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/hdreg.h>
44 #include <linux/completion.h>
45 #include <linux/reboot.h>
46 #include <linux/cdrom.h>
47 #include <linux/seq_file.h>
48 #include <linux/device.h>
49 #include <linux/kmod.h>
50 #include <linux/scatterlist.h>
51 #include <linux/bitops.h>
53 #include <asm/byteorder.h>
55 #include <asm/uaccess.h>
58 static int __ide_end_request(ide_drive_t
*drive
, struct request
*rq
,
59 int uptodate
, unsigned int nr_bytes
, int dequeue
)
65 error
= uptodate
? uptodate
: -EIO
;
68 * if failfast is set on a request, override number of sectors and
69 * complete the whole request right now
71 if (blk_noretry_request(rq
) && error
)
72 nr_bytes
= rq
->hard_nr_sectors
<< 9;
74 if (!blk_fs_request(rq
) && error
&& !rq
->errors
)
78 * decide whether to reenable DMA -- 3 is a random magic for now,
79 * if we DMA timeout more than 3 times, just stay in PIO
81 if ((drive
->dev_flags
& IDE_DFLAG_DMA_PIO_RETRY
) &&
82 drive
->retry_pio
<= 3) {
83 drive
->dev_flags
&= ~IDE_DFLAG_DMA_PIO_RETRY
;
87 if (!blk_end_request(rq
, error
, nr_bytes
))
90 if (ret
== 0 && dequeue
)
91 drive
->hwif
->rq
= NULL
;
97 * ide_end_request - complete an IDE I/O
98 * @drive: IDE device for the I/O
100 * @nr_sectors: number of sectors completed
102 * This is our end_request wrapper function. We complete the I/O
103 * update random number input and dequeue the request, which if
104 * it was tagged may be out of order.
107 int ide_end_request (ide_drive_t
*drive
, int uptodate
, int nr_sectors
)
109 unsigned int nr_bytes
= nr_sectors
<< 9;
110 struct request
*rq
= drive
->hwif
->rq
;
113 if (blk_pc_request(rq
))
114 nr_bytes
= rq
->data_len
;
116 nr_bytes
= rq
->hard_cur_sectors
<< 9;
119 return __ide_end_request(drive
, rq
, uptodate
, nr_bytes
, 1);
121 EXPORT_SYMBOL(ide_end_request
);
124 * ide_end_dequeued_request - complete an IDE I/O
125 * @drive: IDE device for the I/O
127 * @nr_sectors: number of sectors completed
129 * Complete an I/O that is no longer on the request queue. This
130 * typically occurs when we pull the request and issue a REQUEST_SENSE.
131 * We must still finish the old request but we must not tamper with the
132 * queue in the meantime.
134 * NOTE: This path does not handle barrier, but barrier is not supported
138 int ide_end_dequeued_request(ide_drive_t
*drive
, struct request
*rq
,
139 int uptodate
, int nr_sectors
)
141 BUG_ON(!blk_rq_started(rq
));
143 return __ide_end_request(drive
, rq
, uptodate
, nr_sectors
<< 9, 0);
145 EXPORT_SYMBOL_GPL(ide_end_dequeued_request
);
148 * ide_end_drive_cmd - end an explicit drive command
153 * Clean up after success/failure of an explicit drive command.
154 * These get thrown onto the queue so they are synchronized with
155 * real I/O operations on the drive.
157 * In LBA48 mode we have to read the register set twice to get
158 * all the extra information out.
