Commit | Line | Data |
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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> |
126a4fe0 | 36 | #include <linux/idr.h> |
1da177e4 LT |
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 | ||
98663067 BVA |
45 | static int shost_eh_deadline = -1; |
46 | ||
47 | module_param_named(eh_deadline, shost_eh_deadline, int, S_IRUGO|S_IWUSR); | |
48 | MODULE_PARM_DESC(eh_deadline, | |
49 | "SCSI EH timeout in seconds (should be between 0 and 2^31-1)"); | |
50 | ||
126a4fe0 | 51 | static DEFINE_IDA(host_index_ida); |
1da177e4 LT |
52 | |
53 | ||
ee959b00 | 54 | static void scsi_host_cls_release(struct device *dev) |
1da177e4 | 55 | { |
ee959b00 | 56 | put_device(&class_to_shost(dev)->shost_gendev); |
1da177e4 LT |
57 | } |
58 | ||
59 | static struct class shost_class = { | |
60 | .name = "scsi_host", | |
ee959b00 | 61 | .dev_release = scsi_host_cls_release, |
1da177e4 LT |
62 | }; |
63 | ||
d3301874 | 64 | /** |
eb44820c | 65 | * scsi_host_set_state - Take the given host through the host state model. |
d3301874 MA |
66 | * @shost: scsi host to change the state of. |
67 | * @state: state to change to. | |
68 | * | |
69 | * Returns zero if unsuccessful or an error if the requested | |
70 | * transition is illegal. | |
71 | **/ | |
72 | int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) | |
73 | { | |
74 | enum scsi_host_state oldstate = shost->shost_state; | |
75 | ||
76 | if (state == oldstate) | |
77 | return 0; | |
78 | ||
79 | switch (state) { | |
80 | case SHOST_CREATED: | |
81 | /* There are no legal states that come back to | |
82 | * created. This is the manually initialised start | |
83 | * state */ | |
84 | goto illegal; | |
85 | ||
86 | case SHOST_RUNNING: | |
87 | switch (oldstate) { | |
88 | case SHOST_CREATED: | |
89 | case SHOST_RECOVERY: | |
90 | break; | |
91 | default: | |
92 | goto illegal; | |
93 | } | |
94 | break; | |
95 | ||
96 | case SHOST_RECOVERY: | |
97 | switch (oldstate) { | |
98 | case SHOST_RUNNING: | |
99 | break; | |
100 | default: | |
101 | goto illegal; | |
102 | } | |
103 | break; | |
104 | ||
105 | case SHOST_CANCEL: | |
106 | switch (oldstate) { | |
107 | case SHOST_CREATED: | |
108 | case SHOST_RUNNING: | |
939647ee | 109 | case SHOST_CANCEL_RECOVERY: |
d3301874 MA |
110 | break; |
111 | default: | |
112 | goto illegal; | |
113 | } | |
114 | break; | |
115 | ||
116 | case SHOST_DEL: | |
117 | switch (oldstate) { | |
118 | case SHOST_CANCEL: | |
939647ee | 119 | case SHOST_DEL_RECOVERY: |
d3301874 MA |
120 | break; |
121 | default: | |
122 | goto illegal; | |
123 | } | |
124 | break; | |
125 | ||
939647ee JB |
126 | case SHOST_CANCEL_RECOVERY: |
127 | switch (oldstate) { | |
128 | case SHOST_CANCEL: | |
129 | case SHOST_RECOVERY: | |
130 | break; | |
131 | default: | |
132 | goto illegal; | |
133 | } | |
134 | break; | |
135 | ||
136 | case SHOST_DEL_RECOVERY: | |
137 | switch (oldstate) { | |
138 | case SHOST_CANCEL_RECOVERY: | |
139 | break; | |
140 | default: | |
141 | goto illegal; | |
142 | } | |
143 | break; | |
d3301874 MA |
144 | } |
145 | shost->shost_state = state; | |
146 | return 0; | |
147 | ||
148 | illegal: | |
149 | SCSI_LOG_ERROR_RECOVERY(1, | |
9ccfc756 JB |
150 | shost_printk(KERN_ERR, shost, |
151 | "Illegal host state transition" | |
152 | "%s->%s\n", | |
153 | scsi_host_state_name(oldstate), | |
154 | scsi_host_state_name(state))); | |
