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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> | |
c5478def | 27 | #include <linux/kthread.h> |
1da177e4 LT |
28 | #include <linux/string.h> |
29 | #include <linux/mm.h> | |
30 | #include <linux/init.h> | |
31 | #include <linux/completion.h> | |
32 | #include <linux/transport_class.h> | |
33 | ||
34 | #include <scsi/scsi_device.h> | |
35 | #include <scsi/scsi_host.h> | |
36 | #include <scsi/scsi_transport.h> | |
37 | ||
38 | #include "scsi_priv.h" | |
39 | #include "scsi_logging.h" | |
40 | ||
41 | ||
42 | static int scsi_host_next_hn; /* host_no for next new host */ | |
43 | ||
44 | ||
45 | static void scsi_host_cls_release(struct class_device *class_dev) | |
46 | { | |
47 | put_device(&class_to_shost(class_dev)->shost_gendev); | |
48 | } | |
49 | ||
50 | static struct class shost_class = { | |
51 | .name = "scsi_host", | |
52 | .release = scsi_host_cls_release, | |
53 | }; | |
54 | ||
d3301874 MA |
55 | /** |
56 | * scsi_host_set_state - Take the given host through the host | |
57 | * state model. | |
58 | * @shost: scsi host to change the state of. | |
59 | * @state: state to change to. | |
60 | * | |
61 | * Returns zero if unsuccessful or an error if the requested | |
62 | * transition is illegal. | |
63 | **/ | |
64 | int scsi_host_set_state(struct Scsi_Host *shost, enum scsi_host_state state) | |
65 | { | |
66 | enum scsi_host_state oldstate = shost->shost_state; | |
67 | ||
68 | if (state == oldstate) | |
69 | return 0; | |
70 | ||
71 | switch (state) { | |
72 | case SHOST_CREATED: | |
73 | /* There are no legal states that come back to | |
74 | * created. This is the manually initialised start | |
75 | * state */ | |
76 | goto illegal; | |
77 | ||
78 | case SHOST_RUNNING: | |
79 | switch (oldstate) { | |
80 | case SHOST_CREATED: | |
81 | case SHOST_RECOVERY: | |
82 | break; | |
83 | default: | |
84 | goto illegal; | |
85 | } | |
86 | break; | |
87 | ||
88 | case SHOST_RECOVERY: | |
89 | switch (oldstate) { | |
90 | case SHOST_RUNNING: | |
91 | break; | |
92 | default: | |
93 | goto illegal; | |
94 | } | |
95 | break; | |
96 | ||
97 | case SHOST_CANCEL: | |
98 | switch (oldstate) { | |
99 | case SHOST_CREATED: | |
100 | case SHOST_RUNNING: | |
939647ee | 101 | case SHOST_CANCEL_RECOVERY: |
d3301874 MA |
102 | break; |
103 | default: | |
104 | goto illegal; | |
105 | } | |
106 | break; | |
107 | ||
108 | case SHOST_DEL: | |
109 | switch (oldstate) { | |
110 | case SHOST_CANCEL: | |
939647ee | 111 | case SHOST_DEL_RECOVERY: |
d3301874 MA |
112 | break; |
113 | default: | |
114 | goto illegal; | |
115 | } | |
116 | break; | |
117 | ||
939647ee JB |
118 | case SHOST_CANCEL_RECOVERY: |
119 | switch (oldstate) { | |
120 | case SHOST_CANCEL: | |
121 | case SHOST_RECOVERY: | |
122 | break; | |
123 | default: | |
124 | goto illegal; | |
125 | } | |
126 | break; | |
127 | ||
128 | case SHOST_DEL_RECOVERY: | |
129 | switch (oldstate) { | |
130 | case SHOST_CANCEL_RECOVERY: | |
131 | break; | |
132 | default: | |
133 | goto illegal; | |
134 | } | |
135 | break; | |
d3301874 MA |
136 | } |
137 | shost->shost_state = state; | |
138 | return 0; | |
139 | ||
140 | illegal: | |
141 | SCSI_LOG_ERROR_RECOVERY(1, | |
142 | dev_printk(KERN_ERR, &shost->shost_gendev, | |
143 | "Illegal host state transition" | |
144 | "%s->%s\n", | |
145 | scsi_host_state_name(oldstate), | |
146 | scsi_host_state_name(state))); | |
