xref: /linux/drivers/ata/libata-core.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 /*
2  *  libata-core.c - helper library for ATA
3  *
4  *  Maintained by:  Tejun Heo <tj@kernel.org>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
9  *  Copyright 2003-2004 Jeff Garzik
10  *
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2, or (at your option)
15  *  any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; see the file COPYING.  If not, write to
24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  *  Standards documents from:
34  *	http://www.t13.org (ATA standards, PCI DMA IDE spec)
35  *	http://www.t10.org (SCSI MMC - for ATAPI MMC)
36  *	http://www.sata-io.org (SATA)
37  *	http://www.compactflash.org (CF)
38  *	http://www.qic.org (QIC157 - Tape and DSC)
39  *	http://www.ce-ata.org (CE-ATA: not supported)
40  *
41  */
42 
43 #include <linux/kernel.h>
44 #include <linux/module.h>
45 #include <linux/pci.h>
46 #include <linux/init.h>
47 #include <linux/list.h>
48 #include <linux/mm.h>
49 #include <linux/spinlock.h>
50 #include <linux/blkdev.h>
51 #include <linux/delay.h>
52 #include <linux/timer.h>
53 #include <linux/interrupt.h>
54 #include <linux/completion.h>
55 #include <linux/suspend.h>
56 #include <linux/workqueue.h>
57 #include <linux/scatterlist.h>
58 #include <linux/io.h>
59 #include <linux/async.h>
60 #include <linux/log2.h>
61 #include <linux/slab.h>
62 #include <linux/glob.h>
63 #include <scsi/scsi.h>
64 #include <scsi/scsi_cmnd.h>
65 #include <scsi/scsi_host.h>
66 #include <linux/libata.h>
67 #include <asm/byteorder.h>
68 #include <linux/cdrom.h>
69 #include <linux/ratelimit.h>
70 #include <linux/pm_runtime.h>
71 #include <linux/platform_device.h>
72 
73 #define CREATE_TRACE_POINTS
74 #include <trace/events/libata.h>
75 
76 #include "libata.h"
77 #include "libata-transport.h"
78 
79 /* debounce timing parameters in msecs { interval, duration, timeout } */
80 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
81 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
82 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
83 
84 const struct ata_port_operations ata_base_port_ops = {
85 	.prereset		= ata_std_prereset,
86 	.postreset		= ata_std_postreset,
87 	.error_handler		= ata_std_error_handler,
88 	.sched_eh		= ata_std_sched_eh,
89 	.end_eh			= ata_std_end_eh,
90 };
91 
92 const struct ata_port_operations sata_port_ops = {
93 	.inherits		= &ata_base_port_ops,
94 
95 	.qc_defer		= ata_std_qc_defer,
96 	.hardreset		= sata_std_hardreset,
97 };
98 
99 static unsigned int ata_dev_init_params(struct ata_device *dev,
100 					u16 heads, u16 sectors);
101 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
102 static void ata_dev_xfermask(struct ata_device *dev);
103 static unsigned long ata_dev_blacklisted(const struct ata_device *dev);
104 
105 atomic_t ata_print_id = ATOMIC_INIT(0);
106 
107 struct ata_force_param {
108 	const char	*name;
109 	unsigned int	cbl;
110 	int		spd_limit;
111 	unsigned long	xfer_mask;
112 	unsigned int	horkage_on;
113 	unsigned int	horkage_off;
114 	unsigned int	lflags;
115 };
116 
117 struct ata_force_ent {
118 	int			port;
119 	int			device;
120 	struct ata_force_param	param;
121 };
122 
123 static struct ata_force_ent *ata_force_tbl;
124 static int ata_force_tbl_size;
125 
126 static char ata_force_param_buf[PAGE_SIZE] __initdata;
127 /* param_buf is thrown away after initialization, disallow read */
128 module_param_string(force, ata_force_param_buf, sizeof(ata_force_param_buf), 0);
129 MODULE_PARM_DESC(force, "Force ATA configurations including cable type, link speed and transfer mode (see Documentation/kernel-parameters.txt for details)");
130 
131 static int atapi_enabled = 1;
132 module_param(atapi_enabled, int, 0444);
133 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on [default])");
134 
135 static int atapi_dmadir = 0;
136 module_param(atapi_dmadir, int, 0444);
137 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off [default], 1=on)");
138 
139 int atapi_passthru16 = 1;
140 module_param(atapi_passthru16, int, 0444);
141 MODULE_PARM_DESC(atapi_passthru16, "Enable ATA_16 passthru for ATAPI devices (0=off, 1=on [default])");
142 
143 int libata_fua = 0;
144 module_param_named(fua, libata_fua, int, 0444);
145 MODULE_PARM_DESC(fua, "FUA support (0=off [default], 1=on)");
146 
147 static int ata_ignore_hpa;
148 module_param_named(ignore_hpa, ata_ignore_hpa, int, 0644);
149 MODULE_PARM_DESC(ignore_hpa, "Ignore HPA limit (0=keep BIOS limits, 1=ignore limits, using full disk)");
150 
151 static int libata_dma_mask = ATA_DMA_MASK_ATA|ATA_DMA_MASK_ATAPI|ATA_DMA_MASK_CFA;
152 module_param_named(dma, libata_dma_mask, int, 0444);
153 MODULE_PARM_DESC(dma, "DMA enable/disable (0x1==ATA, 0x2==ATAPI, 0x4==CF)");
154 
155 static int ata_probe_timeout;
156 module_param(ata_probe_timeout, int, 0444);
157 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
158 
159 int libata_noacpi = 0;
160 module_param_named(noacpi, libata_noacpi, int, 0444);
161 MODULE_PARM_DESC(noacpi, "Disable the use of ACPI in probe/suspend/resume (0=off [default], 1=on)");
162 
163 int libata_allow_tpm = 0;
164 module_param_named(allow_tpm, libata_allow_tpm, int, 0444);
165 MODULE_PARM_DESC(allow_tpm, "Permit the use of TPM commands (0=off [default], 1=on)");
166 
167 static int atapi_an;
168 module_param(atapi_an, int, 0444);
169 MODULE_PARM_DESC(atapi_an, "Enable ATAPI AN media presence notification (0=0ff [default], 1=on)");
170 
171 MODULE_AUTHOR("Jeff Garzik");
172 MODULE_DESCRIPTION("Library module for ATA devices");
173 MODULE_LICENSE("GPL");
174 MODULE_VERSION(DRV_VERSION);
175 
176 
177 static bool ata_sstatus_online(u32 sstatus)
178 {
179 	return (sstatus & 0xf) == 0x3;
180 }
181 
182 /**
183  *	ata_link_next - link iteration helper
184  *	@link: the previous link, NULL to start
185  *	@ap: ATA port containing links to iterate
186  *	@mode: iteration mode, one of ATA_LITER_*
187  *
188  *	LOCKING:
189  *	Host lock or EH context.
190  *
191  *	RETURNS:
192  *	Pointer to the next link.
193  */
194 struct ata_link *ata_link_next(struct ata_link *link, struct ata_port *ap,
195 			       enum ata_link_iter_mode mode)
196 {
197 	BUG_ON(mode != ATA_LITER_EDGE &&
198 	       mode != ATA_LITER_PMP_FIRST && mode != ATA_LITER_HOST_FIRST);
199 
200 	/* NULL link indicates start of iteration */
201 	if (!link)
202 		switch (mode) {
203 		case ATA_LITER_EDGE:
204 		case ATA_LITER_PMP_FIRST:
205 			if (sata_pmp_attached(ap))
206 				return ap->pmp_link;
207 			/* fall through */
208 		case ATA_LITER_HOST_FIRST:
209 			return &ap->link;
210 		}
211 
212 	/* we just iterated over the host link, what's next? */
213 	if (link == &ap->link)
214 		switch (mode) {
215 		case ATA_LITER_HOST_FIRST:
216 			if (sata_pmp_attached(ap))
217 				return ap->pmp_link;
218 			/* fall through */
219 		case ATA_LITER_PMP_FIRST:
220 			if (unlikely(ap->slave_link))
221 				return ap->slave_link;
222 			/* fall through */
223 		case ATA_LITER_EDGE:
224 			return NULL;
225 		}
226 
227 	/* slave_link excludes PMP */
228 	if (unlikely(link == ap->slave_link))
229 		return NULL;
230 
231 	/* we were over a PMP link */
232 	if (++link < ap->pmp_link + ap->nr_pmp_links)
233 		return link;
234 
235 	if (mode == ATA_LITER_PMP_FIRST)
236 		return &ap->link;
237 
238 	return NULL;
239 }
240 
241 /**
242  *	ata_dev_next - device iteration helper
243  *	@dev: the previous device, NULL to start
244  *	@link: ATA link containing devices to iterate
245  *	@mode: iteration mode, one of ATA_DITER_*
246  *
247  *	LOCKING:
248  *	Host lock or EH context.
249  *
250  *	RETURNS:
251  *	Pointer to the next device.
252  */
253 struct ata_device *ata_dev_next(struct ata_device *dev, struct ata_link *link,
254 				enum ata_dev_iter_mode mode)
255 {
256 	BUG_ON(mode != ATA_DITER_ENABLED && mode != ATA_DITER_ENABLED_REVERSE &&
257 	       mode != ATA_DITER_ALL && mode != ATA_DITER_ALL_REVERSE);
258 
259 	/* NULL dev indicates start of iteration */
260 	if (!dev)
261 		switch (mode) {
262 		case ATA_DITER_ENABLED:
263 		case ATA_DITER_ALL:
264 			dev = link->device;
265 			goto check;
266 		case ATA_DITER_ENABLED_REVERSE:
267 		case ATA_DITER_ALL_REVERSE:
268 			dev = link->device + ata_link_max_devices(link) - 1;
269 			goto check;
270 		}
271 
272  next:
273 	/* move to the next one */
274 	switch (mode) {
275 	case ATA_DITER_ENABLED:
276 	case ATA_DITER_ALL:
277 		if (++dev < link->device + ata_link_max_devices(link))
278 			goto check;
279 		return NULL;
280 	case ATA_DITER_ENABLED_REVERSE:
281 	case ATA_DITER_ALL_REVERSE:
282 		if (--dev >= link->device)
283 			goto check;
284 		return NULL;
285 	}
286 
287  check:
288 	if ((mode == ATA_DITER_ENABLED || mode == ATA_DITER_ENABLED_REVERSE) &&
289 	    !ata_dev_enabled(dev))
290 		goto next;
291 	return dev;
292 }
293 
294 /**
295  *	ata_dev_phys_link - find physical link for a device
296  *	@dev: ATA device to look up physical link for
297  *
298  *	Look up physical link which @dev is attached to.  Note that
299  *	this is different from @dev->link only when @dev is on slave
300  *	link.  For all other cases, it's the same as @dev->link.
301  *
302  *	LOCKING:
303  *	Don't care.
304  *
305  *	RETURNS:
306  *	Pointer to the found physical link.
307  */
308 struct ata_link *ata_dev_phys_link(struct ata_device *dev)
309 {
310 	struct ata_port *ap = dev->link->ap;
311 
312 	if (!ap->slave_link)
313 		return dev->link;
314 	if (!dev->devno)
315 		return &ap->link;
316 	return ap->slave_link;
317 }
318 
319 /**
320  *	ata_force_cbl - force cable type according to libata.force
321  *	@ap: ATA port of interest
322  *
323  *	Force cable type according to libata.force and whine about it.
324  *	The last entry which has matching port number is used, so it
325  *	can be specified as part of device force parameters.  For
326  *	example, both "a:40c,1.00:udma4" and "1.00:40c,udma4" have the
327  *	same effect.
328  *
329  *	LOCKING:
330  *	EH context.
331  */
332 void ata_force_cbl(struct ata_port *ap)
333 {
334 	int i;
335 
336 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
337 		const struct ata_force_ent *fe = &ata_force_tbl[i];
338 
339 		if (fe->port != -1 && fe->port != ap->print_id)
340 			continue;
341 
342 		if (fe->param.cbl == ATA_CBL_NONE)
343 			continue;
344 
345 		ap->cbl = fe->param.cbl;
346 		ata_port_notice(ap, "FORCE: cable set to %s\n", fe->param.name);
347 		return;
348 	}
349 }
350 
351 /**
352  *	ata_force_link_limits - force link limits according to libata.force
353  *	@link: ATA link of interest
354  *
355  *	Force link flags and SATA spd limit according to libata.force
356  *	and whine about it.  When only the port part is specified
357  *	(e.g. 1:), the limit applies to all links connected to both
358  *	the host link and all fan-out ports connected via PMP.  If the
359  *	device part is specified as 0 (e.g. 1.00:), it specifies the
360  *	first fan-out link not the host link.  Device number 15 always
361  *	points to the host link whether PMP is attached or not.  If the
362  *	controller has slave link, device number 16 points to it.
363  *
364  *	LOCKING:
365  *	EH context.
366  */
367 static void ata_force_link_limits(struct ata_link *link)
368 {
369 	bool did_spd = false;
370 	int linkno = link->pmp;
371 	int i;
372 
373 	if (ata_is_host_link(link))
374 		linkno += 15;
375 
376 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
377 		const struct ata_force_ent *fe = &ata_force_tbl[i];
378 
379 		if (fe->port != -1 && fe->port != link->ap->print_id)
380 			continue;
381 
382 		if (fe->device != -1 && fe->device != linkno)
383 			continue;
384 
385 		/* only honor the first spd limit */
386 		if (!did_spd && fe->param.spd_limit) {
387 			link->hw_sata_spd_limit = (1 << fe->param.spd_limit) - 1;
388 			ata_link_notice(link, "FORCE: PHY spd limit set to %s\n",
389 					fe->param.name);
390 			did_spd = true;
391 		}
392 
393 		/* let lflags stack */
394 		if (fe->param.lflags) {
395 			link->flags |= fe->param.lflags;
396 			ata_link_notice(link,
397 					"FORCE: link flag 0x%x forced -> 0x%x\n",
398 					fe->param.lflags, link->flags);
399 		}
400 	}
401 }
402 
403 /**
404  *	ata_force_xfermask - force xfermask according to libata.force
405  *	@dev: ATA device of interest
406  *
407  *	Force xfer_mask according to libata.force and whine about it.
408  *	For consistency with link selection, device number 15 selects
409  *	the first device connected to the host link.
410  *
411  *	LOCKING:
412  *	EH context.
413  */
414 static void ata_force_xfermask(struct ata_device *dev)
415 {
416 	int devno = dev->link->pmp + dev->devno;
417 	int alt_devno = devno;
418 	int i;
419 
420 	/* allow n.15/16 for devices attached to host port */
421 	if (ata_is_host_link(dev->link))
422 		alt_devno += 15;
423 
424 	for (i = ata_force_tbl_size - 1; i >= 0; i--) {
425 		const struct ata_force_ent *fe = &ata_force_tbl[i];
426 		unsigned long pio_mask, mwdma_mask, udma_mask;
427 
428 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
429 			continue;
430 
431 		if (fe->device != -1 && fe->device != devno &&
432 		    fe->device != alt_devno)
433 			continue;
434 
435 		if (!fe->param.xfer_mask)
436 			continue;
437 
438 		ata_unpack_xfermask(fe->param.xfer_mask,
439 				    &pio_mask, &mwdma_mask, &udma_mask);
440 		if (udma_mask)
441 			dev->udma_mask = udma_mask;
442 		else if (mwdma_mask) {
443 			dev->udma_mask = 0;
444 			dev->mwdma_mask = mwdma_mask;
445 		} else {
446 			dev->udma_mask = 0;
447 			dev->mwdma_mask = 0;
448 			dev->pio_mask = pio_mask;
449 		}
450 
451 		ata_dev_notice(dev, "FORCE: xfer_mask set to %s\n",
452 			       fe->param.name);
453 		return;
454 	}
455 }
456 
457 /**
458  *	ata_force_horkage - force horkage according to libata.force
459  *	@dev: ATA device of interest
460  *
461  *	Force horkage according to libata.force and whine about it.
462  *	For consistency with link selection, device number 15 selects
463  *	the first device connected to the host link.
464  *
465  *	LOCKING:
466  *	EH context.
467  */
468 static void ata_force_horkage(struct ata_device *dev)
469 {
470 	int devno = dev->link->pmp + dev->devno;
471 	int alt_devno = devno;
472 	int i;
473 
474 	/* allow n.15/16 for devices attached to host port */
475 	if (ata_is_host_link(dev->link))
476 		alt_devno += 15;
477 
478 	for (i = 0; i < ata_force_tbl_size; i++) {
479 		const struct ata_force_ent *fe = &ata_force_tbl[i];
480 
481 		if (fe->port != -1 && fe->port != dev->link->ap->print_id)
482 			continue;
483 
484 		if (fe->device != -1 && fe->device != devno &&
485 		    fe->device != alt_devno)
486 			continue;
487 
488 		if (!(~dev->horkage & fe->param.horkage_on) &&
489 		    !(dev->horkage & fe->param.horkage_off))
490 			continue;
491 
492 		dev->horkage |= fe->param.horkage_on;
493 		dev->horkage &= ~fe->param.horkage_off;
494 
495 		ata_dev_notice(dev, "FORCE: horkage modified (%s)\n",
496 			       fe->param.name);
497 	}
498 }
499 
500 /**
501  *	atapi_cmd_type - Determine ATAPI command type from SCSI opcode
502  *	@opcode: SCSI opcode
503  *
504  *	Determine ATAPI command type from @opcode.
505  *
506  *	LOCKING:
507  *	None.
508  *
509  *	RETURNS:
510  *	ATAPI_{READ|WRITE|READ_CD|PASS_THRU|MISC}
511  */
512 int atapi_cmd_type(u8 opcode)
513 {
514 	switch (opcode) {
515 	case GPCMD_READ_10:
516 	case GPCMD_READ_12:
517 		return ATAPI_READ;
518 
519 	case GPCMD_WRITE_10:
520 	case GPCMD_WRITE_12:
521 	case GPCMD_WRITE_AND_VERIFY_10:
522 		return ATAPI_WRITE;
523 
524 	case GPCMD_READ_CD:
525 	case GPCMD_READ_CD_MSF:
526 		return ATAPI_READ_CD;
527 
528 	case ATA_16:
529 	case ATA_12:
530 		if (atapi_passthru16)
531 			return ATAPI_PASS_THRU;
532 		/* fall thru */
533 	default:
534 		return ATAPI_MISC;
535 	}
536 }
537 
538 /**
539  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
540  *	@tf: Taskfile to convert
541  *	@pmp: Port multiplier port
542  *	@is_cmd: This FIS is for command
543  *	@fis: Buffer into which data will output
544  *
545  *	Converts a standard ATA taskfile to a Serial ATA
546  *	FIS structure (Register - Host to Device).
547  *
548  *	LOCKING:
549  *	Inherited from caller.
550  */
551 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 pmp, int is_cmd, u8 *fis)
552 {
553 	fis[0] = 0x27;			/* Register - Host to Device FIS */
554 	fis[1] = pmp & 0xf;		/* Port multiplier number*/
555 	if (is_cmd)
556 		fis[1] |= (1 << 7);	/* bit 7 indicates Command FIS */
557 
558 	fis[2] = tf->command;
559 	fis[3] = tf->feature;
560 
561 	fis[4] = tf->lbal;
562 	fis[5] = tf->lbam;
563 	fis[6] = tf->lbah;
564 	fis[7] = tf->device;
565 
566 	fis[8] = tf->hob_lbal;
567 	fis[9] = tf->hob_lbam;
568 	fis[10] = tf->hob_lbah;
569 	fis[11] = tf->hob_feature;
570 
571 	fis[12] = tf->nsect;
572 	fis[13] = tf->hob_nsect;
573 	fis[14] = 0;
574 	fis[15] = tf->ctl;
575 
576 	fis[16] = tf->auxiliary & 0xff;
577 	fis[17] = (tf->auxiliary >> 8) & 0xff;
578 	fis[18] = (tf->auxiliary >> 16) & 0xff;
579 	fis[19] = (tf->auxiliary >> 24) & 0xff;
580 }
581 
582 /**
583  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
584  *	@fis: Buffer from which data will be input
585  *	@tf: Taskfile to output
586  *
587  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
588  *
589  *	LOCKING:
590  *	Inherited from caller.
591  */
592 
593 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
594 {
595 	tf->command	= fis[2];	/* status */
596 	tf->feature	= fis[3];	/* error */
597 
598 	tf->lbal	= fis[4];
599 	tf->lbam	= fis[5];
600 	tf->lbah	= fis[6];
601 	tf->device	= fis[7];
602 
603 	tf->hob_lbal	= fis[8];
604 	tf->hob_lbam	= fis[9];
605 	tf->hob_lbah	= fis[10];
606 
607 	tf->nsect	= fis[12];
608 	tf->hob_nsect	= fis[13];
609 }
610 
611 static const u8 ata_rw_cmds[] = {
612 	/* pio multi */
613 	ATA_CMD_READ_MULTI,
614 	ATA_CMD_WRITE_MULTI,
615 	ATA_CMD_READ_MULTI_EXT,
616 	ATA_CMD_WRITE_MULTI_EXT,
617 	0,
618 	0,
619 	0,
620 	ATA_CMD_WRITE_MULTI_FUA_EXT,
621 	/* pio */
622 	ATA_CMD_PIO_READ,
623 	ATA_CMD_PIO_WRITE,
624 	ATA_CMD_PIO_READ_EXT,
625 	ATA_CMD_PIO_WRITE_EXT,
626 	0,
627 	0,
628 	0,
629 	0,
630 	/* dma */
631 	ATA_CMD_READ,
632 	ATA_CMD_WRITE,
633 	ATA_CMD_READ_EXT,
634 	ATA_CMD_WRITE_EXT,
635 	0,
636 	0,
637 	0,
638 	ATA_CMD_WRITE_FUA_EXT
639 };
640 
641 /**
642  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
643  *	@tf: command to examine and configure
644  *	@dev: device tf belongs to
645  *
646  *	Examine the device configuration and tf->flags to calculate
647  *	the proper read/write commands and protocol to use.
648  *
649  *	LOCKING:
650  *	caller.
651  */
652 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
653 {
654 	u8 cmd;
655 
656 	int index, fua, lba48, write;
657 
658 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
659 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
660 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
661 
662 	if (dev->flags & ATA_DFLAG_PIO) {
663 		tf->protocol = ATA_PROT_PIO;
664 		index = dev->multi_count ? 0 : 8;
665 	} else if (lba48 && (dev->link->ap->flags & ATA_FLAG_PIO_LBA48)) {
666 		/* Unable to use DMA due to host limitation */
667 		tf->protocol = ATA_PROT_PIO;
668 		index = dev->multi_count ? 0 : 8;
669 	} else {
670 		tf->protocol = ATA_PROT_DMA;
671 		index = 16;
672 	}
673 
674 	cmd = ata_rw_cmds[index + fua + lba48 + write];
675 	if (cmd) {
676 		tf->command = cmd;
677 		return 0;
678 	}
679 	return -1;
680 }
681 
682 /**
683  *	ata_tf_read_block - Read block address from ATA taskfile
684  *	@tf: ATA taskfile of interest
685  *	@dev: ATA device @tf belongs to
686  *
687  *	LOCKING:
688  *	None.
689  *
690  *	Read block address from @tf.  This function can handle all
691  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
692  *	flags select the address format to use.
693  *
694  *	RETURNS:
695  *	Block address read from @tf.
696  */
697 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
698 {
699 	u64 block = 0;
700 
701 	if (tf->flags & ATA_TFLAG_LBA) {
702 		if (tf->flags & ATA_TFLAG_LBA48) {
703 			block |= (u64)tf->hob_lbah << 40;
704 			block |= (u64)tf->hob_lbam << 32;
705 			block |= (u64)tf->hob_lbal << 24;
706 		} else
707 			block |= (tf->device & 0xf) << 24;
708 
709 		block |= tf->lbah << 16;
710 		block |= tf->lbam << 8;
711 		block |= tf->lbal;
712 	} else {
713 		u32 cyl, head, sect;
714 
715 		cyl = tf->lbam | (tf->lbah << 8);
716 		head = tf->device & 0xf;
717 		sect = tf->lbal;
718 
719 		if (!sect) {
720 			ata_dev_warn(dev,
721 				     "device reported invalid CHS sector 0\n");
722 			sect = 1; /* oh well */
723 		}
724 
725 		block = (cyl * dev->heads + head) * dev->sectors + sect - 1;
726 	}
727 
728 	return block;
729 }
730 
731 /**
732  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
733  *	@tf: Target ATA taskfile
734  *	@dev: ATA device @tf belongs to
735  *	@block: Block address
736  *	@n_block: Number of blocks
737  *	@tf_flags: RW/FUA etc...
738  *	@tag: tag
739  *
740  *	LOCKING:
741  *	None.
742  *
743  *	Build ATA taskfile @tf for read/write request described by
744  *	@block, @n_block, @tf_flags and @tag on @dev.
745  *
746  *	RETURNS:
747  *
748  *	0 on success, -ERANGE if the request is too large for @dev,
749  *	-EINVAL if the request is invalid.
750  */
751 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
752 		    u64 block, u32 n_block, unsigned int tf_flags,
753 		    unsigned int tag)
754 {
755 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
756 	tf->flags |= tf_flags;
757 
758 	if (ata_ncq_enabled(dev) && likely(tag != ATA_TAG_INTERNAL)) {
759 		/* yay, NCQ */
760 		if (!lba_48_ok(block, n_block))
761 			return -ERANGE;
762 
763 		tf->protocol = ATA_PROT_NCQ;
764 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
765 
766 		if (tf->flags & ATA_TFLAG_WRITE)
767 			tf->command = ATA_CMD_FPDMA_WRITE;
768 		else
769 			tf->command = ATA_CMD_FPDMA_READ;
770 
771 		tf->nsect = tag << 3;
772 		tf->hob_feature = (n_block >> 8) & 0xff;
773 		tf->feature = n_block & 0xff;
774 
775 		tf->hob_lbah = (block >> 40) & 0xff;
776 		tf->hob_lbam = (block >> 32) & 0xff;
777 		tf->hob_lbal = (block >> 24) & 0xff;
778 		tf->lbah = (block >> 16) & 0xff;
779 		tf->lbam = (block >> 8) & 0xff;
780 		tf->lbal = block & 0xff;
781 
782 		tf->device = ATA_LBA;
783 		if (tf->flags & ATA_TFLAG_FUA)
784 			tf->device |= 1 << 7;
785 	} else if (dev->flags & ATA_DFLAG_LBA) {
786 		tf->flags |= ATA_TFLAG_LBA;
787 
788 		if (lba_28_ok(block, n_block)) {
789 			/* use LBA28 */
790 			tf->device |= (block >> 24) & 0xf;
791 		} else if (lba_48_ok(block, n_block)) {
792 			if (!(dev->flags & ATA_DFLAG_LBA48))
793 				return -ERANGE;
794 
795 			/* use LBA48 */
796 			tf->flags |= ATA_TFLAG_LBA48;
797 
798 			tf->hob_nsect = (n_block >> 8) & 0xff;
799 
800 			tf->hob_lbah = (block >> 40) & 0xff;
801 			tf->hob_lbam = (block >> 32) & 0xff;
802 			tf->hob_lbal = (block >> 24) & 0xff;
803 		} else
804 			/* request too large even for LBA48 */
805 			return -ERANGE;
806 
807 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
808 			return -EINVAL;
809 
810 		tf->nsect = n_block & 0xff;
811 
812 		tf->lbah = (block >> 16) & 0xff;
813 		tf->lbam = (block >> 8) & 0xff;
814 		tf->lbal = block & 0xff;
815 
816 		tf->device |= ATA_LBA;
817 	} else {
818 		/* CHS */
819 		u32 sect, head, cyl, track;
820 
821 		/* The request -may- be too large for CHS addressing. */
822 		if (!lba_28_ok(block, n_block))
823 			return -ERANGE;
824 
825 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
826 			return -EINVAL;
827 
828 		/* Convert LBA to CHS */
829 		track = (u32)block / dev->sectors;
830 		cyl   = track / dev->heads;
831 		head  = track % dev->heads;
832 		sect  = (u32)block % dev->sectors + 1;
833 
834 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
835 			(u32)block, track, cyl, head, sect);
836 
837 		/* Check whether the converted CHS can fit.
838 		   Cylinder: 0-65535
839 		   Head: 0-15
840 		   Sector: 1-255*/
841 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
842 			return -ERANGE;
843 
844 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
845 		tf->lbal = sect;
846 		tf->lbam = cyl;
847 		tf->lbah = cyl >> 8;
848 		tf->device |= head;
849 	}
850 
851 	return 0;
852 }
853 
854 /**
855  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
856  *	@pio_mask: pio_mask
857  *	@mwdma_mask: mwdma_mask
858  *	@udma_mask: udma_mask
859  *
860  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
861  *	unsigned int xfer_mask.
862  *
863  *	LOCKING:
864  *	None.
865  *
866  *	RETURNS:
867  *	Packed xfer_mask.
868  */
869 unsigned long ata_pack_xfermask(unsigned long pio_mask,
870 				unsigned long mwdma_mask,
871 				unsigned long udma_mask)
872 {
873 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
874 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
875 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
876 }
877 
878 /**
879  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
880  *	@xfer_mask: xfer_mask to unpack
881  *	@pio_mask: resulting pio_mask
882  *	@mwdma_mask: resulting mwdma_mask
883  *	@udma_mask: resulting udma_mask
884  *
885  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
886  *	Any NULL distination masks will be ignored.
887  */
888 void ata_unpack_xfermask(unsigned long xfer_mask, unsigned long *pio_mask,
889 			 unsigned long *mwdma_mask, unsigned long *udma_mask)
890 {
891 	if (pio_mask)
892 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
893 	if (mwdma_mask)
894 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
895 	if (udma_mask)
896 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
897 }
898 
899 static const struct ata_xfer_ent {
900 	int shift, bits;
901 	u8 base;
902 } ata_xfer_tbl[] = {
903 	{ ATA_SHIFT_PIO, ATA_NR_PIO_MODES, XFER_PIO_0 },
904 	{ ATA_SHIFT_MWDMA, ATA_NR_MWDMA_MODES, XFER_MW_DMA_0 },
905 	{ ATA_SHIFT_UDMA, ATA_NR_UDMA_MODES, XFER_UDMA_0 },
906 	{ -1, },
907 };
908 
909 /**
910  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
911  *	@xfer_mask: xfer_mask of interest
912  *
913  *	Return matching XFER_* value for @xfer_mask.  Only the highest
914  *	bit of @xfer_mask is considered.
915  *
916  *	LOCKING:
917  *	None.
918  *
919  *	RETURNS:
920  *	Matching XFER_* value, 0xff if no match found.
921  */
922 u8 ata_xfer_mask2mode(unsigned long xfer_mask)
923 {
924 	int highbit = fls(xfer_mask) - 1;
925 	const struct ata_xfer_ent *ent;
926 
927 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
928 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
929 			return ent->base + highbit - ent->shift;
930 	return 0xff;
931 }
932 
933 /**
934  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
935  *	@xfer_mode: XFER_* of interest
936  *
937  *	Return matching xfer_mask for @xfer_mode.
938  *
939  *	LOCKING:
940  *	None.
941  *
942  *	RETURNS:
943  *	Matching xfer_mask, 0 if no match found.
944  */
945 unsigned long ata_xfer_mode2mask(u8 xfer_mode)
946 {
947 	const struct ata_xfer_ent *ent;
948 
949 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
950 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
951 			return ((2 << (ent->shift + xfer_mode - ent->base)) - 1)
952 				& ~((1 << ent->shift) - 1);
953 	return 0;
954 }
955 
956 /**
957  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
958  *	@xfer_mode: XFER_* of interest
959  *
960  *	Return matching xfer_shift for @xfer_mode.
961  *
962  *	LOCKING:
963  *	None.
964  *
965  *	RETURNS:
966  *	Matching xfer_shift, -1 if no match found.
967  */
968 int ata_xfer_mode2shift(unsigned long xfer_mode)
969 {
970 	const struct ata_xfer_ent *ent;
971 
972 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
973 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
974 			return ent->shift;
975 	return -1;
976 }
977 
978 /**
979  *	ata_mode_string - convert xfer_mask to string
980  *	@xfer_mask: mask of bits supported; only highest bit counts.
981  *
982  *	Determine string which represents the highest speed
983  *	(highest bit in @modemask).
984  *
985  *	LOCKING:
986  *	None.
