sctp: walk the list of asoc safely
[linux/fpc-iii.git] / drivers / misc / enclosure.c
blob5a17bfeb80d398c023278ff9f0ed691d6785ef53
1 /*
2 * Enclosure Services
4 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
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.
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.
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.
21 **-----------------------------------------------------------------------------
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>
32 static LIST_HEAD(container_list);
33 static DEFINE_MUTEX(container_list_lock);
34 static struct class enclosure_class;
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)
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.
54 struct enclosure_device *enclosure_find(struct device *dev,
55 struct enclosure_device *start)
57 struct enclosure_device *edev;
59 mutex_lock(&container_list_lock);
60 edev = list_prepare_entry(start, &container_list, node);
61 if (start)
62 put_device(&start->edev);
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;
74 parent = parent->parent;
77 mutex_unlock(&container_list_lock);
79 return NULL;
81 EXPORT_SYMBOL_GPL(enclosure_find);
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
88 * Loops over all the enclosures calling the function.
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
95 int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
96 void *data)
98 int error = 0;
99 struct enclosure_device *edev;
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;
107 mutex_unlock(&container_list_lock);
109 return error;
111 EXPORT_SYMBOL_GPL(enclosure_for_each_device);
114 * enclosure_register - register device as an enclosure
116 * @dev: device containing the enclosure
117 * @components: number of components in the enclosure
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
123 struct enclosure_device *
124 enclosure_register(struct device *dev, const char *name, int components,
125 struct enclosure_component_callbacks *cb)
127 struct enclosure_device *edev =
128 kzalloc(sizeof(struct enclosure_device) +
129 sizeof(struct enclosure_component)*components,
130 GFP_KERNEL);
131 int err, i;
133 BUG_ON(!cb);
135 if (!edev)
136 return ERR_PTR(-ENOMEM);
138 edev->components = components;
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;
148 for (i = 0; i < components; i++) {
149 edev->component[i].number = -1;
150 edev->component[i].slot = -1;
151 edev->component[i].power_status = -1;
154 mutex_lock(&container_list_lock);
155 list_add_tail(&edev->node, &container_list);
156 mutex_unlock(&container_list_lock);
158 return edev;
160 err:
161 put_device(edev->edev.parent);
162 kfree(edev);
163 return ERR_PTR(err);
165 EXPORT_SYMBOL_GPL(enclosure_register);
167 static struct enclosure_component_callbacks enclosure_null_callbacks;
170 * enclosure_unregister - remove an enclosure
172 * @edev: the registered enclosure to remove;
174 void enclosure_unregister(struct enclosure_device *edev)
176 int i;
178 mutex_lock(&container_list_lock);
179 list_del(&edev->node);
180 mutex_unlock(&container_list_lock);
182 for (i = 0; i < edev->components; i++)
183 if (edev->component[i].number != -1)
184 device_unregister(&edev->component[i].cdev);
186 /* prevent any callbacks into service user */
187 edev->cb = &enclosure_null_callbacks;
188 device_unregister(&edev->edev);
190 EXPORT_SYMBOL_GPL(enclosure_unregister);
192 #define ENCLOSURE_NAME_SIZE 64
193 #define COMPONENT_NAME_SIZE 64
195 static void enclosure_link_name(struct enclosure_component *cdev, char *name)
197 strcpy(name, "enclosure_device:");
198 strcat(name, dev_name(&cdev->cdev));
201 static void enclosure_remove_links(struct enclosure_component *cdev)
203 char name[ENCLOSURE_NAME_SIZE];
205 enclosure_link_name(cdev, name);
208 * In odd circumstances, like multipath devices, something else may
209 * already have removed the links, so check for this condition first.
