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
);
74 void ide_complete_cmd(ide_drive_t
*drive
, struct ide_cmd
*cmd
, u8 stat
, u8 err
)
76 const struct ide_tp_ops
*tp_ops
= drive
->hwif
->tp_ops
;
77 struct ide_taskfile
*tf
= &cmd
->tf
;
78 struct request
*rq
= cmd
->rq
;
79 u8 tf_cmd
= tf
->command
;
84 if (cmd
->ftf_flags
& IDE_FTFLAG_IN_DATA
) {
87 tp_ops
->input_data(drive
, cmd
, data
, 2);
89 cmd
->tf
.data
= data
[0];
90 cmd
->hob
.data
= data
[1];
93 ide_tf_readback(drive
, cmd
);
95 if ((cmd
->tf_flags
& IDE_TFLAG_CUSTOM_HANDLER
) &&
96 tf_cmd
== ATA_CMD_IDLEIMMEDIATE
) {
97 if (tf
->lbal
!= 0xc4) {
98 printk(KERN_ERR
"%s: head unload failed!\n",
100 ide_tf_dump(drive
->name
, cmd
);
102 drive
->dev_flags
|= IDE_DFLAG_PARKED
;
105 if (rq
&& rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
106 memcpy(rq
->special
, cmd
, sizeof(*cmd
));
108 if (cmd
->tf_flags
& IDE_TFLAG_DYN
)
112 /* obsolete, blk_rq_bytes() should be used instead */
113 unsigned int ide_rq_bytes(struct request
*rq
)
115 if (blk_pc_request(rq
))
118 return rq
->hard_cur_sectors
<< 9;
120 EXPORT_SYMBOL_GPL(ide_rq_bytes
);
122 int ide_complete_rq(ide_drive_t
*drive
, int error
, unsigned int nr_bytes
)
124 ide_hwif_t
*hwif
= drive
->hwif
;
125 struct request
*rq
= hwif
->rq
;
129 * if failfast is set on a request, override number of sectors
130 * and complete the whole request right now
132 if (blk_noretry_request(rq
) && error
<= 0)
133 nr_bytes
= rq
->hard_nr_sectors
<< 9;
135 rc
= ide_end_rq(drive
, rq
, error
, nr_bytes
);
141 EXPORT_SYMBOL(ide_complete_rq
);
143 void ide_kill_rq(ide_drive_t
*drive
, struct request
*rq
)
145 u8 drv_req
= blk_special_request(rq
) && rq
->rq_disk
;
146 u8 media
= drive
->media
;
148 drive
->failed_pc
= NULL
;
150 if ((media
== ide_floppy
|| media
== ide_tape
) && drv_req
) {
152 ide_complete_rq(drive
, 0, blk_rq_bytes(rq
));
154 if (media
== ide_tape
)
155 rq
->errors
= IDE_DRV_ERROR_GENERAL
;
156 else if (blk_fs_request(rq
) == 0 && rq
->errors
== 0)
158 ide_complete_rq(drive
, -EIO
, ide_rq_bytes(rq
));
162 static void ide_tf_set_specify_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
164 tf
->nsect
= drive
->sect
;
165 tf
->lbal
= drive
->sect
;
166 tf
->lbam
= drive
->cyl
;
167 tf
->lbah
= drive
->cyl
>> 8;
168 tf
->device
= (drive
->head
- 1) | drive
->select
;
169 tf
->command
= ATA_CMD_INIT_DEV_PARAMS
;
172 static void ide_tf_set_restore_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
174 tf
->nsect
= drive
->sect
;
175 tf
->command
= ATA_CMD_RESTORE
;
178 static void ide_tf_set_setmult_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
180 tf
->nsect
= drive
->mult_req
;
181 tf
->command
= ATA_CMD_SET_MULTI
;
184 static ide_startstop_t
ide_disk_special(ide_drive_t
*drive
)
186 special_t
*s
= &drive
->special
;
189 memset(&cmd
, 0, sizeof(cmd
));
190 cmd
.protocol
= ATA_PROT_NODATA
;
192 if (s
->b
.set_geometry
) {
193 s
->b
.set_geometry
= 0;
194 ide_tf_set_specify_cmd(drive
, &cmd
.tf
);
195 } else if (s
->b
.recalibrate
) {
196 s
->b
.recalibrate
= 0;
197 ide_tf_set_restore_cmd(drive
, &cmd
.tf
);
198 } else if (s
->b
.set_multmode
) {
199 s
->b
.set_multmode
= 0;
200 ide_tf_set_setmult_cmd(drive
, &cmd
.tf
);
202 int special
= s
->all
;
204 printk(KERN_ERR
"%s: bad special flag: 0x%02x\n", drive
->name
, special
);
208 cmd
.valid
.out
.tf
= IDE_VALID_OUT_TF
| IDE_VALID_DEVICE
;
209 cmd
.valid
.in
.tf
= IDE_VALID_IN_TF
| IDE_VALID_DEVICE
;
210 cmd
.tf_flags
= IDE_TFLAG_CUSTOM_HANDLER
;
212 do_rw_taskfile(drive
, &cmd
);
218 * do_special - issue some special commands
219 * @drive: drive the command is for
221 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
222 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
224 * It used to do much more, but has been scaled back.
