blob: 6660fa92ffa149a3419ca3c87f7744453e3706fb [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>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090027#include <linux/slab.h>
Christoph Hellwigc5478de2005-09-06 14:04:26 +020028#include <linux/kthread.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <linux/string.h>
30#include <linux/mm.h>
31#include <linux/init.h>
32#include <linux/completion.h>
33#include <linux/transport_class.h>
Russell Kingd052d1b2005-10-29 19:07:23 +010034#include <linux/platform_device.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070035
36#include <scsi/scsi_device.h>
37#include <scsi/scsi_host.h>
38#include <scsi/scsi_transport.h>
39
40#include "scsi_priv.h"
41#include "scsi_logging.h"
42
43
Joe Eykholt30c9afa2009-06-15 23:22:14 -070044static atomic_t scsi_host_next_hn; /* host_no for next new host */
Linus Torvalds1da177e2005-04-16 15:20:36 -070045
46
Tony Jonesee959b02008-02-22 00:13:36 +010047static void scsi_host_cls_release(struct device *dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
Tony Jonesee959b02008-02-22 00:13:36 +010049 put_device(&class_to_shost(dev)->shost_gendev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070050}
51
52static struct class shost_class = {
53 .name = "scsi_host",
Tony Jonesee959b02008-02-22 00:13:36 +010054 .dev_release = scsi_host_cls_release,
Linus Torvalds1da177e2005-04-16 15:20:36 -070055};
56
57/**
Rob Landleyeb448202007-11-03 13:30:39 -050058 * scsi_host_set_state - Take the given host through the host state model.
Mike Andersond3301872005-06-16 11:12:38 -070059 * @shost: scsi host to change the state of.
60 * @state: state to change to.
61 *
62 * Returns zero if unsuccessful or an error if the requested
63 * transition is illegal.
64 **/
65int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state)
66{
67 enum scsi_host_state oldstate = shost->shost_state;
68
69 if (state == oldstate)
70 return 0;
71
72 switch (state) {
73 case SHOST_CREATED:
74 /* There are no legal states that come back to
75 * created. This is the manually initialised start
76 * state */
77 goto illegal;
78
79 case SHOST_RUNNING:
80 switch (oldstate) {
81 case SHOST_CREATED:
82 case SHOST_RECOVERY:
83 break;
84 default:
85 goto illegal;
86 }
87 break;
88
89 case SHOST_RECOVERY:
90 switch (oldstate) {
91 case SHOST_RUNNING:
92 break;
93 default:
94 goto illegal;
95 }
96 break;
97
98 case SHOST_CANCEL:
99 switch (oldstate) {
100 case SHOST_CREATED:
101 case SHOST_RUNNING:
James Bottomley939647e2005-09-18 15:05:20 -0500102 case SHOST_CANCEL_RECOVERY:
Mike Andersond3301872005-06-16 11:12:38 -0700103 break;
104 default:
105 goto illegal;
106 }
107 break;
108
109 case SHOST_DEL:
110 switch (oldstate) {
111 case SHOST_CANCEL:
James Bottomley939647e2005-09-18 15:05:20 -0500112 case SHOST_DEL_RECOVERY:
Mike Andersond3301872005-06-16 11:12:38 -0700113 break;
114 default:
115 goto illegal;
116 }
117 break;
118
James Bottomley939647e2005-09-18 15:05:20 -0500119 case SHOST_CANCEL_RECOVERY:
120 switch (oldstate) {
121 case SHOST_CANCEL:
122 case SHOST_RECOVERY:
123 break;
124 default:
125 goto illegal;
126 }
127 break;
128
129 case SHOST_DEL_RECOVERY:
130 switch (oldstate) {
131 case SHOST_CANCEL_RECOVERY:
132 break;
133 default:
134 goto illegal;
135 }
136 break;
Mike Andersond3301872005-06-16 11:12:38 -0700137 }
138 shost->shost_state = state;
139 return 0;
140
141 illegal:
142 SCSI_LOG_ERROR_RECOVERY(1,
James Bottomley9ccfc752005-10-02 11:45:08 -0500143 shost_printk(KERN_ERR, shost,
144 "Illegal host state transition"
145 "%s->%s\n",
146 scsi_host_state_name(oldstate),
147 scsi_host_state_name(state)));
Mike Andersond3301872005-06-16 11:12:38 -0700148 return -EINVAL;
149}
150EXPORT_SYMBOL(scsi_host_set_state);
151
152/**
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 * scsi_remove_host - remove a scsi host
154 * @shost: a pointer to a scsi host to remove
155 **/
156void scsi_remove_host(struct Scsi_Host *shost)
157{
James Bottomley939647e2005-09-18 15:05:20 -0500158 unsigned long flags;
Arjan van de Ven0b950672006-01-11 13:16:10 +0100159 mutex_lock(&shost->scan_mutex);
James Bottomley939647e2005-09-18 15:05:20 -0500160 spin_lock_irqsave(shost->host_lock, flags);
161 if (scsi_host_set_state(shost, SHOST_CANCEL))
162 if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) {
163 spin_unlock_irqrestore(shost->host_lock, flags);
