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1 /*
2 * Enclosure Services
3 *
4 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
5 *
6 **-----------------------------------------------------------------------------
7 **
8 ** This program is free software; you can redistribute it and/or
9 ** modify it under the terms of the GNU General Public License
10 ** version 2 as published by the Free Software Foundation.
11 **
12 ** This program is distributed in the hope that it will be useful,
13 ** but WITHOUT ANY WARRANTY; without even the implied warranty of
14 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 ** GNU General Public License for more details.
16 **
17 ** You should have received a copy of the GNU General Public License
18 ** along with this program; if not, write to the Free Software
19 ** Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 **
21 **-----------------------------------------------------------------------------
22 */
23 #include <linux/device.h>
24 #include <linux/enclosure.h>
25 #include <linux/err.h>
26 #include <linux/list.h>
27 #include <linux/kernel.h>
28 #include <linux/module.h>
29 #include <linux/mutex.h>
30 #include <linux/slab.h>
31
32 static LIST_HEAD(container_list);
33 static DEFINE_MUTEX(container_list_lock);
34 static struct class enclosure_class;
35
36 /**
37 * enclosure_find - find an enclosure given a parent device
38 * @dev: the parent to match against
39 * @start: Optional enclosure device to start from (NULL if none)
40 *
41 * Looks through the list of registered enclosures to find all those
42 * with @dev as a parent. Returns NULL if no enclosure is
43 * found. @start can be used as a starting point to obtain multiple
44 * enclosures per parent (should begin with NULL and then be set to
45 * each returned enclosure device). Obtains a reference to the
46 * enclosure class device which must be released with device_put().
47 * If @start is not NULL, a reference must be taken on it which is
48 * released before returning (this allows a loop through all
49 * enclosures to exit with only the reference on the enclosure of
50 * interest held). Note that the @dev may correspond to the actual
51 * device housing the enclosure, in which case no iteration via @start
52 * is required.
53 */
54 struct enclosure_device *enclosure_find(struct device *dev,
55 struct enclosure_device *start)
56 {
57 struct enclosure_device *edev;
58
59 mutex_lock(&container_list_lock);
60 edev = list_prepare_entry(start, &container_list, node);
61 if (start)
62 put_device(&start->edev);
63
64 list_for_each_entry_continue(edev, &container_list, node) {
65 struct device *parent = edev->edev.parent;
66 /* parent might not be immediate, so iterate up to
67 * the root of the tree if necessary */
68 while (parent) {
69 if (parent == dev) {
70 get_device(&edev->edev);
71 mutex_unlock(&container_list_lock);
72 return edev;
73 }
74 parent = parent->parent;
75 }
76 }
77 mutex_unlock(&container_list_lock);
78
79 return NULL;
80 }
81 EXPORT_SYMBOL_GPL(enclosure_find);
82
83 /**
84 * enclosure_for_each_device - calls a function for each enclosure
85 * @fn: the function to call
86 * @data: the data to pass to each call
87 *
88 * Loops over all the enclosures calling the function.
89 *
90 * Note, this function uses a mutex which will be held across calls to
91 * @fn, so it must have non atomic context, and @fn may (although it
92 * should not) sleep or otherwise cause the mutex to be held for
93 * indefinite periods
94 */
95 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
96 void *data)
97 {
98 int error = 0;
99 struct enclosure_device *edev;
100
101 mutex_lock(&container_list_lock);
102 list_for_each_entry(edev, &container_list, node) {
103 error = fn(edev, data);
104 if (error)
105 break;
106 }
107 mutex_unlock(&container_list_lock);
108
109 return error;
110 }
111 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
112
113 /**
114 * enclosure_register - register device as an enclosure
115 *
116 * @dev: device containing the enclosure
117 * @components: number of components in the enclosure
118 *
119 * This sets up the device for being an enclosure. Note that @dev does
120 * not have to be a dedicated enclosure device. It may be some other type
121 * of device that additionally responds to enclosure services
122 */
123 struct enclosure_device *
124 enclosure_register(struct device *dev, const char *name, int components,
125 struct enclosure_component_callbacks *cb)
126 {
127 struct enclosure_device *edev =
128 kzalloc(sizeof(struct enclosure_device) +