227 static ide_startstop_t
do_special (ide_drive_t
*drive
)
229 special_t
*s
= &drive
->special
;
232 printk("%s: do_special: 0x%02x\n", drive
->name
, s
->all
);
234 if (drive
->media
== ide_disk
)
235 return ide_disk_special(drive
);
242 void ide_map_sg(ide_drive_t
*drive
, struct ide_cmd
*cmd
)
244 ide_hwif_t
*hwif
= drive
->hwif
;
245 struct scatterlist
*sg
= hwif
->sg_table
;
246 struct request
*rq
= cmd
->rq
;
248 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
) {
249 sg_init_one(sg
, rq
->buffer
, rq
->nr_sectors
* SECTOR_SIZE
);
251 } else if (!rq
->bio
) {
252 sg_init_one(sg
, rq
->data
, rq
->data_len
);
255 cmd
->sg_nents
= blk_rq_map_sg(drive
->queue
, rq
, sg
);
257 EXPORT_SYMBOL_GPL(ide_map_sg
);
259 void ide_init_sg_cmd(struct ide_cmd
*cmd
, unsigned int nr_bytes
)
261 cmd
->nbytes
= cmd
->nleft
= nr_bytes
;
265 EXPORT_SYMBOL_GPL(ide_init_sg_cmd
);
268 * execute_drive_command - issue special drive command
269 * @drive: the drive to issue the command on
270 * @rq: the request structure holding the command
272 * execute_drive_cmd() issues a special drive command, usually
273 * initiated by ioctl() from the external hdparm program. The
274 * command can be a drive command, drive task or taskfile
275 * operation. Weirdly you can call it with NULL to wait for
276 * all commands to finish. Don't do this as that is due to change
279 static ide_startstop_t
execute_drive_cmd (ide_drive_t
*drive
,
282 struct ide_cmd
*cmd
= rq
->special
;
285 if (cmd
->protocol
== ATA_PROT_PIO
) {
286 ide_init_sg_cmd(cmd
, rq
->nr_sectors
<< 9);
287 ide_map_sg(drive
, cmd
);
290 return do_rw_taskfile(drive
, cmd
);
294 * NULL is actually a valid way of waiting for
295 * all current requests to be flushed from the queue.
298 printk("%s: DRIVE_CMD (null)\n", drive
->name
);
301 ide_complete_rq(drive
, 0, blk_rq_bytes(rq
));
306 static ide_startstop_t
ide_special_rq(ide_drive_t
*drive
, struct request
*rq
)
312 case REQ_UNPARK_HEADS
:
313 return ide_do_park_unpark(drive
, rq
);
314 case REQ_DEVSET_EXEC
:
315 return ide_do_devset(drive
, rq
);
316 case REQ_DRIVE_RESET
:
317 return ide_do_reset(drive
);
324 * start_request - start of I/O and command issuing for IDE
326 * start_request() initiates handling of a new I/O request. It
327 * accepts commands and I/O (read/write) requests.
