blob: c01615dec2024f84efba781769a78d341d69a69d [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Adrian Bunka7ff7d42006-02-03 03:04:56 -080058static int __ide_end_request(ide_drive_t *drive, struct request *rq,
59 int uptodate, int nr_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
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
Jens Axboeba027de2006-01-12 20:44:12 +010084 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
85 add_disk_randomness(rq->rq_disk);
Linus Torvalds1da177e2005-04-16 15:20:36 -070086 blkdev_dequeue_request(rq);
87 HWGROUP(drive)->rq = NULL;
Jens Axboeba027de2006-01-12 20:44:12 +010088 end_that_request_last(rq, uptodate);
Linus Torvalds1da177e2005-04-16 15:20:36 -070089 ret = 0;
90 }
Jens Axboe8672d572006-01-09 16:03:35 +010091
Linus Torvalds1da177e2005-04-16 15:20:36 -070092 return ret;
93}
Linus Torvalds1da177e2005-04-16 15:20:36 -070094
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{
108 struct request *rq;
109 unsigned long flags;
110 int ret = 1;
111
Jens Axboe8672d572006-01-09 16:03:35 +0100112 /*
113 * room for locking improvements here, the calls below don't
114 * need the queue lock held at all
115 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700116 spin_lock_irqsave(&ide_lock, flags);
117 rq = HWGROUP(drive)->rq;
118
119 if (!nr_sectors)
120 nr_sectors = rq->hard_cur_sectors;
121
Tejun Heo3e087b52006-01-06 09:57:31 +0100122 ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700123
124 spin_unlock_irqrestore(&ide_lock, flags);
125 return ret;
126}
127EXPORT_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
135enum {
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
143static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
144{
145 if (drive->media != ide_disk)
146 return;
147
148 switch (rq->pm->pm_step) {
149 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
Michal Schmidt46dacba2005-09-03 15:57:01 -0700150 if (rq->pm->pm_state == PM_EVENT_FREEZE)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151 rq->pm->pm_step = ide_pm_state_completed;
152 else
153 rq->pm->pm_step = idedisk_pm_standby;
154 break;
155 case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
156 rq->pm->pm_step = ide_pm_state_completed;
157 break;
158 case idedisk_pm_idle: /* Resume step 1 (idle) complete */
159 rq->pm->pm_step = ide_pm_restore_dma;
160 break;
161 }
162}
163
164static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
165{
166 ide_task_t *args = rq->special;
167
168 memset(args, 0, sizeof(*args));
169
170 if (drive->media != ide_disk) {
171 /* skip idedisk_pm_idle for ATAPI devices */
172 if (rq->pm->pm_step == idedisk_pm_idle)
173 rq->pm->pm_step = ide_pm_restore_dma;
174 }
175
176 switch (rq->pm->pm_step) {
177 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */
178 if (drive->media != ide_disk)
179 break;
180 /* Not supported? Switch to next step now. */
181 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
182 ide_complete_power_step(drive, rq, 0, 0);
183 return ide_stopped;
184 }
185 if (ide_id_has_flush_cache_ext(drive->id))
186 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT;
187 else
188 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE;
189 args->command_type = IDE_DRIVE_TASK_NO_DATA;
190 args->handler = &task_no_data_intr;
191 return do_rw_taskfile(drive, args);
192
193 case idedisk_pm_standby: /* Suspend step 2 (standby) */
194 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1;
195 args->command_type = IDE_DRIVE_TASK_NO_DATA;
196 args->handler = &task_no_data_intr;
197 return do_rw_taskfile(drive, args);
198
199 case idedisk_pm_idle: /* Resume step 1 (idle) */
200 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE;
201 args->command_type = IDE_DRIVE_TASK_NO_DATA;
202 args->handler = task_no_data_intr;
203 return do_rw_taskfile(drive, args);
204
205 case ide_pm_restore_dma: /* Resume step 2 (restore DMA) */
206 /*
207 * Right now, all we do is call hwif->ide_dma_check(drive),
208 * we could be smarter and check for current xfer_speed
209 * in struct drive etc...
210 */
211 if ((drive->id->capability & 1) == 0)
212 break;
213 if (drive->hwif->ide_dma_check == NULL)
214 break;
215 drive->hwif->ide_dma_check(drive);
216 break;
217 }
218 rq->pm->pm_step = ide_pm_state_completed;
219 return ide_stopped;
220}
221
222/**
223 * ide_complete_pm_request - end the current Power Management request
224 * @drive: target drive
225 * @rq: request
226 *
227 * This function cleans up the current PM request and stops the queue
228 * if necessary.
229 */
230static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
231{
232 unsigned long flags;
233
234#ifdef DEBUG_PM
235 printk("%s: completing PM request, %s\n", drive->name,
236 blk_pm_suspend_request(rq) ? "suspend" : "resume");
237#endif
238 spin_lock_irqsave(&ide_lock, flags);
239 if (blk_pm_suspend_request(rq)) {
240 blk_stop_queue(drive->queue);
241 } else {
242 drive->blocked = 0;
243 blk_start_queue(drive->queue);
244 }
245 blkdev_dequeue_request(rq);
246 HWGROUP(drive)->rq = NULL;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100247 end_that_request_last(rq, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 spin_unlock_irqrestore(&ide_lock, flags);
249}
250
251/*
252 * FIXME: probably move this somewhere else, name is bad too :)
253 */
254u64 ide_get_error_location(ide_drive_t *drive, char *args)
255{
256 u32 high, low;
257 u8 hcyl, lcyl, sect;
258 u64 sector;
259
260 high = 0;
261 hcyl = args[5];
262 lcyl = args[4];
263 sect = args[3];
264
265 if (ide_id_has_flush_cache_ext(drive->id)) {
266 low = (hcyl << 16) | (lcyl << 8) | sect;
267 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
268 high = ide_read_24(drive);
269 } else {
270 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
271 if (cur & 0x40) {
272 high = cur & 0xf;
273 low = (hcyl << 16) | (lcyl << 8) | sect;
274 } else {
275 low = hcyl * drive->head * drive->sect;
276 low += lcyl * drive->sect;
277 low += sect - 1;
278 }
279 }
280
281 sector = ((u64) high << 24) | low;
282 return sector;
283}
284EXPORT_SYMBOL(ide_get_error_location);
285
286/**
287 * ide_end_drive_cmd - end an explicit drive command
288 * @drive: command
289 * @stat: status bits
290 * @err: error bits
291 *
292 * Clean up after success/failure of an explicit drive command.
