xref: /linux/drivers/ata/libata-core.c (revision b454cc6636d254fbf6049b73e9560aee76fb04a3)
1 /*
2  *  libata-core.c - helper library for ATA
3  *
4  *  Maintained by:  Jeff Garzik <jgarzik@pobox.com>
5  *    		    Please ALWAYS copy linux-ide@vger.kernel.org
6  *		    on emails.
7  *
8  *  Copyright 2003-2004 Red Hat, Inc.  All rights reserved.
9  *  Copyright 2003-2004 Jeff Garzik
10  *
11  *
12  *  This program is free software; you can redistribute it and/or modify
13  *  it under the terms of the GNU General Public License as published by
14  *  the Free Software Foundation; either version 2, or (at your option)
15  *  any later version.
16  *
17  *  This program is distributed in the hope that it will be useful,
18  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
19  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
20  *  GNU General Public License for more details.
21  *
22  *  You should have received a copy of the GNU General Public License
23  *  along with this program; see the file COPYING.  If not, write to
24  *  the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
25  *
26  *
27  *  libata documentation is available via 'make {ps|pdf}docs',
28  *  as Documentation/DocBook/libata.*
29  *
30  *  Hardware documentation available from http://www.t13.org/ and
31  *  http://www.sata-io.org/
32  *
33  */
34 
35 #include <linux/kernel.h>
36 #include <linux/module.h>
37 #include <linux/pci.h>
38 #include <linux/init.h>
39 #include <linux/list.h>
40 #include <linux/mm.h>
41 #include <linux/highmem.h>
42 #include <linux/spinlock.h>
43 #include <linux/blkdev.h>
44 #include <linux/delay.h>
45 #include <linux/timer.h>
46 #include <linux/interrupt.h>
47 #include <linux/completion.h>
48 #include <linux/suspend.h>
49 #include <linux/workqueue.h>
50 #include <linux/jiffies.h>
51 #include <linux/scatterlist.h>
52 #include <scsi/scsi.h>
53 #include <scsi/scsi_cmnd.h>
54 #include <scsi/scsi_host.h>
55 #include <linux/libata.h>
56 #include <asm/io.h>
57 #include <asm/semaphore.h>
58 #include <asm/byteorder.h>
59 
60 #include "libata.h"
61 
62 /* debounce timing parameters in msecs { interval, duration, timeout } */
63 const unsigned long sata_deb_timing_normal[]		= {   5,  100, 2000 };
64 const unsigned long sata_deb_timing_hotplug[]		= {  25,  500, 2000 };
65 const unsigned long sata_deb_timing_long[]		= { 100, 2000, 5000 };
66 
67 static unsigned int ata_dev_init_params(struct ata_device *dev,
68 					u16 heads, u16 sectors);
69 static unsigned int ata_dev_set_xfermode(struct ata_device *dev);
70 static void ata_dev_xfermask(struct ata_device *dev);
71 
72 static unsigned int ata_unique_id = 1;
73 static struct workqueue_struct *ata_wq;
74 
75 struct workqueue_struct *ata_aux_wq;
76 
77 int atapi_enabled = 1;
78 module_param(atapi_enabled, int, 0444);
79 MODULE_PARM_DESC(atapi_enabled, "Enable discovery of ATAPI devices (0=off, 1=on)");
80 
81 int atapi_dmadir = 0;
82 module_param(atapi_dmadir, int, 0444);
83 MODULE_PARM_DESC(atapi_dmadir, "Enable ATAPI DMADIR bridge support (0=off, 1=on)");
84 
85 int libata_fua = 0;
86 module_param_named(fua, libata_fua, int, 0444);
87 MODULE_PARM_DESC(fua, "FUA support (0=off, 1=on)");
88 
89 static int ata_probe_timeout = ATA_TMOUT_INTERNAL / HZ;
90 module_param(ata_probe_timeout, int, 0444);
91 MODULE_PARM_DESC(ata_probe_timeout, "Set ATA probing timeout (seconds)");
92 
93 MODULE_AUTHOR("Jeff Garzik");
94 MODULE_DESCRIPTION("Library module for ATA devices");
95 MODULE_LICENSE("GPL");
96 MODULE_VERSION(DRV_VERSION);
97 
98 
99 /**
100  *	ata_tf_to_fis - Convert ATA taskfile to SATA FIS structure
101  *	@tf: Taskfile to convert
102  *	@fis: Buffer into which data will output
103  *	@pmp: Port multiplier port
104  *
105  *	Converts a standard ATA taskfile to a Serial ATA
106  *	FIS structure (Register - Host to Device).
107  *
108  *	LOCKING:
109  *	Inherited from caller.
110  */
111 
112 void ata_tf_to_fis(const struct ata_taskfile *tf, u8 *fis, u8 pmp)
113 {
114 	fis[0] = 0x27;	/* Register - Host to Device FIS */
115 	fis[1] = (pmp & 0xf) | (1 << 7); /* Port multiplier number,
116 					    bit 7 indicates Command FIS */
117 	fis[2] = tf->command;
118 	fis[3] = tf->feature;
119 
120 	fis[4] = tf->lbal;
121 	fis[5] = tf->lbam;
122 	fis[6] = tf->lbah;
123 	fis[7] = tf->device;
124 
125 	fis[8] = tf->hob_lbal;
126 	fis[9] = tf->hob_lbam;
127 	fis[10] = tf->hob_lbah;
128 	fis[11] = tf->hob_feature;
129 
130 	fis[12] = tf->nsect;
131 	fis[13] = tf->hob_nsect;
132 	fis[14] = 0;
133 	fis[15] = tf->ctl;
134 
135 	fis[16] = 0;
136 	fis[17] = 0;
137 	fis[18] = 0;
138 	fis[19] = 0;
139 }
140 
141 /**
142  *	ata_tf_from_fis - Convert SATA FIS to ATA taskfile
143  *	@fis: Buffer from which data will be input
144  *	@tf: Taskfile to output
145  *
146  *	Converts a serial ATA FIS structure to a standard ATA taskfile.
147  *
148  *	LOCKING:
149  *	Inherited from caller.
150  */
151 
152 void ata_tf_from_fis(const u8 *fis, struct ata_taskfile *tf)
153 {
154 	tf->command	= fis[2];	/* status */
155 	tf->feature	= fis[3];	/* error */
156 
157 	tf->lbal	= fis[4];
158 	tf->lbam	= fis[5];
159 	tf->lbah	= fis[6];
160 	tf->device	= fis[7];
161 
162 	tf->hob_lbal	= fis[8];
163 	tf->hob_lbam	= fis[9];
164 	tf->hob_lbah	= fis[10];
165 
166 	tf->nsect	= fis[12];
167 	tf->hob_nsect	= fis[13];
168 }
169 
170 static const u8 ata_rw_cmds[] = {
171 	/* pio multi */
172 	ATA_CMD_READ_MULTI,
173 	ATA_CMD_WRITE_MULTI,
174 	ATA_CMD_READ_MULTI_EXT,
175 	ATA_CMD_WRITE_MULTI_EXT,
176 	0,
177 	0,
178 	0,
179 	ATA_CMD_WRITE_MULTI_FUA_EXT,
180 	/* pio */
181 	ATA_CMD_PIO_READ,
182 	ATA_CMD_PIO_WRITE,
183 	ATA_CMD_PIO_READ_EXT,
184 	ATA_CMD_PIO_WRITE_EXT,
185 	0,
186 	0,
187 	0,
188 	0,
189 	/* dma */
190 	ATA_CMD_READ,
191 	ATA_CMD_WRITE,
192 	ATA_CMD_READ_EXT,
193 	ATA_CMD_WRITE_EXT,
194 	0,
195 	0,
196 	0,
197 	ATA_CMD_WRITE_FUA_EXT
198 };
199 
200 /**
201  *	ata_rwcmd_protocol - set taskfile r/w commands and protocol
202  *	@tf: command to examine and configure
203  *	@dev: device tf belongs to
204  *
205  *	Examine the device configuration and tf->flags to calculate
206  *	the proper read/write commands and protocol to use.
207  *
208  *	LOCKING:
209  *	caller.
210  */
211 static int ata_rwcmd_protocol(struct ata_taskfile *tf, struct ata_device *dev)
212 {
213 	u8 cmd;
214 
215 	int index, fua, lba48, write;
216 
217 	fua = (tf->flags & ATA_TFLAG_FUA) ? 4 : 0;
218 	lba48 = (tf->flags & ATA_TFLAG_LBA48) ? 2 : 0;
219 	write = (tf->flags & ATA_TFLAG_WRITE) ? 1 : 0;
220 
221 	if (dev->flags & ATA_DFLAG_PIO) {
222 		tf->protocol = ATA_PROT_PIO;
223 		index = dev->multi_count ? 0 : 8;
224 	} else if (lba48 && (dev->ap->flags & ATA_FLAG_PIO_LBA48)) {
225 		/* Unable to use DMA due to host limitation */
226 		tf->protocol = ATA_PROT_PIO;
227 		index = dev->multi_count ? 0 : 8;
228 	} else {
229 		tf->protocol = ATA_PROT_DMA;
230 		index = 16;
231 	}
232 
233 	cmd = ata_rw_cmds[index + fua + lba48 + write];
234 	if (cmd) {
235 		tf->command = cmd;
236 		return 0;
237 	}
238 	return -1;
239 }
240 
241 /**
242  *	ata_tf_read_block - Read block address from ATA taskfile
243  *	@tf: ATA taskfile of interest
244  *	@dev: ATA device @tf belongs to
245  *
246  *	LOCKING:
247  *	None.
248  *
249  *	Read block address from @tf.  This function can handle all
250  *	three address formats - LBA, LBA48 and CHS.  tf->protocol and
251  *	flags select the address format to use.
252  *
253  *	RETURNS:
254  *	Block address read from @tf.
255  */
256 u64 ata_tf_read_block(struct ata_taskfile *tf, struct ata_device *dev)
257 {
258 	u64 block = 0;
259 
260 	if (tf->flags & ATA_TFLAG_LBA) {
261 		if (tf->flags & ATA_TFLAG_LBA48) {
262 			block |= (u64)tf->hob_lbah << 40;
263 			block |= (u64)tf->hob_lbam << 32;
264 			block |= tf->hob_lbal << 24;
265 		} else
266 			block |= (tf->device & 0xf) << 24;
267 
268 		block |= tf->lbah << 16;
269 		block |= tf->lbam << 8;
270 		block |= tf->lbal;
271 	} else {
272 		u32 cyl, head, sect;
273 
274 		cyl = tf->lbam | (tf->lbah << 8);
275 		head = tf->device & 0xf;
276 		sect = tf->lbal;
277 
278 		block = (cyl * dev->heads + head) * dev->sectors + sect;
279 	}
280 
281 	return block;
282 }
283 
284 /**
285  *	ata_build_rw_tf - Build ATA taskfile for given read/write request
286  *	@tf: Target ATA taskfile
287  *	@dev: ATA device @tf belongs to
288  *	@block: Block address
289  *	@n_block: Number of blocks
290  *	@tf_flags: RW/FUA etc...
291  *	@tag: tag
292  *
293  *	LOCKING:
294  *	None.
295  *
296  *	Build ATA taskfile @tf for read/write request described by
297  *	@block, @n_block, @tf_flags and @tag on @dev.
298  *
299  *	RETURNS:
300  *
301  *	0 on success, -ERANGE if the request is too large for @dev,
302  *	-EINVAL if the request is invalid.
303  */
304 int ata_build_rw_tf(struct ata_taskfile *tf, struct ata_device *dev,
305 		    u64 block, u32 n_block, unsigned int tf_flags,
306 		    unsigned int tag)
307 {
308 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
309 	tf->flags |= tf_flags;
310 
311 	if ((dev->flags & (ATA_DFLAG_PIO | ATA_DFLAG_NCQ_OFF |
312 			   ATA_DFLAG_NCQ)) == ATA_DFLAG_NCQ &&
313 	    likely(tag != ATA_TAG_INTERNAL)) {
314 		/* yay, NCQ */
315 		if (!lba_48_ok(block, n_block))
316 			return -ERANGE;
317 
318 		tf->protocol = ATA_PROT_NCQ;
319 		tf->flags |= ATA_TFLAG_LBA | ATA_TFLAG_LBA48;
320 
321 		if (tf->flags & ATA_TFLAG_WRITE)
322 			tf->command = ATA_CMD_FPDMA_WRITE;
323 		else
324 			tf->command = ATA_CMD_FPDMA_READ;
325 
326 		tf->nsect = tag << 3;
327 		tf->hob_feature = (n_block >> 8) & 0xff;
328 		tf->feature = n_block & 0xff;
329 
330 		tf->hob_lbah = (block >> 40) & 0xff;
331 		tf->hob_lbam = (block >> 32) & 0xff;
332 		tf->hob_lbal = (block >> 24) & 0xff;
333 		tf->lbah = (block >> 16) & 0xff;
334 		tf->lbam = (block >> 8) & 0xff;
335 		tf->lbal = block & 0xff;
336 
337 		tf->device = 1 << 6;
338 		if (tf->flags & ATA_TFLAG_FUA)
339 			tf->device |= 1 << 7;
340 	} else if (dev->flags & ATA_DFLAG_LBA) {
341 		tf->flags |= ATA_TFLAG_LBA;
342 
343 		if (lba_28_ok(block, n_block)) {
344 			/* use LBA28 */
345 			tf->device |= (block >> 24) & 0xf;
346 		} else if (lba_48_ok(block, n_block)) {
347 			if (!(dev->flags & ATA_DFLAG_LBA48))
348 				return -ERANGE;
349 
350 			/* use LBA48 */
351 			tf->flags |= ATA_TFLAG_LBA48;
352 
353 			tf->hob_nsect = (n_block >> 8) & 0xff;
354 
355 			tf->hob_lbah = (block >> 40) & 0xff;
356 			tf->hob_lbam = (block >> 32) & 0xff;
357 			tf->hob_lbal = (block >> 24) & 0xff;
358 		} else
359 			/* request too large even for LBA48 */
360 			return -ERANGE;
361 
362 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
363 			return -EINVAL;
364 
365 		tf->nsect = n_block & 0xff;
366 
367 		tf->lbah = (block >> 16) & 0xff;
368 		tf->lbam = (block >> 8) & 0xff;
369 		tf->lbal = block & 0xff;
370 
371 		tf->device |= ATA_LBA;
372 	} else {
373 		/* CHS */
374 		u32 sect, head, cyl, track;
375 
376 		/* The request -may- be too large for CHS addressing. */
377 		if (!lba_28_ok(block, n_block))
378 			return -ERANGE;
379 
380 		if (unlikely(ata_rwcmd_protocol(tf, dev) < 0))
381 			return -EINVAL;
382 
383 		/* Convert LBA to CHS */
384 		track = (u32)block / dev->sectors;
385 		cyl   = track / dev->heads;
386 		head  = track % dev->heads;
387 		sect  = (u32)block % dev->sectors + 1;
388 
389 		DPRINTK("block %u track %u cyl %u head %u sect %u\n",
390 			(u32)block, track, cyl, head, sect);
391 
392 		/* Check whether the converted CHS can fit.
393 		   Cylinder: 0-65535
394 		   Head: 0-15
395 		   Sector: 1-255*/
396 		if ((cyl >> 16) || (head >> 4) || (sect >> 8) || (!sect))
397 			return -ERANGE;
398 
399 		tf->nsect = n_block & 0xff; /* Sector count 0 means 256 sectors */
400 		tf->lbal = sect;
401 		tf->lbam = cyl;
402 		tf->lbah = cyl >> 8;
403 		tf->device |= head;
404 	}
405 
406 	return 0;
407 }
408 
409 /**
410  *	ata_pack_xfermask - Pack pio, mwdma and udma masks into xfer_mask
411  *	@pio_mask: pio_mask
412  *	@mwdma_mask: mwdma_mask
413  *	@udma_mask: udma_mask
414  *
415  *	Pack @pio_mask, @mwdma_mask and @udma_mask into a single
416  *	unsigned int xfer_mask.
417  *
418  *	LOCKING:
419  *	None.
420  *
421  *	RETURNS:
422  *	Packed xfer_mask.
423  */
424 static unsigned int ata_pack_xfermask(unsigned int pio_mask,
425 				      unsigned int mwdma_mask,
426 				      unsigned int udma_mask)
427 {
428 	return ((pio_mask << ATA_SHIFT_PIO) & ATA_MASK_PIO) |
429 		((mwdma_mask << ATA_SHIFT_MWDMA) & ATA_MASK_MWDMA) |
430 		((udma_mask << ATA_SHIFT_UDMA) & ATA_MASK_UDMA);
431 }
432 
433 /**
434  *	ata_unpack_xfermask - Unpack xfer_mask into pio, mwdma and udma masks
435  *	@xfer_mask: xfer_mask to unpack
436  *	@pio_mask: resulting pio_mask
437  *	@mwdma_mask: resulting mwdma_mask
438  *	@udma_mask: resulting udma_mask
439  *
440  *	Unpack @xfer_mask into @pio_mask, @mwdma_mask and @udma_mask.
441  *	Any NULL distination masks will be ignored.
442  */
443 static void ata_unpack_xfermask(unsigned int xfer_mask,
444 				unsigned int *pio_mask,
445 				unsigned int *mwdma_mask,
446 				unsigned int *udma_mask)
447 {
448 	if (pio_mask)
449 		*pio_mask = (xfer_mask & ATA_MASK_PIO) >> ATA_SHIFT_PIO;
450 	if (mwdma_mask)
451 		*mwdma_mask = (xfer_mask & ATA_MASK_MWDMA) >> ATA_SHIFT_MWDMA;
452 	if (udma_mask)
453 		*udma_mask = (xfer_mask & ATA_MASK_UDMA) >> ATA_SHIFT_UDMA;
454 }
455 
456 static const struct ata_xfer_ent {
457 	int shift, bits;
458 	u8 base;
459 } ata_xfer_tbl[] = {
460 	{ ATA_SHIFT_PIO, ATA_BITS_PIO, XFER_PIO_0 },
461 	{ ATA_SHIFT_MWDMA, ATA_BITS_MWDMA, XFER_MW_DMA_0 },
462 	{ ATA_SHIFT_UDMA, ATA_BITS_UDMA, XFER_UDMA_0 },
463 	{ -1, },
464 };
465 
466 /**
467  *	ata_xfer_mask2mode - Find matching XFER_* for the given xfer_mask
468  *	@xfer_mask: xfer_mask of interest
469  *
470  *	Return matching XFER_* value for @xfer_mask.  Only the highest
471  *	bit of @xfer_mask is considered.
472  *
473  *	LOCKING:
474  *	None.
475  *
476  *	RETURNS:
477  *	Matching XFER_* value, 0 if no match found.
478  */
479 static u8 ata_xfer_mask2mode(unsigned int xfer_mask)
480 {
481 	int highbit = fls(xfer_mask) - 1;
482 	const struct ata_xfer_ent *ent;
483 
484 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
485 		if (highbit >= ent->shift && highbit < ent->shift + ent->bits)
486 			return ent->base + highbit - ent->shift;
487 	return 0;
488 }
489 
490 /**
491  *	ata_xfer_mode2mask - Find matching xfer_mask for XFER_*
492  *	@xfer_mode: XFER_* of interest
493  *
494  *	Return matching xfer_mask for @xfer_mode.
495  *
496  *	LOCKING:
497  *	None.
498  *
499  *	RETURNS:
500  *	Matching xfer_mask, 0 if no match found.
501  */
502 static unsigned int ata_xfer_mode2mask(u8 xfer_mode)
503 {
504 	const struct ata_xfer_ent *ent;
505 
506 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
507 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
508 			return 1 << (ent->shift + xfer_mode - ent->base);
509 	return 0;
510 }
511 
512 /**
513  *	ata_xfer_mode2shift - Find matching xfer_shift for XFER_*
514  *	@xfer_mode: XFER_* of interest
515  *
516  *	Return matching xfer_shift for @xfer_mode.
517  *
518  *	LOCKING:
519  *	None.
520  *
521  *	RETURNS:
522  *	Matching xfer_shift, -1 if no match found.
523  */
524 static int ata_xfer_mode2shift(unsigned int xfer_mode)
525 {
526 	const struct ata_xfer_ent *ent;
527 
528 	for (ent = ata_xfer_tbl; ent->shift >= 0; ent++)
529 		if (xfer_mode >= ent->base && xfer_mode < ent->base + ent->bits)
530 			return ent->shift;
531 	return -1;
532 }
533 
534 /**
535  *	ata_mode_string - convert xfer_mask to string
536  *	@xfer_mask: mask of bits supported; only highest bit counts.
537  *
538  *	Determine string which represents the highest speed
539  *	(highest bit in @modemask).
540  *
541  *	LOCKING:
542  *	None.
543  *
544  *	RETURNS:
545  *	Constant C string representing highest speed listed in
546  *	@mode_mask, or the constant C string "<n/a>".
547  */
548 static const char *ata_mode_string(unsigned int xfer_mask)
549 {
550 	static const char * const xfer_mode_str[] = {
551 		"PIO0",
552 		"PIO1",
553 		"PIO2",
554 		"PIO3",
555 		"PIO4",
556 		"PIO5",
557 		"PIO6",
558 		"MWDMA0",
559 		"MWDMA1",
560 		"MWDMA2",
561 		"MWDMA3",
562 		"MWDMA4",
563 		"UDMA/16",
564 		"UDMA/25",
565 		"UDMA/33",
566 		"UDMA/44",
567 		"UDMA/66",
568 		"UDMA/100",
569 		"UDMA/133",
570 		"UDMA7",
571 	};
572 	int highbit;
573 
574 	highbit = fls(xfer_mask) - 1;
575 	if (highbit >= 0 && highbit < ARRAY_SIZE(xfer_mode_str))
576 		return xfer_mode_str[highbit];
577 	return "<n/a>";
578 }
579 
580 static const char *sata_spd_string(unsigned int spd)
581 {
582 	static const char * const spd_str[] = {
583 		"1.5 Gbps",
584 		"3.0 Gbps",
585 	};
586 
587 	if (spd == 0 || (spd - 1) >= ARRAY_SIZE(spd_str))
588 		return "<unknown>";
589 	return spd_str[spd - 1];
590 }
591 
592 void ata_dev_disable(struct ata_device *dev)
593 {
594 	if (ata_dev_enabled(dev) && ata_msg_drv(dev->ap)) {
595 		ata_dev_printk(dev, KERN_WARNING, "disabled\n");
596 		dev->class++;
597 	}
598 }
599 
600 /**
601  *	ata_pio_devchk - PATA device presence detection
602  *	@ap: ATA channel to examine
603  *	@device: Device to examine (starting at zero)
604  *
605  *	This technique was originally described in
606  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
607  *	later found its way into the ATA/ATAPI spec.
608  *
609  *	Write a pattern to the ATA shadow registers,
610  *	and if a device is present, it will respond by
611  *	correctly storing and echoing back the
612  *	ATA shadow register contents.
613  *
614  *	LOCKING:
615  *	caller.
616  */
617 
618 static unsigned int ata_pio_devchk(struct ata_port *ap,
619 				   unsigned int device)
620 {
621 	struct ata_ioports *ioaddr = &ap->ioaddr;
622 	u8 nsect, lbal;
623 
624 	ap->ops->dev_select(ap, device);
625 
626 	outb(0x55, ioaddr->nsect_addr);
627 	outb(0xaa, ioaddr->lbal_addr);
628 
629 	outb(0xaa, ioaddr->nsect_addr);
630 	outb(0x55, ioaddr->lbal_addr);
631 
632 	outb(0x55, ioaddr->nsect_addr);
633 	outb(0xaa, ioaddr->lbal_addr);
634 
635 	nsect = inb(ioaddr->nsect_addr);
636 	lbal = inb(ioaddr->lbal_addr);
637 
638 	if ((nsect == 0x55) && (lbal == 0xaa))
639 		return 1;	/* we found a device */
640 
641 	return 0;		/* nothing found */
642 }
643 
644 /**
645  *	ata_mmio_devchk - PATA device presence detection
646  *	@ap: ATA channel to examine
647  *	@device: Device to examine (starting at zero)
648  *
649  *	This technique was originally described in
650  *	Hale Landis's ATADRVR (www.ata-atapi.com), and
651  *	later found its way into the ATA/ATAPI spec.
652  *
653  *	Write a pattern to the ATA shadow registers,
654  *	and if a device is present, it will respond by
655  *	correctly storing and echoing back the
656  *	ATA shadow register contents.
657  *
658  *	LOCKING:
659  *	caller.
660  */
661 
662 static unsigned int ata_mmio_devchk(struct ata_port *ap,
663 				    unsigned int device)
664 {
665 	struct ata_ioports *ioaddr = &ap->ioaddr;
666 	u8 nsect, lbal;
667 
668 	ap->ops->dev_select(ap, device);
669 
670 	writeb(0x55, (void __iomem *) ioaddr->nsect_addr);
671 	writeb(0xaa, (void __iomem *) ioaddr->lbal_addr);
672 
673 	writeb(0xaa, (void __iomem *) ioaddr->nsect_addr);
674 	writeb(0x55, (void __iomem *) ioaddr->lbal_addr);
675 
676 	writeb(0x55, (void __iomem *) ioaddr->nsect_addr);
677 	writeb(0xaa, (void __iomem *) ioaddr->lbal_addr);
678 
679 	nsect = readb((void __iomem *) ioaddr->nsect_addr);
680 	lbal = readb((void __iomem *) ioaddr->lbal_addr);
681 
682 	if ((nsect == 0x55) && (lbal == 0xaa))
683 		return 1;	/* we found a device */
684 
685 	return 0;		/* nothing found */
686 }
687 
688 /**
689  *	ata_devchk - PATA device presence detection
690  *	@ap: ATA channel to examine
691  *	@device: Device to examine (starting at zero)
692  *
693  *	Dispatch ATA device presence detection, depending
694  *	on whether we are using PIO or MMIO to talk to the
695  *	ATA shadow registers.
696  *
697  *	LOCKING:
698  *	caller.
699  */
700 
701 static unsigned int ata_devchk(struct ata_port *ap,
702 				    unsigned int device)
703 {
704 	if (ap->flags & ATA_FLAG_MMIO)
705 		return ata_mmio_devchk(ap, device);
706 	return ata_pio_devchk(ap, device);
707 }
708 
709 /**
710  *	ata_dev_classify - determine device type based on ATA-spec signature
711  *	@tf: ATA taskfile register set for device to be identified
712  *
713  *	Determine from taskfile register contents whether a device is
714  *	ATA or ATAPI, as per "Signature and persistence" section
715  *	of ATA/PI spec (volume 1, sect 5.14).
716  *
717  *	LOCKING:
718  *	None.
719  *
720  *	RETURNS:
721  *	Device type, %ATA_DEV_ATA, %ATA_DEV_ATAPI, or %ATA_DEV_UNKNOWN
722  *	the event of failure.
723  */
724 
725 unsigned int ata_dev_classify(const struct ata_taskfile *tf)
726 {
727 	/* Apple's open source Darwin code hints that some devices only
728 	 * put a proper signature into the LBA mid/high registers,
729 	 * So, we only check those.  It's sufficient for uniqueness.
730 	 */
731 
732 	if (((tf->lbam == 0) && (tf->lbah == 0)) ||
733 	    ((tf->lbam == 0x3c) && (tf->lbah == 0xc3))) {
734 		DPRINTK("found ATA device by sig\n");
735 		return ATA_DEV_ATA;
736 	}
737 
738 	if (((tf->lbam == 0x14) && (tf->lbah == 0xeb)) ||
739 	    ((tf->lbam == 0x69) && (tf->lbah == 0x96))) {
740 		DPRINTK("found ATAPI device by sig\n");
741 		return ATA_DEV_ATAPI;
742 	}
743 
744 	DPRINTK("unknown device\n");
745 	return ATA_DEV_UNKNOWN;
746 }
747 
748 /**
749  *	ata_dev_try_classify - Parse returned ATA device signature
750  *	@ap: ATA channel to examine
751  *	@device: Device to examine (starting at zero)
752  *	@r_err: Value of error register on completion
753  *
754  *	After an event -- SRST, E.D.D., or SATA COMRESET -- occurs,
755  *	an ATA/ATAPI-defined set of values is placed in the ATA
756  *	shadow registers, indicating the results of device detection
757  *	and diagnostics.
758  *
759  *	Select the ATA device, and read the values from the ATA shadow
760  *	registers.  Then parse according to the Error register value,
761  *	and the spec-defined values examined by ata_dev_classify().
762  *
763  *	LOCKING:
764  *	caller.
765  *
766  *	RETURNS:
767  *	Device type - %ATA_DEV_ATA, %ATA_DEV_ATAPI or %ATA_DEV_NONE.
768  */
769 
770 static unsigned int
771 ata_dev_try_classify(struct ata_port *ap, unsigned int device, u8 *r_err)
772 {
773 	struct ata_taskfile tf;
774 	unsigned int class;
775 	u8 err;
776 
777 	ap->ops->dev_select(ap, device);
778 
779 	memset(&tf, 0, sizeof(tf));
780 
781 	ap->ops->tf_read(ap, &tf);
782 	err = tf.feature;
783 	if (r_err)
784 		*r_err = err;
785 
786 	/* see if device passed diags: if master then continue and warn later */
787 	if (err == 0 && device == 0)
788 		/* diagnostic fail : do nothing _YET_ */
789 		ap->device[device].horkage |= ATA_HORKAGE_DIAGNOSTIC;
790 	else if (err == 1)
791 		/* do nothing */ ;
792 	else if ((device == 0) && (err == 0x81))
793 		/* do nothing */ ;
794 	else
795 		return ATA_DEV_NONE;
796 
797 	/* determine if device is ATA or ATAPI */
798 	class = ata_dev_classify(&tf);
799 
800 	if (class == ATA_DEV_UNKNOWN)
801 		return ATA_DEV_NONE;
802 	if ((class == ATA_DEV_ATA) && (ata_chk_status(ap) == 0))
803 		return ATA_DEV_NONE;
804 	return class;
805 }
806 
807 /**
808  *	ata_id_string - Convert IDENTIFY DEVICE page into string
809  *	@id: IDENTIFY DEVICE results we will examine
810  *	@s: string into which data is output
811  *	@ofs: offset into identify device page
812  *	@len: length of string to return. must be an even number.
813  *
814  *	The strings in the IDENTIFY DEVICE page are broken up into
815  *	16-bit chunks.  Run through the string, and output each
816  *	8-bit chunk linearly, regardless of platform.
817  *
818  *	LOCKING:
819  *	caller.
820  */
821 
822 void ata_id_string(const u16 *id, unsigned char *s,
823 		   unsigned int ofs, unsigned int len)
824 {
825 	unsigned int c;
826 
827 	while (len > 0) {
828 		c = id[ofs] >> 8;
829 		*s = c;
830 		s++;
831 
832 		c = id[ofs] & 0xff;
833 		*s = c;
834 		s++;
835 
836 		ofs++;
837 		len -= 2;
838 	}
839 }
840 
841 /**
842  *	ata_id_c_string - Convert IDENTIFY DEVICE page into C string
843  *	@id: IDENTIFY DEVICE results we will examine
844  *	@s: string into which data is output
845  *	@ofs: offset into identify device page
846  *	@len: length of string to return. must be an odd number.
847  *
848  *	This function is identical to ata_id_string except that it
849  *	trims trailing spaces and terminates the resulting string with
850  *	null.  @len must be actual maximum length (even number) + 1.
851  *
852  *	LOCKING:
853  *	caller.
