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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
27 #include <linux/config.h>
28 #include <linux/module.h>
29 #include <linux/types.h>
30 #include <linux/string.h>
31 #include <linux/kernel.h>
32 #include <linux/timer.h>
33 #include <linux/mm.h>
34 #include <linux/interrupt.h>
35 #include <linux/major.h>
36 #include <linux/errno.h>
37 #include <linux/genhd.h>
38 #include <linux/blkpg.h>
39 #include <linux/slab.h>
40 #include <linux/init.h>
41 #include <linux/pci.h>
42 #include <linux/delay.h>
43 #include <linux/ide.h>
44 #include <linux/completion.h>
45 #include <linux/reboot.h>
46 #include <linux/cdrom.h>
47 #include <linux/seq_file.h>
48 #include <linux/device.h>
49 #include <linux/kmod.h>
50 #include <linux/scatterlist.h>
51
52 #include <asm/byteorder.h>
53 #include <asm/irq.h>
54 #include <asm/uaccess.h>
55 #include <asm/io.h>
56 #include <asm/bitops.h>
57
58 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
59 int uptodate, int nr_sectors)
60 {
61 int ret = 1;
62
63 BUG_ON(!(rq->flags & REQ_STARTED));
64
65 /*
66 * if failfast is set on a request, override number of sectors and
67 * complete the whole request right now
68 */
69 if (blk_noretry_request(rq) && end_io_error(uptodate))
70 nr_sectors = rq->hard_nr_sectors;
71
72 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
73 rq->errors = -EIO;
74
75 /*
76 * decide whether to reenable DMA -- 3 is a random magic for now,
77 * if we DMA timeout more than 3 times, just stay in PIO
78 */
79 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
80 drive->state = 0;
81 HWGROUP(drive)->hwif->ide_dma_on(drive);
82 }
83
84 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
85 add_disk_randomness(rq->rq_disk);
86 blkdev_dequeue_request(rq);
87 HWGROUP(drive)->rq = NULL;
88 end_that_request_last(rq, uptodate);
89 ret = 0;
90 }
91
92 return ret;
93 }
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
106 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
107 {
108 struct request *rq;
109 unsigned long flags;
110 int ret = 1;
111
112 /*
113 * room for locking improvements here, the calls below don't
114 * need the queue lock held at all
115 */
116 spin_lock_irqsave(&ide_lock, flags);
117 rq = HWGROUP(drive)->rq;
118
119 if (!nr_sectors)
120 nr_sectors = rq->hard_cur_sectors;
121
122 ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
123
124 spin_unlock_irqrestore(&ide_lock, flags);
125 return ret;
126 }
127 EXPORT_SYMBOL(ide_end_request);
128
129 /*
130 * Power Management state machine. This one is rather trivial for now,
131 * we should probably add more, like switching back to PIO on suspend
132 * to help some BIOSes, re-do the door locking on resume, etc...
133 */
134
135 enum {
136 ide_pm_flush_cache = ide_pm_state_start_suspend,
137 idedisk_pm_standby,
138
139 idedisk_pm_idle = ide_pm_state_start_resume,
140 ide_pm_restore_dma,
141 };
142
143 static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
144 {
145 struct request_pm_state *pm = rq->end_io_data;
146
147 if (drive->media != ide_disk)
148 return;
149
150 switch (pm->pm_step) {
151 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
152 if (pm->pm_state == PM_EVENT_FREEZE)
153 pm->pm_step = ide_pm_state_completed;
154 else
155 pm->pm_step = idedisk_pm_standby;
156 break;
157 case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
158 pm->pm_step = ide_pm_state_completed;
159 break;
160 case idedisk_pm_idle: /* Resume step 1 (idle) complete */
161 pm->pm_step = ide_pm_restore_dma;
162 break;
163 }
164 }
165
166 static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
167 {
168 struct request_pm_state *pm = rq->end_io_data;
169 ide_task_t *args = rq->special;
170
171 memset(args, 0, sizeof(*args));
172
173 if (drive->media != ide_disk) {
174 /* skip idedisk_pm_idle for ATAPI devices */
175 if (pm->pm_step == idedisk_pm_idle)
176 pm->pm_step = ide_pm_restore_dma;
177 }
178
179 switch (pm->pm_step) {
180 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */
181 if (drive->media != ide_disk)
182 break;
183 /* Not supported? Switch to next step now. */
184 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
185 ide_complete_power_step(drive, rq, 0, 0);
186 return ide_stopped;
187 }
188 if (ide_id_has_flush_cache_ext(drive->id))
189 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT;
190 else
191 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE;
192 args->command_type = IDE_DRIVE_TASK_NO_DATA;
193 args->handler = &task_no_data_intr;
194 return do_rw_taskfile(drive, args);
195
196 case idedisk_pm_standby: /* Suspend step 2 (standby) */
197 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1;
198 args->command_type = IDE_DRIVE_TASK_NO_DATA;
199 args->handler = &task_no_data_intr;
200 return do_rw_taskfile(drive, args);
201
202 case idedisk_pm_idle: /* Resume step 1 (idle) */
203 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE;
204 args->command_type = IDE_DRIVE_TASK_NO_DATA;
205 args->handler = task_no_data_intr;
206 return do_rw_taskfile(drive, args);
207
208 case ide_pm_restore_dma: /* Resume step 2 (restore DMA) */
209 /*
210 * Right now, all we do is call hwif->ide_dma_check(drive),
211 * we could be smarter and check for current xfer_speed
212 * in struct drive etc...
213 */
214 if ((drive->id->capability & 1) == 0)
215 break;
216 if (drive->hwif->ide_dma_check == NULL)
217 break;
218 drive->hwif->ide_dma_check(drive);
219 break;
220 }
221 pm->pm_step = ide_pm_state_completed;
222 return ide_stopped;
223 }
224
225 /**
226 * ide_end_dequeued_request - complete an IDE I/O
227 * @drive: IDE device for the I/O
228 * @uptodate:
229 * @nr_sectors: number of sectors completed
230 *
231 * Complete an I/O that is no longer on the request queue. This
232 * typically occurs when we pull the request and issue a REQUEST_SENSE.
233 * We must still finish the old request but we must not tamper with the
234 * queue in the meantime.
235 *
236 * NOTE: This path does not handle barrier, but barrier is not supported
237 * on ide-cd anyway.
