blob: 2614f41b5074ea2d203767be2eefa6a4b5505f45 [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
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include <linux/module.h>
28#include <linux/types.h>
29#include <linux/string.h>
30#include <linux/kernel.h>
31#include <linux/timer.h>
32#include <linux/mm.h>
33#include <linux/interrupt.h>
34#include <linux/major.h>
35#include <linux/errno.h>
36#include <linux/genhd.h>
37#include <linux/blkpg.h>
38#include <linux/slab.h>
39#include <linux/init.h>
40#include <linux/pci.h>
41#include <linux/delay.h>
42#include <linux/ide.h>
43#include <linux/completion.h>
44#include <linux/reboot.h>
45#include <linux/cdrom.h>
46#include <linux/seq_file.h>
47#include <linux/device.h>
48#include <linux/kmod.h>
49#include <linux/scatterlist.h>
50
51#include <asm/byteorder.h>
52#include <asm/irq.h>
53#include <asm/uaccess.h>
54#include <asm/io.h>
55#include <asm/bitops.h>
56
Adrian Bunka7ff7d42006-02-03 03:04:56 -080057static int __ide_end_request(ide_drive_t *drive, struct request *rq,
58 int uptodate, int nr_sectors)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 int ret = 1;
61
Linus Torvalds1da177e2005-04-16 15:20:36 -070062 /*
63 * if failfast is set on a request, override number of sectors and
64 * complete the whole request right now
65 */
66 if (blk_noretry_request(rq) && end_io_error(uptodate))
67 nr_sectors = rq->hard_nr_sectors;
68
69 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
70 rq->errors = -EIO;
71
72 /*
73 * decide whether to reenable DMA -- 3 is a random magic for now,
74 * if we DMA timeout more than 3 times, just stay in PIO
75 */
76 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
77 drive->state = 0;
78 HWGROUP(drive)->hwif->ide_dma_on(drive);
79 }
80
Jens Axboeba027de2006-01-12 20:44:12 +010081 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
82 add_disk_randomness(rq->rq_disk);
Hua Zhongce42f192006-10-03 01:14:15 -070083 if (!list_empty(&rq->queuelist))
84 blkdev_dequeue_request(rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -070085 HWGROUP(drive)->rq = NULL;
Jens Axboeba027de2006-01-12 20:44:12 +010086 end_that_request_last(rq, uptodate);
Linus Torvalds1da177e2005-04-16 15:20:36 -070087 ret = 0;
88 }
Jens Axboe8672d572006-01-09 16:03:35 +010089
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 return ret;
91}
Linus Torvalds1da177e2005-04-16 15:20:36 -070092
93/**
94 * ide_end_request - complete an IDE I/O
95 * @drive: IDE device for the I/O
96 * @uptodate:
97 * @nr_sectors: number of sectors completed
98 *
99 * This is our end_request wrapper function. We complete the I/O
100 * update random number input and dequeue the request, which if
101 * it was tagged may be out of order.
102 */
103
104int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
105{
106 struct request *rq;
107 unsigned long flags;
108 int ret = 1;
109
Jens Axboe8672d572006-01-09 16:03:35 +0100110 /*
111 * room for locking improvements here, the calls below don't
112 * need the queue lock held at all
113 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 spin_lock_irqsave(&ide_lock, flags);
115 rq = HWGROUP(drive)->rq;
116
117 if (!nr_sectors)
118 nr_sectors = rq->hard_cur_sectors;
119
Tejun Heo3e087b52006-01-06 09:57:31 +0100120 ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121
122 spin_unlock_irqrestore(&ide_lock, flags);
123 return ret;
124}
125EXPORT_SYMBOL(ide_end_request);
126
127/*
128 * Power Management state machine. This one is rather trivial for now,
129 * we should probably add more, like switching back to PIO on suspend
130 * to help some BIOSes, re-do the door locking on resume, etc...
131 */
132
133enum {
134 ide_pm_flush_cache = ide_pm_state_start_suspend,
135 idedisk_pm_standby,
136
Jason Lunz8c2c0112006-10-03 01:14:26 -0700137 idedisk_pm_restore_pio = ide_pm_state_start_resume,
138 idedisk_pm_idle,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700139 ide_pm_restore_dma,
140};
141
142static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
143{
Jens Axboec00895a2006-09-30 20:29:12 +0200144 struct request_pm_state *pm = rq->data;
Jens Axboead3cadd2006-06-13 08:46:57 +0200145
Linus Torvalds1da177e2005-04-16 15:20:36 -0700146 if (drive->media != ide_disk)
147 return;
148
Jens Axboead3cadd2006-06-13 08:46:57 +0200149 switch (pm->pm_step) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700150 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
Jens Axboead3cadd2006-06-13 08:46:57 +0200151 if (pm->pm_state == PM_EVENT_FREEZE)
152 pm->pm_step = ide_pm_state_completed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 else
Jens Axboead3cadd2006-06-13 08:46:57 +0200154 pm->pm_step = idedisk_pm_standby;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 break;
156 case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
Jens Axboead3cadd2006-06-13 08:46:57 +0200157 pm->pm_step = ide_pm_state_completed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700158 break;
Jason Lunz8c2c0112006-10-03 01:14:26 -0700159 case idedisk_pm_restore_pio: /* Resume step 1 complete */
160 pm->pm_step = idedisk_pm_idle;
161 break;
162 case idedisk_pm_idle: /* Resume step 2 (idle) complete */
Jens Axboead3cadd2006-06-13 08:46:57 +0200163 pm->pm_step = ide_pm_restore_dma;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164 break;
165 }
166}
167
168static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
169{
Jens Axboec00895a2006-09-30 20:29:12 +0200170 struct request_pm_state *pm = rq->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700171 ide_task_t *args = rq->special;
172
173 memset(args, 0, sizeof(*args));
174
175 if (drive->media != ide_disk) {
Jason Lunz8c2c0112006-10-03 01:14:26 -0700176 /*
177 * skip idedisk_pm_restore_pio and idedisk_pm_idle for ATAPI
178 * devices
179 */
180 if (pm->pm_step == idedisk_pm_restore_pio)
Jens Axboead3cadd2006-06-13 08:46:57 +0200181 pm->pm_step = ide_pm_restore_dma;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700182 }
183
Jens Axboead3cadd2006-06-13 08:46:57 +0200184 switch (pm->pm_step) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */
186 if (drive->media != ide_disk)
187 break;
188 /* Not supported? Switch to next step now. */
189 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
190 ide_complete_power_step(drive, rq, 0, 0);
191 return ide_stopped;
192 }
193 if (ide_id_has_flush_cache_ext(drive->id))
194 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE_EXT;
195 else
196 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_FLUSH_CACHE;
197 args->command_type = IDE_DRIVE_TASK_NO_DATA;
198 args->handler = &task_no_data_intr;
199 return do_rw_taskfile(drive, args);
200
201 case idedisk_pm_standby: /* Suspend step 2 (standby) */
202 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_STANDBYNOW1;
203 args->command_type = IDE_DRIVE_TASK_NO_DATA;
204 args->handler = &task_no_data_intr;
205 return do_rw_taskfile(drive, args);
206
Jason Lunz8c2c0112006-10-03 01:14:26 -0700207 case idedisk_pm_restore_pio: /* Resume step 1 (restore PIO) */
208 if (drive->hwif->tuneproc != NULL)
209 drive->hwif->tuneproc(drive, 255);
210 ide_complete_power_step(drive, rq, 0, 0);
211 return ide_stopped;
212
213 case idedisk_pm_idle: /* Resume step 2 (idle) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 args->tfRegister[IDE_COMMAND_OFFSET] = WIN_IDLEIMMEDIATE;
215 args->command_type = IDE_DRIVE_TASK_NO_DATA;
216 args->handler = task_no_data_intr;
217 return do_rw_taskfile(drive, args);
218
Jason Lunz8c2c0112006-10-03 01:14:26 -0700219 case ide_pm_restore_dma: /* Resume step 3 (restore DMA) */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 /*
221 * Right now, all we do is call hwif->ide_dma_check(drive),
222 * we could be smarter and check for current xfer_speed
223 * in struct drive etc...