854  */
855 void ata_id_c_string(const u16 *id, unsigned char *s,
856 		     unsigned int ofs, unsigned int len)
857 {
858 	unsigned char *p;
859 
860 	WARN_ON(!(len & 1));
861 
862 	ata_id_string(id, s, ofs, len - 1);
863 
864 	p = s + strnlen(s, len - 1);
865 	while (p > s && p[-1] == ' ')
866 		p--;
867 	*p = '\0';
868 }
869 
870 static u64 ata_id_n_sectors(const u16 *id)
871 {
872 	if (ata_id_has_lba(id)) {
873 		if (ata_id_has_lba48(id))
874 			return ata_id_u64(id, 100);
875 		else
876 			return ata_id_u32(id, 60);
877 	} else {
878 		if (ata_id_current_chs_valid(id))
879 			return ata_id_u32(id, 57);
880 		else
881 			return id[1] * id[3] * id[6];
882 	}
883 }
884 
885 /**
886  *	ata_noop_dev_select - Select device 0/1 on ATA bus
887  *	@ap: ATA channel to manipulate
888  *	@device: ATA device (numbered from zero) to select
889  *
890  *	This function performs no actual function.
891  *
892  *	May be used as the dev_select() entry in ata_port_operations.
893  *
894  *	LOCKING:
895  *	caller.
896  */
897 void ata_noop_dev_select (struct ata_port *ap, unsigned int device)
898 {
899 }
900 
901 
902 /**
903  *	ata_std_dev_select - Select device 0/1 on ATA bus
904  *	@ap: ATA channel to manipulate
905  *	@device: ATA device (numbered from zero) to select
906  *
907  *	Use the method defined in the ATA specification to
908  *	make either device 0, or device 1, active on the
909  *	ATA channel.  Works with both PIO and MMIO.
910  *
911  *	May be used as the dev_select() entry in ata_port_operations.
912  *
913  *	LOCKING:
914  *	caller.
915  */
916 
917 void ata_std_dev_select (struct ata_port *ap, unsigned int device)
918 {
919 	u8 tmp;
920 
921 	if (device == 0)
922 		tmp = ATA_DEVICE_OBS;
923 	else
924 		tmp = ATA_DEVICE_OBS | ATA_DEV1;
925 
926 	if (ap->flags & ATA_FLAG_MMIO) {
927 		writeb(tmp, (void __iomem *) ap->ioaddr.device_addr);
928 	} else {
929 		outb(tmp, ap->ioaddr.device_addr);
930 	}
931 	ata_pause(ap);		/* needed; also flushes, for mmio */
932 }
933 
934 /**
935  *	ata_dev_select - Select device 0/1 on ATA bus
936  *	@ap: ATA channel to manipulate
937  *	@device: ATA device (numbered from zero) to select
938  *	@wait: non-zero to wait for Status register BSY bit to clear
939  *	@can_sleep: non-zero if context allows sleeping
940  *
941  *	Use the method defined in the ATA specification to
942  *	make either device 0, or device 1, active on the
943  *	ATA channel.
944  *
945  *	This is a high-level version of ata_std_dev_select(),
946  *	which additionally provides the services of inserting
947  *	the proper pauses and status polling, where needed.
948  *
949  *	LOCKING:
950  *	caller.
951  */
952 
953 void ata_dev_select(struct ata_port *ap, unsigned int device,
954 			   unsigned int wait, unsigned int can_sleep)
955 {
956 	if (ata_msg_probe(ap))
957 		ata_port_printk(ap, KERN_INFO, "ata_dev_select: ENTER, ata%u: "
958 				"device %u, wait %u\n", ap->id, device, wait);
959 
960 	if (wait)
961 		ata_wait_idle(ap);
962 
963 	ap->ops->dev_select(ap, device);
964 
965 	if (wait) {
966 		if (can_sleep && ap->device[device].class == ATA_DEV_ATAPI)
967 			msleep(150);
968 		ata_wait_idle(ap);
969 	}
970 }
971 
972 /**
973  *	ata_dump_id - IDENTIFY DEVICE info debugging output
974  *	@id: IDENTIFY DEVICE page to dump
975  *
976  *	Dump selected 16-bit words from the given IDENTIFY DEVICE
977  *	page.
978  *
979  *	LOCKING:
980  *	caller.
981  */
982 
983 static inline void ata_dump_id(const u16 *id)
984 {
985 	DPRINTK("49==0x%04x  "
986 		"53==0x%04x  "
987 		"63==0x%04x  "
988 		"64==0x%04x  "
989 		"75==0x%04x  \n",
990 		id[49],
991 		id[53],
992 		id[63],
993 		id[64],
994 		id[75]);
995 	DPRINTK("80==0x%04x  "
996 		"81==0x%04x  "
997 		"82==0x%04x  "
998 		"83==0x%04x  "
999 		"84==0x%04x  \n",
1000 		id[80],
1001 		id[81],
1002 		id[82],
1003 		id[83],
1004 		id[84]);
1005 	DPRINTK("88==0x%04x  "
1006 		"93==0x%04x\n",
1007 		id[88],
1008 		id[93]);
1009 }
1010 
1011 /**
1012  *	ata_id_xfermask - Compute xfermask from the given IDENTIFY data
1013  *	@id: IDENTIFY data to compute xfer mask from
1014  *
1015  *	Compute the xfermask for this device. This is not as trivial
1016  *	as it seems if we must consider early devices correctly.
1017  *
1018  *	FIXME: pre IDE drive timing (do we care ?).
1019  *
1020  *	LOCKING:
1021  *	None.
1022  *
1023  *	RETURNS:
1024  *	Computed xfermask
1025  */
1026 static unsigned int ata_id_xfermask(const u16 *id)
1027 {
1028 	unsigned int pio_mask, mwdma_mask, udma_mask;
1029 
1030 	/* Usual case. Word 53 indicates word 64 is valid */
1031 	if (id[ATA_ID_FIELD_VALID] & (1 << 1)) {
1032 		pio_mask = id[ATA_ID_PIO_MODES] & 0x03;
1033 		pio_mask <<= 3;
1034 		pio_mask |= 0x7;
1035 	} else {
1036 		/* If word 64 isn't valid then Word 51 high byte holds
1037 		 * the PIO timing number for the maximum. Turn it into
1038 		 * a mask.
1039 		 */
1040 		u8 mode = (id[ATA_ID_OLD_PIO_MODES] >> 8) & 0xFF;
1041 		if (mode < 5)	/* Valid PIO range */
1042                 	pio_mask = (2 << mode) - 1;
1043 		else
1044 			pio_mask = 1;
1045 
1046 		/* But wait.. there's more. Design your standards by
1047 		 * committee and you too can get a free iordy field to
1048 		 * process. However its the speeds not the modes that
1049 		 * are supported... Note drivers using the timing API
1050 		 * will get this right anyway
1051 		 */
1052 	}
1053 
1054 	mwdma_mask = id[ATA_ID_MWDMA_MODES] & 0x07;
1055 
1056 	if (ata_id_is_cfa(id)) {
1057 		/*
1058 		 *	Process compact flash extended modes
1059 		 */
1060 		int pio = id[163] & 0x7;
1061 		int dma = (id[163] >> 3) & 7;
1062 
1063 		if (pio)
1064 			pio_mask |= (1 << 5);
1065 		if (pio > 1)
1066 			pio_mask |= (1 << 6);
1067 		if (dma)
1068 			mwdma_mask |= (1 << 3);
1069 		if (dma > 1)
1070 			mwdma_mask |= (1 << 4);
1071 	}
1072 
1073 	udma_mask = 0;
1074 	if (id[ATA_ID_FIELD_VALID] & (1 << 2))
1075 		udma_mask = id[ATA_ID_UDMA_MODES] & 0xff;
1076 
1077 	return ata_pack_xfermask(pio_mask, mwdma_mask, udma_mask);
1078 }
1079 
1080 /**
1081  *	ata_port_queue_task - Queue port_task
1082  *	@ap: The ata_port to queue port_task for
1083  *	@fn: workqueue function to be scheduled
1084  *	@data: data for @fn to use
1085  *	@delay: delay time for workqueue function
1086  *
1087  *	Schedule @fn(@data) for execution after @delay jiffies using
1088  *	port_task.  There is one port_task per port and it's the
1089  *	user(low level driver)'s responsibility to make sure that only
1090  *	one task is active at any given time.
1091  *
1092  *	libata core layer takes care of synchronization between
1093  *	port_task and EH.  ata_port_queue_task() may be ignored for EH
1094  *	synchronization.
1095  *
1096  *	LOCKING:
1097  *	Inherited from caller.
1098  */
1099 void ata_port_queue_task(struct ata_port *ap, work_func_t fn, void *data,
1100 			 unsigned long delay)
1101 {
1102 	int rc;
1103 
1104 	if (ap->pflags & ATA_PFLAG_FLUSH_PORT_TASK)
1105 		return;
1106 
1107 	PREPARE_DELAYED_WORK(&ap->port_task, fn);
1108 	ap->port_task_data = data;
1109 
1110 	rc = queue_delayed_work(ata_wq, &ap->port_task, delay);
1111 
1112 	/* rc == 0 means that another user is using port task */
1113 	WARN_ON(rc == 0);
1114 }
1115 
1116 /**
1117  *	ata_port_flush_task - Flush port_task
1118  *	@ap: The ata_port to flush port_task for
1119  *
1120  *	After this function completes, port_task is guranteed not to
1121  *	be running or scheduled.
1122  *
1123  *	LOCKING:
1124  *	Kernel thread context (may sleep)
1125  */
1126 void ata_port_flush_task(struct ata_port *ap)
1127 {
1128 	unsigned long flags;
1129 
1130 	DPRINTK("ENTER\n");
1131 
1132 	spin_lock_irqsave(ap->lock, flags);
1133 	ap->pflags |= ATA_PFLAG_FLUSH_PORT_TASK;
1134 	spin_unlock_irqrestore(ap->lock, flags);
1135 
1136 	DPRINTK("flush #1\n");
1137 	flush_workqueue(ata_wq);
1138 
1139 	/*
1140 	 * At this point, if a task is running, it's guaranteed to see
1141 	 * the FLUSH flag; thus, it will never queue pio tasks again.
1142 	 * Cancel and flush.
1143 	 */
1144 	if (!cancel_delayed_work(&ap->port_task)) {
1145 		if (ata_msg_ctl(ap))
1146 			ata_port_printk(ap, KERN_DEBUG, "%s: flush #2\n",
1147 					__FUNCTION__);
1148 		flush_workqueue(ata_wq);
1149 	}
1150 
1151 	spin_lock_irqsave(ap->lock, flags);
1152 	ap->pflags &= ~ATA_PFLAG_FLUSH_PORT_TASK;
1153 	spin_unlock_irqrestore(ap->lock, flags);
1154 
1155 	if (ata_msg_ctl(ap))
1156 		ata_port_printk(ap, KERN_DEBUG, "%s: EXIT\n", __FUNCTION__);
1157 }
1158 
1159 void ata_qc_complete_internal(struct ata_queued_cmd *qc)
1160 {
1161 	struct completion *waiting = qc->private_data;
1162 
1163 	complete(waiting);
1164 }
1165 
1166 /**
1167  *	ata_exec_internal_sg - execute libata internal command
1168  *	@dev: Device to which the command is sent
1169  *	@tf: Taskfile registers for the command and the result
1170  *	@cdb: CDB for packet command
1171  *	@dma_dir: Data tranfer direction of the command
1172  *	@sg: sg list for the data buffer of the command
1173  *	@n_elem: Number of sg entries
1174  *
1175  *	Executes libata internal command with timeout.  @tf contains
1176  *	command on entry and result on return.  Timeout and error
1177  *	conditions are reported via return value.  No recovery action
1178  *	is taken after a command times out.  It's caller's duty to
1179  *	clean up after timeout.
1180  *
1181  *	LOCKING:
1182  *	None.  Should be called with kernel context, might sleep.
1183  *
1184  *	RETURNS:
1185  *	Zero on success, AC_ERR_* mask on failure
1186  */
1187 unsigned ata_exec_internal_sg(struct ata_device *dev,
1188 			      struct ata_taskfile *tf, const u8 *cdb,
1189 			      int dma_dir, struct scatterlist *sg,
1190 			      unsigned int n_elem)
1191 {
1192 	struct ata_port *ap = dev->ap;
1193 	u8 command = tf->command;
1194 	struct ata_queued_cmd *qc;
1195 	unsigned int tag, preempted_tag;
1196 	u32 preempted_sactive, preempted_qc_active;
1197 	DECLARE_COMPLETION_ONSTACK(wait);
1198 	unsigned long flags;
1199 	unsigned int err_mask;
1200 	int rc;
1201 
1202 	spin_lock_irqsave(ap->lock, flags);
1203 
1204 	/* no internal command while frozen */
1205 	if (ap->pflags & ATA_PFLAG_FROZEN) {
1206 		spin_unlock_irqrestore(ap->lock, flags);
1207 		return AC_ERR_SYSTEM;
1208 	}
1209 
1210 	/* initialize internal qc */
1211 
1212 	/* XXX: Tag 0 is used for drivers with legacy EH as some
1213 	 * drivers choke if any other tag is given.  This breaks
1214 	 * ata_tag_internal() test for those drivers.  Don't use new
1215 	 * EH stuff without converting to it.
1216 	 */
1217 	if (ap->ops->error_handler)
1218 		tag = ATA_TAG_INTERNAL;
1219 	else
1220 		tag = 0;
1221 
1222 	if (test_and_set_bit(tag, &ap->qc_allocated))
1223 		BUG();
1224 	qc = __ata_qc_from_tag(ap, tag);
1225 
1226 	qc->tag = tag;
1227 	qc->scsicmd = NULL;
1228 	qc->ap = ap;
1229 	qc->dev = dev;
1230 	ata_qc_reinit(qc);
1231 
1232 	preempted_tag = ap->active_tag;
1233 	preempted_sactive = ap->sactive;
1234 	preempted_qc_active = ap->qc_active;
1235 	ap->active_tag = ATA_TAG_POISON;
1236 	ap->sactive = 0;
1237 	ap->qc_active = 0;
1238 
1239 	/* prepare & issue qc */
1240 	qc->tf = *tf;
1241 	if (cdb)
1242 		memcpy(qc->cdb, cdb, ATAPI_CDB_LEN);
1243 	qc->flags |= ATA_QCFLAG_RESULT_TF;
1244 	qc->dma_dir = dma_dir;
1245 	if (dma_dir != DMA_NONE) {
1246 		unsigned int i, buflen = 0;
1247 
1248 		for (i = 0; i < n_elem; i++)
1249 			buflen += sg[i].length;
1250 
1251 		ata_sg_init(qc, sg, n_elem);
1252 		qc->nsect = buflen / ATA_SECT_SIZE;
1253 		qc->nbytes = buflen;
1254 	}
1255 
1256 	qc->private_data = &wait;
1257 	qc->complete_fn = ata_qc_complete_internal;
1258 
1259 	ata_qc_issue(qc);
1260 
1261 	spin_unlock_irqrestore(ap->lock, flags);
1262 
1263 	rc = wait_for_completion_timeout(&wait, ata_probe_timeout);
1264 
1265 	ata_port_flush_task(ap);
1266 
1267 	if (!rc) {
1268 		spin_lock_irqsave(ap->lock, flags);
1269 
1270 		/* We're racing with irq here.  If we lose, the
1271 		 * following test prevents us from completing the qc
1272 		 * twice.  If we win, the port is frozen and will be
1273 		 * cleaned up by ->post_internal_cmd().
1274 		 */
1275 		if (qc->flags & ATA_QCFLAG_ACTIVE) {
1276 			qc->err_mask |= AC_ERR_TIMEOUT;
1277 
1278 			if (ap->ops->error_handler)
1279 				ata_port_freeze(ap);
1280 			else
1281 				ata_qc_complete(qc);
1282 
1283 			if (ata_msg_warn(ap))
1284 				ata_dev_printk(dev, KERN_WARNING,
1285 					"qc timeout (cmd 0x%x)\n", command);
1286 		}
1287 
1288 		spin_unlock_irqrestore(ap->lock, flags);
1289 	}
1290 
1291 	/* do post_internal_cmd */
1292 	if (ap->ops->post_internal_cmd)
1293 		ap->ops->post_internal_cmd(qc);
1294 
1295 	if (qc->flags & ATA_QCFLAG_FAILED && !qc->err_mask) {
1296 		if (ata_msg_warn(ap))
1297 			ata_dev_printk(dev, KERN_WARNING,
1298 				"zero err_mask for failed "
1299 				"internal command, assuming AC_ERR_OTHER\n");
1300 		qc->err_mask |= AC_ERR_OTHER;
1301 	}
1302 
1303 	/* finish up */
1304 	spin_lock_irqsave(ap->lock, flags);
1305 
1306 	*tf = qc->result_tf;
1307 	err_mask = qc->err_mask;
1308 
1309 	ata_qc_free(qc);
1310 	ap->active_tag = preempted_tag;
1311 	ap->sactive = preempted_sactive;
1312 	ap->qc_active = preempted_qc_active;
1313 
1314 	/* XXX - Some LLDDs (sata_mv) disable port on command failure.
1315 	 * Until those drivers are fixed, we detect the condition
1316 	 * here, fail the command with AC_ERR_SYSTEM and reenable the
1317 	 * port.
1318 	 *
1319 	 * Note that this doesn't change any behavior as internal
1320 	 * command failure results in disabling the device in the
1321 	 * higher layer for LLDDs without new reset/EH callbacks.
1322 	 *
1323 	 * Kill the following code as soon as those drivers are fixed.
1324 	 */
1325 	if (ap->flags & ATA_FLAG_DISABLED) {
1326 		err_mask |= AC_ERR_SYSTEM;
1327 		ata_port_probe(ap);
1328 	}
1329 
1330 	spin_unlock_irqrestore(ap->lock, flags);
1331 
1332 	return err_mask;
1333 }
1334 
1335 /**
1336  *	ata_exec_internal - execute libata internal command
1337  *	@dev: Device to which the command is sent
1338  *	@tf: Taskfile registers for the command and the result
1339  *	@cdb: CDB for packet command
1340  *	@dma_dir: Data tranfer direction of the command
1341  *	@buf: Data buffer of the command
1342  *	@buflen: Length of data buffer
1343  *
1344  *	Wrapper around ata_exec_internal_sg() which takes simple
1345  *	buffer instead of sg list.
1346  *
1347  *	LOCKING:
1348  *	None.  Should be called with kernel context, might sleep.
1349  *
1350  *	RETURNS:
1351  *	Zero on success, AC_ERR_* mask on failure
1352  */
1353 unsigned ata_exec_internal(struct ata_device *dev,
1354 			   struct ata_taskfile *tf, const u8 *cdb,
1355 			   int dma_dir, void *buf, unsigned int buflen)
1356 {
1357 	struct scatterlist *psg = NULL, sg;
1358 	unsigned int n_elem = 0;
1359 
1360 	if (dma_dir != DMA_NONE) {
1361 		WARN_ON(!buf);
1362 		sg_init_one(&sg, buf, buflen);
1363 		psg = &sg;
1364 		n_elem++;
1365 	}
1366 
1367 	return ata_exec_internal_sg(dev, tf, cdb, dma_dir, psg, n_elem);
1368 }
1369 
1370 /**
1371  *	ata_do_simple_cmd - execute simple internal command
1372  *	@dev: Device to which the command is sent
1373  *	@cmd: Opcode to execute
1374  *
1375  *	Execute a 'simple' command, that only consists of the opcode
1376  *	'cmd' itself, without filling any other registers
1377  *
1378  *	LOCKING:
1379  *	Kernel thread context (may sleep).
1380  *
1381  *	RETURNS:
1382  *	Zero on success, AC_ERR_* mask on failure
1383  */
1384 unsigned int ata_do_simple_cmd(struct ata_device *dev, u8 cmd)
1385 {
1386 	struct ata_taskfile tf;
1387 
1388 	ata_tf_init(dev, &tf);
1389 
1390 	tf.command = cmd;
1391 	tf.flags |= ATA_TFLAG_DEVICE;
1392 	tf.protocol = ATA_PROT_NODATA;
1393 
1394 	return ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
1395 }
1396 
1397 /**
1398  *	ata_pio_need_iordy	-	check if iordy needed
1399  *	@adev: ATA device
1400  *
1401  *	Check if the current speed of the device requires IORDY. Used
1402  *	by various controllers for chip configuration.
1403  */
1404 
1405 unsigned int ata_pio_need_iordy(const struct ata_device *adev)
1406 {
1407 	int pio;
1408 	int speed = adev->pio_mode - XFER_PIO_0;
1409 
1410 	if (speed < 2)
1411 		return 0;
1412 	if (speed > 2)
1413 		return 1;
1414 
1415 	/* If we have no drive specific rule, then PIO 2 is non IORDY */
1416 
1417 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE */
1418 		pio = adev->id[ATA_ID_EIDE_PIO];
1419 		/* Is the speed faster than the drive allows non IORDY ? */
1420 		if (pio) {
1421 			/* This is cycle times not frequency - watch the logic! */
1422 			if (pio > 240)	/* PIO2 is 240nS per cycle */
1423 				return 1;
1424 			return 0;
1425 		}
1426 	}
1427 	return 0;
1428 }
1429 
1430 /**
1431  *	ata_dev_read_id - Read ID data from the specified device
1432  *	@dev: target device
1433  *	@p_class: pointer to class of the target device (may be changed)
1434  *	@flags: ATA_READID_* flags
1435  *	@id: buffer to read IDENTIFY data into
1436  *
1437  *	Read ID data from the specified device.  ATA_CMD_ID_ATA is
1438  *	performed on ATA devices and ATA_CMD_ID_ATAPI on ATAPI
1439  *	devices.  This function also issues ATA_CMD_INIT_DEV_PARAMS
1440  *	for pre-ATA4 drives.
1441  *
1442  *	LOCKING:
1443  *	Kernel thread context (may sleep)
1444  *
1445  *	RETURNS:
1446  *	0 on success, -errno otherwise.
1447  */
1448 int ata_dev_read_id(struct ata_device *dev, unsigned int *p_class,
1449 		    unsigned int flags, u16 *id)
1450 {
1451 	struct ata_port *ap = dev->ap;
1452 	unsigned int class = *p_class;
1453 	struct ata_taskfile tf;
1454 	unsigned int err_mask = 0;
1455 	const char *reason;
1456 	int rc;
1457 
1458 	if (ata_msg_ctl(ap))
1459 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER, host %u, dev %u\n",
1460 			       __FUNCTION__, ap->id, dev->devno);
1461 
1462 	ata_dev_select(ap, dev->devno, 1, 1); /* select device 0/1 */
1463 
1464  retry:
1465 	ata_tf_init(dev, &tf);
1466 
1467 	switch (class) {
1468 	case ATA_DEV_ATA:
1469 		tf.command = ATA_CMD_ID_ATA;
1470 		break;
1471 	case ATA_DEV_ATAPI:
1472 		tf.command = ATA_CMD_ID_ATAPI;
1473 		break;
1474 	default:
1475 		rc = -ENODEV;
1476 		reason = "unsupported class";
1477 		goto err_out;
1478 	}
1479 
1480 	tf.protocol = ATA_PROT_PIO;
1481 	tf.flags |= ATA_TFLAG_POLLING; /* for polling presence detection */
1482 
1483 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_FROM_DEVICE,
1484 				     id, sizeof(id[0]) * ATA_ID_WORDS);
1485 	if (err_mask) {
1486 		if (err_mask & AC_ERR_NODEV_HINT) {
1487 			DPRINTK("ata%u.%d: NODEV after polling detection\n",
1488 				ap->id, dev->devno);
1489 			return -ENOENT;
1490 		}
1491 
1492 		rc = -EIO;
1493 		reason = "I/O error";
1494 		goto err_out;
1495 	}
1496 
1497 	swap_buf_le16(id, ATA_ID_WORDS);
1498 
1499 	/* sanity check */
1500 	rc = -EINVAL;
1501 	reason = "device reports illegal type";
1502 
1503 	if (class == ATA_DEV_ATA) {
1504 		if (!ata_id_is_ata(id) && !ata_id_is_cfa(id))
1505 			goto err_out;
1506 	} else {
1507 		if (ata_id_is_ata(id))
1508 			goto err_out;
1509 	}
1510 
1511 	if ((flags & ATA_READID_POSTRESET) && class == ATA_DEV_ATA) {
1512 		/*
1513 		 * The exact sequence expected by certain pre-ATA4 drives is:
1514 		 * SRST RESET
1515 		 * IDENTIFY
1516 		 * INITIALIZE DEVICE PARAMETERS
1517 		 * anything else..
1518 		 * Some drives were very specific about that exact sequence.
1519 		 */
1520 		if (ata_id_major_version(id) < 4 || !ata_id_has_lba(id)) {
1521 			err_mask = ata_dev_init_params(dev, id[3], id[6]);
1522 			if (err_mask) {
1523 				rc = -EIO;
1524 				reason = "INIT_DEV_PARAMS failed";
1525 				goto err_out;
1526 			}
1527 
1528 			/* current CHS translation info (id[53-58]) might be
1529 			 * changed. reread the identify device info.
1530 			 */
1531 			flags &= ~ATA_READID_POSTRESET;
1532 			goto retry;
1533 		}
1534 	}
1535 
1536 	*p_class = class;
1537 
1538 	return 0;
1539 
1540  err_out:
1541 	if (ata_msg_warn(ap))
1542 		ata_dev_printk(dev, KERN_WARNING, "failed to IDENTIFY "
1543 			       "(%s, err_mask=0x%x)\n", reason, err_mask);
1544 	return rc;
1545 }
1546 
1547 static inline u8 ata_dev_knobble(struct ata_device *dev)
1548 {
1549 	return ((dev->ap->cbl == ATA_CBL_SATA) && (!ata_id_is_sata(dev->id)));
1550 }
1551 
1552 static void ata_dev_config_ncq(struct ata_device *dev,
1553 			       char *desc, size_t desc_sz)
1554 {
1555 	struct ata_port *ap = dev->ap;
1556 	int hdepth = 0, ddepth = ata_id_queue_depth(dev->id);
1557 
1558 	if (!ata_id_has_ncq(dev->id)) {
1559 		desc[0] = '\0';
1560 		return;
1561 	}
1562 	if (ata_device_blacklisted(dev) & ATA_HORKAGE_NONCQ) {
1563 		snprintf(desc, desc_sz, "NCQ (not used)");
1564 		return;
1565 	}
1566 	if (ap->flags & ATA_FLAG_NCQ) {
1567 		hdepth = min(ap->scsi_host->can_queue, ATA_MAX_QUEUE - 1);
1568 		dev->flags |= ATA_DFLAG_NCQ;
1569 	}
1570 
1571 	if (hdepth >= ddepth)
1572 		snprintf(desc, desc_sz, "NCQ (depth %d)", ddepth);
1573 	else
1574 		snprintf(desc, desc_sz, "NCQ (depth %d/%d)", hdepth, ddepth);
1575 }
1576 
1577 static void ata_set_port_max_cmd_len(struct ata_port *ap)
1578 {
1579 	int i;
1580 
1581 	if (ap->scsi_host) {
1582 		unsigned int len = 0;
1583 
1584 		for (i = 0; i < ATA_MAX_DEVICES; i++)
1585 			len = max(len, ap->device[i].cdb_len);
1586 
1587 		ap->scsi_host->max_cmd_len = len;
1588 	}
1589 }
1590 
1591 /**
1592  *	ata_dev_configure - Configure the specified ATA/ATAPI device
1593  *	@dev: Target device to configure
1594  *
1595  *	Configure @dev according to @dev->id.  Generic and low-level
1596  *	driver specific fixups are also applied.
