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>
50 #include <linux/scatterlist.h>
52 #include <asm/byteorder.h>
54 #include <asm/uaccess.h>
56 #include <asm/bitops.h>
58 static void ide_fill_flush_cmd(ide_drive_t *drive, struct request *rq)
63 * reuse cdb space for ata command
65 memset(buf, 0, sizeof(rq->cmd));
67 rq->flags |= REQ_DRIVE_TASK | REQ_STARTED;
69 rq->buffer[0] = WIN_FLUSH_CACHE;
71 if (ide_id_has_flush_cache_ext(drive->id) &&
72 (drive->capacity64 >= (1UL << 28)))
73 rq->buffer[0] = WIN_FLUSH_CACHE_EXT;
77 * preempt pending requests, and store this cache flush for immediate
80 static struct request *ide_queue_flush_cmd(ide_drive_t *drive,
81 struct request *rq, int post)
83 struct request *flush_rq = &HWGROUP(drive)->wrq;
86 * write cache disabled, clear the barrier bit and treat it like
90 rq->flags |= REQ_BAR_PREFLUSH;
94 ide_init_drive_cmd(flush_rq);
95 ide_fill_flush_cmd(drive, flush_rq);
97 flush_rq->special = rq;
98 flush_rq->nr_sectors = rq->nr_sectors;
101 drive->doing_barrier = 1;
102 flush_rq->flags |= REQ_BAR_PREFLUSH;
103 blkdev_dequeue_request(rq);
105 flush_rq->flags |= REQ_BAR_POSTFLUSH;
107 __elv_add_request(drive->queue, flush_rq, ELEVATOR_INSERT_FRONT, 0);
108 HWGROUP(drive)->rq = NULL;
112 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
113 int uptodate, int nr_sectors)
117 BUG_ON(!(rq->flags & REQ_STARTED));
120 * if failfast is set on a request, override number of sectors and
121 * complete the whole request right now
123 if (blk_noretry_request(rq) && end_io_error(uptodate))
124 nr_sectors = rq->hard_nr_sectors;
126 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
130 * decide whether to reenable DMA -- 3 is a random magic for now,
131 * if we DMA timeout more than 3 times, just stay in PIO
133 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
135 HWGROUP(drive)->hwif->ide_dma_on(drive);
138 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
139 add_disk_randomness(rq->rq_disk);
141 if (blk_rq_tagged(rq))
142 blk_queue_end_tag(drive->queue, rq);
144 blkdev_dequeue_request(rq);
145 HWGROUP(drive)->rq = NULL;
146 end_that_request_last(rq);
153 * ide_end_request - complete an IDE I/O
154 * @drive: IDE device for the I/O
156 * @nr_sectors: number of sectors completed
158 * This is our end_request wrapper function. We complete the I/O
159 * update random number input and dequeue the request, which if
160 * it was tagged may be out of order.
163 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
169 spin_lock_irqsave(&ide_lock, flags);
170 rq = HWGROUP(drive)->rq;
173 nr_sectors = rq->hard_cur_sectors;
175 if (!blk_barrier_rq(rq) || !drive->wcache)
176 ret = __ide_end_request(drive, rq, uptodate, nr_sectors);
178 struct request *flush_rq = &HWGROUP(drive)->wrq;
180 flush_rq->nr_sectors -= nr_sectors;
181 if (!flush_rq->nr_sectors) {
182 ide_queue_flush_cmd(drive, rq, 1);
187 spin_unlock_irqrestore(&ide_lock, flags);
190 EXPORT_SYMBOL(ide_end_request);
193 * ide_complete_pm_request - end the current Power Management request
194 * @drive: target drive
197 * This function cleans up the current PM request and stops the queue
200 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
205 printk("%s: completing PM request, %s\n", drive->name,
206 blk_pm_suspend_request(rq) ? "suspend" : "resume");
208 spin_lock_irqsave(&ide_lock, flags);
209 if (blk_pm_suspend_request(rq)) {
210 blk_stop_queue(drive->queue);
213 blk_start_queue(drive->queue);
215 blkdev_dequeue_request(rq);
216 HWGROUP(drive)->rq = NULL;
217 end_that_request_last(rq);
218 spin_unlock_irqrestore(&ide_lock, flags);
222 * FIXME: probably move this somewhere else, name is bad too :)
224 u64 ide_get_error_location(ide_drive_t *drive, char *args)
235 if (ide_id_has_flush_cache_ext(drive->id)) {
236 low = (hcyl << 16) | (lcyl << 8) | sect;
237 HWIF(drive)->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
238 high = ide_read_24(drive);
240 u8 cur = HWIF(drive)->INB(IDE_SELECT_REG);
243 low = (hcyl << 16) | (lcyl << 8) | sect;
245 low = hcyl * drive->head * drive->sect;
246 low += lcyl * drive->sect;
251 sector = ((u64) high << 24) | low;
254 EXPORT_SYMBOL(ide_get_error_location);
256 static void ide_complete_barrier(ide_drive_t *drive, struct request *rq,
259 struct request *real_rq = rq->special;
260 int good_sectors, bad_sectors;
264 if (blk_barrier_postflush(rq)) {
266 * this completes the barrier write
268 __ide_end_request(drive, real_rq, 1, real_rq->hard_nr_sectors);
269 drive->doing_barrier = 0;
272 * just indicate that we did the pre flush
274 real_rq->flags |= REQ_BAR_PREFLUSH;
275 elv_requeue_request(drive->queue, real_rq);
278 * all is fine, return
284 * we need to end real_rq, but it's not on the queue currently.
