofs, unsigned int len)
857 {
858 	unsigned char *p;
859 
860 	WARN_ON(!(len & 1));
861 
862 	ata_id_string(id, s, ofs, len - 1);
863 
864 	p = s + strnlen(s, len - 1);
865 	while (p > s && p[-1] == ' ')
866 		p--;
867 	*p = '\0';
868 }
869 
870 static u64 ata_id_n_sectors(const u16 *id)
871 {
872 	if (ata_id_has_lba(id)) {
873 		if (ata_id_has_lba48(id))
874 			return ata_id_u64(id, 100);
875 		else
876 			return ata_id_u32(id, 60);
877 	} else {
878 		if (ata_id_current_chs_valid(id))
879 			return ata_id_u32(id, 57);
880 		else
881 			return id[1] * id[3] * id[6];
882 	}
883 }
884 
885 /**
886  *	ata_noop_dev_select - Select device 0/1 on ATA bus
887  *	@ap: ATA channel to manipulate
888  *	@device: ATA device (numbered from zero) to select
889  *
890  *	This function performs no actual function.
891  *
892  *	May be used as the dev_select() entry in ata_port_operations.
893  *
894  *	LOCKING:
895  *	caller.
896  */
897 void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
898 {
899 }
900 
901 
902 /**
903  *	ata_std_dev_select - Select device 0/1 on ATA bus
904  *	@ap: ATA channel to manipulate
905  *	@device: ATA device (numbered from zero) to select
906  *
907  *	Use the method defined in the ATA specification to
908  *	make either device 0, or device 1, active on the
909  *	ATA channel.  Works with both PIO and MMIO.
910  *
911  *	May be used as the dev_select() entry in ata_port_operations.
912  *
913  *	LOCKING:
914  *	caller.
915  */
916 
917 void ata_std_dev_select (struct ata_port *ap, unsigned int device)
918 {
919 	u8 tmp;
920 
921 	if (device == 0)
922 		tmp = ATA_DEVICE_OBS;
923 	else
924 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
925 
926 	if (ap->flags & ATA_FLAG_MMIO) {
927 		writeb(tmp, (void __iomem *) ap->ioaddr.device_addr);
928 	} else {
929 		outb(tmp, ap->ioaddr.device_addr);
930 	}
931 	ata_pause(ap);		/* needed; also flushes, for mmio */
932 }
933 
934 /**
935  *	ata_dev_select - Select device 0/1 on ATA bus
936  *	@ap: ATA channel to manipulate
937  *	@device: ATA device (numbered from zero) to select
938  *	@wait: non-zero to wait for Status register BSY bit to clear
939  *	@can_sleep: non-zero if context allows sleeping
940  *
941  *	Use the method defined in the ATA specification to
942  *	make either device 0, or device 1, active on the
943  *	ATA channel.
944  *
945  *	This is a high-level version of ata_std_dev_select(),
946  *	which additionally provides the services of inserting
947  *	the proper pauses and status polling, where needed.
948  *
949  *	LOCKING:
950  *	caller.
951  */
952 
953 void ata_dev_select(struct ata_port *ap, unsigned int device,
954 			   unsigned int wait, unsigned int can_sleep)
955 {
956 	if (ata_msg_probe(ap))
957 		ata_port_printk(ap, KERN_INFO, "ata_dev_select: ENTER, ata%u: "
958 				"device %u, wait %u\n", ap->id, device, wait);
959 
960 	if (wait)
961 		ata_wait_idle(ap);
962 
963 	ap->ops->dev_select(ap, device);
964 
965 	if (wait) {
966 		if (can_sleep && ap->device[device].class == ATA_DEV_ATAPI)
967 			msleep(150);
968 		ata_wait_idle(ap);
969 	}
970 }
971 
972 /**
973  *	ata_dump_id - IDENTIFY DEVICE info debugging output
974  *	@id: IDENTIFY DEVICE page to dump
975  *
976  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
977  *	page.
978  *
979  *	LOCKING:
980  *	caller.
981  */
982 
983 static inline void ata_dump_id(const u16 *id)
984 {
985 	DPRINTK("49==0x%04x  "
986 		"53==0x%04x  "
987 		"63==0x%04x  "
988 		"64==0x%04x  "
989 		"75==0x%04x  \n",
990 		id[49],
991 		id[53],
992 		id[63],
993 		id[64],
994 		id[75]);
995 	DPRINTK("80==0x%04x  "
996 		"81==0x%04x  "
997 		"82==0x%04x  "
998 		"83==0x%04x  "
999 		"84==0x%04x  \n",
1000 		id[80],
1001 		id[81],
1002 		id[82],
1003 		id[83],
1004 		id[84]);
1005 	DPRINTK("88==0x%04x  "
1006 		"93==0x%04x\n",
1007 		id[88],
1008 		id[93]);
1009 }
1010 
1011 /**
1012  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1013  *	@id: IDENTIFY data to compute xfer mask from
1014  *
1015  *	Compute the xfermask for this device. This is not as trivial
1016  *	as it seems if we must consider early devices correctly.
1017  *
1018  *	FIXME: pre IDE drive timing (do we care ?).
1019  *
1020  *	LOCKING:
1021  *	None.
1022  *
1023  *	RETURNS:
1024  *	Computed xfermask
1025  */
1026 static unsigned int ata_id_xfermask(const u16 *id)
1027 {
1028 	unsigned int pio_mask, mwdma_mask, udma_mask;
1029 
1030 	/* Usual case. Word 53 indicates word 64 is valid */
1031 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1032 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1033 		pio_mask <<= 3;
1034 		pio_mask |= 0x7;
1035 	} else {
1036 		/* If word 64 isn't valid then Word 51 high byte holds
1037 		 * the PIO timing number for the maximum. Turn it into
1038 		 * a mask.
1039 		 */
1040 		u8 mode = id[ATA_ID_OLD_PIO_MODES] & 0xFF;
1041 		if (mode < 5)	/* Valid PIO range */
1042                 	pio_mask = (2 << mode) - 1;
1043 		else
1044 			pio_mask = 1;
1045 
1046 		/* But wait.. there's more. Design your standards by
1047 		 * committee and you too can get a free iordy field to
1048 		 * process. However its the speeds not the modes that
1049 		 * are supported... Note drivers using the timing API
1050 		 * will get this right anyway
1051 		 */
1052 	}
1053 
1054 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1055 
1056 	if (ata_id_is_cfa(id)) {
1057 		/*
1058 		 *	Process compact flash extended modes
1059 		 */
1060 		int pio = id[163] & 0x7;
1061 		int dma = (id[163] >> 3) & 7;
1062 
1063 		if (pio)
1064 			pio_mask |= (1 << 5);
1065 		if (pio > 1)
1066 			pio_mask |= (1 << 6);
1067 		if (dma)
1068 			mwdma_mask |= (1 << 3);
1069 		if (dma > 1)
1070 			mwdma_mask |= (1 << 4);
1071 	}
1072 
1073 	udma_mask = 0;
1074 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1075 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1076 
1077 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1078 }
1079 
1080 /**
1081  *	ata_port_queue_task - Queue port_task
1082  *	@ap: The ata_port to queue port_task for
1083  *	@fn: workqueue function to be scheduled
1084  *	@data: data for @fn to use
1085  *	@delay: delay time for workqueue function
1086  *
1087  *	Schedule @fn(@data) for execution after @delay jiffies using
1088  *	port_task.  There is one port_task per port and it's the
1089  *	user(low level driver)'s responsibility to make sure that only
1090  *	one task is active at any given time.
1091  *
1092  *	libata core layer takes care of synchronization between
1093  *	port_task and EH.  ata_port_queue_task() may be ignored for EH
1094  *	synchronization.
1095  *
1096  *	LOCKING:
1097  *	Inherited from caller.
1098  */
1099 void ata_port_queue_task(struct ata_port *ap, work_func_t fn, void *data,
1100 			 unsigned long delay)
1101 {
1102 	int rc;
1103 
1104 	if (ap->pflags & ATA_PFLAG_FLUSH_PORT_TASK)
1105 		return;
1106 
1107 	PREPARE_DELAYED_WORK(&ap->port_task, fn);
1108 	ap->port_task_data = data;
1109 
1110 	rc = queue_delayed_work(ata_wq, &ap->port_task, delay);
1111 
1112 	/* rc == 0 means that another user is using port task */
1113 	WARN_ON(rc == 0);
1114 }
1115 
1116 /**
1117  *	ata_port_flush_task - Flush port_task
1118  *	@ap: The ata_port to flush port_task for
1119  *
1120  *	After this function completes, port_task is guranteed not to
1121  *	be running or scheduled.
1122  *
1123  *	LOCKING:
1124  *	Kernel thread context (may sleep)
1125  */
1126 void ata_port_flush_task(struct ata_port *ap)
1127 {
1128 	unsigned long flags;
1129 
1130 	DPRINTK("ENTER\n");
1131 
1132 	spin_lock_irqsave(ap->lock, flags);
1133 	ap->pflags |= ATA_PFLAG_FLUSH_PORT_TASK;
1134 	spin_unlock_irqrestore(ap->lock, flags);
1135 
1136 	DPRINTK("flush #1\n");
1137 	flush_workqueue(ata_wq);
1138 
1139 	/*
1140 	 * At this point, if a task is running, it's guaranteed to see
1141 	 * the FLUSH flag; thus, it will never queue pio tasks again.
1142 	 * Cancel and flush.
1143 	 */
1144 	if (!cancel_delayed_work(&ap->port_task)) {
1145 		if (ata_msg_ctl(ap))
1146 			ata_port_printk(ap, KERN_DEBUG, "%s: flush #2\n",
1147 					__FUNCTION__);
1148 		flush_workqueue(ata_wq);
1149 	}
1150 
1151 	spin_lock_irqsave(ap->lock, flags);
1152 	ap->pflags &= ~ATA_PFLAG_FLUSH_PORT_TASK;
1153 	spin_unlock_irqrestore(ap->lock, flags);
1154 
1155 	if (ata_msg_ctl(ap))
1156 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __FUNCTION__);
1157 }
1158 
1159 void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1160 {
1161 	struct completion *waiting = qc->private_data;
1162 
1163 	complete(waiting);
1164 }
1165 
1166 /**
1167  *	ata_exec_internal_sg - execute libata internal command
1168  *	@dev: Device to which the command is sent
1169  *	@tf: Taskfile registers for the command and the result
1170  *	@cdb: CDB for packet command
1171  *	@dma_dir: Data tranfer direction of the command
1172  *	@sg: sg list for the data buffer of the command
1173  *	@n_elem: Number of sg entries
1174  *
1175  *	Executes libata internal command with timeout.  @tf contains
1176  *	command on entry and result on return.  Timeout and error
1177  *	conditions are reported via return value.  No recovery action
1178  *	is taken after a command times out.  It's caller's duty to
1179  *	clean up after timeout.
1180  *
1181  *	LOCKING:
1182  *	None.  Should be called with kernel context, might sleep.
1183  *
1184  *	RETURNS:
1185  *	Zero on success, AC_ERR_* mask on failure
1186  */
1187 unsigned ata_exec_internal_sg(struct ata_device *dev,
1188 			      struct ata_taskfile *tf, const u8 *cdb,
1189 			      int dma_dir, struct scatterlist *sg,
1190 			      unsigned int n_elem)
1191 {
1192 	struct ata_port *ap = dev->ap;
1193 	u8 command = tf->command;
1194 	struct ata_queued_cmd *qc;
1195 	unsigned int tag, preempted_tag;
1196 	u32 preempted_sactive, preempted_qc_active;
1197 	DECLARE_COMPLETION_ONSTACK(wait);
1198 	unsigned long flags;
1199 	unsigned int err_mask;
1200 	int rc;
1201 
1202 	spin_lock_irqsave(ap->lock, flags);
1203 
1204 	/* no internal command while frozen */
1205 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1206 		spin_unlock_irqrestore(ap->lock, flags);
1207 		return AC_ERR_SYSTEM;
1208 	}
1209 
1210 	/* initialize internal qc */
1211 
1212 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1213 	 * drivers choke if any other tag is given.  This breaks
1214 	 * ata_tag_internal() test for those drivers.  Don't use new
1215 	 * EH stuff without converting to it.
1216 	 */
1217 	if (ap->ops->error_handler)
1218 		tag = ATA_TAG_INTERNAL;
1219 	else
1220 		tag = 0;
1221 
1222 	if (test_and_set_bit(tag, &ap->qc_allocated))
1223 		BUG();
1224 	qc = __ata_qc_from_tag(ap, tag);
1225 
1226 	qc->tag = tag;
1227 	qc->scsicmd = NULL;
1228 	qc->ap = ap;
1229 	qc->dev = dev;
1230 	ata_qc_reinit(qc);
1231 
1232 	preempted_tag = ap->active_tag;
1233 	preempted_sactive = ap->sactive;
1234 	preempted_qc_active = ap->qc_active;
1235 	ap->active_tag = ATA_TAG_POISON;
1236 	ap->sactive = 0;
1237 	ap->qc_active = 0;
1238 
1239 	/* prepare & issue qc */
1240 	qc->tf = *tf;
1241 	if (cdb)
1242 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1243 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1244 	qc->dma_dir = dma_dir;
1245 	if (dma_dir != DMA_NONE) {
1246 		unsigned int i, buflen = 0;
1247 
1248 		for (i = 0; i < n_elem; i++)
1249 			buflen += sg[i].length;
1250 
1251 		ata_sg_init(qc, sg, n_elem);
1252 		qc->nsect = buflen / ATA_SECT_SIZE;
1253 	}
1254 
1255 	qc->private_data = &wait;
1256 	qc->complete_fn = ata_qc_complete_internal;
1257 
1258 	ata_qc_issue(qc);
1259 
1260 	spin_unlock_irqrestore(ap->lock, flags);
1261 
1262 	rc = wait_for_completion_timeout(&wait, ata_probe_timeout);
1263 
1264 	ata_port_flush_task(ap);
1265 
1266 	if (!rc) {
1267 		spin_lock_irqsave(ap->lock, flags);
1268 
1269 		/* We're racing with irq here.  If we lose, the
1270 		 * following test prevents us from completing the qc
1271 		 * twice.  If we win, the port is frozen and will be
1272 		 * cleaned up by ->post_internal_cmd().
1273 		 */
1274 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1275 			qc->err_mask |= AC_ERR_TIMEOUT;
1276 
1277 			if (ap->ops->error_handler)
1278 				ata_port_freeze(ap);
1279 			else
1280 				ata_qc_complete(qc);
1281 
1282 			if (ata_msg_warn(ap))
1283 				ata_dev_printk(dev, KERN_WARNING,
1284 					"qc timeout (cmd 0x%x)\n", command);
1285 		}
1286 
1287 		spin_unlock_irqrestore(ap->lock, flags);
1288 	}
1289 
1290 	/* do post_internal_cmd */
1291 	if (ap->ops->post_internal_cmd)
1292 		ap->ops->post_internal_cmd(qc);
1293 
1294 	if (qc->flags & ATA_QCFLAG_FAILED && !qc->err_mask) {
1295 		if (ata_msg_warn(ap))
1296 			ata_dev_printk(dev, KERN_WARNING,
1297 				"zero err_mask for failed "
1298 				"internal command, assuming AC_ERR_OTHER\n");
1299 		qc->err_mask |= AC_ERR_OTHER;
1300 	}
1301 
1302 	/* finish up */
1303 	spin_lock_irqsave(ap->lock, flags);
1304 
1305 	*tf = qc->result_tf;
1306 	err_mask = qc->err_mask;
1307 
1308 	ata_qc_free(qc);
1309 	ap->active_tag = preempted_tag;
1310 	ap->sactive = preempted_sactive;
1311 	ap->qc_active = preempted_qc_active;
1312 
1313 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1314 	 * Until those drivers are fixed, we detect the condition
1315 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1316 	 * port.
1317 	 *
1318 	 * Note that this doesn't change any behavior as internal
1319 	 * command failure results in disabling the device in the
1320 	 * higher layer for LLDDs without new reset/EH callbacks.
1321 	 *
1322 	 * Kill the following code as soon as those drivers are fixed.
1323 	 */
1324 	if (ap->flags & ATA_FLAG_DISABLED) {
1325 		err_mask |= AC_ERR_SYSTEM;
1326 		ata_port_probe(ap);
1327 	}
1328 
1329 	spin_unlock_irqrestore(ap->lock, flags);
1330 
1331 	return err_mask;
1332 }
1333 
1334 /**
1335  *	ata_exec_internal_sg - execute libata internal command
1336  *	@dev: Device to which the command is sent
1337  *	@tf: Taskfile registers for the command and the result
1338  *	@cdb: CDB for packet command
1339  *	@dma_dir: Data tranfer direction of the command
1340  *	@buf: Data buffer of the command
1341  *	@buflen: Length of data buffer
1342  *
1343  *	Wrapper around ata_exec_internal_sg() which takes simple
1344  *	buffer instead of sg list.
1345  *
1346  *	LOCKING:
1347  *	None.  Should be called with kernel context, might sleep.
1348  *
1349  *	RETURNS:
1350  *	Zero on success, AC_ERR_* mask on failure
1351  */
1352 unsigned ata_exec_internal(struct ata_device *dev,
1353 			   struct ata_taskfile *tf, const u8 *cdb,
1354 			   int dma_dir, void *buf, unsigned int buflen)
1355 {
1356 	struct scatterlist sg;
1357 
1358 	sg_init_one(&sg, buf, buflen);
1359 
1360 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, &sg, 1);
1361 }
1362 
1363 /**
1364  *	ata_do_simple_cmd - execute simple internal command
1365  *	@dev: Device to which the command is sent
1366  *	@cmd: Opcode to execute
1367  *
1368  *	Execute a 'simple' command, that only consists of the opcode
1369  *	'cmd' itself, without filling any other registers
1370  *
1371  *	LOCKING:
1372  *	Kernel thread context (may sleep).
1373  *
1374  *	RETURNS:
1375  *	Zero on success, AC_ERR_* mask on failure
1376  */
1377 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
1378 {
1379 	struct ata_taskfile tf;
1380 
1381 	ata_tf_init(dev, &tf);
1382 
1383 	tf.command = cmd;
1384 	tf.flags |= ATA_TFLAG_DEVICE;
1385 	tf.protocol = ATA_PROT_NODATA;
1386 
1387 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
1388 }
1389 
1390 /**
1391  *	ata_pio_need_iordy	-	check if iordy needed
1392  *	@adev: ATA device
1393  *
1394  *	Check if the current speed of the device requires IORDY. Used
1395  *	by various controllers for chip configuration.
1396  */
1397 
1398 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1399 {
1400 	int pio;
1401 	int speed = adev->pio_mode - XFER_PIO_0;
1402 
1403 	if (speed < 2)
1404 		return 0;
1405 	if (speed > 2)
1406 		return 1;
1407 
1408 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1409 
1410 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1411 		pio = adev->id[ATA_ID_EIDE_PIO];
1412 		/* Is the speed faster than the drive allows non IORDY ? */
1413 		if (pio) {
1414 			/* This is cycle times not frequency - watch the logic! */
1415 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1416 				return 1;
1417 			return 0;
1418 		}
1419 	}
1420 	return 0;
1421 }
1422 
1423 /**
1424  *	ata_dev_read_id - Read ID data from the specified device
1425  *	@dev: target device
1426  *	@p_class: pointer to class of the target device (may be changed)
1427  *	@flags: ATA_READID_* flags
1428  *	@id: buffer to read IDENTIFY data into
1429  *
1430  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1431  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1432  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1433  *	for pre-ATA4 drives.
1434  *
1435  *	LOCKING:
1436  *	Kernel thread context (may sleep)
1437  *
1438  *	RETURNS:
1439  *	0 on success, -errno otherwise.
1440  */
1441 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1442 		    unsigned int flags, u16 *id)
1443 {
1444 	struct ata_port *ap = dev->ap;
1445 	unsigned int class = *p_class;
1446 	struct ata_taskfile tf;
1447 	unsigned int err_mask = 0;
1448 	const char *reason;
1449 	int rc;
1450 
1451 	if (ata_msg_ctl(ap))
1452 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER, host %u, dev %u\n",
1453 			       __FUNCTION__, ap->id, dev->devno);
1454 
1455 	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
1456 
1457  retry:
1458 	ata_tf_init(dev, &tf);
1459 
1460 	switch (class) {
1461 	case ATA_DEV_ATA:
1462 		tf.command = ATA_CMD_ID_ATA;
1463 		break;
1464 	case ATA_DEV_ATAPI:
1465 		tf.command = ATA_CMD_ID_ATAPI;
1466 		break;
1467 	default:
1468 		rc = -ENODEV;
1469 		reason = "unsupported class";
1470 		goto err_out;
1471 	}
1472 
1473 	tf.protocol = ATA_PROT_PIO;
1474 	tf.flags |= ATA_TFLAG_POLLING; /* for polling presence detection */
1475 
1476 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1477 				     id, sizeof(id[0]) * ATA_ID_WORDS);
1478 	if (err_mask) {
1479 		if (err_mask & AC_ERR_NODEV_HINT) {
1480 			DPRINTK("ata%u.%d: NODEV after polling detection\n",
1481 				ap->id, dev->devno);
1482 			return -ENOENT;
1483 		}
1484 
1485 		rc = -EIO;
1486 		reason = "I/O error";
1487 		goto err_out;
1488 	}
1489 
1490 	swap_buf_le16(id, ATA_ID_WORDS);
1491 
1492 	/* sanity check */
1493 	rc = -EINVAL;
1494 	reason = "device reports illegal type";
1495 
1496 	if (class == ATA_DEV_ATA) {
1497 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
1498 			goto err_out;
1499 	} else {
1500 		if (ata_id_is_ata(id))
1501 			goto err_out;
1502 	}
1503 
1504 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
1505 		/*
1506 		 * The exact sequence expected by certain pre-ATA4 drives is:
1507 		 * SRST RESET
1508 		 * IDENTIFY
1509 		 * INITIALIZE DEVICE PARAMETERS
1510 		 * anything else..
1511 		 * Some drives were very specific about that exact sequence.
1512 		 */
1513 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
1514 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
1515 			if (err_mask) {
1516 				rc = -EIO;
1517 				reason = "INIT_DEV_PARAMS failed";
1518 				goto err_out;
1519 			}
1520 
1521 			/* current CHS translation info (id[53-58]) might be
1522 			 * changed. reread the identify device info.
1523 			 */
1524 			flags &= ~ATA_READID_POSTRESET;
1525 			goto retry;
1526 		}
1527 	}
1528 
1529 	*p_class = class;
1530 
1531 	return 0;
1532 
1533  err_out:
1534 	if (ata_msg_warn(ap))
1535 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
1536 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
1537 	return rc;
1538 }
1539 
1540 static inline u8 ata_dev_knobble(struct ata_device *dev)
1541 {
1542 	return ((dev->ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
1543 }
1544 
1545 static void ata_dev_config_ncq(struct ata_device *dev,
1546 			       char *desc, size_t desc_sz)
1547 {
1548 	struct ata_port *ap = dev->ap;
1549 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
1550 
1551 	if (!ata_id_has_ncq(dev->id)) {
1552 		desc[0] = '\0';
1553 		return;
1554 	}
1555 	if (ata_device_blacklisted(dev) & ATA_HORKAGE_NONCQ) {
1556 		snprintf(desc, desc_sz, "NCQ (not used)");
1557 		return;
1558 	}
1559 	if (ap->flags & ATA_FLAG_NCQ) {
1560 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
1561 		dev->flags |= ATA_DFLAG_NCQ;
1562 	}
1563 
1564 	if (hdepth >= ddepth)
1565 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
1566 	else
1567 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
1568 }
1569 
1570 static void ata_set_port_max_cmd_len(struct ata_port *ap)
1571 {
1572 	int i;
1573 
1574 	if (ap->scsi_host) {
1575 		unsigned int len = 0;
1576 
1577 		for (i = 0; i < ATA_MAX_DEVICES; i++)
1578 			len = max(len, ap->device[i].cdb_len);
1579 
1580 		ap->scsi_host->max_cmd_len = len;
1581 	}
1582 }
1583 
1584 /**
1585  *	ata_dev_configure - Configure the specified ATA/ATAPI device
1586  *	@dev: Target device to configure
1587  *
1588  *	Configure @dev according to @dev->id.  Generic and low-level
1589  *	driver specific fixups are also applied.
