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/module.h>
28 #include <linux/types.h>
29 #include <linux/string.h>
30 #include <linux/kernel.h>
31 #include <linux/timer.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 #include <linux/bitops.h>
52 #include <asm/byteorder.h>
54 #include <asm/uaccess.h>
57 static int __ide_end_request(ide_drive_t *drive, struct request *rq,
58 int uptodate, unsigned int nr_bytes, int dequeue)
63 * if failfast is set on a request, override number of sectors and
64 * complete the whole request right now
66 if (blk_noretry_request(rq) && end_io_error(uptodate))
67 nr_bytes = rq->hard_nr_sectors << 9;
69 if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
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
76 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
78 HWGROUP(drive)->hwif->ide_dma_on(drive);
81 if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
82 add_disk_randomness(rq->rq_disk);
84 if (!list_empty(&rq->queuelist))
85 blkdev_dequeue_request(rq);
86 HWGROUP(drive)->rq = NULL;
88 end_that_request_last(rq, uptodate);
96 * ide_end_request - complete an IDE I/O
97 * @drive: IDE device for the I/O
99 * @nr_sectors: number of sectors completed
101 * This is our end_request wrapper function. We complete the I/O
102 * update random number input and dequeue the request, which if
103 * it was tagged may be out of order.
106 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
108 unsigned int nr_bytes = nr_sectors << 9;
114 * room for locking improvements here, the calls below don't
115 * need the queue lock held at all
117 spin_lock_irqsave(&ide_lock, flags);
118 rq = HWGROUP(drive)->rq;
121 if (blk_pc_request(rq))
122 nr_bytes = rq->data_len;
124 nr_bytes = rq->hard_cur_sectors << 9;
127 ret = __ide_end_request(drive, rq, uptodate, nr_bytes, 1);
129 spin_unlock_irqrestore(&ide_lock, flags);
132 EXPORT_SYMBOL(ide_end_request);
135 * Power Management state machine. This one is rather trivial for now,
136 * we should probably add more, like switching back to PIO on suspend
137 * to help some BIOSes, re-do the door locking on resume, etc...
141 ide_pm_flush_cache = ide_pm_state_start_suspend,
144 idedisk_pm_restore_pio = ide_pm_state_start_resume,
149 static void ide_complete_power_step(ide_drive_t *drive, struct request *rq, u8 stat, u8 error)
151 struct request_pm_state *pm = rq->data;
153 if (drive->media != ide_disk)
156 switch (pm->pm_step) {
157 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) complete */
158 if (pm->pm_state == PM_EVENT_FREEZE)
159 pm->pm_step = ide_pm_state_completed;
161 pm->pm_step = idedisk_pm_standby;
163 case idedisk_pm_standby: /* Suspend step 2 (standby) complete */
164 pm->pm_step = ide_pm_state_completed;
166 case idedisk_pm_restore_pio: /* Resume step 1 complete */
167 pm->pm_step = idedisk_pm_idle;
169 case idedisk_pm_idle: /* Resume step 2 (idle) complete */
170 pm->pm_step = ide_pm_restore_dma;
175 static ide_startstop_t ide_start_power_step(ide_drive_t *drive, struct request *rq)
177 struct request_pm_state *pm = rq->data;
178 ide_task_t *args = rq->special;
180 memset(args, 0, sizeof(*args));
182 switch (pm->pm_step) {
183 case ide_pm_flush_cache: /* Suspend step 1 (flush cache) */
184 if (drive->media != ide_disk)
186 /* Not supported? Switch to next step now. */
187 if (!drive->wcache || !ide_id_has_flush_cache(drive->id)) {
188 ide_complete_power_step(drive, rq, 0, 0);
191 if (ide_id_has_flush_cache_ext(drive->id))
192 args->tf.command = WIN_FLUSH_CACHE_EXT;
194 args->tf.command = WIN_FLUSH_CACHE;
197 case idedisk_pm_standby: /* Suspend step 2 (standby) */
198 args->tf.command = WIN_STANDBYNOW1;
201 case idedisk_pm_restore_pio: /* Resume step 1 (restore PIO) */
202 ide_set_max_pio(drive);
204 * skip idedisk_pm_idle for ATAPI devices
206 if (drive->media != ide_disk)
207 pm->pm_step = ide_pm_restore_dma;
209 ide_complete_power_step(drive, rq, 0, 0);
212 case idedisk_pm_idle: /* Resume step 2 (idle) */
213 args->tf.command = WIN_IDLEIMMEDIATE;
216 case ide_pm_restore_dma: /* Resume step 3 (restore DMA) */
218 * Right now, all we do is call ide_set_dma(drive),
219 * we could be smarter and check for current xfer_speed
220 * in struct drive etc...
222 if (drive->hwif->ide_dma_on == NULL)
224 drive->hwif->dma_off_quietly(drive);
226 * TODO: respect ->using_dma setting
231 pm->pm_step = ide_pm_state_completed;
235 args->tf_flags = IDE_TFLAG_OUT_TF;
236 if (drive->addressing == 1)
237 args->tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_OUT_HOB);
238 args->command_type = IDE_DRIVE_TASK_NO_DATA;
239 args->handler = task_no_data_intr;
240 return do_rw_taskfile(drive, args);
244 * ide_end_dequeued_request - complete an IDE I/O
245 * @drive: IDE device for the I/O
247 * @nr_sectors: number of sectors completed
249 * Complete an I/O that is no longer on the request queue. This
250 * typically occurs when we pull the request and issue a REQUEST_SENSE.
251 * We must still finish the old request but we must not tamper with the
252 * queue in the meantime.