161 void ide_end_drive_cmd (ide_drive_t
*drive
, u8 stat
, u8 err
)
163 ide_hwif_t
*hwif
= drive
->hwif
;
164 struct request
*rq
= hwif
->rq
;
166 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
) {
167 ide_task_t
*task
= (ide_task_t
*)rq
->special
;
170 struct ide_taskfile
*tf
= &task
->tf
;
175 drive
->hwif
->tp_ops
->tf_read(drive
, task
);
177 if (task
->tf_flags
& IDE_TFLAG_DYN
)
180 } else if (blk_pm_request(rq
)) {
181 struct request_pm_state
*pm
= rq
->data
;
183 ide_complete_power_step(drive
, rq
);
184 if (pm
->pm_step
== IDE_PM_COMPLETED
)
185 ide_complete_pm_request(drive
, rq
);
193 if (unlikely(blk_end_request(rq
, (rq
->errors
? -EIO
: 0),
197 EXPORT_SYMBOL(ide_end_drive_cmd
);
199 void ide_kill_rq(ide_drive_t
*drive
, struct request
*rq
)
202 struct ide_driver
*drv
;
204 drv
= *(struct ide_driver
**)rq
->rq_disk
->private_data
;
205 drv
->end_request(drive
, 0, 0);
207 ide_end_request(drive
, 0, 0);
210 static void ide_tf_set_specify_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
212 tf
->nsect
= drive
->sect
;
213 tf
->lbal
= drive
->sect
;
214 tf
->lbam
= drive
->cyl
;
215 tf
->lbah
= drive
->cyl
>> 8;
216 tf
->device
= (drive
->head
- 1) | drive
->select
;
217 tf
->command
= ATA_CMD_INIT_DEV_PARAMS
;
220 static void ide_tf_set_restore_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
222 tf
->nsect
= drive
->sect
;
223 tf
->command
= ATA_CMD_RESTORE
;
226 static void ide_tf_set_setmult_cmd(ide_drive_t
*drive
, struct ide_taskfile
*tf
)
228 tf
->nsect
= drive
->mult_req
;
229 tf
->command
= ATA_CMD_SET_MULTI
;
232 static ide_startstop_t
ide_disk_special(ide_drive_t
*drive
)
234 special_t
*s
= &drive
->special
;
237 memset(&args
, 0, sizeof(ide_task_t
));
238 args
.data_phase
= TASKFILE_NO_DATA
;
240 if (s
->b
.set_geometry
) {
241 s
->b
.set_geometry
= 0;
242 ide_tf_set_specify_cmd(drive
, &args
.tf
);
243 } else if (s
->b
.recalibrate
) {
244 s
->b
.recalibrate
= 0;
245 ide_tf_set_restore_cmd(drive
, &args
.tf
);
246 } else if (s
->b
.set_multmode
) {
247 s
->b
.set_multmode
= 0;
248 ide_tf_set_setmult_cmd(drive
, &args
.tf
);
250 int special
= s
->all
;
252 printk(KERN_ERR
"%s: bad special flag: 0x%02x\n", drive
->name
, special
);
256 args
.tf_flags
= IDE_TFLAG_TF
| IDE_TFLAG_DEVICE
|
257 IDE_TFLAG_CUSTOM_HANDLER
;
259 do_rw_taskfile(drive
, &args
);
265 * do_special - issue some special commands
266 * @drive: drive the command is for
268 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
269 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
271 * It used to do much more, but has been scaled back.
