Linux Audio

Check our new training course

Loading...
v3.1
  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);
v5.4
  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;
237	struct request *rq = cmd->rq;
238
239	cmd->sg_nents = blk_rq_map_sg(drive->queue, rq, sg);
240}
241EXPORT_SYMBOL_GPL(ide_map_sg);
242
243void ide_init_sg_cmd(struct ide_cmd *cmd, unsigned int nr_bytes)
244{
245	cmd->nbytes = cmd->nleft = nr_bytes;
246	cmd->cursg_ofs = 0;
247	cmd->cursg = NULL;
248}
249EXPORT_SYMBOL_GPL(ide_init_sg_cmd);
250
251/**
252 *	execute_drive_command	-	issue special drive command
253 *	@drive: the drive to issue the command on
254 *	@rq: the request structure holding the command
255 *
256 *	execute_drive_cmd() issues a special drive command,  usually 
257 *	initiated by ioctl() from the external hdparm program. The
258 *	command can be a drive command, drive task or taskfile 
259 *	operation. Weirdly you can call it with NULL to wait for
260 *	all commands to finish. Don't do this as that is due to change
261 */
262
263static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
264		struct request *rq)
265{
266	struct ide_cmd *cmd = ide_req(rq)->special;
267
268	if (cmd) {
269		if (cmd->protocol == ATA_PROT_PIO) {
270			ide_init_sg_cmd(cmd, blk_rq_sectors(rq) << 9);
271			ide_map_sg(drive, cmd);
272		}
273
274		return do_rw_taskfile(drive, cmd);
275	}
276
277 	/*
278 	 * NULL is actually a valid way of waiting for
279 	 * all current requests to be flushed from the queue.
280 	 */
281#ifdef DEBUG
282 	printk("%s: DRIVE_CMD (null)\n", drive->name);
283#endif
284	scsi_req(rq)->result = 0;
285	ide_complete_rq(drive, BLK_STS_OK, blk_rq_bytes(rq));
286
287 	return ide_stopped;
288}
289
290static ide_startstop_t ide_special_rq(ide_drive_t *drive, struct request *rq)
291{
292	u8 cmd = scsi_req(rq)->cmd[0];
293
294	switch (cmd) {
295	case REQ_PARK_HEADS:
296	case REQ_UNPARK_HEADS:
297		return ide_do_park_unpark(drive, rq);
298	case REQ_DEVSET_EXEC:
299		return ide_do_devset(drive, rq);
300	case REQ_DRIVE_RESET:
301		return ide_do_reset(drive);
302	default:
303		BUG();
304	}
305}
306
307/**
308 *	start_request	-	start of I/O and command issuing for IDE
309 *
310 *	start_request() initiates handling of a new I/O request. It
311 *	accepts commands and I/O (read/write) requests.
312 *
313 *	FIXME: this function needs a rename
314 */
315 
316static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
317{
318	ide_startstop_t startstop;
319
 