224 */
225 if ((drive->id->capability & 1) == 0)
226 break;
227 if (drive->hwif->ide_dma_check == NULL)
228 break;
229 drive->hwif->ide_dma_check(drive);
230 break;
231 }
Jens Axboead3cadd2006-06-13 08:46:57 +0200232 pm->pm_step = ide_pm_state_completed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700233 return ide_stopped;
234}
235
236/**
Alan Coxdbe217a2006-06-25 05:47:44 -0700237 * ide_end_dequeued_request - complete an IDE I/O
238 * @drive: IDE device for the I/O
239 * @uptodate:
240 * @nr_sectors: number of sectors completed
241 *
242 * Complete an I/O that is no longer on the request queue. This
243 * typically occurs when we pull the request and issue a REQUEST_SENSE.
244 * We must still finish the old request but we must not tamper with the
245 * queue in the meantime.
246 *
247 * NOTE: This path does not handle barrier, but barrier is not supported
248 * on ide-cd anyway.
249 */
250
251int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
252 int uptodate, int nr_sectors)
253{
254 unsigned long flags;
255 int ret = 1;
256
257 spin_lock_irqsave(&ide_lock, flags);
258
Jens Axboe4aff5e22006-08-10 08:44:47 +0200259 BUG_ON(!blk_rq_started(rq));
Alan Coxdbe217a2006-06-25 05:47:44 -0700260
261 /*
262 * if failfast is set on a request, override number of sectors and
263 * complete the whole request right now
264 */
265 if (blk_noretry_request(rq) && end_io_error(uptodate))
266 nr_sectors = rq->hard_nr_sectors;
267
268 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
269 rq->errors = -EIO;
270
271 /*
272 * decide whether to reenable DMA -- 3 is a random magic for now,
273 * if we DMA timeout more than 3 times, just stay in PIO
274 */
275 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
276 drive->state = 0;
277 HWGROUP(drive)->hwif->ide_dma_on(drive);
278 }
279
280 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
281 add_disk_randomness(rq->rq_disk);
282 if (blk_rq_tagged(rq))
283 blk_queue_end_tag(drive->queue, rq);
284 end_that_request_last(rq, uptodate);
285 ret = 0;
286 }
287 spin_unlock_irqrestore(&ide_lock, flags);
288 return ret;
289}
290EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
291
292
293/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 * ide_complete_pm_request - end the current Power Management request
295 * @drive: target drive
296 * @rq: request
297 *
298 * This function cleans up the current PM request and stops the queue
299 * if necessary.
300 */
301static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
302{
303 unsigned long flags;
304
305#ifdef DEBUG_PM
306 printk("%s: completing PM request, %s\n", drive->name,
307 blk_pm_suspend_request(rq) ? "suspend" : "resume");
308#endif
309 spin_lock_irqsave(&ide_lock, flags);
310 if (blk_pm_suspend_request(rq)) {
311 blk_stop_queue(drive->queue);
312 } else {
313 drive->blocked = 0;
314 blk_start_queue(drive->queue);
315 }
316 blkdev_dequeue_request(rq);
317 HWGROUP(drive)->rq = NULL;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100318 end_that_request_last(rq, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 spin_unlock_irqrestore(&ide_lock, flags);
320}
321
322/*
323 * FIXME: probably move this somewhere else, name is bad too :)
324 */
325u64 ide_get_error_location(ide_drive_t *drive, char *args)
326{
327 u32 high, low;
328 u8 hcyl, lcyl, sect;
329 u64 sector;
330
331 high = 0;
332 hcyl = args[5];
333 lcyl = args[4];
334 sect = args[3];
335
336 if (ide_id_has_flush_cache_ext(drive->id)) {
337 low = (hcyl << 16) | (lcyl << 8) | sect;
338 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
339 high = ide_read_24(drive);
340 } else {
341 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
342 if (cur & 0x40) {
343 high = cur & 0xf;
344 low = (hcyl << 16) | (lcyl << 8) | sect;
345 } else {
346 low = hcyl * drive->head * drive->sect;
347 low += lcyl * drive->sect;
348 low += sect - 1;
349 }
350 }
351
352 sector = ((u64) high << 24) | low;
353 return sector;
354}
355EXPORT_SYMBOL(ide_get_error_location);
356
357/**
358 * ide_end_drive_cmd - end an explicit drive command
359 * @drive: command
360 * @stat: status bits
361 * @err: error bits
362 *
363 * Clean up after success/failure of an explicit drive command.
364 * These get thrown onto the queue so they are synchronized with
365 * real I/O operations on the drive.
366 *
367 * In LBA48 mode we have to read the register set twice to get
368 * all the extra information out.
369 */
370
371void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
372{
373 ide_hwif_t *hwif = HWIF(drive);
374 unsigned long flags;
375 struct request *rq;
376
377 spin_lock_irqsave(&ide_lock, flags);
378 rq = HWGROUP(drive)->rq;
379 spin_unlock_irqrestore(&ide_lock, flags);
380
Jens Axboe4aff5e22006-08-10 08:44:47 +0200381 if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382 u8 *args = (u8 *) rq->buffer;
383 if (rq->errors == 0)
384 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
385
386 if (args) {
387 args[0] = stat;
388 args[1] = err;
389 args[2] = hwif->INB(IDE_NSECTOR_REG);
390 }
Jens Axboe4aff5e22006-08-10 08:44:47 +0200391 } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 u8 *args = (u8 *) rq->buffer;
393 if (rq->errors == 0)
394 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
395
396 if (args) {
397 args[0] = stat;
398 args[1] = err;
399 args[2] = hwif->INB(IDE_NSECTOR_REG);
400 args[3] = hwif->INB(IDE_SECTOR_REG);
401 args[4] = hwif->INB(IDE_LCYL_REG);
402 args[5] = hwif->INB(IDE_HCYL_REG);
403 args[6] = hwif->INB(IDE_SELECT_REG);
404 }
Jens Axboe4aff5e22006-08-10 08:44:47 +0200405 } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 ide_task_t *args = (ide_task_t *) rq->special;
407 if (rq->errors == 0)
408 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
409
410 if (args) {
411 if (args->tf_in_flags.b.data) {
412 u16 data = hwif->INW(IDE_DATA_REG);
413 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
414 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
415 }
416 args->tfRegister[IDE_ERROR_OFFSET] = err;
417 /* be sure we're looking at the low order bits */
418 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
419 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
420 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
421 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
422 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
423 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
424 args->tfRegister[IDE_STATUS_OFFSET] = stat;
425
426 if (drive->addressing == 1) {
427 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
428 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
429 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
430 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
431 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
432 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
433 }
434 }
435 } else if (blk_pm_request(rq)) {
Jens Axboec00895a2006-09-30 20:29:12 +0200436 struct request_pm_state *pm = rq->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437#ifdef DEBUG_PM
438 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
439 drive->name, rq->pm->pm_step, stat, err);
440#endif
441 ide_complete_power_step(drive, rq, stat, err);
Jens Axboead3cadd2006-06-13 08:46:57 +0200442 if (pm->pm_step == ide_pm_state_completed)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443 ide_complete_pm_request(drive, rq);
444 return;
445 }
446
447 spin_lock_irqsave(&ide_lock, flags);
448 blkdev_dequeue_request(rq);
449 HWGROUP(drive)->rq = NULL;
450 rq->errors = err;
Tejun Heo8ffdc652006-01-06 09:49:03 +0100451 end_that_request_last(rq, !rq->errors);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700452 spin_unlock_irqrestore(&ide_lock, flags);
453}
454
455EXPORT_SYMBOL(ide_end_drive_cmd);
456
457/**
458 * try_to_flush_leftover_data - flush junk
459 * @drive: drive to flush
460 *
461 * try_to_flush_leftover_data() is invoked in response to a drive
462 * unexpectedly having its DRQ_STAT bit set. As an alternative to
463 * resetting the drive, this routine tries to clear the condition
464 * by read a sector's worth of data from the drive. Of course,
465 * this may not help if the drive is *waiting* for data from *us*.