Arjan van de Ven0b950672006-01-11 13:16:10 +0100164 mutex_unlock(&shost->scan_mutex);
James Bottomley939647e2005-09-18 15:05:20 -0500165 return;
166 }
167 spin_unlock_irqrestore(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 scsi_forget_host(shost);
Alexey Kuznetsov4e46bf82009-11-17 14:10:11 -0800169 mutex_unlock(&shost->scan_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700170 scsi_proc_host_rm(shost);
171
James Bottomley939647e2005-09-18 15:05:20 -0500172 spin_lock_irqsave(shost->host_lock, flags);
173 if (scsi_host_set_state(shost, SHOST_DEL))
174 BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY));
175 spin_unlock_irqrestore(shost->host_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176
177 transport_unregister_device(&shost->shost_gendev);
Tony Jonesee959b02008-02-22 00:13:36 +0100178 device_unregister(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700179 device_del(&shost->shost_gendev);
180}
181EXPORT_SYMBOL(scsi_remove_host);
182
183/**
James Bottomleyd139b9b2009-11-05 13:33:12 -0600184 * scsi_add_host_with_dma - add a scsi host with dma device
Linus Torvalds1da177e2005-04-16 15:20:36 -0700185 * @shost: scsi host pointer to add
186 * @dev: a struct device of type scsi class
James Bottomleyd139b9b2009-11-05 13:33:12 -0600187 * @dma_dev: dma device for the host
188 *
189 * Note: You rarely need to worry about this unless you're in a
190 * virtualised host environments, so use the simpler scsi_add_host()
191 * function instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 *
193 * Return value:
194 * 0 on success / != 0 for error
195 **/
James Bottomleyd139b9b2009-11-05 13:33:12 -0600196int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev,
197 struct device *dma_dev)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700198{
199 struct scsi_host_template *sht = shost->hostt;
200 int error = -EINVAL;
201
202 printk(KERN_INFO "scsi%d : %s\n", shost->host_no,
203 sht->info ? sht->info(shost) : sht->name);
204
205 if (!shost->can_queue) {
206 printk(KERN_ERR "%s: can_queue = 0 no longer supported\n",
207 sht->name);
James Bottomley542bd132008-04-21 10:57:20 -0500208 goto fail;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 }
210
James Bottomley542bd132008-04-21 10:57:20 -0500211 error = scsi_setup_command_freelist(shost);
212 if (error)
213 goto fail;
214
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 if (!shost->shost_gendev.parent)
216 shost->shost_gendev.parent = dev ? dev : &platform_bus;
James Bottomleyd139b9b2009-11-05 13:33:12 -0600217 shost->dma_dev = dma_dev;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
Rafael J. Wysocki4cb077d2010-02-08 19:18:26 +0100219 device_enable_async_suspend(&shost->shost_gendev);
220
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 error = device_add(&shost->shost_gendev);
222 if (error)
223 goto out;
224
Mike Andersond3301872005-06-16 11:12:38 -0700225 scsi_host_set_state(shost, SHOST_RUNNING);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 get_device(shost->shost_gendev.parent);
227
Rafael J. Wysocki4cb077d2010-02-08 19:18:26 +0100228 device_enable_async_suspend(&shost->shost_dev);
229
Tony Jonesee959b02008-02-22 00:13:36 +0100230 error = device_add(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 if (error)
232 goto out_del_gendev;
233
234 get_device(&shost->shost_gendev);
235
James Smart77cca462008-03-21 17:18:23 -0400236 if (shost->transportt->host_size) {
237 shost->shost_data = kzalloc(shost->transportt->host_size,
238 GFP_KERNEL);
239 if (shost->shost_data == NULL) {
240 error = -ENOMEM;
Tony Jonesee959b02008-02-22 00:13:36 +0100241 goto out_del_dev;
James Smart77cca462008-03-21 17:18:23 -0400242 }
243 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
245 if (shost->transportt->create_work_queue) {
Kay Sieversaab0de22008-05-02 06:02:41 +0200246 snprintf(shost->work_q_name, sizeof(shost->work_q_name),
247 "scsi_wq_%d", shost->host_no);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248 shost->work_q = create_singlethread_workqueue(
249 shost->work_q_name);
James Smart77cca462008-03-21 17:18:23 -0400250 if (!shost->work_q) {
251 error = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 goto out_free_shost_data;
James Smart77cca462008-03-21 17:18:23 -0400253 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254 }
255
256 error = scsi_sysfs_add_host(shost);