1597  *
1598  *	LOCKING:
1599  *	Kernel thread context (may sleep)
1600  *
1601  *	RETURNS:
1602  *	0 on success, -errno otherwise
1603  */
1604 int ata_dev_configure(struct ata_device *dev)
1605 {
1606 	struct ata_port *ap = dev->ap;
1607 	int print_info = ap->eh_context.i.flags & ATA_EHI_PRINTINFO;
1608 	const u16 *id = dev->id;
1609 	unsigned int xfer_mask;
1610 	char revbuf[7];		/* XYZ-99\0 */
1611 	int rc;
1612 
1613 	if (!ata_dev_enabled(dev) && ata_msg_info(ap)) {
1614 		ata_dev_printk(dev, KERN_INFO,
1615 			       "%s: ENTER/EXIT (host %u, dev %u) -- nodev\n",
1616 			       __FUNCTION__, ap->id, dev->devno);
1617 		return 0;
1618 	}
1619 
1620 	if (ata_msg_probe(ap))
1621 		ata_dev_printk(dev, KERN_DEBUG, "%s: ENTER, host %u, dev %u\n",
1622 			       __FUNCTION__, ap->id, dev->devno);
1623 
1624 	/* print device capabilities */
1625 	if (ata_msg_probe(ap))
1626 		ata_dev_printk(dev, KERN_DEBUG,
1627 			       "%s: cfg 49:%04x 82:%04x 83:%04x 84:%04x "
1628 			       "85:%04x 86:%04x 87:%04x 88:%04x\n",
1629 			       __FUNCTION__,
1630 			       id[49], id[82], id[83], id[84],
1631 			       id[85], id[86], id[87], id[88]);
1632 
1633 	/* initialize to-be-configured parameters */
1634 	dev->flags &= ~ATA_DFLAG_CFG_MASK;
1635 	dev->max_sectors = 0;
1636 	dev->cdb_len = 0;
1637 	dev->n_sectors = 0;
1638 	dev->cylinders = 0;
1639 	dev->heads = 0;
1640 	dev->sectors = 0;
1641 
1642 	/*
1643 	 * common ATA, ATAPI feature tests
1644 	 */
1645 
1646 	/* find max transfer mode; for printk only */
1647 	xfer_mask = ata_id_xfermask(id);
1648 
1649 	if (ata_msg_probe(ap))
1650 		ata_dump_id(id);
1651 
1652 	/* ATA-specific feature tests */
1653 	if (dev->class == ATA_DEV_ATA) {
1654 		if (ata_id_is_cfa(id)) {
1655 			if (id[162] & 1) /* CPRM may make this media unusable */
1656 				ata_dev_printk(dev, KERN_WARNING, "ata%u: device %u  supports DRM functions and may not be fully accessable.\n",
1657 					ap->id, dev->devno);
1658 			snprintf(revbuf, 7, "CFA");
1659 		}
1660 		else
1661 			snprintf(revbuf, 7, "ATA-%d",  ata_id_major_version(id));
1662 
1663 		dev->n_sectors = ata_id_n_sectors(id);
1664 
1665 		if (ata_id_has_lba(id)) {
1666 			const char *lba_desc;
1667 			char ncq_desc[20];
1668 
1669 			lba_desc = "LBA";
1670 			dev->flags |= ATA_DFLAG_LBA;
1671 			if (ata_id_has_lba48(id)) {
1672 				dev->flags |= ATA_DFLAG_LBA48;
1673 				lba_desc = "LBA48";
1674 
1675 				if (dev->n_sectors >= (1UL << 28) &&
1676 				    ata_id_has_flush_ext(id))
1677 					dev->flags |= ATA_DFLAG_FLUSH_EXT;
1678 			}
1679 
1680 			/* config NCQ */
1681 			ata_dev_config_ncq(dev, ncq_desc, sizeof(ncq_desc));
1682 
1683 			/* print device info to dmesg */
1684 			if (ata_msg_drv(ap) && print_info)
1685 				ata_dev_printk(dev, KERN_INFO, "%s, "
1686 					"max %s, %Lu sectors: %s %s\n",
1687 					revbuf,
1688 					ata_mode_string(xfer_mask),
1689 					(unsigned long long)dev->n_sectors,
1690 					lba_desc, ncq_desc);
1691 		} else {
1692 			/* CHS */
1693 
1694 			/* Default translation */
1695 			dev->cylinders	= id[1];
1696 			dev->heads	= id[3];
1697 			dev->sectors	= id[6];
1698 
1699 			if (ata_id_current_chs_valid(id)) {
1700 				/* Current CHS translation is valid. */
1701 				dev->cylinders = id[54];
1702 				dev->heads     = id[55];
1703 				dev->sectors   = id[56];
1704 			}
1705 
1706 			/* print device info to dmesg */
1707 			if (ata_msg_drv(ap) && print_info)
1708 				ata_dev_printk(dev, KERN_INFO, "%s, "
1709 					"max %s, %Lu sectors: CHS %u/%u/%u\n",
1710 					revbuf,
1711 					ata_mode_string(xfer_mask),
1712 					(unsigned long long)dev->n_sectors,
1713 					dev->cylinders, dev->heads,
1714 					dev->sectors);
1715 		}
1716 
1717 		if (dev->id[59] & 0x100) {
1718 			dev->multi_count = dev->id[59] & 0xff;
1719 			if (ata_msg_drv(ap) && print_info)
1720 				ata_dev_printk(dev, KERN_INFO,
1721 					"ata%u: dev %u multi count %u\n",
1722 					ap->id, dev->devno, dev->multi_count);
1723 		}
1724 
1725 		dev->cdb_len = 16;
1726 	}
1727 
1728 	/* ATAPI-specific feature tests */
1729 	else if (dev->class == ATA_DEV_ATAPI) {
1730 		char *cdb_intr_string = "";
1731 
1732 		rc = atapi_cdb_len(id);
1733 		if ((rc < 12) || (rc > ATAPI_CDB_LEN)) {
1734 			if (ata_msg_warn(ap))
1735 				ata_dev_printk(dev, KERN_WARNING,
1736 					       "unsupported CDB len\n");
1737 			rc = -EINVAL;
1738 			goto err_out_nosup;
1739 		}
1740 		dev->cdb_len = (unsigned int) rc;
1741 
1742 		if (ata_id_cdb_intr(dev->id)) {
1743 			dev->flags |= ATA_DFLAG_CDB_INTR;
1744 			cdb_intr_string = ", CDB intr";
1745 		}
1746 
1747 		/* print device info to dmesg */
1748 		if (ata_msg_drv(ap) && print_info)
1749 			ata_dev_printk(dev, KERN_INFO, "ATAPI, max %s%s\n",
1750 				       ata_mode_string(xfer_mask),
1751 				       cdb_intr_string);
1752 	}
1753 
1754 	/* determine max_sectors */
1755 	dev->max_sectors = ATA_MAX_SECTORS;
1756 	if (dev->flags & ATA_DFLAG_LBA48)
1757 		dev->max_sectors = ATA_MAX_SECTORS_LBA48;
1758 
1759 	if (dev->horkage & ATA_HORKAGE_DIAGNOSTIC) {
1760 		/* Let the user know. We don't want to disallow opens for
1761 		   rescue purposes, or in case the vendor is just a blithering
1762 		   idiot */
1763                 if (print_info) {
1764 			ata_dev_printk(dev, KERN_WARNING,
1765 "Drive reports diagnostics failure. This may indicate a drive\n");
1766 			ata_dev_printk(dev, KERN_WARNING,
1767 "fault or invalid emulation. Contact drive vendor for information.\n");
1768 		}
1769 	}
1770 
1771 	ata_set_port_max_cmd_len(ap);
1772 
1773 	/* limit bridge transfers to udma5, 200 sectors */
1774 	if (ata_dev_knobble(dev)) {
1775 		if (ata_msg_drv(ap) && print_info)
1776 			ata_dev_printk(dev, KERN_INFO,
1777 				       "applying bridge limits\n");
1778 		dev->udma_mask &= ATA_UDMA5;
1779 		dev->max_sectors = ATA_MAX_SECTORS;
1780 	}
1781 
1782 	if (ap->ops->dev_config)
1783 		ap->ops->dev_config(ap, dev);
1784 
1785 	if (ata_msg_probe(ap))
1786 		ata_dev_printk(dev, KERN_DEBUG, "%s: EXIT, drv_stat = 0x%x\n",
1787 			__FUNCTION__, ata_chk_status(ap));
1788 	return 0;
1789 
1790 err_out_nosup:
1791 	if (ata_msg_probe(ap))
1792 		ata_dev_printk(dev, KERN_DEBUG,
1793 			       "%s: EXIT, err\n", __FUNCTION__);
1794 	return rc;
1795 }
1796 
1797 /**
1798  *	ata_bus_probe - Reset and probe ATA bus
1799  *	@ap: Bus to probe
1800  *
1801  *	Master ATA bus probing function.  Initiates a hardware-dependent
1802  *	bus reset, then attempts to identify any devices found on
1803  *	the bus.
1804  *
1805  *	LOCKING:
1806  *	PCI/etc. bus probe sem.
1807  *
1808  *	RETURNS:
1809  *	Zero on success, negative errno otherwise.
1810  */
1811 
1812 int ata_bus_probe(struct ata_port *ap)
1813 {
1814 	unsigned int classes[ATA_MAX_DEVICES];
1815 	int tries[ATA_MAX_DEVICES];
1816 	int i, rc, down_xfermask;
1817 	struct ata_device *dev;
1818 
1819 	ata_port_probe(ap);
1820 
1821 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1822 		tries[i] = ATA_PROBE_MAX_TRIES;
1823 
1824  retry:
1825 	down_xfermask = 0;
1826 
1827 	/* reset and determine device classes */
1828 	ap->ops->phy_reset(ap);
1829 
1830 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
1831 		dev = &ap->device[i];
1832 
1833 		if (!(ap->flags & ATA_FLAG_DISABLED) &&
1834 		    dev->class != ATA_DEV_UNKNOWN)
1835 			classes[dev->devno] = dev->class;
1836 		else
1837 			classes[dev->devno] = ATA_DEV_NONE;
1838 
1839 		dev->class = ATA_DEV_UNKNOWN;
1840 	}
1841 
1842 	ata_port_probe(ap);
1843 
1844 	/* after the reset the device state is PIO 0 and the controller
1845 	   state is undefined. Record the mode */
1846 
1847 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1848 		ap->device[i].pio_mode = XFER_PIO_0;
1849 
1850 	/* read IDENTIFY page and configure devices */
1851 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
1852 		dev = &ap->device[i];
1853 
1854 		if (tries[i])
1855 			dev->class = classes[i];
1856 
1857 		if (!ata_dev_enabled(dev))
1858 			continue;
1859 
1860 		rc = ata_dev_read_id(dev, &dev->class, ATA_READID_POSTRESET,
1861 				     dev->id);
1862 		if (rc)
1863 			goto fail;
1864 
1865 		ap->eh_context.i.flags |= ATA_EHI_PRINTINFO;
1866 		rc = ata_dev_configure(dev);
1867 		ap->eh_context.i.flags &= ~ATA_EHI_PRINTINFO;
1868 		if (rc)
1869 			goto fail;
1870 	}
1871 
1872 	/* configure transfer mode */
1873 	rc = ata_set_mode(ap, &dev);
1874 	if (rc) {
1875 		down_xfermask = 1;
1876 		goto fail;
1877 	}
1878 
1879 	for (i = 0; i < ATA_MAX_DEVICES; i++)
1880 		if (ata_dev_enabled(&ap->device[i]))
1881 			return 0;
1882 
1883 	/* no device present, disable port */
1884 	ata_port_disable(ap);
1885 	ap->ops->port_disable(ap);
1886 	return -ENODEV;
1887 
1888  fail:
1889 	switch (rc) {
1890 	case -EINVAL:
1891 	case -ENODEV:
1892 		tries[dev->devno] = 0;
1893 		break;
1894 	case -EIO:
1895 		sata_down_spd_limit(ap);
1896 		/* fall through */
1897 	default:
1898 		tries[dev->devno]--;
1899 		if (down_xfermask &&
1900 		    ata_down_xfermask_limit(dev, tries[dev->devno] == 1))
1901 			tries[dev->devno] = 0;
1902 	}
1903 
1904 	if (!tries[dev->devno]) {
1905 		ata_down_xfermask_limit(dev, 1);
1906 		ata_dev_disable(dev);
1907 	}
1908 
1909 	goto retry;
1910 }
1911 
1912 /**
1913  *	ata_port_probe - Mark port as enabled
1914  *	@ap: Port for which we indicate enablement
1915  *
1916  *	Modify @ap data structure such that the system
1917  *	thinks that the entire port is enabled.
1918  *
1919  *	LOCKING: host lock, or some other form of
1920  *	serialization.
1921  */
1922 
1923 void ata_port_probe(struct ata_port *ap)
1924 {
1925 	ap->flags &= ~ATA_FLAG_DISABLED;
1926 }
1927 
1928 /**
1929  *	sata_print_link_status - Print SATA link status
1930  *	@ap: SATA port to printk link status about
1931  *
1932  *	This function prints link speed and status of a SATA link.
1933  *
1934  *	LOCKING:
1935  *	None.
1936  */
1937 static void sata_print_link_status(struct ata_port *ap)
1938 {
1939 	u32 sstatus, scontrol, tmp;
1940 
1941 	if (sata_scr_read(ap, SCR_STATUS, &sstatus))
1942 		return;
1943 	sata_scr_read(ap, SCR_CONTROL, &scontrol);
1944 
1945 	if (ata_port_online(ap)) {
1946 		tmp = (sstatus >> 4) & 0xf;
1947 		ata_port_printk(ap, KERN_INFO,
1948 				"SATA link up %s (SStatus %X SControl %X)\n",
1949 				sata_spd_string(tmp), sstatus, scontrol);
1950 	} else {
1951 		ata_port_printk(ap, KERN_INFO,
1952 				"SATA link down (SStatus %X SControl %X)\n",
1953 				sstatus, scontrol);
1954 	}
1955 }
1956 
1957 /**
1958  *	__sata_phy_reset - Wake/reset a low-level SATA PHY
1959  *	@ap: SATA port associated with target SATA PHY.
1960  *
1961  *	This function issues commands to standard SATA Sxxx
1962  *	PHY registers, to wake up the phy (and device), and
1963  *	clear any reset condition.
1964  *
1965  *	LOCKING:
1966  *	PCI/etc. bus probe sem.
1967  *
1968  */
1969 void __sata_phy_reset(struct ata_port *ap)
1970 {
1971 	u32 sstatus;
1972 	unsigned long timeout = jiffies + (HZ * 5);
1973 
1974 	if (ap->flags & ATA_FLAG_SATA_RESET) {
1975 		/* issue phy wake/reset */
1976 		sata_scr_write_flush(ap, SCR_CONTROL, 0x301);
1977 		/* Couldn't find anything in SATA I/II specs, but
1978 		 * AHCI-1.1 10.4.2 says at least 1 ms. */
1979 		mdelay(1);
1980 	}
1981 	/* phy wake/clear reset */
1982 	sata_scr_write_flush(ap, SCR_CONTROL, 0x300);
1983 
1984 	/* wait for phy to become ready, if necessary */
1985 	do {
1986 		msleep(200);
1987 		sata_scr_read(ap, SCR_STATUS, &sstatus);
1988 		if ((sstatus & 0xf) != 1)
1989 			break;
1990 	} while (time_before(jiffies, timeout));
1991 
1992 	/* print link status */
1993 	sata_print_link_status(ap);
1994 
1995 	/* TODO: phy layer with polling, timeouts, etc. */
1996 	if (!ata_port_offline(ap))
1997 		ata_port_probe(ap);
1998 	else
1999 		ata_port_disable(ap);
2000 
2001 	if (ap->flags & ATA_FLAG_DISABLED)
2002 		return;
2003 
2004 	if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
2005 		ata_port_disable(ap);
2006 		return;
2007 	}
2008 
2009 	ap->cbl = ATA_CBL_SATA;
2010 }
2011 
2012 /**
2013  *	sata_phy_reset - Reset SATA bus.
2014  *	@ap: SATA port associated with target SATA PHY.
2015  *
2016  *	This function resets the SATA bus, and then probes
2017  *	the bus for devices.
2018  *
2019  *	LOCKING:
2020  *	PCI/etc. bus probe sem.
2021  *
2022  */
2023 void sata_phy_reset(struct ata_port *ap)
2024 {
2025 	__sata_phy_reset(ap);
2026 	if (ap->flags & ATA_FLAG_DISABLED)
2027 		return;
2028 	ata_bus_reset(ap);
2029 }
2030 
2031 /**
2032  *	ata_dev_pair		-	return other device on cable
2033  *	@adev: device
2034  *
2035  *	Obtain the other device on the same cable, or if none is
2036  *	present NULL is returned
2037  */
2038 
2039 struct ata_device *ata_dev_pair(struct ata_device *adev)
2040 {
2041 	struct ata_port *ap = adev->ap;
2042 	struct ata_device *pair = &ap->device[1 - adev->devno];
2043 	if (!ata_dev_enabled(pair))
2044 		return NULL;
2045 	return pair;
2046 }
2047 
2048 /**
2049  *	ata_port_disable - Disable port.
2050  *	@ap: Port to be disabled.
2051  *
2052  *	Modify @ap data structure such that the system
2053  *	thinks that the entire port is disabled, and should
2054  *	never attempt to probe or communicate with devices
2055  *	on this port.
2056  *
2057  *	LOCKING: host lock, or some other form of
2058  *	serialization.
2059  */
2060 
2061 void ata_port_disable(struct ata_port *ap)
2062 {
2063 	ap->device[0].class = ATA_DEV_NONE;
2064 	ap->device[1].class = ATA_DEV_NONE;
2065 	ap->flags |= ATA_FLAG_DISABLED;
2066 }
2067 
2068 /**
2069  *	sata_down_spd_limit - adjust SATA spd limit downward
2070  *	@ap: Port to adjust SATA spd limit for
2071  *
2072  *	Adjust SATA spd limit of @ap downward.  Note that this
2073  *	function only adjusts the limit.  The change must be applied
2074  *	using sata_set_spd().
2075  *
2076  *	LOCKING:
2077  *	Inherited from caller.
2078  *
2079  *	RETURNS:
2080  *	0 on success, negative errno on failure
2081  */
2082 int sata_down_spd_limit(struct ata_port *ap)
2083 {
2084 	u32 sstatus, spd, mask;
2085 	int rc, highbit;
2086 
2087 	rc = sata_scr_read(ap, SCR_STATUS, &sstatus);
2088 	if (rc)
2089 		return rc;
2090 
2091 	mask = ap->sata_spd_limit;
2092 	if (mask <= 1)
2093 		return -EINVAL;
2094 	highbit = fls(mask) - 1;
2095 	mask &= ~(1 << highbit);
2096 
2097 	spd = (sstatus >> 4) & 0xf;
2098 	if (spd <= 1)
2099 		return -EINVAL;
2100 	spd--;
2101 	mask &= (1 << spd) - 1;
2102 	if (!mask)
2103 		return -EINVAL;
2104 
2105 	ap->sata_spd_limit = mask;
2106 
2107 	ata_port_printk(ap, KERN_WARNING, "limiting SATA link speed to %s\n",
2108 			sata_spd_string(fls(mask)));
2109 
2110 	return 0;
2111 }
2112 
2113 static int __sata_set_spd_needed(struct ata_port *ap, u32 *scontrol)
2114 {
2115 	u32 spd, limit;
2116 
2117 	if (ap->sata_spd_limit == UINT_MAX)
2118 		limit = 0;
2119 	else
2120 		limit = fls(ap->sata_spd_limit);
2121 
2122 	spd = (*scontrol >> 4) & 0xf;
2123 	*scontrol = (*scontrol & ~0xf0) | ((limit & 0xf) << 4);
2124 
2125 	return spd != limit;
2126 }
2127 
2128 /**
2129  *	sata_set_spd_needed - is SATA spd configuration needed
2130  *	@ap: Port in question
2131  *
2132  *	Test whether the spd limit in SControl matches
2133  *	@ap->sata_spd_limit.  This function is used to determine
2134  *	whether hardreset is necessary to apply SATA spd
2135  *	configuration.
2136  *
2137  *	LOCKING:
2138  *	Inherited from caller.
2139  *
2140  *	RETURNS:
2141  *	1 if SATA spd configuration is needed, 0 otherwise.
2142  */
2143 int sata_set_spd_needed(struct ata_port *ap)
2144 {
2145 	u32 scontrol;
2146 
2147 	if (sata_scr_read(ap, SCR_CONTROL, &scontrol))
2148 		return 0;
2149 
2150 	return __sata_set_spd_needed(ap, &scontrol);
2151 }
2152 
2153 /**
2154  *	sata_set_spd - set SATA spd according to spd limit
2155  *	@ap: Port to set SATA spd for
2156  *
2157  *	Set SATA spd of @ap according to sata_spd_limit.
2158  *
2159  *	LOCKING:
2160  *	Inherited from caller.
2161  *
2162  *	RETURNS:
2163  *	0 if spd doesn't need to be changed, 1 if spd has been
2164  *	changed.  Negative errno if SCR registers are inaccessible.
2165  */
2166 int sata_set_spd(struct ata_port *ap)
2167 {
2168 	u32 scontrol;
2169 	int rc;
2170 
2171 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
2172 		return rc;
2173 
2174 	if (!__sata_set_spd_needed(ap, &scontrol))
2175 		return 0;
2176 
2177 	if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
2178 		return rc;
2179 
2180 	return 1;
2181 }
2182 
2183 /*
2184  * This mode timing computation functionality is ported over from
2185  * drivers/ide/ide-timing.h and was originally written by Vojtech Pavlik
2186  */
2187 /*
2188  * PIO 0-4, MWDMA 0-2 and UDMA 0-6 timings (in nanoseconds).
2189  * These were taken from ATA/ATAPI-6 standard, rev 0a, except
2190  * for UDMA6, which is currently supported only by Maxtor drives.
2191  *
2192  * For PIO 5/6 MWDMA 3/4 see the CFA specification 3.0.
2193  */
2194 
2195 static const struct ata_timing ata_timing[] = {
2196 
2197 	{ XFER_UDMA_6,     0,   0,   0,   0,   0,   0,   0,  15 },
2198 	{ XFER_UDMA_5,     0,   0,   0,   0,   0,   0,   0,  20 },
2199 	{ XFER_UDMA_4,     0,   0,   0,   0,   0,   0,   0,  30 },
2200 	{ XFER_UDMA_3,     0,   0,   0,   0,   0,   0,   0,  45 },
2201 
2202 	{ XFER_MW_DMA_4,  25,   0,   0,   0,  55,  20,  80,   0 },
2203 	{ XFER_MW_DMA_3,  25,   0,   0,   0,  65,  25, 100,   0 },
2204 	{ XFER_UDMA_2,     0,   0,   0,   0,   0,   0,   0,  60 },
2205 	{ XFER_UDMA_1,     0,   0,   0,   0,   0,   0,   0,  80 },
2206 	{ XFER_UDMA_0,     0,   0,   0,   0,   0,   0,   0, 120 },
2207 
2208 /*	{ XFER_UDMA_SLOW,  0,   0,   0,   0,   0,   0,   0, 150 }, */
2209 
2210 	{ XFER_MW_DMA_2,  25,   0,   0,   0,  70,  25, 120,   0 },
2211 	{ XFER_MW_DMA_1,  45,   0,   0,   0,  80,  50, 150,   0 },
2212 	{ XFER_MW_DMA_0,  60,   0,   0,   0, 215, 215, 480,   0 },
2213 
2214 	{ XFER_SW_DMA_2,  60,   0,   0,   0, 120, 120, 240,   0 },
2215 	{ XFER_SW_DMA_1,  90,   0,   0,   0, 240, 240, 480,   0 },
2216 	{ XFER_SW_DMA_0, 120,   0,   0,   0, 480, 480, 960,   0 },
2217 
2218 	{ XFER_PIO_6,     10,  55,  20,  80,  55,  20,  80,   0 },
2219 	{ XFER_PIO_5,     15,  65,  25, 100,  65,  25, 100,   0 },
2220 	{ XFER_PIO_4,     25,  70,  25, 120,  70,  25, 120,   0 },
2221 	{ XFER_PIO_3,     30,  80,  70, 180,  80,  70, 180,   0 },
2222 
2223 	{ XFER_PIO_2,     30, 290,  40, 330, 100,  90, 240,   0 },
2224 	{ XFER_PIO_1,     50, 290,  93, 383, 125, 100, 383,   0 },
2225 	{ XFER_PIO_0,     70, 290, 240, 600, 165, 150, 600,   0 },
2226 
2227 /*	{ XFER_PIO_SLOW, 120, 290, 240, 960, 290, 240, 960,   0 }, */
2228 
2229 	{ 0xFF }
2230 };
2231 
2232 #define ENOUGH(v,unit)		(((v)-1)/(unit)+1)
2233 #define EZ(v,unit)		((v)?ENOUGH(v,unit):0)
2234 
2235 static void ata_timing_quantize(const struct ata_timing *t, struct ata_timing *q, int T, int UT)
2236 {
2237 	q->setup   = EZ(t->setup   * 1000,  T);
2238 	q->act8b   = EZ(t->act8b   * 1000,  T);
2239 	q->rec8b   = EZ(t->rec8b   * 1000,  T);
2240 	q->cyc8b   = EZ(t->cyc8b   * 1000,  T);
2241 	q->active  = EZ(t->active  * 1000,  T);
2242 	q->recover = EZ(t->recover * 1000,  T);
2243 	q->cycle   = EZ(t->cycle   * 1000,  T);
2244 	q->udma    = EZ(t->udma    * 1000, UT);
2245 }
2246 
2247 void ata_timing_merge(const struct ata_timing *a, const struct ata_timing *b,
2248 		      struct ata_timing *m, unsigned int what)
2249 {
2250 	if (what & ATA_TIMING_SETUP  ) m->setup   = max(a->setup,   b->setup);
2251 	if (what & ATA_TIMING_ACT8B  ) m->act8b   = max(a->act8b,   b->act8b);
2252 	if (what & ATA_TIMING_REC8B  ) m->rec8b   = max(a->rec8b,   b->rec8b);
2253 	if (what & ATA_TIMING_CYC8B  ) m->cyc8b   = max(a->cyc8b,   b->cyc8b);
2254 	if (what & ATA_TIMING_ACTIVE ) m->active  = max(a->active,  b->active);
2255 	if (what & ATA_TIMING_RECOVER) m->recover = max(a->recover, b->recover);
2256 	if (what & ATA_TIMING_CYCLE  ) m->cycle   = max(a->cycle,   b->cycle);
2257 	if (what & ATA_TIMING_UDMA   ) m->udma    = max(a->udma,    b->udma);
2258 }
2259 
2260 static const struct ata_timing* ata_timing_find_mode(unsigned short speed)
2261 {
2262 	const struct ata_timing *t;
2263 
2264 	for (t = ata_timing; t->mode != speed; t++)
2265 		if (t->mode == 0xFF)
2266 			return NULL;
2267 	return t;
2268 }
2269 
2270 int ata_timing_compute(struct ata_device *adev, unsigned short speed,
2271 		       struct ata_timing *t, int T, int UT)
2272 {
2273 	const struct ata_timing *s;
2274 	struct ata_timing p;
2275 
2276 	/*
2277 	 * Find the mode.
2278 	 */
2279 
2280 	if (!(s = ata_timing_find_mode(speed)))
2281 		return -EINVAL;
2282 
2283 	memcpy(t, s, sizeof(*s));
2284 
2285 	/*
2286 	 * If the drive is an EIDE drive, it can tell us it needs extended
2287 	 * PIO/MW_DMA cycle timing.
2288 	 */
2289 
2290 	if (adev->id[ATA_ID_FIELD_VALID] & 2) {	/* EIDE drive */
2291 		memset(&p, 0, sizeof(p));
2292 		if(speed >= XFER_PIO_0 && speed <= XFER_SW_DMA_0) {
2293 			if (speed <= XFER_PIO_2) p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO];
2294 					    else p.cycle = p.cyc8b = adev->id[ATA_ID_EIDE_PIO_IORDY];
2295 		} else if(speed >= XFER_MW_DMA_0 && speed <= XFER_MW_DMA_2) {
2296 			p.cycle = adev->id[ATA_ID_EIDE_DMA_MIN];
2297 		}
2298 		ata_timing_merge(&p, t, t, ATA_TIMING_CYCLE | ATA_TIMING_CYC8B);
2299 	}
2300 
2301 	/*
2302 	 * Convert the timing to bus clock counts.
2303 	 */
2304 
2305 	ata_timing_quantize(t, t, T, UT);
2306 
2307 	/*
2308 	 * Even in DMA/UDMA modes we still use PIO access for IDENTIFY,
2309 	 * S.M.A.R.T * and some other commands. We have to ensure that the
2310 	 * DMA cycle timing is slower/equal than the fastest PIO timing.
2311 	 */
2312 
2313 	if (speed > XFER_PIO_6) {
2314 		ata_timing_compute(adev, adev->pio_mode, &p, T, UT);
2315 		ata_timing_merge(&p, t, t, ATA_TIMING_ALL);
2316 	}
2317 
2318 	/*
2319 	 * Lengthen active & recovery time so that cycle time is correct.
2320 	 */
2321 
2322 	if (t->act8b + t->rec8b < t->cyc8b) {
2323 		t->act8b += (t->cyc8b - (t->act8b + t->rec8b)) / 2;
2324 		t->rec8b = t->cyc8b - t->act8b;
2325 	}
2326 
2327 	if (t->active + t->recover < t->cycle) {
2328 		t->active += (t->cycle - (t->active + t->recover)) / 2;
2329 		t->recover = t->cycle - t->active;
2330 	}
2331 
2332 	return 0;
2333 }
2334 
2335 /**
2336  *	ata_down_xfermask_limit - adjust dev xfer masks downward
2337  *	@dev: Device to adjust xfer masks
2338  *	@force_pio0: Force PIO0
2339  *
2340  *	Adjust xfer masks of @dev downward.  Note that this function
2341  *	does not apply the change.  Invoking ata_set_mode() afterwards
2342  *	will apply the limit.
2343  *
2344  *	LOCKING:
2345  *	Inherited from caller.
2346  *
2347  *	RETURNS:
2348  *	0 on success, negative errno on failure
2349  */
2350 int ata_down_xfermask_limit(struct ata_device *dev, int force_pio0)
2351 {
2352 	unsigned long xfer_mask;
2353 	int highbit;
2354 
2355 	xfer_mask = ata_pack_xfermask(dev->pio_mask, dev->mwdma_mask,
2356 				      dev->udma_mask);
2357 
2358 	if (!xfer_mask)
2359 		goto fail;
2360 	/* don't gear down to MWDMA from UDMA, go directly to PIO */
2361 	if (xfer_mask & ATA_MASK_UDMA)
2362 		xfer_mask &= ~ATA_MASK_MWDMA;
2363 
2364 	highbit = fls(xfer_mask) - 1;
2365 	xfer_mask &= ~(1 << highbit);
2366 	if (force_pio0)
2367 		xfer_mask &= 1 << ATA_SHIFT_PIO;
2368 	if (!xfer_mask)
2369 		goto fail;
2370 
2371 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask, &dev->mwdma_mask,
2372 			    &dev->udma_mask);
2373 
2374 	ata_dev_printk(dev, KERN_WARNING, "limiting speed to %s\n",
2375 		       ata_mode_string(xfer_mask));
2376 
2377 	return 0;
2378 
2379  fail:
2380 	return -EINVAL;
2381 }
2382 
2383 static int ata_dev_set_mode(struct ata_device *dev)
2384 {
2385 	struct ata_eh_context *ehc = &dev->ap->eh_context;
2386 	unsigned int err_mask;
2387 	int rc;
2388 
2389 	dev->flags &= ~ATA_DFLAG_PIO;
2390 	if (dev->xfer_shift == ATA_SHIFT_PIO)
2391 		dev->flags |= ATA_DFLAG_PIO;
2392 
2393 	err_mask = ata_dev_set_xfermode(dev);
2394 	if (err_mask) {
2395 		ata_dev_printk(dev, KERN_ERR, "failed to set xfermode "
2396 			       "(err_mask=0x%x)\n", err_mask);
2397 		return -EIO;
2398 	}
2399 
2400 	ehc->i.flags |= ATA_EHI_POST_SETMODE;
2401 	rc = ata_dev_revalidate(dev, 0);
2402 	ehc->i.flags &= ~ATA_EHI_POST_SETMODE;
2403 	if (rc)
2404 		return rc;
2405 
2406 	DPRINTK("xfer_shift=%u, xfer_mode=0x%x\n",
2407 		dev->xfer_shift, (int)dev->xfer_mode);
2408 
2409 	ata_dev_printk(dev, KERN_INFO, "configured for %s\n",
2410 		       ata_mode_string(ata_xfer_mode2mask(dev->xfer_mode)));
2411 	return 0;
2412 }
2413 
2414 /**
2415  *	ata_set_mode - Program timings and issue SET FEATURES - XFER
2416  *	@ap: port on which timings will be programmed
2417  *	@r_failed_dev: out paramter for failed device
2418  *
2419  *	Set ATA device disk transfer mode (PIO3, UDMA6, etc.).  If
2420  *	ata_set_mode() fails, pointer to the failing device is
2421  *	returned in @r_failed_dev.
2422  *
2423  *	LOCKING:
2424  *	PCI/etc. bus probe sem.
2425  *
2426  *	RETURNS:
2427  *	0 on success, negative errno otherwise
2428  */
2429 int ata_set_mode(struct ata_port *ap, struct ata_device **r_failed_dev)
2430 {
2431 	struct ata_device *dev;
2432 	int i, rc = 0, used_dma = 0, found = 0;
2433 
2434 	/* has private set_mode? */
2435 	if (ap->ops->set_mode)
2436 		return ap->ops->set_mode(ap, r_failed_dev);
2437 
2438 	/* step 1: calculate xfer_mask */
2439 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2440 		unsigned int pio_mask, dma_mask;
2441 
2442 		dev = &ap->device[i];
2443 
2444 		if (!ata_dev_enabled(dev))
2445 			continue;
2446 
2447 		ata_dev_xfermask(dev);
2448 
2449 		pio_mask = ata_pack_xfermask(dev->pio_mask, 0, 0);
2450 		dma_mask = ata_pack_xfermask(0, dev->mwdma_mask, dev->udma_mask);
2451 		dev->pio_mode = ata_xfer_mask2mode(pio_mask);
2452 		dev->dma_mode = ata_xfer_mask2mode(dma_mask);
2453 
2454 		found = 1;
2455 		if (dev->dma_mode)
2456 			used_dma = 1;
2457 	}
2458 	if (!found)
2459 		goto out;
2460 
2461 	/* step 2: always set host PIO timings */
2462 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2463 		dev = &ap->device[i];
2464 		if (!ata_dev_enabled(dev))
2465 			continue;
2466 
2467 		if (!dev->pio_mode) {
2468 			ata_dev_printk(dev, KERN_WARNING, "no PIO support\n");
2469 			rc = -EINVAL;
2470 			goto out;
2471 		}
2472 
2473 		dev->xfer_mode = dev->pio_mode;
2474 		dev->xfer_shift = ATA_SHIFT_PIO;
2475 		if (ap->ops->set_piomode)
2476 			ap->ops->set_piomode(ap, dev);
2477 	}
2478 
2479 	/* step 3: set host DMA timings */
2480 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2481 		dev = &ap->device[i];
2482 
2483 		if (!ata_dev_enabled(dev) || !dev->dma_mode)
2484 			continue;
2485 
2486 		dev->xfer_mode = dev->dma_mode;
2487 		dev->xfer_shift = ata_xfer_mode2shift(dev->dma_mode);
2488 		if (ap->ops->set_dmamode)
2489 			ap->ops->set_dmamode(ap, dev);
2490 	}
2491 
2492 	/* step 4: update devices' xfer mode */
2493 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
2494 		dev = &ap->device[i];
2495 
2496 		/* don't udpate suspended devices' xfer mode */
2497 		if (!ata_dev_ready(dev))
2498 			continue;
2499 
2500 		rc = ata_dev_set_mode(dev);
2501 		if (rc)
2502 			goto out;
2503 	}
2504 
2505 	/* Record simplex status. If we selected DMA then the other
2506 	 * host channels are not permitted to do so.