238 */
239
240 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
241 int uptodate, int nr_sectors)
242 {
243 unsigned long flags;
244 int ret = 1;
245
246 spin_lock_irqsave(&ide_lock, flags);
247
248 BUG_ON(!(rq->flags & REQ_STARTED));
249
250 /*
251 * if failfast is set on a request, override number of sectors and
252 * complete the whole request right now
253 */
254 if (blk_noretry_request(rq) && end_io_error(uptodate))
255 nr_sectors = rq->hard_nr_sectors;
256
257 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
258 rq->errors = -EIO;
259
260 /*
261 * decide whether to reenable DMA -- 3 is a random magic for now,
262 * if we DMA timeout more than 3 times, just stay in PIO
263 */
264 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
265 drive->state = 0;
266 HWGROUP(drive)->hwif->ide_dma_on(drive);
267 }
268
269 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
270 add_disk_randomness(rq->rq_disk);
271 if (blk_rq_tagged(rq))
272 blk_queue_end_tag(drive->queue, rq);
273 end_that_request_last(rq, uptodate);
274 ret = 0;
275 }
276 spin_unlock_irqrestore(&ide_lock, flags);
277 return ret;
278 }
279 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
280
281
282 /**
283 * ide_complete_pm_request - end the current Power Management request
284 * @drive: target drive
285 * @rq: request
286 *
287 * This function cleans up the current PM request and stops the queue
288 * if necessary.
289 */
290 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
291 {
292 unsigned long flags;
293
294 #ifdef DEBUG_PM
295 printk("%s: completing PM request, %s\n", drive->name,
296 blk_pm_suspend_request(rq) ? "suspend" : "resume");
297 #endif
298 spin_lock_irqsave(&ide_lock, flags);
299 if (blk_pm_suspend_request(rq)) {
300 blk_stop_queue(drive->queue);
301 } else {
302 drive->blocked = 0;
303 blk_start_queue(drive->queue);
304 }
305 blkdev_dequeue_request(rq);
306 HWGROUP(drive)->rq = NULL;
307 end_that_request_last(rq, 1);
308 spin_unlock_irqrestore(&ide_lock, flags);
309 }
310
311 /*
312 * FIXME: probably move this somewhere else, name is bad too :)
313 */
314 u64 ide_get_error_location(ide_drive_t *drive, char *args)
315 {
316 u32 high, low;
317 u8 hcyl, lcyl, sect;
318 u64 sector;
319
320 high = 0;
321 hcyl = args[5];
322 lcyl = args[4];
323 sect = args[3];
324
325 if (ide_id_has_flush_cache_ext(drive->id)) {
326 low = (hcyl << 16) | (lcyl << 8) | sect;
327 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
328 high = ide_read_24(drive);
329 } else {
330 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
331 if (cur & 0x40) {
332 high = cur & 0xf;
333 low = (hcyl << 16) | (lcyl << 8) | sect;
334 } else {
335 low = hcyl * drive->head * drive->sect;
336 low += lcyl * drive->sect;
337 low += sect - 1;
338 }
339 }
340
341 sector = ((u64) high << 24) | low;
342 return sector;
343 }
344 EXPORT_SYMBOL(ide_get_error_location);
345
346 /**
347 * ide_end_drive_cmd - end an explicit drive command
348 * @drive: command
349 * @stat: status bits
350 * @err: error bits
351 *
352 * Clean up after success/failure of an explicit drive command.
353 * These get thrown onto the queue so they are synchronized with
354 * real I/O operations on the drive.
355 *
356 * In LBA48 mode we have to read the register set twice to get
357 * all the extra information out.
358 */
359
360 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
361 {
362 ide_hwif_t *hwif = HWIF(drive);
363 unsigned long flags;
364 struct request *rq;
365
366 spin_lock_irqsave(&ide_lock, flags);
367 rq = HWGROUP(drive)->rq;
368 spin_unlock_irqrestore(&ide_lock, flags);
369
370 if (rq->flags & REQ_DRIVE_CMD) {
371 u8 *args = (u8 *) rq->buffer;
372 if (rq->errors == 0)
373 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
374
375 if (args) {
376 args[0] = stat;
377 args[1] = err;
378 args[2] = hwif->INB(IDE_NSECTOR_REG);
379 }
380 } else if (rq->flags & REQ_DRIVE_TASK) {
381 u8 *args = (u8 *) rq->buffer;
382 if (rq->errors == 0)
383 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
384
385 if (args) {
386 args[0] = stat;
387 args[1] = err;
388 args[2] = hwif->INB(IDE_NSECTOR_REG);
389 args[3] = hwif->INB(IDE_SECTOR_REG);
390 args[4] = hwif->INB(IDE_LCYL_REG);
391 args[5] = hwif->INB(IDE_HCYL_REG);
392 args[6] = hwif->INB(IDE_SELECT_REG);
393 }
394 } else if (rq->flags & REQ_DRIVE_TASKFILE) {
395 ide_task_t *args = (ide_task_t *) rq->special;
396 if (rq->errors == 0)
397 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
398
399 if (args) {
400 if (args->tf_in_flags.b.data) {
401 u16 data = hwif->INW(IDE_DATA_REG);
402 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
403 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
404 }
405 args->tfRegister[IDE_ERROR_OFFSET] = err;
406 /* be sure we're looking at the low order bits */
407 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
408 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
409 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
410 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
411 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
412 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
413 args->tfRegister[IDE_STATUS_OFFSET] = stat;
414
415 if (drive->addressing == 1) {
416 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
417 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
418 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
419 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
420 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
421 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
422 }
423 }
424 } else if (blk_pm_request(rq)) {
425 struct request_pm_state *pm = rq->end_io_data;
426 #ifdef DEBUG_PM
427 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
428 drive->name, rq->pm->pm_step, stat, err);
429 #endif
430 ide_complete_power_step(drive, rq, stat, err);
431 if (pm->pm_step == ide_pm_state_completed)
432 ide_complete_pm_request(drive, rq);
433 return;
434 }
435
436 spin_lock_irqsave(&ide_lock, flags);
437 blkdev_dequeue_request(rq);
438 HWGROUP(drive)->rq = NULL;
439 rq->errors = err;
440 end_that_request_last(rq, !rq->errors);
441 spin_unlock_irqrestore(&ide_lock, flags);
442 }
443
444 EXPORT_SYMBOL(ide_end_drive_cmd);
445
446 /**
447 * try_to_flush_leftover_data - flush junk
448 * @drive: drive to flush
449 *
450 * try_to_flush_leftover_data() is invoked in response to a drive
451 * unexpectedly having its DRQ_STAT bit set. As an alternative to
452 * resetting the drive, this routine tries to clear the condition
453 * by read a sector's worth of data from the drive. Of course,
454 * this may not help if the drive is *waiting* for data from *us*.
