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 int ide_end_rq(ide_drive_t
*drive
, struct request
*rq
, int error
,
58 unsigned int nr_bytes
)
61 * decide whether to reenable DMA -- 3 is a random magic for now,
62 * if we DMA timeout more than 3 times, just stay in PIO
64 if ((drive
->dev_flags
& IDE_DFLAG_DMA_PIO_RETRY
) &&
65 drive
->retry_pio
<= 3) {
66 drive
->dev_flags
&= ~IDE_DFLAG_DMA_PIO_RETRY
;
70 return blk_end_request(rq
, error
, nr_bytes
);
72 EXPORT_SYMBOL_GPL(ide_end_rq
);
75 * ide_end_request - complete an IDE I/O
76 * @drive: IDE device for the I/O
78 * @nr_sectors: number of sectors completed
80 * This is our end_request wrapper function. We complete the I/O
81 * update random number input and dequeue the request, which if
82 * it was tagged may be out of order.
85 int ide_end_request (ide_drive_t
*drive
, int uptodate
, int nr_sectors
)
87 unsigned int nr_bytes
= nr_sectors
<< 9;
88 struct request
*rq
= drive
->hwif
->rq
;
92 if (blk_pc_request(rq
))
93 nr_bytes
= rq
->data_len
;
95 nr_bytes
= rq
->hard_cur_sectors
<< 9;
99 * if failfast is set on a request, override number of sectors
100 * and complete the whole request right now
102 if (blk_noretry_request(rq
) && uptodate
<= 0)
103 nr_bytes
= rq
->hard_nr_sectors
<< 9;
105 if (blk_fs_request(rq
) == 0 && uptodate
<= 0 && rq
->errors
== 0)
109 error
= uptodate
? uptodate
: -EIO
;
111 rc
= ide_end_rq(drive
, rq
, error
, nr_bytes
);
113 drive
->hwif
->rq
= NULL
;
117 EXPORT_SYMBOL(ide_end_request
);
119 void ide_complete_cmd(ide_drive_t
*drive
, struct ide_cmd
*cmd
, u8 stat
, u8 err
)
121 struct ide_taskfile
*tf
= &cmd
->tf
;
122 struct request
*rq
= cmd
->rq
;
123 u8 tf_cmd
= tf
->command
;
128 drive
->hwif
->tp_ops
->tf_read(drive
, cmd
);
130 if ((cmd
->tf_flags
& IDE_TFLAG_CUSTOM_HANDLER
) &&
131 tf_cmd
== ATA_CMD_IDLEIMMEDIATE
) {
132 if (tf
->lbal
!= 0xc4) {
133 printk(KERN_ERR
"%s: head unload failed!\n",
135 ide_tf_dump(drive
->name
, tf
);
137 drive
->dev_flags
|= IDE_DFLAG_PARKED
;
140 if (rq
&& rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
141 memcpy(rq
->special
, cmd
, sizeof(*cmd
));
143 if (cmd
->tf_flags
& IDE_TFLAG_DYN
)
147 void ide_complete_rq(ide_drive_t
*drive
, int error
)
149 ide_hwif_t
*hwif
= drive
->hwif
;
150 struct request
*rq
= hwif
->rq
;
154 if (unlikely(blk_end_request(rq
, error
, blk_rq_bytes(rq
))))
157 EXPORT_SYMBOL(ide_complete_rq
);
159 void ide_kill_rq(ide_drive_t
*drive
, struct request
*rq
)
161 u8 drv_req
= blk_special_request(rq
) && rq
->rq_disk
;
162 u8 media
= drive
->media
;
164 drive
->failed_pc
= NULL
;
166 if ((media
== ide_floppy
|| media
== ide_tape
) && drv_req
) {
168 ide_complete_rq(drive
, 0);
170 if (media
== ide_tape
)
171 rq
->errors
= IDE_DRV_ERROR_GENERAL
;
172 ide_end_request(drive
, 0, 0);
176 static void ide_tf_set_specify_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
178 tf
->nsect
= drive
->sect
;
179 tf
->lbal
= drive
->sect
;
180 tf
->lbam
= drive
->cyl
;
181 tf
->lbah
= drive
->cyl
>> 8;
182 tf
->device
= (drive
->head
- 1) | drive
->select
;
183 tf
->command
= ATA_CMD_INIT_DEV_PARAMS
;
186 static void ide_tf_set_restore_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
188 tf
->nsect
= drive
->sect
;
189 tf
->command
= ATA_CMD_RESTORE
;
192 static void ide_tf_set_setmult_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
