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;
106 error
= uptodate
? uptodate
: -EIO
;
108 rc
= ide_end_rq(drive
, rq
, error
, nr_bytes
);
110 drive
->hwif
->rq
= NULL
;
114 EXPORT_SYMBOL(ide_end_request
);
116 void ide_complete_cmd(ide_drive_t
*drive
, struct ide_cmd
*cmd
, u8 stat
, u8 err
)
118 struct ide_taskfile
*tf
= &cmd
->tf
;
119 struct request
*rq
= cmd
->rq
;
120 u8 tf_cmd
= tf
->command
;
125 drive
->hwif
->tp_ops
->tf_read(drive
, cmd
);
127 if ((cmd
->tf_flags
& IDE_TFLAG_CUSTOM_HANDLER
) &&
128 tf_cmd
== ATA_CMD_IDLEIMMEDIATE
) {
129 if (tf
->lbal
!= 0xc4) {
130 printk(KERN_ERR
"%s: head unload failed!\n",
132 ide_tf_dump(drive
->name
, tf
);
134 drive
->dev_flags
|= IDE_DFLAG_PARKED
;
137 if (rq
&& rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
138 memcpy(rq
->special
, cmd
, sizeof(*cmd
));
140 if (cmd
->tf_flags
& IDE_TFLAG_DYN
)
144 int ide_complete_rq(ide_drive_t
*drive
, int error
, unsigned int nr_bytes
)
146 ide_hwif_t
*hwif
= drive
->hwif
;
147 struct request
*rq
= hwif
->rq
;
150 rc
= blk_end_request(rq
, error
, nr_bytes
);
156 EXPORT_SYMBOL(ide_complete_rq
);
158 void ide_kill_rq(ide_drive_t
*drive
, struct request
*rq
)
160 u8 drv_req
= blk_special_request(rq
) && rq
->rq_disk
;
161 u8 media
= drive
->media
;
163 drive
->failed_pc
= NULL
;
165 if ((media
== ide_floppy
|| media
== ide_tape
) && drv_req
) {
167 ide_complete_rq(drive
, 0, blk_rq_bytes(rq
));
169 if (media
== ide_tape
)
170 rq
->errors
= IDE_DRV_ERROR_GENERAL
;
171 else if (blk_fs_request(rq
) == 0 && rq
->errors
== 0)
173 ide_end_request(drive
, 0, 0);
177 static void ide_tf_set_specify_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
179 tf
->nsect
= drive
->sect
;
180 tf
->lbal
= drive
->sect
;
181 tf
->lbam
= drive
->cyl
;
182 tf
->lbah
= drive
->cyl
>> 8;
183 tf
->device
= (drive
->head
- 1) | drive
->select
;
184 tf
->command
= ATA_CMD_INIT_DEV_PARAMS
;
187 static void ide_tf_set_restore_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
189 tf
->nsect
= drive
->sect
;
190 tf
->command
= ATA_CMD_RESTORE
;
193 static void ide_tf_set_setmult_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
195 tf
->nsect
= drive
->mult_req
;
196 tf
->command
= ATA_CMD_SET_MULTI
;
199 static ide_startstop_t
ide_disk_special(ide_drive_t
*drive
)
201 special_t
*s
= &drive
->special
;
204 memset(&cmd
, 0, sizeof(cmd
));
205 cmd
.protocol
= ATA_PROT_NODATA
;
207 if (s
->b
.set_geometry
) {
208 s
->b
.set_geometry
= 0;
209 ide_tf_set_specify_cmd(drive
, &cmd
.tf
);
210 } else if (s
->b
.recalibrate
) {
211 s
->b
.recalibrate
= 0;
212 ide_tf_set_restore_cmd(drive
, &cmd
.tf
);
213 } else if (s
->b
.set_multmode
) {
214 s
->b
.set_multmode
= 0;
215 ide_tf_set_setmult_cmd(drive
, &cmd
.tf
);
217 int special
= s
->all
;
219 printk(KERN_ERR
"%s: bad special flag: 0x%02x\n", drive
->name
, special
);
223 cmd
.tf_flags
= IDE_TFLAG_TF
| IDE_TFLAG_DEVICE
|
224 IDE_TFLAG_CUSTOM_HANDLER
;
226 do_rw_taskfile(drive
, &cmd
);
232 * do_special - issue some special commands
233 * @drive: drive the command is for
235 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
236 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
238 * It used to do much more, but has been scaled back.