254 * NOTE: This path does not handle barrier, but barrier is not supported
258 int ide_end_dequeued_request(ide_drive_t *drive, struct request *rq,
259 int uptodate, int nr_sectors)
264 spin_lock_irqsave(&ide_lock, flags);
265 BUG_ON(!blk_rq_started(rq));
266 ret = __ide_end_request(drive, rq, uptodate, nr_sectors << 9, 0);
267 spin_unlock_irqrestore(&ide_lock, flags);
271 EXPORT_SYMBOL_GPL(ide_end_dequeued_request);
275 * ide_complete_pm_request - end the current Power Management request
276 * @drive: target drive
279 * This function cleans up the current PM request and stops the queue
282 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
287 printk("%s: completing PM request, %s\n", drive->name,
288 blk_pm_suspend_request(rq) ? "suspend" : "resume");
290 spin_lock_irqsave(&ide_lock, flags);
291 if (blk_pm_suspend_request(rq)) {
292 blk_stop_queue(drive->queue);
295 blk_start_queue(drive->queue);
297 blkdev_dequeue_request(rq);
298 HWGROUP(drive)->rq = NULL;
299 end_that_request_last(rq, 1);
300 spin_unlock_irqrestore(&ide_lock, flags);
304 * ide_end_drive_cmd - end an explicit drive command
309 * Clean up after success/failure of an explicit drive command.
310 * These get thrown onto the queue so they are synchronized with
311 * real I/O operations on the drive.
313 * In LBA48 mode we have to read the register set twice to get
314 * all the extra information out.
317 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
319 ide_hwif_t *hwif = HWIF(drive);
323 spin_lock_irqsave(&ide_lock, flags);
324 rq = HWGROUP(drive)->rq;
325 spin_unlock_irqrestore(&ide_lock, flags);
327 if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
328 u8 *args = (u8 *) rq->buffer;
330 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
335 args[2] = hwif->INB(IDE_NSECTOR_REG);
337 } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
338 u8 *args = (u8 *) rq->buffer;
340 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
345 /* be sure we're looking at the low order bits */
346 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
347 args[2] = hwif->INB(IDE_NSECTOR_REG);
348 args[3] = hwif->INB(IDE_SECTOR_REG);
349 args[4] = hwif->INB(IDE_LCYL_REG);
350 args[5] = hwif->INB(IDE_HCYL_REG);
351 args[6] = hwif->INB(IDE_SELECT_REG);
353 } else if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
354 ide_task_t *args = (ide_task_t *) rq->special;
356 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
359 struct ide_taskfile *tf = &args->tf;
361 if (args->tf_in_flags.b.data) {
362 u16 data = hwif->INW(IDE_DATA_REG);
364 tf->data = data & 0xff;
365 tf->hob_data = (data >> 8) & 0xff;
368 /* be sure we're looking at the low order bits */
369 hwif->OUTB(drive->ctl & ~0x80, IDE_CONTROL_REG);
370 tf->nsect = hwif->INB(IDE_NSECTOR_REG);
371 tf->lbal = hwif->INB(IDE_SECTOR_REG);
372 tf->lbam = hwif->INB(IDE_LCYL_REG);
373 tf->lbah = hwif->INB(IDE_HCYL_REG);
374 tf->device = hwif->INB(IDE_SELECT_REG);
377 if (drive->addressing == 1) {
378 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
379 tf->hob_feature = hwif->INB(IDE_FEATURE_REG);
380 tf->hob_nsect = hwif->INB(IDE_NSECTOR_REG);
381 tf->hob_lbal = hwif->INB(IDE_SECTOR_REG);
382 tf->hob_lbam = hwif->INB(IDE_LCYL_REG);
383 tf->hob_lbah = hwif->INB(IDE_HCYL_REG);
386 } else if (blk_pm_request(rq)) {
387 struct request_pm_state *pm = rq->data;
389 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
390 drive->name, rq->pm->pm_step, stat, err);
392 ide_complete_power_step(drive, rq, stat, err);
393 if (pm->pm_step == ide_pm_state_completed)
394 ide_complete_pm_request(drive, rq);
398 spin_lock_irqsave(&ide_lock, flags);
399 blkdev_dequeue_request(rq);
400 HWGROUP(drive)->rq = NULL;
402 end_that_request_last(rq, !rq->errors);
403 spin_unlock_irqrestore(&ide_lock, flags);
406 EXPORT_SYMBOL(ide_end_drive_cmd);
409 * try_to_flush_leftover_data - flush junk
410 * @drive: drive to flush
412 * try_to_flush_leftover_data() is invoked in response to a drive
413 * unexpectedly having its DRQ_STAT bit set. As an alternative to
414 * resetting the drive, this routine tries to clear the condition
415 * by read a sector's worth of data from the drive. Of course,
416 * this may not help if the drive is *waiting* for data from *us*.
418 static void try_to_flush_leftover_data (ide_drive_t *drive)
420 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
422 if (drive->media != ide_disk)
426 u32 wcount = (i > 16) ? 16 : i;
429 HWIF(drive)->ata_input_data(drive, buffer, wcount);
433 static void ide_kill_rq(ide_drive_t *drive, struct request *rq)
438 drv = *(ide_driver_t **)rq->rq_disk->private_data;
439 drv->end_request(drive, 0, 0);
441 ide_end_request(drive, 0, 0);
444 static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
446 ide_hwif_t *hwif = drive->hwif;
448 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
449 /* other bits are useless when BUSY */
450 rq->errors |= ERROR_RESET;
451 } else if (stat & ERR_STAT) {
452 /* err has different meaning on cdrom and tape */
453 if (err == ABRT_ERR) {
454 if (drive->select.b.lba &&
455 /* some newer drives don't support WIN_SPECIFY */
456 hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY)
458 } else if ((err & BAD_CRC) == BAD_CRC) {
459 /* UDMA crc error, just retry the operation */
461 } else if (err & (BBD_ERR | ECC_ERR)) {
462 /* retries won't help these */
463 rq->errors = ERROR_MAX;
464 } else if (err & TRK0_ERR) {
465 /* help it find track zero */
466 rq->errors |= ERROR_RECAL;
470 if ((stat & DRQ_STAT) && rq_data_dir(rq) == READ &&
471 (hwif->host_flags & IDE_HFLAG_ERROR_STOPS_FIFO) == 0)
472 try_to_flush_leftover_data(drive);
474 if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
475 ide_kill_rq(drive, rq);
479 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
480 rq->errors |= ERROR_RESET;
482 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
484 return ide_do_reset(drive);
487 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
488 drive->special.b.recalibrate = 1;
495 static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
497 ide_hwif_t *hwif = drive->hwif;
499 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
500 /* other bits are useless when BUSY */
501 rq->errors |= ERROR_RESET;
503 /* add decoding error stuff */
506 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT))
508 hwif->OUTB(WIN_IDLEIMMEDIATE, IDE_COMMAND_REG);
510 if (rq->errors >= ERROR_MAX) {
511 ide_kill_rq(drive, rq);
513 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
515 return ide_do_reset(drive);
524 __ide_error(ide_drive_t *drive, struct request *rq, u8 stat, u8 err)
526 if (drive->media == ide_disk)
527 return ide_ata_error(drive, rq, stat, err);
528 return ide_atapi_error(drive, rq, stat, err);
531 EXPORT_SYMBOL_GPL(__ide_error);
534 * ide_error - handle an error on the IDE
535 * @drive: drive the error occurred on
536 * @msg: message to report
539 * ide_error() takes action based on the error returned by the drive.
