4 * Basic PIO and command management functionality.
6 * This code was split off from ide.c. See ide.c for history and original
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
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.
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.
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>
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>
51 #include <asm/byteorder.h>
53 #include <asm/uaccess.h>
55 #include <asm/bitops.h>
57 static void ide_fill_flush_cmd(ide_drive_t *drive, struct request *rq)
62 * reuse cdb space for ata command
64 memset(buf, 0, sizeof(rq->cmd));
66 rq->flags |= REQ_DRIVE_TASK | REQ_STARTED;
68 rq->buffer[0] = WIN_FLUSH_CACHE;
70 if (ide_id_has_flush_cache_ext(drive->id) &&
71 (drive->capacity64 >= (1UL << 28)))
72 rq->buffer[0] = WIN_FLUSH_CACHE_EXT;
76 * preempt pending requests, and store this cache flush for immediate
79 static struct request *ide_queue_flush_cmd(ide_drive_t *drive,
80 struct request *rq, int post)
82 struct request *flush_rq = &HWGROUP(drive)->wrq;
85 * write cache disabled, clear the barrier bit and treat it like
89 rq->flags |= REQ_BAR_PREFLUSH;
93 ide_init_drive_cmd(flush_rq);
94 ide_fill_flush_cmd(drive, flush_rq);
96 flush_rq->special = rq;
97 flush_rq->nr_sectors = rq->nr_sectors;
100 drive->doing_barrier = 1;
101 flush_rq->flags |= REQ_BAR_PREFLUSH;
102 blkdev_dequeue_request(rq);
104 flush_rq->flags |= REQ_BAR_POSTFLUSH;
106 __elv_add_request(drive->queue, flush_rq, ELEVATOR_INSERT_FRONT, 0);
107 HWGROUP(drive)->rq = NULL;
111 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
112 int uptodate, int nr_sectors)
116 BUG_ON(!(rq->flags & REQ_STARTED));
119 * if failfast is set on a request, override number of sectors and
120 * complete the whole request right now
122 if (blk_noretry_request(rq) && end_io_error(uptodate))
123 nr_sectors = rq->hard_nr_sectors;
125 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
129 * decide whether to reenable DMA -- 3 is a random magic for now,
130 * if we DMA timeout more than 3 times, just stay in PIO
132 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
134 HWGROUP(drive)->hwif->ide_dma_on(drive);
137 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
138 add_disk_randomness(rq->rq_disk);
140 if (blk_rq_tagged(rq))
141 blk_queue_end_tag(drive->queue, rq);
143 blkdev_dequeue_request(rq);
144 HWGROUP(drive)->rq = NULL;
145 end_that_request_last(rq);
152 * ide_end_request - complete an IDE I/O
153 * @drive: IDE device for the I/O
155 * @nr_sectors: number of sectors completed
157 * This is our end_request wrapper function. We complete the I/O
158 * update random number input and dequeue the request, which if
159 * it was tagged may be out of order.
162 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
168 spin_lock_irqsave(&ide_lock, flags);
169 rq = HWGROUP(drive)->rq;
172 nr_sectors = rq->hard_cur_sectors;
174 if (!blk_barrier_rq(rq) || !drive->wcache)
175 ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
177 struct request *flush_rq = &HWGROUP(drive)->wrq;
179 flush_rq->nr_sectors -= nr_sectors;
180 if (!flush_rq->nr_sectors) {
181 ide_queue_flush_cmd(drive, rq, 1);
186 spin_unlock_irqrestore(&ide_lock, flags);
189 EXPORT_SYMBOL(ide_end_request);
192 * ide_complete_pm_request - end the current Power Management request
193 * @drive: target drive
196 * This function cleans up the current PM request and stops the queue
199 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
204 printk("%s: completing PM request, %s\n", drive->name,
205 blk_pm_suspend_request(rq) ? "suspend" : "resume");
207 spin_lock_irqsave(&ide_lock, flags);
208 if (blk_pm_suspend_request(rq)) {
209 blk_stop_queue(drive->queue);
212 blk_start_queue(drive->queue);
214 blkdev_dequeue_request(rq);
215 HWGROUP(drive)->rq = NULL;
216 end_that_request_last(rq);
217 spin_unlock_irqrestore(&ide_lock, flags);
221 * FIXME: probably move this somewhere else, name is bad too :)
223 u64 ide_get_error_location(ide_drive_t *drive, char *args)
234 if (ide_id_has_flush_cache_ext(drive->id)) {
235 low = (hcyl << 16) | (lcyl << 8) | sect;
236 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
237 high = ide_read_24(drive);
239 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
241 low = (hcyl << 16) | (lcyl << 8) | sect;
243 low = hcyl * drive->head * drive->sect;
244 low += lcyl * drive->sect;
249 sector = ((u64) high << 24) | low;
252 EXPORT_SYMBOL(ide_get_error_location);
254 static void ide_complete_barrier(ide_drive_t *drive, struct request *rq,
257 struct request *real_rq = rq->special;
258 int good_sectors, bad_sectors;
262 if (blk_barrier_postflush(rq)) {
264 * this completes the barrier write
266 __ide_end_request(drive, real_rq, 1, real_rq->hard_nr_sectors);
267 drive->doing_barrier = 0;
270 * just indicate that we did the pre flush
272 real_rq->flags |= REQ_BAR_PREFLUSH;
273 elv_requeue_request(drive->queue, real_rq);
276 * all is fine, return
282 * we need to end real_rq, but it's not on the queue currently.