 
320#ifdef DEBUG
321	printk("%s: start_request: current=0x%08lx\n",
322		drive->hwif->name, (unsigned long) rq);
323#endif
324
325	/* bail early if we've exceeded max_failures */
326	if (drive->max_failures && (drive->failures > drive->max_failures)) {
327		rq->rq_flags |= RQF_FAILED;
328		goto kill_rq;
329	}
330
331	if (drive->prep_rq && !drive->prep_rq(drive, rq))
332		return ide_stopped;
333
334	if (ata_pm_request(rq))
335		ide_check_pm_state(drive, rq);
336
337	drive->hwif->tp_ops->dev_select(drive);
338	if (ide_wait_stat(&startstop, drive, drive->ready_stat,
339			  ATA_BUSY | ATA_DRQ, WAIT_READY)) {
340		printk(KERN_ERR "%s: drive not ready for command\n", drive->name);
341		return startstop;
342	}
343
344	if (drive->special_flags == 0) {
345		struct ide_driver *drv;
346
347		/*
348		 * We reset the drive so we need to issue a SETFEATURES.
349		 * Do it _after_ do_special() restored device parameters.
350		 */
351		if (drive->current_speed == 0xff)
352			ide_config_drive_speed(drive, drive->desired_speed);
353
354		if (ata_taskfile_request(rq))
355			return execute_drive_cmd(drive, rq);
356		else if (ata_pm_request(rq)) {
357			struct ide_pm_state *pm = ide_req(rq)->special;
358#ifdef DEBUG_PM
359			printk("%s: start_power_step(step: %d)\n",
360				drive->name, pm->pm_step);
361#endif
362			startstop = ide_start_power_step(drive, rq);
363			if (startstop == ide_stopped &&
364			    pm->pm_step == IDE_PM_COMPLETED)
365				ide_complete_pm_rq(drive, rq);
366			return startstop;
367		} else if (!rq->rq_disk && ata_misc_request(rq))
368			/*
369			 * TODO: Once all ULDs have been modified to
370			 * check for specific op codes rather than
371			 * blindly accepting any special request, the
372			 * check for ->rq_disk above may be replaced
373			 * by a more suitable mechanism or even
374			 * dropped entirely.
375			 */
376			return ide_special_rq(drive, rq);
377
378		drv = *(struct ide_driver **)rq->rq_disk->private_data;
379
380		return drv->do_request(drive, rq, blk_rq_pos(rq));
381	}
382	return do_special(drive);
383kill_rq:
384	ide_kill_rq(drive, rq);
385	return ide_stopped;
386}
387
388/**
389 *	ide_stall_queue		-	pause an IDE device
390 *	@drive: drive to stall
391 *	@timeout: time to stall for (jiffies)
392 *
393 *	ide_stall_queue() can be used by a drive to give excess bandwidth back
394 *	to the port by sleeping for timeout jiffies.
395 */
396 
397void ide_stall_queue (ide_drive_t *drive, unsigned long timeout)
398{
399	if (timeout > WAIT_WORSTCASE)
400		timeout = WAIT_WORSTCASE;
401	drive->sleep = timeout + jiffies;
402	drive->dev_flags |= IDE_DFLAG_SLEEPING;
403}
404EXPORT_SYMBOL(ide_stall_queue);
405
406static inline int ide_lock_port(ide_hwif_t *hwif)
407{
408	if (hwif->busy)
409		return 1;
410
411	hwif->busy = 1;
412
413	return 0;
414}
415
416static inline void ide_unlock_port(ide_hwif_t *hwif)
417{
418	hwif->busy = 0;
419}
420
421static inline int ide_lock_host(struct ide_host *host, ide_hwif_t *hwif)
422{
423	int rc = 0;
424
425	if (host->host_flags & IDE_HFLAG_SERIALIZE) {
426		rc = test_and_set_bit_lock(IDE_HOST_BUSY, &host->host_busy);
427		if (rc == 0) {
428			if (host->get_lock)
429				host->get_lock(ide_intr, hwif);
430		}
431	}
432	return rc;
433}
434
435static inline void ide_unlock_host(struct ide_host *host)
436{
437	if (host->host_flags & IDE_HFLAG_SERIALIZE) {
438		if (host->release_lock)
439			host->release_lock();
440		clear_bit_unlock(IDE_HOST_BUSY, &host->host_busy);
441	}
442}
443
 
 
 
 
 
 
 
 
 
 
444void ide_requeue_and_plug(ide_drive_t *drive, struct request *rq)
445{
446	struct request_queue *q = drive->queue;
 
447
448	/* Use 3ms as that was the old plug delay */
449	if (rq) {
450		blk_mq_requeue_request(rq, false);
451		blk_mq_delay_kick_requeue_list(q, 3);
452	} else
453		blk_mq_delay_run_hw_queue(q->queue_hw_ctx[0], 3);
454}
455
456blk_status_t ide_issue_rq(ide_drive_t *drive, struct request *rq,
457			  bool local_requeue)
 
 
458{
459	ide_hwif_t *hwif = drive->hwif;
 
460	struct ide_host *host = hwif->host;
 
461	ide_startstop_t	startstop;
 