241 static ide_startstop_t
do_special (ide_drive_t
*drive
)
243 special_t
*s
= &drive
->special
;
246 printk("%s: do_special: 0x%02x\n", drive
->name
, s
->all
);
248 if (drive
->media
== ide_disk
)
249 return ide_disk_special(drive
);
256 void ide_map_sg(ide_drive_t
*drive
, struct request
*rq
)
258 ide_hwif_t
*hwif
= drive
->hwif
;
259 struct ide_cmd
*cmd
= &hwif
->cmd
;
260 struct scatterlist
*sg
= hwif
->sg_table
;
262 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
) {
263 sg_init_one(sg
, rq
->buffer
, rq
->nr_sectors
* SECTOR_SIZE
);
265 } else if (!rq
->bio
) {
266 sg_init_one(sg
, rq
->data
, rq
->data_len
);
269 cmd
->sg_nents
= blk_rq_map_sg(drive
->queue
, rq
, sg
);
271 EXPORT_SYMBOL_GPL(ide_map_sg
);
273 void ide_init_sg_cmd(struct ide_cmd
*cmd
, int nsect
)
275 cmd
->nsect
= cmd
->nleft
= nsect
;
279 EXPORT_SYMBOL_GPL(ide_init_sg_cmd
);
282 * execute_drive_command - issue special drive command
283 * @drive: the drive to issue the command on
284 * @rq: the request structure holding the command
286 * execute_drive_cmd() issues a special drive command, usually
287 * initiated by ioctl() from the external hdparm program. The
288 * command can be a drive command, drive task or taskfile
289 * operation. Weirdly you can call it with NULL to wait for
290 * all commands to finish. Don't do this as that is due to change
293 static ide_startstop_t
execute_drive_cmd (ide_drive_t
*drive
,
296 struct ide_cmd
*cmd
= rq
->special
;
299 if (cmd
->protocol
== ATA_PROT_PIO
) {
300 ide_init_sg_cmd(cmd
, rq
->nr_sectors
);
301 ide_map_sg(drive
, rq
);
304 return do_rw_taskfile(drive
, cmd
);
308 * NULL is actually a valid way of waiting for
309 * all current requests to be flushed from the queue.
312 printk("%s: DRIVE_CMD (null)\n", drive
->name
);
315 ide_complete_rq(drive
, 0, blk_rq_bytes(rq
));
320 static ide_startstop_t
ide_special_rq(ide_drive_t
*drive
, struct request
*rq
)
326 case REQ_UNPARK_HEADS
:
327 return ide_do_park_unpark(drive
, rq
);
328 case REQ_DEVSET_EXEC
:
329 return ide_do_devset(drive
, rq
);
330 case REQ_DRIVE_RESET
:
331 return ide_do_reset(drive
);
338 * start_request - start of I/O and command issuing for IDE
340 * start_request() initiates handling of a new I/O request. It
341 * accepts commands and I/O (read/write) requests.
343 * FIXME: this function needs a rename
346 static ide_startstop_t
start_request (ide_drive_t
*drive
, struct request
*rq
)
348 ide_startstop_t startstop
;
350 BUG_ON(!blk_rq_started(rq
));
353 printk("%s: start_request: current=0x%08lx\n",
354 drive
->hwif
->name
, (unsigned long) rq
);
357 /* bail early if we've exceeded max_failures */
358 if (drive
->max_failures
&& (drive
->failures
> drive
->max_failures
)) {
359 rq
->cmd_flags
|= REQ_FAILED
;
363 if (blk_pm_request(rq
))
364 ide_check_pm_state(drive
, rq
);
367 if (ide_wait_stat(&startstop
, drive
, drive
->ready_stat
,
368 ATA_BUSY
| ATA_DRQ
, WAIT_READY
)) {
369 printk(KERN_ERR
"%s: drive not ready for command\n", drive
->name
);
372 if (!drive
->special
.all
) {
373 struct ide_driver
*drv
;
376 * We reset the drive so we need to issue a SETFEATURES.
