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/config.h>
28 #include <linux/module.h>
29 #include <linux/types.h>
30 #include <linux/string.h>
31 #include <linux/kernel.h>
32 #include <linux/timer.h>
34 #include <linux/interrupt.h>
35 #include <linux/major.h>
36 #include <linux/errno.h>
37 #include <linux/genhd.h>
38 #include <linux/blkpg.h>
39 #include <linux/slab.h>
40 #include <linux/init.h>
41 #include <linux/pci.h>
42 #include <linux/delay.h>
43 #include <linux/ide.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>
51 #include <asm/byteorder.h>
53 #include <asm/uaccess.h>
55 #include <asm/bitops.h>
58 * ide_end_request - complete an IDE I/O
59 * @drive: IDE device for the I/O
61 * @nr_sectors: number of sectors completed
63 * This is our end_request wrapper function. We complete the I/O
64 * update random number input and dequeue the request, which if
65 * it was tagged may be out of order.
68 int ide_end_request (ide_drive_t *drive, int uptodate, int nr_sectors)
74 spin_lock_irqsave(&ide_lock, flags);
75 rq = HWGROUP(drive)->rq;
77 BUG_ON(!(rq->flags & REQ_STARTED));
80 nr_sectors = rq->hard_cur_sectors;
83 * if failfast is set on a request, override number of sectors and
84 * complete the whole request right now
86 if (blk_noretry_request(rq) && !uptodate)
87 nr_sectors = rq->hard_nr_sectors;
90 * decide whether to reenable DMA -- 3 is a random magic for now,
91 * if we DMA timeout more than 3 times, just stay in PIO
93 if (drive->state == DMA_PIO_RETRY && drive->retry_pio <= 3) {
95 HWGROUP(drive)->hwif->ide_dma_on(drive);
98 if (!end_that_request_first(rq, uptodate, nr_sectors)) {
99 add_disk_randomness(rq->rq_disk);
100 if (!blk_rq_tagged(rq))
101 blkdev_dequeue_request(rq);
103 blk_queue_end_tag(drive->queue, rq);
104 HWGROUP(drive)->rq = NULL;
105 end_that_request_last(rq);
108 spin_unlock_irqrestore(&ide_lock, flags);
112 EXPORT_SYMBOL(ide_end_request);
115 * ide_complete_pm_request - end the current Power Management request
116 * @drive: target drive
119 * This function cleans up the current PM request and stops the queue
122 static void ide_complete_pm_request (ide_drive_t *drive, struct request *rq)
127 printk("%s: completing PM request, %s\n", drive->name,
128 blk_pm_suspend_request(rq) ? "suspend" : "resume");
130 spin_lock_irqsave(&ide_lock, flags);
131 if (blk_pm_suspend_request(rq)) {
132 blk_stop_queue(drive->queue);
135 blk_start_queue(drive->queue);
137 blkdev_dequeue_request(rq);
138 HWGROUP(drive)->rq = NULL;
139 end_that_request_last(rq);
140 spin_unlock_irqrestore(&ide_lock, flags);
144 * ide_end_drive_cmd - end an explicit drive command
149 * Clean up after success/failure of an explicit drive command.
150 * These get thrown onto the queue so they are synchronized with
151 * real I/O operations on the drive.
153 * In LBA48 mode we have to read the register set twice to get
154 * all the extra information out.
157 void ide_end_drive_cmd (ide_drive_t *drive, u8 stat, u8 err)
159 ide_hwif_t *hwif = HWIF(drive);
163 spin_lock_irqsave(&ide_lock, flags);
164 rq = HWGROUP(drive)->rq;
165 spin_unlock_irqrestore(&ide_lock, flags);
167 if (rq->flags & REQ_DRIVE_CMD) {
168 u8 *args = (u8 *) rq->buffer;
170 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
175 args[2] = hwif->INB(IDE_NSECTOR_REG);
177 } else if (rq->flags & REQ_DRIVE_TASK) {
178 u8 *args = (u8 *) rq->buffer;
180 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
185 args[2] = hwif->INB(IDE_NSECTOR_REG);
186 args[3] = hwif->INB(IDE_SECTOR_REG);
187 args[4] = hwif->INB(IDE_LCYL_REG);
188 args[5] = hwif->INB(IDE_HCYL_REG);
189 args[6] = hwif->INB(IDE_SELECT_REG);
191 } else if (rq->flags & REQ_DRIVE_TASKFILE) {
192 ide_task_t *args = (ide_task_t *) rq->special;
194 rq->errors = !OK_STAT(stat,READY_STAT,BAD_STAT);
197 if (args->tf_in_flags.b.data) {
198 u16 data = hwif->INW(IDE_DATA_REG);
199 args->tfRegister[IDE_DATA_OFFSET] = (data) & 0xFF;
200 args->hobRegister[IDE_DATA_OFFSET] = (data >> 8) & 0xFF;
202 args->tfRegister[IDE_ERROR_OFFSET] = err;
203 args->tfRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
204 args->tfRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
205 args->tfRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
206 args->tfRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
207 args->tfRegister[IDE_SELECT_OFFSET] = hwif->INB(IDE_SELECT_REG);
208 args->tfRegister[IDE_STATUS_OFFSET] = stat;
210 if (drive->addressing == 1) {
211 hwif->OUTB(drive->ctl|0x80, IDE_CONTROL_REG);
212 args->hobRegister[IDE_FEATURE_OFFSET] = hwif->INB(IDE_FEATURE_REG);
213 args->hobRegister[IDE_NSECTOR_OFFSET] = hwif->INB(IDE_NSECTOR_REG);
214 args->hobRegister[IDE_SECTOR_OFFSET] = hwif->INB(IDE_SECTOR_REG);
215 args->hobRegister[IDE_LCYL_OFFSET] = hwif->INB(IDE_LCYL_REG);
216 args->hobRegister[IDE_HCYL_OFFSET] = hwif->INB(IDE_HCYL_REG);
219 } else if (blk_pm_request(rq)) {
221 printk("%s: complete_power_step(step: %d, stat: %x, err: %x)\n",
222 drive->name, rq->pm->pm_step, stat, err);
224 DRIVER(drive)->complete_power_step(drive, rq, stat, err);
225 if (rq->pm->pm_step == ide_pm_state_completed)
226 ide_complete_pm_request(drive, rq);
230 spin_lock_irqsave(&ide_lock, flags);
231 blkdev_dequeue_request(rq);
232 HWGROUP(drive)->rq = NULL;
233 end_that_request_last(rq);
234 spin_unlock_irqrestore(&ide_lock, flags);
237 EXPORT_SYMBOL(ide_end_drive_cmd);
240 * try_to_flush_leftover_data - flush junk
241 * @drive: drive to flush
243 * try_to_flush_leftover_data() is invoked in response to a drive
244 * unexpectedly having its DRQ_STAT bit set. As an alternative to
245 * resetting the drive, this routine tries to clear the condition
246 * by read a sector's worth of data from the drive. Of course,
247 * this may not help if the drive is *waiting* for data from *us*.