987  *
988  *	RETURNS:
989  *	Constant C string representing highest speed listed in
990  *	@mode_mask, or the constant C string "<n/a>".
991  */
992 const char *ata_mode_string(unsigned long xfer_mask)
993 {
994 	static const char * const xfer_mode_str[] = {
995 		"PIO0",
996 		"PIO1",
997 		"PIO2",
998 		"PIO3",
999 		"PIO4",
1000 		"PIO5",
1001 		"PIO6",
1002 		"MWDMA0",
1003 		"MWDMA1",
1004 		"MWDMA2",
1005 		"MWDMA3",
1006 		"MWDMA4",
1007 		"UDMA/16",
1008 		"UDMA/25",
1009 		"UDMA/33",
1010 		"UDMA/44",
1011 		"UDMA/66",
1012 		"UDMA/100",
1013 		"UDMA/133",
1014 		"UDMA7",
1015 	};
1016 	int highbit;
1017 
1018 	highbit = fls(xfer_mask) - 1;
1019 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
1020 		return xfer_mode_str[highbit];
1021 	return "<n/a>";
1022 }
1023 
1024 const char *sata_spd_string(unsigned int spd)
1025 {
1026 	static const char * const spd_str[] = {
1027 		"1.5 Gbps",
1028 		"3.0 Gbps",
1029 		"6.0 Gbps",
1030 	};
1031 
1032 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
1033 		return "<unknown>";
1034 	return spd_str[spd - 1];
1035 }
1036 
1037 /**
1038  *	ata_dev_classify - determine device type based on ATA-spec signature
1039  *	@tf: ATA taskfile register set for device to be identified
1040  *
1041  *	Determine from taskfile register contents whether a device is
1042  *	ATA or ATAPI, as per "Signature and persistence" section
1043  *	of ATA/PI spec (volume 1, sect 5.14).
1044  *
1045  *	LOCKING:
1046  *	None.
1047  *
1048  *	RETURNS:
1049  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, %ATA_DEV_PMP,
1050  *	%ATA_DEV_ZAC, or %ATA_DEV_UNKNOWN the event of failure.
1051  */
1052 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
1053 {
1054 	/* Apple's open source Darwin code hints that some devices only
1055 	 * put a proper signature into the LBA mid/high registers,
1056 	 * So, we only check those.  It's sufficient for uniqueness.
1057 	 *
1058 	 * ATA/ATAPI-7 (d1532v1r1: Feb. 19, 2003) specified separate
1059 	 * signatures for ATA and ATAPI devices attached on SerialATA,
1060 	 * 0x3c/0xc3 and 0x69/0x96 respectively.  However, SerialATA
1061 	 * spec has never mentioned about using different signatures
1062 	 * for ATA/ATAPI devices.  Then, Serial ATA II: Port
1063 	 * Multiplier specification began to use 0x69/0x96 to identify
1064 	 * port multpliers and 0x3c/0xc3 to identify SEMB device.
1065 	 * ATA/ATAPI-7 dropped descriptions about 0x3c/0xc3 and
1066 	 * 0x69/0x96 shortly and described them as reserved for
1067 	 * SerialATA.
1068 	 *
1069 	 * We follow the current spec and consider that 0x69/0x96
1070 	 * identifies a port multiplier and 0x3c/0xc3 a SEMB device.
1071 	 * Unfortunately, WDC WD1600JS-62MHB5 (a hard drive) reports
1072 	 * SEMB signature.  This is worked around in
1073 	 * ata_dev_read_id().
1074 	 */
1075 	if ((tf->lbam == 0) && (tf->lbah == 0)) {
1076 		DPRINTK("found ATA device by sig\n");
1077 		return ATA_DEV_ATA;
1078 	}
1079 
1080 	if ((tf->lbam == 0x14) && (tf->lbah == 0xeb)) {
1081 		DPRINTK("found ATAPI device by sig\n");
1082 		return ATA_DEV_ATAPI;
1083 	}
1084 
1085 	if ((tf->lbam == 0x69) && (tf->lbah == 0x96)) {
1086 		DPRINTK("found PMP device by sig\n");
1087 		return ATA_DEV_PMP;
1088 	}
1089 
1090 	if ((tf->lbam == 0x3c) && (tf->lbah == 0xc3)) {
1091 		DPRINTK("found SEMB device by sig (could be ATA device)\n");
1092 		return ATA_DEV_SEMB;
1093 	}
1094 
1095 	if ((tf->lbam == 0xcd) && (tf->lbah == 0xab)) {
1096 		DPRINTK("found ZAC device by sig\n");
1097 		return ATA_DEV_ZAC;
1098 	}
1099 
1100 	DPRINTK("unknown device\n");
1101 	return ATA_DEV_UNKNOWN;
1102 }
1103 
1104 /**
1105  *	ata_id_string - Convert IDENTIFY DEVICE page into string
1106  *	@id: IDENTIFY DEVICE results we will examine
1107  *	@s: string into which data is output
1108  *	@ofs: offset into identify device page
1109  *	@len: length of string to return. must be an even number.
1110  *
1111  *	The strings in the IDENTIFY DEVICE page are broken up into
1112  *	16-bit chunks.  Run through the string, and output each
1113  *	8-bit chunk linearly, regardless of platform.
1114  *
1115  *	LOCKING:
1116  *	caller.
1117  */
1118 
1119 void ata_id_string(const u16 *id, unsigned char *s,
1120 		   unsigned int ofs, unsigned int len)
1121 {
1122 	unsigned int c;
1123 
1124 	BUG_ON(len & 1);
1125 
1126 	while (len > 0) {
1127 		c = id[ofs] >> 8;
1128 		*s = c;
1129 		s++;
1130 
1131 		c = id[ofs] & 0xff;
1132 		*s = c;
1133 		s++;
1134 
1135 		ofs++;
1136 		len -= 2;
1137 	}
1138 }
1139 
1140 /**
1141  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
1142  *	@id: IDENTIFY DEVICE results we will examine
1143  *	@s: string into which data is output
1144  *	@ofs: offset into identify device page
1145  *	@len: length of string to return. must be an odd number.
1146  *
1147  *	This function is identical to ata_id_string except that it
1148  *	trims trailing spaces and terminates the resulting string with
1149  *	null.  @len must be actual maximum length (even number) + 1.
1150  *
1151  *	LOCKING:
1152  *	caller.
1153  */
1154 void ata_id_c_string(const u16 *id, unsigned char *s,
1155 		     unsigned int ofs, unsigned int len)
1156 {
1157 	unsigned char *p;
1158 
1159 	ata_id_string(id, s, ofs, len - 1);
1160 
1161 	p = s + strnlen(s, len - 1);
1162 	while (p > s && p[-1] == ' ')
1163 		p--;
1164 	*p = '\0';
1165 }
1166 
1167 static u64 ata_id_n_sectors(const u16 *id)
1168 {
1169 	if (ata_id_has_lba(id)) {
1170 		if (ata_id_has_lba48(id))
1171 			return ata_id_u64(id, ATA_ID_LBA_CAPACITY_2);
1172 		else
1173 			return ata_id_u32(id, ATA_ID_LBA_CAPACITY);
1174 	} else {
1175 		if (ata_id_current_chs_valid(id))
1176 			return id[ATA_ID_CUR_CYLS] * id[ATA_ID_CUR_HEADS] *
1177 			       id[ATA_ID_CUR_SECTORS];
1178 		else
1179 			return id[ATA_ID_CYLS] * id[ATA_ID_HEADS] *
1180 			       id[ATA_ID_SECTORS];
1181 	}
1182 }
1183 
1184 u64 ata_tf_to_lba48(const struct ata_taskfile *tf)
1185 {
1186 	u64 sectors = 0;
1187 
1188 	sectors |= ((u64)(tf->hob_lbah & 0xff)) << 40;
1189 	sectors |= ((u64)(tf->hob_lbam & 0xff)) << 32;
1190 	sectors |= ((u64)(tf->hob_lbal & 0xff)) << 24;
1191 	sectors |= (tf->lbah & 0xff) << 16;
1192 	sectors |= (tf->lbam & 0xff) << 8;
1193 	sectors |= (tf->lbal & 0xff);
1194 
1195 	return sectors;
1196 }
1197 
1198 u64 ata_tf_to_lba(const struct ata_taskfile *tf)
1199 {
1200 	u64 sectors = 0;
1201 
1202 	sectors |= (tf->device & 0x0f) << 24;
1203 	sectors |= (tf->lbah & 0xff) << 16;
1204 	sectors |= (tf->lbam & 0xff) << 8;
1205 	sectors |= (tf->lbal & 0xff);
1206 
1207 	return sectors;
1208 }
1209 
1210 /**
1211  *	ata_read_native_max_address - Read native max address
1212  *	@dev: target device
1213  *	@max_sectors: out parameter for the result native max address
1214  *
1215  *	Perform an LBA48 or LBA28 native size query upon the device in
1216  *	question.
1217  *
1218  *	RETURNS:
1219  *	0 on success, -EACCES if command is aborted by the drive.
1220  *	-EIO on other errors.
1221  */
1222 static int ata_read_native_max_address(struct ata_device *dev, u64 *max_sectors)
1223 {
1224 	unsigned int err_mask;
1225 	struct ata_taskfile tf;
1226 	int lba48 = ata_id_has_lba48(dev->id);
1227 
1228 	ata_tf_init(dev, &tf);
1229 
1230 	/* always clear all address registers */
1231 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1232 
1233 	if (lba48) {
1234 		tf.command = ATA_CMD_READ_NATIVE_MAX_EXT;
1235 		tf.flags |= ATA_TFLAG_LBA48;
1236 	} else
1237 		tf.command = ATA_CMD_READ_NATIVE_MAX;
1238 
1239 	tf.protocol |= ATA_PROT_NODATA;
1240 	tf.device |= ATA_LBA;
1241 
1242 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1243 	if (err_mask) {
1244 		ata_dev_warn(dev,
1245 			     "failed to read native max address (err_mask=0x%x)\n",
1246 			     err_mask);
1247 		if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
1248 			return -EACCES;
1249 		return -EIO;
1250 	}
1251 
1252 	if (lba48)
1253 		*max_sectors = ata_tf_to_lba48(&tf) + 1;
1254 	else
1255 		*max_sectors = ata_tf_to_lba(&tf) + 1;
1256 	if (dev->horkage & ATA_HORKAGE_HPA_SIZE)
1257 		(*max_sectors)--;
1258 	return 0;
1259 }
1260 
1261 /**
1262  *	ata_set_max_sectors - Set max sectors
1263  *	@dev: target device
1264  *	@new_sectors: new max sectors value to set for the device
1265  *
1266  *	Set max sectors of @dev to @new_sectors.
1267  *
1268  *	RETURNS:
1269  *	0 on success, -EACCES if command is aborted or denied (due to
1270  *	previous non-volatile SET_MAX) by the drive.  -EIO on other
1271  *	errors.
1272  */
1273 static int ata_set_max_sectors(struct ata_device *dev, u64 new_sectors)
1274 {
1275 	unsigned int err_mask;
1276 	struct ata_taskfile tf;
1277 	int lba48 = ata_id_has_lba48(dev->id);
1278 
1279 	new_sectors--;
1280 
1281 	ata_tf_init(dev, &tf);
1282 
1283 	tf.flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
1284 
1285 	if (lba48) {
1286 		tf.command = ATA_CMD_SET_MAX_EXT;
1287 		tf.flags |= ATA_TFLAG_LBA48;
1288 
1289 		tf.hob_lbal = (new_sectors >> 24) & 0xff;
1290 		tf.hob_lbam = (new_sectors >> 32) & 0xff;
1291 		tf.hob_lbah = (new_sectors >> 40) & 0xff;
1292 	} else {
1293 		tf.command = ATA_CMD_SET_MAX;
1294 
1295 		tf.device |= (new_sectors >> 24) & 0xf;
1296 	}
1297 
1298 	tf.protocol |= ATA_PROT_NODATA;
1299 	tf.device |= ATA_LBA;
1300 
1301 	tf.lbal = (new_sectors >> 0) & 0xff;
1302 	tf.lbam = (new_sectors >> 8) & 0xff;
1303 	tf.lbah = (new_sectors >> 16) & 0xff;
1304 
1305 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
1306 	if (err_mask) {
1307 		ata_dev_warn(dev,
1308 			     "failed to set max address (err_mask=0x%x)\n",
1309 			     err_mask);
1310 		if (err_mask == AC_ERR_DEV &&
1311 		    (tf.feature & (ATA_ABORTED | ATA_IDNF)))
1312 			return -EACCES;
1313 		return -EIO;
1314 	}
1315 
1316 	return 0;
1317 }
1318 
1319 /**
1320  *	ata_hpa_resize		-	Resize a device with an HPA set
1321  *	@dev: Device to resize
1322  *
1323  *	Read the size of an LBA28 or LBA48 disk with HPA features and resize
1324  *	it if required to the full size of the media. The caller must check
1325  *	the drive has the HPA feature set enabled.
1326  *
1327  *	RETURNS:
1328  *	0 on success, -errno on failure.
1329  */
1330 static int ata_hpa_resize(struct ata_device *dev)
1331 {
1332 	struct ata_eh_context *ehc = &dev->link->eh_context;
1333 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
1334 	bool unlock_hpa = ata_ignore_hpa || dev->flags & ATA_DFLAG_UNLOCK_HPA;
1335 	u64 sectors = ata_id_n_sectors(dev->id);
1336 	u64 native_sectors;
1337 	int rc;
1338 
1339 	/* do we need to do it? */
1340 	if ((dev->class != ATA_DEV_ATA && dev->class != ATA_DEV_ZAC) ||
1341 	    !ata_id_has_lba(dev->id) || !ata_id_hpa_enabled(dev->id) ||
1342 	    (dev->horkage & ATA_HORKAGE_BROKEN_HPA))
1343 		return 0;
1344 
1345 	/* read native max address */
1346 	rc = ata_read_native_max_address(dev, &native_sectors);
1347 	if (rc) {
1348 		/* If device aborted the command or HPA isn't going to
1349 		 * be unlocked, skip HPA resizing.
1350 		 */
1351 		if (rc == -EACCES || !unlock_hpa) {
1352 			ata_dev_warn(dev,
1353 				     "HPA support seems broken, skipping HPA handling\n");
1354 			dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1355 
1356 			/* we can continue if device aborted the command */
1357 			if (rc == -EACCES)
1358 				rc = 0;
1359 		}
1360 
1361 		return rc;
1362 	}
1363 	dev->n_native_sectors = native_sectors;
1364 
1365 	/* nothing to do? */
1366 	if (native_sectors <= sectors || !unlock_hpa) {
1367 		if (!print_info || native_sectors == sectors)
1368 			return 0;
1369 
1370 		if (native_sectors > sectors)
1371 			ata_dev_info(dev,
1372 				"HPA detected: current %llu, native %llu\n",
1373 				(unsigned long long)sectors,
1374 				(unsigned long long)native_sectors);
1375 		else if (native_sectors < sectors)
1376 			ata_dev_warn(dev,
1377 				"native sectors (%llu) is smaller than sectors (%llu)\n",
1378 				(unsigned long long)native_sectors,
1379 				(unsigned long long)sectors);
1380 		return 0;
1381 	}
1382 
1383 	/* let's unlock HPA */
1384 	rc = ata_set_max_sectors(dev, native_sectors);
1385 	if (rc == -EACCES) {
1386 		/* if device aborted the command, skip HPA resizing */
1387 		ata_dev_warn(dev,
1388 			     "device aborted resize (%llu -> %llu), skipping HPA handling\n",
1389 			     (unsigned long long)sectors,
1390 			     (unsigned long long)native_sectors);
1391 		dev->horkage |= ATA_HORKAGE_BROKEN_HPA;
1392 		return 0;
1393 	} else if (rc)
1394 		return rc;
1395 
1396 	/* re-read IDENTIFY data */
1397 	rc = ata_dev_reread_id(dev, 0);
1398 	if (rc) {
1399 		ata_dev_err(dev,
1400 			    "failed to re-read IDENTIFY data after HPA resizing\n");
1401 		return rc;
1402 	}
1403 
1404 	if (print_info) {
1405 		u64 new_sectors = ata_id_n_sectors(dev->id);
1406 		ata_dev_info(dev,
1407 			"HPA unlocked: %llu -> %llu, native %llu\n",
1408 			(unsigned long long)sectors,
1409 			(unsigned long long)new_sectors,
1410 			(unsigned long long)native_sectors);
1411 	}
1412 
1413 	return 0;
1414 }
1415 
1416 /**
1417  *	ata_dump_id - IDENTIFY DEVICE info debugging output
1418  *	@id: IDENTIFY DEVICE page to dump
1419  *
1420  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
1421  *	page.
1422  *
1423  *	LOCKING:
1424  *	caller.
1425  */
1426 
1427 static inline void ata_dump_id(const u16 *id)
1428 {
1429 	DPRINTK("49==0x%04x  "
1430 		"53==0x%04x  "
1431 		"63==0x%04x  "
1432 		"64==0x%04x  "
1433 		"75==0x%04x  \n",
1434 		id[49],
1435 		id[53],
1436 		id[63],
1437 		id[64],
1438 		id[75]);
1439 	DPRINTK("80==0x%04x  "
1440 		"81==0x%04x  "
1441 		"82==0x%04x  "
1442 		"83==0x%04x  "
1443 		"84==0x%04x  \n",
1444 		id[80],
1445 		id[81],
1446 		id[82],
1447 		id[83],
1448 		id[84]);
1449 	DPRINTK("88==0x%04x  "
1450 		"93==0x%04x\n",
1451 		id[88],
1452 		id[93]);
1453 }
1454 
1455 /**
1456  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1457  *	@id: IDENTIFY data to compute xfer mask from
1458  *
1459  *	Compute the xfermask for this device. This is not as trivial
1460  *	as it seems if we must consider early devices correctly.
1461  *
1462  *	FIXME: pre IDE drive timing (do we care ?).
1463  *
1464  *	LOCKING:
1465  *	None.
1466  *
1467  *	RETURNS:
1468  *	Computed xfermask
1469  */
1470 unsigned long ata_id_xfermask(const u16 *id)
1471 {
1472 	unsigned long pio_mask, mwdma_mask, udma_mask;
1473 
1474 	/* Usual case. Word 53 indicates word 64 is valid */
1475 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1476 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1477 		pio_mask <<= 3;
1478 		pio_mask |= 0x7;
1479 	} else {
1480 		/* If word 64 isn't valid then Word 51 high byte holds
1481 		 * the PIO timing number for the maximum. Turn it into
1482 		 * a mask.
1483 		 */
1484 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1485 		if (mode < 5)	/* Valid PIO range */
1486 			pio_mask = (2 << mode) - 1;
1487 		else
1488 			pio_mask = 1;
1489 
1490 		/* But wait.. there's more. Design your standards by
1491 		 * committee and you too can get a free iordy field to
1492 		 * process. However its the speeds not the modes that
1493 		 * are supported... Note drivers using the timing API
1494 		 * will get this right anyway
1495 		 */
1496 	}
1497 
1498 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1499 
1500 	if (ata_id_is_cfa(id)) {
1501 		/*
1502 		 *	Process compact flash extended modes
1503 		 */
1504 		int pio = (id[ATA_ID_CFA_MODES] >> 0) & 0x7;
1505 		int dma = (id[ATA_ID_CFA_MODES] >> 3) & 0x7;
1506 
1507 		if (pio)
1508 			pio_mask |= (1 << 5);
1509 		if (pio > 1)
1510 			pio_mask |= (1 << 6);
1511 		if (dma)
1512 			mwdma_mask |= (1 << 3);
1513 		if (dma > 1)
1514 			mwdma_mask |= (1 << 4);
1515 	}
1516 
1517 	udma_mask = 0;
1518 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1519 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1520 
1521 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1522 }
1523 
1524 static void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1525 {
1526 	struct completion *waiting = qc->private_data;
1527 
1528 	complete(waiting);
1529 }
1530 
1531 /**
1532  *	ata_exec_internal_sg - execute libata internal command
1533  *	@dev: Device to which the command is sent
1534  *	@tf: Taskfile registers for the command and the result
1535  *	@cdb: CDB for packet command
1536  *	@dma_dir: Data transfer direction of the command
1537  *	@sgl: sg list for the data buffer of the command
1538  *	@n_elem: Number of sg entries
1539  *	@timeout: Timeout in msecs (0 for default)
1540  *
1541  *	Executes libata internal command with timeout.  @tf contains
1542  *	command on entry and result on return.  Timeout and error
1543  *	conditions are reported via return value.  No recovery action
1544  *	is taken after a command times out.  It's caller's duty to
1545  *	clean up after timeout.
1546  *
1547  *	LOCKING:
1548  *	None.  Should be called with kernel context, might sleep.
1549  *
1550  *	RETURNS:
1551  *	Zero on success, AC_ERR_* mask on failure
1552  */
1553 unsigned ata_exec_internal_sg(struct ata_device *dev,
1554 			      struct ata_taskfile *tf, const u8 *cdb,
1555 			      int dma_dir, struct scatterlist *sgl,
1556 			      unsigned int n_elem, unsigned long timeout)
1557 {
1558 	struct ata_link *link = dev->link;
1559 	struct ata_port *ap = link->ap;
1560 	u8 command = tf->command;
1561 	int auto_timeout = 0;
1562 	struct ata_queued_cmd *qc;
1563 	unsigned int tag, preempted_tag;
1564 	u32 preempted_sactive, preempted_qc_active;
1565 	int preempted_nr_active_links;
1566 	DECLARE_COMPLETION_ONSTACK(wait);
1567 	unsigned long flags;
1568 	unsigned int err_mask;
1569 	int rc;
1570 
1571 	spin_lock_irqsave(ap->lock, flags);
1572 
1573 	/* no internal command while frozen */
1574 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1575 		spin_unlock_irqrestore(ap->lock, flags);
1576 		return AC_ERR_SYSTEM;
1577 	}
1578 
1579 	/* initialize internal qc */
1580 
1581 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1582 	 * drivers choke if any other tag is given.  This breaks
1583 	 * ata_tag_internal() test for those drivers.  Don't use new
1584 	 * EH stuff without converting to it.
1585 	 */
1586 	if (ap->ops->error_handler)
1587 		tag = ATA_TAG_INTERNAL;
1588 	else
1589 		tag = 0;
1590 
1591 	qc = __ata_qc_from_tag(ap, tag);
1592 
1593 	qc->tag = tag;
1594 	qc->scsicmd = NULL;
1595 	qc->ap = ap;
1596 	qc->dev = dev;
1597 	ata_qc_reinit(qc);
1598 
1599 	preempted_tag = link->active_tag;
1600 	preempted_sactive = link->sactive;
1601 	preempted_qc_active = ap->qc_active;
1602 	preempted_nr_active_links = ap->nr_active_links;
1603 	link->active_tag = ATA_TAG_POISON;
1604 	link->sactive = 0;
1605 	ap->qc_active = 0;
1606 	ap->nr_active_links = 0;
1607 
1608 	/* prepare & issue qc */
1609 	qc->tf = *tf;
1610 	if (cdb)
1611 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1612 
1613 	/* some SATA bridges need us to indicate data xfer direction */
1614 	if (tf->protocol == ATAPI_PROT_DMA && (dev->flags & ATA_DFLAG_DMADIR) &&
1615 	    dma_dir == DMA_FROM_DEVICE)
1616 		qc->tf.feature |= ATAPI_DMADIR;
1617 
1618 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1619 	qc->dma_dir = dma_dir;
1620 	if (dma_dir != DMA_NONE) {
1621 		unsigned int i, buflen = 0;
1622 		struct scatterlist *sg;
1623 
1624 		for_each_sg(sgl, sg, n_elem, i)
1625 			buflen += sg->length;
1626 
1627 		ata_sg_init(qc, sgl, n_elem);
1628 		qc->nbytes = buflen;
1629 	}
1630 
1631 	qc->private_data = &wait;
1632 	qc->complete_fn = ata_qc_complete_internal;
1633 
1634 	ata_qc_issue(qc);
1635 
1636 	spin_unlock_irqrestore(ap->lock, flags);
1637 
1638 	if (!timeout) {
1639 		if (ata_probe_timeout)
1640 			timeout = ata_probe_timeout * 1000;
1641 		else {
1642 			timeout = ata_internal_cmd_timeout(dev, command);
1643 			auto_timeout = 1;
1644 		}
1645 	}
1646 
1647 	if (ap->ops->error_handler)
1648 		ata_eh_release(ap);
1649 
1650 	rc = wait_for_completion_timeout(&wait, msecs_to_jiffies(timeout));
1651 
1652 	if (ap->ops->error_handler)
1653 		ata_eh_acquire(ap);
1654 
1655 	ata_sff_flush_pio_task(ap);
1656 
1657 	if (!rc) {
1658 		spin_lock_irqsave(ap->lock, flags);
1659 
1660 		/* We're racing with irq here.  If we lose, the
1661 		 * following test prevents us from completing the qc
1662 		 * twice.  If we win, the port is frozen and will be
1663 		 * cleaned up by ->post_internal_cmd().
1664 		 */
1665 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1666 			qc->err_mask |= AC_ERR_TIMEOUT;
1667 
1668 			if (ap->ops->error_handler)
1669 				ata_port_freeze(ap);
1670 			else
1671 				ata_qc_complete(qc);
1672 
1673 			if (ata_msg_warn(ap))
1674 				ata_dev_warn(dev, "qc timeout (cmd 0x%x)\n",
1675 					     command);
1676 		}
1677 
1678 		spin_unlock_irqrestore(ap->lock, flags);
1679 	}
1680 
1681 	/* do post_internal_cmd */
1682 	if (ap->ops->post_internal_cmd)
1683 		ap->ops->post_internal_cmd(qc);
1684 
1685 	/* perform minimal error analysis */
1686 	if (qc->flags & ATA_QCFLAG_FAILED) {
1687 		if (qc->result_tf.command & (ATA_ERR | ATA_DF))
1688 			qc->err_mask |= AC_ERR_DEV;
1689 
1690 		if (!qc->err_mask)
1691 			qc->err_mask |= AC_ERR_OTHER;
1692 
1693 		if (qc->err_mask & ~AC_ERR_OTHER)
1694 			qc->err_mask &= ~AC_ERR_OTHER;
1695 	}
1696 
1697 	/* finish up */
1698 	spin_lock_irqsave(ap->lock, flags);
1699 
1700 	*tf = qc->result_tf;
1701 	err_mask = qc->err_mask;
1702 
1703 	ata_qc_free(qc);
1704 	link->active_tag = preempted_tag;
1705 	link->sactive = preempted_sactive;
1706 	ap->qc_active = preempted_qc_active;
1707 	ap->nr_active_links = preempted_nr_active_links;
1708 
1709 	spin_unlock_irqrestore(ap->lock, flags);
1710 
1711 	if ((err_mask & AC_ERR_TIMEOUT) && auto_timeout)
1712 		ata_internal_cmd_timed_out(dev, command);
1713 
1714 	return err_mask;
1715 }
1716 
1717 /**
1718  *	ata_exec_internal - execute libata internal command
1719  *	@dev: Device to which the command is sent
1720  *	@tf: Taskfile registers for the command and the result
1721  *	@cdb: CDB for packet command
1722  *	@dma_dir: Data transfer direction of the command
1723  *	@buf: Data buffer of the command
1724  *	@buflen: Length of data buffer
1725  *	@timeout: Timeout in msecs (0 for default)
1726  *
1727  *	Wrapper around ata_exec_internal_sg() which takes simple
1728  *	buffer instead of sg list.
1729  *
1730  *	LOCKING:
1731  *	None.  Should be called with kernel context, might sleep.
1732  *
1733  *	RETURNS:
1734  *	Zero on success, AC_ERR_* mask on failure
1735  */
1736 unsigned ata_exec_internal(struct ata_device *dev,
1737 			   struct ata_taskfile *tf, const u8 *cdb,
1738 			   int dma_dir, void *buf, unsigned int buflen,
1739 			   unsigned long timeout)
1740 {
1741 	struct scatterlist *psg = NULL, sg;
1742 	unsigned int n_elem = 0;
1743 
1744 	if (dma_dir != DMA_NONE) {
1745 		WARN_ON(!buf);
1746 		sg_init_one(&sg, buf, buflen);
1747 		psg = &sg;
1748 		n_elem++;
1749 	}
1750 
1751 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem,
1752 				    timeout);
1753 }
1754 
1755 /**
1756  *	ata_pio_need_iordy	-	check if iordy needed
1757  *	@adev: ATA device
1758  *
1759  *	Check if the current speed of the device requires IORDY. Used
1760  *	by various controllers for chip configuration.
1761  */
1762 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1763 {
1764 	/* Don't set IORDY if we're preparing for reset.  IORDY may
1765 	 * lead to controller lock up on certain controllers if the
1766 	 * port is not occupied.  See bko#11703 for details.
1767 	 */
1768 	if (adev->link->ap->pflags & ATA_PFLAG_RESETTING)
1769 		return 0;
1770 	/* Controller doesn't support IORDY.  Probably a pointless
1771 	 * check as the caller should know this.
1772 	 */
1773 	if (adev->link->ap->flags & ATA_FLAG_NO_IORDY)
1774 		return 0;
1775 	/* CF spec. r4.1 Table 22 says no iordy on PIO5 and PIO6.  */
1776 	if (ata_id_is_cfa(adev->id)
1777 	    && (adev->pio_mode == XFER_PIO_5 || adev->pio_mode == XFER_PIO_6))
1778 		return 0;
1779 	/* PIO3 and higher it is mandatory */
1780 	if (adev->pio_mode > XFER_PIO_2)
1781 		return 1;
1782 	/* We turn it on when possible */
1783 	if (ata_id_has_iordy(adev->id))
1784 		return 1;
1785 	return 0;
1786 }
1787 
1788 /**
1789  *	ata_pio_mask_no_iordy	-	Return the non IORDY mask
1790  *	@adev: ATA device
1791  *
1792  *	Compute the highest mode possible if we are not using iordy. Return
1793  *	-1 if no iordy mode is available.
1794  */
1795 static u32 ata_pio_mask_no_iordy(const struct ata_device *adev)
1796 {
1797 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1798 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1799 		u16 pio = adev->id[ATA_ID_EIDE_PIO];
1800 		/* Is the speed faster than the drive allows non IORDY ? */
1801 		if (pio) {
1802 			/* This is cycle times not frequency - watch the logic! */
1803 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1804 				return 3 << ATA_SHIFT_PIO;
1805 			return 7 << ATA_SHIFT_PIO;
1806 		}
1807 	}
1808 	return 3 << ATA_SHIFT_PIO;
1809 }
1810 
1811 /**
1812  *	ata_do_dev_read_id		-	default ID read method
1813  *	@dev: device
1814  *	@tf: proposed taskfile
1815  *	@id: data buffer
1816  *
1817  *	Issue the identify taskfile and hand back the buffer containing
1818  *	identify data. For some RAID controllers and for pre ATA devices
1819  *	this function is wrapped or replaced by the driver
1820  */
1821 unsigned int ata_do_dev_read_id(struct ata_device *dev,
1822 					struct ata_taskfile *tf, u16 *id)
1823 {
1824 	return ata_exec_internal(dev, tf, NULL, DMA_FROM_DEVICE,
1825 				     id, sizeof(id[0]) * ATA_ID_WORDS, 0);
1826 }
1827 
1828 /**
1829  *	ata_dev_read_id - Read ID data from the specified device
1830  *	@dev: target device
1831  *	@p_class: pointer to class of the target device (may be changed)
1832  *	@flags: ATA_READID_* flags
1833  *	@id: buffer to read IDENTIFY data into
1834  *
1835  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1836  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1837  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1838  *	for pre-ATA4 drives.
1839  *
1840  *	FIXME: ATA_CMD_ID_ATA is optional for early drives and right
1841  *	now we abort if we hit that case.
1842  *
1843  *	LOCKING:
1844  *	Kernel thread context (may sleep)
1845  *
1846  *	RETURNS:
1847  *	0 on success, -errno otherwise.
