ide: fix registers loading order in ide_dump_ata_status()
[deliverable/linux.git] / drivers / ide / ide-io.c
CommitLineData
1da177e4
LT
1/*
2 * IDE I/O functions
3 *
4 * Basic PIO and command management functionality.
5 *
6 * This code was split off from ide.c. See ide.c for history and original
7 * copyrights.
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2, or (at your option) any
12 * later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * For the avoidance of doubt the "preferred form" of this code is one which
20 * is in an open non patent encumbered format. Where cryptographic key signing
21 * forms part of the process of creating an executable the information
22 * including keys needed to generate an equivalently functional executable
23 * are deemed to be part of the source code.
24 */
25
26
1da177e4
LT
27#include <linux/module.h>
28#include <linux/types.h>
29#include <linux/string.h>
30#include <linux/kernel.h>
31#include <linux/timer.h>
32#include <linux/mm.h>
33#include <linux/interrupt.h>
34#include <linux/major.h>
35#include <linux/errno.h>
36#include <linux/genhd.h>
37#include <linux/blkpg.h>
38#include <linux/slab.h>
39#include <linux/init.h>
40#include <linux/pci.h>
41#include <linux/delay.h>
42#include <linux/ide.h>
43#include <linux/completion.h>
44#include <linux/reboot.h>
45#include <linux/cdrom.h>
46#include <linux/seq_file.h>
47#include <linux/device.h>
48#include <linux/kmod.h>
49#include <linux/scatterlist.h>
1977f032 50#include <linux/bitops.h>
1da177e4
LT
51
52#include <asm/byteorder.h>
53#include <asm/irq.h>
54#include <asm/uaccess.h>
55#include <asm/io.h>
1da177e4 56
a7ff7d41 57static int __ide_end_request(ide_drive_t *drive, struct request *rq,
bbc615b1 58 int uptodate, unsigned int nr_bytes, int dequeue)
1da177e4
LT
59{
60 int ret = 1;
61
1da177e4
LT
62 /*
63 * if failfast is set on a request, override number of sectors and
64 * complete the whole request right now
65 */
66 if (blk_noretry_request(rq) && end_io_error(uptodate))
41e9d344 67 nr_bytes = rq->hard_nr_sectors << 9;
1da177e4
LT
68
69 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
70 rq->errors = -EIO;
71
72 /*
73 * decide whether to reenable DMA -- 3 is a random magic for now,
74 * if we DMA timeout more than 3 times, just stay in PIO
75 */
76 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
77 drive->state = 0;
78 HWGROUP(drive)->hwif->ide_dma_on(drive);
79 }
80
41e9d344 81 if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
ba027def 82 add_disk_randomness(rq->rq_disk);
bbc615b1
BZ
83 if (dequeue) {
84 if (!list_empty(&rq->queuelist))
85 blkdev_dequeue_request(rq);
86 HWGROUP(drive)->rq = NULL;
87 }
ba027def 88 end_that_request_last(rq, uptodate);
1da177e4
LT
89 ret = 0;
90 }
8672d571 91
1da177e4
LT
92 return ret;
93}
1da177e4
LT
94
95/**
96 * ide_end_request - complete an IDE I/O
97 * @drive: IDE device for the I/O
98 * @uptodate:
99 * @nr_sectors: number of sectors completed
100 *
101 * This is our end_request wrapper function. We complete the I/O
102 * update random number input and dequeue the request, which if
103 * it was tagged may be out of order.
104 */
105
106int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
107{
41e9d344 108 unsigned int nr_bytes = nr_sectors << 9;
1da177e4
LT
109 struct request *rq;
110 unsigned long flags;
111 int ret = 1;
112
8672d571
JA
113 /*
114 * room for locking improvements here, the calls below don't
115 * need the queue lock held at all
116 */
1da177e4
LT
117 spin_lock_irqsave(&ide_lock, flags);
118 rq = HWGROUP(drive)->rq;
119
41e9d344
JA
120 if (!nr_bytes) {
121 if (blk_pc_request(rq))
122 nr_bytes = rq->data_len;
123 else
124 nr_bytes = rq->hard_cur_sectors << 9;
125 }
1da177e4 126
bbc615b1 127 ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
1da177e4
LT
128
129 spin_unlock_irqrestore(&ide_lock, flags);
130 return ret;
131}
132EXPORT_SYMBOL(ide_end_request);
133
134/*
135 * Power Management state machine. This one is rather trivial for now,
136 * we should probably add more, like switching back to PIO on suspend
137 * to help some BIOSes, re-do the door locking on resume, etc...
138 */
139
140enum {
141 ide_pm_flush_cache = ide_pm_state_start_suspend,
142 idedisk_pm_standby,
143
8c2c0118
JL
144 idedisk_pm_restore_pio = ide_pm_state_start_resume,
145 idedisk_pm_idle,
1da177e4
LT
146 ide_pm_restore_dma,
147};
148
149static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
150{
c00895ab 151 struct request_pm_state *pm = rq->data;
ad3cadda 152
1da177e4
LT
153 if (drive->media != ide_disk)
154 return;
155
ad3cadda 156 switch (pm->pm_step) {
1da177e4 157 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
ad3cadda
JA
158 if (pm->pm_state == PM_EVENT_FREEZE)
159 pm->pm_step = ide_pm_state_completed;
1da177e4 160 else
ad3cadda 161 pm->pm_step = idedisk_pm_standby;
1da177e4
LT
162 break;
163 case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
ad3cadda 164 pm->pm_step = ide_pm_state_completed;
1da177e4 165 break;
8c2c0118
JL
166 case idedisk_pm_restore_pio: /* Resume step 1 complete */
167 pm->pm_step = idedisk_pm_idle;
168 break;
169 case idedisk_pm_idle: /* Resume step 2 (idle) complete */
ad3cadda 170 pm->pm_step = ide_pm_restore_dma;
1da177e4
LT
171 break;
172 }
173}
174
175static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
176{
c00895ab 177 struct request_pm_state *pm = rq->data;
1da177e4
LT
178 ide_task_t *args = rq->special;
179
180 memset(args, 0, sizeof(*args));
181
ad3cadda 182 switch (pm->pm_step) {
1da177e4
LT
183 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */
184 if (drive->media != ide_disk)
185 break;
186 /* Not supported? Switch to next step now. */
187 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
188 ide_complete_power_step(drive, rq, 0, 0);
189 return ide_stopped;
190 }
191 if (ide_id_has_flush_cache_ext(drive->id))
650d841d 192 args->tf.command = WIN_FLUSH_CACHE_EXT;
1da177e4 193 else
650d841d 194 args->tf.command = WIN_FLUSH_CACHE;
74095a91 195 goto out_do_tf;
1da177e4
LT
196
197 case idedisk_pm_standby: /* Suspend step 2 (standby) */
650d841d 198 args->tf.command = WIN_STANDBYNOW1;
74095a91 199 goto out_do_tf;
1da177e4 200
8c2c0118 201 case idedisk_pm_restore_pio: /* Resume step 1 (restore PIO) */
26bcb879 202 ide_set_max_pio(drive);
317a46a2
BZ
203 /*
204 * skip idedisk_pm_idle for ATAPI devices
205 */
206 if (drive->media != ide_disk)
207 pm->pm_step = ide_pm_restore_dma;
208 else
209 ide_complete_power_step(drive, rq, 0, 0);
8c2c0118
JL
210 return ide_stopped;
211
212 case idedisk_pm_idle: /* Resume step 2 (idle) */
650d841d 213 args->tf.command = WIN_IDLEIMMEDIATE;
74095a91 214 goto out_do_tf;
1da177e4 215
8c2c0118 216 case ide_pm_restore_dma: /* Resume step 3 (restore DMA) */
1da177e4 217 /*
0ae2e178 218 * Right now, all we do is call ide_set_dma(drive),
1da177e4
LT
219 * we could be smarter and check for current xfer_speed
220 * in struct drive etc...
