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1/*
2 * IDE I/O functions
3 *
4 * Basic PIO and command management functionality.
5 *
6 * This code was split off from ide.c. See ide.c for history and original
7 * copyrights.
8 *
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.
13 *
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.
18 *
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.
24 */
25
26
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>
51
52#include <asm/byteorder.h>
53#include <asm/irq.h>
54#include <linux/uaccess.h>
55#include <asm/io.h>
56
57int ide_end_rq(ide_drive_t *drive, struct request *rq, blk_status_t error,
58 unsigned int nr_bytes)
59{
60 /*
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
63 */
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);
68 }
69
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;
74 }
75
76 __blk_mq_end_request(rq, error);
77 return 0;
78 }
79
80 return 1;
81}
82EXPORT_SYMBOL_GPL(ide_end_rq);
83
84void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
85{
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;
90
91 tf->error = err;
92 tf->status = stat;
93
94 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
95 u8 data[2];
96
97 tp_ops->input_data(drive, cmd, data, 2);
98
99 cmd->tf.data = data[0];
100 cmd->hob.data = data[1];
101 }
102
103 ide_tf_readback(drive, cmd);
104
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",
109 drive->name);
110 ide_tf_dump(drive->name, cmd);
111 } else
112 drive->dev_flags |= IDE_DFLAG_PARKED;
113 }
114
115 if (rq && ata_taskfile_request(rq)) {
116 struct ide_cmd *orig_cmd = ide_req(rq)->special;
117
118 if (cmd->tf_flags & IDE_TFLAG_DYN)
119 kfree(orig_cmd);
120 else if (cmd != orig_cmd)
121 memcpy(orig_cmd, cmd, sizeof(*cmd));
122 }
123}
124
125int ide_complete_rq(ide_drive_t *drive, blk_status_t error, unsigned int nr_bytes)
126{
127 ide_hwif_t *hwif = drive->hwif;
128 struct request *rq = hwif->rq;
129 int rc;
130
131 /*
132 * if failfast is set on a request, override number of sectors
133 * and complete the whole request right now
134 */
135 if (blk_noretry_request(rq) && error)
136 nr_bytes = blk_rq_sectors(rq) << 9;
137
138 rc = ide_end_rq(drive, rq, error, nr_bytes);
139 if (rc == 0)
140 hwif->rq = NULL;
141
142 return rc;
143}
144EXPORT_SYMBOL(ide_complete_rq);
145
146void ide_kill_rq(ide_drive_t *drive, struct request *rq)
147{
148 u8 drv_req = ata_misc_request(rq) && rq->rq_disk;
149 u8 media = drive->media;
150
151 drive->failed_pc = NULL;
152
153 if ((media == ide_floppy || media == ide_tape) && drv_req) {
154 scsi_req(rq)->result = 0;
155 } else {
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;
160 }
161
162 ide_complete_rq(drive, BLK_STS_IOERR, blk_rq_bytes(rq));
163}
164
165static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
166{
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;
173}
174
175static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
176{
177 tf->nsect = drive->sect;
178 tf->command = ATA_CMD_RESTORE;
179}
180
181static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
182{
183 tf->nsect = drive->mult_req;
184 tf->command = ATA_CMD_SET_MULTI;
185}
186
187/**
188 * do_special - issue some special commands
189 * @drive: drive the command is for
190 *
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.
193 */
194
195static ide_startstop_t do_special(ide_drive_t *drive)
196{
197 struct ide_cmd cmd;
198
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;
207 }
208
209 memset(&cmd, 0, sizeof(cmd));
210 cmd.protocol = ATA_PROT_NODATA;
211
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();
223
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;
227
228 do_rw_taskfile(drive, &cmd);
229
230 return ide_started;
231}
232
233void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
234{
235 ide_hwif_t *hwif = drive->hwif;
236 struct scatterlist *sg = hwif->sg_table, *last_sg = NULL;
237 struct request *rq = cmd->rq;
238
239 cmd->sg_nents = __blk_rq_map_sg(drive->queue, rq, sg, &last_sg);
240 if (blk_rq_bytes(rq) && (blk_rq_bytes(rq) & rq->q->dma_pad_mask))
241 last_sg->length +=
242 (rq->q->dma_pad_mask & ~blk_rq_bytes(rq)) + 1;
243}
244EXPORT_SYMBOL_GPL(ide_map_sg);
245
246void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
247{
248 cmd->nbytes = cmd->nleft = nr_bytes;
249 cmd->cursg_ofs = 0;
250 cmd->cursg = NULL;
251}
252EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
253
254/**
255 * execute_drive_command - issue special drive command
256 * @drive: the drive to issue the command on
257 * @rq: the request structure holding the command
258 *
259 * execute_drive_cmd() issues a special drive command, usually
260 * initiated by ioctl() from the external hdparm program. The
261 * command can be a drive command, drive task or taskfile
262 * operation. Weirdly you can call it with NULL to wait for
263 * all commands to finish. Don't do this as that is due to change
264 */
265
266static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
267 struct request *rq)
268{
269 struct ide_cmd *cmd = ide_req(rq)->special;
270
271 if (cmd) {
272 if (cmd->protocol == ATA_PROT_PIO) {
273 ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
274 ide_map_sg(drive, cmd);
275 }
276
277 return do_rw_taskfile(drive, cmd);
278 }
279
280 /*
281 * NULL is actually a valid way of waiting for
282 * all current requests to be flushed from the queue.
283 */
284#ifdef DEBUG
285 printk("%s: DRIVE_CMD (null)\n", drive->name);
286#endif
287 scsi_req(rq)->result = 0;
288 ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq));
289
290 return ide_stopped;
291}
292
293static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
294{
295 u8 cmd = scsi_req(rq)->cmd[0];
296
297 switch (cmd) {
298 case REQ_PARK_HEADS:
299 case REQ_UNPARK_HEADS:
300 return ide_do_park_unpark(drive, rq);
301 case REQ_DEVSET_EXEC:
302 return ide_do_devset(drive, rq);
303 case REQ_DRIVE_RESET:
304 return ide_do_reset(drive);
305 default:
306 BUG();
307 }
308}
309
310/**
311 * start_request - start of I/O and command issuing for IDE
312 *
313 * start_request() initiates handling of a new I/O request. It
314 * accepts commands and I/O (read/write) requests.
