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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> | |
27 | #include <linux/string.h> | |
28 | #include <linux/mm.h> | |
29 | #include <linux/init.h> | |
30 | #include <linux/completion.h> | |
31 | #include <linux/transport_class.h> | |
32 | ||
33 | #include <scsi/scsi_device.h> | |
34 | #include <scsi/scsi_host.h> | |
35 | #include <scsi/scsi_transport.h> | |
36 | ||
37 | #include "scsi_priv.h" | |
38 | #include "scsi_logging.h" | |
39 | ||
40 | ||
41 | static int scsi_host_next_hn; /* host_no for next new host */ | |
42 | ||
43 | ||
44 | static void scsi_host_cls_release(struct class_device *class_dev) | |
45 | { | |
46 | put_device(&class_to_shost(class_dev)->shost_gendev); | |
47 | } | |
48 | ||
49 | static struct class shost_class = { | |
50 | .name = "scsi_host", | |
51 | .release = scsi_host_cls_release, | |
52 | }; | |
53 | ||
54 | /** | |
55 | * scsi_host_cancel - cancel outstanding IO to this host | |
56 | * @shost: pointer to struct Scsi_Host | |
57 | * recovery: recovery requested to run. | |
58 | **/ | |
59 | void scsi_host_cancel(struct Scsi_Host *shost, int recovery) | |
60 | { | |
61 | struct scsi_device *sdev; | |
62 | ||
63 | set_bit(SHOST_CANCEL, &shost->shost_state); | |
64 | shost_for_each_device(sdev, shost) { | |
65 | scsi_device_cancel(sdev, recovery); | |
66 | } | |
67 | wait_event(shost->host_wait, (!test_bit(SHOST_RECOVERY, | |
68 | &shost->shost_state))); | |
69 | } | |
70 | ||
71 | /** | |
72 | * scsi_remove_host - remove a scsi host | |
73 | * @shost: a pointer to a scsi host to remove | |
74 | **/ | |
75 | void scsi_remove_host(struct Scsi_Host *shost) | |
76 | { | |
77 | scsi_forget_host(shost); | |
78 | scsi_host_cancel(shost, 0); | |
79 | scsi_proc_host_rm(shost); | |
80 | ||
81 | set_bit(SHOST_DEL, &shost->shost_state); | |
82 | ||
83 | transport_unregister_device(&shost->shost_gendev); | |
84 | class_device_unregister(&shost->shost_classdev); | |
85 | device_del(&shost->shost_gendev); | |
86 | } | |
87 | EXPORT_SYMBOL(scsi_remove_host); | |
88 | ||
89 | /** | |
90 | * scsi_add_host - add a scsi host | |
91 | * @shost: scsi host pointer to add | |
92 | * @dev: a struct device of type scsi class | |
93 | * | |
94 | * Return value: | |
95 | * 0 on success / != 0 for error | |
96 | **/ | |
97 | int scsi_add_host(struct Scsi_Host *shost, struct device *dev) | |
98 | { | |
99 | struct scsi_host_template *sht = shost->hostt; | |
100 | int error = -EINVAL; | |
101 | ||
102 | printk(KERN_INFO "scsi%d : %s\n", shost->host_no, | |
103 | sht->info ? sht->info(shost) : sht->name); | |
104 | ||
105 | if (!shost->can_queue) { | |
106 | printk(KERN_ERR "%s: can_queue = 0 no longer supported\n", | |
107 | sht->name); | |
108 | goto out; | |
109 | } | |
110 | ||
111 | if (!shost->shost_gendev.parent) | |
112 | shost->shost_gendev.parent = dev ? dev : &platform_bus; | |
113 | ||
114 | error = device_add(&shost->shost_gendev); | |
115 | if (error) | |
116 | goto out; | |
117 | ||
118 | set_bit(SHOST_ADD, &shost->shost_state); | |
119 | get_device(shost->shost_gendev.parent); | |
120 | ||
121 | error = class_device_add(&shost->shost_classdev); | |
122 | if (error) | |
123 | goto out_del_gendev; | |
124 | ||
125 | get_device(&shost->shost_gendev); | |
126 | ||
127 | if (shost->transportt->host_size && | |
128 | (shost->shost_data = kmalloc(shost->transportt->host_size, | |
129 | GFP_KERNEL)) == NULL) | |
130 | goto out_del_classdev; | |
131 | ||
132 | if (shost->transportt->create_work_queue) { | |
133 | snprintf(shost->work_q_name, KOBJ_NAME_LEN, "scsi_wq_%d", | |
134 | shost->host_no); | |
135 | shost->work_q = create_singlethread_workqueue( | |