249 void try_to_flush_leftover_data (ide_drive_t *drive)
251 int i = (drive->mult_count ? drive->mult_count : 1) * SECTOR_WORDS;
253 if (drive->media != ide_disk)
257 u32 wcount = (i > 16) ? 16 : i;
260 HWIF(drive)->ata_input_data(drive, buffer, wcount);
264 EXPORT_SYMBOL(try_to_flush_leftover_data);
267 * FIXME Add an ATAPI error
271 * ide_error - handle an error on the IDE
272 * @drive: drive the error occurred on
273 * @msg: message to report
276 * ide_error() takes action based on the error returned by the drive.
277 * For normal I/O that may well include retries. We deal with
278 * both new-style (taskfile) and old style command handling here.
279 * In the case of taskfile command handling there is work left to
283 ide_startstop_t ide_error (ide_drive_t *drive, const char *msg, u8 stat)
289 err = ide_dump_status(drive, msg, stat);
290 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
294 /* retry only "normal" I/O: */
295 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
297 ide_end_drive_cmd(drive, stat, err);
300 if (rq->flags & REQ_DRIVE_TASKFILE) {
302 ide_end_drive_cmd(drive, stat, err);
306 if (stat & BUSY_STAT || ((stat & WRERR_STAT) && !drive->nowerr)) {
307 /* other bits are useless when BUSY */
308 rq->errors |= ERROR_RESET;
310 if (drive->media != ide_disk)
313 if (stat & ERR_STAT) {
314 /* err has different meaning on cdrom and tape */
315 if (err == ABRT_ERR) {
316 if (drive->select.b.lba &&
317 (hwif->INB(IDE_COMMAND_REG) == WIN_SPECIFY))
318 /* some newer drives don't
319 * support WIN_SPECIFY
322 } else if ((err & BAD_CRC) == BAD_CRC) {
324 /* UDMA crc error -- just retry the operation */
325 } else if (err & (BBD_ERR | ECC_ERR)) {
326 /* retries won't help these */
327 rq->errors = ERROR_MAX;
328 } else if (err & TRK0_ERR) {
329 /* help it find track zero */
330 rq->errors |= ERROR_RECAL;
334 if ((stat & DRQ_STAT) && rq_data_dir(rq) != WRITE)
335 try_to_flush_leftover_data(drive);
337 if (hwif->INB(IDE_STATUS_REG) & (BUSY_STAT|DRQ_STAT)) {
339 hwif->OUTB(WIN_IDLEIMMEDIATE,IDE_COMMAND_REG);
341 if (rq->errors >= ERROR_MAX) {
342 DRIVER(drive)->end_request(drive, 0, 0);
344 if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
346 return ide_do_reset(drive);
348 if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
349 drive->special.b.recalibrate = 1;
355 EXPORT_SYMBOL(ide_error);
358 * ide_abort - abort pending IDE operatins
359 * @drive: drive the error occurred on
360 * @msg: message to report
362 * ide_abort kills and cleans up when we are about to do a
363 * host initiated reset on active commands. Longer term we
364 * want handlers to have sensible abort handling themselves
366 * This differs fundamentally from ide_error because in
367 * this case the command is doing just fine when we
371 ide_startstop_t ide_abort(ide_drive_t *drive, const char *msg)
376 if (drive == NULL || (rq = HWGROUP(drive)->rq) == NULL)
380 /* retry only "normal" I/O: */
381 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK)) {
383 ide_end_drive_cmd(drive, BUSY_STAT, 0);
386 if (rq->flags & REQ_DRIVE_TASKFILE) {
388 ide_end_drive_cmd(drive, BUSY_STAT, 0);
392 rq->errors |= ERROR_RESET;
393 DRIVER(drive)->end_request(drive, 0, 0);
397 EXPORT_SYMBOL(ide_abort);
400 * ide_cmd - issue a simple drive command
401 * @drive: drive the command is for
403 * @nsect: sector byte
404 * @handler: handler for the command completion
406 * Issue a simple drive command with interrupts.