315 *
316 * FIXME: this function needs a rename
317 */
318
319static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
320{
321 ide_startstop_t startstop;
322
323#ifdef DEBUG
324 printk("%s: start_request: current=0x%08lx\n",
325 drive->hwif->name, (unsigned long) rq);
326#endif
327
328 /* bail early if we've exceeded max_failures */
329 if (drive->max_failures && (drive->failures > drive->max_failures)) {
330 rq->rq_flags |= RQF_FAILED;
331 goto kill_rq;
332 }
333
334 if (drive->prep_rq && !drive->prep_rq(drive, rq))
335 return ide_stopped;
336
337 if (ata_pm_request(rq))
338 ide_check_pm_state(drive, rq);
339
340 drive->hwif->tp_ops->dev_select(drive);
341 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
342 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
343 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
344 return startstop;
345 }
346
347 if (drive->special_flags == 0) {
348 struct ide_driver *drv;
349
350 /*
351 * We reset the drive so we need to issue a SETFEATURES.
352 * Do it _after_ do_special() restored device parameters.
353 */
354 if (drive->current_speed == 0xff)
355 ide_config_drive_speed(drive, drive->desired_speed);
356
357 if (ata_taskfile_request(rq))
358 return execute_drive_cmd(drive, rq);
359 else if (ata_pm_request(rq)) {
360 struct ide_pm_state *pm = ide_req(rq)->special;
361#ifdef DEBUG_PM
362 printk("%s: start_power_step(step: %d)\n",
363 drive->name, pm->pm_step);
364#endif
365 startstop = ide_start_power_step(drive, rq);
366 if (startstop == ide_stopped &&
367 pm->pm_step == IDE_PM_COMPLETED)
368 ide_complete_pm_rq(drive, rq);
369 return startstop;
370 } else if (!rq->rq_disk && ata_misc_request(rq))
371 /*
372 * TODO: Once all ULDs have been modified to
373 * check for specific op codes rather than
374 * blindly accepting any special request, the
375 * check for ->rq_disk above may be replaced
376 * by a more suitable mechanism or even
377 * dropped entirely.
378 */
379 return ide_special_rq(drive, rq);
380
381 drv = *(struct ide_driver **)rq->rq_disk->private_data;
382
383 return drv->do_request(drive, rq, blk_rq_pos(rq));
384 }
385 return do_special(drive);
386kill_rq:
387 ide_kill_rq(drive, rq);
388 return ide_stopped;
389}
390
391/**
392 * ide_stall_queue - pause an IDE device
393 * @drive: drive to stall
394 * @timeout: time to stall for (jiffies)
395 *
396 * ide_stall_queue() can be used by a drive to give excess bandwidth back
397 * to the port by sleeping for timeout jiffies.
398 */
399
400void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
401{
402 if (timeout > WAIT_WORSTCASE)
403 timeout = WAIT_WORSTCASE;
404 drive->sleep = timeout + jiffies;
405 drive->dev_flags |= IDE_DFLAG_SLEEPING;
406}
407EXPORT_SYMBOL(ide_stall_queue);
408
409static inline int ide_lock_port(ide_hwif_t *hwif)
410{
411 if (hwif->busy)
412 return 1;
413
414 hwif->busy = 1;
415
416 return 0;
417}
418
419static inline void ide_unlock_port(ide_hwif_t *hwif)
420{
421 hwif->busy = 0;
422}
423
424static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
425{
426 int rc = 0;
427
428 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
429 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
430 if (rc == 0) {
431 if (host->get_lock)
432 host->get_lock(ide_intr, hwif);
433 }
434 }
435 return rc;
436}
437
438static inline void ide_unlock_host(struct ide_host *host)
439{
440 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
441 if (host->release_lock)
442 host->release_lock();
443 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
444 }
445}
446
447void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
448{
449 struct request_queue *q = drive->queue;
450
451 /* Use 3ms as that was the old plug delay */
452 if (rq) {
453 blk_mq_requeue_request(rq, false);
454 blk_mq_delay_kick_requeue_list(q, 3);
455 } else
456 blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
457}
458
459blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
460 bool local_requeue)
461{
462 ide_hwif_t *hwif = drive->hwif;
463 struct ide_host *host = hwif->host;
464 ide_startstop_t startstop;
465
466 if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) {
467 rq->rq_flags |= RQF_DONTPREP;
468 ide_req(rq)->special = NULL;
469 }
470
471 /* HLD do_request() callback might sleep, make sure it's okay */
472 might_sleep();
473
474 if (ide_lock_host(host, hwif))
475 return BLK_STS_DEV_RESOURCE;
476
477 spin_lock_irq(&hwif->lock);
478
479 if (!ide_lock_port(hwif)) {
480 ide_hwif_t *prev_port;
481
482 WARN_ON_ONCE(hwif->rq);
483repeat:
484 prev_port = hwif->host->cur_port;
485 if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
486 time_after(drive->sleep, jiffies)) {
487 ide_unlock_port(hwif);
488 goto plug_device;
489 }
490
491 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
492 hwif != prev_port) {
493 ide_drive_t *cur_dev =
494 prev_port ? prev_port->cur_dev : NULL;
495
496 /*
497 * set nIEN for previous port, drives in the
498 * quirk list may not like intr setups/cleanups
499 */
500 if (cur_dev &&
501 (cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
502 prev_port->tp_ops->write_devctl(prev_port,
503 ATA_NIEN |
504 ATA_DEVCTL_OBS);
505
506 hwif->host->cur_port = hwif;
507 }
508 hwif->cur_dev = drive;
509 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
510
511 /*
512 * Sanity: don't accept a request that isn't a PM request
513 * if we are currently power managed. This is very important as
514 * blk_stop_queue() doesn't prevent the blk_fetch_request()
515 * above to return us whatever is in the queue. Since we call
516 * ide_do_request() ourselves, we end up taking requests while
517 * the queue is blocked...
518 *
519 * We let requests forced at head of queue with ide-preempt
520 * though. I hope that doesn't happen too much, hopefully not
521 * unless the subdriver triggers such a thing in its own PM
522 * state machine.
523 */
524 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
525 ata_pm_request(rq) == 0 &&
526 (rq->rq_flags & RQF_PREEMPT) == 0) {
527 /* there should be no pending command at this point */
528 ide_unlock_port(hwif);
529 goto plug_device;
530 }
531
532 scsi_req(rq)->resid_len = blk_rq_bytes(rq);
533 hwif->rq = rq;
534
535 spin_unlock_irq(&hwif->lock);
536 startstop = start_request(drive, rq);
537 spin_lock_irq(&hwif->lock);
538
539 if (startstop == ide_stopped) {
540 rq = hwif->rq;
541 hwif->rq = NULL;
542 if (rq)
543 goto repeat;
544 ide_unlock_port(hwif);
545 goto out;
546 }
547 } else {
548plug_device:
549 if (local_requeue)
550 list_add(&rq->queuelist, &drive->rq_list);
551 spin_unlock_irq(&hwif->lock);
552 ide_unlock_host(host);
553 if (!local_requeue)
554 ide_requeue_and_plug(drive, rq);
555 return BLK_STS_OK;
556 }
557
558out:
559 spin_unlock_irq(&hwif->lock);
560 if (rq == NULL)
561 ide_unlock_host(host);
562 return BLK_STS_OK;
563}
564
565/*
566 * Issue a new request to a device.
