Commit | Line | Data |
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a6a8d9f8 CS |
1 | /* |
2 | * SCSI device handler infrastruture. | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify it | |
5 | * under the terms of the GNU General Public License as published by the | |
6 | * Free Software Foundation; either version 2 of the License, or (at your | |
7 | * option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, but | |
10 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
12 | * General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License along | |
15 | * with this program; if not, write to the Free Software Foundation, Inc., | |
16 | * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright IBM Corporation, 2007 | |
19 | * Authors: | |
20 | * Chandra Seetharaman <sekharan@us.ibm.com> | |
21 | * Mike Anderson <andmike@linux.vnet.ibm.com> | |
22 | */ | |
23 | ||
5a0e3ad6 | 24 | #include <linux/slab.h> |
acf3368f | 25 | #include <linux/module.h> |
a6a8d9f8 | 26 | #include <scsi/scsi_dh.h> |
daaa858b | 27 | #include "scsi_priv.h" |
a6a8d9f8 CS |
28 | |
29 | static DEFINE_SPINLOCK(list_lock); | |
30 | static LIST_HEAD(scsi_dh_list); | |
31 | ||
d95dbff2 CH |
32 | struct scsi_dh_blist { |
33 | const char *vendor; | |
34 | const char *model; | |
35 | const char *driver; | |
36 | }; | |
37 | ||
38 | static const struct scsi_dh_blist scsi_dh_blist[] = { | |
39 | {"DGC", "RAID", "clariion" }, | |
40 | {"DGC", "DISK", "clariion" }, | |
41 | {"DGC", "VRAID", "clariion" }, | |
42 | ||
43 | {"COMPAQ", "MSA1000 VOLUME", "hp_sw" }, | |
44 | {"COMPAQ", "HSV110", "hp_sw" }, | |
45 | {"HP", "HSV100", "hp_sw"}, | |
46 | {"DEC", "HSG80", "hp_sw"}, | |
47 | ||
48 | {"IBM", "1722", "rdac", }, | |
49 | {"IBM", "1724", "rdac", }, | |
50 | {"IBM", "1726", "rdac", }, | |
51 | {"IBM", "1742", "rdac", }, | |
52 | {"IBM", "1745", "rdac", }, | |
53 | {"IBM", "1746", "rdac", }, | |
54 | {"IBM", "1813", "rdac", }, | |
55 | {"IBM", "1814", "rdac", }, | |
56 | {"IBM", "1815", "rdac", }, | |
57 | {"IBM", "1818", "rdac", }, | |
58 | {"IBM", "3526", "rdac", }, | |
59 | {"SGI", "TP9", "rdac", }, | |
60 | {"SGI", "IS", "rdac", }, | |
61 | {"STK", "OPENstorage D280", "rdac", }, | |
62 | {"STK", "FLEXLINE 380", "rdac", }, | |
63 | {"SUN", "CSM", "rdac", }, | |
64 | {"SUN", "LCSM100", "rdac", }, | |
65 | {"SUN", "STK6580_6780", "rdac", }, | |
66 | {"SUN", "SUN_6180", "rdac", }, | |
67 | {"SUN", "ArrayStorage", "rdac", }, | |
68 | {"DELL", "MD3", "rdac", }, | |
69 | {"NETAPP", "INF-01-00", "rdac", }, | |
70 | {"LSI", "INF-01-00", "rdac", }, | |
71 | {"ENGENIO", "INF-01-00", "rdac", }, | |
72 | {NULL, NULL, NULL }, | |
73 | }; | |
74 | ||
75 | static const char * | |
76 | scsi_dh_find_driver(struct scsi_device *sdev) | |
77 | { | |
78 | const struct scsi_dh_blist *b; | |
79 | ||
80 | if (scsi_device_tpgs(sdev)) | |
81 | return "alua"; | |
82 | ||
83 | for (b = scsi_dh_blist; b->vendor; b++) { | |
84 | if (!strncmp(sdev->vendor, b->vendor, strlen(b->vendor)) && | |
85 | !strncmp(sdev->model, b->model, strlen(b->model))) { | |
86 | return b->driver; | |
87 | } | |
88 | } | |
89 | return NULL; | |
90 | } | |
91 | ||
92 | ||
566079c8 | 93 | static struct scsi_device_handler *__scsi_dh_lookup(const char *name) |
a6a8d9f8 CS |
94 | { |
95 | struct scsi_device_handler *tmp, *found = NULL; | |
96 | ||
97 | spin_lock(&list_lock); | |
