Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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> | |
5a0e3ad6 | 27 | #include <linux/slab.h> |
c5478def | 28 | #include <linux/kthread.h> |
1da177e4 LT |
29 | #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> | |
d052d1be | 34 | #include <linux/platform_device.h> |
bc4f2401 | 35 | #include <linux/pm_runtime.h> |
1da177e4 LT |
36 | |
37 | #include <scsi/scsi_device.h> | |
38 | #include <scsi/scsi_host.h> | |
39 | #include <scsi/scsi_transport.h> | |
40 | ||
41 | #include "scsi_priv.h" | |
42 | #include "scsi_logging.h" | |
43 | ||
44 | ||
9e1a1537 | 45 | static atomic_t scsi_host_next_hn = ATOMIC_INIT(0); /* host_no for next new host */ |
1da177e4 LT |
46 | |
47 | ||
ee959b00 | 48 | static void scsi_host_cls_release(struct device *dev) |
1da177e4 | 49 | { |
ee959b00 | 50 | put_device(&class_to_shost(dev)->shost_gendev); |
1da177e4 LT |
51 | } |
52 | ||
53 | static struct class shost_class = { | |
54 | .name = "scsi_host", | |
ee959b00 | 55 | .dev_release = scsi_host_cls_release, |
1da177e4 LT |
56 | }; |
57 | ||
d3301874 | 58 | /** |
eb44820c | 59 | * scsi_host_set_state - Take the given host through the host state model. |
d3301874 MA |
60 | * @shost: scsi host to change the state of. |
61 | * @state: state to change to. | |
62 | * | |
63 | * Returns zero if unsuccessful or an error if the requested | |
64 | * transition is illegal. | |
65 | **/ | |
66 | int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) | |
67 | { | |
68 | enum scsi_host_state oldstate = shost->shost_state; | |
69 | ||
70 | if (state == oldstate) | |
71 | return 0; | |
72 | ||
73 | switch (state) { | |
74 | case SHOST_CREATED: | |
75 | /* There are no legal states that come back to | |
76 | * created. This is the manually initialised start | |
77 | * state */ | |
78 | goto illegal; | |
79 | ||
80 | case SHOST_RUNNING: | |
81 | switch (oldstate) { | |
82 | case SHOST_CREATED: | |
83 | case SHOST_RECOVERY: | |
84 | break; | |
85 | default: | |
86 | goto illegal; | |
87 | } | |
88 | break; | |
89 | ||
90 | case SHOST_RECOVERY: | |
91 | switch (oldstate) { | |
92 | case SHOST_RUNNING: | |
93 | break; | |
94 | default: | |
95 | goto illegal; | |
96 | } | |
97 | break; | |
98 | ||
99 | case SHOST_CANCEL: | |
100 | switch (oldstate) { | |
101 | case SHOST_CREATED: | |
102 | case SHOST_RUNNING: | |
939647ee | 103 | case SHOST_CANCEL_RECOVERY: |
d3301874 MA |
104 | break; |
105 | default: | |
106 | goto illegal; | |
107 | } | |
108 | break; | |
109 | ||
110 | case SHOST_DEL: | |
111 | switch (oldstate) { | |
112 | case SHOST_CANCEL: | |
939647ee | 113 | case SHOST_DEL_RECOVERY: |
d3301874 MA |
114 | break; |
115 | default: | |
116 | goto illegal; | |
117 | } | |
118 | break; | |
119 | ||
939647ee JB |
120 | case SHOST_CANCEL_RECOVERY: |
121 | switch (oldstate) { | |
122 | case SHOST_CANCEL: | |
123 | case SHOST_RECOVERY: | |
124 | break; | |
125 | default: | |
126 | goto illegal; | |
127 | } | |
128 | break; | |
129 | ||
130 | case SHOST_DEL_RECOVERY: | |
131 | switch (oldstate) { | |
132 | case SHOST_CANCEL_RECOVERY: | |
133 | break; | |
134 | default: | |
135 | goto illegal; | |
136 | } | |
137 | break; | |
d3301874 MA |
138 | } |
139 | shost->shost_state = state; | |
140 | return 0; | |
141 | ||
142 | illegal: | |
143 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
144 | shost_printk(KERN_ERR, shost, |
145 | "Illegal host state transition" | |
146 | "%s->%s\n", | |
147 | scsi_host_state_name(oldstate), | |