283 * put it back on the queue, so we don't have to special case
284 * anything else for completing it
286 if (!blk_barrier_postflush(rq))
287 elv_requeue_request(drive->queue, real_rq);
290 * drive aborted flush command, assume FLUSH_CACHE_* doesn't
291 * work and disable barrier support
293 if (error & ABRT_ERR) {
294 printk(KERN_ERR "%s: barrier support doesn't work\n", drive->name);
295 __ide_end_request(drive, real_rq, -EOPNOTSUPP, real_rq->hard_nr_sectors);
296 blk_queue_ordered(drive->queue, 0);
297 blk_queue_issue_flush_fn(drive->queue, NULL);
300 * find out what part of the request failed
303 if (blk_barrier_postflush(rq)) {
304 sector = ide_get_error_location(drive, rq->buffer);
306 if ((sector >= real_rq->hard_sector) &&
307 (sector < real_rq->hard_sector + real_rq->hard_nr_sectors))
308 good_sectors = sector - real_rq->hard_sector;
310 sector = real_rq->hard_sector;
312 bad_sectors = real_rq->hard_nr_sectors - good_sectors;
314 __ide_end_request(drive, real_rq, 1, good_sectors);
316 __ide_end_request(drive, real_rq, 0, bad_sectors);
318 printk(KERN_ERR "%s: failed barrier write: "
319 "sector=%Lx(good=%d/bad=%d)\n",
320 drive->name, (unsigned long long)sector,
321 good_sectors, bad_sectors);
324 drive->doing_barrier = 0;
328 * ide_end_drive_cmd - end an explicit drive command
333 * Clean up after success/failure of an explicit drive command.
334 * These get thrown onto the queue so they are synchronized with
335 * real I/O operations on the drive.
337 * In LBA48 mode we have to read the register set twice to get
338 * all the extra information out.
341 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
343 ide_hwif_t *hwif = HWIF(drive);
347 spin_lock_irqsave(&ide_lock, flags);
348 rq = HWGROUP(drive)->rq;
349 spin_unlock_irqrestore(&ide_lock, flags);
351 if (rq->flags & REQ_DRIVE_CMD) {
352 u8 *args = (u8 *) rq->buffer;
354 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
359 args[2] = hwif->INB(IDE_NSECTOR_REG);
361 } else if (rq->flags & REQ_DRIVE_TASK) {
362 u8 *args = (u8 *) rq->buffer;
364 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
369 args[2] = hwif->INB(IDE_NSECTOR_REG);
370 args[3] = hwif->INB(IDE_SECTOR_REG);
371 args[4] = hwif->INB(IDE_LCYL_REG);
372 args[5] = hwif->INB(IDE_HCYL_REG);
373 args[6] = hwif->INB(IDE_SELECT_REG);
375 } else if (rq->flags & REQ_DRIVE_TASKFILE) {
376 ide_task_t *args = (ide_task_t *) rq->special;
378 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
381 if (args->tf_in_flags.b.data) {
382 u16 data = hwif->INW(IDE_DATA_REG);
383 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
384 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
386 args->tfRegister[IDE_ERROR_OFFSET] = err;
387 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
388 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
389 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
390 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
391 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
392 args->tfRegister[IDE_STATUS_OFFSET] = stat;
394 if (drive->addressing == 1) {
395 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
396 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
397 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
398 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
399 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
400 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
403 } else if (blk_pm_request(rq)) {
405 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
406 drive->name, rq->pm->pm_step, stat, err);
408 DRIVER(drive)->complete_power_step(drive, rq, stat, err);
409 if (rq->pm->pm_step == ide_pm_state_completed)
410 ide_complete_pm_request(drive, rq);
414 spin_lock_irqsave(&ide_lock, flags);
415 blkdev_dequeue_request(rq);
417 if (blk_barrier_preflush(rq) || blk_barrier_postflush(rq))
418 ide_complete_barrier(drive, rq, err);
420 HWGROUP(drive)->rq = NULL;
421 end_that_request_last(rq);
422 spin_unlock_irqrestore(&ide_lock, flags);
425 EXPORT_SYMBOL(ide_end_drive_cmd);
428 * try_to_flush_leftover_data - flush junk
429 * @drive: drive to flush
431 * try_to_flush_leftover_data() is invoked in response to a drive
432 * unexpectedly having its DRQ_STAT bit set. As an alternative to
433 * resetting the drive, this routine tries to clear the condition
434 * by read a sector's worth of data from the drive. Of course,
435 * this may not help if the drive is *waiting* for data from *us*.
437 void try_to_flush_leftover_data (ide_drive_t *drive)
439 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
441 if (drive->media != ide_disk)
445 u32 wcount = (i > 16) ? 16 : i;
448 HWIF(drive)->ata_input_data(drive, buffer, wcount);
452 EXPORT_SYMBOL(try_to_flush_leftover_data);
455 * FIXME Add an ATAPI error
459 * ide_error - handle an error on the IDE
460 * @drive: drive the error occurred on
461 * @msg: message to report
464 * ide_error() takes action based on the error returned by the drive.
465 * For normal I/O that may well include retries. We deal with
466 * both new-style (taskfile) and old style command handling here.
