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 <linux/uaccess.h>
57 int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t 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 if (!blk_update_request(rq, error, nr_bytes)) {
71 if (rq == drive->sense_rq) {
72 drive->sense_rq = NULL;
73 drive->sense_rq_active = false;
76 __blk_mq_end_request(rq, error);
82 EXPORT_SYMBOL_GPL(ide_end_rq);
84 void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
86 const struct ide_tp_ops *tp_ops = drive->hwif->tp_ops;
87 struct ide_taskfile *tf = &cmd->tf;
88 struct request *rq = cmd->rq;
89 u8 tf_cmd = tf->command;
94 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
97 tp_ops->input_data(drive, cmd, data, 2);
99 cmd->tf.data = data[0];
100 cmd->hob.data = data[1];
103 ide_tf_readback(drive, cmd);
105 if ((cmd->tf_flags & IDE_TFLAG_CUSTOM_HANDLER) &&
106 tf_cmd == ATA_CMD_IDLEIMMEDIATE) {
107 if (tf->lbal != 0xc4) {
108 printk(KERN_ERR "%s: head unload failed!\n",
110 ide_tf_dump(drive->name, cmd);
112 drive->dev_flags |= IDE_DFLAG_PARKED;
115 if (rq && ata_taskfile_request(rq)) {
116 struct ide_cmd *orig_cmd = ide_req(rq)->special;
118 if (cmd->tf_flags & IDE_TFLAG_DYN)
120 else if (cmd != orig_cmd)
121 memcpy(orig_cmd, cmd, sizeof(*cmd));
125 int ide_complete_rq(ide_drive_t *drive, blk_status_t error, unsigned int nr_bytes)
127 ide_hwif_t *hwif = drive->hwif;
128 struct request *rq = hwif->rq;
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)
136 nr_bytes = blk_rq_sectors(rq) << 9;
138 rc = ide_end_rq(drive, rq, error, nr_bytes);
144 EXPORT_SYMBOL(ide_complete_rq);
146 void ide_kill_rq(ide_drive_t *drive, struct request *rq)
148 u8 drv_req = ata_misc_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 scsi_req(rq)->result = 0;
156 if (media == ide_tape)
157 scsi_req(rq)->result = IDE_DRV_ERROR_GENERAL;
158 else if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
159 scsi_req(rq)->result = -EIO;
162 ide_complete_rq(drive, BLK_STS_IOERR, blk_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)
200 printk(KERN_DEBUG "%s: %s: 0x%02x\n", drive->name, __func__,
201 drive->special_flags);
203 if (drive->media != ide_disk) {
204 drive->special_flags = 0;
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);
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);
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;
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,
266 struct ide_cmd *cmd = ide_req(rq)->special;
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.
282 printk("%s: DRIVE_CMD (null)\n", drive->name);
284 scsi_req(rq)->result = 0;
285 ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq));
290 static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
292 u8 cmd = scsi_req(rq)->cmd[0];
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);
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;
321 printk("%s: start_request: current=0x%08lx\n",
322 drive->hwif->name, (unsigned long) rq);
325 /* bail early if we've exceeded max_failures */
326 if (drive->max_failures && (drive->failures > drive->max_failures)) {
327 rq->rq_flags |= RQF_FAILED;
331 if (drive->prep_rq && !drive->prep_rq(drive, rq))
334 if (ata_pm_request(rq))
335 ide_check_pm_state(drive, rq);
337 drive->hwif->tp_ops->dev_select(drive);
338 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
339 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
340 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
344 if (drive->special_flags == 0) {
345 struct ide_driver *drv;
348 * We reset the drive so we need to issue a SETFEATURES.
349 * Do it _after_ do_special() restored device parameters.
351 if (drive->current_speed == 0xff)
352 ide_config_drive_speed(drive, drive->desired_speed);
354 if (ata_taskfile_request(rq))
355 return execute_drive_cmd(drive, rq);
356 else if (ata_pm_request(rq)) {
357 struct ide_pm_state *pm = ide_req(rq)->special;
359 printk("%s: start_power_step(step: %d)\n",
360 drive->name, pm->pm_step);
362 startstop = ide_start_power_step(drive, rq);
363 if (startstop == ide_stopped &&
364 pm->pm_step == IDE_PM_COMPLETED)
365 ide_complete_pm_rq(drive, rq);
367 } else if (!rq->rq_disk && ata_misc_request(rq))
369 * TODO: Once all ULDs have been modified to
370 * check for specific op codes rather than
371 * blindly accepting any special request, the
372 * check for ->rq_disk above may be replaced
373 * by a more suitable mechanism or even
376 return ide_special_rq(drive, rq);
378 drv = *(struct ide_driver **)rq->rq_disk->private_data;
380 return drv->do_request(drive, rq, blk_rq_pos(rq));
382 return do_special(drive);
384 ide_kill_rq(drive, rq);
389 * ide_stall_queue - pause an IDE device
390 * @drive: drive to stall
391 * @timeout: time to stall for (jiffies)
393 * ide_stall_queue() can be used by a drive to give excess bandwidth back
394 * to the port by sleeping for timeout jiffies.