194 tf
->nsect
= drive
->mult_req
;
195 tf
->command
= ATA_CMD_SET_MULTI
;
198 static ide_startstop_t
ide_disk_special(ide_drive_t
*drive
)
200 special_t
*s
= &drive
->special
;
203 memset(&cmd
, 0, sizeof(cmd
));
204 cmd
.protocol
= ATA_PROT_NODATA
;
206 if (s
->b
.set_geometry
) {
207 s
->b
.set_geometry
= 0;
208 ide_tf_set_specify_cmd(drive
, &cmd
.tf
);
209 } else if (s
->b
.recalibrate
) {
210 s
->b
.recalibrate
= 0;
211 ide_tf_set_restore_cmd(drive
, &cmd
.tf
);
212 } else if (s
->b
.set_multmode
) {
213 s
->b
.set_multmode
= 0;
214 ide_tf_set_setmult_cmd(drive
, &cmd
.tf
);
216 int special
= s
->all
;
218 printk(KERN_ERR
"%s: bad special flag: 0x%02x\n", drive
->name
, special
);
222 cmd
.tf_flags
= IDE_TFLAG_TF
| IDE_TFLAG_DEVICE
|
223 IDE_TFLAG_CUSTOM_HANDLER
;
225 do_rw_taskfile(drive
, &cmd
);
231 * do_special - issue some special commands
232 * @drive: drive the command is for
234 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
235 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
237 * It used to do much more, but has been scaled back.
240 static ide_startstop_t
do_special (ide_drive_t
*drive
)
242 special_t
*s
= &drive
->special
;
245 printk("%s: do_special: 0x%02x\n", drive
->name
, s
->all
);
247 if (drive
->media
== ide_disk
)
248 return ide_disk_special(drive
);
255 void ide_map_sg(ide_drive_t
*drive
, struct request
*rq
)
257 ide_hwif_t
*hwif
= drive
->hwif
;
258 struct ide_cmd
*cmd
= &hwif
->cmd
;
259 struct scatterlist
*sg
= hwif
->sg_table
;
261 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
) {
262 sg_init_one(sg
, rq
->buffer
, rq
->nr_sectors
* SECTOR_SIZE
);
264 } else if (!rq
->bio
) {
265 sg_init_one(sg
, rq
->data
, rq
->data_len
);
268 cmd
->sg_nents
= blk_rq_map_sg(drive
->queue
, rq
, sg
);
270 EXPORT_SYMBOL_GPL(ide_map_sg
);
272 void ide_init_sg_cmd(struct ide_cmd
*cmd
, int nsect
)
274 cmd
->nsect
= cmd
->nleft
= nsect
;
278 EXPORT_SYMBOL_GPL(ide_init_sg_cmd
);
281 * execute_drive_command - issue special drive command
282 * @drive: the drive to issue the command on
283 * @rq: the request structure holding the command
285 * execute_drive_cmd() issues a special drive command, usually
286 * initiated by ioctl() from the external hdparm program. The
287 * command can be a drive command, drive task or taskfile
288 * operation. Weirdly you can call it with NULL to wait for
289 * all commands to finish. Don't do this as that is due to change
292 static ide_startstop_t
execute_drive_cmd (ide_drive_t
*drive
,
295 struct ide_cmd
*cmd
= rq
->special
;
298 if (cmd
->protocol
== ATA_PROT_PIO
) {
299 ide_init_sg_cmd(cmd
, rq
->nr_sectors
);
300 ide_map_sg(drive
, rq
);
303 return do_rw_taskfile(drive
, cmd
);
307 * NULL is actually a valid way of waiting for
308 * all current requests to be flushed from the queue.
311 printk("%s: DRIVE_CMD (null)\n", drive
->name
);
314 ide_complete_rq(drive
, 0);
319 static ide_startstop_t
ide_special_rq(ide_drive_t
*drive
, struct request
*rq
)
325 case REQ_UNPARK_HEADS
:
326 return ide_do_park_unpark(drive
, rq
);
327 case REQ_DEVSET_EXEC
:
328 return ide_do_devset(drive
, rq
);
329 case REQ_DRIVE_RESET
:
330 return ide_do_reset(drive
);
337 * start_request - start of I/O and command issuing for IDE
339 * start_request() initiates handling of a new I/O request. It
340 * accepts commands and I/O (read/write) requests.
