blob: 09dbcb847b73c307ecb835e6463735f00ce9139c [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * hosts.c Copyright (C) 1992 Drew Eckhardt
3 * Copyright (C) 1993, 1994, 1995 Eric Youngdale
4 * Copyright (C) 2002-2003 Christoph Hellwig
5 *
6 * mid to lowlevel SCSI driver interface
7 * Initial versions: Drew Eckhardt
8 * Subsequent revisions: Eric Youngdale
9 *
10 * <drew@colorado.edu>
11 *
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
15 *
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>
19 *
20 * Restructured scsi_host lists and associated functions.
21 * September 04, 2002 Mike Anderson (andmike@us.ibm.com)
22 */
23
24#include <linux/module.h>
25#include <linux/blkdev.h>
26#include <linux/kernel.h>
Christoph Hellwigc5478de2005-09-06 14:04:26 +020027#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070028#include <linux/string.h>
29#include <linux/mm.h>
30#include <linux/init.h>
31#include <linux/completion.h>
32#include <linux/transport_class.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010033#include <linux/platform_device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35#include <scsi/scsi_device.h>
36#include <scsi/scsi_host.h>
37#include <scsi/scsi_transport.h>
38
39#include "scsi_priv.h"
40#include "scsi_logging.h"
41
42
Joe Eykholt30c9afa2009-06-15 23:22:14 -070043static atomic_t scsi_host_next_hn; /* host_no for next new host */
Linus Torvalds1da177e2005-04-16 15:20:36 -070044
45
Tony Jonesee959b02008-02-22 00:13:36 +010046static void scsi_host_cls_release(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070047{
Tony Jonesee959b02008-02-22 00:13:36 +010048 put_device(&class_to_shost(dev)->shost_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070049}
50
51static struct class shost_class = {
52 .name = "scsi_host",
Tony Jonesee959b02008-02-22 00:13:36 +010053 .dev_release = scsi_host_cls_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -070054};
55
56/**
Rob Landleyeb448202007-11-03 13:30:39 -050057 * scsi_host_set_state - Take the given host through the host state model.
Mike Andersond3301872005-06-16 11:12:38 -070058 * @shost: scsi host to change the state of.
59 * @state: state to change to.
60 *
61 * Returns zero if unsuccessful or an error if the requested
62 * transition is illegal.
63 **/
64int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
65{
66 enum scsi_host_state oldstate = shost->shost_state;
67
68 if (state == oldstate)
69 return 0;
70
71 switch (state) {
72 case SHOST_CREATED:
73 /* There are no legal states that come back to
74 * created. This is the manually initialised start
75 * state */
76 goto illegal;
77
78 case SHOST_RUNNING:
79 switch (oldstate) {
80 case SHOST_CREATED:
81 case SHOST_RECOVERY:
82 break;
83 default:
84 goto illegal;
85 }
86 break;
87
88 case SHOST_RECOVERY:
89 switch (oldstate) {
90 case SHOST_RUNNING:
91 break;
92 default:
93 goto illegal;
94 }
95 break;
96
97 case SHOST_CANCEL:
98 switch (oldstate) {
99 case SHOST_CREATED:
100 case SHOST_RUNNING:
James Bottomley939647e2005-09-18 15:05:20 -0500101 case SHOST_CANCEL_RECOVERY:
Mike Andersond3301872005-06-16 11:12:38 -0700102 break;
103 default:
104 goto illegal;
105 }
106 break;
107
108 case SHOST_DEL:
109 switch (oldstate) {
110 case SHOST_CANCEL:
James Bottomley939647e2005-09-18 15:05:20 -0500111 case SHOST_DEL_RECOVERY:
Mike Andersond3301872005-06-16 11:12:38 -0700112 break;
113 default:
114 goto illegal;
115 }
116 break;
117
James Bottomley939647e2005-09-18 15:05:20 -0500118 case SHOST_CANCEL_RECOVERY:
119 switch (oldstate) {
120 case SHOST_CANCEL:
121 case SHOST_RECOVERY:
122 break;
123 default:
124 goto illegal;
125 }
126 break;
127
128 case SHOST_DEL_RECOVERY:
129 switch (oldstate) {