377 * Do it _after_ do_special() restored device parameters.
379 if (drive
->current_speed
== 0xff)
380 ide_config_drive_speed(drive
, drive
->desired_speed
);
382 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
383 return execute_drive_cmd(drive
, rq
);
384 else if (blk_pm_request(rq
)) {
385 struct request_pm_state
*pm
= rq
->data
;
387 printk("%s: start_power_step(step: %d)\n",
388 drive
->name
, pm
->pm_step
);
390 startstop
= ide_start_power_step(drive
, rq
);
391 if (startstop
== ide_stopped
&&
392 pm
->pm_step
== IDE_PM_COMPLETED
)
393 ide_complete_pm_rq(drive
, rq
);
395 } else if (!rq
->rq_disk
&& blk_special_request(rq
))
397 * TODO: Once all ULDs have been modified to
398 * check for specific op codes rather than
399 * blindly accepting any special request, the
400 * check for ->rq_disk above may be replaced
401 * by a more suitable mechanism or even
404 return ide_special_rq(drive
, rq
);
406 drv
= *(struct ide_driver
**)rq
->rq_disk
->private_data
;
408 return drv
->do_request(drive
, rq
, rq
->sector
);
410 return do_special(drive
);
412 ide_kill_rq(drive
, rq
);
417 * ide_stall_queue - pause an IDE device
418 * @drive: drive to stall
419 * @timeout: time to stall for (jiffies)
421 * ide_stall_queue() can be used by a drive to give excess bandwidth back
422 * to the port by sleeping for timeout jiffies.
425 void ide_stall_queue (ide_drive_t
*drive
, unsigned long timeout
)
427 if (timeout
> WAIT_WORSTCASE
)
428 timeout
= WAIT_WORSTCASE
;
429 drive
->sleep
= timeout
+ jiffies
;
430 drive
->dev_flags
|= IDE_DFLAG_SLEEPING
;
432 EXPORT_SYMBOL(ide_stall_queue
);
434 static inline int ide_lock_port(ide_hwif_t
*hwif
)
444 static inline void ide_unlock_port(ide_hwif_t
*hwif
)
449 static inline int ide_lock_host(struct ide_host
*host
, ide_hwif_t
*hwif
)
453 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
454 rc
= test_and_set_bit_lock(IDE_HOST_BUSY
, &host
->host_busy
);
457 host
->get_lock(ide_intr
, hwif
);
463 static inline void ide_unlock_host(struct ide_host
*host
)
465 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
466 if (host
->release_lock
)
467 host
->release_lock();
468 clear_bit_unlock(IDE_HOST_BUSY
, &host
->host_busy
);
473 * Issue a new request to a device.
475 void do_ide_request(struct request_queue
*q
)
477 ide_drive_t
*drive
= q
->queuedata
;
478 ide_hwif_t
*hwif
= drive
->hwif
;
479 struct ide_host
*host
= hwif
->host
;
480 struct request
*rq
= NULL
;
481 ide_startstop_t startstop
;
484 * drive is doing pre-flush, ordered write, post-flush sequence. even
485 * though that is 3 requests, it must be seen as a single transaction.