221 */
0ae2e178 222 if (drive->hwif->ide_dma_on == NULL)
1da177e4 223 break;
793a9722 224 drive->hwif->dma_off_quietly(drive);
8987d21b
BZ
225 /*
226 * TODO: respect ->using_dma setting
227 */
3608b5d7 228 ide_set_dma(drive);
1da177e4
LT
229 break;
230 }
ad3cadda 231 pm->pm_step = ide_pm_state_completed;
1da177e4 232 return ide_stopped;
74095a91
BZ
233
234out_do_tf:
ac026ff2
BZ
235 args->tf_flags = IDE_TFLAG_OUT_TF | IDE_TFLAG_OUT_DEVICE;
236 args->data_phase = TASKFILE_NO_DATA;
74095a91 237 return do_rw_taskfile(drive, args);
1da177e4
LT
238}
239
dbe217af
AC
240/**
241 * ide_end_dequeued_request - complete an IDE I/O
242 * @drive: IDE device for the I/O
243 * @uptodate:
244 * @nr_sectors: number of sectors completed
245 *
246 * Complete an I/O that is no longer on the request queue. This
247 * typically occurs when we pull the request and issue a REQUEST_SENSE.
248 * We must still finish the old request but we must not tamper with the
249 * queue in the meantime.
250 *
251 * NOTE: This path does not handle barrier, but barrier is not supported
252 * on ide-cd anyway.
253 */
254
255int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
256 int uptodate, int nr_sectors)
257{
258 unsigned long flags;
bbc615b1 259 int ret;
dbe217af
AC
260
261 spin_lock_irqsave(&ide_lock, flags);
4aff5e23 262 BUG_ON(!blk_rq_started(rq));
bbc615b1 263 ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
dbe217af 264 spin_unlock_irqrestore(&ide_lock, flags);
bbc615b1 265
dbe217af
AC
266 return ret;
267}
268EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
269
270
1da177e4
LT
271/**
272 * ide_complete_pm_request - end the current Power Management request
273 * @drive: target drive
274 * @rq: request
275 *
276 * This function cleans up the current PM request and stops the queue
277 * if necessary.
278 */
279static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
280{
281 unsigned long flags;
282
283#ifdef DEBUG_PM
284 printk("%s: completing PM request, %s\n", drive->name,
285 blk_pm_suspend_request(rq) ? "suspend" : "resume");
286#endif
287 spin_lock_irqsave(&ide_lock, flags);
288 if (blk_pm_suspend_request(rq)) {
289 blk_stop_queue(drive->queue);
290 } else {
291 drive->blocked = 0;
292 blk_start_queue(drive->queue);
293 }
294 blkdev_dequeue_request(rq);
295 HWGROUP(drive)->rq = NULL;
8ffdc655 296 end_that_request_last(rq, 1);
1da177e4
LT
297 spin_unlock_irqrestore(&ide_lock, flags);
298}
299
1da177e4
LT
300/**
301 * ide_end_drive_cmd - end an explicit drive command
302 * @drive: command
303 * @stat: status bits
304 * @err: error bits
305 *
306 * Clean up after success/failure of an explicit drive command.
307 * These get thrown onto the queue so they are synchronized with
308 * real I/O operations on the drive.
309 *
310 * In LBA48 mode we have to read the register set twice to get
311 * all the extra information out.
312 */
313
314void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
315{
316 ide_hwif_t *hwif = HWIF(drive);
317 unsigned long flags;
318 struct request *rq;
319
320 spin_lock_irqsave(&ide_lock, flags);
321 rq = HWGROUP(drive)->rq;
322 spin_unlock_irqrestore(&ide_lock, flags);
323
4aff5e23 324 if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
1da177e4
LT
325 u8 *args = (u8 *) rq->buffer;
326 if (rq->errors == 0)
327 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
328
329 if (args) {
330 args[0] = stat;
331 args[1] = err;
332 args[2] = hwif->INB(IDE_NSECTOR_REG);
333 }
4aff5e23 334 } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
1da177e4
LT
335 ide_task_t *args = (ide_task_t *) rq->special;
336 if (rq->errors == 0)
337 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
338
339 if (args) {
650d841d
BZ
340 struct ide_taskfile *tf = &args->tf;
341
866e2ec9 342 if (args->tf_flags & IDE_TFLAG_IN_DATA) {
650d841d
BZ
343 u16 data = hwif->INW(IDE_DATA_REG);
344
345 tf->data = data & 0xff;
346 tf->hob_data = (data >> 8) & 0xff;
1da177e4 347 }
650d841d 348 tf->error = err;
1da177e4
LT
349 /* be sure we're looking at the low order bits */
350 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
650d841d
BZ
351 tf->nsect = hwif->INB(IDE_NSECTOR_REG);
352 tf->lbal = hwif->INB(IDE_SECTOR_REG);
353 tf->lbam = hwif->INB(IDE_LCYL_REG);
354 tf->lbah = hwif->INB(IDE_HCYL_REG);
355 tf->device = hwif->INB(IDE_SELECT_REG);
356 tf->status = stat;
1da177e4 357
868e672a 358 if (args->tf_flags & IDE_TFLAG_LBA48) {
1da177e4 359 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
650d841d
BZ
360 tf->hob_feature = hwif->INB(IDE_FEATURE_REG);
361 tf->hob_nsect = hwif->INB(IDE_NSECTOR_REG);
362 tf->hob_lbal = hwif->INB(IDE_SECTOR_REG);
363 tf->hob_lbam = hwif->INB(IDE_LCYL_REG);
364 tf->hob_lbah = hwif->INB(IDE_HCYL_REG);
1da177e4
LT
365 }
366 }
367 } else if (blk_pm_request(rq)) {
c00895ab 368 struct request_pm_state *pm = rq->data;
1da177e4
LT
369#ifdef DEBUG_PM
370 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
371 drive->name, rq->pm->pm_step, stat, err);
372#endif
373 ide_complete_power_step(drive, rq, stat, err);
ad3cadda 374 if (pm->pm_step == ide_pm_state_completed)
1da177e4
LT
375 ide_complete_pm_request(drive, rq);
376 return;
377 }
378
379 spin_lock_irqsave(&ide_lock, flags);
380 blkdev_dequeue_request(rq);
381 HWGROUP(drive)->rq = NULL;
382 rq->errors = err;
8ffdc655 383 end_that_request_last(rq, !rq->errors);
1da177e4
LT
384 spin_unlock_irqrestore(&ide_lock, flags);
385}
386
387EXPORT_SYMBOL(ide_end_drive_cmd);
388
389/**
390 * try_to_flush_leftover_data - flush junk
391 * @drive: drive to flush
392 *
393 * try_to_flush_leftover_data() is invoked in response to a drive
394 * unexpectedly having its DRQ_STAT bit set. As an alternative to
395 * resetting the drive, this routine tries to clear the condition
396 * by read a sector's worth of data from the drive. Of course,
397 * this may not help if the drive is *waiting* for data from *us*.
