2 * hosts.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995 Eric Youngdale
4 * Copyright (C) 2002-2003 Christoph Hellwig
6 * mid to lowlevel SCSI driver interface
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
12 * Jiffies wrap fixes (host->resetting), 3 Dec 1998 Andrea Arcangeli
13 * Added QLOGIC QLA1280 SCSI controller kernel host support.
14 * August 4, 1999 Fred Lewis, Intel DuPont
16 * Updated to reflect the new initialization scheme for the higher
17 * level of scsi drivers (sd/sr/st)
18 * September 17, 2000 Torben Mathiasen <tmm@image.dk>
20 * Restructured scsi_host lists and associated functions.
21 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
24 #include <linux/module.h>
25 #include <linux/blkdev.h>
26 #include <linux/kernel.h>
27 #include <linux/kthread.h>
28 #include <linux/string.h>
30 #include <linux/init.h>
31 #include <linux/completion.h>
32 #include <linux/transport_class.h>
33 #include <linux/platform_device.h>
35 #include <scsi/scsi_device.h>
36 #include <scsi/scsi_host.h>
37 #include <scsi/scsi_transport.h>
39 #include "scsi_priv.h"
40 #include "scsi_logging.h"
43 static atomic_t scsi_host_next_hn
; /* host_no for next new host */
46 static void scsi_host_cls_release(struct device
*dev
)
48 put_device(&class_to_shost(dev
)->shost_gendev
);
51 static struct class shost_class
= {
53 .dev_release
= scsi_host_cls_release
,
57 * scsi_host_set_state - Take the given host through the host state model.
58 * @shost: scsi host to change the state of.
59 * @state: state to change to.
61 * Returns zero if unsuccessful or an error if the requested
62 * transition is illegal.
64 int scsi_host_set_state(struct Scsi_Host
*shost
, enum scsi_host_state state
)
66 enum scsi_host_state oldstate
= shost
->shost_state
;
68 if (state
== oldstate
)
73 /* There are no legal states that come back to
74 * created. This is the manually initialised start
101 case SHOST_CANCEL_RECOVERY
:
111 case SHOST_DEL_RECOVERY
:
118 case SHOST_CANCEL_RECOVERY
:
128 case SHOST_DEL_RECOVERY
:
130 case SHOST_CANCEL_RECOVERY
:
137 shost
->shost_state
= state
;
141 SCSI_LOG_ERROR_RECOVERY(1,
142 shost_printk(KERN_ERR
, shost
,
143 "Illegal host state transition"
145 scsi_host_state_name(oldstate
),
146 scsi_host_state_name(state
)));
149 EXPORT_SYMBOL(scsi_host_set_state
);
152 * scsi_remove_host - remove a scsi host
153 * @shost: a pointer to a scsi host to remove
155 void scsi_remove_host(struct Scsi_Host
*shost
)
158 mutex_lock(&shost
->scan_mutex
);
159 spin_lock_irqsave(shost
->host_lock
, flags
);
160 if (scsi_host_set_state(shost
, SHOST_CANCEL
))
161 if (scsi_host_set_state(shost
, SHOST_CANCEL_RECOVERY
)) {
162 spin_unlock_irqrestore(shost
->host_lock
, flags
);
163 mutex_unlock(&shost
->scan_mutex
);
166 spin_unlock_irqrestore(shost
->host_lock
, flags
);
167 scsi_forget_host(shost
);
168 mutex_unlock(&shost
->scan_mutex
);
169 scsi_proc_host_rm(shost
);
171 spin_lock_irqsave(shost
->host_lock
, flags
);
172 if (scsi_host_set_state(shost
, SHOST_DEL
))
173 BUG_ON(scsi_host_set_state(shost
, SHOST_DEL_RECOVERY