486 * we must not preempt this drive until that is complete
488 if (blk_queue_flushing(q
))
490 * small race where queue could get replugged during
491 * the 3-request flush cycle, just yank the plug since
492 * we want it to finish asap
496 spin_unlock_irq(q
->queue_lock
);
498 if (ide_lock_host(host
, hwif
))
501 spin_lock_irq(&hwif
->lock
);
503 if (!ide_lock_port(hwif
)) {
504 ide_hwif_t
*prev_port
;
506 prev_port
= hwif
->host
->cur_port
;
509 if (drive
->dev_flags
& IDE_DFLAG_SLEEPING
) {
510 if (time_before(drive
->sleep
, jiffies
)) {
511 ide_unlock_port(hwif
);
516 if ((hwif
->host
->host_flags
& IDE_HFLAG_SERIALIZE
) &&
519 * set nIEN for previous port, drives in the
520 * quirk_list may not like intr setups/cleanups
522 if (prev_port
&& prev_port
->cur_dev
->quirk_list
== 0)
523 prev_port
->tp_ops
->set_irq(prev_port
, 0);
525 hwif
->host
->cur_port
= hwif
;
527 hwif
->cur_dev
= drive
;
528 drive
->dev_flags
&= ~(IDE_DFLAG_SLEEPING
| IDE_DFLAG_PARKED
);
530 spin_unlock_irq(&hwif
->lock
);
531 spin_lock_irq(q
->queue_lock
);
533 * we know that the queue isn't empty, but this can happen
534 * if the q->prep_rq_fn() decides to kill a request
536 rq
= elv_next_request(drive
->queue
);
537 spin_unlock_irq(q
->queue_lock
);
538 spin_lock_irq(&hwif
->lock
);
541 ide_unlock_port(hwif
);
546 * Sanity: don't accept a request that isn't a PM request
547 * if we are currently power managed. This is very important as
548 * blk_stop_queue() doesn't prevent the elv_next_request()
549 * above to return us whatever is in the queue. Since we call
550 * ide_do_request() ourselves, we end up taking requests while
551 * the queue is blocked...
553 * We let requests forced at head of queue with ide-preempt
554 * though. I hope that doesn't happen too much, hopefully not
555 * unless the subdriver triggers such a thing in its own PM
558 if ((drive
->dev_flags
& IDE_DFLAG_BLOCKED
) &&
559 blk_pm_request(rq
) == 0 &&
560 (rq
->cmd_flags
& REQ_PREEMPT
) == 0) {
561 /* there should be no pending command at this point */
562 ide_unlock_port(hwif
);
568 spin_unlock_irq(&hwif
->lock
);
569 startstop
= start_request(drive
, rq
);
570 spin_lock_irq(&hwif
->lock
);
572 if (startstop
== ide_stopped
)
577 spin_unlock_irq(&hwif
->lock
);
579 ide_unlock_host(host
);
580 spin_lock_irq(q
->queue_lock
);
584 spin_unlock_irq(&hwif
->lock
);
585 ide_unlock_host(host
);
587 spin_lock_irq(q
->queue_lock
);
589 if (!elv_queue_empty(q
))
593 static void ide_plug_device(ide_drive_t
*drive
)
595 struct request_queue
*q
= drive
->queue
;
598 spin_lock_irqsave(q
->queue_lock
, flags
);
599 if (!elv_queue_empty(q
))
601 spin_unlock_irqrestore(q
->queue_lock
, flags
);
604 static int drive_is_ready(ide_drive_t
*drive
)
606 ide_hwif_t
*hwif
= drive
->hwif
;
609 if (drive
->waiting_for_dma
)
610 return hwif
->dma_ops
->dma_test_irq(drive
);
612 if (hwif
->io_ports
.ctl_addr
&&
613 (hwif
->host_flags
& IDE_HFLAG_BROKEN_ALTSTATUS
) == 0)
614 stat
= hwif
->tp_ops
->read_altstatus(hwif
);
616 /* Note: this may clear a pending IRQ!! */
617 stat
= hwif
->tp_ops
->read_status(hwif
);
620 /* drive busy: definitely not interrupting */
623 /* drive ready: *might* be interrupting */
628 * ide_timer_expiry - handle lack of an IDE interrupt
629 * @data: timer callback magic (hwif)
631 * An IDE command has timed out before the expected drive return
632 * occurred. At this point we attempt to clean up the current
633 * mess. If the current handler includes an expiry handler then
634 * we invoke the expiry handler, and providing it is happy the
635 * work is done. If that fails we apply generic recovery rules
636 * invoking the handler and checking the drive DMA status. We
637 * have an excessively incestuous relationship with the DMA
638 * logic that wants cleaning up.
641 void ide_timer_expiry (unsigned long data
)
643 ide_hwif_t
*hwif
= (ide_hwif_t
*)data
;
644 ide_drive_t
*uninitialized_var(drive
);
645 ide_handler_t
*handler
;
650 spin_lock_irqsave(&hwif
->lock
, flags
);
652 handler
= hwif
->handler
;
654 if (handler
== NULL
|| hwif
->req_gen
!= hwif
->req_gen_timer
) {
656 * Either a marginal timeout occurred
657 * (got the interrupt just as timer expired),
658 * or we were "sleeping" to give other devices a chance.
