2 * scsi.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4 * Copyright (C) 2002, 2003 Christoph Hellwig
6 * generic mid-level SCSI driver
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
12 * Bug correction thanks go to :
13 * Rik Faith <faith@cs.unc.edu>
14 * Tommy Thorn <tthorn>
15 * Thomas Wuensche <tw@fgb1.fgb.mw.tu-muenchen.de>
17 * Modified by Eric Youngdale eric@andante.org or ericy@gnu.ai.mit.edu to
18 * add scatter-gather, multiple outstanding request, and other
21 * Native multichannel, wide scsi, /proc/scsi and hot plugging
22 * support added by Michael Neuffer <mike@i-connect.net>
24 * Added request_module("scsi_hostadapter") for kerneld:
25 * (Put an "alias scsi_hostadapter your_hostadapter" in /etc/modprobe.conf)
26 * Bjorn Ekwall <bj0rn@blox.se>
29 * Major improvements to the timeout, abort, and reset processing,
30 * as well as performance modifications for large queue depths by
31 * Leonard N. Zubkoff <lnz@dandelion.com>
33 * Converted cli() code to spinlocks, Ingo Molnar
35 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
37 * out_of_space hacks, D. Gilbert (dpg) 990608
40 #include <linux/module.h>
41 #include <linux/moduleparam.h>
42 #include <linux/kernel.h>
43 #include <linux/sched.h>
44 #include <linux/timer.h>
45 #include <linux/string.h>
46 #include <linux/slab.h>
47 #include <linux/blkdev.h>
48 #include <linux/delay.h>
49 #include <linux/init.h>
50 #include <linux/completion.h>
51 #include <linux/unistd.h>
52 #include <linux/spinlock.h>
53 #include <linux/kmod.h>
54 #include <linux/interrupt.h>
55 #include <linux/notifier.h>
56 #include <linux/cpu.h>
57 #include <linux/mutex.h>
59 #include <scsi/scsi.h>
60 #include <scsi/scsi_cmnd.h>
61 #include <scsi/scsi_dbg.h>
62 #include <scsi/scsi_device.h>
63 #include <scsi/scsi_eh.h>
64 #include <scsi/scsi_host.h>
65 #include <scsi/scsi_tcq.h>
67 #include "scsi_priv.h"
68 #include "scsi_logging.h"
70 static void scsi_done(struct scsi_cmnd *cmd);
73 * Definitions and constants.
76 #define MIN_RESET_DELAY (2*HZ)
78 /* Do not call reset on error if we just did a reset within 15 sec. */
79 #define MIN_RESET_PERIOD (15*HZ)
82 * Macro to determine the size of SCSI command. This macro takes vendor
83 * unique commands into account. SCSI commands in groups 6 and 7 are
84 * vendor unique and we will depend upon the command length being
85 * supplied correctly in cmd_len.
87 #define CDB_SIZE(cmd) (((((cmd)->cmnd[0] >> 5) & 7) < 6) ? \
88 COMMAND_SIZE((cmd)->cmnd[0]) : (cmd)->cmd_len)
91 * Note - the initial logging level can be set here to log events at boot time.
92 * After the system is up, you may enable logging via the /proc interface.