455 */
456 static void try_to_flush_leftover_data (ide_drive_t *drive)
457 {
458 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
459
460 if (drive->media != ide_disk)
461 return;
462 while (i > 0) {
463 u32 buffer[16];
464 u32 wcount = (i > 16) ? 16 : i;
465
466 i -= wcount;
467 HWIF(drive)->ata_input_data(drive, buffer, wcount);
468 }
469 }
470
471 static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
472 {
473 if (rq->rq_disk) {
474 ide_driver_t *drv;
475
476 drv = *(ide_driver_t **)rq->rq_disk->private_data;
477 drv->end_request(drive, 0, 0);
478 } else
479 ide_end_request(drive, 0, 0);
480 }
481
482 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
483 {
484 ide_hwif_t *hwif = drive->hwif;
485
486 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
487 /* other bits are useless when BUSY */
488 rq->errors |= ERROR_RESET;
489 } else if (stat & ERR_STAT) {
490 /* err has different meaning on cdrom and tape */
491 if (err == ABRT_ERR) {
492 if (drive->select.b.lba &&
493 /* some newer drives don't support WIN_SPECIFY */
494 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
495 return ide_stopped;
496 } else if ((err & BAD_CRC) == BAD_CRC) {
497 /* UDMA crc error, just retry the operation */
498 drive->crc_count++;
499 } else if (err & (BBD_ERR | ECC_ERR)) {
500 /* retries won't help these */
501 rq->errors = ERROR_MAX;
502 } else if (err & TRK0_ERR) {
503 /* help it find track zero */
504 rq->errors |= ERROR_RECAL;
505 }
506 }
507
508 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ)
509 try_to_flush_leftover_data(drive);
510
511 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
512 /* force an abort */
513 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
514
515 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq))
516 ide_kill_rq(drive, rq);
517 else {
518 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
519 ++rq->errors;
520 return ide_do_reset(drive);
521 }
522 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
523 drive->special.b.recalibrate = 1;
524 ++rq->errors;
525 }
526 return ide_stopped;
527 }
528
529 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
530 {
531 ide_hwif_t *hwif = drive->hwif;
532
533 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
534 /* other bits are useless when BUSY */
535 rq->errors |= ERROR_RESET;
536 } else {
537 /* add decoding error stuff */
538 }
539
540 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
541 /* force an abort */
542 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
543
544 if (rq->errors >= ERROR_MAX) {
545 ide_kill_rq(drive, rq);
546 } else {
547 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
548 ++rq->errors;
549 return ide_do_reset(drive);
550 }
551 ++rq->errors;
552 }
553
554 return ide_stopped;
555 }
556
557 ide_startstop_t
558 __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
559 {
560 if (drive->media == ide_disk)
561 return ide_ata_error(drive, rq, stat, err);
562 return ide_atapi_error(drive, rq, stat, err);
563 }
564
565 EXPORT_SYMBOL_GPL(__ide_error);
566
567 /**
568 * ide_error - handle an error on the IDE
569 * @drive: drive the error occurred on
570 * @msg: message to report
571 * @stat: status bits
572 *
573 * ide_error() takes action based on the error returned by the drive.
574 * For normal I/O that may well include retries. We deal with
575 * both new-style (taskfile) and old style command handling here.
576 * In the case of taskfile command handling there is work left to
577 * do
578 */
579
580 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
581 {
582 struct request *rq;
583 u8 err;
584
585 err = ide_dump_status(drive, msg, stat);
586
587 if ((rq = HWGROUP(drive)->rq) == NULL)
588 return ide_stopped;
589
590 /* retry only "normal" I/O: */
591 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
592 rq->errors = 1;
593 ide_end_drive_cmd(drive, stat, err);
594 return ide_stopped;
595 }
596
597 if (rq->rq_disk) {
598 ide_driver_t *drv;
599
600 drv = *(ide_driver_t **)rq->rq_disk->private_data;
601 return drv->error(drive, rq, stat, err);
602 } else
603 return __ide_error(drive, rq, stat, err);
604 }
605
606 EXPORT_SYMBOL_GPL(ide_error);
607
608 ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
609 {
610 if (drive->media != ide_disk)
611 rq->errors |= ERROR_RESET;
612
613 ide_kill_rq(drive, rq);
614
615 return ide_stopped;
616 }
617
618 EXPORT_SYMBOL_GPL(__ide_abort);
619
620 /**
621 * ide_abort - abort pending IDE operations
622 * @drive: drive the error occurred on
623 * @msg: message to report
624 *
625 * ide_abort kills and cleans up when we are about to do a
626 * host initiated reset on active commands. Longer term we
627 * want handlers to have sensible abort handling themselves
628 *
629 * This differs fundamentally from ide_error because in
630 * this case the command is doing just fine when we
631 * blow it away.
632 */
633
634 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
635 {
636 struct request *rq;
637
638 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
639 return ide_stopped;
640
641 /* retry only "normal" I/O: */
642 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
643 rq->errors = 1;
644 ide_end_drive_cmd(drive, BUSY_STAT, 0);
645 return ide_stopped;
646 }
647
648 if (rq->rq_disk) {
649 ide_driver_t *drv;
650
651 drv = *(ide_driver_t **)rq->rq_disk->private_data;
652 return drv->abort(drive, rq);
653 } else
654 return __ide_abort(drive, rq);
655 }
656
657 /**
658 * ide_cmd - issue a simple drive command
659 * @drive: drive the command is for
660 * @cmd: command byte
661 * @nsect: sector byte
662 * @handler: handler for the command completion
663 *
664 * Issue a simple drive command with interrupts.
665 * The drive must be selected beforehand.
666 */
667
668 static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
669 ide_handler_t *handler)
670 {
671 ide_hwif_t *hwif = HWIF(drive);
672 if (IDE_CONTROL_REG)
673 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
674 SELECT_MASK(drive,0);
675 hwif->OUTB(nsect,IDE_NSECTOR_REG);
676 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
677 }
678
679 /**
680 * drive_cmd_intr - drive command completion interrupt
681 * @drive: drive the completion interrupt occurred on
682 *
683 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
684 * We do any necessary data reading and then wait for the drive to
685 * go non busy. At that point we may read the error data and complete
686 * the request
687 */
688
689 static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
690 {
691 struct request *rq = HWGROUP(drive)->rq;
692 ide_hwif_t *hwif = HWIF(drive);
693 u8 *args = (u8 *) rq->buffer;
694 u8 stat = hwif->INB(IDE_STATUS_REG);
695 int retries = 10;
696
697 local_irq_enable();
698 if ((stat & DRQ_STAT) && args && args[3]) {
699 u8 io_32bit = drive->io_32bit;
700 drive->io_32bit = 0;
701 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
702 drive->io_32bit = io_32bit;
703 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
704 udelay(100);
705 }
706
707 if (!OK_STAT(stat, READY_STAT, BAD_STAT))
708 return ide_error(drive, "drive_cmd", stat);
709 /* calls ide_end_drive_cmd */
710 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
711 return ide_stopped;
712 }
713
714 static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
715 {
716 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
717 task->tfRegister[IDE_SECTOR_OFFSET] = drive->sect;
718 task->tfRegister[IDE_LCYL_OFFSET] = drive->cyl;
719 task->tfRegister[IDE_HCYL_OFFSET] = drive->cyl>>8;
720 task->tfRegister[IDE_SELECT_OFFSET] = ((drive->head-1)|drive->select.all)&0xBF;
721 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY;
722
723 task->handler = &set_geometry_intr;
724 }
725
726 static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
727 {
728 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
729 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE;
730
731 task->handler = &recal_intr;
732 }
733
734 static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
735 {
736 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req;
737 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT;
738
739 task->handler = &set_multmode_intr;
740 }
741
742 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
743 {
744 special_t *s = &drive->special;
745 ide_task_t args;
746
747 memset(&args, 0, sizeof(ide_task_t));
748 args.command_type = IDE_DRIVE_TASK_NO_DATA;
749
750 if (s->b.set_geometry) {
751 s->b.set_geometry = 0;
752 ide_init_specify_cmd(drive, &args);
753 } else if (s->b.recalibrate) {
754 s->b.recalibrate = 0;
755 ide_init_restore_cmd(drive, &args);
756 } else if (s->b.set_multmode) {
757 s->b.set_multmode = 0;
758 if (drive->mult_req > drive->id->max_multsect)
759 drive->mult_req = drive->id->max_multsect;
760 ide_init_setmult_cmd(drive, &args);
761 } else if (s->all) {
762 int special = s->all;
763 s->all = 0;
764 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
765 return ide_stopped;
766 }
767
768 do_rw_taskfile(drive, &args);
769
770 return ide_started;
771 }
772
773 /**
774 * do_special - issue some special commands
775 * @drive: drive the command is for
776 *
777 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
778 * commands to a drive. It used to do much more, but has been scaled
779 * back.