398 */
399static void try_to_flush_leftover_data (ide_drive_t *drive)
400{
401 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
402
403 if (drive->media != ide_disk)
404 return;
405 while (i > 0) {
406 u32 buffer[16];
407 u32 wcount = (i > 16) ? 16 : i;
408
409 i -= wcount;
410 HWIF(drive)->ata_input_data(drive, buffer, wcount);
411 }
412}
413
414static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
415{
416 if (rq->rq_disk) {
417 ide_driver_t *drv;
418
419 drv = *(ide_driver_t **)rq->rq_disk->private_data;
420 drv->end_request(drive, 0, 0);
421 } else
422 ide_end_request(drive, 0, 0);
423}
424
425static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
426{
427 ide_hwif_t *hwif = drive->hwif;
428
429 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
430 /* other bits are useless when BUSY */
431 rq->errors |= ERROR_RESET;
432 } else if (stat & ERR_STAT) {
433 /* err has different meaning on cdrom and tape */
434 if (err == ABRT_ERR) {
435 if (drive->select.b.lba &&
436 /* some newer drives don't support WIN_SPECIFY */
437 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
438 return ide_stopped;
439 } else if ((err & BAD_CRC) == BAD_CRC) {
440 /* UDMA crc error, just retry the operation */
441 drive->crc_count++;
442 } else if (err & (BBD_ERR | ECC_ERR)) {
443 /* retries won't help these */
444 rq->errors = ERROR_MAX;
445 } else if (err & TRK0_ERR) {
446 /* help it find track zero */
447 rq->errors |= ERROR_RECAL;
448 }
449 }
450
ed67b923
BZ
451 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ &&
452 (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0)
1da177e4
LT
453 try_to_flush_leftover_data(drive);
454
513daadd
SS
455 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
456 ide_kill_rq(drive, rq);
457 return ide_stopped;
458 }
459
1da177e4 460 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
513daadd 461 rq->errors |= ERROR_RESET;
1da177e4 462
513daadd 463 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
1da177e4 464 ++rq->errors;
513daadd 465 return ide_do_reset(drive);
1da177e4 466 }
513daadd
SS
467
468 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
469 drive->special.b.recalibrate = 1;
470
471 ++rq->errors;
472
1da177e4
LT
473 return ide_stopped;
474}
475
476static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
477{
478 ide_hwif_t *hwif = drive->hwif;
479
480 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
481 /* other bits are useless when BUSY */
482 rq->errors |= ERROR_RESET;
483 } else {
484 /* add decoding error stuff */
485 }
486
487 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
488 /* force an abort */
489 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
490
491 if (rq->errors >= ERROR_MAX) {
492 ide_kill_rq(drive, rq);
493 } else {
494 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
495 ++rq->errors;
496 return ide_do_reset(drive);
497 }
498 ++rq->errors;
499 }
500
501 return ide_stopped;
502}
503
504ide_startstop_t
505__ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
506{
507 if (drive->media == ide_disk)
508 return ide_ata_error(drive, rq, stat, err);
509 return ide_atapi_error(drive, rq, stat, err);
510}
511
512EXPORT_SYMBOL_GPL(__ide_error);
513
514/**
515 * ide_error - handle an error on the IDE
516 * @drive: drive the error occurred on
517 * @msg: message to report
518 * @stat: status bits
519 *
520 * ide_error() takes action based on the error returned by the drive.
521 * For normal I/O that may well include retries. We deal with
522 * both new-style (taskfile) and old style command handling here.
523 * In the case of taskfile command handling there is work left to
524 * do
525 */
526
527ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
528{
529 struct request *rq;
530 u8 err;
531
532 err = ide_dump_status(drive, msg, stat);
533
534 if ((rq = HWGROUP(drive)->rq) == NULL)
535 return ide_stopped;
536
537 /* retry only "normal" I/O: */
4aff5e23 538 if (!blk_fs_request(rq)) {
1da177e4
LT
539 rq->errors = 1;
540 ide_end_drive_cmd(drive, stat, err);
541 return ide_stopped;
542 }
543
544 if (rq->rq_disk) {
545 ide_driver_t *drv;
546
547 drv = *(ide_driver_t **)rq->rq_disk->private_data;
548 return drv->error(drive, rq, stat, err);
549 } else
550 return __ide_error(drive, rq, stat, err);
551}
552
553EXPORT_SYMBOL_GPL(ide_error);
554
555ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
556{
557 if (drive->media != ide_disk)
558 rq->errors |= ERROR_RESET;
559
560 ide_kill_rq(drive, rq);
561
562 return ide_stopped;
563}
564
565EXPORT_SYMBOL_GPL(__ide_abort);
566
567/**
338cec32 568 * ide_abort - abort pending IDE operations
1da177e4
LT
569 * @drive: drive the error occurred on
570 * @msg: message to report
571 *
572 * ide_abort kills and cleans up when we are about to do a
573 * host initiated reset on active commands. Longer term we
574 * want handlers to have sensible abort handling themselves
575 *
576 * This differs fundamentally from ide_error because in
577 * this case the command is doing just fine when we
578 * blow it away.
579 */
580
581ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
582{
583 struct request *rq;
584
585 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
586 return ide_stopped;
587
588 /* retry only "normal" I/O: */
4aff5e23 589 if (!blk_fs_request(rq)) {
1da177e4
LT
590 rq->errors = 1;
591 ide_end_drive_cmd(drive, BUSY_STAT, 0);
592 return ide_stopped;
593 }
594
595 if (rq->rq_disk) {
596 ide_driver_t *drv;
597
598 drv = *(ide_driver_t **)rq->rq_disk->private_data;
599 return drv->abort(drive, rq);
600 } else
601 return __ide_abort(drive, rq);
602}
603
1da177e4
LT
604/**
605 * drive_cmd_intr - drive command completion interrupt
606 * @drive: drive the completion interrupt occurred on
607 *
608 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
338cec32 609 * We do any necessary data reading and then wait for the drive to
1da177e4
LT
610 * go non busy. At that point we may read the error data and complete
611 * the request
612 */
613
614static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
615{
616 struct request *rq = HWGROUP(drive)->rq;
617 ide_hwif_t *hwif = HWIF(drive);
618 u8 *args = (u8 *) rq->buffer;
619 u8 stat = hwif->INB(IDE_STATUS_REG);
620 int retries = 10;
621
366c7f55 622 local_irq_enable_in_hardirq();
320112bd
BZ
623 if (rq->cmd_type == REQ_TYPE_ATA_CMD &&
624 (stat & DRQ_STAT) && args && args[3]) {
1da177e4
LT
625 u8 io_32bit = drive->io_32bit;
626 drive->io_32bit = 0;
627 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
628 drive->io_32bit = io_32bit;
629 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
630 udelay(100);
631 }
632
633 if (!OK_STAT(stat, READY_STAT, BAD_STAT))
634 return ide_error(drive, "drive_cmd", stat);
635 /* calls ide_end_drive_cmd */
636 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
637 return ide_stopped;
638}
639
57d7366b 640static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
1da177e4 641{
57d7366b
BZ
642 tf->nsect = drive->sect;
643 tf->lbal = drive->sect;
644 tf->lbam = drive->cyl;
645 tf->lbah = drive->cyl >> 8;
646 tf->device = ((drive->head - 1) | drive->select.all) & ~ATA_LBA;
647 tf->command = WIN_SPECIFY;
1da177e4
LT
648}
649
57d7366b 650static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
1da177e4 651{
57d7366b
BZ
652 tf->nsect = drive->sect;
653 tf->command = WIN_RESTORE;
1da177e4
LT
654}
655
57d7366b 656static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
1da177e4 657{
57d7366b
BZ
658 tf->nsect = drive->mult_req;
659 tf->command = WIN_SETMULT;
1da177e4
LT
660}
661
662static ide_startstop_t ide_disk_special(ide_drive_t *drive)
663{
664 special_t *s = &drive->special;
665 ide_task_t args;
666
667 memset(&args, 0, sizeof(ide_task_t));
ac026ff2 668 args.data_phase = TASKFILE_NO_DATA;
1da177e4
LT
669
670 if (s->b.set_geometry) {
671 s->b.set_geometry = 0;
57d7366b 672 ide_tf_set_specify_cmd(drive, &args.tf);
1da177e4
LT
673 } else if (s->b.recalibrate) {
674 s->b.recalibrate = 0;
57d7366b 675 ide_tf_set_restore_cmd(drive, &args.tf);
1da177e4
LT
676 } else if (s->b.set_multmode) {
677 s->b.set_multmode = 0;
678 if (drive->mult_req > drive->id->max_multsect)
679 drive->mult_req = drive->id->max_multsect;
57d7366b 680 ide_tf_set_setmult_cmd(drive, &args.tf);
1da177e4
LT
681 } else if (s->all) {
682 int special = s->all;
683 s->all = 0;
684 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
685 return ide_stopped;
686 }
687
57d7366b
BZ
688 args.tf_flags = IDE_TFLAG_OUT_TF | IDE_TFLAG_OUT_DEVICE |
689 IDE_TFLAG_CUSTOM_HANDLER;
74095a91 690
1da177e4
LT
691 do_rw_taskfile(drive, &args);
692
693 return ide_started;
694}
695
26bcb879
BZ
696/*
697 * handle HDIO_SET_PIO_MODE ioctl abusers here, eventually it will go away
698 */
699static int set_pio_mode_abuse(ide_hwif_t *hwif, u8 req_pio)
700{
701 switch (req_pio) {
702 case 202:
703 case 201:
704 case 200:
705 case 102:
706 case 101:
707 case 100:
708 return (hwif->host_flags & IDE_HFLAG_ABUSE_DMA_MODES) ? 1 : 0;
709 case 9:
710 case 8:
711 return (hwif->host_flags & IDE_HFLAG_ABUSE_PREFETCH) ? 1 : 0;
712 case 7:
713 case 6:
714 return (hwif->host_flags & IDE_HFLAG_ABUSE_FAST_DEVSEL) ? 1 : 0;
715 default:
716 return 0;
717 }
718}
719
1da177e4
LT
720/**
721 * do_special - issue some special commands
722 * @drive: drive the command is for
723 *
724 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
725 * commands to a drive. It used to do much more, but has been scaled
726 * back.
