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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; | |
64d513ac CH |
220 | } else { |
221 | shost->bqt = blk_init_tags(shost->can_queue, | |
222 | shost->hostt->tag_alloc_policy); | |
223 | if (!shost->bqt) { | |
224 | error = -ENOMEM; | |
225 | goto fail; | |
226 | } | |
d285203c CH |
227 | } |
228 | ||
229 | /* | |
230 | * Note that we allocate the freelist even for the MQ case for now, | |
231 | * as we need a command set aside for scsi_reset_provider. Having | |
232 | * the full host freelist and one command available for that is a | |
233 | * little heavy-handed, but avoids introducing a special allocator | |
234 | * just for this. Eventually the structure of scsi_reset_provider | |
235 | * will need a major overhaul. | |
236 | */ | |
542bd137 JB |
237 | error = scsi_setup_command_freelist(shost); |
238 | if (error) | |
d285203c CH |
239 | goto out_destroy_tags; |
240 | ||
542bd137 | 241 | |
1da177e4 LT |
242 | if (!shost->shost_gendev.parent) |
243 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
3c8d9a95 JB |
244 | if (!dma_dev) |
245 | dma_dev = shost->shost_gendev.parent; | |
246 | ||
d139b9bd | 247 | shost->dma_dev = dma_dev; |
1da177e4 LT |
248 | |
249 | error = device_add(&shost->shost_gendev); | |
250 | if (error) | |
d285203c | 251 | goto out_destroy_freelist; |
1da177e4 | 252 | |
bc4f2401 AS |
253 | pm_runtime_set_active(&shost->shost_gendev); |
254 | pm_runtime_enable(&shost->shost_gendev); | |
255 | device_enable_async_suspend(&shost->shost_gendev); | |
256 | ||
d3301874 | 257 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
258 | get_device(shost->shost_gendev.parent); |
259 | ||
4cb077d9 RW |
260 | device_enable_async_suspend(&shost->shost_dev); |
261 | ||
ee959b00 | 262 | error = device_add(&shost->shost_dev); |
1da177e4 LT |
263 | if (error) |
264 | goto out_del_gendev; | |
265 | ||
266 | get_device(&shost->shost_gendev); | |
267 | ||
77cca462 JS |
268 | if (shost->transportt->host_size) { |
269 | shost->shost_data = kzalloc(shost->transportt->host_size, | |
270 | GFP_KERNEL); | |
271 | if (shost->shost_data == NULL) { | |
272 | error = -ENOMEM; | |
ee959b00 | 273 | goto out_del_dev; |
77cca462 JS |
274 | } |
275 | } | |
1da177e4 LT |
276 | |
277 | if (shost->transportt->create_work_queue) { | |
aab0de24 KS |
278 | snprintf(shost->work_q_name, sizeof(shost->work_q_name), |
279 | "scsi_wq_%d", shost->host_no); | |
1da177e4 LT |
280 | shost->work_q = create_singlethread_workqueue( |
281 | shost->work_q_name); | |
77cca462 JS |
282 | if (!shost->work_q) { |
283 | error = -EINVAL; | |
1da177e4 | 284 | goto out_free_shost_data; |
77cca462 | 285 | } |
1da177e4 LT |
286 | } |
287 | ||
288 | error = scsi_sysfs_add_host(shost); | |
289 | if (error) | |
290 | goto out_destroy_host; | |
291 | ||
292 | scsi_proc_host_add(shost); | |
293 | return error; | |
294 | ||
295 | out_destroy_host: | |
296 | if (shost->work_q) | |
297 | destroy_workqueue(shost->work_q); | |
298 | out_free_shost_data: | |
299 | kfree(shost->shost_data); | |
ee959b00 TJ |
300 | out_del_dev: |
301 | device_del(&shost->shost_dev); | |
1da177e4 LT |
302 | out_del_gendev: |
303 | device_del(&shost->shost_gendev); | |
d285203c | 304 | out_destroy_freelist: |
542bd137 | 305 | scsi_destroy_command_freelist(shost); |
d285203c CH |
306 | out_destroy_tags: |
307 | if (shost_use_blk_mq(shost)) | |
308 | scsi_mq_destroy_tags(shost); | |
542bd137 | 309 | fail: |
1da177e4 LT |
310 | return error; |
311 | } | |
d139b9bd | 312 | EXPORT_SYMBOL(scsi_add_host_with_dma); |
1da177e4 LT |
313 | |
314 | static void scsi_host_dev_release(struct device *dev) | |
315 | { | |
316 | struct Scsi_Host *shost = dev_to_shost(dev); | |
317 | struct device *parent = dev->parent; | |
3308511c | 318 | struct request_queue *q; |
67bd9413 | 319 | void *queuedata; |
1da177e4 | 320 | |
77c01976 AS |
321 | scsi_proc_hostdir_rm(shost->hostt); |
322 | ||
e494f6a7 HR |
323 | if (shost->tmf_work_q) |
324 | destroy_workqueue(shost->tmf_work_q); | |