567 */
568blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
569 const struct blk_mq_queue_data *bd)
570{
571 ide_drive_t *drive = hctx->queue->queuedata;
572 ide_hwif_t *hwif = drive->hwif;
573
574 spin_lock_irq(&hwif->lock);
575 if (drive->sense_rq_active) {
576 spin_unlock_irq(&hwif->lock);
577 return BLK_STS_DEV_RESOURCE;
578 }
579 spin_unlock_irq(&hwif->lock);
580
581 blk_mq_start_request(bd->rq);
582 return ide_issue_rq(drive, bd->rq, false);
583}
584
585static int drive_is_ready(ide_drive_t *drive)
586{
587 ide_hwif_t *hwif = drive->hwif;
588 u8 stat = 0;
589
590 if (drive->waiting_for_dma)
591 return hwif->dma_ops->dma_test_irq(drive);
592
593 if (hwif->io_ports.ctl_addr &&
594 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
595 stat = hwif->tp_ops->read_altstatus(hwif);
596 else
597 /* Note: this may clear a pending IRQ!! */
598 stat = hwif->tp_ops->read_status(hwif);
599
600 if (stat & ATA_BUSY)
601 /* drive busy: definitely not interrupting */
602 return 0;
603
604 /* drive ready: *might* be interrupting */
605 return 1;
606}
607
608/**
609 * ide_timer_expiry - handle lack of an IDE interrupt
610 * @data: timer callback magic (hwif)
611 *
612 * An IDE command has timed out before the expected drive return
613 * occurred. At this point we attempt to clean up the current
614 * mess. If the current handler includes an expiry handler then
615 * we invoke the expiry handler, and providing it is happy the
616 * work is done. If that fails we apply generic recovery rules
617 * invoking the handler and checking the drive DMA status. We
618 * have an excessively incestuous relationship with the DMA
619 * logic that wants cleaning up.
620 */
621
622void ide_timer_expiry (struct timer_list *t)
623{
624 ide_hwif_t *hwif = from_timer(hwif, t, timer);
625 ide_drive_t *drive;
626 ide_handler_t *handler;
627 unsigned long flags;
628 int wait = -1;
629 int plug_device = 0;
630 struct request *rq_in_flight;
631
632 spin_lock_irqsave(&hwif->lock, flags);
633
634 handler = hwif->handler;
635
636 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
637 /*
638 * Either a marginal timeout occurred
639 * (got the interrupt just as timer expired),
640 * or we were "sleeping" to give other devices a chance.
641 * Either way, we don't really want to complain about anything.
642 */
643 } else {
644 ide_expiry_t *expiry = hwif->expiry;
645 ide_startstop_t startstop = ide_stopped;
646
647 drive = hwif->cur_dev;
648
649 if (expiry) {
650 wait = expiry(drive);
651 if (wait > 0) { /* continue */
652 /* reset timer */
653 hwif->timer.expires = jiffies + wait;
654 hwif->req_gen_timer = hwif->req_gen;
655 add_timer(&hwif->timer);
656 spin_unlock_irqrestore(&hwif->lock, flags);
657 return;
658 }
659 }
660 hwif->handler = NULL;
661 hwif->expiry = NULL;
662 /*
663 * We need to simulate a real interrupt when invoking
664 * the handler() function, which means we need to
665 * globally mask the specific IRQ:
666 */
667 spin_unlock(&hwif->lock);
668 /* disable_irq_nosync ?? */
669 disable_irq(hwif->irq);
670
671 if (hwif->polling) {
672 startstop = handler(drive);
673 } else if (drive_is_ready(drive)) {
674 if (drive->waiting_for_dma)
675 hwif->dma_ops->dma_lost_irq(drive);
676 if (hwif->port_ops && hwif->port_ops->clear_irq)
677 hwif->port_ops->clear_irq(drive);
678
679 printk(KERN_WARNING "%s: lost interrupt\n",
680 drive->name);
681 startstop = handler(drive);
682 } else {
683 if (drive->waiting_for_dma)
684 startstop = ide_dma_timeout_retry(drive, wait);
685 else
686 startstop = ide_error(drive, "irq timeout",
687 hwif->tp_ops->read_status(hwif));
688 }
689 /* Disable interrupts again, `handler' might have enabled it */
690 spin_lock_irq(&hwif->lock);
691 enable_irq(hwif->irq);
692 if (startstop == ide_stopped && hwif->polling == 0) {
693 rq_in_flight = hwif->rq;
694 hwif->rq = NULL;
695 ide_unlock_port(hwif);
696 plug_device = 1;
697 }
698 }
699 spin_unlock_irqrestore(&hwif->lock, flags);
700
701 if (plug_device) {
702 ide_unlock_host(hwif->host);
703 ide_requeue_and_plug(drive, rq_in_flight);
704 }
705}
706
707/**
708 * unexpected_intr - handle an unexpected IDE interrupt
709 * @irq: interrupt line
710 * @hwif: port being processed
711 *
712 * There's nothing really useful we can do with an unexpected interrupt,
713 * other than reading the status register (to clear it), and logging it.
714 * There should be no way that an irq can happen before we're ready for it,
715 * so we needn't worry much about losing an "important" interrupt here.
716 *
717 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
718 * the drive enters "idle", "standby", or "sleep" mode, so if the status
719 * looks "good", we just ignore the interrupt completely.
720 *
721 * This routine assumes __cli() is in effect when called.
722 *
723 * If an unexpected interrupt happens on irq15 while we are handling irq14
724 * and if the two interfaces are "serialized" (CMD640), then it looks like
725 * we could screw up by interfering with a new request being set up for
726 * irq15.
727 *
728 * In reality, this is a non-issue. The new command is not sent unless
729 * the drive is ready to accept one, in which case we know the drive is
730 * not trying to interrupt us. And ide_set_handler() is always invoked
731 * before completing the issuance of any new drive command, so we will not
732 * be accidentally invoked as a result of any valid command completion
733 * interrupt.