148 | scsi_host_state_name(state))); | |
d3301874 MA |
149 | return -EINVAL; |
150 | } | |
151 | EXPORT_SYMBOL(scsi_host_set_state); | |
152 | ||
1da177e4 LT |
153 | /** |
154 | * scsi_remove_host - remove a scsi host | |
155 | * @shost: a pointer to a scsi host to remove | |
156 | **/ | |
157 | void scsi_remove_host(struct Scsi_Host *shost) | |
158 | { | |
939647ee | 159 | unsigned long flags; |
bc4f2401 | 160 | |
0b950672 | 161 | mutex_lock(&shost->scan_mutex); |
939647ee JB |
162 | spin_lock_irqsave(shost->host_lock, flags); |
163 | if (scsi_host_set_state(shost, SHOST_CANCEL)) | |
164 | if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { | |
165 | spin_unlock_irqrestore(shost->host_lock, flags); | |
0b950672 | 166 | mutex_unlock(&shost->scan_mutex); |
939647ee JB |
167 | return; |
168 | } | |
169 | spin_unlock_irqrestore(shost->host_lock, flags); | |
bc4f2401 AS |
170 | |
171 | scsi_autopm_get_host(shost); | |
e494f6a7 | 172 | flush_workqueue(shost->tmf_work_q); |
1da177e4 | 173 | scsi_forget_host(shost); |
4e46bf89 | 174 | mutex_unlock(&shost->scan_mutex); |
1da177e4 LT |
175 | scsi_proc_host_rm(shost); |
176 | ||
939647ee JB |
177 | spin_lock_irqsave(shost->host_lock, flags); |
178 | if (scsi_host_set_state(shost, SHOST_DEL)) | |
179 | BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); | |
180 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1da177e4 LT |
181 | |
182 | transport_unregister_device(&shost->shost_gendev); | |
ee959b00 | 183 | device_unregister(&shost->shost_dev); |
1da177e4 LT |
184 | device_del(&shost->shost_gendev); |
185 | } | |
186 | EXPORT_SYMBOL(scsi_remove_host); | |
187 | ||
188 | /** | |
d139b9bd | 189 | * scsi_add_host_with_dma - add a scsi host with dma device |
1da177e4 LT |
190 | * @shost: scsi host pointer to add |
191 | * @dev: a struct device of type scsi class | |
d139b9bd JB |
192 | * @dma_dev: dma device for the host |
193 | * | |
194 | * Note: You rarely need to worry about this unless you're in a | |
195 | * virtualised host environments, so use the simpler scsi_add_host() | |
196 | * function instead. | |
1da177e4 LT |
197 | * |
198 | * Return value: | |
199 | * 0 on success / != 0 for error | |
200 | **/ | |
d139b9bd JB |
201 | int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, |
202 | struct device *dma_dev) | |
1da177e4 LT |
203 | { |
204 | struct scsi_host_template *sht = shost->hostt; | |
205 | int error = -EINVAL; | |
206 | ||
207 | printk(KERN_INFO "scsi%d : %s\n", shost->host_no, | |
208 | sht->info ? sht->info(shost) : sht->name); | |
209 | ||
210 | if (!shost->can_queue) { | |
211 | printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", | |
212 | sht->name); | |
542bd137 | 213 | goto fail; |
1da177e4 LT |
214 | } |
215 | ||
542bd137 JB |
216 | error = scsi_setup_command_freelist(shost); |
217 | if (error) | |
218 | goto fail; | |
219 | ||
1da177e4 LT |
220 | if (!shost->shost_gendev.parent) |
221 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
3c8d9a95 JB |
222 | if (!dma_dev) |
223 | dma_dev = shost->shost_gendev.parent; | |
224 | ||
d139b9bd | 225 | shost->dma_dev = dma_dev; |
1da177e4 LT |
226 | |
227 | error = device_add(&shost->shost_gendev); | |
228 | if (error) | |
229 | goto out; | |
230 | ||
bc4f2401 AS |
231 | pm_runtime_set_active(&shost->shost_gendev); |
232 | pm_runtime_enable(&shost->shost_gendev); | |
233 | device_enable_async_suspend(&shost->shost_gendev); | |
234 | ||
d3301874 | 235 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