466 */
467static void try_to_flush_leftover_data (ide_drive_t *drive)
468{
469 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
470
471 if (drive->media != ide_disk)
472 return;
473 while (i > 0) {
474 u32 buffer[16];
475 u32 wcount = (i > 16) ? 16 : i;
476
477 i -= wcount;
478 HWIF(drive)->ata_input_data(drive, buffer, wcount);
479 }
480}
481
482static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
483{
484 if (rq->rq_disk) {
485 ide_driver_t *drv;
486
487 drv = *(ide_driver_t **)rq->rq_disk->private_data;
488 drv->end_request(drive, 0, 0);
489 } else
490 ide_end_request(drive, 0, 0);
491}
492
493static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
494{
495 ide_hwif_t *hwif = drive->hwif;
496
497 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
498 /* other bits are useless when BUSY */
499 rq->errors |= ERROR_RESET;
500 } else if (stat & ERR_STAT) {
501 /* err has different meaning on cdrom and tape */
502 if (err == ABRT_ERR) {
503 if (drive->select.b.lba &&
504 /* some newer drives don't support WIN_SPECIFY */
505 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
506 return ide_stopped;
507 } else if ((err & BAD_CRC) == BAD_CRC) {
508 /* UDMA crc error, just retry the operation */
509 drive->crc_count++;
510 } else if (err & (BBD_ERR | ECC_ERR)) {
511 /* retries won't help these */
512 rq->errors = ERROR_MAX;
513 } else if (err & TRK0_ERR) {
514 /* help it find track zero */
515 rq->errors |= ERROR_RECAL;
516 }
517 }
518
Alan Coxda574af2006-06-28 04:27:01 -0700519 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ && hwif->err_stops_fifo == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 try_to_flush_leftover_data(drive);
521
522 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
523 /* force an abort */
524 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
525
526 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq))
527 ide_kill_rq(drive, rq);
528 else {
529 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
530 ++rq->errors;
531 return ide_do_reset(drive);
532 }
533 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
534 drive->special.b.recalibrate = 1;
535 ++rq->errors;
536 }
537 return ide_stopped;
538}
539
540static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
541{
542 ide_hwif_t *hwif = drive->hwif;
543
544 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
545 /* other bits are useless when BUSY */
546 rq->errors |= ERROR_RESET;
547 } else {
548 /* add decoding error stuff */
549 }
550
551 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
552 /* force an abort */
553 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
554
555 if (rq->errors >= ERROR_MAX) {
556 ide_kill_rq(drive, rq);
557 } else {
558 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
559 ++rq->errors;
560 return ide_do_reset(drive);
561 }
562 ++rq->errors;
563 }
564
565 return ide_stopped;
566}
567
568ide_startstop_t
569__ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
570{
571 if (drive->media == ide_disk)
572 return ide_ata_error(drive, rq, stat, err);
573 return ide_atapi_error(drive, rq, stat, err);
574}
575
576EXPORT_SYMBOL_GPL(__ide_error);
577
578/**
579 * ide_error - handle an error on the IDE
580 * @drive: drive the error occurred on
581 * @msg: message to report
582 * @stat: status bits
583 *
584 * ide_error() takes action based on the error returned by the drive.
585 * For normal I/O that may well include retries. We deal with
586 * both new-style (taskfile) and old style command handling here.
587 * In the case of taskfile command handling there is work left to
588 * do
589 */
590
591ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
592{
593 struct request *rq;
594 u8 err;
595
596 err = ide_dump_status(drive, msg, stat);
597
598 if ((rq = HWGROUP(drive)->rq) == NULL)
599 return ide_stopped;
600
601 /* retry only "normal" I/O: */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200602 if (!blk_fs_request(rq)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603 rq->errors = 1;
604 ide_end_drive_cmd(drive, stat, err);
605 return ide_stopped;
606 }
607
608 if (rq->rq_disk) {
609 ide_driver_t *drv;
610
611 drv = *(ide_driver_t **)rq->rq_disk->private_data;
612 return drv->error(drive, rq, stat, err);
613 } else
614 return __ide_error(drive, rq, stat, err);
615}
616
617EXPORT_SYMBOL_GPL(ide_error);
618
619ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
620{
621 if (drive->media != ide_disk)
622 rq->errors |= ERROR_RESET;
623
624 ide_kill_rq(drive, rq);
625
626 return ide_stopped;
627}
628
629EXPORT_SYMBOL_GPL(__ide_abort);
630
631/**
Adrian Bunk338cec32005-09-10 00:26:54 -0700632 * ide_abort - abort pending IDE operations
Linus Torvalds1da177e2005-04-16 15:20:36 -0700633 * @drive: drive the error occurred on
634 * @msg: message to report
635 *
636 * ide_abort kills and cleans up when we are about to do a
637 * host initiated reset on active commands. Longer term we
638 * want handlers to have sensible abort handling themselves
639 *
640 * This differs fundamentally from ide_error because in
641 * this case the command is doing just fine when we
642 * blow it away.
643 */
644
645ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
646{
647 struct request *rq;
648
649 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
650 return ide_stopped;
651
652 /* retry only "normal" I/O: */
Jens Axboe4aff5e22006-08-10 08:44:47 +0200653 if (!blk_fs_request(rq)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654 rq->errors = 1;
655 ide_end_drive_cmd(drive, BUSY_STAT, 0);
656 return ide_stopped;
657 }
658
659 if (rq->rq_disk) {
660 ide_driver_t *drv;
661
662 drv = *(ide_driver_t **)rq->rq_disk->private_data;
663 return drv->abort(drive, rq);
664 } else
665 return __ide_abort(drive, rq);
666}
667
668/**
669 * ide_cmd - issue a simple drive command
670 * @drive: drive the command is for
671 * @cmd: command byte
672 * @nsect: sector byte
673 * @handler: handler for the command completion
674 *
675 * Issue a simple drive command with interrupts.
676 * The drive must be selected beforehand.