147 | return -EINVAL; | |
148 | } | |
149 | EXPORT_SYMBOL(scsi_host_set_state); | |
150 | ||
1da177e4 LT |
151 | /** |
152 | * scsi_remove_host - remove a scsi host | |
153 | * @shost: a pointer to a scsi host to remove | |
154 | **/ | |
155 | void scsi_remove_host(struct Scsi_Host *shost) | |
156 | { | |
939647ee | 157 | unsigned long flags; |
82f29467 | 158 | down(&shost->scan_mutex); |
939647ee JB |
159 | spin_lock_irqsave(shost->host_lock, flags); |
160 | if (scsi_host_set_state(shost, SHOST_CANCEL)) | |
161 | if (scsi_host_set_state(shost, SHOST_CANCEL_RECOVERY)) { | |
162 | spin_unlock_irqrestore(shost->host_lock, flags); | |
163 | up(&shost->scan_mutex); | |
164 | return; | |
165 | } | |
166 | spin_unlock_irqrestore(shost->host_lock, flags); | |
82f29467 | 167 | up(&shost->scan_mutex); |
1da177e4 | 168 | scsi_forget_host(shost); |
1da177e4 LT |
169 | scsi_proc_host_rm(shost); |
170 | ||
939647ee JB |
171 | spin_lock_irqsave(shost->host_lock, flags); |
172 | if (scsi_host_set_state(shost, SHOST_DEL)) | |
173 | BUG_ON(scsi_host_set_state(shost, SHOST_DEL_RECOVERY)); | |
174 | spin_unlock_irqrestore(shost->host_lock, flags); | |
1da177e4 LT |
175 | |
176 | transport_unregister_device(&shost->shost_gendev); | |
177 | class_device_unregister(&shost->shost_classdev); | |
178 | device_del(&shost->shost_gendev); | |
9e70592f | 179 | scsi_proc_hostdir_rm(shost->hostt); |
1da177e4 LT |
180 | } |
181 | EXPORT_SYMBOL(scsi_remove_host); | |
182 | ||
183 | /** | |
184 | * scsi_add_host - add a scsi host | |
185 | * @shost: scsi host pointer to add | |
186 | * @dev: a struct device of type scsi class | |
187 | * | |
188 | * Return value: | |
189 | * 0 on success / != 0 for error | |
190 | **/ | |
191 | int scsi_add_host(struct Scsi_Host *shost, struct device *dev) | |
192 | { | |
193 | struct scsi_host_template *sht = shost->hostt; | |
194 | int error = -EINVAL; | |
195 | ||
196 | printk(KERN_INFO "scsi%d : %s\n", shost->host_no, | |
197 | sht->info ? sht->info(shost) : sht->name); | |
198 | ||
199 | if (!shost->can_queue) { | |
200 | printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", | |
201 | sht->name); | |
202 | goto out; | |
203 | } | |
204 | ||
205 | if (!shost->shost_gendev.parent) | |
206 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
207 | ||
208 | error = device_add(&shost->shost_gendev); | |
209 | if (error) | |
210 | goto out; | |
211 | ||
d3301874 | 212 | scsi_host_set_state(shost, SHOST_RUNNING); |
1da177e4 LT |
213 | get_device(shost->shost_gendev.parent); |
214 | ||
215 | error = class_device_add(&shost->shost_classdev); | |
216 | if (error) | |
217 | goto out_del_gendev; | |
218 | ||
219 | get_device(&shost->shost_gendev); | |
220 | ||
221 | if (shost->transportt->host_size && | |
222 | (shost->shost_data = kmalloc(shost->transportt->host_size, | |
223 | GFP_KERNEL)) == NULL) | |
224 | goto out_del_classdev; | |
225 | ||
226 | if (shost->transportt->create_work_queue) { | |
227 | snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", | |
228 | shost->host_no); | |
229 | shost->work_q = create_singlethread_workqueue( | |
230 | shost->work_q_name); | |
231 | if (!shost->work_q) | |
232 | goto out_free_shost_data; | |
233 | } | |
234 | ||
235 | error = scsi_sysfs_add_host(shost); | |
236 | if (error) | |
237 | goto out_destroy_host; | |
238 | ||
239 | scsi_proc_host_add(shost); | |
240 | return error; | |
241 | ||
242 | out_destroy_host: | |
