pcmcia/cm4000: fix lock imbalance
[linux-2.6/mini2440.git] / drivers / ide / ide-io.c
blob1059f809b809bb0f94048361d8b03e990953ccee
1 /*
2 * IDE I/O functions
4 * Basic PIO and command management functionality.
6 * This code was split off from ide.c. See ide.c for history and original
7 * copyrights.
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
12 * later version.
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>
32 #include <linux/mm.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>
53 #include <asm/irq.h>
54 #include <asm/uaccess.h>
55 #include <asm/io.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;
67 ide_dma_on(drive);
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;
81 tf->error = err;
82 tf->status = stat;
84 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
85 u8 data[2];
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",
99 drive->name);
100 ide_tf_dump(drive->name, cmd);
101 } else
102 drive->dev_flags |= IDE_DFLAG_PARKED;
105 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
106 struct ide_cmd *orig_cmd = rq->special;
108 if (cmd->tf_flags & IDE_TFLAG_DYN)
109 kfree(orig_cmd);
110 else
111 memcpy(orig_cmd, cmd, sizeof(*cmd));
115 /* obsolete, blk_rq_bytes() should be used instead */
116 unsigned int ide_rq_bytes(struct request *rq)
118 if (blk_pc_request(rq))
119 return blk_rq_bytes(rq);
120 else
121 return blk_rq_cur_sectors(rq) << 9;
123 EXPORT_SYMBOL_GPL(ide_rq_bytes);
125 int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
127 ide_hwif_t *hwif = drive->hwif;
128 struct request *rq = hwif->rq;
129 int rc;
132 * if failfast is set on a request, override number of sectors
133 * and complete the whole request right now
135 if (blk_noretry_request(rq) && error <= 0)
136 nr_bytes = blk_rq_sectors(rq) << 9;
138 rc = ide_end_rq(drive, rq, error, nr_bytes);
139 if (rc == 0)
140 hwif->rq = NULL;
142 return rc;
144 EXPORT_SYMBOL(ide_complete_rq);
146 void ide_kill_rq(ide_drive_t *drive, struct request *rq)
148 u8 drv_req = blk_special_request(rq) && rq->rq_disk;
149 u8 media = drive->media;
151 drive->failed_pc = NULL;
153 if ((media == ide_floppy || media == ide_tape) && drv_req) {
154 rq->errors = 0;
155 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
156 } else {
157 if (media == ide_tape)
158 rq->errors = IDE_DRV_ERROR_GENERAL;
159 else if (blk_fs_request(rq) == 0 && rq->errors == 0)
160 rq->errors = -EIO;
161 ide_complete_rq(drive, -EIO, ide_rq_bytes(rq));
165 static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
167 tf->nsect = drive->sect;
168 tf->lbal = drive->sect;
169 tf->lbam = drive->cyl;
170 tf->lbah = drive->cyl >> 8;
171 tf->device = (drive->head - 1) | drive->select;
172 tf->command = ATA_CMD_INIT_DEV_PARAMS;
175 static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
177 tf->nsect = drive->sect;
178 tf->command = ATA_CMD_RESTORE;
181 static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
183 tf->nsect = drive->mult_req;
184 tf->command = ATA_CMD_SET_MULTI;
188 * do_special - issue some special commands
189 * @drive: drive the command is for
191 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
192 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
195 static ide_startstop_t do_special(ide_drive_t *drive)
197 struct ide_cmd cmd;
199 #ifdef DEBUG
200 printk(KERN_DEBUG "%s: %s: 0x%02x\n", drive->name, __func__,
201 drive->special_flags);
202 #endif
203 if (drive->media != ide_disk) {
204 drive->special_flags = 0;
205 drive->mult_req = 0;
206 return ide_stopped;
209 memset(&cmd, 0, sizeof(cmd));
210 cmd.protocol = ATA_PROT_NODATA;
212 if (drive->special_flags & IDE_SFLAG_SET_GEOMETRY) {
213 drive->special_flags &= ~IDE_SFLAG_SET_GEOMETRY;
214 ide_tf_set_specify_cmd(drive, &cmd.tf);
215 } else if (drive->special_flags & IDE_SFLAG_RECALIBRATE) {
216 drive->special_flags &= ~IDE_SFLAG_RECALIBRATE;
217 ide_tf_set_restore_cmd(drive, &cmd.tf);
218 } else if (drive->special_flags & IDE_SFLAG_SET_MULTMODE) {
219 drive->special_flags &= ~IDE_SFLAG_SET_MULTMODE;
220 ide_tf_set_setmult_cmd(drive, &cmd.tf);
221 } else
222 BUG();
224 cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