467 * In the case of taskfile command handling there is work left to
471 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
477 err = ide_dump_status(drive, msg, stat);
478 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
482 /* retry only "normal" I/O: */
483 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
485 ide_end_drive_cmd(drive, stat, err);
488 if (rq->flags & REQ_DRIVE_TASKFILE) {
490 ide_end_drive_cmd(drive, stat, err);
494 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
495 /* other bits are useless when BUSY */
496 rq->errors |= ERROR_RESET;
498 if (drive->media != ide_disk)
501 if (stat & ERR_STAT) {
502 /* err has different meaning on cdrom and tape */
503 if (err == ABRT_ERR) {
504 if (drive->select.b.lba &&
505 (hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY))
506 /* some newer drives don't
507 * support WIN_SPECIFY
510 } else if ((err & BAD_CRC) == BAD_CRC) {
512 /* UDMA crc error -- just retry the operation */
513 } else if (err & (BBD_ERR | ECC_ERR)) {
514 /* retries won't help these */
515 rq->errors = ERROR_MAX;
516 } else if (err & TRK0_ERR) {
517 /* help it find track zero */
518 rq->errors |= ERROR_RECAL;
522 if ((stat & DRQ_STAT) && rq_data_dir(rq) != WRITE)
523 try_to_flush_leftover_data(drive);
525 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT)) {
527 hwif->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);
529 if (rq->errors >= ERROR_MAX) {
530 DRIVER(drive)->end_request(drive, 0, 0);
532 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
534 return ide_do_reset(drive);
536 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
537 drive->special.b.recalibrate = 1;
543 EXPORT_SYMBOL(ide_error);
546 * ide_abort - abort pending IDE operatins
547 * @drive: drive the error occurred on
548 * @msg: message to report
550 * ide_abort kills and cleans up when we are about to do a
551 * host initiated reset on active commands. Longer term we
552 * want handlers to have sensible abort handling themselves
554 * This differs fundamentally from ide_error because in
555 * this case the command is doing just fine when we
559 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
564 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
568 /* retry only "normal" I/O: */
569 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
571 ide_end_drive_cmd(drive, BUSY_STAT, 0);
574 if (rq->flags & REQ_DRIVE_TASKFILE) {
576 ide_end_drive_cmd(drive, BUSY_STAT, 0);
580 rq->errors |= ERROR_RESET;
581 DRIVER(drive)->end_request(drive, 0, 0);
585 EXPORT_SYMBOL(ide_abort);
588 * ide_cmd - issue a simple drive command
589 * @drive: drive the command is for
591 * @nsect: sector byte
592 * @handler: handler for the command completion
594 * Issue a simple drive command with interrupts.
595 * The drive must be selected beforehand.
598 void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, ide_handler_t *handler)
600 ide_hwif_t *hwif = HWIF(drive);
602 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
603 SELECT_MASK(drive,0);
604 hwif->OUTB(nsect,IDE_NSECTOR_REG);
605 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
608 EXPORT_SYMBOL(ide_cmd);
611 * drive_cmd_intr - drive command completion interrupt
612 * @drive: drive the completion interrupt occurred on
614 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
615 * We do any necessary daya reading and then wait for the drive to
616 * go non busy. At that point we may read the error data and complete
620 ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
622 struct request *rq = HWGROUP(drive)->rq;
623 ide_hwif_t *hwif = HWIF(drive);
624 u8 *args = (u8 *) rq->buffer;
625 u8 stat = hwif->INB(IDE_STATUS_REG);
629 if ((stat & DRQ_STAT) && args && args[3]) {
630 u8 io_32bit = drive->io_32bit;
632 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
633 drive->io_32bit = io_32bit;
634 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
638 if (!OK_STAT(stat, READY_STAT, BAD_STAT) && DRIVER(drive) != NULL)
639 return DRIVER(drive)->error(drive, "drive_cmd", stat);
640 /* calls ide_end_drive_cmd */
641 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
645 EXPORT_SYMBOL(drive_cmd_intr);
648 * do_special - issue some special commands
649 * @drive: drive the command is for
651 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
652 * commands to a drive. It used to do much more, but has been scaled
656 ide_startstop_t do_special (ide_drive_t *drive)
658 special_t *s = &drive->special;
661 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
665 if (HWIF(drive)->tuneproc != NULL)
666 HWIF(drive)->tuneproc(drive, drive->tune_req);
670 return DRIVER(drive)->special(drive);
673 EXPORT_SYMBOL(do_special);
676 * execute_drive_command - issue special drive command
677 * @drive: the drive to issue th command on
678 * @rq: the request structure holding the command
680 * execute_drive_cmd() issues a special drive command, usually
681 * initiated by ioctl() from the external hdparm program. The
682 * command can be a drive command, drive task or taskfile
683 * operation. Weirdly you can call it with NULL to wait for
684 * all commands to finish. Don't do this as that is due to change
687 ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq)
689 ide_hwif_t *hwif = HWIF(drive);
690 if (rq->flags & REQ_DRIVE_TASKFILE) {
691 ide_task_t *args = rq->special;
696 if (args->tf_out_flags.all != 0)
697 return flagged_taskfile(drive, args);
698 return do_rw_taskfile(drive, args);
699 } else if (rq->flags & REQ_DRIVE_TASK) {
700 u8 *args = rq->buffer;
706 printk("%s: DRIVE_TASK_CMD ", drive->name);
707 printk("cmd=0x%02x ", args[0]);
708 printk("fr=0x%02x ", args[1]);
709 printk("ns=0x%02x ", args[2]);
710 printk("sc=0x%02x ", args[3]);
711 printk("lcyl=0x%02x ", args[4]);
712 printk("hcyl=0x%02x ", args[5]);
713 printk("sel=0x%02x\n", args[6]);
715 hwif->OUTB(args[1], IDE_FEATURE_REG);
716 hwif->OUTB(args[3], IDE_SECTOR_REG);
717 hwif->OUTB(args[4], IDE_LCYL_REG);
718 hwif->OUTB(args[5], IDE_HCYL_REG);
719 sel = (args[6] & ~0x10);
720 if (drive->select.b.unit)
722 hwif->OUTB(sel, IDE_SELECT_REG);
723 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
725 } else if (rq->flags & REQ_DRIVE_CMD) {
726 u8 *args = rq->buffer;
731 printk("%s: DRIVE_CMD ", drive->name);
732 printk("cmd=0x%02x ", args[0]);
733 printk("sc=0x%02x ", args[1]);
734 printk("fr=0x%02x ", args[2]);
735 printk("xx=0x%02x\n", args[3]);
737 if (args[0] == WIN_SMART) {
738 hwif->OUTB(0x4f, IDE_LCYL_REG);
739 hwif->OUTB(0xc2, IDE_HCYL_REG);
740 hwif->OUTB(args[2],IDE_FEATURE_REG);
741 hwif->OUTB(args[1],IDE_SECTOR_REG);
742 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
745 hwif->OUTB(args[2],IDE_FEATURE_REG);
746 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
752 * NULL is actually a valid way of waiting for
753 * all current requests to be flushed from the queue.