397 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
399 if (timeout > WAIT_WORSTCASE)
400 timeout = WAIT_WORSTCASE;
401 drive->sleep = timeout + jiffies;
402 drive->dev_flags |= IDE_DFLAG_SLEEPING;
404 EXPORT_SYMBOL(ide_stall_queue);
406 static inline int ide_lock_port(ide_hwif_t *hwif)
416 static inline void ide_unlock_port(ide_hwif_t *hwif)
421 static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
425 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
426 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
429 host->get_lock(ide_intr, hwif);
435 static inline void ide_unlock_host(struct ide_host *host)
437 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
438 if (host->release_lock)
439 host->release_lock();
440 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
444 void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
446 struct request_queue *q = drive->queue;
448 /* Use 3ms as that was the old plug delay */
450 blk_mq_requeue_request(rq, false);
451 blk_mq_delay_kick_requeue_list(q, 3);
453 blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
456 blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
459 ide_hwif_t *hwif = drive->hwif;
460 struct ide_host *host = hwif->host;
461 ide_startstop_t startstop;
463 if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) {
464 rq->rq_flags |= RQF_DONTPREP;
465 ide_req(rq)->special = NULL;
468 /* HLD do_request() callback might sleep, make sure it's okay */
471 if (ide_lock_host(host, hwif))
472 return BLK_STS_DEV_RESOURCE;
474 spin_lock_irq(&hwif->lock);
476 if (!ide_lock_port(hwif)) {
477 ide_hwif_t *prev_port;
479 WARN_ON_ONCE(hwif->rq);
481 prev_port = hwif->host->cur_port;
482 if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
483 time_after(drive->sleep, jiffies)) {
484 ide_unlock_port(hwif);
488 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
490 ide_drive_t *cur_dev =
491 prev_port ? prev_port->cur_dev : NULL;
494 * set nIEN for previous port, drives in the
495 * quirk list may not like intr setups/cleanups
498 (cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
499 prev_port->tp_ops->write_devctl(prev_port,
503 hwif->host->cur_port = hwif;
505 hwif->cur_dev = drive;
506 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
509 * Sanity: don't accept a request that isn't a PM request
510 * if we are currently power managed. This is very important as
511 * blk_stop_queue() doesn't prevent the blk_fetch_request()
512 * above to return us whatever is in the queue. Since we call
513 * ide_do_request() ourselves, we end up taking requests while
514 * the queue is blocked...
516 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
517 ata_pm_request(rq) == 0 &&
518 (rq->rq_flags & RQF_PREEMPT) == 0) {
519 /* there should be no pending command at this point */
520 ide_unlock_port(hwif);
524 scsi_req(rq)->resid_len = blk_rq_bytes(rq);
527 spin_unlock_irq(&hwif->lock);
528 startstop = start_request(drive, rq);
529 spin_lock_irq(&hwif->lock);
531 if (startstop == ide_stopped) {
536 ide_unlock_port(hwif);
542 list_add(&rq->queuelist, &drive->rq_list);
543 spin_unlock_irq(&hwif->lock);
544 ide_unlock_host(host);
546 ide_requeue_and_plug(drive, rq);
551 spin_unlock_irq(&hwif->lock);
553 ide_unlock_host(host);
558 * Issue a new request to a device.
560 blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
561 const struct blk_mq_queue_data *bd)
563 ide_drive_t *drive = hctx->queue->queuedata;
564 ide_hwif_t *hwif = drive->hwif;
566 spin_lock_irq(&hwif->lock);
567 if (drive->sense_rq_active) {
568 spin_unlock_irq(&hwif->lock);
569 return BLK_STS_DEV_RESOURCE;
571 spin_unlock_irq(&hwif->lock);
573 blk_mq_start_request(bd->rq);
574 return ide_issue_rq(drive, bd->rq, false);
577 static int drive_is_ready(ide_drive_t *drive)
579 ide_hwif_t *hwif = drive->hwif;
582 if (drive->waiting_for_dma)
583 return hwif->dma_ops->dma_test_irq(drive);
585 if (hwif->io_ports.ctl_addr &&
586 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
587 stat = hwif->tp_ops->read_altstatus(hwif);
589 /* Note: this may clear a pending IRQ!! */
590 stat = hwif->tp_ops->read_status(hwif);
593 /* drive busy: definitely not interrupting */
596 /* drive ready: *might* be interrupting */
601 * ide_timer_expiry - handle lack of an IDE interrupt
602 * @data: timer callback magic (hwif)
604 * An IDE command has timed out before the expected drive return
605 * occurred. At this point we attempt to clean up the current
606 * mess. If the current handler includes an expiry handler then
607 * we invoke the expiry handler, and providing it is happy the
608 * work is done. If that fails we apply generic recovery rules
609 * invoking the handler and checking the drive DMA status. We
610 * have an excessively incestuous relationship with the DMA
611 * logic that wants cleaning up.
