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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 | ||
91921e01 | 207 | shost_printk(KERN_INFO, shost, "%s\n", |
1da177e4 LT |
208 | sht->info ? sht->info(shost) : sht->name); |
209 | ||
210 | if (!shost->can_queue) { | |
91921e01 HR |
211 | shost_printk(KERN_ERR, shost, |
212 | "can_queue = 0 no longer supported\n"); | |
542bd137 | 213 | goto fail; |
1da177e4 LT |
214 | } |
215 | ||
d285203c CH |
216 | if (shost_use_blk_mq(shost)) { |
217 | error = scsi_mq_setup_tags(shost); | |
218 | if (error) | |
219 | goto fail; | |
220 | } | |
221 | ||
222 | /* | |
223 | * Note that we allocate the freelist even for the MQ case for now, | |
224 | * as we need a command set aside for scsi_reset_provider. Having | |
225 | * the full host freelist and one command available for that is a | |
226 | * little heavy-handed, but avoids introducing a special allocator | |
227 | * just for this. Eventually the structure of scsi_reset_provider | |
228 | * will need a major overhaul. | |
229 | */ | |
542bd137 JB |
230 | error = scsi_setup_command_freelist(shost); |
231 | if (error) | |
d285203c CH |
232 | goto out_destroy_tags; |
233 | ||
542bd137 | 234 | |
1da177e4 LT |
235 | if (!shost->shost_gendev.parent) |
236 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
3c8d9a95 JB |
237 | if (!dma_dev) |
238 | dma_dev = shost->shost_gendev.parent; | |
239 | ||
d139b9bd | 240 | shost->dma_dev = dma_dev; |
1da177e4 LT |
241 | |
242 | error = device_add(&shost->shost_gendev); | |
243 | if (error) | |
d285203c | 244 | goto out_destroy_freelist; |
1da177e4 | 245 | |
bc4f2401 AS |
246 | pm_runtime_set_active(&shost->shost_gendev); |
247 | pm_runtime_enable(&shost->shost_gendev); | |
248 | device_enable_async_suspend(&shost->shost_gendev); | |
249 | ||
d3301874 | 250 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
251 | get_device(shost->shost_gendev.parent); |
252 | ||
4cb077d9 RW |
253 | device_enable_async_suspend(&shost->shost_dev); |
254 | ||
ee959b00 | 255 | error = device_add(&shost->shost_dev); |
1da177e4 LT |
256 | if (error) |
257 | goto out_del_gendev; | |
258 | ||
259 | get_device(&shost->shost_gendev); | |
260 | ||
77cca462 JS |
261 | if (shost->transportt->host_size) { |
262 | shost->shost_data = kzalloc(shost->transportt->host_size, | |
263 | GFP_KERNEL); | |
264 | if (shost->shost_data == NULL) { | |
265 | error = -ENOMEM; | |
ee959b00 | 266 | goto out_del_dev; |
77cca462 JS |
267 | } |
268 | } | |
1da177e4 LT |
269 | |
270 | if (shost->transportt->create_work_queue) { | |
aab0de24 KS |
271 | snprintf(shost->work_q_name, sizeof(shost->work_q_name), |
272 | "scsi_wq_%d", shost->host_no); | |
1da177e4 LT |
273 | shost->work_q = create_singlethread_workqueue( |
274 | shost->work_q_name); | |
77cca462 JS |
275 | if (!shost->work_q) { |
276 | error = -EINVAL; | |
1da177e4 | 277 | goto out_free_shost_data; |
77cca462 | 278 | } |
1da177e4 LT |
279 | } |
280 | ||
281 | error = scsi_sysfs_add_host(shost); | |
282 | if (error) | |
283 | goto out_destroy_host; | |
284 | ||
285 | scsi_proc_host_add(shost); | |
286 | return error; | |
287 | ||
288 | out_destroy_host: | |
289 | if (shost->work_q) | |
290 | destroy_workqueue(shost->work_q); | |
291 | out_free_shost_data: | |
292 | kfree(shost->shost_data); | |
ee959b00 TJ |
293 | out_del_dev: |
294 | device_del(&shost->shost_dev); | |
1da177e4 LT |
295 | out_del_gendev: |
296 | device_del(&shost->shost_gendev); | |
d285203c | 297 | out_destroy_freelist: |
542bd137 | 298 | scsi_destroy_command_freelist(shost); |
d285203c CH |
299 | out_destroy_tags: |
300 | if (shost_use_blk_mq(shost)) | |
301 | scsi_mq_destroy_tags(shost); | |
542bd137 | 302 | fail: |
1da177e4 LT |
303 | return error; |
304 | } | |
d139b9bd | 305 | EXPORT_SYMBOL(scsi_add_host_with_dma); |
1da177e4 LT |
306 | |
307 | static void scsi_host_dev_release(struct device *dev) | |
308 | { | |
309 | struct Scsi_Host *shost = dev_to_shost(dev); | |
310 | struct device *parent = dev->parent; | |
3308511c | 311 | struct request_queue *q; |