727 */
728
729static ide_startstop_t do_special (ide_drive_t *drive)
730{
731 special_t *s = &drive->special;
732
733#ifdef DEBUG
734 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
735#endif
736 if (s->b.set_tune) {
26bcb879
BZ
737 ide_hwif_t *hwif = drive->hwif;
738 u8 req_pio = drive->tune_req;
739
1da177e4 740 s->b.set_tune = 0;
26bcb879
BZ
741
742 if (set_pio_mode_abuse(drive->hwif, req_pio)) {
d393aa03
BZ
743
744 if (hwif->set_pio_mode == NULL)
745 return ide_stopped;
746
747 /*
748 * take ide_lock for drive->[no_]unmask/[no_]io_32bit
749 */
750 if (req_pio == 8 || req_pio == 9) {
751 unsigned long flags;
752
753 spin_lock_irqsave(&ide_lock, flags);
754 hwif->set_pio_mode(drive, req_pio);
755 spin_unlock_irqrestore(&ide_lock, flags);
756 } else
26bcb879 757 hwif->set_pio_mode(drive, req_pio);
aedea591
BZ
758 } else {
759 int keep_dma = drive->using_dma;
760
26bcb879
BZ
761 ide_set_pio(drive, req_pio);
762
aedea591
BZ
763 if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
764 if (keep_dma)
765 hwif->ide_dma_on(drive);
766 }
767 }
768
1da177e4
LT
769 return ide_stopped;
770 } else {
771 if (drive->media == ide_disk)
772 return ide_disk_special(drive);
773
774 s->all = 0;
775 drive->mult_req = 0;
776 return ide_stopped;
777 }
778}
779
780void ide_map_sg(ide_drive_t *drive, struct request *rq)
781{
782 ide_hwif_t *hwif = drive->hwif;
783 struct scatterlist *sg = hwif->sg_table;
784
785 if (hwif->sg_mapped) /* needed by ide-scsi */
786 return;
787
4aff5e23 788 if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
1da177e4
LT
789 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
790 } else {
791 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
792 hwif->sg_nents = 1;
793 }
794}
795
796EXPORT_SYMBOL_GPL(ide_map_sg);
797
798void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
799{
800 ide_hwif_t *hwif = drive->hwif;
801
802 hwif->nsect = hwif->nleft = rq->nr_sectors;
55c16a70
JA
803 hwif->cursg_ofs = 0;
804 hwif->cursg = NULL;
1da177e4
LT
805}
806
807EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
808
809/**
810 * execute_drive_command - issue special drive command
338cec32 811 * @drive: the drive to issue the command on
1da177e4
LT
812 * @rq: the request structure holding the command
813 *
814 * execute_drive_cmd() issues a special drive command, usually
815 * initiated by ioctl() from the external hdparm program. The
816 * command can be a drive command, drive task or taskfile
817 * operation. Weirdly you can call it with NULL to wait for
818 * all commands to finish. Don't do this as that is due to change
819 */
820
821static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
822 struct request *rq)
823{
824 ide_hwif_t *hwif = HWIF(drive);
21d535c9 825 u8 *args = rq->buffer;
807e35d6
BZ
826 ide_task_t ltask;
827 struct ide_taskfile *tf = &ltask.tf;
21d535c9 828
4aff5e23 829 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
21d535c9 830 ide_task_t *task = rq->special;
1da177e4 831
21d535c9 832 if (task == NULL)
1da177e4
LT
833 goto done;
834
21d535c9 835 hwif->data_phase = task->data_phase;
1da177e4
LT
836
837 switch (hwif->data_phase) {
838 case TASKFILE_MULTI_OUT:
839 case TASKFILE_OUT:
840 case TASKFILE_MULTI_IN:
841 case TASKFILE_IN:
842 ide_init_sg_cmd(drive, rq);
843 ide_map_sg(drive, rq);
844 default:
845 break;
846 }
74095a91 847
21d535c9
BZ
848 return do_rw_taskfile(drive, task);
849 }
850
851 if (args == NULL)
852 goto done;
853
807e35d6 854 memset(&ltask, 0, sizeof(ltask));
29ed2a5f 855 if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
1da177e4 856#ifdef DEBUG
807e35d6 857 printk("%s: DRIVE_CMD\n", drive->name);
1da177e4 858#endif
807e35d6
BZ
859 tf->feature = args[2];
860 if (args[0] == WIN_SMART) {
861 tf->nsect = args[3];
862 tf->lbal = args[1];
863 tf->lbam = 0x4f;
864 tf->lbah = 0xc2;
865 ltask.tf_flags = IDE_TFLAG_OUT_TF;
866 } else {
867 tf->nsect = args[1];
868 ltask.tf_flags = IDE_TFLAG_OUT_FEATURE |
869 IDE_TFLAG_OUT_NSECT;
870 }
1da177e4 871 }
807e35d6
BZ
872 tf->command = args[0];
873 ide_tf_load(drive, &ltask);
1f2564b8 874 ide_execute_command(drive, args[0], &drive_cmd_intr, WAIT_WORSTCASE, NULL);
21d535c9
BZ
875 return ide_started;
876
1da177e4
LT
877done:
878 /*
879 * NULL is actually a valid way of waiting for
880 * all current requests to be flushed from the queue.
881 */
882#ifdef DEBUG
883 printk("%s: DRIVE_CMD (null)\n", drive->name);
884#endif
885 ide_end_drive_cmd(drive,
886 hwif->INB(IDE_STATUS_REG),
887 hwif->INB(IDE_ERROR_REG));
888 return ide_stopped;
889}
890
ad3cadda
JA
891static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
892{
c00895ab 893 struct request_pm_state *pm = rq->data;
ad3cadda
JA
894
895 if (blk_pm_suspend_request(rq) &&
896 pm->pm_step == ide_pm_state_start_suspend)
897 /* Mark drive blocked when starting the suspend sequence. */
898 drive->blocked = 1;
899 else if (blk_pm_resume_request(rq) &&
900 pm->pm_step == ide_pm_state_start_resume) {
901 /*
902 * The first thing we do on wakeup is to wait for BSY bit to
903 * go away (with a looong timeout) as a drive on this hwif may
904 * just be POSTing itself.