293 * These get thrown onto the queue so they are synchronized with
294 * real I/O operations on the drive.
295 *
296 * In LBA48 mode we have to read the register set twice to get
297 * all the extra information out.
298 */
299
300void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
301{
302 ide_hwif_t *hwif = HWIF(drive);
303 unsigned long flags;
304 struct request *rq;
305
306 spin_lock_irqsave(&ide_lock, flags);
307 rq = HWGROUP(drive)->rq;
308 spin_unlock_irqrestore(&ide_lock, flags);
309
310 if (rq->flags & REQ_DRIVE_CMD) {
311 u8 *args = (u8 *) rq->buffer;
312 if (rq->errors == 0)
313 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
314
315 if (args) {
316 args[0] = stat;
317 args[1] = err;
318 args[2] = hwif->INB(IDE_NSECTOR_REG);
319 }
320 } else if (rq->flags & REQ_DRIVE_TASK) {
321 u8 *args = (u8 *) rq->buffer;
322 if (rq->errors == 0)
323 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
324
325 if (args) {
326 args[0] = stat;
327 args[1] = err;
328 args[2] = hwif->INB(IDE_NSECTOR_REG);
329 args[3] = hwif->INB(IDE_SECTOR_REG);
330 args[4] = hwif->INB(IDE_LCYL_REG);
331 args[5] = hwif->INB(IDE_HCYL_REG);
332 args[6] = hwif->INB(IDE_SELECT_REG);
333 }
334 } else if (rq->flags & REQ_DRIVE_TASKFILE) {
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) {
340 if (args->tf_in_flags.b.data) {
341 u16 data = hwif->INW(IDE_DATA_REG);
342 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
343 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
344 }
345 args->tfRegister[IDE_ERROR_OFFSET] = err;
346 /* be sure we're looking at the low order bits */
347 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
348 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
349 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
350 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
351 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
352 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
353 args->tfRegister[IDE_STATUS_OFFSET] = stat;
354
355 if (drive->addressing == 1) {
356 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
357 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
358 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
359 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
360 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
361 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
362 }
363 }
364 } else if (blk_pm_request(rq)) {
365#ifdef DEBUG_PM
366 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
367 drive->name, rq->pm->pm_step, stat, err);
368#endif
369 ide_complete_power_step(drive, rq, stat, err);
370 if (rq->pm->pm_step == ide_pm_state_completed)
371 ide_complete_pm_request(drive, rq);
372 return;
373 }
374
375 spin_lock_irqsave(&ide_lock, flags);
376 blkdev_dequeue_request(rq);
377 HWGROUP(drive)->rq = NULL;
378 rq->errors = err;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100379 end_that_request_last(rq, !rq->errors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 spin_unlock_irqrestore(&ide_lock, flags);
381}
382
383EXPORT_SYMBOL(ide_end_drive_cmd);
384
385/**
386 * try_to_flush_leftover_data - flush junk
387 * @drive: drive to flush
388 *
389 * try_to_flush_leftover_data() is invoked in response to a drive
390 * unexpectedly having its DRQ_STAT bit set. As an alternative to
391 * resetting the drive, this routine tries to clear the condition
392 * by read a sector's worth of data from the drive. Of course,
393 * this may not help if the drive is *waiting* for data from *us*.
394 */
395static void try_to_flush_leftover_data (ide_drive_t *drive)
396{
397 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
398
399 if (drive->media != ide_disk)
400 return;
401 while (i > 0) {
402 u32 buffer[16];
403 u32 wcount = (i > 16) ? 16 : i;
404
405 i -= wcount;
406 HWIF(drive)->ata_input_data(drive, buffer, wcount);
407 }
408}
409
410static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
411{
412 if (rq->rq_disk) {
413 ide_driver_t *drv;
414
415 drv = *(ide_driver_t **)rq->rq_disk->private_data;
416 drv->end_request(drive, 0, 0);
417 } else
418 ide_end_request(drive, 0, 0);
419}
420
421static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
422{
423 ide_hwif_t *hwif = drive->hwif;
424
425 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
426 /* other bits are useless when BUSY */
427 rq->errors |= ERROR_RESET;
428 } else if (stat & ERR_STAT) {
429 /* err has different meaning on cdrom and tape */
430 if (err == ABRT_ERR) {
431 if (drive->select.b.lba &&
432 /* some newer drives don't support WIN_SPECIFY */
433 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
434 return ide_stopped;
435 } else if ((err & BAD_CRC) == BAD_CRC) {
436 /* UDMA crc error, just retry the operation */
437 drive->crc_count++;
438 } else if (err & (BBD_ERR | ECC_ERR)) {
439 /* retries won't help these */
440 rq->errors = ERROR_MAX;
441 } else if (err & TRK0_ERR) {
442 /* help it find track zero */
443 rq->errors |= ERROR_RECAL;
444 }
445 }
446
447 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ)
448 try_to_flush_leftover_data(drive);
449
450 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
451 /* force an abort */
452 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
453
454 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq))
455 ide_kill_rq(drive, rq);
456 else {
457 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
458 ++rq->errors;
459 return ide_do_reset(drive);
460 }
461 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
462 drive->special.b.recalibrate = 1;
463 ++rq->errors;
464 }
465 return ide_stopped;
466}
467
468static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
469{
470 ide_hwif_t *hwif = drive->hwif;
471
472 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
473 /* other bits are useless when BUSY */
474 rq->errors |= ERROR_RESET;
475 } else {
476 /* add decoding error stuff */
477 }
478
479 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
480 /* force an abort */
481 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
482
483 if (rq->errors >= ERROR_MAX) {
484 ide_kill_rq(drive, rq);
485 } else {
486 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
487 ++rq->errors;
488 return ide_do_reset(drive);
489 }
490 ++rq->errors;
491 }
492
493 return ide_stopped;
494}
495
496ide_startstop_t
497__ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
498{
499 if (drive->media == ide_disk)
500 return ide_ata_error(drive, rq, stat, err);
501 return ide_atapi_error(drive, rq, stat, err);
502}
503
504EXPORT_SYMBOL_GPL(__ide_error);
505
506/**
507 * ide_error - handle an error on the IDE
508 * @drive: drive the error occurred on
509 * @msg: message to report
510 * @stat: status bits
511 *
512 * ide_error() takes action based on the error returned by the drive.
513 * For normal I/O that may well include retries. We deal with
514 * both new-style (taskfile) and old style command handling here.