462
463	if (!blk_rq_is_passthrough(rq) && !(rq->rq_flags & RQF_DONTPREP)) {
464		rq->rq_flags |= RQF_DONTPREP;
465		ide_req(rq)->special = NULL;
466	}
467
468	/* HLD do_request() callback might sleep, make sure it's okay */
469	might_sleep();
470
471	if (ide_lock_host(host, hwif))
472		return BLK_STS_DEV_RESOURCE;
473
474	spin_lock_irq(&hwif->lock);
475
476	if (!ide_lock_port(hwif)) {
477		ide_hwif_t *prev_port;
478
479		WARN_ON_ONCE(hwif->rq);
480repeat:
481		prev_port = hwif->host->cur_port;
482		if (drive->dev_flags & IDE_DFLAG_SLEEPING &&
483		    time_after(drive->sleep, jiffies)) {
 
 
 
484			ide_unlock_port(hwif);
485			goto plug_device;
486		}
487
488		if ((hwif->host->host_flags & IDE_HFLAG_SERIALIZE) &&
489		    hwif != prev_port) {
490			ide_drive_t *cur_dev =
491				prev_port ? prev_port->cur_dev : NULL;
492
493			/*
494			 * set nIEN for previous port, drives in the
495			 * quirk list may not like intr setups/cleanups
496			 */
497			if (cur_dev &&
498			    (cur_dev->dev_flags & IDE_DFLAG_NIEN_QUIRK) == 0)
499				prev_port->tp_ops->write_devctl(prev_port,
500								ATA_NIEN |
501								ATA_DEVCTL_OBS);
502
503			hwif->host->cur_port = hwif;
504		}
505		hwif->cur_dev = drive;
506		drive->dev_flags &= ~(IDE_DFLAG_SLEEPING | IDE_DFLAG_PARKED);
507
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
508		/*
509		 * Sanity: don't accept a request that isn't a PM request
510		 * if we are currently power managed. This is very important as
511		 * blk_stop_queue() doesn't prevent the blk_fetch_request()
512		 * above to return us whatever is in the queue. Since we call
513		 * ide_do_request() ourselves, we end up taking requests while
514		 * the queue is blocked...
515		 * 
516		 * We let requests forced at head of queue with ide-preempt
517		 * though. I hope that doesn't happen too much, hopefully not
518		 * unless the subdriver triggers such a thing in its own PM
519		 * state machine.
520		 */
521		if ((drive->dev_flags & IDE_DFLAG_BLOCKED) &&
522		    ata_pm_request(rq) == 0 &&
523		    (rq->rq_flags & RQF_PREEMPT) == 0) {
524			/* there should be no pending command at this point */
525			ide_unlock_port(hwif);
526			goto plug_device;
527		}
528
529		scsi_req(rq)->resid_len = blk_rq_bytes(rq);
530		hwif->rq = rq;
531
532		spin_unlock_irq(&hwif->lock);
533		startstop = start_request(drive, rq);
534		spin_lock_irq(&hwif->lock);
535
536		if (startstop == ide_stopped) {
537			rq = hwif->rq;
538			hwif->rq = NULL;
539			if (rq)
540				goto repeat;
541			ide_unlock_port(hwif);
542			goto out;
543		}
544	} else {
545plug_device:
546		if (local_requeue)
547			list_add(&rq->queuelist, &drive->rq_list);
548		spin_unlock_irq(&hwif->lock);
549		ide_unlock_host(host);
550		if (!local_requeue)
551			ide_requeue_and_plug(drive, rq);
552		return BLK_STS_OK;
553	}
554
555out:
556	spin_unlock_irq(&hwif->lock);
557	if (rq == NULL)
558		ide_unlock_host(host);
559	return BLK_STS_OK;
560}
561
562/*
563 * Issue a new request to a device.
564 */
565blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
566			  const struct blk_mq_queue_data *bd)
567{
568	ide_drive_t *drive = hctx->queue->queuedata;
569	ide_hwif_t *hwif = drive->hwif;
570
571	spin_lock_irq(&hwif->lock);
572	if (drive->sense_rq_active) {
573		spin_unlock_irq(&hwif->lock);
574		return BLK_STS_DEV_RESOURCE;
575	}
576	spin_unlock_irq(&hwif->lock);
577
578	blk_mq_start_request(bd->rq);
579	return ide_issue_rq(drive, bd->rq, false);
 