734 */
735
736static void unexpected_intr(int irq, ide_hwif_t *hwif)
737{
738 u8 stat = hwif->tp_ops->read_status(hwif);
739
740 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
741 /* Try to not flood the console with msgs */
742 static unsigned long last_msgtime, count;
743 ++count;
744
745 if (time_after(jiffies, last_msgtime + HZ)) {
746 last_msgtime = jiffies;
747 printk(KERN_ERR "%s: unexpected interrupt, "
748 "status=0x%02x, count=%ld\n",
749 hwif->name, stat, count);
750 }
751 }
752}
753
754/**
755 * ide_intr - default IDE interrupt handler
756 * @irq: interrupt number
757 * @dev_id: hwif
758 * @regs: unused weirdness from the kernel irq layer
759 *
760 * This is the default IRQ handler for the IDE layer. You should
761 * not need to override it. If you do be aware it is subtle in
762 * places
763 *
764 * hwif is the interface in the group currently performing
765 * a command. hwif->cur_dev is the drive and hwif->handler is
766 * the IRQ handler to call. As we issue a command the handlers
767 * step through multiple states, reassigning the handler to the
768 * next step in the process. Unlike a smart SCSI controller IDE
769 * expects the main processor to sequence the various transfer
770 * stages. We also manage a poll timer to catch up with most
771 * timeout situations. There are still a few where the handlers
772 * don't ever decide to give up.
773 *
774 * The handler eventually returns ide_stopped to indicate the
775 * request completed. At this point we issue the next request
776 * on the port and the process begins again.
777 */
778
779irqreturn_t ide_intr (int irq, void *dev_id)
780{
781 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
782 struct ide_host *host = hwif->host;
783 ide_drive_t *drive;
784 ide_handler_t *handler;
785 unsigned long flags;
786 ide_startstop_t startstop;
787 irqreturn_t irq_ret = IRQ_NONE;
788 int plug_device = 0;
789 struct request *rq_in_flight;
790
791 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
792 if (hwif != host->cur_port)
793 goto out_early;
794 }
795
796 spin_lock_irqsave(&hwif->lock, flags);
797
798 if (hwif->port_ops && hwif->port_ops->test_irq &&
799 hwif->port_ops->test_irq(hwif) == 0)
800 goto out;
801
802 handler = hwif->handler;
803
804 if (handler == NULL || hwif->polling) {
805 /*
806 * Not expecting an interrupt from this drive.
807 * That means this could be:
808 * (1) an interrupt from another PCI device
809 * sharing the same PCI INT# as us.
810 * or (2) a drive just entered sleep or standby mode,
811 * and is interrupting to let us know.
812 * or (3) a spurious interrupt of unknown origin.
813 *
814 * For PCI, we cannot tell the difference,
815 * so in that case we just ignore it and hope it goes away.
816 */
817 if ((host->irq_flags & IRQF_SHARED) == 0) {
818 /*
819 * Probably not a shared PCI interrupt,
820 * so we can safely try to do something about it:
821 */
822 unexpected_intr(irq, hwif);
823 } else {
824 /*
825 * Whack the status register, just in case
826 * we have a leftover pending IRQ.
827 */
828 (void)hwif->tp_ops->read_status(hwif);
829 }
830 goto out;
831 }
832
833 drive = hwif->cur_dev;
834
835 if (!drive_is_ready(drive))
836 /*
837 * This happens regularly when we share a PCI IRQ with
838 * another device. Unfortunately, it can also happen
839 * with some buggy drives that trigger the IRQ before
840 * their status register is up to date. Hopefully we have
841 * enough advance overhead that the latter isn't a problem.
842 */
843 goto out;
844
845 hwif->handler = NULL;
846 hwif->expiry = NULL;
847 hwif->req_gen++;
848 del_timer(&hwif->timer);
849 spin_unlock(&hwif->lock);
850
851 if (hwif->port_ops && hwif->port_ops->clear_irq)
852 hwif->port_ops->clear_irq(drive);
853
854 if (drive->dev_flags & IDE_DFLAG_UNMASK)
855 local_irq_enable_in_hardirq();
856
857 /* service this interrupt, may set handler for next interrupt */
858 startstop = handler(drive);
859
860 spin_lock_irq(&hwif->lock);
861 /*
862 * Note that handler() may have set things up for another
863 * interrupt to occur soon, but it cannot happen until
864 * we exit from this routine, because it will be the
865 * same irq as is currently being serviced here, and Linux
866 * won't allow another of the same (on any CPU) until we return.
867 */
868 if (startstop == ide_stopped && hwif->polling == 0) {
869 BUG_ON(hwif->handler);
870 rq_in_flight = hwif->rq;
871 hwif->rq = NULL;
872 ide_unlock_port(hwif);
873 plug_device = 1;
874 }
875 irq_ret = IRQ_HANDLED;
876out:
877 spin_unlock_irqrestore(&hwif->lock, flags);
878out_early:
879 if (plug_device) {
880 ide_unlock_host(hwif->host);
881 ide_requeue_and_plug(drive, rq_in_flight);
882 }
883
884 return irq_ret;
885}
886EXPORT_SYMBOL_GPL(ide_intr);
887
888void ide_pad_transfer(ide_drive_t *drive, int write, int len)
889{
890 ide_hwif_t *hwif = drive->hwif;
891 u8 buf[4] = { 0 };
892
893 while (len > 0) {
894 if (write)
895 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
896 else
897 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
898 len -= 4;
899 }
900}
901EXPORT_SYMBOL_GPL(ide_pad_transfer);
902
903void ide_insert_request_head(ide_drive_t *drive, struct request *rq)
904{
905 drive->sense_rq_active = true;
906 list_add_tail(&rq->queuelist, &drive->rq_list);
907 kblockd_schedule_work(&drive->rq_work);
908}
909EXPORT_SYMBOL_GPL(ide_insert_request_head);
1/*
2 * IDE I/O functions
3 *
4 * Basic PIO and command management functionality.
5 *
6 * This code was split off from ide.c. See ide.c for history and original
7 * copyrights.
8 *
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.
13 *
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.
18 *
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.