1590  *
1591  *	LOCKING:
1592  *	Kernel thread context (may sleep)
1593  *
1594  *	RETURNS:
1595  *	0 on success, -errno otherwise
1596  */
1597 int ata_dev_configure(struct ata_device *dev)
1598 {
1599 	struct ata_port *ap = dev->ap;
1600 	int print_info = ap->eh_context.i.flags & ATA_EHI_PRINTINFO;
1601 	const u16 *id = dev->id;
1602 	unsigned int xfer_mask;
1603 	char revbuf[7];		/* XYZ-99\0 */
1604 	int rc;
1605 
1606 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
1607 		ata_dev_printk(dev, KERN_INFO,
1608 			       "%s: ENTER/EXIT (host %u, dev %u) -- nodev\n",
1609 			       __FUNCTION__, ap->id, dev->devno);
1610 		return 0;
1611 	}
1612 
1613 	if (ata_msg_probe(ap))
1614 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER, host %u, dev %u\n",
1615 			       __FUNCTION__, ap->id, dev->devno);
1616 
1617 	/* print device capabilities */
1618 	if (ata_msg_probe(ap))
1619 		ata_dev_printk(dev, KERN_DEBUG,
1620 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
1621 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
1622 			       __FUNCTION__,
1623 			       id[49], id[82], id[83], id[84],
1624 			       id[85], id[86], id[87], id[88]);
1625 
1626 	/* initialize to-be-configured parameters */
1627 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
1628 	dev->max_sectors = 0;
1629 	dev->cdb_len = 0;
1630 	dev->n_sectors = 0;
1631 	dev->cylinders = 0;
1632 	dev->heads = 0;
1633 	dev->sectors = 0;
1634 
1635 	/*
1636 	 * common ATA, ATAPI feature tests
1637 	 */
1638 
1639 	/* find max transfer mode; for printk only */
1640 	xfer_mask = ata_id_xfermask(id);
1641 
1642 	if (ata_msg_probe(ap))
1643 		ata_dump_id(id);
1644 
1645 	/* ATA-specific feature tests */
1646 	if (dev->class == ATA_DEV_ATA) {
1647 		if (ata_id_is_cfa(id)) {
1648 			if (id[162] & 1) /* CPRM may make this media unusable */
1649 				ata_dev_printk(dev, KERN_WARNING, "ata%u: device %u  supports DRM functions and may not be fully accessable.\n",
1650 					ap->id, dev->devno);
1651 			snprintf(revbuf, 7, "CFA");
1652 		}
1653 		else
1654 			snprintf(revbuf, 7, "ATA-%d",  ata_id_major_version(id));
1655 
1656 		dev->n_sectors = ata_id_n_sectors(id);
1657 
1658 		if (ata_id_has_lba(id)) {
1659 			const char *lba_desc;
1660 			char ncq_desc[20];
1661 
1662 			lba_desc = "LBA";
1663 			dev->flags |= ATA_DFLAG_LBA;
1664 			if (ata_id_has_lba48(id)) {
1665 				dev->flags |= ATA_DFLAG_LBA48;
1666 				lba_desc = "LBA48";
1667 
1668 				if (dev->n_sectors >= (1UL << 28) &&
1669 				    ata_id_has_flush_ext(id))
1670 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
1671 			}
1672 
1673 			/* config NCQ */
1674 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
1675 
1676 			/* print device info to dmesg */
1677 			if (ata_msg_drv(ap) && print_info)
1678 				ata_dev_printk(dev, KERN_INFO, "%s, "
1679 					"max %s, %Lu sectors: %s %s\n",
1680 					revbuf,
1681 					ata_mode_string(xfer_mask),
1682 					(unsigned long long)dev->n_sectors,
1683 					lba_desc, ncq_desc);
1684 		} else {
1685 			/* CHS */
1686 
1687 			/* Default translation */
1688 			dev->cylinders	= id[1];
1689 			dev->heads	= id[3];
1690 			dev->sectors	= id[6];
1691 
1692 			if (ata_id_current_chs_valid(id)) {
1693 				/* Current CHS translation is valid. */
1694 				dev->cylinders = id[54];
1695 				dev->heads     = id[55];
1696 				dev->sectors   = id[56];
1697 			}
1698 
1699 			/* print device info to dmesg */
1700 			if (ata_msg_drv(ap) && print_info)
1701 				ata_dev_printk(dev, KERN_INFO, "%s, "
1702 					"max %s, %Lu sectors: CHS %u/%u/%u\n",
1703 					revbuf,
1704 					ata_mode_string(xfer_mask),
1705 					(unsigned long long)dev->n_sectors,
1706 					dev->cylinders, dev->heads,
1707 					dev->sectors);
1708 		}
1709 
1710 		if (dev->id[59] & 0x100) {
1711 			dev->multi_count = dev->id[59] & 0xff;
1712 			if (ata_msg_drv(ap) && print_info)
1713 				ata_dev_printk(dev, KERN_INFO,
1714 					"ata%u: dev %u multi count %u\n",
1715 					ap->id, dev->devno, dev->multi_count);
1716 		}
1717 
1718 		dev->cdb_len = 16;
1719 	}
1720 
1721 	/* ATAPI-specific feature tests */
1722 	else if (dev->class == ATA_DEV_ATAPI) {
1723 		char *cdb_intr_string = "";
1724 
1725 		rc = atapi_cdb_len(id);
1726 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
1727 			if (ata_msg_warn(ap))
1728 				ata_dev_printk(dev, KERN_WARNING,
1729 					       "unsupported CDB len\n");
1730 			rc = -EINVAL;
1731 			goto err_out_nosup;
1732 		}
1733 		dev->cdb_len = (unsigned int) rc;
1734 
1735 		if (ata_id_cdb_intr(dev->id)) {
1736 			dev->flags |= ATA_DFLAG_CDB_INTR;
1737 			cdb_intr_string = ", CDB intr";
1738 		}
1739 
1740 		/* print device info to dmesg */
1741 		if (ata_msg_drv(ap) && print_info)
1742 			ata_dev_printk(dev, KERN_INFO, "ATAPI, max %s%s\n",
1743 				       ata_mode_string(xfer_mask),
1744 				       cdb_intr_string);
1745 	}
1746 
1747 	/* determine max_sectors */
1748 	dev->max_sectors = ATA_MAX_SECTORS;
1749 	if (dev->flags & ATA_DFLAG_LBA48)
1750 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
1751 
1752 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
1753 		/* Let the user know. We don't want to disallow opens for
1754 		   rescue purposes, or in case the vendor is just a blithering
1755 		   idiot */
1756                 if (print_info) {
1757 			ata_dev_printk(dev, KERN_WARNING,
1758 "Drive reports diagnostics failure. This may indicate a drive\n");
1759 			ata_dev_printk(dev, KERN_WARNING,
1760 "fault or invalid emulation. Contact drive vendor for information.\n");
1761 		}
1762 	}
1763 
1764 	ata_set_port_max_cmd_len(ap);
1765 
1766 	/* limit bridge transfers to udma5, 200 sectors */
1767 	if (ata_dev_knobble(dev)) {
1768 		if (ata_msg_drv(ap) && print_info)
1769 			ata_dev_printk(dev, KERN_INFO,
1770 				       "applying bridge limits\n");
1771 		dev->udma_mask &= ATA_UDMA5;
1772 		dev->max_sectors = ATA_MAX_SECTORS;
1773 	}
1774 
1775 	if (ap->ops->dev_config)
1776 		ap->ops->dev_config(ap, dev);
1777 
1778 	if (ata_msg_probe(ap))
1779 		ata_dev_printk(dev, KERN_DEBUG, "%s: EXIT, drv_stat = 0x%x\n",
1780 			__FUNCTION__, ata_chk_status(ap));
1781 	return 0;
1782 
1783 err_out_nosup:
1784 	if (ata_msg_probe(ap))
1785 		ata_dev_printk(dev, KERN_DEBUG,
1786 			       "%s: EXIT, err\n", __FUNCTION__);
1787 	return rc;
1788 }
1789 
1790 /**
1791  *	ata_bus_probe - Reset and probe ATA bus
1792  *	@ap: Bus to probe
1793  *
1794  *	Master ATA bus probing function.  Initiates a hardware-dependent
1795  *	bus reset, then attempts to identify any devices found on
1796  *	the bus.
1797  *
1798  *	LOCKING:
1799  *	PCI/etc. bus probe sem.
1800  *
1801  *	RETURNS:
1802  *	Zero on success, negative errno otherwise.
1803  */
1804 
1805 int ata_bus_probe(struct ata_port *ap)
1806 {
1807 	unsigned int classes[ATA_MAX_DEVICES];
1808 	int tries[ATA_MAX_DEVICES];
1809 	int i, rc, down_xfermask;
1810 	struct ata_device *dev;
1811 
1812 	ata_port_probe(ap);
1813 
1814 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1815 		tries[i] = ATA_PROBE_MAX_TRIES;
1816 
1817  retry:
1818 	down_xfermask = 0;
1819 
1820 	/* reset and determine device classes */
1821 	ap->ops->phy_reset(ap);
1822 
1823 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
1824 		dev = &ap->device[i];
1825 
1826 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
1827 		    dev->class != ATA_DEV_UNKNOWN)
1828 			classes[dev->devno] = dev->class;
1829 		else
1830 			classes[dev->devno] = ATA_DEV_NONE;
1831 
1832 		dev->class = ATA_DEV_UNKNOWN;
1833 	}
1834 
1835 	ata_port_probe(ap);
1836 
1837 	/* after the reset the device state is PIO 0 and the controller
1838 	   state is undefined. Record the mode */
1839 
1840 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1841 		ap->device[i].pio_mode = XFER_PIO_0;
1842 
1843 	/* read IDENTIFY page and configure devices */
1844 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
1845 		dev = &ap->device[i];
1846 
1847 		if (tries[i])
1848 			dev->class = classes[i];
1849 
1850 		if (!ata_dev_enabled(dev))
1851 			continue;
1852 
1853 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
1854 				     dev->id);
1855 		if (rc)
1856 			goto fail;
1857 
1858 		ap->eh_context.i.flags |= ATA_EHI_PRINTINFO;
1859 		rc = ata_dev_configure(dev);
1860 		ap->eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
1861 		if (rc)
1862 			goto fail;
1863 	}
1864 
1865 	/* configure transfer mode */
1866 	rc = ata_set_mode(ap, &dev);
1867 	if (rc) {
1868 		down_xfermask = 1;
1869 		goto fail;
1870 	}
1871 
1872 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1873 		if (ata_dev_enabled(&ap->device[i]))
1874 			return 0;
1875 
1876 	/* no device present, disable port */
1877 	ata_port_disable(ap);
1878 	ap->ops->port_disable(ap);
1879 	return -ENODEV;
1880 
1881  fail:
1882 	switch (rc) {
1883 	case -EINVAL:
1884 	case -ENODEV:
1885 		tries[dev->devno] = 0;
1886 		break;
1887 	case -EIO:
1888 		sata_down_spd_limit(ap);
1889 		/* fall through */
1890 	default:
1891 		tries[dev->devno]--;
1892 		if (down_xfermask &&
1893 		    ata_down_xfermask_limit(dev, tries[dev->devno] == 1))
1894 			tries[dev->devno] = 0;
1895 	}
1896 
1897 	if (!tries[dev->devno]) {
1898 		ata_down_xfermask_limit(dev, 1);
1899 		ata_dev_disable(dev);
1900 	}
1901 
1902 	goto retry;
1903 }
1904 
1905 /**
1906  *	ata_port_probe - Mark port as enabled
1907  *	@ap: Port for which we indicate enablement
1908  *
1909  *	Modify @ap data structure such that the system
1910  *	thinks that the entire port is enabled.
1911  *
1912  *	LOCKING: host lock, or some other form of
1913  *	serialization.
1914  */
1915 
1916 void ata_port_probe(struct ata_port *ap)
1917 {
1918 	ap->flags &= ~ATA_FLAG_DISABLED;
1919 }
1920 
1921 /**
1922  *	sata_print_link_status - Print SATA link status
1923  *	@ap: SATA port to printk link status about
1924  *
1925  *	This function prints link speed and status of a SATA link.
1926  *
1927  *	LOCKING:
1928  *	None.
1929  */
1930 static void sata_print_link_status(struct ata_port *ap)
1931 {
1932 	u32 sstatus, scontrol, tmp;
1933 
1934 	if (sata_scr_read(ap, SCR_STATUS, &sstatus))
1935 		return;
1936 	sata_scr_read(ap, SCR_CONTROL, &scontrol);
1937 
1938 	if (ata_port_online(ap)) {
1939 		tmp = (sstatus >> 4) & 0xf;
1940 		ata_port_printk(ap, KERN_INFO,
1941 				"SATA link up %s (SStatus %X SControl %X)\n",
1942 				sata_spd_string(tmp), sstatus, scontrol);
1943 	} else {
1944 		ata_port_printk(ap, KERN_INFO,
1945 				"SATA link down (SStatus %X SControl %X)\n",
1946 				sstatus, scontrol);
1947 	}
1948 }
1949 
1950 /**
1951  *	__sata_phy_reset - Wake/reset a low-level SATA PHY
1952  *	@ap: SATA port associated with target SATA PHY.
1953  *
1954  *	This function issues commands to standard SATA Sxxx
1955  *	PHY registers, to wake up the phy (and device), and
1956  *	clear any reset condition.
1957  *
1958  *	LOCKING:
1959  *	PCI/etc. bus probe sem.
1960  *
1961  */
1962 void __sata_phy_reset(struct ata_port *ap)
1963 {
1964 	u32 sstatus;
1965 	unsigned long timeout = jiffies + (HZ * 5);
1966 
1967 	if (ap->flags & ATA_FLAG_SATA_RESET) {
1968 		/* issue phy wake/reset */
1969 		sata_scr_write_flush(ap, SCR_CONTROL, 0x301);
1970 		/* Couldn't find anything in SATA I/II specs, but
1971 		 * AHCI-1.1 10.4.2 says at least 1 ms. */
1972 		mdelay(1);
1973 	}
1974 	/* phy wake/clear reset */
1975 	sata_scr_write_flush(ap, SCR_CONTROL, 0x300);
1976 
1977 	/* wait for phy to become ready, if necessary */
1978 	do {
1979 		msleep(200);
1980 		sata_scr_read(ap, SCR_STATUS, &sstatus);
1981 		if ((sstatus & 0xf) != 1)
1982 			break;
1983 	} while (time_before(jiffies, timeout));
1984 
1985 	/* print link status */
1986 	sata_print_link_status(ap);
1987 
1988 	/* TODO: phy layer with polling, timeouts, etc. */
1989 	if (!ata_port_offline(ap))
1990 		ata_port_probe(ap);
1991 	else
1992 		ata_port_disable(ap);
1993 
1994 	if (ap->flags & ATA_FLAG_DISABLED)
1995 		return;
1996 
1997 	if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
1998 		ata_port_disable(ap);
1999 		return;
2000 	}
2001 
2002 	ap->cbl = ATA_CBL_SATA;
2003 }
2004 
2005 /**
2006  *	sata_phy_reset - Reset SATA bus.
2007  *	@ap: SATA port associated with target SATA PHY.
2008  *
2009  *	This function resets the SATA bus, and then probes
2010  *	the bus for devices.
2011  *
2012  *	LOCKING:
2013  *	PCI/etc. bus probe sem.
2014  *
2015  */
2016 void sata_phy_reset(struct ata_port *ap)
2017 {
2018 	__sata_phy_reset(ap);
2019 	if (ap->flags & ATA_FLAG_DISABLED)
2020 		return;
2021 	ata_bus_reset(ap);
2022 }
2023 
2024 /**
2025  *	ata_dev_pair		-	return other device on cable
2026  *	@adev: device
2027  *
2028  *	Obtain the other device on the same cable, or if none is
2029  *	present NULL is returned
2030  */
2031 
2032 struct ata_device *ata_dev_pair(struct ata_device *adev)
2033 {
2034 	struct ata_port *ap = adev->ap;
2035 	struct ata_device *pair = &ap->device[1 - adev->devno];
2036 	if (!ata_dev_enabled(pair))
2037 		return NULL;
2038 	return pair;
2039 }
2040 
2041 /**
2042  *	ata_port_disable - Disable port.
2043  *	@ap: Port to be disabled.
2044  *
2045  *	Modify @ap data structure such that the system
2046  *	thinks that the entire port is disabled, and should
2047  *	never attempt to probe or communicate with devices
2048  *	on this port.
2049  *
2050  *	LOCKING: host lock, or some other form of
2051  *	serialization.
2052  */
2053 
2054 void ata_port_disable(struct ata_port *ap)
2055 {
2056 	ap->device[0].class = ATA_DEV_NONE;
2057 	ap->device[1].class = ATA_DEV_NONE;
2058 	ap->flags |= ATA_FLAG_DISABLED;
2059 }
2060 
2061 /**
2062  *	sata_down_spd_limit - adjust SATA spd limit downward
2063  *	@ap: Port to adjust SATA spd limit for
2064  *
2065  *	Adjust SATA spd limit of @ap downward.  Note that this
2066  *	function only adjusts the limit.  The change must be applied
2067  *	using sata_set_spd().
2068  *
2069  *	LOCKING:
2070  *	Inherited from caller.
2071  *
2072  *	RETURNS:
2073  *	0 on success, negative errno on failure
2074  */
2075 int sata_down_spd_limit(struct ata_port *ap)
2076 {
2077 	u32 sstatus, spd, mask;
2078 	int rc, highbit;
2079 
2080 	rc = sata_scr_read(ap, SCR_STATUS, &sstatus);
2081 	if (rc)
2082 		return rc;
2083 
2084 	mask = ap->sata_spd_limit;
2085 	if (mask <= 1)
2086 		return -EINVAL;
2087 	highbit = fls(mask) - 1;
2088 	mask &= ~(1 << highbit);
2089 
2090 	spd = (sstatus >> 4) & 0xf;
2091 	if (spd <= 1)
2092 		return -EINVAL;
2093 	spd--;
2094 	mask &= (1 << spd) - 1;
2095 	if (!mask)
2096 		return -EINVAL;
2097 
2098 	ap->sata_spd_limit = mask;
2099 
2100 	ata_port_printk(ap, KERN_WARNING, "limiting SATA link speed to %s\n",
2101 			sata_spd_string(fls(mask)));
2102 
2103 	return 0;
2104 }
2105 
2106 static int __sata_set_spd_needed(struct ata_port *ap, u32 *scontrol)
2107 {
2108 	u32 spd, limit;
2109 
2110 	if (ap->sata_spd_limit == UINT_MAX)
2111 		limit = 0;
2112 	else
2113 		limit = fls(ap->sata_spd_limit);
2114 
2115 	spd = (*scontrol >> 4) & 0xf;
2116 	*scontrol = (*scontrol & ~0xf0) | ((limit & 0xf) << 4);
2117 
2118 	return spd != limit;
2119 }
2120 
2121 /**
2122  *	sata_set_spd_needed - is SATA spd configuration needed
2123  *	@ap: Port in question
2124  *
2125  *	Test whether the spd limit in SControl matches
2126  *	@ap->sata_spd_limit.  This function is used to determine
2127  *	whether hardreset is necessary to apply SATA spd
2128  *	configuration.
2129  *
2130  *	LOCKING:
2131  *	Inherited from caller.
2132  *
2133  *	RETURNS:
2134  *	1 if SATA spd configuration is needed, 0 otherwise.
2135  */
2136 int sata_set_spd_needed(struct ata_port *ap)
2137 {
2138 	u32 scontrol;
2139 
2140 	if (sata_scr_read(ap, SCR_CONTROL, &scontrol))
2141 		return 0;
2142 
2143 	return __sata_set_spd_needed(ap, &scontrol);
2144 }
2145 
2146 /**
2147  *	sata_set_spd - set SATA spd according to spd limit
2148  *	@ap: Port to set SATA spd for
2149  *
2150  *	Set SATA spd of @ap according to sata_spd_limit.
2151  *
2152  *	LOCKING:
2153  *	Inherited from caller.
2154  *
2155  *	RETURNS:
2156  *	0 if spd doesn't need to be changed, 1 if spd has been
2157  *	changed.  Negative errno if SCR registers are inaccessible.
2158  */
2159 int sata_set_spd(struct ata_port *ap)
2160 {
2161 	u32 scontrol;
2162 	int rc;
2163 
2164 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
2165 		return rc;
2166 
2167 	if (!__sata_set_spd_needed(ap, &scontrol))
2168 		return 0;
2169 
2170 	if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
2171 		return rc;
2172 
2173 	return 1;
2174 }
2175 
2176 /*
2177  * This mode timing computation functionality is ported over from
2178  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2179  */
2180 /*
2181  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2182  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2183  * for UDMA6, which is currently supported only by Maxtor drives.
2184  *
2185  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2186  */
2187 
2188 static const struct ata_timing ata_timing[] = {
2189 
2190 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
2191 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
2192 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
2193 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
2194 
2195 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
2196 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
2197 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
2198 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
2199 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
2200 
2201 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
2202 
2203 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
2204 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
2205 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
2206 
2207 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
2208 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
2209 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
2210 
2211 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
2212 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
2213 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
2214 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
2215 
2216 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
2217 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
2218 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
2219 
2220 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
2221 
2222 	{ 0xFF }
2223 };
2224 
2225 #define ENOUGH(v,unit)		(((v)-1)/(unit)+1)
2226 #define EZ(v,unit)		((v)?ENOUGH(v,unit):0)
2227 
2228 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2229 {
2230 	q->setup   = EZ(t->setup   * 1000,  T);
2231 	q->act8b   = EZ(t->act8b   * 1000,  T);
2232 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
2233 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
2234 	q->active  = EZ(t->active  * 1000,  T);
2235 	q->recover = EZ(t->recover * 1000,  T);
2236 	q->cycle   = EZ(t->cycle   * 1000,  T);
2237 	q->udma    = EZ(t->udma    * 1000, UT);
2238 }
2239 
2240 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2241 		      struct ata_timing *m, unsigned int what)
2242 {
2243 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2244 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2245 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2246 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2247 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
2248 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
2249 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
2250 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
2251 }
2252 
2253 static const struct ata_timing* ata_timing_find_mode(unsigned short speed)
2254 {
2255 	const struct ata_timing *t;
2256 
2257 	for (t = ata_timing; t->mode != speed; t++)
2258 		if (t->mode == 0xFF)
2259 			return NULL;
2260 	return t;
2261 }
2262 
2263 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
2264 		       struct ata_timing *t, int T, int UT)
2265 {
2266 	const struct ata_timing *s;
2267 	struct ata_timing p;
2268 
2269 	/*
2270 	 * Find the mode.
2271 	 */
2272 
2273 	if (!(s = ata_timing_find_mode(speed)))
2274 		return -EINVAL;
2275 
2276 	memcpy(t, s, sizeof(*s));
2277 
2278 	/*
2279 	 * If the drive is an EIDE drive, it can tell us it needs extended
2280 	 * PIO/MW_DMA cycle timing.
2281 	 */
2282 
2283 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
2284 		memset(&p, 0, sizeof(p));
2285 		if(speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
2286 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
2287 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
2288 		} else if(speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
2289 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
2290 		}
2291 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
2292 	}
2293 
2294 	/*
2295 	 * Convert the timing to bus clock counts.
2296 	 */
2297 
2298 	ata_timing_quantize(t, t, T, UT);
2299 
2300 	/*
2301 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
2302 	 * S.M.A.R.T * and some other commands. We have to ensure that the
2303 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
2304 	 */
2305 
2306 	if (speed > XFER_PIO_6) {
2307 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
2308 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
2309 	}
2310 
2311 	/*
2312 	 * Lengthen active & recovery time so that cycle time is correct.