659 * Either way, we don't really want to complain about anything.
662 ide_expiry_t
*expiry
= hwif
->expiry
;
663 ide_startstop_t startstop
= ide_stopped
;
665 drive
= hwif
->cur_dev
;
668 wait
= expiry(drive
);
669 if (wait
> 0) { /* continue */
671 hwif
->timer
.expires
= jiffies
+ wait
;
672 hwif
->req_gen_timer
= hwif
->req_gen
;
673 add_timer(&hwif
->timer
);
674 spin_unlock_irqrestore(&hwif
->lock
, flags
);
678 hwif
->handler
= NULL
;
680 * We need to simulate a real interrupt when invoking
681 * the handler() function, which means we need to
682 * globally mask the specific IRQ:
684 spin_unlock(&hwif
->lock
);
685 /* disable_irq_nosync ?? */
686 disable_irq(hwif
->irq
);
687 /* local CPU only, as if we were handling an interrupt */
690 startstop
= handler(drive
);
691 } else if (drive_is_ready(drive
)) {
692 if (drive
->waiting_for_dma
)
693 hwif
->dma_ops
->dma_lost_irq(drive
);
695 hwif
->ack_intr(hwif
);
696 printk(KERN_WARNING
"%s: lost interrupt\n",
698 startstop
= handler(drive
);
700 if (drive
->waiting_for_dma
)
701 startstop
= ide_dma_timeout_retry(drive
, wait
);
703 startstop
= ide_error(drive
, "irq timeout",
704 hwif
->tp_ops
->read_status(hwif
));
706 spin_lock_irq(&hwif
->lock
);
707 enable_irq(hwif
->irq
);
708 if (startstop
== ide_stopped
) {
709 ide_unlock_port(hwif
);
713 spin_unlock_irqrestore(&hwif
->lock
, flags
);
716 ide_unlock_host(hwif
->host
);
717 ide_plug_device(drive
);
722 * unexpected_intr - handle an unexpected IDE interrupt
723 * @irq: interrupt line
724 * @hwif: port being processed
726 * There's nothing really useful we can do with an unexpected interrupt,
727 * other than reading the status register (to clear it), and logging it.
728 * There should be no way that an irq can happen before we're ready for it,
729 * so we needn't worry much about losing an "important" interrupt here.
731 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
732 * the drive enters "idle", "standby", or "sleep" mode, so if the status
733 * looks "good", we just ignore the interrupt completely.
735 * This routine assumes __cli() is in effect when called.
737 * If an unexpected interrupt happens on irq15 while we are handling irq14
738 * and if the two interfaces are "serialized" (CMD640), then it looks like
739 * we could screw up by interfering with a new request being set up for
742 * In reality, this is a non-issue. The new command is not sent unless
743 * the drive is ready to accept one, in which case we know the drive is
744 * not trying to interrupt us. And ide_set_handler() is always invoked
745 * before completing the issuance of any new drive command, so we will not
746 * be accidentally invoked as a result of any valid command completion
750 static void unexpected_intr(int irq
, ide_hwif_t
*hwif
)
752 u8 stat
= hwif
->tp_ops
->read_status(hwif
);
754 if (!OK_STAT(stat
, ATA_DRDY
, BAD_STAT
)) {
755 /* Try to not flood the console with msgs */
756 static unsigned long last_msgtime
, count
;
759 if (time_after(jiffies
, last_msgtime
+ HZ
)) {
760 last_msgtime
= jiffies
;
761 printk(KERN_ERR
"%s: unexpected interrupt, "
762 "status=0x%02x, count=%ld\n",
763 hwif
->name
, stat
, count
);
769 * ide_intr - default IDE interrupt handler
770 * @irq: interrupt number
772 * @regs: unused weirdness from the kernel irq layer
774 * This is the default IRQ handler for the IDE layer. You should
775 * not need to override it. If you do be aware it is subtle in
778 * hwif is the interface in the group currently performing
779 * a command. hwif->cur_dev is the drive and hwif->handler is
780 * the IRQ handler to call. As we issue a command the handlers
781 * step through multiple states, reassigning the handler to the
782 * next step in the process. Unlike a smart SCSI controller IDE
783 * expects the main processor to sequence the various transfer
784 * stages. We also manage a poll timer to catch up with most
785 * timeout situations. There are still a few where the handlers
786 * don't ever decide to give up.