540 * For normal I/O that may well include retries. We deal with
541 * both new-style (taskfile) and old style command handling here.
542 * In the case of taskfile command handling there is work left to
546 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
551 err = ide_dump_status(drive, msg, stat);
553 if ((rq = HWGROUP(drive)->rq) == NULL)
556 /* retry only "normal" I/O: */
557 if (!blk_fs_request(rq)) {
559 ide_end_drive_cmd(drive, stat, err);
566 drv = *(ide_driver_t **)rq->rq_disk->private_data;
567 return drv->error(drive, rq, stat, err);
569 return __ide_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 ide_kill_rq(drive, rq);
584 EXPORT_SYMBOL_GPL(__ide_abort);
587 * ide_abort - abort pending IDE operations
588 * @drive: drive the error occurred on
589 * @msg: message to report
591 * ide_abort kills and cleans up when we are about to do a
592 * host initiated reset on active commands. Longer term we
593 * want handlers to have sensible abort handling themselves
595 * This differs fundamentally from ide_error because in
596 * this case the command is doing just fine when we
600 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
604 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
607 /* retry only "normal" I/O: */
608 if (!blk_fs_request(rq)) {
610 ide_end_drive_cmd(drive, BUSY_STAT, 0);
617 drv = *(ide_driver_t **)rq->rq_disk->private_data;
618 return drv->abort(drive, rq);
620 return __ide_abort(drive, rq);
624 * ide_cmd - issue a simple drive command
625 * @drive: drive the command is for
627 * @nsect: sector byte
628 * @handler: handler for the command completion
630 * Issue a simple drive command with interrupts.
631 * The drive must be selected beforehand.
634 static void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect,
635 ide_handler_t *handler)
637 ide_hwif_t *hwif = HWIF(drive);
639 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
640 SELECT_MASK(drive,0);
641 hwif->OUTB(nsect,IDE_NSECTOR_REG);
642 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
646 * drive_cmd_intr - drive command completion interrupt
647 * @drive: drive the completion interrupt occurred on
649 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
650 * We do any necessary data reading and then wait for the drive to
651 * go non busy. At that point we may read the error data and complete
655 static ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
657 struct request *rq = HWGROUP(drive)->rq;
658 ide_hwif_t *hwif = HWIF(drive);
659 u8 *args = (u8 *) rq->buffer;
660 u8 stat = hwif->INB(IDE_STATUS_REG);
663 local_irq_enable_in_hardirq();
664 if (rq->cmd_type == REQ_TYPE_ATA_CMD &&
665 (stat & DRQ_STAT) && args && args[3]) {
666 u8 io_32bit = drive->io_32bit;
668 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
669 drive->io_32bit = io_32bit;
670 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
674 if (!OK_STAT(stat, READY_STAT, BAD_STAT))
675 return ide_error(drive, "drive_cmd", stat);
676 /* calls ide_end_drive_cmd */
677 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
681 static void ide_init_specify_cmd(ide_drive_t *drive, ide_task_t *task)
683 task->tf.nsect = drive->sect;
684 task->tf.lbal = drive->sect;
685 task->tf.lbam = drive->cyl;
686 task->tf.lbah = drive->cyl >> 8;
687 task->tf.device = ((drive->head - 1) | drive->select.all) & ~ATA_LBA;
688 task->tf.command = WIN_SPECIFY;
690 task->handler = &set_geometry_intr;
693 static void ide_init_restore_cmd(ide_drive_t *drive, ide_task_t *task)
695 task->tf.nsect = drive->sect;
696 task->tf.command = WIN_RESTORE;
698 task->handler = &recal_intr;
701 static void ide_init_setmult_cmd(ide_drive_t *drive, ide_task_t *task)
703 task->tf.nsect = drive->mult_req;
704 task->tf.command = WIN_SETMULT;
706 task->handler = &set_multmode_intr;
709 static ide_startstop_t ide_disk_special(ide_drive_t *drive)
711 special_t *s = &drive->special;
714 memset(&args, 0, sizeof(ide_task_t));
715 args.command_type = IDE_DRIVE_TASK_NO_DATA;
717 if (s->b.set_geometry) {
718 s->b.set_geometry = 0;
719 ide_init_specify_cmd(drive, &args);
720 } else if (s->b.recalibrate) {
721 s->b.recalibrate = 0;
722 ide_init_restore_cmd(drive, &args);
723 } else if (s->b.set_multmode) {
724 s->b.set_multmode = 0;
725 if (drive->mult_req > drive->id->max_multsect)
726 drive->mult_req = drive->id->max_multsect;
727 ide_init_setmult_cmd(drive, &args);
729 int special = s->all;
731 printk(KERN_ERR "%s: bad special flag: 0x%02x\n", drive->name, special);
735 args.tf_flags = IDE_TFLAG_OUT_TF;
736 if (drive->addressing == 1)
737 args.tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_OUT_HOB);
739 do_rw_taskfile(drive, &args);
745 * handle HDIO_SET_PIO_MODE ioctl abusers here, eventually it will go away
747 static int set_pio_mode_abuse(ide_hwif_t *hwif, u8 req_pio)
756 return (hwif->host_flags & IDE_HFLAG_ABUSE_DMA_MODES) ? 1 : 0;