2313 	 */
2314 
2315 	if (t->act8b + t->rec8b < t->cyc8b) {
2316 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
2317 		t->rec8b = t->cyc8b - t->act8b;
2318 	}
2319 
2320 	if (t->active + t->recover < t->cycle) {
2321 		t->active += (t->cycle - (t->active + t->recover)) / 2;
2322 		t->recover = t->cycle - t->active;
2323 	}
2324 
2325 	return 0;
2326 }
2327 
2328 /**
2329  *	ata_down_xfermask_limit - adjust dev xfer masks downward
2330  *	@dev: Device to adjust xfer masks
2331  *	@force_pio0: Force PIO0
2332  *
2333  *	Adjust xfer masks of @dev downward.  Note that this function
2334  *	does not apply the change.  Invoking ata_set_mode() afterwards
2335  *	will apply the limit.
2336  *
2337  *	LOCKING:
2338  *	Inherited from caller.
2339  *
2340  *	RETURNS:
2341  *	0 on success, negative errno on failure
2342  */
2343 int ata_down_xfermask_limit(struct ata_device *dev, int force_pio0)
2344 {
2345 	unsigned long xfer_mask;
2346 	int highbit;
2347 
2348 	xfer_mask = ata_pack_xfermask(dev->pio_mask, dev->mwdma_mask,
2349 				      dev->udma_mask);
2350 
2351 	if (!xfer_mask)
2352 		goto fail;
2353 	/* don't gear down to MWDMA from UDMA, go directly to PIO */
2354 	if (xfer_mask & ATA_MASK_UDMA)
2355 		xfer_mask &= ~ATA_MASK_MWDMA;
2356 
2357 	highbit = fls(xfer_mask) - 1;
2358 	xfer_mask &= ~(1 << highbit);
2359 	if (force_pio0)
2360 		xfer_mask &= 1 << ATA_SHIFT_PIO;
2361 	if (!xfer_mask)
2362 		goto fail;
2363 
2364 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
2365 			    &dev->udma_mask);
2366 
2367 	ata_dev_printk(dev, KERN_WARNING, "limiting speed to %s\n",
2368 		       ata_mode_string(xfer_mask));
2369 
2370 	return 0;
2371 
2372  fail:
2373 	return -EINVAL;
2374 }
2375 
2376 static int ata_dev_set_mode(struct ata_device *dev)
2377 {
2378 	struct ata_eh_context *ehc = &dev->ap->eh_context;
2379 	unsigned int err_mask;
2380 	int rc;
2381 
2382 	dev->flags &= ~ATA_DFLAG_PIO;
2383 	if (dev->xfer_shift == ATA_SHIFT_PIO)
2384 		dev->flags |= ATA_DFLAG_PIO;
2385 
2386 	err_mask = ata_dev_set_xfermode(dev);
2387 	if (err_mask) {
2388 		ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
2389 			       "(err_mask=0x%x)\n", err_mask);
2390 		return -EIO;
2391 	}
2392 
2393 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
2394 	rc = ata_dev_revalidate(dev, 0);
2395 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
2396 	if (rc)
2397 		return rc;
2398 
2399 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
2400 		dev->xfer_shift, (int)dev->xfer_mode);
2401 
2402 	ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
2403 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)));
2404 	return 0;
2405 }
2406 
2407 /**
2408  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
2409  *	@ap: port on which timings will be programmed
2410  *	@r_failed_dev: out paramter for failed device
2411  *
2412  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
2413  *	ata_set_mode() fails, pointer to the failing device is
2414  *	returned in @r_failed_dev.
2415  *
2416  *	LOCKING:
2417  *	PCI/etc. bus probe sem.
2418  *
2419  *	RETURNS:
2420  *	0 on success, negative errno otherwise
2421  */
2422 int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
2423 {
2424 	struct ata_device *dev;
2425 	int i, rc = 0, used_dma = 0, found = 0;
2426 
2427 	/* has private set_mode? */
2428 	if (ap->ops->set_mode) {
2429 		/* FIXME: make ->set_mode handle no device case and
2430 		 * return error code and failing device on failure.
2431 		 */
2432 		for (i = 0; i < ATA_MAX_DEVICES; i++) {
2433 			if (ata_dev_ready(&ap->device[i])) {
2434 				ap->ops->set_mode(ap);
2435 				break;
2436 			}
2437 		}
2438 		return 0;
2439 	}
2440 
2441 	/* step 1: calculate xfer_mask */
2442 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2443 		unsigned int pio_mask, dma_mask;
2444 
2445 		dev = &ap->device[i];
2446 
2447 		if (!ata_dev_enabled(dev))
2448 			continue;
2449 
2450 		ata_dev_xfermask(dev);
2451 
2452 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
2453 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
2454 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
2455 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
2456 
2457 		found = 1;
2458 		if (dev->dma_mode)
2459 			used_dma = 1;
2460 	}
2461 	if (!found)
2462 		goto out;
2463 
2464 	/* step 2: always set host PIO timings */
2465 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2466 		dev = &ap->device[i];
2467 		if (!ata_dev_enabled(dev))
2468 			continue;
2469 
2470 		if (!dev->pio_mode) {
2471 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
2472 			rc = -EINVAL;
2473 			goto out;
2474 		}
2475 
2476 		dev->xfer_mode = dev->pio_mode;
2477 		dev->xfer_shift = ATA_SHIFT_PIO;
2478 		if (ap->ops->set_piomode)
2479 			ap->ops->set_piomode(ap, dev);
2480 	}
2481 
2482 	/* step 3: set host DMA timings */
2483 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2484 		dev = &ap->device[i];
2485 
2486 		if (!ata_dev_enabled(dev) || !dev->dma_mode)
2487 			continue;
2488 
2489 		dev->xfer_mode = dev->dma_mode;
2490 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
2491 		if (ap->ops->set_dmamode)
2492 			ap->ops->set_dmamode(ap, dev);
2493 	}
2494 
2495 	/* step 4: update devices' xfer mode */
2496 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2497 		dev = &ap->device[i];
2498 
2499 		/* don't udpate suspended devices' xfer mode */
2500 		if (!ata_dev_ready(dev))
2501 			continue;
2502 
2503 		rc = ata_dev_set_mode(dev);
2504 		if (rc)
2505 			goto out;
2506 	}
2507 
2508 	/* Record simplex status. If we selected DMA then the other
2509 	 * host channels are not permitted to do so.
2510 	 */
2511 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
2512 		ap->host->simplex_claimed = 1;
2513 
2514 	/* step5: chip specific finalisation */
2515 	if (ap->ops->post_set_mode)
2516 		ap->ops->post_set_mode(ap);
2517 
2518  out:
2519 	if (rc)
2520 		*r_failed_dev = dev;
2521 	return rc;
2522 }
2523 
2524 /**
2525  *	ata_tf_to_host - issue ATA taskfile to host controller
2526  *	@ap: port to which command is being issued
2527  *	@tf: ATA taskfile register set
2528  *
2529  *	Issues ATA taskfile register set to ATA host controller,
2530  *	with proper synchronization with interrupt handler and
2531  *	other threads.
2532  *
2533  *	LOCKING:
2534  *	spin_lock_irqsave(host lock)
2535  */
2536 
2537 static inline void ata_tf_to_host(struct ata_port *ap,
2538 				  const struct ata_taskfile *tf)
2539 {
2540 	ap->ops->tf_load(ap, tf);
2541 	ap->ops->exec_command(ap, tf);
2542 }
2543 
2544 /**
2545  *	ata_busy_sleep - sleep until BSY clears, or timeout
2546  *	@ap: port containing status register to be polled
2547  *	@tmout_pat: impatience timeout
2548  *	@tmout: overall timeout
2549  *
2550  *	Sleep until ATA Status register bit BSY clears,
2551  *	or a timeout occurs.
2552  *
2553  *	LOCKING:
2554  *	Kernel thread context (may sleep).
2555  *
2556  *	RETURNS:
2557  *	0 on success, -errno otherwise.
2558  */
2559 int ata_busy_sleep(struct ata_port *ap,
2560 		   unsigned long tmout_pat, unsigned long tmout)
2561 {
2562 	unsigned long timer_start, timeout;
2563 	u8 status;
2564 
2565 	status = ata_busy_wait(ap, ATA_BUSY, 300);
2566 	timer_start = jiffies;
2567 	timeout = timer_start + tmout_pat;
2568 	while (status != 0xff && (status & ATA_BUSY) &&
2569 	       time_before(jiffies, timeout)) {
2570 		msleep(50);
2571 		status = ata_busy_wait(ap, ATA_BUSY, 3);
2572 	}
2573 
2574 	if (status != 0xff && (status & ATA_BUSY))
2575 		ata_port_printk(ap, KERN_WARNING,
2576 				"port is slow to respond, please be patient "
2577 				"(Status 0x%x)\n", status);
2578 
2579 	timeout = timer_start + tmout;
2580 	while (status != 0xff && (status & ATA_BUSY) &&
2581 	       time_before(jiffies, timeout)) {
2582 		msleep(50);
2583 		status = ata_chk_status(ap);
2584 	}
2585 
2586 	if (status == 0xff)
2587 		return -ENODEV;
2588 
2589 	if (status & ATA_BUSY) {
2590 		ata_port_printk(ap, KERN_ERR, "port failed to respond "
2591 				"(%lu secs, Status 0x%x)\n",
2592 				tmout / HZ, status);
2593 		return -EBUSY;
2594 	}
2595 
2596 	return 0;
2597 }
2598 
2599 static void ata_bus_post_reset(struct ata_port *ap, unsigned int devmask)
2600 {
2601 	struct ata_ioports *ioaddr = &ap->ioaddr;
2602 	unsigned int dev0 = devmask & (1 << 0);
2603 	unsigned int dev1 = devmask & (1 << 1);
2604 	unsigned long timeout;
2605 
2606 	/* if device 0 was found in ata_devchk, wait for its
2607 	 * BSY bit to clear
2608 	 */
2609 	if (dev0)
2610 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2611 
2612 	/* if device 1 was found in ata_devchk, wait for
2613 	 * register access, then wait for BSY to clear
2614 	 */
2615 	timeout = jiffies + ATA_TMOUT_BOOT;
2616 	while (dev1) {
2617 		u8 nsect, lbal;
2618 
2619 		ap->ops->dev_select(ap, 1);
2620 		if (ap->flags & ATA_FLAG_MMIO) {
2621 			nsect = readb((void __iomem *) ioaddr->nsect_addr);
2622 			lbal = readb((void __iomem *) ioaddr->lbal_addr);
2623 		} else {
2624 			nsect = inb(ioaddr->nsect_addr);
2625 			lbal = inb(ioaddr->lbal_addr);
2626 		}
2627 		if ((nsect == 1) && (lbal == 1))
2628 			break;
2629 		if (time_after(jiffies, timeout)) {
2630 			dev1 = 0;
2631 			break;
2632 		}
2633 		msleep(50);	/* give drive a breather */
2634 	}
2635 	if (dev1)
2636 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2637 
2638 	/* is all this really necessary? */
2639 	ap->ops->dev_select(ap, 0);
2640 	if (dev1)
2641 		ap->ops->dev_select(ap, 1);
2642 	if (dev0)
2643 		ap->ops->dev_select(ap, 0);
2644 }
2645 
2646 static unsigned int ata_bus_softreset(struct ata_port *ap,
2647 				      unsigned int devmask)
2648 {
2649 	struct ata_ioports *ioaddr = &ap->ioaddr;
2650 
2651 	DPRINTK("ata%u: bus reset via SRST\n", ap->id);
2652 
2653 	/* software reset.  causes dev0 to be selected */
2654 	if (ap->flags & ATA_FLAG_MMIO) {
2655 		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2656 		udelay(20);	/* FIXME: flush */
2657 		writeb(ap->ctl | ATA_SRST, (void __iomem *) ioaddr->ctl_addr);
2658 		udelay(20);	/* FIXME: flush */
2659 		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2660 	} else {
2661 		outb(ap->ctl, ioaddr->ctl_addr);
2662 		udelay(10);
2663 		outb(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
2664 		udelay(10);
2665 		outb(ap->ctl, ioaddr->ctl_addr);
2666 	}
2667 
2668 	/* spec mandates ">= 2ms" before checking status.
2669 	 * We wait 150ms, because that was the magic delay used for
2670 	 * ATAPI devices in Hale Landis's ATADRVR, for the period of time
2671 	 * between when the ATA command register is written, and then
2672 	 * status is checked.  Because waiting for "a while" before
2673 	 * checking status is fine, post SRST, we perform this magic
2674 	 * delay here as well.
2675 	 *
2676 	 * Old drivers/ide uses the 2mS rule and then waits for ready
2677 	 */
2678 	msleep(150);
2679 
2680 	/* Before we perform post reset processing we want to see if
2681 	 * the bus shows 0xFF because the odd clown forgets the D7
2682 	 * pulldown resistor.
2683 	 */
2684 	if (ata_check_status(ap) == 0xFF)
2685 		return 0;
2686 
2687 	ata_bus_post_reset(ap, devmask);
2688 
2689 	return 0;
2690 }
2691 
2692 /**
2693  *	ata_bus_reset - reset host port and associated ATA channel
2694  *	@ap: port to reset
2695  *
2696  *	This is typically the first time we actually start issuing
2697  *	commands to the ATA channel.  We wait for BSY to clear, then
2698  *	issue EXECUTE DEVICE DIAGNOSTIC command, polling for its
2699  *	result.  Determine what devices, if any, are on the channel
2700  *	by looking at the device 0/1 error register.  Look at the signature
2701  *	stored in each device's taskfile registers, to determine if
2702  *	the device is ATA or ATAPI.
2703  *
2704  *	LOCKING:
2705  *	PCI/etc. bus probe sem.
2706  *	Obtains host lock.
2707  *
2708  *	SIDE EFFECTS:
2709  *	Sets ATA_FLAG_DISABLED if bus reset fails.
2710  */
2711 
2712 void ata_bus_reset(struct ata_port *ap)
2713 {
2714 	struct ata_ioports *ioaddr = &ap->ioaddr;
2715 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
2716 	u8 err;
2717 	unsigned int dev0, dev1 = 0, devmask = 0;
2718 
2719 	DPRINTK("ENTER, host %u, port %u\n", ap->id, ap->port_no);
2720 
2721 	/* determine if device 0/1 are present */
2722 	if (ap->flags & ATA_FLAG_SATA_RESET)
2723 		dev0 = 1;
2724 	else {
2725 		dev0 = ata_devchk(ap, 0);
2726 		if (slave_possible)
2727 			dev1 = ata_devchk(ap, 1);
2728 	}
2729 
2730 	if (dev0)
2731 		devmask |= (1 << 0);
2732 	if (dev1)
2733 		devmask |= (1 << 1);
2734 
2735 	/* select device 0 again */
2736 	ap->ops->dev_select(ap, 0);
2737 
2738 	/* issue bus reset */
2739 	if (ap->flags & ATA_FLAG_SRST)
2740 		if (ata_bus_softreset(ap, devmask))
2741 			goto err_out;
2742 
2743 	/*
2744 	 * determine by signature whether we have ATA or ATAPI devices
2745 	 */
2746 	ap->device[0].class = ata_dev_try_classify(ap, 0, &err);
2747 	if ((slave_possible) && (err != 0x81))
2748 		ap->device[1].class = ata_dev_try_classify(ap, 1, &err);
2749 
2750 	/* re-enable interrupts */
2751 	if (ap->ioaddr.ctl_addr)	/* FIXME: hack. create a hook instead */
2752 		ata_irq_on(ap);
2753 
2754 	/* is double-select really necessary? */
2755 	if (ap->device[1].class != ATA_DEV_NONE)
2756 		ap->ops->dev_select(ap, 1);
2757 	if (ap->device[0].class != ATA_DEV_NONE)
2758 		ap->ops->dev_select(ap, 0);
2759 
2760 	/* if no devices were detected, disable this port */
2761 	if ((ap->device[0].class == ATA_DEV_NONE) &&
2762 	    (ap->device[1].class == ATA_DEV_NONE))
2763 		goto err_out;
2764 
2765 	if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
2766 		/* set up device control for ATA_FLAG_SATA_RESET */
2767 		if (ap->flags & ATA_FLAG_MMIO)
2768 			writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2769 		else
2770 			outb(ap->ctl, ioaddr->ctl_addr);
2771 	}
2772 
2773 	DPRINTK("EXIT\n");
2774 	return;
2775 
2776 err_out:
2777 	ata_port_printk(ap, KERN_ERR, "disabling port\n");
2778 	ap->ops->port_disable(ap);
2779 
2780 	DPRINTK("EXIT\n");
2781 }
2782 
2783 /**
2784  *	sata_phy_debounce - debounce SATA phy status
2785  *	@ap: ATA port to debounce SATA phy status for
2786  *	@params: timing parameters { interval, duratinon, timeout } in msec
2787  *
2788  *	Make sure SStatus of @ap reaches stable state, determined by
2789  *	holding the same value where DET is not 1 for @duration polled
2790  *	every @interval, before @timeout.  Timeout constraints the
2791  *	beginning of the stable state.  Because, after hot unplugging,
2792  *	DET gets stuck at 1 on some controllers, this functions waits
2793  *	until timeout then returns 0 if DET is stable at 1.
2794  *
2795  *	LOCKING:
2796  *	Kernel thread context (may sleep)
2797  *
2798  *	RETURNS:
2799  *	0 on success, -errno on failure.
2800  */
2801 int sata_phy_debounce(struct ata_port *ap, const unsigned long *params)
2802 {
2803 	unsigned long interval_msec = params[0];
2804 	unsigned long duration = params[1] * HZ / 1000;
2805 	unsigned long timeout = jiffies + params[2] * HZ / 1000;
2806 	unsigned long last_jiffies;
2807 	u32 last, cur;
2808 	int rc;
2809 
2810 	if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
2811 		return rc;
2812 	cur &= 0xf;
2813 
2814 	last = cur;
2815 	last_jiffies = jiffies;
2816 
2817 	while (1) {
2818 		msleep(interval_msec);
2819 		if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
2820 			return rc;
2821 		cur &= 0xf;
2822 
2823 		/* DET stable? */
2824 		if (cur == last) {
2825 			if (cur == 1 && time_before(jiffies, timeout))
2826 				continue;
2827 			if (time_after(jiffies, last_jiffies + duration))
2828 				return 0;
2829 			continue;
2830 		}
2831 
2832 		/* unstable, start over */
2833 		last = cur;
2834 		last_jiffies = jiffies;
2835 
2836 		/* check timeout */
2837 		if (time_after(jiffies, timeout))
2838 			return -EBUSY;
2839 	}
2840 }
2841 
2842 /**
2843  *	sata_phy_resume - resume SATA phy
2844  *	@ap: ATA port to resume SATA phy for
2845  *	@params: timing parameters { interval, duratinon, timeout } in msec
2846  *
2847  *	Resume SATA phy of @ap and debounce it.
2848  *
2849  *	LOCKING:
2850  *	Kernel thread context (may sleep)
2851  *
2852  *	RETURNS:
2853  *	0 on success, -errno on failure.
2854  */
2855 int sata_phy_resume(struct ata_port *ap, const unsigned long *params)
2856 {
2857 	u32 scontrol;
2858 	int rc;
2859 
2860 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
2861 		return rc;
2862 
2863 	scontrol = (scontrol & 0x0f0) | 0x300;
2864 
2865 	if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
2866 		return rc;
2867 
2868 	/* Some PHYs react badly if SStatus is pounded immediately
2869 	 * after resuming.  Delay 200ms before debouncing.
2870 	 */
2871 	msleep(200);
2872 
2873 	return sata_phy_debounce(ap, params);
2874 }
2875 
2876 static void ata_wait_spinup(struct ata_port *ap)
2877 {
2878 	struct ata_eh_context *ehc = &ap->eh_context;
2879 	unsigned long end, secs;
2880 	int rc;
2881 
2882 	/* first, debounce phy if SATA */
2883 	if (ap->cbl == ATA_CBL_SATA) {
2884 		rc = sata_phy_debounce(ap, sata_deb_timing_hotplug);
2885 
2886 		/* if debounced successfully and offline, no need to wait */
2887 		if ((rc == 0 || rc == -EOPNOTSUPP) && ata_port_offline(ap))
2888 			return;
2889 	}
2890 
2891 	/* okay, let's give the drive time to spin up */
2892 	end = ehc->i.hotplug_timestamp + ATA_SPINUP_WAIT * HZ / 1000;
2893 	secs = ((end - jiffies) + HZ - 1) / HZ;
2894 
2895 	if (time_after(jiffies, end))
2896 		return;
2897 
2898 	if (secs > 5)
2899 		ata_port_printk(ap, KERN_INFO, "waiting for device to spin up "
2900 				"(%lu secs)\n", secs);
2901 
2902 	schedule_timeout_uninterruptible(end - jiffies);
2903 }
2904 
2905 /**
2906  *	ata_std_prereset - prepare for reset
2907  *	@ap: ATA port to be reset
2908  *
2909  *	@ap is about to be reset.  Initialize it.
2910  *
2911  *	LOCKING:
2912  *	Kernel thread context (may sleep)
2913  *
2914  *	RETURNS:
2915  *	0 on success, -errno otherwise.
2916  */
2917 int ata_std_prereset(struct ata_port *ap)
2918 {
2919 	struct ata_eh_context *ehc = &ap->eh_context;
2920 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
2921 	int rc;
2922 
2923 	/* handle link resume & hotplug spinup */
2924 	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
2925 	    (ap->flags & ATA_FLAG_HRST_TO_RESUME))
2926 		ehc->i.action |= ATA_EH_HARDRESET;
2927 
2928 	if ((ehc->i.flags & ATA_EHI_HOTPLUGGED) &&
2929 	    (ap->flags & ATA_FLAG_SKIP_D2H_BSY))
2930 		ata_wait_spinup(ap);
2931 
2932 	/* if we're about to do hardreset, nothing more to do */
2933 	if (ehc->i.action & ATA_EH_HARDRESET)
2934 		return 0;
2935 
2936 	/* if SATA, resume phy */
2937 	if (ap->cbl == ATA_CBL_SATA) {
2938 		rc = sata_phy_resume(ap, timing);
2939 		if (rc && rc != -EOPNOTSUPP) {
2940 			/* phy resume failed */
2941 			ata_port_printk(ap, KERN_WARNING, "failed to resume "
2942 					"link for reset (errno=%d)\n", rc);
2943 			return rc;
2944 		}
2945 	}
2946 
2947 	/* Wait for !BSY if the controller can wait for the first D2H
2948 	 * Reg FIS and we don't know that no device is attached.
2949 	 */
2950 	if (!(ap->flags & ATA_FLAG_SKIP_D2H_BSY) && !ata_port_offline(ap))
2951 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2952 
2953 	return 0;
2954 }
2955 
2956 /**
2957  *	ata_std_softreset - reset host port via ATA SRST
2958  *	@ap: port to reset
2959  *	@classes: resulting classes of attached devices
2960  *
2961  *	Reset host port using ATA SRST.
2962  *
2963  *	LOCKING:
2964  *	Kernel thread context (may sleep)
2965  *
2966  *	RETURNS:
2967  *	0 on success, -errno otherwise.