225 cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
226 cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER;
228 do_rw_taskfile(drive, &cmd);
230 return ide_started;
233 void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
235 ide_hwif_t *hwif = drive->hwif;
236 struct scatterlist *sg = hwif->sg_table;
237 struct request *rq = cmd->rq;
239 cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
241 EXPORT_SYMBOL_GPL(ide_map_sg);
243 void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
245 cmd->nbytes = cmd->nleft = nr_bytes;
246 cmd->cursg_ofs = 0;
247 cmd->cursg = NULL;
249 EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
252 * execute_drive_command - issue special drive command
253 * @drive: the drive to issue the command on
254 * @rq: the request structure holding the command
256 * execute_drive_cmd() issues a special drive command, usually
257 * initiated by ioctl() from the external hdparm program. The
258 * command can be a drive command, drive task or taskfile
259 * operation. Weirdly you can call it with NULL to wait for
260 * all commands to finish. Don't do this as that is due to change
263 static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
264 struct request *rq)
266 struct ide_cmd *cmd = rq->special;
268 if (cmd) {
269 if (cmd->protocol == ATA_PROT_PIO) {
270 ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
271 ide_map_sg(drive, cmd);
274 return do_rw_taskfile(drive, cmd);
278 * NULL is actually a valid way of waiting for
279 * all current requests to be flushed from the queue.
281 #ifdef DEBUG
282 printk("%s: DRIVE_CMD (null)\n", drive->name);
283 #endif
284 rq->errors = 0;
285 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
287 return ide_stopped;
290 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
292 u8 cmd = rq->cmd[0];
294 switch (cmd) {
295 case REQ_PARK_HEADS:
296 case REQ_UNPARK_HEADS:
297 return ide_do_park_unpark(drive, rq);
298 case REQ_DEVSET_EXEC:
299 return ide_do_devset(drive, rq);
300 case REQ_DRIVE_RESET:
301 return ide_do_reset(drive);
302 default:
303 BUG();
308 * start_request - start of I/O and command issuing for IDE
310 * start_request() initiates handling of a new I/O request. It
311 * accepts commands and I/O (read/write) requests.
313 * FIXME: this function needs a rename
316 static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
318 ide_startstop_t startstop;
320 BUG_ON(!blk_rq_started(rq));
322 #ifdef DEBUG
323 printk("%s: start_request: current=0x%08lx\n",
324 drive->hwif->name, (unsigned long) rq);
325 #endif
327 /* bail early if we've exceeded max_failures */
328 if (drive->max_failures && (drive->failures > drive->max_failures)) {
329 rq->cmd_flags |= REQ_FAILED;
330 goto kill_rq;
333 if (blk_pm_request(rq))
334 ide_check_pm_state(drive, rq);
336 drive->hwif->tp_ops->dev_select(drive);
337 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
338 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
339 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
340 return startstop;
343 if (drive->special_flags == 0) {
344 struct ide_driver *drv;
347 * We reset the drive so we need to issue a SETFEATURES.
348 * Do it _after_ do_special() restored device parameters.
350 if (drive->current_speed == 0xff)
351 ide_config_drive_speed(drive, drive->desired_speed);
353 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
354 return execute_drive_cmd(drive, rq);
355 else if (blk_pm_request(rq)) {
356 struct request_pm_state *pm = rq->special;
357 #ifdef DEBUG_PM
358 printk("%s: start_power_step(step: %d)\n",
359 drive->name, pm->pm_step);
360 #endif
361 startstop = ide_start_power_step(drive, rq);
362 if (startstop == ide_stopped &&
363 pm->pm_step == IDE_PM_COMPLETED)
364 ide_complete_pm_rq(drive, rq);
365 return startstop;
366 } else if (!rq->rq_disk && blk_special_request(rq))
368 * TODO: Once all ULDs have been modified to
369 * check for specific op codes rather than
370 * blindly accepting any special request, the
371 * check for ->rq_disk above may be replaced
372 * by a more suitable mechanism or even
373 * dropped entirely.