407 * The drive must be selected beforehand.
410 void ide_cmd (ide_drive_t *drive, u8 cmd, u8 nsect, ide_handler_t *handler)
412 ide_hwif_t *hwif = HWIF(drive);
414 hwif->OUTB(drive->ctl,IDE_CONTROL_REG); /* clear nIEN */
415 SELECT_MASK(drive,0);
416 hwif->OUTB(nsect,IDE_NSECTOR_REG);
417 ide_execute_command(drive, cmd, handler, WAIT_CMD, NULL);
420 EXPORT_SYMBOL(ide_cmd);
423 * drive_cmd_intr - drive command completion interrupt
424 * @drive: drive the completion interrupt occurred on
426 * drive_cmd_intr() is invoked on completion of a special DRIVE_CMD.
427 * We do any necessary daya reading and then wait for the drive to
428 * go non busy. At that point we may read the error data and complete
432 ide_startstop_t drive_cmd_intr (ide_drive_t *drive)
434 struct request *rq = HWGROUP(drive)->rq;
435 ide_hwif_t *hwif = HWIF(drive);
436 u8 *args = (u8 *) rq->buffer;
437 u8 stat = hwif->INB(IDE_STATUS_REG);
441 if ((stat & DRQ_STAT) && args && args[3]) {
442 u8 io_32bit = drive->io_32bit;
444 hwif->ata_input_data(drive, &args[4], args[3] * SECTOR_WORDS);
445 drive->io_32bit = io_32bit;
446 while (((stat = hwif->INB(IDE_STATUS_REG)) & BUSY_STAT) && retries--)
450 if (!OK_STAT(stat, READY_STAT, BAD_STAT) && DRIVER(drive) != NULL)
451 return DRIVER(drive)->error(drive, "drive_cmd", stat);
452 /* calls ide_end_drive_cmd */
453 ide_end_drive_cmd(drive, stat, hwif->INB(IDE_ERROR_REG));
457 EXPORT_SYMBOL(drive_cmd_intr);
460 * do_special - issue some special commands
461 * @drive: drive the command is for
463 * do_special() is used to issue WIN_SPECIFY, WIN_RESTORE, and WIN_SETMULT
464 * commands to a drive. It used to do much more, but has been scaled
468 ide_startstop_t do_special (ide_drive_t *drive)
470 special_t *s = &drive->special;
473 printk("%s: do_special: 0x%02x\n", drive->name, s->all);
477 if (HWIF(drive)->tuneproc != NULL)
478 HWIF(drive)->tuneproc(drive, drive->tune_req);
482 return DRIVER(drive)->special(drive);
485 EXPORT_SYMBOL(do_special);
488 * execute_drive_command - issue special drive command
489 * @drive: the drive to issue th command on
490 * @rq: the request structure holding the command
492 * execute_drive_cmd() issues a special drive command, usually
493 * initiated by ioctl() from the external hdparm program. The
494 * command can be a drive command, drive task or taskfile
495 * operation. Weirdly you can call it with NULL to wait for
496 * all commands to finish. Don't do this as that is due to change
499 ide_startstop_t execute_drive_cmd (ide_drive_t *drive, struct request *rq)
501 ide_hwif_t *hwif = HWIF(drive);
502 if (rq->flags & REQ_DRIVE_TASKFILE) {
503 ide_task_t *args = rq->special;
508 if (args->tf_out_flags.all != 0)
509 return flagged_taskfile(drive, args);
510 return do_rw_taskfile(drive, args);
511 } else if (rq->flags & REQ_DRIVE_TASK) {
512 u8 *args = rq->buffer;
518 printk("%s: DRIVE_TASK_CMD ", drive->name);
519 printk("cmd=0x%02x ", args[0]);
520 printk("fr=0x%02x ", args[1]);
521 printk("ns=0x%02x ", args[2]);
522 printk("sc=0x%02x ", args[3]);
523 printk("lcyl=0x%02x ", args[4]);
524 printk("hcyl=0x%02x ", args[5]);
525 printk("sel=0x%02x\n", args[6]);
527 hwif->OUTB(args[1], IDE_FEATURE_REG);
528 hwif->OUTB(args[3], IDE_SECTOR_REG);
529 hwif->OUTB(args[4], IDE_LCYL_REG);
530 hwif->OUTB(args[5], IDE_HCYL_REG);
531 sel = (args[6] & ~0x10);
532 if (drive->select.b.unit)
534 hwif->OUTB(sel, IDE_SELECT_REG);
535 ide_cmd(drive, args[0], args[2], &drive_cmd_intr);
537 } else if (rq->flags & REQ_DRIVE_CMD) {
538 u8 *args = rq->buffer;
543 printk("%s: DRIVE_CMD ", drive->name);
544 printk("cmd=0x%02x ", args[0]);
545 printk("sc=0x%02x ", args[1]);
546 printk("fr=0x%02x ", args[2]);
547 printk("xx=0x%02x\n", args[3]);
549 if (args[0] == WIN_SMART) {
550 hwif->OUTB(0x4f, IDE_LCYL_REG);
551 hwif->OUTB(0xc2, IDE_HCYL_REG);
552 hwif->OUTB(args[2],IDE_FEATURE_REG);
553 hwif->OUTB(args[1],IDE_SECTOR_REG);
554 ide_cmd(drive, args[0], args[3], &drive_cmd_intr);
557 hwif->OUTB(args[2],IDE_FEATURE_REG);
558 ide_cmd(drive, args[0], args[1], &drive_cmd_intr);
564 * NULL is actually a valid way of waiting for
565 * all current requests to be flushed from the queue.