211 if (cdev->dev->kobj.sd)
212 sysfs_remove_link(&cdev->dev->kobj, name);
214 if (cdev->cdev.kobj.sd)
215 sysfs_remove_link(&cdev->cdev.kobj, "device");
218 static int enclosure_add_links(struct enclosure_component *cdev)
220 int error;
221 char name[ENCLOSURE_NAME_SIZE];
223 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
224 if (error)
225 return error;
227 enclosure_link_name(cdev, name);
228 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
229 if (error)
230 sysfs_remove_link(&cdev->cdev.kobj, "device");
232 return error;
235 static void enclosure_release(struct device *cdev)
237 struct enclosure_device *edev = to_enclosure_device(cdev);
239 put_device(cdev->parent);
240 kfree(edev);
243 static void enclosure_component_release(struct device *dev)
245 struct enclosure_component *cdev = to_enclosure_component(dev);
247 if (cdev->dev) {
248 enclosure_remove_links(cdev);
249 put_device(cdev->dev);
251 put_device(dev->parent);
254 static struct enclosure_component *
255 enclosure_component_find_by_name(struct enclosure_device *edev,
256 const char *name)
258 int i;
259 const char *cname;
260 struct enclosure_component *ecomp;
262 if (!edev || !name || !name[0])
263 return NULL;
265 for (i = 0; i < edev->components; i++) {
266 ecomp = &edev->component[i];
267 cname = dev_name(&ecomp->cdev);
268 if (ecomp->number != -1 &&
269 cname && cname[0] &&
270 !strcmp(cname, name))
271 return ecomp;
274 return NULL;
277 static const struct attribute_group *enclosure_component_groups[];
280 * enclosure_component_alloc - prepare a new enclosure component
281 * @edev: the enclosure to add the component
282 * @num: the device number
283 * @type: the type of component being added
284 * @name: an optional name to appear in sysfs (leave NULL if none)
286 * The name is optional for enclosures that give their components a unique
287 * name. If not, leave the field NULL and a name will be assigned.
289 * Returns a pointer to the enclosure component or an error.
291 struct enclosure_component *
292 enclosure_component_alloc(struct enclosure_device *edev,
293 unsigned int number,
294 enum enclosure_component_type type,
295 const char *name)
297 struct enclosure_component *ecomp;
298 struct device *cdev;
299 int i;
300 char newname[COMPONENT_NAME_SIZE];
302 if (number >= edev->components)
303 return ERR_PTR(-EINVAL);
305 ecomp = &edev->component[number];
307 if (ecomp->number != -1)
308 return ERR_PTR(-EINVAL);
310 ecomp->type = type;
311 ecomp->number = number;
312 cdev = &ecomp->cdev;
313 cdev->parent = get_device(&edev->edev);
315 if (name && name[0]) {
316 /* Some hardware (e.g. enclosure in RX300 S6) has components
317 * with non unique names. Registering duplicates in sysfs
318 * will lead to warnings during bootup. So make the names
319 * unique by appending consecutive numbers -1, -2, ... */
320 i = 1;
321 snprintf(newname, COMPONENT_NAME_SIZE,
322 "%s", name);
323 while (enclosure_component_find_by_name(edev, newname))
324 snprintf(newname, COMPONENT_NAME_SIZE,
325 "%s-%i", name, i++);
326 dev_set_name(cdev, "%s", newname);
327 } else
328 dev_set_name(cdev, "%u", number);
330 cdev->release = enclosure_component_release;
331 cdev->groups = enclosure_component_groups;
333 return ecomp;
335 EXPORT_SYMBOL_GPL(enclosure_component_alloc);
338 * enclosure_component_register - publishes an initialized enclosure component
339 * @ecomp: component to add
341 * Returns 0 on successful registration, releases the component otherwise
343 int enclosure_component_register(struct enclosure_component *ecomp)
345 struct device *cdev;
346 int err;
348 cdev = &ecomp->cdev;
349 err = device_register(cdev);
350 if (err) {
351 ecomp->number = -1;
352 put_device(cdev);
353 return err;
356 return 0;
358 EXPORT_SYMBOL_GPL(enclosure_component_register);
361 * enclosure_add_device - add a device as being part of an enclosure
362 * @edev: the enclosure device being added to.
363 * @num: the number of the component
364 * @dev: the device being added
366 * Declares a real device to reside in slot (or identifier) @num of an
367 * enclosure. This will cause the relevant sysfs links to appear.
368 * This function may also be used to change a device associated with
369 * an enclosure without having to call enclosure_remove_device() in
370 * between.
372 * Returns zero on success or an error.