1848  */
1849 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1850 		    unsigned int flags, u16 *id)
1851 {
1852 	struct ata_port *ap = dev->link->ap;
1853 	unsigned int class = *p_class;
1854 	struct ata_taskfile tf;
1855 	unsigned int err_mask = 0;
1856 	const char *reason;
1857 	bool is_semb = class == ATA_DEV_SEMB;
1858 	int may_fallback = 1, tried_spinup = 0;
1859 	int rc;
1860 
1861 	if (ata_msg_ctl(ap))
1862 		ata_dev_dbg(dev, "%s: ENTER\n", __func__);
1863 
1864 retry:
1865 	ata_tf_init(dev, &tf);
1866 
1867 	switch (class) {
1868 	case ATA_DEV_SEMB:
1869 		class = ATA_DEV_ATA;	/* some hard drives report SEMB sig */
1870 	case ATA_DEV_ATA:
1871 	case ATA_DEV_ZAC:
1872 		tf.command = ATA_CMD_ID_ATA;
1873 		break;
1874 	case ATA_DEV_ATAPI:
1875 		tf.command = ATA_CMD_ID_ATAPI;
1876 		break;
1877 	default:
1878 		rc = -ENODEV;
1879 		reason = "unsupported class";
1880 		goto err_out;
1881 	}
1882 
1883 	tf.protocol = ATA_PROT_PIO;
1884 
1885 	/* Some devices choke if TF registers contain garbage.  Make
1886 	 * sure those are properly initialized.
1887 	 */
1888 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
1889 
1890 	/* Device presence detection is unreliable on some
1891 	 * controllers.  Always poll IDENTIFY if available.
1892 	 */
1893 	tf.flags |= ATA_TFLAG_POLLING;
1894 
1895 	if (ap->ops->read_id)
1896 		err_mask = ap->ops->read_id(dev, &tf, id);
1897 	else
1898 		err_mask = ata_do_dev_read_id(dev, &tf, id);
1899 
1900 	if (err_mask) {
1901 		if (err_mask & AC_ERR_NODEV_HINT) {
1902 			ata_dev_dbg(dev, "NODEV after polling detection\n");
1903 			return -ENOENT;
1904 		}
1905 
1906 		if (is_semb) {
1907 			ata_dev_info(dev,
1908 		     "IDENTIFY failed on device w/ SEMB sig, disabled\n");
1909 			/* SEMB is not supported yet */
1910 			*p_class = ATA_DEV_SEMB_UNSUP;
1911 			return 0;
1912 		}
1913 
1914 		if ((err_mask == AC_ERR_DEV) && (tf.feature & ATA_ABORTED)) {
1915 			/* Device or controller might have reported
1916 			 * the wrong device class.  Give a shot at the
1917 			 * other IDENTIFY if the current one is
1918 			 * aborted by the device.
1919 			 */
1920 			if (may_fallback) {
1921 				may_fallback = 0;
1922 
1923 				if (class == ATA_DEV_ATA)
1924 					class = ATA_DEV_ATAPI;
1925 				else
1926 					class = ATA_DEV_ATA;
1927 				goto retry;
1928 			}
1929 
1930 			/* Control reaches here iff the device aborted
1931 			 * both flavors of IDENTIFYs which happens
1932 			 * sometimes with phantom devices.
1933 			 */
1934 			ata_dev_dbg(dev,
1935 				    "both IDENTIFYs aborted, assuming NODEV\n");
1936 			return -ENOENT;
1937 		}
1938 
1939 		rc = -EIO;
1940 		reason = "I/O error";
1941 		goto err_out;
1942 	}
1943 
1944 	if (dev->horkage & ATA_HORKAGE_DUMP_ID) {
1945 		ata_dev_dbg(dev, "dumping IDENTIFY data, "
1946 			    "class=%d may_fallback=%d tried_spinup=%d\n",
1947 			    class, may_fallback, tried_spinup);
1948 		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET,
1949 			       16, 2, id, ATA_ID_WORDS * sizeof(*id), true);
1950 	}
1951 
1952 	/* Falling back doesn't make sense if ID data was read
1953 	 * successfully at least once.
1954 	 */
1955 	may_fallback = 0;
1956 
1957 	swap_buf_le16(id, ATA_ID_WORDS);
1958 
1959 	/* sanity check */
1960 	rc = -EINVAL;
1961 	reason = "device reports invalid type";
1962 
1963 	if (class == ATA_DEV_ATA || class == ATA_DEV_ZAC) {
1964 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
1965 			goto err_out;
1966 		if (ap->host->flags & ATA_HOST_IGNORE_ATA &&
1967 							ata_id_is_ata(id)) {
1968 			ata_dev_dbg(dev,
1969 				"host indicates ignore ATA devices, ignored\n");
1970 			return -ENOENT;
1971 		}
1972 	} else {
1973 		if (ata_id_is_ata(id))
1974 			goto err_out;
1975 	}
1976 
1977 	if (!tried_spinup && (id[2] == 0x37c8 || id[2] == 0x738c)) {
1978 		tried_spinup = 1;
1979 		/*
1980 		 * Drive powered-up in standby mode, and requires a specific
1981 		 * SET_FEATURES spin-up subcommand before it will accept
1982 		 * anything other than the original IDENTIFY command.
1983 		 */
1984 		err_mask = ata_dev_set_feature(dev, SETFEATURES_SPINUP, 0);
1985 		if (err_mask && id[2] != 0x738c) {
1986 			rc = -EIO;
1987 			reason = "SPINUP failed";
1988 			goto err_out;
1989 		}
1990 		/*
1991 		 * If the drive initially returned incomplete IDENTIFY info,
1992 		 * we now must reissue the IDENTIFY command.
1993 		 */
1994 		if (id[2] == 0x37c8)
1995 			goto retry;
1996 	}
1997 
1998 	if ((flags & ATA_READID_POSTRESET) &&
1999 	    (class == ATA_DEV_ATA || class == ATA_DEV_ZAC)) {
2000 		/*
2001 		 * The exact sequence expected by certain pre-ATA4 drives is:
2002 		 * SRST RESET
2003 		 * IDENTIFY (optional in early ATA)
2004 		 * INITIALIZE DEVICE PARAMETERS (later IDE and ATA)
2005 		 * anything else..
2006 		 * Some drives were very specific about that exact sequence.
2007 		 *
2008 		 * Note that ATA4 says lba is mandatory so the second check
2009 		 * should never trigger.
2010 		 */
2011 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
2012 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
2013 			if (err_mask) {
2014 				rc = -EIO;
2015 				reason = "INIT_DEV_PARAMS failed";
2016 				goto err_out;
2017 			}
2018 
2019 			/* current CHS translation info (id[53-58]) might be
2020 			 * changed. reread the identify device info.
2021 			 */
2022 			flags &= ~ATA_READID_POSTRESET;
2023 			goto retry;
2024 		}
2025 	}
2026 
2027 	*p_class = class;
2028 
2029 	return 0;
2030 
2031  err_out:
2032 	if (ata_msg_warn(ap))
2033 		ata_dev_warn(dev, "failed to IDENTIFY (%s, err_mask=0x%x)\n",
2034 			     reason, err_mask);
2035 	return rc;
2036 }
2037 
2038 static int ata_do_link_spd_horkage(struct ata_device *dev)
2039 {
2040 	struct ata_link *plink = ata_dev_phys_link(dev);
2041 	u32 target, target_limit;
2042 
2043 	if (!sata_scr_valid(plink))
2044 		return 0;
2045 
2046 	if (dev->horkage & ATA_HORKAGE_1_5_GBPS)
2047 		target = 1;
2048 	else
2049 		return 0;
2050 
2051 	target_limit = (1 << target) - 1;
2052 
2053 	/* if already on stricter limit, no need to push further */
2054 	if (plink->sata_spd_limit <= target_limit)
2055 		return 0;
2056 
2057 	plink->sata_spd_limit = target_limit;
2058 
2059 	/* Request another EH round by returning -EAGAIN if link is
2060 	 * going faster than the target speed.  Forward progress is
2061 	 * guaranteed by setting sata_spd_limit to target_limit above.
2062 	 */
2063 	if (plink->sata_spd > target) {
2064 		ata_dev_info(dev, "applying link speed limit horkage to %s\n",
2065 			     sata_spd_string(target));
2066 		return -EAGAIN;
2067 	}
2068 	return 0;
2069 }
2070 
2071 static inline u8 ata_dev_knobble(struct ata_device *dev)
2072 {
2073 	struct ata_port *ap = dev->link->ap;
2074 
2075 	if (ata_dev_blacklisted(dev) & ATA_HORKAGE_BRIDGE_OK)
2076 		return 0;
2077 
2078 	return ((ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
2079 }
2080 
2081 static int ata_dev_config_ncq(struct ata_device *dev,
2082 			       char *desc, size_t desc_sz)
2083 {
2084 	struct ata_port *ap = dev->link->ap;
2085 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
2086 	unsigned int err_mask;
2087 	char *aa_desc = "";
2088 
2089 	if (!ata_id_has_ncq(dev->id)) {
2090 		desc[0] = '\0';
2091 		return 0;
2092 	}
2093 	if (dev->horkage & ATA_HORKAGE_NONCQ) {
2094 		snprintf(desc, desc_sz, "NCQ (not used)");
2095 		return 0;
2096 	}
2097 	if (ap->flags & ATA_FLAG_NCQ) {
2098 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
2099 		dev->flags |= ATA_DFLAG_NCQ;
2100 	}
2101 
2102 	if (!(dev->horkage & ATA_HORKAGE_BROKEN_FPDMA_AA) &&
2103 		(ap->flags & ATA_FLAG_FPDMA_AA) &&
2104 		ata_id_has_fpdma_aa(dev->id)) {
2105 		err_mask = ata_dev_set_feature(dev, SETFEATURES_SATA_ENABLE,
2106 			SATA_FPDMA_AA);
2107 		if (err_mask) {
2108 			ata_dev_err(dev,
2109 				    "failed to enable AA (error_mask=0x%x)\n",
2110 				    err_mask);
2111 			if (err_mask != AC_ERR_DEV) {
2112 				dev->horkage |= ATA_HORKAGE_BROKEN_FPDMA_AA;
2113 				return -EIO;
2114 			}
2115 		} else
2116 			aa_desc = ", AA";
2117 	}
2118 
2119 	if (hdepth >= ddepth)
2120 		snprintf(desc, desc_sz, "NCQ (depth %d)%s", ddepth, aa_desc);
2121 	else
2122 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)%s", hdepth,
2123 			ddepth, aa_desc);
2124 
2125 	if ((ap->flags & ATA_FLAG_FPDMA_AUX) &&
2126 	    ata_id_has_ncq_send_and_recv(dev->id)) {
2127 		err_mask = ata_read_log_page(dev, ATA_LOG_NCQ_SEND_RECV,
2128 					     0, ap->sector_buf, 1);
2129 		if (err_mask) {
2130 			ata_dev_dbg(dev,
2131 				    "failed to get NCQ Send/Recv Log Emask 0x%x\n",
2132 				    err_mask);
2133 		} else {
2134 			u8 *cmds = dev->ncq_send_recv_cmds;
2135 
2136 			dev->flags |= ATA_DFLAG_NCQ_SEND_RECV;
2137 			memcpy(cmds, ap->sector_buf, ATA_LOG_NCQ_SEND_RECV_SIZE);
2138 
2139 			if (dev->horkage & ATA_HORKAGE_NO_NCQ_TRIM) {
2140 				ata_dev_dbg(dev, "disabling queued TRIM support\n");
2141 				cmds[ATA_LOG_NCQ_SEND_RECV_DSM_OFFSET] &=
2142 					~ATA_LOG_NCQ_SEND_RECV_DSM_TRIM;
2143 			}
2144 		}
2145 	}
2146 
2147 	return 0;
2148 }
2149 
2150 /**
2151  *	ata_dev_configure - Configure the specified ATA/ATAPI device
2152  *	@dev: Target device to configure
2153  *
2154  *	Configure @dev according to @dev->id.  Generic and low-level
2155  *	driver specific fixups are also applied.
2156  *
2157  *	LOCKING:
2158  *	Kernel thread context (may sleep)
2159  *
2160  *	RETURNS:
2161  *	0 on success, -errno otherwise
2162  */
2163 int ata_dev_configure(struct ata_device *dev)
2164 {
2165 	struct ata_port *ap = dev->link->ap;
2166 	struct ata_eh_context *ehc = &dev->link->eh_context;
2167 	int print_info = ehc->i.flags & ATA_EHI_PRINTINFO;
2168 	const u16 *id = dev->id;
2169 	unsigned long xfer_mask;
2170 	unsigned int err_mask;
2171 	char revbuf[7];		/* XYZ-99\0 */
2172 	char fwrevbuf[ATA_ID_FW_REV_LEN+1];
2173 	char modelbuf[ATA_ID_PROD_LEN+1];
2174 	int rc;
2175 
2176 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
2177 		ata_dev_info(dev, "%s: ENTER/EXIT -- nodev\n", __func__);
2178 		return 0;
2179 	}
2180 
2181 	if (ata_msg_probe(ap))
2182 		ata_dev_dbg(dev, "%s: ENTER\n", __func__);
2183 
2184 	/* set horkage */
2185 	dev->horkage |= ata_dev_blacklisted(dev);
2186 	ata_force_horkage(dev);
2187 
2188 	if (dev->horkage & ATA_HORKAGE_DISABLE) {
2189 		ata_dev_info(dev, "unsupported device, disabling\n");
2190 		ata_dev_disable(dev);
2191 		return 0;
2192 	}
2193 
2194 	if ((!atapi_enabled || (ap->flags & ATA_FLAG_NO_ATAPI)) &&
2195 	    dev->class == ATA_DEV_ATAPI) {
2196 		ata_dev_warn(dev, "WARNING: ATAPI is %s, device ignored\n",
2197 			     atapi_enabled ? "not supported with this driver"
2198 			     : "disabled");
2199 		ata_dev_disable(dev);
2200 		return 0;
2201 	}
2202 
2203 	rc = ata_do_link_spd_horkage(dev);
2204 	if (rc)
2205 		return rc;
2206 
2207 	/* some WD SATA-1 drives have issues with LPM, turn on NOLPM for them */
2208 	if ((dev->horkage & ATA_HORKAGE_WD_BROKEN_LPM) &&
2209 	    (id[ATA_ID_SATA_CAPABILITY] & 0xe) == 0x2)
2210 		dev->horkage |= ATA_HORKAGE_NOLPM;
2211 
2212 	if (dev->horkage & ATA_HORKAGE_NOLPM) {
2213 		ata_dev_warn(dev, "LPM support broken, forcing max_power\n");
2214 		dev->link->ap->target_lpm_policy = ATA_LPM_MAX_POWER;
2215 	}
2216 
2217 	/* let ACPI work its magic */
2218 	rc = ata_acpi_on_devcfg(dev);
2219 	if (rc)
2220 		return rc;
2221 
2222 	/* massage HPA, do it early as it might change IDENTIFY data */
2223 	rc = ata_hpa_resize(dev);
2224 	if (rc)
2225 		return rc;
2226 
2227 	/* print device capabilities */
2228 	if (ata_msg_probe(ap))
2229 		ata_dev_dbg(dev,
2230 			    "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
2231 			    "85:%04x 86:%04x 87:%04x 88:%04x\n",
2232 			    __func__,
2233 			    id[49], id[82], id[83], id[84],
2234 			    id[85], id[86], id[87], id[88]);
2235 
2236 	/* initialize to-be-configured parameters */
2237 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
2238 	dev->max_sectors = 0;
2239 	dev->cdb_len = 0;
2240 	dev->n_sectors = 0;
2241 	dev->cylinders = 0;
2242 	dev->heads = 0;
2243 	dev->sectors = 0;
2244 	dev->multi_count = 0;
2245 
2246 	/*
2247 	 * common ATA, ATAPI feature tests
2248 	 */
2249 
2250 	/* find max transfer mode; for printk only */
2251 	xfer_mask = ata_id_xfermask(id);
2252 
2253 	if (ata_msg_probe(ap))
2254 		ata_dump_id(id);
2255 
2256 	/* SCSI only uses 4-char revisions, dump full 8 chars from ATA */
2257 	ata_id_c_string(dev->id, fwrevbuf, ATA_ID_FW_REV,
2258 			sizeof(fwrevbuf));
2259 
2260 	ata_id_c_string(dev->id, modelbuf, ATA_ID_PROD,
2261 			sizeof(modelbuf));
2262 
2263 	/* ATA-specific feature tests */
2264 	if (dev->class == ATA_DEV_ATA || dev->class == ATA_DEV_ZAC) {
2265 		if (ata_id_is_cfa(id)) {
2266 			/* CPRM may make this media unusable */
2267 			if (id[ATA_ID_CFA_KEY_MGMT] & 1)
2268 				ata_dev_warn(dev,
2269 	"supports DRM functions and may not be fully accessible\n");
2270 			snprintf(revbuf, 7, "CFA");
2271 		} else {
2272 			snprintf(revbuf, 7, "ATA-%d", ata_id_major_version(id));
2273 			/* Warn the user if the device has TPM extensions */
2274 			if (ata_id_has_tpm(id))
2275 				ata_dev_warn(dev,
2276 	"supports DRM functions and may not be fully accessible\n");
2277 		}
2278 
2279 		dev->n_sectors = ata_id_n_sectors(id);
2280 
2281 		/* get current R/W Multiple count setting */
2282 		if ((dev->id[47] >> 8) == 0x80 && (dev->id[59] & 0x100)) {
2283 			unsigned int max = dev->id[47] & 0xff;
2284 			unsigned int cnt = dev->id[59] & 0xff;
2285 			/* only recognize/allow powers of two here */
2286 			if (is_power_of_2(max) && is_power_of_2(cnt))
2287 				if (cnt <= max)
2288 					dev->multi_count = cnt;
2289 		}
2290 
2291 		if (ata_id_has_lba(id)) {
2292 			const char *lba_desc;
2293 			char ncq_desc[24];
2294 
2295 			lba_desc = "LBA";
2296 			dev->flags |= ATA_DFLAG_LBA;
2297 			if (ata_id_has_lba48(id)) {
2298 				dev->flags |= ATA_DFLAG_LBA48;
2299 				lba_desc = "LBA48";
2300 
2301 				if (dev->n_sectors >= (1UL << 28) &&
2302 				    ata_id_has_flush_ext(id))
2303 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
2304 			}
2305 
2306 			/* config NCQ */
2307 			rc = ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
2308 			if (rc)
2309 				return rc;
2310 
2311 			/* print device info to dmesg */
2312 			if (ata_msg_drv(ap) && print_info) {
2313 				ata_dev_info(dev, "%s: %s, %s, max %s\n",
2314 					     revbuf, modelbuf, fwrevbuf,
2315 					     ata_mode_string(xfer_mask));
2316 				ata_dev_info(dev,
2317 					     "%llu sectors, multi %u: %s %s\n",
2318 					(unsigned long long)dev->n_sectors,
2319 					dev->multi_count, lba_desc, ncq_desc);
2320 			}
2321 		} else {
2322 			/* CHS */
2323 
2324 			/* Default translation */
2325 			dev->cylinders	= id[1];
2326 			dev->heads	= id[3];
2327 			dev->sectors	= id[6];
2328 
2329 			if (ata_id_current_chs_valid(id)) {
2330 				/* Current CHS translation is valid. */
2331 				dev->cylinders = id[54];
2332 				dev->heads     = id[55];
2333 				dev->sectors   = id[56];
2334 			}
2335 
2336 			/* print device info to dmesg */
2337 			if (ata_msg_drv(ap) && print_info) {
2338 				ata_dev_info(dev, "%s: %s, %s, max %s\n",
2339 					     revbuf,	modelbuf, fwrevbuf,
2340 					     ata_mode_string(xfer_mask));
2341 				ata_dev_info(dev,
2342 					     "%llu sectors, multi %u, CHS %u/%u/%u\n",
2343 					     (unsigned long long)dev->n_sectors,
2344 					     dev->multi_count, dev->cylinders,
2345 					     dev->heads, dev->sectors);
2346 			}
2347 		}
2348 
2349 		/* Check and mark DevSlp capability. Get DevSlp timing variables
2350 		 * from SATA Settings page of Identify Device Data Log.
2351 		 */
2352 		if (ata_id_has_devslp(dev->id)) {
2353 			u8 *sata_setting = ap->sector_buf;
2354 			int i, j;
2355 
2356 			dev->flags |= ATA_DFLAG_DEVSLP;
2357 			err_mask = ata_read_log_page(dev,
2358 						     ATA_LOG_SATA_ID_DEV_DATA,
2359 						     ATA_LOG_SATA_SETTINGS,
2360 						     sata_setting,
2361 						     1);
2362 			if (err_mask)
2363 				ata_dev_dbg(dev,
2364 					    "failed to get Identify Device Data, Emask 0x%x\n",
2365 					    err_mask);
2366 			else
2367 				for (i = 0; i < ATA_LOG_DEVSLP_SIZE; i++) {
2368 					j = ATA_LOG_DEVSLP_OFFSET + i;
2369 					dev->devslp_timing[i] = sata_setting[j];
2370 				}
2371 		}
2372 
2373 		dev->cdb_len = 16;
2374 	}
2375 
2376 	/* ATAPI-specific feature tests */
2377 	else if (dev->class == ATA_DEV_ATAPI) {
2378 		const char *cdb_intr_string = "";
2379 		const char *atapi_an_string = "";
2380 		const char *dma_dir_string = "";
2381 		u32 sntf;
2382 
2383 		rc = atapi_cdb_len(id);
2384 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
2385 			if (ata_msg_warn(ap))
2386 				ata_dev_warn(dev, "unsupported CDB len\n");
2387 			rc = -EINVAL;
2388 			goto err_out_nosup;
2389 		}
2390 		dev->cdb_len = (unsigned int) rc;
2391 
2392 		/* Enable ATAPI AN if both the host and device have
2393 		 * the support.  If PMP is attached, SNTF is required
2394 		 * to enable ATAPI AN to discern between PHY status
2395 		 * changed notifications and ATAPI ANs.
2396 		 */
2397 		if (atapi_an &&
2398 		    (ap->flags & ATA_FLAG_AN) && ata_id_has_atapi_AN(id) &&
2399 		    (!sata_pmp_attached(ap) ||
2400 		     sata_scr_read(&ap->link, SCR_NOTIFICATION, &sntf) == 0)) {
2401 			/* issue SET feature command to turn this on */
2402 			err_mask = ata_dev_set_feature(dev,
2403 					SETFEATURES_SATA_ENABLE, SATA_AN);
2404 			if (err_mask)
2405 				ata_dev_err(dev,
2406 					    "failed to enable ATAPI AN (err_mask=0x%x)\n",
2407 					    err_mask);
2408 			else {
2409 				dev->flags |= ATA_DFLAG_AN;
2410 				atapi_an_string = ", ATAPI AN";
2411 			}
2412 		}
2413 
2414 		if (ata_id_cdb_intr(dev->id)) {
2415 			dev->flags |= ATA_DFLAG_CDB_INTR;
2416 			cdb_intr_string = ", CDB intr";
2417 		}
2418 
2419 		if (atapi_dmadir || (dev->horkage & ATA_HORKAGE_ATAPI_DMADIR) || atapi_id_dmadir(dev->id)) {
2420 			dev->flags |= ATA_DFLAG_DMADIR;
2421 			dma_dir_string = ", DMADIR";
2422 		}
2423 
2424 		if (ata_id_has_da(dev->id)) {
2425 			dev->flags |= ATA_DFLAG_DA;
2426 			zpodd_init(dev);
2427 		}
2428 
2429 		/* print device info to dmesg */
2430 		if (ata_msg_drv(ap) && print_info)
2431 			ata_dev_info(dev,
2432 				     "ATAPI: %s, %s, max %s%s%s%s\n",
2433 				     modelbuf, fwrevbuf,
2434 				     ata_mode_string(xfer_mask),
2435 				     cdb_intr_string, atapi_an_string,
2436 				     dma_dir_string);
2437 	}
2438 
2439 	/* determine max_sectors */
2440 	dev->max_sectors = ATA_MAX_SECTORS;
2441 	if (dev->flags & ATA_DFLAG_LBA48)
2442 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2443 
2444 	/* Limit PATA drive on SATA cable bridge transfers to udma5,
2445 	   200 sectors */
2446 	if (ata_dev_knobble(dev)) {
2447 		if (ata_msg_drv(ap) && print_info)
2448 			ata_dev_info(dev, "applying bridge limits\n");
2449 		dev->udma_mask &= ATA_UDMA5;
2450 		dev->max_sectors = ATA_MAX_SECTORS;
2451 	}
2452 
2453 	if ((dev->class == ATA_DEV_ATAPI) &&
2454 	    (atapi_command_packet_set(id) == TYPE_TAPE)) {
2455 		dev->max_sectors = ATA_MAX_SECTORS_TAPE;
2456 		dev->horkage |= ATA_HORKAGE_STUCK_ERR;
2457 	}
2458 
2459 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_128)
2460 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_128,
2461 					 dev->max_sectors);
2462 
2463 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_1024)
2464 		dev->max_sectors = min_t(unsigned int, ATA_MAX_SECTORS_1024,
2465 					 dev->max_sectors);
2466 
2467 	if (dev->horkage & ATA_HORKAGE_MAX_SEC_LBA48)
2468 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
2469 
2470 	if (ap->ops->dev_config)
2471 		ap->ops->dev_config(dev);
2472 
2473 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
2474 		/* Let the user know. We don't want to disallow opens for
2475 		   rescue purposes, or in case the vendor is just a blithering
2476 		   idiot. Do this after the dev_config call as some controllers
2477 		   with buggy firmware may want to avoid reporting false device
2478 		   bugs */
2479 
2480 		if (print_info) {
2481 			ata_dev_warn(dev,
2482 "Drive reports diagnostics failure. This may indicate a drive\n");
2483 			ata_dev_warn(dev,
2484 "fault or invalid emulation. Contact drive vendor for information.\n");
2485 		}
2486 	}
2487 
2488 	if ((dev->horkage & ATA_HORKAGE_FIRMWARE_WARN) && print_info) {
2489 		ata_dev_warn(dev, "WARNING: device requires firmware update to be fully functional\n");
2490 		ata_dev_warn(dev, "         contact the vendor or visit http://ata.wiki.kernel.org\n");
2491 	}
2492 
2493 	return 0;
2494 
2495 err_out_nosup:
2496 	if (ata_msg_probe(ap))
2497 		ata_dev_dbg(dev, "%s: EXIT, err\n", __func__);
2498 	return rc;
2499 }
2500 
2501 /**
2502  *	ata_cable_40wire	-	return 40 wire cable type
2503  *	@ap: port
2504  *
2505  *	Helper method for drivers which want to hardwire 40 wire cable
2506  *	detection.
2507  */
2508 
2509 int ata_cable_40wire(struct ata_port *ap)
2510 {
2511 	return ATA_CBL_PATA40;
2512 }
2513 
2514 /**
2515  *	ata_cable_80wire	-	return 80 wire cable type
2516  *	@ap: port
2517  *
2518  *	Helper method for drivers which want to hardwire 80 wire cable
2519  *	detection.
2520  */
2521 
2522 int ata_cable_80wire(struct ata_port *ap)
2523 {
2524 	return ATA_CBL_PATA80;
2525 }
2526 
2527 /**
2528  *	ata_cable_unknown	-	return unknown PATA cable.
2529  *	@ap: port
2530  *
2531  *	Helper method for drivers which have no PATA cable detection.
2532  */
2533 
2534 int ata_cable_unknown(struct ata_port *ap)
2535 {
2536 	return ATA_CBL_PATA_UNK;
2537 }
2538 
2539 /**
2540  *	ata_cable_ignore	-	return ignored PATA cable.
2541  *	@ap: port
2542  *
2543  *	Helper method for drivers which don't use cable type to limit
2544  *	transfer mode.
2545  */
2546 int ata_cable_ignore(struct ata_port *ap)
2547 {
2548 	return ATA_CBL_PATA_IGN;
2549 }
2550 
2551 /**
2552  *	ata_cable_sata	-	return SATA cable type
2553  *	@ap: port
2554  *
2555  *	Helper method for drivers which have SATA cables
2556  */
2557 
2558 int ata_cable_sata(struct ata_port *ap)
2559 {
2560 	return ATA_CBL_SATA;
2561 }
2562 
2563 /**
2564  *	ata_bus_probe - Reset and probe ATA bus
2565  *	@ap: Bus to probe
2566  *
2567  *	Master ATA bus probing function.  Initiates a hardware-dependent
2568  *	bus reset, then attempts to identify any devices found on
2569  *	the bus.
2570  *
2571  *	LOCKING:
2572  *	PCI/etc. bus probe sem.
2573  *
2574  *	RETURNS:
2575  *	Zero on success, negative errno otherwise.
2576  */
2577 
2578 int ata_bus_probe(struct ata_port *ap)
2579 {
2580 	unsigned int classes[ATA_MAX_DEVICES];
2581 	int tries[ATA_MAX_DEVICES];
2582 	int rc;
2583 	struct ata_device *dev;
2584 
2585 	ata_for_each_dev(dev, &ap->link, ALL)
2586 		tries[dev->devno] = ATA_PROBE_MAX_TRIES;
2587 
2588  retry:
2589 	ata_for_each_dev(dev, &ap->link, ALL) {
2590 		/* If we issue an SRST then an ATA drive (not ATAPI)
2591 		 * may change configuration and be in PIO0 timing. If
2592 		 * we do a hard reset (or are coming from power on)
2593 		 * this is true for ATA or ATAPI. Until we've set a
2594 		 * suitable controller mode we should not touch the
2595 		 * bus as we may be talking too fast.
2596 		 */
2597 		dev->pio_mode = XFER_PIO_0;
2598 		dev->dma_mode = 0xff;
2599 
2600 		/* If the controller has a pio mode setup function
2601 		 * then use it to set the chipset to rights. Don't
2602 		 * touch the DMA setup as that will be dealt with when
2603 		 * configuring devices.
2604 		 */
2605 		if (ap->ops->set_piomode)
2606 			ap->ops->set_piomode(ap, dev);
2607 	}
2608 
2609 	/* reset and determine device classes */
2610 	ap->ops->phy_reset(ap);
2611 
2612 	ata_for_each_dev(dev, &ap->link, ALL) {
2613 		if (dev->class != ATA_DEV_UNKNOWN)
2614 			classes[dev->devno] = dev->class;
2615 		else
2616 			classes[dev->devno] = ATA_DEV_NONE;
2617 
2618 		dev->class = ATA_DEV_UNKNOWN;
2619 	}
2620 
2621 	/* read IDENTIFY page and configure devices. We have to do the identify
2622 	   specific sequence bass-ackwards so that PDIAG- is released by
2623 	   the slave device */
2624 
2625 	ata_for_each_dev(dev, &ap->link, ALL_REVERSE) {
2626 		if (tries[dev->devno])
2627 			dev->class = classes[dev->devno];
2628 
2629 		if (!ata_dev_enabled(dev))
2630 			continue;
2631 
2632 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
2633 				     dev->id);
2634 		if (rc)
2635 			goto fail;
2636 	}
2637 
2638 	/* Now ask for the cable type as PDIAG- should have been released */
2639 	if (ap->ops->cable_detect)
2640 		ap->cbl = ap->ops->cable_detect(ap);
2641 
2642 	/* We may have SATA bridge glue hiding here irrespective of
2643 	 * the reported cable types and sensed types.  When SATA
2644 	 * drives indicate we have a bridge, we don't know which end
2645 	 * of the link the bridge is which is a problem.
2646 	 */
2647 	ata_for_each_dev(dev, &ap->link, ENABLED)
2648 		if (ata_id_is_sata(dev->id))
2649 			ap->cbl = ATA_CBL_SATA;
2650 
2651 	/* After the identify sequence we can now set up the devices. We do
2652 	   this in the normal order so that the user doesn't get confused */
2653 
2654 	ata_for_each_dev(dev, &ap->link, ENABLED) {
2655 		ap->link.eh_context.i.flags |= ATA_EHI_PRINTINFO;
2656 		rc = ata_dev_configure(dev);
2657 		ap->link.eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
2658 		if (rc)
2659 			goto fail;
2660 	}
2661 
2662 	/* configure transfer mode */
2663 	rc = ata_set_mode(&ap->link, &dev);
2664 	if (rc)
2665 		goto fail;
2666 
2667 	ata_for_each_dev(dev, &ap->link, ENABLED)
2668 		return 0;
2669 
2670 	return -ENODEV;
2671 
2672  fail:
2673 	tries[dev->devno]--;
2674 
2675 	switch (rc) {
2676 	case -EINVAL:
2677 		/* eeek, something went very wrong, give up */
2678 		tries[dev->devno] = 0;
2679 		break;
2680 
2681 	case -ENODEV:
2682 		/* give it just one more chance */
2683 		tries[dev->devno] = min(tries[dev->devno], 1);
2684 	case -EIO:
2685 		if (tries[dev->devno] == 1) {
2686 			/* This is the last chance, better to slow
2687 			 * down than lose it.