236 | get_device(shost->shost_gendev.parent); |
237 | ||
4cb077d9 RW |
238 | device_enable_async_suspend(&shost->shost_dev); |
239 | ||
ee959b00 | 240 | error = device_add(&shost->shost_dev); |
1da177e4 LT |
241 | if (error) |
242 | goto out_del_gendev; | |
243 | ||
244 | get_device(&shost->shost_gendev); | |
245 | ||
77cca462 JS |
246 | if (shost->transportt->host_size) { |
247 | shost->shost_data = kzalloc(shost->transportt->host_size, | |
248 | GFP_KERNEL); | |
249 | if (shost->shost_data == NULL) { | |
250 | error = -ENOMEM; | |
ee959b00 | 251 | goto out_del_dev; |
77cca462 JS |
252 | } |
253 | } | |
1da177e4 LT |
254 | |
255 | if (shost->transportt->create_work_queue) { | |
aab0de24 KS |
256 | snprintf(shost->work_q_name, sizeof(shost->work_q_name), |
257 | "scsi_wq_%d", shost->host_no); | |
1da177e4 LT |
258 | shost->work_q = create_singlethread_workqueue( |
259 | shost->work_q_name); | |
77cca462 JS |
260 | if (!shost->work_q) { |
261 | error = -EINVAL; | |
1da177e4 | 262 | goto out_free_shost_data; |
77cca462 | 263 | } |
1da177e4 LT |
264 | } |
265 | ||
266 | error = scsi_sysfs_add_host(shost); | |
267 | if (error) | |
268 | goto out_destroy_host; | |
269 | ||
270 | scsi_proc_host_add(shost); | |
271 | return error; | |
272 | ||
273 | out_destroy_host: | |
274 | if (shost->work_q) | |
275 | destroy_workqueue(shost->work_q); | |
276 | out_free_shost_data: | |
277 | kfree(shost->shost_data); | |
ee959b00 TJ |
278 | out_del_dev: |
279 | device_del(&shost->shost_dev); | |
1da177e4 LT |
280 | out_del_gendev: |
281 | device_del(&shost->shost_gendev); | |
282 | out: | |
542bd137 JB |
283 | scsi_destroy_command_freelist(shost); |
284 | fail: | |
1da177e4 LT |
285 | return error; |
286 | } | |
d139b9bd | 287 | EXPORT_SYMBOL(scsi_add_host_with_dma); |
1da177e4 LT |
288 | |
289 | static void scsi_host_dev_release(struct device *dev) | |
290 | { | |
291 | struct Scsi_Host *shost = dev_to_shost(dev); | |
292 | struct device *parent = dev->parent; | |
3308511c | 293 | struct request_queue *q; |
67bd9413 | 294 | void *queuedata; |
1da177e4 | 295 | |
77c01976 AS |
296 | scsi_proc_hostdir_rm(shost->hostt); |
297 | ||
e494f6a7 HR |
298 | if (shost->tmf_work_q) |
299 | destroy_workqueue(shost->tmf_work_q); | |
c5478def CH |
300 | if (shost->ehandler) |
301 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
302 | if (shost->work_q) |
303 | destroy_workqueue(shost->work_q); | |
3308511c BVA |
304 | q = shost->uspace_req_q; |
305 | if (q) { | |
67bd9413 BVA |
306 | queuedata = q->queuedata; |
307 | blk_cleanup_queue(q); | |
308 | kfree(queuedata); | |
b58d9154 | 309 | } |
1da177e4 | 310 | |
1da177e4 | 311 | scsi_destroy_command_freelist(shost); |
86e33a29 JB |
312 | if (shost->bqt) |
313 | blk_free_tags(shost->bqt); | |
314 | ||
1da177e4 LT |
315 | kfree(shost->shost_data); |
316 | ||
1da177e4 LT |
317 | if (parent) |
318 | put_device(parent); | |
319 | kfree(shost); | |
320 | } | |
321 | ||
bb3b621a | 322 | static int shost_eh_deadline = -1; |
b4562022 | 323 | |
bb3b621a | 324 | module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); |
b4562022 | 325 | MODULE_PARM_DESC(eh_deadline, |
bb3b621a | 326 | "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); |
b4562022 | 327 | |
453cd0f3 | 328 | static struct device_type scsi_host_type = { |
b0ed4336 HR |
329 | .name = "scsi_host", |
330 | .release = scsi_host_dev_release, | |
331 | }; | |
332 | ||
1da177e4 LT |
333 | /** |
334 | * scsi_host_alloc - register a scsi host adapter instance. | |