98 | list_for_each_entry(tmp, &scsi_dh_list, list) { | |
765cbc6d | 99 | if (!strncmp(tmp->name, name, strlen(tmp->name))) { |
a6a8d9f8 CS |
100 | found = tmp; |
101 | break; | |
102 | } | |
103 | } | |
104 | spin_unlock(&list_lock); | |
105 | return found; | |
106 | } | |
107 | ||
566079c8 CH |
108 | static struct scsi_device_handler *scsi_dh_lookup(const char *name) |
109 | { | |
110 | struct scsi_device_handler *dh; | |
111 | ||
112 | dh = __scsi_dh_lookup(name); | |
113 | if (!dh) { | |
114 | request_module(name); | |
115 | dh = __scsi_dh_lookup(name); | |
116 | } | |
117 | ||
118 | return dh; | |
119 | } | |
120 | ||
a6a8d9f8 | 121 | /* |
765cbc6d HR |
122 | * scsi_dh_handler_attach - Attach a device handler to a device |
123 | * @sdev - SCSI device the device handler should attach to | |
124 | * @scsi_dh - The device handler to attach | |
125 | */ | |
126 | static int scsi_dh_handler_attach(struct scsi_device *sdev, | |
127 | struct scsi_device_handler *scsi_dh) | |
128 | { | |
1d520328 | 129 | struct scsi_dh_data *d; |
765cbc6d | 130 | |
1f12ffa5 CH |
131 | if (!try_module_get(scsi_dh->module)) |
132 | return -EINVAL; | |
27c888f0 | 133 | |
1d520328 CH |
134 | d = scsi_dh->attach(sdev); |
135 | if (IS_ERR(d)) { | |
136 | sdev_printk(KERN_ERR, sdev, "%s: Attach failed (%ld)\n", | |
137 | scsi_dh->name, PTR_ERR(d)); | |
1f12ffa5 | 138 | module_put(scsi_dh->module); |
1d520328 | 139 | return PTR_ERR(d); |
6c10db72 | 140 | } |
1f12ffa5 | 141 | |
1d520328 | 142 | d->scsi_dh = scsi_dh; |
1d520328 CH |
143 | d->sdev = sdev; |
144 | ||
145 | spin_lock_irq(sdev->request_queue->queue_lock); | |
146 | sdev->scsi_dh_data = d; | |
147 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
148 | return 0; | |
765cbc6d HR |
149 | } |
150 | ||
1bab0de0 CH |
151 | /* |
152 | * scsi_dh_handler_detach - Detach a device handler from a device | |
153 | * @sdev - SCSI device the device handler should be detached from | |
154 | */ | |
155 | static void scsi_dh_handler_detach(struct scsi_device *sdev) | |
6c10db72 | 156 | { |
1bab0de0 | 157 | struct scsi_dh_data *scsi_dh_data = sdev->scsi_dh_data; |
27c888f0 | 158 | struct scsi_device_handler *scsi_dh = scsi_dh_data->scsi_dh; |
1d520328 | 159 | |
28072ad5 MC |
160 | scsi_dh->detach(sdev); |
161 | ||
1d520328 CH |
162 | spin_lock_irq(sdev->request_queue->queue_lock); |
163 | sdev->scsi_dh_data = NULL; | |
164 | spin_unlock_irq(sdev->request_queue->queue_lock); | |
27c888f0 | 165 | |
1d520328 | 166 | sdev_printk(KERN_NOTICE, sdev, "%s: Detached\n", scsi_dh->name); |
27c888f0 | 167 | module_put(scsi_dh->module); |
6c10db72 CS |
168 | } |
169 | ||
4c05ae52 HR |
170 | /* |
171 | * Functions for sysfs attribute 'dh_state' | |
172 | */ | |
173 | static ssize_t | |
174 | store_dh_state(struct device *dev, struct device_attribute *attr, | |
175 | const char *buf, size_t count) | |
176 | { | |
177 | struct scsi_device *sdev = to_scsi_device(dev); | |
178 | struct scsi_device_handler *scsi_dh; | |
179 | int err = -EINVAL; | |
180 | ||
6bc8d2a0 HR |
181 | if (sdev->sdev_state == SDEV_CANCEL || |
182 | sdev->sdev_state == SDEV_DEL) | |
183 | return -ENODEV; | |
184 | ||
4c05ae52 HR |
185 | if (!sdev->scsi_dh_data) { |
186 | /* | |
187 | * Attach to a device handler | |
188 | */ | |
566079c8 CH |
189 | scsi_dh = scsi_dh_lookup(buf); |
190 | if (!scsi_dh) | |
4c05ae52 HR |
191 | return err; |