756 printk("%s: DRIVE_CMD (null)\n", drive->name);
758 ide_end_drive_cmd(drive,
759 hwif->INB(IDE_STATUS_REG),
760 hwif->INB(IDE_ERROR_REG));
764 EXPORT_SYMBOL(execute_drive_cmd);
767 * start_request - start of I/O and command issuing for IDE
769 * start_request() initiates handling of a new I/O request. It
770 * accepts commands and I/O (read/write) requests. It also does
771 * the final remapping for weird stuff like EZDrive. Once
772 * device mapper can work sector level the EZDrive stuff can go away
774 * FIXME: this function needs a rename
777 ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
779 ide_startstop_t startstop;
782 BUG_ON(!(rq->flags & REQ_STARTED));
785 printk("%s: start_request: current=0x%08lx\n",
786 HWIF(drive)->name, (unsigned long) rq);
789 /* bail early if we've exceeded max_failures */
790 if (drive->max_failures && (drive->failures > drive->max_failures)) {
795 * bail early if we've sent a device to sleep, however how to wake
796 * this needs to be a masked flag. FIXME for proper operations.
798 if (drive->suspend_reset)
802 if (blk_fs_request(rq) &&
803 (drive->media == ide_disk || drive->media == ide_floppy)) {
804 block += drive->sect0;
806 /* Yecch - this will shift the entire interval,
807 possibly killing some innocent following sector */
808 if (block == 0 && drive->remap_0_to_1 == 1)
809 block = 1; /* redirect MBR access to EZ-Drive partn table */
811 if (blk_pm_suspend_request(rq) &&
812 rq->pm->pm_step == ide_pm_state_start_suspend)
813 /* Mark drive blocked when starting the suspend sequence. */
815 else if (blk_pm_resume_request(rq) &&
816 rq->pm->pm_step == ide_pm_state_start_resume) {
818 * The first thing we do on wakeup is to wait for BSY bit to
819 * go away (with a looong timeout) as a drive on this hwif may
820 * just be POSTing itself.
821 * We do that before even selecting as the "other" device on
822 * the bus may be broken enough to walk on our toes at this
827 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
829 rc = ide_wait_not_busy(HWIF(drive), 35000);
831 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
833 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
834 rc = ide_wait_not_busy(HWIF(drive), 10000);
836 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
840 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
841 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
844 if (!drive->special.all) {
845 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK))
846 return execute_drive_cmd(drive, rq);
847 else if (rq->flags & REQ_DRIVE_TASKFILE)
848 return execute_drive_cmd(drive, rq);
849 else if (blk_pm_request(rq)) {
851 printk("%s: start_power_step(step: %d)\n",
852 drive->name, rq->pm->pm_step);
854 startstop = DRIVER(drive)->start_power_step(drive, rq);
855 if (startstop == ide_stopped &&
856 rq->pm->pm_step == ide_pm_state_completed)
857 ide_complete_pm_request(drive, rq);
860 return (DRIVER(drive)->do_request(drive, rq, block));
862 return do_special(drive);
864 DRIVER(drive)->end_request(drive, 0, 0);
868 EXPORT_SYMBOL(start_request);
871 * ide_stall_queue - pause an IDE device
872 * @drive: drive to stall
873 * @timeout: time to stall for (jiffies)
875 * ide_stall_queue() can be used by a drive to give excess bandwidth back
876 * to the hwgroup by sleeping for timeout jiffies.