257 if (error)
258 goto out_destroy_host;
259
260 scsi_proc_host_add(shost);
261 return error;
262
263 out_destroy_host:
264 if (shost->work_q)
265 destroy_workqueue(shost->work_q);
266 out_free_shost_data:
267 kfree(shost->shost_data);
Tony Jonesee959b02008-02-22 00:13:36 +0100268 out_del_dev:
269 device_del(&shost->shost_dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270 out_del_gendev:
271 device_del(&shost->shost_gendev);
272 out:
James Bottomley542bd132008-04-21 10:57:20 -0500273 scsi_destroy_command_freelist(shost);
274 fail:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700275 return error;
276}
James Bottomleyd139b9b2009-11-05 13:33:12 -0600277EXPORT_SYMBOL(scsi_add_host_with_dma);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278
279static void scsi_host_dev_release(struct device *dev)
280{
281 struct Scsi_Host *shost = dev_to_shost(dev);
282 struct device *parent = dev->parent;
283
Alan Stern77c01972009-02-27 16:51:42 -0500284 scsi_proc_hostdir_rm(shost->hostt);
285
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200286 if (shost->ehandler)
287 kthread_stop(shost->ehandler);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700288 if (shost->work_q)
289 destroy_workqueue(shost->work_q);
FUJITA Tomonorib58d9152006-11-16 19:24:10 +0900290 if (shost->uspace_req_q) {
291 kfree(shost->uspace_req_q->queuedata);
292 scsi_free_queue(shost->uspace_req_q);
293 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295 scsi_destroy_command_freelist(shost);
James Bottomley86e33a22006-08-30 09:45:51 -0400296 if (shost->bqt)
297 blk_free_tags(shost->bqt);
298
Linus Torvalds1da177e2005-04-16 15:20:36 -0700299 kfree(shost->shost_data);
300
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 if (parent)
302 put_device(parent);
303 kfree(shost);
304}
305
Adrian Bunk453cd0f2008-07-03 23:47:33 -0700306static struct device_type scsi_host_type = {
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100307 .name = "scsi_host",
308 .release = scsi_host_dev_release,
309};
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311/**
312 * scsi_host_alloc - register a scsi host adapter instance.
313 * @sht: pointer to scsi host template
314 * @privsize: extra bytes to allocate for driver
315 *
316 * Note:
317 * Allocate a new Scsi_Host and perform basic initialization.
318 * The host is not published to the scsi midlayer until scsi_add_host
319 * is called.
320 *
321 * Return value:
322 * Pointer to a new Scsi_Host
323 **/
324struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize)
325{
326 struct Scsi_Host *shost;
Al Viroc53033f2005-10-21 03:22:08 -0400327 gfp_t gfp_mask = GFP_KERNEL;
328 int rval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700329
330 if (sht->unchecked_isa_dma && privsize)
331 gfp_mask |= __GFP_DMA;
332
Jes Sorensen24669f752006-01-16 10:31:18 -0500333 shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700334 if (!shost)
335 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336
Christoph Hellwig4f777ed22006-11-04 20:11:36 +0100337 shost->host_lock = &shost->default_lock;
338 spin_lock_init(shost->host_lock);
Mike Andersond3301872005-06-16 11:12:38 -0700339 shost->shost_state = SHOST_CREATED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 INIT_LIST_HEAD(&shost->__devices);
341 INIT_LIST_HEAD(&shost->__targets);
342 INIT_LIST_HEAD(&shost->eh_cmd_q);
343 INIT_LIST_HEAD(&shost->starved_list);
344 init_waitqueue_head(&shost->host_wait);
345
Arjan van de Ven0b950672006-01-11 13:16:10 +0100346 mutex_init(&shost->scan_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347
Joe Eykholt30c9afa2009-06-15 23:22:14 -0700348 /*
349 * subtract one because we increment first then return, but we need to
350 * know what the next host number was before increment
351 */
352 shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700353 shost->dma_channel = 0xff;
354
355 /* These three are default values which can be overridden */
356 shost->max_channel = 0;
357 shost->max_id = 8;
358 shost->max_lun = 8;
359
360 /* Give each shost a default transportt */
361 shost->transportt = &blank_transport_template;
362
363 /*
364 * All drivers right now should be able to handle 12 byte
365 * commands. Every so often there are requests for 16 byte
366 * commands, but individual low-level drivers need to certify that
367 * they actually do something sensible with such commands.