d3301874 MA |
155 | return -EINVAL; |
156 | } | |
d3301874 | 157 | |
1da177e4 LT |
158 | /** |
159 | * scsi_remove_host - remove a scsi host | |
160 | * @shost: a pointer to a scsi host to remove | |
161 | **/ | |
162 | void scsi_remove_host(struct Scsi_Host *shost) | |
163 | { | |
939647ee | 164 | unsigned long flags; |
bc4f2401 | 165 | |
0b950672 | 166 | mutex_lock(&shost->scan_mutex); |
939647ee JB |
167 | spin_lock_irqsave(shost->host_lock, flags); |
168 | if (scsi_host_set_state(shost, SHOST_CANCEL)) | |
169 | if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { | |
170 | spin_unlock_irqrestore(shost->host_lock, flags); | |
0b950672 | 171 | mutex_unlock(&shost->scan_mutex); |
939647ee JB |
172 | return; |
173 | } | |
174 | spin_unlock_irqrestore(shost->host_lock, flags); | |
bc4f2401 AS |
175 | |
176 | scsi_autopm_get_host(shost); | |
e494f6a7 | 177 | flush_workqueue(shost->tmf_work_q); |
1da177e4 | 178 | scsi_forget_host(shost); |
4e46bf89 | 179 | mutex_unlock(&shost->scan_mutex); |
1da177e4 LT |
180 | scsi_proc_host_rm(shost); |
181 | ||
939647ee JB |
182 | spin_lock_irqsave(shost->host_lock, flags); |
183 | if (scsi_host_set_state(shost, SHOST_DEL)) | |
184 | BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); | |
185 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1da177e4 LT |
186 | |
187 | transport_unregister_device(&shost->shost_gendev); | |
ee959b00 | 188 | device_unregister(&shost->shost_dev); |
1da177e4 LT |
189 | device_del(&shost->shost_gendev); |
190 | } | |
191 | EXPORT_SYMBOL(scsi_remove_host); | |
192 | ||
193 | /** | |
d139b9bd | 194 | * scsi_add_host_with_dma - add a scsi host with dma device |
1da177e4 LT |
195 | * @shost: scsi host pointer to add |
196 | * @dev: a struct device of type scsi class | |
d139b9bd JB |
197 | * @dma_dev: dma device for the host |
198 | * | |
199 | * Note: You rarely need to worry about this unless you're in a | |
200 | * virtualised host environments, so use the simpler scsi_add_host() | |
201 | * function instead. | |
1da177e4 LT |
202 | * |
203 | * Return value: | |
204 | * 0 on success / != 0 for error | |
205 | **/ | |
d139b9bd JB |
206 | int scsi_add_host_with_dma(struct Scsi_Host *shost, struct device *dev, |
207 | struct device *dma_dev) | |
1da177e4 LT |
208 | { |
209 | struct scsi_host_template *sht = shost->hostt; | |
210 | int error = -EINVAL; | |
211 | ||
91921e01 | 212 | shost_printk(KERN_INFO, shost, "%s\n", |
1da177e4 LT |
213 | sht->info ? sht->info(shost) : sht->name); |
214 | ||
215 | if (!shost->can_queue) { | |
91921e01 HR |
216 | shost_printk(KERN_ERR, shost, |
217 | "can_queue = 0 no longer supported\n"); | |
542bd137 | 218 | goto fail; |
1da177e4 LT |
219 | } |
220 | ||
0a6ac4ee CH |
221 | error = scsi_init_sense_cache(shost); |
222 | if (error) | |
223 | goto fail; | |
224 | ||
f664a3cc JA |
225 | error = scsi_mq_setup_tags(shost); |
226 | if (error) | |
227 | goto fail; | |
d285203c | 228 | |
1da177e4 LT |
229 | if (!shost->shost_gendev.parent) |
230 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
3c8d9a95 JB |
231 | if (!dma_dev) |
232 | dma_dev = shost->shost_gendev.parent; | |
233 | ||
d139b9bd | 234 | shost->dma_dev = dma_dev; |
1da177e4 | 235 | |
5c6fab9d MW |
236 | /* |
237 | * Increase usage count temporarily here so that calling | |
238 | * scsi_autopm_put_host() will trigger runtime idle if there is | |