335 | * @sht: pointer to scsi host template | |
336 | * @privsize: extra bytes to allocate for driver | |
337 | * | |
338 | * Note: | |
339 | * Allocate a new Scsi_Host and perform basic initialization. | |
340 | * The host is not published to the scsi midlayer until scsi_add_host | |
341 | * is called. | |
342 | * | |
343 | * Return value: | |
344 | * Pointer to a new Scsi_Host | |
345 | **/ | |
346 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
347 | { | |
348 | struct Scsi_Host *shost; | |
c53033f6 | 349 | gfp_t gfp_mask = GFP_KERNEL; |
1da177e4 LT |
350 | |
351 | if (sht->unchecked_isa_dma && privsize) | |
352 | gfp_mask |= __GFP_DMA; | |
353 | ||
24669f75 | 354 | shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); |
1da177e4 LT |
355 | if (!shost) |
356 | return NULL; | |
1da177e4 | 357 | |
4f777ed2 CH |
358 | shost->host_lock = &shost->default_lock; |
359 | spin_lock_init(shost->host_lock); | |
d3301874 | 360 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
361 | INIT_LIST_HEAD(&shost->__devices); |
362 | INIT_LIST_HEAD(&shost->__targets); | |
363 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
364 | INIT_LIST_HEAD(&shost->starved_list); | |
365 | init_waitqueue_head(&shost->host_wait); | |
0b950672 | 366 | mutex_init(&shost->scan_mutex); |
1da177e4 | 367 | |
30c9afa6 JE |
368 | /* |
369 | * subtract one because we increment first then return, but we need to | |
370 | * know what the next host number was before increment | |
371 | */ | |
372 | shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; | |
1da177e4 LT |
373 | shost->dma_channel = 0xff; |
374 | ||
375 | /* These three are default values which can be overridden */ | |
376 | shost->max_channel = 0; | |
377 | shost->max_id = 8; | |
378 | shost->max_lun = 8; | |
379 | ||
380 | /* Give each shost a default transportt */ | |
381 | shost->transportt = &blank_transport_template; | |
382 | ||
383 | /* | |
384 | * All drivers right now should be able to handle 12 byte | |
385 | * commands. Every so often there are requests for 16 byte | |
386 | * commands, but individual low-level drivers need to certify that | |
387 | * they actually do something sensible with such commands. | |
388 | */ | |
389 | shost->max_cmd_len = 12; | |
390 | shost->hostt = sht; | |
391 | shost->this_id = sht->this_id; | |
392 | shost->can_queue = sht->can_queue; | |
393 | shost->sg_tablesize = sht->sg_tablesize; | |
13f05c8d | 394 | shost->sg_prot_tablesize = sht->sg_prot_tablesize; |
1da177e4 LT |
395 | shost->cmd_per_lun = sht->cmd_per_lun; |
396 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
397 | shost->use_clustering = sht->use_clustering; | |
1da177e4 | 398 | shost->ordered_tag = sht->ordered_tag; |
54b2b50c | 399 | shost->no_write_same = sht->no_write_same; |
1da177e4 | 400 | |
ad469a57 | 401 | if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) |
bb3b621a RM |
402 | shost->eh_deadline = -1; |
403 | else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { | |
404 | shost_printk(KERN_WARNING, shost, | |
405 | "eh_deadline %u too large, setting to %u\n", | |
406 | shost_eh_deadline, INT_MAX / HZ); | |
407 | shost->eh_deadline = INT_MAX; | |
408 | } else | |
409 | shost->eh_deadline = shost_eh_deadline * HZ; | |
410 | ||
7a39ac3f JB |
411 | if (sht->supported_mode == MODE_UNKNOWN) |
412 | /* means we didn't set it ... default to INITIATOR */ | |
413 | shost->active_mode = MODE_INITIATOR; | |
414 | else | |