342 * FIXME: this function needs a rename
345 static ide_startstop_t
start_request (ide_drive_t
*drive
, struct request
*rq
)
347 ide_startstop_t startstop
;
349 BUG_ON(!blk_rq_started(rq
));
352 printk("%s: start_request: current=0x%08lx\n",
353 drive
->hwif
->name
, (unsigned long) rq
);
356 /* bail early if we've exceeded max_failures */
357 if (drive
->max_failures
&& (drive
->failures
> drive
->max_failures
)) {
358 rq
->cmd_flags
|= REQ_FAILED
;
362 if (blk_pm_request(rq
))
363 ide_check_pm_state(drive
, rq
);
366 if (ide_wait_stat(&startstop
, drive
, drive
->ready_stat
,
367 ATA_BUSY
| ATA_DRQ
, WAIT_READY
)) {
368 printk(KERN_ERR
"%s: drive not ready for command\n", drive
->name
);
371 if (!drive
->special
.all
) {
372 struct ide_driver
*drv
;
375 * We reset the drive so we need to issue a SETFEATURES.
376 * Do it _after_ do_special() restored device parameters.
378 if (drive
->current_speed
== 0xff)
379 ide_config_drive_speed(drive
, drive
->desired_speed
);
381 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
382 return execute_drive_cmd(drive
, rq
);
383 else if (blk_pm_request(rq
)) {
384 struct request_pm_state
*pm
= rq
->data
;
386 printk("%s: start_power_step(step: %d)\n",
387 drive
->name
, pm
->pm_step
);
389 startstop
= ide_start_power_step(drive
, rq
);
390 if (startstop
== ide_stopped
&&
391 pm
->pm_step
== IDE_PM_COMPLETED
)
392 ide_complete_pm_rq(drive
, rq
);
394 } else if (!rq
->rq_disk
&& blk_special_request(rq
))
396 * TODO: Once all ULDs have been modified to
397 * check for specific op codes rather than
398 * blindly accepting any special request, the
399 * check for ->rq_disk above may be replaced
400 * by a more suitable mechanism or even
403 return ide_special_rq(drive
, rq
);
405 drv
= *(struct ide_driver
**)rq
->rq_disk
->private_data
;
407 return drv
->do_request(drive
, rq
, rq
->sector
);
409 return do_special(drive
);
411 ide_kill_rq(drive
, rq
);
416 * ide_stall_queue - pause an IDE device
417 * @drive: drive to stall
418 * @timeout: time to stall for (jiffies)
420 * ide_stall_queue() can be used by a drive to give excess bandwidth back
421 * to the port by sleeping for timeout jiffies.
424 void ide_stall_queue (ide_drive_t
*drive
, unsigned long timeout
)
426 if (timeout
> WAIT_WORSTCASE
)
427 timeout
= WAIT_WORSTCASE
;
428 drive
->sleep
= timeout
+ jiffies
;
429 drive
->dev_flags
|= IDE_DFLAG_SLEEPING
;
431 EXPORT_SYMBOL(ide_stall_queue
);
433 static inline int ide_lock_port(ide_hwif_t
*hwif
)
443 static inline void ide_unlock_port(ide_hwif_t
*hwif
)
448 static inline int ide_lock_host(struct ide_host
*host
, ide_hwif_t
*hwif
)
452 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
453 rc
= test_and_set_bit_lock(IDE_HOST_BUSY
, &host
->host_busy
);
456 host
->get_lock(ide_intr
, hwif
);
462 static inline void ide_unlock_host(struct ide_host
*host
)
464 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
465 if (host
->release_lock
)
466 host
->release_lock();
467 clear_bit_unlock(IDE_HOST_BUSY
, &host
->host_busy
);
472 * Issue a new request to a device.
474 void do_ide_request(struct request_queue
*q
)
476 ide_drive_t
*drive
= q
->queuedata
;
477 ide_hwif_t
*hwif
= drive
->hwif
;
478 struct ide_host
*host
= hwif
->host
;
479 struct request
*rq
= NULL
;
480 ide_startstop_t startstop
;
483 * drive is doing pre-flush, ordered write, post-flush sequence. even
484 * though that is 3 requests, it must be seen as a single transaction.