329 * FIXME: this function needs a rename
332 static ide_startstop_t
start_request (ide_drive_t
*drive
, struct request
*rq
)
334 ide_startstop_t startstop
;
336 BUG_ON(!blk_rq_started(rq
));
339 printk("%s: start_request: current=0x%08lx\n",
340 drive
->hwif
->name
, (unsigned long) rq
);
343 /* bail early if we've exceeded max_failures */
344 if (drive
->max_failures
&& (drive
->failures
> drive
->max_failures
)) {
345 rq
->cmd_flags
|= REQ_FAILED
;
349 if (blk_pm_request(rq
))
350 ide_check_pm_state(drive
, rq
);
352 drive
->hwif
->tp_ops
->dev_select(drive
);
353 if (ide_wait_stat(&startstop
, drive
, drive
->ready_stat
,
354 ATA_BUSY
| ATA_DRQ
, WAIT_READY
)) {
355 printk(KERN_ERR
"%s: drive not ready for command\n", drive
->name
);
358 if (!drive
->special
.all
) {
359 struct ide_driver
*drv
;
362 * We reset the drive so we need to issue a SETFEATURES.
363 * Do it _after_ do_special() restored device parameters.
365 if (drive
->current_speed
== 0xff)
366 ide_config_drive_speed(drive
, drive
->desired_speed
);
368 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
369 return execute_drive_cmd(drive
, rq
);
370 else if (blk_pm_request(rq
)) {
371 struct request_pm_state
*pm
= rq
->data
;
373 printk("%s: start_power_step(step: %d)\n",
374 drive
->name
, pm
->pm_step
);
376 startstop
= ide_start_power_step(drive
, rq
);
377 if (startstop
== ide_stopped
&&
378 pm
->pm_step
== IDE_PM_COMPLETED
)
379 ide_complete_pm_rq(drive
, rq
);
381 } else if (!rq
->rq_disk
&& blk_special_request(rq
))
383 * TODO: Once all ULDs have been modified to
384 * check for specific op codes rather than
385 * blindly accepting any special request, the
386 * check for ->rq_disk above may be replaced
387 * by a more suitable mechanism or even
390 return ide_special_rq(drive
, rq
);
392 drv
= *(struct ide_driver
**)rq
->rq_disk
->private_data
;
394 return drv
->do_request(drive
, rq
, rq
->sector
);
396 return do_special(drive
);
398 ide_kill_rq(drive
, rq
);
403 * ide_stall_queue - pause an IDE device
404 * @drive: drive to stall
405 * @timeout: time to stall for (jiffies)
407 * ide_stall_queue() can be used by a drive to give excess bandwidth back
408 * to the port by sleeping for timeout jiffies.
411 void ide_stall_queue (ide_drive_t
*drive
, unsigned long timeout
)
413 if (timeout
> WAIT_WORSTCASE
)
414 timeout
= WAIT_WORSTCASE
;
415 drive
->sleep
= timeout
+ jiffies
;
416 drive
->dev_flags
|= IDE_DFLAG_SLEEPING
;
418 EXPORT_SYMBOL(ide_stall_queue
);
420 static inline int ide_lock_port(ide_hwif_t
*hwif
)
430 static inline void ide_unlock_port(ide_hwif_t
*hwif
)
435 static inline int ide_lock_host(struct ide_host
*host
, ide_hwif_t
*hwif
)
439 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
440 rc
= test_and_set_bit_lock(IDE_HOST_BUSY
, &host
->host_busy
);
443 host
->get_lock(ide_intr
, hwif
);
449 static inline void ide_unlock_host(struct ide_host
*host
)
451 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
452 if (host
->release_lock
)
453 host
->release_lock();
454 clear_bit_unlock(IDE_HOST_BUSY
, &host
->host_busy
);
459 * Issue a new request to a device.
461 void do_ide_request(struct request_queue
*q
)
463 ide_drive_t
*drive
= q
->queuedata
;
464 ide_hwif_t
*hwif
= drive
->hwif
;
465 struct ide_host
*host
= hwif
->host
;
466 struct request
*rq
= NULL
;
467 ide_startstop_t startstop
;
470 * drive is doing pre-flush, ordered write, post-flush sequence. even
471 * though that is 3 requests, it must be seen as a single transaction.