780 */
781
782 static ide_startstop_t do_special (ide_drive_t *drive)
783 {
784 special_t *s = &drive->special;
785
786 #ifdef DEBUG
787 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
788 #endif
789 if (s->b.set_tune) {
790 s->b.set_tune = 0;
791 if (HWIF(drive)->tuneproc != NULL)
792 HWIF(drive)->tuneproc(drive, drive->tune_req);
793 return ide_stopped;
794 } else {
795 if (drive->media == ide_disk)
796 return ide_disk_special(drive);
797
798 s->all = 0;
799 drive->mult_req = 0;
800 return ide_stopped;
801 }
802 }
803
804 void ide_map_sg(ide_drive_t *drive, struct request *rq)
805 {
806 ide_hwif_t *hwif = drive->hwif;
807 struct scatterlist *sg = hwif->sg_table;
808
809 if (hwif->sg_mapped) /* needed by ide-scsi */
810 return;
811
812 if ((rq->flags & REQ_DRIVE_TASKFILE) == 0) {
813 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
814 } else {
815 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
816 hwif->sg_nents = 1;
817 }
818 }
819
820 EXPORT_SYMBOL_GPL(ide_map_sg);
821
822 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
823 {
824 ide_hwif_t *hwif = drive->hwif;
825
826 hwif->nsect = hwif->nleft = rq->nr_sectors;
827 hwif->cursg = hwif->cursg_ofs = 0;
828 }
829
830 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
831
832 /**
833 * execute_drive_command - issue special drive command
834 * @drive: the drive to issue the command on
835 * @rq: the request structure holding the command
836 *
837 * execute_drive_cmd() issues a special drive command, usually
838 * initiated by ioctl() from the external hdparm program. The
839 * command can be a drive command, drive task or taskfile
840 * operation. Weirdly you can call it with NULL to wait for
841 * all commands to finish. Don't do this as that is due to change
842 */
843
844 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
845 struct request *rq)
846 {
847 ide_hwif_t *hwif = HWIF(drive);
848 if (rq->flags & REQ_DRIVE_TASKFILE) {
849 ide_task_t *args = rq->special;
850
851 if (!args)
852 goto done;
853
854 hwif->data_phase = args->data_phase;
855
856 switch (hwif->data_phase) {
857 case TASKFILE_MULTI_OUT:
858 case TASKFILE_OUT:
859 case TASKFILE_MULTI_IN:
860 case TASKFILE_IN:
861 ide_init_sg_cmd(drive, rq);
862 ide_map_sg(drive, rq);
863 default:
864 break;
865 }
866
867 if (args->tf_out_flags.all != 0)
868 return flagged_taskfile(drive, args);
869 return do_rw_taskfile(drive, args);
870 } else if (rq->flags & REQ_DRIVE_TASK) {
871 u8 *args = rq->buffer;
872 u8 sel;
873
874 if (!args)
875 goto done;
876 #ifdef DEBUG
877 printk("%s: DRIVE_TASK_CMD ", drive->name);
878 printk("cmd=0x%02x ", args[0]);
879 printk("fr=0x%02x ", args[1]);
880 printk("ns=0x%02x ", args[2]);
881 printk("sc=0x%02x ", args[3]);
882 printk("lcyl=0x%02x ", args[4]);
883 printk("hcyl=0x%02x ", args[5]);
884 printk("sel=0x%02x\n", args[6]);
885 #endif
886 hwif->OUTB(args[1], IDE_FEATURE_REG);
887 hwif->OUTB(args[3], IDE_SECTOR_REG);
888 hwif->OUTB(args[4], IDE_LCYL_REG);
889 hwif->OUTB(args[5], IDE_HCYL_REG);
890 sel = (args[6] & ~0x10);
891 if (drive->select.b.unit)
892 sel |= 0x10;
893 hwif->OUTB(sel, IDE_SELECT_REG);
894 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
895 return ide_started;
896 } else if (rq->flags & REQ_DRIVE_CMD) {
897 u8 *args = rq->buffer;
898
899 if (!args)
900 goto done;
901 #ifdef DEBUG
902 printk("%s: DRIVE_CMD ", drive->name);
903 printk("cmd=0x%02x ", args[0]);
904 printk("sc=0x%02x ", args[1]);
905 printk("fr=0x%02x ", args[2]);
906 printk("xx=0x%02x\n", args[3]);
907 #endif
908 if (args[0] == WIN_SMART) {
909 hwif->OUTB(0x4f, IDE_LCYL_REG);
910 hwif->OUTB(0xc2, IDE_HCYL_REG);
911 hwif->OUTB(args[2],IDE_FEATURE_REG);
912 hwif->OUTB(args[1],IDE_SECTOR_REG);
913 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
914 return ide_started;
915 }
916 hwif->OUTB(args[2],IDE_FEATURE_REG);
917 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
918 return ide_started;
919 }
920
921 done:
922 /*
923 * NULL is actually a valid way of waiting for
924 * all current requests to be flushed from the queue.
925 */
926 #ifdef DEBUG
927 printk("%s: DRIVE_CMD (null)\n", drive->name);
928 #endif
929 ide_end_drive_cmd(drive,
930 hwif->INB(IDE_STATUS_REG),
931 hwif->INB(IDE_ERROR_REG));
932 return ide_stopped;
933 }
934
935 static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
936 {
937 struct request_pm_state *pm = rq->end_io_data;
938
939 if (blk_pm_suspend_request(rq) &&
940 pm->pm_step == ide_pm_state_start_suspend)
941 /* Mark drive blocked when starting the suspend sequence. */
942 drive->blocked = 1;
943 else if (blk_pm_resume_request(rq) &&
944 pm->pm_step == ide_pm_state_start_resume) {
945 /*
946 * The first thing we do on wakeup is to wait for BSY bit to
947 * go away (with a looong timeout) as a drive on this hwif may
948 * just be POSTing itself.
949 * We do that before even selecting as the "other" device on
950 * the bus may be broken enough to walk on our toes at this
951 * point.