2507 	 */
2508 	if (used_dma && (ap->host->flags & ATA_HOST_SIMPLEX))
2509 		ap->host->simplex_claimed = 1;
2510 
2511 	/* step5: chip specific finalisation */
2512 	if (ap->ops->post_set_mode)
2513 		ap->ops->post_set_mode(ap);
2514 
2515  out:
2516 	if (rc)
2517 		*r_failed_dev = dev;
2518 	return rc;
2519 }
2520 
2521 /**
2522  *	ata_tf_to_host - issue ATA taskfile to host controller
2523  *	@ap: port to which command is being issued
2524  *	@tf: ATA taskfile register set
2525  *
2526  *	Issues ATA taskfile register set to ATA host controller,
2527  *	with proper synchronization with interrupt handler and
2528  *	other threads.
2529  *
2530  *	LOCKING:
2531  *	spin_lock_irqsave(host lock)
2532  */
2533 
2534 static inline void ata_tf_to_host(struct ata_port *ap,
2535 				  const struct ata_taskfile *tf)
2536 {
2537 	ap->ops->tf_load(ap, tf);
2538 	ap->ops->exec_command(ap, tf);
2539 }
2540 
2541 /**
2542  *	ata_busy_sleep - sleep until BSY clears, or timeout
2543  *	@ap: port containing status register to be polled
2544  *	@tmout_pat: impatience timeout
2545  *	@tmout: overall timeout
2546  *
2547  *	Sleep until ATA Status register bit BSY clears,
2548  *	or a timeout occurs.
2549  *
2550  *	LOCKING:
2551  *	Kernel thread context (may sleep).
2552  *
2553  *	RETURNS:
2554  *	0 on success, -errno otherwise.
2555  */
2556 int ata_busy_sleep(struct ata_port *ap,
2557 		   unsigned long tmout_pat, unsigned long tmout)
2558 {
2559 	unsigned long timer_start, timeout;
2560 	u8 status;
2561 
2562 	status = ata_busy_wait(ap, ATA_BUSY, 300);
2563 	timer_start = jiffies;
2564 	timeout = timer_start + tmout_pat;
2565 	while (status != 0xff && (status & ATA_BUSY) &&
2566 	       time_before(jiffies, timeout)) {
2567 		msleep(50);
2568 		status = ata_busy_wait(ap, ATA_BUSY, 3);
2569 	}
2570 
2571 	if (status != 0xff && (status & ATA_BUSY))
2572 		ata_port_printk(ap, KERN_WARNING,
2573 				"port is slow to respond, please be patient "
2574 				"(Status 0x%x)\n", status);
2575 
2576 	timeout = timer_start + tmout;
2577 	while (status != 0xff && (status & ATA_BUSY) &&
2578 	       time_before(jiffies, timeout)) {
2579 		msleep(50);
2580 		status = ata_chk_status(ap);
2581 	}
2582 
2583 	if (status == 0xff)
2584 		return -ENODEV;
2585 
2586 	if (status & ATA_BUSY) {
2587 		ata_port_printk(ap, KERN_ERR, "port failed to respond "
2588 				"(%lu secs, Status 0x%x)\n",
2589 				tmout / HZ, status);
2590 		return -EBUSY;
2591 	}
2592 
2593 	return 0;
2594 }
2595 
2596 static void ata_bus_post_reset(struct ata_port *ap, unsigned int devmask)
2597 {
2598 	struct ata_ioports *ioaddr = &ap->ioaddr;
2599 	unsigned int dev0 = devmask & (1 << 0);
2600 	unsigned int dev1 = devmask & (1 << 1);
2601 	unsigned long timeout;
2602 
2603 	/* if device 0 was found in ata_devchk, wait for its
2604 	 * BSY bit to clear
2605 	 */
2606 	if (dev0)
2607 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2608 
2609 	/* if device 1 was found in ata_devchk, wait for
2610 	 * register access, then wait for BSY to clear
2611 	 */
2612 	timeout = jiffies + ATA_TMOUT_BOOT;
2613 	while (dev1) {
2614 		u8 nsect, lbal;
2615 
2616 		ap->ops->dev_select(ap, 1);
2617 		if (ap->flags & ATA_FLAG_MMIO) {
2618 			nsect = readb((void __iomem *) ioaddr->nsect_addr);
2619 			lbal = readb((void __iomem *) ioaddr->lbal_addr);
2620 		} else {
2621 			nsect = inb(ioaddr->nsect_addr);
2622 			lbal = inb(ioaddr->lbal_addr);
2623 		}
2624 		if ((nsect == 1) && (lbal == 1))
2625 			break;
2626 		if (time_after(jiffies, timeout)) {
2627 			dev1 = 0;
2628 			break;
2629 		}
2630 		msleep(50);	/* give drive a breather */
2631 	}
2632 	if (dev1)
2633 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2634 
2635 	/* is all this really necessary? */
2636 	ap->ops->dev_select(ap, 0);
2637 	if (dev1)
2638 		ap->ops->dev_select(ap, 1);
2639 	if (dev0)
2640 		ap->ops->dev_select(ap, 0);
2641 }
2642 
2643 static unsigned int ata_bus_softreset(struct ata_port *ap,
2644 				      unsigned int devmask)
2645 {
2646 	struct ata_ioports *ioaddr = &ap->ioaddr;
2647 
2648 	DPRINTK("ata%u: bus reset via SRST\n", ap->id);
2649 
2650 	/* software reset.  causes dev0 to be selected */
2651 	if (ap->flags & ATA_FLAG_MMIO) {
2652 		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2653 		udelay(20);	/* FIXME: flush */
2654 		writeb(ap->ctl | ATA_SRST, (void __iomem *) ioaddr->ctl_addr);
2655 		udelay(20);	/* FIXME: flush */
2656 		writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2657 	} else {
2658 		outb(ap->ctl, ioaddr->ctl_addr);
2659 		udelay(10);
2660 		outb(ap->ctl | ATA_SRST, ioaddr->ctl_addr);
2661 		udelay(10);
2662 		outb(ap->ctl, ioaddr->ctl_addr);
2663 	}
2664 
2665 	/* spec mandates ">= 2ms" before checking status.
2666 	 * We wait 150ms, because that was the magic delay used for
2667 	 * ATAPI devices in Hale Landis's ATADRVR, for the period of time
2668 	 * between when the ATA command register is written, and then
2669 	 * status is checked.  Because waiting for "a while" before
2670 	 * checking status is fine, post SRST, we perform this magic
2671 	 * delay here as well.
2672 	 *
2673 	 * Old drivers/ide uses the 2mS rule and then waits for ready
2674 	 */
2675 	msleep(150);
2676 
2677 	/* Before we perform post reset processing we want to see if
2678 	 * the bus shows 0xFF because the odd clown forgets the D7
2679 	 * pulldown resistor.
2680 	 */
2681 	if (ata_check_status(ap) == 0xFF)
2682 		return 0;
2683 
2684 	ata_bus_post_reset(ap, devmask);
2685 
2686 	return 0;
2687 }
2688 
2689 /**
2690  *	ata_bus_reset - reset host port and associated ATA channel
2691  *	@ap: port to reset
2692  *
2693  *	This is typically the first time we actually start issuing
2694  *	commands to the ATA channel.  We wait for BSY to clear, then
2695  *	issue EXECUTE DEVICE DIAGNOSTIC command, polling for its
2696  *	result.  Determine what devices, if any, are on the channel
2697  *	by looking at the device 0/1 error register.  Look at the signature
2698  *	stored in each device's taskfile registers, to determine if
2699  *	the device is ATA or ATAPI.
2700  *
2701  *	LOCKING:
2702  *	PCI/etc. bus probe sem.
2703  *	Obtains host lock.
2704  *
2705  *	SIDE EFFECTS:
2706  *	Sets ATA_FLAG_DISABLED if bus reset fails.
2707  */
2708 
2709 void ata_bus_reset(struct ata_port *ap)
2710 {
2711 	struct ata_ioports *ioaddr = &ap->ioaddr;
2712 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
2713 	u8 err;
2714 	unsigned int dev0, dev1 = 0, devmask = 0;
2715 
2716 	DPRINTK("ENTER, host %u, port %u\n", ap->id, ap->port_no);
2717 
2718 	/* determine if device 0/1 are present */
2719 	if (ap->flags & ATA_FLAG_SATA_RESET)
2720 		dev0 = 1;
2721 	else {
2722 		dev0 = ata_devchk(ap, 0);
2723 		if (slave_possible)
2724 			dev1 = ata_devchk(ap, 1);
2725 	}
2726 
2727 	if (dev0)
2728 		devmask |= (1 << 0);
2729 	if (dev1)
2730 		devmask |= (1 << 1);
2731 
2732 	/* select device 0 again */
2733 	ap->ops->dev_select(ap, 0);
2734 
2735 	/* issue bus reset */
2736 	if (ap->flags & ATA_FLAG_SRST)
2737 		if (ata_bus_softreset(ap, devmask))
2738 			goto err_out;
2739 
2740 	/*
2741 	 * determine by signature whether we have ATA or ATAPI devices
2742 	 */
2743 	ap->device[0].class = ata_dev_try_classify(ap, 0, &err);
2744 	if ((slave_possible) && (err != 0x81))
2745 		ap->device[1].class = ata_dev_try_classify(ap, 1, &err);
2746 
2747 	/* re-enable interrupts */
2748 	if (ap->ioaddr.ctl_addr)	/* FIXME: hack. create a hook instead */
2749 		ata_irq_on(ap);
2750 
2751 	/* is double-select really necessary? */
2752 	if (ap->device[1].class != ATA_DEV_NONE)
2753 		ap->ops->dev_select(ap, 1);
2754 	if (ap->device[0].class != ATA_DEV_NONE)
2755 		ap->ops->dev_select(ap, 0);
2756 
2757 	/* if no devices were detected, disable this port */
2758 	if ((ap->device[0].class == ATA_DEV_NONE) &&
2759 	    (ap->device[1].class == ATA_DEV_NONE))
2760 		goto err_out;
2761 
2762 	if (ap->flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST)) {
2763 		/* set up device control for ATA_FLAG_SATA_RESET */
2764 		if (ap->flags & ATA_FLAG_MMIO)
2765 			writeb(ap->ctl, (void __iomem *) ioaddr->ctl_addr);
2766 		else
2767 			outb(ap->ctl, ioaddr->ctl_addr);
2768 	}
2769 
2770 	DPRINTK("EXIT\n");
2771 	return;
2772 
2773 err_out:
2774 	ata_port_printk(ap, KERN_ERR, "disabling port\n");
2775 	ap->ops->port_disable(ap);
2776 
2777 	DPRINTK("EXIT\n");
2778 }
2779 
2780 /**
2781  *	sata_phy_debounce - debounce SATA phy status
2782  *	@ap: ATA port to debounce SATA phy status for
2783  *	@params: timing parameters { interval, duratinon, timeout } in msec
2784  *
2785  *	Make sure SStatus of @ap reaches stable state, determined by
2786  *	holding the same value where DET is not 1 for @duration polled
2787  *	every @interval, before @timeout.  Timeout constraints the
2788  *	beginning of the stable state.  Because, after hot unplugging,
2789  *	DET gets stuck at 1 on some controllers, this functions waits
2790  *	until timeout then returns 0 if DET is stable at 1.
2791  *
2792  *	LOCKING:
2793  *	Kernel thread context (may sleep)
2794  *
2795  *	RETURNS:
2796  *	0 on success, -errno on failure.
2797  */
2798 int sata_phy_debounce(struct ata_port *ap, const unsigned long *params)
2799 {
2800 	unsigned long interval_msec = params[0];
2801 	unsigned long duration = params[1] * HZ / 1000;
2802 	unsigned long timeout = jiffies + params[2] * HZ / 1000;
2803 	unsigned long last_jiffies;
2804 	u32 last, cur;
2805 	int rc;
2806 
2807 	if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
2808 		return rc;
2809 	cur &= 0xf;
2810 
2811 	last = cur;
2812 	last_jiffies = jiffies;
2813 
2814 	while (1) {
2815 		msleep(interval_msec);
2816 		if ((rc = sata_scr_read(ap, SCR_STATUS, &cur)))
2817 			return rc;
2818 		cur &= 0xf;
2819 
2820 		/* DET stable? */
2821 		if (cur == last) {
2822 			if (cur == 1 && time_before(jiffies, timeout))
2823 				continue;
2824 			if (time_after(jiffies, last_jiffies + duration))
2825 				return 0;
2826 			continue;
2827 		}
2828 
2829 		/* unstable, start over */
2830 		last = cur;
2831 		last_jiffies = jiffies;
2832 
2833 		/* check timeout */
2834 		if (time_after(jiffies, timeout))
2835 			return -EBUSY;
2836 	}
2837 }
2838 
2839 /**
2840  *	sata_phy_resume - resume SATA phy
2841  *	@ap: ATA port to resume SATA phy for
2842  *	@params: timing parameters { interval, duratinon, timeout } in msec
2843  *
2844  *	Resume SATA phy of @ap and debounce it.
2845  *
2846  *	LOCKING:
2847  *	Kernel thread context (may sleep)
2848  *
2849  *	RETURNS:
2850  *	0 on success, -errno on failure.
2851  */
2852 int sata_phy_resume(struct ata_port *ap, const unsigned long *params)
2853 {
2854 	u32 scontrol;
2855 	int rc;
2856 
2857 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
2858 		return rc;
2859 
2860 	scontrol = (scontrol & 0x0f0) | 0x300;
2861 
2862 	if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
2863 		return rc;
2864 
2865 	/* Some PHYs react badly if SStatus is pounded immediately
2866 	 * after resuming.  Delay 200ms before debouncing.
2867 	 */
2868 	msleep(200);
2869 
2870 	return sata_phy_debounce(ap, params);
2871 }
2872 
2873 static void ata_wait_spinup(struct ata_port *ap)
2874 {
2875 	struct ata_eh_context *ehc = &ap->eh_context;
2876 	unsigned long end, secs;
2877 	int rc;
2878 
2879 	/* first, debounce phy if SATA */
2880 	if (ap->cbl == ATA_CBL_SATA) {
2881 		rc = sata_phy_debounce(ap, sata_deb_timing_hotplug);
2882 
2883 		/* if debounced successfully and offline, no need to wait */
2884 		if ((rc == 0 || rc == -EOPNOTSUPP) && ata_port_offline(ap))
2885 			return;
2886 	}
2887 
2888 	/* okay, let's give the drive time to spin up */
2889 	end = ehc->i.hotplug_timestamp + ATA_SPINUP_WAIT * HZ / 1000;
2890 	secs = ((end - jiffies) + HZ - 1) / HZ;
2891 
2892 	if (time_after(jiffies, end))
2893 		return;
2894 
2895 	if (secs > 5)
2896 		ata_port_printk(ap, KERN_INFO, "waiting for device to spin up "
2897 				"(%lu secs)\n", secs);
2898 
2899 	schedule_timeout_uninterruptible(end - jiffies);
2900 }
2901 
2902 /**
2903  *	ata_std_prereset - prepare for reset
2904  *	@ap: ATA port to be reset
2905  *
2906  *	@ap is about to be reset.  Initialize it.
2907  *
2908  *	LOCKING:
2909  *	Kernel thread context (may sleep)
2910  *
2911  *	RETURNS:
2912  *	0 on success, -errno otherwise.
2913  */
2914 int ata_std_prereset(struct ata_port *ap)
2915 {
2916 	struct ata_eh_context *ehc = &ap->eh_context;
2917 	const unsigned long *timing = sata_ehc_deb_timing(ehc);
2918 	int rc;
2919 
2920 	/* handle link resume & hotplug spinup */
2921 	if ((ehc->i.flags & ATA_EHI_RESUME_LINK) &&
2922 	    (ap->flags & ATA_FLAG_HRST_TO_RESUME))
2923 		ehc->i.action |= ATA_EH_HARDRESET;
2924 
2925 	if ((ehc->i.flags & ATA_EHI_HOTPLUGGED) &&
2926 	    (ap->flags & ATA_FLAG_SKIP_D2H_BSY))
2927 		ata_wait_spinup(ap);
2928 
2929 	/* if we're about to do hardreset, nothing more to do */
2930 	if (ehc->i.action & ATA_EH_HARDRESET)
2931 		return 0;
2932 
2933 	/* if SATA, resume phy */
2934 	if (ap->cbl == ATA_CBL_SATA) {
2935 		rc = sata_phy_resume(ap, timing);
2936 		if (rc && rc != -EOPNOTSUPP) {
2937 			/* phy resume failed */
2938 			ata_port_printk(ap, KERN_WARNING, "failed to resume "
2939 					"link for reset (errno=%d)\n", rc);
2940 			return rc;
2941 		}
2942 	}
2943 
2944 	/* Wait for !BSY if the controller can wait for the first D2H
2945 	 * Reg FIS and we don't know that no device is attached.
2946 	 */
2947 	if (!(ap->flags & ATA_FLAG_SKIP_D2H_BSY) && !ata_port_offline(ap))
2948 		ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT);
2949 
2950 	return 0;
2951 }
2952 
2953 /**
2954  *	ata_std_softreset - reset host port via ATA SRST
2955  *	@ap: port to reset
2956  *	@classes: resulting classes of attached devices
2957  *
2958  *	Reset host port using ATA SRST.
2959  *
2960  *	LOCKING:
2961  *	Kernel thread context (may sleep)
2962  *
2963  *	RETURNS:
2964  *	0 on success, -errno otherwise.
2965  */
2966 int ata_std_softreset(struct ata_port *ap, unsigned int *classes)
2967 {
2968 	unsigned int slave_possible = ap->flags & ATA_FLAG_SLAVE_POSS;
2969 	unsigned int devmask = 0, err_mask;
2970 	u8 err;
2971 
2972 	DPRINTK("ENTER\n");
2973 
2974 	if (ata_port_offline(ap)) {
2975 		classes[0] = ATA_DEV_NONE;
2976 		goto out;
2977 	}
2978 
2979 	/* determine if device 0/1 are present */
2980 	if (ata_devchk(ap, 0))
2981 		devmask |= (1 << 0);
2982 	if (slave_possible && ata_devchk(ap, 1))
2983 		devmask |= (1 << 1);
2984 
2985 	/* select device 0 again */
2986 	ap->ops->dev_select(ap, 0);
2987 
2988 	/* issue bus reset */
2989 	DPRINTK("about to softreset, devmask=%x\n", devmask);
2990 	err_mask = ata_bus_softreset(ap, devmask);
2991 	if (err_mask) {
2992 		ata_port_printk(ap, KERN_ERR, "SRST failed (err_mask=0x%x)\n",
2993 				err_mask);
2994 		return -EIO;
2995 	}
2996 
2997 	/* determine by signature whether we have ATA or ATAPI devices */
2998 	classes[0] = ata_dev_try_classify(ap, 0, &err);
2999 	if (slave_possible && err != 0x81)
3000 		classes[1] = ata_dev_try_classify(ap, 1, &err);
3001 
3002  out:
3003 	DPRINTK("EXIT, classes[0]=%u [1]=%u\n", classes[0], classes[1]);
3004 	return 0;
3005 }
3006 
3007 /**
3008  *	sata_port_hardreset - reset port via SATA phy reset
3009  *	@ap: port to reset
3010  *	@timing: timing parameters { interval, duratinon, timeout } in msec
3011  *
3012  *	SATA phy-reset host port using DET bits of SControl register.
3013  *
3014  *	LOCKING:
3015  *	Kernel thread context (may sleep)
3016  *
3017  *	RETURNS:
3018  *	0 on success, -errno otherwise.
3019  */
3020 int sata_port_hardreset(struct ata_port *ap, const unsigned long *timing)
3021 {
3022 	u32 scontrol;
3023 	int rc;
3024 
3025 	DPRINTK("ENTER\n");
3026 
3027 	if (sata_set_spd_needed(ap)) {
3028 		/* SATA spec says nothing about how to reconfigure
3029 		 * spd.  To be on the safe side, turn off phy during
3030 		 * reconfiguration.  This works for at least ICH7 AHCI
3031 		 * and Sil3124.
3032 		 */
3033 		if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
3034 			goto out;
3035 
3036 		scontrol = (scontrol & 0x0f0) | 0x304;
3037 
3038 		if ((rc = sata_scr_write(ap, SCR_CONTROL, scontrol)))
3039 			goto out;
3040 
3041 		sata_set_spd(ap);
3042 	}
3043 
3044 	/* issue phy wake/reset */
3045 	if ((rc = sata_scr_read(ap, SCR_CONTROL, &scontrol)))
3046 		goto out;
3047 
3048 	scontrol = (scontrol & 0x0f0) | 0x301;
3049 
3050 	if ((rc = sata_scr_write_flush(ap, SCR_CONTROL, scontrol)))
3051 		goto out;
3052 
3053 	/* Couldn't find anything in SATA I/II specs, but AHCI-1.1
3054 	 * 10.4.2 says at least 1 ms.
3055 	 */
3056 	msleep(1);
3057 
3058 	/* bring phy back */
3059 	rc = sata_phy_resume(ap, timing);
3060  out:
3061 	DPRINTK("EXIT, rc=%d\n", rc);
3062 	return rc;
3063 }
3064 
3065 /**
3066  *	sata_std_hardreset - reset host port via SATA phy reset
3067  *	@ap: port to reset
3068  *	@class: resulting class of attached device
3069  *
3070  *	SATA phy-reset host port using DET bits of SControl register,
3071  *	wait for !BSY and classify the attached device.
3072  *
3073  *	LOCKING:
3074  *	Kernel thread context (may sleep)
3075  *
3076  *	RETURNS:
3077  *	0 on success, -errno otherwise.
3078  */
3079 int sata_std_hardreset(struct ata_port *ap, unsigned int *class)
3080 {
3081 	const unsigned long *timing = sata_ehc_deb_timing(&ap->eh_context);
3082 	int rc;
3083 
3084 	DPRINTK("ENTER\n");
3085 
3086 	/* do hardreset */
3087 	rc = sata_port_hardreset(ap, timing);
3088 	if (rc) {
3089 		ata_port_printk(ap, KERN_ERR,
3090 				"COMRESET failed (errno=%d)\n", rc);
3091 		return rc;
3092 	}
3093 
3094 	/* TODO: phy layer with polling, timeouts, etc. */
3095 	if (ata_port_offline(ap)) {
3096 		*class = ATA_DEV_NONE;
3097 		DPRINTK("EXIT, link offline\n");
3098 		return 0;
3099 	}
3100 
3101 	if (ata_busy_sleep(ap, ATA_TMOUT_BOOT_QUICK, ATA_TMOUT_BOOT)) {
3102 		ata_port_printk(ap, KERN_ERR,
3103 				"COMRESET failed (device not ready)\n");
3104 		return -EIO;
3105 	}
3106 
3107 	ap->ops->dev_select(ap, 0);	/* probably unnecessary */
3108 
3109 	*class = ata_dev_try_classify(ap, 0, NULL);
3110 
3111 	DPRINTK("EXIT, class=%u\n", *class);
3112 	return 0;
3113 }
3114 
3115 /**
3116  *	ata_std_postreset - standard postreset callback
3117  *	@ap: the target ata_port
3118  *	@classes: classes of attached devices
3119  *
3120  *	This function is invoked after a successful reset.  Note that
3121  *	the device might have been reset more than once using
3122  *	different reset methods before postreset is invoked.
3123  *
3124  *	LOCKING:
3125  *	Kernel thread context (may sleep)
3126  */
3127 void ata_std_postreset(struct ata_port *ap, unsigned int *classes)
3128 {
3129 	u32 serror;
3130 
3131 	DPRINTK("ENTER\n");
3132 
3133 	/* print link status */
3134 	sata_print_link_status(ap);
3135 
3136 	/* clear SError */
3137 	if (sata_scr_read(ap, SCR_ERROR, &serror) == 0)
3138 		sata_scr_write(ap, SCR_ERROR, serror);
3139 
3140 	/* re-enable interrupts */
3141 	if (!ap->ops->error_handler) {
3142 		/* FIXME: hack. create a hook instead */
3143 		if (ap->ioaddr.ctl_addr)
3144 			ata_irq_on(ap);
3145 	}
3146 
3147 	/* is double-select really necessary? */
3148 	if (classes[0] != ATA_DEV_NONE)
3149 		ap->ops->dev_select(ap, 1);
3150 	if (classes[1] != ATA_DEV_NONE)
3151 		ap->ops->dev_select(ap, 0);
3152 
3153 	/* bail out if no device is present */
3154 	if (classes[0] == ATA_DEV_NONE && classes[1] == ATA_DEV_NONE) {
3155 		DPRINTK("EXIT, no device\n");
3156 		return;
3157 	}
3158 
3159 	/* set up device control */
3160 	if (ap->ioaddr.ctl_addr) {
3161 		if (ap->flags & ATA_FLAG_MMIO)
3162 			writeb(ap->ctl, (void __iomem *) ap->ioaddr.ctl_addr);
3163 		else
3164 			outb(ap->ctl, ap->ioaddr.ctl_addr);
3165 	}
3166 
3167 	DPRINTK("EXIT\n");
3168 }
3169 
3170 /**
3171  *	ata_dev_same_device - Determine whether new ID matches configured device
3172  *	@dev: device to compare against
3173  *	@new_class: class of the new device
3174  *	@new_id: IDENTIFY page of the new device
3175  *
3176  *	Compare @new_class and @new_id against @dev and determine
3177  *	whether @dev is the device indicated by @new_class and
3178  *	@new_id.
3179  *
3180  *	LOCKING:
3181  *	None.
3182  *
3183  *	RETURNS:
3184  *	1 if @dev matches @new_class and @new_id, 0 otherwise.
3185  */
3186 static int ata_dev_same_device(struct ata_device *dev, unsigned int new_class,
3187 			       const u16 *new_id)
3188 {
3189 	const u16 *old_id = dev->id;
3190 	unsigned char model[2][41], serial[2][21];
3191 	u64 new_n_sectors;
3192 
3193 	if (dev->class != new_class) {
3194 		ata_dev_printk(dev, KERN_INFO, "class mismatch %d != %d\n",
3195 			       dev->class, new_class);
3196 		return 0;
3197 	}
3198 
3199 	ata_id_c_string(old_id, model[0], ATA_ID_PROD_OFS, sizeof(model[0]));
3200 	ata_id_c_string(new_id, model[1], ATA_ID_PROD_OFS, sizeof(model[1]));
3201 	ata_id_c_string(old_id, serial[0], ATA_ID_SERNO_OFS, sizeof(serial[0]));
3202 	ata_id_c_string(new_id, serial[1], ATA_ID_SERNO_OFS, sizeof(serial[1]));
3203 	new_n_sectors = ata_id_n_sectors(new_id);
3204 
3205 	if (strcmp(model[0], model[1])) {
3206 		ata_dev_printk(dev, KERN_INFO, "model number mismatch "
3207 			       "'%s' != '%s'\n", model[0], model[1]);
3208 		return 0;
3209 	}
3210 
3211 	if (strcmp(serial[0], serial[1])) {
3212 		ata_dev_printk(dev, KERN_INFO, "serial number mismatch "
3213 			       "'%s' != '%s'\n", serial[0], serial[1]);
3214 		return 0;
3215 	}
3216 
3217 	if (dev->class == ATA_DEV_ATA && dev->n_sectors != new_n_sectors) {
3218 		ata_dev_printk(dev, KERN_INFO, "n_sectors mismatch "
3219 			       "%llu != %llu\n",
3220 			       (unsigned long long)dev->n_sectors,
3221 			       (unsigned long long)new_n_sectors);
3222 		return 0;
3223 	}
3224 
3225 	return 1;
3226 }
3227 
3228 /**
3229  *	ata_dev_revalidate - Revalidate ATA device
3230  *	@dev: device to revalidate
3231  *	@readid_flags: read ID flags
3232  *
3233  *	Re-read IDENTIFY page and make sure @dev is still attached to
3234  *	the port.