94 unsigned int scsi_logging_level;
95 #if defined(CONFIG_SCSI_LOGGING)
96 EXPORT_SYMBOL(scsi_logging_level);
99 const char *const scsi_device_types[MAX_SCSI_DEVICE_CODE] = {
116 EXPORT_SYMBOL(scsi_device_types);
118 struct scsi_host_cmd_pool {
122 unsigned int slab_flags;
126 static struct scsi_host_cmd_pool scsi_cmd_pool = {
127 .name = "scsi_cmd_cache",
128 .slab_flags = SLAB_HWCACHE_ALIGN,
131 static struct scsi_host_cmd_pool scsi_cmd_dma_pool = {
132 .name = "scsi_cmd_cache(DMA)",
133 .slab_flags = SLAB_HWCACHE_ALIGN|SLAB_CACHE_DMA,
134 .gfp_mask = __GFP_DMA,
137 static DEFINE_MUTEX(host_cmd_pool_mutex);
139 static struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost,
142 struct scsi_cmnd *cmd;
144 cmd = kmem_cache_alloc(shost->cmd_pool->slab,
145 gfp_mask | shost->cmd_pool->gfp_mask);
147 if (unlikely(!cmd)) {
150 spin_lock_irqsave(&shost->free_list_lock, flags);
151 if (likely(!list_empty(&shost->free_list))) {
152 cmd = list_entry(shost->free_list.next,
153 struct scsi_cmnd, list);
154 list_del_init(&cmd->list);
156 spin_unlock_irqrestore(&shost->free_list_lock, flags);
163 * Function: scsi_get_command()
165 * Purpose: Allocate and setup a scsi command block
167 * Arguments: dev - parent scsi device
168 * gfp_mask- allocator flags
170 * Returns: The allocated scsi command structure.
172 struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
174 struct scsi_cmnd *cmd;
176 /* Bail if we can't get a reference to the device */
177 if (!get_device(&dev->sdev_gendev))
180 cmd = __scsi_get_command(dev->host, gfp_mask);
182 if (likely(cmd != NULL)) {
185 memset(cmd, 0, sizeof(*cmd));
187 init_timer(&cmd->eh_timeout);
188 INIT_LIST_HEAD(&cmd->list);
189 spin_lock_irqsave(&dev->list_lock, flags);
190 list_add_tail(&cmd->list, &dev->cmd_list);
191 spin_unlock_irqrestore(&dev->list_lock, flags);
192 cmd->jiffies_at_alloc = jiffies;
194 put_device(&dev->sdev_gendev);
198 EXPORT_SYMBOL(scsi_get_command);
201 * Function: scsi_put_command()
203 * Purpose: Free a scsi command block
205 * Arguments: cmd - command block to free
209 * Notes: The command must not belong to any lists.
211 void scsi_put_command(struct scsi_cmnd *cmd)
213 struct scsi_device *sdev = cmd->device;
214 struct Scsi_Host *shost = sdev->host;
217 /* serious error if the command hasn't come from a device list */
218 spin_lock_irqsave(&cmd->device->list_lock, flags);
219 BUG_ON(list_empty(&cmd->list));
220 list_del_init(&cmd->list);
221 spin_unlock(&cmd->device->list_lock);
222 /* changing locks here, don't need to restore the irq state */
223 spin_lock(&shost->free_list_lock);
224 if (unlikely(list_empty(&shost->free_list))) {
225 list_add(&cmd->list, &shost->free_list);
228 spin_unlock_irqrestore(&shost->free_list_lock, flags);
230 if (likely(cmd != NULL))
231 kmem_cache_free(shost->cmd_pool->slab, cmd);
233 put_device(&sdev->sdev_gendev);
235 EXPORT_SYMBOL(scsi_put_command);
238 * Function: scsi_setup_command_freelist()
240 * Purpose: Setup the command freelist for a scsi host.
242 * Arguments: shost - host to allocate the freelist for.
246 int scsi_setup_command_freelist(struct Scsi_Host *shost)
248 struct scsi_host_cmd_pool *pool;
249 struct scsi_cmnd *cmd;
251 spin_lock_init(&shost->free_list_lock);
252 INIT_LIST_HEAD(&shost->free_list);
255 * Select a command slab for this host and create it if not
258 mutex_lock(&host_cmd_pool_mutex);
259 pool = (shost->unchecked_isa_dma ? &scsi_cmd_dma_pool : &scsi_cmd_pool);
261 pool->slab = kmem_cache_create(pool->name,
262 sizeof(struct scsi_cmnd), 0,
263 pool->slab_flags, NULL, NULL);
269 shost->cmd_pool = pool;
270 mutex_unlock(&host_cmd_pool_mutex);
273 * Get one backup command for this host.