285 * put it back on the queue, so we don't have to special case
286 * anything else for completing it
288 if (!blk_barrier_postflush(rq))
289 elv_requeue_request(drive->queue, real_rq);
292 * drive aborted flush command, assume FLUSH_CACHE_* doesn't
293 * work and disable barrier support
295 if (error & ABRT_ERR) {
296 printk(KERN_ERR "%s: barrier support doesn't work\n", drive->name);
297 __ide_end_request(drive, real_rq, -EOPNOTSUPP, real_rq->hard_nr_sectors);
298 blk_queue_ordered(drive->queue, 0);
299 blk_queue_issue_flush_fn(drive->queue, NULL);
302 * find out what part of the request failed
305 if (blk_barrier_postflush(rq)) {
306 sector = ide_get_error_location(drive, rq->buffer);
308 if ((sector >= real_rq->hard_sector) &&
309 (sector < real_rq->hard_sector + real_rq->hard_nr_sectors))
310 good_sectors = sector - real_rq->hard_sector;
312 sector = real_rq->hard_sector;
314 bad_sectors = real_rq->hard_nr_sectors - good_sectors;
316 __ide_end_request(drive, real_rq, 1, good_sectors);
318 __ide_end_request(drive, real_rq, 0, bad_sectors);
320 printk(KERN_ERR "%s: failed barrier write: "
321 "sector=%Lx(good=%d/bad=%d)\n",
322 drive->name, (unsigned long long)sector,
323 good_sectors, bad_sectors);
326 drive->doing_barrier = 0;
330 * ide_end_drive_cmd - end an explicit drive command
335 * Clean up after success/failure of an explicit drive command.
336 * These get thrown onto the queue so they are synchronized with
337 * real I/O operations on the drive.
339 * In LBA48 mode we have to read the register set twice to get
340 * all the extra information out.
343 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
345 ide_hwif_t *hwif = HWIF(drive);
349 spin_lock_irqsave(&ide_lock, flags);
350 rq = HWGROUP(drive)->rq;
351 spin_unlock_irqrestore(&ide_lock, flags);
353 if (rq->flags & REQ_DRIVE_CMD) {
354 u8 *args = (u8 *) rq->buffer;
356 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
361 args[2] = hwif->INB(IDE_NSECTOR_REG);
363 } else if (rq->flags & REQ_DRIVE_TASK) {
364 u8 *args = (u8 *) rq->buffer;
366 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
371 args[2] = hwif->INB(IDE_NSECTOR_REG);
372 args[3] = hwif->INB(IDE_SECTOR_REG);
373 args[4] = hwif->INB(IDE_LCYL_REG);
374 args[5] = hwif->INB(IDE_HCYL_REG);
375 args[6] = hwif->INB(IDE_SELECT_REG);
377 } else if (rq->flags & REQ_DRIVE_TASKFILE) {
378 ide_task_t *args = (ide_task_t *) rq->special;
380 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
383 if (args->tf_in_flags.b.data) {
384 u16 data = hwif->INW(IDE_DATA_REG);
385 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
386 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
388 args->tfRegister[IDE_ERROR_OFFSET] = err;
389 /* be sure we're looking at the low order bits */
390 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
391 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
392 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
393 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
394 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
395 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
396 args->tfRegister[IDE_STATUS_OFFSET] = stat;
398 if (drive->addressing == 1) {
399 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
400 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
401 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
402 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
403 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
404 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
407 } else if (blk_pm_request(rq)) {
409 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
410 drive->name, rq->pm->pm_step, stat, err);
412 DRIVER(drive)->complete_power_step(drive, rq, stat, err);
413 if (rq->pm->pm_step == ide_pm_state_completed)
414 ide_complete_pm_request(drive, rq);
418 spin_lock_irqsave(&ide_lock, flags);
419 blkdev_dequeue_request(rq);
421 if (blk_barrier_preflush(rq) || blk_barrier_postflush(rq))
422 ide_complete_barrier(drive, rq, err);
424 HWGROUP(drive)->rq = NULL;
425 end_that_request_last(rq);
426 spin_unlock_irqrestore(&ide_lock, flags);
429 EXPORT_SYMBOL(ide_end_drive_cmd);
432 * try_to_flush_leftover_data - flush junk
433 * @drive: drive to flush
435 * try_to_flush_leftover_data() is invoked in response to a drive
436 * unexpectedly having its DRQ_STAT bit set. As an alternative to
437 * resetting the drive, this routine tries to clear the condition
438 * by read a sector's worth of data from the drive. Of course,
439 * this may not help if the drive is *waiting* for data from *us*.