239 | * nothing else preventing suspending the device. | |
240 | */ | |
241 | pm_runtime_get_noresume(&shost->shost_gendev); | |
bc4f2401 AS |
242 | pm_runtime_set_active(&shost->shost_gendev); |
243 | pm_runtime_enable(&shost->shost_gendev); | |
244 | device_enable_async_suspend(&shost->shost_gendev); | |
245 | ||
0d5644b7 HK |
246 | error = device_add(&shost->shost_gendev); |
247 | if (error) | |
e9c787e6 | 248 | goto out_disable_runtime_pm; |
0d5644b7 | 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); | |
5c6fab9d | 286 | scsi_autopm_put_host(shost); |
1da177e4 LT |
287 | return error; |
288 | ||
289 | out_destroy_host: | |
290 | if (shost->work_q) | |
291 | destroy_workqueue(shost->work_q); | |
292 | out_free_shost_data: | |
293 | kfree(shost->shost_data); | |
ee959b00 TJ |
294 | out_del_dev: |
295 | device_del(&shost->shost_dev); | |
1da177e4 LT |
296 | out_del_gendev: |
297 | device_del(&shost->shost_gendev); | |
e9c787e6 | 298 | out_disable_runtime_pm: |
0d5644b7 HK |
299 | device_disable_async_suspend(&shost->shost_gendev); |
300 | pm_runtime_disable(&shost->shost_gendev); | |
301 | pm_runtime_set_suspended(&shost->shost_gendev); | |
302 | pm_runtime_put_noidle(&shost->shost_gendev); | |
f664a3cc | 303 | scsi_mq_destroy_tags(shost); |
542bd137 | 304 | fail: |
1da177e4 LT |
305 | return error; |
306 | } | |
d139b9bd | 307 | EXPORT_SYMBOL(scsi_add_host_with_dma); |
1da177e4 LT |
308 | |
309 | static void scsi_host_dev_release(struct device *dev) | |
310 | { | |
311 | struct Scsi_Host *shost = dev_to_shost(dev); | |
312 | struct device *parent = dev->parent; | |
313 | ||
77c01976 AS |
314 | scsi_proc_hostdir_rm(shost->hostt); |
315 | ||
3bd6f43f BVA |
316 | /* Wait for functions invoked through call_rcu(&shost->rcu, ...) */ |
317 | rcu_barrier(); | |
318 | ||
e494f6a7 HR |
319 | if (shost->tmf_work_q) |
320 | destroy_workqueue(shost->tmf_work_q); | |
c5478def CH |
321 | if (shost->ehandler) |
322 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
323 | if (shost->work_q) |
324 | destroy_workqueue(shost->work_q); | |
325 | ||
b49493f9 BVA |
326 | if (shost->shost_state == SHOST_CREATED) { |
327 | /* | |
328 | * Free the shost_dev device name here if scsi_host_alloc() | |
329 | * and scsi_host_put() have been called but neither | |
330 | * scsi_host_add() nor scsi_host_remove() has been called. | |
331 | * This avoids that the memory allocated for the shost_dev | |
332 | * name is leaked. | |
333 | */ | |
334 | kfree(dev_name(&shost->shost_dev)); | |
335 | } | |
336 | ||
f664a3cc JA |
337 | if (shost->tag_set.tags) |
338 | scsi_mq_destroy_tags(shost); | |
86e33a29 | 339 | |
1da177e4 LT |
340 | kfree(shost->shost_data); |
341 | ||
126a4fe0 LD |
342 | ida_simple_remove(&host_index_ida, shost->host_no); |
343 | ||
1da177e4 LT |
344 | if (parent) |
345 | put_device(parent); | |
346 | kfree(shost); | |
347 | } | |
348 | ||
453cd0f3 | 349 | static struct device_type scsi_host_type = { |
b0ed4336 HR |
350 | .name = "scsi_host", |
351 | .release = scsi_host_dev_release, | |
352 | }; | |
353 | ||
1da177e4 LT |
354 | /** |
355 | * scsi_host_alloc - register a scsi host adapter instance. | |
356 | * @sht: pointer to scsi host template | |
357 | * @privsize: extra bytes to allocate for driver | |
358 | * | |
359 | * Note: | |
360 | * Allocate a new Scsi_Host and perform basic initialization. | |