));
174 spin_unlock_irqrestore(shost
->host_lock
, flags
);
176 transport_unregister_device(&shost
->shost_gendev
);
177 device_unregister(&shost
->shost_dev
);
178 device_del(&shost
->shost_gendev
);
180 EXPORT_SYMBOL(scsi_remove_host
);
183 * scsi_add_host_with_dma - add a scsi host with dma device
184 * @shost: scsi host pointer to add
185 * @dev: a struct device of type scsi class
186 * @dma_dev: dma device for the host
188 * Note: You rarely need to worry about this unless you're in a
189 * virtualised host environments, so use the simpler scsi_add_host()
193 * 0 on success / != 0 for error
195 int scsi_add_host_with_dma(struct Scsi_Host
*shost
, struct device
*dev
,
196 struct device
*dma_dev
)
198 struct scsi_host_template
*sht
= shost
->hostt
;
201 printk(KERN_INFO
"scsi%d : %s\n", shost
->host_no
,
202 sht
->info
? sht
->info(shost
) : sht
->name
);
204 if (!shost
->can_queue
) {
205 printk(KERN_ERR
"%s: can_queue = 0 no longer supported\n",
210 error
= scsi_setup_command_freelist(shost
);
214 if (!shost
->shost_gendev
.parent
)
215 shost
->shost_gendev
.parent
= dev
? dev
: &platform_bus
;
216 shost
->dma_dev
= dma_dev
;
218 device_enable_async_suspend(&shost
->shost_gendev
);
220 error
= device_add(&shost
->shost_gendev
);
224 scsi_host_set_state(shost
, SHOST_RUNNING
);
225 get_device(shost
->shost_gendev
.parent
);
227 device_enable_async_suspend(&shost
->shost_dev
);
229 error
= device_add(&shost
->shost_dev
);
233 get_device(&shost
->shost_gendev
);
235 if (shost
->transportt
->host_size
) {
236 shost
->shost_data
= kzalloc(shost
->transportt
->host_size
,
238 if (shost
->shost_data
== NULL
) {
244 if (shost
->transportt
->create_work_queue
) {
245 snprintf(shost
->work_q_name
, sizeof(shost
->work_q_name
),
246 "scsi_wq_%d", shost
->host_no
);
247 shost
->work_q
= create_singlethread_workqueue(
249 if (!shost
->work_q
) {
251 goto out_free_shost_data
;
255 error
= scsi_sysfs_add_host(shost
);
257 goto out_destroy_host
;
259 scsi_proc_host_add(shost
);
264 destroy_workqueue(shost
->work_q
);
266 kfree(shost
->shost_data
);
268 device_del(&shost
->shost_dev
);
270 device_del(&shost
->shost_gendev
);
272 scsi_destroy_command_freelist(shost
);
276 EXPORT_SYMBOL(scsi_add_host_with_dma
);
278 static void scsi_host_dev_release(struct device
*dev
)
280 struct Scsi_Host
*shost
= dev_to_shost(dev
);
281 struct device
*parent
= dev
->parent
;
283 scsi_proc_hostdir_rm(shost
->hostt
);
286 kthread_stop(shost
->ehandler
);
288 destroy_workqueue(shost
->work_q
);
289 if (shost
->uspace_req_q
) {
290 kfree(shost
->uspace_req_q
->queuedata
);
291 scsi_free_queue(shost
->uspace_req_q
);
294 scsi_destroy_command_freelist(shost
);
296 blk_free_tags(shost
->bqt
);
298 kfree(shost
->shost_data
);
305 static struct device_type scsi_host_type
= {
307 .release
= scsi_host_dev_release
,
311 * scsi_host_alloc - register a scsi host adapter instance.
312 * @sht: pointer to scsi host template
313 * @privsize: extra bytes to allocate for driver
316 * Allocate a new Scsi_Host and perform basic initialization.