441 static void try_to_flush_leftover_data (ide_drive_t *drive)
443 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
445 if (drive->media != ide_disk)
449 u32 wcount = (i > 16) ? 16 : i;
452 HWIF(drive)->ata_input_data(drive, buffer, wcount);
456 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
458 ide_hwif_t *hwif = drive->hwif;
460 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
461 /* other bits are useless when BUSY */
462 rq->errors |= ERROR_RESET;
463 } else if (stat & ERR_STAT) {
464 /* err has different meaning on cdrom and tape */
465 if (err == ABRT_ERR) {
466 if (drive->select.b.lba &&
467 /* some newer drives don't support WIN_SPECIFY */
468 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
470 } else if ((err & BAD_CRC) == BAD_CRC) {
471 /* UDMA crc error, just retry the operation */
473 } else if (err & (BBD_ERR | ECC_ERR)) {
474 /* retries won't help these */
475 rq->errors = ERROR_MAX;
476 } else if (err & TRK0_ERR) {
477 /* help it find track zero */
478 rq->errors |= ERROR_RECAL;
482 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ)
483 try_to_flush_leftover_data(drive);
485 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
487 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
489 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq))
490 drive->driver->end_request(drive, 0, 0);
492 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
494 return ide_do_reset(drive);
496 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
497 drive->special.b.recalibrate = 1;
503 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
505 ide_hwif_t *hwif = drive->hwif;
507 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
508 /* other bits are useless when BUSY */
509 rq->errors |= ERROR_RESET;
511 /* add decoding error stuff */
514 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
516 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
518 if (rq->errors >= ERROR_MAX) {
519 drive->driver->end_request(drive, 0, 0);
521 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
523 return ide_do_reset(drive);
532 __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
534 if (drive->media == ide_disk)
535 return ide_ata_error(drive, rq, stat, err);
536 return ide_atapi_error(drive, rq, stat, err);
540 * ide_error - handle an error on the IDE
541 * @drive: drive the error occurred on
542 * @msg: message to report
545 * ide_error() takes action based on the error returned by the drive.
546 * For normal I/O that may well include retries. We deal with
547 * both new-style (taskfile) and old style command handling here.
548 * In the case of taskfile command handling there is work left to
552 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
557 err = ide_dump_status(drive, msg, stat);
559 if ((rq = HWGROUP(drive)->rq) == NULL)
562 /* retry only "normal" I/O: */
563 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
565 ide_end_drive_cmd(drive, stat, err);
569 return drive->driver->error(drive, rq, stat, err);
572 EXPORT_SYMBOL_GPL(ide_error);
574 ide_startstop_t __ide_abort(ide_drive_t *drive, struct request *rq)
576 if (drive->media != ide_disk)
577 rq->errors |= ERROR_RESET;
579 DRIVER(drive)->end_request(drive, 0, 0);
584 * ide_abort - abort pending IDE operatins
585 * @drive: drive the error occurred on
586 * @msg: message to report
588 * ide_abort kills and cleans up when we are about to do a
589 * host initiated reset on active commands. Longer term we
590 * want handlers to have sensible abort handling themselves
592 * This differs fundamentally from ide_error because in
593 * this case the command is doing just fine when we
597 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
601 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
604 /* retry only "normal" I/O: */
605 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK | REQ_DRIVE_TASKFILE)) {
607 ide_end_drive_cmd(drive, BUSY_STAT, 0);
611 return drive->driver->abort(drive, rq);
615 * ide_cmd - issue a simple drive command
616 * @drive: drive the command is for
618 * @nsect: sector byte
619 * @handler: handler for the command completion
621 * Issue a simple drive command with interrupts.
622 * The drive must be selected beforehand.
625 static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
626 ide_handler_t *handler)
628 ide_hwif_t *hwif = HWIF(drive);
630 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
631 SELECT_MASK(drive,0);
632 hwif->OUTB(nsect,IDE_NSECTOR_REG);
633 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
637 * drive_cmd_intr - drive command completion interrupt
638 * @drive: drive the completion interrupt occurred on
640 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
641 * We do any necessary daya reading and then wait for the drive to
642 * go non busy. At that point we may read the error data and complete
646 static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
648 struct request *rq = HWGROUP(drive)->rq;
649 ide_hwif_t *hwif = HWIF(drive);
650 u8 *args = (u8 *) rq->buffer;
651 u8 stat = hwif->INB(IDE_STATUS_REG);
655 if ((stat & DRQ_STAT) && args && args[3]) {
656 u8 io_32bit = drive->io_32bit;
658 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
659 drive->io_32bit = io_32bit;
660 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