c5478def CH |
325 | if (shost->ehandler) |
326 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
327 | if (shost->work_q) |
328 | destroy_workqueue(shost->work_q); | |
3308511c BVA |
329 | q = shost->uspace_req_q; |
330 | if (q) { | |
67bd9413 BVA |
331 | queuedata = q->queuedata; |
332 | blk_cleanup_queue(q); | |
333 | kfree(queuedata); | |
b58d9154 | 334 | } |
1da177e4 | 335 | |
1da177e4 | 336 | scsi_destroy_command_freelist(shost); |
d285203c CH |
337 | if (shost_use_blk_mq(shost)) { |
338 | if (shost->tag_set.tags) | |
339 | scsi_mq_destroy_tags(shost); | |
340 | } else { | |
341 | if (shost->bqt) | |
342 | blk_free_tags(shost->bqt); | |
343 | } | |
86e33a29 | 344 | |
1da177e4 LT |
345 | kfree(shost->shost_data); |
346 | ||
1da177e4 LT |
347 | if (parent) |
348 | put_device(parent); | |
349 | kfree(shost); | |
350 | } | |
351 | ||
bb3b621a | 352 | static int shost_eh_deadline = -1; |
b4562022 | 353 | |
bb3b621a | 354 | module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); |
b4562022 | 355 | MODULE_PARM_DESC(eh_deadline, |
bb3b621a | 356 | "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); |
b4562022 | 357 | |
453cd0f3 | 358 | static struct device_type scsi_host_type = { |
b0ed4336 HR |
359 | .name = "scsi_host", |
360 | .release = scsi_host_dev_release, | |
361 | }; | |
362 | ||
1da177e4 LT |
363 | /** |
364 | * scsi_host_alloc - register a scsi host adapter instance. | |
365 | * @sht: pointer to scsi host template | |
366 | * @privsize: extra bytes to allocate for driver | |
367 | * | |
368 | * Note: | |
369 | * Allocate a new Scsi_Host and perform basic initialization. | |
370 | * The host is not published to the scsi midlayer until scsi_add_host | |
371 | * is called. | |
372 | * | |
373 | * Return value: | |
374 | * Pointer to a new Scsi_Host | |
375 | **/ | |
376 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
377 | { | |
378 | struct Scsi_Host *shost; | |
c53033f6 | 379 | gfp_t gfp_mask = GFP_KERNEL; |
1da177e4 LT |
380 | |
381 | if (sht->unchecked_isa_dma && privsize) | |
382 | gfp_mask |= __GFP_DMA; | |
383 | ||
24669f75 | 384 | shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); |
1da177e4 LT |
385 | if (!shost) |
386 | return NULL; | |
1da177e4 | 387 | |
4f777ed2 CH |
388 | shost->host_lock = &shost->default_lock; |
389 | spin_lock_init(shost->host_lock); | |
d3301874 | 390 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
391 | INIT_LIST_HEAD(&shost->__devices); |
392 | INIT_LIST_HEAD(&shost->__targets); | |
393 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
394 | INIT_LIST_HEAD(&shost->starved_list); | |
395 | init_waitqueue_head(&shost->host_wait); | |
0b950672 | 396 | mutex_init(&shost->scan_mutex); |
1da177e4 | 397 | |
30c9afa6 JE |
398 | /* |
399 | * subtract one because we increment first then return, but we need to | |
400 | * know what the next host number was before increment | |
401 | */ | |
402 | shost->host_no = atomic_inc_return(&scsi_host_next_hn) - 1; | |
1da177e4 LT |
403 | shost->dma_channel = 0xff; |
404 | ||
405 | /* These three are default values which can be overridden */ | |
406 | shost->max_channel = 0; | |
407 | shost->max_id = 8; | |
408 | shost->max_lun = 8; | |
409 | ||
410 | /* Give each shost a default transportt */ | |
411 | shost->transportt = &blank_transport_template; | |
412 | ||
413 | /* | |
414 | * All drivers right now should be able to handle 12 byte | |
415 | * commands. Every so often there are requests for 16 byte | |
416 | * commands, but individual low-level drivers need to certify that | |
417 | * they actually do something sensible with such commands. | |
418 | */ | |
419 | shost->max_cmd_len = 12; | |
420 | shost->hostt = sht; | |
421 | shost->this_id = sht->this_id; | |
422 | shost->can_queue = sht->can_queue; | |
423 | shost->sg_tablesize = sht->sg_tablesize; | |
13f05c8d | 424 | shost->sg_prot_tablesize = sht->sg_prot_tablesize; |
1da177e4 LT |
425 | shost->cmd_per_lun = sht->cmd_per_lun; |