192 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
193 | } else { | |
194 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
195 | if (!strncmp(buf, "detach", 6)) { | |
196 | /* | |
197 | * Detach from a device handler | |
198 | */ | |
1bab0de0 | 199 | scsi_dh_handler_detach(sdev); |
4c05ae52 HR |
200 | err = 0; |
201 | } else if (!strncmp(buf, "activate", 8)) { | |
202 | /* | |
203 | * Activate a device handler | |
204 | */ | |
205 | if (scsi_dh->activate) | |
3ae31f6a | 206 | err = scsi_dh->activate(sdev, NULL, NULL); |
4c05ae52 HR |
207 | else |
208 | err = 0; | |
209 | } | |
210 | } | |
211 | ||
212 | return err<0?err:count; | |
213 | } | |
214 | ||
215 | static ssize_t | |
216 | show_dh_state(struct device *dev, struct device_attribute *attr, char *buf) | |
217 | { | |
218 | struct scsi_device *sdev = to_scsi_device(dev); | |
219 | ||
220 | if (!sdev->scsi_dh_data) | |
221 | return snprintf(buf, 20, "detached\n"); | |
222 | ||
223 | return snprintf(buf, 20, "%s\n", sdev->scsi_dh_data->scsi_dh->name); | |
224 | } | |
225 | ||
226 | static struct device_attribute scsi_dh_state_attr = | |
227 | __ATTR(dh_state, S_IRUGO | S_IWUSR, show_dh_state, | |
228 | store_dh_state); | |
229 | ||
086b91d0 | 230 | int scsi_dh_add_device(struct scsi_device *sdev) |
4c05ae52 | 231 | { |
d95dbff2 CH |
232 | struct scsi_device_handler *devinfo = NULL; |
233 | const char *drv; | |
4c05ae52 HR |
234 | int err; |
235 | ||
086b91d0 CH |
236 | err = device_create_file(&sdev->sdev_gendev, &scsi_dh_state_attr); |
237 | if (err) | |
238 | return err; | |
4c05ae52 | 239 | |
d95dbff2 CH |
240 | drv = scsi_dh_find_driver(sdev); |
241 | if (drv) | |
242 | devinfo = scsi_dh_lookup(drv); | |
086b91d0 CH |
243 | if (devinfo) |
244 | err = scsi_dh_handler_attach(sdev, devinfo); | |
765cbc6d | 245 | return err; |
a6a8d9f8 | 246 | } |
a6a8d9f8 | 247 | |
086b91d0 | 248 | void scsi_dh_remove_device(struct scsi_device *sdev) |
765cbc6d | 249 | { |
086b91d0 | 250 | if (sdev->scsi_dh_data) |
1bab0de0 | 251 | scsi_dh_handler_detach(sdev); |
086b91d0 | 252 | device_remove_file(&sdev->sdev_gendev, &scsi_dh_state_attr); |
a6a8d9f8 CS |
253 | } |
254 | ||
765cbc6d HR |
255 | /* |
256 | * scsi_register_device_handler - register a device handler personality | |
257 | * module. | |
258 | * @scsi_dh - device handler to be registered. | |
259 | * | |
260 | * Returns 0 on success, -EBUSY if handler already registered. | |
261 | */ | |
262 | int scsi_register_device_handler(struct scsi_device_handler *scsi_dh) | |
263 | { | |
566079c8 | 264 | if (__scsi_dh_lookup(scsi_dh->name)) |
765cbc6d HR |
265 | return -EBUSY; |
266 | ||
1f12ffa5 CH |
267 | if (!scsi_dh->attach || !scsi_dh->detach) |
268 | return -EINVAL; | |
269 | ||
765cbc6d HR |
270 | spin_lock(&list_lock); |
271 | list_add(&scsi_dh->list, &scsi_dh_list); | |
272 | spin_unlock(&list_lock); | |
940d7faa | 273 | |
765cbc6d HR |
274 | printk(KERN_INFO "%s: device handler registered\n", scsi_dh->name); |
275 | ||
276 | return SCSI_DH_OK; | |
277 | } | |
278 | EXPORT_SYMBOL_GPL(scsi_register_device_handler); | |
279 | ||
a6a8d9f8 CS |
280 | /* |
281 | * scsi_unregister_device_handler - register a device handler personality | |
282 | * module. | |
283 | * @scsi_dh - device handler to be unregistered. | |
284 | * | |
285 | * Returns 0 on success, -ENODEV if handler not registered. | |
286 | */ | |