664 if (!OK_STAT(stat, READY_STAT, BAD_STAT) && DRIVER(drive) != NULL)
665 return ide_error(drive, "drive_cmd", stat);
666 /* calls ide_end_drive_cmd */
667 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
672 * do_special - issue some special commands
673 * @drive: drive the command is for
675 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
676 * commands to a drive. It used to do much more, but has been scaled
680 static ide_startstop_t do_special (ide_drive_t *drive)
682 special_t *s = &drive->special;
685 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
689 if (HWIF(drive)->tuneproc != NULL)
690 HWIF(drive)->tuneproc(drive, drive->tune_req);
694 return DRIVER(drive)->special(drive);
697 void ide_map_sg(ide_drive_t *drive, struct request *rq)
699 ide_hwif_t *hwif = drive->hwif;
700 struct scatterlist *sg = hwif->sg_table;
702 if (hwif->sg_mapped) /* needed by ide-scsi */
705 if ((rq->flags & REQ_DRIVE_TASKFILE) == 0) {
706 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
708 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
713 EXPORT_SYMBOL_GPL(ide_map_sg);
715 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
717 ide_hwif_t *hwif = drive->hwif;
719 hwif->nsect = hwif->nleft = rq->nr_sectors;
720 hwif->cursg = hwif->cursg_ofs = 0;
723 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
726 * execute_drive_command - issue special drive command
727 * @drive: the drive to issue th command on
728 * @rq: the request structure holding the command
730 * execute_drive_cmd() issues a special drive command, usually
731 * initiated by ioctl() from the external hdparm program. The
732 * command can be a drive command, drive task or taskfile
733 * operation. Weirdly you can call it with NULL to wait for
734 * all commands to finish. Don't do this as that is due to change
737 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
740 ide_hwif_t *hwif = HWIF(drive);
741 if (rq->flags & REQ_DRIVE_TASKFILE) {
742 ide_task_t *args = rq->special;
747 hwif->data_phase = args->data_phase;
749 switch (hwif->data_phase) {
750 case TASKFILE_MULTI_OUT:
752 case TASKFILE_MULTI_IN:
754 ide_init_sg_cmd(drive, rq);
755 ide_map_sg(drive, rq);
760 if (args->tf_out_flags.all != 0)
761 return flagged_taskfile(drive, args);
762 return do_rw_taskfile(drive, args);
763 } else if (rq->flags & REQ_DRIVE_TASK) {
764 u8 *args = rq->buffer;
770 printk("%s: DRIVE_TASK_CMD ", drive->name);
771 printk("cmd=0x%02x ", args[0]);
772 printk("fr=0x%02x ", args[1]);
773 printk("ns=0x%02x ", args[2]);
774 printk("sc=0x%02x ", args[3]);
775 printk("lcyl=0x%02x ", args[4]);
776 printk("hcyl=0x%02x ", args[5]);
777 printk("sel=0x%02x\n", args[6]);
779 hwif->OUTB(args[1], IDE_FEATURE_REG);
780 hwif->OUTB(args[3], IDE_SECTOR_REG);
781 hwif->OUTB(args[4], IDE_LCYL_REG);
782 hwif->OUTB(args[5], IDE_HCYL_REG);
783 sel = (args[6] & ~0x10);
784 if (drive->select.b.unit)
786 hwif->OUTB(sel, IDE_SELECT_REG);
787 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
789 } else if (rq->flags & REQ_DRIVE_CMD) {
790 u8 *args = rq->buffer;
795 printk("%s: DRIVE_CMD ", drive->name);
796 printk("cmd=0x%02x ", args[0]);
797 printk("sc=0x%02x ", args[1]);
798 printk("fr=0x%02x ", args[2]);
799 printk("xx=0x%02x\n", args[3]);
801 if (args[0] == WIN_SMART) {
802 hwif->OUTB(0x4f, IDE_LCYL_REG);
803 hwif->OUTB(0xc2, IDE_HCYL_REG);
804 hwif->OUTB(args[2],IDE_FEATURE_REG);
805 hwif->OUTB(args[1],IDE_SECTOR_REG);
806 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
809 hwif->OUTB(args[2],IDE_FEATURE_REG);
810 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
816 * NULL is actually a valid way of waiting for
817 * all current requests to be flushed from the queue.
820 printk("%s: DRIVE_CMD (null)\n", drive->name);
822 ide_end_drive_cmd(drive,
823 hwif->INB(IDE_STATUS_REG),
824 hwif->INB(IDE_ERROR_REG));
829 * start_request - start of I/O and command issuing for IDE
831 * start_request() initiates handling of a new I/O request. It
832 * accepts commands and I/O (read/write) requests. It also does
833 * the final remapping for weird stuff like EZDrive. Once
834 * device mapper can work sector level the EZDrive stuff can go away
836 * FIXME: this function needs a rename
839 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
841 ide_startstop_t startstop;
844 BUG_ON(!(rq->flags & REQ_STARTED));
847 printk("%s: start_request: current=0x%08lx\n",
848 HWIF(drive)->name, (unsigned long) rq);
851 /* bail early if we've exceeded max_failures */
852 if (drive->max_failures && (drive->failures > drive->max_failures)) {
857 if (blk_fs_request(rq) &&
858 (drive->media == ide_disk || drive->media == ide_floppy)) {
859 block += drive->sect0;
861 /* Yecch - this will shift the entire interval,
862 possibly killing some innocent following sector */
863 if (block == 0 && drive->remap_0_to_1 == 1)
864 block = 1; /* redirect MBR access to EZ-Drive partn table */
866 if (blk_pm_suspend_request(rq) &&
867 rq->pm->pm_step == ide_pm_state_start_suspend)
868 /* Mark drive blocked when starting the suspend sequence. */
870 else if (blk_pm_resume_request(rq) &&
871 rq->pm->pm_step == ide_pm_state_start_resume) {
873 * The first thing we do on wakeup is to wait for BSY bit to
874 * go away (with a looong timeout) as a drive on this hwif may
875 * just be POSTing itself.