614 void ide_timer_expiry (struct timer_list *t)
616 ide_hwif_t *hwif = from_timer(hwif, t, timer);
617 ide_drive_t *uninitialized_var(drive);
618 ide_handler_t *handler;
622 struct request *uninitialized_var(rq_in_flight);
624 spin_lock_irqsave(&hwif->lock, flags);
626 handler = hwif->handler;
628 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
630 * Either a marginal timeout occurred
631 * (got the interrupt just as timer expired),
632 * or we were "sleeping" to give other devices a chance.
633 * Either way, we don't really want to complain about anything.
636 ide_expiry_t *expiry = hwif->expiry;
637 ide_startstop_t startstop = ide_stopped;
639 drive = hwif->cur_dev;
642 wait = expiry(drive);
643 if (wait > 0) { /* continue */
645 hwif->timer.expires = jiffies + wait;
646 hwif->req_gen_timer = hwif->req_gen;
647 add_timer(&hwif->timer);
648 spin_unlock_irqrestore(&hwif->lock, flags);
652 hwif->handler = NULL;
655 * We need to simulate a real interrupt when invoking
656 * the handler() function, which means we need to
657 * globally mask the specific IRQ:
659 spin_unlock(&hwif->lock);
660 /* disable_irq_nosync ?? */
661 disable_irq(hwif->irq);
664 startstop = handler(drive);
665 } else if (drive_is_ready(drive)) {
666 if (drive->waiting_for_dma)
667 hwif->dma_ops->dma_lost_irq(drive);
668 if (hwif->port_ops && hwif->port_ops->clear_irq)
669 hwif->port_ops->clear_irq(drive);
671 printk(KERN_WARNING "%s: lost interrupt\n",
673 startstop = handler(drive);
675 if (drive->waiting_for_dma)
676 startstop = ide_dma_timeout_retry(drive, wait);
678 startstop = ide_error(drive, "irq timeout",
679 hwif->tp_ops->read_status(hwif));
681 /* Disable interrupts again, `handler' might have enabled it */
682 spin_lock_irq(&hwif->lock);
683 enable_irq(hwif->irq);
684 if (startstop == ide_stopped && hwif->polling == 0) {
685 rq_in_flight = hwif->rq;
687 ide_unlock_port(hwif);
691 spin_unlock_irqrestore(&hwif->lock, flags);
694 ide_unlock_host(hwif->host);
695 ide_requeue_and_plug(drive, rq_in_flight);
700 * unexpected_intr - handle an unexpected IDE interrupt
701 * @irq: interrupt line
702 * @hwif: port being processed
704 * There's nothing really useful we can do with an unexpected interrupt,
705 * other than reading the status register (to clear it), and logging it.
706 * There should be no way that an irq can happen before we're ready for it,
707 * so we needn't worry much about losing an "important" interrupt here.
709 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
710 * the drive enters "idle", "standby", or "sleep" mode, so if the status
711 * looks "good", we just ignore the interrupt completely.
713 * This routine assumes __cli() is in effect when called.