274 static ide_startstop_t
do_special (ide_drive_t
*drive
)
276 special_t
*s
= &drive
->special
;
279 printk("%s: do_special: 0x%02x\n", drive
->name
, s
->all
);
281 if (drive
->media
== ide_disk
)
282 return ide_disk_special(drive
);
289 void ide_map_sg(ide_drive_t
*drive
, struct request
*rq
)
291 ide_hwif_t
*hwif
= drive
->hwif
;
292 struct scatterlist
*sg
= hwif
->sg_table
;
294 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
) {
295 sg_init_one(sg
, rq
->buffer
, rq
->nr_sectors
* SECTOR_SIZE
);
297 } else if (!rq
->bio
) {
298 sg_init_one(sg
, rq
->data
, rq
->data_len
);
301 hwif
->sg_nents
= blk_rq_map_sg(drive
->queue
, rq
, sg
);
305 EXPORT_SYMBOL_GPL(ide_map_sg
);
307 void ide_init_sg_cmd(ide_drive_t
*drive
, struct request
*rq
)
309 ide_hwif_t
*hwif
= drive
->hwif
;
311 hwif
->nsect
= hwif
->nleft
= rq
->nr_sectors
;
316 EXPORT_SYMBOL_GPL(ide_init_sg_cmd
);
319 * execute_drive_command - issue special drive command
320 * @drive: the drive to issue the command on
321 * @rq: the request structure holding the command
323 * execute_drive_cmd() issues a special drive command, usually
324 * initiated by ioctl() from the external hdparm program. The
325 * command can be a drive command, drive task or taskfile
326 * operation. Weirdly you can call it with NULL to wait for
327 * all commands to finish. Don't do this as that is due to change
330 static ide_startstop_t
execute_drive_cmd (ide_drive_t
*drive
,
333 ide_hwif_t
*hwif
= drive
->hwif
;
334 ide_task_t
*task
= rq
->special
;
337 hwif
->data_phase
= task
->data_phase
;
339 switch (hwif
->data_phase
) {
340 case TASKFILE_MULTI_OUT
:
342 case TASKFILE_MULTI_IN
:
344 ide_init_sg_cmd(drive
, rq
);
345 ide_map_sg(drive
, rq
);
350 return do_rw_taskfile(drive
, task
);
354 * NULL is actually a valid way of waiting for
355 * all current requests to be flushed from the queue.
358 printk("%s: DRIVE_CMD (null)\n", drive
->name
);
360 ide_end_drive_cmd(drive
, hwif
->tp_ops
->read_status(hwif
),
361 ide_read_error(drive
));
366 static ide_startstop_t
ide_special_rq(ide_drive_t
*drive
, struct request
*rq
)
372 case REQ_UNPARK_HEADS
:
373 return ide_do_park_unpark(drive
, rq
);
374 case REQ_DEVSET_EXEC
:
375 return ide_do_devset(drive
, rq
);
376 case REQ_DRIVE_RESET
:
377 return ide_do_reset(drive
);
379 blk_dump_rq_flags(rq
, "ide_special_rq - bad request");
380 ide_end_request(drive
, 0, 0);
386 * start_request - start of I/O and command issuing for IDE
388 * start_request() initiates handling of a new I/O request. It
389 * accepts commands and I/O (read/write) requests.
391 * FIXME: this function needs a rename
394 static ide_startstop_t
start_request (ide_drive_t
*drive
, struct request
*rq
)
396 ide_startstop_t startstop
;
398 BUG_ON(!blk_rq_started(rq
));
401 printk("%s: start_request: current=0x%08lx\n",
402 drive
->hwif
->name
, (unsigned long) rq
);
405 /* bail early if we've exceeded max_failures */
406 if (drive
->max_failures
&& (drive
->failures
> drive
->max_failures
)) {
407 rq
->cmd_flags
|= REQ_FAILED
;
411 if (blk_pm_request(rq
))
412 ide_check_pm_state(drive
, rq
);
415 if (ide_wait_stat(&startstop
, drive
, drive
->ready_stat
,
416 ATA_BUSY
| ATA_DRQ
, WAIT_READY
)) {
417 printk(KERN_ERR
"%s: drive not ready for command\n", drive
->name
);
420 if (!drive
->special
.all
) {
421 struct ide_driver
*drv
;
424 * We reset the drive so we need to issue a SETFEATURES.
425 * Do it _after_ do_special() restored device parameters.