515 * In the case of taskfile command handling there is work left to
516 * do
517 */
518
519ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
520{
521 struct request *rq;
522 u8 err;
523
524 err = ide_dump_status(drive, msg, stat);
525
526 if ((rq = HWGROUP(drive)->rq) == NULL)
527 return ide_stopped;
528
529 /* retry only "normal" I/O: */
530 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
531 rq->errors = 1;
532 ide_end_drive_cmd(drive, stat, err);
533 return ide_stopped;
534 }
535
536 if (rq->rq_disk) {
537 ide_driver_t *drv;
538
539 drv = *(ide_driver_t **)rq->rq_disk->private_data;
540 return drv->error(drive, rq, stat, err);
541 } else
542 return __ide_error(drive, rq, stat, err);
543}
544
545EXPORT_SYMBOL_GPL(ide_error);
546
547ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
548{
549 if (drive->media != ide_disk)
550 rq->errors |= ERROR_RESET;
551
552 ide_kill_rq(drive, rq);
553
554 return ide_stopped;
555}
556
557EXPORT_SYMBOL_GPL(__ide_abort);
558
559/**
Adrian Bunk338cec32005-09-10 00:26:54 -0700560 * ide_abort - abort pending IDE operations
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 * @drive: drive the error occurred on
562 * @msg: message to report
563 *
564 * ide_abort kills and cleans up when we are about to do a
565 * host initiated reset on active commands. Longer term we
566 * want handlers to have sensible abort handling themselves
567 *
568 * This differs fundamentally from ide_error because in
569 * this case the command is doing just fine when we
570 * blow it away.
571 */
572
573ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
574{
575 struct request *rq;
576
577 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
578 return ide_stopped;
579
580 /* retry only "normal" I/O: */
581 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
582 rq->errors = 1;
583 ide_end_drive_cmd(drive, BUSY_STAT, 0);
584 return ide_stopped;
585 }
586
587 if (rq->rq_disk) {
588 ide_driver_t *drv;
589
590 drv = *(ide_driver_t **)rq->rq_disk->private_data;
591 return drv->abort(drive, rq);
592 } else
593 return __ide_abort(drive, rq);
594}
595
596/**
597 * ide_cmd - issue a simple drive command
598 * @drive: drive the command is for
599 * @cmd: command byte
600 * @nsect: sector byte
601 * @handler: handler for the command completion
602 *
603 * Issue a simple drive command with interrupts.
604 * The drive must be selected beforehand.
605 */
606
607static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
608 ide_handler_t *handler)
609{
610 ide_hwif_t *hwif = HWIF(drive);
611 if (IDE_CONTROL_REG)
612 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
613 SELECT_MASK(drive,0);
614 hwif->OUTB(nsect,IDE_NSECTOR_REG);
615 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
616}
617
618/**
619 * drive_cmd_intr - drive command completion interrupt
620 * @drive: drive the completion interrupt occurred on
621 *
622 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
Adrian Bunk338cec32005-09-10 00:26:54 -0700623 * We do any necessary data reading and then wait for the drive to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 * go non busy. At that point we may read the error data and complete
625 * the request
626 */
627
628static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
629{
630 struct request *rq = HWGROUP(drive)->rq;
631 ide_hwif_t *hwif = HWIF(drive);
632 u8 *args = (u8 *) rq->buffer;
633 u8 stat = hwif->INB(IDE_STATUS_REG);
634 int retries = 10;
635
636 local_irq_enable();
637 if ((stat & DRQ_STAT) && args && args[3]) {
638 u8 io_32bit = drive->io_32bit;
639 drive->io_32bit = 0;
640 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
641 drive->io_32bit = io_32bit;
642 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
643 udelay(100);
644 }
645
646 if (!OK_STAT(stat, READY_STAT, BAD_STAT))
647 return ide_error(drive, "drive_cmd", stat);
648 /* calls ide_end_drive_cmd */
649 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
650 return ide_stopped;
651}
652
653static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
654{
655 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
656 task->tfRegister[IDE_SECTOR_OFFSET] = drive->sect;
657 task->tfRegister[IDE_LCYL_OFFSET] = drive->cyl;
658 task->tfRegister[IDE_HCYL_OFFSET] = drive->cyl>>8;
659 task->tfRegister[IDE_SELECT_OFFSET] = ((drive->head-1)|drive->select.all)&0xBF;
660 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY;
661
662 task->handler = &set_geometry_intr;
663}
664
665static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
666{
667 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
668 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE;
669
670 task->handler = &recal_intr;
671}
672
673static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
674{
675 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req;
676 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT;
677
678 task->handler = &set_multmode_intr;
679}
680
681static ide_startstop_t ide_disk_special(ide_drive_t *drive)
682{
683 special_t *s = &drive->special;
684 ide_task_t args;
685
686 memset(&args, 0, sizeof(ide_task_t));
687 args.command_type = IDE_DRIVE_TASK_NO_DATA;
688
689 if (s->b.set_geometry) {
690 s->b.set_geometry = 0;
691 ide_init_specify_cmd(drive, &args);
692 } else if (s->b.recalibrate) {
693 s->b.recalibrate = 0;
694 ide_init_restore_cmd(drive, &args);
695 } else if (s->b.set_multmode) {
696 s->b.set_multmode = 0;
697 if (drive->mult_req > drive->id->max_multsect)
698 drive->mult_req = drive->id->max_multsect;
699 ide_init_setmult_cmd(drive, &args);
700 } else if (s->all) {
701 int special = s->all;
702 s->all = 0;
703 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
704 return ide_stopped;
705 }
706
707 do_rw_taskfile(drive, &args);
708
709 return ide_started;
710}
711
712/**
713 * do_special - issue some special commands
714 * @drive: drive the command is for
715 *
716 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
717 * commands to a drive. It used to do much more, but has been scaled
718 * back.