317 * The host is not published to the scsi midlayer until scsi_add_host
321 * Pointer to a new Scsi_Host
323 struct Scsi_Host
*scsi_host_alloc(struct scsi_host_template
*sht
, int privsize
)
325 struct Scsi_Host
*shost
;
326 gfp_t gfp_mask
= GFP_KERNEL
;
329 if (sht
->unchecked_isa_dma
&& privsize
)
330 gfp_mask
|= __GFP_DMA
;
332 shost
= kzalloc(sizeof(struct Scsi_Host
) + privsize
, gfp_mask
);
336 shost
->host_lock
= &shost
->default_lock
;
337 spin_lock_init(shost
->host_lock
);
338 shost
->shost_state
= SHOST_CREATED
;
339 INIT_LIST_HEAD(&shost
->__devices
);
340 INIT_LIST_HEAD(&shost
->__targets
);
341 INIT_LIST_HEAD(&shost
->eh_cmd_q
);
342 INIT_LIST_HEAD(&shost
->starved_list
);
343 init_waitqueue_head(&shost
->host_wait
);
345 mutex_init(&shost
->scan_mutex
);
348 * subtract one because we increment first then return, but we need to
349 * know what the next host number was before increment
351 shost
->host_no
= atomic_inc_return(&scsi_host_next_hn
) - 1;
352 shost
->dma_channel
= 0xff;
354 /* These three are default values which can be overridden */
355 shost
->max_channel
= 0;
359 /* Give each shost a default transportt */
360 shost
->transportt
= &blank_transport_template
;
363 * All drivers right now should be able to handle 12 byte
364 * commands. Every so often there are requests for 16 byte
365 * commands, but individual low-level drivers need to certify that
366 * they actually do something sensible with such commands.
368 shost
->max_cmd_len
= 12;
370 shost
->this_id
= sht
->this_id
;
371 shost
->can_queue
= sht
->can_queue
;
372 shost
->sg_tablesize
= sht
->sg_tablesize
;
373 shost
->cmd_per_lun
= sht
->cmd_per_lun
;
374 shost
->unchecked_isa_dma
= sht
->unchecked_isa_dma
;
375 shost
->use_clustering
= sht
->use_clustering
;
376 shost
->ordered_tag
= sht
->ordered_tag
;
378 if (sht
->supported_mode
== MODE_UNKNOWN
)
379 /* means we didn't set it ... default to INITIATOR */
380 shost
->active_mode
= MODE_INITIATOR
;
382 shost
->active_mode
= sht
->supported_mode
;
384 if (sht
->max_host_blocked
)
385 shost
->max_host_blocked
= sht
->max_host_blocked
;
387 shost
->max_host_blocked
= SCSI_DEFAULT_HOST_BLOCKED
;
390 * If the driver imposes no hard sector transfer limit, start at
391 * machine infinity initially.
393 if (sht
->max_sectors
)
394 shost
->max_sectors
= sht
->max_sectors
;
396 shost
->max_sectors
= SCSI_DEFAULT_MAX_SECTORS
;
399 * assume a 4GB boundary, if not set
401 if (sht
->dma_boundary
)
402 shost
->dma_boundary
= sht
->dma_boundary
;
404 shost
->dma_boundary
= 0xffffffff;
406 device_initialize(&shost
->shost_gendev
);
407 dev_set_name(&shost
->shost_gendev
, "host%d", shost
->host_no
);
408 #ifndef CONFIG_SYSFS_DEPRECATED
409 shost
->shost_gendev
.bus
= &scsi_bus_type
;
411 shost
->shost_gendev
.type
= &scsi_host_type
;
413 device_initialize(&shost
->shost_dev
);
414 shost
->shost_dev
.parent
= &shost
->shost_gendev
;
415 shost
->shost_dev
.class = &shost_class
;
416 dev_set_name(&shost
->shost_dev
, "host%d", shost
->host_no
);
417 shost
->shost_dev
.groups
= scsi_sysfs_shost_attr_groups
;
419 shost
->ehandler
= kthread_run(scsi_error_handler
, shost
,
420 "scsi_eh_%d", shost