2968  */
2969 int ata_std_softreset(struct ata_port *ap, unsigned int *classes)
2970 {
2971 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
2972 	unsigned int devmask = 0, err_mask;
2973 	u8 err;
2974 
2975 	DPRINTK("ENTER\n");
2976 
2977 	if (ata_port_offline(ap)) {
2978 		classes[0] = ATA_DEV_NONE;
2979 		goto out;
2980 	}
2981 
2982 	/* determine if device 0/1 are present */
2983 	if (ata_devchk(ap, 0))
2984 		devmask |= (1 << 0);
2985 	if (slave_possible && ata_devchk(ap, 1))
2986 		devmask |= (1 << 1);
2987 
2988 	/* select device 0 again */
2989 	ap->ops->dev_select(ap, 0);
2990 
2991 	/* issue bus reset */
2992 	DPRINTK("about to softreset, devmask=%x\n", devmask);
2993 	err_mask = ata_bus_softreset(ap, devmask);
2994 	if (err_mask) {
2995 		ata_port_printk(ap, KERN_ERR, "SRST failed (err_mask=0x%x)\n",
2996 				err_mask);
2997 		return -EIO;
2998 	}
2999 
3000 	/* determine by signature whether we have ATA or ATAPI devices */
3001 	classes[0] = ata_dev_try_classify(ap, 0, &err);
3002 	if (slave_possible && err != 0x81)
3003 		classes[1] = ata_dev_try_classify(ap, 1, &err);
3004 
3005  out:
3006 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
3007 	return 0;
3008 }
3009 
3010 /**
3011  *	sata_port_hardreset - reset port via SATA phy reset
3012  *	@ap: port to reset
3013  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3014  *
3015  *	SATA phy-reset host port using DET bits of SControl register.
3016  *
3017  *	LOCKING:
3018  *	Kernel thread context (may sleep)
3019  *
3020  *	RETURNS:
3021  *	0 on success, -errno otherwise.
3022  */
3023 int sata_port_hardreset(struct ata_port *ap, const unsigned long *timing)
3024 {
3025 	u32 scontrol;
3026 	int rc;
3027 
3028 	DPRINTK("ENTER\n");
3029 
3030 	if (sata_set_spd_needed(ap)) {
3031 		/* SATA spec says nothing about how to reconfigure
3032 		 * spd.  To be on the safe side, turn off phy during
3033 		 * reconfiguration.  This works for at least ICH7 AHCI
3034 		 * and Sil3124.
3035 		 */
3036 		if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
3037 			goto out;
3038 
3039 		scontrol = (scontrol & 0x0f0) | 0x304;
3040 
3041 		if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
3042 			goto out;
3043 
3044 		sata_set_spd(ap);
3045 	}
3046 
3047 	/* issue phy wake/reset */
3048 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
3049 		goto out;
3050 
3051 	scontrol = (scontrol & 0x0f0) | 0x301;
3052 
3053 	if ((rc = sata_scr_write_flush(ap, SCR_CONTROL, scontrol)))
3054 		goto out;
3055 
3056 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3057 	 * 10.4.2 says at least 1 ms.
3058 	 */
3059 	msleep(1);
3060 
3061 	/* bring phy back */
3062 	rc = sata_phy_resume(ap, timing);
3063  out:
3064 	DPRINTK("EXIT, rc=%d\n", rc);
3065 	return rc;
3066 }
3067 
3068 /**
3069  *	sata_std_hardreset - reset host port via SATA phy reset
3070  *	@ap: port to reset
3071  *	@class: resulting class of attached device
3072  *
3073  *	SATA phy-reset host port using DET bits of SControl register,
3074  *	wait for !BSY and classify the attached device.
3075  *
3076  *	LOCKING:
3077  *	Kernel thread context (may sleep)
3078  *
3079  *	RETURNS:
3080  *	0 on success, -errno otherwise.
3081  */
3082 int sata_std_hardreset(struct ata_port *ap, unsigned int *class)
3083 {
3084 	const unsigned long *timing = sata_ehc_deb_timing(&ap->eh_context);
3085 	int rc;
3086 
3087 	DPRINTK("ENTER\n");
3088 
3089 	/* do hardreset */
3090 	rc = sata_port_hardreset(ap, timing);
3091 	if (rc) {
3092 		ata_port_printk(ap, KERN_ERR,
3093 				"COMRESET failed (errno=%d)\n", rc);
3094 		return rc;
3095 	}
3096 
3097 	/* TODO: phy layer with polling, timeouts, etc. */
3098 	if (ata_port_offline(ap)) {
3099 		*class = ATA_DEV_NONE;
3100 		DPRINTK("EXIT, link offline\n");
3101 		return 0;
3102 	}
3103 
3104 	if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
3105 		ata_port_printk(ap, KERN_ERR,
3106 				"COMRESET failed (device not ready)\n");
3107 		return -EIO;
3108 	}
3109 
3110 	ap->ops->dev_select(ap, 0);	/* probably unnecessary */
3111 
3112 	*class = ata_dev_try_classify(ap, 0, NULL);
3113 
3114 	DPRINTK("EXIT, class=%u\n", *class);
3115 	return 0;
3116 }
3117 
3118 /**
3119  *	ata_std_postreset - standard postreset callback
3120  *	@ap: the target ata_port
3121  *	@classes: classes of attached devices
3122  *
3123  *	This function is invoked after a successful reset.  Note that
3124  *	the device might have been reset more than once using
3125  *	different reset methods before postreset is invoked.
3126  *
3127  *	LOCKING:
3128  *	Kernel thread context (may sleep)
3129  */
3130 void ata_std_postreset(struct ata_port *ap, unsigned int *classes)
3131 {
3132 	u32 serror;
3133 
3134 	DPRINTK("ENTER\n");
3135 
3136 	/* print link status */
3137 	sata_print_link_status(ap);
3138 
3139 	/* clear SError */
3140 	if (sata_scr_read(ap, SCR_ERROR, &serror) == 0)
3141 		sata_scr_write(ap, SCR_ERROR, serror);
3142 
3143 	/* re-enable interrupts */
3144 	if (!ap->ops->error_handler) {
3145 		/* FIXME: hack. create a hook instead */
3146 		if (ap->ioaddr.ctl_addr)
3147 			ata_irq_on(ap);
3148 	}
3149 
3150 	/* is double-select really necessary? */
3151 	if (classes[0] != ATA_DEV_NONE)
3152 		ap->ops->dev_select(ap, 1);
3153 	if (classes[1] != ATA_DEV_NONE)
3154 		ap->ops->dev_select(ap, 0);
3155 
3156 	/* bail out if no device is present */
3157 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
3158 		DPRINTK("EXIT, no device\n");
3159 		return;
3160 	}
3161 
3162 	/* set up device control */
3163 	if (ap->ioaddr.ctl_addr) {
3164 		if (ap->flags & ATA_FLAG_MMIO)
3165 			writeb(ap->ctl, (void __iomem *) ap->ioaddr.ctl_addr);
3166 		else
3167 			outb(ap->ctl, ap->ioaddr.ctl_addr);
3168 	}
3169 
3170 	DPRINTK("EXIT\n");
3171 }
3172 
3173 /**
3174  *	ata_dev_same_device - Determine whether new ID matches configured device
3175  *	@dev: device to compare against
3176  *	@new_class: class of the new device
3177  *	@new_id: IDENTIFY page of the new device
3178  *
3179  *	Compare @new_class and @new_id against @dev and determine
3180  *	whether @dev is the device indicated by @new_class and
3181  *	@new_id.
3182  *
3183  *	LOCKING:
3184  *	None.
3185  *
3186  *	RETURNS:
3187  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3188  */
3189 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3190 			       const u16 *new_id)
3191 {
3192 	const u16 *old_id = dev->id;
3193 	unsigned char model[2][41], serial[2][21];
3194 	u64 new_n_sectors;
3195 
3196 	if (dev->class != new_class) {
3197 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
3198 			       dev->class, new_class);
3199 		return 0;
3200 	}
3201 
3202 	ata_id_c_string(old_id, model[0], ATA_ID_PROD_OFS, sizeof(model[0]));
3203 	ata_id_c_string(new_id, model[1], ATA_ID_PROD_OFS, sizeof(model[1]));
3204 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO_OFS, sizeof(serial[0]));
3205 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO_OFS, sizeof(serial[1]));
3206 	new_n_sectors = ata_id_n_sectors(new_id);
3207 
3208 	if (strcmp(model[0], model[1])) {
3209 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
3210 			       "'%s' != '%s'\n", model[0], model[1]);
3211 		return 0;
3212 	}
3213 
3214 	if (strcmp(serial[0], serial[1])) {
3215 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
3216 			       "'%s' != '%s'\n", serial[0], serial[1]);
3217 		return 0;
3218 	}
3219 
3220 	if (dev->class == ATA_DEV_ATA && dev->n_sectors != new_n_sectors) {
3221 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
3222 			       "%llu != %llu\n",
3223 			       (unsigned long long)dev->n_sectors,
3224 			       (unsigned long long)new_n_sectors);
3225 		return 0;
3226 	}
3227 
3228 	return 1;
3229 }
3230 
3231 /**
3232  *	ata_dev_revalidate - Revalidate ATA device
3233  *	@dev: device to revalidate
3234  *	@readid_flags: read ID flags
3235  *
3236  *	Re-read IDENTIFY page and make sure @dev is still attached to
3237  *	the port.
3238  *
3239  *	LOCKING:
3240  *	Kernel thread context (may sleep)
3241  *
3242  *	RETURNS:
3243  *	0 on success, negative errno otherwise
3244  */
3245 int ata_dev_revalidate(struct ata_device *dev, unsigned int readid_flags)
3246 {
3247 	unsigned int class = dev->class;
3248 	u16 *id = (void *)dev->ap->sector_buf;
3249 	int rc;
3250 
3251 	if (!ata_dev_enabled(dev)) {
3252 		rc = -ENODEV;
3253 		goto fail;
3254 	}
3255 
3256 	/* read ID data */
3257 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
3258 	if (rc)
3259 		goto fail;
3260 
3261 	/* is the device still there? */
3262 	if (!ata_dev_same_device(dev, class, id)) {
3263 		rc = -ENODEV;
3264 		goto fail;
3265 	}
3266 
3267 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
3268 
3269 	/* configure device according to the new ID */
3270 	rc = ata_dev_configure(dev);
3271 	if (rc == 0)
3272 		return 0;
3273 
3274  fail:
3275 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
3276 	return rc;
3277 }
3278 
3279 struct ata_blacklist_entry {
3280 	const char *model_num;
3281 	const char *model_rev;
3282 	unsigned long horkage;
3283 };
3284 
3285 static const struct ata_blacklist_entry ata_device_blacklist [] = {
3286 	/* Devices with DMA related problems under Linux */
3287 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
3288 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
3289 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
3290 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
3291 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
3292 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
3293 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
3294 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
3295 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
3296 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
3297 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
3298 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
3299 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
3300 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
3301 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
3302 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
3303 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
3304 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
3305 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
3306 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
3307 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
3308 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
3309 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
3310 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
3311 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
3312 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
3313 	{ "SanDisk SDP3B-64", 	NULL,		ATA_HORKAGE_NODMA },
3314 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
3315 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
3316 	{ "SAMSUNG CD-ROM SN-124","N001",	ATA_HORKAGE_NODMA },
3317 
3318 	/* Devices we expect to fail diagnostics */
3319 
3320 	/* Devices where NCQ should be avoided */
3321 	/* NCQ is slow */
3322         { "WDC WD740ADFD-00",   NULL,		ATA_HORKAGE_NONCQ },
3323 
3324 	/* Devices with NCQ limits */
3325 
3326 	/* End Marker */
3327 	{ }
3328 };
3329 
3330 static int ata_strim(char *s, size_t len)
3331 {
3332 	len = strnlen(s, len);
3333 
3334 	/* ATAPI specifies that empty space is blank-filled; remove blanks */
3335 	while ((len > 0) && (s[len - 1] == ' ')) {
3336 		len--;
3337 		s[len] = 0;
3338 	}
3339 	return len;
3340 }
3341 
3342 unsigned long ata_device_blacklisted(const struct ata_device *dev)
3343 {
3344 	unsigned char model_num[40];
3345 	unsigned char model_rev[16];
3346 	unsigned int nlen, rlen;
3347 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
3348 
3349 	ata_id_string(dev->id, model_num, ATA_ID_PROD_OFS,
3350 			  sizeof(model_num));
3351 	ata_id_string(dev->id, model_rev, ATA_ID_FW_REV_OFS,
3352 			  sizeof(model_rev));
3353 	nlen = ata_strim(model_num, sizeof(model_num));
3354 	rlen = ata_strim(model_rev, sizeof(model_rev));
3355 
3356 	while (ad->model_num) {
3357 		if (!strncmp(ad->model_num, model_num, nlen)) {
3358 			if (ad->model_rev == NULL)
3359 				return ad->horkage;
3360 			if (!strncmp(ad->model_rev, model_rev, rlen))
3361 				return ad->horkage;
3362 		}
3363 		ad++;
3364 	}
3365 	return 0;
3366 }
3367 
3368 static int ata_dma_blacklisted(const struct ata_device *dev)
3369 {
3370 	/* We don't support polling DMA.
3371 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
3372 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
3373 	 */
3374 	if ((dev->ap->flags & ATA_FLAG_PIO_POLLING) &&
3375 	    (dev->flags & ATA_DFLAG_CDB_INTR))
3376 		return 1;
3377 	return (ata_device_blacklisted(dev) & ATA_HORKAGE_NODMA) ? 1 : 0;
3378 }
3379 
3380 /**
3381  *	ata_dev_xfermask - Compute supported xfermask of the given device
3382  *	@dev: Device to compute xfermask for
3383  *
3384  *	Compute supported xfermask of @dev and store it in
3385  *	dev->*_mask.  This function is responsible for applying all
3386  *	known limits including host controller limits, device
3387  *	blacklist, etc...
3388  *
3389  *	LOCKING:
3390  *	None.
3391  */
3392 static void ata_dev_xfermask(struct ata_device *dev)
3393 {
3394 	struct ata_port *ap = dev->ap;
3395 	struct ata_host *host = ap->host;
3396 	unsigned long xfer_mask;
3397 
3398 	/* controller modes available */
3399 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
3400 				      ap->mwdma_mask, ap->udma_mask);
3401 
3402 	/* Apply cable rule here.  Don't apply it early because when
3403 	 * we handle hot plug the cable type can itself change.
3404 	 */
3405 	if (ap->cbl == ATA_CBL_PATA40)
3406 		xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
3407 	/* Apply drive side cable rule. Unknown or 80 pin cables reported
3408 	 * host side are checked drive side as well. Cases where we know a
3409 	 * 40wire cable is used safely for 80 are not checked here.
3410 	 */
3411         if (ata_drive_40wire(dev->id) && (ap->cbl == ATA_CBL_PATA_UNK || ap->cbl == ATA_CBL_PATA80))
3412 		xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
3413 
3414 
3415 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
3416 				       dev->mwdma_mask, dev->udma_mask);
3417 	xfer_mask &= ata_id_xfermask(dev->id);
3418 
3419 	/*
3420 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
3421 	 *	cable
3422 	 */
3423 	if (ata_dev_pair(dev)) {
3424 		/* No PIO5 or PIO6 */
3425 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
3426 		/* No MWDMA3 or MWDMA 4 */
3427 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
3428 	}
3429 
3430 	if (ata_dma_blacklisted(dev)) {
3431 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
3432 		ata_dev_printk(dev, KERN_WARNING,
3433 			       "device is on DMA blacklist, disabling DMA\n");
3434 	}
3435 
3436 	if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed) {
3437 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
3438 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
3439 			       "other device, disabling DMA\n");
3440 	}
3441 
3442 	if (ap->ops->mode_filter)
3443 		xfer_mask = ap->ops->mode_filter(ap, dev, xfer_mask);
3444 
3445 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
3446 			    &dev->mwdma_mask, &dev->udma_mask);
3447 }
3448 
3449 /**
3450  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
3451  *	@dev: Device to which command will be sent
3452  *
3453  *	Issue SET FEATURES - XFER MODE command to device @dev
3454  *	on port @ap.
3455  *
3456  *	LOCKING:
3457  *	PCI/etc. bus probe sem.
3458  *
3459  *	RETURNS:
3460  *	0 on success, AC_ERR_* mask otherwise.
3461  */
3462 
3463 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
3464 {
3465 	struct ata_taskfile tf;
3466 	unsigned int err_mask;
3467 
3468 	/* set up set-features taskfile */
3469 	DPRINTK("set features - xfer mode\n");
3470 
3471 	ata_tf_init(dev, &tf);
3472 	tf.command = ATA_CMD_SET_FEATURES;
3473 	tf.feature = SETFEATURES_XFER;
3474 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
3475 	tf.protocol = ATA_PROT_NODATA;
3476 	tf.nsect = dev->xfer_mode;
3477 
3478 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
3479 
3480 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
3481 	return err_mask;
3482 }
3483 
3484 /**
3485  *	ata_dev_init_params - Issue INIT DEV PARAMS command
3486  *	@dev: Device to which command will be sent
3487  *	@heads: Number of heads (taskfile parameter)
3488  *	@sectors: Number of sectors (taskfile parameter)
3489  *
3490  *	LOCKING:
3491  *	Kernel thread context (may sleep)
3492  *
3493  *	RETURNS:
3494  *	0 on success, AC_ERR_* mask otherwise.
3495  */
3496 static unsigned int ata_dev_init_params(struct ata_device *dev,
3497 					u16 heads, u16 sectors)
3498 {
3499 	struct ata_taskfile tf;
3500 	unsigned int err_mask;
3501 
3502 	/* Number of sectors per track 1-255. Number of heads 1-16 */
3503 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
3504 		return AC_ERR_INVALID;
3505 
3506 	/* set up init dev params taskfile */
3507 	DPRINTK("init dev params \n");
3508 
3509 	ata_tf_init(dev, &tf);
3510 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
3511 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
3512 	tf.protocol = ATA_PROT_NODATA;
3513 	tf.nsect = sectors;
3514 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
3515 
3516 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
3517 
3518 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
3519 	return err_mask;
3520 }
3521 
3522 /**
3523  *	ata_sg_clean - Unmap DMA memory associated with command
3524  *	@qc: Command containing DMA memory to be released
3525  *
3526  *	Unmap all mapped DMA memory associated with this command.
3527  *
3528  *	LOCKING:
3529  *	spin_lock_irqsave(host lock)
3530  */
3531 void ata_sg_clean(struct ata_queued_cmd *qc)
3532 {
3533 	struct ata_port *ap = qc->ap;
3534 	struct scatterlist *sg = qc->__sg;
3535 	int dir = qc->dma_dir;
3536 	void *pad_buf = NULL;
3537 
3538 	WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
3539 	WARN_ON(sg == NULL);
3540 
3541 	if (qc->flags & ATA_QCFLAG_SINGLE)
3542 		WARN_ON(qc->n_elem > 1);
3543 
3544 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
3545 
3546 	/* if we padded the buffer out to 32-bit bound, and data
3547 	 * xfer direction is from-device, we must copy from the
3548 	 * pad buffer back into the supplied buffer
3549 	 */
3550 	if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
3551 		pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3552 
3553 	if (qc->flags & ATA_QCFLAG_SG) {
3554 		if (qc->n_elem)
3555 			dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
3556 		/* restore last sg */
3557 		sg[qc->orig_n_elem - 1].length += qc->pad_len;
3558 		if (pad_buf) {
3559 			struct scatterlist *psg = &qc->pad_sgent;
3560 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
3561 			memcpy(addr + psg->offset, pad_buf, qc->pad_len);
3562 			kunmap_atomic(addr, KM_IRQ0);
3563 		}
3564 	} else {
3565 		if (qc->n_elem)
3566 			dma_unmap_single(ap->dev,
3567 				sg_dma_address(&sg[0]), sg_dma_len(&sg[0]),
3568 				dir);
3569 		/* restore sg */
3570 		sg->length += qc->pad_len;
3571 		if (pad_buf)
3572 			memcpy(qc->buf_virt + sg->length - qc->pad_len,
3573 			       pad_buf, qc->pad_len);
3574 	}
3575 
3576 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
3577 	qc->__sg = NULL;
3578 }
3579 
3580 /**
3581  *	ata_fill_sg - Fill PCI IDE PRD table
3582  *	@qc: Metadata associated with taskfile to be transferred
3583  *
3584  *	Fill PCI IDE PRD (scatter-gather) table with segments
3585  *	associated with the current disk command.
3586  *
3587  *	LOCKING:
3588  *	spin_lock_irqsave(host lock)
3589  *
3590  */
3591 static void ata_fill_sg(struct ata_queued_cmd *qc)
3592 {
3593 	struct ata_port *ap = qc->ap;
3594 	struct scatterlist *sg;
3595 	unsigned int idx;
3596 
3597 	WARN_ON(qc->__sg == NULL);
3598 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
3599 
3600 	idx = 0;
3601 	ata_for_each_sg(sg, qc) {
3602 		u32 addr, offset;
3603 		u32 sg_len, len;
3604 
3605 		/* determine if physical DMA addr spans 64K boundary.
3606 		 * Note h/w doesn't support 64-bit, so we unconditionally
3607 		 * truncate dma_addr_t to u32.
3608 		 */
3609 		addr = (u32) sg_dma_address(sg);
3610 		sg_len = sg_dma_len(sg);
3611 
3612 		while (sg_len) {
3613 			offset = addr & 0xffff;
3614 			len = sg_len;
3615 			if ((offset + sg_len) > 0x10000)
3616 				len = 0x10000 - offset;
3617 
3618 			ap->prd[idx].addr = cpu_to_le32(addr);
3619 			ap->prd[idx].flags_len = cpu_to_le32(len & 0xffff);
3620 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
3621 
3622 			idx++;
3623 			sg_len -= len;
3624 			addr += len;
3625 		}
3626 	}
3627 
3628 	if (idx)
3629 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
3630 }
3631 /**
3632  *	ata_check_atapi_dma - Check whether ATAPI DMA can be supported
3633  *	@qc: Metadata associated with taskfile to check
3634  *
3635  *	Allow low-level driver to filter ATA PACKET commands, returning
3636  *	a status indicating whether or not it is OK to use DMA for the
3637  *	supplied PACKET command.
3638  *
3639  *	LOCKING:
3640  *	spin_lock_irqsave(host lock)
3641  *
3642  *	RETURNS: 0 when ATAPI DMA can be used
3643  *               nonzero otherwise
3644  */
3645 int ata_check_atapi_dma(struct ata_queued_cmd *qc)
3646 {
3647 	struct ata_port *ap = qc->ap;
3648 	int rc = 0; /* Assume ATAPI DMA is OK by default */
3649 
3650 	if (ap->ops->check_atapi_dma)
3651 		rc = ap->ops->check_atapi_dma(qc);
3652 
3653 	return rc;
3654 }
3655 /**
3656  *	ata_qc_prep - Prepare taskfile for submission
3657  *	@qc: Metadata associated with taskfile to be prepared
3658  *
3659  *	Prepare ATA taskfile for submission.
3660  *
3661  *	LOCKING:
3662  *	spin_lock_irqsave(host lock)
3663  */
3664 void ata_qc_prep(struct ata_queued_cmd *qc)
3665 {
3666 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
3667 		return;
3668 
3669 	ata_fill_sg(qc);
3670 }
3671 
3672 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
3673 
3674 /**
3675  *	ata_sg_init_one - Associate command with memory buffer
3676  *	@qc: Command to be associated
3677  *	@buf: Memory buffer
3678  *	@buflen: Length of memory buffer, in bytes.
3679  *
3680  *	Initialize the data-related elements of queued_cmd @qc
3681  *	to point to a single memory buffer, @buf of byte length @buflen.
3682  *
3683  *	LOCKING:
3684  *	spin_lock_irqsave(host lock)
3685  */
3686 
3687 void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
3688 {
3689 	qc->flags |= ATA_QCFLAG_SINGLE;
3690 
3691 	qc->__sg = &qc->sgent;
3692 	qc->n_elem = 1;
3693 	qc->orig_n_elem = 1;
3694 	qc->buf_virt = buf;
3695 	qc->nbytes = buflen;
3696 
3697 	sg_init_one(&qc->sgent, buf, buflen);
3698 }
3699 
3700 /**
3701  *	ata_sg_init - Associate command with scatter-gather table.
3702  *	@qc: Command to be associated
3703  *	@sg: Scatter-gather table.
3704  *	@n_elem: Number of elements in s/g table.
3705  *
3706  *	Initialize the data-related elements of queued_cmd @qc
3707  *	to point to a scatter-gather table @sg, containing @n_elem
3708  *	elements.