568 printk("%s: DRIVE_CMD (null)\n", drive->name);
570 ide_end_drive_cmd(drive,
571 hwif->INB(IDE_STATUS_REG),
572 hwif->INB(IDE_ERROR_REG));
576 EXPORT_SYMBOL(execute_drive_cmd);
579 * start_request - start of I/O and command issuing for IDE
581 * start_request() initiates handling of a new I/O request. It
582 * accepts commands and I/O (read/write) requests. It also does
583 * the final remapping for weird stuff like EZDrive. Once
584 * device mapper can work sector level the EZDrive stuff can go away
586 * FIXME: this function needs a rename
589 ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
591 ide_startstop_t startstop;
594 BUG_ON(!(rq->flags & REQ_STARTED));
597 printk("%s: start_request: current=0x%08lx\n",
598 HWIF(drive)->name, (unsigned long) rq);
601 /* bail early if we've exceeded max_failures */
602 if (drive->max_failures && (drive->failures > drive->max_failures)) {
607 * bail early if we've sent a device to sleep, however how to wake
608 * this needs to be a masked flag. FIXME for proper operations.
610 if (drive->suspend_reset)
614 if (blk_fs_request(rq) &&
615 (drive->media == ide_disk || drive->media == ide_floppy)) {
616 block += drive->sect0;
618 /* Yecch - this will shift the entire interval,
619 possibly killing some innocent following sector */
620 if (block == 0 && drive->remap_0_to_1 == 1)
621 block = 1; /* redirect MBR access to EZ-Drive partn table */
623 if (blk_pm_suspend_request(rq) &&
624 rq->pm->pm_step == ide_pm_state_start_suspend)
625 /* Mark drive blocked when starting the suspend sequence. */
627 else if (blk_pm_resume_request(rq) &&
628 rq->pm->pm_step == ide_pm_state_start_resume) {
630 * The first thing we do on wakeup is to wait for BSY bit to
631 * go away (with a looong timeout) as a drive on this hwif may
632 * just be POSTing itself.
633 * We do that before even selecting as the "other" device on
634 * the bus may be broken enough to walk on our toes at this
639 printk("%s: Wakeup request inited, waiting for !BSY...\n", drive->name);
641 rc = ide_wait_not_busy(HWIF(drive), 35000);
643 printk(KERN_WARNING "%s: bus not ready on wakeup\n", drive->name);
645 HWIF(drive)->OUTB(8, HWIF(drive)->io_ports[IDE_CONTROL_OFFSET]);
646 rc = ide_wait_not_busy(HWIF(drive), 10000);
648 printk(KERN_WARNING "%s: drive not ready on wakeup\n", drive->name);
652 if (ide_wait_stat(&startstop, drive, drive->ready_stat, BUSY_STAT|DRQ_STAT, WAIT_READY)) {
653 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
656 if (!drive->special.all) {
657 if (rq->flags & (REQ_DRIVE_CMD | REQ_DRIVE_TASK))
658 return execute_drive_cmd(drive, rq);
659 else if (rq->flags & REQ_DRIVE_TASKFILE)
660 return execute_drive_cmd(drive, rq);
661 else if (blk_pm_request(rq)) {
663 printk("%s: start_power_step(step: %d)\n",
664 drive->name, rq->pm->pm_step);
666 startstop = DRIVER(drive)->start_power_step(drive, rq);
667 if (startstop == ide_stopped &&
668 rq->pm->pm_step == ide_pm_state_completed)
669 ide_complete_pm_request(drive, rq);
672 return (DRIVER(drive)->do_request(drive, rq, block));
674 return do_special(drive);
676 DRIVER(drive)->end_request(drive, 0, 0);
680 EXPORT_SYMBOL(start_request);
683 * ide_stall_queue - pause an IDE device
684 * @drive: drive to stall
685 * @timeout: time to stall for (jiffies)
687 * ide_stall_queue() can be used by a drive to give excess bandwidth back
688 * to the hwgroup by sleeping for timeout jiffies.
691 void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
693 if (timeout > WAIT_WORSTCASE)
694 timeout = WAIT_WORSTCASE;
695 drive->sleep = timeout + jiffies;
698 EXPORT_SYMBOL(ide_stall_queue);
700 #define WAKEUP(drive) ((drive)->service_start + 2 * (drive)->service_time)
703 * choose_drive - select a drive to service
704 * @hwgroup: hardware group to select on
706 * choose_drive() selects the next drive which will be serviced.
707 * This is necessary because the IDE layer can't issue commands
708 * to both drives on the same cable, unlike SCSI.
711 static inline ide_drive_t *choose_drive (ide_hwgroup_t *hwgroup)
713 ide_drive_t *drive, *best;
717 drive = hwgroup->drive;
719 if ((!drive->sleep || time_after_eq(jiffies, drive->sleep))
720 && !elv_queue_empty(drive->queue)) {
722 || (drive->sleep && (!best->sleep || 0 < (signed long)(best->sleep - drive->sleep)))
723 || (!best->sleep && 0 < (signed long)(WAKEUP(best) - WAKEUP(drive))))
725 if (!blk_queue_plugged(drive->queue))
729 } while ((drive = drive->next) != hwgroup->drive);
730 if (best && best->nice1 && !best->sleep && best != hwgroup->drive && best->service_time > WAIT_MIN_SLEEP) {
731 long t = (signed long)(WAKEUP(best) - jiffies);
732 if (t >= WAIT_MIN_SLEEP) {
734 * We *may* have some time to spare, but first let's see if
735 * someone can potentially benefit from our nice mood today..