136 | shost->work_q_name); | |
137 | if (!shost->work_q) | |
138 | goto out_free_shost_data; | |
139 | } | |
140 | ||
141 | error = scsi_sysfs_add_host(shost); | |
142 | if (error) | |
143 | goto out_destroy_host; | |
144 | ||
145 | scsi_proc_host_add(shost); | |
146 | return error; | |
147 | ||
148 | out_destroy_host: | |
149 | if (shost->work_q) | |
150 | destroy_workqueue(shost->work_q); | |
151 | out_free_shost_data: | |
152 | kfree(shost->shost_data); | |
153 | out_del_classdev: | |
154 | class_device_del(&shost->shost_classdev); | |
155 | out_del_gendev: | |
156 | device_del(&shost->shost_gendev); | |
157 | out: | |
158 | return error; | |
159 | } | |
160 | EXPORT_SYMBOL(scsi_add_host); | |
161 | ||
162 | static void scsi_host_dev_release(struct device *dev) | |
163 | { | |
164 | struct Scsi_Host *shost = dev_to_shost(dev); | |
165 | struct device *parent = dev->parent; | |
166 | ||
167 | if (shost->ehandler) { | |
168 | DECLARE_COMPLETION(sem); | |
169 | shost->eh_notify = &sem; | |
170 | shost->eh_kill = 1; | |
171 | up(shost->eh_wait); | |
172 | wait_for_completion(&sem); | |
173 | shost->eh_notify = NULL; | |
174 | } | |
175 | ||
176 | if (shost->work_q) | |
177 | destroy_workqueue(shost->work_q); | |
178 | ||
179 | scsi_proc_hostdir_rm(shost->hostt); | |
180 | scsi_destroy_command_freelist(shost); | |
181 | kfree(shost->shost_data); | |
182 | ||
183 | /* | |
184 | * Some drivers (eg aha1542) do scsi_register()/scsi_unregister() | |
185 | * during probing without performing a scsi_set_device() in between. | |
186 | * In this case dev->parent is NULL. | |
187 | */ | |
188 | if (parent) | |
189 | put_device(parent); | |
190 | kfree(shost); | |
191 | } | |
192 | ||
193 | /** | |
194 | * scsi_host_alloc - register a scsi host adapter instance. | |
195 | * @sht: pointer to scsi host template | |
196 | * @privsize: extra bytes to allocate for driver | |
197 | * | |
198 | * Note: | |
199 | * Allocate a new Scsi_Host and perform basic initialization. | |
200 | * The host is not published to the scsi midlayer until scsi_add_host | |
201 | * is called. | |
202 | * | |
203 | * Return value: | |
204 | * Pointer to a new Scsi_Host | |
205 | **/ | |
206 | struct Scsi_Host *scsi_host_alloc(struct scsi_host_template *sht, int privsize) | |
207 | { | |
208 | struct Scsi_Host *shost; | |
209 | int gfp_mask = GFP_KERNEL, rval; | |
210 | DECLARE_COMPLETION(complete); | |
211 | ||
212 | if (sht->unchecked_isa_dma && privsize) | |
213 | gfp_mask |= __GFP_DMA; | |
214 | ||
215 | /* Check to see if this host has any error handling facilities */ | |
216 | if (!sht->eh_strategy_handler && !sht->eh_abort_handler && | |
217 | !sht->eh_device_reset_handler && !sht->eh_bus_reset_handler && | |
218 | !sht->eh_host_reset_handler) { | |
219 | printk(KERN_ERR "ERROR: SCSI host `%s' has no error handling\n" | |
220 | "ERROR: This is not a safe way to run your " | |
221 | "SCSI host\n" | |
222 | "ERROR: The error handling must be added to " | |
223 | "this driver\n", sht->proc_name); | |
224 | dump_stack(); | |
225 | } | |
226 | ||
227 | shost = kmalloc(sizeof(struct Scsi_Host) + privsize, gfp_mask); | |
228 | if (!shost) | |
229 | return NULL; | |
230 | memset(shost, 0, sizeof(struct Scsi_Host) + privsize); | |
231 | ||
232 | spin_lock_init(&shost->default_lock); | |
233 | scsi_assign_lock(shost, &shost->default_lock); | |
234 | INIT_LIST_HEAD(&shost->__devices); | |
235 | INIT_LIST_HEAD(&shost->__targets); | |
236 | INIT_LIST_HEAD(&shost->eh_cmd_q); | |
237 | INIT_LIST_HEAD(&shost->starved_list); | |
238 | init_waitqueue_head(&shost->host_wait); | |
239 | ||
240 | init_MUTEX(&shost->scan_mutex); | |
241 | ||
242 | shost->host_no = scsi_host_next_hn++; /* XXX(hch): still racy */ | |