485 * we must not preempt this drive until that is complete
487 if (blk_queue_flushing(q
))
489 * small race where queue could get replugged during
490 * the 3-request flush cycle, just yank the plug since
491 * we want it to finish asap
495 spin_unlock_irq(q
->queue_lock
);
497 if (ide_lock_host(host
, hwif
))
500 spin_lock_irq(&hwif
->lock
);
502 if (!ide_lock_port(hwif
)) {
503 ide_hwif_t
*prev_port
;
505 prev_port
= hwif
->host
->cur_port
;
508 if (drive
->dev_flags
& IDE_DFLAG_SLEEPING
) {
509 if (time_before(drive
->sleep
, jiffies
)) {
510 ide_unlock_port(hwif
);
515 if ((hwif
->host
->host_flags
& IDE_HFLAG_SERIALIZE
) &&
518 * set nIEN for previous port, drives in the
519 * quirk_list may not like intr setups/cleanups
521 if (prev_port
&& prev_port
->cur_dev
->quirk_list
== 0)
522 prev_port
->tp_ops
->set_irq(prev_port
, 0);
524 hwif
->host
->cur_port
= hwif
;
526 hwif
->cur_dev
= drive
;
527 drive
->dev_flags
&= ~(IDE_DFLAG_SLEEPING
| IDE_DFLAG_PARKED
);
529 spin_unlock_irq(&hwif
->lock
);
530 spin_lock_irq(q
->queue_lock
);
532 * we know that the queue isn't empty, but this can happen
533 * if the q->prep_rq_fn() decides to kill a request
535 rq
= elv_next_request(drive
->queue
);
536 spin_unlock_irq(q
->queue_lock
);
537 spin_lock_irq(&hwif
->lock
);
540 ide_unlock_port(hwif
);
545 * Sanity: don't accept a request that isn't a PM request
546 * if we are currently power managed. This is very important as
547 * blk_stop_queue() doesn't prevent the elv_next_request()
548 * above to return us whatever is in the queue. Since we call
549 * ide_do_request() ourselves, we end up taking requests while
550 * the queue is blocked...
552 * We let requests forced at head of queue with ide-preempt
553 * though. I hope that doesn't happen too much, hopefully not
554 * unless the subdriver triggers such a thing in its own PM
557 if ((drive
->dev_flags
& IDE_DFLAG_BLOCKED
) &&
558 blk_pm_request(rq
) == 0 &&
559 (rq
->cmd_flags
& REQ_PREEMPT
) == 0) {
560 /* there should be no pending command at this point */
561 ide_unlock_port(hwif
);
567 spin_unlock_irq(&hwif
->lock
);
568 startstop
= start_request(drive
, rq
);
569 spin_lock_irq(&hwif
->lock
);
571 if (startstop
== ide_stopped
)
576 spin_unlock_irq(&hwif
->lock
);
578 ide_unlock_host(host
);
579 spin_lock_irq(q
->queue_lock
);
583 spin_unlock_irq(&hwif
->lock
);
584 ide_unlock_host(host
);
586 spin_lock_irq(q
->queue_lock
);
588 if (!elv_queue_empty(q
))
592 static void ide_plug_device(ide_drive_t
*drive
)
594 struct request_queue
*q
= drive
->queue
;
597 spin_lock_irqsave(q
->queue_lock
, flags
);
598 if (!elv_queue_empty(q
))
600 spin_unlock_irqrestore(q
->queue_lock
, flags
);
603 static int drive_is_ready(ide_drive_t
*drive
)
605 ide_hwif_t
*hwif
= drive
->hwif
;
608 if (drive
->waiting_for_dma
)
609 return hwif
->dma_ops
->dma_test_irq(drive
);
611 if (hwif
->io_ports
.ctl_addr
&&
612 (hwif
->host_flags
& IDE_HFLAG_BROKEN_ALTSTATUS
) == 0)
613 stat
= hwif
->tp_ops
->read_altstatus(hwif
);
615 /* Note: this may clear a pending IRQ!! */
616 stat
= hwif
->tp_ops
->read_status(hwif
);
619 /* drive busy: definitely not interrupting */
622 /* drive ready: *might* be interrupting */
627 * ide_timer_expiry - handle lack of an IDE interrupt
628 * @data: timer callback magic (hwif)
630 * An IDE command has timed out before the expected drive return
631 * occurred. At this point we attempt to clean up the current
632 * mess. If the current handler includes an expiry handler then
633 * we invoke the expiry handler, and providing it is happy the
634 * work is done. If that fails we apply generic recovery rules
635 * invoking the handler and checking the drive DMA status. We
636 * have an excessively incestuous relationship with the DMA
637 * logic that wants cleaning up.