879 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
881 if (timeout > WAIT_WORSTCASE)
882 timeout = WAIT_WORSTCASE;
883 drive->sleep = timeout + jiffies;
886 void ide_unpin_hwgroup(ide_drive_t *drive)
888 ide_hwgroup_t *hwgroup = HWGROUP(drive);
891 spin_lock_irq(&ide_lock);
892 HWGROUP(drive)->busy = 0;
894 do_ide_request(drive->queue);
895 spin_unlock_irq(&ide_lock);
899 void ide_pin_hwgroup(ide_drive_t *drive)
901 ide_hwgroup_t *hwgroup = HWGROUP(drive);
904 * should only happen very early, so not a problem
909 spin_lock_irq(&ide_lock);
911 if (!hwgroup->busy && !drive->blocked && !drive->doing_barrier)
913 spin_unlock_irq(&ide_lock);
914 schedule_timeout(HZ/100);
915 spin_lock_irq(&ide_lock);
916 } while (hwgroup->busy || drive->blocked || drive->doing_barrier);
919 * we've now secured exclusive access to this hwgroup
923 spin_unlock_irq(&ide_lock);
926 EXPORT_SYMBOL(ide_stall_queue);
928 #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
931 * choose_drive - select a drive to service
932 * @hwgroup: hardware group to select on
934 * choose_drive() selects the next drive which will be serviced.
935 * This is necessary because the IDE layer can't issue commands
936 * to both drives on the same cable, unlike SCSI.
939 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
941 ide_drive_t *drive, *best;
945 drive = hwgroup->drive;
948 * drive is doing pre-flush, ordered write, post-flush sequence. even
949 * though that is 3 requests, it must be seen as a single transaction.
950 * we must not preempt this drive until that is complete
952 if (drive->doing_barrier) {
954 * small race where queue could get replugged during
955 * the 3-request flush cycle, just yank the plug since
956 * we want it to finish asap
958 blk_remove_plug(drive->queue);
963 if ((!drive->sleep || time_after_eq(jiffies, drive->sleep))
964 && !elv_queue_empty(drive->queue)) {
966 || (drive->sleep && (!best->sleep || 0 < (signed long)(best->sleep - drive->sleep)))
967 || (!best->sleep && 0 < (signed long)(WAKEUP(best) - WAKEUP(drive))))
969 if (!blk_queue_plugged(drive->queue))
973 } while ((drive = drive->next) != hwgroup->drive);
974 if (best && best->nice1 && !best->sleep && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
975 long t = (signed long)(WAKEUP(best) - jiffies);
976 if (t >= WAIT_MIN_SLEEP) {
978 * We *may* have some time to spare, but first let's see if
979 * someone can potentially benefit from our nice mood today..
984 /* FIXME: use time_before */
985 && 0 < (signed long)(WAKEUP(drive) - (jiffies - best->service_time))
986 && 0 < (signed long)((jiffies + t) - WAKEUP(drive)))
988 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
991 } while ((drive = drive->next) != best);
998 * Issue a new request to a drive from hwgroup
999 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1001 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1002 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1003 * may have both interfaces in a single hwgroup to "serialize" access.
1004 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1005 * together into one hwgroup for serialized access.
1007 * Note also that several hwgroups can end up sharing a single IRQ,
1008 * possibly along with many other devices. This is especially common in
1009 * PCI-based systems with off-board IDE controller cards.
1011 * The IDE driver uses the single global ide_lock spinlock to protect
1012 * access to the request queues, and to protect the hwgroup->busy flag.
1014 * The first thread into the driver for a particular hwgroup sets the
1015 * hwgroup->busy flag to indicate that this hwgroup is now active,
1016 * and then initiates processing of the top request from the request queue.
1018 * Other threads attempting entry notice the busy setting, and will simply
1019 * queue their new requests and exit immediately. Note that hwgroup->busy
1020 * remains set even when the driver is merely awaiting the next interrupt.
1021 * Thus, the meaning is "this hwgroup is busy processing a request".
1023 * When processing of a request completes, the completing thread or IRQ-handler
1024 * will start the next request from the queue. If no more work remains,
1025 * the driver will clear the hwgroup->busy flag and exit.
1027 * The ide_lock (spinlock) is used to protect all access to the
1028 * hwgroup->busy flag, but is otherwise not needed for most processing in
1029 * the driver. This makes the driver much more friendlier to shared IRQs
1030 * than previous designs, while remaining 100% (?) SMP safe and capable.
1032 /* --BenH: made non-static as ide-pmac.c uses it to kick the hwgroup back
1033 * into life on wakeup from machine sleep.
1035 void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1040 ide_startstop_t startstop;
1042 /* for atari only: POSSIBLY BROKEN HERE(?) */
1043 ide_get_lock(ide_intr, hwgroup);
1045 /* caller must own ide_lock */
1046 BUG_ON(!irqs_disabled());
1048 while (!hwgroup->busy) {
1050 drive = choose_drive(hwgroup);
1051 if (drive == NULL) {
1052 unsigned long sleep = 0;
1054 drive = hwgroup->drive;
1056 if (drive->sleep && (!sleep || 0 < (signed long)(sleep - drive->sleep)))
1057 sleep = drive->sleep;
1058 } while ((drive = drive->next) != hwgroup->drive);
1061 * Take a short snooze, and then wake up this hwgroup again.
1062 * This gives other hwgroups on the same a chance to
1063 * play fairly with us, just in case there are big differences
1064 * in relative throughputs.. don't want to hog the cpu too much.
1066 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1067 sleep = jiffies + WAIT_MIN_SLEEP;
1069 if (timer_pending(&hwgroup->timer))
1070 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1072 /* so that ide_timer_expiry knows what to do */
1073 hwgroup->sleeping = 1;
1074 mod_timer(&hwgroup->timer, sleep);
1075 /* we purposely leave hwgroup->busy==1
1078 /* Ugly, but how can we sleep for the lock
1079 * otherwise? perhaps from tq_disk?