905 * We do that before even selecting as the "other" device on
906 * the bus may be broken enough to walk on our toes at this
907 * point.
908 */
909 int rc;
910#ifdef DEBUG_PM
911 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
912#endif
913 rc = ide_wait_not_busy(HWIF(drive), 35000);
914 if (rc)
915 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
916 SELECT_DRIVE(drive);
ad0e74d3
BZ
917 if (IDE_CONTROL_REG)
918 HWIF(drive)->OUTB(drive->ctl, IDE_CONTROL_REG);
178184b6 919 rc = ide_wait_not_busy(HWIF(drive), 100000);
ad3cadda
JA
920 if (rc)
921 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
922 }
923}
924
1da177e4
LT
925/**
926 * start_request - start of I/O and command issuing for IDE
927 *
928 * start_request() initiates handling of a new I/O request. It
929 * accepts commands and I/O (read/write) requests. It also does
930 * the final remapping for weird stuff like EZDrive. Once
931 * device mapper can work sector level the EZDrive stuff can go away
932 *
933 * FIXME: this function needs a rename
934 */
935
936static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
937{
938 ide_startstop_t startstop;
939 sector_t block;
940
4aff5e23 941 BUG_ON(!blk_rq_started(rq));
1da177e4
LT
942
943#ifdef DEBUG
944 printk("%s: start_request: current=0x%08lx\n",
945 HWIF(drive)->name, (unsigned long) rq);
946#endif
947
948 /* bail early if we've exceeded max_failures */
949 if (drive->max_failures && (drive->failures > drive->max_failures)) {
b5e1a4e2 950 rq->cmd_flags |= REQ_FAILED;
1da177e4
LT
951 goto kill_rq;
952 }
953
954 block = rq->sector;
955 if (blk_fs_request(rq) &&
956 (drive->media == ide_disk || drive->media == ide_floppy)) {
957 block += drive->sect0;
958 }
959 /* Yecch - this will shift the entire interval,
960 possibly killing some innocent following sector */
961 if (block == 0 && drive->remap_0_to_1 == 1)
962 block = 1; /* redirect MBR access to EZ-Drive partn table */
963
ad3cadda
JA
964 if (blk_pm_request(rq))
965 ide_check_pm_state(drive, rq);
1da177e4
LT
966
967 SELECT_DRIVE(drive);
968 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
969 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
970 return startstop;
971 }
972 if (!drive->special.all) {
973 ide_driver_t *drv;
974
513daadd
SS
975 /*
976 * We reset the drive so we need to issue a SETFEATURES.
977 * Do it _after_ do_special() restored device parameters.
978 */
979 if (drive->current_speed == 0xff)
980 ide_config_drive_speed(drive, drive->desired_speed);
981
4aff5e23 982 if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
4aff5e23 983 rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
1da177e4
LT
984 return execute_drive_cmd(drive, rq);
985 else if (blk_pm_request(rq)) {
c00895ab 986 struct request_pm_state *pm = rq->data;
1da177e4
LT
987#ifdef DEBUG_PM
988 printk("%s: start_power_step(step: %d)\n",
989 drive->name, rq->pm->pm_step);
990#endif
991 startstop = ide_start_power_step(drive, rq);
992 if (startstop == ide_stopped &&
ad3cadda 993 pm->pm_step == ide_pm_state_completed)
1da177e4
LT
994 ide_complete_pm_request(drive, rq);
995 return startstop;
996 }
997
998 drv = *(ide_driver_t **)rq->rq_disk->private_data;
999 return drv->do_request(drive, rq, block);
1000 }
1001 return do_special(drive);
1002kill_rq:
1003 ide_kill_rq(drive, rq);
1004 return ide_stopped;
1005}
1006
1007/**
1008 * ide_stall_queue - pause an IDE device
1009 * @drive: drive to stall
1010 * @timeout: time to stall for (jiffies)
1011 *
1012 * ide_stall_queue() can be used by a drive to give excess bandwidth back
1013 * to the hwgroup by sleeping for timeout jiffies.
1014 */
1015
1016void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1017{
1018 if (timeout > WAIT_WORSTCASE)
1019 timeout = WAIT_WORSTCASE;
1020 drive->sleep = timeout + jiffies;
1021 drive->sleeping = 1;
1022}
1023
1024EXPORT_SYMBOL(ide_stall_queue);
1025
1026#define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
1027
1028/**
1029 * choose_drive - select a drive to service
1030 * @hwgroup: hardware group to select on
1031 *
1032 * choose_drive() selects the next drive which will be serviced.
1033 * This is necessary because the IDE layer can't issue commands
1034 * to both drives on the same cable, unlike SCSI.
1035 */
1036
1037static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1038{
1039 ide_drive_t *drive, *best;
1040
1041repeat:
1042 best = NULL;
1043 drive = hwgroup->drive;
1044
1045 /*
1046 * drive is doing pre-flush, ordered write, post-flush sequence. even
1047 * though that is 3 requests, it must be seen as a single transaction.
1048 * we must not preempt this drive until that is complete
1049 */
1050 if (blk_queue_flushing(drive->queue)) {
1051 /*
1052 * small race where queue could get replugged during
1053 * the 3-request flush cycle, just yank the plug since
1054 * we want it to finish asap
1055 */
1056 blk_remove_plug(drive->queue);
1057 return drive;
1058 }
1059
1060 do {
1061 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1062 && !elv_queue_empty(drive->queue)) {
1063 if (!best
1064 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1065 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1066 {
1067 if (!blk_queue_plugged(drive->queue))
1068 best = drive;
1069 }
1070 }
1071 } while ((drive = drive->next) != hwgroup->drive);
1072 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1073 long t = (signed long)(WAKEUP(best) - jiffies);
1074 if (t >= WAIT_MIN_SLEEP) {
1075 /*
1076 * We *may* have some time to spare, but first let's see if
1077 * someone can potentially benefit from our nice mood today..
1078 */
1079 drive = best->next;
1080 do {
1081 if (!drive->sleeping
1082 && time_before(jiffies - best->service_time, WAKEUP(drive))
1083 && time_before(WAKEUP(drive), jiffies + t))
1084 {
1085 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1086 goto repeat;
1087 }
1088 } while ((drive = drive->next) != best);
1089 }
1090 }
1091 return best;
1092}
1093
1094/*
1095 * Issue a new request to a drive from hwgroup
1096 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1097 *
1098 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1099 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1100 * may have both interfaces in a single hwgroup to "serialize" access.
1101 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1102 * together into one hwgroup for serialized access.
1103 *
1104 * Note also that several hwgroups can end up sharing a single IRQ,
1105 * possibly along with many other devices. This is especially common in
1106 * PCI-based systems with off-board IDE controller cards.
1107 *
1108 * The IDE driver uses the single global ide_lock spinlock to protect
1109 * access to the request queues, and to protect the hwgroup->busy flag.
1110 *
1111 * The first thread into the driver for a particular hwgroup sets the
1112 * hwgroup->busy flag to indicate that this hwgroup is now active,
1113 * and then initiates processing of the top request from the request queue.
1114 *
1115 * Other threads attempting entry notice the busy setting, and will simply
1116 * queue their new requests and exit immediately. Note that hwgroup->busy
1117 * remains set even when the driver is merely awaiting the next interrupt.
1118 * Thus, the meaning is "this hwgroup is busy processing a request".
1119 *
1120 * When processing of a request completes, the completing thread or IRQ-handler
1121 * will start the next request from the queue. If no more work remains,
1122 * the driver will clear the hwgroup->busy flag and exit.
1123 *
1124 * The ide_lock (spinlock) is used to protect all access to the
1125 * hwgroup->busy flag, but is otherwise not needed for most processing in
1126 * the driver. This makes the driver much more friendlier to shared IRQs
1127 * than previous designs, while remaining 100% (?) SMP safe and capable.