243 | shost->dma_channel = 0xff; | |
244 | ||
245 | /* These three are default values which can be overridden */ | |
246 | shost->max_channel = 0; | |
247 | shost->max_id = 8; | |
248 | shost->max_lun = 8; | |
249 | ||
250 | /* Give each shost a default transportt */ | |
251 | shost->transportt = &blank_transport_template; | |
252 | ||
253 | /* | |
254 | * All drivers right now should be able to handle 12 byte | |
255 | * commands. Every so often there are requests for 16 byte | |
256 | * commands, but individual low-level drivers need to certify that | |
257 | * they actually do something sensible with such commands. | |
258 | */ | |
259 | shost->max_cmd_len = 12; | |
260 | shost->hostt = sht; | |
261 | shost->this_id = sht->this_id; | |
262 | shost->can_queue = sht->can_queue; | |
263 | shost->sg_tablesize = sht->sg_tablesize; | |
264 | shost->cmd_per_lun = sht->cmd_per_lun; | |
265 | shost->unchecked_isa_dma = sht->unchecked_isa_dma; | |
266 | shost->use_clustering = sht->use_clustering; | |
267 | shost->ordered_flush = sht->ordered_flush; | |
268 | shost->ordered_tag = sht->ordered_tag; | |
269 | ||
270 | /* | |
271 | * hosts/devices that do queueing must support ordered tags | |
272 | */ | |
273 | if (shost->can_queue > 1 && shost->ordered_flush) { | |
274 | printk(KERN_ERR "scsi: ordered flushes don't support queueing\n"); | |
275 | shost->ordered_flush = 0; | |
276 | } | |
277 | ||
278 | if (sht->max_host_blocked) | |
279 | shost->max_host_blocked = sht->max_host_blocked; | |
280 | else | |
281 | shost->max_host_blocked = SCSI_DEFAULT_HOST_BLOCKED; | |
282 | ||
283 | /* | |
284 | * If the driver imposes no hard sector transfer limit, start at | |
285 | * machine infinity initially. | |
286 | */ | |
287 | if (sht->max_sectors) | |
288 | shost->max_sectors = sht->max_sectors; | |
289 | else | |
290 | shost->max_sectors = SCSI_DEFAULT_MAX_SECTORS; | |
291 | ||
292 | /* | |
293 | * assume a 4GB boundary, if not set | |
294 | */ | |
295 | if (sht->dma_boundary) | |
296 | shost->dma_boundary = sht->dma_boundary; | |
297 | else | |
298 | shost->dma_boundary = 0xffffffff; | |
299 | ||
300 | rval = scsi_setup_command_freelist(shost); | |
301 | if (rval) | |
302 | goto fail_kfree; | |
303 | ||
304 | device_initialize(&shost->shost_gendev); | |
305 | snprintf(shost->shost_gendev.bus_id, BUS_ID_SIZE, "host%d", | |
306 | shost->host_no); | |
307 | shost->shost_gendev.release = scsi_host_dev_release; | |
308 | ||
309 | class_device_initialize(&shost->shost_classdev); | |
310 | shost->shost_classdev.dev = &shost->shost_gendev; | |
311 | shost->shost_classdev.class = &shost_class; | |
312 | snprintf(shost->shost_classdev.class_id, BUS_ID_SIZE, "host%d", | |
313 | shost->host_no); | |
314 | ||
315 | shost->eh_notify = &complete; | |
316 | rval = kernel_thread(scsi_error_handler, shost, 0); | |
317 | if (rval < 0) | |
318 | goto fail_destroy_freelist; | |
319 | wait_for_completion(&complete); | |
320 | shost->eh_notify = NULL; | |
321 | ||
322 | scsi_proc_hostdir_add(shost->hostt); | |
323 | return shost; | |
324 | ||
325 | fail_destroy_freelist: | |
326 | scsi_destroy_command_freelist(shost); | |
327 | fail_kfree: | |
328 | kfree(shost); | |
329 | return NULL; | |
330 | } | |
331 | EXPORT_SYMBOL(scsi_host_alloc); | |
332 | ||
333 | struct Scsi_Host *scsi_register(struct scsi_host_template *sht, int privsize) | |
334 | { | |
335 | struct Scsi_Host *shost = scsi_host_alloc(sht, privsize); | |
336 | ||
337 | if (!sht->detect) { | |
338 | printk(KERN_WARNING "scsi_register() called on new-style " | |
339 | "template for driver %s\n", sht->name); | |
340 | dump_stack(); | |
341 | } | |
342 | ||
343 | if (shost) | |