640 void ide_timer_expiry (unsigned long data
)
642 ide_hwif_t
*hwif
= (ide_hwif_t
*)data
;
643 ide_drive_t
*uninitialized_var(drive
);
644 ide_handler_t
*handler
;
649 spin_lock_irqsave(&hwif
->lock
, flags
);
651 handler
= hwif
->handler
;
653 if (handler
== NULL
|| hwif
->req_gen
!= hwif
->req_gen_timer
) {
655 * Either a marginal timeout occurred
656 * (got the interrupt just as timer expired),
657 * or we were "sleeping" to give other devices a chance.
658 * Either way, we don't really want to complain about anything.
661 ide_expiry_t
*expiry
= hwif
->expiry
;
662 ide_startstop_t startstop
= ide_stopped
;
664 drive
= hwif
->cur_dev
;
667 wait
= expiry(drive
);
668 if (wait
> 0) { /* continue */
670 hwif
->timer
.expires
= jiffies
+ wait
;
671 hwif
->req_gen_timer
= hwif
->req_gen
;
672 add_timer(&hwif
->timer
);
673 spin_unlock_irqrestore(&hwif
->lock
, flags
);
677 hwif
->handler
= NULL
;
679 * We need to simulate a real interrupt when invoking
680 * the handler() function, which means we need to
681 * globally mask the specific IRQ:
683 spin_unlock(&hwif
->lock
);
684 /* disable_irq_nosync ?? */
685 disable_irq(hwif
->irq
);
686 /* local CPU only, as if we were handling an interrupt */
689 startstop
= handler(drive
);
690 } else if (drive_is_ready(drive
)) {
691 if (drive
->waiting_for_dma
)
692 hwif
->dma_ops
->dma_lost_irq(drive
);
694 hwif
->ack_intr(hwif
);
695 printk(KERN_WARNING
"%s: lost interrupt\n",
697 startstop
= handler(drive
);
699 if (drive
->waiting_for_dma
)
700 startstop
= ide_dma_timeout_retry(drive
, wait
);
702 startstop
= ide_error(drive
, "irq timeout",
703 hwif
->tp_ops
->read_status(hwif
));
705 spin_lock_irq(&hwif
->lock
);
706 enable_irq(hwif
->irq
);
707 if (startstop
== ide_stopped
) {
708 ide_unlock_port(hwif
);
712 spin_unlock_irqrestore(&hwif
->lock
, flags
);
715 ide_unlock_host(hwif
->host
);
716 ide_plug_device(drive
);
721 * unexpected_intr - handle an unexpected IDE interrupt
722 * @irq: interrupt line
723 * @hwif: port being processed
725 * There's nothing really useful we can do with an unexpected interrupt,
726 * other than reading the status register (to clear it), and logging it.
727 * There should be no way that an irq can happen before we're ready for it,
728 * so we needn't worry much about losing an "important" interrupt here.
730 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
731 * the drive enters "idle", "standby", or "sleep" mode, so if the status
732 * looks "good", we just ignore the interrupt completely.
734 * This routine assumes __cli() is in effect when called.
736 * If an unexpected interrupt happens on irq15 while we are handling irq14
737 * and if the two interfaces are "serialized" (CMD640), then it looks like
738 * we could screw up by interfering with a new request being set up for
741 * In reality, this is a non-issue. The new command is not sent unless
742 * the drive is ready to accept one, in which case we know the drive is
743 * not trying to interrupt us. And ide_set_handler() is always invoked
744 * before completing the issuance of any new drive command, so we will not
745 * be accidentally invoked as a result of any valid command completion
749 static void unexpected_intr(int irq
, ide_hwif_t
*hwif
)
751 u8 stat
= hwif
->tp_ops
->read_status(hwif
);
753 if (!OK_STAT(stat
, ATA_DRDY
, BAD_STAT
)) {
754 /* Try to not flood the console with msgs */
755 static unsigned long last_msgtime
, count
;
758 if (time_after(jiffies
, last_msgtime
+ HZ
)) {
759 last_msgtime
= jiffies
;
760 printk(KERN_ERR
"%s: unexpected interrupt, "
761 "status=0x%02x, count=%ld\n",
762 hwif
->name
, stat
, count
);
768 * ide_intr - default IDE interrupt handler
769 * @irq: interrupt number
771 * @regs: unused weirdness from the kernel irq layer
773 * This is the default IRQ handler for the IDE layer. You should
774 * not need to override it. If you do be aware it is subtle in
777 * hwif is the interface in the group currently performing
778 * a command. hwif->cur_dev is the drive and hwif->handler is
779 * the IRQ handler to call. As we issue a command the handlers
780 * step through multiple states, reassigning the handler to the
781 * next step in the process. Unlike a smart SCSI controller IDE
782 * expects the main processor to sequence the various transfer
783 * stages. We also manage a poll timer to catch up with most
784 * timeout situations. There are still a few where the handlers
785 * don't ever decide to give up.