2688 			 */
2689 			sata_down_spd_limit(&ap->link, 0);
2690 			ata_down_xfermask_limit(dev, ATA_DNXFER_PIO);
2691 		}
2692 	}
2693 
2694 	if (!tries[dev->devno])
2695 		ata_dev_disable(dev);
2696 
2697 	goto retry;
2698 }
2699 
2700 /**
2701  *	sata_print_link_status - Print SATA link status
2702  *	@link: SATA link to printk link status about
2703  *
2704  *	This function prints link speed and status of a SATA link.
2705  *
2706  *	LOCKING:
2707  *	None.
2708  */
2709 static void sata_print_link_status(struct ata_link *link)
2710 {
2711 	u32 sstatus, scontrol, tmp;
2712 
2713 	if (sata_scr_read(link, SCR_STATUS, &sstatus))
2714 		return;
2715 	sata_scr_read(link, SCR_CONTROL, &scontrol);
2716 
2717 	if (ata_phys_link_online(link)) {
2718 		tmp = (sstatus >> 4) & 0xf;
2719 		ata_link_info(link, "SATA link up %s (SStatus %X SControl %X)\n",
2720 			      sata_spd_string(tmp), sstatus, scontrol);
2721 	} else {
2722 		ata_link_info(link, "SATA link down (SStatus %X SControl %X)\n",
2723 			      sstatus, scontrol);
2724 	}
2725 }
2726 
2727 /**
2728  *	ata_dev_pair		-	return other device on cable
2729  *	@adev: device
2730  *
2731  *	Obtain the other device on the same cable, or if none is
2732  *	present NULL is returned
2733  */
2734 
2735 struct ata_device *ata_dev_pair(struct ata_device *adev)
2736 {
2737 	struct ata_link *link = adev->link;
2738 	struct ata_device *pair = &link->device[1 - adev->devno];
2739 	if (!ata_dev_enabled(pair))
2740 		return NULL;
2741 	return pair;
2742 }
2743 
2744 /**
2745  *	sata_down_spd_limit - adjust SATA spd limit downward
2746  *	@link: Link to adjust SATA spd limit for
2747  *	@spd_limit: Additional limit
2748  *
2749  *	Adjust SATA spd limit of @link downward.  Note that this
2750  *	function only adjusts the limit.  The change must be applied
2751  *	using sata_set_spd().
2752  *
2753  *	If @spd_limit is non-zero, the speed is limited to equal to or
2754  *	lower than @spd_limit if such speed is supported.  If
2755  *	@spd_limit is slower than any supported speed, only the lowest
2756  *	supported speed is allowed.
2757  *
2758  *	LOCKING:
2759  *	Inherited from caller.
2760  *
2761  *	RETURNS:
2762  *	0 on success, negative errno on failure
2763  */
2764 int sata_down_spd_limit(struct ata_link *link, u32 spd_limit)
2765 {
2766 	u32 sstatus, spd, mask;
2767 	int rc, bit;
2768 
2769 	if (!sata_scr_valid(link))
2770 		return -EOPNOTSUPP;
2771 
2772 	/* If SCR can be read, use it to determine the current SPD.
2773 	 * If not, use cached value in link->sata_spd.
2774 	 */
2775 	rc = sata_scr_read(link, SCR_STATUS, &sstatus);
2776 	if (rc == 0 && ata_sstatus_online(sstatus))
2777 		spd = (sstatus >> 4) & 0xf;
2778 	else
2779 		spd = link->sata_spd;
2780 
2781 	mask = link->sata_spd_limit;
2782 	if (mask <= 1)
2783 		return -EINVAL;
2784 
2785 	/* unconditionally mask off the highest bit */
2786 	bit = fls(mask) - 1;
2787 	mask &= ~(1 << bit);
2788 
2789 	/* Mask off all speeds higher than or equal to the current
2790 	 * one.  Force 1.5Gbps if current SPD is not available.
2791 	 */
2792 	if (spd > 1)
2793 		mask &= (1 << (spd - 1)) - 1;
2794 	else
2795 		mask &= 1;
2796 
2797 	/* were we already at the bottom? */
2798 	if (!mask)
2799 		return -EINVAL;
2800 
2801 	if (spd_limit) {
2802 		if (mask & ((1 << spd_limit) - 1))
2803 			mask &= (1 << spd_limit) - 1;
2804 		else {
2805 			bit = ffs(mask) - 1;
2806 			mask = 1 << bit;
2807 		}
2808 	}
2809 
2810 	link->sata_spd_limit = mask;
2811 
2812 	ata_link_warn(link, "limiting SATA link speed to %s\n",
2813 		      sata_spd_string(fls(mask)));
2814 
2815 	return 0;
2816 }
2817 
2818 static int __sata_set_spd_needed(struct ata_link *link, u32 *scontrol)
2819 {
2820 	struct ata_link *host_link = &link->ap->link;
2821 	u32 limit, target, spd;
2822 
2823 	limit = link->sata_spd_limit;
2824 
2825 	/* Don't configure downstream link faster than upstream link.
2826 	 * It doesn't speed up anything and some PMPs choke on such
2827 	 * configuration.
2828 	 */
2829 	if (!ata_is_host_link(link) && host_link->sata_spd)
2830 		limit &= (1 << host_link->sata_spd) - 1;
2831 
2832 	if (limit == UINT_MAX)
2833 		target = 0;
2834 	else
2835 		target = fls(limit);
2836 
2837 	spd = (*scontrol >> 4) & 0xf;
2838 	*scontrol = (*scontrol & ~0xf0) | ((target & 0xf) << 4);
2839 
2840 	return spd != target;
2841 }
2842 
2843 /**
2844  *	sata_set_spd_needed - is SATA spd configuration needed
2845  *	@link: Link in question
2846  *
2847  *	Test whether the spd limit in SControl matches
2848  *	@link->sata_spd_limit.  This function is used to determine
2849  *	whether hardreset is necessary to apply SATA spd
2850  *	configuration.
2851  *
2852  *	LOCKING:
2853  *	Inherited from caller.
2854  *
2855  *	RETURNS:
2856  *	1 if SATA spd configuration is needed, 0 otherwise.
2857  */
2858 static int sata_set_spd_needed(struct ata_link *link)
2859 {
2860 	u32 scontrol;
2861 
2862 	if (sata_scr_read(link, SCR_CONTROL, &scontrol))
2863 		return 1;
2864 
2865 	return __sata_set_spd_needed(link, &scontrol);
2866 }
2867 
2868 /**
2869  *	sata_set_spd - set SATA spd according to spd limit
2870  *	@link: Link to set SATA spd for
2871  *
2872  *	Set SATA spd of @link according to sata_spd_limit.
2873  *
2874  *	LOCKING:
2875  *	Inherited from caller.
2876  *
2877  *	RETURNS:
2878  *	0 if spd doesn't need to be changed, 1 if spd has been
2879  *	changed.  Negative errno if SCR registers are inaccessible.
2880  */
2881 int sata_set_spd(struct ata_link *link)
2882 {
2883 	u32 scontrol;
2884 	int rc;
2885 
2886 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
2887 		return rc;
2888 
2889 	if (!__sata_set_spd_needed(link, &scontrol))
2890 		return 0;
2891 
2892 	if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
2893 		return rc;
2894 
2895 	return 1;
2896 }
2897 
2898 /*
2899  * This mode timing computation functionality is ported over from
2900  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2901  */
2902 /*
2903  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2904  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2905  * for UDMA6, which is currently supported only by Maxtor drives.
2906  *
2907  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2908  */
2909 
2910 static const struct ata_timing ata_timing[] = {
2911 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 0,  960,   0 }, */
2912 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 0,  600,   0 },
2913 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 0,  383,   0 },
2914 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 0,  240,   0 },
2915 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 0,  180,   0 },
2916 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 0,  120,   0 },
2917 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 0,  100,   0 },
2918 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20, 0,   80,   0 },
2919 
2920 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 50, 960,   0 },
2921 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 30, 480,   0 },
2922 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 20, 240,   0 },
2923 
2924 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 20, 480,   0 },
2925 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 5,  150,   0 },
2926 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 5,  120,   0 },
2927 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 5,  100,   0 },
2928 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20, 5,   80,   0 },
2929 
2930 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0, 0,    0, 150 }, */
2931 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0, 0,    0, 120 },
2932 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0, 0,    0,  80 },
2933 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0, 0,    0,  60 },
2934 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0, 0,    0,  45 },
2935 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0, 0,    0,  30 },
2936 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0, 0,    0,  20 },
2937 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0, 0,    0,  15 },
2938 
2939 	{ 0xFF }
2940 };
2941 
2942 #define ENOUGH(v, unit)		(((v)-1)/(unit)+1)
2943 #define EZ(v, unit)		((v)?ENOUGH(v, unit):0)
2944 
2945 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2946 {
2947 	q->setup	= EZ(t->setup      * 1000,  T);
2948 	q->act8b	= EZ(t->act8b      * 1000,  T);
2949 	q->rec8b	= EZ(t->rec8b      * 1000,  T);
2950 	q->cyc8b	= EZ(t->cyc8b      * 1000,  T);
2951 	q->active	= EZ(t->active     * 1000,  T);
2952 	q->recover	= EZ(t->recover    * 1000,  T);
2953 	q->dmack_hold	= EZ(t->dmack_hold * 1000,  T);
2954 	q->cycle	= EZ(t->cycle      * 1000,  T);
2955 	q->udma		= EZ(t->udma       * 1000, UT);
2956 }
2957 
2958 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2959 		      struct ata_timing *m, unsigned int what)
2960 {
2961 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2962 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2963 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2964 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2965 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
2966 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
2967 	if (what & ATA_TIMING_DMACK_HOLD) m->dmack_hold = max(a->dmack_hold, b->dmack_hold);
2968 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
2969 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
2970 }
2971 
2972 const struct ata_timing *ata_timing_find_mode(u8 xfer_mode)
2973 {
2974 	const struct ata_timing *t = ata_timing;
2975 
2976 	while (xfer_mode > t->mode)
2977 		t++;
2978 
2979 	if (xfer_mode == t->mode)
2980 		return t;
2981 
2982 	WARN_ONCE(true, "%s: unable to find timing for xfer_mode 0x%x\n",
2983 			__func__, xfer_mode);
2984 
2985 	return NULL;
2986 }
2987 
2988 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
2989 		       struct ata_timing *t, int T, int UT)
2990 {
2991 	const u16 *id = adev->id;
2992 	const struct ata_timing *s;
2993 	struct ata_timing p;
2994 
2995 	/*
2996 	 * Find the mode.
2997 	 */
2998 
2999 	if (!(s = ata_timing_find_mode(speed)))
3000 		return -EINVAL;
3001 
3002 	memcpy(t, s, sizeof(*s));
3003 
3004 	/*
3005 	 * If the drive is an EIDE drive, it can tell us it needs extended
3006 	 * PIO/MW_DMA cycle timing.
3007 	 */
3008 
3009 	if (id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
3010 		memset(&p, 0, sizeof(p));
3011 
3012 		if (speed >= XFER_PIO_0 && speed < XFER_SW_DMA_0) {
3013 			if (speed <= XFER_PIO_2)
3014 				p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO];
3015 			else if ((speed <= XFER_PIO_4) ||
3016 				 (speed == XFER_PIO_5 && !ata_id_is_cfa(id)))
3017 				p.cycle = p.cyc8b = id[ATA_ID_EIDE_PIO_IORDY];
3018 		} else if (speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2)
3019 			p.cycle = id[ATA_ID_EIDE_DMA_MIN];
3020 
3021 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
3022 	}
3023 
3024 	/*
3025 	 * Convert the timing to bus clock counts.
3026 	 */
3027 
3028 	ata_timing_quantize(t, t, T, UT);
3029 
3030 	/*
3031 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
3032 	 * S.M.A.R.T * and some other commands. We have to ensure that the
3033 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
3034 	 */
3035 
3036 	if (speed > XFER_PIO_6) {
3037 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
3038 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
3039 	}
3040 
3041 	/*
3042 	 * Lengthen active & recovery time so that cycle time is correct.
3043 	 */
3044 
3045 	if (t->act8b + t->rec8b < t->cyc8b) {
3046 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
3047 		t->rec8b = t->cyc8b - t->act8b;
3048 	}
3049 
3050 	if (t->active + t->recover < t->cycle) {
3051 		t->active += (t->cycle - (t->active + t->recover)) / 2;
3052 		t->recover = t->cycle - t->active;
3053 	}
3054 
3055 	/* In a few cases quantisation may produce enough errors to
3056 	   leave t->cycle too low for the sum of active and recovery
3057 	   if so we must correct this */
3058 	if (t->active + t->recover > t->cycle)
3059 		t->cycle = t->active + t->recover;
3060 
3061 	return 0;
3062 }
3063 
3064 /**
3065  *	ata_timing_cycle2mode - find xfer mode for the specified cycle duration
3066  *	@xfer_shift: ATA_SHIFT_* value for transfer type to examine.
3067  *	@cycle: cycle duration in ns
3068  *
3069  *	Return matching xfer mode for @cycle.  The returned mode is of
3070  *	the transfer type specified by @xfer_shift.  If @cycle is too
3071  *	slow for @xfer_shift, 0xff is returned.  If @cycle is faster
3072  *	than the fastest known mode, the fasted mode is returned.
3073  *
3074  *	LOCKING:
3075  *	None.
3076  *
3077  *	RETURNS:
3078  *	Matching xfer_mode, 0xff if no match found.
3079  */
3080 u8 ata_timing_cycle2mode(unsigned int xfer_shift, int cycle)
3081 {
3082 	u8 base_mode = 0xff, last_mode = 0xff;
3083 	const struct ata_xfer_ent *ent;
3084 	const struct ata_timing *t;
3085 
3086 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
3087 		if (ent->shift == xfer_shift)
3088 			base_mode = ent->base;
3089 
3090 	for (t = ata_timing_find_mode(base_mode);
3091 	     t && ata_xfer_mode2shift(t->mode) == xfer_shift; t++) {
3092 		unsigned short this_cycle;
3093 
3094 		switch (xfer_shift) {
3095 		case ATA_SHIFT_PIO:
3096 		case ATA_SHIFT_MWDMA:
3097 			this_cycle = t->cycle;
3098 			break;
3099 		case ATA_SHIFT_UDMA:
3100 			this_cycle = t->udma;
3101 			break;
3102 		default:
3103 			return 0xff;
3104 		}
3105 
3106 		if (cycle > this_cycle)
3107 			break;
3108 
3109 		last_mode = t->mode;
3110 	}
3111 
3112 	return last_mode;
3113 }
3114 
3115 /**
3116  *	ata_down_xfermask_limit - adjust dev xfer masks downward
3117  *	@dev: Device to adjust xfer masks
3118  *	@sel: ATA_DNXFER_* selector
3119  *
3120  *	Adjust xfer masks of @dev downward.  Note that this function
3121  *	does not apply the change.  Invoking ata_set_mode() afterwards
3122  *	will apply the limit.
3123  *
3124  *	LOCKING:
3125  *	Inherited from caller.
3126  *
3127  *	RETURNS:
3128  *	0 on success, negative errno on failure
3129  */
3130 int ata_down_xfermask_limit(struct ata_device *dev, unsigned int sel)
3131 {
3132 	char buf[32];
3133 	unsigned long orig_mask, xfer_mask;
3134 	unsigned long pio_mask, mwdma_mask, udma_mask;
3135 	int quiet, highbit;
3136 
3137 	quiet = !!(sel & ATA_DNXFER_QUIET);
3138 	sel &= ~ATA_DNXFER_QUIET;
3139 
3140 	xfer_mask = orig_mask = ata_pack_xfermask(dev->pio_mask,
3141 						  dev->mwdma_mask,
3142 						  dev->udma_mask);
3143 	ata_unpack_xfermask(xfer_mask, &pio_mask, &mwdma_mask, &udma_mask);
3144 
3145 	switch (sel) {
3146 	case ATA_DNXFER_PIO:
3147 		highbit = fls(pio_mask) - 1;
3148 		pio_mask &= ~(1 << highbit);
3149 		break;
3150 
3151 	case ATA_DNXFER_DMA:
3152 		if (udma_mask) {
3153 			highbit = fls(udma_mask) - 1;
3154 			udma_mask &= ~(1 << highbit);
3155 			if (!udma_mask)
3156 				return -ENOENT;
3157 		} else if (mwdma_mask) {
3158 			highbit = fls(mwdma_mask) - 1;
3159 			mwdma_mask &= ~(1 << highbit);
3160 			if (!mwdma_mask)
3161 				return -ENOENT;
3162 		}
3163 		break;
3164 
3165 	case ATA_DNXFER_40C:
3166 		udma_mask &= ATA_UDMA_MASK_40C;
3167 		break;
3168 
3169 	case ATA_DNXFER_FORCE_PIO0:
3170 		pio_mask &= 1;
3171 	case ATA_DNXFER_FORCE_PIO:
3172 		mwdma_mask = 0;
3173 		udma_mask = 0;
3174 		break;
3175 
3176 	default:
3177 		BUG();
3178 	}
3179 
3180 	xfer_mask &= ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
3181 
3182 	if (!(xfer_mask & ATA_MASK_PIO) || xfer_mask == orig_mask)
3183 		return -ENOENT;
3184 
3185 	if (!quiet) {
3186 		if (xfer_mask & (ATA_MASK_MWDMA | ATA_MASK_UDMA))
3187 			snprintf(buf, sizeof(buf), "%s:%s",
3188 				 ata_mode_string(xfer_mask),
3189 				 ata_mode_string(xfer_mask & ATA_MASK_PIO));
3190 		else
3191 			snprintf(buf, sizeof(buf), "%s",
3192 				 ata_mode_string(xfer_mask));
3193 
3194 		ata_dev_warn(dev, "limiting speed to %s\n", buf);
3195 	}
3196 
3197 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
3198 			    &dev->udma_mask);
3199 
3200 	return 0;
3201 }
3202 
3203 static int ata_dev_set_mode(struct ata_device *dev)
3204 {
3205 	struct ata_port *ap = dev->link->ap;
3206 	struct ata_eh_context *ehc = &dev->link->eh_context;
3207 	const bool nosetxfer = dev->horkage & ATA_HORKAGE_NOSETXFER;
3208 	const char *dev_err_whine = "";
3209 	int ign_dev_err = 0;
3210 	unsigned int err_mask = 0;
3211 	int rc;
3212 
3213 	dev->flags &= ~ATA_DFLAG_PIO;
3214 	if (dev->xfer_shift == ATA_SHIFT_PIO)
3215 		dev->flags |= ATA_DFLAG_PIO;
3216 
3217 	if (nosetxfer && ap->flags & ATA_FLAG_SATA && ata_id_is_sata(dev->id))
3218 		dev_err_whine = " (SET_XFERMODE skipped)";
3219 	else {
3220 		if (nosetxfer)
3221 			ata_dev_warn(dev,
3222 				     "NOSETXFER but PATA detected - can't "
3223 				     "skip SETXFER, might malfunction\n");
3224 		err_mask = ata_dev_set_xfermode(dev);
3225 	}
3226 
3227 	if (err_mask & ~AC_ERR_DEV)
3228 		goto fail;
3229 
3230 	/* revalidate */
3231 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
3232 	rc = ata_dev_revalidate(dev, ATA_DEV_UNKNOWN, 0);
3233 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
3234 	if (rc)
3235 		return rc;
3236 
3237 	if (dev->xfer_shift == ATA_SHIFT_PIO) {
3238 		/* Old CFA may refuse this command, which is just fine */
3239 		if (ata_id_is_cfa(dev->id))
3240 			ign_dev_err = 1;
3241 		/* Catch several broken garbage emulations plus some pre
3242 		   ATA devices */
3243 		if (ata_id_major_version(dev->id) == 0 &&
3244 					dev->pio_mode <= XFER_PIO_2)
3245 			ign_dev_err = 1;
3246 		/* Some very old devices and some bad newer ones fail
3247 		   any kind of SET_XFERMODE request but support PIO0-2
3248 		   timings and no IORDY */
3249 		if (!ata_id_has_iordy(dev->id) && dev->pio_mode <= XFER_PIO_2)
3250 			ign_dev_err = 1;
3251 	}
3252 	/* Early MWDMA devices do DMA but don't allow DMA mode setting.
3253 	   Don't fail an MWDMA0 set IFF the device indicates it is in MWDMA0 */
3254 	if (dev->xfer_shift == ATA_SHIFT_MWDMA &&
3255 	    dev->dma_mode == XFER_MW_DMA_0 &&
3256 	    (dev->id[63] >> 8) & 1)
3257 		ign_dev_err = 1;
3258 
3259 	/* if the device is actually configured correctly, ignore dev err */
3260 	if (dev->xfer_mode == ata_xfer_mask2mode(ata_id_xfermask(dev->id)))
3261 		ign_dev_err = 1;
3262 
3263 	if (err_mask & AC_ERR_DEV) {
3264 		if (!ign_dev_err)
3265 			goto fail;
3266 		else
3267 			dev_err_whine = " (device error ignored)";
3268 	}
3269 
3270 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
3271 		dev->xfer_shift, (int)dev->xfer_mode);
3272 
3273 	ata_dev_info(dev, "configured for %s%s\n",
3274 		     ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)),
3275 		     dev_err_whine);
3276 
3277 	return 0;
3278 
3279  fail:
3280 	ata_dev_err(dev, "failed to set xfermode (err_mask=0x%x)\n", err_mask);
3281 	return -EIO;
3282 }
3283 
3284 /**
3285  *	ata_do_set_mode - Program timings and issue SET FEATURES - XFER
3286  *	@link: link on which timings will be programmed
3287  *	@r_failed_dev: out parameter for failed device
3288  *
3289  *	Standard implementation of the function used to tune and set
3290  *	ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
3291  *	ata_dev_set_mode() fails, pointer to the failing device is
3292  *	returned in @r_failed_dev.
3293  *
3294  *	LOCKING:
3295  *	PCI/etc. bus probe sem.
3296  *
3297  *	RETURNS:
3298  *	0 on success, negative errno otherwise
3299  */
3300 
3301 int ata_do_set_mode(struct ata_link *link, struct ata_device **r_failed_dev)
3302 {
3303 	struct ata_port *ap = link->ap;
3304 	struct ata_device *dev;
3305 	int rc = 0, used_dma = 0, found = 0;
3306 
3307 	/* step 1: calculate xfer_mask */
3308 	ata_for_each_dev(dev, link, ENABLED) {
3309 		unsigned long pio_mask, dma_mask;
3310 		unsigned int mode_mask;
3311 
3312 		mode_mask = ATA_DMA_MASK_ATA;
3313 		if (dev->class == ATA_DEV_ATAPI)
3314 			mode_mask = ATA_DMA_MASK_ATAPI;
3315 		else if (ata_id_is_cfa(dev->id))
3316 			mode_mask = ATA_DMA_MASK_CFA;
3317 
3318 		ata_dev_xfermask(dev);
3319 		ata_force_xfermask(dev);
3320 
3321 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
3322 
3323 		if (libata_dma_mask & mode_mask)
3324 			dma_mask = ata_pack_xfermask(0, dev->mwdma_mask,
3325 						     dev->udma_mask);
3326 		else
3327 			dma_mask = 0;
3328 
3329 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
3330 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
3331 
3332 		found = 1;
3333 		if (ata_dma_enabled(dev))
3334 			used_dma = 1;
3335 	}
3336 	if (!found)
3337 		goto out;
3338 
3339 	/* step 2: always set host PIO timings */
3340 	ata_for_each_dev(dev, link, ENABLED) {
3341 		if (dev->pio_mode == 0xff) {
3342 			ata_dev_warn(dev, "no PIO support\n");
3343 			rc = -EINVAL;
3344 			goto out;
3345 		}
3346 
3347 		dev->xfer_mode = dev->pio_mode;
3348 		dev->xfer_shift = ATA_SHIFT_PIO;
3349 		if (ap->ops->set_piomode)
3350 			ap->ops->set_piomode(ap, dev);
3351 	}
3352 
3353 	/* step 3: set host DMA timings */
3354 	ata_for_each_dev(dev, link, ENABLED) {
3355 		if (!ata_dma_enabled(dev))
3356 			continue;
3357 
3358 		dev->xfer_mode = dev->dma_mode;
3359 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
3360 		if (ap->ops->set_dmamode)
3361 			ap->ops->set_dmamode(ap, dev);
3362 	}
3363 
3364 	/* step 4: update devices' xfer mode */
3365 	ata_for_each_dev(dev, link, ENABLED) {
3366 		rc = ata_dev_set_mode(dev);
3367 		if (rc)
3368 			goto out;
3369 	}
3370 
3371 	/* Record simplex status. If we selected DMA then the other
3372 	 * host channels are not permitted to do so.
3373 	 */
3374 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
3375 		ap->host->simplex_claimed = ap;
3376 
3377  out:
3378 	if (rc)
3379 		*r_failed_dev = dev;
3380 	return rc;
3381 }
3382 
3383 /**
3384  *	ata_wait_ready - wait for link to become ready
3385  *	@link: link to be waited on
3386  *	@deadline: deadline jiffies for the operation
3387  *	@check_ready: callback to check link readiness
3388  *
3389  *	Wait for @link to become ready.  @check_ready should return
3390  *	positive number if @link is ready, 0 if it isn't, -ENODEV if
3391  *	link doesn't seem to be occupied, other errno for other error
3392  *	conditions.
3393  *
3394  *	Transient -ENODEV conditions are allowed for
3395  *	ATA_TMOUT_FF_WAIT.
3396  *
3397  *	LOCKING:
3398  *	EH context.
3399  *
3400  *	RETURNS:
3401  *	0 if @linke is ready before @deadline; otherwise, -errno.
3402  */
3403 int ata_wait_ready(struct ata_link *link, unsigned long deadline,
3404 		   int (*check_ready)(struct ata_link *link))
3405 {
3406 	unsigned long start = jiffies;
3407 	unsigned long nodev_deadline;
3408 	int warned = 0;
3409 
3410 	/* choose which 0xff timeout to use, read comment in libata.h */
3411 	if (link->ap->host->flags & ATA_HOST_PARALLEL_SCAN)
3412 		nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT_LONG);
3413 	else
3414 		nodev_deadline = ata_deadline(start, ATA_TMOUT_FF_WAIT);
3415 
3416 	/* Slave readiness can't be tested separately from master.  On
3417 	 * M/S emulation configuration, this function should be called
3418 	 * only on the master and it will handle both master and slave.
3419 	 */
3420 	WARN_ON(link == link->ap->slave_link);
3421 
3422 	if (time_after(nodev_deadline, deadline))
3423 		nodev_deadline = deadline;
3424 
3425 	while (1) {
3426 		unsigned long now = jiffies;
3427 		int ready, tmp;
3428 
3429 		ready = tmp = check_ready(link);
3430 		if (ready > 0)
3431 			return 0;
3432 
3433 		/*
3434 		 * -ENODEV could be transient.  Ignore -ENODEV if link
3435 		 * is online.  Also, some SATA devices take a long
3436 		 * time to clear 0xff after reset.  Wait for
3437 		 * ATA_TMOUT_FF_WAIT[_LONG] on -ENODEV if link isn't
3438 		 * offline.
3439 		 *
3440 		 * Note that some PATA controllers (pata_ali) explode
3441 		 * if status register is read more than once when
3442 		 * there's no device attached.
3443 		 */
3444 		if (ready == -ENODEV) {
3445 			if (ata_link_online(link))
3446 				ready = 0;
3447 			else if ((link->ap->flags & ATA_FLAG_SATA) &&
3448 				 !ata_link_offline(link) &&
3449 				 time_before(now, nodev_deadline))
3450 				ready = 0;
3451 		}
3452 
3453 		if (ready)
3454 			return ready;
3455 		if (time_after(now, deadline))
3456 			return -EBUSY;
3457 
3458 		if (!warned && time_after(now, start + 5 * HZ) &&
3459 		    (deadline - now > 3 * HZ)) {
3460 			ata_link_warn(link,
3461 				"link is slow to respond, please be patient "
3462 				"(ready=%d)\n", tmp);
3463 			warned = 1;
3464 		}
3465 
3466 		ata_msleep(link->ap, 50);
3467 	}
3468 }
3469 
3470 /**
3471  *	ata_wait_after_reset - wait for link to become ready after reset
3472  *	@link: link to be waited on
3473  *	@deadline: deadline jiffies for the operation
3474  *	@check_ready: callback to check link readiness
3475  *
3476  *	Wait for @link to become ready after reset.
3477  *
3478  *	LOCKING:
3479  *	EH context.
3480  *
3481  *	RETURNS:
3482  *	0 if @linke is ready before @deadline; otherwise, -errno.
3483  */
3484 int ata_wait_after_reset(struct ata_link *link, unsigned long deadline,
3485 				int (*check_ready)(struct ata_link *link))
3486 {
3487 	ata_msleep(link->ap, ATA_WAIT_AFTER_RESET);
3488 
3489 	return ata_wait_ready(link, deadline, check_ready);
3490 }
3491 
3492 /**
3493  *	sata_link_debounce - debounce SATA phy status
3494  *	@link: ATA link to debounce SATA phy status for
3495  *	@params: timing parameters { interval, duratinon, timeout } in msec
3496  *	@deadline: deadline jiffies for the operation
3497  *
3498  *	Make sure SStatus of @link reaches stable state, determined by
3499  *	holding the same value where DET is not 1 for @duration polled
3500  *	every @interval, before @timeout.  Timeout constraints the
3501  *	beginning of the stable state.  Because DET gets stuck at 1 on
3502  *	some controllers after hot unplugging, this functions waits
3503  *	until timeout then returns 0 if DET is stable at 1.
3504  *
3505  *	@timeout is further limited by @deadline.  The sooner of the
3506  *	two is used.
3507  *
3508  *	LOCKING:
3509  *	Kernel thread context (may sleep)
3510  *
3511  *	RETURNS:
3512  *	0 on success, -errno on failure.
3513  */
3514 int sata_link_debounce(struct ata_link *link, const unsigned long *params,
3515 		       unsigned long deadline)
3516 {
3517 	unsigned long interval = params[0];
3518 	unsigned long duration = params[1];
3519 	unsigned long last_jiffies, t;
3520 	u32 last, cur;
3521 	int rc;
3522 
3523 	t = ata_deadline(jiffies, params[2]);
3524 	if (time_before(t, deadline))
3525 		deadline = t;
3526 
3527 	if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3528 		return rc;
3529 	cur &= 0xf;
3530 
3531 	last = cur;
3532 	last_jiffies = jiffies;
3533 
3534 	while (1) {
3535 		ata_msleep(link->ap, interval);
3536 		if ((rc = sata_scr_read(link, SCR_STATUS, &cur)))
3537 			return rc;
3538 		cur &= 0xf;
3539 
3540 		/* DET stable? */
3541 		if (cur == last) {
3542 			if (cur == 1 && time_before(jiffies, deadline))
3543 				continue;
3544 			if (time_after(jiffies,
3545 				       ata_deadline(last_jiffies, duration)))
3546 				return 0;
3547 			continue;
3548 		}
3549 
3550 		/* unstable, start over */
3551 		last = cur;
3552 		last_jiffies = jiffies;
3553 
3554 		/* Check deadline.  If debouncing failed, return
3555 		 * -EPIPE to tell upper layer to lower link speed.
3556 		 */
3557 		if (time_after(jiffies, deadline))
3558 			return -EPIPE;
3559 	}
3560 }
3561 
3562 /**
3563  *	sata_link_resume - resume SATA link
3564  *	@link: ATA link to resume SATA
3565  *	@params: timing parameters { interval, duratinon, timeout } in msec
3566  *	@deadline: deadline jiffies for the operation
3567  *
3568  *	Resume SATA phy @link and debounce it.
3569  *
3570  *	LOCKING:
3571  *	Kernel thread context (may sleep)
3572  *
3573  *	RETURNS:
3574  *	0 on success, -errno on failure.