952 */
953 int rc;
954 #ifdef DEBUG_PM
955 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
956 #endif
957 rc = ide_wait_not_busy(HWIF(drive), 35000);
958 if (rc)
959 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
960 SELECT_DRIVE(drive);
961 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
962 rc = ide_wait_not_busy(HWIF(drive), 10000);
963 if (rc)
964 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
965 }
966 }
967
968 /**
969 * start_request - start of I/O and command issuing for IDE
970 *
971 * start_request() initiates handling of a new I/O request. It
972 * accepts commands and I/O (read/write) requests. It also does
973 * the final remapping for weird stuff like EZDrive. Once
974 * device mapper can work sector level the EZDrive stuff can go away
975 *
976 * FIXME: this function needs a rename
977 */
978
979 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
980 {
981 ide_startstop_t startstop;
982 sector_t block;
983
984 BUG_ON(!(rq->flags & REQ_STARTED));
985
986 #ifdef DEBUG
987 printk("%s: start_request: current=0x%08lx\n",
988 HWIF(drive)->name, (unsigned long) rq);
989 #endif
990
991 /* bail early if we've exceeded max_failures */
992 if (drive->max_failures && (drive->failures > drive->max_failures)) {
993 goto kill_rq;
994 }
995
996 block = rq->sector;
997 if (blk_fs_request(rq) &&
998 (drive->media == ide_disk || drive->media == ide_floppy)) {
999 block += drive->sect0;
1000 }
1001 /* Yecch - this will shift the entire interval,
1002 possibly killing some innocent following sector */
1003 if (block == 0 && drive->remap_0_to_1 == 1)
1004 block = 1; /* redirect MBR access to EZ-Drive partn table */
1005
1006 if (blk_pm_request(rq))
1007 ide_check_pm_state(drive, rq);
1008
1009 SELECT_DRIVE(drive);
1010 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
1011 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
1012 return startstop;
1013 }
1014 if (!drive->special.all) {
1015 ide_driver_t *drv;
1016
1017 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK))
1018 return execute_drive_cmd(drive, rq);
1019 else if (rq->flags & REQ_DRIVE_TASKFILE)
1020 return execute_drive_cmd(drive, rq);
1021 else if (blk_pm_request(rq)) {
1022 struct request_pm_state *pm = rq->end_io_data;
1023 #ifdef DEBUG_PM
1024 printk("%s: start_power_step(step: %d)\n",
1025 drive->name, rq->pm->pm_step);
1026 #endif
1027 startstop = ide_start_power_step(drive, rq);
1028 if (startstop == ide_stopped &&
1029 pm->pm_step == ide_pm_state_completed)
1030 ide_complete_pm_request(drive, rq);
1031 return startstop;
1032 }
1033
1034 drv = *(ide_driver_t **)rq->rq_disk->private_data;
1035 return drv->do_request(drive, rq, block);
1036 }
1037 return do_special(drive);
1038 kill_rq:
1039 ide_kill_rq(drive, rq);
1040 return ide_stopped;
1041 }
1042
1043 /**
1044 * ide_stall_queue - pause an IDE device
1045 * @drive: drive to stall
1046 * @timeout: time to stall for (jiffies)
1047 *
1048 * ide_stall_queue() can be used by a drive to give excess bandwidth back
1049 * to the hwgroup by sleeping for timeout jiffies.
1050 */
1051
1052 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1053 {
1054 if (timeout > WAIT_WORSTCASE)
1055 timeout = WAIT_WORSTCASE;
1056 drive->sleep = timeout + jiffies;
1057 drive->sleeping = 1;
1058 }
1059
1060 EXPORT_SYMBOL(ide_stall_queue);
1061
1062 #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
1063
1064 /**
1065 * choose_drive - select a drive to service
1066 * @hwgroup: hardware group to select on
1067 *
1068 * choose_drive() selects the next drive which will be serviced.
1069 * This is necessary because the IDE layer can't issue commands
1070 * to both drives on the same cable, unlike SCSI.
1071 */
1072
1073 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1074 {
1075 ide_drive_t *drive, *best;
1076
1077 repeat:
1078 best = NULL;
1079 drive = hwgroup->drive;
1080
1081 /*
1082 * drive is doing pre-flush, ordered write, post-flush sequence. even
1083 * though that is 3 requests, it must be seen as a single transaction.
1084 * we must not preempt this drive until that is complete
1085 */
1086 if (blk_queue_flushing(drive->queue)) {
1087 /*
1088 * small race where queue could get replugged during
1089 * the 3-request flush cycle, just yank the plug since
1090 * we want it to finish asap
1091 */
1092 blk_remove_plug(drive->queue);
1093 return drive;
1094 }
1095
1096 do {
1097 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1098 && !elv_queue_empty(drive->queue)) {
1099 if (!best
1100 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1101 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1102 {
1103 if (!blk_queue_plugged(drive->queue))
1104 best = drive;
1105 }
1106 }
1107 } while ((drive = drive->next) != hwgroup->drive);
1108 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1109 long t = (signed long)(WAKEUP(best) - jiffies);
1110 if (t >= WAIT_MIN_SLEEP) {
1111 /*
1112 * We *may* have some time to spare, but first let's see if
1113 * someone can potentially benefit from our nice mood today..
1114 */
1115 drive = best->next;
1116 do {
1117 if (!drive->sleeping
1118 && time_before(jiffies - best->service_time, WAKEUP(drive))
1119 && time_before(WAKEUP(drive), jiffies + t))
1120 {
1121 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1122 goto repeat;
1123 }
1124 } while ((drive = drive->next) != best);
1125 }
1126 }
1127 return best;
1128 }
1129
1130 /*
1131 * Issue a new request to a drive from hwgroup
1132 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1133 *
1134 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1135 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1136 * may have both interfaces in a single hwgroup to "serialize" access.
1137 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1138 * together into one hwgroup for serialized access.
1139 *
1140 * Note also that several hwgroups can end up sharing a single IRQ,
1141 * possibly along with many other devices. This is especially common in
1142 * PCI-based systems with off-board IDE controller cards.
1143 *
1144 * The IDE driver uses the single global ide_lock spinlock to protect
1145 * access to the request queues, and to protect the hwgroup->busy flag.
1146 *
1147 * The first thread into the driver for a particular hwgroup sets the
1148 * hwgroup->busy flag to indicate that this hwgroup is now active,
1149 * and then initiates processing of the top request from the request queue.
1150 *
1151 * Other threads attempting entry notice the busy setting, and will simply
1152 * queue their new requests and exit immediately. Note that hwgroup->busy
1153 * remains set even when the driver is merely awaiting the next interrupt.
1154 * Thus, the meaning is "this hwgroup is busy processing a request".
1155 *
1156 * When processing of a request completes, the completing thread or IRQ-handler
1157 * will start the next request from the queue. If no more work remains,
1158 * the driver will clear the hwgroup->busy flag and exit.