759 return (hwif->host_flags & IDE_HFLAG_ABUSE_PREFETCH) ? 1 : 0;
762 return (hwif->host_flags & IDE_HFLAG_ABUSE_FAST_DEVSEL) ? 1 : 0;
769 * do_special - issue some special commands
770 * @drive: drive the command is for
772 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
773 * commands to a drive. It used to do much more, but has been scaled
777 static ide_startstop_t do_special (ide_drive_t *drive)
779 special_t *s = &drive->special;
782 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
785 ide_hwif_t *hwif = drive->hwif;
786 u8 req_pio = drive->tune_req;
790 if (set_pio_mode_abuse(drive->hwif, req_pio)) {
792 if (hwif->set_pio_mode == NULL)
796 * take ide_lock for drive->[no_]unmask/[no_]io_32bit
798 if (req_pio == 8 || req_pio == 9) {
801 spin_lock_irqsave(&ide_lock, flags);
802 hwif->set_pio_mode(drive, req_pio);
803 spin_unlock_irqrestore(&ide_lock, flags);
805 hwif->set_pio_mode(drive, req_pio);
807 int keep_dma = drive->using_dma;
809 ide_set_pio(drive, req_pio);
811 if (hwif->host_flags & IDE_HFLAG_SET_PIO_MODE_KEEP_DMA) {
813 hwif->ide_dma_on(drive);
819 if (drive->media == ide_disk)
820 return ide_disk_special(drive);
828 void ide_map_sg(ide_drive_t *drive, struct request *rq)
830 ide_hwif_t *hwif = drive->hwif;
831 struct scatterlist *sg = hwif->sg_table;
833 if (hwif->sg_mapped) /* needed by ide-scsi */
836 if (rq->cmd_type != REQ_TYPE_ATA_TASKFILE) {
837 hwif->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
839 sg_init_one(sg, rq->buffer, rq->nr_sectors * SECTOR_SIZE);
844 EXPORT_SYMBOL_GPL(ide_map_sg);
846 void ide_init_sg_cmd(ide_drive_t *drive, struct request *rq)
848 ide_hwif_t *hwif = drive->hwif;
850 hwif->nsect = hwif->nleft = rq->nr_sectors;
855 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
858 * execute_drive_command - issue special drive command
859 * @drive: the drive to issue the command on
860 * @rq: the request structure holding the command
862 * execute_drive_cmd() issues a special drive command, usually
863 * initiated by ioctl() from the external hdparm program. The
864 * command can be a drive command, drive task or taskfile
865 * operation. Weirdly you can call it with NULL to wait for
866 * all commands to finish. Don't do this as that is due to change
869 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
872 ide_hwif_t *hwif = HWIF(drive);
873 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
874 ide_task_t *args = rq->special;
879 hwif->data_phase = args->data_phase;
881 switch (hwif->data_phase) {
882 case TASKFILE_MULTI_OUT:
884 case TASKFILE_MULTI_IN:
886 ide_init_sg_cmd(drive, rq);
887 ide_map_sg(drive, rq);
892 if (args->tf_flags & IDE_TFLAG_FLAGGED)
893 return flagged_taskfile(drive, args);
895 args->tf_flags |= IDE_TFLAG_OUT_TF;
896 if (drive->addressing == 1)
897 args->tf_flags |= (IDE_TFLAG_LBA48 | IDE_TFLAG_OUT_HOB);
899 return do_rw_taskfile(drive, args);
900 } else if (rq->cmd_type == REQ_TYPE_ATA_TASK) {
901 u8 *args = rq->buffer;
906 printk("%s: DRIVE_TASK_CMD ", drive->name);
907 printk("cmd=0x%02x ", args[0]);
908 printk("fr=0x%02x ", args[1]);
909 printk("ns=0x%02x ", args[2]);
910 printk("sc=0x%02x ", args[3]);
911 printk("lcyl=0x%02x ", args[4]);
912 printk("hcyl=0x%02x ", args[5]);
913 printk("sel=0x%02x\n", args[6]);
915 hwif->OUTB(args[1], IDE_FEATURE_REG);
916 hwif->OUTB(args[3], IDE_SECTOR_REG);
917 hwif->OUTB(args[4], IDE_LCYL_REG);
918 hwif->OUTB(args[5], IDE_HCYL_REG);
919 hwif->OUTB((args[6] & 0xEF)|drive->select.all, IDE_SELECT_REG);
920 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
922 } else if (rq->cmd_type == REQ_TYPE_ATA_CMD) {
923 u8 *args = rq->buffer;
928 printk("%s: DRIVE_CMD ", drive->name);
929 printk("cmd=0x%02x ", args[0]);
930 printk("sc=0x%02x ", args[1]);
931 printk("fr=0x%02x ", args[2]);
932 printk("xx=0x%02x\n", args[3]);
934 if (args[0] == WIN_SMART) {
935 hwif->OUTB(args[2],IDE_FEATURE_REG);
936 hwif->OUTB(args[1],IDE_SECTOR_REG);
937 hwif->OUTB(0x4f, IDE_LCYL_REG);
938 hwif->OUTB(0xc2, IDE_HCYL_REG);
939 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
942 hwif->OUTB(args[2],IDE_FEATURE_REG);
943 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
949 * NULL is actually a valid way of waiting for
950 * all current requests to be flushed from the queue.
953 printk("%s: DRIVE_CMD (null)\n", drive->name);
955 ide_end_drive_cmd(drive,
956 hwif->INB(IDE_STATUS_REG),
957 hwif->INB(IDE_ERROR_REG));
961 static void ide_check_pm_state(ide_drive_t *drive, struct request *rq)
963 struct request_pm_state *pm = rq->data;
965 if (blk_pm_suspend_request(rq) &&
966 pm->pm_step == ide_pm_state_start_suspend)
967 /* Mark drive blocked when starting the suspend sequence. */
969 else if (blk_pm_resume_request(rq) &&
970 pm->pm_step == ide_pm_state_start_resume) {
972 * The first thing we do on wakeup is to wait for BSY bit to
973 * go away (with a looong timeout) as a drive on this hwif may
974 * just be POSTing itself.