3709  *
3710  *	LOCKING:
3711  *	spin_lock_irqsave(host lock)
3712  */
3713 
3714 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
3715 		 unsigned int n_elem)
3716 {
3717 	qc->flags |= ATA_QCFLAG_SG;
3718 	qc->__sg = sg;
3719 	qc->n_elem = n_elem;
3720 	qc->orig_n_elem = n_elem;
3721 }
3722 
3723 /**
3724  *	ata_sg_setup_one - DMA-map the memory buffer associated with a command.
3725  *	@qc: Command with memory buffer to be mapped.
3726  *
3727  *	DMA-map the memory buffer associated with queued_cmd @qc.
3728  *
3729  *	LOCKING:
3730  *	spin_lock_irqsave(host lock)
3731  *
3732  *	RETURNS:
3733  *	Zero on success, negative on error.
3734  */
3735 
3736 static int ata_sg_setup_one(struct ata_queued_cmd *qc)
3737 {
3738 	struct ata_port *ap = qc->ap;
3739 	int dir = qc->dma_dir;
3740 	struct scatterlist *sg = qc->__sg;
3741 	dma_addr_t dma_address;
3742 	int trim_sg = 0;
3743 
3744 	/* we must lengthen transfers to end on a 32-bit boundary */
3745 	qc->pad_len = sg->length & 3;
3746 	if (qc->pad_len) {
3747 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3748 		struct scatterlist *psg = &qc->pad_sgent;
3749 
3750 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
3751 
3752 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
3753 
3754 		if (qc->tf.flags & ATA_TFLAG_WRITE)
3755 			memcpy(pad_buf, qc->buf_virt + sg->length - qc->pad_len,
3756 			       qc->pad_len);
3757 
3758 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
3759 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
3760 		/* trim sg */
3761 		sg->length -= qc->pad_len;
3762 		if (sg->length == 0)
3763 			trim_sg = 1;
3764 
3765 		DPRINTK("padding done, sg->length=%u pad_len=%u\n",
3766 			sg->length, qc->pad_len);
3767 	}
3768 
3769 	if (trim_sg) {
3770 		qc->n_elem--;
3771 		goto skip_map;
3772 	}
3773 
3774 	dma_address = dma_map_single(ap->dev, qc->buf_virt,
3775 				     sg->length, dir);
3776 	if (dma_mapping_error(dma_address)) {
3777 		/* restore sg */
3778 		sg->length += qc->pad_len;
3779 		return -1;
3780 	}
3781 
3782 	sg_dma_address(sg) = dma_address;
3783 	sg_dma_len(sg) = sg->length;
3784 
3785 skip_map:
3786 	DPRINTK("mapped buffer of %d bytes for %s\n", sg_dma_len(sg),
3787 		qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
3788 
3789 	return 0;
3790 }
3791 
3792 /**
3793  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
3794  *	@qc: Command with scatter-gather table to be mapped.
3795  *
3796  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
3797  *
3798  *	LOCKING:
3799  *	spin_lock_irqsave(host lock)
3800  *
3801  *	RETURNS:
3802  *	Zero on success, negative on error.
3803  *
3804  */
3805 
3806 static int ata_sg_setup(struct ata_queued_cmd *qc)
3807 {
3808 	struct ata_port *ap = qc->ap;
3809 	struct scatterlist *sg = qc->__sg;
3810 	struct scatterlist *lsg = &sg[qc->n_elem - 1];
3811 	int n_elem, pre_n_elem, dir, trim_sg = 0;
3812 
3813 	VPRINTK("ENTER, ata%u\n", ap->id);
3814 	WARN_ON(!(qc->flags & ATA_QCFLAG_SG));
3815 
3816 	/* we must lengthen transfers to end on a 32-bit boundary */
3817 	qc->pad_len = lsg->length & 3;
3818 	if (qc->pad_len) {
3819 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3820 		struct scatterlist *psg = &qc->pad_sgent;
3821 		unsigned int offset;
3822 
3823 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
3824 
3825 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
3826 
3827 		/*
3828 		 * psg->page/offset are used to copy to-be-written
3829 		 * data in this function or read data in ata_sg_clean.
3830 		 */
3831 		offset = lsg->offset + lsg->length - qc->pad_len;
3832 		psg->page = nth_page(lsg->page, offset >> PAGE_SHIFT);
3833 		psg->offset = offset_in_page(offset);
3834 
3835 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
3836 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
3837 			memcpy(pad_buf, addr + psg->offset, qc->pad_len);
3838 			kunmap_atomic(addr, KM_IRQ0);
3839 		}
3840 
3841 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
3842 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
3843 		/* trim last sg */
3844 		lsg->length -= qc->pad_len;
3845 		if (lsg->length == 0)
3846 			trim_sg = 1;
3847 
3848 		DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
3849 			qc->n_elem - 1, lsg->length, qc->pad_len);
3850 	}
3851 
3852 	pre_n_elem = qc->n_elem;
3853 	if (trim_sg && pre_n_elem)
3854 		pre_n_elem--;
3855 
3856 	if (!pre_n_elem) {
3857 		n_elem = 0;
3858 		goto skip_map;
3859 	}
3860 
3861 	dir = qc->dma_dir;
3862 	n_elem = dma_map_sg(ap->dev, sg, pre_n_elem, dir);
3863 	if (n_elem < 1) {
3864 		/* restore last sg */
3865 		lsg->length += qc->pad_len;
3866 		return -1;
3867 	}
3868 
3869 	DPRINTK("%d sg elements mapped\n", n_elem);
3870 
3871 skip_map:
3872 	qc->n_elem = n_elem;
3873 
3874 	return 0;
3875 }
3876 
3877 /**
3878  *	swap_buf_le16 - swap halves of 16-bit words in place
3879  *	@buf:  Buffer to swap
3880  *	@buf_words:  Number of 16-bit words in buffer.
3881  *
3882  *	Swap halves of 16-bit words if needed to convert from
3883  *	little-endian byte order to native cpu byte order, or
3884  *	vice-versa.
3885  *
3886  *	LOCKING:
3887  *	Inherited from caller.
3888  */
3889 void swap_buf_le16(u16 *buf, unsigned int buf_words)
3890 {
3891 #ifdef __BIG_ENDIAN
3892 	unsigned int i;
3893 
3894 	for (i = 0; i < buf_words; i++)
3895 		buf[i] = le16_to_cpu(buf[i]);
3896 #endif /* __BIG_ENDIAN */
3897 }
3898 
3899 /**
3900  *	ata_mmio_data_xfer - Transfer data by MMIO
3901  *	@adev: device for this I/O
3902  *	@buf: data buffer
3903  *	@buflen: buffer length
3904  *	@write_data: read/write
3905  *
3906  *	Transfer data from/to the device data register by MMIO.
3907  *
3908  *	LOCKING:
3909  *	Inherited from caller.
3910  */
3911 
3912 void ata_mmio_data_xfer(struct ata_device *adev, unsigned char *buf,
3913 			unsigned int buflen, int write_data)
3914 {
3915 	struct ata_port *ap = adev->ap;
3916 	unsigned int i;
3917 	unsigned int words = buflen >> 1;
3918 	u16 *buf16 = (u16 *) buf;
3919 	void __iomem *mmio = (void __iomem *)ap->ioaddr.data_addr;
3920 
3921 	/* Transfer multiple of 2 bytes */
3922 	if (write_data) {
3923 		for (i = 0; i < words; i++)
3924 			writew(le16_to_cpu(buf16[i]), mmio);
3925 	} else {
3926 		for (i = 0; i < words; i++)
3927 			buf16[i] = cpu_to_le16(readw(mmio));
3928 	}
3929 
3930 	/* Transfer trailing 1 byte, if any. */
3931 	if (unlikely(buflen & 0x01)) {
3932 		u16 align_buf[1] = { 0 };
3933 		unsigned char *trailing_buf = buf + buflen - 1;
3934 
3935 		if (write_data) {
3936 			memcpy(align_buf, trailing_buf, 1);
3937 			writew(le16_to_cpu(align_buf[0]), mmio);
3938 		} else {
3939 			align_buf[0] = cpu_to_le16(readw(mmio));
3940 			memcpy(trailing_buf, align_buf, 1);
3941 		}
3942 	}
3943 }
3944 
3945 /**
3946  *	ata_pio_data_xfer - Transfer data by PIO
3947  *	@adev: device to target
3948  *	@buf: data buffer
3949  *	@buflen: buffer length
3950  *	@write_data: read/write
3951  *
3952  *	Transfer data from/to the device data register by PIO.
3953  *
3954  *	LOCKING:
3955  *	Inherited from caller.
3956  */
3957 
3958 void ata_pio_data_xfer(struct ata_device *adev, unsigned char *buf,
3959 		       unsigned int buflen, int write_data)
3960 {
3961 	struct ata_port *ap = adev->ap;
3962 	unsigned int words = buflen >> 1;
3963 
3964 	/* Transfer multiple of 2 bytes */
3965 	if (write_data)
3966 		outsw(ap->ioaddr.data_addr, buf, words);
3967 	else
3968 		insw(ap->ioaddr.data_addr, buf, words);
3969 
3970 	/* Transfer trailing 1 byte, if any. */
3971 	if (unlikely(buflen & 0x01)) {
3972 		u16 align_buf[1] = { 0 };
3973 		unsigned char *trailing_buf = buf + buflen - 1;
3974 
3975 		if (write_data) {
3976 			memcpy(align_buf, trailing_buf, 1);
3977 			outw(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
3978 		} else {
3979 			align_buf[0] = cpu_to_le16(inw(ap->ioaddr.data_addr));
3980 			memcpy(trailing_buf, align_buf, 1);
3981 		}
3982 	}
3983 }
3984 
3985 /**
3986  *	ata_pio_data_xfer_noirq - Transfer data by PIO
3987  *	@adev: device to target
3988  *	@buf: data buffer
3989  *	@buflen: buffer length
3990  *	@write_data: read/write
3991  *
3992  *	Transfer data from/to the device data register by PIO. Do the
3993  *	transfer with interrupts disabled.
3994  *
3995  *	LOCKING:
3996  *	Inherited from caller.
3997  */
3998 
3999 void ata_pio_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
4000 				    unsigned int buflen, int write_data)
4001 {
4002 	unsigned long flags;
4003 	local_irq_save(flags);
4004 	ata_pio_data_xfer(adev, buf, buflen, write_data);
4005 	local_irq_restore(flags);
4006 }
4007 
4008 
4009 /**
4010  *	ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
4011  *	@qc: Command on going
4012  *
4013  *	Transfer ATA_SECT_SIZE of data from/to the ATA device.
4014  *
4015  *	LOCKING:
4016  *	Inherited from caller.
4017  */
4018 
4019 static void ata_pio_sector(struct ata_queued_cmd *qc)
4020 {
4021 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4022 	struct scatterlist *sg = qc->__sg;
4023 	struct ata_port *ap = qc->ap;
4024 	struct page *page;
4025 	unsigned int offset;
4026 	unsigned char *buf;
4027 
4028 	if (qc->cursect == (qc->nsect - 1))
4029 		ap->hsm_task_state = HSM_ST_LAST;
4030 
4031 	page = sg[qc->cursg].page;
4032 	offset = sg[qc->cursg].offset + qc->cursg_ofs * ATA_SECT_SIZE;
4033 
4034 	/* get the current page and offset */
4035 	page = nth_page(page, (offset >> PAGE_SHIFT));
4036 	offset %= PAGE_SIZE;
4037 
4038 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4039 
4040 	if (PageHighMem(page)) {
4041 		unsigned long flags;
4042 
4043 		/* FIXME: use a bounce buffer */
4044 		local_irq_save(flags);
4045 		buf = kmap_atomic(page, KM_IRQ0);
4046 
4047 		/* do the actual data transfer */
4048 		ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
4049 
4050 		kunmap_atomic(buf, KM_IRQ0);
4051 		local_irq_restore(flags);
4052 	} else {
4053 		buf = page_address(page);
4054 		ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
4055 	}
4056 
4057 	qc->cursect++;
4058 	qc->cursg_ofs++;
4059 
4060 	if ((qc->cursg_ofs * ATA_SECT_SIZE) == (&sg[qc->cursg])->length) {
4061 		qc->cursg++;
4062 		qc->cursg_ofs = 0;
4063 	}
4064 }
4065 
4066 /**
4067  *	ata_pio_sectors - Transfer one or many 512-byte sectors.
4068  *	@qc: Command on going
4069  *
4070  *	Transfer one or many ATA_SECT_SIZE of data from/to the
4071  *	ATA device for the DRQ request.
4072  *
4073  *	LOCKING:
4074  *	Inherited from caller.
4075  */
4076 
4077 static void ata_pio_sectors(struct ata_queued_cmd *qc)
4078 {
4079 	if (is_multi_taskfile(&qc->tf)) {
4080 		/* READ/WRITE MULTIPLE */
4081 		unsigned int nsect;
4082 
4083 		WARN_ON(qc->dev->multi_count == 0);
4084 
4085 		nsect = min(qc->nsect - qc->cursect, qc->dev->multi_count);
4086 		while (nsect--)
4087 			ata_pio_sector(qc);
4088 	} else
4089 		ata_pio_sector(qc);
4090 }
4091 
4092 /**
4093  *	atapi_send_cdb - Write CDB bytes to hardware
4094  *	@ap: Port to which ATAPI device is attached.
4095  *	@qc: Taskfile currently active
4096  *
4097  *	When device has indicated its readiness to accept
4098  *	a CDB, this function is called.  Send the CDB.
4099  *
4100  *	LOCKING:
4101  *	caller.
4102  */
4103 
4104 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
4105 {
4106 	/* send SCSI cdb */
4107 	DPRINTK("send cdb\n");
4108 	WARN_ON(qc->dev->cdb_len < 12);
4109 
4110 	ap->ops->data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
4111 	ata_altstatus(ap); /* flush */
4112 
4113 	switch (qc->tf.protocol) {
4114 	case ATA_PROT_ATAPI:
4115 		ap->hsm_task_state = HSM_ST;
4116 		break;
4117 	case ATA_PROT_ATAPI_NODATA:
4118 		ap->hsm_task_state = HSM_ST_LAST;
4119 		break;
4120 	case ATA_PROT_ATAPI_DMA:
4121 		ap->hsm_task_state = HSM_ST_LAST;
4122 		/* initiate bmdma */
4123 		ap->ops->bmdma_start(qc);
4124 		break;
4125 	}
4126 }
4127 
4128 /**
4129  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
4130  *	@qc: Command on going
4131  *	@bytes: number of bytes
4132  *
4133  *	Transfer Transfer data from/to the ATAPI device.
4134  *
4135  *	LOCKING:
4136  *	Inherited from caller.
4137  *
4138  */
4139 
4140 static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
4141 {
4142 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4143 	struct scatterlist *sg = qc->__sg;
4144 	struct ata_port *ap = qc->ap;
4145 	struct page *page;
4146 	unsigned char *buf;
4147 	unsigned int offset, count;
4148 
4149 	if (qc->curbytes + bytes >= qc->nbytes)
4150 		ap->hsm_task_state = HSM_ST_LAST;
4151 
4152 next_sg:
4153 	if (unlikely(qc->cursg >= qc->n_elem)) {
4154 		/*
4155 		 * The end of qc->sg is reached and the device expects
4156 		 * more data to transfer. In order not to overrun qc->sg
4157 		 * and fulfill length specified in the byte count register,
4158 		 *    - for read case, discard trailing data from the device
4159 		 *    - for write case, padding zero data to the device
4160 		 */
4161 		u16 pad_buf[1] = { 0 };
4162 		unsigned int words = bytes >> 1;
4163 		unsigned int i;
4164 
4165 		if (words) /* warning if bytes > 1 */
4166 			ata_dev_printk(qc->dev, KERN_WARNING,
4167 				       "%u bytes trailing data\n", bytes);
4168 
4169 		for (i = 0; i < words; i++)
4170 			ap->ops->data_xfer(qc->dev, (unsigned char*)pad_buf, 2, do_write);
4171 
4172 		ap->hsm_task_state = HSM_ST_LAST;
4173 		return;
4174 	}
4175 
4176 	sg = &qc->__sg[qc->cursg];
4177 
4178 	page = sg->page;
4179 	offset = sg->offset + qc->cursg_ofs;
4180 
4181 	/* get the current page and offset */
4182 	page = nth_page(page, (offset >> PAGE_SHIFT));
4183 	offset %= PAGE_SIZE;
4184 
4185 	/* don't overrun current sg */
4186 	count = min(sg->length - qc->cursg_ofs, bytes);
4187 
4188 	/* don't cross page boundaries */
4189 	count = min(count, (unsigned int)PAGE_SIZE - offset);
4190 
4191 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4192 
4193 	if (PageHighMem(page)) {
4194 		unsigned long flags;
4195 
4196 		/* FIXME: use bounce buffer */
4197 		local_irq_save(flags);
4198 		buf = kmap_atomic(page, KM_IRQ0);
4199 
4200 		/* do the actual data transfer */
4201 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
4202 
4203 		kunmap_atomic(buf, KM_IRQ0);
4204 		local_irq_restore(flags);
4205 	} else {
4206 		buf = page_address(page);
4207 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
4208 	}
4209 
4210 	bytes -= count;
4211 	qc->curbytes += count;
4212 	qc->cursg_ofs += count;
4213 
4214 	if (qc->cursg_ofs == sg->length) {
4215 		qc->cursg++;
4216 		qc->cursg_ofs = 0;
4217 	}
4218 
4219 	if (bytes)
4220 		goto next_sg;
4221 }
4222 
4223 /**
4224  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
4225  *	@qc: Command on going
4226  *
4227  *	Transfer Transfer data from/to the ATAPI device.
4228  *
4229  *	LOCKING:
4230  *	Inherited from caller.
4231  */
4232 
4233 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
4234 {
4235 	struct ata_port *ap = qc->ap;
4236 	struct ata_device *dev = qc->dev;
4237 	unsigned int ireason, bc_lo, bc_hi, bytes;
4238 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
4239 
4240 	/* Abuse qc->result_tf for temp storage of intermediate TF
4241 	 * here to save some kernel stack usage.
4242 	 * For normal completion, qc->result_tf is not relevant. For
4243 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
4244 	 * So, the correctness of qc->result_tf is not affected.
4245 	 */
4246 	ap->ops->tf_read(ap, &qc->result_tf);
4247 	ireason = qc->result_tf.nsect;
4248 	bc_lo = qc->result_tf.lbam;
4249 	bc_hi = qc->result_tf.lbah;
4250 	bytes = (bc_hi << 8) | bc_lo;
4251 
4252 	/* shall be cleared to zero, indicating xfer of data */
4253 	if (ireason & (1 << 0))
4254 		goto err_out;
4255 
4256 	/* make sure transfer direction matches expected */
4257 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
4258 	if (do_write != i_write)
4259 		goto err_out;
4260 
4261 	VPRINTK("ata%u: xfering %d bytes\n", ap->id, bytes);
4262 
4263 	__atapi_pio_bytes(qc, bytes);
4264 
4265 	return;
4266 
4267 err_out:
4268 	ata_dev_printk(dev, KERN_INFO, "ATAPI check failed\n");
4269 	qc->err_mask |= AC_ERR_HSM;
4270 	ap->hsm_task_state = HSM_ST_ERR;
4271 }
4272 
4273 /**
4274  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
4275  *	@ap: the target ata_port
4276  *	@qc: qc on going
4277  *
4278  *	RETURNS:
4279  *	1 if ok in workqueue, 0 otherwise.
4280  */
4281 
4282 static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
4283 {
4284 	if (qc->tf.flags & ATA_TFLAG_POLLING)
4285 		return 1;
4286 
4287 	if (ap->hsm_task_state == HSM_ST_FIRST) {
4288 		if (qc->tf.protocol == ATA_PROT_PIO &&
4289 		    (qc->tf.flags & ATA_TFLAG_WRITE))
4290 		    return 1;
4291 
4292 		if (is_atapi_taskfile(&qc->tf) &&
4293 		    !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
4294 			return 1;
4295 	}
4296 
4297 	return 0;
4298 }
4299 
4300 /**
4301  *	ata_hsm_qc_complete - finish a qc running on standard HSM
4302  *	@qc: Command to complete
4303  *	@in_wq: 1 if called from workqueue, 0 otherwise
4304  *
4305  *	Finish @qc which is running on standard HSM.
4306  *
4307  *	LOCKING:
4308  *	If @in_wq is zero, spin_lock_irqsave(host lock).
4309  *	Otherwise, none on entry and grabs host lock.
4310  */
4311 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
4312 {
4313 	struct ata_port *ap = qc->ap;
4314 	unsigned long flags;
4315 
4316 	if (ap->ops->error_handler) {
4317 		if (in_wq) {
4318 			spin_lock_irqsave(ap->lock, flags);
4319 
4320 			/* EH might have kicked in while host lock is
4321 			 * released.
4322 			 */
4323 			qc = ata_qc_from_tag(ap, qc->tag);
4324 			if (qc) {
4325 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
4326 					ata_irq_on(ap);
4327 					ata_qc_complete(qc);
4328 				} else
4329 					ata_port_freeze(ap);
4330 			}
4331 
4332 			spin_unlock_irqrestore(ap->lock, flags);
4333 		} else {
4334 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
4335 				ata_qc_complete(qc);
4336 			else
4337 				ata_port_freeze(ap);
4338 		}
4339 	} else {
4340 		if (in_wq) {
4341 			spin_lock_irqsave(ap->lock, flags);
4342 			ata_irq_on(ap);
4343 			ata_qc_complete(qc);
4344 			spin_unlock_irqrestore(ap->lock, flags);
4345 		} else
4346 			ata_qc_complete(qc);
4347 	}
4348 
4349 	ata_altstatus(ap); /* flush */
4350 }
4351 
4352 /**
4353  *	ata_hsm_move - move the HSM to the next state.
4354  *	@ap: the target ata_port
4355  *	@qc: qc on going
4356  *	@status: current device status
4357  *	@in_wq: 1 if called from workqueue, 0 otherwise
4358  *
4359  *	RETURNS:
4360  *	1 when poll next status needed, 0 otherwise.
4361  */
4362 int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
4363 		 u8 status, int in_wq)
4364 {
4365 	unsigned long flags = 0;
4366 	int poll_next;
4367 
4368 	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
4369 
4370 	/* Make sure ata_qc_issue_prot() does not throw things
4371 	 * like DMA polling into the workqueue. Notice that
4372 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
4373 	 */
4374 	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
4375 
4376 fsm_start:
4377 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
4378 		ap->id, qc->tf.protocol, ap->hsm_task_state, status);
4379 
4380 	switch (ap->hsm_task_state) {
4381 	case HSM_ST_FIRST:
4382 		/* Send first data block or PACKET CDB */
4383 
4384 		/* If polling, we will stay in the work queue after
4385 		 * sending the data. Otherwise, interrupt handler
4386 		 * takes over after sending the data.
4387 		 */
4388 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
4389 
4390 		/* check device status */
4391 		if (unlikely((status & ATA_DRQ) == 0)) {
4392 			/* handle BSY=0, DRQ=0 as error */
4393 			if (likely(status & (ATA_ERR | ATA_DF)))
4394 				/* device stops HSM for abort/error */
4395 				qc->err_mask |= AC_ERR_DEV;
4396 			else
4397 				/* HSM violation. Let EH handle this */
4398 				qc->err_mask |= AC_ERR_HSM;
4399 
4400 			ap->hsm_task_state = HSM_ST_ERR;
4401 			goto fsm_start;
4402 		}
4403 
4404 		/* Device should not ask for data transfer (DRQ=1)
4405 		 * when it finds something wrong.
4406 		 * We ignore DRQ here and stop the HSM by
4407 		 * changing hsm_task_state to HSM_ST_ERR and
4408 		 * let the EH abort the command or reset the device.
4409 		 */
4410 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
4411 			printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
4412 			       ap->id, status);
4413 			qc->err_mask |= AC_ERR_HSM;
4414 			ap->hsm_task_state = HSM_ST_ERR;
4415 			goto fsm_start;
4416 		}
4417 
4418 		/* Send the CDB (atapi) or the first data block (ata pio out).