719 */
720
721static ide_startstop_t do_special (ide_drive_t *drive)
722{
723 special_t *s = &drive->special;
724
725#ifdef DEBUG
726 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
727#endif
728 if (s->b.set_tune) {
729 s->b.set_tune = 0;
730 if (HWIF(drive)->tuneproc != NULL)
731 HWIF(drive)->tuneproc(drive, drive->tune_req);
732 return ide_stopped;
733 } else {
734 if (drive->media == ide_disk)
735 return ide_disk_special(drive);
736
737 s->all = 0;
738 drive->mult_req = 0;
739 return ide_stopped;
740 }
741}
742
743void ide_map_sg(ide_drive_t *drive, struct request *rq)
744{
745 ide_hwif_t *hwif = drive->hwif;
746 struct scatterlist *sg = hwif->sg_table;
747
748 if (hwif->sg_mapped) /* needed by ide-scsi */
749 return;
750
751 if ((rq->flags & REQ_DRIVE_TASKFILE) == 0) {
752 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
753 } else {
754 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
755 hwif->sg_nents = 1;
756 }
757}
758
759EXPORT_SYMBOL_GPL(ide_map_sg);
760
761void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
762{
763 ide_hwif_t *hwif = drive->hwif;
764
765 hwif->nsect = hwif->nleft = rq->nr_sectors;
766 hwif->cursg = hwif->cursg_ofs = 0;
767}
768
769EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
770
771/**
772 * execute_drive_command - issue special drive command
Adrian Bunk338cec32005-09-10 00:26:54 -0700773 * @drive: the drive to issue the command on
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 * @rq: the request structure holding the command
775 *
776 * execute_drive_cmd() issues a special drive command, usually
777 * initiated by ioctl() from the external hdparm program. The
778 * command can be a drive command, drive task or taskfile
779 * operation. Weirdly you can call it with NULL to wait for
780 * all commands to finish. Don't do this as that is due to change
781 */
782
783static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
784 struct request *rq)
785{
786 ide_hwif_t *hwif = HWIF(drive);
787 if (rq->flags & REQ_DRIVE_TASKFILE) {
788 ide_task_t *args = rq->special;
789
790 if (!args)
791 goto done;
792
793 hwif->data_phase = args->data_phase;
794
795 switch (hwif->data_phase) {
796 case TASKFILE_MULTI_OUT:
797 case TASKFILE_OUT:
798 case TASKFILE_MULTI_IN:
799 case TASKFILE_IN:
800 ide_init_sg_cmd(drive, rq);
801 ide_map_sg(drive, rq);
802 default:
803 break;
804 }
805
806 if (args->tf_out_flags.all != 0)
807 return flagged_taskfile(drive, args);
808 return do_rw_taskfile(drive, args);
809 } else if (rq->flags & REQ_DRIVE_TASK) {
810 u8 *args = rq->buffer;
811 u8 sel;
812
813 if (!args)
814 goto done;
815#ifdef DEBUG
816 printk("%s: DRIVE_TASK_CMD ", drive->name);
817 printk("cmd=0x%02x ", args[0]);
818 printk("fr=0x%02x ", args[1]);
819 printk("ns=0x%02x ", args[2]);
820 printk("sc=0x%02x ", args[3]);
821 printk("lcyl=0x%02x ", args[4]);
822 printk("hcyl=0x%02x ", args[5]);
823 printk("sel=0x%02x\n", args[6]);
824#endif
825 hwif->OUTB(args[1], IDE_FEATURE_REG);
826 hwif->OUTB(args[3], IDE_SECTOR_REG);
827 hwif->OUTB(args[4], IDE_LCYL_REG);
828 hwif->OUTB(args[5], IDE_HCYL_REG);
829 sel = (args[6] & ~0x10);
830 if (drive->select.b.unit)
831 sel |= 0x10;
832 hwif->OUTB(sel, IDE_SELECT_REG);
833 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
834 return ide_started;
835 } else if (rq->flags & REQ_DRIVE_CMD) {
836 u8 *args = rq->buffer;
837
838 if (!args)
839 goto done;
840#ifdef DEBUG
841 printk("%s: DRIVE_CMD ", drive->name);
842 printk("cmd=0x%02x ", args[0]);
843 printk("sc=0x%02x ", args[1]);
844 printk("fr=0x%02x ", args[2]);
845 printk("xx=0x%02x\n", args[3]);
846#endif
847 if (args[0] == WIN_SMART) {
848 hwif->OUTB(0x4f, IDE_LCYL_REG);
849 hwif->OUTB(0xc2, IDE_HCYL_REG);
850 hwif->OUTB(args[2],IDE_FEATURE_REG);
851 hwif->OUTB(args[1],IDE_SECTOR_REG);
852 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
853 return ide_started;
854 }
855 hwif->OUTB(args[2],IDE_FEATURE_REG);
856 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
857 return ide_started;
858 }
859
860done:
861 /*
862 * NULL is actually a valid way of waiting for
863 * all current requests to be flushed from the queue.
864 */
865#ifdef DEBUG
866 printk("%s: DRIVE_CMD (null)\n", drive->name);
867#endif
868 ide_end_drive_cmd(drive,
869 hwif->INB(IDE_STATUS_REG),
870 hwif->INB(IDE_ERROR_REG));
871 return ide_stopped;
872}
873
874/**
875 * start_request - start of I/O and command issuing for IDE
876 *
877 * start_request() initiates handling of a new I/O request. It
878 * accepts commands and I/O (read/write) requests. It also does
879 * the final remapping for weird stuff like EZDrive. Once
880 * device mapper can work sector level the EZDrive stuff can go away
881 *
882 * FIXME: this function needs a rename
883 */
884
885static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
886{
887 ide_startstop_t startstop;
888 sector_t block;
889
890 BUG_ON(!(rq->flags & REQ_STARTED));
891
892#ifdef DEBUG
893 printk("%s: start_request: current=0x%08lx\n",
894 HWIF(drive)->name, (unsigned long) rq);
895#endif
896
897 /* bail early if we've exceeded max_failures */
898 if (drive->max_failures && (drive->failures > drive->max_failures)) {
899 goto kill_rq;
900 }
901
902 block = rq->sector;
903 if (blk_fs_request(rq) &&
904 (drive->media == ide_disk || drive->media == ide_floppy)) {
905 block += drive->sect0;
906 }
907 /* Yecch - this will shift the entire interval,
908 possibly killing some innocent following sector */
909 if (block == 0 && drive->remap_0_to_1 == 1)
910 block = 1; /* redirect MBR access to EZ-Drive partn table */
911
912 if (blk_pm_suspend_request(rq) &&
913 rq->pm->pm_step == ide_pm_state_start_suspend)
914 /* Mark drive blocked when starting the suspend sequence. */
915 drive->blocked = 1;
916 else if (blk_pm_resume_request(rq) &&
917 rq->pm->pm_step == ide_pm_state_start_resume) {
918 /*
919 * The first thing we do on wakeup is to wait for BSY bit to
920 * go away (with a looong timeout) as a drive on this hwif may
921 * just be POSTing itself.
922 * We do that before even selecting as the "other" device on
923 * the bus may be broken enough to walk on our toes at this
924 * point.