1128 */
1129static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1130{
1131 ide_drive_t *drive;
1132 ide_hwif_t *hwif;
1133 struct request *rq;
1134 ide_startstop_t startstop;
867f8b4e 1135 int loops = 0;
1da177e4
LT
1136
1137 /* for atari only: POSSIBLY BROKEN HERE(?) */
1138 ide_get_lock(ide_intr, hwgroup);
1139
1140 /* caller must own ide_lock */
1141 BUG_ON(!irqs_disabled());
1142
1143 while (!hwgroup->busy) {
1144 hwgroup->busy = 1;
1145 drive = choose_drive(hwgroup);
1146 if (drive == NULL) {
1147 int sleeping = 0;
1148 unsigned long sleep = 0; /* shut up, gcc */
1149 hwgroup->rq = NULL;
1150 drive = hwgroup->drive;
1151 do {
1152 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1153 sleeping = 1;
1154 sleep = drive->sleep;
1155 }
1156 } while ((drive = drive->next) != hwgroup->drive);
1157 if (sleeping) {
1158 /*
1159 * Take a short snooze, and then wake up this hwgroup again.
1160 * This gives other hwgroups on the same a chance to
1161 * play fairly with us, just in case there are big differences
1162 * in relative throughputs.. don't want to hog the cpu too much.
1163 */
1164 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1165 sleep = jiffies + WAIT_MIN_SLEEP;
1166#if 1
1167 if (timer_pending(&hwgroup->timer))
1168 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1169#endif
1170 /* so that ide_timer_expiry knows what to do */
1171 hwgroup->sleeping = 1;
23450319 1172 hwgroup->req_gen_timer = hwgroup->req_gen;
1da177e4
LT
1173 mod_timer(&hwgroup->timer, sleep);
1174 /* we purposely leave hwgroup->busy==1
1175 * while sleeping */
1176 } else {
1177 /* Ugly, but how can we sleep for the lock
1178 * otherwise? perhaps from tq_disk?
1179 */
1180
1181 /* for atari only */
1182 ide_release_lock();
1183 hwgroup->busy = 0;
1184 }
1185
1186 /* no more work for this hwgroup (for now) */
1187 return;
1188 }
867f8b4e 1189 again:
1da177e4
LT
1190 hwif = HWIF(drive);
1191 if (hwgroup->hwif->sharing_irq &&
1192 hwif != hwgroup->hwif &&
1193 hwif->io_ports[IDE_CONTROL_OFFSET]) {
7299a391
BZ
1194 /*
1195 * set nIEN for previous hwif, drives in the
1196 * quirk_list may not like intr setups/cleanups
1197 */
1198 if (drive->quirk_list != 1)
f919790f 1199 hwif->OUTB(drive->ctl | 2, IDE_CONTROL_REG);
1da177e4
LT
1200 }
1201 hwgroup->hwif = hwif;
1202 hwgroup->drive = drive;
1203 drive->sleeping = 0;
1204 drive->service_start = jiffies;
1205
1206 if (blk_queue_plugged(drive->queue)) {
1207 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1208 break;
1209 }
1210
1211 /*
1212 * we know that the queue isn't empty, but this can happen
1213 * if the q->prep_rq_fn() decides to kill a request
1214 */
1215 rq = elv_next_request(drive->queue);
1216 if (!rq) {
1217 hwgroup->busy = 0;
1218 break;
1219 }
1220
1221 /*
1222 * Sanity: don't accept a request that isn't a PM request
1223 * if we are currently power managed. This is very important as
1224 * blk_stop_queue() doesn't prevent the elv_next_request()
1225 * above to return us whatever is in the queue. Since we call
1226 * ide_do_request() ourselves, we end up taking requests while
1227 * the queue is blocked...
1228 *
1229 * We let requests forced at head of queue with ide-preempt
1230 * though. I hope that doesn't happen too much, hopefully not
1231 * unless the subdriver triggers such a thing in its own PM
1232 * state machine.
867f8b4e
BH
1233 *
1234 * We count how many times we loop here to make sure we service
1235 * all drives in the hwgroup without looping for ever
1da177e4 1236 */
4aff5e23 1237 if (drive->blocked && !blk_pm_request(rq) && !(rq->cmd_flags & REQ_PREEMPT)) {
867f8b4e
BH
1238 drive = drive->next ? drive->next : hwgroup->drive;
1239 if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1240 goto again;
1da177e4
LT
1241 /* We clear busy, there should be no pending ATA command at this point. */
1242 hwgroup->busy = 0;
1243 break;
1244 }
1245
1246 hwgroup->rq = rq;
1247
1248 /*
1249 * Some systems have trouble with IDE IRQs arriving while
1250 * the driver is still setting things up. So, here we disable
1251 * the IRQ used by this interface while the request is being started.
1252 * This may look bad at first, but pretty much the same thing
1253 * happens anyway when any interrupt comes in, IDE or otherwise
1254 * -- the kernel masks the IRQ while it is being handled.
1255 */
1256 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1257 disable_irq_nosync(hwif->irq);
1258 spin_unlock(&ide_lock);
366c7f55 1259 local_irq_enable_in_hardirq();
1da177e4
LT
1260 /* allow other IRQs while we start this request */
1261 startstop = start_request(drive, rq);
1262 spin_lock_irq(&ide_lock);
1263 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1264 enable_irq(hwif->irq);
1265 if (startstop == ide_stopped)
1266 hwgroup->busy = 0;
1267 }
1268}
1269
1270/*
1271 * Passes the stuff to ide_do_request
1272 */
165125e1 1273void do_ide_request(struct request_queue *q)
1da177e4
LT
1274{
1275 ide_drive_t *drive = q->queuedata;
1276
1277 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1278}
1279
1280/*
1281 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1282 * retry the current request in pio mode instead of risking tossing it
1283 * all away
1284 */
1285static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1286{
1287 ide_hwif_t *hwif = HWIF(drive);
1288 struct request *rq;
1289 ide_startstop_t ret = ide_stopped;
1290
1291 /*
1292 * end current dma transaction
1293 */
1294
1295 if (error < 0) {
1296 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1297 (void)HWIF(drive)->ide_dma_end(drive);
1298 ret = ide_error(drive, "dma timeout error",
1299 hwif->INB(IDE_STATUS_REG));
1300 } else {
1301 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
c283f5db 1302 hwif->dma_timeout(drive);
1da177e4
LT
1303 }
1304
1305 /*
1306 * disable dma for now, but remember that we did so because of
1307 * a timeout -- we'll reenable after we finish this next request
1308 * (or rather the first chunk of it) in pio.
1309 */
1310 drive->retry_pio++;
1311 drive->state = DMA_PIO_RETRY;
7469aaf6 1312 hwif->dma_off_quietly(drive);
1da177e4
LT
1313
1314 /*
1315 * un-busy drive etc (hwgroup->busy is cleared on return) and
1316 * make sure request is sane
1317 */
1318 rq = HWGROUP(drive)->rq;
ce42f191
HZ
1319
1320 if (!rq)
1321 goto out;
1322
1da177e4
LT
1323 HWGROUP(drive)->rq = NULL;
1324
1325 rq->errors = 0;
1326
1327 if (!rq->bio)
1328 goto out;
1329
1330 rq->sector = rq->bio->bi_sector;
1331 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1332 rq->hard_cur_sectors = rq->current_nr_sectors;
1333 rq->buffer = bio_data(rq->bio);
1334out:
1335 return ret;
1336}
1337
1338/**
1339 * ide_timer_expiry - handle lack of an IDE interrupt
1340 * @data: timer callback magic (hwgroup)
1341 *
1342 * An IDE command has timed out before the expected drive return
1343 * occurred. At this point we attempt to clean up the current
1344 * mess. If the current handler includes an expiry handler then
1345 * we invoke the expiry handler, and providing it is happy the
1346 * work is done. If that fails we apply generic recovery rules
1347 * invoking the handler and checking the drive DMA status. We
1348 * have an excessively incestuous relationship with the DMA
1349 * logic that wants cleaning up.