375 return ide_special_rq(drive, rq);
377 drv = *(struct ide_driver **)rq->rq_disk->private_data;
379 return drv->do_request(drive, rq, blk_rq_pos(rq));
381 return do_special(drive);
382 kill_rq:
383 ide_kill_rq(drive, rq);
384 return ide_stopped;
388 * ide_stall_queue - pause an IDE device
389 * @drive: drive to stall
390 * @timeout: time to stall for (jiffies)
392 * ide_stall_queue() can be used by a drive to give excess bandwidth back
393 * to the port by sleeping for timeout jiffies.
396 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
398 if (timeout > WAIT_WORSTCASE)
399 timeout = WAIT_WORSTCASE;
400 drive->sleep = timeout + jiffies;
401 drive->dev_flags |= IDE_DFLAG_SLEEPING;
403 EXPORT_SYMBOL(ide_stall_queue);
405 static inline int ide_lock_port(ide_hwif_t *hwif)
407 if (hwif->busy)
408 return 1;
410 hwif->busy = 1;
412 return 0;
415 static inline void ide_unlock_port(ide_hwif_t *hwif)
417 hwif->busy = 0;
420 static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
422 int rc = 0;
424 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
425 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
426 if (rc == 0) {
427 if (host->get_lock)
428 host->get_lock(ide_intr, hwif);
431 return rc;
434 static inline void ide_unlock_host(struct ide_host *host)
436 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
437 if (host->release_lock)
438 host->release_lock();
439 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
444 * Issue a new request to a device.
446 void do_ide_request(struct request_queue *q)
448 ide_drive_t *drive = q->queuedata;
449 ide_hwif_t *hwif = drive->hwif;
450 struct ide_host *host = hwif->host;
451 struct request *rq = NULL;
452 ide_startstop_t startstop;
455 * drive is doing pre-flush, ordered write, post-flush sequence. even
456 * though that is 3 requests, it must be seen as a single transaction.
457 * we must not preempt this drive until that is complete
459 if (blk_queue_flushing(q))
461 * small race where queue could get replugged during
462 * the 3-request flush cycle, just yank the plug since
463 * we want it to finish asap
465 blk_remove_plug(q);
467 spin_unlock_irq(q->queue_lock);
469 /* HLD do_request() callback might sleep, make sure it's okay */
470 might_sleep();
472 if (ide_lock_host(host, hwif))
473 goto plug_device_2;
475 spin_lock_irq(&hwif->lock);
477 if (!ide_lock_port(hwif)) {
478 ide_hwif_t *prev_port;
480 WARN_ON_ONCE(hwif->rq);
481 repeat:
482 prev_port = hwif->host->cur_port;
483 if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
484 time_after(drive->sleep, jiffies)) {
485 ide_unlock_port(hwif);
486 goto plug_device;
489 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
490 hwif != prev_port) {
491 ide_drive_t *cur_dev =
492 prev_port ? prev_port->cur_dev : NULL;
495 * set nIEN for previous port, drives in the
496 * quirk list may not like intr setups/cleanups
498 if (cur_dev &&
499 (cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
500 prev_port->tp_ops->write_devctl(prev_port,
501 ATA_NIEN |
502 ATA_DEVCTL_OBS);
504 hwif->host->cur_port = hwif;
506 hwif->cur_dev = drive;
507 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
509 spin_unlock_irq(&hwif->lock);
510 spin_lock_irq(q->queue_lock);
512 * we know that the queue isn't empty, but this can happen
513 * if the q->prep_rq_fn() decides to kill a request
515 if (!rq)
516 rq = blk_fetch_request(drive->queue);
518 spin_unlock_irq(q->queue_lock);
519 spin_lock_irq(&hwif->lock);
521 if (!rq) {
522 ide_unlock_port(hwif);
523 goto out;
527 * Sanity: don't accept a request that isn't a PM request
528 * if we are currently power managed. This is very important as
529 * blk_stop_queue() doesn't prevent the blk_fetch_request()
530 * above to return us whatever is in the queue. Since we call
531 * ide_do_request() ourselves, we end up taking requests while
532 * the queue is blocked...