275 cmd = kmem_cache_alloc(shost->cmd_pool->slab,
276 GFP_KERNEL | shost->cmd_pool->gfp_mask);
279 list_add(&cmd->list, &shost->free_list);
284 kmem_cache_destroy(pool->slab);
287 mutex_unlock(&host_cmd_pool_mutex);
293 * Function: scsi_destroy_command_freelist()
295 * Purpose: Release the command freelist for a scsi host.
297 * Arguments: shost - host that's freelist is going to be destroyed
299 void scsi_destroy_command_freelist(struct Scsi_Host *shost)
301 while (!list_empty(&shost->free_list)) {
302 struct scsi_cmnd *cmd;
304 cmd = list_entry(shost->free_list.next, struct scsi_cmnd, list);
305 list_del_init(&cmd->list);
306 kmem_cache_free(shost->cmd_pool->slab, cmd);
309 mutex_lock(&host_cmd_pool_mutex);
310 if (!--shost->cmd_pool->users)
311 kmem_cache_destroy(shost->cmd_pool->slab);
312 mutex_unlock(&host_cmd_pool_mutex);
315 #ifdef CONFIG_SCSI_LOGGING
316 void scsi_log_send(struct scsi_cmnd *cmd)
319 struct scsi_device *sdev;
322 * If ML QUEUE log level is greater than or equal to:
324 * 1: nothing (match completion)
326 * 2: log opcode + command of all commands
328 * 3: same as 2 plus dump cmd address
330 * 4: same as 3 plus dump extra junk
332 if (unlikely(scsi_logging_level)) {
333 level = SCSI_LOG_LEVEL(SCSI_LOG_MLQUEUE_SHIFT,
334 SCSI_LOG_MLQUEUE_BITS);
337 sdev_printk(KERN_INFO, sdev, "send ");
339 printk("0x%p ", cmd);
341 * spaces to match disposition and cmd->result
342 * output in scsi_log_completion.
345 scsi_print_command(cmd);
347 printk(KERN_INFO "buffer = 0x%p, bufflen = %d,"
348 " done = 0x%p, queuecommand 0x%p\n",
349 cmd->request_buffer, cmd->request_bufflen,
351 sdev->host->hostt->queuecommand);
358 void scsi_log_completion(struct scsi_cmnd *cmd, int disposition)
361 struct scsi_device *sdev;
364 * If ML COMPLETE log level is greater than or equal to:
366 * 1: log disposition, result, opcode + command, and conditionally
367 * sense data for failures or non SUCCESS dispositions.
369 * 2: same as 1 but for all command completions.
371 * 3: same as 2 plus dump cmd address
373 * 4: same as 3 plus dump extra junk
375 if (unlikely(scsi_logging_level)) {
376 level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,
377 SCSI_LOG_MLCOMPLETE_BITS);
378 if (((level > 0) && (cmd->result || disposition != SUCCESS)) ||
381 sdev_printk(KERN_INFO, sdev, "done ");
383 printk("0x%p ", cmd);
385 * Dump truncated values, so we usually fit within
388 switch (disposition) {
403 * If called via scsi_times_out.
410 printk(" %8x ", cmd->result);
411 scsi_print_command(cmd);
412 if (status_byte(cmd->result) & CHECK_CONDITION) {
414 * XXX The scsi_print_sense formatting/prefix
415 * doesn't match this function.
417 scsi_print_sense("", cmd);
420 printk(KERN_INFO "scsi host busy %d failed %d\n",
421 sdev->host->host_busy,
422 sdev->host->host_failed);
430 * Assign a serial number and pid to the request for error recovery
431 * and debugging purposes. Protected by the Host_Lock of host.
433 static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
435 cmd->serial_number = host->cmd_serial_number++;
436 if (cmd->serial_number == 0)
437 cmd->serial_number = host->cmd_serial_number++;
439 cmd->pid = host->cmd_pid++;
441 cmd->pid = host->cmd_pid++;
445 * Function: scsi_dispatch_command
447 * Purpose: Dispatch a command to the low-level driver.
449 * Arguments: cmd - command block we are dispatching.