3575  */
3576 int sata_link_resume(struct ata_link *link, const unsigned long *params,
3577 		     unsigned long deadline)
3578 {
3579 	int tries = ATA_LINK_RESUME_TRIES;
3580 	u32 scontrol, serror;
3581 	int rc;
3582 
3583 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3584 		return rc;
3585 
3586 	/*
3587 	 * Writes to SControl sometimes get ignored under certain
3588 	 * controllers (ata_piix SIDPR).  Make sure DET actually is
3589 	 * cleared.
3590 	 */
3591 	do {
3592 		scontrol = (scontrol & 0x0f0) | 0x300;
3593 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3594 			return rc;
3595 		/*
3596 		 * Some PHYs react badly if SStatus is pounded
3597 		 * immediately after resuming.  Delay 200ms before
3598 		 * debouncing.
3599 		 */
3600 		ata_msleep(link->ap, 200);
3601 
3602 		/* is SControl restored correctly? */
3603 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3604 			return rc;
3605 	} while ((scontrol & 0xf0f) != 0x300 && --tries);
3606 
3607 	if ((scontrol & 0xf0f) != 0x300) {
3608 		ata_link_warn(link, "failed to resume link (SControl %X)\n",
3609 			     scontrol);
3610 		return 0;
3611 	}
3612 
3613 	if (tries < ATA_LINK_RESUME_TRIES)
3614 		ata_link_warn(link, "link resume succeeded after %d retries\n",
3615 			      ATA_LINK_RESUME_TRIES - tries);
3616 
3617 	if ((rc = sata_link_debounce(link, params, deadline)))
3618 		return rc;
3619 
3620 	/* clear SError, some PHYs require this even for SRST to work */
3621 	if (!(rc = sata_scr_read(link, SCR_ERROR, &serror)))
3622 		rc = sata_scr_write(link, SCR_ERROR, serror);
3623 
3624 	return rc != -EINVAL ? rc : 0;
3625 }
3626 
3627 /**
3628  *	sata_link_scr_lpm - manipulate SControl IPM and SPM fields
3629  *	@link: ATA link to manipulate SControl for
3630  *	@policy: LPM policy to configure
3631  *	@spm_wakeup: initiate LPM transition to active state
3632  *
3633  *	Manipulate the IPM field of the SControl register of @link
3634  *	according to @policy.  If @policy is ATA_LPM_MAX_POWER and
3635  *	@spm_wakeup is %true, the SPM field is manipulated to wake up
3636  *	the link.  This function also clears PHYRDY_CHG before
3637  *	returning.
3638  *
3639  *	LOCKING:
3640  *	EH context.
3641  *
3642  *	RETURNS:
3643  *	0 on success, -errno otherwise.
3644  */
3645 int sata_link_scr_lpm(struct ata_link *link, enum ata_lpm_policy policy,
3646 		      bool spm_wakeup)
3647 {
3648 	struct ata_eh_context *ehc = &link->eh_context;
3649 	bool woken_up = false;
3650 	u32 scontrol;
3651 	int rc;
3652 
3653 	rc = sata_scr_read(link, SCR_CONTROL, &scontrol);
3654 	if (rc)
3655 		return rc;
3656 
3657 	switch (policy) {
3658 	case ATA_LPM_MAX_POWER:
3659 		/* disable all LPM transitions */
3660 		scontrol |= (0x7 << 8);
3661 		/* initiate transition to active state */
3662 		if (spm_wakeup) {
3663 			scontrol |= (0x4 << 12);
3664 			woken_up = true;
3665 		}
3666 		break;
3667 	case ATA_LPM_MED_POWER:
3668 		/* allow LPM to PARTIAL */
3669 		scontrol &= ~(0x1 << 8);
3670 		scontrol |= (0x6 << 8);
3671 		break;
3672 	case ATA_LPM_MIN_POWER:
3673 		if (ata_link_nr_enabled(link) > 0)
3674 			/* no restrictions on LPM transitions */
3675 			scontrol &= ~(0x7 << 8);
3676 		else {
3677 			/* empty port, power off */
3678 			scontrol &= ~0xf;
3679 			scontrol |= (0x1 << 2);
3680 		}
3681 		break;
3682 	default:
3683 		WARN_ON(1);
3684 	}
3685 
3686 	rc = sata_scr_write(link, SCR_CONTROL, scontrol);
3687 	if (rc)
3688 		return rc;
3689 
3690 	/* give the link time to transit out of LPM state */
3691 	if (woken_up)
3692 		msleep(10);
3693 
3694 	/* clear PHYRDY_CHG from SError */
3695 	ehc->i.serror &= ~SERR_PHYRDY_CHG;
3696 	return sata_scr_write(link, SCR_ERROR, SERR_PHYRDY_CHG);
3697 }
3698 
3699 /**
3700  *	ata_std_prereset - prepare for reset
3701  *	@link: ATA link to be reset
3702  *	@deadline: deadline jiffies for the operation
3703  *
3704  *	@link is about to be reset.  Initialize it.  Failure from
3705  *	prereset makes libata abort whole reset sequence and give up
3706  *	that port, so prereset should be best-effort.  It does its
3707  *	best to prepare for reset sequence but if things go wrong, it
3708  *	should just whine, not fail.
3709  *
3710  *	LOCKING:
3711  *	Kernel thread context (may sleep)
3712  *
3713  *	RETURNS:
3714  *	0 on success, -errno otherwise.
3715  */
3716 int ata_std_prereset(struct ata_link *link, unsigned long deadline)
3717 {
3718 	struct ata_port *ap = link->ap;
3719 	struct ata_eh_context *ehc = &link->eh_context;
3720 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
3721 	int rc;
3722 
3723 	/* if we're about to do hardreset, nothing more to do */
3724 	if (ehc->i.action & ATA_EH_HARDRESET)
3725 		return 0;
3726 
3727 	/* if SATA, resume link */
3728 	if (ap->flags & ATA_FLAG_SATA) {
3729 		rc = sata_link_resume(link, timing, deadline);
3730 		/* whine about phy resume failure but proceed */
3731 		if (rc && rc != -EOPNOTSUPP)
3732 			ata_link_warn(link,
3733 				      "failed to resume link for reset (errno=%d)\n",
3734 				      rc);
3735 	}
3736 
3737 	/* no point in trying softreset on offline link */
3738 	if (ata_phys_link_offline(link))
3739 		ehc->i.action &= ~ATA_EH_SOFTRESET;
3740 
3741 	return 0;
3742 }
3743 
3744 /**
3745  *	sata_link_hardreset - reset link via SATA phy reset
3746  *	@link: link to reset
3747  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3748  *	@deadline: deadline jiffies for the operation
3749  *	@online: optional out parameter indicating link onlineness
3750  *	@check_ready: optional callback to check link readiness
3751  *
3752  *	SATA phy-reset @link using DET bits of SControl register.
3753  *	After hardreset, link readiness is waited upon using
3754  *	ata_wait_ready() if @check_ready is specified.  LLDs are
3755  *	allowed to not specify @check_ready and wait itself after this
3756  *	function returns.  Device classification is LLD's
3757  *	responsibility.
3758  *
3759  *	*@online is set to one iff reset succeeded and @link is online
3760  *	after reset.
3761  *
3762  *	LOCKING:
3763  *	Kernel thread context (may sleep)
3764  *
3765  *	RETURNS:
3766  *	0 on success, -errno otherwise.
3767  */
3768 int sata_link_hardreset(struct ata_link *link, const unsigned long *timing,
3769 			unsigned long deadline,
3770 			bool *online, int (*check_ready)(struct ata_link *))
3771 {
3772 	u32 scontrol;
3773 	int rc;
3774 
3775 	DPRINTK("ENTER\n");
3776 
3777 	if (online)
3778 		*online = false;
3779 
3780 	if (sata_set_spd_needed(link)) {
3781 		/* SATA spec says nothing about how to reconfigure
3782 		 * spd.  To be on the safe side, turn off phy during
3783 		 * reconfiguration.  This works for at least ICH7 AHCI
3784 		 * and Sil3124.
3785 		 */
3786 		if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3787 			goto out;
3788 
3789 		scontrol = (scontrol & 0x0f0) | 0x304;
3790 
3791 		if ((rc = sata_scr_write(link, SCR_CONTROL, scontrol)))
3792 			goto out;
3793 
3794 		sata_set_spd(link);
3795 	}
3796 
3797 	/* issue phy wake/reset */
3798 	if ((rc = sata_scr_read(link, SCR_CONTROL, &scontrol)))
3799 		goto out;
3800 
3801 	scontrol = (scontrol & 0x0f0) | 0x301;
3802 
3803 	if ((rc = sata_scr_write_flush(link, SCR_CONTROL, scontrol)))
3804 		goto out;
3805 
3806 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3807 	 * 10.4.2 says at least 1 ms.
3808 	 */
3809 	ata_msleep(link->ap, 1);
3810 
3811 	/* bring link back */
3812 	rc = sata_link_resume(link, timing, deadline);
3813 	if (rc)
3814 		goto out;
3815 	/* if link is offline nothing more to do */
3816 	if (ata_phys_link_offline(link))
3817 		goto out;
3818 
3819 	/* Link is online.  From this point, -ENODEV too is an error. */
3820 	if (online)
3821 		*online = true;
3822 
3823 	if (sata_pmp_supported(link->ap) && ata_is_host_link(link)) {
3824 		/* If PMP is supported, we have to do follow-up SRST.
3825 		 * Some PMPs don't send D2H Reg FIS after hardreset if
3826 		 * the first port is empty.  Wait only for
3827 		 * ATA_TMOUT_PMP_SRST_WAIT.
3828 		 */
3829 		if (check_ready) {
3830 			unsigned long pmp_deadline;
3831 
3832 			pmp_deadline = ata_deadline(jiffies,
3833 						    ATA_TMOUT_PMP_SRST_WAIT);
3834 			if (time_after(pmp_deadline, deadline))
3835 				pmp_deadline = deadline;
3836 			ata_wait_ready(link, pmp_deadline, check_ready);
3837 		}
3838 		rc = -EAGAIN;
3839 		goto out;
3840 	}
3841 
3842 	rc = 0;
3843 	if (check_ready)
3844 		rc = ata_wait_ready(link, deadline, check_ready);
3845  out:
3846 	if (rc && rc != -EAGAIN) {
3847 		/* online is set iff link is online && reset succeeded */
3848 		if (online)
3849 			*online = false;
3850 		ata_link_err(link, "COMRESET failed (errno=%d)\n", rc);
3851 	}
3852 	DPRINTK("EXIT, rc=%d\n", rc);
3853 	return rc;
3854 }
3855 
3856 /**
3857  *	sata_std_hardreset - COMRESET w/o waiting or classification
3858  *	@link: link to reset
3859  *	@class: resulting class of attached device
3860  *	@deadline: deadline jiffies for the operation
3861  *
3862  *	Standard SATA COMRESET w/o waiting or classification.
3863  *
3864  *	LOCKING:
3865  *	Kernel thread context (may sleep)
3866  *
3867  *	RETURNS:
3868  *	0 if link offline, -EAGAIN if link online, -errno on errors.
3869  */
3870 int sata_std_hardreset(struct ata_link *link, unsigned int *class,
3871 		       unsigned long deadline)
3872 {
3873 	const unsigned long *timing = sata_ehc_deb_timing(&link->eh_context);
3874 	bool online;
3875 	int rc;
3876 
3877 	/* do hardreset */
3878 	rc = sata_link_hardreset(link, timing, deadline, &online, NULL);
3879 	return online ? -EAGAIN : rc;
3880 }
3881 
3882 /**
3883  *	ata_std_postreset - standard postreset callback
3884  *	@link: the target ata_link
3885  *	@classes: classes of attached devices
3886  *
3887  *	This function is invoked after a successful reset.  Note that
3888  *	the device might have been reset more than once using
3889  *	different reset methods before postreset is invoked.
3890  *
3891  *	LOCKING:
3892  *	Kernel thread context (may sleep)
3893  */
3894 void ata_std_postreset(struct ata_link *link, unsigned int *classes)
3895 {
3896 	u32 serror;
3897 
3898 	DPRINTK("ENTER\n");
3899 
3900 	/* reset complete, clear SError */
3901 	if (!sata_scr_read(link, SCR_ERROR, &serror))
3902 		sata_scr_write(link, SCR_ERROR, serror);
3903 
3904 	/* print link status */
3905 	sata_print_link_status(link);
3906 
3907 	DPRINTK("EXIT\n");
3908 }
3909 
3910 /**
3911  *	ata_dev_same_device - Determine whether new ID matches configured device
3912  *	@dev: device to compare against
3913  *	@new_class: class of the new device
3914  *	@new_id: IDENTIFY page of the new device
3915  *
3916  *	Compare @new_class and @new_id against @dev and determine
3917  *	whether @dev is the device indicated by @new_class and
3918  *	@new_id.
3919  *
3920  *	LOCKING:
3921  *	None.
3922  *
3923  *	RETURNS:
3924  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3925  */
3926 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3927 			       const u16 *new_id)
3928 {
3929 	const u16 *old_id = dev->id;
3930 	unsigned char model[2][ATA_ID_PROD_LEN + 1];
3931 	unsigned char serial[2][ATA_ID_SERNO_LEN + 1];
3932 
3933 	if (dev->class != new_class) {
3934 		ata_dev_info(dev, "class mismatch %d != %d\n",
3935 			     dev->class, new_class);
3936 		return 0;
3937 	}
3938 
3939 	ata_id_c_string(old_id, model[0], ATA_ID_PROD, sizeof(model[0]));
3940 	ata_id_c_string(new_id, model[1], ATA_ID_PROD, sizeof(model[1]));
3941 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO, sizeof(serial[0]));
3942 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO, sizeof(serial[1]));
3943 
3944 	if (strcmp(model[0], model[1])) {
3945 		ata_dev_info(dev, "model number mismatch '%s' != '%s'\n",
3946 			     model[0], model[1]);
3947 		return 0;
3948 	}
3949 
3950 	if (strcmp(serial[0], serial[1])) {
3951 		ata_dev_info(dev, "serial number mismatch '%s' != '%s'\n",
3952 			     serial[0], serial[1]);
3953 		return 0;
3954 	}
3955 
3956 	return 1;
3957 }
3958 
3959 /**
3960  *	ata_dev_reread_id - Re-read IDENTIFY data
3961  *	@dev: target ATA device
3962  *	@readid_flags: read ID flags
3963  *
3964  *	Re-read IDENTIFY page and make sure @dev is still attached to
3965  *	the port.
3966  *
3967  *	LOCKING:
3968  *	Kernel thread context (may sleep)
3969  *
3970  *	RETURNS:
3971  *	0 on success, negative errno otherwise
3972  */
3973 int ata_dev_reread_id(struct ata_device *dev, unsigned int readid_flags)
3974 {
3975 	unsigned int class = dev->class;
3976 	u16 *id = (void *)dev->link->ap->sector_buf;
3977 	int rc;
3978 
3979 	/* read ID data */
3980 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
3981 	if (rc)
3982 		return rc;
3983 
3984 	/* is the device still there? */
3985 	if (!ata_dev_same_device(dev, class, id))
3986 		return -ENODEV;
3987 
3988 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
3989 	return 0;
3990 }
3991 
3992 /**
3993  *	ata_dev_revalidate - Revalidate ATA device
3994  *	@dev: device to revalidate
3995  *	@new_class: new class code
3996  *	@readid_flags: read ID flags
3997  *
3998  *	Re-read IDENTIFY page, make sure @dev is still attached to the
3999  *	port and reconfigure it according to the new IDENTIFY page.
4000  *
4001  *	LOCKING:
4002  *	Kernel thread context (may sleep)
4003  *
4004  *	RETURNS:
4005  *	0 on success, negative errno otherwise
4006  */
4007 int ata_dev_revalidate(struct ata_device *dev, unsigned int new_class,
4008 		       unsigned int readid_flags)
4009 {
4010 	u64 n_sectors = dev->n_sectors;
4011 	u64 n_native_sectors = dev->n_native_sectors;
4012 	int rc;
4013 
4014 	if (!ata_dev_enabled(dev))
4015 		return -ENODEV;
4016 
4017 	/* fail early if !ATA && !ATAPI to avoid issuing [P]IDENTIFY to PMP */
4018 	if (ata_class_enabled(new_class) &&
4019 	    new_class != ATA_DEV_ATA &&
4020 	    new_class != ATA_DEV_ATAPI &&
4021 	    new_class != ATA_DEV_ZAC &&
4022 	    new_class != ATA_DEV_SEMB) {
4023 		ata_dev_info(dev, "class mismatch %u != %u\n",
4024 			     dev->class, new_class);
4025 		rc = -ENODEV;
4026 		goto fail;
4027 	}
4028 
4029 	/* re-read ID */
4030 	rc = ata_dev_reread_id(dev, readid_flags);
4031 	if (rc)
4032 		goto fail;
4033 
4034 	/* configure device according to the new ID */
4035 	rc = ata_dev_configure(dev);
4036 	if (rc)
4037 		goto fail;
4038 
4039 	/* verify n_sectors hasn't changed */
4040 	if (dev->class != ATA_DEV_ATA || !n_sectors ||
4041 	    dev->n_sectors == n_sectors)
4042 		return 0;
4043 
4044 	/* n_sectors has changed */
4045 	ata_dev_warn(dev, "n_sectors mismatch %llu != %llu\n",
4046 		     (unsigned long long)n_sectors,
4047 		     (unsigned long long)dev->n_sectors);
4048 
4049 	/*
4050 	 * Something could have caused HPA to be unlocked
4051 	 * involuntarily.  If n_native_sectors hasn't changed and the
4052 	 * new size matches it, keep the device.
4053 	 */
4054 	if (dev->n_native_sectors == n_native_sectors &&
4055 	    dev->n_sectors > n_sectors && dev->n_sectors == n_native_sectors) {
4056 		ata_dev_warn(dev,
4057 			     "new n_sectors matches native, probably "
4058 			     "late HPA unlock, n_sectors updated\n");
4059 		/* use the larger n_sectors */
4060 		return 0;
4061 	}
4062 
4063 	/*
4064 	 * Some BIOSes boot w/o HPA but resume w/ HPA locked.  Try
4065 	 * unlocking HPA in those cases.
4066 	 *
4067 	 * https://bugzilla.kernel.org/show_bug.cgi?id=15396
4068 	 */
4069 	if (dev->n_native_sectors == n_native_sectors &&
4070 	    dev->n_sectors < n_sectors && n_sectors == n_native_sectors &&
4071 	    !(dev->horkage & ATA_HORKAGE_BROKEN_HPA)) {
4072 		ata_dev_warn(dev,
4073 			     "old n_sectors matches native, probably "
4074 			     "late HPA lock, will try to unlock HPA\n");
4075 		/* try unlocking HPA */
4076 		dev->flags |= ATA_DFLAG_UNLOCK_HPA;
4077 		rc = -EIO;
4078 	} else
4079 		rc = -ENODEV;
4080 
4081 	/* restore original n_[native_]sectors and fail */
4082 	dev->n_native_sectors = n_native_sectors;
4083 	dev->n_sectors = n_sectors;
4084  fail:
4085 	ata_dev_err(dev, "revalidation failed (errno=%d)\n", rc);
4086 	return rc;
4087 }
4088 
4089 struct ata_blacklist_entry {
4090 	const char *model_num;
4091 	const char *model_rev;
4092 	unsigned long horkage;
4093 };
4094 
4095 static const struct ata_blacklist_entry ata_device_blacklist [] = {
4096 	/* Devices with DMA related problems under Linux */
4097 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
4098 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
4099 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
4100 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
4101 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
4102 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
4103 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
4104 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
4105 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
4106 	{ "CRD-848[02]B",	NULL,		ATA_HORKAGE_NODMA },
4107 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
4108 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
4109 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
4110 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
4111 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
4112 	{ "HITACHI CDR-8[34]35",NULL,		ATA_HORKAGE_NODMA },
4113 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
4114 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
4115 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
4116 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
4117 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
4118 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
4119 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
4120 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
4121 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
4122 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
4123 	{ "SAMSUNG CD-ROM SN-124", "N001",	ATA_HORKAGE_NODMA },
4124 	{ "Seagate STT20000A", NULL,		ATA_HORKAGE_NODMA },
4125 	{ " 2GB ATA Flash Disk", "ADMA428M",	ATA_HORKAGE_NODMA },
4126 	/* Odd clown on sil3726/4726 PMPs */
4127 	{ "Config  Disk",	NULL,		ATA_HORKAGE_DISABLE },
4128 
4129 	/* Weird ATAPI devices */
4130 	{ "TORiSAN DVD-ROM DRD-N216", NULL,	ATA_HORKAGE_MAX_SEC_128 },
4131 	{ "QUANTUM DAT    DAT72-000", NULL,	ATA_HORKAGE_ATAPI_MOD16_DMA },
4132 	{ "Slimtype DVD A  DS8A8SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
4133 	{ "Slimtype DVD A  DS8A9SH", NULL,	ATA_HORKAGE_MAX_SEC_LBA48 },
4134 
4135 	/*
4136 	 * Causes silent data corruption with higher max sects.
4137 	 * http://lkml.kernel.org/g/x49wpy40ysk.fsf@segfault.boston.devel.redhat.com
4138 	 */
4139 	{ "ST380013AS",		"3.20",		ATA_HORKAGE_MAX_SEC_1024 },
4140 
4141 	/* Devices we expect to fail diagnostics */
4142 
4143 	/* Devices where NCQ should be avoided */
4144 	/* NCQ is slow */
4145 	{ "WDC WD740ADFD-00",	NULL,		ATA_HORKAGE_NONCQ },
4146 	{ "WDC WD740ADFD-00NLR1", NULL,		ATA_HORKAGE_NONCQ, },
4147 	/* http://thread.gmane.org/gmane.linux.ide/14907 */
4148 	{ "FUJITSU MHT2060BH",	NULL,		ATA_HORKAGE_NONCQ },
4149 	/* NCQ is broken */
4150 	{ "Maxtor *",		"BANC*",	ATA_HORKAGE_NONCQ },
4151 	{ "Maxtor 7V300F0",	"VA111630",	ATA_HORKAGE_NONCQ },
4152 	{ "ST380817AS",		"3.42",		ATA_HORKAGE_NONCQ },
4153 	{ "ST3160023AS",	"3.42",		ATA_HORKAGE_NONCQ },
4154 	{ "OCZ CORE_SSD",	"02.10104",	ATA_HORKAGE_NONCQ },
4155 
4156 	/* Seagate NCQ + FLUSH CACHE firmware bug */
4157 	{ "ST31500341AS",	"SD1[5-9]",	ATA_HORKAGE_NONCQ |
4158 						ATA_HORKAGE_FIRMWARE_WARN },
4159 
4160 	{ "ST31000333AS",	"SD1[5-9]",	ATA_HORKAGE_NONCQ |
4161 						ATA_HORKAGE_FIRMWARE_WARN },
4162 
4163 	{ "ST3640[36]23AS",	"SD1[5-9]",	ATA_HORKAGE_NONCQ |
4164 						ATA_HORKAGE_FIRMWARE_WARN },
4165 
4166 	{ "ST3320[68]13AS",	"SD1[5-9]",	ATA_HORKAGE_NONCQ |
4167 						ATA_HORKAGE_FIRMWARE_WARN },
4168 
4169 	/* drives which fail FPDMA_AA activation (some may freeze afterwards) */
4170 	{ "ST1000LM024 HN-M101MBB", "2AR10001",	ATA_HORKAGE_BROKEN_FPDMA_AA },
4171 	{ "ST1000LM024 HN-M101MBB", "2BA30001",	ATA_HORKAGE_BROKEN_FPDMA_AA },
4172 	{ "VB0250EAVER",	"HPG7",		ATA_HORKAGE_BROKEN_FPDMA_AA },
4173 
4174 	/* Blacklist entries taken from Silicon Image 3124/3132
4175 	   Windows driver .inf file - also several Linux problem reports */
4176 	{ "HTS541060G9SA00",    "MB3OC60D",     ATA_HORKAGE_NONCQ, },
4177 	{ "HTS541080G9SA00",    "MB4OC60D",     ATA_HORKAGE_NONCQ, },
4178 	{ "HTS541010G9SA00",    "MBZOC60D",     ATA_HORKAGE_NONCQ, },
4179 
4180 	/* https://bugzilla.kernel.org/show_bug.cgi?id=15573 */
4181 	{ "C300-CTFDDAC128MAG",	"0001",		ATA_HORKAGE_NONCQ, },
4182 
4183 	/* devices which puke on READ_NATIVE_MAX */
4184 	{ "HDS724040KLSA80",	"KFAOA20N",	ATA_HORKAGE_BROKEN_HPA, },
4185 	{ "WDC WD3200JD-00KLB0", "WD-WCAMR1130137", ATA_HORKAGE_BROKEN_HPA },
4186 	{ "WDC WD2500JD-00HBB0", "WD-WMAL71490727", ATA_HORKAGE_BROKEN_HPA },
4187 	{ "MAXTOR 6L080L4",	"A93.0500",	ATA_HORKAGE_BROKEN_HPA },
4188 
4189 	/* this one allows HPA unlocking but fails IOs on the area */
4190 	{ "OCZ-VERTEX",		    "1.30",	ATA_HORKAGE_BROKEN_HPA },
4191 
4192 	/* Devices which report 1 sector over size HPA */
4193 	{ "ST340823A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4194 	{ "ST320413A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4195 	{ "ST310211A",		NULL,		ATA_HORKAGE_HPA_SIZE, },
4196 
4197 	/* Devices which get the IVB wrong */
4198 	{ "QUANTUM FIREBALLlct10 05", "A03.0900", ATA_HORKAGE_IVB, },
4199 	/* Maybe we should just blacklist TSSTcorp... */
4200 	{ "TSSTcorp CDDVDW SH-S202[HJN]", "SB0[01]",  ATA_HORKAGE_IVB, },
4201 
4202 	/* Devices that do not need bridging limits applied */
4203 	{ "MTRON MSP-SATA*",		NULL,	ATA_HORKAGE_BRIDGE_OK, },
4204 	{ "BUFFALO HD-QSU2/R5",		NULL,	ATA_HORKAGE_BRIDGE_OK, },
4205 
4206 	/* Devices which aren't very happy with higher link speeds */
4207 	{ "WD My Book",			NULL,	ATA_HORKAGE_1_5_GBPS, },
4208 	{ "Seagate FreeAgent GoFlex",	NULL,	ATA_HORKAGE_1_5_GBPS, },
4209 
4210 	/*
4211 	 * Devices which choke on SETXFER.  Applies only if both the
4212 	 * device and controller are SATA.
4213 	 */
4214 	{ "PIONEER DVD-RW  DVRTD08",	NULL,	ATA_HORKAGE_NOSETXFER },
4215 	{ "PIONEER DVD-RW  DVRTD08A",	NULL,	ATA_HORKAGE_NOSETXFER },
4216 	{ "PIONEER DVD-RW  DVR-215",	NULL,	ATA_HORKAGE_NOSETXFER },
4217 	{ "PIONEER DVD-RW  DVR-212D",	NULL,	ATA_HORKAGE_NOSETXFER },
4218 	{ "PIONEER DVD-RW  DVR-216D",	NULL,	ATA_HORKAGE_NOSETXFER },
4219 
4220 	/* devices that don't properly handle queued TRIM commands */
4221 	{ "Micron_M500_*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
4222 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4223 	{ "Crucial_CT*M500*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
4224 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4225 	{ "Micron_M5[15]0_*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
4226 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4227 	{ "Crucial_CT*M550*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
4228 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4229 	{ "Crucial_CT*MX100*",		"MU01",	ATA_HORKAGE_NO_NCQ_TRIM |
4230 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4231 	{ "Samsung SSD 8*",		NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
4232 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4233 	{ "FCCT*M500*",			NULL,	ATA_HORKAGE_NO_NCQ_TRIM |
4234 						ATA_HORKAGE_ZERO_AFTER_TRIM, },
4235 
4236 	/* devices that don't properly handle TRIM commands */
4237 	{ "SuperSSpeed S238*",		NULL,	ATA_HORKAGE_NOTRIM, },
4238 
4239 	/*
4240 	 * As defined, the DRAT (Deterministic Read After Trim) and RZAT
4241 	 * (Return Zero After Trim) flags in the ATA Command Set are
4242 	 * unreliable in the sense that they only define what happens if
4243 	 * the device successfully executed the DSM TRIM command. TRIM
4244 	 * is only advisory, however, and the device is free to silently
4245 	 * ignore all or parts of the request.
4246 	 *
4247 	 * Whitelist drives that are known to reliably return zeroes
4248 	 * after TRIM.
4249 	 */
4250 
4251 	/*
4252 	 * The intel 510 drive has buggy DRAT/RZAT. Explicitly exclude
4253 	 * that model before whitelisting all other intel SSDs.
4254 	 */
4255 	{ "INTEL*SSDSC2MH*",		NULL,	0, },
4256 
4257 	{ "Micron*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4258 	{ "Crucial*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4259 	{ "INTEL*SSD*", 		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4260 	{ "SSD*INTEL*",			NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4261 	{ "Samsung*SSD*",		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4262 	{ "SAMSUNG*SSD*",		NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4263 	{ "ST[1248][0248]0[FH]*",	NULL,	ATA_HORKAGE_ZERO_AFTER_TRIM, },
4264 
4265 	/*
4266 	 * Some WD SATA-I drives spin up and down erratically when the link
4267 	 * is put into the slumber mode.  We don't have full list of the
4268 	 * affected devices.  Disable LPM if the device matches one of the
4269 	 * known prefixes and is SATA-1.  As a side effect LPM partial is
4270 	 * lost too.
4271 	 *
4272 	 * https://bugzilla.kernel.org/show_bug.cgi?id=57211
4273 	 */
4274 	{ "WDC WD800JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4275 	{ "WDC WD1200JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4276 	{ "WDC WD1600JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4277 	{ "WDC WD2000JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4278 	{ "WDC WD2500JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4279 	{ "WDC WD3000JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4280 	{ "WDC WD3200JD-*",		NULL,	ATA_HORKAGE_WD_BROKEN_LPM },
4281 
4282 	/* End Marker */
4283 	{ }
4284 };
4285 
4286 static unsigned long ata_dev_blacklisted(const struct ata_device *dev)
4287 {
4288 	unsigned char model_num[ATA_ID_PROD_LEN + 1];
4289 	unsigned char model_rev[ATA_ID_FW_REV_LEN + 1];
4290 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
4291 
4292 	ata_id_c_string(dev->id, model_num, ATA_ID_PROD, sizeof(model_num));
4293 	ata_id_c_string(dev->id, model_rev, ATA_ID_FW_REV, sizeof(model_rev));
4294 
4295 	while (ad->model_num) {
4296 		if (glob_match(ad->model_num, model_num)) {
4297 			if (ad->model_rev == NULL)
4298 				return ad->horkage;
4299 			if (glob_match(ad->model_rev, model_rev))
4300 				return ad->horkage;
4301 		}
4302 		ad++;
4303 	}
4304 	return 0;
4305 }
4306 
4307 static int ata_dma_blacklisted(const struct ata_device *dev)
4308 {
4309 	/* We don't support polling DMA.
4310 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
4311 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
4312 	 */
4313 	if ((dev->link->ap->flags & ATA_FLAG_PIO_POLLING) &&
4314 	    (dev->flags & ATA_DFLAG_CDB_INTR))
4315 		return 1;
4316 	return (dev->horkage & ATA_HORKAGE_NODMA) ? 1 : 0;
4317 }
4318 
4319 /**
4320  *	ata_is_40wire		-	check drive side detection
4321  *	@dev: device
4322  *
4323  *	Perform drive side detection decoding, allowing for device vendors
4324  *	who can't follow the documentation.
4325  */
4326 
4327 static int ata_is_40wire(struct ata_device *dev)
4328 {
4329 	if (dev->horkage & ATA_HORKAGE_IVB)
4330 		return ata_drive_40wire_relaxed(dev->id);
4331 	return ata_drive_40wire(dev->id);
4332 }
4333 
4334 /**
4335  *	cable_is_40wire		-	40/80/SATA decider
4336  *	@ap: port to consider
4337  *
4338  *	This function encapsulates the policy for speed management
4339  *	in one place. At the moment we don't cache the result but
4340  *	there is a good case for setting ap->cbl to the result when
4341  *	we are called with unknown cables (and figuring out if it
4342  *	impacts hotplug at all).
4343  *
4344  *	Return 1 if the cable appears to be 40 wire.