876 * We do that before even selecting as the "other" device on
877 * the bus may be broken enough to walk on our toes at this
882 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
884 rc = ide_wait_not_busy(HWIF(drive), 35000);
886 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
888 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
889 rc = ide_wait_not_busy(HWIF(drive), 10000);
891 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
895 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
896 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
899 if (!drive->special.all) {
900 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK))
901 return execute_drive_cmd(drive, rq);
902 else if (rq->flags & REQ_DRIVE_TASKFILE)
903 return execute_drive_cmd(drive, rq);
904 else if (blk_pm_request(rq)) {
906 printk("%s: start_power_step(step: %d)\n",
907 drive->name, rq->pm->pm_step);
909 startstop = DRIVER(drive)->start_power_step(drive, rq);
910 if (startstop == ide_stopped &&
911 rq->pm->pm_step == ide_pm_state_completed)
912 ide_complete_pm_request(drive, rq);
915 return (DRIVER(drive)->do_request(drive, rq, block));
917 return do_special(drive);
919 DRIVER(drive)->end_request(drive, 0, 0);
924 * ide_stall_queue - pause an IDE device
925 * @drive: drive to stall
926 * @timeout: time to stall for (jiffies)
928 * ide_stall_queue() can be used by a drive to give excess bandwidth back
929 * to the hwgroup by sleeping for timeout jiffies.
932 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
934 if (timeout > WAIT_WORSTCASE)
935 timeout = WAIT_WORSTCASE;
936 drive->sleep = timeout + jiffies;
940 EXPORT_SYMBOL(ide_stall_queue);
942 #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
945 * choose_drive - select a drive to service
946 * @hwgroup: hardware group to select on
948 * choose_drive() selects the next drive which will be serviced.
949 * This is necessary because the IDE layer can't issue commands
950 * to both drives on the same cable, unlike SCSI.
953 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
955 ide_drive_t *drive, *best;
959 drive = hwgroup->drive;
962 * drive is doing pre-flush, ordered write, post-flush sequence. even
963 * though that is 3 requests, it must be seen as a single transaction.
964 * we must not preempt this drive until that is complete
966 if (drive->doing_barrier) {
968 * small race where queue could get replugged during
969 * the 3-request flush cycle, just yank the plug since
970 * we want it to finish asap
972 blk_remove_plug(drive->queue);
977 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
978 && !elv_queue_empty(drive->queue)) {
980 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
981 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
983 if (!blk_queue_plugged(drive->queue))
987 } while ((drive = drive->next) != hwgroup->drive);
988 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
989 long t = (signed long)(WAKEUP(best) - jiffies);
990 if (t >= WAIT_MIN_SLEEP) {
992 * We *may* have some time to spare, but first let's see if
993 * someone can potentially benefit from our nice mood today..
998 && time_before(jiffies - best->service_time, WAKEUP(drive))
999 && time_before(WAKEUP(drive), jiffies + t))
1001 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1004 } while ((drive = drive->next) != best);
1011 * Issue a new request to a drive from hwgroup
1012 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1014 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1015 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1016 * may have both interfaces in a single hwgroup to "serialize" access.
1017 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1018 * together into one hwgroup for serialized access.
1020 * Note also that several hwgroups can end up sharing a single IRQ,
1021 * possibly along with many other devices. This is especially common in
1022 * PCI-based systems with off-board IDE controller cards.
1024 * The IDE driver uses the single global ide_lock spinlock to protect
1025 * access to the request queues, and to protect the hwgroup->busy flag.
1027 * The first thread into the driver for a particular hwgroup sets the
1028 * hwgroup->busy flag to indicate that this hwgroup is now active,
1029 * and then initiates processing of the top request from the request queue.
1031 * Other threads attempting entry notice the busy setting, and will simply
1032 * queue their new requests and exit immediately. Note that hwgroup->busy
1033 * remains set even when the driver is merely awaiting the next interrupt.
1034 * Thus, the meaning is "this hwgroup is busy processing a request".
1036 * When processing of a request completes, the completing thread or IRQ-handler
1037 * will start the next request from the queue. If no more work remains,
1038 * the driver will clear the hwgroup->busy flag and exit.
1040 * The ide_lock (spinlock) is used to protect all access to the
1041 * hwgroup->busy flag, but is otherwise not needed for most processing in
1042 * the driver. This makes the driver much more friendlier to shared IRQs
1043 * than previous designs, while remaining 100% (?) SMP safe and capable.
1045 static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1050 ide_startstop_t startstop;
1052 /* for atari only: POSSIBLY BROKEN HERE(?) */
1053 ide_get_lock(ide_intr, hwgroup);
1055 /* caller must own ide_lock */
1056 BUG_ON(!irqs_disabled());
1058 while (!hwgroup->busy) {
1060 drive = choose_drive(hwgroup);
1061 if (drive == NULL) {
1063 unsigned long sleep = 0; /* shut up, gcc */
1065 drive = hwgroup->drive;
1067 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1069 sleep = drive->sleep;
1071 } while ((drive = drive->next) != hwgroup->drive);
1074 * Take a short snooze, and then wake up this hwgroup again.
1075 * This gives other hwgroups on the same a chance to
1076 * play fairly with us, just in case there are big differences
1077 * in relative throughputs.. don't want to hog the cpu too much.