1350 */
1351
1352void ide_timer_expiry (unsigned long data)
1353{
1354 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1355 ide_handler_t *handler;
1356 ide_expiry_t *expiry;
1357 unsigned long flags;
1358 unsigned long wait = -1;
1359
1360 spin_lock_irqsave(&ide_lock, flags);
1361
23450319
SS
1362 if (((handler = hwgroup->handler) == NULL) ||
1363 (hwgroup->req_gen != hwgroup->req_gen_timer)) {
1da177e4
LT
1364 /*
1365 * Either a marginal timeout occurred
1366 * (got the interrupt just as timer expired),
1367 * or we were "sleeping" to give other devices a chance.
1368 * Either way, we don't really want to complain about anything.
1369 */
1370 if (hwgroup->sleeping) {
1371 hwgroup->sleeping = 0;
1372 hwgroup->busy = 0;
1373 }
1374 } else {
1375 ide_drive_t *drive = hwgroup->drive;
1376 if (!drive) {
1377 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1378 hwgroup->handler = NULL;
1379 } else {
1380 ide_hwif_t *hwif;
1381 ide_startstop_t startstop = ide_stopped;
1382 if (!hwgroup->busy) {
1383 hwgroup->busy = 1; /* paranoia */
1384 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1385 }
1386 if ((expiry = hwgroup->expiry) != NULL) {
1387 /* continue */
1388 if ((wait = expiry(drive)) > 0) {
1389 /* reset timer */
1390 hwgroup->timer.expires = jiffies + wait;
23450319 1391 hwgroup->req_gen_timer = hwgroup->req_gen;
1da177e4
LT
1392 add_timer(&hwgroup->timer);
1393 spin_unlock_irqrestore(&ide_lock, flags);
1394 return;
1395 }
1396 }
1397 hwgroup->handler = NULL;
1398 /*
1399 * We need to simulate a real interrupt when invoking
1400 * the handler() function, which means we need to
1401 * globally mask the specific IRQ:
1402 */
1403 spin_unlock(&ide_lock);
1404 hwif = HWIF(drive);
1da177e4
LT
1405 /* disable_irq_nosync ?? */
1406 disable_irq(hwif->irq);
1da177e4
LT
1407 /* local CPU only,
1408 * as if we were handling an interrupt */
1409 local_irq_disable();
1410 if (hwgroup->polling) {
1411 startstop = handler(drive);
1412 } else if (drive_is_ready(drive)) {
1413 if (drive->waiting_for_dma)
841d2a9b 1414 hwgroup->hwif->dma_lost_irq(drive);
1da177e4
LT
1415 (void)ide_ack_intr(hwif);
1416 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1417 startstop = handler(drive);
1418 } else {
1419 if (drive->waiting_for_dma) {
1420 startstop = ide_dma_timeout_retry(drive, wait);
1421 } else
1422 startstop =
1423 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1424 }
1425 drive->service_time = jiffies - drive->service_start;
1426 spin_lock_irq(&ide_lock);
1427 enable_irq(hwif->irq);
1428 if (startstop == ide_stopped)
1429 hwgroup->busy = 0;
1430 }
1431 }
1432 ide_do_request(hwgroup, IDE_NO_IRQ);
1433 spin_unlock_irqrestore(&ide_lock, flags);
1434}
1435
1436/**
1437 * unexpected_intr - handle an unexpected IDE interrupt
1438 * @irq: interrupt line
1439 * @hwgroup: hwgroup being processed
1440 *
1441 * There's nothing really useful we can do with an unexpected interrupt,
1442 * other than reading the status register (to clear it), and logging it.
1443 * There should be no way that an irq can happen before we're ready for it,
1444 * so we needn't worry much about losing an "important" interrupt here.
1445 *
1446 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1447 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1448 * looks "good", we just ignore the interrupt completely.
1449 *
1450 * This routine assumes __cli() is in effect when called.
1451 *
1452 * If an unexpected interrupt happens on irq15 while we are handling irq14
1453 * and if the two interfaces are "serialized" (CMD640), then it looks like
1454 * we could screw up by interfering with a new request being set up for
1455 * irq15.
1456 *
1457 * In reality, this is a non-issue. The new command is not sent unless
1458 * the drive is ready to accept one, in which case we know the drive is
1459 * not trying to interrupt us. And ide_set_handler() is always invoked
1460 * before completing the issuance of any new drive command, so we will not
1461 * be accidentally invoked as a result of any valid command completion
1462 * interrupt.
1463 *
1464 * Note that we must walk the entire hwgroup here. We know which hwif
1465 * is doing the current command, but we don't know which hwif burped
1466 * mysteriously.
1467 */
1468
1469static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1470{
1471 u8 stat;
1472 ide_hwif_t *hwif = hwgroup->hwif;
1473
1474 /*
1475 * handle the unexpected interrupt
1476 */
1477 do {
1478 if (hwif->irq == irq) {
1479 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1480 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1481 /* Try to not flood the console with msgs */
1482 static unsigned long last_msgtime, count;
1483 ++count;
1484 if (time_after(jiffies, last_msgtime + HZ)) {
1485 last_msgtime = jiffies;
1486 printk(KERN_ERR "%s%s: unexpected interrupt, "
1487 "status=0x%02x, count=%ld\n",
1488 hwif->name,
1489 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1490 }
1491 }
1492 }
1493 } while ((hwif = hwif->next) != hwgroup->hwif);
1494}
1495
1496/**
1497 * ide_intr - default IDE interrupt handler
1498 * @irq: interrupt number
1499 * @dev_id: hwif group
1500 * @regs: unused weirdness from the kernel irq layer
1501 *
1502 * This is the default IRQ handler for the IDE layer. You should
1503 * not need to override it. If you do be aware it is subtle in
1504 * places
1505 *
1506 * hwgroup->hwif is the interface in the group currently performing
1507 * a command. hwgroup->drive is the drive and hwgroup->handler is
1508 * the IRQ handler to call. As we issue a command the handlers
1509 * step through multiple states, reassigning the handler to the
1510 * next step in the process. Unlike a smart SCSI controller IDE
1511 * expects the main processor to sequence the various transfer
1512 * stages. We also manage a poll timer to catch up with most
1513 * timeout situations. There are still a few where the handlers
1514 * don't ever decide to give up.
1515 *
1516 * The handler eventually returns ide_stopped to indicate the
1517 * request completed. At this point we issue the next request
1518 * on the hwgroup and the process begins again.
1519 */
1520
7d12e780 1521irqreturn_t ide_intr (int irq, void *dev_id)
1da177e4
LT
1522{
1523 unsigned long flags;
1524 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1525 ide_hwif_t *hwif;
1526 ide_drive_t *drive;
1527 ide_handler_t *handler;
1528 ide_startstop_t startstop;
1529
1530 spin_lock_irqsave(&ide_lock, flags);
1531 hwif = hwgroup->hwif;
1532
1533 if (!ide_ack_intr(hwif)) {
1534 spin_unlock_irqrestore(&ide_lock, flags);
1535 return IRQ_NONE;
1536 }
1537
1538 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1539 /*
1540 * Not expecting an interrupt from this drive.
1541 * That means this could be:
1542 * (1) an interrupt from another PCI device
1543 * sharing the same PCI INT# as us.
1544 * or (2) a drive just entered sleep or standby mode,
1545 * and is interrupting to let us know.
1546 * or (3) a spurious interrupt of unknown origin.
1547 *
1548 * For PCI, we cannot tell the difference,
1549 * so in that case we just ignore it and hope it goes away.