4345  */
4346 
4347 static int cable_is_40wire(struct ata_port *ap)
4348 {
4349 	struct ata_link *link;
4350 	struct ata_device *dev;
4351 
4352 	/* If the controller thinks we are 40 wire, we are. */
4353 	if (ap->cbl == ATA_CBL_PATA40)
4354 		return 1;
4355 
4356 	/* If the controller thinks we are 80 wire, we are. */
4357 	if (ap->cbl == ATA_CBL_PATA80 || ap->cbl == ATA_CBL_SATA)
4358 		return 0;
4359 
4360 	/* If the system is known to be 40 wire short cable (eg
4361 	 * laptop), then we allow 80 wire modes even if the drive
4362 	 * isn't sure.
4363 	 */
4364 	if (ap->cbl == ATA_CBL_PATA40_SHORT)
4365 		return 0;
4366 
4367 	/* If the controller doesn't know, we scan.
4368 	 *
4369 	 * Note: We look for all 40 wire detects at this point.  Any
4370 	 *       80 wire detect is taken to be 80 wire cable because
4371 	 * - in many setups only the one drive (slave if present) will
4372 	 *   give a valid detect
4373 	 * - if you have a non detect capable drive you don't want it
4374 	 *   to colour the choice
4375 	 */
4376 	ata_for_each_link(link, ap, EDGE) {
4377 		ata_for_each_dev(dev, link, ENABLED) {
4378 			if (!ata_is_40wire(dev))
4379 				return 0;
4380 		}
4381 	}
4382 	return 1;
4383 }
4384 
4385 /**
4386  *	ata_dev_xfermask - Compute supported xfermask of the given device
4387  *	@dev: Device to compute xfermask for
4388  *
4389  *	Compute supported xfermask of @dev and store it in
4390  *	dev->*_mask.  This function is responsible for applying all
4391  *	known limits including host controller limits, device
4392  *	blacklist, etc...
4393  *
4394  *	LOCKING:
4395  *	None.
4396  */
4397 static void ata_dev_xfermask(struct ata_device *dev)
4398 {
4399 	struct ata_link *link = dev->link;
4400 	struct ata_port *ap = link->ap;
4401 	struct ata_host *host = ap->host;
4402 	unsigned long xfer_mask;
4403 
4404 	/* controller modes available */
4405 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
4406 				      ap->mwdma_mask, ap->udma_mask);
4407 
4408 	/* drive modes available */
4409 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
4410 				       dev->mwdma_mask, dev->udma_mask);
4411 	xfer_mask &= ata_id_xfermask(dev->id);
4412 
4413 	/*
4414 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
4415 	 *	cable
4416 	 */
4417 	if (ata_dev_pair(dev)) {
4418 		/* No PIO5 or PIO6 */
4419 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
4420 		/* No MWDMA3 or MWDMA 4 */
4421 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
4422 	}
4423 
4424 	if (ata_dma_blacklisted(dev)) {
4425 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4426 		ata_dev_warn(dev,
4427 			     "device is on DMA blacklist, disabling DMA\n");
4428 	}
4429 
4430 	if ((host->flags & ATA_HOST_SIMPLEX) &&
4431 	    host->simplex_claimed && host->simplex_claimed != ap) {
4432 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
4433 		ata_dev_warn(dev,
4434 			     "simplex DMA is claimed by other device, disabling DMA\n");
4435 	}
4436 
4437 	if (ap->flags & ATA_FLAG_NO_IORDY)
4438 		xfer_mask &= ata_pio_mask_no_iordy(dev);
4439 
4440 	if (ap->ops->mode_filter)
4441 		xfer_mask = ap->ops->mode_filter(dev, xfer_mask);
4442 
4443 	/* Apply cable rule here.  Don't apply it early because when
4444 	 * we handle hot plug the cable type can itself change.
4445 	 * Check this last so that we know if the transfer rate was
4446 	 * solely limited by the cable.
4447 	 * Unknown or 80 wire cables reported host side are checked
4448 	 * drive side as well. Cases where we know a 40wire cable
4449 	 * is used safely for 80 are not checked here.
4450 	 */
4451 	if (xfer_mask & (0xF8 << ATA_SHIFT_UDMA))
4452 		/* UDMA/44 or higher would be available */
4453 		if (cable_is_40wire(ap)) {
4454 			ata_dev_warn(dev,
4455 				     "limited to UDMA/33 due to 40-wire cable\n");
4456 			xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
4457 		}
4458 
4459 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
4460 			    &dev->mwdma_mask, &dev->udma_mask);
4461 }
4462 
4463 /**
4464  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
4465  *	@dev: Device to which command will be sent
4466  *
4467  *	Issue SET FEATURES - XFER MODE command to device @dev
4468  *	on port @ap.
4469  *
4470  *	LOCKING:
4471  *	PCI/etc. bus probe sem.
4472  *
4473  *	RETURNS:
4474  *	0 on success, AC_ERR_* mask otherwise.
4475  */
4476 
4477 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
4478 {
4479 	struct ata_taskfile tf;
4480 	unsigned int err_mask;
4481 
4482 	/* set up set-features taskfile */
4483 	DPRINTK("set features - xfer mode\n");
4484 
4485 	/* Some controllers and ATAPI devices show flaky interrupt
4486 	 * behavior after setting xfer mode.  Use polling instead.
4487 	 */
4488 	ata_tf_init(dev, &tf);
4489 	tf.command = ATA_CMD_SET_FEATURES;
4490 	tf.feature = SETFEATURES_XFER;
4491 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE | ATA_TFLAG_POLLING;
4492 	tf.protocol = ATA_PROT_NODATA;
4493 	/* If we are using IORDY we must send the mode setting command */
4494 	if (ata_pio_need_iordy(dev))
4495 		tf.nsect = dev->xfer_mode;
4496 	/* If the device has IORDY and the controller does not - turn it off */
4497  	else if (ata_id_has_iordy(dev->id))
4498 		tf.nsect = 0x01;
4499 	else /* In the ancient relic department - skip all of this */
4500 		return 0;
4501 
4502 	/* On some disks, this command causes spin-up, so we need longer timeout */
4503 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 15000);
4504 
4505 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4506 	return err_mask;
4507 }
4508 
4509 /**
4510  *	ata_dev_set_feature - Issue SET FEATURES - SATA FEATURES
4511  *	@dev: Device to which command will be sent
4512  *	@enable: Whether to enable or disable the feature
4513  *	@feature: The sector count represents the feature to set
4514  *
4515  *	Issue SET FEATURES - SATA FEATURES command to device @dev
4516  *	on port @ap with sector count
4517  *
4518  *	LOCKING:
4519  *	PCI/etc. bus probe sem.
4520  *
4521  *	RETURNS:
4522  *	0 on success, AC_ERR_* mask otherwise.
4523  */
4524 unsigned int ata_dev_set_feature(struct ata_device *dev, u8 enable, u8 feature)
4525 {
4526 	struct ata_taskfile tf;
4527 	unsigned int err_mask;
4528 
4529 	/* set up set-features taskfile */
4530 	DPRINTK("set features - SATA features\n");
4531 
4532 	ata_tf_init(dev, &tf);
4533 	tf.command = ATA_CMD_SET_FEATURES;
4534 	tf.feature = enable;
4535 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4536 	tf.protocol = ATA_PROT_NODATA;
4537 	tf.nsect = feature;
4538 
4539 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4540 
4541 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4542 	return err_mask;
4543 }
4544 EXPORT_SYMBOL_GPL(ata_dev_set_feature);
4545 
4546 /**
4547  *	ata_dev_init_params - Issue INIT DEV PARAMS command
4548  *	@dev: Device to which command will be sent
4549  *	@heads: Number of heads (taskfile parameter)
4550  *	@sectors: Number of sectors (taskfile parameter)
4551  *
4552  *	LOCKING:
4553  *	Kernel thread context (may sleep)
4554  *
4555  *	RETURNS:
4556  *	0 on success, AC_ERR_* mask otherwise.
4557  */
4558 static unsigned int ata_dev_init_params(struct ata_device *dev,
4559 					u16 heads, u16 sectors)
4560 {
4561 	struct ata_taskfile tf;
4562 	unsigned int err_mask;
4563 
4564 	/* Number of sectors per track 1-255. Number of heads 1-16 */
4565 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
4566 		return AC_ERR_INVALID;
4567 
4568 	/* set up init dev params taskfile */
4569 	DPRINTK("init dev params \n");
4570 
4571 	ata_tf_init(dev, &tf);
4572 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
4573 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
4574 	tf.protocol = ATA_PROT_NODATA;
4575 	tf.nsect = sectors;
4576 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
4577 
4578 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
4579 	/* A clean abort indicates an original or just out of spec drive
4580 	   and we should continue as we issue the setup based on the
4581 	   drive reported working geometry */
4582 	if (err_mask == AC_ERR_DEV && (tf.feature & ATA_ABORTED))
4583 		err_mask = 0;
4584 
4585 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
4586 	return err_mask;
4587 }
4588 
4589 /**
4590  *	ata_sg_clean - Unmap DMA memory associated with command
4591  *	@qc: Command containing DMA memory to be released
4592  *
4593  *	Unmap all mapped DMA memory associated with this command.
4594  *
4595  *	LOCKING:
4596  *	spin_lock_irqsave(host lock)
4597  */
4598 void ata_sg_clean(struct ata_queued_cmd *qc)
4599 {
4600 	struct ata_port *ap = qc->ap;
4601 	struct scatterlist *sg = qc->sg;
4602 	int dir = qc->dma_dir;
4603 
4604 	WARN_ON_ONCE(sg == NULL);
4605 
4606 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
4607 
4608 	if (qc->n_elem)
4609 		dma_unmap_sg(ap->dev, sg, qc->orig_n_elem, dir);
4610 
4611 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4612 	qc->sg = NULL;
4613 }
4614 
4615 /**
4616  *	atapi_check_dma - Check whether ATAPI DMA can be supported
4617  *	@qc: Metadata associated with taskfile to check
4618  *
4619  *	Allow low-level driver to filter ATA PACKET commands, returning
4620  *	a status indicating whether or not it is OK to use DMA for the
4621  *	supplied PACKET command.
4622  *
4623  *	LOCKING:
4624  *	spin_lock_irqsave(host lock)
4625  *
4626  *	RETURNS: 0 when ATAPI DMA can be used
4627  *               nonzero otherwise
4628  */
4629 int atapi_check_dma(struct ata_queued_cmd *qc)
4630 {
4631 	struct ata_port *ap = qc->ap;
4632 
4633 	/* Don't allow DMA if it isn't multiple of 16 bytes.  Quite a
4634 	 * few ATAPI devices choke on such DMA requests.
4635 	 */
4636 	if (!(qc->dev->horkage & ATA_HORKAGE_ATAPI_MOD16_DMA) &&
4637 	    unlikely(qc->nbytes & 15))
4638 		return 1;
4639 
4640 	if (ap->ops->check_atapi_dma)
4641 		return ap->ops->check_atapi_dma(qc);
4642 
4643 	return 0;
4644 }
4645 
4646 /**
4647  *	ata_std_qc_defer - Check whether a qc needs to be deferred
4648  *	@qc: ATA command in question
4649  *
4650  *	Non-NCQ commands cannot run with any other command, NCQ or
4651  *	not.  As upper layer only knows the queue depth, we are
4652  *	responsible for maintaining exclusion.  This function checks
4653  *	whether a new command @qc can be issued.
4654  *
4655  *	LOCKING:
4656  *	spin_lock_irqsave(host lock)
4657  *
4658  *	RETURNS:
4659  *	ATA_DEFER_* if deferring is needed, 0 otherwise.
4660  */
4661 int ata_std_qc_defer(struct ata_queued_cmd *qc)
4662 {
4663 	struct ata_link *link = qc->dev->link;
4664 
4665 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4666 		if (!ata_tag_valid(link->active_tag))
4667 			return 0;
4668 	} else {
4669 		if (!ata_tag_valid(link->active_tag) && !link->sactive)
4670 			return 0;
4671 	}
4672 
4673 	return ATA_DEFER_LINK;
4674 }
4675 
4676 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
4677 
4678 /**
4679  *	ata_sg_init - Associate command with scatter-gather table.
4680  *	@qc: Command to be associated
4681  *	@sg: Scatter-gather table.
4682  *	@n_elem: Number of elements in s/g table.
4683  *
4684  *	Initialize the data-related elements of queued_cmd @qc
4685  *	to point to a scatter-gather table @sg, containing @n_elem
4686  *	elements.
4687  *
4688  *	LOCKING:
4689  *	spin_lock_irqsave(host lock)
4690  */
4691 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
4692 		 unsigned int n_elem)
4693 {
4694 	qc->sg = sg;
4695 	qc->n_elem = n_elem;
4696 	qc->cursg = qc->sg;
4697 }
4698 
4699 /**
4700  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
4701  *	@qc: Command with scatter-gather table to be mapped.
4702  *
4703  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
4704  *
4705  *	LOCKING:
4706  *	spin_lock_irqsave(host lock)
4707  *
4708  *	RETURNS:
4709  *	Zero on success, negative on error.
4710  *
4711  */
4712 static int ata_sg_setup(struct ata_queued_cmd *qc)
4713 {
4714 	struct ata_port *ap = qc->ap;
4715 	unsigned int n_elem;
4716 
4717 	VPRINTK("ENTER, ata%u\n", ap->print_id);
4718 
4719 	n_elem = dma_map_sg(ap->dev, qc->sg, qc->n_elem, qc->dma_dir);
4720 	if (n_elem < 1)
4721 		return -1;
4722 
4723 	DPRINTK("%d sg elements mapped\n", n_elem);
4724 	qc->orig_n_elem = qc->n_elem;
4725 	qc->n_elem = n_elem;
4726 	qc->flags |= ATA_QCFLAG_DMAMAP;
4727 
4728 	return 0;
4729 }
4730 
4731 /**
4732  *	swap_buf_le16 - swap halves of 16-bit words in place
4733  *	@buf:  Buffer to swap
4734  *	@buf_words:  Number of 16-bit words in buffer.
4735  *
4736  *	Swap halves of 16-bit words if needed to convert from
4737  *	little-endian byte order to native cpu byte order, or
4738  *	vice-versa.
4739  *
4740  *	LOCKING:
4741  *	Inherited from caller.
4742  */
4743 void swap_buf_le16(u16 *buf, unsigned int buf_words)
4744 {
4745 #ifdef __BIG_ENDIAN
4746 	unsigned int i;
4747 
4748 	for (i = 0; i < buf_words; i++)
4749 		buf[i] = le16_to_cpu(buf[i]);
4750 #endif /* __BIG_ENDIAN */
4751 }
4752 
4753 /**
4754  *	ata_qc_new_init - Request an available ATA command, and initialize it
4755  *	@dev: Device from whom we request an available command structure
4756  *	@tag: tag
4757  *
4758  *	LOCKING:
4759  *	None.
4760  */
4761 
4762 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev, int tag)
4763 {
4764 	struct ata_port *ap = dev->link->ap;
4765 	struct ata_queued_cmd *qc;
4766 
4767 	/* no command while frozen */
4768 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
4769 		return NULL;
4770 
4771 	/* libsas case */
4772 	if (ap->flags & ATA_FLAG_SAS_HOST) {
4773 		tag = ata_sas_allocate_tag(ap);
4774 		if (tag < 0)
4775 			return NULL;
4776 	}
4777 
4778 	qc = __ata_qc_from_tag(ap, tag);
4779 	qc->tag = tag;
4780 	qc->scsicmd = NULL;
4781 	qc->ap = ap;
4782 	qc->dev = dev;
4783 
4784 	ata_qc_reinit(qc);
4785 
4786 	return qc;
4787 }
4788 
4789 /**
4790  *	ata_qc_free - free unused ata_queued_cmd
4791  *	@qc: Command to complete
4792  *
4793  *	Designed to free unused ata_queued_cmd object
4794  *	in case something prevents using it.
4795  *
4796  *	LOCKING:
4797  *	spin_lock_irqsave(host lock)
4798  */
4799 void ata_qc_free(struct ata_queued_cmd *qc)
4800 {
4801 	struct ata_port *ap;
4802 	unsigned int tag;
4803 
4804 	WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
4805 	ap = qc->ap;
4806 
4807 	qc->flags = 0;
4808 	tag = qc->tag;
4809 	if (likely(ata_tag_valid(tag))) {
4810 		qc->tag = ATA_TAG_POISON;
4811 		if (ap->flags & ATA_FLAG_SAS_HOST)
4812 			ata_sas_free_tag(tag, ap);
4813 	}
4814 }
4815 
4816 void __ata_qc_complete(struct ata_queued_cmd *qc)
4817 {
4818 	struct ata_port *ap;
4819 	struct ata_link *link;
4820 
4821 	WARN_ON_ONCE(qc == NULL); /* ata_qc_from_tag _might_ return NULL */
4822 	WARN_ON_ONCE(!(qc->flags & ATA_QCFLAG_ACTIVE));
4823 	ap = qc->ap;
4824 	link = qc->dev->link;
4825 
4826 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
4827 		ata_sg_clean(qc);
4828 
4829 	/* command should be marked inactive atomically with qc completion */
4830 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4831 		link->sactive &= ~(1 << qc->tag);
4832 		if (!link->sactive)
4833 			ap->nr_active_links--;
4834 	} else {
4835 		link->active_tag = ATA_TAG_POISON;
4836 		ap->nr_active_links--;
4837 	}
4838 
4839 	/* clear exclusive status */
4840 	if (unlikely(qc->flags & ATA_QCFLAG_CLEAR_EXCL &&
4841 		     ap->excl_link == link))
4842 		ap->excl_link = NULL;
4843 
4844 	/* atapi: mark qc as inactive to prevent the interrupt handler
4845 	 * from completing the command twice later, before the error handler
4846 	 * is called. (when rc != 0 and atapi request sense is needed)
4847 	 */
4848 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
4849 	ap->qc_active &= ~(1 << qc->tag);
4850 
4851 	/* call completion callback */
4852 	qc->complete_fn(qc);
4853 }
4854 
4855 static void fill_result_tf(struct ata_queued_cmd *qc)
4856 {
4857 	struct ata_port *ap = qc->ap;
4858 
4859 	qc->result_tf.flags = qc->tf.flags;
4860 	ap->ops->qc_fill_rtf(qc);
4861 }
4862 
4863 static void ata_verify_xfer(struct ata_queued_cmd *qc)
4864 {
4865 	struct ata_device *dev = qc->dev;
4866 
4867 	if (ata_is_nodata(qc->tf.protocol))
4868 		return;
4869 
4870 	if ((dev->mwdma_mask || dev->udma_mask) && ata_is_pio(qc->tf.protocol))
4871 		return;
4872 
4873 	dev->flags &= ~ATA_DFLAG_DUBIOUS_XFER;
4874 }
4875 
4876 /**
4877  *	ata_qc_complete - Complete an active ATA command
4878  *	@qc: Command to complete
4879  *
4880  *	Indicate to the mid and upper layers that an ATA command has
4881  *	completed, with either an ok or not-ok status.
4882  *
4883  *	Refrain from calling this function multiple times when
4884  *	successfully completing multiple NCQ commands.
4885  *	ata_qc_complete_multiple() should be used instead, which will
4886  *	properly update IRQ expect state.
4887  *
4888  *	LOCKING:
4889  *	spin_lock_irqsave(host lock)
4890  */
4891 void ata_qc_complete(struct ata_queued_cmd *qc)
4892 {
4893 	struct ata_port *ap = qc->ap;
4894 
4895 	/* XXX: New EH and old EH use different mechanisms to
4896 	 * synchronize EH with regular execution path.
4897 	 *
4898 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
4899 	 * Normal execution path is responsible for not accessing a
4900 	 * failed qc.  libata core enforces the rule by returning NULL
4901 	 * from ata_qc_from_tag() for failed qcs.
4902 	 *
4903 	 * Old EH depends on ata_qc_complete() nullifying completion
4904 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
4905 	 * not synchronize with interrupt handler.  Only PIO task is
4906 	 * taken care of.
4907 	 */
4908 	if (ap->ops->error_handler) {
4909 		struct ata_device *dev = qc->dev;
4910 		struct ata_eh_info *ehi = &dev->link->eh_info;
4911 
4912 		if (unlikely(qc->err_mask))
4913 			qc->flags |= ATA_QCFLAG_FAILED;
4914 
4915 		/*
4916 		 * Finish internal commands without any further processing
4917 		 * and always with the result TF filled.
4918 		 */
4919 		if (unlikely(ata_tag_internal(qc->tag))) {
4920 			fill_result_tf(qc);
4921 			trace_ata_qc_complete_internal(qc);
4922 			__ata_qc_complete(qc);
4923 			return;
4924 		}
4925 
4926 		/*
4927 		 * Non-internal qc has failed.  Fill the result TF and
4928 		 * summon EH.
4929 		 */
4930 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
4931 			fill_result_tf(qc);
4932 			trace_ata_qc_complete_failed(qc);
4933 			ata_qc_schedule_eh(qc);
4934 			return;
4935 		}
4936 
4937 		WARN_ON_ONCE(ap->pflags & ATA_PFLAG_FROZEN);
4938 
4939 		/* read result TF if requested */
4940 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
4941 			fill_result_tf(qc);
4942 
4943 		trace_ata_qc_complete_done(qc);
4944 		/* Some commands need post-processing after successful
4945 		 * completion.
4946 		 */
4947 		switch (qc->tf.command) {
4948 		case ATA_CMD_SET_FEATURES:
4949 			if (qc->tf.feature != SETFEATURES_WC_ON &&
4950 			    qc->tf.feature != SETFEATURES_WC_OFF)
4951 				break;
4952 			/* fall through */
4953 		case ATA_CMD_INIT_DEV_PARAMS: /* CHS translation changed */
4954 		case ATA_CMD_SET_MULTI: /* multi_count changed */
4955 			/* revalidate device */
4956 			ehi->dev_action[dev->devno] |= ATA_EH_REVALIDATE;
4957 			ata_port_schedule_eh(ap);
4958 			break;
4959 
4960 		case ATA_CMD_SLEEP:
4961 			dev->flags |= ATA_DFLAG_SLEEPING;
4962 			break;
4963 		}
4964 
4965 		if (unlikely(dev->flags & ATA_DFLAG_DUBIOUS_XFER))
4966 			ata_verify_xfer(qc);
4967 
4968 		__ata_qc_complete(qc);
4969 	} else {
4970 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
4971 			return;
4972 
4973 		/* read result TF if failed or requested */
4974 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
4975 			fill_result_tf(qc);
4976 
4977 		__ata_qc_complete(qc);
4978 	}
4979 }
4980 
4981 /**
4982  *	ata_qc_complete_multiple - Complete multiple qcs successfully
4983  *	@ap: port in question
4984  *	@qc_active: new qc_active mask
4985  *
4986  *	Complete in-flight commands.  This functions is meant to be
4987  *	called from low-level driver's interrupt routine to complete
4988  *	requests normally.  ap->qc_active and @qc_active is compared
4989  *	and commands are completed accordingly.
4990  *
4991  *	Always use this function when completing multiple NCQ commands
4992  *	from IRQ handlers instead of calling ata_qc_complete()
4993  *	multiple times to keep IRQ expect status properly in sync.
4994  *
4995  *	LOCKING:
4996  *	spin_lock_irqsave(host lock)
4997  *
4998  *	RETURNS:
4999  *	Number of completed commands on success, -errno otherwise.
5000  */
5001 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active)
5002 {
5003 	int nr_done = 0;
5004 	u32 done_mask;
5005 
5006 	done_mask = ap->qc_active ^ qc_active;
5007 
5008 	if (unlikely(done_mask & qc_active)) {
5009 		ata_port_err(ap, "illegal qc_active transition (%08x->%08x)\n",
5010 			     ap->qc_active, qc_active);
5011 		return -EINVAL;
5012 	}
5013 
5014 	while (done_mask) {
5015 		struct ata_queued_cmd *qc;
5016 		unsigned int tag = __ffs(done_mask);
5017 
5018 		qc = ata_qc_from_tag(ap, tag);
5019 		if (qc) {
5020 			ata_qc_complete(qc);
5021 			nr_done++;
5022 		}
5023 		done_mask &= ~(1 << tag);
5024 	}
5025 
5026 	return nr_done;
5027 }
5028 
5029 /**
5030  *	ata_qc_issue - issue taskfile to device
5031  *	@qc: command to issue to device
5032  *
5033  *	Prepare an ATA command to submission to device.
5034  *	This includes mapping the data into a DMA-able
5035  *	area, filling in the S/G table, and finally
5036  *	writing the taskfile to hardware, starting the command.
5037  *
5038  *	LOCKING:
5039  *	spin_lock_irqsave(host lock)
5040  */
5041 void ata_qc_issue(struct ata_queued_cmd *qc)
5042 {
5043 	struct ata_port *ap = qc->ap;
5044 	struct ata_link *link = qc->dev->link;
5045 	u8 prot = qc->tf.protocol;
5046 
5047 	/* Make sure only one non-NCQ command is outstanding.  The
5048 	 * check is skipped for old EH because it reuses active qc to
5049 	 * request ATAPI sense.
5050 	 */
5051 	WARN_ON_ONCE(ap->ops->error_handler && ata_tag_valid(link->active_tag));
5052 
5053 	if (ata_is_ncq(prot)) {
5054 		WARN_ON_ONCE(link->sactive & (1 << qc->tag));
5055 
5056 		if (!link->sactive)
5057 			ap->nr_active_links++;
5058 		link->sactive |= 1 << qc->tag;
5059 	} else {
5060 		WARN_ON_ONCE(link->sactive);
5061 
5062 		ap->nr_active_links++;
5063 		link->active_tag = qc->tag;
5064 	}
5065 
5066 	qc->flags |= ATA_QCFLAG_ACTIVE;
5067 	ap->qc_active |= 1 << qc->tag;
5068 
5069 	/*
5070 	 * We guarantee to LLDs that they will have at least one
5071 	 * non-zero sg if the command is a data command.
5072 	 */
5073 	if (WARN_ON_ONCE(ata_is_data(prot) &&
5074 			 (!qc->sg || !qc->n_elem || !qc->nbytes)))
5075 		goto sys_err;
5076 
5077 	if (ata_is_dma(prot) || (ata_is_pio(prot) &&
5078 				 (ap->flags & ATA_FLAG_PIO_DMA)))
5079 		if (ata_sg_setup(qc))
5080 			goto sys_err;
5081 
5082 	/* if device is sleeping, schedule reset and abort the link */
5083 	if (unlikely(qc->dev->flags & ATA_DFLAG_SLEEPING)) {
5084 		link->eh_info.action |= ATA_EH_RESET;
5085 		ata_ehi_push_desc(&link->eh_info, "waking up from sleep");
5086 		ata_link_abort(link);
5087 		return;
5088 	}
5089 
5090 	ap->ops->qc_prep(qc);
5091 	trace_ata_qc_issue(qc);
5092 	qc->err_mask |= ap->ops->qc_issue(qc);
5093 	if (unlikely(qc->err_mask))
5094 		goto err;
5095 	return;
5096 
5097 sys_err:
5098 	qc->err_mask |= AC_ERR_SYSTEM;
5099 err:
5100 	ata_qc_complete(qc);
5101 }
5102 
5103 /**
5104  *	sata_scr_valid - test whether SCRs are accessible
5105  *	@link: ATA link to test SCR accessibility for
5106  *
5107  *	Test whether SCRs are accessible for @link.
5108  *
5109  *	LOCKING:
5110  *	None.
5111  *
5112  *	RETURNS:
5113  *	1 if SCRs are accessible, 0 otherwise.
5114  */
5115 int sata_scr_valid(struct ata_link *link)
5116 {
5117 	struct ata_port *ap = link->ap;
5118 
5119 	return (ap->flags & ATA_FLAG_SATA) && ap->ops->scr_read;
5120 }
5121 
5122 /**
5123  *	sata_scr_read - read SCR register of the specified port
5124  *	@link: ATA link to read SCR for
5125  *	@reg: SCR to read
5126  *	@val: Place to store read value
5127  *
5128  *	Read SCR register @reg of @link into *@val.  This function is
5129  *	guaranteed to succeed if @link is ap->link, the cable type of
5130  *	the port is SATA and the port implements ->scr_read.
5131  *
5132  *	LOCKING:
5133  *	None if @link is ap->link.  Kernel thread context otherwise.
5134  *
5135  *	RETURNS:
5136  *	0 on success, negative errno on failure.
5137  */
5138 int sata_scr_read(struct ata_link *link, int reg, u32 *val)
5139 {
5140 	if (ata_is_host_link(link)) {
5141 		if (sata_scr_valid(link))
5142 			return link->ap->ops->scr_read(link, reg, val);
5143 		return -EOPNOTSUPP;
5144 	}
5145 
5146 	return sata_pmp_scr_read(link, reg, val);
5147 }
5148 
5149 /**
5150  *	sata_scr_write - write SCR register of the specified port
5151  *	@link: ATA link to write SCR for
5152  *	@reg: SCR to write
5153  *	@val: value to write
5154  *
5155  *	Write @val to SCR register @reg of @link.  This function is
5156  *	guaranteed to succeed if @link is ap->link, the cable type of
5157  *	the port is SATA and the port implements ->scr_read.
5158  *
5159  *	LOCKING:
5160  *	None if @link is ap->link.  Kernel thread context otherwise.
5161  *
5162  *	RETURNS:
5163  *	0 on success, negative errno on failure.
5164  */
5165 int sata_scr_write(struct ata_link *link, int reg, u32 val)
5166 {
5167 	if (ata_is_host_link(link)) {
5168 		if (sata_scr_valid(link))
5169 			return link->ap->ops->scr_write(link, reg, val);
5170 		return -EOPNOTSUPP;
5171 	}
5172 
5173 	return sata_pmp_scr_write(link, reg, val);
5174 }
5175 
5176 /**
5177  *	sata_scr_write_flush - write SCR register of the specified port and flush
5178  *	@link: ATA link to write SCR for
5179  *	@reg: SCR to write
5180  *	@val: value to write
5181  *
5182  *	This function is identical to sata_scr_write() except that this
5183  *	function performs flush after writing to the register.
5184  *
5185  *	LOCKING:
5186  *	None if @link is ap->link.  Kernel thread context otherwise.
5187  *
5188  *	RETURNS:
5189  *	0 on success, negative errno on failure.
5190  */
5191 int sata_scr_write_flush(struct ata_link *link, int reg, u32 val)
5192 {
5193 	if (ata_is_host_link(link)) {
5194 		int rc;
5195 
5196 		if (sata_scr_valid(link)) {
5197 			rc = link->ap->ops->scr_write(link, reg, val);
5198 			if (rc == 0)
5199 				rc = link->ap->ops->scr_read(link, reg, &val);
5200 			return rc;
5201 		}
5202 		return -EOPNOTSUPP;
5203 	}
5204 
5205 	return sata_pmp_scr_write(link, reg, val);
5206 }
5207 
5208 /**
5209  *	ata_phys_link_online - test whether the given link is online
5210  *	@link: ATA link to test
5211  *
5212  *	Test whether @link is online.  Note that this function returns
5213  *	0 if online status of @link cannot be obtained, so
5214  *	ata_link_online(link) != !ata_link_offline(link).
5215  *
5216  *	LOCKING:
5217  *	None.
5218  *
5219  *	RETURNS:
5220  *	True if the port online status is available and online.
5221  */
5222 bool ata_phys_link_online(struct ata_link *link)
5223 {
5224 	u32 sstatus;
5225 
5226 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
5227 	    ata_sstatus_online(sstatus))
5228 		return true;
5229 	return false;
5230 }
5231 
5232 /**
5233  *	ata_phys_link_offline - test whether the given link is offline
5234  *	@link: ATA link to test
5235  *
5236  *	Test whether @link is offline.  Note that this function
5237  *	returns 0 if offline status of @link cannot be obtained, so
5238  *	ata_link_online(link) != !ata_link_offline(link).
5239  *
5240  *	LOCKING:
5241  *	None.
5242  *
5243  *	RETURNS:
5244  *	True if the port offline status is available and offline.
5245  */
5246 bool ata_phys_link_offline(struct ata_link *link)
5247 {
5248 	u32 sstatus;
5249 
5250 	if (sata_scr_read(link, SCR_STATUS, &sstatus) == 0 &&
5251 	    !ata_sstatus_online(sstatus))
5252 		return true;
5253 	return false;
5254 }
5255 
5256 /**
5257  *	ata_link_online - test whether the given link is online
5258  *	@link: ATA link to test
5259  *
5260  *	Test whether @link is online.  This is identical to
5261  *	ata_phys_link_online() when there's no slave link.  When
5262  *	there's a slave link, this function should only be called on
5263  *	the master link and will return true if any of M/S links is
5264  *	online.