3235  *
3236  *	LOCKING:
3237  *	Kernel thread context (may sleep)
3238  *
3239  *	RETURNS:
3240  *	0 on success, negative errno otherwise
3241  */
3242 int ata_dev_revalidate(struct ata_device *dev, unsigned int readid_flags)
3243 {
3244 	unsigned int class = dev->class;
3245 	u16 *id = (void *)dev->ap->sector_buf;
3246 	int rc;
3247 
3248 	if (!ata_dev_enabled(dev)) {
3249 		rc = -ENODEV;
3250 		goto fail;
3251 	}
3252 
3253 	/* read ID data */
3254 	rc = ata_dev_read_id(dev, &class, readid_flags, id);
3255 	if (rc)
3256 		goto fail;
3257 
3258 	/* is the device still there? */
3259 	if (!ata_dev_same_device(dev, class, id)) {
3260 		rc = -ENODEV;
3261 		goto fail;
3262 	}
3263 
3264 	memcpy(dev->id, id, sizeof(id[0]) * ATA_ID_WORDS);
3265 
3266 	/* configure device according to the new ID */
3267 	rc = ata_dev_configure(dev);
3268 	if (rc == 0)
3269 		return 0;
3270 
3271  fail:
3272 	ata_dev_printk(dev, KERN_ERR, "revalidation failed (errno=%d)\n", rc);
3273 	return rc;
3274 }
3275 
3276 struct ata_blacklist_entry {
3277 	const char *model_num;
3278 	const char *model_rev;
3279 	unsigned long horkage;
3280 };
3281 
3282 static const struct ata_blacklist_entry ata_device_blacklist [] = {
3283 	/* Devices with DMA related problems under Linux */
3284 	{ "WDC AC11000H",	NULL,		ATA_HORKAGE_NODMA },
3285 	{ "WDC AC22100H",	NULL,		ATA_HORKAGE_NODMA },
3286 	{ "WDC AC32500H",	NULL,		ATA_HORKAGE_NODMA },
3287 	{ "WDC AC33100H",	NULL,		ATA_HORKAGE_NODMA },
3288 	{ "WDC AC31600H",	NULL,		ATA_HORKAGE_NODMA },
3289 	{ "WDC AC32100H",	"24.09P07",	ATA_HORKAGE_NODMA },
3290 	{ "WDC AC23200L",	"21.10N21",	ATA_HORKAGE_NODMA },
3291 	{ "Compaq CRD-8241B", 	NULL,		ATA_HORKAGE_NODMA },
3292 	{ "CRD-8400B",		NULL, 		ATA_HORKAGE_NODMA },
3293 	{ "CRD-8480B",		NULL,		ATA_HORKAGE_NODMA },
3294 	{ "CRD-8482B",		NULL,		ATA_HORKAGE_NODMA },
3295 	{ "CRD-84",		NULL,		ATA_HORKAGE_NODMA },
3296 	{ "SanDisk SDP3B",	NULL,		ATA_HORKAGE_NODMA },
3297 	{ "SanDisk SDP3B-64",	NULL,		ATA_HORKAGE_NODMA },
3298 	{ "SANYO CD-ROM CRD",	NULL,		ATA_HORKAGE_NODMA },
3299 	{ "HITACHI CDR-8",	NULL,		ATA_HORKAGE_NODMA },
3300 	{ "HITACHI CDR-8335",	NULL,		ATA_HORKAGE_NODMA },
3301 	{ "HITACHI CDR-8435",	NULL,		ATA_HORKAGE_NODMA },
3302 	{ "Toshiba CD-ROM XM-6202B", NULL,	ATA_HORKAGE_NODMA },
3303 	{ "TOSHIBA CD-ROM XM-1702BC", NULL,	ATA_HORKAGE_NODMA },
3304 	{ "CD-532E-A", 		NULL,		ATA_HORKAGE_NODMA },
3305 	{ "E-IDE CD-ROM CR-840",NULL,		ATA_HORKAGE_NODMA },
3306 	{ "CD-ROM Drive/F5A",	NULL,		ATA_HORKAGE_NODMA },
3307 	{ "WPI CDD-820", 	NULL,		ATA_HORKAGE_NODMA },
3308 	{ "SAMSUNG CD-ROM SC-148C", NULL,	ATA_HORKAGE_NODMA },
3309 	{ "SAMSUNG CD-ROM SC",	NULL,		ATA_HORKAGE_NODMA },
3310 	{ "SanDisk SDP3B-64", 	NULL,		ATA_HORKAGE_NODMA },
3311 	{ "ATAPI CD-ROM DRIVE 40X MAXIMUM",NULL,ATA_HORKAGE_NODMA },
3312 	{ "_NEC DV5800A", 	NULL,		ATA_HORKAGE_NODMA },
3313 	{ "SAMSUNG CD-ROM SN-124","N001",	ATA_HORKAGE_NODMA },
3314 
3315 	/* Devices we expect to fail diagnostics */
3316 
3317 	/* Devices where NCQ should be avoided */
3318 	/* NCQ is slow */
3319         { "WDC WD740ADFD-00",   NULL,		ATA_HORKAGE_NONCQ },
3320 
3321 	/* Devices with NCQ limits */
3322 
3323 	/* End Marker */
3324 	{ }
3325 };
3326 
3327 static int ata_strim(char *s, size_t len)
3328 {
3329 	len = strnlen(s, len);
3330 
3331 	/* ATAPI specifies that empty space is blank-filled; remove blanks */
3332 	while ((len > 0) && (s[len - 1] == ' ')) {
3333 		len--;
3334 		s[len] = 0;
3335 	}
3336 	return len;
3337 }
3338 
3339 unsigned long ata_device_blacklisted(const struct ata_device *dev)
3340 {
3341 	unsigned char model_num[40];
3342 	unsigned char model_rev[16];
3343 	unsigned int nlen, rlen;
3344 	const struct ata_blacklist_entry *ad = ata_device_blacklist;
3345 
3346 	ata_id_string(dev->id, model_num, ATA_ID_PROD_OFS,
3347 			  sizeof(model_num));
3348 	ata_id_string(dev->id, model_rev, ATA_ID_FW_REV_OFS,
3349 			  sizeof(model_rev));
3350 	nlen = ata_strim(model_num, sizeof(model_num));
3351 	rlen = ata_strim(model_rev, sizeof(model_rev));
3352 
3353 	while (ad->model_num) {
3354 		if (!strncmp(ad->model_num, model_num, nlen)) {
3355 			if (ad->model_rev == NULL)
3356 				return ad->horkage;
3357 			if (!strncmp(ad->model_rev, model_rev, rlen))
3358 				return ad->horkage;
3359 		}
3360 		ad++;
3361 	}
3362 	return 0;
3363 }
3364 
3365 static int ata_dma_blacklisted(const struct ata_device *dev)
3366 {
3367 	/* We don't support polling DMA.
3368 	 * DMA blacklist those ATAPI devices with CDB-intr (and use PIO)
3369 	 * if the LLDD handles only interrupts in the HSM_ST_LAST state.
3370 	 */
3371 	if ((dev->ap->flags & ATA_FLAG_PIO_POLLING) &&
3372 	    (dev->flags & ATA_DFLAG_CDB_INTR))
3373 		return 1;
3374 	return (ata_device_blacklisted(dev) & ATA_HORKAGE_NODMA) ? 1 : 0;
3375 }
3376 
3377 /**
3378  *	ata_dev_xfermask - Compute supported xfermask of the given device
3379  *	@dev: Device to compute xfermask for
3380  *
3381  *	Compute supported xfermask of @dev and store it in
3382  *	dev->*_mask.  This function is responsible for applying all
3383  *	known limits including host controller limits, device
3384  *	blacklist, etc...
3385  *
3386  *	LOCKING:
3387  *	None.
3388  */
3389 static void ata_dev_xfermask(struct ata_device *dev)
3390 {
3391 	struct ata_port *ap = dev->ap;
3392 	struct ata_host *host = ap->host;
3393 	unsigned long xfer_mask;
3394 
3395 	/* controller modes available */
3396 	xfer_mask = ata_pack_xfermask(ap->pio_mask,
3397 				      ap->mwdma_mask, ap->udma_mask);
3398 
3399 	/* Apply cable rule here.  Don't apply it early because when
3400 	 * we handle hot plug the cable type can itself change.
3401 	 */
3402 	if (ap->cbl == ATA_CBL_PATA40)
3403 		xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
3404 	/* Apply drive side cable rule. Unknown or 80 pin cables reported
3405 	 * host side are checked drive side as well. Cases where we know a
3406 	 * 40wire cable is used safely for 80 are not checked here.
3407 	 */
3408         if (ata_drive_40wire(dev->id) && (ap->cbl == ATA_CBL_PATA_UNK || ap->cbl == ATA_CBL_PATA80))
3409 		xfer_mask &= ~(0xF8 << ATA_SHIFT_UDMA);
3410 
3411 
3412 	xfer_mask &= ata_pack_xfermask(dev->pio_mask,
3413 				       dev->mwdma_mask, dev->udma_mask);
3414 	xfer_mask &= ata_id_xfermask(dev->id);
3415 
3416 	/*
3417 	 *	CFA Advanced TrueIDE timings are not allowed on a shared
3418 	 *	cable
3419 	 */
3420 	if (ata_dev_pair(dev)) {
3421 		/* No PIO5 or PIO6 */
3422 		xfer_mask &= ~(0x03 << (ATA_SHIFT_PIO + 5));
3423 		/* No MWDMA3 or MWDMA 4 */
3424 		xfer_mask &= ~(0x03 << (ATA_SHIFT_MWDMA + 3));
3425 	}
3426 
3427 	if (ata_dma_blacklisted(dev)) {
3428 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
3429 		ata_dev_printk(dev, KERN_WARNING,
3430 			       "device is on DMA blacklist, disabling DMA\n");
3431 	}
3432 
3433 	if ((host->flags & ATA_HOST_SIMPLEX) && host->simplex_claimed) {
3434 		xfer_mask &= ~(ATA_MASK_MWDMA | ATA_MASK_UDMA);
3435 		ata_dev_printk(dev, KERN_WARNING, "simplex DMA is claimed by "
3436 			       "other device, disabling DMA\n");
3437 	}
3438 
3439 	if (ap->ops->mode_filter)
3440 		xfer_mask = ap->ops->mode_filter(ap, dev, xfer_mask);
3441 
3442 	ata_unpack_xfermask(xfer_mask, &dev->pio_mask,
3443 			    &dev->mwdma_mask, &dev->udma_mask);
3444 }
3445 
3446 /**
3447  *	ata_dev_set_xfermode - Issue SET FEATURES - XFER MODE command
3448  *	@dev: Device to which command will be sent
3449  *
3450  *	Issue SET FEATURES - XFER MODE command to device @dev
3451  *	on port @ap.
3452  *
3453  *	LOCKING:
3454  *	PCI/etc. bus probe sem.
3455  *
3456  *	RETURNS:
3457  *	0 on success, AC_ERR_* mask otherwise.
3458  */
3459 
3460 static unsigned int ata_dev_set_xfermode(struct ata_device *dev)
3461 {
3462 	struct ata_taskfile tf;
3463 	unsigned int err_mask;
3464 
3465 	/* set up set-features taskfile */
3466 	DPRINTK("set features - xfer mode\n");
3467 
3468 	ata_tf_init(dev, &tf);
3469 	tf.command = ATA_CMD_SET_FEATURES;
3470 	tf.feature = SETFEATURES_XFER;
3471 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
3472 	tf.protocol = ATA_PROT_NODATA;
3473 	tf.nsect = dev->xfer_mode;
3474 
3475 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
3476 
3477 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
3478 	return err_mask;
3479 }
3480 
3481 /**
3482  *	ata_dev_init_params - Issue INIT DEV PARAMS command
3483  *	@dev: Device to which command will be sent
3484  *	@heads: Number of heads (taskfile parameter)
3485  *	@sectors: Number of sectors (taskfile parameter)
3486  *
3487  *	LOCKING:
3488  *	Kernel thread context (may sleep)
3489  *
3490  *	RETURNS:
3491  *	0 on success, AC_ERR_* mask otherwise.
3492  */
3493 static unsigned int ata_dev_init_params(struct ata_device *dev,
3494 					u16 heads, u16 sectors)
3495 {
3496 	struct ata_taskfile tf;
3497 	unsigned int err_mask;
3498 
3499 	/* Number of sectors per track 1-255. Number of heads 1-16 */
3500 	if (sectors < 1 || sectors > 255 || heads < 1 || heads > 16)
3501 		return AC_ERR_INVALID;
3502 
3503 	/* set up init dev params taskfile */
3504 	DPRINTK("init dev params \n");
3505 
3506 	ata_tf_init(dev, &tf);
3507 	tf.command = ATA_CMD_INIT_DEV_PARAMS;
3508 	tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
3509 	tf.protocol = ATA_PROT_NODATA;
3510 	tf.nsect = sectors;
3511 	tf.device |= (heads - 1) & 0x0f; /* max head = num. of heads - 1 */
3512 
3513 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0);
3514 
3515 	DPRINTK("EXIT, err_mask=%x\n", err_mask);
3516 	return err_mask;
3517 }
3518 
3519 /**
3520  *	ata_sg_clean - Unmap DMA memory associated with command
3521  *	@qc: Command containing DMA memory to be released
3522  *
3523  *	Unmap all mapped DMA memory associated with this command.
3524  *
3525  *	LOCKING:
3526  *	spin_lock_irqsave(host lock)
3527  */
3528 void ata_sg_clean(struct ata_queued_cmd *qc)
3529 {
3530 	struct ata_port *ap = qc->ap;
3531 	struct scatterlist *sg = qc->__sg;
3532 	int dir = qc->dma_dir;
3533 	void *pad_buf = NULL;
3534 
3535 	WARN_ON(!(qc->flags & ATA_QCFLAG_DMAMAP));
3536 	WARN_ON(sg == NULL);
3537 
3538 	if (qc->flags & ATA_QCFLAG_SINGLE)
3539 		WARN_ON(qc->n_elem > 1);
3540 
3541 	VPRINTK("unmapping %u sg elements\n", qc->n_elem);
3542 
3543 	/* if we padded the buffer out to 32-bit bound, and data
3544 	 * xfer direction is from-device, we must copy from the
3545 	 * pad buffer back into the supplied buffer
3546 	 */
3547 	if (qc->pad_len && !(qc->tf.flags & ATA_TFLAG_WRITE))
3548 		pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3549 
3550 	if (qc->flags & ATA_QCFLAG_SG) {
3551 		if (qc->n_elem)
3552 			dma_unmap_sg(ap->dev, sg, qc->n_elem, dir);
3553 		/* restore last sg */
3554 		sg[qc->orig_n_elem - 1].length += qc->pad_len;
3555 		if (pad_buf) {
3556 			struct scatterlist *psg = &qc->pad_sgent;
3557 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
3558 			memcpy(addr + psg->offset, pad_buf, qc->pad_len);
3559 			kunmap_atomic(addr, KM_IRQ0);
3560 		}
3561 	} else {
3562 		if (qc->n_elem)
3563 			dma_unmap_single(ap->dev,
3564 				sg_dma_address(&sg[0]), sg_dma_len(&sg[0]),
3565 				dir);
3566 		/* restore sg */
3567 		sg->length += qc->pad_len;
3568 		if (pad_buf)
3569 			memcpy(qc->buf_virt + sg->length - qc->pad_len,
3570 			       pad_buf, qc->pad_len);
3571 	}
3572 
3573 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
3574 	qc->__sg = NULL;
3575 }
3576 
3577 /**
3578  *	ata_fill_sg - Fill PCI IDE PRD table
3579  *	@qc: Metadata associated with taskfile to be transferred
3580  *
3581  *	Fill PCI IDE PRD (scatter-gather) table with segments
3582  *	associated with the current disk command.
3583  *
3584  *	LOCKING:
3585  *	spin_lock_irqsave(host lock)
3586  *
3587  */
3588 static void ata_fill_sg(struct ata_queued_cmd *qc)
3589 {
3590 	struct ata_port *ap = qc->ap;
3591 	struct scatterlist *sg;
3592 	unsigned int idx;
3593 
3594 	WARN_ON(qc->__sg == NULL);
3595 	WARN_ON(qc->n_elem == 0 && qc->pad_len == 0);
3596 
3597 	idx = 0;
3598 	ata_for_each_sg(sg, qc) {
3599 		u32 addr, offset;
3600 		u32 sg_len, len;
3601 
3602 		/* determine if physical DMA addr spans 64K boundary.
3603 		 * Note h/w doesn't support 64-bit, so we unconditionally
3604 		 * truncate dma_addr_t to u32.
3605 		 */
3606 		addr = (u32) sg_dma_address(sg);
3607 		sg_len = sg_dma_len(sg);
3608 
3609 		while (sg_len) {
3610 			offset = addr & 0xffff;
3611 			len = sg_len;
3612 			if ((offset + sg_len) > 0x10000)
3613 				len = 0x10000 - offset;
3614 
3615 			ap->prd[idx].addr = cpu_to_le32(addr);
3616 			ap->prd[idx].flags_len = cpu_to_le32(len & 0xffff);
3617 			VPRINTK("PRD[%u] = (0x%X, 0x%X)\n", idx, addr, len);
3618 
3619 			idx++;
3620 			sg_len -= len;
3621 			addr += len;
3622 		}
3623 	}
3624 
3625 	if (idx)
3626 		ap->prd[idx - 1].flags_len |= cpu_to_le32(ATA_PRD_EOT);
3627 }
3628 /**
3629  *	ata_check_atapi_dma - Check whether ATAPI DMA can be supported
3630  *	@qc: Metadata associated with taskfile to check
3631  *
3632  *	Allow low-level driver to filter ATA PACKET commands, returning
3633  *	a status indicating whether or not it is OK to use DMA for the
3634  *	supplied PACKET command.
3635  *
3636  *	LOCKING:
3637  *	spin_lock_irqsave(host lock)
3638  *
3639  *	RETURNS: 0 when ATAPI DMA can be used
3640  *               nonzero otherwise
3641  */
3642 int ata_check_atapi_dma(struct ata_queued_cmd *qc)
3643 {
3644 	struct ata_port *ap = qc->ap;
3645 	int rc = 0; /* Assume ATAPI DMA is OK by default */
3646 
3647 	if (ap->ops->check_atapi_dma)
3648 		rc = ap->ops->check_atapi_dma(qc);
3649 
3650 	return rc;
3651 }
3652 /**
3653  *	ata_qc_prep - Prepare taskfile for submission
3654  *	@qc: Metadata associated with taskfile to be prepared
3655  *
3656  *	Prepare ATA taskfile for submission.
3657  *
3658  *	LOCKING:
3659  *	spin_lock_irqsave(host lock)
3660  */
3661 void ata_qc_prep(struct ata_queued_cmd *qc)
3662 {
3663 	if (!(qc->flags & ATA_QCFLAG_DMAMAP))
3664 		return;
3665 
3666 	ata_fill_sg(qc);
3667 }
3668 
3669 void ata_noop_qc_prep(struct ata_queued_cmd *qc) { }
3670 
3671 /**
3672  *	ata_sg_init_one - Associate command with memory buffer
3673  *	@qc: Command to be associated
3674  *	@buf: Memory buffer
3675  *	@buflen: Length of memory buffer, in bytes.
3676  *
3677  *	Initialize the data-related elements of queued_cmd @qc
3678  *	to point to a single memory buffer, @buf of byte length @buflen.
3679  *
3680  *	LOCKING:
3681  *	spin_lock_irqsave(host lock)
3682  */
3683 
3684 void ata_sg_init_one(struct ata_queued_cmd *qc, void *buf, unsigned int buflen)
3685 {
3686 	qc->flags |= ATA_QCFLAG_SINGLE;
3687 
3688 	qc->__sg = &qc->sgent;
3689 	qc->n_elem = 1;
3690 	qc->orig_n_elem = 1;
3691 	qc->buf_virt = buf;
3692 	qc->nbytes = buflen;
3693 
3694 	sg_init_one(&qc->sgent, buf, buflen);
3695 }
3696 
3697 /**
3698  *	ata_sg_init - Associate command with scatter-gather table.
3699  *	@qc: Command to be associated
3700  *	@sg: Scatter-gather table.
3701  *	@n_elem: Number of elements in s/g table.
3702  *
3703  *	Initialize the data-related elements of queued_cmd @qc
3704  *	to point to a scatter-gather table @sg, containing @n_elem
3705  *	elements.
3706  *
3707  *	LOCKING:
3708  *	spin_lock_irqsave(host lock)
3709  */
3710 
3711 void ata_sg_init(struct ata_queued_cmd *qc, struct scatterlist *sg,
3712 		 unsigned int n_elem)
3713 {
3714 	qc->flags |= ATA_QCFLAG_SG;
3715 	qc->__sg = sg;
3716 	qc->n_elem = n_elem;
3717 	qc->orig_n_elem = n_elem;
3718 }
3719 
3720 /**
3721  *	ata_sg_setup_one - DMA-map the memory buffer associated with a command.
3722  *	@qc: Command with memory buffer to be mapped.
3723  *
3724  *	DMA-map the memory buffer associated with queued_cmd @qc.
3725  *
3726  *	LOCKING:
3727  *	spin_lock_irqsave(host lock)
3728  *
3729  *	RETURNS:
3730  *	Zero on success, negative on error.
3731  */
3732 
3733 static int ata_sg_setup_one(struct ata_queued_cmd *qc)
3734 {
3735 	struct ata_port *ap = qc->ap;
3736 	int dir = qc->dma_dir;
3737 	struct scatterlist *sg = qc->__sg;
3738 	dma_addr_t dma_address;
3739 	int trim_sg = 0;
3740 
3741 	/* we must lengthen transfers to end on a 32-bit boundary */
3742 	qc->pad_len = sg->length & 3;
3743 	if (qc->pad_len) {
3744 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3745 		struct scatterlist *psg = &qc->pad_sgent;
3746 
3747 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
3748 
3749 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
3750 
3751 		if (qc->tf.flags & ATA_TFLAG_WRITE)
3752 			memcpy(pad_buf, qc->buf_virt + sg->length - qc->pad_len,
3753 			       qc->pad_len);
3754 
3755 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
3756 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
3757 		/* trim sg */
3758 		sg->length -= qc->pad_len;
3759 		if (sg->length == 0)
3760 			trim_sg = 1;
3761 
3762 		DPRINTK("padding done, sg->length=%u pad_len=%u\n",
3763 			sg->length, qc->pad_len);
3764 	}
3765 
3766 	if (trim_sg) {
3767 		qc->n_elem--;
3768 		goto skip_map;
3769 	}
3770 
3771 	dma_address = dma_map_single(ap->dev, qc->buf_virt,
3772 				     sg->length, dir);
3773 	if (dma_mapping_error(dma_address)) {
3774 		/* restore sg */
3775 		sg->length += qc->pad_len;
3776 		return -1;
3777 	}
3778 
3779 	sg_dma_address(sg) = dma_address;
3780 	sg_dma_len(sg) = sg->length;
3781 
3782 skip_map:
3783 	DPRINTK("mapped buffer of %d bytes for %s\n", sg_dma_len(sg),
3784 		qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
3785 
3786 	return 0;
3787 }
3788 
3789 /**
3790  *	ata_sg_setup - DMA-map the scatter-gather table associated with a command.
3791  *	@qc: Command with scatter-gather table to be mapped.
3792  *
3793  *	DMA-map the scatter-gather table associated with queued_cmd @qc.
3794  *
3795  *	LOCKING:
3796  *	spin_lock_irqsave(host lock)
3797  *
3798  *	RETURNS:
3799  *	Zero on success, negative on error.
3800  *
3801  */
3802 
3803 static int ata_sg_setup(struct ata_queued_cmd *qc)
3804 {
3805 	struct ata_port *ap = qc->ap;
3806 	struct scatterlist *sg = qc->__sg;
3807 	struct scatterlist *lsg = &sg[qc->n_elem - 1];
3808 	int n_elem, pre_n_elem, dir, trim_sg = 0;
3809 
3810 	VPRINTK("ENTER, ata%u\n", ap->id);
3811 	WARN_ON(!(qc->flags & ATA_QCFLAG_SG));
3812 
3813 	/* we must lengthen transfers to end on a 32-bit boundary */
3814 	qc->pad_len = lsg->length & 3;
3815 	if (qc->pad_len) {
3816 		void *pad_buf = ap->pad + (qc->tag * ATA_DMA_PAD_SZ);
3817 		struct scatterlist *psg = &qc->pad_sgent;
3818 		unsigned int offset;
3819 
3820 		WARN_ON(qc->dev->class != ATA_DEV_ATAPI);
3821 
3822 		memset(pad_buf, 0, ATA_DMA_PAD_SZ);
3823 
3824 		/*
3825 		 * psg->page/offset are used to copy to-be-written
3826 		 * data in this function or read data in ata_sg_clean.
3827 		 */
3828 		offset = lsg->offset + lsg->length - qc->pad_len;
3829 		psg->page = nth_page(lsg->page, offset >> PAGE_SHIFT);
3830 		psg->offset = offset_in_page(offset);
3831 
3832 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
3833 			void *addr = kmap_atomic(psg->page, KM_IRQ0);
3834 			memcpy(pad_buf, addr + psg->offset, qc->pad_len);
3835 			kunmap_atomic(addr, KM_IRQ0);
3836 		}
3837 
3838 		sg_dma_address(psg) = ap->pad_dma + (qc->tag * ATA_DMA_PAD_SZ);
3839 		sg_dma_len(psg) = ATA_DMA_PAD_SZ;
3840 		/* trim last sg */
3841 		lsg->length -= qc->pad_len;
3842 		if (lsg->length == 0)
3843 			trim_sg = 1;
3844 
3845 		DPRINTK("padding done, sg[%d].length=%u pad_len=%u\n",
3846 			qc->n_elem - 1, lsg->length, qc->pad_len);
3847 	}
3848 
3849 	pre_n_elem = qc->n_elem;
3850 	if (trim_sg && pre_n_elem)
3851 		pre_n_elem--;
3852 
3853 	if (!pre_n_elem) {
3854 		n_elem = 0;
3855 		goto skip_map;
3856 	}
3857 
3858 	dir = qc->dma_dir;
3859 	n_elem = dma_map_sg(ap->dev, sg, pre_n_elem, dir);
3860 	if (n_elem < 1) {
3861 		/* restore last sg */
3862 		lsg->length += qc->pad_len;
3863 		return -1;
3864 	}
3865 
3866 	DPRINTK("%d sg elements mapped\n", n_elem);
3867 
3868 skip_map:
3869 	qc->n_elem = n_elem;
3870 
3871 	return 0;
3872 }
3873 
3874 /**
3875  *	swap_buf_le16 - swap halves of 16-bit words in place
3876  *	@buf:  Buffer to swap
3877  *	@buf_words:  Number of 16-bit words in buffer.
3878  *
3879  *	Swap halves of 16-bit words if needed to convert from
3880  *	little-endian byte order to native cpu byte order, or
3881  *	vice-versa.
3882  *
3883  *	LOCKING:
3884  *	Inherited from caller.
3885  */
3886 void swap_buf_le16(u16 *buf, unsigned int buf_words)
3887 {
3888 #ifdef __BIG_ENDIAN
3889 	unsigned int i;
3890 
3891 	for (i = 0; i < buf_words; i++)
3892 		buf[i] = le16_to_cpu(buf[i]);
3893 #endif /* __BIG_ENDIAN */
3894 }
3895 
3896 /**
3897  *	ata_mmio_data_xfer - Transfer data by MMIO
3898  *	@adev: device for this I/O
3899  *	@buf: data buffer
3900  *	@buflen: buffer length
3901  *	@write_data: read/write
3902  *
3903  *	Transfer data from/to the device data register by MMIO.
3904  *
3905  *	LOCKING:
3906  *	Inherited from caller.
3907  */
3908 
3909 void ata_mmio_data_xfer(struct ata_device *adev, unsigned char *buf,
3910 			unsigned int buflen, int write_data)
3911 {
3912 	struct ata_port *ap = adev->ap;
3913 	unsigned int i;
3914 	unsigned int words = buflen >> 1;
3915 	u16 *buf16 = (u16 *) buf;
3916 	void __iomem *mmio = (void __iomem *)ap->ioaddr.data_addr;
3917 
3918 	/* Transfer multiple of 2 bytes */
3919 	if (write_data) {
3920 		for (i = 0; i < words; i++)
3921 			writew(le16_to_cpu(buf16[i]), mmio);
3922 	} else {
3923 		for (i = 0; i < words; i++)
3924 			buf16[i] = cpu_to_le16(readw(mmio));
3925 	}
3926 
3927 	/* Transfer trailing 1 byte, if any. */
3928 	if (unlikely(buflen & 0x01)) {
3929 		u16 align_buf[1] = { 0 };
3930 		unsigned char *trailing_buf = buf + buflen - 1;
3931 
3932 		if (write_data) {
3933 			memcpy(align_buf, trailing_buf, 1);
3934 			writew(le16_to_cpu(align_buf[0]), mmio);
3935 		} else {
3936 			align_buf[0] = cpu_to_le16(readw(mmio));
3937 			memcpy(trailing_buf, align_buf, 1);
3938 		}
3939 	}
3940 }
3941 
3942 /**
3943  *	ata_pio_data_xfer - Transfer data by PIO
3944  *	@adev: device to target
3945  *	@buf: data buffer
3946  *	@buflen: buffer length
3947  *	@write_data: read/write
3948  *
3949  *	Transfer data from/to the device data register by PIO.
3950  *
3951  *	LOCKING:
3952  *	Inherited from caller.
3953  */
3954 
3955 void ata_pio_data_xfer(struct ata_device *adev, unsigned char *buf,
3956 		       unsigned int buflen, int write_data)
3957 {
3958 	struct ata_port *ap = adev->ap;
3959 	unsigned int words = buflen >> 1;
3960 
3961 	/* Transfer multiple of 2 bytes */
3962 	if (write_data)
3963 		outsw(ap->ioaddr.data_addr, buf, words);
3964 	else
3965 		insw(ap->ioaddr.data_addr, buf, words);
3966 
3967 	/* Transfer trailing 1 byte, if any. */
3968 	if (unlikely(buflen & 0x01)) {
3969 		u16 align_buf[1] = { 0 };
3970 		unsigned char *trailing_buf = buf + buflen - 1;
3971 
3972 		if (write_data) {
3973 			memcpy(align_buf, trailing_buf, 1);
3974 			outw(le16_to_cpu(align_buf[0]), ap->ioaddr.data_addr);
3975 		} else {
3976 			align_buf[0] = cpu_to_le16(inw(ap->ioaddr.data_addr));
3977 			memcpy(trailing_buf, align_buf, 1);
3978 		}
3979 	}
3980 }
3981 
3982 /**
3983  *	ata_pio_data_xfer_noirq - Transfer data by PIO
3984  *	@adev: device to target
3985  *	@buf: data buffer
3986  *	@buflen: buffer length
3987  *	@write_data: read/write
3988  *
3989  *	Transfer data from/to the device data register by PIO. Do the
3990  *	transfer with interrupts disabled.
3991  *
3992  *	LOCKING:
3993  *	Inherited from caller.
3994  */
3995 
3996 void ata_pio_data_xfer_noirq(struct ata_device *adev, unsigned char *buf,
3997 				    unsigned int buflen, int write_data)
3998 {
3999 	unsigned long flags;
4000 	local_irq_save(flags);
4001 	ata_pio_data_xfer(adev, buf, buflen, write_data);
4002 	local_irq_restore(flags);
4003 }
4004 
4005 
4006 /**
4007  *	ata_pio_sector - Transfer ATA_SECT_SIZE (512 bytes) of data.
4008  *	@qc: Command on going
4009  *
4010  *	Transfer ATA_SECT_SIZE of data from/to the ATA device.
4011  *
4012  *	LOCKING:
4013  *	Inherited from caller.
4014  */
4015 
4016 static void ata_pio_sector(struct ata_queued_cmd *qc)
4017 {
4018 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4019 	struct scatterlist *sg = qc->__sg;
4020 	struct ata_port *ap = qc->ap;
4021 	struct page *page;
4022 	unsigned int offset;
4023 	unsigned char *buf;
4024 
4025 	if (qc->cursect == (qc->nsect - 1))
4026 		ap->hsm_task_state = HSM_ST_LAST;
4027 
4028 	page = sg[qc->cursg].page;
4029 	offset = sg[qc->cursg].offset + qc->cursg_ofs * ATA_SECT_SIZE;
4030 
4031 	/* get the current page and offset */
4032 	page = nth_page(page, (offset >> PAGE_SHIFT));
4033 	offset %= PAGE_SIZE;
4034 
4035 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4036 
4037 	if (PageHighMem(page)) {
4038 		unsigned long flags;
4039 
4040 		/* FIXME: use a bounce buffer */
4041 		local_irq_save(flags);
4042 		buf = kmap_atomic(page, KM_IRQ0);
4043 
4044 		/* do the actual data transfer */
4045 		ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
4046 
4047 		kunmap_atomic(buf, KM_IRQ0);
4048 		local_irq_restore(flags);
4049 	} else {
4050 		buf = page_address(page);
4051 		ap->ops->data_xfer(qc->dev, buf + offset, ATA_SECT_SIZE, do_write);
4052 	}
4053 
4054 	qc->cursect++;
4055 	qc->cursg_ofs++;
4056 
4057 	if ((qc->cursg_ofs * ATA_SECT_SIZE) == (&sg[qc->cursg])->length) {
4058 		qc->cursg++;
4059 		qc->cursg_ofs = 0;
4060 	}
4061 }
4062 
4063 /**
4064  *	ata_pio_sectors - Transfer one or many 512-byte sectors.
4065  *	@qc: Command on going
4066  *
4067  *	Transfer one or many ATA_SECT_SIZE of data from/to the
4068  *	ATA device for the DRQ request.
4069  *
4070  *	LOCKING:
4071  *	Inherited from caller.
4072  */
4073 
4074 static void ata_pio_sectors(struct ata_queued_cmd *qc)
4075 {
4076 	if (is_multi_taskfile(&qc->tf)) {
4077 		/* READ/WRITE MULTIPLE */
4078 		unsigned int nsect;
4079 
4080 		WARN_ON(qc->dev->multi_count == 0);
4081 
4082 		nsect = min(qc->nsect - qc->cursect, qc->dev->multi_count);
4083 		while (nsect--)
4084 			ata_pio_sector(qc);
4085 	} else
4086 		ata_pio_sector(qc);
4087 }
4088 
4089 /**
4090  *	atapi_send_cdb - Write CDB bytes to hardware
4091  *	@ap: Port to which ATAPI device is attached.