129 sizeof(struct enclosure_component)*components,
130 GFP_KERNEL);
131 int err, i;
132
133 BUG_ON(!cb);
134
135 if (!edev)
136 return ERR_PTR(-ENOMEM);
137
138 edev->components = components;
139
140 edev->edev.class = &enclosure_class;
141 edev->edev.parent = get_device(dev);
142 edev->cb = cb;
143 dev_set_name(&edev->edev, "%s", name);
144 err = device_register(&edev->edev);
145 if (err)
146 goto err;
147
148 for (i = 0; i < components; i++)
149 edev->component[i].number = -1;
150
151 mutex_lock(&container_list_lock);
152 list_add_tail(&edev->node, &container_list);
153 mutex_unlock(&container_list_lock);
154
155 return edev;
156
157 err:
158 put_device(edev->edev.parent);
159 kfree(edev);
160 return ERR_PTR(err);
161 }
162 EXPORT_SYMBOL_GPL(enclosure_register);
163
164 static struct enclosure_component_callbacks enclosure_null_callbacks;
165
166 /**
167 * enclosure_unregister - remove an enclosure
168 *
169 * @edev: the registered enclosure to remove;
170 */
171 void enclosure_unregister(struct enclosure_device *edev)
172 {
173 int i;
174
175 mutex_lock(&container_list_lock);
176 list_del(&edev->node);
177 mutex_unlock(&container_list_lock);
178
179 for (i = 0; i < edev->components; i++)
180 if (edev->component[i].number != -1)
181 device_unregister(&edev->component[i].cdev);
182
183 /* prevent any callbacks into service user */
184 edev->cb = &enclosure_null_callbacks;
185 device_unregister(&edev->edev);
186 }
187 EXPORT_SYMBOL_GPL(enclosure_unregister);
188
189 #define ENCLOSURE_NAME_SIZE 64
190
191 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
192 {
193 strcpy(name, "enclosure_device:");
194 strcat(name, dev_name(&cdev->cdev));
195 }
196
197 static void enclosure_remove_links(struct enclosure_component *cdev)
198 {
199 char name[ENCLOSURE_NAME_SIZE];
200
201 enclosure_link_name(cdev, name);
202 sysfs_remove_link(&cdev->dev->kobj, name);
203 sysfs_remove_link(&cdev->cdev.kobj, "device");
204 }
205
206 static int enclosure_add_links(struct enclosure_component *cdev)
207 {
208 int error;
209 char name[ENCLOSURE_NAME_SIZE];
210
211 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
212 if (error)
213 return error;
214
215 enclosure_link_name(cdev, name);
216 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
217 if (error)
218 sysfs_remove_link(&cdev->cdev.kobj, "device");
219
220 return error;
221 }
222
223 static void enclosure_release(struct device *cdev)
224 {
225 struct enclosure_device *edev = to_enclosure_device(cdev);
226
227 put_device(cdev->parent);
228 kfree(edev);
229 }
230
231 static void enclosure_component_release(struct device *dev)
232 {
233 struct enclosure_component *cdev = to_enclosure_component(dev);
234
235 if (cdev->dev) {
236 enclosure_remove_links(cdev);
237 put_device(cdev->dev);
238 }
239 put_device(dev->parent);
240 }
241
242 static const struct attribute_group *enclosure_groups[];
243
244 /**
245 * enclosure_component_register - add a particular component to an enclosure
246 * @edev: the enclosure to add the component
247 * @num: the device number
248 * @type: the type of component being added
249 * @name: an optional name to appear in sysfs (leave NULL if none)
250 *
251 * Registers the component. The name is optional for enclosures that
252 * give their components a unique name. If not, leave the field NULL
253 * and a name will be assigned.
254 *
255 * Returns a pointer to the enclosure component or an error.
256 */
257 struct enclosure_component *
258 enclosure_component_register(struct enclosure_device *edev,
259 unsigned int number,
260 enum enclosure_component_type type,
261 const char *name)
262 {
263 struct enclosure_component *ecomp;
264 struct device *cdev;
265 int err;
266
267 if (number >= edev->components)
268 return ERR_PTR(-EINVAL);
269
270 ecomp = &edev->component[number];
271
272 if (ecomp->number != -1)
273 return ERR_PTR(-EINVAL);
274
275 ecomp->type = type;
276 ecomp->number = number;
277 cdev = &ecomp->cdev;
278 cdev->parent = get_device(&edev->edev);
279 if (name && name[0])
280 dev_set_name(cdev, "%s", name);
281 else
282 dev_set_name(cdev, "%u", number);
283
284 cdev->release = enclosure_component_release;
285 cdev->groups = enclosure_groups;
286
287 err = device_register(cdev);
288 if (err) {
289 ecomp->number = -1;
290 put_device(cdev);
291 return ERR_PTR(err);
292 }
293
294 return ecomp;
295 }
296 EXPORT_SYMBOL_GPL(enclosure_component_register);
297
298 /**
299 * enclosure_add_device - add a device as being part of an enclosure
300 * @edev: the enclosure device being added to.