5265  *
5266  *	LOCKING:
5267  *	None.
5268  *
5269  *	RETURNS:
5270  *	True if the port online status is available and online.
5271  */
5272 bool ata_link_online(struct ata_link *link)
5273 {
5274 	struct ata_link *slave = link->ap->slave_link;
5275 
5276 	WARN_ON(link == slave);	/* shouldn't be called on slave link */
5277 
5278 	return ata_phys_link_online(link) ||
5279 		(slave && ata_phys_link_online(slave));
5280 }
5281 
5282 /**
5283  *	ata_link_offline - test whether the given link is offline
5284  *	@link: ATA link to test
5285  *
5286  *	Test whether @link is offline.  This is identical to
5287  *	ata_phys_link_offline() when there's no slave link.  When
5288  *	there's a slave link, this function should only be called on
5289  *	the master link and will return true if both M/S links are
5290  *	offline.
5291  *
5292  *	LOCKING:
5293  *	None.
5294  *
5295  *	RETURNS:
5296  *	True if the port offline status is available and offline.
5297  */
5298 bool ata_link_offline(struct ata_link *link)
5299 {
5300 	struct ata_link *slave = link->ap->slave_link;
5301 
5302 	WARN_ON(link == slave);	/* shouldn't be called on slave link */
5303 
5304 	return ata_phys_link_offline(link) &&
5305 		(!slave || ata_phys_link_offline(slave));
5306 }
5307 
5308 #ifdef CONFIG_PM
5309 static void ata_port_request_pm(struct ata_port *ap, pm_message_t mesg,
5310 				unsigned int action, unsigned int ehi_flags,
5311 				bool async)
5312 {
5313 	struct ata_link *link;
5314 	unsigned long flags;
5315 
5316 	/* Previous resume operation might still be in
5317 	 * progress.  Wait for PM_PENDING to clear.
5318 	 */
5319 	if (ap->pflags & ATA_PFLAG_PM_PENDING) {
5320 		ata_port_wait_eh(ap);
5321 		WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5322 	}
5323 
5324 	/* request PM ops to EH */
5325 	spin_lock_irqsave(ap->lock, flags);
5326 
5327 	ap->pm_mesg = mesg;
5328 	ap->pflags |= ATA_PFLAG_PM_PENDING;
5329 	ata_for_each_link(link, ap, HOST_FIRST) {
5330 		link->eh_info.action |= action;
5331 		link->eh_info.flags |= ehi_flags;
5332 	}
5333 
5334 	ata_port_schedule_eh(ap);
5335 
5336 	spin_unlock_irqrestore(ap->lock, flags);
5337 
5338 	if (!async) {
5339 		ata_port_wait_eh(ap);
5340 		WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5341 	}
5342 }
5343 
5344 /*
5345  * On some hardware, device fails to respond after spun down for suspend.  As
5346  * the device won't be used before being resumed, we don't need to touch the
5347  * device.  Ask EH to skip the usual stuff and proceed directly to suspend.
5348  *
5349  * http://thread.gmane.org/gmane.linux.ide/46764
5350  */
5351 static const unsigned int ata_port_suspend_ehi = ATA_EHI_QUIET
5352 						 | ATA_EHI_NO_AUTOPSY
5353 						 | ATA_EHI_NO_RECOVERY;
5354 
5355 static void ata_port_suspend(struct ata_port *ap, pm_message_t mesg)
5356 {
5357 	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, false);
5358 }
5359 
5360 static void ata_port_suspend_async(struct ata_port *ap, pm_message_t mesg)
5361 {
5362 	ata_port_request_pm(ap, mesg, 0, ata_port_suspend_ehi, true);
5363 }
5364 
5365 static int ata_port_pm_suspend(struct device *dev)
5366 {
5367 	struct ata_port *ap = to_ata_port(dev);
5368 
5369 	if (pm_runtime_suspended(dev))
5370 		return 0;
5371 
5372 	ata_port_suspend(ap, PMSG_SUSPEND);
5373 	return 0;
5374 }
5375 
5376 static int ata_port_pm_freeze(struct device *dev)
5377 {
5378 	struct ata_port *ap = to_ata_port(dev);
5379 
5380 	if (pm_runtime_suspended(dev))
5381 		return 0;
5382 
5383 	ata_port_suspend(ap, PMSG_FREEZE);
5384 	return 0;
5385 }
5386 
5387 static int ata_port_pm_poweroff(struct device *dev)
5388 {
5389 	ata_port_suspend(to_ata_port(dev), PMSG_HIBERNATE);
5390 	return 0;
5391 }
5392 
5393 static const unsigned int ata_port_resume_ehi = ATA_EHI_NO_AUTOPSY
5394 						| ATA_EHI_QUIET;
5395 
5396 static void ata_port_resume(struct ata_port *ap, pm_message_t mesg)
5397 {
5398 	ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, false);
5399 }
5400 
5401 static void ata_port_resume_async(struct ata_port *ap, pm_message_t mesg)
5402 {
5403 	ata_port_request_pm(ap, mesg, ATA_EH_RESET, ata_port_resume_ehi, true);
5404 }
5405 
5406 static int ata_port_pm_resume(struct device *dev)
5407 {
5408 	ata_port_resume_async(to_ata_port(dev), PMSG_RESUME);
5409 	pm_runtime_disable(dev);
5410 	pm_runtime_set_active(dev);
5411 	pm_runtime_enable(dev);
5412 	return 0;
5413 }
5414 
5415 /*
5416  * For ODDs, the upper layer will poll for media change every few seconds,
5417  * which will make it enter and leave suspend state every few seconds. And
5418  * as each suspend will cause a hard/soft reset, the gain of runtime suspend
5419  * is very little and the ODD may malfunction after constantly being reset.
5420  * So the idle callback here will not proceed to suspend if a non-ZPODD capable
5421  * ODD is attached to the port.
5422  */
5423 static int ata_port_runtime_idle(struct device *dev)
5424 {
5425 	struct ata_port *ap = to_ata_port(dev);
5426 	struct ata_link *link;
5427 	struct ata_device *adev;
5428 
5429 	ata_for_each_link(link, ap, HOST_FIRST) {
5430 		ata_for_each_dev(adev, link, ENABLED)
5431 			if (adev->class == ATA_DEV_ATAPI &&
5432 			    !zpodd_dev_enabled(adev))
5433 				return -EBUSY;
5434 	}
5435 
5436 	return 0;
5437 }
5438 
5439 static int ata_port_runtime_suspend(struct device *dev)
5440 {
5441 	ata_port_suspend(to_ata_port(dev), PMSG_AUTO_SUSPEND);
5442 	return 0;
5443 }
5444 
5445 static int ata_port_runtime_resume(struct device *dev)
5446 {
5447 	ata_port_resume(to_ata_port(dev), PMSG_AUTO_RESUME);
5448 	return 0;
5449 }
5450 
5451 static const struct dev_pm_ops ata_port_pm_ops = {
5452 	.suspend = ata_port_pm_suspend,
5453 	.resume = ata_port_pm_resume,
5454 	.freeze = ata_port_pm_freeze,
5455 	.thaw = ata_port_pm_resume,
5456 	.poweroff = ata_port_pm_poweroff,
5457 	.restore = ata_port_pm_resume,
5458 
5459 	.runtime_suspend = ata_port_runtime_suspend,
5460 	.runtime_resume = ata_port_runtime_resume,
5461 	.runtime_idle = ata_port_runtime_idle,
5462 };
5463 
5464 /* sas ports don't participate in pm runtime management of ata_ports,
5465  * and need to resume ata devices at the domain level, not the per-port
5466  * level. sas suspend/resume is async to allow parallel port recovery
5467  * since sas has multiple ata_port instances per Scsi_Host.
5468  */
5469 void ata_sas_port_suspend(struct ata_port *ap)
5470 {
5471 	ata_port_suspend_async(ap, PMSG_SUSPEND);
5472 }
5473 EXPORT_SYMBOL_GPL(ata_sas_port_suspend);
5474 
5475 void ata_sas_port_resume(struct ata_port *ap)
5476 {
5477 	ata_port_resume_async(ap, PMSG_RESUME);
5478 }
5479 EXPORT_SYMBOL_GPL(ata_sas_port_resume);
5480 
5481 /**
5482  *	ata_host_suspend - suspend host
5483  *	@host: host to suspend
5484  *	@mesg: PM message
5485  *
5486  *	Suspend @host.  Actual operation is performed by port suspend.
5487  */
5488 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
5489 {
5490 	host->dev->power.power_state = mesg;
5491 	return 0;
5492 }
5493 
5494 /**
5495  *	ata_host_resume - resume host
5496  *	@host: host to resume
5497  *
5498  *	Resume @host.  Actual operation is performed by port resume.
5499  */
5500 void ata_host_resume(struct ata_host *host)
5501 {
5502 	host->dev->power.power_state = PMSG_ON;
5503 }
5504 #endif
5505 
5506 struct device_type ata_port_type = {
5507 	.name = "ata_port",
5508 #ifdef CONFIG_PM
5509 	.pm = &ata_port_pm_ops,
5510 #endif
5511 };
5512 
5513 /**
5514  *	ata_dev_init - Initialize an ata_device structure
5515  *	@dev: Device structure to initialize
5516  *
5517  *	Initialize @dev in preparation for probing.
5518  *
5519  *	LOCKING:
5520  *	Inherited from caller.
5521  */
5522 void ata_dev_init(struct ata_device *dev)
5523 {
5524 	struct ata_link *link = ata_dev_phys_link(dev);
5525 	struct ata_port *ap = link->ap;
5526 	unsigned long flags;
5527 
5528 	/* SATA spd limit is bound to the attached device, reset together */
5529 	link->sata_spd_limit = link->hw_sata_spd_limit;
5530 	link->sata_spd = 0;
5531 
5532 	/* High bits of dev->flags are used to record warm plug
5533 	 * requests which occur asynchronously.  Synchronize using
5534 	 * host lock.
5535 	 */
5536 	spin_lock_irqsave(ap->lock, flags);
5537 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
5538 	dev->horkage = 0;
5539 	spin_unlock_irqrestore(ap->lock, flags);
5540 
5541 	memset((void *)dev + ATA_DEVICE_CLEAR_BEGIN, 0,
5542 	       ATA_DEVICE_CLEAR_END - ATA_DEVICE_CLEAR_BEGIN);
5543 	dev->pio_mask = UINT_MAX;
5544 	dev->mwdma_mask = UINT_MAX;
5545 	dev->udma_mask = UINT_MAX;
5546 }
5547 
5548 /**
5549  *	ata_link_init - Initialize an ata_link structure
5550  *	@ap: ATA port link is attached to
5551  *	@link: Link structure to initialize
5552  *	@pmp: Port multiplier port number
5553  *
5554  *	Initialize @link.
5555  *
5556  *	LOCKING:
5557  *	Kernel thread context (may sleep)
5558  */
5559 void ata_link_init(struct ata_port *ap, struct ata_link *link, int pmp)
5560 {
5561 	int i;
5562 
5563 	/* clear everything except for devices */
5564 	memset((void *)link + ATA_LINK_CLEAR_BEGIN, 0,
5565 	       ATA_LINK_CLEAR_END - ATA_LINK_CLEAR_BEGIN);
5566 
5567 	link->ap = ap;
5568 	link->pmp = pmp;
5569 	link->active_tag = ATA_TAG_POISON;
5570 	link->hw_sata_spd_limit = UINT_MAX;
5571 
5572 	/* can't use iterator, ap isn't initialized yet */
5573 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
5574 		struct ata_device *dev = &link->device[i];
5575 
5576 		dev->link = link;
5577 		dev->devno = dev - link->device;
5578 #ifdef CONFIG_ATA_ACPI
5579 		dev->gtf_filter = ata_acpi_gtf_filter;
5580 #endif
5581 		ata_dev_init(dev);
5582 	}
5583 }
5584 
5585 /**
5586  *	sata_link_init_spd - Initialize link->sata_spd_limit
5587  *	@link: Link to configure sata_spd_limit for
5588  *
5589  *	Initialize @link->[hw_]sata_spd_limit to the currently
5590  *	configured value.
5591  *
5592  *	LOCKING:
5593  *	Kernel thread context (may sleep).
5594  *
5595  *	RETURNS:
5596  *	0 on success, -errno on failure.
5597  */
5598 int sata_link_init_spd(struct ata_link *link)
5599 {
5600 	u8 spd;
5601 	int rc;
5602 
5603 	rc = sata_scr_read(link, SCR_CONTROL, &link->saved_scontrol);
5604 	if (rc)
5605 		return rc;
5606 
5607 	spd = (link->saved_scontrol >> 4) & 0xf;
5608 	if (spd)
5609 		link->hw_sata_spd_limit &= (1 << spd) - 1;
5610 
5611 	ata_force_link_limits(link);
5612 
5613 	link->sata_spd_limit = link->hw_sata_spd_limit;
5614 
5615 	return 0;
5616 }
5617 
5618 /**
5619  *	ata_port_alloc - allocate and initialize basic ATA port resources
5620  *	@host: ATA host this allocated port belongs to
5621  *
5622  *	Allocate and initialize basic ATA port resources.
5623  *
5624  *	RETURNS:
5625  *	Allocate ATA port on success, NULL on failure.
5626  *
5627  *	LOCKING:
5628  *	Inherited from calling layer (may sleep).
5629  */
5630 struct ata_port *ata_port_alloc(struct ata_host *host)
5631 {
5632 	struct ata_port *ap;
5633 
5634 	DPRINTK("ENTER\n");
5635 
5636 	ap = kzalloc(sizeof(*ap), GFP_KERNEL);
5637 	if (!ap)
5638 		return NULL;
5639 
5640 	ap->pflags |= ATA_PFLAG_INITIALIZING | ATA_PFLAG_FROZEN;
5641 	ap->lock = &host->lock;
5642 	ap->print_id = -1;
5643 	ap->local_port_no = -1;
5644 	ap->host = host;
5645 	ap->dev = host->dev;
5646 
5647 #if defined(ATA_VERBOSE_DEBUG)
5648 	/* turn on all debugging levels */
5649 	ap->msg_enable = 0x00FF;
5650 #elif defined(ATA_DEBUG)
5651 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
5652 #else
5653 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
5654 #endif
5655 
5656 	mutex_init(&ap->scsi_scan_mutex);
5657 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
5658 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
5659 	INIT_LIST_HEAD(&ap->eh_done_q);
5660 	init_waitqueue_head(&ap->eh_wait_q);
5661 	init_completion(&ap->park_req_pending);
5662 	init_timer_deferrable(&ap->fastdrain_timer);
5663 	ap->fastdrain_timer.function = ata_eh_fastdrain_timerfn;
5664 	ap->fastdrain_timer.data = (unsigned long)ap;
5665 
5666 	ap->cbl = ATA_CBL_NONE;
5667 
5668 	ata_link_init(ap, &ap->link, 0);
5669 
5670 #ifdef ATA_IRQ_TRAP
5671 	ap->stats.unhandled_irq = 1;
5672 	ap->stats.idle_irq = 1;
5673 #endif
5674 	ata_sff_port_init(ap);
5675 
5676 	return ap;
5677 }
5678 
5679 static void ata_host_release(struct device *gendev, void *res)
5680 {
5681 	struct ata_host *host = dev_get_drvdata(gendev);
5682 	int i;
5683 
5684 	for (i = 0; i < host->n_ports; i++) {
5685 		struct ata_port *ap = host->ports[i];
5686 
5687 		if (!ap)
5688 			continue;
5689 
5690 		if (ap->scsi_host)
5691 			scsi_host_put(ap->scsi_host);
5692 
5693 		kfree(ap->pmp_link);
5694 		kfree(ap->slave_link);
5695 		kfree(ap);
5696 		host->ports[i] = NULL;
5697 	}
5698 
5699 	dev_set_drvdata(gendev, NULL);
5700 }
5701 
5702 /**
5703  *	ata_host_alloc - allocate and init basic ATA host resources
5704  *	@dev: generic device this host is associated with
5705  *	@max_ports: maximum number of ATA ports associated with this host
5706  *
5707  *	Allocate and initialize basic ATA host resources.  LLD calls
5708  *	this function to allocate a host, initializes it fully and
5709  *	attaches it using ata_host_register().
5710  *
5711  *	@max_ports ports are allocated and host->n_ports is
5712  *	initialized to @max_ports.  The caller is allowed to decrease
5713  *	host->n_ports before calling ata_host_register().  The unused
5714  *	ports will be automatically freed on registration.
5715  *
5716  *	RETURNS:
5717  *	Allocate ATA host on success, NULL on failure.
5718  *
5719  *	LOCKING:
5720  *	Inherited from calling layer (may sleep).
5721  */
5722 struct ata_host *ata_host_alloc(struct device *dev, int max_ports)
5723 {
5724 	struct ata_host *host;
5725 	size_t sz;
5726 	int i;
5727 
5728 	DPRINTK("ENTER\n");
5729 
5730 	if (!devres_open_group(dev, NULL, GFP_KERNEL))
5731 		return NULL;
5732 
5733 	/* alloc a container for our list of ATA ports (buses) */
5734 	sz = sizeof(struct ata_host) + (max_ports + 1) * sizeof(void *);
5735 	/* alloc a container for our list of ATA ports (buses) */
5736 	host = devres_alloc(ata_host_release, sz, GFP_KERNEL);
5737 	if (!host)
5738 		goto err_out;
5739 
5740 	devres_add(dev, host);
5741 	dev_set_drvdata(dev, host);
5742 
5743 	spin_lock_init(&host->lock);
5744 	mutex_init(&host->eh_mutex);
5745 	host->dev = dev;
5746 	host->n_ports = max_ports;
5747 
5748 	/* allocate ports bound to this host */
5749 	for (i = 0; i < max_ports; i++) {
5750 		struct ata_port *ap;
5751 
5752 		ap = ata_port_alloc(host);
5753 		if (!ap)
5754 			goto err_out;
5755 
5756 		ap->port_no = i;
5757 		host->ports[i] = ap;
5758 	}
5759 
5760 	devres_remove_group(dev, NULL);
5761 	return host;
5762 
5763  err_out:
5764 	devres_release_group(dev, NULL);
5765 	return NULL;
5766 }
5767 
5768 /**
5769  *	ata_host_alloc_pinfo - alloc host and init with port_info array
5770  *	@dev: generic device this host is associated with
5771  *	@ppi: array of ATA port_info to initialize host with
5772  *	@n_ports: number of ATA ports attached to this host
5773  *
5774  *	Allocate ATA host and initialize with info from @ppi.  If NULL
5775  *	terminated, @ppi may contain fewer entries than @n_ports.  The
5776  *	last entry will be used for the remaining ports.
5777  *
5778  *	RETURNS:
5779  *	Allocate ATA host on success, NULL on failure.
5780  *
5781  *	LOCKING:
5782  *	Inherited from calling layer (may sleep).
5783  */
5784 struct ata_host *ata_host_alloc_pinfo(struct device *dev,
5785 				      const struct ata_port_info * const * ppi,
5786 				      int n_ports)
5787 {
5788 	const struct ata_port_info *pi;
5789 	struct ata_host *host;
5790 	int i, j;
5791 
5792 	host = ata_host_alloc(dev, n_ports);
5793 	if (!host)
5794 		return NULL;
5795 
5796 	for (i = 0, j = 0, pi = NULL; i < host->n_ports; i++) {
5797 		struct ata_port *ap = host->ports[i];
5798 
5799 		if (ppi[j])
5800 			pi = ppi[j++];
5801 
5802 		ap->pio_mask = pi->pio_mask;
5803 		ap->mwdma_mask = pi->mwdma_mask;
5804 		ap->udma_mask = pi->udma_mask;
5805 		ap->flags |= pi->flags;
5806 		ap->link.flags |= pi->link_flags;
5807 		ap->ops = pi->port_ops;
5808 
5809 		if (!host->ops && (pi->port_ops != &ata_dummy_port_ops))
5810 			host->ops = pi->port_ops;
5811 	}
5812 
5813 	return host;
5814 }
5815 
5816 /**
5817  *	ata_slave_link_init - initialize slave link
5818  *	@ap: port to initialize slave link for
5819  *
5820  *	Create and initialize slave link for @ap.  This enables slave
5821  *	link handling on the port.
5822  *
5823  *	In libata, a port contains links and a link contains devices.
5824  *	There is single host link but if a PMP is attached to it,
5825  *	there can be multiple fan-out links.  On SATA, there's usually
5826  *	a single device connected to a link but PATA and SATA
5827  *	controllers emulating TF based interface can have two - master
5828  *	and slave.
5829  *
5830  *	However, there are a few controllers which don't fit into this
5831  *	abstraction too well - SATA controllers which emulate TF
5832  *	interface with both master and slave devices but also have
5833  *	separate SCR register sets for each device.  These controllers
5834  *	need separate links for physical link handling
5835  *	(e.g. onlineness, link speed) but should be treated like a
5836  *	traditional M/S controller for everything else (e.g. command
5837  *	issue, softreset).
5838  *
5839  *	slave_link is libata's way of handling this class of
5840  *	controllers without impacting core layer too much.  For
5841  *	anything other than physical link handling, the default host
5842  *	link is used for both master and slave.  For physical link
5843  *	handling, separate @ap->slave_link is used.  All dirty details
5844  *	are implemented inside libata core layer.  From LLD's POV, the
5845  *	only difference is that prereset, hardreset and postreset are
5846  *	called once more for the slave link, so the reset sequence
5847  *	looks like the following.
5848  *
5849  *	prereset(M) -> prereset(S) -> hardreset(M) -> hardreset(S) ->
5850  *	softreset(M) -> postreset(M) -> postreset(S)
5851  *
5852  *	Note that softreset is called only for the master.  Softreset
5853  *	resets both M/S by definition, so SRST on master should handle
5854  *	both (the standard method will work just fine).
5855  *
5856  *	LOCKING:
5857  *	Should be called before host is registered.
5858  *
5859  *	RETURNS:
5860  *	0 on success, -errno on failure.
5861  */
5862 int ata_slave_link_init(struct ata_port *ap)
5863 {
5864 	struct ata_link *link;
5865 
5866 	WARN_ON(ap->slave_link);
5867 	WARN_ON(ap->flags & ATA_FLAG_PMP);
5868 
5869 	link = kzalloc(sizeof(*link), GFP_KERNEL);
5870 	if (!link)
5871 		return -ENOMEM;
5872 
5873 	ata_link_init(ap, link, 1);
5874 	ap->slave_link = link;
5875 	return 0;
5876 }
5877 
5878 static void ata_host_stop(struct device *gendev, void *res)
5879 {
5880 	struct ata_host *host = dev_get_drvdata(gendev);
5881 	int i;
5882 
5883 	WARN_ON(!(host->flags & ATA_HOST_STARTED));
5884 
5885 	for (i = 0; i < host->n_ports; i++) {
5886 		struct ata_port *ap = host->ports[i];
5887 
5888 		if (ap->ops->port_stop)
5889 			ap->ops->port_stop(ap);
5890 	}
5891 
5892 	if (host->ops->host_stop)
5893 		host->ops->host_stop(host);
5894 }
5895 
5896 /**
5897  *	ata_finalize_port_ops - finalize ata_port_operations
5898  *	@ops: ata_port_operations to finalize
5899  *
5900  *	An ata_port_operations can inherit from another ops and that
5901  *	ops can again inherit from another.  This can go on as many
5902  *	times as necessary as long as there is no loop in the
5903  *	inheritance chain.
5904  *
5905  *	Ops tables are finalized when the host is started.  NULL or
5906  *	unspecified entries are inherited from the closet ancestor
5907  *	which has the method and the entry is populated with it.
5908  *	After finalization, the ops table directly points to all the
5909  *	methods and ->inherits is no longer necessary and cleared.
5910  *
5911  *	Using ATA_OP_NULL, inheriting ops can force a method to NULL.
5912  *
5913  *	LOCKING:
5914  *	None.
5915  */
5916 static void ata_finalize_port_ops(struct ata_port_operations *ops)
5917 {
5918 	static DEFINE_SPINLOCK(lock);
5919 	const struct ata_port_operations *cur;
5920 	void **begin = (void **)ops;
5921 	void **end = (void **)&ops->inherits;
5922 	void **pp;
5923 
5924 	if (!ops || !ops->inherits)
5925 		return;
5926 
5927 	spin_lock(&lock);
5928 
5929 	for (cur = ops->inherits; cur; cur = cur->inherits) {
5930 		void **inherit = (void **)cur;
5931 
5932 		for (pp = begin; pp < end; pp++, inherit++)
5933 			if (!*pp)
5934 				*pp = *inherit;
5935 	}
5936 
5937 	for (pp = begin; pp < end; pp++)
5938 		if (IS_ERR(*pp))
5939 			*pp = NULL;
5940 
5941 	ops->inherits = NULL;
5942 
5943 	spin_unlock(&lock);
5944 }
5945 
5946 /**
5947  *	ata_host_start - start and freeze ports of an ATA host
5948  *	@host: ATA host to start ports for
5949  *
5950  *	Start and then freeze ports of @host.  Started status is
5951  *	recorded in host->flags, so this function can be called
5952  *	multiple times.  Ports are guaranteed to get started only
5953  *	once.  If host->ops isn't initialized yet, its set to the
5954  *	first non-dummy port ops.
5955  *
5956  *	LOCKING:
5957  *	Inherited from calling layer (may sleep).
5958  *
5959  *	RETURNS:
5960  *	0 if all ports are started successfully, -errno otherwise.
5961  */
5962 int ata_host_start(struct ata_host *host)
5963 {
5964 	int have_stop = 0;
5965 	void *start_dr = NULL;
5966 	int i, rc;
5967 
5968 	if (host->flags & ATA_HOST_STARTED)
5969 		return 0;
5970 
5971 	ata_finalize_port_ops(host->ops);
5972 
5973 	for (i = 0; i < host->n_ports; i++) {
5974 		struct ata_port *ap = host->ports[i];
5975 
5976 		ata_finalize_port_ops(ap->ops);
5977 
5978 		if (!host->ops && !ata_port_is_dummy(ap))
5979 			host->ops = ap->ops;
5980 
5981 		if (ap->ops->port_stop)
5982 			have_stop = 1;
5983 	}
5984 
5985 	if (host->ops->host_stop)
5986 		have_stop = 1;
5987 
5988 	if (have_stop) {
5989 		start_dr = devres_alloc(ata_host_stop, 0, GFP_KERNEL);
5990 		if (!start_dr)
5991 			return -ENOMEM;
5992 	}
5993 
5994 	for (i = 0; i < host->n_ports; i++) {
5995 		struct ata_port *ap = host->ports[i];
5996 
5997 		if (ap->ops->port_start) {
5998 			rc = ap->ops->port_start(ap);
5999 			if (rc) {
6000 				if (rc != -ENODEV)
6001 					dev_err(host->dev,
6002 						"failed to start port %d (errno=%d)\n",
6003 						i, rc);
6004 				goto err_out;
6005 			}
6006 		}
6007 		ata_eh_freeze_port(ap);
6008 	}
6009 
6010 	if (start_dr)
6011 		devres_add(host->dev, start_dr);
6012 	host->flags |= ATA_HOST_STARTED;
6013 	return 0;
6014 
6015  err_out:
6016 	while (--i >= 0) {
6017 		struct ata_port *ap = host->ports[i];
6018 
6019 		if (ap->ops->port_stop)
6020 			ap->ops->port_stop(ap);
6021 	}
6022 	devres_free(start_dr);
6023 	return rc;
6024 }
6025 
6026 /**
6027  *	ata_sas_host_init - Initialize a host struct for sas (ipr, libsas)
6028  *	@host:	host to initialize
6029  *	@dev:	device host is attached to
6030  *	@ops:	port_ops
6031  *
6032  */
6033 void ata_host_init(struct ata_host *host, struct device *dev,
6034 		   struct ata_port_operations *ops)
6035 {
6036 	spin_lock_init(&host->lock);
6037 	mutex_init(&host->eh_mutex);
6038 	host->n_tags = ATA_MAX_QUEUE - 1;
6039 	host->dev = dev;
6040 	host->ops = ops;
6041 }
6042 
6043 void __ata_port_probe(struct ata_port *ap)
6044 {
6045 	struct ata_eh_info *ehi = &ap->link.eh_info;
6046 	unsigned long flags;
6047 
6048 	/* kick EH for boot probing */
6049 	spin_lock_irqsave(ap->lock, flags);
6050 
6051 	ehi->probe_mask |= ATA_ALL_DEVICES;
6052 	ehi->action |= ATA_EH_RESET;
6053 	ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
6054 
6055 	ap->pflags &= ~ATA_PFLAG_INITIALIZING;
6056 	ap->pflags |= ATA_PFLAG_LOADING;
6057 	ata_port_schedule_eh(ap);
6058 
6059 	spin_unlock_irqrestore(ap->lock, flags);
6060 }
6061 
6062 int ata_port_probe(struct ata_port *ap)
6063 {
6064 	int rc = 0;
6065 
6066 	if (ap->ops->error_handler) {
6067 		__ata_port_probe(ap);
6068 		ata_port_wait_eh(ap);
6069 	} else {
6070 		DPRINTK("ata%u: bus probe begin\n", ap->print_id);
6071 		rc = ata_bus_probe(ap);
6072 		DPRINTK("ata%u: bus probe end\n", ap->print_id);
6073 	}
6074 	return rc;
6075 }
6076 
6077 
6078 static void async_port_probe(void *data, async_cookie_t cookie)
6079 {
6080 	struct ata_port *ap = data;
6081 
6082 	/*
6083 	 * If we're not allowed to scan this host in parallel,
6084 	 * we need to wait until all previous scans have completed
6085 	 * before going further.
6086 	 * Jeff Garzik says this is only within a controller, so we
6087 	 * don't need to wait for port 0, only for later ports.
6088 	 */
6089 	if (!(ap->host->flags & ATA_HOST_PARALLEL_SCAN) && ap->port_no != 0)
6090 		async_synchronize_cookie(cookie);
6091 
6092 	(void)ata_port_probe(ap);
6093 
6094 	/* in order to keep device order, we need to synchronize at this point */
6095 	async_synchronize_cookie(cookie);
6096 
6097 	ata_scsi_scan_host(ap, 1);
6098 }
6099 
6100 /**
6101  *	ata_host_register - register initialized ATA host
6102  *	@host: ATA host to register
6103  *	@sht: template for SCSI host
6104  *
6105  *	Register initialized ATA host.  @host is allocated using
6106  *	ata_host_alloc() and fully initialized by LLD.  This function
6107  *	starts ports, registers @host with ATA and SCSI layers and
6108  *	probe registered devices.
6109  *
6110  *	LOCKING:
6111  *	Inherited from calling layer (may sleep).
6112  *
6113  *	RETURNS:
6114  *	0 on success, -errno otherwise.
6115  */
6116 int ata_host_register(struct ata_host *host, struct scsi_host_template *sht)
6117 {
6118 	int i, rc;
6119 
6120 	host->n_tags = clamp(sht->can_queue, 1, ATA_MAX_QUEUE - 1);
6121 
6122 	/* host must have been started */
6123 	if (!(host->flags & ATA_HOST_STARTED)) {
6124 		dev_err(host->dev, "BUG: trying to register unstarted host\n");
6125 		WARN_ON(1);
6126 		return -EINVAL;
6127 	}
6128 
6129 	/* Blow away unused ports.  This happens when LLD can't
6130 	 * determine the exact number of ports to allocate at
6131 	 * allocation time.