4419 		 * During the state transition, interrupt handler shouldn't
4420 		 * be invoked before the data transfer is complete and
4421 		 * hsm_task_state is changed. Hence, the following locking.
4422 		 */
4423 		if (in_wq)
4424 			spin_lock_irqsave(ap->lock, flags);
4425 
4426 		if (qc->tf.protocol == ATA_PROT_PIO) {
4427 			/* PIO data out protocol.
4428 			 * send first data block.
4429 			 */
4430 
4431 			/* ata_pio_sectors() might change the state
4432 			 * to HSM_ST_LAST. so, the state is changed here
4433 			 * before ata_pio_sectors().
4434 			 */
4435 			ap->hsm_task_state = HSM_ST;
4436 			ata_pio_sectors(qc);
4437 			ata_altstatus(ap); /* flush */
4438 		} else
4439 			/* send CDB */
4440 			atapi_send_cdb(ap, qc);
4441 
4442 		if (in_wq)
4443 			spin_unlock_irqrestore(ap->lock, flags);
4444 
4445 		/* if polling, ata_pio_task() handles the rest.
4446 		 * otherwise, interrupt handler takes over from here.
4447 		 */
4448 		break;
4449 
4450 	case HSM_ST:
4451 		/* complete command or read/write the data register */
4452 		if (qc->tf.protocol == ATA_PROT_ATAPI) {
4453 			/* ATAPI PIO protocol */
4454 			if ((status & ATA_DRQ) == 0) {
4455 				/* No more data to transfer or device error.
4456 				 * Device error will be tagged in HSM_ST_LAST.
4457 				 */
4458 				ap->hsm_task_state = HSM_ST_LAST;
4459 				goto fsm_start;
4460 			}
4461 
4462 			/* Device should not ask for data transfer (DRQ=1)
4463 			 * when it finds something wrong.
4464 			 * We ignore DRQ here and stop the HSM by
4465 			 * changing hsm_task_state to HSM_ST_ERR and
4466 			 * let the EH abort the command or reset the device.
4467 			 */
4468 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
4469 				printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
4470 				       ap->id, status);
4471 				qc->err_mask |= AC_ERR_HSM;
4472 				ap->hsm_task_state = HSM_ST_ERR;
4473 				goto fsm_start;
4474 			}
4475 
4476 			atapi_pio_bytes(qc);
4477 
4478 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
4479 				/* bad ireason reported by device */
4480 				goto fsm_start;
4481 
4482 		} else {
4483 			/* ATA PIO protocol */
4484 			if (unlikely((status & ATA_DRQ) == 0)) {
4485 				/* handle BSY=0, DRQ=0 as error */
4486 				if (likely(status & (ATA_ERR | ATA_DF)))
4487 					/* device stops HSM for abort/error */
4488 					qc->err_mask |= AC_ERR_DEV;
4489 				else
4490 					/* HSM violation. Let EH handle this.
4491 					 * Phantom devices also trigger this
4492 					 * condition.  Mark hint.
4493 					 */
4494 					qc->err_mask |= AC_ERR_HSM |
4495 							AC_ERR_NODEV_HINT;
4496 
4497 				ap->hsm_task_state = HSM_ST_ERR;
4498 				goto fsm_start;
4499 			}
4500 
4501 			/* For PIO reads, some devices may ask for
4502 			 * data transfer (DRQ=1) alone with ERR=1.
4503 			 * We respect DRQ here and transfer one
4504 			 * block of junk data before changing the
4505 			 * hsm_task_state to HSM_ST_ERR.
4506 			 *
4507 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
4508 			 * sense since the data block has been
4509 			 * transferred to the device.
4510 			 */
4511 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
4512 				/* data might be corrputed */
4513 				qc->err_mask |= AC_ERR_DEV;
4514 
4515 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
4516 					ata_pio_sectors(qc);
4517 					ata_altstatus(ap);
4518 					status = ata_wait_idle(ap);
4519 				}
4520 
4521 				if (status & (ATA_BUSY | ATA_DRQ))
4522 					qc->err_mask |= AC_ERR_HSM;
4523 
4524 				/* ata_pio_sectors() might change the
4525 				 * state to HSM_ST_LAST. so, the state
4526 				 * is changed after ata_pio_sectors().
4527 				 */
4528 				ap->hsm_task_state = HSM_ST_ERR;
4529 				goto fsm_start;
4530 			}
4531 
4532 			ata_pio_sectors(qc);
4533 
4534 			if (ap->hsm_task_state == HSM_ST_LAST &&
4535 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
4536 				/* all data read */
4537 				ata_altstatus(ap);
4538 				status = ata_wait_idle(ap);
4539 				goto fsm_start;
4540 			}
4541 		}
4542 
4543 		ata_altstatus(ap); /* flush */
4544 		poll_next = 1;
4545 		break;
4546 
4547 	case HSM_ST_LAST:
4548 		if (unlikely(!ata_ok(status))) {
4549 			qc->err_mask |= __ac_err_mask(status);
4550 			ap->hsm_task_state = HSM_ST_ERR;
4551 			goto fsm_start;
4552 		}
4553 
4554 		/* no more data to transfer */
4555 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
4556 			ap->id, qc->dev->devno, status);
4557 
4558 		WARN_ON(qc->err_mask);
4559 
4560 		ap->hsm_task_state = HSM_ST_IDLE;
4561 
4562 		/* complete taskfile transaction */
4563 		ata_hsm_qc_complete(qc, in_wq);
4564 
4565 		poll_next = 0;
4566 		break;
4567 
4568 	case HSM_ST_ERR:
4569 		/* make sure qc->err_mask is available to
4570 		 * know what's wrong and recover
4571 		 */
4572 		WARN_ON(qc->err_mask == 0);
4573 
4574 		ap->hsm_task_state = HSM_ST_IDLE;
4575 
4576 		/* complete taskfile transaction */
4577 		ata_hsm_qc_complete(qc, in_wq);
4578 
4579 		poll_next = 0;
4580 		break;
4581 	default:
4582 		poll_next = 0;
4583 		BUG();
4584 	}
4585 
4586 	return poll_next;
4587 }
4588 
4589 static void ata_pio_task(struct work_struct *work)
4590 {
4591 	struct ata_port *ap =
4592 		container_of(work, struct ata_port, port_task.work);
4593 	struct ata_queued_cmd *qc = ap->port_task_data;
4594 	u8 status;
4595 	int poll_next;
4596 
4597 fsm_start:
4598 	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
4599 
4600 	/*
4601 	 * This is purely heuristic.  This is a fast path.
4602 	 * Sometimes when we enter, BSY will be cleared in
4603 	 * a chk-status or two.  If not, the drive is probably seeking
4604 	 * or something.  Snooze for a couple msecs, then
4605 	 * chk-status again.  If still busy, queue delayed work.
4606 	 */
4607 	status = ata_busy_wait(ap, ATA_BUSY, 5);
4608 	if (status & ATA_BUSY) {
4609 		msleep(2);
4610 		status = ata_busy_wait(ap, ATA_BUSY, 10);
4611 		if (status & ATA_BUSY) {
4612 			ata_port_queue_task(ap, ata_pio_task, qc, ATA_SHORT_PAUSE);
4613 			return;
4614 		}
4615 	}
4616 
4617 	/* move the HSM */
4618 	poll_next = ata_hsm_move(ap, qc, status, 1);
4619 
4620 	/* another command or interrupt handler
4621 	 * may be running at this point.
4622 	 */
4623 	if (poll_next)
4624 		goto fsm_start;
4625 }
4626 
4627 /**
4628  *	ata_qc_new - Request an available ATA command, for queueing
4629  *	@ap: Port associated with device @dev
4630  *	@dev: Device from whom we request an available command structure
4631  *
4632  *	LOCKING:
4633  *	None.
4634  */
4635 
4636 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
4637 {
4638 	struct ata_queued_cmd *qc = NULL;
4639 	unsigned int i;
4640 
4641 	/* no command while frozen */
4642 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
4643 		return NULL;
4644 
4645 	/* the last tag is reserved for internal command. */
4646 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
4647 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
4648 			qc = __ata_qc_from_tag(ap, i);
4649 			break;
4650 		}
4651 
4652 	if (qc)
4653 		qc->tag = i;
4654 
4655 	return qc;
4656 }
4657 
4658 /**
4659  *	ata_qc_new_init - Request an available ATA command, and initialize it
4660  *	@dev: Device from whom we request an available command structure
4661  *
4662  *	LOCKING:
4663  *	None.
4664  */
4665 
4666 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
4667 {
4668 	struct ata_port *ap = dev->ap;
4669 	struct ata_queued_cmd *qc;
4670 
4671 	qc = ata_qc_new(ap);
4672 	if (qc) {
4673 		qc->scsicmd = NULL;
4674 		qc->ap = ap;
4675 		qc->dev = dev;
4676 
4677 		ata_qc_reinit(qc);
4678 	}
4679 
4680 	return qc;
4681 }
4682 
4683 /**
4684  *	ata_qc_free - free unused ata_queued_cmd
4685  *	@qc: Command to complete
4686  *
4687  *	Designed to free unused ata_queued_cmd object
4688  *	in case something prevents using it.
4689  *
4690  *	LOCKING:
4691  *	spin_lock_irqsave(host lock)
4692  */
4693 void ata_qc_free(struct ata_queued_cmd *qc)
4694 {
4695 	struct ata_port *ap = qc->ap;
4696 	unsigned int tag;
4697 
4698 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4699 
4700 	qc->flags = 0;
4701 	tag = qc->tag;
4702 	if (likely(ata_tag_valid(tag))) {
4703 		qc->tag = ATA_TAG_POISON;
4704 		clear_bit(tag, &ap->qc_allocated);
4705 	}
4706 }
4707 
4708 void __ata_qc_complete(struct ata_queued_cmd *qc)
4709 {
4710 	struct ata_port *ap = qc->ap;
4711 
4712 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4713 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
4714 
4715 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
4716 		ata_sg_clean(qc);
4717 
4718 	/* command should be marked inactive atomically with qc completion */
4719 	if (qc->tf.protocol == ATA_PROT_NCQ)
4720 		ap->sactive &= ~(1 << qc->tag);
4721 	else
4722 		ap->active_tag = ATA_TAG_POISON;
4723 
4724 	/* atapi: mark qc as inactive to prevent the interrupt handler
4725 	 * from completing the command twice later, before the error handler
4726 	 * is called. (when rc != 0 and atapi request sense is needed)
4727 	 */
4728 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
4729 	ap->qc_active &= ~(1 << qc->tag);
4730 
4731 	/* call completion callback */
4732 	qc->complete_fn(qc);
4733 }
4734 
4735 static void fill_result_tf(struct ata_queued_cmd *qc)
4736 {
4737 	struct ata_port *ap = qc->ap;
4738 
4739 	ap->ops->tf_read(ap, &qc->result_tf);
4740 	qc->result_tf.flags = qc->tf.flags;
4741 }
4742 
4743 /**
4744  *	ata_qc_complete - Complete an active ATA command
4745  *	@qc: Command to complete
4746  *	@err_mask: ATA Status register contents
4747  *
4748  *	Indicate to the mid and upper layers that an ATA
4749  *	command has completed, with either an ok or not-ok status.
4750  *
4751  *	LOCKING:
4752  *	spin_lock_irqsave(host lock)
4753  */
4754 void ata_qc_complete(struct ata_queued_cmd *qc)
4755 {
4756 	struct ata_port *ap = qc->ap;
4757 
4758 	/* XXX: New EH and old EH use different mechanisms to
4759 	 * synchronize EH with regular execution path.
4760 	 *
4761 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
4762 	 * Normal execution path is responsible for not accessing a
4763 	 * failed qc.  libata core enforces the rule by returning NULL
4764 	 * from ata_qc_from_tag() for failed qcs.
4765 	 *
4766 	 * Old EH depends on ata_qc_complete() nullifying completion
4767 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
4768 	 * not synchronize with interrupt handler.  Only PIO task is
4769 	 * taken care of.
4770 	 */
4771 	if (ap->ops->error_handler) {
4772 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
4773 
4774 		if (unlikely(qc->err_mask))
4775 			qc->flags |= ATA_QCFLAG_FAILED;
4776 
4777 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
4778 			if (!ata_tag_internal(qc->tag)) {
4779 				/* always fill result TF for failed qc */
4780 				fill_result_tf(qc);
4781 				ata_qc_schedule_eh(qc);
4782 				return;
4783 			}
4784 		}
4785 
4786 		/* read result TF if requested */
4787 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
4788 			fill_result_tf(qc);
4789 
4790 		__ata_qc_complete(qc);
4791 	} else {
4792 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
4793 			return;
4794 
4795 		/* read result TF if failed or requested */
4796 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
4797 			fill_result_tf(qc);
4798 
4799 		__ata_qc_complete(qc);
4800 	}
4801 }
4802 
4803 /**
4804  *	ata_qc_complete_multiple - Complete multiple qcs successfully
4805  *	@ap: port in question
4806  *	@qc_active: new qc_active mask
4807  *	@finish_qc: LLDD callback invoked before completing a qc
4808  *
4809  *	Complete in-flight commands.  This functions is meant to be
4810  *	called from low-level driver's interrupt routine to complete
4811  *	requests normally.  ap->qc_active and @qc_active is compared
4812  *	and commands are completed accordingly.
4813  *
4814  *	LOCKING:
4815  *	spin_lock_irqsave(host lock)
4816  *
4817  *	RETURNS:
4818  *	Number of completed commands on success, -errno otherwise.
4819  */
4820 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
4821 			     void (*finish_qc)(struct ata_queued_cmd *))
4822 {
4823 	int nr_done = 0;
4824 	u32 done_mask;
4825 	int i;
4826 
4827 	done_mask = ap->qc_active ^ qc_active;
4828 
4829 	if (unlikely(done_mask & qc_active)) {
4830 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
4831 				"(%08x->%08x)\n", ap->qc_active, qc_active);
4832 		return -EINVAL;
4833 	}
4834 
4835 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
4836 		struct ata_queued_cmd *qc;
4837 
4838 		if (!(done_mask & (1 << i)))
4839 			continue;
4840 
4841 		if ((qc = ata_qc_from_tag(ap, i))) {
4842 			if (finish_qc)
4843 				finish_qc(qc);
4844 			ata_qc_complete(qc);
4845 			nr_done++;
4846 		}
4847 	}
4848 
4849 	return nr_done;
4850 }
4851 
4852 static inline int ata_should_dma_map(struct ata_queued_cmd *qc)
4853 {
4854 	struct ata_port *ap = qc->ap;
4855 
4856 	switch (qc->tf.protocol) {
4857 	case ATA_PROT_NCQ:
4858 	case ATA_PROT_DMA:
4859 	case ATA_PROT_ATAPI_DMA:
4860 		return 1;
4861 
4862 	case ATA_PROT_ATAPI:
4863 	case ATA_PROT_PIO:
4864 		if (ap->flags & ATA_FLAG_PIO_DMA)
4865 			return 1;
4866 
4867 		/* fall through */
4868 
4869 	default:
4870 		return 0;
4871 	}
4872 
4873 	/* never reached */
4874 }
4875 
4876 /**
4877  *	ata_qc_issue - issue taskfile to device
4878  *	@qc: command to issue to device
4879  *
4880  *	Prepare an ATA command to submission to device.
4881  *	This includes mapping the data into a DMA-able
4882  *	area, filling in the S/G table, and finally
4883  *	writing the taskfile to hardware, starting the command.
4884  *
4885  *	LOCKING:
4886  *	spin_lock_irqsave(host lock)
4887  */
4888 void ata_qc_issue(struct ata_queued_cmd *qc)
4889 {
4890 	struct ata_port *ap = qc->ap;
4891 
4892 	/* Make sure only one non-NCQ command is outstanding.  The
4893 	 * check is skipped for old EH because it reuses active qc to
4894 	 * request ATAPI sense.
4895 	 */
4896 	WARN_ON(ap->ops->error_handler && ata_tag_valid(ap->active_tag));
4897 
4898 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4899 		WARN_ON(ap->sactive & (1 << qc->tag));
4900 		ap->sactive |= 1 << qc->tag;
4901 	} else {
4902 		WARN_ON(ap->sactive);
4903 		ap->active_tag = qc->tag;
4904 	}
4905 
4906 	qc->flags |= ATA_QCFLAG_ACTIVE;
4907 	ap->qc_active |= 1 << qc->tag;
4908 
4909 	if (ata_should_dma_map(qc)) {
4910 		if (qc->flags & ATA_QCFLAG_SG) {
4911 			if (ata_sg_setup(qc))
4912 				goto sg_err;
4913 		} else if (qc->flags & ATA_QCFLAG_SINGLE) {
4914 			if (ata_sg_setup_one(qc))
4915 				goto sg_err;
4916 		}
4917 	} else {
4918 		qc->flags &= ~ATA_QCFLAG_DMAMAP;
4919 	}
4920 
4921 	ap->ops->qc_prep(qc);
4922 
4923 	qc->err_mask |= ap->ops->qc_issue(qc);
4924 	if (unlikely(qc->err_mask))
4925 		goto err;
4926 	return;
4927 
4928 sg_err:
4929 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4930 	qc->err_mask |= AC_ERR_SYSTEM;
4931 err:
4932 	ata_qc_complete(qc);
4933 }
4934 
4935 /**
4936  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
4937  *	@qc: command to issue to device
4938  *
4939  *	Using various libata functions and hooks, this function
4940  *	starts an ATA command.  ATA commands are grouped into
4941  *	classes called "protocols", and issuing each type of protocol
4942  *	is slightly different.
4943  *
4944  *	May be used as the qc_issue() entry in ata_port_operations.
4945  *
4946  *	LOCKING:
4947  *	spin_lock_irqsave(host lock)
4948  *
4949  *	RETURNS:
4950  *	Zero on success, AC_ERR_* mask on failure
4951  */
4952 
4953 unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
4954 {
4955 	struct ata_port *ap = qc->ap;
4956 
4957 	/* Use polling pio if the LLD doesn't handle
4958 	 * interrupt driven pio and atapi CDB interrupt.
4959 	 */
4960 	if (ap->flags & ATA_FLAG_PIO_POLLING) {
4961 		switch (qc->tf.protocol) {
4962 		case ATA_PROT_PIO:
4963 		case ATA_PROT_NODATA:
4964 		case ATA_PROT_ATAPI:
4965 		case ATA_PROT_ATAPI_NODATA:
4966 			qc->tf.flags |= ATA_TFLAG_POLLING;
4967 			break;
4968 		case ATA_PROT_ATAPI_DMA:
4969 			if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
4970 				/* see ata_dma_blacklisted() */
4971 				BUG();
4972 			break;
4973 		default:
4974 			break;
4975 		}
4976 	}
4977 
4978 	/* Some controllers show flaky interrupt behavior after
4979 	 * setting xfer mode.  Use polling instead.
4980 	 */
4981 	if (unlikely(qc->tf.command == ATA_CMD_SET_FEATURES &&
4982 		     qc->tf.feature == SETFEATURES_XFER) &&
4983 	    (ap->flags & ATA_FLAG_SETXFER_POLLING))
4984 		qc->tf.flags |= ATA_TFLAG_POLLING;
4985 
4986 	/* select the device */
4987 	ata_dev_select(ap, qc->dev->devno, 1, 0);
4988 
4989 	/* start the command */
4990 	switch (qc->tf.protocol) {
4991 	case ATA_PROT_NODATA:
4992 		if (qc->tf.flags & ATA_TFLAG_POLLING)
4993 			ata_qc_set_polling(qc);
4994 
4995 		ata_tf_to_host(ap, &qc->tf);
4996 		ap->hsm_task_state = HSM_ST_LAST;
4997 
4998 		if (qc->tf.flags & ATA_TFLAG_POLLING)
4999 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5000 
5001 		break;
5002 
5003 	case ATA_PROT_DMA:
5004 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5005 
5006 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5007 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5008 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
5009 		ap->hsm_task_state = HSM_ST_LAST;
5010 		break;
5011 
5012 	case ATA_PROT_PIO:
5013 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5014 			ata_qc_set_polling(qc);
5015 
5016 		ata_tf_to_host(ap, &qc->tf);
5017 
5018 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
5019 			/* PIO data out protocol */
5020 			ap->hsm_task_state = HSM_ST_FIRST;
5021 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5022 
5023 			/* always send first data block using
5024 			 * the ata_pio_task() codepath.
5025 			 */
5026 		} else {
5027 			/* PIO data in protocol */
5028 			ap->hsm_task_state = HSM_ST;
5029 
5030 			if (qc->tf.flags & ATA_TFLAG_POLLING)
5031 				ata_port_queue_task(ap, ata_pio_task, qc, 0);
5032 
5033 			/* if polling, ata_pio_task() handles the rest.
5034 			 * otherwise, interrupt handler takes over from here.
5035 			 */
5036 		}
5037 
5038 		break;
5039 
5040 	case ATA_PROT_ATAPI:
5041 	case ATA_PROT_ATAPI_NODATA:
5042 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5043 			ata_qc_set_polling(qc);
5044 
5045 		ata_tf_to_host(ap, &qc->tf);
5046 
5047 		ap->hsm_task_state = HSM_ST_FIRST;
5048 
5049 		/* send cdb by polling if no cdb interrupt */
5050 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
5051 		    (qc->tf.flags & ATA_TFLAG_POLLING))
5052 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5053 		break;
5054 
5055 	case ATA_PROT_ATAPI_DMA:
5056 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5057 
5058 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5059 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5060 		ap->hsm_task_state = HSM_ST_FIRST;
5061 
5062 		/* send cdb by polling if no cdb interrupt */
5063 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5064 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5065 		break;
5066 
5067 	default:
5068 		WARN_ON(1);
5069 		return AC_ERR_SYSTEM;
5070 	}
5071 
5072 	return 0;
5073 }
5074 
5075 /**
5076  *	ata_host_intr - Handle host interrupt for given (port, task)
5077  *	@ap: Port on which interrupt arrived (possibly...)
5078  *	@qc: Taskfile currently active in engine
5079  *
5080  *	Handle host interrupt for given queued command.  Currently,
5081  *	only DMA interrupts are handled.  All other commands are
5082  *	handled via polling with interrupts disabled (nIEN bit).
5083  *
5084  *	LOCKING:
5085  *	spin_lock_irqsave(host lock)
5086  *
5087  *	RETURNS:
5088  *	One if interrupt was handled, zero if not (shared irq).
5089  */
5090 
5091 inline unsigned int ata_host_intr (struct ata_port *ap,
5092 				   struct ata_queued_cmd *qc)
5093 {
5094 	struct ata_eh_info *ehi = &ap->eh_info;
5095 	u8 status, host_stat = 0;
5096 
5097 	VPRINTK("ata%u: protocol %d task_state %d\n",
5098 		ap->id, qc->tf.protocol, ap->hsm_task_state);
5099 
5100 	/* Check whether we are expecting interrupt in this state */
5101 	switch (ap->hsm_task_state) {
5102 	case HSM_ST_FIRST:
5103 		/* Some pre-ATAPI-4 devices assert INTRQ
5104 		 * at this state when ready to receive CDB.
5105 		 */
5106 
5107 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
5108 		 * The flag was turned on only for atapi devices.
5109 		 * No need to check is_atapi_taskfile(&qc->tf) again.