24 */
25
26
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>
51
52#include <asm/byteorder.h>
53#include <asm/irq.h>
54#include <asm/uaccess.h>
55#include <asm/io.h>
56
57int ide_end_rq(ide_drive_t *drive, struct request *rq, int error,
58 unsigned int nr_bytes)
59{
60 /*
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
63 */
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);
68 }
69
70 return blk_end_request(rq, error, nr_bytes);
71}
72EXPORT_SYMBOL_GPL(ide_end_rq);
73
74void ide_complete_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat, u8 err)
75{
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;
80
81 tf->error = err;
82 tf->status = stat;
83
84 if (cmd->ftf_flags & IDE_FTFLAG_IN_DATA) {
85 u8 data[2];
86
87 tp_ops->input_data(drive, cmd, data, 2);
88
89 cmd->tf.data = data[0];
90 cmd->hob.data = data[1];
91 }
92
93 ide_tf_readback(drive, cmd);
94
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;
103 }
104
105 if (rq && rq->cmd_type == REQ_TYPE_ATA_TASKFILE) {
106 struct ide_cmd *orig_cmd = rq->special;
107
108 if (cmd->tf_flags & IDE_TFLAG_DYN)
109 kfree(orig_cmd);
110 else
111 memcpy(orig_cmd, cmd, sizeof(*cmd));
112 }
113}
114
115int ide_complete_rq(ide_drive_t *drive, int error, unsigned int nr_bytes)
116{
117 ide_hwif_t *hwif = drive->hwif;
118 struct request *rq = hwif->rq;
119 int rc;
120
121 /*
122 * if failfast is set on a request, override number of sectors
123 * and complete the whole request right now
124 */
125 if (blk_noretry_request(rq) && error <= 0)
126 nr_bytes = blk_rq_sectors(rq) << 9;
127
128 rc = ide_end_rq(drive, rq, error, nr_bytes);
129 if (rc == 0)
130 hwif->rq = NULL;
131
132 return rc;
133}
134EXPORT_SYMBOL(ide_complete_rq);
135
136void ide_kill_rq(ide_drive_t *drive, struct request *rq)
137{
138 u8 drv_req = (rq->cmd_type == REQ_TYPE_SPECIAL) && rq->rq_disk;
139 u8 media = drive->media;
140
141 drive->failed_pc = NULL;
142
143 if ((media == ide_floppy || media == ide_tape) && drv_req) {
144 rq->errors = 0;
145 } else {
146 if (media == ide_tape)
147 rq->errors = IDE_DRV_ERROR_GENERAL;
148 else if (rq->cmd_type != REQ_TYPE_FS && rq->errors == 0)
149 rq->errors = -EIO;
150 }
151
152 ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
153}
154
155static void ide_tf_set_specify_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
156{
157 tf->nsect = drive->sect;
158 tf->lbal = drive->sect;
159 tf->lbam = drive->cyl;
160 tf->lbah = drive->cyl >> 8;
161 tf->device = (drive->head - 1) | drive->select;
162 tf->command = ATA_CMD_INIT_DEV_PARAMS;
163}
164
165static void ide_tf_set_restore_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
166{
167 tf->nsect = drive->sect;
168 tf->command = ATA_CMD_RESTORE;
169}
170
171static void ide_tf_set_setmult_cmd(ide_drive_t *drive, struct ide_taskfile *tf)
172{
173 tf->nsect = drive->mult_req;
174 tf->command = ATA_CMD_SET_MULTI;
175}
176
177/**
178 * do_special - issue some special commands
179 * @drive: drive the command is for
180 *
181 * do_special() is used to issue ATA_CMD_INIT_DEV_PARAMS,
182 * ATA_CMD_RESTORE and ATA_CMD_SET_MULTI commands to a drive.
183 */
184
185static ide_startstop_t do_special(ide_drive_t *drive)
186{
187 struct ide_cmd cmd;
188
189#ifdef DEBUG
190 printk(KERN_DEBUG "%s: %s: 0x%02x\n", drive->name, __func__,
191 drive->special_flags);
192#endif
193 if (drive->media != ide_disk) {
194 drive->special_flags = 0;
195 drive->mult_req = 0;
196 return ide_stopped;
197 }
198
199 memset(&cmd, 0, sizeof(cmd));
200 cmd.protocol = ATA_PROT_NODATA;
201
202 if (drive->special_flags & IDE_SFLAG_SET_GEOMETRY) {
203 drive->special_flags &= ~IDE_SFLAG_SET_GEOMETRY;
204 ide_tf_set_specify_cmd(drive, &cmd.tf);
205 } else if (drive->special_flags & IDE_SFLAG_RECALIBRATE) {
206 drive->special_flags &= ~IDE_SFLAG_RECALIBRATE;
207 ide_tf_set_restore_cmd(drive, &cmd.tf);
208 } else if (drive->special_flags & IDE_SFLAG_SET_MULTMODE) {
209 drive->special_flags &= ~IDE_SFLAG_SET_MULTMODE;
210 ide_tf_set_setmult_cmd(drive, &cmd.tf);
211 } else
212 BUG();
213
214 cmd.valid.out.tf = IDE_VALID_OUT_TF | IDE_VALID_DEVICE;
215 cmd.valid.in.tf = IDE_VALID_IN_TF | IDE_VALID_DEVICE;
216 cmd.tf_flags = IDE_TFLAG_CUSTOM_HANDLER;
217
218 do_rw_taskfile(drive, &cmd);
219
220 return ide_started;
221}
222
223void ide_map_sg(ide_drive_t *drive, struct ide_cmd *cmd)
224{
225 ide_hwif_t *hwif = drive->hwif;
226 struct scatterlist *sg = hwif->sg_table;
227 struct request *rq = cmd->rq;
228
229 cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
230}
231EXPORT_SYMBOL_GPL(ide_map_sg);
232
233void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
234{
235 cmd->nbytes = cmd->nleft = nr_bytes;
236 cmd->cursg_ofs = 0;
237 cmd->cursg = NULL;
238}
239EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
240
241/**
242 * execute_drive_command - issue special drive command
243 * @drive: the drive to issue the command on
244 * @rq: the request structure holding the command
245 *
246 * execute_drive_cmd() issues a special drive command, usually
247 * initiated by ioctl() from the external hdparm program. The
248 * command can be a drive command, drive task or taskfile
249 * operation. Weirdly you can call it with NULL to wait for
250 * all commands to finish. Don't do this as that is due to change
251 */
252
253static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
254 struct request *rq)
255{
256 struct ide_cmd *cmd = rq->special;
257
258 if (cmd) {
259 if (cmd->protocol == ATA_PROT_PIO) {
260 ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
261 ide_map_sg(drive, cmd);
262 }
263
264 return do_rw_taskfile(drive, cmd);
265 }
266
267 /*
268 * NULL is actually a valid way of waiting for
269 * all current requests to be flushed from the queue.