6132 	 */
6133 	for (i = host->n_ports; host->ports[i]; i++)
6134 		kfree(host->ports[i]);
6135 
6136 	/* give ports names and add SCSI hosts */
6137 	for (i = 0; i < host->n_ports; i++) {
6138 		host->ports[i]->print_id = atomic_inc_return(&ata_print_id);
6139 		host->ports[i]->local_port_no = i + 1;
6140 	}
6141 
6142 	/* Create associated sysfs transport objects  */
6143 	for (i = 0; i < host->n_ports; i++) {
6144 		rc = ata_tport_add(host->dev,host->ports[i]);
6145 		if (rc) {
6146 			goto err_tadd;
6147 		}
6148 	}
6149 
6150 	rc = ata_scsi_add_hosts(host, sht);
6151 	if (rc)
6152 		goto err_tadd;
6153 
6154 	/* set cable, sata_spd_limit and report */
6155 	for (i = 0; i < host->n_ports; i++) {
6156 		struct ata_port *ap = host->ports[i];
6157 		unsigned long xfer_mask;
6158 
6159 		/* set SATA cable type if still unset */
6160 		if (ap->cbl == ATA_CBL_NONE && (ap->flags & ATA_FLAG_SATA))
6161 			ap->cbl = ATA_CBL_SATA;
6162 
6163 		/* init sata_spd_limit to the current value */
6164 		sata_link_init_spd(&ap->link);
6165 		if (ap->slave_link)
6166 			sata_link_init_spd(ap->slave_link);
6167 
6168 		/* print per-port info to dmesg */
6169 		xfer_mask = ata_pack_xfermask(ap->pio_mask, ap->mwdma_mask,
6170 					      ap->udma_mask);
6171 
6172 		if (!ata_port_is_dummy(ap)) {
6173 			ata_port_info(ap, "%cATA max %s %s\n",
6174 				      (ap->flags & ATA_FLAG_SATA) ? 'S' : 'P',
6175 				      ata_mode_string(xfer_mask),
6176 				      ap->link.eh_info.desc);
6177 			ata_ehi_clear_desc(&ap->link.eh_info);
6178 		} else
6179 			ata_port_info(ap, "DUMMY\n");
6180 	}
6181 
6182 	/* perform each probe asynchronously */
6183 	for (i = 0; i < host->n_ports; i++) {
6184 		struct ata_port *ap = host->ports[i];
6185 		async_schedule(async_port_probe, ap);
6186 	}
6187 
6188 	return 0;
6189 
6190  err_tadd:
6191 	while (--i >= 0) {
6192 		ata_tport_delete(host->ports[i]);
6193 	}
6194 	return rc;
6195 
6196 }
6197 
6198 /**
6199  *	ata_host_activate - start host, request IRQ and register it
6200  *	@host: target ATA host
6201  *	@irq: IRQ to request
6202  *	@irq_handler: irq_handler used when requesting IRQ
6203  *	@irq_flags: irq_flags used when requesting IRQ
6204  *	@sht: scsi_host_template to use when registering the host
6205  *
6206  *	After allocating an ATA host and initializing it, most libata
6207  *	LLDs perform three steps to activate the host - start host,
6208  *	request IRQ and register it.  This helper takes necessasry
6209  *	arguments and performs the three steps in one go.
6210  *
6211  *	An invalid IRQ skips the IRQ registration and expects the host to
6212  *	have set polling mode on the port. In this case, @irq_handler
6213  *	should be NULL.
6214  *
6215  *	LOCKING:
6216  *	Inherited from calling layer (may sleep).
6217  *
6218  *	RETURNS:
6219  *	0 on success, -errno otherwise.
6220  */
6221 int ata_host_activate(struct ata_host *host, int irq,
6222 		      irq_handler_t irq_handler, unsigned long irq_flags,
6223 		      struct scsi_host_template *sht)
6224 {
6225 	int i, rc;
6226 
6227 	rc = ata_host_start(host);
6228 	if (rc)
6229 		return rc;
6230 
6231 	/* Special case for polling mode */
6232 	if (!irq) {
6233 		WARN_ON(irq_handler);
6234 		return ata_host_register(host, sht);
6235 	}
6236 
6237 	rc = devm_request_irq(host->dev, irq, irq_handler, irq_flags,
6238 			      dev_name(host->dev), host);
6239 	if (rc)
6240 		return rc;
6241 
6242 	for (i = 0; i < host->n_ports; i++)
6243 		ata_port_desc(host->ports[i], "irq %d", irq);
6244 
6245 	rc = ata_host_register(host, sht);
6246 	/* if failed, just free the IRQ and leave ports alone */
6247 	if (rc)
6248 		devm_free_irq(host->dev, irq, host);
6249 
6250 	return rc;
6251 }
6252 
6253 /**
6254  *	ata_port_detach - Detach ATA port in prepration of device removal
6255  *	@ap: ATA port to be detached
6256  *
6257  *	Detach all ATA devices and the associated SCSI devices of @ap;
6258  *	then, remove the associated SCSI host.  @ap is guaranteed to
6259  *	be quiescent on return from this function.
6260  *
6261  *	LOCKING:
6262  *	Kernel thread context (may sleep).
6263  */
6264 static void ata_port_detach(struct ata_port *ap)
6265 {
6266 	unsigned long flags;
6267 	struct ata_link *link;
6268 	struct ata_device *dev;
6269 
6270 	if (!ap->ops->error_handler)
6271 		goto skip_eh;
6272 
6273 	/* tell EH we're leaving & flush EH */
6274 	spin_lock_irqsave(ap->lock, flags);
6275 	ap->pflags |= ATA_PFLAG_UNLOADING;
6276 	ata_port_schedule_eh(ap);
6277 	spin_unlock_irqrestore(ap->lock, flags);
6278 
6279 	/* wait till EH commits suicide */
6280 	ata_port_wait_eh(ap);
6281 
6282 	/* it better be dead now */
6283 	WARN_ON(!(ap->pflags & ATA_PFLAG_UNLOADED));
6284 
6285 	cancel_delayed_work_sync(&ap->hotplug_task);
6286 
6287  skip_eh:
6288 	/* clean up zpodd on port removal */
6289 	ata_for_each_link(link, ap, HOST_FIRST) {
6290 		ata_for_each_dev(dev, link, ALL) {
6291 			if (zpodd_dev_enabled(dev))
6292 				zpodd_exit(dev);
6293 		}
6294 	}
6295 	if (ap->pmp_link) {
6296 		int i;
6297 		for (i = 0; i < SATA_PMP_MAX_PORTS; i++)
6298 			ata_tlink_delete(&ap->pmp_link[i]);
6299 	}
6300 	/* remove the associated SCSI host */
6301 	scsi_remove_host(ap->scsi_host);
6302 	ata_tport_delete(ap);
6303 }
6304 
6305 /**
6306  *	ata_host_detach - Detach all ports of an ATA host
6307  *	@host: Host to detach
6308  *
6309  *	Detach all ports of @host.
6310  *
6311  *	LOCKING:
6312  *	Kernel thread context (may sleep).
6313  */
6314 void ata_host_detach(struct ata_host *host)
6315 {
6316 	int i;
6317 
6318 	for (i = 0; i < host->n_ports; i++)
6319 		ata_port_detach(host->ports[i]);
6320 
6321 	/* the host is dead now, dissociate ACPI */
6322 	ata_acpi_dissociate(host);
6323 }
6324 
6325 #ifdef CONFIG_PCI
6326 
6327 /**
6328  *	ata_pci_remove_one - PCI layer callback for device removal
6329  *	@pdev: PCI device that was removed
6330  *
6331  *	PCI layer indicates to libata via this hook that hot-unplug or
6332  *	module unload event has occurred.  Detach all ports.  Resource
6333  *	release is handled via devres.
6334  *
6335  *	LOCKING:
6336  *	Inherited from PCI layer (may sleep).
6337  */
6338 void ata_pci_remove_one(struct pci_dev *pdev)
6339 {
6340 	struct ata_host *host = pci_get_drvdata(pdev);
6341 
6342 	ata_host_detach(host);
6343 }
6344 
6345 /* move to PCI subsystem */
6346 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
6347 {
6348 	unsigned long tmp = 0;
6349 
6350 	switch (bits->width) {
6351 	case 1: {
6352 		u8 tmp8 = 0;
6353 		pci_read_config_byte(pdev, bits->reg, &tmp8);
6354 		tmp = tmp8;
6355 		break;
6356 	}
6357 	case 2: {
6358 		u16 tmp16 = 0;
6359 		pci_read_config_word(pdev, bits->reg, &tmp16);
6360 		tmp = tmp16;
6361 		break;
6362 	}
6363 	case 4: {
6364 		u32 tmp32 = 0;
6365 		pci_read_config_dword(pdev, bits->reg, &tmp32);
6366 		tmp = tmp32;
6367 		break;
6368 	}
6369 
6370 	default:
6371 		return -EINVAL;
6372 	}
6373 
6374 	tmp &= bits->mask;
6375 
6376 	return (tmp == bits->val) ? 1 : 0;
6377 }
6378 
6379 #ifdef CONFIG_PM
6380 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
6381 {
6382 	pci_save_state(pdev);
6383 	pci_disable_device(pdev);
6384 
6385 	if (mesg.event & PM_EVENT_SLEEP)
6386 		pci_set_power_state(pdev, PCI_D3hot);
6387 }
6388 
6389 int ata_pci_device_do_resume(struct pci_dev *pdev)
6390 {
6391 	int rc;
6392 
6393 	pci_set_power_state(pdev, PCI_D0);
6394 	pci_restore_state(pdev);
6395 
6396 	rc = pcim_enable_device(pdev);
6397 	if (rc) {
6398 		dev_err(&pdev->dev,
6399 			"failed to enable device after resume (%d)\n", rc);
6400 		return rc;
6401 	}
6402 
6403 	pci_set_master(pdev);
6404 	return 0;
6405 }
6406 
6407 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
6408 {
6409 	struct ata_host *host = pci_get_drvdata(pdev);
6410 	int rc = 0;
6411 
6412 	rc = ata_host_suspend(host, mesg);
6413 	if (rc)
6414 		return rc;
6415 
6416 	ata_pci_device_do_suspend(pdev, mesg);
6417 
6418 	return 0;
6419 }
6420 
6421 int ata_pci_device_resume(struct pci_dev *pdev)
6422 {
6423 	struct ata_host *host = pci_get_drvdata(pdev);
6424 	int rc;
6425 
6426 	rc = ata_pci_device_do_resume(pdev);
6427 	if (rc == 0)
6428 		ata_host_resume(host);
6429 	return rc;
6430 }
6431 #endif /* CONFIG_PM */
6432 
6433 #endif /* CONFIG_PCI */
6434 
6435 /**
6436  *	ata_platform_remove_one - Platform layer callback for device removal
6437  *	@pdev: Platform device that was removed
6438  *
6439  *	Platform layer indicates to libata via this hook that hot-unplug or
6440  *	module unload event has occurred.  Detach all ports.  Resource
6441  *	release is handled via devres.
6442  *
6443  *	LOCKING:
6444  *	Inherited from platform layer (may sleep).
6445  */
6446 int ata_platform_remove_one(struct platform_device *pdev)
6447 {
6448 	struct ata_host *host = platform_get_drvdata(pdev);
6449 
6450 	ata_host_detach(host);
6451 
6452 	return 0;
6453 }
6454 
6455 static int __init ata_parse_force_one(char **cur,
6456 				      struct ata_force_ent *force_ent,
6457 				      const char **reason)
6458 {
6459 	static const struct ata_force_param force_tbl[] __initconst = {
6460 		{ "40c",	.cbl		= ATA_CBL_PATA40 },
6461 		{ "80c",	.cbl		= ATA_CBL_PATA80 },
6462 		{ "short40c",	.cbl		= ATA_CBL_PATA40_SHORT },
6463 		{ "unk",	.cbl		= ATA_CBL_PATA_UNK },
6464 		{ "ign",	.cbl		= ATA_CBL_PATA_IGN },
6465 		{ "sata",	.cbl		= ATA_CBL_SATA },
6466 		{ "1.5Gbps",	.spd_limit	= 1 },
6467 		{ "3.0Gbps",	.spd_limit	= 2 },
6468 		{ "noncq",	.horkage_on	= ATA_HORKAGE_NONCQ },
6469 		{ "ncq",	.horkage_off	= ATA_HORKAGE_NONCQ },
6470 		{ "noncqtrim",	.horkage_on	= ATA_HORKAGE_NO_NCQ_TRIM },
6471 		{ "ncqtrim",	.horkage_off	= ATA_HORKAGE_NO_NCQ_TRIM },
6472 		{ "dump_id",	.horkage_on	= ATA_HORKAGE_DUMP_ID },
6473 		{ "pio0",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 0) },
6474 		{ "pio1",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 1) },
6475 		{ "pio2",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 2) },
6476 		{ "pio3",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 3) },
6477 		{ "pio4",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 4) },
6478 		{ "pio5",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 5) },
6479 		{ "pio6",	.xfer_mask	= 1 << (ATA_SHIFT_PIO + 6) },
6480 		{ "mwdma0",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 0) },
6481 		{ "mwdma1",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 1) },
6482 		{ "mwdma2",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 2) },
6483 		{ "mwdma3",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 3) },
6484 		{ "mwdma4",	.xfer_mask	= 1 << (ATA_SHIFT_MWDMA + 4) },
6485 		{ "udma0",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6486 		{ "udma16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6487 		{ "udma/16",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 0) },
6488 		{ "udma1",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6489 		{ "udma25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6490 		{ "udma/25",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 1) },
6491 		{ "udma2",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6492 		{ "udma33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6493 		{ "udma/33",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 2) },
6494 		{ "udma3",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6495 		{ "udma44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6496 		{ "udma/44",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 3) },
6497 		{ "udma4",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6498 		{ "udma66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6499 		{ "udma/66",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 4) },
6500 		{ "udma5",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6501 		{ "udma100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6502 		{ "udma/100",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 5) },
6503 		{ "udma6",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6504 		{ "udma133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6505 		{ "udma/133",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 6) },
6506 		{ "udma7",	.xfer_mask	= 1 << (ATA_SHIFT_UDMA + 7) },
6507 		{ "nohrst",	.lflags		= ATA_LFLAG_NO_HRST },
6508 		{ "nosrst",	.lflags		= ATA_LFLAG_NO_SRST },
6509 		{ "norst",	.lflags		= ATA_LFLAG_NO_HRST | ATA_LFLAG_NO_SRST },
6510 		{ "rstonce",	.lflags		= ATA_LFLAG_RST_ONCE },
6511 		{ "atapi_dmadir", .horkage_on	= ATA_HORKAGE_ATAPI_DMADIR },
6512 		{ "disable",	.horkage_on	= ATA_HORKAGE_DISABLE },
6513 	};
6514 	char *start = *cur, *p = *cur;
6515 	char *id, *val, *endp;
6516 	const struct ata_force_param *match_fp = NULL;
6517 	int nr_matches = 0, i;
6518 
6519 	/* find where this param ends and update *cur */
6520 	while (*p != '\0' && *p != ',')
6521 		p++;
6522 
6523 	if (*p == '\0')
6524 		*cur = p;
6525 	else
6526 		*cur = p + 1;
6527 
6528 	*p = '\0';
6529 
6530 	/* parse */
6531 	p = strchr(start, ':');
6532 	if (!p) {
6533 		val = strstrip(start);
6534 		goto parse_val;
6535 	}
6536 	*p = '\0';
6537 
6538 	id = strstrip(start);
6539 	val = strstrip(p + 1);
6540 
6541 	/* parse id */
6542 	p = strchr(id, '.');
6543 	if (p) {
6544 		*p++ = '\0';
6545 		force_ent->device = simple_strtoul(p, &endp, 10);
6546 		if (p == endp || *endp != '\0') {
6547 			*reason = "invalid device";
6548 			return -EINVAL;
6549 		}
6550 	}
6551 
6552 	force_ent->port = simple_strtoul(id, &endp, 10);
6553 	if (p == endp || *endp != '\0') {
6554 		*reason = "invalid port/link";
6555 		return -EINVAL;
6556 	}
6557 
6558  parse_val:
6559 	/* parse val, allow shortcuts so that both 1.5 and 1.5Gbps work */
6560 	for (i = 0; i < ARRAY_SIZE(force_tbl); i++) {
6561 		const struct ata_force_param *fp = &force_tbl[i];
6562 
6563 		if (strncasecmp(val, fp->name, strlen(val)))
6564 			continue;
6565 
6566 		nr_matches++;
6567 		match_fp = fp;
6568 
6569 		if (strcasecmp(val, fp->name) == 0) {
6570 			nr_matches = 1;
6571 			break;
6572 		}
6573 	}
6574 
6575 	if (!nr_matches) {
6576 		*reason = "unknown value";
6577 		return -EINVAL;
6578 	}
6579 	if (nr_matches > 1) {
6580 		*reason = "ambigious value";
6581 		return -EINVAL;
6582 	}
6583 
6584 	force_ent->param = *match_fp;
6585 
6586 	return 0;
6587 }
6588 
6589 static void __init ata_parse_force_param(void)
6590 {
6591 	int idx = 0, size = 1;
6592 	int last_port = -1, last_device = -1;
6593 	char *p, *cur, *next;
6594 
6595 	/* calculate maximum number of params and allocate force_tbl */
6596 	for (p = ata_force_param_buf; *p; p++)
6597 		if (*p == ',')
6598 			size++;
6599 
6600 	ata_force_tbl = kzalloc(sizeof(ata_force_tbl[0]) * size, GFP_KERNEL);
6601 	if (!ata_force_tbl) {
6602 		printk(KERN_WARNING "ata: failed to extend force table, "
6603 		       "libata.force ignored\n");
6604 		return;
6605 	}
6606 
6607 	/* parse and populate the table */
6608 	for (cur = ata_force_param_buf; *cur != '\0'; cur = next) {
6609 		const char *reason = "";
6610 		struct ata_force_ent te = { .port = -1, .device = -1 };
6611 
6612 		next = cur;
6613 		if (ata_parse_force_one(&next, &te, &reason)) {
6614 			printk(KERN_WARNING "ata: failed to parse force "
6615 			       "parameter \"%s\" (%s)\n",
6616 			       cur, reason);
6617 			continue;
6618 		}
6619 
6620 		if (te.port == -1) {
6621 			te.port = last_port;
6622 			te.device = last_device;
6623 		}
6624 
6625 		ata_force_tbl[idx++] = te;
6626 
6627 		last_port = te.port;
6628 		last_device = te.device;
6629 	}
6630 
6631 	ata_force_tbl_size = idx;
6632 }
6633 
6634 static int __init ata_init(void)
6635 {
6636 	int rc;
6637 
6638 	ata_parse_force_param();
6639 
6640 	rc = ata_sff_init();
6641 	if (rc) {
6642 		kfree(ata_force_tbl);
6643 		return rc;
6644 	}
6645 
6646 	libata_transport_init();
6647 	ata_scsi_transport_template = ata_attach_transport();
6648 	if (!ata_scsi_transport_template) {
6649 		ata_sff_exit();
6650 		rc = -ENOMEM;
6651 		goto err_out;
6652 	}
6653 
6654 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
6655 	return 0;
6656 
6657 err_out:
6658 	return rc;
6659 }
6660 
6661 static void __exit ata_exit(void)
6662 {
6663 	ata_release_transport(ata_scsi_transport_template);
6664 	libata_transport_exit();
6665 	ata_sff_exit();
6666 	kfree(ata_force_tbl);
6667 }
6668 
6669 subsys_initcall(ata_init);
6670 module_exit(ata_exit);
6671 
6672 static DEFINE_RATELIMIT_STATE(ratelimit, HZ / 5, 1);
6673 
6674 int ata_ratelimit(void)
6675 {
6676 	return __ratelimit(&ratelimit);
6677 }
6678 
6679 /**
6680  *	ata_msleep - ATA EH owner aware msleep
6681  *	@ap: ATA port to attribute the sleep to
6682  *	@msecs: duration to sleep in milliseconds
6683  *
6684  *	Sleeps @msecs.  If the current task is owner of @ap's EH, the
6685  *	ownership is released before going to sleep and reacquired
6686  *	after the sleep is complete.  IOW, other ports sharing the
6687  *	@ap->host will be allowed to own the EH while this task is
6688  *	sleeping.
6689  *
6690  *	LOCKING:
6691  *	Might sleep.
6692  */
6693 void ata_msleep(struct ata_port *ap, unsigned int msecs)
6694 {
6695 	bool owns_eh = ap && ap->host->eh_owner == current;
6696 
6697 	if (owns_eh)
6698 		ata_eh_release(ap);
6699 
6700 	msleep(msecs);
6701 
6702 	if (owns_eh)
6703 		ata_eh_acquire(ap);
6704 }
6705 
6706 /**
6707  *	ata_wait_register - wait until register value changes
6708  *	@ap: ATA port to wait register for, can be NULL
6709  *	@reg: IO-mapped register
6710  *	@mask: Mask to apply to read register value
6711  *	@val: Wait condition
6712  *	@interval: polling interval in milliseconds
6713  *	@timeout: timeout in milliseconds
6714  *
6715  *	Waiting for some bits of register to change is a common
6716  *	operation for ATA controllers.  This function reads 32bit LE
6717  *	IO-mapped register @reg and tests for the following condition.
6718  *
6719  *	(*@reg & mask) != val
6720  *
6721  *	If the condition is met, it returns; otherwise, the process is
6722  *	repeated after @interval_msec until timeout.
6723  *
6724  *	LOCKING:
6725  *	Kernel thread context (may sleep)
6726  *
6727  *	RETURNS:
6728  *	The final register value.
6729  */
6730 u32 ata_wait_register(struct ata_port *ap, void __iomem *reg, u32 mask, u32 val,
6731 		      unsigned long interval, unsigned long timeout)
6732 {
6733 	unsigned long deadline;
6734 	u32 tmp;
6735 
6736 	tmp = ioread32(reg);
6737 
6738 	/* Calculate timeout _after_ the first read to make sure
6739 	 * preceding writes reach the controller before starting to
6740 	 * eat away the timeout.
6741 	 */
6742 	deadline = ata_deadline(jiffies, timeout);
6743 
6744 	while ((tmp & mask) == val && time_before(jiffies, deadline)) {
6745 		ata_msleep(ap, interval);
6746 		tmp = ioread32(reg);
6747 	}
6748 
6749 	return tmp;
6750 }
6751 
6752 /**
6753  *	sata_lpm_ignore_phy_events - test if PHY event should be ignored
6754  *	@link: Link receiving the event
6755  *
6756  *	Test whether the received PHY event has to be ignored or not.
6757  *
6758  *	LOCKING:
6759  *	None:
6760  *
6761  *	RETURNS:
6762  *	True if the event has to be ignored.
6763  */
6764 bool sata_lpm_ignore_phy_events(struct ata_link *link)
6765 {
6766 	unsigned long lpm_timeout = link->last_lpm_change +
6767 				    msecs_to_jiffies(ATA_TMOUT_SPURIOUS_PHY);
6768 
6769 	/* if LPM is enabled, PHYRDY doesn't mean anything */
6770 	if (link->lpm_policy > ATA_LPM_MAX_POWER)
6771 		return true;
6772 
6773 	/* ignore the first PHY event after the LPM policy changed
6774 	 * as it is might be spurious
6775 	 */
6776 	if ((link->flags & ATA_LFLAG_CHANGED) &&
6777 	    time_before(jiffies, lpm_timeout))
6778 		return true;
6779 
6780 	return false;
6781 }
6782 EXPORT_SYMBOL_GPL(sata_lpm_ignore_phy_events);
6783 
6784 /*
6785  * Dummy port_ops
6786  */
6787 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
6788 {
6789 	return AC_ERR_SYSTEM;
6790 }
6791 
6792 static void ata_dummy_error_handler(struct ata_port *ap)
6793 {
6794 	/* truly dummy */
6795 }
6796 
6797 struct ata_port_operations ata_dummy_port_ops = {
6798 	.qc_prep		= ata_noop_qc_prep,
6799 	.qc_issue		= ata_dummy_qc_issue,
6800 	.error_handler		= ata_dummy_error_handler,
6801 	.sched_eh		= ata_std_sched_eh,
6802 	.end_eh			= ata_std_end_eh,
6803 };
6804 
6805 const struct ata_port_info ata_dummy_port_info = {
6806 	.port_ops		= &ata_dummy_port_ops,
6807 };
6808 
6809 /*
6810  * Utility print functions
6811  */
6812 void ata_port_printk(const struct ata_port *ap, const char *level,
6813 		     const char *fmt, ...)
6814 {
6815 	struct va_format vaf;
6816 	va_list args;
6817 
6818 	va_start(args, fmt);
6819 
6820 	vaf.fmt = fmt;
6821 	vaf.va = &args;
6822 
6823 	printk("%sata%u: %pV", level, ap->print_id, &vaf);
6824 
6825 	va_end(args);
6826 }
6827 EXPORT_SYMBOL(ata_port_printk);
6828 
6829 void ata_link_printk(const struct ata_link *link, const char *level,
6830 		     const char *fmt, ...)
6831 {
6832 	struct va_format vaf;
6833 	va_list args;
6834 
6835 	va_start(args, fmt);
6836 
6837 	vaf.fmt = fmt;
6838 	vaf.va = &args;
6839 
6840 	if (sata_pmp_attached(link->ap) || link->ap->slave_link)
6841 		printk("%sata%u.%02u: %pV",
6842 		       level, link->ap->print_id, link->pmp, &vaf);
6843 	else
6844 		printk("%sata%u: %pV",
6845 		       level, link->ap->print_id, &vaf);
6846 
6847 	va_end(args);
6848 }
6849 EXPORT_SYMBOL(ata_link_printk);
6850 
6851 void ata_dev_printk(const struct ata_device *dev, const char *level,
6852 		    const char *fmt, ...)
6853 {
6854 	struct va_format vaf;
6855 	va_list args;
6856 
6857 	va_start(args, fmt);
6858 
6859 	vaf.fmt = fmt;
6860 	vaf.va = &args;
6861 
6862 	printk("%sata%u.%02u: %pV",
6863 	       level, dev->link->ap->print_id, dev->link->pmp + dev->devno,
6864 	       &vaf);
6865 
6866 	va_end(args);
6867 }
6868 EXPORT_SYMBOL(ata_dev_printk);
6869 
6870 void ata_print_version(const struct device *dev, const char *version)
6871 {
6872 	dev_printk(KERN_DEBUG, dev, "version %s\n", version);
6873 }
6874 EXPORT_SYMBOL(ata_print_version);
6875 
6876 /*
6877  * libata is essentially a library of internal helper functions for
6878  * low-level ATA host controller drivers.  As such, the API/ABI is
6879  * likely to change as new drivers are added and updated.
6880  * Do not depend on ABI/API stability.
6881  */
6882 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
6883 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
6884 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
6885 EXPORT_SYMBOL_GPL(ata_base_port_ops);
6886 EXPORT_SYMBOL_GPL(sata_port_ops);
6887 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
6888 EXPORT_SYMBOL_GPL(ata_dummy_port_info);
6889 EXPORT_SYMBOL_GPL(ata_link_next);
6890 EXPORT_SYMBOL_GPL(ata_dev_next);
6891 EXPORT_SYMBOL_GPL(ata_std_bios_param);
6892 EXPORT_SYMBOL_GPL(ata_scsi_unlock_native_capacity);
6893 EXPORT_SYMBOL_GPL(ata_host_init);
6894 EXPORT_SYMBOL_GPL(ata_host_alloc);
6895 EXPORT_SYMBOL_GPL(ata_host_alloc_pinfo);
6896 EXPORT_SYMBOL_GPL(ata_slave_link_init);
6897 EXPORT_SYMBOL_GPL(ata_host_start);
6898 EXPORT_SYMBOL_GPL(ata_host_register);
6899 EXPORT_SYMBOL_GPL(ata_host_activate);
6900 EXPORT_SYMBOL_GPL(ata_host_detach);
6901 EXPORT_SYMBOL_GPL(ata_sg_init);
6902 EXPORT_SYMBOL_GPL(ata_qc_complete);
6903 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
6904 EXPORT_SYMBOL_GPL(atapi_cmd_type);
6905 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
6906 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
6907 EXPORT_SYMBOL_GPL(ata_pack_xfermask);
6908 EXPORT_SYMBOL_GPL(ata_unpack_xfermask);
6909 EXPORT_SYMBOL_GPL(ata_xfer_mask2mode);
6910 EXPORT_SYMBOL_GPL(ata_xfer_mode2mask);
6911 EXPORT_SYMBOL_GPL(ata_xfer_mode2shift);
6912 EXPORT_SYMBOL_GPL(ata_mode_string);
6913 EXPORT_SYMBOL_GPL(ata_id_xfermask);
6914 EXPORT_SYMBOL_GPL(ata_do_set_mode);
6915 EXPORT_SYMBOL_GPL(ata_std_qc_defer);
6916 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
6917 EXPORT_SYMBOL_GPL(ata_dev_disable);
6918 EXPORT_SYMBOL_GPL(sata_set_spd);
6919 EXPORT_SYMBOL_GPL(ata_wait_after_reset);
6920 EXPORT_SYMBOL_GPL(sata_link_debounce);
6921 EXPORT_SYMBOL_GPL(sata_link_resume);
6922 EXPORT_SYMBOL_GPL(sata_link_scr_lpm);
6923 EXPORT_SYMBOL_GPL(ata_std_prereset);
6924 EXPORT_SYMBOL_GPL(sata_link_hardreset);
6925 EXPORT_SYMBOL_GPL(sata_std_hardreset);
6926 EXPORT_SYMBOL_GPL(ata_std_postreset);
6927 EXPORT_SYMBOL_GPL(ata_dev_classify);
6928 EXPORT_SYMBOL_GPL(ata_dev_pair);
6929 EXPORT_SYMBOL_GPL(ata_ratelimit);
6930 EXPORT_SYMBOL_GPL(ata_msleep);
6931 EXPORT_SYMBOL_GPL(ata_wait_register);
6932 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
6933 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
6934 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
6935 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
6936 EXPORT_SYMBOL_GPL(__ata_change_queue_depth);
6937 EXPORT_SYMBOL_GPL(sata_scr_valid);
6938 EXPORT_SYMBOL_GPL(sata_scr_read);
6939 EXPORT_SYMBOL_GPL(sata_scr_write);
6940 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
6941 EXPORT_SYMBOL_GPL(ata_link_online);
6942 EXPORT_SYMBOL_GPL(ata_link_offline);
6943 #ifdef CONFIG_PM
6944 EXPORT_SYMBOL_GPL(ata_host_suspend);
6945 EXPORT_SYMBOL_GPL(ata_host_resume);
6946 #endif /* CONFIG_PM */
6947 EXPORT_SYMBOL_GPL(ata_id_string);
6948 EXPORT_SYMBOL_GPL(ata_id_c_string);
6949 EXPORT_SYMBOL_GPL(ata_do_dev_read_id);
6950 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
6951 
6952 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
6953 EXPORT_SYMBOL_GPL(ata_timing_find_mode);
6954 EXPORT_SYMBOL_GPL(ata_timing_compute);
6955 EXPORT_SYMBOL_GPL(ata_timing_merge);
6956 EXPORT_SYMBOL_GPL(ata_timing_cycle2mode);
6957 
6958 #ifdef CONFIG_PCI
6959 EXPORT_SYMBOL_GPL(pci_test_config_bits);
6960 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
6961 #ifdef CONFIG_PM
6962 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
6963 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
6964 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
6965 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
6966 #endif /* CONFIG_PM */
6967 #endif /* CONFIG_PCI */
6968 
6969 EXPORT_SYMBOL_GPL(ata_platform_remove_one);
6970 
6971 EXPORT_SYMBOL_GPL(__ata_ehi_push_desc);
6972 EXPORT_SYMBOL_GPL(ata_ehi_push_desc);
6973 EXPORT_SYMBOL_GPL(ata_ehi_clear_desc);
6974 EXPORT_SYMBOL_GPL(ata_port_desc);
6975 #ifdef CONFIG_PCI
6976 EXPORT_SYMBOL_GPL(ata_port_pbar_desc);
6977 #endif /* CONFIG_PCI */
6978 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
6979 EXPORT_SYMBOL_GPL(ata_link_abort);
6980 EXPORT_SYMBOL_GPL(ata_port_abort);
6981 EXPORT_SYMBOL_GPL(ata_port_freeze);
6982 EXPORT_SYMBOL_GPL(sata_async_notification);
6983 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
6984 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
6985 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
6986 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
6987 EXPORT_SYMBOL_GPL(ata_eh_analyze_ncq_error);
6988 EXPORT_SYMBOL_GPL(ata_do_eh);
6989 EXPORT_SYMBOL_GPL(ata_std_error_handler);
6990 
6991 EXPORT_SYMBOL_GPL(ata_cable_40wire);
6992 EXPORT_SYMBOL_GPL(ata_cable_80wire);
6993 EXPORT_SYMBOL_GPL(ata_cable_unknown);
6994 EXPORT_SYMBOL_GPL(ata_cable_ignore);
6995 EXPORT_SYMBOL_GPL(ata_cable_sata);
6996