472 * we must not preempt this drive until that is complete
474 if (blk_queue_flushing(q
))
476 * small race where queue could get replugged during
477 * the 3-request flush cycle, just yank the plug since
478 * we want it to finish asap
482 spin_unlock_irq(q
->queue_lock
);
484 if (ide_lock_host(host
, hwif
))
487 spin_lock_irq(&hwif
->lock
);
489 if (!ide_lock_port(hwif
)) {
490 ide_hwif_t
*prev_port
;
492 prev_port
= hwif
->host
->cur_port
;
495 if (drive
->dev_flags
& IDE_DFLAG_SLEEPING
&&
496 time_after(drive
->sleep
, jiffies
)) {
497 ide_unlock_port(hwif
);
501 if ((hwif
->host
->host_flags
& IDE_HFLAG_SERIALIZE
) &&
504 * set nIEN for previous port, drives in the
505 * quirk_list may not like intr setups/cleanups
507 if (prev_port
&& prev_port
->cur_dev
->quirk_list
== 0)
508 prev_port
->tp_ops
->write_devctl(prev_port
,
512 hwif
->host
->cur_port
= hwif
;
514 hwif
->cur_dev
= drive
;
515 drive
->dev_flags
&= ~(IDE_DFLAG_SLEEPING
| IDE_DFLAG_PARKED
);
517 spin_unlock_irq(&hwif
->lock
);
518 spin_lock_irq(q
->queue_lock
);
520 * we know that the queue isn't empty, but this can happen
521 * if the q->prep_rq_fn() decides to kill a request
523 rq
= elv_next_request(drive
->queue
);
524 spin_unlock_irq(q
->queue_lock
);
525 spin_lock_irq(&hwif
->lock
);
528 ide_unlock_port(hwif
);
533 * Sanity: don't accept a request that isn't a PM request
534 * if we are currently power managed. This is very important as
535 * blk_stop_queue() doesn't prevent the elv_next_request()
536 * above to return us whatever is in the queue. Since we call
537 * ide_do_request() ourselves, we end up taking requests while
538 * the queue is blocked...
540 * We let requests forced at head of queue with ide-preempt
541 * though. I hope that doesn't happen too much, hopefully not
542 * unless the subdriver triggers such a thing in its own PM
545 if ((drive
->dev_flags
& IDE_DFLAG_BLOCKED
) &&
546 blk_pm_request(rq
) == 0 &&
547 (rq
->cmd_flags
& REQ_PREEMPT
) == 0) {
548 /* there should be no pending command at this point */
549 ide_unlock_port(hwif
);
555 spin_unlock_irq(&hwif
->lock
);
556 startstop
= start_request(drive
, rq
);
557 spin_lock_irq(&hwif
->lock
);
559 if (startstop
== ide_stopped
)
564 spin_unlock_irq(&hwif
->lock
);
566 ide_unlock_host(host
);
567 spin_lock_irq(q
->queue_lock
);
571 spin_unlock_irq(&hwif
->lock
);
572 ide_unlock_host(host
);
574 spin_lock_irq(q
->queue_lock
);
576 if (!elv_queue_empty(q
))
580 static void ide_plug_device(ide_drive_t
*drive
)
582 struct request_queue
*q
= drive
->queue
;
585 spin_lock_irqsave(q
->queue_lock
, flags
);
586 if (!elv_queue_empty(q
))
588 spin_unlock_irqrestore(q
->queue_lock
, flags
);
591 static int drive_is_ready(ide_drive_t
*drive
)
593 ide_hwif_t
*hwif
= drive
->hwif
;
596 if (drive
->waiting_for_dma
)
597 return hwif
->dma_ops
->dma_test_irq(drive
);
599 if (hwif
->io_ports
.ctl_addr
&&
600 (hwif
->host_flags
& IDE_HFLAG_BROKEN_ALTSTATUS
) == 0)
601 stat
= hwif
->tp_ops
->read_altstatus(hwif
);
603 /* Note: this may clear a pending IRQ!! */
604 stat
= hwif
->tp_ops
->read_status(hwif
);
607 /* drive busy: definitely not interrupting */
610 /* drive ready: *might* be interrupting */
615 * ide_timer_expiry - handle lack of an IDE interrupt
616 * @data: timer callback magic (hwif)
618 * An IDE command has timed out before the expected drive return
619 * occurred. At this point we attempt to clean up the current
620 * mess. If the current handler includes an expiry handler then
621 * we invoke the expiry handler, and providing it is happy the
622 * work is done. If that fails we apply generic recovery rules
623 * invoking the handler and checking the drive DMA status. We
624 * have an excessively incestuous relationship with the DMA
625 * logic that wants cleaning up.