130 case SHOST_CANCEL_RECOVERY:
131 break;
132 default:
133 goto illegal;
134 }
135 break;
Mike Andersond3301872005-06-16 11:12:38 -0700136 }
137 shost->shost_state = state;
138 return 0;
139
140 illegal:
141 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -0500142 shost_printk(KERN_ERR, shost,
143 "Illegal host state transition"
144 "%s->%s\n",
145 scsi_host_state_name(oldstate),
146 scsi_host_state_name(state)));
Mike Andersond3301872005-06-16 11:12:38 -0700147 return -EINVAL;
148}
149EXPORT_SYMBOL(scsi_host_set_state);
150
151/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 * scsi_remove_host - remove a scsi host
153 * @shost: a pointer to a scsi host to remove
154 **/
155void scsi_remove_host(struct Scsi_Host *shost)
156{
James Bottomley939647e2005-09-18 15:05:20 -0500157 unsigned long flags;
Arjan van de Ven0b950672006-01-11 13:16:10 +0100158 mutex_lock(&shost->scan_mutex);
James Bottomley939647e2005-09-18 15:05:20 -0500159 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);
Arjan van de Ven0b950672006-01-11 13:16:10 +0100163 mutex_unlock(&shost->scan_mutex);
James Bottomley939647e2005-09-18 15:05:20 -0500164 return;
165 }
166 spin_unlock_irqrestore(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 scsi_forget_host(shost);
Alexey Kuznetsov4e46bf82009-11-17 14:10:11 -0800168 mutex_unlock(&shost->scan_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700169 scsi_proc_host_rm(shost);
170
James Bottomley939647e2005-09-18 15:05:20 -0500171 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);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700175
176 transport_unregister_device(&shost->shost_gendev);
Tony Jonesee959b02008-02-22 00:13:36 +0100177 device_unregister(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 device_del(&shost->shost_gendev);
179}
180EXPORT_SYMBOL(scsi_remove_host);
181
182/**
James Bottomleyd139b9b2009-11-05 13:33:12 -0600183 * scsi_add_host_with_dma - add a scsi host with dma device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184 * @shost: scsi host pointer to add
185 * @dev: a struct device of type scsi class
James Bottomleyd139b9b2009-11-05 13:33:12 -0600186 * @dma_dev: dma device for the host
187 *
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()
190 * function instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 *
192 * Return value:
193 * 0 on success / != 0 for error
194 **/
James Bottomleyd139b9b2009-11-05 13:33:12 -0600195int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
196 struct device *dma_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700197{
198 struct scsi_host_template *sht = shost->hostt;
199 int error = -EINVAL;
200
201 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
202 sht->info ? sht->info(shost) : sht->name);
203
204 if (!shost->can_queue) {
205 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
206 sht->name);
James Bottomley542bd132008-04-21 10:57:20 -0500207 goto fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 }
209
James Bottomley542bd132008-04-21 10:57:20 -0500210 error = scsi_setup_command_freelist(shost);
211 if (error)
212 goto fail;
213
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 if (!shost->shost_gendev.parent)
215 shost->shost_gendev.parent = dev ? dev : &platform_bus;
James Bottomleyd139b9b2009-11-05 13:33:12 -0600216 shost->dma_dev = dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217
Rafael J. Wysocki4cb077d2010-02-08 19:18:26 +0100218 device_enable_async_suspend(&shost->shost_gendev);
219
Linus Torvalds1da177e2005-04-16 15:20:36 -0700220 error = device_add(&shost->shost_gendev);
221 if (error)
222 goto out;
223