1159 *
1160 * The ide_lock (spinlock) is used to protect all access to the
1161 * hwgroup->busy flag, but is otherwise not needed for most processing in
1162 * the driver. This makes the driver much more friendlier to shared IRQs
1163 * than previous designs, while remaining 100% (?) SMP safe and capable.
1164 */
1165 static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1166 {
1167 ide_drive_t *drive;
1168 ide_hwif_t *hwif;
1169 struct request *rq;
1170 ide_startstop_t startstop;
1171 int loops = 0;
1172
1173 /* for atari only: POSSIBLY BROKEN HERE(?) */
1174 ide_get_lock(ide_intr, hwgroup);
1175
1176 /* caller must own ide_lock */
1177 BUG_ON(!irqs_disabled());
1178
1179 while (!hwgroup->busy) {
1180 hwgroup->busy = 1;
1181 drive = choose_drive(hwgroup);
1182 if (drive == NULL) {
1183 int sleeping = 0;
1184 unsigned long sleep = 0; /* shut up, gcc */
1185 hwgroup->rq = NULL;
1186 drive = hwgroup->drive;
1187 do {
1188 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1189 sleeping = 1;
1190 sleep = drive->sleep;
1191 }
1192 } while ((drive = drive->next) != hwgroup->drive);
1193 if (sleeping) {
1194 /*
1195 * Take a short snooze, and then wake up this hwgroup again.
1196 * This gives other hwgroups on the same a chance to
1197 * play fairly with us, just in case there are big differences
1198 * in relative throughputs.. don't want to hog the cpu too much.
1199 */
1200 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1201 sleep = jiffies + WAIT_MIN_SLEEP;
1202 #if 1
1203 if (timer_pending(&hwgroup->timer))
1204 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1205 #endif
1206 /* so that ide_timer_expiry knows what to do */
1207 hwgroup->sleeping = 1;
1208 mod_timer(&hwgroup->timer, sleep);
1209 /* we purposely leave hwgroup->busy==1
1210 * while sleeping */
1211 } else {
1212 /* Ugly, but how can we sleep for the lock
1213 * otherwise? perhaps from tq_disk?
1214 */
1215
1216 /* for atari only */
1217 ide_release_lock();
1218 hwgroup->busy = 0;
1219 }
1220
1221 /* no more work for this hwgroup (for now) */
1222 return;
1223 }
1224 again:
1225 hwif = HWIF(drive);
1226 if (hwgroup->hwif->sharing_irq &&
1227 hwif != hwgroup->hwif &&
1228 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1229 /* set nIEN for previous hwif */
1230 SELECT_INTERRUPT(drive);
1231 }
1232 hwgroup->hwif = hwif;
1233 hwgroup->drive = drive;
1234 drive->sleeping = 0;
1235 drive->service_start = jiffies;
1236
1237 if (blk_queue_plugged(drive->queue)) {
1238 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1239 break;
1240 }
1241
1242 /*
1243 * we know that the queue isn't empty, but this can happen
1244 * if the q->prep_rq_fn() decides to kill a request
1245 */
1246 rq = elv_next_request(drive->queue);
1247 if (!rq) {
1248 hwgroup->busy = 0;
1249 break;
1250 }
1251
1252 /*
1253 * Sanity: don't accept a request that isn't a PM request
1254 * if we are currently power managed. This is very important as
1255 * blk_stop_queue() doesn't prevent the elv_next_request()
1256 * above to return us whatever is in the queue. Since we call
1257 * ide_do_request() ourselves, we end up taking requests while
1258 * the queue is blocked...
1259 *
1260 * We let requests forced at head of queue with ide-preempt
1261 * though. I hope that doesn't happen too much, hopefully not
1262 * unless the subdriver triggers such a thing in its own PM
1263 * state machine.
1264 *
1265 * We count how many times we loop here to make sure we service
1266 * all drives in the hwgroup without looping for ever
1267 */
1268 if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
1269 drive = drive->next ? drive->next : hwgroup->drive;
1270 if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1271 goto again;
1272 /* We clear busy, there should be no pending ATA command at this point. */
1273 hwgroup->busy = 0;
1274 break;
1275 }
1276
1277 hwgroup->rq = rq;
1278
1279 /*
1280 * Some systems have trouble with IDE IRQs arriving while
1281 * the driver is still setting things up. So, here we disable
1282 * the IRQ used by this interface while the request is being started.
1283 * This may look bad at first, but pretty much the same thing
1284 * happens anyway when any interrupt comes in, IDE or otherwise
1285 * -- the kernel masks the IRQ while it is being handled.
1286 */
1287 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1288 disable_irq_nosync(hwif->irq);
1289 spin_unlock(&ide_lock);
1290 local_irq_enable();
1291 /* allow other IRQs while we start this request */
1292 startstop = start_request(drive, rq);
1293 spin_lock_irq(&ide_lock);
1294 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1295 enable_irq(hwif->irq);
1296 if (startstop == ide_stopped)
1297 hwgroup->busy = 0;
1298 }
1299 }
1300
1301 /*
1302 * Passes the stuff to ide_do_request
1303 */
1304 void do_ide_request(request_queue_t *q)
1305 {
1306 ide_drive_t *drive = q->queuedata;
1307
1308 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1309 }
1310
1311 /*
1312 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1313 * retry the current request in pio mode instead of risking tossing it
1314 * all away
1315 */
1316 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1317 {
1318 ide_hwif_t *hwif = HWIF(drive);
1319 struct request *rq;
1320 ide_startstop_t ret = ide_stopped;
1321
1322 /*
1323 * end current dma transaction
1324 */
1325
1326 if (error < 0) {
1327 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1328 (void)HWIF(drive)->ide_dma_end(drive);
1329 ret = ide_error(drive, "dma timeout error",
1330 hwif->INB(IDE_STATUS_REG));
1331 } else {
1332 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1333 (void) hwif->ide_dma_timeout(drive);
1334 }
1335
1336 /*
1337 * disable dma for now, but remember that we did so because of
1338 * a timeout -- we'll reenable after we finish this next request
1339 * (or rather the first chunk of it) in pio.
1340 */
1341 drive->retry_pio++;
1342 drive->state = DMA_PIO_RETRY;
1343 (void) hwif->ide_dma_off_quietly(drive);
1344
1345 /*
1346 * un-busy drive etc (hwgroup->busy is cleared on return) and
1347 * make sure request is sane
1348 */
1349 rq = HWGROUP(drive)->rq;
1350 HWGROUP(drive)->rq = NULL;
1351
1352 rq->errors = 0;
1353
1354 if (!rq->bio)
1355 goto out;
1356
1357 rq->sector = rq->bio->bi_sector;
1358 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1359 rq->hard_cur_sectors = rq->current_nr_sectors;
1360 rq->buffer = bio_data(rq->bio);
1361 out:
1362 return ret;
1363 }
1364
1365 /**
1366 * ide_timer_expiry - handle lack of an IDE interrupt
1367 * @data: timer callback magic (hwgroup)
1368 *
1369 * An IDE command has timed out before the expected drive return
1370 * occurred. At this point we attempt to clean up the current
1371 * mess. If the current handler includes an expiry handler then
1372 * we invoke the expiry handler, and providing it is happy the
1373 * work is done. If that fails we apply generic recovery rules
1374 * invoking the handler and checking the drive DMA status. We
1375 * have an excessively incestuous relationship with the DMA
1376 * logic that wants cleaning up.