427 if (drive
->current_speed
== 0xff)
428 ide_config_drive_speed(drive
, drive
->desired_speed
);
430 if (rq
->cmd_type
== REQ_TYPE_ATA_TASKFILE
)
431 return execute_drive_cmd(drive
, rq
);
432 else if (blk_pm_request(rq
)) {
433 struct request_pm_state
*pm
= rq
->data
;
435 printk("%s: start_power_step(step: %d)\n",
436 drive
->name
, pm
->pm_step
);
438 startstop
= ide_start_power_step(drive
, rq
);
439 if (startstop
== ide_stopped
&&
440 pm
->pm_step
== IDE_PM_COMPLETED
)
441 ide_complete_pm_request(drive
, rq
);
443 } else if (!rq
->rq_disk
&& blk_special_request(rq
))
445 * TODO: Once all ULDs have been modified to
446 * check for specific op codes rather than
447 * blindly accepting any special request, the
448 * check for ->rq_disk above may be replaced
449 * by a more suitable mechanism or even
452 return ide_special_rq(drive
, rq
);
454 drv
= *(struct ide_driver
**)rq
->rq_disk
->private_data
;
456 return drv
->do_request(drive
, rq
, rq
->sector
);
458 return do_special(drive
);
460 ide_kill_rq(drive
, rq
);
465 * ide_stall_queue - pause an IDE device
466 * @drive: drive to stall
467 * @timeout: time to stall for (jiffies)
469 * ide_stall_queue() can be used by a drive to give excess bandwidth back
470 * to the port by sleeping for timeout jiffies.
473 void ide_stall_queue (ide_drive_t
*drive
, unsigned long timeout
)
475 if (timeout
> WAIT_WORSTCASE
)
476 timeout
= WAIT_WORSTCASE
;
477 drive
->sleep
= timeout
+ jiffies
;
478 drive
->dev_flags
|= IDE_DFLAG_SLEEPING
;
480 EXPORT_SYMBOL(ide_stall_queue
);
482 static inline int ide_lock_port(ide_hwif_t
*hwif
)
492 static inline void ide_unlock_port(ide_hwif_t
*hwif
)
497 static inline int ide_lock_host(struct ide_host
*host
, ide_hwif_t
*hwif
)
501 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
502 rc
= test_and_set_bit_lock(IDE_HOST_BUSY
, &host
->host_busy
);
505 ide_get_lock(ide_intr
, hwif
);
511 static inline void ide_unlock_host(struct ide_host
*host
)
513 if (host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
516 clear_bit_unlock(IDE_HOST_BUSY
, &host
->host_busy
);
521 * Issue a new request to a device.
523 void do_ide_request(struct request_queue
*q
)
525 ide_drive_t
*drive
= q
->queuedata
;
526 ide_hwif_t
*hwif
= drive
->hwif
;
527 struct ide_host
*host
= hwif
->host
;
528 struct request
*rq
= NULL
;
529 ide_startstop_t startstop
;
532 * drive is doing pre-flush, ordered write, post-flush sequence. even
533 * though that is 3 requests, it must be seen as a single transaction.
534 * we must not preempt this drive until that is complete
536 if (blk_queue_flushing(q
))
538 * small race where queue could get replugged during
539 * the 3-request flush cycle, just yank the plug since
540 * we want it to finish asap
544 spin_unlock_irq(q
->queue_lock
);
546 if (ide_lock_host(host
, hwif
))
549 spin_lock_irq(&hwif
->lock
);
551 if (!ide_lock_port(hwif
)) {
552 ide_hwif_t
*prev_port
;
554 prev_port
= hwif
->host
->cur_port
;
557 if (drive
->dev_flags
& IDE_DFLAG_SLEEPING
) {
558 if (time_before(drive
->sleep
, jiffies
)) {
559 ide_unlock_port(hwif
);
564 if ((hwif
->host
->host_flags
& IDE_HFLAG_SERIALIZE
) &&
567 * set nIEN for previous port, drives in the
568 * quirk_list may not like intr setups/cleanups
570 if (prev_port
&& prev_port
->cur_dev
->quirk_list
== 0)
571 prev_port
->tp_ops
->set_irq(prev_port
, 0);
573 hwif
->host
->cur_port
= hwif
;
575 hwif
->cur_dev
= drive
;
576 drive
->dev_flags
&= ~(IDE_DFLAG_SLEEPING
| IDE_DFLAG_PARKED
);
578 spin_unlock_irq(&hwif
->lock
);
579 spin_lock_irq(q
->queue_lock
);
581 * we know that the queue isn't empty, but this can happen
582 * if the q->prep_rq_fn() decides to kill a request
584 rq
= elv_next_request(drive
->queue
);
585 spin_unlock_irq(q
->queue_lock
);
586 spin_lock_irq(&hwif
->lock
);
589 ide_unlock_port(hwif
);
594 * Sanity: don't accept a request that isn't a PM request
595 * if we are currently power managed. This is very important as
596 * blk_stop_queue() doesn't prevent the elv_next_request()
597 * above to return us whatever is in the queue. Since we call
598 * ide_do_request() ourselves, we end up taking requests while
599 * the queue is blocked...