Mike Andersond3301872005-06-16 11:12:38 -0700224 scsi_host_set_state(shost, SHOST_RUNNING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225 get_device(shost->shost_gendev.parent);
226
Rafael J. Wysocki4cb077d2010-02-08 19:18:26 +0100227 device_enable_async_suspend(&shost->shost_dev);
228
Tony Jonesee959b02008-02-22 00:13:36 +0100229 error = device_add(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 if (error)
231 goto out_del_gendev;
232
233 get_device(&shost->shost_gendev);
234
James Smart77cca462008-03-21 17:18:23 -0400235 if (shost->transportt->host_size) {
236 shost->shost_data = kzalloc(shost->transportt->host_size,
237 GFP_KERNEL);
238 if (shost->shost_data == NULL) {
239 error = -ENOMEM;
Tony Jonesee959b02008-02-22 00:13:36 +0100240 goto out_del_dev;
James Smart77cca462008-03-21 17:18:23 -0400241 }
242 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
244 if (shost->transportt->create_work_queue) {
Kay Sieversaab0de22008-05-02 06:02:41 +0200245 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
246 "scsi_wq_%d", shost->host_no);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247 shost->work_q = create_singlethread_workqueue(
248 shost->work_q_name);
James Smart77cca462008-03-21 17:18:23 -0400249 if (!shost->work_q) {
250 error = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 goto out_free_shost_data;
James Smart77cca462008-03-21 17:18:23 -0400252 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253 }
254
255 error = scsi_sysfs_add_host(shost);
256 if (error)
257 goto out_destroy_host;
258
259 scsi_proc_host_add(shost);
260 return error;
261
262 out_destroy_host:
263 if (shost->work_q)
264 destroy_workqueue(shost->work_q);
265 out_free_shost_data:
266 kfree(shost->shost_data);
Tony Jonesee959b02008-02-22 00:13:36 +0100267 out_del_dev:
268 device_del(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269 out_del_gendev:
270 device_del(&shost->shost_gendev);
271 out:
James Bottomley542bd132008-04-21 10:57:20 -0500272 scsi_destroy_command_freelist(shost);
273 fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 return error;
275}
James Bottomleyd139b9b2009-11-05 13:33:12 -0600276EXPORT_SYMBOL(scsi_add_host_with_dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700277
278static void scsi_host_dev_release(struct device *dev)
279{
280 struct Scsi_Host *shost = dev_to_shost(dev);
281 struct device *parent = dev->parent;
282
Alan Stern77c01972009-02-27 16:51:42 -0500283 scsi_proc_hostdir_rm(shost->hostt);
284
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200285 if (shost->ehandler)
286 kthread_stop(shost->ehandler);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 if (shost->work_q)
288 destroy_workqueue(shost->work_q);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900289 if (shost->uspace_req_q) {
290 kfree(shost->uspace_req_q->queuedata);
291 scsi_free_queue(shost->uspace_req_q);
292 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 scsi_destroy_command_freelist(shost);
James Bottomley86e33a22006-08-30 09:45:51 -0400295 if (shost->bqt)
296 blk_free_tags(shost->bqt);
297
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 kfree(shost->shost_data);
299
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 if (parent)
301 put_device(parent);
302 kfree(shost);
303}
304
Adrian Bunk453cd0f2008-07-03 23:47:33 -0700305static struct device_type scsi_host_type = {
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100306 .name = "scsi_host",
307 .release = scsi_host_dev_release,
308};
309
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310/**
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
314 *
315 * Note:
316 * Allocate a new Scsi_Host and perform basic initialization.
317 * The host is not published to the scsi midlayer until scsi_add_host
318 * is called.