287 | int scsi_unregister_device_handler(struct scsi_device_handler *scsi_dh) | |
288 | { | |
566079c8 | 289 | if (!__scsi_dh_lookup(scsi_dh->name)) |
765cbc6d | 290 | return -ENODEV; |
a6a8d9f8 | 291 | |
a6a8d9f8 CS |
292 | spin_lock(&list_lock); |
293 | list_del(&scsi_dh->list); | |
294 | spin_unlock(&list_lock); | |
765cbc6d | 295 | printk(KERN_INFO "%s: device handler unregistered\n", scsi_dh->name); |
a6a8d9f8 | 296 | |
765cbc6d | 297 | return SCSI_DH_OK; |
a6a8d9f8 CS |
298 | } |
299 | EXPORT_SYMBOL_GPL(scsi_unregister_device_handler); | |
300 | ||
301 | /* | |
302 | * scsi_dh_activate - activate the path associated with the scsi_device | |
303 | * corresponding to the given request queue. | |
3ae31f6a CS |
304 | * Returns immediately without waiting for activation to be completed. |
305 | * @q - Request queue that is associated with the scsi_device to be | |
306 | * activated. | |
307 | * @fn - Function to be called upon completion of the activation. | |
308 | * Function fn is called with data (below) and the error code. | |
309 | * Function fn may be called from the same calling context. So, | |
310 | * do not hold the lock in the caller which may be needed in fn. | |
311 | * @data - data passed to the function fn upon completion. | |
312 | * | |
a6a8d9f8 | 313 | */ |
3ae31f6a | 314 | int scsi_dh_activate(struct request_queue *q, activate_complete fn, void *data) |
a6a8d9f8 CS |
315 | { |
316 | int err = 0; | |
317 | unsigned long flags; | |
318 | struct scsi_device *sdev; | |
319 | struct scsi_device_handler *scsi_dh = NULL; | |
0b839357 | 320 | struct device *dev = NULL; |
a6a8d9f8 CS |
321 | |
322 | spin_lock_irqsave(q->queue_lock, flags); | |
323 | sdev = q->queuedata; | |
a18a920c MB |
324 | if (!sdev) { |
325 | spin_unlock_irqrestore(q->queue_lock, flags); | |
326 | err = SCSI_DH_NOSYS; | |
327 | if (fn) | |
328 | fn(data, err); | |
329 | return err; | |
330 | } | |
331 | ||
332 | if (sdev->scsi_dh_data) | |
a6a8d9f8 | 333 | scsi_dh = sdev->scsi_dh_data->scsi_dh; |
0b839357 MS |
334 | dev = get_device(&sdev->sdev_gendev); |
335 | if (!scsi_dh || !dev || | |
db422318 MH |
336 | sdev->sdev_state == SDEV_CANCEL || |
337 | sdev->sdev_state == SDEV_DEL) | |
a6a8d9f8 | 338 | err = SCSI_DH_NOSYS; |
db422318 MH |
339 | if (sdev->sdev_state == SDEV_OFFLINE) |
340 | err = SCSI_DH_DEV_OFFLINED; | |
a6a8d9f8 CS |
341 | spin_unlock_irqrestore(q->queue_lock, flags); |
342 | ||
db422318 MH |
343 | if (err) { |
344 | if (fn) | |
345 | fn(data, err); | |
0b839357 | 346 | goto out; |
db422318 | 347 | } |
a6a8d9f8 CS |
348 | |
349 | if (scsi_dh->activate) | |
3ae31f6a | 350 | err = scsi_dh->activate(sdev, fn, data); |
0b839357 MS |
351 | out: |
352 | put_device(dev); | |
a6a8d9f8 CS |
353 | return err; |
354 | } | |
355 | EXPORT_SYMBOL_GPL(scsi_dh_activate); | |
356 | ||
18ee70c9 CS |
357 | /* |
358 | * scsi_dh_set_params - set the parameters for the device as per the | |
359 | * string specified in params. | |
360 | * @q - Request queue that is associated with the scsi_device for | |
361 | * which the parameters to be set. | |
362 | * @params - parameters in the following format | |
363 | * "no_of_params\0param1\0param2\0param3\0...\0" | |
364 | * for example, string for 2 parameters with value 10 and 21 | |
365 | * is specified as "2\010\021\0". | |
366 | */ | |
367 | int scsi_dh_set_params(struct request_queue *q, const char *params) | |