787 * The handler eventually returns ide_stopped to indicate the
788 * request completed. At this point we issue the next request
789 * on the port and the process begins again.
792 irqreturn_t
ide_intr (int irq
, void *dev_id
)
794 ide_hwif_t
*hwif
= (ide_hwif_t
*)dev_id
;
795 struct ide_host
*host
= hwif
->host
;
796 ide_drive_t
*uninitialized_var(drive
);
797 ide_handler_t
*handler
;
799 ide_startstop_t startstop
;
800 irqreturn_t irq_ret
= IRQ_NONE
;
803 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
804 if (hwif
!= host
->cur_port
)
808 spin_lock_irqsave(&hwif
->lock
, flags
);
810 if (hwif
->ack_intr
&& hwif
->ack_intr(hwif
) == 0)
813 handler
= hwif
->handler
;
815 if (handler
== NULL
|| hwif
->polling
) {
817 * Not expecting an interrupt from this drive.
818 * That means this could be:
819 * (1) an interrupt from another PCI device
820 * sharing the same PCI INT# as us.
821 * or (2) a drive just entered sleep or standby mode,
822 * and is interrupting to let us know.
823 * or (3) a spurious interrupt of unknown origin.
825 * For PCI, we cannot tell the difference,
826 * so in that case we just ignore it and hope it goes away.
828 if ((host
->irq_flags
& IRQF_SHARED
) == 0) {
830 * Probably not a shared PCI interrupt,
831 * so we can safely try to do something about it:
833 unexpected_intr(irq
, hwif
);
836 * Whack the status register, just in case
837 * we have a leftover pending IRQ.
839 (void)hwif
->tp_ops
->read_status(hwif
);
844 drive
= hwif
->cur_dev
;
846 if (!drive_is_ready(drive
))
848 * This happens regularly when we share a PCI IRQ with
849 * another device. Unfortunately, it can also happen
850 * with some buggy drives that trigger the IRQ before
851 * their status register is up to date. Hopefully we have
852 * enough advance overhead that the latter isn't a problem.
856 hwif
->handler
= NULL
;
858 del_timer(&hwif
->timer
);
859 spin_unlock(&hwif
->lock
);
861 if (hwif
->port_ops
&& hwif
->port_ops
->clear_irq
)
862 hwif
->port_ops
->clear_irq(drive
);
864 if (drive
->dev_flags
& IDE_DFLAG_UNMASK
)
865 local_irq_enable_in_hardirq();
867 /* service this interrupt, may set handler for next interrupt */
868 startstop
= handler(drive
);
870 spin_lock_irq(&hwif
->lock
);
872 * Note that handler() may have set things up for another
873 * interrupt to occur soon, but it cannot happen until
874 * we exit from this routine, because it will be the
875 * same irq as is currently being serviced here, and Linux
876 * won't allow another of the same (on any CPU) until we return.
878 if (startstop
== ide_stopped
) {
879 BUG_ON(hwif
->handler
);
880 ide_unlock_port(hwif
);
883 irq_ret
= IRQ_HANDLED
;
885 spin_unlock_irqrestore(&hwif
->lock
, flags
);
888 ide_unlock_host(hwif
->host
);
889 ide_plug_device(drive
);
894 EXPORT_SYMBOL_GPL(ide_intr
);
896 void ide_pad_transfer(ide_drive_t
*drive
, int write
, int len
)
898 ide_hwif_t
*hwif
= drive
->hwif
;
903 hwif
->tp_ops
->output_data(drive
, NULL
, buf
, min(4, len
));
905 hwif
->tp_ops
->input_data(drive
, NULL
, buf
, min(4, len
));
909 EXPORT_SYMBOL_GPL(ide_pad_transfer
);