453 int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
455 struct Scsi_Host *host = cmd->device->host;
456 unsigned long flags = 0;
457 unsigned long timeout;
460 /* check if the device is still usable */
461 if (unlikely(cmd->device->sdev_state == SDEV_DEL)) {
462 /* in SDEV_DEL we error all commands. DID_NO_CONNECT
463 * returns an immediate error upwards, and signals
464 * that the device is no longer present */
465 cmd->result = DID_NO_CONNECT << 16;
466 atomic_inc(&cmd->device->iorequest_cnt);
468 /* return 0 (because the command has been processed) */
472 /* Check to see if the scsi lld put this device into state SDEV_BLOCK. */
473 if (unlikely(cmd->device->sdev_state == SDEV_BLOCK)) {
475 * in SDEV_BLOCK, the command is just put back on the device
476 * queue. The suspend state has already blocked the queue so
477 * future requests should not occur until the device
478 * transitions out of the suspend state.
480 scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY);
482 SCSI_LOG_MLQUEUE(3, printk("queuecommand : device blocked \n"));
485 * NOTE: rtn is still zero here because we don't need the
486 * queue to be plugged on return (it's already stopped)
492 * If SCSI-2 or lower, store the LUN value in cmnd.
494 if (cmd->device->scsi_level <= SCSI_2 &&
495 cmd->device->scsi_level != SCSI_UNKNOWN) {
496 cmd->cmnd[1] = (cmd->cmnd[1] & 0x1f) |
497 (cmd->device->lun << 5 & 0xe0);
501 * We will wait MIN_RESET_DELAY clock ticks after the last reset so
502 * we can avoid the drive not being ready.
504 timeout = host->last_reset + MIN_RESET_DELAY;
506 if (host->resetting && time_before(jiffies, timeout)) {
507 int ticks_remaining = timeout - jiffies;
509 * NOTE: This may be executed from within an interrupt
510 * handler! This is bad, but for now, it'll do. The irq
511 * level of the interrupt handler has been masked out by the
512 * platform dependent interrupt handling code already, so the
513 * sti() here will not cause another call to the SCSI host's
514 * interrupt handler (assuming there is one irq-level per
517 while (--ticks_remaining >= 0)
518 mdelay(1 + 999 / HZ);
523 * AK: unlikely race here: for some reason the timer could
524 * expire before the serial number is set up below.
526 scsi_add_timer(cmd, cmd->timeout_per_command, scsi_times_out);
531 * We will use a queued command if possible, otherwise we will
532 * emulate the queuing and calling of completion function ourselves.
534 atomic_inc(&cmd->device->iorequest_cnt);
537 * Before we queue this command, check if the command
538 * length exceeds what the host adapter can handle.
540 if (CDB_SIZE(cmd) > cmd->device->host->max_cmd_len) {
542 printk("queuecommand : command too long.\n"));
543 cmd->result = (DID_ABORT << 16);
549 spin_lock_irqsave(host->host_lock, flags);
550 scsi_cmd_get_serial(host, cmd);
552 if (unlikely(host->shost_state == SHOST_DEL)) {
553 cmd->result = (DID_NO_CONNECT << 16);
556 rtn = host->hostt->queuecommand(cmd, scsi_done);
558 spin_unlock_irqrestore(host->host_lock, flags);
560 if (scsi_delete_timer(cmd)) {
561 atomic_inc(&cmd->device->iodone_cnt);
562 scsi_queue_insert(cmd,
563 (rtn == SCSI_MLQUEUE_DEVICE_BUSY) ?
564 rtn : SCSI_MLQUEUE_HOST_BUSY);
567 printk("queuecommand : request rejected\n"));
571 SCSI_LOG_MLQUEUE(3, printk("leaving scsi_dispatch_cmnd()\n"));
577 * Per-CPU I/O completion queue.
579 static DEFINE_PER_CPU(struct list_head, scsi_done_q);
582 * scsi_req_abort_cmd -- Request command recovery for the specified command
583 * cmd: pointer to the SCSI command of interest
585 * This function requests that SCSI Core start recovery for the
586 * command by deleting the timer and adding the command to the eh
587 * queue. It can be called by either LLDDs or SCSI Core. LLDDs who
588 * implement their own error recovery MAY ignore the timeout event if
589 * they generated scsi_req_abort_cmd.