4092  *	@qc: Taskfile currently active
4093  *
4094  *	When device has indicated its readiness to accept
4095  *	a CDB, this function is called.  Send the CDB.
4096  *
4097  *	LOCKING:
4098  *	caller.
4099  */
4100 
4101 static void atapi_send_cdb(struct ata_port *ap, struct ata_queued_cmd *qc)
4102 {
4103 	/* send SCSI cdb */
4104 	DPRINTK("send cdb\n");
4105 	WARN_ON(qc->dev->cdb_len < 12);
4106 
4107 	ap->ops->data_xfer(qc->dev, qc->cdb, qc->dev->cdb_len, 1);
4108 	ata_altstatus(ap); /* flush */
4109 
4110 	switch (qc->tf.protocol) {
4111 	case ATA_PROT_ATAPI:
4112 		ap->hsm_task_state = HSM_ST;
4113 		break;
4114 	case ATA_PROT_ATAPI_NODATA:
4115 		ap->hsm_task_state = HSM_ST_LAST;
4116 		break;
4117 	case ATA_PROT_ATAPI_DMA:
4118 		ap->hsm_task_state = HSM_ST_LAST;
4119 		/* initiate bmdma */
4120 		ap->ops->bmdma_start(qc);
4121 		break;
4122 	}
4123 }
4124 
4125 /**
4126  *	__atapi_pio_bytes - Transfer data from/to the ATAPI device.
4127  *	@qc: Command on going
4128  *	@bytes: number of bytes
4129  *
4130  *	Transfer Transfer data from/to the ATAPI device.
4131  *
4132  *	LOCKING:
4133  *	Inherited from caller.
4134  *
4135  */
4136 
4137 static void __atapi_pio_bytes(struct ata_queued_cmd *qc, unsigned int bytes)
4138 {
4139 	int do_write = (qc->tf.flags & ATA_TFLAG_WRITE);
4140 	struct scatterlist *sg = qc->__sg;
4141 	struct ata_port *ap = qc->ap;
4142 	struct page *page;
4143 	unsigned char *buf;
4144 	unsigned int offset, count;
4145 
4146 	if (qc->curbytes + bytes >= qc->nbytes)
4147 		ap->hsm_task_state = HSM_ST_LAST;
4148 
4149 next_sg:
4150 	if (unlikely(qc->cursg >= qc->n_elem)) {
4151 		/*
4152 		 * The end of qc->sg is reached and the device expects
4153 		 * more data to transfer. In order not to overrun qc->sg
4154 		 * and fulfill length specified in the byte count register,
4155 		 *    - for read case, discard trailing data from the device
4156 		 *    - for write case, padding zero data to the device
4157 		 */
4158 		u16 pad_buf[1] = { 0 };
4159 		unsigned int words = bytes >> 1;
4160 		unsigned int i;
4161 
4162 		if (words) /* warning if bytes > 1 */
4163 			ata_dev_printk(qc->dev, KERN_WARNING,
4164 				       "%u bytes trailing data\n", bytes);
4165 
4166 		for (i = 0; i < words; i++)
4167 			ap->ops->data_xfer(qc->dev, (unsigned char*)pad_buf, 2, do_write);
4168 
4169 		ap->hsm_task_state = HSM_ST_LAST;
4170 		return;
4171 	}
4172 
4173 	sg = &qc->__sg[qc->cursg];
4174 
4175 	page = sg->page;
4176 	offset = sg->offset + qc->cursg_ofs;
4177 
4178 	/* get the current page and offset */
4179 	page = nth_page(page, (offset >> PAGE_SHIFT));
4180 	offset %= PAGE_SIZE;
4181 
4182 	/* don't overrun current sg */
4183 	count = min(sg->length - qc->cursg_ofs, bytes);
4184 
4185 	/* don't cross page boundaries */
4186 	count = min(count, (unsigned int)PAGE_SIZE - offset);
4187 
4188 	DPRINTK("data %s\n", qc->tf.flags & ATA_TFLAG_WRITE ? "write" : "read");
4189 
4190 	if (PageHighMem(page)) {
4191 		unsigned long flags;
4192 
4193 		/* FIXME: use bounce buffer */
4194 		local_irq_save(flags);
4195 		buf = kmap_atomic(page, KM_IRQ0);
4196 
4197 		/* do the actual data transfer */
4198 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
4199 
4200 		kunmap_atomic(buf, KM_IRQ0);
4201 		local_irq_restore(flags);
4202 	} else {
4203 		buf = page_address(page);
4204 		ap->ops->data_xfer(qc->dev,  buf + offset, count, do_write);
4205 	}
4206 
4207 	bytes -= count;
4208 	qc->curbytes += count;
4209 	qc->cursg_ofs += count;
4210 
4211 	if (qc->cursg_ofs == sg->length) {
4212 		qc->cursg++;
4213 		qc->cursg_ofs = 0;
4214 	}
4215 
4216 	if (bytes)
4217 		goto next_sg;
4218 }
4219 
4220 /**
4221  *	atapi_pio_bytes - Transfer data from/to the ATAPI device.
4222  *	@qc: Command on going
4223  *
4224  *	Transfer Transfer data from/to the ATAPI device.
4225  *
4226  *	LOCKING:
4227  *	Inherited from caller.
4228  */
4229 
4230 static void atapi_pio_bytes(struct ata_queued_cmd *qc)
4231 {
4232 	struct ata_port *ap = qc->ap;
4233 	struct ata_device *dev = qc->dev;
4234 	unsigned int ireason, bc_lo, bc_hi, bytes;
4235 	int i_write, do_write = (qc->tf.flags & ATA_TFLAG_WRITE) ? 1 : 0;
4236 
4237 	/* Abuse qc->result_tf for temp storage of intermediate TF
4238 	 * here to save some kernel stack usage.
4239 	 * For normal completion, qc->result_tf is not relevant. For
4240 	 * error, qc->result_tf is later overwritten by ata_qc_complete().
4241 	 * So, the correctness of qc->result_tf is not affected.
4242 	 */
4243 	ap->ops->tf_read(ap, &qc->result_tf);
4244 	ireason = qc->result_tf.nsect;
4245 	bc_lo = qc->result_tf.lbam;
4246 	bc_hi = qc->result_tf.lbah;
4247 	bytes = (bc_hi << 8) | bc_lo;
4248 
4249 	/* shall be cleared to zero, indicating xfer of data */
4250 	if (ireason & (1 << 0))
4251 		goto err_out;
4252 
4253 	/* make sure transfer direction matches expected */
4254 	i_write = ((ireason & (1 << 1)) == 0) ? 1 : 0;
4255 	if (do_write != i_write)
4256 		goto err_out;
4257 
4258 	VPRINTK("ata%u: xfering %d bytes\n", ap->id, bytes);
4259 
4260 	__atapi_pio_bytes(qc, bytes);
4261 
4262 	return;
4263 
4264 err_out:
4265 	ata_dev_printk(dev, KERN_INFO, "ATAPI check failed\n");
4266 	qc->err_mask |= AC_ERR_HSM;
4267 	ap->hsm_task_state = HSM_ST_ERR;
4268 }
4269 
4270 /**
4271  *	ata_hsm_ok_in_wq - Check if the qc can be handled in the workqueue.
4272  *	@ap: the target ata_port
4273  *	@qc: qc on going
4274  *
4275  *	RETURNS:
4276  *	1 if ok in workqueue, 0 otherwise.
4277  */
4278 
4279 static inline int ata_hsm_ok_in_wq(struct ata_port *ap, struct ata_queued_cmd *qc)
4280 {
4281 	if (qc->tf.flags & ATA_TFLAG_POLLING)
4282 		return 1;
4283 
4284 	if (ap->hsm_task_state == HSM_ST_FIRST) {
4285 		if (qc->tf.protocol == ATA_PROT_PIO &&
4286 		    (qc->tf.flags & ATA_TFLAG_WRITE))
4287 		    return 1;
4288 
4289 		if (is_atapi_taskfile(&qc->tf) &&
4290 		    !(qc->dev->flags & ATA_DFLAG_CDB_INTR))
4291 			return 1;
4292 	}
4293 
4294 	return 0;
4295 }
4296 
4297 /**
4298  *	ata_hsm_qc_complete - finish a qc running on standard HSM
4299  *	@qc: Command to complete
4300  *	@in_wq: 1 if called from workqueue, 0 otherwise
4301  *
4302  *	Finish @qc which is running on standard HSM.
4303  *
4304  *	LOCKING:
4305  *	If @in_wq is zero, spin_lock_irqsave(host lock).
4306  *	Otherwise, none on entry and grabs host lock.
4307  */
4308 static void ata_hsm_qc_complete(struct ata_queued_cmd *qc, int in_wq)
4309 {
4310 	struct ata_port *ap = qc->ap;
4311 	unsigned long flags;
4312 
4313 	if (ap->ops->error_handler) {
4314 		if (in_wq) {
4315 			spin_lock_irqsave(ap->lock, flags);
4316 
4317 			/* EH might have kicked in while host lock is
4318 			 * released.
4319 			 */
4320 			qc = ata_qc_from_tag(ap, qc->tag);
4321 			if (qc) {
4322 				if (likely(!(qc->err_mask & AC_ERR_HSM))) {
4323 					ata_irq_on(ap);
4324 					ata_qc_complete(qc);
4325 				} else
4326 					ata_port_freeze(ap);
4327 			}
4328 
4329 			spin_unlock_irqrestore(ap->lock, flags);
4330 		} else {
4331 			if (likely(!(qc->err_mask & AC_ERR_HSM)))
4332 				ata_qc_complete(qc);
4333 			else
4334 				ata_port_freeze(ap);
4335 		}
4336 	} else {
4337 		if (in_wq) {
4338 			spin_lock_irqsave(ap->lock, flags);
4339 			ata_irq_on(ap);
4340 			ata_qc_complete(qc);
4341 			spin_unlock_irqrestore(ap->lock, flags);
4342 		} else
4343 			ata_qc_complete(qc);
4344 	}
4345 
4346 	ata_altstatus(ap); /* flush */
4347 }
4348 
4349 /**
4350  *	ata_hsm_move - move the HSM to the next state.
4351  *	@ap: the target ata_port
4352  *	@qc: qc on going
4353  *	@status: current device status
4354  *	@in_wq: 1 if called from workqueue, 0 otherwise
4355  *
4356  *	RETURNS:
4357  *	1 when poll next status needed, 0 otherwise.
4358  */
4359 int ata_hsm_move(struct ata_port *ap, struct ata_queued_cmd *qc,
4360 		 u8 status, int in_wq)
4361 {
4362 	unsigned long flags = 0;
4363 	int poll_next;
4364 
4365 	WARN_ON((qc->flags & ATA_QCFLAG_ACTIVE) == 0);
4366 
4367 	/* Make sure ata_qc_issue_prot() does not throw things
4368 	 * like DMA polling into the workqueue. Notice that
4369 	 * in_wq is not equivalent to (qc->tf.flags & ATA_TFLAG_POLLING).
4370 	 */
4371 	WARN_ON(in_wq != ata_hsm_ok_in_wq(ap, qc));
4372 
4373 fsm_start:
4374 	DPRINTK("ata%u: protocol %d task_state %d (dev_stat 0x%X)\n",
4375 		ap->id, qc->tf.protocol, ap->hsm_task_state, status);
4376 
4377 	switch (ap->hsm_task_state) {
4378 	case HSM_ST_FIRST:
4379 		/* Send first data block or PACKET CDB */
4380 
4381 		/* If polling, we will stay in the work queue after
4382 		 * sending the data. Otherwise, interrupt handler
4383 		 * takes over after sending the data.
4384 		 */
4385 		poll_next = (qc->tf.flags & ATA_TFLAG_POLLING);
4386 
4387 		/* check device status */
4388 		if (unlikely((status & ATA_DRQ) == 0)) {
4389 			/* handle BSY=0, DRQ=0 as error */
4390 			if (likely(status & (ATA_ERR | ATA_DF)))
4391 				/* device stops HSM for abort/error */
4392 				qc->err_mask |= AC_ERR_DEV;
4393 			else
4394 				/* HSM violation. Let EH handle this */
4395 				qc->err_mask |= AC_ERR_HSM;
4396 
4397 			ap->hsm_task_state = HSM_ST_ERR;
4398 			goto fsm_start;
4399 		}
4400 
4401 		/* Device should not ask for data transfer (DRQ=1)
4402 		 * when it finds something wrong.
4403 		 * We ignore DRQ here and stop the HSM by
4404 		 * changing hsm_task_state to HSM_ST_ERR and
4405 		 * let the EH abort the command or reset the device.
4406 		 */
4407 		if (unlikely(status & (ATA_ERR | ATA_DF))) {
4408 			printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
4409 			       ap->id, status);
4410 			qc->err_mask |= AC_ERR_HSM;
4411 			ap->hsm_task_state = HSM_ST_ERR;
4412 			goto fsm_start;
4413 		}
4414 
4415 		/* Send the CDB (atapi) or the first data block (ata pio out).
4416 		 * During the state transition, interrupt handler shouldn't
4417 		 * be invoked before the data transfer is complete and
4418 		 * hsm_task_state is changed. Hence, the following locking.
4419 		 */
4420 		if (in_wq)
4421 			spin_lock_irqsave(ap->lock, flags);
4422 
4423 		if (qc->tf.protocol == ATA_PROT_PIO) {
4424 			/* PIO data out protocol.
4425 			 * send first data block.
4426 			 */
4427 
4428 			/* ata_pio_sectors() might change the state
4429 			 * to HSM_ST_LAST. so, the state is changed here
4430 			 * before ata_pio_sectors().
4431 			 */
4432 			ap->hsm_task_state = HSM_ST;
4433 			ata_pio_sectors(qc);
4434 			ata_altstatus(ap); /* flush */
4435 		} else
4436 			/* send CDB */
4437 			atapi_send_cdb(ap, qc);
4438 
4439 		if (in_wq)
4440 			spin_unlock_irqrestore(ap->lock, flags);
4441 
4442 		/* if polling, ata_pio_task() handles the rest.
4443 		 * otherwise, interrupt handler takes over from here.
4444 		 */
4445 		break;
4446 
4447 	case HSM_ST:
4448 		/* complete command or read/write the data register */
4449 		if (qc->tf.protocol == ATA_PROT_ATAPI) {
4450 			/* ATAPI PIO protocol */
4451 			if ((status & ATA_DRQ) == 0) {
4452 				/* No more data to transfer or device error.
4453 				 * Device error will be tagged in HSM_ST_LAST.
4454 				 */
4455 				ap->hsm_task_state = HSM_ST_LAST;
4456 				goto fsm_start;
4457 			}
4458 
4459 			/* Device should not ask for data transfer (DRQ=1)
4460 			 * when it finds something wrong.
4461 			 * We ignore DRQ here and stop the HSM by
4462 			 * changing hsm_task_state to HSM_ST_ERR and
4463 			 * let the EH abort the command or reset the device.
4464 			 */
4465 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
4466 				printk(KERN_WARNING "ata%d: DRQ=1 with device error, dev_stat 0x%X\n",
4467 				       ap->id, status);
4468 				qc->err_mask |= AC_ERR_HSM;
4469 				ap->hsm_task_state = HSM_ST_ERR;
4470 				goto fsm_start;
4471 			}
4472 
4473 			atapi_pio_bytes(qc);
4474 
4475 			if (unlikely(ap->hsm_task_state == HSM_ST_ERR))
4476 				/* bad ireason reported by device */
4477 				goto fsm_start;
4478 
4479 		} else {
4480 			/* ATA PIO protocol */
4481 			if (unlikely((status & ATA_DRQ) == 0)) {
4482 				/* handle BSY=0, DRQ=0 as error */
4483 				if (likely(status & (ATA_ERR | ATA_DF)))
4484 					/* device stops HSM for abort/error */
4485 					qc->err_mask |= AC_ERR_DEV;
4486 				else
4487 					/* HSM violation. Let EH handle this.
4488 					 * Phantom devices also trigger this
4489 					 * condition.  Mark hint.
4490 					 */
4491 					qc->err_mask |= AC_ERR_HSM |
4492 							AC_ERR_NODEV_HINT;
4493 
4494 				ap->hsm_task_state = HSM_ST_ERR;
4495 				goto fsm_start;
4496 			}
4497 
4498 			/* For PIO reads, some devices may ask for
4499 			 * data transfer (DRQ=1) alone with ERR=1.
4500 			 * We respect DRQ here and transfer one
4501 			 * block of junk data before changing the
4502 			 * hsm_task_state to HSM_ST_ERR.
4503 			 *
4504 			 * For PIO writes, ERR=1 DRQ=1 doesn't make
4505 			 * sense since the data block has been
4506 			 * transferred to the device.
4507 			 */
4508 			if (unlikely(status & (ATA_ERR | ATA_DF))) {
4509 				/* data might be corrputed */
4510 				qc->err_mask |= AC_ERR_DEV;
4511 
4512 				if (!(qc->tf.flags & ATA_TFLAG_WRITE)) {
4513 					ata_pio_sectors(qc);
4514 					ata_altstatus(ap);
4515 					status = ata_wait_idle(ap);
4516 				}
4517 
4518 				if (status & (ATA_BUSY | ATA_DRQ))
4519 					qc->err_mask |= AC_ERR_HSM;
4520 
4521 				/* ata_pio_sectors() might change the
4522 				 * state to HSM_ST_LAST. so, the state
4523 				 * is changed after ata_pio_sectors().
4524 				 */
4525 				ap->hsm_task_state = HSM_ST_ERR;
4526 				goto fsm_start;
4527 			}
4528 
4529 			ata_pio_sectors(qc);
4530 
4531 			if (ap->hsm_task_state == HSM_ST_LAST &&
4532 			    (!(qc->tf.flags & ATA_TFLAG_WRITE))) {
4533 				/* all data read */
4534 				ata_altstatus(ap);
4535 				status = ata_wait_idle(ap);
4536 				goto fsm_start;
4537 			}
4538 		}
4539 
4540 		ata_altstatus(ap); /* flush */
4541 		poll_next = 1;
4542 		break;
4543 
4544 	case HSM_ST_LAST:
4545 		if (unlikely(!ata_ok(status))) {
4546 			qc->err_mask |= __ac_err_mask(status);
4547 			ap->hsm_task_state = HSM_ST_ERR;
4548 			goto fsm_start;
4549 		}
4550 
4551 		/* no more data to transfer */
4552 		DPRINTK("ata%u: dev %u command complete, drv_stat 0x%x\n",
4553 			ap->id, qc->dev->devno, status);
4554 
4555 		WARN_ON(qc->err_mask);
4556 
4557 		ap->hsm_task_state = HSM_ST_IDLE;
4558 
4559 		/* complete taskfile transaction */
4560 		ata_hsm_qc_complete(qc, in_wq);
4561 
4562 		poll_next = 0;
4563 		break;
4564 
4565 	case HSM_ST_ERR:
4566 		/* make sure qc->err_mask is available to
4567 		 * know what's wrong and recover
4568 		 */
4569 		WARN_ON(qc->err_mask == 0);
4570 
4571 		ap->hsm_task_state = HSM_ST_IDLE;
4572 
4573 		/* complete taskfile transaction */
4574 		ata_hsm_qc_complete(qc, in_wq);
4575 
4576 		poll_next = 0;
4577 		break;
4578 	default:
4579 		poll_next = 0;
4580 		BUG();
4581 	}
4582 
4583 	return poll_next;
4584 }
4585 
4586 static void ata_pio_task(struct work_struct *work)
4587 {
4588 	struct ata_port *ap =
4589 		container_of(work, struct ata_port, port_task.work);
4590 	struct ata_queued_cmd *qc = ap->port_task_data;
4591 	u8 status;
4592 	int poll_next;
4593 
4594 fsm_start:
4595 	WARN_ON(ap->hsm_task_state == HSM_ST_IDLE);
4596 
4597 	/*
4598 	 * This is purely heuristic.  This is a fast path.
4599 	 * Sometimes when we enter, BSY will be cleared in
4600 	 * a chk-status or two.  If not, the drive is probably seeking
4601 	 * or something.  Snooze for a couple msecs, then
4602 	 * chk-status again.  If still busy, queue delayed work.
4603 	 */
4604 	status = ata_busy_wait(ap, ATA_BUSY, 5);
4605 	if (status & ATA_BUSY) {
4606 		msleep(2);
4607 		status = ata_busy_wait(ap, ATA_BUSY, 10);
4608 		if (status & ATA_BUSY) {
4609 			ata_port_queue_task(ap, ata_pio_task, qc, ATA_SHORT_PAUSE);
4610 			return;
4611 		}
4612 	}
4613 
4614 	/* move the HSM */
4615 	poll_next = ata_hsm_move(ap, qc, status, 1);
4616 
4617 	/* another command or interrupt handler
4618 	 * may be running at this point.
4619 	 */
4620 	if (poll_next)
4621 		goto fsm_start;
4622 }
4623 
4624 /**
4625  *	ata_qc_new - Request an available ATA command, for queueing
4626  *	@ap: Port associated with device @dev
4627  *	@dev: Device from whom we request an available command structure
4628  *
4629  *	LOCKING:
4630  *	None.
4631  */
4632 
4633 static struct ata_queued_cmd *ata_qc_new(struct ata_port *ap)
4634 {
4635 	struct ata_queued_cmd *qc = NULL;
4636 	unsigned int i;
4637 
4638 	/* no command while frozen */
4639 	if (unlikely(ap->pflags & ATA_PFLAG_FROZEN))
4640 		return NULL;
4641 
4642 	/* the last tag is reserved for internal command. */
4643 	for (i = 0; i < ATA_MAX_QUEUE - 1; i++)
4644 		if (!test_and_set_bit(i, &ap->qc_allocated)) {
4645 			qc = __ata_qc_from_tag(ap, i);
4646 			break;
4647 		}
4648 
4649 	if (qc)
4650 		qc->tag = i;
4651 
4652 	return qc;
4653 }
4654 
4655 /**
4656  *	ata_qc_new_init - Request an available ATA command, and initialize it
4657  *	@dev: Device from whom we request an available command structure
4658  *
4659  *	LOCKING:
4660  *	None.
4661  */
4662 
4663 struct ata_queued_cmd *ata_qc_new_init(struct ata_device *dev)
4664 {
4665 	struct ata_port *ap = dev->ap;
4666 	struct ata_queued_cmd *qc;
4667 
4668 	qc = ata_qc_new(ap);
4669 	if (qc) {
4670 		qc->scsicmd = NULL;
4671 		qc->ap = ap;
4672 		qc->dev = dev;
4673 
4674 		ata_qc_reinit(qc);
4675 	}
4676 
4677 	return qc;
4678 }
4679 
4680 /**
4681  *	ata_qc_free - free unused ata_queued_cmd
4682  *	@qc: Command to complete
4683  *
4684  *	Designed to free unused ata_queued_cmd object
4685  *	in case something prevents using it.
4686  *
4687  *	LOCKING:
4688  *	spin_lock_irqsave(host lock)
4689  */
4690 void ata_qc_free(struct ata_queued_cmd *qc)
4691 {
4692 	struct ata_port *ap = qc->ap;
4693 	unsigned int tag;
4694 
4695 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4696 
4697 	qc->flags = 0;
4698 	tag = qc->tag;
4699 	if (likely(ata_tag_valid(tag))) {
4700 		qc->tag = ATA_TAG_POISON;
4701 		clear_bit(tag, &ap->qc_allocated);
4702 	}
4703 }
4704 
4705 void __ata_qc_complete(struct ata_queued_cmd *qc)
4706 {
4707 	struct ata_port *ap = qc->ap;
4708 
4709 	WARN_ON(qc == NULL);	/* ata_qc_from_tag _might_ return NULL */
4710 	WARN_ON(!(qc->flags & ATA_QCFLAG_ACTIVE));
4711 
4712 	if (likely(qc->flags & ATA_QCFLAG_DMAMAP))
4713 		ata_sg_clean(qc);
4714 
4715 	/* command should be marked inactive atomically with qc completion */
4716 	if (qc->tf.protocol == ATA_PROT_NCQ)
4717 		ap->sactive &= ~(1 << qc->tag);
4718 	else
4719 		ap->active_tag = ATA_TAG_POISON;
4720 
4721 	/* atapi: mark qc as inactive to prevent the interrupt handler
4722 	 * from completing the command twice later, before the error handler
4723 	 * is called. (when rc != 0 and atapi request sense is needed)
4724 	 */
4725 	qc->flags &= ~ATA_QCFLAG_ACTIVE;
4726 	ap->qc_active &= ~(1 << qc->tag);
4727 
4728 	/* call completion callback */
4729 	qc->complete_fn(qc);
4730 }
4731 
4732 static void fill_result_tf(struct ata_queued_cmd *qc)
4733 {
4734 	struct ata_port *ap = qc->ap;
4735 
4736 	ap->ops->tf_read(ap, &qc->result_tf);
4737 	qc->result_tf.flags = qc->tf.flags;
4738 }
4739 
4740 /**
4741  *	ata_qc_complete - Complete an active ATA command
4742  *	@qc: Command to complete
4743  *	@err_mask: ATA Status register contents
4744  *
4745  *	Indicate to the mid and upper layers that an ATA
4746  *	command has completed, with either an ok or not-ok status.
4747  *
4748  *	LOCKING:
4749  *	spin_lock_irqsave(host lock)
4750  */
4751 void ata_qc_complete(struct ata_queued_cmd *qc)
4752 {
4753 	struct ata_port *ap = qc->ap;
4754 
4755 	/* XXX: New EH and old EH use different mechanisms to
4756 	 * synchronize EH with regular execution path.
4757 	 *
4758 	 * In new EH, a failed qc is marked with ATA_QCFLAG_FAILED.
4759 	 * Normal execution path is responsible for not accessing a
4760 	 * failed qc.  libata core enforces the rule by returning NULL
4761 	 * from ata_qc_from_tag() for failed qcs.
4762 	 *
4763 	 * Old EH depends on ata_qc_complete() nullifying completion
4764 	 * requests if ATA_QCFLAG_EH_SCHEDULED is set.  Old EH does
4765 	 * not synchronize with interrupt handler.  Only PIO task is
4766 	 * taken care of.
4767 	 */
4768 	if (ap->ops->error_handler) {
4769 		WARN_ON(ap->pflags & ATA_PFLAG_FROZEN);
4770 
4771 		if (unlikely(qc->err_mask))
4772 			qc->flags |= ATA_QCFLAG_FAILED;
4773 
4774 		if (unlikely(qc->flags & ATA_QCFLAG_FAILED)) {
4775 			if (!ata_tag_internal(qc->tag)) {
4776 				/* always fill result TF for failed qc */
4777 				fill_result_tf(qc);
4778 				ata_qc_schedule_eh(qc);
4779 				return;
4780 			}
4781 		}
4782 
4783 		/* read result TF if requested */
4784 		if (qc->flags & ATA_QCFLAG_RESULT_TF)
4785 			fill_result_tf(qc);
4786 
4787 		__ata_qc_complete(qc);
4788 	} else {
4789 		if (qc->flags & ATA_QCFLAG_EH_SCHEDULED)
4790 			return;
4791 
4792 		/* read result TF if failed or requested */
4793 		if (qc->err_mask || qc->flags & ATA_QCFLAG_RESULT_TF)
4794 			fill_result_tf(qc);
4795 
4796 		__ata_qc_complete(qc);
4797 	}
4798 }
4799 
4800 /**
4801  *	ata_qc_complete_multiple - Complete multiple qcs successfully
4802  *	@ap: port in question
4803  *	@qc_active: new qc_active mask
4804  *	@finish_qc: LLDD callback invoked before completing a qc
4805  *
4806  *	Complete in-flight commands.  This functions is meant to be
4807  *	called from low-level driver's interrupt routine to complete
4808  *	requests normally.  ap->qc_active and @qc_active is compared
4809  *	and commands are completed accordingly.
4810  *
4811  *	LOCKING:
4812  *	spin_lock_irqsave(host lock)
4813  *
4814  *	RETURNS:
4815  *	Number of completed commands on success, -errno otherwise.
4816  */
4817 int ata_qc_complete_multiple(struct ata_port *ap, u32 qc_active,
4818 			     void (*finish_qc)(struct ata_queued_cmd *))
4819 {
4820 	int nr_done = 0;
4821 	u32 done_mask;
4822 	int i;
4823 
4824 	done_mask = ap->qc_active ^ qc_active;
4825 
4826 	if (unlikely(done_mask & qc_active)) {
4827 		ata_port_printk(ap, KERN_ERR, "illegal qc_active transition "
4828 				"(%08x->%08x)\n", ap->qc_active, qc_active);
4829 		return -EINVAL;
4830 	}
4831 
4832 	for (i = 0; i < ATA_MAX_QUEUE; i++) {
4833 		struct ata_queued_cmd *qc;
4834 
4835 		if (!(done_mask & (1 << i)))
4836 			continue;
4837 
4838 		if ((qc = ata_qc_from_tag(ap, i))) {
4839 			if (finish_qc)
4840 				finish_qc(qc);
4841 			ata_qc_complete(qc);
4842 			nr_done++;
4843 		}
4844 	}
4845 
4846 	return nr_done;
4847 }
4848 
4849 static inline int ata_should_dma_map(struct ata_queued_cmd *qc)
4850 {
4851 	struct ata_port *ap = qc->ap;
4852 
4853 	switch (qc->tf.protocol) {
4854 	case ATA_PROT_NCQ:
4855 	case ATA_PROT_DMA:
4856 	case ATA_PROT_ATAPI_DMA:
4857 		return 1;
4858 
4859 	case ATA_PROT_ATAPI:
4860 	case ATA_PROT_PIO:
4861 		if (ap->flags & ATA_FLAG_PIO_DMA)
4862 			return 1;
4863 
4864 		/* fall through */
4865 
4866 	default:
4867 		return 0;
4868 	}
4869 
4870 	/* never reached */
4871 }
4872 
4873 /**
4874  *	ata_qc_issue - issue taskfile to device
4875  *	@qc: command to issue to device
4876  *
4877  *	Prepare an ATA command to submission to device.
4878  *	This includes mapping the data into a DMA-able
4879  *	area, filling in the S/G table, and finally
4880  *	writing the taskfile to hardware, starting the command.
4881  *
4882  *	LOCKING:
4883  *	spin_lock_irqsave(host lock)
4884  */
4885 void ata_qc_issue(struct ata_queued_cmd *qc)
4886 {
4887 	struct ata_port *ap = qc->ap;
4888 
4889 	/* Make sure only one non-NCQ command is outstanding.  The
4890 	 * check is skipped for old EH because it reuses active qc to
4891 	 * request ATAPI sense.