361 | * The host is not published to the scsi midlayer until scsi_add_host | |
362 | * is called. | |
363 | * | |
364 | * Return value: | |
365 | * Pointer to a new Scsi_Host | |
366 | **/ | |
367 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
368 | { | |
369 | struct Scsi_Host *shost; | |
c53033f6 | 370 | gfp_t gfp_mask = GFP_KERNEL; |
126a4fe0 | 371 | int index; |
1da177e4 LT |
372 | |
373 | if (sht->unchecked_isa_dma && privsize) | |
374 | gfp_mask |= __GFP_DMA; | |
375 | ||
24669f75 | 376 | shost = kzalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); |
1da177e4 LT |
377 | if (!shost) |
378 | return NULL; | |
1da177e4 | 379 | |
4f777ed2 CH |
380 | shost->host_lock = &shost->default_lock; |
381 | spin_lock_init(shost->host_lock); | |
d3301874 | 382 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
383 | INIT_LIST_HEAD(&shost->__devices); |
384 | INIT_LIST_HEAD(&shost->__targets); | |
385 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
386 | INIT_LIST_HEAD(&shost->starved_list); | |
387 | init_waitqueue_head(&shost->host_wait); | |
0b950672 | 388 | mutex_init(&shost->scan_mutex); |
1da177e4 | 389 | |
126a4fe0 LD |
390 | index = ida_simple_get(&host_index_ida, 0, 0, GFP_KERNEL); |
391 | if (index < 0) | |
392 | goto fail_kfree; | |
393 | shost->host_no = index; | |
394 | ||
1da177e4 LT |
395 | shost->dma_channel = 0xff; |
396 | ||
397 | /* These three are default values which can be overridden */ | |
398 | shost->max_channel = 0; | |
399 | shost->max_id = 8; | |
400 | shost->max_lun = 8; | |
401 | ||
402 | /* Give each shost a default transportt */ | |
403 | shost->transportt = &blank_transport_template; | |
404 | ||
405 | /* | |
406 | * All drivers right now should be able to handle 12 byte | |
407 | * commands. Every so often there are requests for 16 byte | |
408 | * commands, but individual low-level drivers need to certify that | |
409 | * they actually do something sensible with such commands. | |
410 | */ | |
411 | shost->max_cmd_len = 12; | |
412 | shost->hostt = sht; | |
413 | shost->this_id = sht->this_id; | |
414 | shost->can_queue = sht->can_queue; | |
415 | shost->sg_tablesize = sht->sg_tablesize; | |
13f05c8d | 416 | shost->sg_prot_tablesize = sht->sg_prot_tablesize; |
1da177e4 LT |
417 | shost->cmd_per_lun = sht->cmd_per_lun; |
418 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
54b2b50c | 419 | shost->no_write_same = sht->no_write_same; |
1da177e4 | 420 | |
ad469a57 | 421 | if (shost_eh_deadline == -1 || !sht->eh_host_reset_handler) |
bb3b621a RM |
422 | shost->eh_deadline = -1; |
423 | else if ((ulong) shost_eh_deadline * HZ > INT_MAX) { | |
424 | shost_printk(KERN_WARNING, shost, | |
425 | "eh_deadline %u too large, setting to %u\n", | |
426 | shost_eh_deadline, INT_MAX / HZ); | |
427 | shost->eh_deadline = INT_MAX; | |
428 | } else | |
429 | shost->eh_deadline = shost_eh_deadline * HZ; | |
430 | ||
7a39ac3f JB |
431 | if (sht->supported_mode == MODE_UNKNOWN) |
432 | /* means we didn't set it ... default to INITIATOR */ | |
433 | shost->active_mode = MODE_INITIATOR; | |
434 | else | |
435 | shost->active_mode = sht->supported_mode; | |
436 | ||
1da177e4 LT |
437 | if (sht->max_host_blocked) |
438 | shost->max_host_blocked = sht->max_host_blocked; | |
439 | else | |
440 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
441 | ||
442 | /* | |
443 | * If the driver imposes no hard sector transfer limit, start at | |