1079 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1080 sleep = jiffies + WAIT_MIN_SLEEP;
1082 if (timer_pending(&hwgroup->timer))
1083 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1085 /* so that ide_timer_expiry knows what to do */
1086 hwgroup->sleeping = 1;
1087 mod_timer(&hwgroup->timer, sleep);
1088 /* we purposely leave hwgroup->busy==1
1091 /* Ugly, but how can we sleep for the lock
1092 * otherwise? perhaps from tq_disk?
1095 /* for atari only */
1100 /* no more work for this hwgroup (for now) */
1104 if (hwgroup->hwif->sharing_irq &&
1105 hwif != hwgroup->hwif &&
1106 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1107 /* set nIEN for previous hwif */
1108 SELECT_INTERRUPT(drive);
1110 hwgroup->hwif = hwif;
1111 hwgroup->drive = drive;
1112 drive->sleeping = 0;
1113 drive->service_start = jiffies;
1115 if (blk_queue_plugged(drive->queue)) {
1116 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1121 * we know that the queue isn't empty, but this can happen
1122 * if the q->prep_rq_fn() decides to kill a request
1124 rq = elv_next_request(drive->queue);
1131 * if rq is a barrier write, issue pre cache flush if not
1134 if (blk_barrier_rq(rq) && !blk_barrier_preflush(rq))
1135 rq = ide_queue_flush_cmd(drive, rq, 0);
1138 * Sanity: don't accept a request that isn't a PM request
1139 * if we are currently power managed. This is very important as
1140 * blk_stop_queue() doesn't prevent the elv_next_request()
1141 * above to return us whatever is in the queue. Since we call
1142 * ide_do_request() ourselves, we end up taking requests while
1143 * the queue is blocked...
1145 * We let requests forced at head of queue with ide-preempt
1146 * though. I hope that doesn't happen too much, hopefully not
1147 * unless the subdriver triggers such a thing in its own PM
1150 if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
1151 /* We clear busy, there should be no pending ATA command at this point. */
1159 * Some systems have trouble with IDE IRQs arriving while
1160 * the driver is still setting things up. So, here we disable
1161 * the IRQ used by this interface while the request is being started.
1162 * This may look bad at first, but pretty much the same thing
1163 * happens anyway when any interrupt comes in, IDE or otherwise
1164 * -- the kernel masks the IRQ while it is being handled.
1166 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1167 disable_irq_nosync(hwif->irq);
1168 spin_unlock(&ide_lock);
1170 /* allow other IRQs while we start this request */
1171 startstop = start_request(drive, rq);
1172 spin_lock_irq(&ide_lock);
1173 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1174 enable_irq(hwif->irq);
1175 if (startstop == ide_stopped)
1181 * Passes the stuff to ide_do_request
1183 void do_ide_request(request_queue_t *q)
1185 ide_drive_t *drive = q->queuedata;
1187 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1191 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1192 * retry the current request in pio mode instead of risking tossing it
1195 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1197 ide_hwif_t *hwif = HWIF(drive);
1199 ide_startstop_t ret = ide_stopped;
1202 * end current dma transaction
1206 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1207 (void)HWIF(drive)->ide_dma_end(drive);
1208 ret = ide_error(drive, "dma timeout error",
1209 hwif->INB(IDE_STATUS_REG));
1211 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1212 (void) hwif->ide_dma_timeout(drive);
1216 * disable dma for now, but remember that we did so because of
1217 * a timeout -- we'll reenable after we finish this next request
1218 * (or rather the first chunk of it) in pio.
1221 drive->state = DMA_PIO_RETRY;
1222 (void) hwif->ide_dma_off_quietly(drive);
1225 * un-busy drive etc (hwgroup->busy is cleared on return) and
1226 * make sure request is sane
1228 rq = HWGROUP(drive)->rq;
1229 HWGROUP(drive)->rq = NULL;
1236 rq->sector = rq->bio->bi_sector;
1237 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1238 rq->hard_cur_sectors = rq->current_nr_sectors;
1239 rq->buffer = bio_data(rq->bio);
1245 * ide_timer_expiry - handle lack of an IDE interrupt
1246 * @data: timer callback magic (hwgroup)
1248 * An IDE command has timed out before the expected drive return
1249 * occurred. At this point we attempt to clean up the current
1250 * mess. If the current handler includes an expiry handler then
1251 * we invoke the expiry handler, and providing it is happy the
1252 * work is done. If that fails we apply generic recovery rules
1253 * invoking the handler and checking the drive DMA status. We
1254 * have an excessively incestuous relationship with the DMA
1255 * logic that wants cleaning up.
1258 void ide_timer_expiry (unsigned long data)
1260 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1261 ide_handler_t *handler;
1262 ide_expiry_t *expiry;
1263 unsigned long flags;
1264 unsigned long wait = -1;
1266 spin_lock_irqsave(&ide_lock, flags);
1268 if ((handler = hwgroup->handler) == NULL) {
1270 * Either a marginal timeout occurred
1271 * (got the interrupt just as timer expired),
1272 * or we were "sleeping" to give other devices a chance.
1273 * Either way, we don't really want to complain about anything.