426 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
427 | shost->use_clustering = sht->use_clustering; | |
54b2b50c | 428 | shost->no_write_same = sht->no_write_same; |
1da177e4 | 429 | |
ad469a57 | 430 | if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) |
bb3b621a RM |
431 | shost->eh_deadline = -1; |
432 | else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { | |
433 | shost_printk(KERN_WARNING, shost, | |
434 | "eh_deadline %u too large, setting to %u\n", | |
435 | shost_eh_deadline, INT_MAX / HZ); | |
436 | shost->eh_deadline = INT_MAX; | |
437 | } else | |
438 | shost->eh_deadline = shost_eh_deadline * HZ; | |
439 | ||
7a39ac3f JB |
440 | if (sht->supported_mode == MODE_UNKNOWN) |
441 | /* means we didn't set it ... default to INITIATOR */ | |
442 | shost->active_mode = MODE_INITIATOR; | |
443 | else | |
444 | shost->active_mode = sht->supported_mode; | |
445 | ||
1da177e4 LT |
446 | if (sht->max_host_blocked) |
447 | shost->max_host_blocked = sht->max_host_blocked; | |
448 | else | |
449 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
450 | ||
451 | /* | |
452 | * If the driver imposes no hard sector transfer limit, start at | |
453 | * machine infinity initially. | |
454 | */ | |
455 | if (sht->max_sectors) | |
456 | shost->max_sectors = sht->max_sectors; | |
457 | else | |
458 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
459 | ||
460 | /* | |
461 | * assume a 4GB boundary, if not set | |
462 | */ | |
463 | if (sht->dma_boundary) | |
464 | shost->dma_boundary = sht->dma_boundary; | |
465 | else | |
466 | shost->dma_boundary = 0xffffffff; | |
467 | ||
d285203c CH |
468 | shost->use_blk_mq = scsi_use_blk_mq && !shost->hostt->disable_blk_mq; |
469 | ||
1da177e4 | 470 | device_initialize(&shost->shost_gendev); |
71610f55 | 471 | dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); |
b0ed4336 | 472 | shost->shost_gendev.bus = &scsi_bus_type; |
b0ed4336 | 473 | shost->shost_gendev.type = &scsi_host_type; |
1da177e4 | 474 | |
ee959b00 TJ |
475 | device_initialize(&shost->shost_dev); |
476 | shost->shost_dev.parent = &shost->shost_gendev; | |
477 | shost->shost_dev.class = &shost_class; | |
71610f55 | 478 | dev_set_name(&shost->shost_dev, "host%d", shost->host_no); |
f7120a4f | 479 | shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; |
1da177e4 | 480 | |
c5478def CH |
481 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
482 | "scsi_eh_%d", shost->host_no); | |
483 | if (IS_ERR(shost->ehandler)) { | |
91921e01 HR |
484 | shost_printk(KERN_WARNING, shost, |
485 | "error handler thread failed to spawn, error = %ld\n", | |
486 | PTR_ERR(shost->ehandler)); | |
542bd137 | 487 | goto fail_kfree; |
c5478def | 488 | } |
1da177e4 | 489 | |
e494f6a7 HR |
490 | shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", |
491 | WQ_UNBOUND | WQ_MEM_RECLAIM, | |
492 | 1, shost->host_no); | |
493 | if (!shost->tmf_work_q) { | |
a222b1e2 HR |
494 | shost_printk(KERN_WARNING, shost, |
495 | "failed to create tmf workq\n"); | |
e494f6a7 HR |
496 | goto fail_kthread; |
497 | } | |
1da177e4 LT |
498 | scsi_proc_hostdir_add(shost->hostt); |
499 | return shost; | |
500 | ||
e494f6a7 HR |
501 | fail_kthread: |
502 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
503 | fail_kfree: |
504 | kfree(shost); | |
505 | return NULL; | |
506 | } | |
507 | EXPORT_SYMBOL(scsi_host_alloc); | |
508 | ||
509 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
510 | { | |
511 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
512 | ||
513 | if (!sht->detect) { | |
514 | printk(KERN_WARNING "scsi_register() called on new-style " | |
515 | "template for driver %s\n", sht->name); | |
516 | dump_stack(); | |
517 | } | |
518 | ||
519 | if (shost) | |
520 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
521 | return shost; | |
522 | } | |
523 | EXPORT_SYMBOL(scsi_register); | |
524 | ||
525 | void scsi_unregister(struct Scsi_Host *shost) | |
526 | { | |
527 | list_del(&shost->sht_legacy_list); | |
528 | scsi_host_put(shost); | |
529 | } | |