580}
581
582static int drive_is_ready(ide_drive_t *drive)
583{
584	ide_hwif_t *hwif = drive->hwif;
585	u8 stat = 0;
586
587	if (drive->waiting_for_dma)
588		return hwif->dma_ops->dma_test_irq(drive);
589
590	if (hwif->io_ports.ctl_addr &&
591	    (hwif->host_flags & IDE_HFLAG_BROKEN_ALTSTATUS) == 0)
592		stat = hwif->tp_ops->read_altstatus(hwif);
593	else
594		/* Note: this may clear a pending IRQ!! */
595		stat = hwif->tp_ops->read_status(hwif);
596
597	if (stat & ATA_BUSY)
598		/* drive busy: definitely not interrupting */
599		return 0;
600
601	/* drive ready: *might* be interrupting */
602	return 1;
603}
604
605/**
606 *	ide_timer_expiry	-	handle lack of an IDE interrupt
607 *	@data: timer callback magic (hwif)
608 *
609 *	An IDE command has timed out before the expected drive return
610 *	occurred. At this point we attempt to clean up the current
611 *	mess. If the current handler includes an expiry handler then
612 *	we invoke the expiry handler, and providing it is happy the
613 *	work is done. If that fails we apply generic recovery rules
614 *	invoking the handler and checking the drive DMA status. We
615 *	have an excessively incestuous relationship with the DMA
616 *	logic that wants cleaning up.
617 */
618 
619void ide_timer_expiry (struct timer_list *t)
620{
621	ide_hwif_t	*hwif = from_timer(hwif, t, timer);
622	ide_drive_t	*uninitialized_var(drive);
623	ide_handler_t	*handler;
624	unsigned long	flags;
625	int		wait = -1;
626	int		plug_device = 0;
627	struct request	*uninitialized_var(rq_in_flight);
628
629	spin_lock_irqsave(&hwif->lock, flags);
630
631	handler = hwif->handler;
632
633	if (handler == NULL || hwif->req_gen != hwif->req_gen_timer) {
634		/*
635		 * Either a marginal timeout occurred
636		 * (got the interrupt just as timer expired),
637		 * or we were "sleeping" to give other devices a chance.
638		 * Either way, we don't really want to complain about anything.
639		 */
640	} else {
641		ide_expiry_t *expiry = hwif->expiry;
642		ide_startstop_t startstop = ide_stopped;
643
644		drive = hwif->cur_dev;
645
646		if (expiry) {
647			wait = expiry(drive);
648			if (wait > 0) { /* continue */
649				/* reset timer */
650				hwif->timer.expires = jiffies + wait;
651				hwif->req_gen_timer = hwif->req_gen;
652				add_timer(&hwif->timer);
653				spin_unlock_irqrestore(&hwif->lock, flags);
654				return;
655			}
656		}
657		hwif->handler = NULL;
658		hwif->expiry = NULL;
659		/*
660		 * We need to simulate a real interrupt when invoking
661		 * the handler() function, which means we need to
662		 * globally mask the specific IRQ:
663		 */
664		spin_unlock(&hwif->lock);
665		/* disable_irq_nosync ?? */
666		disable_irq(hwif->irq);
667
 