740 /* FIXME: use time_before */
741 && 0 < (signed long)(WAKEUP(drive) - (jiffies - best->service_time))
742 && 0 < (signed long)((jiffies + t) - WAKEUP(drive)))
744 ide_stall_queue(best, min_t(long, t, 10 * WAIT_MIN_SLEEP));
747 } while ((drive = drive->next) != best);
754 * Issue a new request to a drive from hwgroup
755 * Caller must have already done spin_lock_irqsave(&ide_lock, ..);
757 * A hwgroup is a serialized group of IDE interfaces. Usually there is
758 * exactly one hwif (interface) per hwgroup, but buggy controllers (eg. CMD640)
759 * may have both interfaces in a single hwgroup to "serialize" access.
760 * Or possibly multiple ISA interfaces can share a common IRQ by being grouped
761 * together into one hwgroup for serialized access.
763 * Note also that several hwgroups can end up sharing a single IRQ,
764 * possibly along with many other devices. This is especially common in
765 * PCI-based systems with off-board IDE controller cards.
767 * The IDE driver uses the single global ide_lock spinlock to protect
768 * access to the request queues, and to protect the hwgroup->busy flag.
770 * The first thread into the driver for a particular hwgroup sets the
771 * hwgroup->busy flag to indicate that this hwgroup is now active,
772 * and then initiates processing of the top request from the request queue.
774 * Other threads attempting entry notice the busy setting, and will simply
775 * queue their new requests and exit immediately. Note that hwgroup->busy
776 * remains set even when the driver is merely awaiting the next interrupt.
777 * Thus, the meaning is "this hwgroup is busy processing a request".
779 * When processing of a request completes, the completing thread or IRQ-handler
780 * will start the next request from the queue. If no more work remains,
781 * the driver will clear the hwgroup->busy flag and exit.
783 * The ide_lock (spinlock) is used to protect all access to the
784 * hwgroup->busy flag, but is otherwise not needed for most processing in
785 * the driver. This makes the driver much more friendlier to shared IRQs
786 * than previous designs, while remaining 100% (?) SMP safe and capable.
788 /* --BenH: made non-static as ide-pmac.c uses it to kick the hwgroup back
789 * into life on wakeup from machine sleep.
791 void ide_do_request (ide_hwgroup_t *hwgroup, int masked_irq)
796 ide_startstop_t startstop;
798 /* for atari only: POSSIBLY BROKEN HERE(?) */
799 ide_get_lock(ide_intr, hwgroup);
801 /* caller must own ide_lock */
802 BUG_ON(!irqs_disabled());
804 while (!hwgroup->busy) {
806 drive = choose_drive(hwgroup);
808 unsigned long sleep = 0;
810 drive = hwgroup->drive;
812 if (drive->sleep && (!sleep || 0 < (signed long)(sleep - drive->sleep)))
813 sleep = drive->sleep;
814 } while ((drive = drive->next) != hwgroup->drive);
817 * Take a short snooze, and then wake up this hwgroup again.
818 * This gives other hwgroups on the same a chance to
819 * play fairly with us, just in case there are big differences
820 * in relative throughputs.. don't want to hog the cpu too much.
822 if (time_before(sleep, jiffies + WAIT_MIN_SLEEP))
823 sleep = jiffies + WAIT_MIN_SLEEP;
825 if (timer_pending(&hwgroup->timer))
826 printk(KERN_CRIT "ide_set_handler: timer already active\n");
828 /* so that ide_timer_expiry knows what to do */
829 hwgroup->sleeping = 1;
830 mod_timer(&hwgroup->timer, sleep);
831 /* we purposely leave hwgroup->busy==1
834 /* Ugly, but how can we sleep for the lock
835 * otherwise? perhaps from tq_disk?
843 /* no more work for this hwgroup (for now) */
847 if (hwgroup->hwif->sharing_irq &&
848 hwif != hwgroup->hwif &&
849 hwif->io_ports[IDE_CONTROL_OFFSET]) {
850 /* set nIEN for previous hwif */
851 SELECT_INTERRUPT(drive);
853 hwgroup->hwif = hwif;
854 hwgroup->drive = drive;
856 drive->service_start = jiffies;
859 if (!ata_can_queue(drive)) {
860 if (!ata_pending_commands(drive))
866 if (blk_queue_plugged(drive->queue)) {
867 if (drive->using_tcq)
870 printk(KERN_ERR "ide: huh? queue was plugged!\n");
875 * we know that the queue isn't empty, but this can happen
876 * if the q->prep_rq_fn() decides to kill a request
878 rq = elv_next_request(drive->queue);
880 hwgroup->busy = !!ata_pending_commands(drive);
885 * Sanity: don't accept a request that isn't a PM request
886 * if we are currently power managed. This is very important as
887 * blk_stop_queue() doesn't prevent the elv_next_request()
888 * above to return us whatever is in the queue. Since we call
889 * ide_do_request() ourselves, we end up taking requests while
890 * the queue is blocked...
892 * We let requests forced at head of queue with ide-preempt
893 * though. I hope that doesn't happen too much, hopefully not
894 * unless the subdriver triggers such a thing in its own PM
897 if (drive->blocked && !blk_pm_request(rq) && !(rq->flags & REQ_PREEMPT)) {
898 /* We clear busy, there should be no pending ATA command at this point. */
903 if (!rq->bio && ata_pending_commands(drive))
909 * Some systems have trouble with IDE IRQs arriving while
910 * the driver is still setting things up. So, here we disable
911 * the IRQ used by this interface while the request is being started.