975 * We do that before even selecting as the "other" device on
976 * the bus may be broken enough to walk on our toes at this
981 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
983 rc = ide_wait_not_busy(HWIF(drive), 35000);
985 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
988 HWIF(drive)->OUTB(drive->ctl, IDE_CONTROL_REG);
989 rc = ide_wait_not_busy(HWIF(drive), 100000);
991 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
996 * start_request - start of I/O and command issuing for IDE
998 * start_request() initiates handling of a new I/O request. It
999 * accepts commands and I/O (read/write) requests. It also does
1000 * the final remapping for weird stuff like EZDrive. Once
1001 * device mapper can work sector level the EZDrive stuff can go away
1003 * FIXME: this function needs a rename
1006 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
1008 ide_startstop_t startstop;
1011 BUG_ON(!blk_rq_started(rq));
1014 printk("%s: start_request: current=0x%08lx\n",
1015 HWIF(drive)->name, (unsigned long) rq);
1018 /* bail early if we've exceeded max_failures */
1019 if (drive->max_failures && (drive->failures > drive->max_failures)) {
1020 rq->cmd_flags |= REQ_FAILED;
1025 if (blk_fs_request(rq) &&
1026 (drive->media == ide_disk || drive->media == ide_floppy)) {
1027 block += drive->sect0;
1029 /* Yecch - this will shift the entire interval,
1030 possibly killing some innocent following sector */
1031 if (block == 0 && drive->remap_0_to_1 == 1)
1032 block = 1; /* redirect MBR access to EZ-Drive partn table */
1034 if (blk_pm_request(rq))
1035 ide_check_pm_state(drive, rq);
1037 SELECT_DRIVE(drive);
1038 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
1039 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
1042 if (!drive->special.all) {
1046 * We reset the drive so we need to issue a SETFEATURES.
1047 * Do it _after_ do_special() restored device parameters.
1049 if (drive->current_speed == 0xff)
1050 ide_config_drive_speed(drive, drive->desired_speed);
1052 if (rq->cmd_type == REQ_TYPE_ATA_CMD ||
1053 rq->cmd_type == REQ_TYPE_ATA_TASK ||
1054 rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
1055 return execute_drive_cmd(drive, rq);
1056 else if (blk_pm_request(rq)) {
1057 struct request_pm_state *pm = rq->data;
1059 printk("%s: start_power_step(step: %d)\n",
1060 drive->name, rq->pm->pm_step);
1062 startstop = ide_start_power_step(drive, rq);
1063 if (startstop == ide_stopped &&
1064 pm->pm_step == ide_pm_state_completed)
1065 ide_complete_pm_request(drive, rq);
1069 drv = *(ide_driver_t **)rq->rq_disk->private_data;
1070 return drv->do_request(drive, rq, block);
1072 return do_special(drive);
1074 ide_kill_rq(drive, rq);
1079 * ide_stall_queue - pause an IDE device
1080 * @drive: drive to stall
1081 * @timeout: time to stall for (jiffies)
1083 * ide_stall_queue() can be used by a drive to give excess bandwidth back
1084 * to the hwgroup by sleeping for timeout jiffies.
1087 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
1089 if (timeout > WAIT_WORSTCASE)
1090 timeout = WAIT_WORSTCASE;
1091 drive->sleep = timeout + jiffies;
1092 drive->sleeping = 1;
1095 EXPORT_SYMBOL(ide_stall_queue);
1097 #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
1100 * choose_drive - select a drive to service
1101 * @hwgroup: hardware group to select on
1103 * choose_drive() selects the next drive which will be serviced.
1104 * This is necessary because the IDE layer can't issue commands
1105 * to both drives on the same cable, unlike SCSI.
1108 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
1110 ide_drive_t *drive, *best;
1114 drive = hwgroup->drive;
1117 * drive is doing pre-flush, ordered write, post-flush sequence. even
1118 * though that is 3 requests, it must be seen as a single transaction.
1119 * we must not preempt this drive until that is complete
1121 if (blk_queue_flushing(drive->queue)) {
1123 * small race where queue could get replugged during
1124 * the 3-request flush cycle, just yank the plug since
1125 * we want it to finish asap
1127 blk_remove_plug(drive->queue);
1132 if ((!drive->sleeping || time_after_eq(jiffies, drive->sleep))
1133 && !elv_queue_empty(drive->queue)) {
1135 || (drive->sleeping && (!best->sleeping || time_before(drive->sleep, best->sleep)))
1136 || (!best->sleeping && time_before(WAKEUP(drive), WAKEUP(best))))
1138 if (!blk_queue_plugged(drive->queue))
1142 } while ((drive = drive->next) != hwgroup->drive);
1143 if (best && best->nice1 && !best->sleeping && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
1144 long t = (signed long)(WAKEUP(best) - jiffies);
1145 if (t >= WAIT_MIN_SLEEP) {
1147 * We *may* have some time to spare, but first let's see if
1148 * someone can potentially benefit from our nice mood today..
1152 if (!drive->sleeping
1153 && time_before(jiffies - best->service_time, WAKEUP(drive))
1154 && time_before(WAKEUP(drive), jiffies + t))
1156 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
1159 } while ((drive = drive->next) != best);
1166 * Issue a new request to a drive from hwgroup
1167 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
1169 * A hwgroup is a serialized group of IDE interfaces. Usually there is
1170 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
1171 * may have both interfaces in a single hwgroup to "serialize" access.
1172 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
1173 * together into one hwgroup for serialized access.
1175 * Note also that several hwgroups can end up sharing a single IRQ,
1176 * possibly along with many other devices. This is especially common in
1177 * PCI-based systems with off-board IDE controller cards.
1179 * The IDE driver uses the single global ide_lock spinlock to protect
1180 * access to the request queues, and to protect the hwgroup->busy flag.
1182 * The first thread into the driver for a particular hwgroup sets the
1183 * hwgroup->busy flag to indicate that this hwgroup is now active,
1184 * and then initiates processing of the top request from the request queue.
1186 * Other threads attempting entry notice the busy setting, and will simply
1187 * queue their new requests and exit immediately. Note that hwgroup->busy
1188 * remains set even when the driver is merely awaiting the next interrupt.