444 | * machine infinity initially. | |
445 | */ | |
446 | if (sht->max_sectors) | |
447 | shost->max_sectors = sht->max_sectors; | |
448 | else | |
449 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
450 | ||
50c2e910 CH |
451 | if (sht->max_segment_size) |
452 | shost->max_segment_size = sht->max_segment_size; | |
453 | else | |
454 | shost->max_segment_size = BLK_MAX_SEGMENT_SIZE; | |
455 | ||
1da177e4 LT |
456 | /* |
457 | * assume a 4GB boundary, if not set | |
458 | */ | |
459 | if (sht->dma_boundary) | |
460 | shost->dma_boundary = sht->dma_boundary; | |
461 | else | |
462 | shost->dma_boundary = 0xffffffff; | |
463 | ||
1da177e4 | 464 | device_initialize(&shost->shost_gendev); |
71610f55 | 465 | dev_set_name(&shost->shost_gendev, "host%d", shost->host_no); |
b0ed4336 | 466 | shost->shost_gendev.bus = &scsi_bus_type; |
b0ed4336 | 467 | shost->shost_gendev.type = &scsi_host_type; |
1da177e4 | 468 | |
ee959b00 TJ |
469 | device_initialize(&shost->shost_dev); |
470 | shost->shost_dev.parent = &shost->shost_gendev; | |
471 | shost->shost_dev.class = &shost_class; | |
71610f55 | 472 | dev_set_name(&shost->shost_dev, "host%d", shost->host_no); |
f7120a4f | 473 | shost->shost_dev.groups = scsi_sysfs_shost_attr_groups; |
1da177e4 | 474 | |
c5478def CH |
475 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
476 | "scsi_eh_%d", shost->host_no); | |
477 | if (IS_ERR(shost->ehandler)) { | |
91921e01 HR |
478 | shost_printk(KERN_WARNING, shost, |
479 | "error handler thread failed to spawn, error = %ld\n", | |
480 | PTR_ERR(shost->ehandler)); | |
126a4fe0 | 481 | goto fail_index_remove; |
c5478def | 482 | } |
1da177e4 | 483 | |
e494f6a7 HR |
484 | shost->tmf_work_q = alloc_workqueue("scsi_tmf_%d", |
485 | WQ_UNBOUND | WQ_MEM_RECLAIM, | |
486 | 1, shost->host_no); | |
487 | if (!shost->tmf_work_q) { | |
a222b1e2 HR |
488 | shost_printk(KERN_WARNING, shost, |
489 | "failed to create tmf workq\n"); | |
e494f6a7 HR |
490 | goto fail_kthread; |
491 | } | |
1da177e4 LT |
492 | scsi_proc_hostdir_add(shost->hostt); |
493 | return shost; | |
494 | ||
e494f6a7 HR |
495 | fail_kthread: |
496 | kthread_stop(shost->ehandler); | |
126a4fe0 LD |
497 | fail_index_remove: |
498 | ida_simple_remove(&host_index_ida, shost->host_no); | |
1da177e4 LT |
499 | fail_kfree: |
500 | kfree(shost); | |
501 | return NULL; | |
502 | } | |
503 | EXPORT_SYMBOL(scsi_host_alloc); | |
504 | ||
9f3b795a | 505 | static int __scsi_host_match(struct device *dev, const void *data) |
9c770108 DY |
506 | { |
507 | struct Scsi_Host *p; | |
9f3b795a | 508 | const unsigned short *hostnum = data; |
9c770108 | 509 | |
ee959b00 | 510 | p = class_to_shost(dev); |
9c770108 DY |
511 | return p->host_no == *hostnum; |
512 | } | |
513 | ||
1da177e4 LT |
514 | /** |
515 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
1da177e4 LT |
516 | * @hostnum: host number to locate |
517 | * | |
518 | * Return value: | |
519 | * A pointer to located Scsi_Host or NULL. | |
3ed78972 MC |
520 | * |
521 | * The caller must do a scsi_host_put() to drop the reference | |
522 | * that scsi_host_get() took. The put_device() below dropped | |
523 | * the reference from class_find_device(). | |
1da177e4 LT |
524 | **/ |
525 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
526 | { | |
ee959b00 | 527 | struct device *cdev; |
315cb0ad | 528 | struct Scsi_Host *shost = NULL; |
1da177e4 | 529 | |