4892 	 */
4893 	WARN_ON(ap->ops->error_handler && ata_tag_valid(ap->active_tag));
4894 
4895 	if (qc->tf.protocol == ATA_PROT_NCQ) {
4896 		WARN_ON(ap->sactive & (1 << qc->tag));
4897 		ap->sactive |= 1 << qc->tag;
4898 	} else {
4899 		WARN_ON(ap->sactive);
4900 		ap->active_tag = qc->tag;
4901 	}
4902 
4903 	qc->flags |= ATA_QCFLAG_ACTIVE;
4904 	ap->qc_active |= 1 << qc->tag;
4905 
4906 	if (ata_should_dma_map(qc)) {
4907 		if (qc->flags & ATA_QCFLAG_SG) {
4908 			if (ata_sg_setup(qc))
4909 				goto sg_err;
4910 		} else if (qc->flags & ATA_QCFLAG_SINGLE) {
4911 			if (ata_sg_setup_one(qc))
4912 				goto sg_err;
4913 		}
4914 	} else {
4915 		qc->flags &= ~ATA_QCFLAG_DMAMAP;
4916 	}
4917 
4918 	ap->ops->qc_prep(qc);
4919 
4920 	qc->err_mask |= ap->ops->qc_issue(qc);
4921 	if (unlikely(qc->err_mask))
4922 		goto err;
4923 	return;
4924 
4925 sg_err:
4926 	qc->flags &= ~ATA_QCFLAG_DMAMAP;
4927 	qc->err_mask |= AC_ERR_SYSTEM;
4928 err:
4929 	ata_qc_complete(qc);
4930 }
4931 
4932 /**
4933  *	ata_qc_issue_prot - issue taskfile to device in proto-dependent manner
4934  *	@qc: command to issue to device
4935  *
4936  *	Using various libata functions and hooks, this function
4937  *	starts an ATA command.  ATA commands are grouped into
4938  *	classes called "protocols", and issuing each type of protocol
4939  *	is slightly different.
4940  *
4941  *	May be used as the qc_issue() entry in ata_port_operations.
4942  *
4943  *	LOCKING:
4944  *	spin_lock_irqsave(host lock)
4945  *
4946  *	RETURNS:
4947  *	Zero on success, AC_ERR_* mask on failure
4948  */
4949 
4950 unsigned int ata_qc_issue_prot(struct ata_queued_cmd *qc)
4951 {
4952 	struct ata_port *ap = qc->ap;
4953 
4954 	/* Use polling pio if the LLD doesn't handle
4955 	 * interrupt driven pio and atapi CDB interrupt.
4956 	 */
4957 	if (ap->flags & ATA_FLAG_PIO_POLLING) {
4958 		switch (qc->tf.protocol) {
4959 		case ATA_PROT_PIO:
4960 		case ATA_PROT_NODATA:
4961 		case ATA_PROT_ATAPI:
4962 		case ATA_PROT_ATAPI_NODATA:
4963 			qc->tf.flags |= ATA_TFLAG_POLLING;
4964 			break;
4965 		case ATA_PROT_ATAPI_DMA:
4966 			if (qc->dev->flags & ATA_DFLAG_CDB_INTR)
4967 				/* see ata_dma_blacklisted() */
4968 				BUG();
4969 			break;
4970 		default:
4971 			break;
4972 		}
4973 	}
4974 
4975 	/* Some controllers show flaky interrupt behavior after
4976 	 * setting xfer mode.  Use polling instead.
4977 	 */
4978 	if (unlikely(qc->tf.command == ATA_CMD_SET_FEATURES &&
4979 		     qc->tf.feature == SETFEATURES_XFER) &&
4980 	    (ap->flags & ATA_FLAG_SETXFER_POLLING))
4981 		qc->tf.flags |= ATA_TFLAG_POLLING;
4982 
4983 	/* select the device */
4984 	ata_dev_select(ap, qc->dev->devno, 1, 0);
4985 
4986 	/* start the command */
4987 	switch (qc->tf.protocol) {
4988 	case ATA_PROT_NODATA:
4989 		if (qc->tf.flags & ATA_TFLAG_POLLING)
4990 			ata_qc_set_polling(qc);
4991 
4992 		ata_tf_to_host(ap, &qc->tf);
4993 		ap->hsm_task_state = HSM_ST_LAST;
4994 
4995 		if (qc->tf.flags & ATA_TFLAG_POLLING)
4996 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
4997 
4998 		break;
4999 
5000 	case ATA_PROT_DMA:
5001 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5002 
5003 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5004 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5005 		ap->ops->bmdma_start(qc);	    /* initiate bmdma */
5006 		ap->hsm_task_state = HSM_ST_LAST;
5007 		break;
5008 
5009 	case ATA_PROT_PIO:
5010 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5011 			ata_qc_set_polling(qc);
5012 
5013 		ata_tf_to_host(ap, &qc->tf);
5014 
5015 		if (qc->tf.flags & ATA_TFLAG_WRITE) {
5016 			/* PIO data out protocol */
5017 			ap->hsm_task_state = HSM_ST_FIRST;
5018 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5019 
5020 			/* always send first data block using
5021 			 * the ata_pio_task() codepath.
5022 			 */
5023 		} else {
5024 			/* PIO data in protocol */
5025 			ap->hsm_task_state = HSM_ST;
5026 
5027 			if (qc->tf.flags & ATA_TFLAG_POLLING)
5028 				ata_port_queue_task(ap, ata_pio_task, qc, 0);
5029 
5030 			/* if polling, ata_pio_task() handles the rest.
5031 			 * otherwise, interrupt handler takes over from here.
5032 			 */
5033 		}
5034 
5035 		break;
5036 
5037 	case ATA_PROT_ATAPI:
5038 	case ATA_PROT_ATAPI_NODATA:
5039 		if (qc->tf.flags & ATA_TFLAG_POLLING)
5040 			ata_qc_set_polling(qc);
5041 
5042 		ata_tf_to_host(ap, &qc->tf);
5043 
5044 		ap->hsm_task_state = HSM_ST_FIRST;
5045 
5046 		/* send cdb by polling if no cdb interrupt */
5047 		if ((!(qc->dev->flags & ATA_DFLAG_CDB_INTR)) ||
5048 		    (qc->tf.flags & ATA_TFLAG_POLLING))
5049 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5050 		break;
5051 
5052 	case ATA_PROT_ATAPI_DMA:
5053 		WARN_ON(qc->tf.flags & ATA_TFLAG_POLLING);
5054 
5055 		ap->ops->tf_load(ap, &qc->tf);	 /* load tf registers */
5056 		ap->ops->bmdma_setup(qc);	    /* set up bmdma */
5057 		ap->hsm_task_state = HSM_ST_FIRST;
5058 
5059 		/* send cdb by polling if no cdb interrupt */
5060 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5061 			ata_port_queue_task(ap, ata_pio_task, qc, 0);
5062 		break;
5063 
5064 	default:
5065 		WARN_ON(1);
5066 		return AC_ERR_SYSTEM;
5067 	}
5068 
5069 	return 0;
5070 }
5071 
5072 /**
5073  *	ata_host_intr - Handle host interrupt for given (port, task)
5074  *	@ap: Port on which interrupt arrived (possibly...)
5075  *	@qc: Taskfile currently active in engine
5076  *
5077  *	Handle host interrupt for given queued command.  Currently,
5078  *	only DMA interrupts are handled.  All other commands are
5079  *	handled via polling with interrupts disabled (nIEN bit).
5080  *
5081  *	LOCKING:
5082  *	spin_lock_irqsave(host lock)
5083  *
5084  *	RETURNS:
5085  *	One if interrupt was handled, zero if not (shared irq).
5086  */
5087 
5088 inline unsigned int ata_host_intr (struct ata_port *ap,
5089 				   struct ata_queued_cmd *qc)
5090 {
5091 	struct ata_eh_info *ehi = &ap->eh_info;
5092 	u8 status, host_stat = 0;
5093 
5094 	VPRINTK("ata%u: protocol %d task_state %d\n",
5095 		ap->id, qc->tf.protocol, ap->hsm_task_state);
5096 
5097 	/* Check whether we are expecting interrupt in this state */
5098 	switch (ap->hsm_task_state) {
5099 	case HSM_ST_FIRST:
5100 		/* Some pre-ATAPI-4 devices assert INTRQ
5101 		 * at this state when ready to receive CDB.
5102 		 */
5103 
5104 		/* Check the ATA_DFLAG_CDB_INTR flag is enough here.
5105 		 * The flag was turned on only for atapi devices.
5106 		 * No need to check is_atapi_taskfile(&qc->tf) again.
5107 		 */
5108 		if (!(qc->dev->flags & ATA_DFLAG_CDB_INTR))
5109 			goto idle_irq;
5110 		break;
5111 	case HSM_ST_LAST:
5112 		if (qc->tf.protocol == ATA_PROT_DMA ||
5113 		    qc->tf.protocol == ATA_PROT_ATAPI_DMA) {
5114 			/* check status of DMA engine */
5115 			host_stat = ap->ops->bmdma_status(ap);
5116 			VPRINTK("ata%u: host_stat 0x%X\n", ap->id, host_stat);
5117 
5118 			/* if it's not our irq... */
5119 			if (!(host_stat & ATA_DMA_INTR))
5120 				goto idle_irq;
5121 
5122 			/* before we do anything else, clear DMA-Start bit */
5123 			ap->ops->bmdma_stop(qc);
5124 
5125 			if (unlikely(host_stat & ATA_DMA_ERR)) {
5126 				/* error when transfering data to/from memory */
5127 				qc->err_mask |= AC_ERR_HOST_BUS;
5128 				ap->hsm_task_state = HSM_ST_ERR;
5129 			}
5130 		}
5131 		break;
5132 	case HSM_ST:
5133 		break;
5134 	default:
5135 		goto idle_irq;
5136 	}
5137 
5138 	/* check altstatus */
5139 	status = ata_altstatus(ap);
5140 	if (status & ATA_BUSY)
5141 		goto idle_irq;
5142 
5143 	/* check main status, clearing INTRQ */
5144 	status = ata_chk_status(ap);
5145 	if (unlikely(status & ATA_BUSY))
5146 		goto idle_irq;
5147 
5148 	/* ack bmdma irq events */
5149 	ap->ops->irq_clear(ap);
5150 
5151 	ata_hsm_move(ap, qc, status, 0);
5152 
5153 	if (unlikely(qc->err_mask) && (qc->tf.protocol == ATA_PROT_DMA ||
5154 				       qc->tf.protocol == ATA_PROT_ATAPI_DMA))
5155 		ata_ehi_push_desc(ehi, "BMDMA stat 0x%x", host_stat);
5156 
5157 	return 1;	/* irq handled */
5158 
5159 idle_irq:
5160 	ap->stats.idle_irq++;
5161 
5162 #ifdef ATA_IRQ_TRAP
5163 	if ((ap->stats.idle_irq % 1000) == 0) {
5164 		ata_irq_ack(ap, 0); /* debug trap */
5165 		ata_port_printk(ap, KERN_WARNING, "irq trap\n");
5166 		return 1;
5167 	}
5168 #endif
5169 	return 0;	/* irq not handled */
5170 }
5171 
5172 /**
5173  *	ata_interrupt - Default ATA host interrupt handler
5174  *	@irq: irq line (unused)
5175  *	@dev_instance: pointer to our ata_host information structure
5176  *
5177  *	Default interrupt handler for PCI IDE devices.  Calls
5178  *	ata_host_intr() for each port that is not disabled.
5179  *
5180  *	LOCKING:
5181  *	Obtains host lock during operation.
5182  *
5183  *	RETURNS:
5184  *	IRQ_NONE or IRQ_HANDLED.
5185  */
5186 
5187 irqreturn_t ata_interrupt (int irq, void *dev_instance)
5188 {
5189 	struct ata_host *host = dev_instance;
5190 	unsigned int i;
5191 	unsigned int handled = 0;
5192 	unsigned long flags;
5193 
5194 	/* TODO: make _irqsave conditional on x86 PCI IDE legacy mode */
5195 	spin_lock_irqsave(&host->lock, flags);
5196 
5197 	for (i = 0; i < host->n_ports; i++) {
5198 		struct ata_port *ap;
5199 
5200 		ap = host->ports[i];
5201 		if (ap &&
5202 		    !(ap->flags & ATA_FLAG_DISABLED)) {
5203 			struct ata_queued_cmd *qc;
5204 
5205 			qc = ata_qc_from_tag(ap, ap->active_tag);
5206 			if (qc && (!(qc->tf.flags & ATA_TFLAG_POLLING)) &&
5207 			    (qc->flags & ATA_QCFLAG_ACTIVE))
5208 				handled |= ata_host_intr(ap, qc);
5209 		}
5210 	}
5211 
5212 	spin_unlock_irqrestore(&host->lock, flags);
5213 
5214 	return IRQ_RETVAL(handled);
5215 }
5216 
5217 /**
5218  *	sata_scr_valid - test whether SCRs are accessible
5219  *	@ap: ATA port to test SCR accessibility for
5220  *
5221  *	Test whether SCRs are accessible for @ap.
5222  *
5223  *	LOCKING:
5224  *	None.
5225  *
5226  *	RETURNS:
5227  *	1 if SCRs are accessible, 0 otherwise.
5228  */
5229 int sata_scr_valid(struct ata_port *ap)
5230 {
5231 	return ap->cbl == ATA_CBL_SATA && ap->ops->scr_read;
5232 }
5233 
5234 /**
5235  *	sata_scr_read - read SCR register of the specified port
5236  *	@ap: ATA port to read SCR for
5237  *	@reg: SCR to read
5238  *	@val: Place to store read value
5239  *
5240  *	Read SCR register @reg of @ap into *@val.  This function is
5241  *	guaranteed to succeed if the cable type of the port is SATA
5242  *	and the port implements ->scr_read.
5243  *
5244  *	LOCKING:
5245  *	None.
5246  *
5247  *	RETURNS:
5248  *	0 on success, negative errno on failure.
5249  */
5250 int sata_scr_read(struct ata_port *ap, int reg, u32 *val)
5251 {
5252 	if (sata_scr_valid(ap)) {
5253 		*val = ap->ops->scr_read(ap, reg);
5254 		return 0;
5255 	}
5256 	return -EOPNOTSUPP;
5257 }
5258 
5259 /**
5260  *	sata_scr_write - write SCR register of the specified port
5261  *	@ap: ATA port to write SCR for
5262  *	@reg: SCR to write
5263  *	@val: value to write
5264  *
5265  *	Write @val to SCR register @reg of @ap.  This function is
5266  *	guaranteed to succeed if the cable type of the port is SATA
5267  *	and the port implements ->scr_read.
5268  *
5269  *	LOCKING:
5270  *	None.
5271  *
5272  *	RETURNS:
5273  *	0 on success, negative errno on failure.
5274  */
5275 int sata_scr_write(struct ata_port *ap, int reg, u32 val)
5276 {
5277 	if (sata_scr_valid(ap)) {
5278 		ap->ops->scr_write(ap, reg, val);
5279 		return 0;
5280 	}
5281 	return -EOPNOTSUPP;
5282 }
5283 
5284 /**
5285  *	sata_scr_write_flush - write SCR register of the specified port and flush
5286  *	@ap: ATA port to write SCR for
5287  *	@reg: SCR to write
5288  *	@val: value to write
5289  *
5290  *	This function is identical to sata_scr_write() except that this
5291  *	function performs flush after writing to the register.
5292  *
5293  *	LOCKING:
5294  *	None.
5295  *
5296  *	RETURNS:
5297  *	0 on success, negative errno on failure.
5298  */
5299 int sata_scr_write_flush(struct ata_port *ap, int reg, u32 val)
5300 {
5301 	if (sata_scr_valid(ap)) {
5302 		ap->ops->scr_write(ap, reg, val);
5303 		ap->ops->scr_read(ap, reg);
5304 		return 0;
5305 	}
5306 	return -EOPNOTSUPP;
5307 }
5308 
5309 /**
5310  *	ata_port_online - test whether the given port is online
5311  *	@ap: ATA port to test
5312  *
5313  *	Test whether @ap is online.  Note that this function returns 0
5314  *	if online status of @ap cannot be obtained, so
5315  *	ata_port_online(ap) != !ata_port_offline(ap).
5316  *
5317  *	LOCKING:
5318  *	None.
5319  *
5320  *	RETURNS:
5321  *	1 if the port online status is available and online.
5322  */
5323 int ata_port_online(struct ata_port *ap)
5324 {
5325 	u32 sstatus;
5326 
5327 	if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) == 0x3)
5328 		return 1;
5329 	return 0;
5330 }
5331 
5332 /**
5333  *	ata_port_offline - test whether the given port is offline
5334  *	@ap: ATA port to test
5335  *
5336  *	Test whether @ap is offline.  Note that this function returns
5337  *	0 if offline status of @ap cannot be obtained, so
5338  *	ata_port_online(ap) != !ata_port_offline(ap).
5339  *
5340  *	LOCKING:
5341  *	None.
5342  *
5343  *	RETURNS:
5344  *	1 if the port offline status is available and offline.
5345  */
5346 int ata_port_offline(struct ata_port *ap)
5347 {
5348 	u32 sstatus;
5349 
5350 	if (!sata_scr_read(ap, SCR_STATUS, &sstatus) && (sstatus & 0xf) != 0x3)
5351 		return 1;
5352 	return 0;
5353 }
5354 
5355 int ata_flush_cache(struct ata_device *dev)
5356 {
5357 	unsigned int err_mask;
5358 	u8 cmd;
5359 
5360 	if (!ata_try_flush_cache(dev))
5361 		return 0;
5362 
5363 	if (dev->flags & ATA_DFLAG_FLUSH_EXT)
5364 		cmd = ATA_CMD_FLUSH_EXT;
5365 	else
5366 		cmd = ATA_CMD_FLUSH;
5367 
5368 	err_mask = ata_do_simple_cmd(dev, cmd);
5369 	if (err_mask) {
5370 		ata_dev_printk(dev, KERN_ERR, "failed to flush cache\n");
5371 		return -EIO;
5372 	}
5373 
5374 	return 0;
5375 }
5376 
5377 static int ata_host_request_pm(struct ata_host *host, pm_message_t mesg,
5378 			       unsigned int action, unsigned int ehi_flags,
5379 			       int wait)
5380 {
5381 	unsigned long flags;
5382 	int i, rc;
5383 
5384 	for (i = 0; i < host->n_ports; i++) {
5385 		struct ata_port *ap = host->ports[i];
5386 
5387 		/* Previous resume operation might still be in
5388 		 * progress.  Wait for PM_PENDING to clear.
5389 		 */
5390 		if (ap->pflags & ATA_PFLAG_PM_PENDING) {
5391 			ata_port_wait_eh(ap);
5392 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5393 		}
5394 
5395 		/* request PM ops to EH */
5396 		spin_lock_irqsave(ap->lock, flags);
5397 
5398 		ap->pm_mesg = mesg;
5399 		if (wait) {
5400 			rc = 0;
5401 			ap->pm_result = &rc;
5402 		}
5403 
5404 		ap->pflags |= ATA_PFLAG_PM_PENDING;
5405 		ap->eh_info.action |= action;
5406 		ap->eh_info.flags |= ehi_flags;
5407 
5408 		ata_port_schedule_eh(ap);
5409 
5410 		spin_unlock_irqrestore(ap->lock, flags);
5411 
5412 		/* wait and check result */
5413 		if (wait) {
5414 			ata_port_wait_eh(ap);
5415 			WARN_ON(ap->pflags & ATA_PFLAG_PM_PENDING);
5416 			if (rc)
5417 				return rc;
5418 		}
5419 	}
5420 
5421 	return 0;
5422 }
5423 
5424 /**
5425  *	ata_host_suspend - suspend host
5426  *	@host: host to suspend
5427  *	@mesg: PM message
5428  *
5429  *	Suspend @host.  Actual operation is performed by EH.  This
5430  *	function requests EH to perform PM operations and waits for EH
5431  *	to finish.
5432  *
5433  *	LOCKING:
5434  *	Kernel thread context (may sleep).
5435  *
5436  *	RETURNS:
5437  *	0 on success, -errno on failure.
5438  */
5439 int ata_host_suspend(struct ata_host *host, pm_message_t mesg)
5440 {
5441 	int i, j, rc;
5442 
5443 	rc = ata_host_request_pm(host, mesg, 0, ATA_EHI_QUIET, 1);
5444 	if (rc)
5445 		goto fail;
5446 
5447 	/* EH is quiescent now.  Fail if we have any ready device.
5448 	 * This happens if hotplug occurs between completion of device
5449 	 * suspension and here.
5450 	 */
5451 	for (i = 0; i < host->n_ports; i++) {
5452 		struct ata_port *ap = host->ports[i];
5453 
5454 		for (j = 0; j < ATA_MAX_DEVICES; j++) {
5455 			struct ata_device *dev = &ap->device[j];
5456 
5457 			if (ata_dev_ready(dev)) {
5458 				ata_port_printk(ap, KERN_WARNING,
5459 						"suspend failed, device %d "
5460 						"still active\n", dev->devno);
5461 				rc = -EBUSY;
5462 				goto fail;
5463 			}
5464 		}
5465 	}
5466 
5467 	host->dev->power.power_state = mesg;
5468 	return 0;
5469 
5470  fail:
5471 	ata_host_resume(host);
5472 	return rc;
5473 }
5474 
5475 /**
5476  *	ata_host_resume - resume host
5477  *	@host: host to resume
5478  *
5479  *	Resume @host.  Actual operation is performed by EH.  This
5480  *	function requests EH to perform PM operations and returns.
5481  *	Note that all resume operations are performed parallely.
5482  *
5483  *	LOCKING:
5484  *	Kernel thread context (may sleep).
5485  */
5486 void ata_host_resume(struct ata_host *host)
5487 {
5488 	ata_host_request_pm(host, PMSG_ON, ATA_EH_SOFTRESET,
5489 			    ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET, 0);
5490 	host->dev->power.power_state = PMSG_ON;
5491 }
5492 
5493 /**
5494  *	ata_port_start - Set port up for dma.
5495  *	@ap: Port to initialize
5496  *
5497  *	Called just after data structures for each port are
5498  *	initialized.  Allocates space for PRD table.
5499  *
5500  *	May be used as the port_start() entry in ata_port_operations.
5501  *
5502  *	LOCKING:
5503  *	Inherited from caller.
5504  */
5505 
5506 int ata_port_start (struct ata_port *ap)
5507 {
5508 	struct device *dev = ap->dev;
5509 	int rc;
5510 
5511 	ap->prd = dma_alloc_coherent(dev, ATA_PRD_TBL_SZ, &ap->prd_dma, GFP_KERNEL);
5512 	if (!ap->prd)
5513 		return -ENOMEM;
5514 
5515 	rc = ata_pad_alloc(ap, dev);
5516 	if (rc) {
5517 		dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
5518 		return rc;
5519 	}
5520 
5521 	DPRINTK("prd alloc, virt %p, dma %llx\n", ap->prd, (unsigned long long) ap->prd_dma);
5522 
5523 	return 0;
5524 }
5525 
5526 
5527 /**
5528  *	ata_port_stop - Undo ata_port_start()
5529  *	@ap: Port to shut down
5530  *
5531  *	Frees the PRD table.
5532  *
5533  *	May be used as the port_stop() entry in ata_port_operations.
5534  *
5535  *	LOCKING:
5536  *	Inherited from caller.
5537  */
5538 
5539 void ata_port_stop (struct ata_port *ap)
5540 {
5541 	struct device *dev = ap->dev;
5542 
5543 	dma_free_coherent(dev, ATA_PRD_TBL_SZ, ap->prd, ap->prd_dma);
5544 	ata_pad_free(ap, dev);
5545 }
5546 
5547 void ata_host_stop (struct ata_host *host)
5548 {
5549 	if (host->mmio_base)
5550 		iounmap(host->mmio_base);
5551 }
5552 
5553 /**
5554  *	ata_dev_init - Initialize an ata_device structure
5555  *	@dev: Device structure to initialize
5556  *
5557  *	Initialize @dev in preparation for probing.
5558  *
5559  *	LOCKING:
5560  *	Inherited from caller.
5561  */
5562 void ata_dev_init(struct ata_device *dev)
5563 {
5564 	struct ata_port *ap = dev->ap;
5565 	unsigned long flags;
5566 
5567 	/* SATA spd limit is bound to the first device */
5568 	ap->sata_spd_limit = ap->hw_sata_spd_limit;
5569 
5570 	/* High bits of dev->flags are used to record warm plug
5571 	 * requests which occur asynchronously.  Synchronize using
5572 	 * host lock.
5573 	 */
5574 	spin_lock_irqsave(ap->lock, flags);
5575 	dev->flags &= ~ATA_DFLAG_INIT_MASK;
5576 	spin_unlock_irqrestore(ap->lock, flags);
5577 
5578 	memset((void *)dev + ATA_DEVICE_CLEAR_OFFSET, 0,
5579 	       sizeof(*dev) - ATA_DEVICE_CLEAR_OFFSET);
5580 	dev->pio_mask = UINT_MAX;
5581 	dev->mwdma_mask = UINT_MAX;
5582 	dev->udma_mask = UINT_MAX;
5583 }
5584 
5585 /**
5586  *	ata_port_init - Initialize an ata_port structure
5587  *	@ap: Structure to initialize
5588  *	@host: Collection of hosts to which @ap belongs
5589  *	@ent: Probe information provided by low-level driver
5590  *	@port_no: Port number associated with this ata_port
5591  *
5592  *	Initialize a new ata_port structure.
5593  *
5594  *	LOCKING:
5595  *	Inherited from caller.
5596  */
5597 void ata_port_init(struct ata_port *ap, struct ata_host *host,
5598 		   const struct ata_probe_ent *ent, unsigned int port_no)
5599 {
5600 	unsigned int i;
5601 
5602 	ap->lock = &host->lock;
5603 	ap->flags = ATA_FLAG_DISABLED;
5604 	ap->id = ata_unique_id++;
5605 	ap->ctl = ATA_DEVCTL_OBS;
5606 	ap->host = host;
5607 	ap->dev = ent->dev;
5608 	ap->port_no = port_no;
5609 	if (port_no == 1 && ent->pinfo2) {
5610 		ap->pio_mask = ent->pinfo2->pio_mask;
5611 		ap->mwdma_mask = ent->pinfo2->mwdma_mask;
5612 		ap->udma_mask = ent->pinfo2->udma_mask;
5613 		ap->flags |= ent->pinfo2->flags;
5614 		ap->ops = ent->pinfo2->port_ops;
5615 	} else {
5616 		ap->pio_mask = ent->pio_mask;
5617 		ap->mwdma_mask = ent->mwdma_mask;
5618 		ap->udma_mask = ent->udma_mask;
5619 		ap->flags |= ent->port_flags;
5620 		ap->ops = ent->port_ops;
5621 	}
5622 	ap->hw_sata_spd_limit = UINT_MAX;
5623 	ap->active_tag = ATA_TAG_POISON;
5624 	ap->last_ctl = 0xFF;
5625 
5626 #if defined(ATA_VERBOSE_DEBUG)
5627 	/* turn on all debugging levels */
5628 	ap->msg_enable = 0x00FF;
5629 #elif defined(ATA_DEBUG)
5630 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_INFO | ATA_MSG_CTL | ATA_MSG_WARN | ATA_MSG_ERR;
5631 #else
5632 	ap->msg_enable = ATA_MSG_DRV | ATA_MSG_ERR | ATA_MSG_WARN;
5633 #endif
5634 
5635 	INIT_DELAYED_WORK(&ap->port_task, NULL);
5636 	INIT_DELAYED_WORK(&ap->hotplug_task, ata_scsi_hotplug);
5637 	INIT_WORK(&ap->scsi_rescan_task, ata_scsi_dev_rescan);
5638 	INIT_LIST_HEAD(&ap->eh_done_q);
5639 	init_waitqueue_head(&ap->eh_wait_q);
5640 
5641 	/* set cable type */
5642 	ap->cbl = ATA_CBL_NONE;
5643 	if (ap->flags & ATA_FLAG_SATA)
5644 		ap->cbl = ATA_CBL_SATA;
5645 
5646 	for (i = 0; i < ATA_MAX_DEVICES; i++) {
5647 		struct ata_device *dev = &ap->device[i];
5648 		dev->ap = ap;
5649 		dev->devno = i;
5650 		ata_dev_init(dev);
5651 	}
5652 
5653 #ifdef ATA_IRQ_TRAP
5654 	ap->stats.unhandled_irq = 1;
5655 	ap->stats.idle_irq = 1;
5656 #endif
5657 
5658 	memcpy(&ap->ioaddr, &ent->port[port_no], sizeof(struct ata_ioports));
5659 }
5660 
5661 /**
5662  *	ata_port_init_shost - Initialize SCSI host associated with ATA port
5663  *	@ap: ATA port to initialize SCSI host for
5664  *	@shost: SCSI host associated with @ap
5665  *
5666  *	Initialize SCSI host @shost associated with ATA port @ap.
5667  *
5668  *	LOCKING:
5669  *	Inherited from caller.
5670  */
5671 static void ata_port_init_shost(struct ata_port *ap, struct Scsi_Host *shost)
5672 {
5673 	ap->scsi_host = shost;
5674 
5675 	shost->unique_id = ap->id;
5676 	shost->max_id = 16;
5677 	shost->max_lun = 1;
5678 	shost->max_channel = 1;
5679 	shost->max_cmd_len = 12;
5680 }
5681 
5682 /**
5683  *	ata_port_add - Attach low-level ATA driver to system
5684  *	@ent: Information provided by low-level driver
5685  *	@host: Collections of ports to which we add
5686  *	@port_no: Port number associated with this host
5687  *
5688  *	Attach low-level ATA driver to system.
5689  *
5690  *	LOCKING:
5691  *	PCI/etc. bus probe sem.
5692  *
5693  *	RETURNS:
5694  *	New ata_port on success, for NULL on error.
5695  */
5696 static struct ata_port * ata_port_add(const struct ata_probe_ent *ent,
5697 				      struct ata_host *host,
5698 				      unsigned int port_no)
5699 {
5700 	struct Scsi_Host *shost;
5701 	struct ata_port *ap;
5702 
5703 	DPRINTK("ENTER\n");
5704 
5705 	if (!ent->port_ops->error_handler &&
5706 	    !(ent->port_flags & (ATA_FLAG_SATA_RESET | ATA_FLAG_SRST))) {
5707 		printk(KERN_ERR "ata%u: no reset mechanism available\n",
5708 		       port_no);
5709 		return NULL;
5710 	}
5711 
5712 	shost = scsi_host_alloc(ent->sht, sizeof(struct ata_port));
5713 	if (!shost)
5714 		return NULL;
5715 
5716 	shost->transportt = &ata_scsi_transport_template;
5717 
5718 	ap = ata_shost_to_port(shost);
5719 
5720 	ata_port_init(ap, host, ent, port_no);
5721 	ata_port_init_shost(ap, shost);
5722 
5723 	return ap;
5724 }
5725 
5726 /**
5727  *	ata_sas_host_init - Initialize a host struct
5728  *	@host:	host to initialize
5729  *	@dev:	device host is attached to
5730  *	@flags:	host flags
5731  *	@ops:	port_ops
5732  *
5733  *	LOCKING:
5734  *	PCI/etc. bus probe sem.
5735  *
5736  */
5737 
5738 void ata_host_init(struct ata_host *host, struct device *dev,
5739 		   unsigned long flags, const struct ata_port_operations *ops)
5740 {
5741 	spin_lock_init(&host->lock);
5742 	host->dev = dev;
5743 	host->flags = flags;
5744 	host->ops = ops;
5745 }
5746 
5747 /**
5748  *	ata_device_add - Register hardware device with ATA and SCSI layers
5749  *	@ent: Probe information describing hardware device to be registered
5750  *
5751  *	This function processes the information provided in the probe
5752  *	information struct @ent, allocates the necessary ATA and SCSI
5753  *	host information structures, initializes them, and registers
5754  *	everything with requisite kernel subsystems.
5755  *
5756  *	This function requests irqs, probes the ATA bus, and probes
5757  *	the SCSI bus.
5758  *
5759  *	LOCKING:
5760  *	PCI/etc. bus probe sem.
5761  *
5762  *	RETURNS:
5763  *	Number of ports registered.  Zero on error (no ports registered).