668		if (hwif->polling) {
669			startstop = handler(drive);
670		} else if (drive_is_ready(drive)) {
671			if (drive->waiting_for_dma)
672				hwif->dma_ops->dma_lost_irq(drive);
673			if (hwif->port_ops && hwif->port_ops->clear_irq)
674				hwif->port_ops->clear_irq(drive);
675
676			printk(KERN_WARNING "%s: lost interrupt\n",
677				drive->name);
678			startstop = handler(drive);
679		} else {
680			if (drive->waiting_for_dma)
681				startstop = ide_dma_timeout_retry(drive, wait);
682			else
683				startstop = ide_error(drive, "irq timeout",
684					hwif->tp_ops->read_status(hwif));
685		}
686		/* Disable interrupts again, `handler' might have enabled it */
687		spin_lock_irq(&hwif->lock);
688		enable_irq(hwif->irq);
689		if (startstop == ide_stopped && hwif->polling == 0) {
690			rq_in_flight = hwif->rq;
691			hwif->rq = NULL;
692			ide_unlock_port(hwif);
693			plug_device = 1;
694		}
695	}
696	spin_unlock_irqrestore(&hwif->lock, flags);
697
698	if (plug_device) {
699		ide_unlock_host(hwif->host);
700		ide_requeue_and_plug(drive, rq_in_flight);
701	}
702}
703
704/**
705 *	unexpected_intr		-	handle an unexpected IDE interrupt
706 *	@irq: interrupt line
707 *	@hwif: port being processed
708 *
709 *	There's nothing really useful we can do with an unexpected interrupt,
710 *	other than reading the status register (to clear it), and logging it.
711 *	There should be no way that an irq can happen before we're ready for it,
712 *	so we needn't worry much about losing an "important" interrupt here.
713 *
714 *	On laptops (and "green" PCs), an unexpected interrupt occurs whenever
715 *	the drive enters "idle", "standby", or "sleep" mode, so if the status
716 *	looks "good", we just ignore the interrupt completely.
717 *
718 *	This routine assumes __cli() is in effect when called.
719 *
720 *	If an unexpected interrupt happens on irq15 while we are handling irq14
721 *	and if the two interfaces are "serialized" (CMD640), then it looks like
722 *	we could screw up by interfering with a new request being set up for 
723 *	irq15.
724 *
725 *	In reality, this is a non-issue.  The new command is not sent unless 
726 *	the drive is ready to accept one, in which case we know the drive is
727 *	not trying to interrupt us.  And ide_set_handler() is always invoked
728 *	before completing the issuance of any new drive command, so we will not
729 *	be accidentally invoked as a result of any valid command completion
730 *	interrupt.
731 */
732
733static void unexpected_intr(int irq, ide_hwif_t *hwif)
734{
735	u8 stat = hwif->tp_ops->read_status(hwif);
736
737	if (!OK_STAT(stat, ATA_DRDY, BAD_STAT)) {
738		/* Try to not flood the console with msgs */
739		static unsigned long last_msgtime, count;
740		++count;
741
742		if (time_after(jiffies, last_msgtime + HZ)) {
743			last_msgtime = jiffies;
744			printk(KERN_ERR "%s: unexpected interrupt, "
745				"status=0x%02x, count=%ld\n",
746				hwif->name, stat, count);
747		}
748	}
749}
750
751/**
752 *	ide_intr	-	default IDE interrupt handler
753 *	@irq: interrupt number
754 *	@dev_id: hwif
755 *	@regs: unused weirdness from the kernel irq layer
756 *
757 *	This is the default IRQ handler for the IDE layer. You should
758 *	not need to override it. If you do be aware it is subtle in
759 *	places
760 *
761 *	hwif is the interface in the group currently performing
762 *	a command. hwif->cur_dev is the drive and hwif->handler is
763 *	the IRQ handler to call. As we issue a command the handlers
764 *	step through multiple states, reassigning the handler to the
765 *	next step in the process. Unlike a smart SCSI controller IDE
766 *	expects the main processor to sequence the various transfer
767 *	stages. We also manage a poll timer to catch up with most
768 *	timeout situations. There are still a few where the handlers
769 *	don't ever decide to give up.
770 *
771 *	The handler eventually returns ide_stopped to indicate the
772 *	request completed. At this point we issue the next request