415 | shost->active_mode = sht->supported_mode; | |
416 | ||
1da177e4 LT |
417 | if (sht->max_host_blocked) |
418 | shost->max_host_blocked = sht->max_host_blocked; | |
419 | else | |
420 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
421 | ||
422 | /* | |
423 | * If the driver imposes no hard sector transfer limit, start at | |
424 | * machine infinity initially. | |
425 | */ | |
426 | if (sht->max_sectors) | |
427 | shost->max_sectors = sht->max_sectors; | |
428 | else | |
429 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
430 | ||
431 | /* | |
432 | * assume a 4GB boundary, if not set | |
433 | */ | |
434 | if (sht->dma_boundary) | |
435 | shost->dma_boundary = sht->dma_boundary; | |
436 | else | |
437 | shost->dma_boundary = 0xffffffff; | |
438 | ||
1da177e4 | 439 | device_initialize(&shost->shost_gendev); |
71610f55 | 440 | dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); |
b0ed4336 | 441 | shost->shost_gendev.bus = &scsi_bus_type; |
b0ed4336 | 442 | shost->shost_gendev.type = &scsi_host_type; |
1da177e4 | 443 | |
ee959b00 TJ |
444 | device_initialize(&shost->shost_dev); |
445 | shost->shost_dev.parent = &shost->shost_gendev; | |
446 | shost->shost_dev.class = &shost_class; | |
71610f55 | 447 | dev_set_name(&shost->shost_dev, "host%d", shost->host_no); |
f7120a4f | 448 | shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; |
1da177e4 | 449 | |
c5478def CH |
450 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
451 | "scsi_eh_%d", shost->host_no); | |
452 | if (IS_ERR(shost->ehandler)) { | |
e4bf25fb JM |
453 | printk(KERN_WARNING "scsi%d: error handler thread failed to spawn, error = %ld\n", |
454 | shost->host_no, PTR_ERR(shost->ehandler)); | |
542bd137 | 455 | goto fail_kfree; |
c5478def | 456 | } |
1da177e4 | 457 | |
e494f6a7 HR |
458 | shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", |
459 | WQ_UNBOUND | WQ_MEM_RECLAIM, | |
460 | 1, shost->host_no); | |
461 | if (!shost->tmf_work_q) { | |
462 | printk(KERN_WARNING "scsi%d: failed to create tmf workq\n", | |
463 | shost->host_no); | |
464 | goto fail_kthread; | |
465 | } | |
1da177e4 LT |
466 | scsi_proc_hostdir_add(shost->hostt); |
467 | return shost; | |
468 | ||
e494f6a7 HR |
469 | fail_kthread: |
470 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
471 | fail_kfree: |
472 | kfree(shost); | |
473 | return NULL; | |
474 | } | |
475 | EXPORT_SYMBOL(scsi_host_alloc); | |
476 | ||
477 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
478 | { | |
479 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
480 | ||
481 | if (!sht->detect) { | |
482 | printk(KERN_WARNING "scsi_register() called on new-style " | |
483 | "template for driver %s\n", sht->name); | |
484 | dump_stack(); | |
485 | } | |
486 | ||
487 | if (shost) | |
488 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
489 | return shost; | |
490 | } | |
491 | EXPORT_SYMBOL(scsi_register); | |
492 | ||
493 | void scsi_unregister(struct Scsi_Host *shost) | |
494 | { | |
495 | list_del(&shost->sht_legacy_list); | |
496 | scsi_host_put(shost); | |
497 | } | |
498 | EXPORT_SYMBOL(scsi_unregister); | |
499 | ||
9f3b795a | 500 | static int __scsi_host_match(struct device *dev, const void *data) |
9c770108 DY |
501 | { |
502 | struct Scsi_Host *p; | |
9f3b795a | 503 | const unsigned short *hostnum = data; |
9c770108 | 504 | |
ee959b00 | 505 | p = class_to_shost(dev); |
9c770108 DY |
506 | return p->host_no == *hostnum; |
507 | } | |
508 | ||
1da177e4 LT |
509 | /** |