925 */
926 int rc;
927#ifdef DEBUG_PM
928 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
929#endif
930 rc = ide_wait_not_busy(HWIF(drive), 35000);
931 if (rc)
932 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
933 SELECT_DRIVE(drive);
934 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
935 rc = ide_wait_not_busy(HWIF(drive), 10000);
936 if (rc)
937 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
938 }
939
940 SELECT_DRIVE(drive);
941 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
942 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
943 return startstop;
944 }
945 if (!drive->special.all) {
946 ide_driver_t *drv;
947
948 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK))
949 return execute_drive_cmd(drive, rq);
950 else if (rq->flags & REQ_DRIVE_TASKFILE)
951 return execute_drive_cmd(drive, rq);
952 else if (blk_pm_request(rq)) {
953#ifdef DEBUG_PM
954 printk("%s: start_power_step(step: %d)\n",
955 drive->name, rq->pm->pm_step);
956#endif
957 startstop = ide_start_power_step(drive, rq);
958 if (startstop == ide_stopped &&
959 rq->pm->pm_step == ide_pm_state_completed)
960 ide_complete_pm_request(drive, rq);
961 return startstop;
962 }
963
964 drv = *(ide_driver_t **)rq->rq_disk->private_data;
965 return drv->do_request(drive, rq, block);
966 }
967 return do_special(drive);
968kill_rq:
969 ide_kill_rq(drive, rq);
970 return ide_stopped;
971}
972
973/**
974 * ide_stall_queue - pause an IDE device
975 * @drive: drive to stall
976 * @timeout: time to stall for (jiffies)
977 *
978 * ide_stall_queue() can be used by a drive to give excess bandwidth back
979 * to the hwgroup by sleeping for timeout jiffies.
980 */
981
982void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
983{
984 if (timeout > WAIT_WORSTCASE)
985 timeout = WAIT_WORSTCASE;
986 drive->sleep = timeout + jiffies;
987 drive->sleeping = 1;
988}
989
990EXPORT_SYMBOL(ide_stall_queue);
991
992#define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
993
994/**
995 * choose_drive - select a drive to service
996 * @hwgroup: hardware group to select on
997 *
998 * choose_drive() selects the next drive which will be serviced.
999 * This is necessary because the IDE layer can't issue commands
1000 * to both drives on the same cable, unlike SCSI.
1001 */
1002
1003static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1004{
1005 ide_drive_t *drive, *best;
1006
1007repeat:
1008 best = NULL;
1009 drive = hwgroup->drive;
1010
1011 /*
1012 * drive is doing pre-flush, ordered write, post-flush sequence. even
1013 * though that is 3 requests, it must be seen as a single transaction.
1014 * we must not preempt this drive until that is complete
1015 */
1016 if (blk_queue_flushing(drive->queue)) {
1017 /*
1018 * small race where queue could get replugged during
1019 * the 3-request flush cycle, just yank the plug since
1020 * we want it to finish asap
1021 */
1022 blk_remove_plug(drive->queue);
1023 return drive;
1024 }
1025
1026 do {
1027 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1028 && !elv_queue_empty(drive->queue)) {
1029 if (!best
1030 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1031 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1032 {
1033 if (!blk_queue_plugged(drive->queue))
1034 best = drive;
1035 }
1036 }
1037 } while ((drive = drive->next) != hwgroup->drive);
1038 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1039 long t = (signed long)(WAKEUP(best) - jiffies);
1040 if (t >= WAIT_MIN_SLEEP) {
1041 /*
1042 * We *may* have some time to spare, but first let's see if
1043 * someone can potentially benefit from our nice mood today..
1044 */
1045 drive = best->next;
1046 do {
1047 if (!drive->sleeping
1048 && time_before(jiffies - best->service_time, WAKEUP(drive))
1049 && time_before(WAKEUP(drive), jiffies + t))
1050 {
1051 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1052 goto repeat;
1053 }
1054 } while ((drive = drive->next) != best);
1055 }
1056 }
1057 return best;
1058}
1059
1060/*
1061 * Issue a new request to a drive from hwgroup
1062 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1063 *
1064 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1065 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1066 * may have both interfaces in a single hwgroup to "serialize" access.
1067 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1068 * together into one hwgroup for serialized access.
1069 *
1070 * Note also that several hwgroups can end up sharing a single IRQ,
1071 * possibly along with many other devices. This is especially common in
1072 * PCI-based systems with off-board IDE controller cards.
1073 *
1074 * The IDE driver uses the single global ide_lock spinlock to protect
1075 * access to the request queues, and to protect the hwgroup->busy flag.
1076 *
1077 * The first thread into the driver for a particular hwgroup sets the
1078 * hwgroup->busy flag to indicate that this hwgroup is now active,
1079 * and then initiates processing of the top request from the request queue.
1080 *
1081 * Other threads attempting entry notice the busy setting, and will simply
1082 * queue their new requests and exit immediately. Note that hwgroup->busy
1083 * remains set even when the driver is merely awaiting the next interrupt.
1084 * Thus, the meaning is "this hwgroup is busy processing a request".
1085 *
1086 * When processing of a request completes, the completing thread or IRQ-handler
1087 * will start the next request from the queue. If no more work remains,
1088 * the driver will clear the hwgroup->busy flag and exit.
1089 *
1090 * The ide_lock (spinlock) is used to protect all access to the
1091 * hwgroup->busy flag, but is otherwise not needed for most processing in
1092 * the driver. This makes the driver much more friendlier to shared IRQs
1093 * than previous designs, while remaining 100% (?) SMP safe and capable.
1094 */
1095static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1096{
1097 ide_drive_t *drive;
1098 ide_hwif_t *hwif;
1099 struct request *rq;
1100 ide_startstop_t startstop;
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001101 int loops = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001102
1103 /* for atari only: POSSIBLY BROKEN HERE(?) */
1104 ide_get_lock(ide_intr, hwgroup);
1105
1106 /* caller must own ide_lock */
1107 BUG_ON(!irqs_disabled());
1108
1109 while (!hwgroup->busy) {
1110 hwgroup->busy = 1;
1111 drive = choose_drive(hwgroup);
1112 if (drive == NULL) {
1113 int sleeping = 0;
1114 unsigned long sleep = 0; /* shut up, gcc */
1115 hwgroup->rq = NULL;
1116 drive = hwgroup->drive;
1117 do {
1118 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1119 sleeping = 1;
1120 sleep = drive->sleep;
1121 }
1122 } while ((drive = drive->next) != hwgroup->drive);
1123 if (sleeping) {
1124 /*
1125 * Take a short snooze, and then wake up this hwgroup again.