5110 		 */
5111 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5112 			goto idle_irq;
5113 		break;
5114 	case HSM_ST_LAST:
5115 		if (qc->tf.protocol == ATA_PROT_DMA ||
5116 		    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
5117 			/* check status of DMA engine */
5118 			host_stat = ap->ops->bmdma_status(ap);
5119 			VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
5120 
5121 			/* if it's not our irq... */
5122 			if (!(host_stat & ATA_DMA_INTR))
5123 				goto idle_irq;
5124 
5125 			/* before we do anything else, clear DMA-Start bit */
5126 			ap->ops->bmdma_stop(qc);
5127 
5128 			if (unlikely(host_stat & ATA_DMA_ERR)) {
5129 				/* error when transfering data to/from memory */
5130 				qc->err_mask |= AC_ERR_HOST_BUS;
5131 				ap->hsm_task_state = HSM_ST_ERR;
5132 			}
5133 		}
5134 		break;
5135 	case HSM_ST:
5136 		break;
5137 	default:
5138 		goto idle_irq;
5139 	}
5140 
5141 	/* check altstatus */
5142 	status = ata_altstatus(ap);
5143 	if (status & ATA_BUSY)
5144 		goto idle_irq;
5145 
5146 	/* check main status, clearing INTRQ */
5147 	status = ata_chk_status(ap);
5148 	if (unlikely(status & ATA_BUSY))
5149 		goto idle_irq;
5150 
5151 	/* ack bmdma irq events */
5152 	ap->ops->irq_clear(ap);
5153 
5154 	ata_hsm_move(ap, qc, status, 0);
5155 
5156 	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
5157 				       qc->tf.protocol == ATA_PROT_ATAPI_DMA))
5158 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
5159 
5160 	return 1;	/* irq handled */
5161 
5162 idle_irq:
5163 	ap->stats.idle_irq++;
5164 
5165 #ifdef ATA_IRQ_TRAP
5166 	if ((ap->stats.idle_irq % 1000) == 0) {
5167 		ata_irq_ack(ap, 0); /* debug trap */
5168 		ata_port_printk(ap, KERN_WARNING, "irq trap\n");
5169 		return 1;
5170 	}
5171 #endif
5172 	return 0;	/* irq not handled */
5173 }
5174 
5175 /**
5176  *	ata_interrupt - Default ATA host interrupt handler
5177  *	@irq: irq line (unused)
5178  *	@dev_instance: pointer to our ata_host information structure
5179  *
5180  *	Default interrupt handler for PCI IDE devices.  Calls
5181  *	ata_host_intr() for each port that is not disabled.
5182  *
5183  *	LOCKING:
5184  *	Obtains host lock during operation.
5185  *
5186  *	RETURNS:
5187  *	IRQ_NONE or IRQ_HANDLED.
5188  */
5189 
5190 irqreturn_t ata_interrupt (int irq, void *dev_instance)
5191 {
5192 	struct ata_host *host = dev_instance;
5193 	unsigned int i;
5194 	unsigned int handled = 0;
5195 	unsigned long flags;
5196 
5197 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
5198 	spin_lock_irqsave(&host->lock, flags);
5199 
5200 	for (i = 0; i < host->n_ports; i++) {
5201 		struct ata_port *ap;
5202 
5203 		ap = host->ports[i];
5204 		if (ap &&
5205 		    !(ap->flags & ATA_FLAG_DISABLED)) {
5206 			struct ata_queued_cmd *qc;
5207 
5208 			qc = ata_qc_from_tag(ap, ap->active_tag);
5209 			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
5210 			    (qc->flags & ATA_QCFLAG_ACTIVE))
5211 				handled |= ata_host_intr(ap, qc);
5212 		}
5213 	}
5214 
5215 	spin_unlock_irqrestore(&host->lock, flags);
5216 
5217 	return IRQ_RETVAL(handled);
5218 }
5219 
5220 /**
5221  *	sata_scr_valid - test whether SCRs are accessible
5222  *	@ap: ATA port to test SCR accessibility for
5223  *
5224  *	Test whether SCRs are accessible for @ap.
5225  *
5226  *	LOCKING:
5227  *	None.
5228  *
5229  *	RETURNS:
5230  *	1 if SCRs are accessible, 0 otherwise.
5231  */
5232 int sata_scr_valid(struct ata_port *ap)
5233 {
5234 	return ap->cbl == ATA_CBL_SATA && ap->ops->scr_read;
5235 }
5236 
5237 /**
5238  *	sata_scr_read - read SCR register of the specified port
5239  *	@ap: ATA port to read SCR for
5240  *	@reg: SCR to read
5241  *	@val: Place to store read value
5242  *
5243  *	Read SCR register @reg of @ap into *@val.  This function is
5244  *	guaranteed to succeed if the cable type of the port is SATA
5245  *	and the port implements ->scr_read.
5246  *
5247  *	LOCKING:
5248  *	None.
5249  *
5250  *	RETURNS:
5251  *	0 on success, negative errno on failure.
5252  */
5253 int sata_scr_read(struct ata_port *ap, int reg, u32 *val)
5254 {
5255 	if (sata_scr_valid(ap)) {
5256 		*val = ap->ops->scr_read(ap, reg);
5257 		return 0;
5258 	}
5259 	return -EOPNOTSUPP;
5260 }
5261 
5262 /**
5263  *	sata_scr_write - write SCR register of the specified port
5264  *	@ap: ATA port to write SCR for
5265  *	@reg: SCR to write
5266  *	@val: value to write
5267  *
5268  *	Write @val to SCR register @reg of @ap.  This function is
5269  *	guaranteed to succeed if the cable type of the port is SATA
5270  *	and the port implements ->scr_read.
5271  *
5272  *	LOCKING:
5273  *	None.
5274  *
5275  *	RETURNS:
5276  *	0 on success, negative errno on failure.
5277  */
5278 int sata_scr_write(struct ata_port *ap, int reg, u32 val)
5279 {
5280 	if (sata_scr_valid(ap)) {
5281 		ap->ops->scr_write(ap, reg, val);
5282 		return 0;
5283 	}
5284 	return -EOPNOTSUPP;
5285 }
5286 
5287 /**
5288  *	sata_scr_write_flush - write SCR register of the specified port and flush
5289  *	@ap: ATA port to write SCR for
5290  *	@reg: SCR to write
5291  *	@val: value to write
5292  *
5293  *	This function is identical to sata_scr_write() except that this
5294  *	function performs flush after writing to the register.
5295  *
5296  *	LOCKING:
5297  *	None.
5298  *
5299  *	RETURNS:
5300  *	0 on success, negative errno on failure.
5301  */
5302 int sata_scr_write_flush(struct ata_port *ap, int reg, u32 val)
5303 {
5304 	if (sata_scr_valid(ap)) {
5305 		ap->ops->scr_write(ap, reg, val);
5306 		ap->ops->scr_read(ap, reg);
5307 		return 0;
5308 	}
5309 	return -EOPNOTSUPP;
5310 }
5311 
5312 /**
5313  *	ata_port_online - test whether the given port is online
5314  *	@ap: ATA port to test
5315  *
5316  *	Test whether @ap is online.  Note that this function returns 0
5317  *	if online status of @ap cannot be obtained, so
5318  *	ata_port_online(ap) != !ata_port_offline(ap).
5319  *
5320  *	LOCKING:
5321  *	None.
5322  *
5323  *	RETURNS:
5324  *	1 if the port online status is available and online.
5325  */
5326 int ata_port_online(struct ata_port *ap)
5327 {
5328 	u32 sstatus;
5329 
5330 	if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) == 0x3)
5331 		return 1;
5332 	return 0;
5333 }
5334 
5335 /**
5336  *	ata_port_offline - test whether the given port is offline
5337  *	@ap: ATA port to test
5338  *
5339  *	Test whether @ap is offline.  Note that this function returns
5340  *	0 if offline status of @ap cannot be obtained, so
5341  *	ata_port_online(ap) != !ata_port_offline(ap).
5342  *
5343  *	LOCKING:
5344  *	None.
5345  *
5346  *	RETURNS:
5347  *	1 if the port offline status is available and offline.
5348  */
5349 int ata_port_offline(struct ata_port *ap)
5350 {
5351 	u32 sstatus;
5352 
5353 	if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) != 0x3)
5354 		return 1;
5355 	return 0;
5356 }
5357 
5358 int ata_flush_cache(struct ata_device *dev)
5359 {
5360 	unsigned int err_mask;
5361 	u8 cmd;
5362 
5363 	if (!ata_try_flush_cache(dev))
5364 		return 0;
5365 
5366 	if (dev->flags & ATA_DFLAG_FLUSH_EXT)
5367 		cmd = ATA_CMD_FLUSH_EXT;
5368 	else
5369 		cmd = ATA_CMD_FLUSH;
5370 
5371 	err_mask = ata_do_simple_cmd(dev, cmd);
5372 	if (err_mask) {
5373 		ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
5374 		return -EIO;
5375 	}
5376 
5377 	return 0;
5378 }
5379 
5380 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
5381 			       unsigned int action, unsigned int ehi_flags,
5382 			       int wait)
5383 {
5384 	unsigned long flags;
5385 	int i, rc;
5386 
5387 	for (i = 0; i < host->n_ports; i++) {
5388 		struct ata_port *ap = host->ports[i];
5389 
5390 		/* Previous resume operation might still be in
5391 		 * progress.  Wait for PM_PENDING to clear.
5392 		 */
5393 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
5394 			ata_port_wait_eh(ap);
5395 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5396 		}
5397 
5398 		/* request PM ops to EH */
5399 		spin_lock_irqsave(ap->lock, flags);
5400 
5401 		ap->pm_mesg = mesg;
5402 		if (wait) {
5403 			rc = 0;
5404 			ap->pm_result = &rc;
5405 		}
5406 
5407 		ap->pflags |= ATA_PFLAG_PM_PENDING;
5408 		ap->eh_info.action |= action;
5409 		ap->eh_info.flags |= ehi_flags;
5410 
5411 		ata_port_schedule_eh(ap);
5412 
5413 		spin_unlock_irqrestore(ap->lock, flags);
5414 
5415 		/* wait and check result */
5416 		if (wait) {
5417 			ata_port_wait_eh(ap);
5418 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5419 			if (rc)
5420 				return rc;
5421 		}
5422 	}
5423 
5424 	return 0;
5425 }
5426 
5427 /**
5428  *	ata_host_suspend - suspend host
5429  *	@host: host to suspend
5430  *	@mesg: PM message
5431  *
5432  *	Suspend @host.  Actual operation is performed by EH.  This
5433  *	function requests EH to perform PM operations and waits for EH
5434  *	to finish.
5435  *
5436  *	LOCKING:
5437  *	Kernel thread context (may sleep).
5438  *
5439  *	RETURNS:
5440  *	0 on success, -errno on failure.
5441  */
5442 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
5443 {
5444 	int i, j, rc;
5445 
5446 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
5447 	if (rc)
5448 		goto fail;
5449 
5450 	/* EH is quiescent now.  Fail if we have any ready device.
5451 	 * This happens if hotplug occurs between completion of device
5452 	 * suspension and here.
5453 	 */
5454 	for (i = 0; i < host->n_ports; i++) {
5455 		struct ata_port *ap = host->ports[i];
5456 
5457 		for (j = 0; j < ATA_MAX_DEVICES; j++) {
5458 			struct ata_device *dev = &ap->device[j];
5459 
5460 			if (ata_dev_ready(dev)) {
5461 				ata_port_printk(ap, KERN_WARNING,
5462 						"suspend failed, device %d "
5463 						"still active\n", dev->devno);
5464 				rc = -EBUSY;
5465 				goto fail;
5466 			}
5467 		}
5468 	}
5469 
5470 	host->dev->power.power_state = mesg;
5471 	return 0;
5472 
5473  fail:
5474 	ata_host_resume(host);
5475 	return rc;
5476 }
5477 
5478 /**
5479  *	ata_host_resume - resume host
5480  *	@host: host to resume
5481  *
5482  *	Resume @host.  Actual operation is performed by EH.  This
5483  *	function requests EH to perform PM operations and returns.
5484  *	Note that all resume operations are performed parallely.
5485  *
5486  *	LOCKING:
5487  *	Kernel thread context (may sleep).
5488  */
5489 void ata_host_resume(struct ata_host *host)
5490 {
5491 	ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
5492 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
5493 	host->dev->power.power_state = PMSG_ON;
5494 }
5495 
5496 /**
5497  *	ata_port_start - Set port up for dma.
5498  *	@ap: Port to initialize
5499  *
5500  *	Called just after data structures for each port are
5501  *	initialized.  Allocates space for PRD table.
5502  *
5503  *	May be used as the port_start() entry in ata_port_operations.
5504  *
5505  *	LOCKING:
5506  *	Inherited from caller.
5507  */
5508 
5509 int ata_port_start (struct ata_port *ap)
5510 {
5511 	struct device *dev = ap->dev;
5512 	int rc;
5513 
5514 	ap->prd = dma_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma, GFP_KERNEL);
5515 	if (!ap->prd)
5516 		return -ENOMEM;
5517 
5518 	rc = ata_pad_alloc(ap, dev);
5519 	if (rc) {
5520 		dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
5521 		return rc;
5522 	}
5523 
5524 	DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd, (unsigned long long) ap->prd_dma);
5525 
5526 	return 0;
5527 }
5528 
5529 
5530 /**
5531  *	ata_port_stop - Undo ata_port_start()
5532  *	@ap: Port to shut down
5533  *
5534  *	Frees the PRD table.
5535  *
5536  *	May be used as the port_stop() entry in ata_port_operations.
5537  *
5538  *	LOCKING:
5539  *	Inherited from caller.
5540  */
5541 
5542 void ata_port_stop (struct ata_port *ap)
5543 {
5544 	struct device *dev = ap->dev;
5545 
5546 	dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
5547 	ata_pad_free(ap, dev);
5548 }
5549 
5550 void ata_host_stop (struct ata_host *host)
5551 {
5552 	if (host->mmio_base)
5553 		iounmap(host->mmio_base);
5554 }
5555 
5556 /**
5557  *	ata_dev_init - Initialize an ata_device structure
5558  *	@dev: Device structure to initialize
5559  *
5560  *	Initialize @dev in preparation for probing.
5561  *
5562  *	LOCKING:
5563  *	Inherited from caller.
5564  */
5565 void ata_dev_init(struct ata_device *dev)
5566 {
5567 	struct ata_port *ap = dev->ap;
5568 	unsigned long flags;
5569 
5570 	/* SATA spd limit is bound to the first device */
5571 	ap->sata_spd_limit = ap->hw_sata_spd_limit;
5572 
5573 	/* High bits of dev->flags are used to record warm plug
5574 	 * requests which occur asynchronously.  Synchronize using
5575 	 * host lock.
5576 	 */
5577 	spin_lock_irqsave(ap->lock, flags);
5578 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
5579 	spin_unlock_irqrestore(ap->lock, flags);
5580 
5581 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
5582 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
5583 	dev->pio_mask = UINT_MAX;
5584 	dev->mwdma_mask = UINT_MAX;
5585 	dev->udma_mask = UINT_MAX;
5586 }
5587 
5588 /**
5589  *	ata_port_init - Initialize an ata_port structure
5590  *	@ap: Structure to initialize
5591  *	@host: Collection of hosts to which @ap belongs
5592  *	@ent: Probe information provided by low-level driver
5593  *	@port_no: Port number associated with this ata_port
5594  *
5595  *	Initialize a new ata_port structure.
5596  *
5597  *	LOCKING:
5598  *	Inherited from caller.
5599  */
5600 void ata_port_init(struct ata_port *ap, struct ata_host *host,
5601 		   const struct ata_probe_ent *ent, unsigned int port_no)
5602 {
5603 	unsigned int i;
5604 
5605 	ap->lock = &host->lock;
5606 	ap->flags = ATA_FLAG_DISABLED;
5607 	ap->id = ata_unique_id++;
5608 	ap->ctl = ATA_DEVCTL_OBS;
5609 	ap->host = host;
5610 	ap->dev = ent->dev;
5611 	ap->port_no = port_no;
5612 	if (port_no == 1 && ent->pinfo2) {
5613 		ap->pio_mask = ent->pinfo2->pio_mask;
5614 		ap->mwdma_mask = ent->pinfo2->mwdma_mask;
5615 		ap->udma_mask = ent->pinfo2->udma_mask;
5616 		ap->flags |= ent->pinfo2->flags;
5617 		ap->ops = ent->pinfo2->port_ops;
5618 	} else {
5619 		ap->pio_mask = ent->pio_mask;
5620 		ap->mwdma_mask = ent->mwdma_mask;
5621 		ap->udma_mask = ent->udma_mask;
5622 		ap->flags |= ent->port_flags;
5623 		ap->ops = ent->port_ops;
5624 	}
5625 	ap->hw_sata_spd_limit = UINT_MAX;
5626 	ap->active_tag = ATA_TAG_POISON;
5627 	ap->last_ctl = 0xFF;
5628 
5629 #if defined(ATA_VERBOSE_DEBUG)
5630 	/* turn on all debugging levels */
5631 	ap->msg_enable = 0x00FF;
5632 #elif defined(ATA_DEBUG)
5633 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
5634 #else
5635 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
5636 #endif
5637 
5638 	INIT_DELAYED_WORK(&ap->port_task, NULL);
5639 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
5640 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
5641 	INIT_LIST_HEAD(&ap->eh_done_q);
5642 	init_waitqueue_head(&ap->eh_wait_q);
5643 
5644 	/* set cable type */
5645 	ap->cbl = ATA_CBL_NONE;
5646 	if (ap->flags & ATA_FLAG_SATA)
5647 		ap->cbl = ATA_CBL_SATA;
5648 
5649 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
5650 		struct ata_device *dev = &ap->device[i];
5651 		dev->ap = ap;
5652 		dev->devno = i;
5653 		ata_dev_init(dev);
5654 	}
5655 
5656 #ifdef ATA_IRQ_TRAP
5657 	ap->stats.unhandled_irq = 1;
5658 	ap->stats.idle_irq = 1;
5659 #endif
5660 
5661 	memcpy(&ap->ioaddr, &ent->port[port_no], sizeof(struct ata_ioports));
5662 }
5663 
5664 /**
5665  *	ata_port_init_shost - Initialize SCSI host associated with ATA port
5666  *	@ap: ATA port to initialize SCSI host for
5667  *	@shost: SCSI host associated with @ap
5668  *
5669  *	Initialize SCSI host @shost associated with ATA port @ap.
5670  *
5671  *	LOCKING:
5672  *	Inherited from caller.
5673  */
5674 static void ata_port_init_shost(struct ata_port *ap, struct Scsi_Host *shost)
5675 {
5676 	ap->scsi_host = shost;
5677 
5678 	shost->unique_id = ap->id;
5679 	shost->max_id = 16;
5680 	shost->max_lun = 1;
5681 	shost->max_channel = 1;
5682 	shost->max_cmd_len = 12;
5683 }
5684 
5685 /**
5686  *	ata_port_add - Attach low-level ATA driver to system
5687  *	@ent: Information provided by low-level driver
5688  *	@host: Collections of ports to which we add
5689  *	@port_no: Port number associated with this host
5690  *
5691  *	Attach low-level ATA driver to system.
5692  *
5693  *	LOCKING:
5694  *	PCI/etc. bus probe sem.
5695  *
5696  *	RETURNS:
5697  *	New ata_port on success, for NULL on error.
5698  */
5699 static struct ata_port * ata_port_add(const struct ata_probe_ent *ent,
5700 				      struct ata_host *host,
5701 				      unsigned int port_no)
5702 {
5703 	struct Scsi_Host *shost;
5704 	struct ata_port *ap;
5705 
5706 	DPRINTK("ENTER\n");
5707 
5708 	if (!ent->port_ops->error_handler &&
5709 	    !(ent->port_flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST))) {
5710 		printk(KERN_ERR "ata%u: no reset mechanism available\n",
5711 		       port_no);
5712 		return NULL;
5713 	}
5714 
5715 	shost = scsi_host_alloc(ent->sht, sizeof(struct ata_port));
5716 	if (!shost)
5717 		return NULL;
5718 
5719 	shost->transportt = &ata_scsi_transport_template;
5720 
5721 	ap = ata_shost_to_port(shost);
5722 
5723 	ata_port_init(ap, host, ent, port_no);
5724 	ata_port_init_shost(ap, shost);
5725 
5726 	return ap;
5727 }
5728 
5729 /**
5730  *	ata_sas_host_init - Initialize a host struct
5731  *	@host:	host to initialize
5732  *	@dev:	device host is attached to
5733  *	@flags:	host flags
5734  *	@ops:	port_ops
5735  *
5736  *	LOCKING:
5737  *	PCI/etc. bus probe sem.
5738  *
5739  */
5740 
5741 void ata_host_init(struct ata_host *host, struct device *dev,
5742 		   unsigned long flags, const struct ata_port_operations *ops)
5743 {
5744 	spin_lock_init(&host->lock);
5745 	host->dev = dev;
5746 	host->flags = flags;
5747 	host->ops = ops;
5748 }
5749 
5750 /**
5751  *	ata_device_add - Register hardware device with ATA and SCSI layers
5752  *	@ent: Probe information describing hardware device to be registered
5753  *
5754  *	This function processes the information provided in the probe
5755  *	information struct @ent, allocates the necessary ATA and SCSI
5756  *	host information structures, initializes them, and registers
5757  *	everything with requisite kernel subsystems.
5758  *
5759  *	This function requests irqs, probes the ATA bus, and probes
5760  *	the SCSI bus.
5761  *
5762  *	LOCKING:
5763  *	PCI/etc. bus probe sem.
5764  *
5765  *	RETURNS:
5766  *	Number of ports registered.  Zero on error (no ports registered).
5767  */
5768 int ata_device_add(const struct ata_probe_ent *ent)
5769 {
5770 	unsigned int i;
5771 	struct device *dev = ent->dev;
5772 	struct ata_host *host;
5773 	int rc;
5774 
5775 	DPRINTK("ENTER\n");
5776 
5777 	if (ent->irq == 0) {
5778 		dev_printk(KERN_ERR, dev, "is not available: No interrupt assigned.\n");
5779 		return 0;
5780 	}
5781 	/* alloc a container for our list of ATA ports (buses) */
5782 	host = kzalloc(sizeof(struct ata_host) +
5783 		       (ent->n_ports * sizeof(void *)), GFP_KERNEL);
5784 	if (!host)
5785 		return 0;
5786 
5787 	ata_host_init(host, dev, ent->_host_flags, ent->port_ops);
5788 	host->n_ports = ent->n_ports;
5789 	host->irq = ent->irq;
5790 	host->irq2 = ent->irq2;
5791 	host->mmio_base = ent->mmio_base;
5792 	host->private_data = ent->private_data;
5793 
5794 	/* register each port bound to this device */
5795 	for (i = 0; i < host->n_ports; i++) {
5796 		struct ata_port *ap;
5797 		unsigned long xfer_mode_mask;
5798 		int irq_line = ent->irq;
5799 
5800 		ap = ata_port_add(ent, host, i);
5801 		host->ports[i] = ap;
5802 		if (!ap)
5803 			goto err_out;
5804 
5805 		/* dummy? */
5806 		if (ent->dummy_port_mask & (1 << i)) {
5807 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
5808 			ap->ops = &ata_dummy_port_ops;
5809 			continue;
5810 		}
5811 
5812 		/* start port */
5813 		rc = ap->ops->port_start(ap);
5814 		if (rc) {
5815 			host->ports[i] = NULL;
5816 			scsi_host_put(ap->scsi_host);
5817 			goto err_out;
5818 		}
5819 
5820 		/* Report the secondary IRQ for second channel legacy */
5821 		if (i == 1 && ent->irq2)
5822 			irq_line = ent->irq2;
5823 
5824 		xfer_mode_mask =(ap->udma_mask << ATA_SHIFT_UDMA) |
5825 				(ap->mwdma_mask << ATA_SHIFT_MWDMA) |
5826 				(ap->pio_mask << ATA_SHIFT_PIO);
5827 
5828 		/* print per-port info to dmesg */
5829 		ata_port_printk(ap, KERN_INFO, "%cATA max %s cmd 0x%lX "
5830 				"ctl 0x%lX bmdma 0x%lX irq %d\n",
5831 				ap->flags & ATA_FLAG_SATA ? 'S' : 'P',
5832 				ata_mode_string(xfer_mode_mask),
5833 				ap->ioaddr.cmd_addr,
5834 				ap->ioaddr.ctl_addr,
5835 				ap->ioaddr.bmdma_addr,
5836 				irq_line);
5837 
5838 		/* freeze port before requesting IRQ */
5839 		ata_eh_freeze_port(ap);
5840 	}
5841 
5842 	/* obtain irq, that may be shared between channels */
5843 	rc = request_irq(ent->irq, ent->port_ops->irq_handler, ent->irq_flags,
5844 			 DRV_NAME, host);
5845 	if (rc) {
5846 		dev_printk(KERN_ERR, dev, "irq %lu request failed: %d\n",
5847 			   ent->irq, rc);
5848 		goto err_out;
5849 	}
5850 
5851 	/* do we have a second IRQ for the other channel, eg legacy mode */
5852 	if (ent->irq2) {
5853 		/* We will get weird core code crashes later if this is true
5854 		   so trap it now */
5855 		BUG_ON(ent->irq == ent->irq2);
5856 
5857 		rc = request_irq(ent->irq2, ent->port_ops->irq_handler, ent->irq_flags,
5858 			 DRV_NAME, host);
5859 		if (rc) {
5860 			dev_printk(KERN_ERR, dev, "irq %lu request failed: %d\n",
5861 				   ent->irq2, rc);
5862 			goto err_out_free_irq;
5863 		}
5864 	}
5865 
5866 	/* perform each probe synchronously */
5867 	DPRINTK("probe begin\n");
5868 	for (i = 0; i < host->n_ports; i++) {
5869 		struct ata_port *ap = host->ports[i];
5870 		u32 scontrol;
5871 		int rc;
5872 
5873 		/* init sata_spd_limit to the current value */
5874 		if (sata_scr_read(ap, SCR_CONTROL, &scontrol) == 0) {
5875 			int spd = (scontrol >> 4) & 0xf;
5876 			ap->hw_sata_spd_limit &= (1 << spd) - 1;
5877 		}
5878 		ap->sata_spd_limit = ap->hw_sata_spd_limit;
5879 
5880 		rc = scsi_add_host(ap->scsi_host, dev);
5881 		if (rc) {
5882 			ata_port_printk(ap, KERN_ERR, "scsi_add_host failed\n");
5883 			/* FIXME: do something useful here */
5884 			/* FIXME: handle unconditional calls to
5885 			 * scsi_scan_host and ata_host_remove, below,
5886 			 * at the very least
5887 			 */
5888 		}
5889 
5890 		if (ap->ops->error_handler) {
5891 			struct ata_eh_info *ehi = &ap->eh_info;
5892 			unsigned long flags;
5893 
5894 			ata_port_probe(ap);
5895 
5896 			/* kick EH for boot probing */
5897 			spin_lock_irqsave(ap->lock, flags);
5898 
5899 			ehi->probe_mask = (1 << ATA_MAX_DEVICES) - 1;
5900 			ehi->action |= ATA_EH_SOFTRESET;
5901 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
5902 
5903 			ap->pflags |= ATA_PFLAG_LOADING;
5904 			ata_port_schedule_eh(ap);
5905 
5906 			spin_unlock_irqrestore(ap->lock, flags);
5907 
5908 			/* wait for EH to finish */
5909 			ata_port_wait_eh(ap);
5910 		} else {
5911 			DPRINTK("ata%u: bus probe begin\n", ap->id);
5912 			rc = ata_bus_probe(ap);
5913 			DPRINTK("ata%u: bus probe end\n", ap->id);
5914 
5915 			if (rc) {
5916 				/* FIXME: do something useful here?