270 */
271#ifdef DEBUG
272 printk("%s: DRIVE_CMD (null)\n", drive->name);
273#endif
274 rq->errors = 0;
275 ide_complete_rq(drive, 0, blk_rq_bytes(rq));
276
277 return ide_stopped;
278}
279
280static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
281{
282 u8 cmd = rq->cmd[0];
283
284 switch (cmd) {
285 case REQ_PARK_HEADS:
286 case REQ_UNPARK_HEADS:
287 return ide_do_park_unpark(drive, rq);
288 case REQ_DEVSET_EXEC:
289 return ide_do_devset(drive, rq);
290 case REQ_DRIVE_RESET:
291 return ide_do_reset(drive);
292 default:
293 BUG();
294 }
295}
296
297/**
298 * start_request - start of I/O and command issuing for IDE
299 *
300 * start_request() initiates handling of a new I/O request. It
301 * accepts commands and I/O (read/write) requests.
302 *
303 * FIXME: this function needs a rename
304 */
305
306static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
307{
308 ide_startstop_t startstop;
309
310 BUG_ON(!(rq->cmd_flags & REQ_STARTED));
311
312#ifdef DEBUG
313 printk("%s: start_request: current=0x%08lx\n",
314 drive->hwif->name, (unsigned long) rq);
315#endif
316
317 /* bail early if we've exceeded max_failures */
318 if (drive->max_failures && (drive->failures > drive->max_failures)) {
319 rq->cmd_flags |= REQ_FAILED;
320 goto kill_rq;
321 }
322
323 if (blk_pm_request(rq))
324 ide_check_pm_state(drive, rq);
325
326 drive->hwif->tp_ops->dev_select(drive);
327 if (ide_wait_stat(&startstop, drive, drive->ready_stat,
328 ATA_BUSY | ATA_DRQ, WAIT_READY)) {
329 printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
330 return startstop;
331 }
332
333 if (drive->special_flags == 0) {
334 struct ide_driver *drv;
335
336 /*
337 * We reset the drive so we need to issue a SETFEATURES.
338 * Do it _after_ do_special() restored device parameters.
339 */
340 if (drive->current_speed == 0xff)
341 ide_config_drive_speed(drive, drive->desired_speed);
342
343 if (rq->cmd_type == REQ_TYPE_ATA_TASKFILE)
344 return execute_drive_cmd(drive, rq);
345 else if (blk_pm_request(rq)) {
346 struct request_pm_state *pm = rq->special;
347#ifdef DEBUG_PM
348 printk("%s: start_power_step(step: %d)\n",
349 drive->name, pm->pm_step);
350#endif
351 startstop = ide_start_power_step(drive, rq);
352 if (startstop == ide_stopped &&
353 pm->pm_step == IDE_PM_COMPLETED)
354 ide_complete_pm_rq(drive, rq);
355 return startstop;
356 } else if (!rq->rq_disk && rq->cmd_type == REQ_TYPE_SPECIAL)
357 /*
358 * TODO: Once all ULDs have been modified to
359 * check for specific op codes rather than
360 * blindly accepting any special request, the
361 * check for ->rq_disk above may be replaced
362 * by a more suitable mechanism or even
363 * dropped entirely.
364 */
365 return ide_special_rq(drive, rq);
366
367 drv = *(struct ide_driver **)rq->rq_disk->private_data;
368
369 return drv->do_request(drive, rq, blk_rq_pos(rq));
370 }
371 return do_special(drive);
372kill_rq:
373 ide_kill_rq(drive, rq);
374 return ide_stopped;
375}
376
377/**
378 * ide_stall_queue - pause an IDE device
379 * @drive: drive to stall
380 * @timeout: time to stall for (jiffies)
381 *
382 * ide_stall_queue() can be used by a drive to give excess bandwidth back
383 * to the port by sleeping for timeout jiffies.
384 */
385
386void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
387{
388 if (timeout > WAIT_WORSTCASE)
389 timeout = WAIT_WORSTCASE;
390 drive->sleep = timeout + jiffies;
391 drive->dev_flags |= IDE_DFLAG_SLEEPING;
392}
393EXPORT_SYMBOL(ide_stall_queue);
394
395static inline int ide_lock_port(ide_hwif_t *hwif)
396{
397 if (hwif->busy)
398 return 1;
399
400 hwif->busy = 1;
401
402 return 0;
403}
404
405static inline void ide_unlock_port(ide_hwif_t *hwif)
406{
407 hwif->busy = 0;
408}
409
410static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
411{
412 int rc = 0;
413
414 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
415 rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
416 if (rc == 0) {
417 if (host->get_lock)
418 host->get_lock(ide_intr, hwif);
419 }
420 }
421 return rc;
422}
423
424static inline void ide_unlock_host(struct ide_host *host)
425{
426 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
427 if (host->release_lock)
428 host->release_lock();
429 clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
430 }
431}
432
433static void __ide_requeue_and_plug(struct request_queue *q, struct request *rq)
434{
435 if (rq)
436 blk_requeue_request(q, rq);
437 if (rq || blk_peek_request(q)) {
438 /* Use 3ms as that was the old plug delay */
439 blk_delay_queue(q, 3);
440 }
441}
442
443void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
444{
445 struct request_queue *q = drive->queue;
446 unsigned long flags;
447
448 spin_lock_irqsave(q->queue_lock, flags);
449 __ide_requeue_and_plug(q, rq);
450 spin_unlock_irqrestore(q->queue_lock, flags);
451}
452
453/*
454 * Issue a new request to a device.
455 */
456void do_ide_request(struct request_queue *q)
457{
458 ide_drive_t *drive = q->queuedata;
459 ide_hwif_t *hwif = drive->hwif;
460 struct ide_host *host = hwif->host;
461 struct request *rq = NULL;
462 ide_startstop_t startstop;
463 unsigned long queue_run_ms = 3; /* old plug delay */
464
465 spin_unlock_irq(q->queue_lock);
466
467 /* HLD do_request() callback might sleep, make sure it's okay */
468 might_sleep();
469
470 if (ide_lock_host(host, hwif))
471 goto plug_device_2;
472
473 spin_lock_irq(&hwif->lock);
474
475 if (!ide_lock_port(hwif)) {
476 ide_hwif_t *prev_port;
477
478 WARN_ON_ONCE(hwif->rq);
479repeat:
480 prev_port = hwif->host->cur_port;
481 if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
482 time_after(drive->sleep, jiffies)) {
483 unsigned long left = jiffies - drive->sleep;
484
485 queue_run_ms = jiffies_to_msecs(left + 1);
486 ide_unlock_port(hwif);
487 goto plug_device;
488 }
489
490 if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
491 hwif != prev_port) {
492 ide_drive_t *cur_dev =
493 prev_port ? prev_port->cur_dev : NULL;
494
495 /*
496 * set nIEN for previous port, drives in the
497 * quirk list may not like intr setups/cleanups
498 */
499 if (cur_dev &&
500 (cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
501 prev_port->tp_ops->write_devctl(prev_port,
502 ATA_NIEN |
503 ATA_DEVCTL_OBS);
504
505 hwif->host->cur_port = hwif;
506 }
507 hwif->cur_dev = drive;
508 drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
509
510 spin_unlock_irq(&hwif->lock);
511 spin_lock_irq(q->queue_lock);
512 /*
513 * we know that the queue isn't empty, but this can happen
514 * if the q->prep_rq_fn() decides to kill a request
515 */
516 if (!rq)
517 rq = blk_fetch_request(drive->queue);
518
519 spin_unlock_irq(q->queue_lock);
520 spin_lock_irq(&hwif->lock);
521
522 if (!rq) {
523 ide_unlock_port(hwif);
524 goto out;
525 }
526
527 /*
528 * Sanity: don't accept a request that isn't a PM request
529 * if we are currently power managed. This is very important as
530 * blk_stop_queue() doesn't prevent the blk_fetch_request()
531 * above to return us whatever is in the queue. Since we call
532 * ide_do_request() ourselves, we end up taking requests while
533 * the queue is blocked...