1189 * Thus, the meaning is "this hwgroup is busy processing a request".
1191 * When processing of a request completes, the completing thread or IRQ-handler
1192 * will start the next request from the queue. If no more work remains,
1193 * the driver will clear the hwgroup->busy flag and exit.
1195 * The ide_lock (spinlock) is used to protect all access to the
1196 * hwgroup->busy flag, but is otherwise not needed for most processing in
1197 * the driver. This makes the driver much more friendlier to shared IRQs
1198 * than previous designs, while remaining 100% (?) SMP safe and capable.
1200 static void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
1205 ide_startstop_t startstop;
1208 /* for atari only: POSSIBLY BROKEN HERE(?) */
1209 ide_get_lock(ide_intr, hwgroup);
1211 /* caller must own ide_lock */
1212 BUG_ON(!irqs_disabled());
1214 while (!hwgroup->busy) {
1216 drive = choose_drive(hwgroup);
1217 if (drive == NULL) {
1219 unsigned long sleep = 0; /* shut up, gcc */
1221 drive = hwgroup->drive;
1223 if (drive->sleeping && (!sleeping || time_before(drive->sleep, sleep))) {
1225 sleep = drive->sleep;
1227 } while ((drive = drive->next) != hwgroup->drive);
1230 * Take a short snooze, and then wake up this hwgroup again.
1231 * This gives other hwgroups on the same a chance to
1232 * play fairly with us, just in case there are big differences
1233 * in relative throughputs.. don't want to hog the cpu too much.
1235 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
1236 sleep = jiffies + WAIT_MIN_SLEEP;
1238 if (timer_pending(&hwgroup->timer))
1239 printk(KERN_CRIT "ide_set_handler: timer already active\n");
1241 /* so that ide_timer_expiry knows what to do */
1242 hwgroup->sleeping = 1;
1243 hwgroup->req_gen_timer = hwgroup->req_gen;
1244 mod_timer(&hwgroup->timer, sleep);
1245 /* we purposely leave hwgroup->busy==1
1248 /* Ugly, but how can we sleep for the lock
1249 * otherwise? perhaps from tq_disk?
1252 /* for atari only */
1257 /* no more work for this hwgroup (for now) */
1262 if (hwgroup->hwif->sharing_irq &&
1263 hwif != hwgroup->hwif &&
1264 hwif->io_ports[IDE_CONTROL_OFFSET]) {
1265 /* set nIEN for previous hwif */
1266 SELECT_INTERRUPT(drive);
1268 hwgroup->hwif = hwif;
1269 hwgroup->drive = drive;
1270 drive->sleeping = 0;
1271 drive->service_start = jiffies;
1273 if (blk_queue_plugged(drive->queue)) {
1274 printk(KERN_ERR "ide: huh? queue was plugged!\n");
1279 * we know that the queue isn't empty, but this can happen
1280 * if the q->prep_rq_fn() decides to kill a request
1282 rq = elv_next_request(drive->queue);
1289 * Sanity: don't accept a request that isn't a PM request
1290 * if we are currently power managed. This is very important as
1291 * blk_stop_queue() doesn't prevent the elv_next_request()
1292 * above to return us whatever is in the queue. Since we call
1293 * ide_do_request() ourselves, we end up taking requests while
1294 * the queue is blocked...
1296 * We let requests forced at head of queue with ide-preempt
1297 * though. I hope that doesn't happen too much, hopefully not
1298 * unless the subdriver triggers such a thing in its own PM
1301 * We count how many times we loop here to make sure we service
1302 * all drives in the hwgroup without looping for ever
1304 if (drive->blocked && !blk_pm_request(rq) && !(rq->cmd_flags & REQ_PREEMPT)) {
1305 drive = drive->next ? drive->next : hwgroup->drive;
1306 if (loops++ < 4 && !blk_queue_plugged(drive->queue))
1308 /* We clear busy, there should be no pending ATA command at this point. */
1316 * Some systems have trouble with IDE IRQs arriving while
1317 * the driver is still setting things up. So, here we disable
1318 * the IRQ used by this interface while the request is being started.
1319 * This may look bad at first, but pretty much the same thing
1320 * happens anyway when any interrupt comes in, IDE or otherwise
1321 * -- the kernel masks the IRQ while it is being handled.
1323 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1324 disable_irq_nosync(hwif->irq);
1325 spin_unlock(&ide_lock);
1326 local_irq_enable_in_hardirq();
1327 /* allow other IRQs while we start this request */
1328 startstop = start_request(drive, rq);
1329 spin_lock_irq(&ide_lock);
1330 if (masked_irq != IDE_NO_IRQ && hwif->irq != masked_irq)
1331 enable_irq(hwif->irq);
1332 if (startstop == ide_stopped)
1338 * Passes the stuff to ide_do_request
1340 void do_ide_request(struct request_queue *q)
1342 ide_drive_t *drive = q->queuedata;
1344 ide_do_request(HWGROUP(drive), IDE_NO_IRQ);
1348 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
1349 * retry the current request in pio mode instead of risking tossing it
1352 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
1354 ide_hwif_t *hwif = HWIF(drive);
1356 ide_startstop_t ret = ide_stopped;
1359 * end current dma transaction
1363 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
1364 (void)HWIF(drive)->ide_dma_end(drive);
1365 ret = ide_error(drive, "dma timeout error",
1366 hwif->INB(IDE_STATUS_REG));
1368 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
1369 hwif->dma_timeout(drive);
1373 * disable dma for now, but remember that we did so because of
1374 * a timeout -- we'll reenable after we finish this next request
1375 * (or rather the first chunk of it) in pio.