1377 */
1378
1379 void ide_timer_expiry (unsigned long data)
1380 {
1381 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1382 ide_handler_t *handler;
1383 ide_expiry_t *expiry;
1384 unsigned long flags;
1385 unsigned long wait = -1;
1386
1387 spin_lock_irqsave(&ide_lock, flags);
1388
1389 if ((handler = hwgroup->handler) == NULL) {
1390 /*
1391 * Either a marginal timeout occurred
1392 * (got the interrupt just as timer expired),
1393 * or we were "sleeping" to give other devices a chance.
1394 * Either way, we don't really want to complain about anything.
1395 */
1396 if (hwgroup->sleeping) {
1397 hwgroup->sleeping = 0;
1398 hwgroup->busy = 0;
1399 }
1400 } else {
1401 ide_drive_t *drive = hwgroup->drive;
1402 if (!drive) {
1403 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1404 hwgroup->handler = NULL;
1405 } else {
1406 ide_hwif_t *hwif;
1407 ide_startstop_t startstop = ide_stopped;
1408 if (!hwgroup->busy) {
1409 hwgroup->busy = 1; /* paranoia */
1410 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1411 }
1412 if ((expiry = hwgroup->expiry) != NULL) {
1413 /* continue */
1414 if ((wait = expiry(drive)) > 0) {
1415 /* reset timer */
1416 hwgroup->timer.expires = jiffies + wait;
1417 add_timer(&hwgroup->timer);
1418 spin_unlock_irqrestore(&ide_lock, flags);
1419 return;
1420 }
1421 }
1422 hwgroup->handler = NULL;
1423 /*
1424 * We need to simulate a real interrupt when invoking
1425 * the handler() function, which means we need to
1426 * globally mask the specific IRQ:
1427 */
1428 spin_unlock(&ide_lock);
1429 hwif = HWIF(drive);
1430 #if DISABLE_IRQ_NOSYNC
1431 disable_irq_nosync(hwif->irq);
1432 #else
1433 /* disable_irq_nosync ?? */
1434 disable_irq(hwif->irq);
1435 #endif /* DISABLE_IRQ_NOSYNC */
1436 /* local CPU only,
1437 * as if we were handling an interrupt */
1438 local_irq_disable();
1439 if (hwgroup->polling) {
1440 startstop = handler(drive);
1441 } else if (drive_is_ready(drive)) {
1442 if (drive->waiting_for_dma)
1443 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1444 (void)ide_ack_intr(hwif);
1445 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1446 startstop = handler(drive);
1447 } else {
1448 if (drive->waiting_for_dma) {
1449 startstop = ide_dma_timeout_retry(drive, wait);
1450 } else
1451 startstop =
1452 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1453 }
1454 drive->service_time = jiffies - drive->service_start;
1455 spin_lock_irq(&ide_lock);
1456 enable_irq(hwif->irq);
1457 if (startstop == ide_stopped)
1458 hwgroup->busy = 0;
1459 }
1460 }
1461 ide_do_request(hwgroup, IDE_NO_IRQ);
1462 spin_unlock_irqrestore(&ide_lock, flags);
1463 }
1464
1465 /**
1466 * unexpected_intr - handle an unexpected IDE interrupt
1467 * @irq: interrupt line
1468 * @hwgroup: hwgroup being processed
1469 *
1470 * There's nothing really useful we can do with an unexpected interrupt,
1471 * other than reading the status register (to clear it), and logging it.
1472 * There should be no way that an irq can happen before we're ready for it,
1473 * so we needn't worry much about losing an "important" interrupt here.
1474 *
1475 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1476 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1477 * looks "good", we just ignore the interrupt completely.
1478 *
1479 * This routine assumes __cli() is in effect when called.
1480 *
1481 * If an unexpected interrupt happens on irq15 while we are handling irq14
1482 * and if the two interfaces are "serialized" (CMD640), then it looks like
1483 * we could screw up by interfering with a new request being set up for
1484 * irq15.
1485 *
1486 * In reality, this is a non-issue. The new command is not sent unless
1487 * the drive is ready to accept one, in which case we know the drive is
1488 * not trying to interrupt us. And ide_set_handler() is always invoked
1489 * before completing the issuance of any new drive command, so we will not
1490 * be accidentally invoked as a result of any valid command completion
1491 * interrupt.
1492 *
1493 * Note that we must walk the entire hwgroup here. We know which hwif
1494 * is doing the current command, but we don't know which hwif burped
1495 * mysteriously.
1496 */
1497
1498 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1499 {
1500 u8 stat;
1501 ide_hwif_t *hwif = hwgroup->hwif;
1502
1503 /*
1504 * handle the unexpected interrupt
1505 */
1506 do {
1507 if (hwif->irq == irq) {
1508 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1509 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1510 /* Try to not flood the console with msgs */
1511 static unsigned long last_msgtime, count;
1512 ++count;
1513 if (time_after(jiffies, last_msgtime + HZ)) {
1514 last_msgtime = jiffies;
1515 printk(KERN_ERR "%s%s: unexpected interrupt, "
1516 "status=0x%02x, count=%ld\n",
1517 hwif->name,
1518 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1519 }
1520 }
1521 }
1522 } while ((hwif = hwif->next) != hwgroup->hwif);
1523 }
1524
1525 /**
1526 * ide_intr - default IDE interrupt handler
1527 * @irq: interrupt number
1528 * @dev_id: hwif group
1529 * @regs: unused weirdness from the kernel irq layer
1530 *
1531 * This is the default IRQ handler for the IDE layer. You should
1532 * not need to override it. If you do be aware it is subtle in
1533 * places
1534 *
1535 * hwgroup->hwif is the interface in the group currently performing
1536 * a command. hwgroup->drive is the drive and hwgroup->handler is
1537 * the IRQ handler to call. As we issue a command the handlers
1538 * step through multiple states, reassigning the handler to the
1539 * next step in the process. Unlike a smart SCSI controller IDE
1540 * expects the main processor to sequence the various transfer
1541 * stages. We also manage a poll timer to catch up with most
1542 * timeout situations. There are still a few where the handlers
1543 * don't ever decide to give up.
1544 *
1545 * The handler eventually returns ide_stopped to indicate the
1546 * request completed. At this point we issue the next request
1547 * on the hwgroup and the process begins again.