534 *
535 * We let requests forced at head of queue with ide-preempt
536 * though. I hope that doesn't happen too much, hopefully not
537 * unless the subdriver triggers such a thing in its own PM
538 * state machine.
539 */
540 if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
541 blk_pm_request(rq) == 0 &&
542 (rq->cmd_flags & REQ_PREEMPT) == 0) {
543 /* there should be no pending command at this point */
544 ide_unlock_port(hwif);
545 goto plug_device;
546 }
547
548 hwif->rq = rq;
549
550 spin_unlock_irq(&hwif->lock);
551 startstop = start_request(drive, rq);
552 spin_lock_irq(&hwif->lock);
553
554 if (startstop == ide_stopped) {
555 rq = hwif->rq;
556 hwif->rq = NULL;
557 goto repeat;
558 }
559 } else
560 goto plug_device;
561out:
562 spin_unlock_irq(&hwif->lock);
563 if (rq == NULL)
564 ide_unlock_host(host);
565 spin_lock_irq(q->queue_lock);
566 return;
567
568plug_device:
569 spin_unlock_irq(&hwif->lock);
570 ide_unlock_host(host);
571plug_device_2:
572 spin_lock_irq(q->queue_lock);
573 __ide_requeue_and_plug(q, rq);
574}
575
576static int drive_is_ready(ide_drive_t *drive)
577{
578 ide_hwif_t *hwif = drive->hwif;
579 u8 stat = 0;
580
581 if (drive->waiting_for_dma)
582 return hwif->dma_ops->dma_test_irq(drive);
583
584 if (hwif->io_ports.ctl_addr &&
585 (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
586 stat = hwif->tp_ops->read_altstatus(hwif);
587 else
588 /* Note: this may clear a pending IRQ!! */
589 stat = hwif->tp_ops->read_status(hwif);
590
591 if (stat & ATA_BUSY)
592 /* drive busy: definitely not interrupting */
593 return 0;
594
595 /* drive ready: *might* be interrupting */
596 return 1;
597}
598
599/**
600 * ide_timer_expiry - handle lack of an IDE interrupt
601 * @data: timer callback magic (hwif)
602 *
603 * An IDE command has timed out before the expected drive return
604 * occurred. At this point we attempt to clean up the current
605 * mess. If the current handler includes an expiry handler then
606 * we invoke the expiry handler, and providing it is happy the
607 * work is done. If that fails we apply generic recovery rules
608 * invoking the handler and checking the drive DMA status. We
609 * have an excessively incestuous relationship with the DMA
610 * logic that wants cleaning up.
611 */
612
613void ide_timer_expiry (unsigned long data)
614{
615 ide_hwif_t *hwif = (ide_hwif_t *)data;
616 ide_drive_t *uninitialized_var(drive);
617 ide_handler_t *handler;
618 unsigned long flags;
619 int wait = -1;
620 int plug_device = 0;
621 struct request *uninitialized_var(rq_in_flight);
622
623 spin_lock_irqsave(&hwif->lock, flags);
624
625 handler = hwif->handler;
626
627 if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
628 /*
629 * Either a marginal timeout occurred
630 * (got the interrupt just as timer expired),
631 * or we were "sleeping" to give other devices a chance.
632 * Either way, we don't really want to complain about anything.
633 */
634 } else {
635 ide_expiry_t *expiry = hwif->expiry;
636 ide_startstop_t startstop = ide_stopped;
637
638 drive = hwif->cur_dev;
639
640 if (expiry) {
641 wait = expiry(drive);
642 if (wait > 0) { /* continue */
643 /* reset timer */
644 hwif->timer.expires = jiffies + wait;
645 hwif->req_gen_timer = hwif->req_gen;
646 add_timer(&hwif->timer);
647 spin_unlock_irqrestore(&hwif->lock, flags);
648 return;
649 }
650 }
651 hwif->handler = NULL;
652 hwif->expiry = NULL;
653 /*
654 * We need to simulate a real interrupt when invoking
655 * the handler() function, which means we need to
656 * globally mask the specific IRQ:
657 */
658 spin_unlock(&hwif->lock);
659 /* disable_irq_nosync ?? */
660 disable_irq(hwif->irq);
661 /* local CPU only, as if we were handling an interrupt */
662 local_irq_disable();
663 if (hwif->polling) {
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);
670
671 printk(KERN_WARNING "%s: lost interrupt\n",
672 drive->name);
673 startstop = handler(drive);
674 } else {
675 if (drive->waiting_for_dma)
676 startstop = ide_dma_timeout_retry(drive, wait);
677 else
678 startstop = ide_error(drive, "irq timeout",
679 hwif->tp_ops->read_status(hwif));
680 }
681 spin_lock_irq(&hwif->lock);
682 enable_irq(hwif->irq);
683 if (startstop == ide_stopped && hwif->polling == 0) {
684 rq_in_flight = hwif->rq;
685 hwif->rq = NULL;
686 ide_unlock_port(hwif);
687 plug_device = 1;
688 }
689 }
690 spin_unlock_irqrestore(&hwif->lock, flags);
691
692 if (plug_device) {
693 ide_unlock_host(hwif->host);
694 ide_requeue_and_plug(drive, rq_in_flight);
695 }
696}
697
698/**
699 * unexpected_intr - handle an unexpected IDE interrupt
700 * @irq: interrupt line
701 * @hwif: port being processed
702 *
703 * There's nothing really useful we can do with an unexpected interrupt,
704 * other than reading the status register (to clear it), and logging it.