1378 drive->state = DMA_PIO_RETRY;
1379 hwif->dma_off_quietly(drive);
1382 * un-busy drive etc (hwgroup->busy is cleared on return) and
1383 * make sure request is sane
1385 rq = HWGROUP(drive)->rq;
1390 HWGROUP(drive)->rq = NULL;
1397 rq->sector = rq->bio->bi_sector;
1398 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
1399 rq->hard_cur_sectors = rq->current_nr_sectors;
1400 rq->buffer = bio_data(rq->bio);
1406 * ide_timer_expiry - handle lack of an IDE interrupt
1407 * @data: timer callback magic (hwgroup)
1409 * An IDE command has timed out before the expected drive return
1410 * occurred. At this point we attempt to clean up the current
1411 * mess. If the current handler includes an expiry handler then
1412 * we invoke the expiry handler, and providing it is happy the
1413 * work is done. If that fails we apply generic recovery rules
1414 * invoking the handler and checking the drive DMA status. We
1415 * have an excessively incestuous relationship with the DMA
1416 * logic that wants cleaning up.
1419 void ide_timer_expiry (unsigned long data)
1421 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1422 ide_handler_t *handler;
1423 ide_expiry_t *expiry;
1424 unsigned long flags;
1425 unsigned long wait = -1;
1427 spin_lock_irqsave(&ide_lock, flags);
1429 if (((handler = hwgroup->handler) == NULL) ||
1430 (hwgroup->req_gen != hwgroup->req_gen_timer)) {
1432 * Either a marginal timeout occurred
1433 * (got the interrupt just as timer expired),
1434 * or we were "sleeping" to give other devices a chance.
1435 * Either way, we don't really want to complain about anything.
1437 if (hwgroup->sleeping) {
1438 hwgroup->sleeping = 0;
1442 ide_drive_t *drive = hwgroup->drive;
1444 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1445 hwgroup->handler = NULL;
1448 ide_startstop_t startstop = ide_stopped;
1449 if (!hwgroup->busy) {
1450 hwgroup->busy = 1; /* paranoia */
1451 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1453 if ((expiry = hwgroup->expiry) != NULL) {
1455 if ((wait = expiry(drive)) > 0) {
1457 hwgroup->timer.expires = jiffies + wait;
1458 hwgroup->req_gen_timer = hwgroup->req_gen;
1459 add_timer(&hwgroup->timer);
1460 spin_unlock_irqrestore(&ide_lock, flags);
1464 hwgroup->handler = NULL;
1466 * We need to simulate a real interrupt when invoking
1467 * the handler() function, which means we need to
1468 * globally mask the specific IRQ:
1470 spin_unlock(&ide_lock);
1472 /* disable_irq_nosync ?? */
1473 disable_irq(hwif->irq);
1475 * as if we were handling an interrupt */
1476 local_irq_disable();
1477 if (hwgroup->polling) {
1478 startstop = handler(drive);
1479 } else if (drive_is_ready(drive)) {
1480 if (drive->waiting_for_dma)
1481 hwgroup->hwif->dma_lost_irq(drive);
1482 (void)ide_ack_intr(hwif);
1483 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1484 startstop = handler(drive);
1486 if (drive->waiting_for_dma) {
1487 startstop = ide_dma_timeout_retry(drive, wait);
1490 ide_error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1492 drive->service_time = jiffies - drive->service_start;
1493 spin_lock_irq(&ide_lock);
1494 enable_irq(hwif->irq);
1495 if (startstop == ide_stopped)
1499 ide_do_request(hwgroup, IDE_NO_IRQ);
1500 spin_unlock_irqrestore(&ide_lock, flags);
1504 * unexpected_intr - handle an unexpected IDE interrupt
1505 * @irq: interrupt line
1506 * @hwgroup: hwgroup being processed
1508 * There's nothing really useful we can do with an unexpected interrupt,
1509 * other than reading the status register (to clear it), and logging it.
1510 * There should be no way that an irq can happen before we're ready for it,
1511 * so we needn't worry much about losing an "important" interrupt here.
1513 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1514 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1515 * looks "good", we just ignore the interrupt completely.
1517 * This routine assumes __cli() is in effect when called.
1519 * If an unexpected interrupt happens on irq15 while we are handling irq14
1520 * and if the two interfaces are "serialized" (CMD640), then it looks like
1521 * we could screw up by interfering with a new request being set up for
1524 * In reality, this is a non-issue. The new command is not sent unless
1525 * the drive is ready to accept one, in which case we know the drive is
1526 * not trying to interrupt us. And ide_set_handler() is always invoked
1527 * before completing the issuance of any new drive command, so we will not
1528 * be accidentally invoked as a result of any valid command completion
1531 * Note that we must walk the entire hwgroup here. We know which hwif
1532 * is doing the current command, but we don't know which hwif burped
1536 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1539 ide_hwif_t *hwif = hwgroup->hwif;
1542 * handle the unexpected interrupt
1545 if (hwif->irq == irq) {
1546 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1547 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1548 /* Try to not flood the console with msgs */
1549 static unsigned long last_msgtime, count;
1551 if (time_after(jiffies, last_msgtime + HZ)) {
1552 last_msgtime = jiffies;
1553 printk(KERN_ERR "%s%s: unexpected interrupt, "
1554 "status=0x%02x, count=%ld\n",
1556 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1560 } while ((hwif = hwif->next) != hwgroup->hwif);
1564 * ide_intr - default IDE interrupt handler
1565 * @irq: interrupt number
1566 * @dev_id: hwif group
1567 * @regs: unused weirdness from the kernel irq layer
1569 * This is the default IRQ handler for the IDE layer. You should
1570 * not need to override it. If you do be aware it is subtle in
1573 * hwgroup->hwif is the interface in the group currently performing
1574 * a command. hwgroup->drive is the drive and hwgroup->handler is
1575 * the IRQ handler to call. As we issue a command the handlers
1576 * step through multiple states, reassigning the handler to the
1577 * next step in the process. Unlike a smart SCSI controller IDE
1578 * expects the main processor to sequence the various transfer
1579 * stages. We also manage a poll timer to catch up with most
1580 * timeout situations. There are still a few where the handlers
1581 * don't ever decide to give up.
1583 * The handler eventually returns ide_stopped to indicate the
1584 * request completed. At this point we issue the next request
1585 * on the hwgroup and the process begins again.