67bd9413 | 312 | void *queuedata; |
1da177e4 | 313 | |
77c01976 AS |
314 | scsi_proc_hostdir_rm(shost->hostt); |
315 | ||
e494f6a7 HR |
316 | if (shost->tmf_work_q) |
317 | destroy_workqueue(shost->tmf_work_q); | |
c5478def CH |
318 | if (shost->ehandler) |
319 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
320 | if (shost->work_q) |
321 | destroy_workqueue(shost->work_q); | |
3308511c BVA |
322 | q = shost->uspace_req_q; |
323 | if (q) { | |
67bd9413 BVA |
324 | queuedata = q->queuedata; |
325 | blk_cleanup_queue(q); | |
326 | kfree(queuedata); | |
b58d9154 | 327 | } |
1da177e4 | 328 | |
1da177e4 | 329 | scsi_destroy_command_freelist(shost); |
d285203c CH |
330 | if (shost_use_blk_mq(shost)) { |
331 | if (shost->tag_set.tags) | |
332 | scsi_mq_destroy_tags(shost); | |
333 | } else { | |
334 | if (shost->bqt) | |
335 | blk_free_tags(shost->bqt); | |
336 | } | |
86e33a29 | 337 | |
1da177e4 LT |
338 | kfree(shost->shost_data); |
339 | ||
1da177e4 LT |
340 | if (parent) |
341 | put_device(parent); | |
342 | kfree(shost); | |
343 | } | |
344 | ||
bb3b621a | 345 | static int shost_eh_deadline = -1; |
b4562022 | 346 | |
bb3b621a | 347 | module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); |
b4562022 | 348 | MODULE_PARM_DESC(eh_deadline, |
bb3b621a | 349 | "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); |
b4562022 | 350 | |
453cd0f3 | 351 | static struct device_type scsi_host_type = { |
b0ed4336 HR |
352 | .name = "scsi_host", |
353 | .release = scsi_host_dev_release, | |
354 | }; | |
355 | ||
1da177e4 LT |
356 | /** |
357 | * scsi_host_alloc - register a scsi host adapter instance. | |
358 | * @sht: pointer to scsi host template | |
359 | * @privsize: extra bytes to allocate for driver | |
360 | * | |
361 | * Note: | |
362 | * Allocate a new Scsi_Host and perform basic initialization. | |
363 | * The host is not published to the scsi midlayer until scsi_add_host | |
364 | * is called. | |
365 | * | |
366 | * Return value: | |
367 | * Pointer to a new Scsi_Host | |
368 | **/ | |
369 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
370 | { | |
371 | struct Scsi_Host *shost; | |
c53033f6 | 372 | gfp_t gfp_mask = GFP_KERNEL; |
1da177e4 LT |
373 | |
374 | if (sht->unchecked_isa_dma && privsize) | |
375 | gfp_mask |= __GFP_DMA; | |
376 | ||
24669f75 | 377 | shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); |
1da177e4 LT |
378 | if (!shost) |
379 | return NULL; | |
1da177e4 | 380 | |
4f777ed2 CH |
381 | shost->host_lock = &shost->default_lock; |
382 | spin_lock_init(shost->host_lock); | |
d3301874 | 383 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
384 | INIT_LIST_HEAD(&shost->__devices); |
385 | INIT_LIST_HEAD(&shost->__targets); | |
386 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
387 | INIT_LIST_HEAD(&shost->starved_list); | |
388 | init_waitqueue_head(&shost->host_wait); | |
0b950672 | 389 | mutex_init(&shost->scan_mutex); |
1da177e4 | 390 | |
30c9afa6 JE |
391 | /* |
392 | * subtract one because we increment first then return, but we need to | |
393 | * know what the next host number was before increment | |
394 | */ | |
395 | shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; | |
1da177e4 LT |
396 | shost->dma_channel = 0xff; |
397 | ||
398 | /* These three are default values which can be overridden */ | |
399 | shost->max_channel = 0; | |
400 | shost->max_id = 8; | |
401 | shost->max_lun = 8; | |
402 | ||
403 | /* Give each shost a default transportt */ | |
404 | shost->transportt = &blank_transport_template; | |
405 | ||
406 | /* | |
407 | * All drivers right now should be able to handle 12 byte | |
408 | * commands. Every so often there are requests for 16 byte | |
409 | * commands, but individual low-level drivers need to certify that | |
410 | * they actually do something sensible with such commands. | |
411 | */ | |
412 | shost->max_cmd_len = 12; | |
413 | shost->hostt = sht; | |
414 | shost->this_id = sht->this_id; | |
415 | shost->can_queue = sht->can_queue; | |
416 | shost->sg_tablesize = sht->sg_tablesize; | |
13f05c8d | 417 | shost->sg_prot_tablesize = sht->sg_prot_tablesize; |