510 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
1da177e4 LT |
511 | * @hostnum: host number to locate |
512 | * | |
513 | * Return value: | |
514 | * A pointer to located Scsi_Host or NULL. | |
3ed78972 MC |
515 | * |
516 | * The caller must do a scsi_host_put() to drop the reference | |
517 | * that scsi_host_get() took. The put_device() below dropped | |
518 | * the reference from class_find_device(). | |
1da177e4 LT |
519 | **/ |
520 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
521 | { | |
ee959b00 | 522 | struct device *cdev; |
315cb0ad | 523 | struct Scsi_Host *shost = NULL; |
1da177e4 | 524 | |
695794ae GKH |
525 | cdev = class_find_device(&shost_class, NULL, &hostnum, |
526 | __scsi_host_match); | |
3ed78972 | 527 | if (cdev) { |
9c770108 | 528 | shost = scsi_host_get(class_to_shost(cdev)); |
3ed78972 MC |
529 | put_device(cdev); |
530 | } | |
1da177e4 LT |
531 | return shost; |
532 | } | |
533 | EXPORT_SYMBOL(scsi_host_lookup); | |
534 | ||
535 | /** | |
536 | * scsi_host_get - inc a Scsi_Host ref count | |
537 | * @shost: Pointer to Scsi_Host to inc. | |
538 | **/ | |
539 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
540 | { | |
d3301874 | 541 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
542 | !get_device(&shost->shost_gendev)) |
543 | return NULL; | |
544 | return shost; | |
545 | } | |
546 | EXPORT_SYMBOL(scsi_host_get); | |
547 | ||
548 | /** | |
549 | * scsi_host_put - dec a Scsi_Host ref count | |
550 | * @shost: Pointer to Scsi_Host to dec. | |
551 | **/ | |
552 | void scsi_host_put(struct Scsi_Host *shost) | |
553 | { | |
554 | put_device(&shost->shost_gendev); | |
555 | } | |
556 | EXPORT_SYMBOL(scsi_host_put); | |
557 | ||
558 | int scsi_init_hosts(void) | |
559 | { | |
560 | return class_register(&shost_class); | |
561 | } | |
562 | ||
563 | void scsi_exit_hosts(void) | |
564 | { | |
565 | class_unregister(&shost_class); | |
566 | } | |
567 | ||
568 | int scsi_is_host_device(const struct device *dev) | |
569 | { | |
b0ed4336 | 570 | return dev->type == &scsi_host_type; |
1da177e4 LT |
571 | } |
572 | EXPORT_SYMBOL(scsi_is_host_device); | |
573 | ||
574 | /** | |
575 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
576 | * @shost: Pointer to Scsi_Host. | |
577 | * @work: Work to queue for execution. | |
578 | * | |
579 | * Return value: | |
dd7e2f22 MR |
580 | * 1 - work queued for execution |
581 | * 0 - work is already queued | |
582 | * -EINVAL - work queue doesn't exist | |
1da177e4 LT |
583 | **/ |
584 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
585 | { | |
586 | if (unlikely(!shost->work_q)) { | |
587 | printk(KERN_ERR | |
588 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " | |
589 | "when no workqueue created.\n", shost->hostt->name); | |
590 | dump_stack(); | |
591 | ||
592 | return -EINVAL; | |
593 | } | |
594 | ||
595 | return queue_work(shost->work_q, work); | |
596 | } | |
597 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
598 | ||
599 | /** | |
600 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
601 | * @shost: Pointer to Scsi_Host. | |
602 | **/ | |
603 | void scsi_flush_work(struct Scsi_Host *shost) | |
604 | { | |
605 | if (!shost->work_q) { | |
606 | printk(KERN_ERR | |
607 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " | |
608 | "when no workqueue created.\n", shost->hostt->name); | |
609 | dump_stack(); | |
610 | return; | |
611 | } | |
612 | ||
613 | flush_workqueue(shost->work_q); | |
614 | } | |
615 | EXPORT_SYMBOL_GPL(scsi_flush_work); |