1126 * This gives other hwgroups on the same a chance to
1127 * play fairly with us, just in case there are big differences
1128 * in relative throughputs.. don't want to hog the cpu too much.
1129 */
1130 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1131 sleep = jiffies + WAIT_MIN_SLEEP;
1132#if 1
1133 if (timer_pending(&hwgroup->timer))
1134 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1135#endif
1136 /* so that ide_timer_expiry knows what to do */
1137 hwgroup->sleeping = 1;
1138 mod_timer(&hwgroup->timer, sleep);
1139 /* we purposely leave hwgroup->busy==1
1140 * while sleeping */
1141 } else {
1142 /* Ugly, but how can we sleep for the lock
1143 * otherwise? perhaps from tq_disk?
1144 */
1145
1146 /* for atari only */
1147 ide_release_lock();
1148 hwgroup->busy = 0;
1149 }
1150
1151 /* no more work for this hwgroup (for now) */
1152 return;
1153 }
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001154 again:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001155 hwif = HWIF(drive);
1156 if (hwgroup->hwif->sharing_irq &&
1157 hwif != hwgroup->hwif &&
1158 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1159 /* set nIEN for previous hwif */
1160 SELECT_INTERRUPT(drive);
1161 }
1162 hwgroup->hwif = hwif;
1163 hwgroup->drive = drive;
1164 drive->sleeping = 0;
1165 drive->service_start = jiffies;
1166
1167 if (blk_queue_plugged(drive->queue)) {
1168 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1169 break;
1170 }
1171
1172 /*
1173 * we know that the queue isn't empty, but this can happen
1174 * if the q->prep_rq_fn() decides to kill a request
1175 */
1176 rq = elv_next_request(drive->queue);
1177 if (!rq) {
1178 hwgroup->busy = 0;
1179 break;
1180 }
1181
1182 /*
1183 * Sanity: don't accept a request that isn't a PM request
1184 * if we are currently power managed. This is very important as
1185 * blk_stop_queue() doesn't prevent the elv_next_request()
1186 * above to return us whatever is in the queue. Since we call
1187 * ide_do_request() ourselves, we end up taking requests while
1188 * the queue is blocked...
1189 *
1190 * We let requests forced at head of queue with ide-preempt
1191 * though. I hope that doesn't happen too much, hopefully not
1192 * unless the subdriver triggers such a thing in its own PM
1193 * state machine.
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001194 *
1195 * We count how many times we loop here to make sure we service
1196 * all drives in the hwgroup without looping for ever
Linus Torvalds1da177e2005-04-16 15:20:36 -07001197 */
1198 if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001199 drive = drive->next ? drive->next : hwgroup->drive;
1200 if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1201 goto again;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001202 /* We clear busy, there should be no pending ATA command at this point. */
1203 hwgroup->busy = 0;
1204 break;
1205 }
1206
1207 hwgroup->rq = rq;
1208
1209 /*
1210 * Some systems have trouble with IDE IRQs arriving while
1211 * the driver is still setting things up. So, here we disable
1212 * the IRQ used by this interface while the request is being started.
1213 * This may look bad at first, but pretty much the same thing
1214 * happens anyway when any interrupt comes in, IDE or otherwise
1215 * -- the kernel masks the IRQ while it is being handled.
1216 */
1217 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1218 disable_irq_nosync(hwif->irq);
1219 spin_unlock(&ide_lock);
1220 local_irq_enable();
1221 /* allow other IRQs while we start this request */
1222 startstop = start_request(drive, rq);
1223 spin_lock_irq(&ide_lock);
1224 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1225 enable_irq(hwif->irq);
1226 if (startstop == ide_stopped)
1227 hwgroup->busy = 0;
1228 }
1229}
1230
1231/*
1232 * Passes the stuff to ide_do_request
1233 */
1234void do_ide_request(request_queue_t *q)
1235{
1236 ide_drive_t *drive = q->queuedata;
1237
1238 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1239}
1240
1241/*
1242 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1243 * retry the current request in pio mode instead of risking tossing it
1244 * all away
1245 */
1246static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1247{
1248 ide_hwif_t *hwif = HWIF(drive);
1249 struct request *rq;
1250 ide_startstop_t ret = ide_stopped;
1251
1252 /*
1253 * end current dma transaction
1254 */
1255
1256 if (error < 0) {
1257 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1258 (void)HWIF(drive)->ide_dma_end(drive);
1259 ret = ide_error(drive, "dma timeout error",
1260 hwif->INB(IDE_STATUS_REG));
1261 } else {
1262 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1263 (void) hwif->ide_dma_timeout(drive);
1264 }
1265
1266 /*
1267 * disable dma for now, but remember that we did so because of
1268 * a timeout -- we'll reenable after we finish this next request
1269 * (or rather the first chunk of it) in pio.
1270 */
1271 drive->retry_pio++;
1272 drive->state = DMA_PIO_RETRY;
1273 (void) hwif->ide_dma_off_quietly(drive);
1274
1275 /*
1276 * un-busy drive etc (hwgroup->busy is cleared on return) and
1277 * make sure request is sane
1278 */
1279 rq = HWGROUP(drive)->rq;
1280 HWGROUP(drive)->rq = NULL;
1281
1282 rq->errors = 0;
1283
1284 if (!rq->bio)
1285 goto out;
1286
1287 rq->sector = rq->bio->bi_sector;
1288 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1289 rq->hard_cur_sectors = rq->current_nr_sectors;
1290 rq->buffer = bio_data(rq->bio);
1291out:
1292 return ret;
1293}
1294
1295/**
1296 * ide_timer_expiry - handle lack of an IDE interrupt
1297 * @data: timer callback magic (hwgroup)
1298 *
1299 * An IDE command has timed out before the expected drive return
1300 * occurred. At this point we attempt to clean up the current
1301 * mess. If the current handler includes an expiry handler then
1302 * we invoke the expiry handler, and providing it is happy the
1303 * work is done. If that fails we apply generic recovery rules
1304 * invoking the handler and checking the drive DMA status. We
1305 * have an excessively incestuous relationship with the DMA
1306 * logic that wants cleaning up.
1307 */
1308
1309void ide_timer_expiry (unsigned long data)
1310{
1311 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1312 ide_handler_t *handler;
1313 ide_expiry_t *expiry;
1314 unsigned long flags;
1315 unsigned long wait = -1;
1316
1317 spin_lock_irqsave(&ide_lock, flags);
1318
1319 if ((handler = hwgroup->handler) == NULL) {
1320 /*
1321 * Either a marginal timeout occurred
1322 * (got the interrupt just as timer expired),
1323 * or we were "sleeping" to give other devices a chance.