319 *
320 * Return value:
321 * Pointer to a new Scsi_Host
322 **/
323struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
324{
325 struct Scsi_Host *shost;
Al Viroc53033f2005-10-21 03:22:08 -0400326 gfp_t gfp_mask = GFP_KERNEL;
327 int rval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700328
329 if (sht->unchecked_isa_dma && privsize)
330 gfp_mask |= __GFP_DMA;
331
Jes Sorensen24669f752006-01-16 10:31:18 -0500332 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 if (!shost)
334 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335
Christoph Hellwig4f777ed22006-11-04 20:11:36 +0100336 shost->host_lock = &shost->default_lock;
337 spin_lock_init(shost->host_lock);
Mike Andersond3301872005-06-16 11:12:38 -0700338 shost->shost_state = SHOST_CREATED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700339 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);
344
Arjan van de Ven0b950672006-01-11 13:16:10 +0100345 mutex_init(&shost->scan_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346
Joe Eykholt30c9afa2009-06-15 23:22:14 -0700347 /*
348 * subtract one because we increment first then return, but we need to
349 * know what the next host number was before increment
350 */
351 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 shost->dma_channel = 0xff;
353
354 /* These three are default values which can be overridden */
355 shost->max_channel = 0;
356 shost->max_id = 8;
357 shost->max_lun = 8;
358
359 /* Give each shost a default transportt */
360 shost->transportt = &blank_transport_template;
361
362 /*
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.
367 */
368 shost->max_cmd_len = 12;
369 shost->hostt = sht;
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;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 shost->ordered_tag = sht->ordered_tag;
377
James Bottomley7a39ac32007-09-25 22:45:53 -0500378 if (sht->supported_mode == MODE_UNKNOWN)
379 /* means we didn't set it ... default to INITIATOR */
380 shost->active_mode = MODE_INITIATOR;
381 else
382 shost->active_mode = sht->supported_mode;
383
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384 if (sht->max_host_blocked)
385 shost->max_host_blocked = sht->max_host_blocked;
386 else
387 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
388
389 /*
390 * If the driver imposes no hard sector transfer limit, start at
391 * machine infinity initially.
392 */
393 if (sht->max_sectors)
394 shost->max_sectors = sht->max_sectors;
395 else
396 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
397
398 /*
399 * assume a 4GB boundary, if not set
400 */
401 if (sht->dma_boundary)
402 shost->dma_boundary = sht->dma_boundary;
403 else
404 shost->dma_boundary = 0xffffffff;
405
Linus Torvalds1da177e2005-04-16 15:20:36 -0700406 device_initialize(&shost->shost_gendev);
Kay Sievers71610f52008-12-03 22:41:36 +0100407 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100408#ifndef CONFIG_SYSFS_DEPRECATED
409 shost->shost_gendev.bus = &scsi_bus_type;
410#endif
411 shost->shost_gendev.type = &scsi_host_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412
Tony Jonesee959b02008-02-22 00:13:36 +0100413 device_initialize(&shost->shost_dev);
414 shost->shost_dev.parent = &shost->shost_gendev;
415 shost->shost_dev.class = &shost_class;
Kay Sievers71610f52008-12-03 22:41:36 +0100416 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
Hannes Reineckef7120a42008-03-18 14:32:28 +0100417 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200419 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);
James Bottomley542bd132008-04-21 10:57:20 -0500423 goto fail_kfree;
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200424 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700425
426 scsi_proc_hostdir_add(shost->hostt);
427 return shost;
428
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429 fail_kfree:
430 kfree(shost);
431 return NULL;
432}
433EXPORT_SYMBOL(scsi_host_alloc);
434
435struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
436{
437 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
438
439 if (!sht->detect) {
440 printk(KERN_WARNING "scsi_register() called on new-style "
441 "template for driver %s\n", sht->name);
442 dump_stack();
443 }
444
445 if (shost)
446 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
447 return shost;
448}
449EXPORT_SYMBOL(scsi_register);
450
451void scsi_unregister(struct Scsi_Host *shost)
452{
453 list_del(&shost->sht_legacy_list);
454 scsi_host_put(shost);
455}
456EXPORT_SYMBOL(scsi_unregister);
457
Tony Jonesee959b02008-02-22 00:13:36 +0100458static int __scsi_host_match(struct device *dev, void *data)
Dave Young9c770102008-01-22 14:01:34 +0800459{
460 struct Scsi_Host *p;
461 unsigned short *hostnum = (unsigned short *)data;
462
Tony Jonesee959b02008-02-22 00:13:36 +0100463 p = class_to_shost(dev);
Dave Young9c770102008-01-22 14:01:34 +0800464 return p->host_no == *hostnum;
465}
466
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467/**
468 * scsi_host_lookup - get a reference to a Scsi_Host by host no
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 * @hostnum: host number to locate
470 *
471 * Return value:
472 * A pointer to located Scsi_Host or NULL.
