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
ide_end_rq(ide_drive_t * drive,struct request * rq,int error,unsigned int nr_bytes)57 int 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 }
72 EXPORT_SYMBOL_GPL(ide_end_rq);
73
ide_complete_cmd(ide_drive_t * drive,struct ide_cmd * cmd,u8 stat,u8 err)74 void 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
ide_complete_rq(ide_drive_t * drive,int error,unsigned int nr_bytes)115 int 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 }
134 EXPORT_SYMBOL(ide_complete_rq);
135
ide_kill_rq(ide_drive_t * drive,struct request * rq)136 void 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
ide_tf_set_specify_cmd(ide_drive_t * drive,struct ide_taskfile * tf)155 static 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
ide_tf_set_restore_cmd(ide_drive_t * drive,struct ide_taskfile * tf)165 static 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
ide_tf_set_setmult_cmd(ide_drive_t * drive,struct ide_taskfile * tf)171 static 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
do_special(ide_drive_t * drive)185 static 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
ide_map_sg(ide_drive_t * drive,struct ide_cmd * cmd)223 void 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 }
231 EXPORT_SYMBOL_GPL(ide_map_sg);
232
ide_init_sg_cmd(struct ide_cmd * cmd,unsigned int nr_bytes)233 void 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 }
239 EXPORT_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
execute_drive_cmd(ide_drive_t * drive,struct request * rq)253 static 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
ide_special_rq(ide_drive_t * drive,struct request * rq)280 static 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
start_request(ide_drive_t * drive,struct request * rq)306 static 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);
372 kill_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
ide_stall_queue(ide_drive_t * drive,unsigned long timeout)386 void 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 }
393 EXPORT_SYMBOL(ide_stall_queue);
394
ide_lock_port(ide_hwif_t * hwif)395 static 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
ide_unlock_port(ide_hwif_t * hwif)405 static inline void ide_unlock_port(ide_hwif_t *hwif)
406 {
407 hwif->busy = 0;
408 }
409
ide_lock_host(struct ide_host * host,ide_hwif_t * hwif)410 static 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
ide_unlock_host(struct ide_host * host)424 static 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
__ide_requeue_and_plug(struct request_queue * q,struct request * rq)433 static 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
ide_requeue_and_plug(ide_drive_t * drive,struct request * rq)443 void 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 */
do_ide_request(struct request_queue * q)456 void 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);
479 repeat:
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;
561 out:
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
568 plug_device:
569 spin_unlock_irq(&hwif->lock);
570 ide_unlock_host(host);
571 plug_device_2:
572 spin_lock_irq(q->queue_lock);
573 __ide_requeue_and_plug(q, rq);
574 }
575
drive_is_ready(ide_drive_t * drive)576 static 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
ide_timer_expiry(unsigned long data)613 void 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
unexpected_intr(int irq,ide_hwif_t * hwif)727 static 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
ide_intr(int irq,void * dev_id)770 irqreturn_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;
867 out:
868 spin_unlock_irqrestore(&hwif->lock, flags);
869 out_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 }
877 EXPORT_SYMBOL_GPL(ide_intr);
878
ide_pad_transfer(ide_drive_t * drive,int write,int len)879 void 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 }
892 EXPORT_SYMBOL_GPL(ide_pad_transfer);
893