344 | list_add_tail(&shost->sht_legacy_list, &sht->legacy_hosts); | |
345 | return shost; | |
346 | } | |
347 | EXPORT_SYMBOL(scsi_register); | |
348 | ||
349 | void scsi_unregister(struct Scsi_Host *shost) | |
350 | { | |
351 | list_del(&shost->sht_legacy_list); | |
352 | scsi_host_put(shost); | |
353 | } | |
354 | EXPORT_SYMBOL(scsi_unregister); | |
355 | ||
356 | /** | |
357 | * scsi_host_lookup - get a reference to a Scsi_Host by host no | |
358 | * | |
359 | * @hostnum: host number to locate | |
360 | * | |
361 | * Return value: | |
362 | * A pointer to located Scsi_Host or NULL. | |
363 | **/ | |
364 | struct Scsi_Host *scsi_host_lookup(unsigned short hostnum) | |
365 | { | |
366 | struct class *class = &shost_class; | |
367 | struct class_device *cdev; | |
368 | struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p; | |
369 | ||
370 | down_read(&class->subsys.rwsem); | |
371 | list_for_each_entry(cdev, &class->children, node) { | |
372 | p = class_to_shost(cdev); | |
373 | if (p->host_no == hostnum) { | |
374 | shost = scsi_host_get(p); | |
375 | break; | |
376 | } | |
377 | } | |
378 | up_read(&class->subsys.rwsem); | |
379 | ||
380 | return shost; | |
381 | } | |
382 | EXPORT_SYMBOL(scsi_host_lookup); | |
383 | ||
384 | /** | |
385 | * scsi_host_get - inc a Scsi_Host ref count | |
386 | * @shost: Pointer to Scsi_Host to inc. | |
387 | **/ | |
388 | struct Scsi_Host *scsi_host_get(struct Scsi_Host *shost) | |
389 | { | |
390 | if (test_bit(SHOST_DEL, &shost->shost_state) || | |
391 | !get_device(&shost->shost_gendev)) | |
392 | return NULL; | |
393 | return shost; | |
394 | } | |
395 | EXPORT_SYMBOL(scsi_host_get); | |
396 | ||
397 | /** | |
398 | * scsi_host_put - dec a Scsi_Host ref count | |
399 | * @shost: Pointer to Scsi_Host to dec. | |
400 | **/ | |
401 | void scsi_host_put(struct Scsi_Host *shost) | |
402 | { | |
403 | put_device(&shost->shost_gendev); | |
404 | } | |
405 | EXPORT_SYMBOL(scsi_host_put); | |
406 | ||
407 | int scsi_init_hosts(void) | |
408 | { | |
409 | return class_register(&shost_class); | |
410 | } | |
411 | ||
412 | void scsi_exit_hosts(void) | |
413 | { | |
414 | class_unregister(&shost_class); | |
415 | } | |
416 | ||
417 | int scsi_is_host_device(const struct device *dev) | |
418 | { | |
419 | return dev->release == scsi_host_dev_release; | |
420 | } | |
421 | EXPORT_SYMBOL(scsi_is_host_device); | |
422 | ||
423 | /** | |
424 | * scsi_queue_work - Queue work to the Scsi_Host workqueue. | |
425 | * @shost: Pointer to Scsi_Host. | |
426 | * @work: Work to queue for execution. | |
427 | * | |
428 | * Return value: | |
429 | * 0 on success / != 0 for error | |
430 | **/ | |
431 | int scsi_queue_work(struct Scsi_Host *shost, struct work_struct *work) | |
432 | { | |
433 | if (unlikely(!shost->work_q)) { | |
434 | printk(KERN_ERR | |
435 | "ERROR: Scsi host '%s' attempted to queue scsi-work, " | |
436 | "when no workqueue created.\n", shost->hostt->name); | |
437 | dump_stack(); | |
438 | ||
439 | return -EINVAL; | |
440 | } | |
441 | ||
442 | return queue_work(shost->work_q, work); | |
443 | } | |
444 | EXPORT_SYMBOL_GPL(scsi_queue_work); | |
445 | ||
446 | /** | |
447 | * scsi_flush_work - Flush a Scsi_Host's workqueue. | |
448 | * @shost: Pointer to Scsi_Host. | |
449 | **/ | |
450 | void scsi_flush_work(struct Scsi_Host *shost) | |
451 | { | |
452 | if (!shost->work_q) { | |
453 | printk(KERN_ERR | |
454 | "ERROR: Scsi host '%s' attempted to flush scsi-work, " | |
455 | "when no workqueue created.\n", shost->hostt->name); | |
456 | dump_stack(); | |
457 | return; | |
458 | } | |
459 | ||
460 | flush_workqueue(shost->work_q); | |
461 | } | |
462 | EXPORT_SYMBOL_GPL(scsi_flush_work); |