368 */
369 shost->max_cmd_len = 12;
370 shost->hostt = sht;
371 shost->this_id = sht->this_id;
372 shost->can_queue = sht->can_queue;
373 shost->sg_tablesize = sht->sg_tablesize;
374 shost->cmd_per_lun = sht->cmd_per_lun;
375 shost->unchecked_isa_dma = sht->unchecked_isa_dma;
376 shost->use_clustering = sht->use_clustering;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377 shost->ordered_tag = sht->ordered_tag;
378
James Bottomley7a39ac32007-09-25 22:45:53 -0500379 if (sht->supported_mode == MODE_UNKNOWN)
380 /* means we didn't set it ... default to INITIATOR */
381 shost->active_mode = MODE_INITIATOR;
382 else
383 shost->active_mode = sht->supported_mode;
384
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 if (sht->max_host_blocked)
386 shost->max_host_blocked = sht->max_host_blocked;
387 else
388 shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED;
389
390 /*
391 * If the driver imposes no hard sector transfer limit, start at
392 * machine infinity initially.
393 */
394 if (sht->max_sectors)
395 shost->max_sectors = sht->max_sectors;
396 else
397 shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS;
398
399 /*
400 * assume a 4GB boundary, if not set
401 */
402 if (sht->dma_boundary)
403 shost->dma_boundary = sht->dma_boundary;
404 else
405 shost->dma_boundary = 0xffffffff;
406
Linus Torvalds1da177e2005-04-16 15:20:36 -0700407 device_initialize(&shost->shost_gendev);
Kay Sievers71610f52008-12-03 22:41:36 +0100408 dev_set_name(&shost->shost_gendev, "host%d", shost->host_no);
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100409#ifndef CONFIG_SYSFS_DEPRECATED
410 shost->shost_gendev.bus = &scsi_bus_type;
411#endif
412 shost->shost_gendev.type = &scsi_host_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413
Tony Jonesee959b02008-02-22 00:13:36 +0100414 device_initialize(&shost->shost_dev);
415 shost->shost_dev.parent = &shost->shost_gendev;
416 shost->shost_dev.class = &shost_class;
Kay Sievers71610f52008-12-03 22:41:36 +0100417 dev_set_name(&shost->shost_dev, "host%d", shost->host_no);
Hannes Reineckef7120a42008-03-18 14:32:28 +0100418 shost->shost_dev.groups = scsi_sysfs_shost_attr_groups;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200420 shost->ehandler = kthread_run(scsi_error_handler, shost,
421 "scsi_eh_%d", shost->host_no);
422 if (IS_ERR(shost->ehandler)) {
423 rval = PTR_ERR(shost->ehandler);
James Bottomley542bd132008-04-21 10:57:20 -0500424 goto fail_kfree;
Christoph Hellwigc5478de2005-09-06 14:04:26 +0200425 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700426
427 scsi_proc_hostdir_add(shost->hostt);
428 return shost;
429
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 fail_kfree:
431 kfree(shost);
432 return NULL;
433}
434EXPORT_SYMBOL(scsi_host_alloc);
435
436struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize)
437{
438 struct Scsi_Host *shost = scsi_host_alloc(sht, privsize);
439
440 if (!sht->detect) {
441 printk(KERN_WARNING "scsi_register() called on new-style "
442 "template for driver %s\n", sht->name);
443 dump_stack();
444 }
445
446 if (shost)
447 list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts);
448 return shost;
449}
450EXPORT_SYMBOL(scsi_register);
451
452void scsi_unregister(struct Scsi_Host *shost)
453{
454 list_del(&shost->sht_legacy_list);
455 scsi_host_put(shost);
456}
457EXPORT_SYMBOL(scsi_unregister);
458
Tony Jonesee959b02008-02-22 00:13:36 +0100459static int __scsi_host_match(struct device *dev, void *data)
Dave Young9c770102008-01-22 14:01:34 +0800460{
461 struct Scsi_Host *p;
462 unsigned short *hostnum = (unsigned short *)data;
463
Tony Jonesee959b02008-02-22 00:13:36 +0100464 p = class_to_shost(dev);
Dave Young9c770102008-01-22 14:01:34 +0800465 return p->host_no == *hostnum;
466}
467
Linus Torvalds1da177e2005-04-16 15:20:36 -0700468/**
469 * scsi_host_lookup - get a reference to a Scsi_Host by host no
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 * @hostnum: host number to locate
471 *
472 * Return value:
473 * A pointer to located Scsi_Host or NULL.