243 | if (shost->work_q) | |
244 | destroy_workqueue(shost->work_q); | |
245 | out_free_shost_data: | |
246 | kfree(shost->shost_data); | |
247 | out_del_classdev: | |
248 | class_device_del(&shost->shost_classdev); | |
249 | out_del_gendev: | |
250 | device_del(&shost->shost_gendev); | |
251 | out: | |
252 | return error; | |
253 | } | |
254 | EXPORT_SYMBOL(scsi_add_host); | |
255 | ||
256 | static void scsi_host_dev_release(struct device *dev) | |
257 | { | |
258 | struct Scsi_Host *shost = dev_to_shost(dev); | |
259 | struct device *parent = dev->parent; | |
260 | ||
c5478def CH |
261 | if (shost->ehandler) |
262 | kthread_stop(shost->ehandler); | |
1da177e4 LT |
263 | if (shost->work_q) |
264 | destroy_workqueue(shost->work_q); | |
265 | ||
1da177e4 LT |
266 | scsi_destroy_command_freelist(shost); |
267 | kfree(shost->shost_data); | |
268 | ||
1da177e4 LT |
269 | if (parent) |
270 | put_device(parent); | |
271 | kfree(shost); | |
272 | } | |
273 | ||
274 | /** | |
275 | * scsi_host_alloc - register a scsi host adapter instance. | |
276 | * @sht: pointer to scsi host template | |
277 | * @privsize: extra bytes to allocate for driver | |
278 | * | |
279 | * Note: | |
280 | * Allocate a new Scsi_Host and perform basic initialization. | |
281 | * The host is not published to the scsi midlayer until scsi_add_host | |
282 | * is called. | |
283 | * | |
284 | * Return value: | |
285 | * Pointer to a new Scsi_Host | |
286 | **/ | |
287 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
288 | { | |
289 | struct Scsi_Host *shost; | |
290 | int gfp_mask = GFP_KERNEL, rval; | |
1da177e4 LT |
291 | |
292 | if (sht->unchecked_isa_dma && privsize) | |
293 | gfp_mask |= __GFP_DMA; | |
294 | ||
295 | /* Check to see if this host has any error handling facilities */ | |
296 | if (!sht->eh_strategy_handler && !sht->eh_abort_handler && | |
297 | !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && | |
298 | !sht->eh_host_reset_handler) { | |
299 | printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" | |
300 | "ERROR: This is not a safe way to run your " | |
301 | "SCSI host\n" | |
302 | "ERROR: The error handling must be added to " | |
303 | "this driver\n", sht->proc_name); | |
304 | dump_stack(); | |
305 | } | |
306 | ||
307 | shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); | |
308 | if (!shost) | |
309 | return NULL; | |
310 | memset(shost, 0, sizeof(struct Scsi_Host) + privsize); | |
311 | ||
312 | spin_lock_init(&shost->default_lock); | |
313 | scsi_assign_lock(shost, &shost->default_lock); | |
d3301874 | 314 | shost->shost_state = SHOST_CREATED; |
1da177e4 LT |
315 | INIT_LIST_HEAD(&shost->__devices); |
316 | INIT_LIST_HEAD(&shost->__targets); | |
317 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
318 | INIT_LIST_HEAD(&shost->starved_list); | |
319 | init_waitqueue_head(&shost->host_wait); | |
320 | ||
321 | init_MUTEX(&shost->scan_mutex); | |
322 | ||
323 | shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ | |
324 | shost->dma_channel = 0xff; | |
325 | ||
326 | /* These three are default values which can be overridden */ | |
327 | shost->max_channel = 0; | |
328 | shost->max_id = 8; | |
329 | shost->max_lun = 8; | |
330 | ||
331 | /* Give each shost a default transportt */ | |
332 | shost->transportt = &blank_transport_template; | |
333 | ||
334 | /* | |
335 | * All drivers right now should be able to handle 12 byte | |