1082 /* for atari only */
1087 /* no more work for this hwgroup (for now) */
1091 if (hwgroup->hwif->sharing_irq &&
1092 hwif != hwgroup->hwif &&
1093 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1094 /* set nIEN for previous hwif */
1095 SELECT_INTERRUPT(drive);
1097 hwgroup->hwif = hwif;
1098 hwgroup->drive = drive;
1100 drive->service_start = jiffies;
1102 if (blk_queue_plugged(drive->queue)) {
1103 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1108 * we know that the queue isn't empty, but this can happen
1109 * if the q->prep_rq_fn() decides to kill a request
1111 rq = elv_next_request(drive->queue);
1118 * if rq is a barrier write, issue pre cache flush if not
1121 if (blk_barrier_rq(rq) && !blk_barrier_preflush(rq))
1122 rq = ide_queue_flush_cmd(drive, rq, 0);
1125 * Sanity: don't accept a request that isn't a PM request
1126 * if we are currently power managed. This is very important as
1127 * blk_stop_queue() doesn't prevent the elv_next_request()
1128 * above to return us whatever is in the queue. Since we call
1129 * ide_do_request() ourselves, we end up taking requests while
1130 * the queue is blocked...
1132 * We let requests forced at head of queue with ide-preempt
1133 * though. I hope that doesn't happen too much, hopefully not
1134 * unless the subdriver triggers such a thing in its own PM
1137 if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
1138 /* We clear busy, there should be no pending ATA command at this point. */
1146 * Some systems have trouble with IDE IRQs arriving while
1147 * the driver is still setting things up. So, here we disable
1148 * the IRQ used by this interface while the request is being started.
1149 * This may look bad at first, but pretty much the same thing
1150 * happens anyway when any interrupt comes in, IDE or otherwise
1151 * -- the kernel masks the IRQ while it is being handled.
1153 if (hwif->irq != masked_irq)
1154 disable_irq_nosync(hwif->irq);
1155 spin_unlock(&ide_lock);
1157 /* allow other IRQs while we start this request */
1158 startstop = start_request(drive, rq);
1159 spin_lock_irq(&ide_lock);
1160 if (hwif->irq != masked_irq)
1161 enable_irq(hwif->irq);
1162 if (startstop == ide_stopped)
1167 EXPORT_SYMBOL(ide_do_request);
1170 * Passes the stuff to ide_do_request
1172 void do_ide_request(request_queue_t *q)
1174 ide_drive_t *drive = q->queuedata;
1176 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1180 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1181 * retry the current request in pio mode instead of risking tossing it
1184 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1186 ide_hwif_t *hwif = HWIF(drive);
1188 ide_startstop_t ret = ide_stopped;
1191 * end current dma transaction
1195 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1196 (void)HWIF(drive)->ide_dma_end(drive);
1197 ret = DRIVER(drive)->error(drive, "dma timeout error",
1198 hwif->INB(IDE_STATUS_REG));
1200 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1201 (void) hwif->ide_dma_timeout(drive);
1205 * disable dma for now, but remember that we did so because of
1206 * a timeout -- we'll reenable after we finish this next request
1207 * (or rather the first chunk of it) in pio.
1210 drive->state = DMA_PIO_RETRY;
1211 (void) hwif->ide_dma_off_quietly(drive);
1214 * un-busy drive etc (hwgroup->busy is cleared on return) and
1215 * make sure request is sane
1217 rq = HWGROUP(drive)->rq;
1218 HWGROUP(drive)->rq = NULL;
1221 rq->sector = rq->bio->bi_sector;
1222 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1223 rq->hard_cur_sectors = rq->current_nr_sectors;
1231 * ide_timer_expiry - handle lack of an IDE interrupt
1232 * @data: timer callback magic (hwgroup)
1234 * An IDE command has timed out before the expected drive return
1235 * occurred. At this point we attempt to clean up the current
1236 * mess. If the current handler includes an expiry handler then
1237 * we invoke the expiry handler, and providing it is happy the
1238 * work is done. If that fails we apply generic recovery rules
1239 * invoking the handler and checking the drive DMA status. We
1240 * have an excessively incestuous relationship with the DMA
1241 * logic that wants cleaning up.
1244 void ide_timer_expiry (unsigned long data)
1246 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1247 ide_handler_t *handler;
1248 ide_expiry_t *expiry;
1249 unsigned long flags;
1250 unsigned long wait = -1;
1252 spin_lock_irqsave(&ide_lock, flags);
1254 if ((handler = hwgroup->handler) == NULL) {
1256 * Either a marginal timeout occurred
1257 * (got the interrupt just as timer expired),
1258 * or we were "sleeping" to give other devices a chance.
1259 * Either way, we don't really want to complain about anything.