677 */
678
679static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
680 ide_handler_t *handler)
681{
682 ide_hwif_t *hwif = HWIF(drive);
683 if (IDE_CONTROL_REG)
684 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
685 SELECT_MASK(drive,0);
686 hwif->OUTB(nsect,IDE_NSECTOR_REG);
687 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
688}
689
690/**
691 * drive_cmd_intr - drive command completion interrupt
692 * @drive: drive the completion interrupt occurred on
693 *
694 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
Adrian Bunk338cec32005-09-10 00:26:54 -0700695 * We do any necessary data reading and then wait for the drive to
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 * go non busy. At that point we may read the error data and complete
697 * the request
698 */
699
700static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
701{
702 struct request *rq = HWGROUP(drive)->rq;
703 ide_hwif_t *hwif = HWIF(drive);
704 u8 *args = (u8 *) rq->buffer;
705 u8 stat = hwif->INB(IDE_STATUS_REG);
706 int retries = 10;
707
Ingo Molnar366c7f52006-07-03 00:25:25 -0700708 local_irq_enable_in_hardirq();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 if ((stat & DRQ_STAT) && args && args[3]) {
710 u8 io_32bit = drive->io_32bit;
711 drive->io_32bit = 0;
712 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
713 drive->io_32bit = io_32bit;
714 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
715 udelay(100);
716 }
717
718 if (!OK_STAT(stat, READY_STAT, BAD_STAT))
719 return ide_error(drive, "drive_cmd", stat);
720 /* calls ide_end_drive_cmd */
721 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
722 return ide_stopped;
723}
724
725static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
726{
727 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
728 task->tfRegister[IDE_SECTOR_OFFSET] = drive->sect;
729 task->tfRegister[IDE_LCYL_OFFSET] = drive->cyl;
730 task->tfRegister[IDE_HCYL_OFFSET] = drive->cyl>>8;
731 task->tfRegister[IDE_SELECT_OFFSET] = ((drive->head-1)|drive->select.all)&0xBF;
732 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SPECIFY;
733
734 task->handler = &set_geometry_intr;
735}
736
737static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
738{
739 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->sect;
740 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_RESTORE;
741
742 task->handler = &recal_intr;
743}
744
745static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
746{
747 task->tfRegister[IDE_NSECTOR_OFFSET] = drive->mult_req;
748 task->tfRegister[IDE_COMMAND_OFFSET] = WIN_SETMULT;
749
750 task->handler = &set_multmode_intr;
751}
752
753static ide_startstop_t ide_disk_special(ide_drive_t *drive)
754{
755 special_t *s = &drive->special;
756 ide_task_t args;
757
758 memset(&args, 0, sizeof(ide_task_t));
759 args.command_type = IDE_DRIVE_TASK_NO_DATA;
760
761 if (s->b.set_geometry) {
762 s->b.set_geometry = 0;
763 ide_init_specify_cmd(drive, &args);
764 } else if (s->b.recalibrate) {
765 s->b.recalibrate = 0;
766 ide_init_restore_cmd(drive, &args);
767 } else if (s->b.set_multmode) {
768 s->b.set_multmode = 0;
769 if (drive->mult_req > drive->id->max_multsect)
770 drive->mult_req = drive->id->max_multsect;
771 ide_init_setmult_cmd(drive, &args);
772 } else if (s->all) {
773 int special = s->all;
774 s->all = 0;
775 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
776 return ide_stopped;
777 }
778
779 do_rw_taskfile(drive, &args);
780
781 return ide_started;
782}
783
784/**
785 * do_special - issue some special commands
786 * @drive: drive the command is for
787 *
788 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
789 * commands to a drive. It used to do much more, but has been scaled
790 * back.
791 */
792
793static ide_startstop_t do_special (ide_drive_t *drive)
794{
795 special_t *s = &drive->special;
796
797#ifdef DEBUG
798 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
799#endif
800 if (s->b.set_tune) {
801 s->b.set_tune = 0;
802 if (HWIF(drive)->tuneproc != NULL)
803 HWIF(drive)->tuneproc(drive, drive->tune_req);
804 return ide_stopped;
805 } else {
806 if (drive->media == ide_disk)
807 return ide_disk_special(drive);
808
809 s->all = 0;
810 drive->mult_req = 0;
811 return ide_stopped;
812 }
813}
814
815void ide_map_sg(ide_drive_t *drive, struct request *rq)
816{
817 ide_hwif_t *hwif = drive->hwif;
818 struct scatterlist *sg = hwif->sg_table;
819
820 if (hwif->sg_mapped) /* needed by ide-scsi */
821 return;
822
Jens Axboe4aff5e22006-08-10 08:44:47 +0200823 if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700824 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
825 } else {
826 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
827 hwif->sg_nents = 1;
828 }
829}
830
831EXPORT_SYMBOL_GPL(ide_map_sg);
832
833void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
834{
835 ide_hwif_t *hwif = drive->hwif;
836
837 hwif->nsect = hwif->nleft = rq->nr_sectors;
838 hwif->cursg = hwif->cursg_ofs = 0;
839}
840
841EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
842
843/**
844 * execute_drive_command - issue special drive command
Adrian Bunk338cec32005-09-10 00:26:54 -0700845 * @drive: the drive to issue the command on
Linus Torvalds1da177e2005-04-16 15:20:36 -0700846 * @rq: the request structure holding the command
847 *
848 * execute_drive_cmd() issues a special drive command, usually
849 * initiated by ioctl() from the external hdparm program. The
850 * command can be a drive command, drive task or taskfile
851 * operation. Weirdly you can call it with NULL to wait for
852 * all commands to finish. Don't do this as that is due to change
853 */
854
855static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
856 struct request *rq)
857{
858 ide_hwif_t *hwif = HWIF(drive);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200859 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700860 ide_task_t *args = rq->special;
861
862 if (!args)
863 goto done;
864
865 hwif->data_phase = args->data_phase;
866
867 switch (hwif->data_phase) {
868 case TASKFILE_MULTI_OUT:
869 case TASKFILE_OUT:
870 case TASKFILE_MULTI_IN:
871 case TASKFILE_IN:
872 ide_init_sg_cmd(drive, rq);
873 ide_map_sg(drive, rq);
874 default:
875 break;
876 }
877
878 if (args->tf_out_flags.all != 0)
879 return flagged_taskfile(drive, args);
880 return do_rw_taskfile(drive, args);
Jens Axboe4aff5e22006-08-10 08:44:47 +0200881 } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 u8 *args = rq->buffer;
883 u8 sel;
884
885 if (!args)
886 goto done;
887#ifdef DEBUG
888 printk("%s: DRIVE_TASK_CMD ", drive->name);
889 printk("cmd=0x%02x ", args[0]);
890 printk("fr=0x%02x ", args[1]);
891 printk("ns=0x%02x ", args[2]);
892 printk("sc=0x%02x ", args[3]);
893 printk("lcyl=0x%02x ", args[4]);
894 printk("hcyl=0x%02x ", args[5]);
895 printk("sel=0x%02x\n", args[6]);
896#endif
897 hwif->OUTB(args[1], IDE_FEATURE_REG);
898 hwif->OUTB(args[3], IDE_SECTOR_REG);
899 hwif->OUTB(args[4], IDE_LCYL_REG);
900 hwif->OUTB(args[5], IDE_HCYL_REG);
901 sel = (args[6] & ~0x10);
902 if (drive->select.b.unit)
903 sel |= 0x10;
904 hwif->OUTB(sel, IDE_SELECT_REG);
905 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
906 return ide_started;
Jens Axboe4aff5e22006-08-10 08:44:47 +0200907 } else if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700908 u8 *args = rq->buffer;
909
910 if (!args)
911 goto done;
912#ifdef DEBUG
913 printk("%s: DRIVE_CMD ", drive->name);
914 printk("cmd=0x%02x ", args[0]);
915 printk("sc=0x%02x ", args[1]);
916 printk("fr=0x%02x ", args[2]);
917 printk("xx=0x%02x\n", args[3]);
918#endif
919 if (args[0] == WIN_SMART) {
920 hwif->OUTB(0x4f, IDE_LCYL_REG);
921 hwif->OUTB(0xc2, IDE_HCYL_REG);
922 hwif->OUTB(args[2],IDE_FEATURE_REG);
923 hwif->OUTB(args[1],IDE_SECTOR_REG);
924 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
925 return ide_started;
926 }
927 hwif->OUTB(args[2],IDE_FEATURE_REG);
928 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
929 return ide_started;
930 }
931
932done:
933 /*
934 * NULL is actually a valid way of waiting for
935 * all current requests to be flushed from the queue.