5764  */
5765 int ata_device_add(const struct ata_probe_ent *ent)
5766 {
5767 	unsigned int i;
5768 	struct device *dev = ent->dev;
5769 	struct ata_host *host;
5770 	int rc;
5771 
5772 	DPRINTK("ENTER\n");
5773 
5774 	if (ent->irq == 0) {
5775 		dev_printk(KERN_ERR, dev, "is not available: No interrupt assigned.\n");
5776 		return 0;
5777 	}
5778 	/* alloc a container for our list of ATA ports (buses) */
5779 	host = kzalloc(sizeof(struct ata_host) +
5780 		       (ent->n_ports * sizeof(void *)), GFP_KERNEL);
5781 	if (!host)
5782 		return 0;
5783 
5784 	ata_host_init(host, dev, ent->_host_flags, ent->port_ops);
5785 	host->n_ports = ent->n_ports;
5786 	host->irq = ent->irq;
5787 	host->irq2 = ent->irq2;
5788 	host->mmio_base = ent->mmio_base;
5789 	host->private_data = ent->private_data;
5790 
5791 	/* register each port bound to this device */
5792 	for (i = 0; i < host->n_ports; i++) {
5793 		struct ata_port *ap;
5794 		unsigned long xfer_mode_mask;
5795 		int irq_line = ent->irq;
5796 
5797 		ap = ata_port_add(ent, host, i);
5798 		host->ports[i] = ap;
5799 		if (!ap)
5800 			goto err_out;
5801 
5802 		/* dummy? */
5803 		if (ent->dummy_port_mask & (1 << i)) {
5804 			ata_port_printk(ap, KERN_INFO, "DUMMY\n");
5805 			ap->ops = &ata_dummy_port_ops;
5806 			continue;
5807 		}
5808 
5809 		/* start port */
5810 		rc = ap->ops->port_start(ap);
5811 		if (rc) {
5812 			host->ports[i] = NULL;
5813 			scsi_host_put(ap->scsi_host);
5814 			goto err_out;
5815 		}
5816 
5817 		/* Report the secondary IRQ for second channel legacy */
5818 		if (i == 1 && ent->irq2)
5819 			irq_line = ent->irq2;
5820 
5821 		xfer_mode_mask =(ap->udma_mask << ATA_SHIFT_UDMA) |
5822 				(ap->mwdma_mask << ATA_SHIFT_MWDMA) |
5823 				(ap->pio_mask << ATA_SHIFT_PIO);
5824 
5825 		/* print per-port info to dmesg */
5826 		ata_port_printk(ap, KERN_INFO, "%cATA max %s cmd 0x%lX "
5827 				"ctl 0x%lX bmdma 0x%lX irq %d\n",
5828 				ap->flags & ATA_FLAG_SATA ? 'S' : 'P',
5829 				ata_mode_string(xfer_mode_mask),
5830 				ap->ioaddr.cmd_addr,
5831 				ap->ioaddr.ctl_addr,
5832 				ap->ioaddr.bmdma_addr,
5833 				irq_line);
5834 
5835 		/* freeze port before requesting IRQ */
5836 		ata_eh_freeze_port(ap);
5837 	}
5838 
5839 	/* obtain irq, that may be shared between channels */
5840 	rc = request_irq(ent->irq, ent->port_ops->irq_handler, ent->irq_flags,
5841 			 DRV_NAME, host);
5842 	if (rc) {
5843 		dev_printk(KERN_ERR, dev, "irq %lu request failed: %d\n",
5844 			   ent->irq, rc);
5845 		goto err_out;
5846 	}
5847 
5848 	/* do we have a second IRQ for the other channel, eg legacy mode */
5849 	if (ent->irq2) {
5850 		/* We will get weird core code crashes later if this is true
5851 		   so trap it now */
5852 		BUG_ON(ent->irq == ent->irq2);
5853 
5854 		rc = request_irq(ent->irq2, ent->port_ops->irq_handler, ent->irq_flags,
5855 			 DRV_NAME, host);
5856 		if (rc) {
5857 			dev_printk(KERN_ERR, dev, "irq %lu request failed: %d\n",
5858 				   ent->irq2, rc);
5859 			goto err_out_free_irq;
5860 		}
5861 	}
5862 
5863 	/* perform each probe synchronously */
5864 	DPRINTK("probe begin\n");
5865 	for (i = 0; i < host->n_ports; i++) {
5866 		struct ata_port *ap = host->ports[i];
5867 		u32 scontrol;
5868 		int rc;
5869 
5870 		/* init sata_spd_limit to the current value */
5871 		if (sata_scr_read(ap, SCR_CONTROL, &scontrol) == 0) {
5872 			int spd = (scontrol >> 4) & 0xf;
5873 			ap->hw_sata_spd_limit &= (1 << spd) - 1;
5874 		}
5875 		ap->sata_spd_limit = ap->hw_sata_spd_limit;
5876 
5877 		rc = scsi_add_host(ap->scsi_host, dev);
5878 		if (rc) {
5879 			ata_port_printk(ap, KERN_ERR, "scsi_add_host failed\n");
5880 			/* FIXME: do something useful here */
5881 			/* FIXME: handle unconditional calls to
5882 			 * scsi_scan_host and ata_host_remove, below,
5883 			 * at the very least
5884 			 */
5885 		}
5886 
5887 		if (ap->ops->error_handler) {
5888 			struct ata_eh_info *ehi = &ap->eh_info;
5889 			unsigned long flags;
5890 
5891 			ata_port_probe(ap);
5892 
5893 			/* kick EH for boot probing */
5894 			spin_lock_irqsave(ap->lock, flags);
5895 
5896 			ehi->probe_mask = (1 << ATA_MAX_DEVICES) - 1;
5897 			ehi->action |= ATA_EH_SOFTRESET;
5898 			ehi->flags |= ATA_EHI_NO_AUTOPSY | ATA_EHI_QUIET;
5899 
5900 			ap->pflags |= ATA_PFLAG_LOADING;
5901 			ata_port_schedule_eh(ap);
5902 
5903 			spin_unlock_irqrestore(ap->lock, flags);
5904 
5905 			/* wait for EH to finish */
5906 			ata_port_wait_eh(ap);
5907 		} else {
5908 			DPRINTK("ata%u: bus probe begin\n", ap->id);
5909 			rc = ata_bus_probe(ap);
5910 			DPRINTK("ata%u: bus probe end\n", ap->id);
5911 
5912 			if (rc) {
5913 				/* FIXME: do something useful here?
5914 				 * Current libata behavior will
5915 				 * tear down everything when
5916 				 * the module is removed
5917 				 * or the h/w is unplugged.
5918 				 */
5919 			}
5920 		}
5921 	}
5922 
5923 	/* probes are done, now scan each port's disk(s) */
5924 	DPRINTK("host probe begin\n");
5925 	for (i = 0; i < host->n_ports; i++) {
5926 		struct ata_port *ap = host->ports[i];
5927 
5928 		ata_scsi_scan_host(ap);
5929 	}
5930 
5931 	dev_set_drvdata(dev, host);
5932 
5933 	VPRINTK("EXIT, returning %u\n", ent->n_ports);
5934 	return ent->n_ports; /* success */
5935 
5936 err_out_free_irq:
5937 	free_irq(ent->irq, host);
5938 err_out:
5939 	for (i = 0; i < host->n_ports; i++) {
5940 		struct ata_port *ap = host->ports[i];
5941 		if (ap) {
5942 			ap->ops->port_stop(ap);
5943 			scsi_host_put(ap->scsi_host);
5944 		}
5945 	}
5946 
5947 	kfree(host);
5948 	VPRINTK("EXIT, returning 0\n");
5949 	return 0;
5950 }
5951 
5952 /**
5953  *	ata_port_detach - Detach ATA port in prepration of device removal
5954  *	@ap: ATA port to be detached
5955  *
5956  *	Detach all ATA devices and the associated SCSI devices of @ap;
5957  *	then, remove the associated SCSI host.  @ap is guaranteed to
5958  *	be quiescent on return from this function.
5959  *
5960  *	LOCKING:
5961  *	Kernel thread context (may sleep).
5962  */
5963 void ata_port_detach(struct ata_port *ap)
5964 {
5965 	unsigned long flags;
5966 	int i;
5967 
5968 	if (!ap->ops->error_handler)
5969 		goto skip_eh;
5970 
5971 	/* tell EH we're leaving & flush EH */
5972 	spin_lock_irqsave(ap->lock, flags);
5973 	ap->pflags |= ATA_PFLAG_UNLOADING;
5974 	spin_unlock_irqrestore(ap->lock, flags);
5975 
5976 	ata_port_wait_eh(ap);
5977 
5978 	/* EH is now guaranteed to see UNLOADING, so no new device
5979 	 * will be attached.  Disable all existing devices.
5980 	 */
5981 	spin_lock_irqsave(ap->lock, flags);
5982 
5983 	for (i = 0; i < ATA_MAX_DEVICES; i++)
5984 		ata_dev_disable(&ap->device[i]);
5985 
5986 	spin_unlock_irqrestore(ap->lock, flags);
5987 
5988 	/* Final freeze & EH.  All in-flight commands are aborted.  EH
5989 	 * will be skipped and retrials will be terminated with bad
5990 	 * target.
5991 	 */
5992 	spin_lock_irqsave(ap->lock, flags);
5993 	ata_port_freeze(ap);	/* won't be thawed */
5994 	spin_unlock_irqrestore(ap->lock, flags);
5995 
5996 	ata_port_wait_eh(ap);
5997 
5998 	/* Flush hotplug task.  The sequence is similar to
5999 	 * ata_port_flush_task().
6000 	 */
6001 	flush_workqueue(ata_aux_wq);
6002 	cancel_delayed_work(&ap->hotplug_task);
6003 	flush_workqueue(ata_aux_wq);
6004 
6005  skip_eh:
6006 	/* remove the associated SCSI host */
6007 	scsi_remove_host(ap->scsi_host);
6008 }
6009 
6010 /**
6011  *	ata_host_remove - PCI layer callback for device removal
6012  *	@host: ATA host set that was removed
6013  *
6014  *	Unregister all objects associated with this host set. Free those
6015  *	objects.
6016  *
6017  *	LOCKING:
6018  *	Inherited from calling layer (may sleep).
6019  */
6020 
6021 void ata_host_remove(struct ata_host *host)
6022 {
6023 	unsigned int i;
6024 
6025 	for (i = 0; i < host->n_ports; i++)
6026 		ata_port_detach(host->ports[i]);
6027 
6028 	free_irq(host->irq, host);
6029 	if (host->irq2)
6030 		free_irq(host->irq2, host);
6031 
6032 	for (i = 0; i < host->n_ports; i++) {
6033 		struct ata_port *ap = host->ports[i];
6034 
6035 		ata_scsi_release(ap->scsi_host);
6036 
6037 		if ((ap->flags & ATA_FLAG_NO_LEGACY) == 0) {
6038 			struct ata_ioports *ioaddr = &ap->ioaddr;
6039 
6040 			/* FIXME: Add -ac IDE pci mods to remove these special cases */
6041 			if (ioaddr->cmd_addr == ATA_PRIMARY_CMD)
6042 				release_region(ATA_PRIMARY_CMD, 8);
6043 			else if (ioaddr->cmd_addr == ATA_SECONDARY_CMD)
6044 				release_region(ATA_SECONDARY_CMD, 8);
6045 		}
6046 
6047 		scsi_host_put(ap->scsi_host);
6048 	}
6049 
6050 	if (host->ops->host_stop)
6051 		host->ops->host_stop(host);
6052 
6053 	kfree(host);
6054 }
6055 
6056 /**
6057  *	ata_scsi_release - SCSI layer callback hook for host unload
6058  *	@shost: libata host to be unloaded
6059  *
6060  *	Performs all duties necessary to shut down a libata port...
6061  *	Kill port kthread, disable port, and release resources.
6062  *
6063  *	LOCKING:
6064  *	Inherited from SCSI layer.
6065  *
6066  *	RETURNS:
6067  *	One.
6068  */
6069 
6070 int ata_scsi_release(struct Scsi_Host *shost)
6071 {
6072 	struct ata_port *ap = ata_shost_to_port(shost);
6073 
6074 	DPRINTK("ENTER\n");
6075 
6076 	ap->ops->port_disable(ap);
6077 	ap->ops->port_stop(ap);
6078 
6079 	DPRINTK("EXIT\n");
6080 	return 1;
6081 }
6082 
6083 struct ata_probe_ent *
6084 ata_probe_ent_alloc(struct device *dev, const struct ata_port_info *port)
6085 {
6086 	struct ata_probe_ent *probe_ent;
6087 
6088 	probe_ent = kzalloc(sizeof(*probe_ent), GFP_KERNEL);
6089 	if (!probe_ent) {
6090 		printk(KERN_ERR DRV_NAME "(%s): out of memory\n",
6091 		       kobject_name(&(dev->kobj)));
6092 		return NULL;
6093 	}
6094 
6095 	INIT_LIST_HEAD(&probe_ent->node);
6096 	probe_ent->dev = dev;
6097 
6098 	probe_ent->sht = port->sht;
6099 	probe_ent->port_flags = port->flags;
6100 	probe_ent->pio_mask = port->pio_mask;
6101 	probe_ent->mwdma_mask = port->mwdma_mask;
6102 	probe_ent->udma_mask = port->udma_mask;
6103 	probe_ent->port_ops = port->port_ops;
6104 	probe_ent->private_data = port->private_data;
6105 
6106 	return probe_ent;
6107 }
6108 
6109 /**
6110  *	ata_std_ports - initialize ioaddr with standard port offsets.
6111  *	@ioaddr: IO address structure to be initialized
6112  *
6113  *	Utility function which initializes data_addr, error_addr,
6114  *	feature_addr, nsect_addr, lbal_addr, lbam_addr, lbah_addr,
6115  *	device_addr, status_addr, and command_addr to standard offsets
6116  *	relative to cmd_addr.
6117  *
6118  *	Does not set ctl_addr, altstatus_addr, bmdma_addr, or scr_addr.
6119  */
6120 
6121 void ata_std_ports(struct ata_ioports *ioaddr)
6122 {
6123 	ioaddr->data_addr = ioaddr->cmd_addr + ATA_REG_DATA;
6124 	ioaddr->error_addr = ioaddr->cmd_addr + ATA_REG_ERR;
6125 	ioaddr->feature_addr = ioaddr->cmd_addr + ATA_REG_FEATURE;
6126 	ioaddr->nsect_addr = ioaddr->cmd_addr + ATA_REG_NSECT;
6127 	ioaddr->lbal_addr = ioaddr->cmd_addr + ATA_REG_LBAL;
6128 	ioaddr->lbam_addr = ioaddr->cmd_addr + ATA_REG_LBAM;
6129 	ioaddr->lbah_addr = ioaddr->cmd_addr + ATA_REG_LBAH;
6130 	ioaddr->device_addr = ioaddr->cmd_addr + ATA_REG_DEVICE;
6131 	ioaddr->status_addr = ioaddr->cmd_addr + ATA_REG_STATUS;
6132 	ioaddr->command_addr = ioaddr->cmd_addr + ATA_REG_CMD;
6133 }
6134 
6135 
6136 #ifdef CONFIG_PCI
6137 
6138 void ata_pci_host_stop (struct ata_host *host)
6139 {
6140 	struct pci_dev *pdev = to_pci_dev(host->dev);
6141 
6142 	pci_iounmap(pdev, host->mmio_base);
6143 }
6144 
6145 /**
6146  *	ata_pci_remove_one - PCI layer callback for device removal
6147  *	@pdev: PCI device that was removed
6148  *
6149  *	PCI layer indicates to libata via this hook that
6150  *	hot-unplug or module unload event has occurred.
6151  *	Handle this by unregistering all objects associated
6152  *	with this PCI device.  Free those objects.  Then finally
6153  *	release PCI resources and disable device.
6154  *
6155  *	LOCKING:
6156  *	Inherited from PCI layer (may sleep).
6157  */
6158 
6159 void ata_pci_remove_one (struct pci_dev *pdev)
6160 {
6161 	struct device *dev = pci_dev_to_dev(pdev);
6162 	struct ata_host *host = dev_get_drvdata(dev);
6163 
6164 	ata_host_remove(host);
6165 
6166 	pci_release_regions(pdev);
6167 	pci_disable_device(pdev);
6168 	dev_set_drvdata(dev, NULL);
6169 }
6170 
6171 /* move to PCI subsystem */
6172 int pci_test_config_bits(struct pci_dev *pdev, const struct pci_bits *bits)
6173 {
6174 	unsigned long tmp = 0;
6175 
6176 	switch (bits->width) {
6177 	case 1: {
6178 		u8 tmp8 = 0;
6179 		pci_read_config_byte(pdev, bits->reg, &tmp8);
6180 		tmp = tmp8;
6181 		break;
6182 	}
6183 	case 2: {
6184 		u16 tmp16 = 0;
6185 		pci_read_config_word(pdev, bits->reg, &tmp16);
6186 		tmp = tmp16;
6187 		break;
6188 	}
6189 	case 4: {
6190 		u32 tmp32 = 0;
6191 		pci_read_config_dword(pdev, bits->reg, &tmp32);
6192 		tmp = tmp32;
6193 		break;
6194 	}
6195 
6196 	default:
6197 		return -EINVAL;
6198 	}
6199 
6200 	tmp &= bits->mask;
6201 
6202 	return (tmp == bits->val) ? 1 : 0;
6203 }
6204 
6205 void ata_pci_device_do_suspend(struct pci_dev *pdev, pm_message_t mesg)
6206 {
6207 	pci_save_state(pdev);
6208 
6209 	if (mesg.event == PM_EVENT_SUSPEND) {
6210 		pci_disable_device(pdev);
6211 		pci_set_power_state(pdev, PCI_D3hot);
6212 	}
6213 }
6214 
6215 void ata_pci_device_do_resume(struct pci_dev *pdev)
6216 {
6217 	pci_set_power_state(pdev, PCI_D0);
6218 	pci_restore_state(pdev);
6219 	pci_enable_device(pdev);
6220 	pci_set_master(pdev);
6221 }
6222 
6223 int ata_pci_device_suspend(struct pci_dev *pdev, pm_message_t mesg)
6224 {
6225 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6226 	int rc = 0;
6227 
6228 	rc = ata_host_suspend(host, mesg);
6229 	if (rc)
6230 		return rc;
6231 
6232 	ata_pci_device_do_suspend(pdev, mesg);
6233 
6234 	return 0;
6235 }
6236 
6237 int ata_pci_device_resume(struct pci_dev *pdev)
6238 {
6239 	struct ata_host *host = dev_get_drvdata(&pdev->dev);
6240 
6241 	ata_pci_device_do_resume(pdev);
6242 	ata_host_resume(host);
6243 	return 0;
6244 }
6245 #endif /* CONFIG_PCI */
6246 
6247 
6248 static int __init ata_init(void)
6249 {
6250 	ata_probe_timeout *= HZ;
6251 	ata_wq = create_workqueue("ata");
6252 	if (!ata_wq)
6253 		return -ENOMEM;
6254 
6255 	ata_aux_wq = create_singlethread_workqueue("ata_aux");
6256 	if (!ata_aux_wq) {
6257 		destroy_workqueue(ata_wq);
6258 		return -ENOMEM;
6259 	}
6260 
6261 	printk(KERN_DEBUG "libata version " DRV_VERSION " loaded.\n");
6262 	return 0;
6263 }
6264 
6265 static void __exit ata_exit(void)
6266 {
6267 	destroy_workqueue(ata_wq);
6268 	destroy_workqueue(ata_aux_wq);
6269 }
6270 
6271 subsys_initcall(ata_init);
6272 module_exit(ata_exit);
6273 
6274 static unsigned long ratelimit_time;
6275 static DEFINE_SPINLOCK(ata_ratelimit_lock);
6276 
6277 int ata_ratelimit(void)
6278 {
6279 	int rc;
6280 	unsigned long flags;
6281 
6282 	spin_lock_irqsave(&ata_ratelimit_lock, flags);
6283 
6284 	if (time_after(jiffies, ratelimit_time)) {
6285 		rc = 1;
6286 		ratelimit_time = jiffies + (HZ/5);
6287 	} else
6288 		rc = 0;
6289 
6290 	spin_unlock_irqrestore(&ata_ratelimit_lock, flags);
6291 
6292 	return rc;
6293 }
6294 
6295 /**
6296  *	ata_wait_register - wait until register value changes
6297  *	@reg: IO-mapped register
6298  *	@mask: Mask to apply to read register value
6299  *	@val: Wait condition
6300  *	@interval_msec: polling interval in milliseconds
6301  *	@timeout_msec: timeout in milliseconds
6302  *
6303  *	Waiting for some bits of register to change is a common
6304  *	operation for ATA controllers.  This function reads 32bit LE
6305  *	IO-mapped register @reg and tests for the following condition.
6306  *
6307  *	(*@reg & mask) != val
6308  *
6309  *	If the condition is met, it returns; otherwise, the process is
6310  *	repeated after @interval_msec until timeout.
6311  *
6312  *	LOCKING:
6313  *	Kernel thread context (may sleep)
6314  *
6315  *	RETURNS:
6316  *	The final register value.
6317  */
6318 u32 ata_wait_register(void __iomem *reg, u32 mask, u32 val,
6319 		      unsigned long interval_msec,
6320 		      unsigned long timeout_msec)
6321 {
6322 	unsigned long timeout;
6323 	u32 tmp;
6324 
6325 	tmp = ioread32(reg);
6326 
6327 	/* Calculate timeout _after_ the first read to make sure
6328 	 * preceding writes reach the controller before starting to
6329 	 * eat away the timeout.
6330 	 */
6331 	timeout = jiffies + (timeout_msec * HZ) / 1000;
6332 
6333 	while ((tmp & mask) == val && time_before(jiffies, timeout)) {
6334 		msleep(interval_msec);
6335 		tmp = ioread32(reg);
6336 	}
6337 
6338 	return tmp;
6339 }
6340 
6341 /*
6342  * Dummy port_ops
6343  */
6344 static void ata_dummy_noret(struct ata_port *ap)	{ }
6345 static int ata_dummy_ret0(struct ata_port *ap)		{ return 0; }
6346 static void ata_dummy_qc_noret(struct ata_queued_cmd *qc) { }
6347 
6348 static u8 ata_dummy_check_status(struct ata_port *ap)
6349 {
6350 	return ATA_DRDY;
6351 }
6352 
6353 static unsigned int ata_dummy_qc_issue(struct ata_queued_cmd *qc)
6354 {
6355 	return AC_ERR_SYSTEM;
6356 }
6357 
6358 const struct ata_port_operations ata_dummy_port_ops = {
6359 	.port_disable		= ata_port_disable,
6360 	.check_status		= ata_dummy_check_status,
6361 	.check_altstatus	= ata_dummy_check_status,
6362 	.dev_select		= ata_noop_dev_select,
6363 	.qc_prep		= ata_noop_qc_prep,
6364 	.qc_issue		= ata_dummy_qc_issue,
6365 	.freeze			= ata_dummy_noret,
6366 	.thaw			= ata_dummy_noret,
6367 	.error_handler		= ata_dummy_noret,
6368 	.post_internal_cmd	= ata_dummy_qc_noret,
6369 	.irq_clear		= ata_dummy_noret,
6370 	.port_start		= ata_dummy_ret0,
6371 	.port_stop		= ata_dummy_noret,
6372 };
6373 
6374 /*
6375  * libata is essentially a library of internal helper functions for
6376  * low-level ATA host controller drivers.  As such, the API/ABI is
6377  * likely to change as new drivers are added and updated.
6378  * Do not depend on ABI/API stability.
6379  */
6380 
6381 EXPORT_SYMBOL_GPL(sata_deb_timing_normal);
6382 EXPORT_SYMBOL_GPL(sata_deb_timing_hotplug);
6383 EXPORT_SYMBOL_GPL(sata_deb_timing_long);
6384 EXPORT_SYMBOL_GPL(ata_dummy_port_ops);
6385 EXPORT_SYMBOL_GPL(ata_std_bios_param);
6386 EXPORT_SYMBOL_GPL(ata_std_ports);
6387 EXPORT_SYMBOL_GPL(ata_host_init);
6388 EXPORT_SYMBOL_GPL(ata_device_add);
6389 EXPORT_SYMBOL_GPL(ata_port_detach);
6390 EXPORT_SYMBOL_GPL(ata_host_remove);
6391 EXPORT_SYMBOL_GPL(ata_sg_init);
6392 EXPORT_SYMBOL_GPL(ata_sg_init_one);
6393 EXPORT_SYMBOL_GPL(ata_hsm_move);
6394 EXPORT_SYMBOL_GPL(ata_qc_complete);
6395 EXPORT_SYMBOL_GPL(ata_qc_complete_multiple);
6396 EXPORT_SYMBOL_GPL(ata_qc_issue_prot);
6397 EXPORT_SYMBOL_GPL(ata_tf_load);
6398 EXPORT_SYMBOL_GPL(ata_tf_read);
6399 EXPORT_SYMBOL_GPL(ata_noop_dev_select);
6400 EXPORT_SYMBOL_GPL(ata_std_dev_select);
6401 EXPORT_SYMBOL_GPL(ata_tf_to_fis);
6402 EXPORT_SYMBOL_GPL(ata_tf_from_fis);
6403 EXPORT_SYMBOL_GPL(ata_check_status);
6404 EXPORT_SYMBOL_GPL(ata_altstatus);
6405 EXPORT_SYMBOL_GPL(ata_exec_command);
6406 EXPORT_SYMBOL_GPL(ata_port_start);
6407 EXPORT_SYMBOL_GPL(ata_port_stop);
6408 EXPORT_SYMBOL_GPL(ata_host_stop);
6409 EXPORT_SYMBOL_GPL(ata_interrupt);
6410 EXPORT_SYMBOL_GPL(ata_mmio_data_xfer);
6411 EXPORT_SYMBOL_GPL(ata_pio_data_xfer);
6412 EXPORT_SYMBOL_GPL(ata_pio_data_xfer_noirq);
6413 EXPORT_SYMBOL_GPL(ata_qc_prep);
6414 EXPORT_SYMBOL_GPL(ata_noop_qc_prep);
6415 EXPORT_SYMBOL_GPL(ata_bmdma_setup);
6416 EXPORT_SYMBOL_GPL(ata_bmdma_start);
6417 EXPORT_SYMBOL_GPL(ata_bmdma_irq_clear);
6418 EXPORT_SYMBOL_GPL(ata_bmdma_status);
6419 EXPORT_SYMBOL_GPL(ata_bmdma_stop);
6420 EXPORT_SYMBOL_GPL(ata_bmdma_freeze);
6421 EXPORT_SYMBOL_GPL(ata_bmdma_thaw);
6422 EXPORT_SYMBOL_GPL(ata_bmdma_drive_eh);
6423 EXPORT_SYMBOL_GPL(ata_bmdma_error_handler);
6424 EXPORT_SYMBOL_GPL(ata_bmdma_post_internal_cmd);
6425 EXPORT_SYMBOL_GPL(ata_port_probe);
6426 EXPORT_SYMBOL_GPL(sata_set_spd);
6427 EXPORT_SYMBOL_GPL(sata_phy_debounce);
6428 EXPORT_SYMBOL_GPL(sata_phy_resume);
6429 EXPORT_SYMBOL_GPL(sata_phy_reset);
6430 EXPORT_SYMBOL_GPL(__sata_phy_reset);
6431 EXPORT_SYMBOL_GPL(ata_bus_reset);
6432 EXPORT_SYMBOL_GPL(ata_std_prereset);
6433 EXPORT_SYMBOL_GPL(ata_std_softreset);
6434 EXPORT_SYMBOL_GPL(sata_port_hardreset);
6435 EXPORT_SYMBOL_GPL(sata_std_hardreset);
6436 EXPORT_SYMBOL_GPL(ata_std_postreset);
6437 EXPORT_SYMBOL_GPL(ata_dev_classify);
6438 EXPORT_SYMBOL_GPL(ata_dev_pair);
6439 EXPORT_SYMBOL_GPL(ata_port_disable);
6440 EXPORT_SYMBOL_GPL(ata_ratelimit);
6441 EXPORT_SYMBOL_GPL(ata_wait_register);
6442 EXPORT_SYMBOL_GPL(ata_busy_sleep);
6443 EXPORT_SYMBOL_GPL(ata_port_queue_task);
6444 EXPORT_SYMBOL_GPL(ata_scsi_ioctl);
6445 EXPORT_SYMBOL_GPL(ata_scsi_queuecmd);
6446 EXPORT_SYMBOL_GPL(ata_scsi_slave_config);
6447 EXPORT_SYMBOL_GPL(ata_scsi_slave_destroy);
6448 EXPORT_SYMBOL_GPL(ata_scsi_change_queue_depth);
6449 EXPORT_SYMBOL_GPL(ata_scsi_release);
6450 EXPORT_SYMBOL_GPL(ata_host_intr);
6451 EXPORT_SYMBOL_GPL(sata_scr_valid);
6452 EXPORT_SYMBOL_GPL(sata_scr_read);
6453 EXPORT_SYMBOL_GPL(sata_scr_write);
6454 EXPORT_SYMBOL_GPL(sata_scr_write_flush);
6455 EXPORT_SYMBOL_GPL(ata_port_online);
6456 EXPORT_SYMBOL_GPL(ata_port_offline);
6457 EXPORT_SYMBOL_GPL(ata_host_suspend);
6458 EXPORT_SYMBOL_GPL(ata_host_resume);
6459 EXPORT_SYMBOL_GPL(ata_id_string);
6460 EXPORT_SYMBOL_GPL(ata_id_c_string);
6461 EXPORT_SYMBOL_GPL(ata_device_blacklisted);
6462 EXPORT_SYMBOL_GPL(ata_scsi_simulate);
6463 
6464 EXPORT_SYMBOL_GPL(ata_pio_need_iordy);
6465 EXPORT_SYMBOL_GPL(ata_timing_compute);
6466 EXPORT_SYMBOL_GPL(ata_timing_merge);
6467 
6468 #ifdef CONFIG_PCI
6469 EXPORT_SYMBOL_GPL(pci_test_config_bits);
6470 EXPORT_SYMBOL_GPL(ata_pci_host_stop);
6471 EXPORT_SYMBOL_GPL(ata_pci_init_native_mode);
6472 EXPORT_SYMBOL_GPL(ata_pci_init_one);
6473 EXPORT_SYMBOL_GPL(ata_pci_remove_one);
6474 EXPORT_SYMBOL_GPL(ata_pci_device_do_suspend);
6475 EXPORT_SYMBOL_GPL(ata_pci_device_do_resume);
6476 EXPORT_SYMBOL_GPL(ata_pci_device_suspend);
6477 EXPORT_SYMBOL_GPL(ata_pci_device_resume);
6478 EXPORT_SYMBOL_GPL(ata_pci_default_filter);
6479 EXPORT_SYMBOL_GPL(ata_pci_clear_simplex);
6480 #endif /* CONFIG_PCI */
6481 
6482 EXPORT_SYMBOL_GPL(ata_scsi_device_suspend);
6483 EXPORT_SYMBOL_GPL(ata_scsi_device_resume);
6484 
6485 EXPORT_SYMBOL_GPL(ata_eng_timeout);
6486 EXPORT_SYMBOL_GPL(ata_port_schedule_eh);
6487 EXPORT_SYMBOL_GPL(ata_port_abort);
6488 EXPORT_SYMBOL_GPL(ata_port_freeze);
6489 EXPORT_SYMBOL_GPL(ata_eh_freeze_port);
6490 EXPORT_SYMBOL_GPL(ata_eh_thaw_port);
6491 EXPORT_SYMBOL_GPL(ata_eh_qc_complete);
6492 EXPORT_SYMBOL_GPL(ata_eh_qc_retry);
6493 EXPORT_SYMBOL_GPL(ata_do_eh);
6494