1261 if (hwgroup->sleeping) {
1262 hwgroup->sleeping = 0;
1266 ide_drive_t *drive = hwgroup->drive;
1268 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1269 hwgroup->handler = NULL;
1272 ide_startstop_t startstop = ide_stopped;
1273 if (!hwgroup->busy) {
1274 hwgroup->busy = 1; /* paranoia */
1275 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1277 if ((expiry = hwgroup->expiry) != NULL) {
1279 if ((wait = expiry(drive)) > 0) {
1281 hwgroup->timer.expires = jiffies + wait;
1282 add_timer(&hwgroup->timer);
1283 spin_unlock_irqrestore(&ide_lock, flags);
1287 hwgroup->handler = NULL;
1289 * We need to simulate a real interrupt when invoking
1290 * the handler() function, which means we need to
1291 * globally mask the specific IRQ:
1293 spin_unlock(&ide_lock);
1295 #if DISABLE_IRQ_NOSYNC
1296 disable_irq_nosync(hwif->irq);
1298 /* disable_irq_nosync ?? */
1299 disable_irq(hwif->irq);
1300 #endif /* DISABLE_IRQ_NOSYNC */
1302 * as if we were handling an interrupt */
1303 local_irq_disable();
1304 if (hwgroup->poll_timeout != 0) {
1305 startstop = handler(drive);
1306 } else if (drive_is_ready(drive)) {
1307 if (drive->waiting_for_dma)
1308 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1309 (void)ide_ack_intr(hwif);
1310 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1311 startstop = handler(drive);
1313 if (drive->waiting_for_dma) {
1314 startstop = ide_dma_timeout_retry(drive, wait);
1317 DRIVER(drive)->error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1319 drive->service_time = jiffies - drive->service_start;
1320 spin_lock_irq(&ide_lock);
1321 enable_irq(hwif->irq);
1322 if (startstop == ide_stopped)
1326 ide_do_request(hwgroup, IDE_NO_IRQ);
1327 spin_unlock_irqrestore(&ide_lock, flags);
1330 EXPORT_SYMBOL(ide_timer_expiry);
1333 * unexpected_intr - handle an unexpected IDE interrupt
1334 * @irq: interrupt line
1335 * @hwgroup: hwgroup being processed
1337 * There's nothing really useful we can do with an unexpected interrupt,
1338 * other than reading the status register (to clear it), and logging it.
1339 * There should be no way that an irq can happen before we're ready for it,
1340 * so we needn't worry much about losing an "important" interrupt here.
1342 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1343 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1344 * looks "good", we just ignore the interrupt completely.
1346 * This routine assumes __cli() is in effect when called.
1348 * If an unexpected interrupt happens on irq15 while we are handling irq14
1349 * and if the two interfaces are "serialized" (CMD640), then it looks like
1350 * we could screw up by interfering with a new request being set up for
1353 * In reality, this is a non-issue. The new command is not sent unless
1354 * the drive is ready to accept one, in which case we know the drive is
1355 * not trying to interrupt us. And ide_set_handler() is always invoked
1356 * before completing the issuance of any new drive command, so we will not
1357 * be accidentally invoked as a result of any valid command completion
1360 * Note that we must walk the entire hwgroup here. We know which hwif
1361 * is doing the current command, but we don't know which hwif burped
1365 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1368 ide_hwif_t *hwif = hwgroup->hwif;
1371 * handle the unexpected interrupt
1374 if (hwif->irq == irq) {
1375 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1376 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1377 /* Try to not flood the console with msgs */
1378 static unsigned long last_msgtime, count;
1380 if (time_after(jiffies, last_msgtime + HZ)) {
1381 last_msgtime = jiffies;
1382 printk(KERN_ERR "%s%s: unexpected interrupt, "
1383 "status=0x%02x, count=%ld\n",
1385 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1389 } while ((hwif = hwif->next) != hwgroup->hwif);
1393 * ide_intr - default IDE interrupt handler
1394 * @irq: interrupt number
1395 * @dev_id: hwif group
1396 * @regs: unused weirdness from the kernel irq layer
1398 * This is the default IRQ handler for the IDE layer. You should
1399 * not need to override it. If you do be aware it is subtle in
1402 * hwgroup->hwif is the interface in the group currently performing
1403 * a command. hwgroup->drive is the drive and hwgroup->handler is
1404 * the IRQ handler to call. As we issue a command the handlers
1405 * step through multiple states, reassigning the handler to the
1406 * next step in the process. Unlike a smart SCSI controller IDE
1407 * expects the main processor to sequence the various transfer
1408 * stages. We also manage a poll timer to catch up with most
1409 * timeout situations. There are still a few where the handlers
1410 * don't ever decide to give up.
1412 * The handler eventually returns ide_stopped to indicate the
1413 * request completed. At this point we issue the next request
1414 * on the hwgroup and the process begins again.
1417 irqreturn_t ide_intr (int irq, void *dev_id, struct pt_regs *regs)
1419 unsigned long flags;
1420 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1423 ide_handler_t *handler;
1424 ide_startstop_t startstop;
1426 spin_lock_irqsave(&ide_lock, flags);
1427 hwif = hwgroup->hwif;
1429 if (!ide_ack_intr(hwif)) {
1430 spin_unlock_irqrestore(&ide_lock, flags);
1434 if ((handler = hwgroup->handler) == NULL ||
1435 hwgroup->poll_timeout != 0) {
1437 * Not expecting an interrupt from this drive.
1438 * That means this could be:
1439 * (1) an interrupt from another PCI device
1440 * sharing the same PCI INT# as us.
1441 * or (2) a drive just entered sleep or standby mode,
1442 * and is interrupting to let us know.
1443 * or (3) a spurious interrupt of unknown origin.
1445 * For PCI, we cannot tell the difference,
1446 * so in that case we just ignore it and hope it goes away.
1448 * FIXME: unexpected_intr should be hwif-> then we can
1449 * remove all the ifdef PCI crap
1451 #ifdef CONFIG_BLK_DEV_IDEPCI
1452 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1453 #endif /* CONFIG_BLK_DEV_IDEPCI */
1456 * Probably not a shared PCI interrupt,
1457 * so we can safely try to do something about it:
1459 unexpected_intr(irq, hwgroup);
1460 #ifdef CONFIG_BLK_DEV_IDEPCI
1463 * Whack the status register, just in case
1464 * we have a leftover pending IRQ.