1da177e4 LT |
418 | shost->cmd_per_lun = sht->cmd_per_lun; |
419 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
420 | shost->use_clustering = sht->use_clustering; | |
54b2b50c | 421 | shost->no_write_same = sht->no_write_same; |
1da177e4 | 422 | |
ad469a57 | 423 | if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) |
bb3b621a RM |
424 | shost->eh_deadline = -1; |
425 | else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { | |
426 | shost_printk(KERN_WARNING, shost, | |
427 | "eh_deadline %u too large, setting to %u\n", | |
428 | shost_eh_deadline, INT_MAX / HZ); | |
429 | shost->eh_deadline = INT_MAX; | |
430 | } else | |
431 | shost->eh_deadline = shost_eh_deadline * HZ; | |
432 | ||
7a39ac3f JB |
433 | if (sht->supported_mode == MODE_UNKNOWN) |
434 | /* means we didn't set it ... default to INITIATOR */ | |
435 | shost->active_mode = MODE_INITIATOR; | |
436 | else | |
437 | shost->active_mode = sht->supported_mode; | |
438 | ||
1da177e4 LT |
439 | if (sht->max_host_blocked) |
440 | shost->max_host_blocked = sht->max_host_blocked; | |
441 | else | |
442 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
443 | ||
444 | /* | |
445 | * If the driver imposes no hard sector transfer limit, start at | |
446 | * machine infinity initially. | |
447 | */ | |
448 | if (sht->max_sectors) | |
449 | shost->max_sectors = sht->max_sectors; | |
450 | else | |
451 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
452 | ||
453 | /* | |
454 | * assume a 4GB boundary, if not set | |
455 | */ | |
456 | if (sht->dma_boundary) | |
457 | shost->dma_boundary = sht->dma_boundary; | |
458 | else | |
459 | shost->dma_boundary = 0xffffffff; | |
460 | ||
d285203c CH |
461 | shost->use_blk_mq = scsi_use_blk_mq && !shost->hostt->disable_blk_mq; |
462 | ||
1da177e4 | 463 | device_initialize(&shost->shost_gendev); |
71610f55 | 464 | dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); |
b0ed4336 | 465 | shost->shost_gendev.bus = &scsi_bus_type; |
b0ed4336 | 466 | shost->shost_gendev.type = &scsi_host_type; |
1da177e4 | 467 | |
ee959b00 TJ |
468 | device_initialize(&shost->shost_dev); |
469 | shost->shost_dev.parent = &shost->shost_gendev; | |
470 | shost->shost_dev.class = &shost_class; | |
71610f55 | 471 | dev_set_name(&shost->shost_dev, "host%d", shost->host_no); |
f7120a4f | 472 | shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; |
1da177e4 | 473 | |
c5478def CH |
474 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
475 | "scsi_eh_%d", shost->host_no); | |
476 | if (IS_ERR(shost->ehandler)) { | |
91921e01 HR |
477 | shost_printk(KERN_WARNING, shost, |
478 | "error handler thread failed to spawn, error = %ld\n", | |
479 | PTR_ERR(shost->ehandler)); | |
542bd137 | 480 | goto fail_kfree; |
c5478def | 481 | } |
1da177e4 | 482 | |
e494f6a7 HR |
483 | shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", |
484 | WQ_UNBOUND | WQ_MEM_RECLAIM, | |
485 | 1, shost->host_no); | |
486 | if (!shost->tmf_work_q) { | |
a222b1e2 HR |
487 | shost_printk(KERN_WARNING, shost, |
488 | "failed to create tmf workq\n"); | |
e494f6a7 HR |
489 | goto fail_kthread; |
490 | } | |
1da177e4 LT |
491 | scsi_proc_hostdir_add(shost->hostt); |
492 | return shost; | |
493 | ||
e494f6a7 HR |
494 | fail_kthread: |
495 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
496 | fail_kfree: |
497 | kfree(shost); | |
498 | return NULL; | |
499 | } | |
500 | EXPORT_SYMBOL(scsi_host_alloc); | |
501 | ||
502 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
503 | { | |
504 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
505 | ||
506 | if (!sht->detect) { | |
507 | printk(KERN_WARNING "scsi_register() called on new-style " | |
508 | "template for driver %s\n", sht->name); | |
509 | dump_stack(); | |
510 | } | |
511 | ||
512 | if (shost) | |
513 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
514 | return shost; | |
515 | } | |
516 | EXPORT_SYMBOL(scsi_register); | |
517 | ||
518 | void scsi_unregister(struct Scsi_Host *shost) | |
519 | { | |
520 | list_del(&shost->sht_legacy_list); | |