534 * We let requests forced at head of queue with ide-preempt
535 * though. I hope that doesn't happen too much, hopefully not
536 * unless the subdriver triggers such a thing in its own PM
537 * state machine.
539 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
540 blk_pm_request(rq) == 0 &&
541 (rq->cmd_flags & REQ_PREEMPT) == 0) {
542 /* there should be no pending command at this point */
543 ide_unlock_port(hwif);
544 goto plug_device;
547 hwif->rq = rq;
549 spin_unlock_irq(&hwif->lock);
550 startstop = start_request(drive, rq);
551 spin_lock_irq(&hwif->lock);
553 if (startstop == ide_stopped) {
554 rq = hwif->rq;
555 hwif->rq = NULL;
556 goto repeat;
558 } else
559 goto plug_device;
560 out:
561 spin_unlock_irq(&hwif->lock);
562 if (rq == NULL)
563 ide_unlock_host(host);
564 spin_lock_irq(q->queue_lock);
565 return;
567 plug_device:
568 spin_unlock_irq(&hwif->lock);
569 ide_unlock_host(host);
570 plug_device_2:
571 spin_lock_irq(q->queue_lock);
573 if (rq)
574 blk_requeue_request(q, rq);
575 if (!elv_queue_empty(q))
576 blk_plug_device(q);
579 static void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
581 struct request_queue *q = drive->queue;
582 unsigned long flags;
584 spin_lock_irqsave(q->queue_lock, flags);
586 if (rq)
587 blk_requeue_request(q, rq);
588 if (!elv_queue_empty(q))
589 blk_plug_device(q);
591 spin_unlock_irqrestore(q->queue_lock, flags);
594 static int drive_is_ready(ide_drive_t *drive)
596 ide_hwif_t *hwif = drive->hwif;
597 u8 stat = 0;
599 if (drive->waiting_for_dma)
600 return hwif->dma_ops->dma_test_irq(drive);
602 if (hwif->io_ports.ctl_addr &&
603 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
604 stat = hwif->tp_ops->read_altstatus(hwif);
605 else
606 /* Note: this may clear a pending IRQ!! */
607 stat = hwif->tp_ops->read_status(hwif);
609 if (stat & ATA_BUSY)
610 /* drive busy: definitely not interrupting */
611 return 0;
613 /* drive ready: *might* be interrupting */
614 return 1;
618 * ide_timer_expiry - handle lack of an IDE interrupt
619 * @data: timer callback magic (hwif)
621 * An IDE command has timed out before the expected drive return
622 * occurred. At this point we attempt to clean up the current
623 * mess. If the current handler includes an expiry handler then
624 * we invoke the expiry handler, and providing it is happy the
625 * work is done. If that fails we apply generic recovery rules
626 * invoking the handler and checking the drive DMA status. We
627 * have an excessively incestuous relationship with the DMA
628 * logic that wants cleaning up.
631 void ide_timer_expiry (unsigned long data)
633 ide_hwif_t *hwif = (ide_hwif_t *)data;
634 ide_drive_t *uninitialized_var(drive);
635 ide_handler_t *handler;
636 unsigned long flags;
637 int wait = -1;
638 int plug_device = 0;
639 struct request *uninitialized_var(rq_in_flight);
641 spin_lock_irqsave(&hwif->lock, flags);
643 handler = hwif->handler;
645 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
647 * Either a marginal timeout occurred
648 * (got the interrupt just as timer expired),
649 * or we were "sleeping" to give other devices a chance.
650 * Either way, we don't really want to complain about anything.