936 */
937#ifdef DEBUG
938 printk("%s: DRIVE_CMD (null)\n", drive->name);
939#endif
940 ide_end_drive_cmd(drive,
941 hwif->INB(IDE_STATUS_REG),
942 hwif->INB(IDE_ERROR_REG));
943 return ide_stopped;
944}
945
Jens Axboead3cadd2006-06-13 08:46:57 +0200946static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
947{
Jens Axboec00895a2006-09-30 20:29:12 +0200948 struct request_pm_state *pm = rq->data;
Jens Axboead3cadd2006-06-13 08:46:57 +0200949
950 if (blk_pm_suspend_request(rq) &&
951 pm->pm_step == ide_pm_state_start_suspend)
952 /* Mark drive blocked when starting the suspend sequence. */
953 drive->blocked = 1;
954 else if (blk_pm_resume_request(rq) &&
955 pm->pm_step == ide_pm_state_start_resume) {
956 /*
957 * The first thing we do on wakeup is to wait for BSY bit to
958 * go away (with a looong timeout) as a drive on this hwif may
959 * just be POSTing itself.
960 * We do that before even selecting as the "other" device on
961 * the bus may be broken enough to walk on our toes at this
962 * point.
963 */
964 int rc;
965#ifdef DEBUG_PM
966 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
967#endif
968 rc = ide_wait_not_busy(HWIF(drive), 35000);
969 if (rc)
970 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
971 SELECT_DRIVE(drive);
972 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
Al Boldi178184b2006-06-26 00:26:13 -0700973 rc = ide_wait_not_busy(HWIF(drive), 100000);
Jens Axboead3cadd2006-06-13 08:46:57 +0200974 if (rc)
975 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
976 }
977}
978
Linus Torvalds1da177e2005-04-16 15:20:36 -0700979/**
980 * start_request - start of I/O and command issuing for IDE
981 *
982 * start_request() initiates handling of a new I/O request. It
983 * accepts commands and I/O (read/write) requests. It also does
984 * the final remapping for weird stuff like EZDrive. Once
985 * device mapper can work sector level the EZDrive stuff can go away
986 *
987 * FIXME: this function needs a rename
988 */
989
990static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
991{
992 ide_startstop_t startstop;
993 sector_t block;
994
Jens Axboe4aff5e22006-08-10 08:44:47 +0200995 BUG_ON(!blk_rq_started(rq));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700996
997#ifdef DEBUG
998 printk("%s: start_request: current=0x%08lx\n",
999 HWIF(drive)->name, (unsigned long) rq);
1000#endif
1001
1002 /* bail early if we've exceeded max_failures */
1003 if (drive->max_failures && (drive->failures > drive->max_failures)) {
1004 goto kill_rq;
1005 }
1006
1007 block = rq->sector;
1008 if (blk_fs_request(rq) &&
1009 (drive->media == ide_disk || drive->media == ide_floppy)) {
1010 block += drive->sect0;
1011 }
1012 /* Yecch - this will shift the entire interval,
1013 possibly killing some innocent following sector */
1014 if (block == 0 && drive->remap_0_to_1 == 1)
1015 block = 1; /* redirect MBR access to EZ-Drive partn table */
1016
Jens Axboead3cadd2006-06-13 08:46:57 +02001017 if (blk_pm_request(rq))
1018 ide_check_pm_state(drive, rq);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001019
1020 SELECT_DRIVE(drive);
1021 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
1022 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
1023 return startstop;
1024 }
1025 if (!drive->special.all) {
1026 ide_driver_t *drv;
1027
Jens Axboe4aff5e22006-08-10 08:44:47 +02001028 if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
1029 rq->cmd_type == REQ_TYPE_ATA_TASK ||
1030 rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001031 return execute_drive_cmd(drive, rq);
1032 else if (blk_pm_request(rq)) {
Jens Axboec00895a2006-09-30 20:29:12 +02001033 struct request_pm_state *pm = rq->data;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001034#ifdef DEBUG_PM
1035 printk("%s: start_power_step(step: %d)\n",
1036 drive->name, rq->pm->pm_step);
1037#endif
1038 startstop = ide_start_power_step(drive, rq);
1039 if (startstop == ide_stopped &&
Jens Axboead3cadd2006-06-13 08:46:57 +02001040 pm->pm_step == ide_pm_state_completed)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 ide_complete_pm_request(drive, rq);
1042 return startstop;
1043 }
1044
1045 drv = *(ide_driver_t **)rq->rq_disk->private_data;
1046 return drv->do_request(drive, rq, block);
1047 }
1048 return do_special(drive);
1049kill_rq:
1050 ide_kill_rq(drive, rq);
1051 return ide_stopped;
1052}
1053
1054/**
1055 * ide_stall_queue - pause an IDE device
1056 * @drive: drive to stall
1057 * @timeout: time to stall for (jiffies)
1058 *
1059 * ide_stall_queue() can be used by a drive to give excess bandwidth back
1060 * to the hwgroup by sleeping for timeout jiffies.
1061 */
1062
1063void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1064{
1065 if (timeout > WAIT_WORSTCASE)
1066 timeout = WAIT_WORSTCASE;
1067 drive->sleep = timeout + jiffies;
1068 drive->sleeping = 1;
1069}
1070
1071EXPORT_SYMBOL(ide_stall_queue);
1072
1073#define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
1074
1075/**
1076 * choose_drive - select a drive to service
1077 * @hwgroup: hardware group to select on
1078 *
1079 * choose_drive() selects the next drive which will be serviced.
1080 * This is necessary because the IDE layer can't issue commands
1081 * to both drives on the same cable, unlike SCSI.
1082 */
1083
1084static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1085{
1086 ide_drive_t *drive, *best;
1087
1088repeat:
1089 best = NULL;
1090 drive = hwgroup->drive;
1091
1092 /*
1093 * drive is doing pre-flush, ordered write, post-flush sequence. even
1094 * though that is 3 requests, it must be seen as a single transaction.
1095 * we must not preempt this drive until that is complete
1096 */
1097 if (blk_queue_flushing(drive->queue)) {
1098 /*
1099 * small race where queue could get replugged during
1100 * the 3-request flush cycle, just yank the plug since
1101 * we want it to finish asap
1102 */
1103 blk_remove_plug(drive->queue);
1104 return drive;
1105 }
1106
1107 do {
1108 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1109 && !elv_queue_empty(drive->queue)) {
1110 if (!best
1111 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1112 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1113 {
1114 if (!blk_queue_plugged(drive->queue))
1115 best = drive;
1116 }
1117 }
1118 } while ((drive = drive->next) != hwgroup->drive);
1119 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1120 long t = (signed long)(WAKEUP(best) - jiffies);
1121 if (t >= WAIT_MIN_SLEEP) {
1122 /*
1123 * We *may* have some time to spare, but first let's see if
1124 * someone can potentially benefit from our nice mood today..
1125 */
1126 drive = best->next;
1127 do {
1128 if (!drive->sleeping
1129 && time_before(jiffies - best->service_time, WAKEUP(drive))
1130 && time_before(WAKEUP(drive), jiffies + t))
1131 {
1132 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1133 goto repeat;
1134 }
1135 } while ((drive = drive->next) != best);
1136 }
1137 }
1138 return best;
1139}
1140
1141/*
1142 * Issue a new request to a drive from hwgroup
1143 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1144 *
1145 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1146 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1147 * may have both interfaces in a single hwgroup to "serialize" access.
1148 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1149 * together into one hwgroup for serialized access.
1150 *
1151 * Note also that several hwgroups can end up sharing a single IRQ,
1152 * possibly along with many other devices. This is especially common in
1153 * PCI-based systems with off-board IDE controller cards.