705 * There should be no way that an irq can happen before we're ready for it,
706 * so we needn't worry much about losing an "important" interrupt here.
707 *
708 * On laptops (and "green" PCs), an unexpected interrupt occurs whenever
709 * the drive enters "idle", "standby", or "sleep" mode, so if the status
710 * looks "good", we just ignore the interrupt completely.
711 *
712 * This routine assumes __cli() is in effect when called.
713 *
714 * If an unexpected interrupt happens on irq15 while we are handling irq14
715 * and if the two interfaces are "serialized" (CMD640), then it looks like
716 * we could screw up by interfering with a new request being set up for
717 * irq15.
718 *
719 * In reality, this is a non-issue. The new command is not sent unless
720 * the drive is ready to accept one, in which case we know the drive is
721 * not trying to interrupt us. And ide_set_handler() is always invoked
722 * before completing the issuance of any new drive command, so we will not
723 * be accidentally invoked as a result of any valid command completion
724 * interrupt.
725 */
726
727static void unexpected_intr(int irq, ide_hwif_t *hwif)
728{
729 u8 stat = hwif->tp_ops->read_status(hwif);
730
731 if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
732 /* Try to not flood the console with msgs */
733 static unsigned long last_msgtime, count;
734 ++count;
735
736 if (time_after(jiffies, last_msgtime + HZ)) {
737 last_msgtime = jiffies;
738 printk(KERN_ERR "%s: unexpected interrupt, "
739 "status=0x%02x, count=%ld\n",
740 hwif->name, stat, count);
741 }
742 }
743}
744
745/**
746 * ide_intr - default IDE interrupt handler
747 * @irq: interrupt number
748 * @dev_id: hwif
749 * @regs: unused weirdness from the kernel irq layer
750 *
751 * This is the default IRQ handler for the IDE layer. You should
752 * not need to override it. If you do be aware it is subtle in
753 * places
754 *
755 * hwif is the interface in the group currently performing
756 * a command. hwif->cur_dev is the drive and hwif->handler is
757 * the IRQ handler to call. As we issue a command the handlers
758 * step through multiple states, reassigning the handler to the
759 * next step in the process. Unlike a smart SCSI controller IDE
760 * expects the main processor to sequence the various transfer
761 * stages. We also manage a poll timer to catch up with most
762 * timeout situations. There are still a few where the handlers
763 * don't ever decide to give up.
764 *
765 * The handler eventually returns ide_stopped to indicate the
766 * request completed. At this point we issue the next request
767 * on the port and the process begins again.
768 */
769
770irqreturn_t ide_intr (int irq, void *dev_id)
771{
772 ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
773 struct ide_host *host = hwif->host;
774 ide_drive_t *uninitialized_var(drive);
775 ide_handler_t *handler;
776 unsigned long flags;
777 ide_startstop_t startstop;
778 irqreturn_t irq_ret = IRQ_NONE;
779 int plug_device = 0;
780 struct request *uninitialized_var(rq_in_flight);
781
782 if (host->host_flags & IDE_HFLAG_SERIALIZE) {
783 if (hwif != host->cur_port)
784 goto out_early;
785 }
786
787 spin_lock_irqsave(&hwif->lock, flags);
788
789 if (hwif->port_ops && hwif->port_ops->test_irq &&
790 hwif->port_ops->test_irq(hwif) == 0)
791 goto out;
792
793 handler = hwif->handler;
794
795 if (handler == NULL || hwif->polling) {
796 /*
797 * Not expecting an interrupt from this drive.
798 * That means this could be:
799 * (1) an interrupt from another PCI device
800 * sharing the same PCI INT# as us.
801 * or (2) a drive just entered sleep or standby mode,
802 * and is interrupting to let us know.
803 * or (3) a spurious interrupt of unknown origin.
804 *
805 * For PCI, we cannot tell the difference,
806 * so in that case we just ignore it and hope it goes away.
807 */
808 if ((host->irq_flags & IRQF_SHARED) == 0) {
809 /*
810 * Probably not a shared PCI interrupt,
811 * so we can safely try to do something about it:
812 */
813 unexpected_intr(irq, hwif);
814 } else {
815 /*
816 * Whack the status register, just in case
817 * we have a leftover pending IRQ.
818 */
819 (void)hwif->tp_ops->read_status(hwif);
820 }
821 goto out;
822 }
823
824 drive = hwif->cur_dev;
825
826 if (!drive_is_ready(drive))
827 /*
828 * This happens regularly when we share a PCI IRQ with
829 * another device. Unfortunately, it can also happen
830 * with some buggy drives that trigger the IRQ before
831 * their status register is up to date. Hopefully we have
832 * enough advance overhead that the latter isn't a problem.
833 */
834 goto out;
835
836 hwif->handler = NULL;
837 hwif->expiry = NULL;
838 hwif->req_gen++;
839 del_timer(&hwif->timer);
840 spin_unlock(&hwif->lock);
841
842 if (hwif->port_ops && hwif->port_ops->clear_irq)
843 hwif->port_ops->clear_irq(drive);
844
845 if (drive->dev_flags & IDE_DFLAG_UNMASK)
846 local_irq_enable_in_hardirq();
847
848 /* service this interrupt, may set handler for next interrupt */
849 startstop = handler(drive);
850
851 spin_lock_irq(&hwif->lock);
852 /*
853 * Note that handler() may have set things up for another
854 * interrupt to occur soon, but it cannot happen until
855 * we exit from this routine, because it will be the
856 * same irq as is currently being serviced here, and Linux
857 * won't allow another of the same (on any CPU) until we return.
858 */
859 if (startstop == ide_stopped && hwif->polling == 0) {
860 BUG_ON(hwif->handler);
861 rq_in_flight = hwif->rq;
862 hwif->rq = NULL;
863 ide_unlock_port(hwif);
864 plug_device = 1;
865 }
866 irq_ret = IRQ_HANDLED;
867out:
868 spin_unlock_irqrestore(&hwif->lock, flags);
869out_early:
870 if (plug_device) {
871 ide_unlock_host(hwif->host);
872 ide_requeue_and_plug(drive, rq_in_flight);
873 }
874
875 return irq_ret;
876}
877EXPORT_SYMBOL_GPL(ide_intr);
878
879void ide_pad_transfer(ide_drive_t *drive, int write, int len)
880{
881 ide_hwif_t *hwif = drive->hwif;
882 u8 buf[4] = { 0 };
883
884 while (len > 0) {
885 if (write)
886 hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
887 else
888 hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
889 len -= 4;
890 }
891}
892EXPORT_SYMBOL_GPL(ide_pad_transfer);