652 } else {
653 ide_expiry_t *expiry = hwif->expiry;
654 ide_startstop_t startstop = ide_stopped;
656 drive = hwif->cur_dev;
658 if (expiry) {
659 wait = expiry(drive);
660 if (wait > 0) { /* continue */
661 /* reset timer */
662 hwif->timer.expires = jiffies + wait;
663 hwif->req_gen_timer = hwif->req_gen;
664 add_timer(&hwif->timer);
665 spin_unlock_irqrestore(&hwif->lock, flags);
666 return;
669 hwif->handler = NULL;
670 hwif->expiry = NULL;
672 * We need to simulate a real interrupt when invoking
673 * the handler() function, which means we need to
674 * globally mask the specific IRQ:
676 spin_unlock(&hwif->lock);
677 /* disable_irq_nosync ?? */
678 disable_irq(hwif->irq);
679 /* local CPU only, as if we were handling an interrupt */
680 local_irq_disable();
681 if (hwif->polling) {
682 startstop = handler(drive);
683 } else if (drive_is_ready(drive)) {
684 if (drive->waiting_for_dma)
685 hwif->dma_ops->dma_lost_irq(drive);
686 if (hwif->port_ops && hwif->port_ops->clear_irq)
687 hwif->port_ops->clear_irq(drive);
689 printk(KERN_WARNING "%s: lost interrupt\n",
690 drive->name);
691 startstop = handler(drive);
692 } else {
693 if (drive->waiting_for_dma)
694 startstop = ide_dma_timeout_retry(drive, wait);
695 else
696 startstop = ide_error(drive, "irq timeout",
697 hwif->tp_ops->read_status(hwif));
699 spin_lock_irq(&hwif->lock);
700 enable_irq(hwif->irq);
701 if (startstop == ide_stopped && hwif->polling == 0) {
702 rq_in_flight = hwif->rq;
703 hwif->rq = NULL;
704 ide_unlock_port(hwif);
705 plug_device = 1;
708 spin_unlock_irqrestore(&hwif->lock, flags);
710 if (plug_device) {
711 ide_unlock_host(hwif->host);
712 ide_requeue_and_plug(drive, rq_in_flight);
717 * unexpected_intr - handle an unexpected IDE interrupt
718 * @irq: interrupt line
719 * @hwif: port being processed
721 * There's nothing really useful we can do with an unexpected interrupt,
722 * other than reading the status register (to clear it), and logging it.
723 * There should be no way that an irq can happen before we're ready for it,
724 * so we needn't worry much about losing an "important" interrupt here.
726 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
727 * the drive enters "idle", "standby", or "sleep" mode, so if the status
728 * looks "good", we just ignore the interrupt completely.
730 * This routine assumes __cli() is in effect when called.
732 * If an unexpected interrupt happens on irq15 while we are handling irq14
733 * and if the two interfaces are "serialized" (CMD640), then it looks like
734 * we could screw up by interfering with a new request being set up for
735 * irq15.
737 * In reality, this is a non-issue. The new command is not sent unless
738 * the drive is ready to accept one, in which case we know the drive is
739 * not trying to interrupt us. And ide_set_handler() is always invoked
740 * before completing the issuance of any new drive command, so we will not
741 * be accidentally invoked as a result of any valid command completion
742 * interrupt.
745 static void unexpected_intr(int irq, ide_hwif_t *hwif)
747 u8 stat = hwif->tp_ops->read_status(hwif);
749 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
750 /* Try to not flood the console with msgs */
751 static unsigned long last_msgtime, count;
752 ++count;
754 if (time_after(jiffies, last_msgtime + HZ)) {
755 last_msgtime = jiffies;
756 printk(KERN_ERR "%s: unexpected interrupt, "
757 "status=0x%02x, count=%ld\n",
758 hwif->name, stat, count);
764 * ide_intr - default IDE interrupt handler
765 * @irq: interrupt number
766 * @dev_id: hwif
767 * @regs: unused weirdness from the kernel irq layer
769 * This is the default IRQ handler for the IDE layer. You should
770 * not need to override it. If you do be aware it is subtle in
771 * places
773 * hwif is the interface in the group currently performing
774 * a command. hwif->cur_dev is the drive and hwif->handler is
775 * the IRQ handler to call. As we issue a command the handlers
776 * step through multiple states, reassigning the handler to the
777 * next step in the process. Unlike a smart SCSI controller IDE
778 * expects the main processor to sequence the various transfer
779 * stages. We also manage a poll timer to catch up with most
780 * timeout situations. There are still a few where the handlers
781 * don't ever decide to give up.