1550 *
1551 * FIXME: unexpected_intr should be hwif-> then we can
1552 * remove all the ifdef PCI crap
1553 */
1554#ifdef CONFIG_BLK_DEV_IDEPCI
1555 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1556#endif /* CONFIG_BLK_DEV_IDEPCI */
1557 {
1558 /*
1559 * Probably not a shared PCI interrupt,
1560 * so we can safely try to do something about it:
1561 */
1562 unexpected_intr(irq, hwgroup);
1563#ifdef CONFIG_BLK_DEV_IDEPCI
1564 } else {
1565 /*
1566 * Whack the status register, just in case
1567 * we have a leftover pending IRQ.
1568 */
1569 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1570#endif /* CONFIG_BLK_DEV_IDEPCI */
1571 }
1572 spin_unlock_irqrestore(&ide_lock, flags);
1573 return IRQ_NONE;
1574 }
1575 drive = hwgroup->drive;
1576 if (!drive) {
1577 /*
1578 * This should NEVER happen, and there isn't much
1579 * we could do about it here.
1580 *
1581 * [Note - this can occur if the drive is hot unplugged]
1582 */
1583 spin_unlock_irqrestore(&ide_lock, flags);
1584 return IRQ_HANDLED;
1585 }
1586 if (!drive_is_ready(drive)) {
1587 /*
1588 * This happens regularly when we share a PCI IRQ with
1589 * another device. Unfortunately, it can also happen
1590 * with some buggy drives that trigger the IRQ before
1591 * their status register is up to date. Hopefully we have
1592 * enough advance overhead that the latter isn't a problem.
1593 */
1594 spin_unlock_irqrestore(&ide_lock, flags);
1595 return IRQ_NONE;
1596 }
1597 if (!hwgroup->busy) {
1598 hwgroup->busy = 1; /* paranoia */
1599 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1600 }
1601 hwgroup->handler = NULL;
23450319 1602 hwgroup->req_gen++;
1da177e4
LT
1603 del_timer(&hwgroup->timer);
1604 spin_unlock(&ide_lock);
1605
f0dd8712
AL
1606 /* Some controllers might set DMA INTR no matter DMA or PIO;
1607 * bmdma status might need to be cleared even for
1608 * PIO interrupts to prevent spurious/lost irq.
1609 */
1610 if (hwif->ide_dma_clear_irq && !(drive->waiting_for_dma))
1611 /* ide_dma_end() needs bmdma status for error checking.
1612 * So, skip clearing bmdma status here and leave it
1613 * to ide_dma_end() if this is dma interrupt.
1614 */
1615 hwif->ide_dma_clear_irq(drive);
1616
1da177e4 1617 if (drive->unmask)
366c7f55 1618 local_irq_enable_in_hardirq();
1da177e4
LT
1619 /* service this interrupt, may set handler for next interrupt */
1620 startstop = handler(drive);
1621 spin_lock_irq(&ide_lock);
1622
1623 /*
1624 * Note that handler() may have set things up for another
1625 * interrupt to occur soon, but it cannot happen until
1626 * we exit from this routine, because it will be the
1627 * same irq as is currently being serviced here, and Linux
1628 * won't allow another of the same (on any CPU) until we return.
1629 */
1630 drive->service_time = jiffies - drive->service_start;
1631 if (startstop == ide_stopped) {
1632 if (hwgroup->handler == NULL) { /* paranoia */
1633 hwgroup->busy = 0;
1634 ide_do_request(hwgroup, hwif->irq);
1635 } else {
1636 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1637 "on exit\n", drive->name);
1638 }
1639 }
1640 spin_unlock_irqrestore(&ide_lock, flags);
1641 return IRQ_HANDLED;
1642}
1643
1644/**
1645 * ide_init_drive_cmd - initialize a drive command request
1646 * @rq: request object
1647 *
1648 * Initialize a request before we fill it in and send it down to
1649 * ide_do_drive_cmd. Commands must be set up by this function. Right
1650 * now it doesn't do a lot, but if that changes abusers will have a
d6e05edc 1651 * nasty surprise.
1da177e4
LT
1652 */
1653
1654void ide_init_drive_cmd (struct request *rq)
1655{
1656 memset(rq, 0, sizeof(*rq));
4aff5e23 1657 rq->cmd_type = REQ_TYPE_ATA_CMD;
1da177e4
LT
1658 rq->ref_count = 1;
1659}
1660
1661EXPORT_SYMBOL(ide_init_drive_cmd);
1662
1663/**
1664 * ide_do_drive_cmd - issue IDE special command
1665 * @drive: device to issue command
1666 * @rq: request to issue
1667 * @action: action for processing
1668 *
1669 * This function issues a special IDE device request
1670 * onto the request queue.
1671 *
1672 * If action is ide_wait, then the rq is queued at the end of the
1673 * request queue, and the function sleeps until it has been processed.
1674 * This is for use when invoked from an ioctl handler.
1675 *
1676 * If action is ide_preempt, then the rq is queued at the head of
1677 * the request queue, displacing the currently-being-processed
1678 * request and this function returns immediately without waiting
1679 * for the new rq to be completed. This is VERY DANGEROUS, and is
1680 * intended for careful use by the ATAPI tape/cdrom driver code.
1681 *
1da177e4
LT
1682 * If action is ide_end, then the rq is queued at the end of the
1683 * request queue, and the function returns immediately without waiting
1684 * for the new rq to be completed. This is again intended for careful
1685 * use by the ATAPI tape/cdrom driver code.
1686 */
1687
1688int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1689{
1690 unsigned long flags;
1691 ide_hwgroup_t *hwgroup = HWGROUP(drive);
60be6b9a 1692 DECLARE_COMPLETION_ONSTACK(wait);
1da177e4
LT
1693 int where = ELEVATOR_INSERT_BACK, err;
1694 int must_wait = (action == ide_wait || action == ide_head_wait);
1695
1696 rq->errors = 0;
1da177e4
LT
1697
1698 /*
1699 * we need to hold an extra reference to request for safe inspection
1700 * after completion
1701 */
1702 if (must_wait) {
1703 rq->ref_count++;
c00895ab 1704 rq->end_io_data = &wait;
1da177e4
LT
1705 rq->end_io = blk_end_sync_rq;
1706 }
1707
1708 spin_lock_irqsave(&ide_lock, flags);
1709 if (action == ide_preempt)
1710 hwgroup->rq = NULL;
1711 if (action == ide_preempt || action == ide_head_wait) {
1712 where = ELEVATOR_INSERT_FRONT;
4aff5e23 1713 rq->cmd_flags |= REQ_PREEMPT;
1da177e4
LT
1714 }
1715 __elv_add_request(drive->queue, rq, where, 0);
1716 ide_do_request(hwgroup, IDE_NO_IRQ);
1717 spin_unlock_irqrestore(&ide_lock, flags);
1718
1719 err = 0;
1720 if (must_wait) {
1721 wait_for_completion(&wait);
1da177e4
LT
1722 if (rq->errors)
1723 err = -EIO;
1724
1725 blk_put_request(rq);
1726 }
1727
1728 return err;
1729}
1730
1731EXPORT_SYMBOL(ide_do_drive_cmd);
2fc57388
BZ
1732
1733void ide_pktcmd_tf_load(ide_drive_t *drive, u32 tf_flags, u16 bcount, u8 dma)
1734{
1735 ide_task_t task;
1736
1737 memset(&task, 0, sizeof(task));
1738 task.tf_flags = IDE_TFLAG_OUT_LBAH | IDE_TFLAG_OUT_LBAM |
1739 IDE_TFLAG_OUT_FEATURE | tf_flags;
1740 task.tf.feature = dma; /* Use PIO/DMA */
1741 task.tf.lbam = bcount & 0xff;
1742 task.tf.lbah = (bcount >> 8) & 0xff;
1743
1744 ide_tf_load(drive, &task);
1745}
1746
1747EXPORT_SYMBOL_GPL(ide_pktcmd_tf_load);
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