591 void scsi_req_abort_cmd(struct scsi_cmnd *cmd)
593 if (!scsi_delete_timer(cmd))
597 EXPORT_SYMBOL(scsi_req_abort_cmd);
600 * scsi_done - Enqueue the finished SCSI command into the done queue.
601 * @cmd: The SCSI Command for which a low-level device driver (LLDD) gives
602 * ownership back to SCSI Core -- i.e. the LLDD has finished with it.
604 * This function is the mid-level's (SCSI Core) interrupt routine, which
605 * regains ownership of the SCSI command (de facto) from a LLDD, and enqueues
606 * the command to the done queue for further processing.
608 * This is the producer of the done queue who enqueues at the tail.
610 * This function is interrupt context safe.
612 static void scsi_done(struct scsi_cmnd *cmd)
615 * We don't have to worry about this one timing out any more.
616 * If we are unable to remove the timer, then the command
617 * has already timed out. In which case, we have no choice but to
618 * let the timeout function run, as we have no idea where in fact
619 * that function could really be. It might be on another processor,
622 if (!scsi_delete_timer(cmd))
627 /* Private entry to scsi_done() to complete a command when the timer
628 * isn't running --- used by scsi_times_out */
629 void __scsi_done(struct scsi_cmnd *cmd)
631 struct request *rq = cmd->request;
634 * Set the serial numbers back to zero
636 cmd->serial_number = 0;
638 atomic_inc(&cmd->device->iodone_cnt);
640 atomic_inc(&cmd->device->ioerr_cnt);
645 * The uptodate/nbytes values don't matter, as we allow partial
646 * completes and thus will check this in the softirq callback
648 rq->completion_data = cmd;
649 blk_complete_request(rq);
653 * Function: scsi_retry_command
655 * Purpose: Send a command back to the low level to be retried.
657 * Notes: This command is always executed in the context of the
658 * bottom half handler, or the error handler thread. Low
659 * level drivers should not become re-entrant as a result of
662 int scsi_retry_command(struct scsi_cmnd *cmd)
665 * Zero the sense information from the last time we tried
668 memset(cmd->sense_buffer, 0, sizeof(cmd->sense_buffer));
670 return scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY);
674 * Function: scsi_finish_command
676 * Purpose: Pass command off to upper layer for finishing of I/O
677 * request, waking processes that are waiting on results,
680 void scsi_finish_command(struct scsi_cmnd *cmd)
682 struct scsi_device *sdev = cmd->device;
683 struct Scsi_Host *shost = sdev->host;
685 scsi_device_unbusy(sdev);
688 * Clear the flags which say that the device/host is no longer
689 * capable of accepting new commands. These are set in scsi_queue.c
690 * for both the queue full condition on a device, and for a
691 * host full condition on the host.
693 * XXX(hch): What about locking?
695 shost->host_blocked = 0;
696 sdev->device_blocked = 0;
699 * If we have valid sense information, then some kind of recovery
700 * must have taken place. Make a note of this.
702 if (SCSI_SENSE_VALID(cmd))
703 cmd->result |= (DRIVER_SENSE << 24);
705 SCSI_LOG_MLCOMPLETE(4, sdev_printk(KERN_INFO, sdev,
706 "Notifying upper driver of completion "
707 "(result %x)\n", cmd->result));
711 EXPORT_SYMBOL(scsi_finish_command);
714 * Function: scsi_adjust_queue_depth()
716 * Purpose: Allow low level drivers to tell us to change the queue depth
717 * on a specific SCSI device
719 * Arguments: sdev - SCSI Device in question
720 * tagged - Do we use tagged queueing (non-0) or do we treat
721 * this device as an untagged device (0)
722 * tags - Number of tags allowed if tagged queueing enabled,
723 * or number of commands the low level driver can
724 * queue up in non-tagged mode (as per cmd_per_lun).