301 * @num: the number of the component
302 * @dev: the device being added
303 *
304 * Declares a real device to reside in slot (or identifier) @num of an
305 * enclosure. This will cause the relevant sysfs links to appear.
306 * This function may also be used to change a device associated with
307 * an enclosure without having to call enclosure_remove_device() in
308 * between.
309 *
310 * Returns zero on success or an error.
311 */
312 int enclosure_add_device(struct enclosure_device *edev, int component,
313 struct device *dev)
314 {
315 struct enclosure_component *cdev;
316
317 if (!edev || component >= edev->components)
318 return -EINVAL;
319
320 cdev = &edev->component[component];
321
322 if (cdev->dev == dev)
323 return -EEXIST;
324
325 if (cdev->dev)
326 enclosure_remove_links(cdev);
327
328 put_device(cdev->dev);
329 cdev->dev = get_device(dev);
330 return enclosure_add_links(cdev);
331 }
332 EXPORT_SYMBOL_GPL(enclosure_add_device);
333
334 /**
335 * enclosure_remove_device - remove a device from an enclosure
336 * @edev: the enclosure device
337 * @num: the number of the component to remove
338 *
339 * Returns zero on success or an error.
340 *
341 */
342 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
343 {
344 struct enclosure_component *cdev;
345 int i;
346
347 if (!edev || !dev)
348 return -EINVAL;
349
350 for (i = 0; i < edev->components; i++) {
351 cdev = &edev->component[i];
352 if (cdev->dev == dev) {
353 enclosure_remove_links(cdev);
354 device_del(&cdev->cdev);
355 put_device(dev);
356 cdev->dev = NULL;
357 return device_add(&cdev->cdev);
358 }
359 }
360 return -ENODEV;
361 }
362 EXPORT_SYMBOL_GPL(enclosure_remove_device);
363
364 /*
365 * sysfs pieces below
366 */
367
368 static ssize_t enclosure_show_components(struct device *cdev,
369 struct device_attribute *attr,
370 char *buf)
371 {
372 struct enclosure_device *edev = to_enclosure_device(cdev);
373
374 return snprintf(buf, 40, "%d\n", edev->components);
375 }
376
377 static struct device_attribute enclosure_attrs[] = {
378 __ATTR(components, S_IRUGO, enclosure_show_components, NULL),
379 __ATTR_NULL
380 };
381
382 static struct class enclosure_class = {
383 .name = "enclosure",
384 .owner = THIS_MODULE,
385 .dev_release = enclosure_release,
386 .dev_attrs = enclosure_attrs,
387 };
388
389 static const char *const enclosure_status [] = {
390 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
391 [ENCLOSURE_STATUS_OK] = "OK",
392 [ENCLOSURE_STATUS_CRITICAL] = "critical",
393 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
394 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
395 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
396 [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
397 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
398 [ENCLOSURE_STATUS_MAX] = NULL,
399 };
400
401 static const char *const enclosure_type [] = {
402 [ENCLOSURE_COMPONENT_DEVICE] = "device",
403 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
404 };
405
406 static ssize_t get_component_fault(struct device *cdev,
407 struct device_attribute *attr, char *buf)
408 {
409 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
410 struct enclosure_component *ecomp = to_enclosure_component(cdev);
411
412 if (edev->cb->get_fault)
413 edev->cb->get_fault(edev, ecomp);
414 return snprintf(buf, 40, "%d\n", ecomp->fault);
415 }
416
417 static ssize_t set_component_fault(struct device *cdev,
418 struct device_attribute *attr,
419 const char *buf, size_t count)
420 {
421 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
422 struct enclosure_component *ecomp = to_enclosure_component(cdev);
423 int val = simple_strtoul(buf, NULL, 0);
424
425 if (edev->cb->set_fault)
426 edev->cb->set_fault(edev, ecomp, val);
427 return count;
428 }
429
430 static ssize_t get_component_status(struct device *cdev,
431 struct device_attribute *attr,char *buf)
432 {
433 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