1154 *
1155 * The IDE driver uses the single global ide_lock spinlock to protect
1156 * access to the request queues, and to protect the hwgroup->busy flag.
1157 *
1158 * The first thread into the driver for a particular hwgroup sets the
1159 * hwgroup->busy flag to indicate that this hwgroup is now active,
1160 * and then initiates processing of the top request from the request queue.
1161 *
1162 * Other threads attempting entry notice the busy setting, and will simply
1163 * queue their new requests and exit immediately. Note that hwgroup->busy
1164 * remains set even when the driver is merely awaiting the next interrupt.
1165 * Thus, the meaning is "this hwgroup is busy processing a request".
1166 *
1167 * When processing of a request completes, the completing thread or IRQ-handler
1168 * will start the next request from the queue. If no more work remains,
1169 * the driver will clear the hwgroup->busy flag and exit.
1170 *
1171 * The ide_lock (spinlock) is used to protect all access to the
1172 * hwgroup->busy flag, but is otherwise not needed for most processing in
1173 * the driver. This makes the driver much more friendlier to shared IRQs
1174 * than previous designs, while remaining 100% (?) SMP safe and capable.
1175 */
1176static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1177{
1178 ide_drive_t *drive;
1179 ide_hwif_t *hwif;
1180 struct request *rq;
1181 ide_startstop_t startstop;
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001182 int loops = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001183
1184 /* for atari only: POSSIBLY BROKEN HERE(?) */
1185 ide_get_lock(ide_intr, hwgroup);
1186
1187 /* caller must own ide_lock */
1188 BUG_ON(!irqs_disabled());
1189
1190 while (!hwgroup->busy) {
1191 hwgroup->busy = 1;
1192 drive = choose_drive(hwgroup);
1193 if (drive == NULL) {
1194 int sleeping = 0;
1195 unsigned long sleep = 0; /* shut up, gcc */
1196 hwgroup->rq = NULL;
1197 drive = hwgroup->drive;
1198 do {
1199 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1200 sleeping = 1;
1201 sleep = drive->sleep;
1202 }
1203 } while ((drive = drive->next) != hwgroup->drive);
1204 if (sleeping) {
1205 /*
1206 * Take a short snooze, and then wake up this hwgroup again.
1207 * This gives other hwgroups on the same a chance to
1208 * play fairly with us, just in case there are big differences
1209 * in relative throughputs.. don't want to hog the cpu too much.
1210 */
1211 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1212 sleep = jiffies + WAIT_MIN_SLEEP;
1213#if 1
1214 if (timer_pending(&hwgroup->timer))
1215 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1216#endif
1217 /* so that ide_timer_expiry knows what to do */
1218 hwgroup->sleeping = 1;
1219 mod_timer(&hwgroup->timer, sleep);
1220 /* we purposely leave hwgroup->busy==1
1221 * while sleeping */
1222 } else {
1223 /* Ugly, but how can we sleep for the lock
1224 * otherwise? perhaps from tq_disk?
1225 */
1226
1227 /* for atari only */
1228 ide_release_lock();
1229 hwgroup->busy = 0;
1230 }
1231
1232 /* no more work for this hwgroup (for now) */
1233 return;
1234 }
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001235 again:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001236 hwif = HWIF(drive);
1237 if (hwgroup->hwif->sharing_irq &&
1238 hwif != hwgroup->hwif &&
1239 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1240 /* set nIEN for previous hwif */
1241 SELECT_INTERRUPT(drive);
1242 }
1243 hwgroup->hwif = hwif;
1244 hwgroup->drive = drive;
1245 drive->sleeping = 0;
1246 drive->service_start = jiffies;
1247
1248 if (blk_queue_plugged(drive->queue)) {
1249 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1250 break;
1251 }
1252
1253 /*
1254 * we know that the queue isn't empty, but this can happen
1255 * if the q->prep_rq_fn() decides to kill a request
1256 */
1257 rq = elv_next_request(drive->queue);
1258 if (!rq) {
1259 hwgroup->busy = 0;
1260 break;
1261 }
1262
1263 /*
1264 * Sanity: don't accept a request that isn't a PM request
1265 * if we are currently power managed. This is very important as
1266 * blk_stop_queue() doesn't prevent the elv_next_request()
1267 * above to return us whatever is in the queue. Since we call
1268 * ide_do_request() ourselves, we end up taking requests while
1269 * the queue is blocked...
1270 *
1271 * We let requests forced at head of queue with ide-preempt
1272 * though. I hope that doesn't happen too much, hopefully not
1273 * unless the subdriver triggers such a thing in its own PM
1274 * state machine.
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001275 *
1276 * We count how many times we loop here to make sure we service
1277 * all drives in the hwgroup without looping for ever
Linus Torvalds1da177e2005-04-16 15:20:36 -07001278 */
Jens Axboe4aff5e22006-08-10 08:44:47 +02001279 if (drive->blocked && !blk_pm_request(rq) && !(rq->cmd_flags & REQ_PREEMPT)) {
Benjamin Herrenschmidt867f8b42005-10-09 10:37:47 +10001280 drive = drive->next ? drive->next : hwgroup->drive;
1281 if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1282 goto again;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001283 /* We clear busy, there should be no pending ATA command at this point. */
1284 hwgroup->busy = 0;
1285 break;
1286 }
1287
1288 hwgroup->rq = rq;
1289
1290 /*
1291 * Some systems have trouble with IDE IRQs arriving while
1292 * the driver is still setting things up. So, here we disable
1293 * the IRQ used by this interface while the request is being started.
1294 * This may look bad at first, but pretty much the same thing
1295 * happens anyway when any interrupt comes in, IDE or otherwise
1296 * -- the kernel masks the IRQ while it is being handled.
1297 */
1298 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1299 disable_irq_nosync(hwif->irq);
1300 spin_unlock(&ide_lock);
Ingo Molnar366c7f52006-07-03 00:25:25 -07001301 local_irq_enable_in_hardirq();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001302 /* allow other IRQs while we start this request */
1303 startstop = start_request(drive, rq);
1304 spin_lock_irq(&ide_lock);
1305 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1306 enable_irq(hwif->irq);
1307 if (startstop == ide_stopped)
1308 hwgroup->busy = 0;
1309 }
1310}
1311
1312/*
1313 * Passes the stuff to ide_do_request
1314 */
1315void do_ide_request(request_queue_t *q)
1316{
1317 ide_drive_t *drive = q->queuedata;
1318
1319 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1320}
1321
1322/*
1323 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1324 * retry the current request in pio mode instead of risking tossing it
1325 * all away
1326 */
1327static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1328{
1329 ide_hwif_t *hwif = HWIF(drive);
1330 struct request *rq;
1331 ide_startstop_t ret = ide_stopped;
1332
1333 /*
1334 * end current dma transaction
1335 */
1336
1337 if (error < 0) {
1338 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1339 (void)HWIF(drive)->ide_dma_end(drive);
1340 ret = ide_error(drive, "dma timeout error",
1341 hwif->INB(IDE_STATUS_REG));
1342 } else {
1343 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1344 (void) hwif->ide_dma_timeout(drive);
1345 }
1346
1347 /*
1348 * disable dma for now, but remember that we did so because of
1349 * a timeout -- we'll reenable after we finish this next request
1350 * (or rather the first chunk of it) in pio.