1588 irqreturn_t ide_intr (int irq, void *dev_id)
1590 unsigned long flags;
1591 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1594 ide_handler_t *handler;
1595 ide_startstop_t startstop;
1597 spin_lock_irqsave(&ide_lock, flags);
1598 hwif = hwgroup->hwif;
1600 if (!ide_ack_intr(hwif)) {
1601 spin_unlock_irqrestore(&ide_lock, flags);
1605 if ((handler = hwgroup->handler) == NULL || hwgroup->polling) {
1607 * Not expecting an interrupt from this drive.
1608 * That means this could be:
1609 * (1) an interrupt from another PCI device
1610 * sharing the same PCI INT# as us.
1611 * or (2) a drive just entered sleep or standby mode,
1612 * and is interrupting to let us know.
1613 * or (3) a spurious interrupt of unknown origin.
1615 * For PCI, we cannot tell the difference,
1616 * so in that case we just ignore it and hope it goes away.
1618 * FIXME: unexpected_intr should be hwif-> then we can
1619 * remove all the ifdef PCI crap
1621 #ifdef CONFIG_BLK_DEV_IDEPCI
1622 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1623 #endif /* CONFIG_BLK_DEV_IDEPCI */
1626 * Probably not a shared PCI interrupt,
1627 * so we can safely try to do something about it:
1629 unexpected_intr(irq, hwgroup);
1630 #ifdef CONFIG_BLK_DEV_IDEPCI
1633 * Whack the status register, just in case
1634 * we have a leftover pending IRQ.
1636 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1637 #endif /* CONFIG_BLK_DEV_IDEPCI */
1639 spin_unlock_irqrestore(&ide_lock, flags);
1642 drive = hwgroup->drive;
1645 * This should NEVER happen, and there isn't much
1646 * we could do about it here.
1648 * [Note - this can occur if the drive is hot unplugged]
1650 spin_unlock_irqrestore(&ide_lock, flags);
1653 if (!drive_is_ready(drive)) {
1655 * This happens regularly when we share a PCI IRQ with
1656 * another device. Unfortunately, it can also happen
1657 * with some buggy drives that trigger the IRQ before
1658 * their status register is up to date. Hopefully we have
1659 * enough advance overhead that the latter isn't a problem.
1661 spin_unlock_irqrestore(&ide_lock, flags);
1664 if (!hwgroup->busy) {
1665 hwgroup->busy = 1; /* paranoia */
1666 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1668 hwgroup->handler = NULL;
1670 del_timer(&hwgroup->timer);
1671 spin_unlock(&ide_lock);
1673 /* Some controllers might set DMA INTR no matter DMA or PIO;
1674 * bmdma status might need to be cleared even for
1675 * PIO interrupts to prevent spurious/lost irq.
1677 if (hwif->ide_dma_clear_irq && !(drive->waiting_for_dma))
1678 /* ide_dma_end() needs bmdma status for error checking.
1679 * So, skip clearing bmdma status here and leave it
1680 * to ide_dma_end() if this is dma interrupt.
1682 hwif->ide_dma_clear_irq(drive);
1685 local_irq_enable_in_hardirq();
1686 /* service this interrupt, may set handler for next interrupt */
1687 startstop = handler(drive);
1688 spin_lock_irq(&ide_lock);
1691 * Note that handler() may have set things up for another
1692 * interrupt to occur soon, but it cannot happen until
1693 * we exit from this routine, because it will be the
1694 * same irq as is currently being serviced here, and Linux
1695 * won't allow another of the same (on any CPU) until we return.
1697 drive->service_time = jiffies - drive->service_start;
1698 if (startstop == ide_stopped) {
1699 if (hwgroup->handler == NULL) { /* paranoia */
1701 ide_do_request(hwgroup, hwif->irq);
1703 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1704 "on exit\n", drive->name);
1707 spin_unlock_irqrestore(&ide_lock, flags);
1712 * ide_init_drive_cmd - initialize a drive command request
1713 * @rq: request object
1715 * Initialize a request before we fill it in and send it down to
1716 * ide_do_drive_cmd. Commands must be set up by this function. Right
1717 * now it doesn't do a lot, but if that changes abusers will have a
1721 void ide_init_drive_cmd (struct request *rq)
1723 memset(rq, 0, sizeof(*rq));
1724 rq->cmd_type = REQ_TYPE_ATA_CMD;
1728 EXPORT_SYMBOL(ide_init_drive_cmd);
1731 * ide_do_drive_cmd - issue IDE special command
1732 * @drive: device to issue command
1733 * @rq: request to issue
1734 * @action: action for processing
1736 * This function issues a special IDE device request
1737 * onto the request queue.
1739 * If action is ide_wait, then the rq is queued at the end of the
1740 * request queue, and the function sleeps until it has been processed.
1741 * This is for use when invoked from an ioctl handler.
1743 * If action is ide_preempt, then the rq is queued at the head of
1744 * the request queue, displacing the currently-being-processed
1745 * request and this function returns immediately without waiting
1746 * for the new rq to be completed. This is VERY DANGEROUS, and is
1747 * intended for careful use by the ATAPI tape/cdrom driver code.
1749 * If action is ide_end, then the rq is queued at the end of the
1750 * request queue, and the function returns immediately without waiting
1751 * for the new rq to be completed. This is again intended for careful
1752 * use by the ATAPI tape/cdrom driver code.
1755 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1757 unsigned long flags;
1758 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1759 DECLARE_COMPLETION_ONSTACK(wait);
1760 int where = ELEVATOR_INSERT_BACK, err;
1761 int must_wait = (action == ide_wait || action == ide_head_wait);
1766 * we need to hold an extra reference to request for safe inspection
1771 rq->end_io_data = &wait;
1772 rq->end_io = blk_end_sync_rq;
1775 spin_lock_irqsave(&ide_lock, flags);
1776 if (action == ide_preempt)
1778 if (action == ide_preempt || action == ide_head_wait) {
1779 where = ELEVATOR_INSERT_FRONT;
1780 rq->cmd_flags |= REQ_PREEMPT;
1782 __elv_add_request(drive->queue, rq, where, 0);
1783 ide_do_request(hwgroup, IDE_NO_IRQ);
1784 spin_unlock_irqrestore(&ide_lock, flags);
1788 wait_for_completion(&wait);
1792 blk_put_request(rq);
1798 EXPORT_SYMBOL(ide_do_drive_cmd);