912 * This may look bad at first, but pretty much the same thing
913 * happens anyway when any interrupt comes in, IDE or otherwise
914 * -- the kernel masks the IRQ while it is being handled.
916 if (hwif->irq != masked_irq)
917 disable_irq_nosync(hwif->irq);
918 spin_unlock(&ide_lock);
920 /* allow other IRQs while we start this request */
921 startstop = start_request(drive, rq);
922 spin_lock_irq(&ide_lock);
923 if (hwif->irq != masked_irq)
924 enable_irq(hwif->irq);
925 if (startstop == ide_released)
927 if (startstop == ide_stopped)
932 EXPORT_SYMBOL(ide_do_request);
935 * Passes the stuff to ide_do_request
937 void do_ide_request(request_queue_t *q)
939 ide_do_request(q->queuedata, IDE_NO_IRQ);
943 * un-busy the hwgroup etc, and clear any pending DMA status. we want to
944 * retry the current request in pio mode instead of risking tossing it
947 static ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
949 ide_hwif_t *hwif = HWIF(drive);
951 ide_startstop_t ret = ide_stopped;
954 * end current dma transaction
958 printk(KERN_WARNING "%s: DMA timeout error\n", drive->name);
959 (void)HWIF(drive)->ide_dma_end(drive);
960 ret = DRIVER(drive)->error(drive, "dma timeout error",
961 hwif->INB(IDE_STATUS_REG));
963 printk(KERN_WARNING "%s: DMA timeout retry\n", drive->name);
964 (void) hwif->ide_dma_timeout(drive);
968 * disable dma for now, but remember that we did so because of
969 * a timeout -- we'll reenable after we finish this next request
970 * (or rather the first chunk of it) in pio.
973 drive->state = DMA_PIO_RETRY;
974 (void) hwif->ide_dma_off_quietly(drive);
977 * un-busy drive etc (hwgroup->busy is cleared on return) and
978 * make sure request is sane
980 rq = HWGROUP(drive)->rq;
981 HWGROUP(drive)->rq = NULL;
984 rq->sector = rq->bio->bi_sector;
985 rq->current_nr_sectors = bio_iovec(rq->bio)->bv_len >> 9;
986 rq->hard_cur_sectors = rq->current_nr_sectors;
994 * ide_timer_expiry - handle lack of an IDE interrupt
995 * @data: timer callback magic (hwgroup)
997 * An IDE command has timed out before the expected drive return
998 * occurred. At this point we attempt to clean up the current
999 * mess. If the current handler includes an expiry handler then
1000 * we invoke the expiry handler, and providing it is happy the
1001 * work is done. If that fails we apply generic recovery rules
1002 * invoking the handler and checking the drive DMA status. We
1003 * have an excessively incestuous relationship with the DMA
1004 * logic that wants cleaning up.
1007 void ide_timer_expiry (unsigned long data)
1009 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *) data;
1010 ide_handler_t *handler;
1011 ide_expiry_t *expiry;
1012 unsigned long flags;
1013 unsigned long wait = -1;
1015 spin_lock_irqsave(&ide_lock, flags);
1017 if ((handler = hwgroup->handler) == NULL) {
1019 * Either a marginal timeout occurred
1020 * (got the interrupt just as timer expired),
1021 * or we were "sleeping" to give other devices a chance.
1022 * Either way, we don't really want to complain about anything.
1024 if (hwgroup->sleeping) {
1025 hwgroup->sleeping = 0;
1029 ide_drive_t *drive = hwgroup->drive;
1031 printk(KERN_ERR "ide_timer_expiry: hwgroup->drive was NULL\n");
1032 hwgroup->handler = NULL;
1035 ide_startstop_t startstop = ide_stopped;
1036 if (!hwgroup->busy) {
1037 hwgroup->busy = 1; /* paranoia */
1038 printk(KERN_ERR "%s: ide_timer_expiry: hwgroup->busy was 0 ??\n", drive->name);
1040 if ((expiry = hwgroup->expiry) != NULL) {
1042 if ((wait = expiry(drive)) > 0) {
1044 hwgroup->timer.expires = jiffies + wait;
1045 add_timer(&hwgroup->timer);
1046 spin_unlock_irqrestore(&ide_lock, flags);
1050 hwgroup->handler = NULL;
1052 * We need to simulate a real interrupt when invoking
1053 * the handler() function, which means we need to
1054 * globally mask the specific IRQ:
1056 spin_unlock(&ide_lock);
1058 #if DISABLE_IRQ_NOSYNC
1059 disable_irq_nosync(hwif->irq);
1061 /* disable_irq_nosync ?? */
1062 disable_irq(hwif->irq);
1063 #endif /* DISABLE_IRQ_NOSYNC */
1065 * as if we were handling an interrupt */
1066 local_irq_disable();
1067 if (hwgroup->poll_timeout != 0) {
1068 startstop = handler(drive);
1069 } else if (drive_is_ready(drive)) {
1070 if (drive->waiting_for_dma)
1071 (void) hwgroup->hwif->ide_dma_lostirq(drive);
1072 (void)ide_ack_intr(hwif);
1073 printk(KERN_WARNING "%s: lost interrupt\n", drive->name);
1074 startstop = handler(drive);
1076 if (drive->waiting_for_dma) {
1077 startstop = ide_dma_timeout_retry(drive, wait);
1080 DRIVER(drive)->error(drive, "irq timeout", hwif->INB(IDE_STATUS_REG));
1082 drive->service_time = jiffies - drive->service_start;
1083 spin_lock_irq(&ide_lock);
1084 enable_irq(hwif->irq);
1085 if (startstop == ide_stopped)
1089 ide_do_request(hwgroup, IDE_NO_IRQ);
1090 spin_unlock_irqrestore(&ide_lock, flags);
1093 EXPORT_SYMBOL(ide_timer_expiry);
1096 * unexpected_intr - handle an unexpected IDE interrupt
1097 * @irq: interrupt line
1098 * @hwgroup: hwgroup being processed
1100 * There's nothing really useful we can do with an unexpected interrupt,
1101 * other than reading the status register (to clear it), and logging it.