374 int enclosure_add_device(struct enclosure_device *edev, int component,
375 struct device *dev)
377 struct enclosure_component *cdev;
378 int err;
380 if (!edev || component >= edev->components)
381 return -EINVAL;
383 cdev = &edev->component[component];
385 if (cdev->dev == dev)
386 return -EEXIST;
388 if (cdev->dev) {
389 enclosure_remove_links(cdev);
390 put_device(cdev->dev);
392 cdev->dev = get_device(dev);
393 err = enclosure_add_links(cdev);
394 if (err) {
395 put_device(cdev->dev);
396 cdev->dev = NULL;
398 return err;
400 EXPORT_SYMBOL_GPL(enclosure_add_device);
403 * enclosure_remove_device - remove a device from an enclosure
404 * @edev: the enclosure device
405 * @num: the number of the component to remove
407 * Returns zero on success or an error.
410 int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
412 struct enclosure_component *cdev;
413 int i;
415 if (!edev || !dev)
416 return -EINVAL;
418 for (i = 0; i < edev->components; i++) {
419 cdev = &edev->component[i];
420 if (cdev->dev == dev) {
421 enclosure_remove_links(cdev);
422 device_del(&cdev->cdev);
423 put_device(dev);
424 cdev->dev = NULL;
425 return device_add(&cdev->cdev);
428 return -ENODEV;
430 EXPORT_SYMBOL_GPL(enclosure_remove_device);
433 * sysfs pieces below
436 static ssize_t components_show(struct device *cdev,
437 struct device_attribute *attr, char *buf)
439 struct enclosure_device *edev = to_enclosure_device(cdev);
441 return snprintf(buf, 40, "%d\n", edev->components);
443 static DEVICE_ATTR_RO(components);
445 static ssize_t id_show(struct device *cdev,
446 struct device_attribute *attr,
447 char *buf)
449 struct enclosure_device *edev = to_enclosure_device(cdev);
451 if (edev->cb->show_id)
452 return edev->cb->show_id(edev, buf);
453 return -EINVAL;
455 static DEVICE_ATTR_RO(id);
457 static struct attribute *enclosure_class_attrs[] = {
458 &dev_attr_components.attr,
459 &dev_attr_id.attr,
460 NULL,
462 ATTRIBUTE_GROUPS(enclosure_class);
464 static struct class enclosure_class = {
465 .name = "enclosure",
466 .owner = THIS_MODULE,
467 .dev_release = enclosure_release,
468 .dev_groups = enclosure_class_groups,
471 static const char *const enclosure_status[] = {
472 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
473 [ENCLOSURE_STATUS_OK] = "OK",
474 [ENCLOSURE_STATUS_CRITICAL] = "critical",
475 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
476 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
477 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
478 [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
479 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
480 [ENCLOSURE_STATUS_MAX] = NULL,
483 static const char *const enclosure_type[] = {
484 [ENCLOSURE_COMPONENT_DEVICE] = "device",
485 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
488 static ssize_t get_component_fault(struct device *cdev,
489 struct device_attribute *attr, char *buf)
491 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
492 struct enclosure_component *ecomp = to_enclosure_component(cdev);
494 if (edev->cb->get_fault)
495 edev->cb->get_fault(edev, ecomp);
496 return snprintf(buf, 40, "%d\n", ecomp->fault);
499 static ssize_t set_component_fault(struct device *cdev,
500 struct device_attribute *attr,
501 const char *buf, size_t count)
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);
507 if (edev->cb->set_fault)
508 edev->cb->set_fault(edev, ecomp, val);
509 return count;
512 static ssize_t get_component_status(struct device *cdev,
513 struct device_attribute *attr,char *buf)
515 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
516 struct enclosure_component *ecomp = to_enclosure_component(cdev);
518 if (edev->cb->get_status)
519 edev->cb->get_status(edev, ecomp);
520 return snprintf(buf, 40, "%s\n", enclosure_status[ecomp->status]);
523 static ssize_t set_component_status(struct device *cdev,
524 struct device_attribute *attr,
525 const char *buf, size_t count)
527 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
528 struct enclosure_component *ecomp = to_enclosure_component(cdev);
529 int i;
531 for (i = 0; enclosure_status[i]; i++) {
532 if (strncmp(buf, enclosure_status[i],
533 strlen(enclosure_status[i])) == 0 &&
534 (buf[strlen(enclosure_status[i])] == '\n' ||