1351 */
1352 drive->retry_pio++;
1353 drive->state = DMA_PIO_RETRY;
1354 (void) hwif->ide_dma_off_quietly(drive);
1355
1356 /*
1357 * un-busy drive etc (hwgroup->busy is cleared on return) and
1358 * make sure request is sane
1359 */
1360 rq = HWGROUP(drive)->rq;
Hua Zhongce42f192006-10-03 01:14:15 -07001361
1362 if (!rq)
1363 goto out;
1364
Linus Torvalds1da177e2005-04-16 15:20:36 -07001365 HWGROUP(drive)->rq = NULL;
1366
1367 rq->errors = 0;
1368
1369 if (!rq->bio)
1370 goto out;
1371
1372 rq->sector = rq->bio->bi_sector;
1373 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1374 rq->hard_cur_sectors = rq->current_nr_sectors;
1375 rq->buffer = bio_data(rq->bio);
1376out:
1377 return ret;
1378}
1379
1380/**
1381 * ide_timer_expiry - handle lack of an IDE interrupt
1382 * @data: timer callback magic (hwgroup)
1383 *
1384 * An IDE command has timed out before the expected drive return
1385 * occurred. At this point we attempt to clean up the current
1386 * mess. If the current handler includes an expiry handler then
1387 * we invoke the expiry handler, and providing it is happy the
1388 * work is done. If that fails we apply generic recovery rules
1389 * invoking the handler and checking the drive DMA status. We
1390 * have an excessively incestuous relationship with the DMA
1391 * logic that wants cleaning up.
1392 */
1393
1394void ide_timer_expiry (unsigned long data)
1395{
1396 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1397 ide_handler_t *handler;
1398 ide_expiry_t *expiry;
1399 unsigned long flags;
1400 unsigned long wait = -1;
1401
1402 spin_lock_irqsave(&ide_lock, flags);
1403
1404 if ((handler = hwgroup->handler) == NULL) {
1405 /*
1406 * Either a marginal timeout occurred
1407 * (got the interrupt just as timer expired),
1408 * or we were "sleeping" to give other devices a chance.
1409 * Either way, we don't really want to complain about anything.
1410 */
1411 if (hwgroup->sleeping) {
1412 hwgroup->sleeping = 0;
1413 hwgroup->busy = 0;
1414 }
1415 } else {
1416 ide_drive_t *drive = hwgroup->drive;
1417 if (!drive) {
1418 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1419 hwgroup->handler = NULL;
1420 } else {
1421 ide_hwif_t *hwif;
1422 ide_startstop_t startstop = ide_stopped;
1423 if (!hwgroup->busy) {
1424 hwgroup->busy = 1; /* paranoia */
1425 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1426 }
1427 if ((expiry = hwgroup->expiry) != NULL) {
1428 /* continue */
1429 if ((wait = expiry(drive)) > 0) {
1430 /* reset timer */
1431 hwgroup->timer.expires = jiffies + wait;
1432 add_timer(&hwgroup->timer);
1433 spin_unlock_irqrestore(&ide_lock, flags);
1434 return;
1435 }
1436 }
1437 hwgroup->handler = NULL;
1438 /*
1439 * We need to simulate a real interrupt when invoking
1440 * the handler() function, which means we need to
1441 * globally mask the specific IRQ:
1442 */
1443 spin_unlock(&ide_lock);
1444 hwif = HWIF(drive);
1445#if DISABLE_IRQ_NOSYNC
1446 disable_irq_nosync(hwif->irq);
1447#else
1448 /* disable_irq_nosync ?? */
1449 disable_irq(hwif->irq);
1450#endif /* DISABLE_IRQ_NOSYNC */
1451 /* local CPU only,
1452 * as if we were handling an interrupt */
1453 local_irq_disable();
1454 if (hwgroup->polling) {
1455 startstop = handler(drive);
1456 } else if (drive_is_ready(drive)) {
1457 if (drive->waiting_for_dma)
1458 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1459 (void)ide_ack_intr(hwif);
1460 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1461 startstop = handler(drive);
1462 } else {
1463 if (drive->waiting_for_dma) {
1464 startstop = ide_dma_timeout_retry(drive, wait);
1465 } else
1466 startstop =
1467 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1468 }
1469 drive->service_time = jiffies - drive->service_start;
1470 spin_lock_irq(&ide_lock);
1471 enable_irq(hwif->irq);
1472 if (startstop == ide_stopped)
1473 hwgroup->busy = 0;
1474 }
1475 }
1476 ide_do_request(hwgroup, IDE_NO_IRQ);
1477 spin_unlock_irqrestore(&ide_lock, flags);
1478}
1479
1480/**
1481 * unexpected_intr - handle an unexpected IDE interrupt
1482 * @irq: interrupt line
1483 * @hwgroup: hwgroup being processed
1484 *
1485 * There's nothing really useful we can do with an unexpected interrupt,
1486 * other than reading the status register (to clear it), and logging it.
1487 * There should be no way that an irq can happen before we're ready for it,
1488 * so we needn't worry much about losing an "important" interrupt here.
1489 *
1490 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1491 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1492 * looks "good", we just ignore the interrupt completely.
1493 *
1494 * This routine assumes __cli() is in effect when called.
1495 *
1496 * If an unexpected interrupt happens on irq15 while we are handling irq14
1497 * and if the two interfaces are "serialized" (CMD640), then it looks like
1498 * we could screw up by interfering with a new request being set up for
1499 * irq15.
1500 *
1501 * In reality, this is a non-issue. The new command is not sent unless
1502 * the drive is ready to accept one, in which case we know the drive is
1503 * not trying to interrupt us. And ide_set_handler() is always invoked
1504 * before completing the issuance of any new drive command, so we will not
1505 * be accidentally invoked as a result of any valid command completion
1506 * interrupt.
1507 *
1508 * Note that we must walk the entire hwgroup here. We know which hwif
1509 * is doing the current command, but we don't know which hwif burped
1510 * mysteriously.
1511 */
1512
1513static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1514{
1515 u8 stat;
1516 ide_hwif_t *hwif = hwgroup->hwif;
1517
1518 /*
1519 * handle the unexpected interrupt
1520 */
1521 do {
1522 if (hwif->irq == irq) {
1523 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1524 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1525 /* Try to not flood the console with msgs */
1526 static unsigned long last_msgtime, count;
1527 ++count;
1528 if (time_after(jiffies, last_msgtime + HZ)) {
1529 last_msgtime = jiffies;
1530 printk(KERN_ERR "%s%s: unexpected interrupt, "
1531 "status=0x%02x, count=%ld\n",
1532 hwif->name,
1533 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1534 }
1535 }
1536 }
1537 } while ((hwif = hwif->next) != hwgroup->hwif);
1538}
1539
1540/**
1541 * ide_intr - default IDE interrupt handler
1542 * @irq: interrupt number
1543 * @dev_id: hwif group
1544 * @regs: unused weirdness from the kernel irq layer
1545 *
1546 * This is the default IRQ handler for the IDE layer. You should
1547 * not need to override it. If you do be aware it is subtle in
1548 * places
1549 *
1550 * hwgroup->hwif is the interface in the group currently performing
1551 * a command. hwgroup->drive is the drive and hwgroup->handler is
1552 * the IRQ handler to call. As we issue a command the handlers
1553 * step through multiple states, reassigning the handler to the
1554 * next step in the process. Unlike a smart SCSI controller IDE
1555 * expects the main processor to sequence the various transfer
1556 * stages. We also manage a poll timer to catch up with most
1557 * timeout situations. There are still a few where the handlers
1558 * don't ever decide to give up.
1559 *
1560 * The handler eventually returns ide_stopped to indicate the
1561 * request completed. At this point we issue the next request
1562 * on the hwgroup and the process begins again.