1548 */
1549
1550 irqreturn_t ide_intr (int irq, void *dev_id, struct pt_regs *regs)
1551 {
1552 unsigned long flags;
1553 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1554 ide_hwif_t *hwif;
1555 ide_drive_t *drive;
1556 ide_handler_t *handler;
1557 ide_startstop_t startstop;
1558
1559 spin_lock_irqsave(&ide_lock, flags);
1560 hwif = hwgroup->hwif;
1561
1562 if (!ide_ack_intr(hwif)) {
1563 spin_unlock_irqrestore(&ide_lock, flags);
1564 return IRQ_NONE;
1565 }
1566
1567 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1568 /*
1569 * Not expecting an interrupt from this drive.
1570 * That means this could be:
1571 * (1) an interrupt from another PCI device
1572 * sharing the same PCI INT# as us.
1573 * or (2) a drive just entered sleep or standby mode,
1574 * and is interrupting to let us know.
1575 * or (3) a spurious interrupt of unknown origin.
1576 *
1577 * For PCI, we cannot tell the difference,
1578 * so in that case we just ignore it and hope it goes away.
1579 *
1580 * FIXME: unexpected_intr should be hwif-> then we can
1581 * remove all the ifdef PCI crap
1582 */
1583 #ifdef CONFIG_BLK_DEV_IDEPCI
1584 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1585 #endif /* CONFIG_BLK_DEV_IDEPCI */
1586 {
1587 /*
1588 * Probably not a shared PCI interrupt,
1589 * so we can safely try to do something about it:
1590 */
1591 unexpected_intr(irq, hwgroup);
1592 #ifdef CONFIG_BLK_DEV_IDEPCI
1593 } else {
1594 /*
1595 * Whack the status register, just in case
1596 * we have a leftover pending IRQ.
1597 */
1598 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1599 #endif /* CONFIG_BLK_DEV_IDEPCI */
1600 }
1601 spin_unlock_irqrestore(&ide_lock, flags);
1602 return IRQ_NONE;
1603 }
1604 drive = hwgroup->drive;
1605 if (!drive) {
1606 /*
1607 * This should NEVER happen, and there isn't much
1608 * we could do about it here.
1609 *
1610 * [Note - this can occur if the drive is hot unplugged]
1611 */
1612 spin_unlock_irqrestore(&ide_lock, flags);
1613 return IRQ_HANDLED;
1614 }
1615 if (!drive_is_ready(drive)) {
1616 /*
1617 * This happens regularly when we share a PCI IRQ with
1618 * another device. Unfortunately, it can also happen
1619 * with some buggy drives that trigger the IRQ before
1620 * their status register is up to date. Hopefully we have
1621 * enough advance overhead that the latter isn't a problem.
1622 */
1623 spin_unlock_irqrestore(&ide_lock, flags);
1624 return IRQ_NONE;
1625 }
1626 if (!hwgroup->busy) {
1627 hwgroup->busy = 1; /* paranoia */
1628 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1629 }
1630 hwgroup->handler = NULL;
1631 del_timer(&hwgroup->timer);
1632 spin_unlock(&ide_lock);
1633
1634 if (drive->unmask)
1635 local_irq_enable();
1636 /* service this interrupt, may set handler for next interrupt */
1637 startstop = handler(drive);
1638 spin_lock_irq(&ide_lock);
1639
1640 /*
1641 * Note that handler() may have set things up for another
1642 * interrupt to occur soon, but it cannot happen until
1643 * we exit from this routine, because it will be the
1644 * same irq as is currently being serviced here, and Linux
1645 * won't allow another of the same (on any CPU) until we return.
1646 */
1647 drive->service_time = jiffies - drive->service_start;
1648 if (startstop == ide_stopped) {
1649 if (hwgroup->handler == NULL) { /* paranoia */
1650 hwgroup->busy = 0;
1651 ide_do_request(hwgroup, hwif->irq);
1652 } else {
1653 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1654 "on exit\n", drive->name);
1655 }
1656 }
1657 spin_unlock_irqrestore(&ide_lock, flags);
1658 return IRQ_HANDLED;
1659 }
1660
1661 /**
1662 * ide_init_drive_cmd - initialize a drive command request
1663 * @rq: request object
1664 *
1665 * Initialize a request before we fill it in and send it down to
1666 * ide_do_drive_cmd. Commands must be set up by this function. Right
1667 * now it doesn't do a lot, but if that changes abusers will have a
1668 * nasty suprise.
1669 */
1670
1671 void ide_init_drive_cmd (struct request *rq)
1672 {
1673 memset(rq, 0, sizeof(*rq));
1674 rq->flags = REQ_DRIVE_CMD;
1675 rq->ref_count = 1;
1676 }
1677
1678 EXPORT_SYMBOL(ide_init_drive_cmd);
1679
1680 /**
1681 * ide_do_drive_cmd - issue IDE special command
1682 * @drive: device to issue command
1683 * @rq: request to issue
1684 * @action: action for processing
1685 *
1686 * This function issues a special IDE device request
1687 * onto the request queue.
1688 *
1689 * If action is ide_wait, then the rq is queued at the end of the
1690 * request queue, and the function sleeps until it has been processed.
1691 * This is for use when invoked from an ioctl handler.
1692 *
1693 * If action is ide_preempt, then the rq is queued at the head of
1694 * the request queue, displacing the currently-being-processed
1695 * request and this function returns immediately without waiting
1696 * for the new rq to be completed. This is VERY DANGEROUS, and is
1697 * intended for careful use by the ATAPI tape/cdrom driver code.
1698 *
1699 * If action is ide_end, then the rq is queued at the end of the
1700 * request queue, and the function returns immediately without waiting
1701 * for the new rq to be completed. This is again intended for careful
1702 * use by the ATAPI tape/cdrom driver code.
1703 */
1704
1705 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1706 {
1707 unsigned long flags;
1708 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1709 DECLARE_COMPLETION(wait);
1710 int where = ELEVATOR_INSERT_BACK, err;
1711 int must_wait = (action == ide_wait || action == ide_head_wait);
1712
1713 rq->errors = 0;
1714 rq->rq_status = RQ_ACTIVE;
1715
1716 /*
1717 * we need to hold an extra reference to request for safe inspection
1718 * after completion
1719 */
1720 if (must_wait) {
1721 rq->ref_count++;
1722 rq->waiting = &wait;
1723 rq->end_io = blk_end_sync_rq;
1724 }
1725
1726 spin_lock_irqsave(&ide_lock, flags);
1727 if (action == ide_preempt)
1728 hwgroup->rq = NULL;
1729 if (action == ide_preempt || action == ide_head_wait) {
1730 where = ELEVATOR_INSERT_FRONT;
1731 rq->flags |= REQ_PREEMPT;
1732 }
1733 __elv_add_request(drive->queue, rq, where, 0);
1734 ide_do_request(hwgroup, IDE_NO_IRQ);
1735 spin_unlock_irqrestore(&ide_lock, flags);
1736
1737 err = 0;
1738 if (must_wait) {
1739 wait_for_completion(&wait);
1740 rq->waiting = NULL;
1741 if (rq->errors)
1742 err = -EIO;
1743
1744 blk_put_request(rq);
1745 }
1746
1747 return err;
1748 }
1749
1750 EXPORT_SYMBOL(ide_do_drive_cmd);