530 | EXPORT_SYMBOL(scsi_unregister); | |
531 | ||
9f3b795a | 532 | static int __scsi_host_match(struct device *dev, const void *data) |
9c770108 DY |
533 | { |
534 | struct Scsi_Host *p; | |
9f3b795a | 535 | const unsigned short *hostnum = data; |
9c770108 | 536 | |
ee959b00 | 537 | p = class_to_shost(dev); |
9c770108 DY |
538 | return p->host_no == *hostnum; |
539 | } | |
540 | ||
1da177e4 LT |
541 | /** |
542 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
1da177e4 LT |
543 | * @hostnum: host number to locate |
544 | * | |
545 | * Return value: | |
546 | * A pointer to located Scsi_Host or NULL. | |
3ed78972 MC |
547 | * |
548 | * The caller must do a scsi_host_put() to drop the reference | |
549 | * that scsi_host_get() took. The put_device() below dropped | |
550 | * the reference from class_find_device(). | |
1da177e4 LT |
551 | **/ |
552 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
553 | { | |
ee959b00 | 554 | struct device *cdev; |
315cb0ad | 555 | struct Scsi_Host *shost = NULL; |
1da177e4 | 556 | |
695794ae GKH |
557 | cdev = class_find_device(&shost_class, NULL, &hostnum, |
558 | __scsi_host_match); | |
3ed78972 | 559 | if (cdev) { |
9c770108 | 560 | shost = scsi_host_get(class_to_shost(cdev)); |
3ed78972 MC |
561 | put_device(cdev); |
562 | } | |
1da177e4 LT |
563 | return shost; |
564 | } | |
565 | EXPORT_SYMBOL(scsi_host_lookup); | |
566 | ||
567 | /** | |
568 | * scsi_host_get - inc a Scsi_Host ref count | |
569 | * @shost: Pointer to Scsi_Host to inc. | |
570 | **/ | |
571 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
572 | { | |
d3301874 | 573 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
574 | !get_device(&shost->shost_gendev)) |
575 | return NULL; | |
576 | return shost; | |
577 | } | |
578 | EXPORT_SYMBOL(scsi_host_get); | |
579 | ||
580 | /** | |
581 | * scsi_host_put - dec a Scsi_Host ref count | |
582 | * @shost: Pointer to Scsi_Host to dec. | |
583 | **/ | |
584 | void scsi_host_put(struct Scsi_Host *shost) | |
585 | { | |
586 | put_device(&shost->shost_gendev); | |
587 | } | |
588 | EXPORT_SYMBOL(scsi_host_put); | |
589 | ||
590 | int scsi_init_hosts(void) | |
591 | { | |
592 | return class_register(&shost_class); | |
593 | } | |
594 | ||
595 | void scsi_exit_hosts(void) | |
596 | { | |
597 | class_unregister(&shost_class); | |
598 | } | |
599 | ||
600 | int scsi_is_host_device(const struct device *dev) | |
601 | { | |
b0ed4336 | 602 | return dev->type == &scsi_host_type; |
1da177e4 LT |
603 | } |
604 | EXPORT_SYMBOL(scsi_is_host_device); | |
605 | ||
606 | /** | |
607 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
608 | * @shost: Pointer to Scsi_Host. | |
609 | * @work: Work to queue for execution. | |
610 | * | |
611 | * Return value: | |
dd7e2f22 MR |
612 | * 1 - work queued for execution |
613 | * 0 - work is already queued | |
614 | * -EINVAL - work queue doesn't exist | |
1da177e4 LT |
615 | **/ |
616 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
617 | { | |
618 | if (unlikely(!shost->work_q)) { | |
91921e01 | 619 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
620 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " |
621 | "when no workqueue created.\n", shost->hostt->name); | |
622 | dump_stack(); | |
623 | ||
624 | return -EINVAL; | |
625 | } | |
626 | ||
627 | return queue_work(shost->work_q, work); | |
628 | } | |
629 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
630 | ||
631 | /** | |
632 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
633 | * @shost: Pointer to Scsi_Host. | |
634 | **/ | |
635 | void scsi_flush_work(struct Scsi_Host *shost) | |
636 | { | |
637 | if (!shost->work_q) { | |
91921e01 | 638 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
639 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " |
640 | "when no workqueue created.\n", shost->hostt->name); | |
641 | dump_stack(); | |
642 | return; | |
643 | } | |
644 | ||
645 | flush_workqueue(shost->work_q); | |
646 | } | |
647 | EXPORT_SYMBOL_GPL(scsi_flush_work); |