601 * We let requests forced at head of queue with ide-preempt
602 * though. I hope that doesn't happen too much, hopefully not
603 * unless the subdriver triggers such a thing in its own PM
606 if ((drive
->dev_flags
& IDE_DFLAG_BLOCKED
) &&
607 blk_pm_request(rq
) == 0 &&
608 (rq
->cmd_flags
& REQ_PREEMPT
) == 0) {
609 /* there should be no pending command at this point */
610 ide_unlock_port(hwif
);
616 spin_unlock_irq(&hwif
->lock
);
617 startstop
= start_request(drive
, rq
);
618 spin_lock_irq(&hwif
->lock
);
620 if (startstop
== ide_stopped
)
625 spin_unlock_irq(&hwif
->lock
);
627 ide_unlock_host(host
);
628 spin_lock_irq(q
->queue_lock
);
632 spin_unlock_irq(&hwif
->lock
);
633 ide_unlock_host(host
);
635 spin_lock_irq(q
->queue_lock
);
637 if (!elv_queue_empty(q
))
641 static void ide_plug_device(ide_drive_t
*drive
)
643 struct request_queue
*q
= drive
->queue
;
646 spin_lock_irqsave(q
->queue_lock
, flags
);
647 if (!elv_queue_empty(q
))
649 spin_unlock_irqrestore(q
->queue_lock
, flags
);
652 static int drive_is_ready(ide_drive_t
*drive
)
654 ide_hwif_t
*hwif
= drive
->hwif
;
657 if (drive
->waiting_for_dma
)
658 return hwif
->dma_ops
->dma_test_irq(drive
);
660 if (hwif
->io_ports
.ctl_addr
&&
661 (hwif
->host_flags
& IDE_HFLAG_BROKEN_ALTSTATUS
) == 0)
662 stat
= hwif
->tp_ops
->read_altstatus(hwif
);
664 /* Note: this may clear a pending IRQ!! */
665 stat
= hwif
->tp_ops
->read_status(hwif
);
668 /* drive busy: definitely not interrupting */
671 /* drive ready: *might* be interrupting */
676 * ide_timer_expiry - handle lack of an IDE interrupt
677 * @data: timer callback magic (hwif)
679 * An IDE command has timed out before the expected drive return
680 * occurred. At this point we attempt to clean up the current
681 * mess. If the current handler includes an expiry handler then
682 * we invoke the expiry handler, and providing it is happy the
683 * work is done. If that fails we apply generic recovery rules
684 * invoking the handler and checking the drive DMA status. We
685 * have an excessively incestuous relationship with the DMA
686 * logic that wants cleaning up.
689 void ide_timer_expiry (unsigned long data
)
691 ide_hwif_t
*hwif
= (ide_hwif_t
*)data
;
692 ide_drive_t
*uninitialized_var(drive
);
693 ide_handler_t
*handler
;
698 spin_lock_irqsave(&hwif
->lock
, flags
);
700 handler
= hwif
->handler
;
702 if (handler
== NULL
|| hwif
->req_gen
!= hwif
->req_gen_timer
) {
704 * Either a marginal timeout occurred
705 * (got the interrupt just as timer expired),
706 * or we were "sleeping" to give other devices a chance.
707 * Either way, we don't really want to complain about anything.