628 void ide_timer_expiry (unsigned long data
)
630 ide_hwif_t
*hwif
= (ide_hwif_t
*)data
;
631 ide_drive_t
*uninitialized_var(drive
);
632 ide_handler_t
*handler
;
637 spin_lock_irqsave(&hwif
->lock
, flags
);
639 handler
= hwif
->handler
;
641 if (handler
== NULL
|| hwif
->req_gen
!= hwif
->req_gen_timer
) {
643 * Either a marginal timeout occurred
644 * (got the interrupt just as timer expired),
645 * or we were "sleeping" to give other devices a chance.
646 * Either way, we don't really want to complain about anything.
649 ide_expiry_t
*expiry
= hwif
->expiry
;
650 ide_startstop_t startstop
= ide_stopped
;
652 drive
= hwif
->cur_dev
;
655 wait
= expiry(drive
);
656 if (wait
> 0) { /* continue */
658 hwif
->timer
.expires
= jiffies
+ wait
;
659 hwif
->req_gen_timer
= hwif
->req_gen
;
660 add_timer(&hwif
->timer
);
661 spin_unlock_irqrestore(&hwif
->lock
, flags
);
665 hwif
->handler
= NULL
;
668 * We need to simulate a real interrupt when invoking
669 * the handler() function, which means we need to
670 * globally mask the specific IRQ:
672 spin_unlock(&hwif
->lock
);
673 /* disable_irq_nosync ?? */
674 disable_irq(hwif
->irq
);
675 /* local CPU only, as if we were handling an interrupt */
678 startstop
= handler(drive
);
679 } else if (drive_is_ready(drive
)) {
680 if (drive
->waiting_for_dma
)
681 hwif
->dma_ops
->dma_lost_irq(drive
);
683 hwif
->ack_intr(hwif
);
684 printk(KERN_WARNING
"%s: lost interrupt\n",
686 startstop
= handler(drive
);
688 if (drive
->waiting_for_dma
)
689 startstop
= ide_dma_timeout_retry(drive
, wait
);
691 startstop
= ide_error(drive
, "irq timeout",
692 hwif
->tp_ops
->read_status(hwif
));
694 spin_lock_irq(&hwif
->lock
);
695 enable_irq(hwif
->irq
);
696 if (startstop
== ide_stopped
) {
697 ide_unlock_port(hwif
);
701 spin_unlock_irqrestore(&hwif
->lock
, flags
);
704 ide_unlock_host(hwif
->host
);
705 ide_plug_device(drive
);
710 * unexpected_intr - handle an unexpected IDE interrupt
711 * @irq: interrupt line
712 * @hwif: port being processed
714 * There's nothing really useful we can do with an unexpected interrupt,
715 * other than reading the status register (to clear it), and logging it.
716 * There should be no way that an irq can happen before we're ready for it,
717 * so we needn't worry much about losing an "important" interrupt here.
719 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
720 * the drive enters "idle", "standby", or "sleep" mode, so if the status
721 * looks "good", we just ignore the interrupt completely.
723 * This routine assumes __cli() is in effect when called.
725 * If an unexpected interrupt happens on irq15 while we are handling irq14
726 * and if the two interfaces are "serialized" (CMD640), then it looks like
727 * we could screw up by interfering with a new request being set up for
730 * In reality, this is a non-issue. The new command is not sent unless
731 * the drive is ready to accept one, in which case we know the drive is
732 * not trying to interrupt us. And ide_set_handler() is always invoked
733 * before completing the issuance of any new drive command, so we will not
734 * be accidentally invoked as a result of any valid command completion
738 static void unexpected_intr(int irq
, ide_hwif_t
*hwif
)
740 u8 stat
= hwif
->tp_ops
->read_status(hwif
);
742 if (!OK_STAT(stat
, ATA_DRDY
, BAD_STAT
)) {
743 /* Try to not flood the console with msgs */
744 static unsigned long last_msgtime
, count
;
747 if (time_after(jiffies
, last_msgtime
+ HZ
)) {
748 last_msgtime
= jiffies
;
749 printk(KERN_ERR
"%s: unexpected interrupt, "
750 "status=0x%02x, count=%ld\n",
751 hwif
->name
, stat
, count
);
757 * ide_intr - default IDE interrupt handler
758 * @irq: interrupt number
760 * @regs: unused weirdness from the kernel irq layer
762 * This is the default IRQ handler for the IDE layer. You should
763 * not need to override it. If you do be aware it is subtle in
766 * hwif is the interface in the group currently performing
767 * a command. hwif->cur_dev is the drive and hwif->handler is
768 * the IRQ handler to call. As we issue a command the handlers
769 * step through multiple states, reassigning the handler to the
770 * next step in the process. Unlike a smart SCSI controller IDE
771 * expects the main processor to sequence the various transfer
772 * stages. We also manage a poll timer to catch up with most
773 * timeout situations. There are still a few where the handlers
774 * don't ever decide to give up.