728 * Lock Status: None held on entry
730 * Notes: Low level drivers may call this at any time and we will do
731 * the right thing depending on whether or not the device is
732 * currently active and whether or not it even has the
733 * command blocks built yet.
735 void scsi_adjust_queue_depth(struct scsi_device *sdev, int tagged, int tags)
740 * refuse to set tagged depth to an unworkable size
745 spin_lock_irqsave(sdev->request_queue->queue_lock, flags);
747 /* Check to see if the queue is managed by the block layer
748 * if it is, and we fail to adjust the depth, exit */
749 if (blk_queue_tagged(sdev->request_queue) &&
750 blk_queue_resize_tags(sdev->request_queue, tags) != 0)
753 sdev->queue_depth = tags;
755 case MSG_ORDERED_TAG:
756 sdev->ordered_tags = 1;
757 sdev->simple_tags = 1;
760 sdev->ordered_tags = 0;
761 sdev->simple_tags = 1;
764 sdev_printk(KERN_WARNING, sdev,
765 "scsi_adjust_queue_depth, bad queue type, "
768 sdev->ordered_tags = sdev->simple_tags = 0;
769 sdev->queue_depth = tags;
773 spin_unlock_irqrestore(sdev->request_queue->queue_lock, flags);
775 EXPORT_SYMBOL(scsi_adjust_queue_depth);
778 * Function: scsi_track_queue_full()
780 * Purpose: This function will track successive QUEUE_FULL events on a
781 * specific SCSI device to determine if and when there is a
782 * need to adjust the queue depth on the device.
784 * Arguments: sdev - SCSI Device in question
785 * depth - Current number of outstanding SCSI commands on
786 * this device, not counting the one returned as
789 * Returns: 0 - No change needed
790 * >0 - Adjust queue depth to this new depth
791 * -1 - Drop back to untagged operation using host->cmd_per_lun
792 * as the untagged command depth
794 * Lock Status: None held on entry
796 * Notes: Low level drivers may call this at any time and we will do
797 * "The Right Thing." We are interrupt context safe.
799 int scsi_track_queue_full(struct scsi_device *sdev, int depth)
801 if ((jiffies >> 4) == sdev->last_queue_full_time)
804 sdev->last_queue_full_time = (jiffies >> 4);
805 if (sdev->last_queue_full_depth != depth) {
806 sdev->last_queue_full_count = 1;
807 sdev->last_queue_full_depth = depth;
809 sdev->last_queue_full_count++;
812 if (sdev->last_queue_full_count <= 10)
814 if (sdev->last_queue_full_depth < 8) {
815 /* Drop back to untagged */
816 scsi_adjust_queue_depth(sdev, 0, sdev->host->cmd_per_lun);
820 if (sdev->ordered_tags)
821 scsi_adjust_queue_depth(sdev, MSG_ORDERED_TAG, depth);
823 scsi_adjust_queue_depth(sdev, MSG_SIMPLE_TAG, depth);
826 EXPORT_SYMBOL(scsi_track_queue_full);
829 * scsi_device_get - get an addition reference to a scsi_device
830 * @sdev: device to get a reference to
832 * Gets a reference to the scsi_device and increments the use count
833 * of the underlying LLDD module. You must hold host_lock of the
834 * parent Scsi_Host or already have a reference when calling this.
836 int scsi_device_get(struct scsi_device *sdev)
838 if (sdev->sdev_state == SDEV_DEL || sdev->sdev_state == SDEV_CANCEL)
840 if (!get_device(&sdev->sdev_gendev))
842 if (!try_module_get(sdev->host->hostt->module)) {
843 put_device(&sdev->sdev_gendev);
848 EXPORT_SYMBOL(scsi_device_get);
851 * scsi_device_put - release a reference to a scsi_device
852 * @sdev: device to release a reference on.