788 * The handler eventually returns ide_stopped to indicate the
789 * request completed. At this point we issue the next request
790 * on the port and the process begins again.
793 irqreturn_t
ide_intr (int irq
, void *dev_id
)
795 ide_hwif_t
*hwif
= (ide_hwif_t
*)dev_id
;
796 struct ide_host
*host
= hwif
->host
;
797 ide_drive_t
*uninitialized_var(drive
);
798 ide_handler_t
*handler
;
800 ide_startstop_t startstop
;
801 irqreturn_t irq_ret
= IRQ_NONE
;
804 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
805 if (hwif
!= host
->cur_port
)
809 spin_lock_irqsave(&hwif
->lock
, flags
);
811 if (hwif
->ack_intr
&& hwif
->ack_intr(hwif
) == 0)
814 handler
= hwif
->handler
;
816 if (handler
== NULL
|| hwif
->polling
) {
818 * Not expecting an interrupt from this drive.
819 * That means this could be:
820 * (1) an interrupt from another PCI device
821 * sharing the same PCI INT# as us.
822 * or (2) a drive just entered sleep or standby mode,
823 * and is interrupting to let us know.
824 * or (3) a spurious interrupt of unknown origin.
826 * For PCI, we cannot tell the difference,
827 * so in that case we just ignore it and hope it goes away.
829 if ((host
->irq_flags
& IRQF_SHARED
) == 0) {
831 * Probably not a shared PCI interrupt,
832 * so we can safely try to do something about it:
834 unexpected_intr(irq
, hwif
);
837 * Whack the status register, just in case
838 * we have a leftover pending IRQ.
840 (void)hwif
->tp_ops
->read_status(hwif
);
845 drive
= hwif
->cur_dev
;
847 if (!drive_is_ready(drive
))
849 * This happens regularly when we share a PCI IRQ with
850 * another device. Unfortunately, it can also happen
851 * with some buggy drives that trigger the IRQ before
852 * their status register is up to date. Hopefully we have
853 * enough advance overhead that the latter isn't a problem.
857 hwif
->handler
= NULL
;
859 del_timer(&hwif
->timer
);
860 spin_unlock(&hwif
->lock
);
862 if (hwif
->port_ops
&& hwif
->port_ops
->clear_irq
)
863 hwif
->port_ops
->clear_irq(drive
);
865 if (drive
->dev_flags
& IDE_DFLAG_UNMASK
)
866 local_irq_enable_in_hardirq();
868 /* service this interrupt, may set handler for next interrupt */
869 startstop
= handler(drive
);
871 spin_lock_irq(&hwif
->lock
);
873 * Note that handler() may have set things up for another
874 * interrupt to occur soon, but it cannot happen until
875 * we exit from this routine, because it will be the
876 * same irq as is currently being serviced here, and Linux
877 * won't allow another of the same (on any CPU) until we return.
879 if (startstop
== ide_stopped
) {
880 BUG_ON(hwif
->handler
);
881 ide_unlock_port(hwif
);
884 irq_ret
= IRQ_HANDLED
;
886 spin_unlock_irqrestore(&hwif
->lock
, flags
);
889 ide_unlock_host(hwif
->host
);
890 ide_plug_device(drive
);
895 EXPORT_SYMBOL_GPL(ide_intr
);
897 void ide_pad_transfer(ide_drive_t
*drive
, int write
, int len
)
899 ide_hwif_t
*hwif
= drive
->hwif
;
904 hwif
->tp_ops
->output_data(drive
, NULL
, buf
, min(4, len
));
906 hwif
->tp_ops
->input_data(drive
, NULL
, buf
, min(4, len
));
910 EXPORT_SYMBOL_GPL(ide_pad_transfer
);