336 | * commands. Every so often there are requests for 16 byte | |
337 | * commands, but individual low-level drivers need to certify that | |
338 | * they actually do something sensible with such commands. | |
339 | */ | |
340 | shost->max_cmd_len = 12; | |
341 | shost->hostt = sht; | |
342 | shost->this_id = sht->this_id; | |
343 | shost->can_queue = sht->can_queue; | |
344 | shost->sg_tablesize = sht->sg_tablesize; | |
345 | shost->cmd_per_lun = sht->cmd_per_lun; | |
346 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
347 | shost->use_clustering = sht->use_clustering; | |
348 | shost->ordered_flush = sht->ordered_flush; | |
349 | shost->ordered_tag = sht->ordered_tag; | |
350 | ||
351 | /* | |
352 | * hosts/devices that do queueing must support ordered tags | |
353 | */ | |
354 | if (shost->can_queue > 1 && shost->ordered_flush) { | |
355 | printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); | |
356 | shost->ordered_flush = 0; | |
357 | } | |
358 | ||
359 | if (sht->max_host_blocked) | |
360 | shost->max_host_blocked = sht->max_host_blocked; | |
361 | else | |
362 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
363 | ||
364 | /* | |
365 | * If the driver imposes no hard sector transfer limit, start at | |
366 | * machine infinity initially. | |
367 | */ | |
368 | if (sht->max_sectors) | |
369 | shost->max_sectors = sht->max_sectors; | |
370 | else | |
371 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
372 | ||
373 | /* | |
374 | * assume a 4GB boundary, if not set | |
375 | */ | |
376 | if (sht->dma_boundary) | |
377 | shost->dma_boundary = sht->dma_boundary; | |
378 | else | |
379 | shost->dma_boundary = 0xffffffff; | |
380 | ||
381 | rval = scsi_setup_command_freelist(shost); | |
382 | if (rval) | |
383 | goto fail_kfree; | |
384 | ||
385 | device_initialize(&shost->shost_gendev); | |
386 | snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", | |
387 | shost->host_no); | |
388 | shost->shost_gendev.release = scsi_host_dev_release; | |
389 | ||
390 | class_device_initialize(&shost->shost_classdev); | |
391 | shost->shost_classdev.dev = &shost->shost_gendev; | |
392 | shost->shost_classdev.class = &shost_class; | |
393 | snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", | |
394 | shost->host_no); | |
395 | ||
c5478def CH |
396 | shost->ehandler = kthread_run(scsi_error_handler, shost, |
397 | "scsi_eh_%d", shost->host_no); | |
398 | if (IS_ERR(shost->ehandler)) { | |
399 | rval = PTR_ERR(shost->ehandler); | |
1da177e4 | 400 | goto fail_destroy_freelist; |
c5478def | 401 | } |
1da177e4 LT |
402 | |
403 | scsi_proc_hostdir_add(shost->hostt); | |
404 | return shost; | |
405 | ||
406 | fail_destroy_freelist: | |
407 | scsi_destroy_command_freelist(shost); | |
408 | fail_kfree: | |
409 | kfree(shost); | |
410 | return NULL; | |
411 | } | |
412 | EXPORT_SYMBOL(scsi_host_alloc); | |
413 | ||
414 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
415 | { | |
416 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
417 | ||
418 | if (!sht->detect) { | |
419 | printk(KERN_WARNING "scsi_register() called on new-style " | |
420 | "template for driver %s\n", sht->name); | |
421 | dump_stack(); | |
422 | } | |
423 | ||
424 | if (shost) | |
425 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
426 | return shost; | |
427 | } | |
428 | EXPORT_SYMBOL(scsi_register); | |
429 | ||
430 | void scsi_unregister(struct Scsi_Host *shost) | |