1102 * There should be no way that an irq can happen before we're ready for it,
1103 * so we needn't worry much about losing an "important" interrupt here.
1105 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
1106 * the drive enters "idle", "standby", or "sleep" mode, so if the status
1107 * looks "good", we just ignore the interrupt completely.
1109 * This routine assumes __cli() is in effect when called.
1111 * If an unexpected interrupt happens on irq15 while we are handling irq14
1112 * and if the two interfaces are "serialized" (CMD640), then it looks like
1113 * we could screw up by interfering with a new request being set up for
1116 * In reality, this is a non-issue. The new command is not sent unless
1117 * the drive is ready to accept one, in which case we know the drive is
1118 * not trying to interrupt us. And ide_set_handler() is always invoked
1119 * before completing the issuance of any new drive command, so we will not
1120 * be accidentally invoked as a result of any valid command completion
1123 * Note that we must walk the entire hwgroup here. We know which hwif
1124 * is doing the current command, but we don't know which hwif burped
1128 static void unexpected_intr (int irq, ide_hwgroup_t *hwgroup)
1131 ide_hwif_t *hwif = hwgroup->hwif;
1134 * handle the unexpected interrupt
1137 if (hwif->irq == irq) {
1138 stat = hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1139 if (!OK_STAT(stat, READY_STAT, BAD_STAT)) {
1140 /* Try to not flood the console with msgs */
1141 static unsigned long last_msgtime, count;
1143 if (time_after(jiffies, last_msgtime + HZ)) {
1144 last_msgtime = jiffies;
1145 printk(KERN_ERR "%s%s: unexpected interrupt, "
1146 "status=0x%02x, count=%ld\n",
1148 (hwif->next==hwgroup->hwif) ? "" : "(?)", stat, count);
1152 } while ((hwif = hwif->next) != hwgroup->hwif);
1156 * ide_intr - default IDE interrupt handler
1157 * @irq: interrupt number
1158 * @dev_id: hwif group
1159 * @regs: unused weirdness from the kernel irq layer
1161 * This is the default IRQ handler for the IDE layer. You should
1162 * not need to override it. If you do be aware it is subtle in
1165 * hwgroup->hwif is the interface in the group currently performing
1166 * a command. hwgroup->drive is the drive and hwgroup->handler is
1167 * the IRQ handler to call. As we issue a command the handlers
1168 * step through multiple states, reassigning the handler to the
1169 * next step in the process. Unlike a smart SCSI controller IDE
1170 * expects the main processor to sequence the various transfer
1171 * stages. We also manage a poll timer to catch up with most
1172 * timeout situations. There are still a few where the handlers
1173 * don't ever decide to give up.
1175 * The handler eventually returns ide_stopped to indicate the
1176 * request completed. At this point we issue the next request
1177 * on the hwgroup and the process begins again.
1180 irqreturn_t ide_intr (int irq, void *dev_id, struct pt_regs *regs)
1182 unsigned long flags;
1183 ide_hwgroup_t *hwgroup = (ide_hwgroup_t *)dev_id;
1186 ide_handler_t *handler;
1187 ide_startstop_t startstop;
1189 spin_lock_irqsave(&ide_lock, flags);
1190 hwif = hwgroup->hwif;
1192 if (!ide_ack_intr(hwif)) {
1193 spin_unlock_irqrestore(&ide_lock, flags);
1197 if ((handler = hwgroup->handler) == NULL ||
1198 hwgroup->poll_timeout != 0) {
1200 * Not expecting an interrupt from this drive.
1201 * That means this could be:
1202 * (1) an interrupt from another PCI device
1203 * sharing the same PCI INT# as us.
1204 * or (2) a drive just entered sleep or standby mode,
1205 * and is interrupting to let us know.
1206 * or (3) a spurious interrupt of unknown origin.
1208 * For PCI, we cannot tell the difference,
1209 * so in that case we just ignore it and hope it goes away.
1211 * FIXME: unexpected_intr should be hwif-> then we can
1212 * remove all the ifdef PCI crap
1214 #ifdef CONFIG_BLK_DEV_IDEPCI
1215 if (hwif->pci_dev && !hwif->pci_dev->vendor)
1216 #endif /* CONFIG_BLK_DEV_IDEPCI */
1219 * Probably not a shared PCI interrupt,
1220 * so we can safely try to do something about it:
1222 unexpected_intr(irq, hwgroup);
1223 #ifdef CONFIG_BLK_DEV_IDEPCI
1226 * Whack the status register, just in case
1227 * we have a leftover pending IRQ.