710 ide_expiry_t
*expiry
= hwif
->expiry
;
711 ide_startstop_t startstop
= ide_stopped
;
713 drive
= hwif
->cur_dev
;
716 wait
= expiry(drive
);
717 if (wait
> 0) { /* continue */
719 hwif
->timer
.expires
= jiffies
+ wait
;
720 hwif
->req_gen_timer
= hwif
->req_gen
;
721 add_timer(&hwif
->timer
);
722 spin_unlock_irqrestore(&hwif
->lock
, flags
);
726 hwif
->handler
= NULL
;
728 * We need to simulate a real interrupt when invoking
729 * the handler() function, which means we need to
730 * globally mask the specific IRQ:
732 spin_unlock(&hwif
->lock
);
733 /* disable_irq_nosync ?? */
734 disable_irq(hwif
->irq
);
735 /* local CPU only, as if we were handling an interrupt */
738 startstop
= handler(drive
);
739 } else if (drive_is_ready(drive
)) {
740 if (drive
->waiting_for_dma
)
741 hwif
->dma_ops
->dma_lost_irq(drive
);
742 (void)ide_ack_intr(hwif
);
743 printk(KERN_WARNING
"%s: lost interrupt\n",
745 startstop
= handler(drive
);
747 if (drive
->waiting_for_dma
)
748 startstop
= ide_dma_timeout_retry(drive
, wait
);
750 startstop
= ide_error(drive
, "irq timeout",
751 hwif
->tp_ops
->read_status(hwif
));
753 spin_lock_irq(&hwif
->lock
);
754 enable_irq(hwif
->irq
);
755 if (startstop
== ide_stopped
) {
756 ide_unlock_port(hwif
);
760 spin_unlock_irqrestore(&hwif
->lock
, flags
);
763 ide_unlock_host(hwif
->host
);
764 ide_plug_device(drive
);
769 * unexpected_intr - handle an unexpected IDE interrupt
770 * @irq: interrupt line
771 * @hwif: port being processed
773 * There's nothing really useful we can do with an unexpected interrupt,
774 * other than reading the status register (to clear it), and logging it.
775 * There should be no way that an irq can happen before we're ready for it,
776 * so we needn't worry much about losing an "important" interrupt here.
778 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
779 * the drive enters "idle", "standby", or "sleep" mode, so if the status
780 * looks "good", we just ignore the interrupt completely.
782 * This routine assumes __cli() is in effect when called.
784 * If an unexpected interrupt happens on irq15 while we are handling irq14
785 * and if the two interfaces are "serialized" (CMD640), then it looks like
786 * we could screw up by interfering with a new request being set up for
789 * In reality, this is a non-issue. The new command is not sent unless
790 * the drive is ready to accept one, in which case we know the drive is
791 * not trying to interrupt us. And ide_set_handler() is always invoked
792 * before completing the issuance of any new drive command, so we will not
793 * be accidentally invoked as a result of any valid command completion
797 static void unexpected_intr(int irq
, ide_hwif_t
*hwif
)
799 u8 stat
= hwif
->tp_ops
->read_status(hwif
);
801 if (!OK_STAT(stat
, ATA_DRDY
, BAD_STAT
)) {
802 /* Try to not flood the console with msgs */
803 static unsigned long last_msgtime
, count
;
806 if (time_after(jiffies
, last_msgtime
+ HZ
)) {
807 last_msgtime
= jiffies
;
808 printk(KERN_ERR
"%s: unexpected interrupt, "
809 "status=0x%02x, count=%ld\n",
810 hwif
->name
, stat
, count
);
816 * ide_intr - default IDE interrupt handler
817 * @irq: interrupt number
819 * @regs: unused weirdness from the kernel irq layer
821 * This is the default IRQ handler for the IDE layer. You should
822 * not need to override it. If you do be aware it is subtle in
825 * hwif is the interface in the group currently performing
826 * a command. hwif->cur_dev is the drive and hwif->handler is
827 * the IRQ handler to call. As we issue a command the handlers
828 * step through multiple states, reassigning the handler to the
829 * next step in the process. Unlike a smart SCSI controller IDE
830 * expects the main processor to sequence the various transfer
831 * stages. We also manage a poll timer to catch up with most
832 * timeout situations. There are still a few where the handlers
833 * don't ever decide to give up.