854 * Release a reference to the scsi_device and decrements the use count
855 * of the underlying LLDD module. The device is freed once the last
858 void scsi_device_put(struct scsi_device *sdev)
860 module_put(sdev->host->hostt->module);
861 put_device(&sdev->sdev_gendev);
863 EXPORT_SYMBOL(scsi_device_put);
865 /* helper for shost_for_each_device, thus not documented */
866 struct scsi_device *__scsi_iterate_devices(struct Scsi_Host *shost,
867 struct scsi_device *prev)
869 struct list_head *list = (prev ? &prev->siblings : &shost->__devices);
870 struct scsi_device *next = NULL;
873 spin_lock_irqsave(shost->host_lock, flags);
874 while (list->next != &shost->__devices) {
875 next = list_entry(list->next, struct scsi_device, siblings);
876 /* skip devices that we can't get a reference to */
877 if (!scsi_device_get(next))
882 spin_unlock_irqrestore(shost->host_lock, flags);
885 scsi_device_put(prev);
888 EXPORT_SYMBOL(__scsi_iterate_devices);
891 * starget_for_each_device - helper to walk all devices of a target
892 * @starget: target whose devices we want to iterate over.
894 * This traverses over each devices of @shost. The devices have
895 * a reference that must be released by scsi_host_put when breaking
898 void starget_for_each_device(struct scsi_target *starget, void * data,
899 void (*fn)(struct scsi_device *, void *))
901 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
902 struct scsi_device *sdev;
904 shost_for_each_device(sdev, shost) {
905 if ((sdev->channel == starget->channel) &&
906 (sdev->id == starget->id))
910 EXPORT_SYMBOL(starget_for_each_device);
913 * __scsi_device_lookup_by_target - find a device given the target (UNLOCKED)
914 * @starget: SCSI target pointer
915 * @lun: SCSI Logical Unit Number
917 * Looks up the scsi_device with the specified @lun for a give
918 * @starget. The returned scsi_device does not have an additional
919 * reference. You must hold the host's host_lock over this call and
920 * any access to the returned scsi_device.
922 * Note: The only reason why drivers would want to use this is because
923 * they're need to access the device list in irq context. Otherwise you
924 * really want to use scsi_device_lookup_by_target instead.
926 struct scsi_device *__scsi_device_lookup_by_target(struct scsi_target *starget,
929 struct scsi_device *sdev;
931 list_for_each_entry(sdev, &starget->devices, same_target_siblings) {
938 EXPORT_SYMBOL(__scsi_device_lookup_by_target);
941 * scsi_device_lookup_by_target - find a device given the target
942 * @starget: SCSI target pointer
943 * @lun: SCSI Logical Unit Number
945 * Looks up the scsi_device with the specified @channel, @id, @lun for a
946 * give host. The returned scsi_device has an additional reference that
947 * needs to be release with scsi_host_put once you're done with it.
949 struct scsi_device *scsi_device_lookup_by_target(struct scsi_target *starget,
952 struct scsi_device *sdev;
953 struct Scsi_Host *shost = dev_to_shost(starget->dev.parent);
956 spin_lock_irqsave(shost->host_lock, flags);
957 sdev = __scsi_device_lookup_by_target(starget, lun);
958 if (sdev && scsi_device_get(sdev))
960 spin_unlock_irqrestore(shost->host_lock, flags);
964 EXPORT_SYMBOL(scsi_device_lookup_by_target);
967 * scsi_device_lookup - find a device given the host (UNLOCKED)
968 * @shost: SCSI host pointer
969 * @channel: SCSI channel (zero if only one channel)
970 * @pun: SCSI target number (physical unit number)
971 * @lun: SCSI Logical Unit Number
973 * Looks up the scsi_device with the specified @channel, @id, @lun for a
974 * give host. The returned scsi_device does not have an additional reference.
975 * You must hold the host's host_lock over this call and any access to the
976 * returned scsi_device.
978 * Note: The only reason why drivers would want to use this is because
979 * they're need to access the device list in irq context. Otherwise you
980 * really want to use scsi_device_lookup instead.