Mike Christie3ed78972008-06-11 19:21:00 -0500474 *
475 * The caller must do a scsi_host_put() to drop the reference
476 * that scsi_host_get() took. The put_device() below dropped
477 * the reference from class_find_device().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 **/
479struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
480{
Tony Jonesee959b02008-02-22 00:13:36 +0100481 struct device *cdev;
James Smart315cb0a2008-08-07 20:49:30 -0400482 struct Scsi_Host *shost = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483
Greg Kroah-Hartman695794a2008-05-22 17:21:08 -0400484 cdev = class_find_device(&shost_class, NULL, &hostnum,
485 __scsi_host_match);
Mike Christie3ed78972008-06-11 19:21:00 -0500486 if (cdev) {
Dave Young9c770102008-01-22 14:01:34 +0800487 shost = scsi_host_get(class_to_shost(cdev));
Mike Christie3ed78972008-06-11 19:21:00 -0500488 put_device(cdev);
489 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 return shost;
491}
492EXPORT_SYMBOL(scsi_host_lookup);
493
494/**
495 * scsi_host_get - inc a Scsi_Host ref count
496 * @shost: Pointer to Scsi_Host to inc.
497 **/
498struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost)
499{
Mike Andersond3301872005-06-16 11:12:38 -0700500 if ((shost->shost_state == SHOST_DEL) ||
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501 !get_device(&shost->shost_gendev))
502 return NULL;
503 return shost;
504}
505EXPORT_SYMBOL(scsi_host_get);
506
507/**
508 * scsi_host_put - dec a Scsi_Host ref count
509 * @shost: Pointer to Scsi_Host to dec.
510 **/
511void scsi_host_put(struct Scsi_Host *shost)
512{
513 put_device(&shost->shost_gendev);
514}
515EXPORT_SYMBOL(scsi_host_put);
516
517int scsi_init_hosts(void)
518{
519 return class_register(&shost_class);
520}
521
522void scsi_exit_hosts(void)
523{
524 class_unregister(&shost_class);
525}
526
527int scsi_is_host_device(const struct device *dev)
528{
Hannes Reineckeb0ed4332008-03-18 14:32:28 +0100529 return dev->type == &scsi_host_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530}
531EXPORT_SYMBOL(scsi_is_host_device);
532
533/**
534 * scsi_queue_work - Queue work to the Scsi_Host workqueue.
535 * @shost: Pointer to Scsi_Host.
536 * @work: Work to queue for execution.
537 *
538 * Return value:
Michael Reeddd7e2f22006-08-04 12:09:24 -0500539 * 1 - work queued for execution
540 * 0 - work is already queued
541 * -EINVAL - work queue doesn't exist
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 **/
543int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work)
544{
545 if (unlikely(!shost->work_q)) {
546 printk(KERN_ERR
547 "ERROR: Scsi host '%s' attempted to queue scsi-work, "
548 "when no workqueue created.\n", shost->hostt->name);
549 dump_stack();
550
551 return -EINVAL;
552 }
553
554 return queue_work(shost->work_q, work);
555}
556EXPORT_SYMBOL_GPL(scsi_queue_work);
557
558/**
559 * scsi_flush_work - Flush a Scsi_Host's workqueue.
560 * @shost: Pointer to Scsi_Host.
561 **/
562void scsi_flush_work(struct Scsi_Host *shost)
563{
564 if (!shost->work_q) {
565 printk(KERN_ERR
566 "ERROR: Scsi host '%s' attempted to flush scsi-work, "
567 "when no workqueue created.\n", shost->hostt->name);
568 dump_stack();
569 return;
570 }
571
572 flush_workqueue(shost->work_q);
573}
574EXPORT_SYMBOL_GPL(scsi_flush_work);