773 *	on the port and the process begins again.
774 */
775
776irqreturn_t ide_intr (int irq, void *dev_id)
777{
778	ide_hwif_t *hwif = (ide_hwif_t *)dev_id;
779	struct ide_host *host = hwif->host;
780	ide_drive_t *uninitialized_var(drive);
781	ide_handler_t *handler;
782	unsigned long flags;
783	ide_startstop_t startstop;
784	irqreturn_t irq_ret = IRQ_NONE;
785	int plug_device = 0;
786	struct request *uninitialized_var(rq_in_flight);
787
788	if (host->host_flags & IDE_HFLAG_SERIALIZE) {
789		if (hwif != host->cur_port)
790			goto out_early;
791	}
792
793	spin_lock_irqsave(&hwif->lock, flags);
794
795	if (hwif->port_ops && hwif->port_ops->test_irq &&
796	    hwif->port_ops->test_irq(hwif) == 0)
797		goto out;
798
799	handler = hwif->handler;
800
801	if (handler == NULL || hwif->polling) {
802		/*
803		 * Not expecting an interrupt from this drive.
804		 * That means this could be:
805		 *	(1) an interrupt from another PCI device
806		 *	sharing the same PCI INT# as us.
807		 * or	(2) a drive just entered sleep or standby mode,
808		 *	and is interrupting to let us know.
809		 * or	(3) a spurious interrupt of unknown origin.
810		 *
811		 * For PCI, we cannot tell the difference,
812		 * so in that case we just ignore it and hope it goes away.
813		 */
814		if ((host->irq_flags & IRQF_SHARED) == 0) {
815			/*
816			 * Probably not a shared PCI interrupt,
817			 * so we can safely try to do something about it:
818			 */
819			unexpected_intr(irq, hwif);
820		} else {
821			/*
822			 * Whack the status register, just in case
823			 * we have a leftover pending IRQ.
824			 */
825			(void)hwif->tp_ops->read_status(hwif);
826		}
827		goto out;
828	}
829
830	drive = hwif->cur_dev;
831
832	if (!drive_is_ready(drive))
833		/*
834		 * This happens regularly when we share a PCI IRQ with
835		 * another device.  Unfortunately, it can also happen
836		 * with some buggy drives that trigger the IRQ before
837		 * their status register is up to date.  Hopefully we have
838		 * enough advance overhead that the latter isn't a problem.
839		 */
840		goto out;
841
842	hwif->handler = NULL;
843	hwif->expiry = NULL;
844	hwif->req_gen++;
845	del_timer(&hwif->timer);
846	spin_unlock(&hwif->lock);
847
848	if (hwif->port_ops && hwif->port_ops->clear_irq)
849		hwif->port_ops->clear_irq(drive);
850
851	if (drive->dev_flags & IDE_DFLAG_UNMASK)
852		local_irq_enable_in_hardirq();
853
854	/* service this interrupt, may set handler for next interrupt */
855	startstop = handler(drive);
856
857	spin_lock_irq(&hwif->lock);
858	/*
859	 * Note that handler() may have set things up for another
860	 * interrupt to occur soon, but it cannot happen until
861	 * we exit from this routine, because it will be the
862	 * same irq as is currently being serviced here, and Linux
863	 * won't allow another of the same (on any CPU) until we return.
864	 */
865	if (startstop == ide_stopped && hwif->polling == 0) {
866		BUG_ON(hwif->handler);
867		rq_in_flight = hwif->rq;
868		hwif->rq = NULL;
869		ide_unlock_port(hwif);
870		plug_device = 1;
871	}
872	irq_ret = IRQ_HANDLED;
873out:
874	spin_unlock_irqrestore(&hwif->lock, flags);
875out_early:
876	if (plug_device) {
877		ide_unlock_host(hwif->host);
878		ide_requeue_and_plug(drive, rq_in_flight);
879	}
880
881	return irq_ret;
882}
883EXPORT_SYMBOL_GPL(ide_intr);
884
885void ide_pad_transfer(ide_drive_t *drive, int write, int len)
886{
887	ide_hwif_t *hwif = drive->hwif;
888	u8 buf[4] = { 0 };
889
890	while (len > 0) {
891		if (write)
892			hwif->tp_ops->output_data(drive, NULL, buf, min(4, len));
893		else
894			hwif->tp_ops->input_data(drive, NULL, buf, min(4, len));
895		len -= 4;
896	}
897}
898EXPORT_SYMBOL_GPL(ide_pad_transfer);
899
900void ide_insert_request_head(ide_drive_t *drive, struct request *rq)
901{
902	drive->sense_rq_active = true;
903	list_add_tail(&rq->queuelist, &drive->rq_list);
904	kblockd_schedule_work(&drive->rq_work);
905}
906EXPORT_SYMBOL_GPL(ide_insert_request_head);