1275 if (hwgroup->sleeping) {
1276 hwgroup->sleeping = 0;
1280 ide_drive_t *drive = hwgroup->drive;
1282 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1283 hwgroup->handler = NULL;
1286 ide_startstop_t startstop = ide_stopped;
1287 if (!hwgroup->busy) {
1288 hwgroup->busy = 1; /* paranoia */
1289 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1291 if ((expiry = hwgroup->expiry) != NULL) {
1293 if ((wait = expiry(drive)) > 0) {
1295 hwgroup->timer.expires = jiffies + wait;
1296 add_timer(&hwgroup->timer);
1297 spin_unlock_irqrestore(&ide_lock, flags);
1301 hwgroup->handler = NULL;
1303 * We need to simulate a real interrupt when invoking
1304 * the handler() function, which means we need to
1305 * globally mask the specific IRQ:
1307 spin_unlock(&ide_lock);
1309 #if DISABLE_IRQ_NOSYNC
1310 disable_irq_nosync(hwif->irq);
1312 /* disable_irq_nosync ?? */
1313 disable_irq(hwif->irq);
1314 #endif /* DISABLE_IRQ_NOSYNC */
1316 * as if we were handling an interrupt */
1317 local_irq_disable();
1318 if (hwgroup->polling) {
1319 startstop = handler(drive);
1320 } else if (drive_is_ready(drive)) {
1321 if (drive->waiting_for_dma)
1322 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1323 (void)ide_ack_intr(hwif);
1324 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1325 startstop = handler(drive);
1327 if (drive->waiting_for_dma) {
1328 startstop = ide_dma_timeout_retry(drive, wait);
1331 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1333 drive->service_time = jiffies - drive->service_start;
1334 spin_lock_irq(&ide_lock);
1335 enable_irq(hwif->irq);
1336 if (startstop == ide_stopped)
1340 ide_do_request(hwgroup, IDE_NO_IRQ);
1341 spin_unlock_irqrestore(&ide_lock, flags);
1345 * unexpected_intr - handle an unexpected IDE interrupt
1346 * @irq: interrupt line
1347 * @hwgroup: hwgroup being processed
1349 * There's nothing really useful we can do with an unexpected interrupt,
1350 * other than reading the status register (to clear it), and logging it.
1351 * There should be no way that an irq can happen before we're ready for it,
1352 * so we needn't worry much about losing an "important" interrupt here.
1354 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1355 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1356 * looks "good", we just ignore the interrupt completely.
1358 * This routine assumes __cli() is in effect when called.
1360 * If an unexpected interrupt happens on irq15 while we are handling irq14
1361 * and if the two interfaces are "serialized" (CMD640), then it looks like
1362 * we could screw up by interfering with a new request being set up for
1365 * In reality, this is a non-issue. The new command is not sent unless
1366 * the drive is ready to accept one, in which case we know the drive is
1367 * not trying to interrupt us. And ide_set_handler() is always invoked
1368 * before completing the issuance of any new drive command, so we will not
1369 * be accidentally invoked as a result of any valid command completion
1372 * Note that we must walk the entire hwgroup here. We know which hwif
1373 * is doing the current command, but we don't know which hwif burped
1377 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1380 ide_hwif_t *hwif = hwgroup->hwif;
1383 * handle the unexpected interrupt
1386 if (hwif->irq == irq) {
1387 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1388 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1389 /* Try to not flood the console with msgs */
1390 static unsigned long last_msgtime, count;
1392 if (time_after(jiffies, last_msgtime + HZ)) {
1393 last_msgtime = jiffies;
1394 printk(KERN_ERR "%s%s: unexpected interrupt, "
1395 "status=0x%02x, count=%ld\n",
1397 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1401 } while ((hwif = hwif->next) != hwgroup->hwif);
1405 * ide_intr - default IDE interrupt handler
1406 * @irq: interrupt number
1407 * @dev_id: hwif group
1408 * @regs: unused weirdness from the kernel irq layer
1410 * This is the default IRQ handler for the IDE layer. You should
1411 * not need to override it. If you do be aware it is subtle in
1414 * hwgroup->hwif is the interface in the group currently performing
1415 * a command. hwgroup->drive is the drive and hwgroup->handler is
1416 * the IRQ handler to call. As we issue a command the handlers
1417 * step through multiple states, reassigning the handler to the
1418 * next step in the process. Unlike a smart SCSI controller IDE
1419 * expects the main processor to sequence the various transfer
1420 * stages. We also manage a poll timer to catch up with most
1421 * timeout situations. There are still a few where the handlers
1422 * don't ever decide to give up.
1424 * The handler eventually returns ide_stopped to indicate the
1425 * request completed. At this point we issue the next request
1426 * on the hwgroup and the process begins again.
1429 irqreturn_t ide_intr (int irq, void *dev_id, struct pt_regs *regs)
1431 unsigned long flags;
1432 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1435 ide_handler_t *handler;
1436 ide_startstop_t startstop;
1438 spin_lock_irqsave(&ide_lock, flags);
1439 hwif = hwgroup->hwif;
1441 if (!ide_ack_intr(hwif)) {
1442 spin_unlock_irqrestore(&ide_lock, flags);
1446 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1448 * Not expecting an interrupt from this drive.
1449 * That means this could be:
1450 * (1) an interrupt from another PCI device
1451 * sharing the same PCI INT# as us.
1452 * or (2) a drive just entered sleep or standby mode,
1453 * and is interrupting to let us know.
1454 * or (3) a spurious interrupt of unknown origin.
1456 * For PCI, we cannot tell the difference,
1457 * so in that case we just ignore it and hope it goes away.