1563 */
1564
David Howells7d12e782006-10-05 14:55:46 +01001565irqreturn_t ide_intr (int irq, void *dev_id)
Linus Torvalds1da177e2005-04-16 15:20:36 -07001566{
1567 unsigned long flags;
1568 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1569 ide_hwif_t *hwif;
1570 ide_drive_t *drive;
1571 ide_handler_t *handler;
1572 ide_startstop_t startstop;
1573
1574 spin_lock_irqsave(&ide_lock, flags);
1575 hwif = hwgroup->hwif;
1576
1577 if (!ide_ack_intr(hwif)) {
1578 spin_unlock_irqrestore(&ide_lock, flags);
1579 return IRQ_NONE;
1580 }
1581
1582 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1583 /*
1584 * Not expecting an interrupt from this drive.
1585 * That means this could be:
1586 * (1) an interrupt from another PCI device
1587 * sharing the same PCI INT# as us.
1588 * or (2) a drive just entered sleep or standby mode,
1589 * and is interrupting to let us know.
1590 * or (3) a spurious interrupt of unknown origin.
1591 *
1592 * For PCI, we cannot tell the difference,
1593 * so in that case we just ignore it and hope it goes away.
1594 *
1595 * FIXME: unexpected_intr should be hwif-> then we can
1596 * remove all the ifdef PCI crap
1597 */
1598#ifdef CONFIG_BLK_DEV_IDEPCI
1599 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1600#endif /* CONFIG_BLK_DEV_IDEPCI */
1601 {
1602 /*
1603 * Probably not a shared PCI interrupt,
1604 * so we can safely try to do something about it:
1605 */
1606 unexpected_intr(irq, hwgroup);
1607#ifdef CONFIG_BLK_DEV_IDEPCI
1608 } else {
1609 /*
1610 * Whack the status register, just in case
1611 * we have a leftover pending IRQ.
1612 */
1613 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1614#endif /* CONFIG_BLK_DEV_IDEPCI */
1615 }
1616 spin_unlock_irqrestore(&ide_lock, flags);
1617 return IRQ_NONE;
1618 }
1619 drive = hwgroup->drive;
1620 if (!drive) {
1621 /*
1622 * This should NEVER happen, and there isn't much
1623 * we could do about it here.
1624 *
1625 * [Note - this can occur if the drive is hot unplugged]
1626 */
1627 spin_unlock_irqrestore(&ide_lock, flags);
1628 return IRQ_HANDLED;
1629 }
1630 if (!drive_is_ready(drive)) {
1631 /*
1632 * This happens regularly when we share a PCI IRQ with
1633 * another device. Unfortunately, it can also happen
1634 * with some buggy drives that trigger the IRQ before
1635 * their status register is up to date. Hopefully we have
1636 * enough advance overhead that the latter isn't a problem.
1637 */
1638 spin_unlock_irqrestore(&ide_lock, flags);
1639 return IRQ_NONE;
1640 }
1641 if (!hwgroup->busy) {
1642 hwgroup->busy = 1; /* paranoia */
1643 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1644 }
1645 hwgroup->handler = NULL;
1646 del_timer(&hwgroup->timer);
1647 spin_unlock(&ide_lock);
1648
1649 if (drive->unmask)
Ingo Molnar366c7f52006-07-03 00:25:25 -07001650 local_irq_enable_in_hardirq();
Linus Torvalds1da177e2005-04-16 15:20:36 -07001651 /* service this interrupt, may set handler for next interrupt */
1652 startstop = handler(drive);
1653 spin_lock_irq(&ide_lock);
1654
1655 /*
1656 * Note that handler() may have set things up for another
1657 * interrupt to occur soon, but it cannot happen until
1658 * we exit from this routine, because it will be the
1659 * same irq as is currently being serviced here, and Linux
1660 * won't allow another of the same (on any CPU) until we return.
1661 */
1662 drive->service_time = jiffies - drive->service_start;
1663 if (startstop == ide_stopped) {
1664 if (hwgroup->handler == NULL) { /* paranoia */
1665 hwgroup->busy = 0;
1666 ide_do_request(hwgroup, hwif->irq);
1667 } else {
1668 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1669 "on exit\n", drive->name);
1670 }
1671 }
1672 spin_unlock_irqrestore(&ide_lock, flags);
1673 return IRQ_HANDLED;
1674}
1675
1676/**
1677 * ide_init_drive_cmd - initialize a drive command request
1678 * @rq: request object
1679 *
1680 * Initialize a request before we fill it in and send it down to
1681 * ide_do_drive_cmd. Commands must be set up by this function. Right
1682 * now it doesn't do a lot, but if that changes abusers will have a
Andreas Mohrd6e05ed2006-06-26 18:35:02 +02001683 * nasty surprise.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001684 */
1685
1686void ide_init_drive_cmd (struct request *rq)
1687{
1688 memset(rq, 0, sizeof(*rq));
Jens Axboe4aff5e22006-08-10 08:44:47 +02001689 rq->cmd_type = REQ_TYPE_ATA_CMD;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001690 rq->ref_count = 1;
1691}
1692
1693EXPORT_SYMBOL(ide_init_drive_cmd);
1694
1695/**
1696 * ide_do_drive_cmd - issue IDE special command
1697 * @drive: device to issue command
1698 * @rq: request to issue
1699 * @action: action for processing
1700 *
1701 * This function issues a special IDE device request
1702 * onto the request queue.
1703 *
1704 * If action is ide_wait, then the rq is queued at the end of the
1705 * request queue, and the function sleeps until it has been processed.
1706 * This is for use when invoked from an ioctl handler.
1707 *
1708 * If action is ide_preempt, then the rq is queued at the head of
1709 * the request queue, displacing the currently-being-processed
1710 * request and this function returns immediately without waiting
1711 * for the new rq to be completed. This is VERY DANGEROUS, and is
1712 * intended for careful use by the ATAPI tape/cdrom driver code.
1713 *
Linus Torvalds1da177e2005-04-16 15:20:36 -07001714 * If action is ide_end, then the rq is queued at the end of the
1715 * request queue, and the function returns immediately without waiting
1716 * for the new rq to be completed. This is again intended for careful
1717 * use by the ATAPI tape/cdrom driver code.
1718 */
1719
1720int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1721{
1722 unsigned long flags;
1723 ide_hwgroup_t *hwgroup = HWGROUP(drive);
Ingo Molnar60be6b92006-07-03 00:25:26 -07001724 DECLARE_COMPLETION_ONSTACK(wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001725 int where = ELEVATOR_INSERT_BACK, err;
1726 int must_wait = (action == ide_wait || action == ide_head_wait);
1727
1728 rq->errors = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001729
1730 /*
1731 * we need to hold an extra reference to request for safe inspection
1732 * after completion
1733 */
1734 if (must_wait) {
1735 rq->ref_count++;
Jens Axboec00895a2006-09-30 20:29:12 +02001736 rq->end_io_data = &wait;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001737 rq->end_io = blk_end_sync_rq;
1738 }
1739
1740 spin_lock_irqsave(&ide_lock, flags);
1741 if (action == ide_preempt)
1742 hwgroup->rq = NULL;
1743 if (action == ide_preempt || action == ide_head_wait) {
1744 where = ELEVATOR_INSERT_FRONT;
Jens Axboe4aff5e22006-08-10 08:44:47 +02001745 rq->cmd_flags |= REQ_PREEMPT;
Linus Torvalds1da177e2005-04-16 15:20:36 -07001746 }
1747 __elv_add_request(drive->queue, rq, where, 0);
1748 ide_do_request(hwgroup, IDE_NO_IRQ);
1749 spin_unlock_irqrestore(&ide_lock, flags);
1750
1751 err = 0;
1752 if (must_wait) {
1753 wait_for_completion(&wait);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001754 if (rq->errors)
1755 err = -EIO;
1756
1757 blk_put_request(rq);
1758 }
1759
1760 return err;
1761}
1762
1763EXPORT_SYMBOL(ide_do_drive_cmd);