835 * The handler eventually returns ide_stopped to indicate the
836 * request completed. At this point we issue the next request
837 * on the port and the process begins again.
840 irqreturn_t
ide_intr (int irq
, void *dev_id
)
842 ide_hwif_t
*hwif
= (ide_hwif_t
*)dev_id
;
843 ide_drive_t
*uninitialized_var(drive
);
844 ide_handler_t
*handler
;
846 ide_startstop_t startstop
;
847 irqreturn_t irq_ret
= IRQ_NONE
;
850 if (hwif
->host
->host_flags
& IDE_HFLAG_SERIALIZE
) {
851 if (hwif
!= hwif
->host
->cur_port
)
855 spin_lock_irqsave(&hwif
->lock
, flags
);
857 if (!ide_ack_intr(hwif
))
860 handler
= hwif
->handler
;
862 if (handler
== NULL
|| hwif
->polling
) {
864 * Not expecting an interrupt from this drive.
865 * That means this could be:
866 * (1) an interrupt from another PCI device
867 * sharing the same PCI INT# as us.
868 * or (2) a drive just entered sleep or standby mode,
869 * and is interrupting to let us know.
870 * or (3) a spurious interrupt of unknown origin.
872 * For PCI, we cannot tell the difference,
873 * so in that case we just ignore it and hope it goes away.
875 * FIXME: unexpected_intr should be hwif-> then we can
876 * remove all the ifdef PCI crap
878 #ifdef CONFIG_BLK_DEV_IDEPCI
879 if (hwif
->chipset
!= ide_pci
)
880 #endif /* CONFIG_BLK_DEV_IDEPCI */
883 * Probably not a shared PCI interrupt,
884 * so we can safely try to do something about it:
886 unexpected_intr(irq
, hwif
);
887 #ifdef CONFIG_BLK_DEV_IDEPCI
890 * Whack the status register, just in case
891 * we have a leftover pending IRQ.
893 (void)hwif
->tp_ops
->read_status(hwif
);
894 #endif /* CONFIG_BLK_DEV_IDEPCI */
899 drive
= hwif
->cur_dev
;
901 if (!drive_is_ready(drive
))
903 * This happens regularly when we share a PCI IRQ with
904 * another device. Unfortunately, it can also happen
905 * with some buggy drives that trigger the IRQ before
906 * their status register is up to date. Hopefully we have
907 * enough advance overhead that the latter isn't a problem.
911 hwif
->handler
= NULL
;
913 del_timer(&hwif
->timer
);
914 spin_unlock(&hwif
->lock
);
916 if (hwif
->port_ops
&& hwif
->port_ops
->clear_irq
)
917 hwif
->port_ops
->clear_irq(drive
);
919 if (drive
->dev_flags
& IDE_DFLAG_UNMASK
)
920 local_irq_enable_in_hardirq();
922 /* service this interrupt, may set handler for next interrupt */
923 startstop
= handler(drive
);
925 spin_lock_irq(&hwif
->lock
);
927 * Note that handler() may have set things up for another
928 * interrupt to occur soon, but it cannot happen until
929 * we exit from this routine, because it will be the
930 * same irq as is currently being serviced here, and Linux
931 * won't allow another of the same (on any CPU) until we return.
933 if (startstop
== ide_stopped
) {
934 BUG_ON(hwif
->handler
);
935 ide_unlock_port(hwif
);
938 irq_ret
= IRQ_HANDLED
;
940 spin_unlock_irqrestore(&hwif
->lock
, flags
);
943 ide_unlock_host(hwif
->host
);
944 ide_plug_device(drive
);
949 EXPORT_SYMBOL_GPL(ide_intr
);
951 void ide_pad_transfer(ide_drive_t
*drive
, int write
, int len
)
953 ide_hwif_t
*hwif
= drive
->hwif
;
958 hwif
->tp_ops
->output_data(drive
, NULL
, buf
, min(4, len
));
960 hwif
->tp_ops
->input_data(drive
, NULL
, buf
, min(4, len
));
964 EXPORT_SYMBOL_GPL(ide_pad_transfer
);