783 * The handler eventually returns ide_stopped to indicate the
784 * request completed. At this point we issue the next request
785 * on the port and the process begins again.
788 irqreturn_t ide_intr (int irq, void *dev_id)
790 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
791 struct ide_host *host = hwif->host;
792 ide_drive_t *uninitialized_var(drive);
793 ide_handler_t *handler;
794 unsigned long flags;
795 ide_startstop_t startstop;
796 irqreturn_t irq_ret = IRQ_NONE;
797 int plug_device = 0;
798 struct request *uninitialized_var(rq_in_flight);
800 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
801 if (hwif != host->cur_port)
802 goto out_early;
805 spin_lock_irqsave(&hwif->lock, flags);
807 if (hwif->port_ops && hwif->port_ops->test_irq &&
808 hwif->port_ops->test_irq(hwif) == 0)
809 goto out;
811 handler = hwif->handler;
813 if (handler == NULL || hwif->polling) {
815 * Not expecting an interrupt from this drive.
816 * That means this could be:
817 * (1) an interrupt from another PCI device
818 * sharing the same PCI INT# as us.
819 * or (2) a drive just entered sleep or standby mode,
820 * and is interrupting to let us know.
821 * or (3) a spurious interrupt of unknown origin.
823 * For PCI, we cannot tell the difference,
824 * so in that case we just ignore it and hope it goes away.
826 if ((host->irq_flags & IRQF_SHARED) == 0) {
828 * Probably not a shared PCI interrupt,
829 * so we can safely try to do something about it:
831 unexpected_intr(irq, hwif);
832 } else {
834 * Whack the status register, just in case
835 * we have a leftover pending IRQ.
837 (void)hwif->tp_ops->read_status(hwif);
839 goto out;
842 drive = hwif->cur_dev;
844 if (!drive_is_ready(drive))
846 * This happens regularly when we share a PCI IRQ with
847 * another device. Unfortunately, it can also happen
848 * with some buggy drives that trigger the IRQ before
849 * their status register is up to date. Hopefully we have
850 * enough advance overhead that the latter isn't a problem.
852 goto out;
854 hwif->handler = NULL;
855 hwif->expiry = NULL;
856 hwif->req_gen++;
857 del_timer(&hwif->timer);
858 spin_unlock(&hwif->lock);
860 if (hwif->port_ops && hwif->port_ops->clear_irq)
861 hwif->port_ops->clear_irq(drive);
863 if (drive->dev_flags & IDE_DFLAG_UNMASK)
864 local_irq_enable_in_hardirq();
866 /* service this interrupt, may set handler for next interrupt */
867 startstop = handler(drive);
869 spin_lock_irq(&hwif->lock);
871 * Note that handler() may have set things up for another
872 * interrupt to occur soon, but it cannot happen until
873 * we exit from this routine, because it will be the
874 * same irq as is currently being serviced here, and Linux
875 * won't allow another of the same (on any CPU) until we return.
877 if (startstop == ide_stopped && hwif->polling == 0) {
878 BUG_ON(hwif->handler);
879 rq_in_flight = hwif->rq;
880 hwif->rq = NULL;
881 ide_unlock_port(hwif);
882 plug_device = 1;
884 irq_ret = IRQ_HANDLED;
885 out:
886 spin_unlock_irqrestore(&hwif->lock, flags);
887 out_early:
888 if (plug_device) {
889 ide_unlock_host(hwif->host);
890 ide_requeue_and_plug(drive, rq_in_flight);
893 return irq_ret;
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;
900 u8 buf[4] = { 0 };
902 while (len > 0) {
903 if (write)
904 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
905 else
906 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
907 len -= 4;
910 EXPORT_SYMBOL_GPL(ide_pad_transfer);