1466 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1467 #endif /* CONFIG_BLK_DEV_IDEPCI */
1469 spin_unlock_irqrestore(&ide_lock, flags);
1472 drive = hwgroup->drive;
1475 * This should NEVER happen, and there isn't much
1476 * we could do about it here.
1478 * [Note - this can occur if the drive is hot unplugged]
1480 spin_unlock_irqrestore(&ide_lock, flags);
1483 if (!drive_is_ready(drive)) {
1485 * This happens regularly when we share a PCI IRQ with
1486 * another device. Unfortunately, it can also happen
1487 * with some buggy drives that trigger the IRQ before
1488 * their status register is up to date. Hopefully we have
1489 * enough advance overhead that the latter isn't a problem.
1491 spin_unlock_irqrestore(&ide_lock, flags);
1494 if (!hwgroup->busy) {
1495 hwgroup->busy = 1; /* paranoia */
1496 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1498 hwgroup->handler = NULL;
1499 del_timer(&hwgroup->timer);
1500 spin_unlock(&ide_lock);
1504 /* service this interrupt, may set handler for next interrupt */
1505 startstop = handler(drive);
1506 spin_lock_irq(&ide_lock);
1509 * Note that handler() may have set things up for another
1510 * interrupt to occur soon, but it cannot happen until
1511 * we exit from this routine, because it will be the
1512 * same irq as is currently being serviced here, and Linux
1513 * won't allow another of the same (on any CPU) until we return.
1515 drive->service_time = jiffies - drive->service_start;
1516 if (startstop == ide_stopped) {
1517 if (hwgroup->handler == NULL) { /* paranoia */
1519 ide_do_request(hwgroup, hwif->irq);
1521 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1522 "on exit\n", drive->name);
1525 spin_unlock_irqrestore(&ide_lock, flags);
1529 EXPORT_SYMBOL(ide_intr);
1532 * ide_init_drive_cmd - initialize a drive command request
1533 * @rq: request object
1535 * Initialize a request before we fill it in and send it down to
1536 * ide_do_drive_cmd. Commands must be set up by this function. Right
1537 * now it doesn't do a lot, but if that changes abusers will have a
1541 void ide_init_drive_cmd (struct request *rq)
1543 memset(rq, 0, sizeof(*rq));
1544 rq->flags = REQ_DRIVE_CMD;
1548 EXPORT_SYMBOL(ide_init_drive_cmd);
1551 * ide_do_drive_cmd - issue IDE special command
1552 * @drive: device to issue command
1553 * @rq: request to issue
1554 * @action: action for processing
1556 * This function issues a special IDE device request
1557 * onto the request queue.
1559 * If action is ide_wait, then the rq is queued at the end of the
1560 * request queue, and the function sleeps until it has been processed.
1561 * This is for use when invoked from an ioctl handler.
1563 * If action is ide_preempt, then the rq is queued at the head of
1564 * the request queue, displacing the currently-being-processed
1565 * request and this function returns immediately without waiting
1566 * for the new rq to be completed. This is VERY DANGEROUS, and is
1567 * intended for careful use by the ATAPI tape/cdrom driver code.
1569 * If action is ide_next, then the rq is queued immediately after
1570 * the currently-being-processed-request (if any), and the function
1571 * returns without waiting for the new rq to be completed. As above,
1572 * This is VERY DANGEROUS, and is intended for careful use by the
1573 * ATAPI tape/cdrom driver code.
1575 * If action is ide_end, then the rq is queued at the end of the
1576 * request queue, and the function returns immediately without waiting
1577 * for the new rq to be completed. This is again intended for careful
1578 * use by the ATAPI tape/cdrom driver code.
1581 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1583 unsigned long flags;
1584 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1585 DECLARE_COMPLETION(wait);
1586 int where = ELEVATOR_INSERT_BACK, err;
1587 int must_wait = (action == ide_wait || action == ide_head_wait);
1589 #ifdef CONFIG_BLK_DEV_PDC4030
1591 * FIXME: there should be a drive or hwif->special
1592 * handler that points here by default, not hacks
1593 * in the ide-io.c code
1595 * FIXME2: That code breaks power management if used with
1596 * this chipset, that really doesn't belong here !
1598 if (HWIF(drive)->chipset == ide_pdc4030 && rq->buffer != NULL)
1599 return -ENOSYS; /* special drive cmds not supported */
1602 rq->rq_status = RQ_ACTIVE;
1604 rq->rq_disk = drive->disk;
1607 * we need to hold an extra reference to request for safe inspection
1612 rq->waiting = &wait;
1615 spin_lock_irqsave(&ide_lock, flags);
1616 if (action == ide_preempt)
1618 if (action == ide_preempt || action == ide_head_wait) {
1619 where = ELEVATOR_INSERT_FRONT;
1620 rq->flags |= REQ_PREEMPT;
1622 __elv_add_request(drive->queue, rq, where, 0);
1623 ide_do_request(hwgroup, IDE_NO_IRQ);
1624 spin_unlock_irqrestore(&ide_lock, flags);
1628 wait_for_completion(&wait);
1633 blk_put_request(rq);
1639 EXPORT_SYMBOL(ide_do_drive_cmd);