1459 * FIXME: unexpected_intr should be hwif-> then we can
1460 * remove all the ifdef PCI crap
1462 #ifdef CONFIG_BLK_DEV_IDEPCI
1463 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1464 #endif /* CONFIG_BLK_DEV_IDEPCI */
1467 * Probably not a shared PCI interrupt,
1468 * so we can safely try to do something about it:
1470 unexpected_intr(irq, hwgroup);
1471 #ifdef CONFIG_BLK_DEV_IDEPCI
1474 * Whack the status register, just in case
1475 * we have a leftover pending IRQ.
1477 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1478 #endif /* CONFIG_BLK_DEV_IDEPCI */
1480 spin_unlock_irqrestore(&ide_lock, flags);
1483 drive = hwgroup->drive;
1486 * This should NEVER happen, and there isn't much
1487 * we could do about it here.
1489 * [Note - this can occur if the drive is hot unplugged]
1491 spin_unlock_irqrestore(&ide_lock, flags);
1494 if (!drive_is_ready(drive)) {
1496 * This happens regularly when we share a PCI IRQ with
1497 * another device. Unfortunately, it can also happen
1498 * with some buggy drives that trigger the IRQ before
1499 * their status register is up to date. Hopefully we have
1500 * enough advance overhead that the latter isn't a problem.
1502 spin_unlock_irqrestore(&ide_lock, flags);
1505 if (!hwgroup->busy) {
1506 hwgroup->busy = 1; /* paranoia */
1507 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1509 hwgroup->handler = NULL;
1510 del_timer(&hwgroup->timer);
1511 spin_unlock(&ide_lock);
1515 /* service this interrupt, may set handler for next interrupt */
1516 startstop = handler(drive);
1517 spin_lock_irq(&ide_lock);
1520 * Note that handler() may have set things up for another
1521 * interrupt to occur soon, but it cannot happen until
1522 * we exit from this routine, because it will be the
1523 * same irq as is currently being serviced here, and Linux
1524 * won't allow another of the same (on any CPU) until we return.
1526 drive->service_time = jiffies - drive->service_start;
1527 if (startstop == ide_stopped) {
1528 if (hwgroup->handler == NULL) { /* paranoia */
1530 ide_do_request(hwgroup, hwif->irq);
1532 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1533 "on exit\n", drive->name);
1536 spin_unlock_irqrestore(&ide_lock, flags);
1541 * ide_init_drive_cmd - initialize a drive command request
1542 * @rq: request object
1544 * Initialize a request before we fill it in and send it down to
1545 * ide_do_drive_cmd. Commands must be set up by this function. Right
1546 * now it doesn't do a lot, but if that changes abusers will have a
1550 void ide_init_drive_cmd (struct request *rq)
1552 memset(rq, 0, sizeof(*rq));
1553 rq->flags = REQ_DRIVE_CMD;
1557 EXPORT_SYMBOL(ide_init_drive_cmd);
1560 * ide_do_drive_cmd - issue IDE special command
1561 * @drive: device to issue command
1562 * @rq: request to issue
1563 * @action: action for processing
1565 * This function issues a special IDE device request
1566 * onto the request queue.
1568 * If action is ide_wait, then the rq is queued at the end of the
1569 * request queue, and the function sleeps until it has been processed.
1570 * This is for use when invoked from an ioctl handler.
1572 * If action is ide_preempt, then the rq is queued at the head of
1573 * the request queue, displacing the currently-being-processed
1574 * request and this function returns immediately without waiting
1575 * for the new rq to be completed. This is VERY DANGEROUS, and is
1576 * intended for careful use by the ATAPI tape/cdrom driver code.
1578 * If action is ide_next, then the rq is queued immediately after
1579 * the currently-being-processed-request (if any), and the function
1580 * returns without waiting for the new rq to be completed. As above,
1581 * This is VERY DANGEROUS, and is intended for careful use by the
1582 * ATAPI tape/cdrom driver code.
1584 * If action is ide_end, then the rq is queued at the end of the
1585 * request queue, and the function returns immediately without waiting
1586 * for the new rq to be completed. This is again intended for careful
1587 * use by the ATAPI tape/cdrom driver code.
1590 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1592 unsigned long flags;
1593 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1594 DECLARE_COMPLETION(wait);
1595 int where = ELEVATOR_INSERT_BACK, err;
1596 int must_wait = (action == ide_wait || action == ide_head_wait);
1599 rq->rq_status = RQ_ACTIVE;
1601 rq->rq_disk = drive->disk;
1604 * we need to hold an extra reference to request for safe inspection
1609 rq->waiting = &wait;
1612 spin_lock_irqsave(&ide_lock, flags);
1613 if (action == ide_preempt)
1615 if (action == ide_preempt || action == ide_head_wait) {
1616 where = ELEVATOR_INSERT_FRONT;
1617 rq->flags |= REQ_PREEMPT;
1619 __elv_add_request(drive->queue, rq, where, 0);
1620 ide_do_request(hwgroup, IDE_NO_IRQ);
1621 spin_unlock_irqrestore(&ide_lock, flags);
1625 wait_for_completion(&wait);
1630 blk_put_request(rq);
1636 EXPORT_SYMBOL(ide_do_drive_cmd);