715 * If an unexpected interrupt happens on irq15 while we are handling irq14
716 * and if the two interfaces are "serialized" (CMD640), then it looks like
717 * we could screw up by interfering with a new request being set up for
720 * In reality, this is a non-issue. The new command is not sent unless
721 * the drive is ready to accept one, in which case we know the drive is
722 * not trying to interrupt us. And ide_set_handler() is always invoked
723 * before completing the issuance of any new drive command, so we will not
724 * be accidentally invoked as a result of any valid command completion
728 static void unexpected_intr(int irq, ide_hwif_t *hwif)
730 u8 stat = hwif->tp_ops->read_status(hwif);
732 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
733 /* Try to not flood the console with msgs */
734 static unsigned long last_msgtime, count;
737 if (time_after(jiffies, last_msgtime + HZ)) {
738 last_msgtime = jiffies;
739 printk(KERN_ERR "%s: unexpected interrupt, "
740 "status=0x%02x, count=%ld\n",
741 hwif->name, stat, count);
747 * ide_intr - default IDE interrupt handler
748 * @irq: interrupt number
750 * @regs: unused weirdness from the kernel irq layer
752 * This is the default IRQ handler for the IDE layer. You should
753 * not need to override it. If you do be aware it is subtle in
756 * hwif is the interface in the group currently performing
757 * a command. hwif->cur_dev is the drive and hwif->handler is
758 * the IRQ handler to call. As we issue a command the handlers
759 * step through multiple states, reassigning the handler to the
760 * next step in the process. Unlike a smart SCSI controller IDE
761 * expects the main processor to sequence the various transfer
762 * stages. We also manage a poll timer to catch up with most
763 * timeout situations. There are still a few where the handlers
764 * don't ever decide to give up.
766 * The handler eventually returns ide_stopped to indicate the
767 * request completed. At this point we issue the next request
768 * on the port and the process begins again.
771 irqreturn_t ide_intr (int irq, void *dev_id)
773 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
774 struct ide_host *host = hwif->host;
775 ide_drive_t *uninitialized_var(drive);
776 ide_handler_t *handler;
778 ide_startstop_t startstop;
779 irqreturn_t irq_ret = IRQ_NONE;
781 struct request *uninitialized_var(rq_in_flight);
783 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
784 if (hwif != host->cur_port)
788 spin_lock_irqsave(&hwif->lock, flags);
790 if (hwif->port_ops && hwif->port_ops->test_irq &&
791 hwif->port_ops->test_irq(hwif) == 0)
794 handler = hwif->handler;
796 if (handler == NULL || hwif->polling) {
798 * Not expecting an interrupt from this drive.
799 * That means this could be:
800 * (1) an interrupt from another PCI device
801 * sharing the same PCI INT# as us.
802 * or (2) a drive just entered sleep or standby mode,
803 * and is interrupting to let us know.
804 * or (3) a spurious interrupt of unknown origin.
806 * For PCI, we cannot tell the difference,
807 * so in that case we just ignore it and hope it goes away.
809 if ((host->irq_flags & IRQF_SHARED) == 0) {
811 * Probably not a shared PCI interrupt,
812 * so we can safely try to do something about it:
814 unexpected_intr(irq, hwif);
817 * Whack the status register, just in case
818 * we have a leftover pending IRQ.
820 (void)hwif->tp_ops->read_status(hwif);
825 drive = hwif->cur_dev;
827 if (!drive_is_ready(drive))
829 * This happens regularly when we share a PCI IRQ with
830 * another device. Unfortunately, it can also happen
831 * with some buggy drives that trigger the IRQ before
832 * their status register is up to date. Hopefully we have
833 * enough advance overhead that the latter isn't a problem.
837 hwif->handler = NULL;
840 del_timer(&hwif->timer);
841 spin_unlock(&hwif->lock);
843 if (hwif->port_ops && hwif->port_ops->clear_irq)
844 hwif->port_ops->clear_irq(drive);
846 if (drive->dev_flags & IDE_DFLAG_UNMASK)
847 local_irq_enable_in_hardirq();
849 /* service this interrupt, may set handler for next interrupt */
850 startstop = handler(drive);
852 spin_lock_irq(&hwif->lock);
854 * Note that handler() may have set things up for another
855 * interrupt to occur soon, but it cannot happen until
856 * we exit from this routine, because it will be the
857 * same irq as is currently being serviced here, and Linux
858 * won't allow another of the same (on any CPU) until we return.
860 if (startstop == ide_stopped && hwif->polling == 0) {
861 BUG_ON(hwif->handler);
862 rq_in_flight = hwif->rq;
864 ide_unlock_port(hwif);
867 irq_ret = IRQ_HANDLED;
869 spin_unlock_irqrestore(&hwif->lock, flags);
872 ide_unlock_host(hwif->host);
873 ide_requeue_and_plug(drive, rq_in_flight);
878 EXPORT_SYMBOL_GPL(ide_intr);
880 void ide_pad_transfer(ide_drive_t *drive, int write, int len)
882 ide_hwif_t *hwif = drive->hwif;
887 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
889 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
893 EXPORT_SYMBOL_GPL(ide_pad_transfer);
895 void ide_insert_request_head(ide_drive_t *drive, struct request *rq)
897 drive->sense_rq_active = true;
898 list_add_tail(&rq->queuelist, &drive->rq_list);
899 kblockd_schedule_work(&drive->rq_work);
901 EXPORT_SYMBOL_GPL(ide_insert_request_head);