1229 (void) hwif->INB(hwif->io_ports[IDE_STATUS_OFFSET]);
1230 #endif /* CONFIG_BLK_DEV_IDEPCI */
1232 spin_unlock_irqrestore(&ide_lock, flags);
1235 drive = hwgroup->drive;
1238 * This should NEVER happen, and there isn't much
1239 * we could do about it here.
1241 * [Note - this can occur if the drive is hot unplugged]
1243 spin_unlock_irqrestore(&ide_lock, flags);
1246 if (!drive_is_ready(drive)) {
1248 * This happens regularly when we share a PCI IRQ with
1249 * another device. Unfortunately, it can also happen
1250 * with some buggy drives that trigger the IRQ before
1251 * their status register is up to date. Hopefully we have
1252 * enough advance overhead that the latter isn't a problem.
1254 spin_unlock_irqrestore(&ide_lock, flags);
1257 if (!hwgroup->busy) {
1258 hwgroup->busy = 1; /* paranoia */
1259 printk(KERN_ERR "%s: ide_intr: hwgroup->busy was 0 ??\n", drive->name);
1261 hwgroup->handler = NULL;
1262 del_timer(&hwgroup->timer);
1263 spin_unlock(&ide_lock);
1267 /* service this interrupt, may set handler for next interrupt */
1268 startstop = handler(drive);
1269 spin_lock_irq(&ide_lock);
1272 * Note that handler() may have set things up for another
1273 * interrupt to occur soon, but it cannot happen until
1274 * we exit from this routine, because it will be the
1275 * same irq as is currently being serviced here, and Linux
1276 * won't allow another of the same (on any CPU) until we return.
1278 drive->service_time = jiffies - drive->service_start;
1279 if (startstop == ide_stopped) {
1280 if (hwgroup->handler == NULL) { /* paranoia */
1282 ide_do_request(hwgroup, hwif->irq);
1284 printk(KERN_ERR "%s: ide_intr: huh? expected NULL handler "
1285 "on exit\n", drive->name);
1288 spin_unlock_irqrestore(&ide_lock, flags);
1292 EXPORT_SYMBOL(ide_intr);
1295 * ide_init_drive_cmd - initialize a drive command request
1296 * @rq: request object
1298 * Initialize a request before we fill it in and send it down to
1299 * ide_do_drive_cmd. Commands must be set up by this function. Right
1300 * now it doesn't do a lot, but if that changes abusers will have a
1304 void ide_init_drive_cmd (struct request *rq)
1306 memset(rq, 0, sizeof(*rq));
1307 rq->flags = REQ_DRIVE_CMD;
1310 EXPORT_SYMBOL(ide_init_drive_cmd);
1313 * ide_do_drive_cmd - issue IDE special command
1314 * @drive: device to issue command
1315 * @rq: request to issue
1316 * @action: action for processing
1318 * This function issues a special IDE device request
1319 * onto the request queue.
1321 * If action is ide_wait, then the rq is queued at the end of the
1322 * request queue, and the function sleeps until it has been processed.
1323 * This is for use when invoked from an ioctl handler.
1325 * If action is ide_preempt, then the rq is queued at the head of
1326 * the request queue, displacing the currently-being-processed
1327 * request and this function returns immediately without waiting
1328 * for the new rq to be completed. This is VERY DANGEROUS, and is
1329 * intended for careful use by the ATAPI tape/cdrom driver code.
1331 * If action is ide_next, then the rq is queued immediately after
1332 * the currently-being-processed-request (if any), and the function
1333 * returns without waiting for the new rq to be completed. As above,
1334 * This is VERY DANGEROUS, and is intended for careful use by the
1335 * ATAPI tape/cdrom driver code.
1337 * If action is ide_end, then the rq is queued at the end of the
1338 * request queue, and the function returns immediately without waiting
1339 * for the new rq to be completed. This is again intended for careful
1340 * use by the ATAPI tape/cdrom driver code.
1343 int ide_do_drive_cmd (ide_drive_t *drive, struct request *rq, ide_action_t action)
1345 unsigned long flags;
1346 ide_hwgroup_t *hwgroup = HWGROUP(drive);
1347 DECLARE_COMPLETION(wait);
1348 int where = ELEVATOR_INSERT_BACK, err;
1349 int must_wait = (action == ide_wait || action == ide_head_wait);
1351 #ifdef CONFIG_BLK_DEV_PDC4030
1353 * FIXME: there should be a drive or hwif->special
1354 * handler that points here by default, not hacks
1355 * in the ide-io.c code
1357 * FIXME2: That code breaks power management if used with
1358 * this chipset, that really doesn't belong here !
1360 if (HWIF(drive)->chipset == ide_pdc4030 && rq->buffer != NULL)
1361 return -ENOSYS; /* special drive cmds not supported */
1364 rq->rq_status = RQ_ACTIVE;
1366 rq->rq_disk = drive->disk;
1369 * we need to hold an extra reference to request for safe inspection
1374 rq->waiting = &wait;
1377 spin_lock_irqsave(&ide_lock, flags);
1378 if (action == ide_preempt)
1380 if (action == ide_preempt || action == ide_head_wait) {
1381 where = ELEVATOR_INSERT_FRONT;
1382 rq->flags |= REQ_PREEMPT;
1384 __elv_add_request(drive->queue, rq, where, 0);
1385 ide_do_request(hwgroup, IDE_NO_IRQ);
1386 spin_unlock_irqrestore(&ide_lock, flags);
1390 wait_for_completion(&wait);
1394 blk_put_request(rq);
1400 EXPORT_SYMBOL(ide_do_drive_cmd);