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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 <asm/uaccess.h> |
55 | #include <asm/io.h> |
56 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
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 | |
405 | static inline void ide_unlock_port(ide_hwif_t *hwif) |
406 | { |
407 | hwif->busy = 0; |
408 | } |
409 | |
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 | |
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 | |
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 | |
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 | */ |
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 | |
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 | |
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 | |
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 | |
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 | |
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 |
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