695794ae GKH |
530 | cdev = class_find_device(&shost_class, NULL, &hostnum, |
531 | __scsi_host_match); | |
3ed78972 | 532 | if (cdev) { |
9c770108 | 533 | shost = scsi_host_get(class_to_shost(cdev)); |
3ed78972 MC |
534 | put_device(cdev); |
535 | } | |
1da177e4 LT |
536 | return shost; |
537 | } | |
538 | EXPORT_SYMBOL(scsi_host_lookup); | |
539 | ||
540 | /** | |
541 | * scsi_host_get - inc a Scsi_Host ref count | |
542 | * @shost: Pointer to Scsi_Host to inc. | |
543 | **/ | |
544 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
545 | { | |
d3301874 | 546 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
547 | !get_device(&shost->shost_gendev)) |
548 | return NULL; | |
549 | return shost; | |
550 | } | |
551 | EXPORT_SYMBOL(scsi_host_get); | |
552 | ||
c84b023a ML |
553 | /** |
554 | * scsi_host_busy - Return the host busy counter | |
555 | * @shost: Pointer to Scsi_Host to inc. | |
556 | **/ | |
557 | int scsi_host_busy(struct Scsi_Host *shost) | |
558 | { | |
d772a65d | 559 | return atomic_read(&shost->host_busy); |
c84b023a ML |
560 | } |
561 | EXPORT_SYMBOL(scsi_host_busy); | |
562 | ||
1da177e4 LT |
563 | /** |
564 | * scsi_host_put - dec a Scsi_Host ref count | |
565 | * @shost: Pointer to Scsi_Host to dec. | |
566 | **/ | |
567 | void scsi_host_put(struct Scsi_Host *shost) | |
568 | { | |
569 | put_device(&shost->shost_gendev); | |
570 | } | |
571 | EXPORT_SYMBOL(scsi_host_put); | |
572 | ||
573 | int scsi_init_hosts(void) | |
574 | { | |
575 | return class_register(&shost_class); | |
576 | } | |
577 | ||
578 | void scsi_exit_hosts(void) | |
579 | { | |
580 | class_unregister(&shost_class); | |
126a4fe0 | 581 | ida_destroy(&host_index_ida); |
1da177e4 LT |
582 | } |
583 | ||
584 | int scsi_is_host_device(const struct device *dev) | |
585 | { | |
b0ed4336 | 586 | return dev->type == &scsi_host_type; |
1da177e4 LT |
587 | } |
588 | EXPORT_SYMBOL(scsi_is_host_device); | |
589 | ||
590 | /** | |
591 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
592 | * @shost: Pointer to Scsi_Host. | |
593 | * @work: Work to queue for execution. | |
594 | * | |
595 | * Return value: | |
dd7e2f22 MR |
596 | * 1 - work queued for execution |
597 | * 0 - work is already queued | |
598 | * -EINVAL - work queue doesn't exist | |
1da177e4 LT |
599 | **/ |
600 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
601 | { | |
602 | if (unlikely(!shost->work_q)) { | |
91921e01 | 603 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
604 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " |
605 | "when no workqueue created.\n", shost->hostt->name); | |
606 | dump_stack(); | |
607 | ||
608 | return -EINVAL; | |
609 | } | |
610 | ||
611 | return queue_work(shost->work_q, work); | |
612 | } | |
613 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
614 | ||
615 | /** | |
616 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
617 | * @shost: Pointer to Scsi_Host. | |
618 | **/ | |
619 | void scsi_flush_work(struct Scsi_Host *shost) | |
620 | { | |
621 | if (!shost->work_q) { | |
91921e01 | 622 | shost_printk(KERN_ERR, shost, |
1da177e4 LT |
623 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " |
624 | "when no workqueue created.\n", shost->hostt->name); | |
625 | dump_stack(); | |
626 | return; | |
627 | } | |
628 | ||
629 | flush_workqueue(shost->work_q); | |
630 | } | |
631 | EXPORT_SYMBOL_GPL(scsi_flush_work); |