1324 * Either way, we don't really want to complain about anything.
1325 */
1326 if (hwgroup->sleeping) {
1327 hwgroup->sleeping = 0;
1328 hwgroup->busy = 0;
1329 }
1330 } else {
1331 ide_drive_t *drive = hwgroup->drive;
1332 if (!drive) {
1333 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1334 hwgroup->handler = NULL;
1335 } else {
1336 ide_hwif_t *hwif;
1337 ide_startstop_t startstop = ide_stopped;
1338 if (!hwgroup->busy) {
1339 hwgroup->busy = 1; /* paranoia */
1340 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1341 }
1342 if ((expiry = hwgroup->expiry) != NULL) {
1343 /* continue */
1344 if ((wait = expiry(drive)) > 0) {
1345 /* reset timer */
1346 hwgroup->timer.expires = jiffies + wait;
1347 add_timer(&hwgroup->timer);
1348 spin_unlock_irqrestore(&ide_lock, flags);
1349 return;
1350 }
1351 }
1352 hwgroup->handler = NULL;
1353 /*
1354 * We need to simulate a real interrupt when invoking
1355 * the handler() function, which means we need to
1356 * globally mask the specific IRQ:
1357 */
1358 spin_unlock(&ide_lock);
1359 hwif = HWIF(drive);
1360#if DISABLE_IRQ_NOSYNC
1361 disable_irq_nosync(hwif->irq);
1362#else
1363 /* disable_irq_nosync ?? */
1364 disable_irq(hwif->irq);
1365#endif /* DISABLE_IRQ_NOSYNC */
1366 /* local CPU only,
1367 * as if we were handling an interrupt */
1368 local_irq_disable();
1369 if (hwgroup->polling) {
1370 startstop = handler(drive);
1371 } else if (drive_is_ready(drive)) {
1372 if (drive->waiting_for_dma)
1373 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1374 (void)ide_ack_intr(hwif);
1375 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1376 startstop = handler(drive);
1377 } else {
1378 if (drive->waiting_for_dma) {
1379 startstop = ide_dma_timeout_retry(drive, wait);
1380 } else
1381 startstop =
1382 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1383 }
1384 drive->service_time = jiffies - drive->service_start;
1385 spin_lock_irq(&ide_lock);
1386 enable_irq(hwif->irq);
1387 if (startstop == ide_stopped)
1388 hwgroup->busy = 0;
1389 }
1390 }
1391 ide_do_request(hwgroup, IDE_NO_IRQ);
1392 spin_unlock_irqrestore(&ide_lock, flags);
1393}
1394
1395/**
1396 * unexpected_intr - handle an unexpected IDE interrupt
1397 * @irq: interrupt line
1398 * @hwgroup: hwgroup being processed
1399 *
1400 * There's nothing really useful we can do with an unexpected interrupt,
1401 * other than reading the status register (to clear it), and logging it.
1402 * There should be no way that an irq can happen before we're ready for it,
1403 * so we needn't worry much about losing an "important" interrupt here.
1404 *
1405 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1406 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1407 * looks "good", we just ignore the interrupt completely.
1408 *
1409 * This routine assumes __cli() is in effect when called.
1410 *
1411 * If an unexpected interrupt happens on irq15 while we are handling irq14
1412 * and if the two interfaces are "serialized" (CMD640), then it looks like
1413 * we could screw up by interfering with a new request being set up for
1414 * irq15.
1415 *
1416 * In reality, this is a non-issue. The new command is not sent unless
1417 * the drive is ready to accept one, in which case we know the drive is
1418 * not trying to interrupt us. And ide_set_handler() is always invoked
1419 * before completing the issuance of any new drive command, so we will not
1420 * be accidentally invoked as a result of any valid command completion
1421 * interrupt.
1422 *
1423 * Note that we must walk the entire hwgroup here. We know which hwif
1424 * is doing the current command, but we don't know which hwif burped
1425 * mysteriously.
1426 */
1427
1428static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1429{
1430 u8 stat;
1431 ide_hwif_t *hwif = hwgroup->hwif;
1432
1433 /*
1434 * handle the unexpected interrupt
1435 */
1436 do {
1437 if (hwif->irq == irq) {
1438 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1439 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1440 /* Try to not flood the console with msgs */
1441 static unsigned long last_msgtime, count;
1442 ++count;
1443 if (time_after(jiffies, last_msgtime + HZ)) {
1444 last_msgtime = jiffies;
1445 printk(KERN_ERR "%s%s: unexpected interrupt, "
1446 "status=0x%02x, count=%ld\n",
1447 hwif->name,
1448 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1449 }
1450 }
1451 }
1452 } while ((hwif = hwif->next) != hwgroup->hwif);
1453}
1454
1455/**
1456 * ide_intr - default IDE interrupt handler
1457 * @irq: interrupt number
1458 * @dev_id: hwif group
1459 * @regs: unused weirdness from the kernel irq layer
1460 *
1461 * This is the default IRQ handler for the IDE layer. You should
1462 * not need to override it. If you do be aware it is subtle in
1463 * places
1464 *
1465 * hwgroup->hwif is the interface in the group currently performing
1466 * a command. hwgroup->drive is the drive and hwgroup->handler is
1467 * the IRQ handler to call. As we issue a command the handlers
1468 * step through multiple states, reassigning the handler to the
1469 * next step in the process. Unlike a smart SCSI controller IDE
1470 * expects the main processor to sequence the various transfer
1471 * stages. We also manage a poll timer to catch up with most
1472 * timeout situations. There are still a few where the handlers
1473 * don't ever decide to give up.
1474 *
1475 * The handler eventually returns ide_stopped to indicate the
1476 * request completed. At this point we issue the next request
1477 * on the hwgroup and the process begins again.
1478 */
1479
1480irqreturn_t ide_intr (int irq, void *dev_id, struct pt_regs *regs)
1481{
1482 unsigned long flags;
1483 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1484 ide_hwif_t *hwif;
1485 ide_drive_t *drive;
1486 ide_handler_t *handler;
1487 ide_startstop_t startstop;
1488
1489 spin_lock_irqsave(&ide_lock, flags);
1490 hwif = hwgroup->hwif;
1491
1492 if (!ide_ack_intr(hwif)) {
1493 spin_unlock_irqrestore(&ide_lock, flags);
1494 return IRQ_NONE;
1495 }
1496
1497 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1498 /*
1499 * Not expecting an interrupt from this drive.
1500 * That means this could be:
1501 * (1) an interrupt from another PCI device
1502 * sharing the same PCI INT# as us.