982 struct scsi_device *__scsi_device_lookup(struct Scsi_Host *shost,
983 uint channel, uint id, uint lun)
985 struct scsi_device *sdev;
987 list_for_each_entry(sdev, &shost->__devices, siblings) {
988 if (sdev->channel == channel && sdev->id == id &&
995 EXPORT_SYMBOL(__scsi_device_lookup);
998 * scsi_device_lookup - find a device given the host
999 * @shost: SCSI host pointer
1000 * @channel: SCSI channel (zero if only one channel)
1001 * @id: SCSI target number (physical unit number)
1002 * @lun: SCSI Logical Unit Number
1004 * Looks up the scsi_device with the specified @channel, @id, @lun for a
1005 * give host. The returned scsi_device has an additional reference that
1006 * needs to be release with scsi_host_put once you're done with it.
1008 struct scsi_device *scsi_device_lookup(struct Scsi_Host *shost,
1009 uint channel, uint id, uint lun)
1011 struct scsi_device *sdev;
1012 unsigned long flags;
1014 spin_lock_irqsave(shost->host_lock, flags);
1015 sdev = __scsi_device_lookup(shost, channel, id, lun);
1016 if (sdev && scsi_device_get(sdev))
1018 spin_unlock_irqrestore(shost->host_lock, flags);
1022 EXPORT_SYMBOL(scsi_device_lookup);
1025 * scsi_device_cancel - cancel outstanding IO to this device
1026 * @sdev: Pointer to struct scsi_device
1027 * @recovery: Boolean instructing function to recover device or not.
1030 int scsi_device_cancel(struct scsi_device *sdev, int recovery)
1032 struct scsi_cmnd *scmd;
1033 LIST_HEAD(active_list);
1034 struct list_head *lh, *lh_sf;
1035 unsigned long flags;
1037 scsi_device_set_state(sdev, SDEV_CANCEL);
1039 spin_lock_irqsave(&sdev->list_lock, flags);
1040 list_for_each_entry(scmd, &sdev->cmd_list, list) {
1041 if (scmd->request && scmd->request->rq_status != RQ_INACTIVE) {
1043 * If we are unable to remove the timer, it means
1044 * that the command has already timed out or
1047 if (!scsi_delete_timer(scmd))
1049 list_add_tail(&scmd->eh_entry, &active_list);
1052 spin_unlock_irqrestore(&sdev->list_lock, flags);
1054 if (!list_empty(&active_list)) {
1055 list_for_each_safe(lh, lh_sf, &active_list) {
1056 scmd = list_entry(lh, struct scsi_cmnd, eh_entry);
1059 !scsi_eh_scmd_add(scmd, SCSI_EH_CANCEL_CMD)) {
1060 scmd->result = (DID_ABORT << 16);
1061 scsi_finish_command(scmd);
1068 EXPORT_SYMBOL(scsi_device_cancel);
1070 MODULE_DESCRIPTION("SCSI core");
1071 MODULE_LICENSE("GPL");
1073 module_param(scsi_logging_level, int, S_IRUGO|S_IWUSR);
1074 MODULE_PARM_DESC(scsi_logging_level, "a bit mask of logging levels");
1076 static int __init init_scsi(void)
1080 error = scsi_init_queue();
1083 error = scsi_init_procfs();
1086 error = scsi_init_devinfo();
1088 goto cleanup_procfs;
1089 error = scsi_init_hosts();
1091 goto cleanup_devlist;
1092 error = scsi_init_sysctl();
1095 error = scsi_sysfs_register();
1097 goto cleanup_sysctl;
1099 for_each_possible_cpu(i)
1100 INIT_LIST_HEAD(&per_cpu(scsi_done_q, i));
1102 printk(KERN_NOTICE "SCSI subsystem initialized\n");
1110 scsi_exit_devinfo();
1115 printk(KERN_ERR "SCSI subsystem failed to initialize, error = %d\n",
1120 static void __exit exit_scsi(void)
1122 scsi_sysfs_unregister();
1125 scsi_exit_devinfo();
1130 subsys_initcall(init_scsi);
1131 module_exit(exit_scsi);