521 | scsi_host_put(shost); | |
522 | } | |
523 | EXPORT_SYMBOL(scsi_unregister); | |
524 | ||
9f3b795a | 525 | static int __scsi_host_match(struct device *dev, const void *data) |
9c770108 DY |
526 | { |
527 | struct Scsi_Host *p; | |
9f3b795a | 528 | const unsigned short *hostnum = data; |
9c770108 | 529 | |
ee959b00 | 530 | p = class_to_shost(dev); |
9c770108 DY |
531 | return p->host_no == *hostnum; |
532 | } | |
533 | ||
1da177e4 LT |
534 | /** |
535 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
1da177e4 LT |
536 | * @hostnum: host number to locate |
537 | * | |
538 | * Return value: | |
539 | * A pointer to located Scsi_Host or NULL. | |
3ed78972 MC |
540 | * |
541 | * The caller must do a scsi_host_put() to drop the reference | |
542 | * that scsi_host_get() took. The put_device() below dropped | |
543 | * the reference from class_find_device(). | |
1da177e4 LT |
544 | **/ |
545 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
546 | { | |
ee959b00 | 547 | struct device *cdev; |
315cb0ad | 548 | struct Scsi_Host *shost = NULL; |
1da177e4 | 549 | |
695794ae GKH |
550 | cdev = class_find_device(&shost_class, NULL, &hostnum, |
551 | __scsi_host_match); | |
3ed78972 | 552 | if (cdev) { |
9c770108 | 553 | shost = scsi_host_get(class_to_shost(cdev)); |
3ed78972 MC |
554 | put_device(cdev); |
555 | } | |
1da177e4 LT |
556 | return shost; |
557 | } | |
558 | EXPORT_SYMBOL(scsi_host_lookup); | |
559 | ||
560 | /** | |
561 | * scsi_host_get - inc a Scsi_Host ref count | |
562 | * @shost: Pointer to Scsi_Host to inc. | |
563 | **/ | |
564 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
565 | { | |
d3301874 | 566 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
567 | !get_device(&shost->shost_gendev)) |
568 | return NULL; | |
569 | return shost; | |
570 | } | |
571 | EXPORT_SYMBOL(scsi_host_get); | |
572 | ||
573 | /** | |
574 | * scsi_host_put - dec a Scsi_Host ref count | |
575 | * @shost: Pointer to Scsi_Host to dec. | |
576 | **/ | |
577 | void scsi_host_put(struct Scsi_Host *shost) | |
578 | { | |
579 | put_device(&shost->shost_gendev); | |
580 | } | |
581 | EXPORT_SYMBOL(scsi_host_put); | |
582 | ||
583 | int scsi_init_hosts(void) | |
584 | { | |
585 | return class_register(&shost_class); | |
586 | } | |
587 | ||
588 | void scsi_exit_hosts(void) | |
589 | { | |
590 | class_unregister(&shost_class); | |
591 | } | |
592 | ||
593 | int scsi_is_host_device(const struct device *dev) | |
594 | { | |
b0ed4336 | 595 | return dev->type == &scsi_host_type; |
1da177e4 LT |
596 | } |
597 | EXPORT_SYMBOL(scsi_is_host_device); | |
598 | ||
599 | /** | |
600 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
601 | * @shost: Pointer to Scsi_Host. | |
602 | * @work: Work to queue for execution. | |
603 | * | |
604 | * Return value: | |
dd7e2f22 MR |
605 | * 1 - work queued for execution |
606 | * 0 - work is already queued | |
607 | * -EINVAL - work queue doesn't exist | |
1da177e4 LT |
608 | **/ |
609 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
610 | { | |
611 | if (unlikely(!shost->work_q)) { | |
91921e01 | 612 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
613 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " |
614 | "when no workqueue created.\n", shost->hostt->name); | |
615 | dump_stack(); | |
616 | ||
617 | return -EINVAL; | |
618 | } | |
619 | ||
620 | return queue_work(shost->work_q, work); | |
621 | } | |
622 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
623 | ||
624 | /** | |
625 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
626 | * @shost: Pointer to Scsi_Host. | |
627 | **/ | |
628 | void scsi_flush_work(struct Scsi_Host *shost) | |
629 | { | |
630 | if (!shost->work_q) { | |
91921e01 | 631 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
632 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " |
633 | "when no workqueue created.\n", shost->hostt->name); | |
634 | dump_stack(); | |
635 | return; | |
636 | } | |
637 | ||
638 | flush_workqueue(shost->work_q); | |
639 | } | |
640 | EXPORT_SYMBOL_GPL(scsi_flush_work); |