->host_no
);
421 if (IS_ERR(shost
->ehandler
)) {
422 rval
= PTR_ERR(shost
->ehandler
);
426 scsi_proc_hostdir_add(shost
->hostt
);
433 EXPORT_SYMBOL(scsi_host_alloc
);
435 struct Scsi_Host
*scsi_register(struct scsi_host_template
*sht
, int privsize
)
437 struct Scsi_Host
*shost
= scsi_host_alloc(sht
, privsize
);
440 printk(KERN_WARNING
"scsi_register() called on new-style "
441 "template for driver %s\n", sht
->name
);
446 list_add_tail(&shost
->sht_legacy_list
, &sht
->legacy_hosts
);
449 EXPORT_SYMBOL(scsi_register
);
451 void scsi_unregister(struct Scsi_Host
*shost
)
453 list_del(&shost
->sht_legacy_list
);
454 scsi_host_put(shost
);
456 EXPORT_SYMBOL(scsi_unregister
);
458 static int __scsi_host_match(struct device
*dev
, void *data
)
461 unsigned short *hostnum
= (unsigned short *)data
;
463 p
= class_to_shost(dev
);
464 return p
->host_no
== *hostnum
;
468 * scsi_host_lookup - get a reference to a Scsi_Host by host no
469 * @hostnum: host number to locate
472 * A pointer to located Scsi_Host or NULL.
474 * The caller must do a scsi_host_put() to drop the reference
475 * that scsi_host_get() took. The put_device() below dropped
476 * the reference from class_find_device().
478 struct Scsi_Host
*scsi_host_lookup(unsigned short hostnum
)
481 struct Scsi_Host
*shost
= NULL
;
483 cdev
= class_find_device(&shost_class
, NULL
, &hostnum
,
486 shost
= scsi_host_get(class_to_shost(cdev
));
491 EXPORT_SYMBOL(scsi_host_lookup
);
494 * scsi_host_get - inc a Scsi_Host ref count
495 * @shost: Pointer to Scsi_Host to inc.
497 struct Scsi_Host
*scsi_host_get(struct Scsi_Host
*shost
)
499 if ((shost
->shost_state
== SHOST_DEL
) ||
500 !get_device(&shost
->shost_gendev
))
504 EXPORT_SYMBOL(scsi_host_get
);
507 * scsi_host_put - dec a Scsi_Host ref count
508 * @shost: Pointer to Scsi_Host to dec.
510 void scsi_host_put(struct Scsi_Host
*shost
)
512 put_device(&shost
->shost_gendev
);
514 EXPORT_SYMBOL(scsi_host_put
);
516 int scsi_init_hosts(void)
518 return class_register(&shost_class
);
521 void scsi_exit_hosts(void)
523 class_unregister(&shost_class
);
526 int scsi_is_host_device(const struct device
*dev
)
528 return dev
->type
== &scsi_host_type
;
530 EXPORT_SYMBOL(scsi_is_host_device
);
533 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
534 * @shost: Pointer to Scsi_Host.
535 * @work: Work to queue for execution.
538 * 1 - work queued for execution
539 * 0 - work is already queued
540 * -EINVAL - work queue doesn't exist
542 int scsi_queue_work(struct Scsi_Host
*shost
, struct work_struct
*work
)
544 if (unlikely(!shost
->work_q
)) {
546 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
547 "when no workqueue created.\n", shost
->hostt
->name
);
553 return queue_work(shost
->work_q
, work
);
555 EXPORT_SYMBOL_GPL(scsi_queue_work
);
558 * scsi_flush_work - Flush a Scsi_Host's workqueue.
559 * @shost: Pointer to Scsi_Host.
561 void scsi_flush_work(struct Scsi_Host
*shost
)
563 if (!shost
->work_q
) {
565 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
566 "when no workqueue created.\n", shost
->hostt
->name
);
571 flush_workqueue(shost
->work_q
);
573 EXPORT_SYMBOL_GPL(scsi_flush_work
);