434 struct enclosure_component *ecomp = to_enclosure_component(cdev);
435
436 if (edev->cb->get_status)
437 edev->cb->get_status(edev, ecomp);
438 return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
439 }
440
441 static ssize_t set_component_status(struct device *cdev,
442 struct device_attribute *attr,
443 const char *buf, size_t count)
444 {
445 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
446 struct enclosure_component *ecomp = to_enclosure_component(cdev);
447 int i;
448
449 for (i = 0; enclosure_status[i]; i++) {
450 if (strncmp(buf, enclosure_status[i],
451 strlen(enclosure_status[i])) == 0 &&
452 (buf[strlen(enclosure_status[i])] == '\n' ||
453 buf[strlen(enclosure_status[i])] == '\0'))
454 break;
455 }
456
457 if (enclosure_status[i] && edev->cb->set_status) {
458 edev->cb->set_status(edev, ecomp, i);
459 return count;
460 } else
461 return -EINVAL;
462 }
463
464 static ssize_t get_component_active(struct device *cdev,
465 struct device_attribute *attr, char *buf)
466 {
467 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
468 struct enclosure_component *ecomp = to_enclosure_component(cdev);
469
470 if (edev->cb->get_active)
471 edev->cb->get_active(edev, ecomp);
472 return snprintf(buf, 40, "%d\n", ecomp->active);
473 }
474
475 static ssize_t set_component_active(struct device *cdev,
476 struct device_attribute *attr,
477 const char *buf, size_t count)
478 {
479 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
480 struct enclosure_component *ecomp = to_enclosure_component(cdev);
481 int val = simple_strtoul(buf, NULL, 0);
482
483 if (edev->cb->set_active)
484 edev->cb->set_active(edev, ecomp, val);
485 return count;
486 }
487
488 static ssize_t get_component_locate(struct device *cdev,
489 struct device_attribute *attr, char *buf)
490 {
491 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
492 struct enclosure_component *ecomp = to_enclosure_component(cdev);
493
494 if (edev->cb->get_locate)
495 edev->cb->get_locate(edev, ecomp);
496 return snprintf(buf, 40, "%d\n", ecomp->locate);
497 }
498
499 static ssize_t set_component_locate(struct device *cdev,
500 struct device_attribute *attr,
501 const char *buf, size_t count)
502 {
503 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
504 struct enclosure_component *ecomp = to_enclosure_component(cdev);
505 int val = simple_strtoul(buf, NULL, 0);
506
507 if (edev->cb->set_locate)
508 edev->cb->set_locate(edev, ecomp, val);
509 return count;
510 }
511
512 static ssize_t get_component_type(struct device *cdev,
513 struct device_attribute *attr, char *buf)
514 {
515 struct enclosure_component *ecomp = to_enclosure_component(cdev);
516
517 return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
518 }
519
520
521 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
522 set_component_fault);
523 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
524 set_component_status);
525 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
526 set_component_active);
527 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
528 set_component_locate);
529 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
530
531 static struct attribute *enclosure_component_attrs[] = {
532 &dev_attr_fault.attr,
533 &dev_attr_status.attr,
534 &dev_attr_active.attr,
535 &dev_attr_locate.attr,
536 &dev_attr_type.attr,
537 NULL
538 };
539
540 static struct attribute_group enclosure_group = {
541 .attrs = enclosure_component_attrs,
542 };
543
544 static const struct attribute_group *enclosure_groups[] = {
545 &enclosure_group,
546 NULL
547 };
548
549 static int __init enclosure_init(void)
550 {
551 int err;
552
553 err = class_register(&enclosure_class);
554 if (err)
555 return err;
556
557 return 0;
558 }
559
560 static void __exit enclosure_exit(void)
561 {
562 class_unregister(&enclosure_class);
563 }
564
565 module_init(enclosure_init);
566 module_exit(enclosure_exit);
567
568 MODULE_AUTHOR("James Bottomley");
569 MODULE_DESCRIPTION("Enclosure Services");
570 MODULE_LICENSE("GPL v2");