776 * The handler eventually returns ide_stopped to indicate the
777 * request completed. At this point we issue the next request
778 * on the port and the process begins again.
781 irqreturn_t
ide_intr (int irq
, void *dev_id
)
783 ide_hwif_t
*hwif
= (ide_hwif_t
*)dev_id
;
784 struct ide_host
*host
= hwif
->host
;
785 ide_drive_t
*uninitialized_var(drive
);
786 ide_handler_t
*handler
;
788 ide_startstop_t startstop
;
789 irqreturn_t irq_ret
= IRQ_NONE
;
792 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
793 if (hwif
!= host
->cur_port
)
797 spin_lock_irqsave(&hwif
->lock
, flags
);
799 if (hwif
->ack_intr
&& hwif
->ack_intr(hwif
) == 0)
802 handler
= hwif
->handler
;
804 if (handler
== NULL
|| hwif
->polling
) {
806 * Not expecting an interrupt from this drive.
807 * That means this could be:
808 * (1) an interrupt from another PCI device
809 * sharing the same PCI INT# as us.
810 * or (2) a drive just entered sleep or standby mode,
811 * and is interrupting to let us know.
812 * or (3) a spurious interrupt of unknown origin.
814 * For PCI, we cannot tell the difference,
815 * so in that case we just ignore it and hope it goes away.
817 if ((host
->irq_flags
& IRQF_SHARED
) == 0) {
819 * Probably not a shared PCI interrupt,
820 * so we can safely try to do something about it:
822 unexpected_intr(irq
, hwif
);
825 * Whack the status register, just in case
826 * we have a leftover pending IRQ.
828 (void)hwif
->tp_ops
->read_status(hwif
);
833 drive
= hwif
->cur_dev
;
835 if (!drive_is_ready(drive
))
837 * This happens regularly when we share a PCI IRQ with
838 * another device. Unfortunately, it can also happen
839 * with some buggy drives that trigger the IRQ before
840 * their status register is up to date. Hopefully we have
841 * enough advance overhead that the latter isn't a problem.
845 hwif
->handler
= NULL
;
848 del_timer(&hwif
->timer
);
849 spin_unlock(&hwif
->lock
);
851 if (hwif
->port_ops
&& hwif
->port_ops
->clear_irq
)
852 hwif
->port_ops
->clear_irq(drive
);
854 if (drive
->dev_flags
& IDE_DFLAG_UNMASK
)
855 local_irq_enable_in_hardirq();
857 /* service this interrupt, may set handler for next interrupt */
858 startstop
= handler(drive
);
860 spin_lock_irq(&hwif
->lock
);
862 * Note that handler() may have set things up for another
863 * interrupt to occur soon, but it cannot happen until
864 * we exit from this routine, because it will be the
865 * same irq as is currently being serviced here, and Linux
866 * won't allow another of the same (on any CPU) until we return.
868 if (startstop
== ide_stopped
) {
869 BUG_ON(hwif
->handler
);
870 ide_unlock_port(hwif
);
873 irq_ret
= IRQ_HANDLED
;
875 spin_unlock_irqrestore(&hwif
->lock
, flags
);
878 ide_unlock_host(hwif
->host
);
879 ide_plug_device(drive
);
884 EXPORT_SYMBOL_GPL(ide_intr
);
886 void ide_pad_transfer(ide_drive_t
*drive
, int write
, int len
)
888 ide_hwif_t
*hwif
= drive
->hwif
;
893 hwif
->tp_ops
->output_data(drive
, NULL
, buf
, min(4, len
));
895 hwif
->tp_ops
->input_data(drive
, NULL
, buf
, min(4, len
));
899 EXPORT_SYMBOL_GPL(ide_pad_transfer
);