431 | { | |
432 | list_del(&shost->sht_legacy_list); | |
433 | scsi_host_put(shost); | |
434 | } | |
435 | EXPORT_SYMBOL(scsi_unregister); | |
436 | ||
437 | /** | |
438 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
439 | * | |
440 | * @hostnum: host number to locate | |
441 | * | |
442 | * Return value: | |
443 | * A pointer to located Scsi_Host or NULL. | |
444 | **/ | |
445 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
446 | { | |
447 | struct class *class = &shost_class; | |
448 | struct class_device *cdev; | |
449 | struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; | |
450 | ||
451 | down_read(&class->subsys.rwsem); | |
452 | list_for_each_entry(cdev, &class->children, node) { | |
453 | p = class_to_shost(cdev); | |
454 | if (p->host_no == hostnum) { | |
455 | shost = scsi_host_get(p); | |
456 | break; | |
457 | } | |
458 | } | |
459 | up_read(&class->subsys.rwsem); | |
460 | ||
461 | return shost; | |
462 | } | |
463 | EXPORT_SYMBOL(scsi_host_lookup); | |
464 | ||
465 | /** | |
466 | * scsi_host_get - inc a Scsi_Host ref count | |
467 | * @shost: Pointer to Scsi_Host to inc. | |
468 | **/ | |
469 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
470 | { | |
d3301874 | 471 | if ((shost->shost_state == SHOST_DEL) || |
1da177e4 LT |
472 | !get_device(&shost->shost_gendev)) |
473 | return NULL; | |
474 | return shost; | |
475 | } | |
476 | EXPORT_SYMBOL(scsi_host_get); | |
477 | ||
478 | /** | |
479 | * scsi_host_put - dec a Scsi_Host ref count | |
480 | * @shost: Pointer to Scsi_Host to dec. | |
481 | **/ | |
482 | void scsi_host_put(struct Scsi_Host *shost) | |
483 | { | |
484 | put_device(&shost->shost_gendev); | |
485 | } | |
486 | EXPORT_SYMBOL(scsi_host_put); | |
487 | ||
488 | int scsi_init_hosts(void) | |
489 | { | |
490 | return class_register(&shost_class); | |
491 | } | |
492 | ||
493 | void scsi_exit_hosts(void) | |
494 | { | |
495 | class_unregister(&shost_class); | |
496 | } | |
497 | ||
498 | int scsi_is_host_device(const struct device *dev) | |
499 | { | |
500 | return dev->release == scsi_host_dev_release; | |
501 | } | |
502 | EXPORT_SYMBOL(scsi_is_host_device); | |
503 | ||
504 | /** | |
505 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
506 | * @shost: Pointer to Scsi_Host. | |
507 | * @work: Work to queue for execution. | |
508 | * | |
509 | * Return value: | |
510 | * 0 on success / != 0 for error | |
511 | **/ | |
512 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
513 | { | |
514 | if (unlikely(!shost->work_q)) { | |
515 | printk(KERN_ERR | |
516 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " | |
517 | "when no workqueue created.\n", shost->hostt->name); | |
518 | dump_stack(); | |
519 | ||
520 | return -EINVAL; | |
521 | } | |
522 | ||
523 | return queue_work(shost->work_q, work); | |
524 | } | |
525 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
526 | ||
527 | /** | |
528 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
529 | * @shost: Pointer to Scsi_Host. | |
530 | **/ | |
531 | void scsi_flush_work(struct Scsi_Host *shost) | |
532 | { | |
533 | if (!shost->work_q) { | |
534 | printk(KERN_ERR | |
535 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " | |
536 | "when no workqueue created.\n", shost->hostt->name); | |
537 | dump_stack(); | |
538 | return; | |
539 | } | |
540 | ||
541 | flush_workqueue(shost->work_q); | |
542 | } | |
543 | EXPORT_SYMBOL_GPL(scsi_flush_work); |