5917 				 * Current libata behavior will
5918 				 * tear down everything when
5919 				 * the module is removed
5920 				 * or the h/w is unplugged.
5921 				 */
5922 			}
5923 		}
5924 	}
5925 
5926 	/* probes are done, now scan each port's disk(s) */
5927 	DPRINTK("host probe begin\n");
5928 	for (i = 0; i < host->n_ports; i++) {
5929 		struct ata_port *ap = host->ports[i];
5930 
5931 		ata_scsi_scan_host(ap);
5932 	}
5933 
5934 	dev_set_drvdata(dev, host);
5935 
5936 	VPRINTK("EXIT, returning %u\n", ent->n_ports);
5937 	return ent->n_ports; /* success */
5938 
5939 err_out_free_irq:
5940 	free_irq(ent->irq, host);
5941 err_out:
5942 	for (i = 0; i < host->n_ports; i++) {
5943 		struct ata_port *ap = host->ports[i];
5944 		if (ap) {
5945 			ap->ops->port_stop(ap);
5946 			scsi_host_put(ap->scsi_host);
5947 		}
5948 	}
5949 
5950 	kfree(host);
5951 	VPRINTK("EXIT, returning 0\n");
5952 	return 0;
5953 }
5954 
5955 /**
5956  *	ata_port_detach - Detach ATA port in prepration of device removal
5957  *	@ap: ATA port to be detached
5958  *
5959  *	Detach all ATA devices and the associated SCSI devices of @ap;
5960  *	then, remove the associated SCSI host.  @ap is guaranteed to
5961  *	be quiescent on return from this function.
5962  *
5963  *	LOCKING:
5964  *	Kernel thread context (may sleep).
5965  */
5966 void ata_port_detach(struct ata_port *ap)
5967 {
5968 	unsigned long flags;
5969 	int i;
5970 
5971 	if (!ap->ops->error_handler)
5972 		goto skip_eh;
5973 
5974 	/* tell EH we're leaving & flush EH */
5975 	spin_lock_irqsave(ap->lock, flags);
5976 	ap->pflags |= ATA_PFLAG_UNLOADING;
5977 	spin_unlock_irqrestore(ap->lock, flags);
5978 
5979 	ata_port_wait_eh(ap);
5980 
5981 	/* EH is now guaranteed to see UNLOADING, so no new device
5982 	 * will be attached.  Disable all existing devices.
5983 	 */
5984 	spin_lock_irqsave(ap->lock, flags);
5985 
5986 	for (i = 0; i < ATA_MAX_DEVICES; i++)
5987 		ata_dev_disable(&ap->device[i]);
5988 
5989 	spin_unlock_irqrestore(ap->lock, flags);
5990 
5991 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
5992 	 * will be skipped and retrials will be terminated with bad
5993 	 * target.
5994 	 */
5995 	spin_lock_irqsave(ap->lock, flags);
5996 	ata_port_freeze(ap);	/* won't be thawed */
5997 	spin_unlock_irqrestore(ap->lock, flags);
5998 
5999 	ata_port_wait_eh(ap);
6000 
6001 	/* Flush hotplug task.  The sequence is similar to
6002 	 * ata_port_flush_task().
6003 	 */
6004 	flush_workqueue(ata_aux_wq);
6005 	cancel_delayed_work(&ap->hotplug_task);
6006 	flush_workqueue(ata_aux_wq);
6007 
6008  skip_eh:
6009 	/* remove the associated SCSI host */
6010 	scsi_remove_host(ap->scsi_host);
6011 }
6012 
6013 /**
6014  *	ata_host_remove - PCI layer callback for device removal
6015  *	@host: ATA host set that was removed
6016  *
6017  *	Unregister all objects associated with this host set. Free those
6018  *	objects.
6019  *
6020  *	LOCKING:
6021  *	Inherited from calling layer (may sleep).
6022  */
6023 
6024 void ata_host_remove(struct ata_host *host)
6025 {
6026 	unsigned int i;
6027 
6028 	for (i = 0; i < host->n_ports; i++)
6029 		ata_port_detach(host->ports[i]);
6030 
6031 	free_irq(host->irq, host);
6032 	if (host->irq2)
6033 		free_irq(host->irq2, host);
6034 
6035 	for (i = 0; i < host->n_ports; i++) {
6036 		struct ata_port *ap = host->ports[i];
6037 
6038 		ata_scsi_release(ap->scsi_host);
6039 
6040 		if ((ap->flags & ATA_FLAG_NO_LEGACY) == 0) {
6041 			struct ata_ioports *ioaddr = &ap->ioaddr;
6042 
6043 			/* FIXME: Add -ac IDE pci mods to remove these special cases */
6044 			if (ioaddr->cmd_addr == ATA_PRIMARY_CMD)
6045 				release_region(ATA_PRIMARY_CMD, 8);
6046 			else if (ioaddr->cmd_addr == ATA_SECONDARY_CMD)
6047 				release_region(ATA_SECONDARY_CMD, 8);
6048 		}
6049 
6050 		scsi_host_put(ap->scsi_host);
6051 	}
6052 
6053 	if (host->ops->host_stop)
6054 		host->ops->host_stop(host);
6055 
6056 	kfree(host);
6057 }
6058 
6059 /**
6060  *	ata_scsi_release - SCSI layer callback hook for host unload
6061  *	@shost: libata host to be unloaded
6062  *
6063  *	Performs all duties necessary to shut down a libata port...
6064  *	Kill port kthread, disable port, and release resources.
6065  *
6066  *	LOCKING:
6067  *	Inherited from SCSI layer.
6068  *
6069  *	RETURNS:
6070  *	One.
6071  */
6072 
6073 int ata_scsi_release(struct Scsi_Host *shost)
6074 {
6075 	struct ata_port *ap = ata_shost_to_port(shost);
6076 
6077 	DPRINTK("ENTER\n");
6078 
6079 	ap->ops->port_disable(ap);
6080 	ap->ops->port_stop(ap);
6081 
6082 	DPRINTK("EXIT\n");
6083 	return 1;
6084 }
6085 
6086 struct ata_probe_ent *
6087 ata_probe_ent_alloc(struct device *dev, const struct ata_port_info *port)
6088 {
6089 	struct ata_probe_ent *probe_ent;
6090 
6091 	probe_ent = kzalloc(sizeof(*probe_ent), GFP_KERNEL);
6092 	if (!probe_ent) {
6093 		printk(KERN_ERR DRV_NAME "(%s): out of memory\n",
6094 		       kobject_name(&(dev->kobj)));
6095 		return NULL;
6096 	}
6097 
6098 	INIT_LIST_HEAD(&probe_ent->node);
6099 	probe_ent->dev = dev;
6100 
6101 	probe_ent->sht = port->sht;
6102 	probe_ent->port_flags = port->flags;
6103 	probe_ent->pio_mask = port->pio_mask;
6104 	probe_ent->mwdma_mask = port->mwdma_mask;
6105 	probe_ent->udma_mask = port->udma_mask;
6106 	probe_ent->port_ops = port->port_ops;
6107 	probe_ent->private_data = port->private_data;
6108 
6109 	return probe_ent;
6110 }
6111 
6112 /**
6113  *	ata_std_ports - initialize ioaddr with standard port offsets.
6114  *	@ioaddr: IO address structure to be initialized
6115  *
6116  *	Utility function which initializes data_addr, error_addr,
6117  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
6118  *	device_addr, status_addr, and command_addr to standard offsets
6119  *	relative to cmd_addr.
6120  *
6121  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
6122  */
6123 
6124 void ata_std_ports(struct ata_ioports *ioaddr)
6125 {
6126 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
6127 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
6128 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
6129 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
6130 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
6131 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
6132 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
6133 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
6134 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
6135 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
6136 }
6137 
6138 
6139 #ifdef CONFIG_PCI
6140 
6141 void ata_pci_host_stop (struct ata_host *host)
6142 {
6143 	struct pci_dev *pdev = to_pci_dev(host->dev);
6144 
6145 	pci_iounmap(pdev, host->mmio_base);
6146 }
6147 
6148 /**
6149  *	ata_pci_remove_one - PCI layer callback for device removal
6150  *	@pdev: PCI device that was removed
6151  *
6152  *	PCI layer indicates to libata via this hook that
6153  *	hot-unplug or module unload event has occurred.
6154  *	Handle this by unregistering all objects associated
6155  *	with this PCI device.  Free those objects.  Then finally
6156  *	release PCI resources and disable device.
6157  *
6158  *	LOCKING:
6159  *	Inherited from PCI layer (may sleep).
6160  */
6161 
6162 void ata_pci_remove_one (struct pci_dev *pdev)
6163 {
6164 	struct device *dev = pci_dev_to_dev(pdev);
6165 	struct ata_host *host = dev_get_drvdata(dev);
6166 
6167 	ata_host_remove(host);
6168 
6169 	pci_release_regions(pdev);
6170 	pci_disable_device(pdev);
6171 	dev_set_drvdata(dev, NULL);
6172 }
6173 
6174 /* move to PCI subsystem */
6175 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
6176 {
6177 	unsigned long tmp = 0;
6178 
6179 	switch (bits->width) {
6180 	case 1: {
6181 		u8 tmp8 = 0;
6182 		pci_read_config_byte(pdev, bits->reg, &tmp8);
6183 		tmp = tmp8;
6184 		break;
6185 	}
6186 	case 2: {
6187 		u16 tmp16 = 0;
6188 		pci_read_config_word(pdev, bits->reg, &tmp16);
6189 		tmp = tmp16;
6190 		break;
6191 	}
6192 	case 4: {
6193 		u32 tmp32 = 0;
6194 		pci_read_config_dword(pdev, bits->reg, &tmp32);
6195 		tmp = tmp32;
6196 		break;
6197 	}
6198 
6199 	default:
6200 		return -EINVAL;
6201 	}
6202 
6203 	tmp &= bits->mask;
6204 
6205 	return (tmp == bits->val) ? 1 : 0;
6206 }
6207 
6208 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
6209 {
6210 	pci_save_state(pdev);
6211 
6212 	if (mesg.event == PM_EVENT_SUSPEND) {
6213 		pci_disable_device(pdev);
6214 		pci_set_power_state(pdev, PCI_D3hot);
6215 	}
6216 }
6217 
6218 void ata_pci_device_do_resume(struct pci_dev *pdev)
6219 {
6220 	pci_set_power_state(pdev, PCI_D0);
6221 	pci_restore_state(pdev);
6222 	pci_enable_device(pdev);
6223 	pci_set_master(pdev);
6224 }
6225 
6226 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
6227 {
6228 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6229 	int rc = 0;
6230 
6231 	rc = ata_host_suspend(host, mesg);
6232 	if (rc)
6233 		return rc;
6234 
6235 	ata_pci_device_do_suspend(pdev, mesg);
6236 
6237 	return 0;
6238 }
6239 
6240 int ata_pci_device_resume(struct pci_dev *pdev)
6241 {
6242 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6243 
6244 	ata_pci_device_do_resume(pdev);
6245 	ata_host_resume(host);
6246 	return 0;
6247 }
6248 #endif /* CONFIG_PCI */
6249 
6250 
6251 static int __init ata_init(void)
6252 {
6253 	ata_probe_timeout *= HZ;
6254 	ata_wq = create_workqueue("ata");
6255 	if (!ata_wq)
6256 		return -ENOMEM;
6257 
6258 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
6259 	if (!ata_aux_wq) {
6260 		destroy_workqueue(ata_wq);
6261 		return -ENOMEM;
6262 	}
6263 
6264 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
6265 	return 0;
6266 }
6267 
6268 static void __exit ata_exit(void)
6269 {
6270 	destroy_workqueue(ata_wq);
6271 	destroy_workqueue(ata_aux_wq);
6272 }
6273 
6274 subsys_initcall(ata_init);
6275 module_exit(ata_exit);
6276 
6277 static unsigned long ratelimit_time;
6278 static DEFINE_SPINLOCK(ata_ratelimit_lock);
6279 
6280 int ata_ratelimit(void)
6281 {
6282 	int rc;
6283 	unsigned long flags;
6284 
6285 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
6286 
6287 	if (time_after(jiffies, ratelimit_time)) {
6288 		rc = 1;
6289 		ratelimit_time = jiffies + (HZ/5);
6290 	} else
6291 		rc = 0;
6292 
6293 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
6294 
6295 	return rc;
6296 }
6297 
6298 /**
6299  *	ata_wait_register - wait until register value changes
6300  *	@reg: IO-mapped register
6301  *	@mask: Mask to apply to read register value
6302  *	@val: Wait condition
6303  *	@interval_msec: polling interval in milliseconds
6304  *	@timeout_msec: timeout in milliseconds
6305  *
6306  *	Waiting for some bits of register to change is a common
6307  *	operation for ATA controllers.  This function reads 32bit LE
6308  *	IO-mapped register @reg and tests for the following condition.
6309  *
6310  *	(*@reg & mask) != val
6311  *
6312  *	If the condition is met, it returns; otherwise, the process is
6313  *	repeated after @interval_msec until timeout.
6314  *
6315  *	LOCKING:
6316  *	Kernel thread context (may sleep)
6317  *
6318  *	RETURNS:
6319  *	The final register value.
6320  */
6321 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
6322 		      unsigned long interval_msec,
6323 		      unsigned long timeout_msec)
6324 {
6325 	unsigned long timeout;
6326 	u32 tmp;
6327 
6328 	tmp = ioread32(reg);
6329 
6330 	/* Calculate timeout _after_ the first read to make sure
6331 	 * preceding writes reach the controller before starting to
6332 	 * eat away the timeout.
6333 	 */
6334 	timeout = jiffies + (timeout_msec * HZ) / 1000;
6335 
6336 	while ((tmp & mask) == val && time_before(jiffies, timeout)) {
6337 		msleep(interval_msec);
6338 		tmp = ioread32(reg);
6339 	}
6340 
6341 	return tmp;
6342 }
6343 
6344 /*
6345  * Dummy port_ops
6346  */
6347 static void ata_dummy_noret(struct ata_port *ap)	{ }
6348 static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
6349 static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
6350 
6351 static u8 ata_dummy_check_status(struct ata_port *ap)
6352 {
6353 	return ATA_DRDY;
6354 }
6355 
6356 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
6357 {
6358 	return AC_ERR_SYSTEM;
6359 }
6360 
6361 const struct ata_port_operations ata_dummy_port_ops = {
6362 	.port_disable		= ata_port_disable,
6363 	.check_status		= ata_dummy_check_status,
6364 	.check_altstatus	= ata_dummy_check_status,
6365 	.dev_select		= ata_noop_dev_select,
6366 	.qc_prep		= ata_noop_qc_prep,
6367 	.qc_issue		= ata_dummy_qc_issue,
6368 	.freeze			= ata_dummy_noret,
6369 	.thaw			= ata_dummy_noret,
6370 	.error_handler		= ata_dummy_noret,
6371 	.post_internal_cmd	= ata_dummy_qc_noret,
6372 	.irq_clear		= ata_dummy_noret,
6373 	.port_start		= ata_dummy_ret0,
6374 	.port_stop		= ata_dummy_noret,
6375 };
6376 
6377 /*
6378  * libata is essentially a library of internal helper functions for
6379  * low-level ATA host controller drivers.  As such, the API/ABI is
6380  * likely to change as new drivers are added and updated.
6381  * Do not depend on ABI/API stability.
6382  */
6383 
6384 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
6385 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
6386 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
6387 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
6388 EXPORT_SYMBOL_GPL(ata_std_bios_param);
6389 EXPORT_SYMBOL_GPL(ata_std_ports);
6390 EXPORT_SYMBOL_GPL(ata_host_init);
6391 EXPORT_SYMBOL_GPL(ata_device_add);
6392 EXPORT_SYMBOL_GPL(ata_port_detach);
6393 EXPORT_SYMBOL_GPL(ata_host_remove);
6394 EXPORT_SYMBOL_GPL(ata_sg_init);
6395 EXPORT_SYMBOL_GPL(ata_sg_init_one);
6396 EXPORT_SYMBOL_GPL(ata_hsm_move);
6397 EXPORT_SYMBOL_GPL(ata_qc_complete);
6398 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
6399 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
6400 EXPORT_SYMBOL_GPL(ata_tf_load);
6401 EXPORT_SYMBOL_GPL(ata_tf_read);
6402 EXPORT_SYMBOL_GPL(ata_noop_dev_select);
6403 EXPORT_SYMBOL_GPL(ata_std_dev_select);
6404 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
6405 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
6406 EXPORT_SYMBOL_GPL(ata_check_status);
6407 EXPORT_SYMBOL_GPL(ata_altstatus);
6408 EXPORT_SYMBOL_GPL(ata_exec_command);
6409 EXPORT_SYMBOL_GPL(ata_port_start);
6410 EXPORT_SYMBOL_GPL(ata_port_stop);
6411 EXPORT_SYMBOL_GPL(ata_host_stop);
6412 EXPORT_SYMBOL_GPL(ata_interrupt);
6413 EXPORT_SYMBOL_GPL(ata_mmio_data_xfer);
6414 EXPORT_SYMBOL_GPL(ata_pio_data_xfer);
6415 EXPORT_SYMBOL_GPL(ata_pio_data_xfer_noirq);
6416 EXPORT_SYMBOL_GPL(ata_qc_prep);
6417 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
6418 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
6419 EXPORT_SYMBOL_GPL(ata_bmdma_start);
6420 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
6421 EXPORT_SYMBOL_GPL(ata_bmdma_status);
6422 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
6423 EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
6424 EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
6425 EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
6426 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
6427 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
6428 EXPORT_SYMBOL_GPL(ata_port_probe);
6429 EXPORT_SYMBOL_GPL(sata_set_spd);
6430 EXPORT_SYMBOL_GPL(sata_phy_debounce);
6431 EXPORT_SYMBOL_GPL(sata_phy_resume);
6432 EXPORT_SYMBOL_GPL(sata_phy_reset);
6433 EXPORT_SYMBOL_GPL(__sata_phy_reset);
6434 EXPORT_SYMBOL_GPL(ata_bus_reset);
6435 EXPORT_SYMBOL_GPL(ata_std_prereset);
6436 EXPORT_SYMBOL_GPL(ata_std_softreset);
6437 EXPORT_SYMBOL_GPL(sata_port_hardreset);
6438 EXPORT_SYMBOL_GPL(sata_std_hardreset);
6439 EXPORT_SYMBOL_GPL(ata_std_postreset);
6440 EXPORT_SYMBOL_GPL(ata_dev_classify);
6441 EXPORT_SYMBOL_GPL(ata_dev_pair);
6442 EXPORT_SYMBOL_GPL(ata_port_disable);
6443 EXPORT_SYMBOL_GPL(ata_ratelimit);
6444 EXPORT_SYMBOL_GPL(ata_wait_register);
6445 EXPORT_SYMBOL_GPL(ata_busy_sleep);
6446 EXPORT_SYMBOL_GPL(ata_port_queue_task);
6447 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
6448 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
6449 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
6450 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
6451 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
6452 EXPORT_SYMBOL_GPL(ata_scsi_release);
6453 EXPORT_SYMBOL_GPL(ata_host_intr);
6454 EXPORT_SYMBOL_GPL(sata_scr_valid);
6455 EXPORT_SYMBOL_GPL(sata_scr_read);
6456 EXPORT_SYMBOL_GPL(sata_scr_write);
6457 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
6458 EXPORT_SYMBOL_GPL(ata_port_online);
6459 EXPORT_SYMBOL_GPL(ata_port_offline);
6460 EXPORT_SYMBOL_GPL(ata_host_suspend);
6461 EXPORT_SYMBOL_GPL(ata_host_resume);
6462 EXPORT_SYMBOL_GPL(ata_id_string);
6463 EXPORT_SYMBOL_GPL(ata_id_c_string);
6464 EXPORT_SYMBOL_GPL(ata_device_blacklisted);
6465 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
6466 
6467 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
6468 EXPORT_SYMBOL_GPL(ata_timing_compute);
6469 EXPORT_SYMBOL_GPL(ata_timing_merge);
6470 
6471 #ifdef CONFIG_PCI
6472 EXPORT_SYMBOL_GPL(pci_test_config_bits);
6473 EXPORT_SYMBOL_GPL(ata_pci_host_stop);
6474 EXPORT_SYMBOL_GPL(ata_pci_init_native_mode);
6475 EXPORT_SYMBOL_GPL(ata_pci_init_one);
6476 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
6477 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
6478 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
6479 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
6480 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
6481 EXPORT_SYMBOL_GPL(ata_pci_default_filter);
6482 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
6483 #endif /* CONFIG_PCI */
6484 
6485 EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
6486 EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
6487 
6488 EXPORT_SYMBOL_GPL(ata_eng_timeout);
6489 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
6490 EXPORT_SYMBOL_GPL(ata_port_abort);
6491 EXPORT_SYMBOL_GPL(ata_port_freeze);
6492 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
6493 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
6494 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
6495 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
6496 EXPORT_SYMBOL_GPL(ata_do_eh);
6497