1503 * or (2) a drive just entered sleep or standby mode,
1504 * and is interrupting to let us know.
1505 * or (3) a spurious interrupt of unknown origin.
1506 *
1507 * For PCI, we cannot tell the difference,
1508 * so in that case we just ignore it and hope it goes away.
1509 *
1510 * FIXME: unexpected_intr should be hwif-> then we can
1511 * remove all the ifdef PCI crap
1512 */
1513#ifdef CONFIG_BLK_DEV_IDEPCI
1514 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1515#endif /* CONFIG_BLK_DEV_IDEPCI */
1516 {
1517 /*
1518 * Probably not a shared PCI interrupt,
1519 * so we can safely try to do something about it:
1520 */
1521 unexpected_intr(irq, hwgroup);
1522#ifdef CONFIG_BLK_DEV_IDEPCI
1523 } else {
1524 /*
1525 * Whack the status register, just in case
1526 * we have a leftover pending IRQ.
1527 */
1528 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1529#endif /* CONFIG_BLK_DEV_IDEPCI */
1530 }
1531 spin_unlock_irqrestore(&ide_lock, flags);
1532 return IRQ_NONE;
1533 }
1534 drive = hwgroup->drive;
1535 if (!drive) {
1536 /*
1537 * This should NEVER happen, and there isn't much
1538 * we could do about it here.
1539 *
1540 * [Note - this can occur if the drive is hot unplugged]
1541 */
1542 spin_unlock_irqrestore(&ide_lock, flags);
1543 return IRQ_HANDLED;
1544 }
1545 if (!drive_is_ready(drive)) {
1546 /*
1547 * This happens regularly when we share a PCI IRQ with
1548 * another device. Unfortunately, it can also happen
1549 * with some buggy drives that trigger the IRQ before
1550 * their status register is up to date. Hopefully we have
1551 * enough advance overhead that the latter isn't a problem.
1552 */
1553 spin_unlock_irqrestore(&ide_lock, flags);
1554 return IRQ_NONE;
1555 }
1556 if (!hwgroup->busy) {
1557 hwgroup->busy = 1; /* paranoia */
1558 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1559 }
1560 hwgroup->handler = NULL;
1561 del_timer(&hwgroup->timer);
1562 spin_unlock(&ide_lock);
1563
1564 if (drive->unmask)
1565 local_irq_enable();
1566 /* service this interrupt, may set handler for next interrupt */
1567 startstop = handler(drive);
1568 spin_lock_irq(&ide_lock);
1569
1570 /*
1571 * Note that handler() may have set things up for another
1572 * interrupt to occur soon, but it cannot happen until
1573 * we exit from this routine, because it will be the
1574 * same irq as is currently being serviced here, and Linux
1575 * won't allow another of the same (on any CPU) until we return.
1576 */
1577 drive->service_time = jiffies - drive->service_start;
1578 if (startstop == ide_stopped) {
1579 if (hwgroup->handler == NULL) { /* paranoia */
1580 hwgroup->busy = 0;
1581 ide_do_request(hwgroup, hwif->irq);
1582 } else {
1583 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1584 "on exit\n", drive->name);
1585 }
1586 }
1587 spin_unlock_irqrestore(&ide_lock, flags);
1588 return IRQ_HANDLED;
1589}
1590
1591/**
1592 * ide_init_drive_cmd - initialize a drive command request
1593 * @rq: request object
1594 *
1595 * Initialize a request before we fill it in and send it down to
1596 * ide_do_drive_cmd. Commands must be set up by this function. Right
1597 * now it doesn't do a lot, but if that changes abusers will have a
1598 * nasty suprise.
1599 */
1600
1601void ide_init_drive_cmd (struct request *rq)
1602{
1603 memset(rq, 0, sizeof(*rq));
1604 rq->flags = REQ_DRIVE_CMD;
1605 rq->ref_count = 1;
1606}
1607
1608EXPORT_SYMBOL(ide_init_drive_cmd);
1609
1610/**
1611 * ide_do_drive_cmd - issue IDE special command
1612 * @drive: device to issue command
1613 * @rq: request to issue
1614 * @action: action for processing
1615 *
1616 * This function issues a special IDE device request
1617 * onto the request queue.
1618 *
1619 * If action is ide_wait, then the rq is queued at the end of the
1620 * request queue, and the function sleeps until it has been processed.
1621 * This is for use when invoked from an ioctl handler.
1622 *
1623 * If action is ide_preempt, then the rq is queued at the head of
1624 * the request queue, displacing the currently-being-processed
1625 * request and this function returns immediately without waiting
1626 * for the new rq to be completed. This is VERY DANGEROUS, and is
1627 * intended for careful use by the ATAPI tape/cdrom driver code.
1628 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001629 * If action is ide_end, then the rq is queued at the end of the
1630 * request queue, and the function returns immediately without waiting
1631 * for the new rq to be completed. This is again intended for careful
1632 * use by the ATAPI tape/cdrom driver code.
1633 */
1634
1635int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1636{
1637 unsigned long flags;
1638 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1639 DECLARE_COMPLETION(wait);
1640 int where = ELEVATOR_INSERT_BACK, err;
1641 int must_wait = (action == ide_wait || action == ide_head_wait);
1642
1643 rq->errors = 0;
1644 rq->rq_status = RQ_ACTIVE;
1645
1646 /*
1647 * we need to hold an extra reference to request for safe inspection
1648 * after completion
1649 */
1650 if (must_wait) {
1651 rq->ref_count++;
1652 rq->waiting = &wait;
1653 rq->end_io = blk_end_sync_rq;
1654 }
1655
1656 spin_lock_irqsave(&ide_lock, flags);
1657 if (action == ide_preempt)
1658 hwgroup->rq = NULL;
1659 if (action == ide_preempt || action == ide_head_wait) {
1660 where = ELEVATOR_INSERT_FRONT;
1661 rq->flags |= REQ_PREEMPT;
1662 }
1663 __elv_add_request(drive->queue, rq, where, 0);
1664 ide_do_request(hwgroup, IDE_NO_IRQ);
1665 spin_unlock_irqrestore(&ide_lock, flags);
1666
1667 err = 0;
1668 if (must_wait) {
1669 wait_for_completion(&wait);
1670 rq->waiting = NULL;
1671 if (rq->errors)
1672 err = -EIO;
1673
1674 blk_put_request(rq);
1675 }
1676
1677 return err;
1678}
1679
1680EXPORT_SYMBOL(ide_do_drive_cmd);