Mike Christie3ed78972008-06-11 19:21:00 -0500473 *
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().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700477 **/
478struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
479{
Tony Jonesee959b02008-02-22 00:13:36 +0100480 struct device *cdev;
James Smart315cb0a2008-08-07 20:49:30 -0400481 struct Scsi_Host *shost = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400483 cdev = class_find_device(&shost_class, NULL, &hostnum,
484 __scsi_host_match);
Mike Christie3ed78972008-06-11 19:21:00 -0500485 if (cdev) {
Dave Young9c770102008-01-22 14:01:34 +0800486 shost = scsi_host_get(class_to_shost(cdev));
Mike Christie3ed78972008-06-11 19:21:00 -0500487 put_device(cdev);
488 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 return shost;
490}
491EXPORT_SYMBOL(scsi_host_lookup);
492
493/**
494 * scsi_host_get - inc a Scsi_Host ref count
495 * @shost: Pointer to Scsi_Host to inc.
496 **/
497struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
498{
Mike Andersond3301872005-06-16 11:12:38 -0700499 if ((shost->shost_state == SHOST_DEL) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700500 !get_device(&shost->shost_gendev))
501 return NULL;
502 return shost;
503}
504EXPORT_SYMBOL(scsi_host_get);
505
506/**
507 * scsi_host_put - dec a Scsi_Host ref count
508 * @shost: Pointer to Scsi_Host to dec.
509 **/
510void scsi_host_put(struct Scsi_Host *shost)
511{
512 put_device(&shost->shost_gendev);
513}
514EXPORT_SYMBOL(scsi_host_put);
515
516int scsi_init_hosts(void)
517{
518 return class_register(&shost_class);
519}
520
521void scsi_exit_hosts(void)
522{
523 class_unregister(&shost_class);
524}
525
526int scsi_is_host_device(const struct device *dev)
527{
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100528 return dev->type == &scsi_host_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700529}
530EXPORT_SYMBOL(scsi_is_host_device);
531
532/**
533 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
534 * @shost: Pointer to Scsi_Host.
535 * @work: Work to queue for execution.
536 *
537 * Return value:
Michael Reeddd7e2f22006-08-04 12:09:24 -0500538 * 1 - work queued for execution
539 * 0 - work is already queued
540 * -EINVAL - work queue doesn't exist
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 **/
542int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
543{
544 if (unlikely(!shost->work_q)) {
545 printk(KERN_ERR
546 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
547 "when no workqueue created.\n", shost->hostt->name);
548 dump_stack();
549
550 return -EINVAL;
551 }
552
553 return queue_work(shost->work_q, work);
554}
555EXPORT_SYMBOL_GPL(scsi_queue_work);
556
557/**
558 * scsi_flush_work - Flush a Scsi_Host's workqueue.
559 * @shost: Pointer to Scsi_Host.
560 **/
561void scsi_flush_work(struct Scsi_Host *shost)
562{
563 if (!shost->work_q) {
564 printk(KERN_ERR
565 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
566 "when no workqueue created.\n", shost->hostt->name);
567 dump_stack();
568 return;
569 }
570
571 flush_workqueue(shost->work_q);
572}
573EXPORT_SYMBOL_GPL(scsi_flush_work);