368 | { | |
369 | int err = -SCSI_DH_NOSYS; | |
370 | unsigned long flags; | |
371 | struct scsi_device *sdev; | |
372 | struct scsi_device_handler *scsi_dh = NULL; | |
373 | ||
374 | spin_lock_irqsave(q->queue_lock, flags); | |
375 | sdev = q->queuedata; | |
376 | if (sdev && sdev->scsi_dh_data) | |
377 | scsi_dh = sdev->scsi_dh_data->scsi_dh; | |
378 | if (scsi_dh && scsi_dh->set_params && get_device(&sdev->sdev_gendev)) | |
379 | err = 0; | |
380 | spin_unlock_irqrestore(q->queue_lock, flags); | |
381 | ||
382 | if (err) | |
383 | return err; | |
384 | err = scsi_dh->set_params(sdev, params); | |
385 | put_device(&sdev->sdev_gendev); | |
386 | return err; | |
387 | } | |
388 | EXPORT_SYMBOL_GPL(scsi_dh_set_params); | |
389 | ||
ae11b1b3 | 390 | /* |
2a9ab40f | 391 | * scsi_dh_attach - Attach device handler |
7e8a74b1 MS |
392 | * @q - Request queue that is associated with the scsi_device |
393 | * the handler should be attached to | |
ae11b1b3 HR |
394 | * @name - name of the handler to attach |
395 | */ | |
396 | int scsi_dh_attach(struct request_queue *q, const char *name) | |
397 | { | |
398 | unsigned long flags; | |
399 | struct scsi_device *sdev; | |
400 | struct scsi_device_handler *scsi_dh; | |
401 | int err = 0; | |
402 | ||
566079c8 | 403 | scsi_dh = scsi_dh_lookup(name); |
ae11b1b3 HR |
404 | if (!scsi_dh) |
405 | return -EINVAL; | |
406 | ||
407 | spin_lock_irqsave(q->queue_lock, flags); | |
408 | sdev = q->queuedata; | |
409 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
410 | err = -ENODEV; | |
411 | spin_unlock_irqrestore(q->queue_lock, flags); | |
412 | ||
1bab0de0 CH |
413 | if (err) |
414 | return err; | |
ae11b1b3 HR |
415 | |
416 | if (sdev->scsi_dh_data) { | |
1bab0de0 CH |
417 | if (sdev->scsi_dh_data->scsi_dh != scsi_dh) |
418 | err = -EBUSY; | |
419 | goto out_put_device; | |
ae11b1b3 | 420 | } |
1bab0de0 CH |
421 | |
422 | err = scsi_dh_handler_attach(sdev, scsi_dh); | |
423 | ||
424 | out_put_device: | |
ae11b1b3 | 425 | put_device(&sdev->sdev_gendev); |
1bab0de0 | 426 | return err; |
ae11b1b3 | 427 | } |
1bab0de0 | 428 | EXPORT_SYMBOL_GPL(scsi_dh_attach); |
ae11b1b3 | 429 | |
7e8a74b1 MS |
430 | /* |
431 | * scsi_dh_attached_handler_name - Get attached device handler's name | |
432 | * @q - Request queue that is associated with the scsi_device | |
433 | * that may have a device handler attached | |
434 | * @gfp - the GFP mask used in the kmalloc() call when allocating memory | |
435 | * | |
436 | * Returns name of attached handler, NULL if no handler is attached. | |
437 | * Caller must take care to free the returned string. | |
438 | */ | |
439 | const char *scsi_dh_attached_handler_name(struct request_queue *q, gfp_t gfp) | |
440 | { | |
441 | unsigned long flags; | |
442 | struct scsi_device *sdev; | |
443 | const char *handler_name = NULL; | |
444 | ||
445 | spin_lock_irqsave(q->queue_lock, flags); | |
446 | sdev = q->queuedata; | |
447 | if (!sdev || !get_device(&sdev->sdev_gendev)) | |
448 | sdev = NULL; | |
449 | spin_unlock_irqrestore(q->queue_lock, flags); | |
450 | ||
451 | if (!sdev) | |
452 | return NULL; | |
453 | ||
454 | if (sdev->scsi_dh_data) | |
455 | handler_name = kstrdup(sdev->scsi_dh_data->scsi_dh->name, gfp); | |
456 | ||
457 | put_device(&sdev->sdev_gendev); | |
458 | return handler_name; | |
459 | } | |
460 | EXPORT_SYMBOL_GPL(scsi_dh_attached_handler_name); |