535 buf[strlen(enclosure_status[i])] == '\0'))
536 break;
539 if (enclosure_status[i] && edev->cb->set_status) {
540 edev->cb->set_status(edev, ecomp, i);
541 return count;
542 } else
543 return -EINVAL;
546 static ssize_t get_component_active(struct device *cdev,
547 struct device_attribute *attr, char *buf)
549 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
550 struct enclosure_component *ecomp = to_enclosure_component(cdev);
552 if (edev->cb->get_active)
553 edev->cb->get_active(edev, ecomp);
554 return snprintf(buf, 40, "%d\n", ecomp->active);
557 static ssize_t set_component_active(struct device *cdev,
558 struct device_attribute *attr,
559 const char *buf, size_t count)
561 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
562 struct enclosure_component *ecomp = to_enclosure_component(cdev);
563 int val = simple_strtoul(buf, NULL, 0);
565 if (edev->cb->set_active)
566 edev->cb->set_active(edev, ecomp, val);
567 return count;
570 static ssize_t get_component_locate(struct device *cdev,
571 struct device_attribute *attr, char *buf)
573 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
574 struct enclosure_component *ecomp = to_enclosure_component(cdev);
576 if (edev->cb->get_locate)
577 edev->cb->get_locate(edev, ecomp);
578 return snprintf(buf, 40, "%d\n", ecomp->locate);
581 static ssize_t set_component_locate(struct device *cdev,
582 struct device_attribute *attr,
583 const char *buf, size_t count)
585 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
586 struct enclosure_component *ecomp = to_enclosure_component(cdev);
587 int val = simple_strtoul(buf, NULL, 0);
589 if (edev->cb->set_locate)
590 edev->cb->set_locate(edev, ecomp, val);
591 return count;
594 static ssize_t get_component_power_status(struct device *cdev,
595 struct device_attribute *attr,
596 char *buf)
598 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
599 struct enclosure_component *ecomp = to_enclosure_component(cdev);
601 if (edev->cb->get_power_status)
602 edev->cb->get_power_status(edev, ecomp);
604 /* If still uninitialized, the callback failed or does not exist. */
605 if (ecomp->power_status == -1)
606 return (edev->cb->get_power_status) ? -EIO : -ENOTTY;
608 return snprintf(buf, 40, "%s\n", ecomp->power_status ? "on" : "off");
611 static ssize_t set_component_power_status(struct device *cdev,
612 struct device_attribute *attr,
613 const char *buf, size_t count)
615 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
616 struct enclosure_component *ecomp = to_enclosure_component(cdev);
617 int val;
619 if (strncmp(buf, "on", 2) == 0 &&
620 (buf[2] == '\n' || buf[2] == '\0'))
621 val = 1;
622 else if (strncmp(buf, "off", 3) == 0 &&
623 (buf[3] == '\n' || buf[3] == '\0'))
624 val = 0;
625 else
626 return -EINVAL;
628 if (edev->cb->set_power_status)
629 edev->cb->set_power_status(edev, ecomp, val);
630 return count;
633 static ssize_t get_component_type(struct device *cdev,
634 struct device_attribute *attr, char *buf)
636 struct enclosure_component *ecomp = to_enclosure_component(cdev);
638 return snprintf(buf, 40, "%s\n", enclosure_type[ecomp->type]);
641 static ssize_t get_component_slot(struct device *cdev,
642 struct device_attribute *attr, char *buf)
644 struct enclosure_component *ecomp = to_enclosure_component(cdev);
645 int slot;
647 /* if the enclosure does not override then use 'number' as a stand-in */
648 if (ecomp->slot >= 0)
649 slot = ecomp->slot;
650 else
651 slot = ecomp->number;
653 return snprintf(buf, 40, "%d\n", slot);
656 static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
657 set_component_fault);
658 static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
659 set_component_status);
660 static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
661 set_component_active);
662 static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
663 set_component_locate);
664 static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
665 set_component_power_status);
666 static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
667 static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
669 static struct attribute *enclosure_component_attrs[] = {
670 &dev_attr_fault.attr,
671 &dev_attr_status.attr,
672 &dev_attr_active.attr,
673 &dev_attr_locate.attr,
674 &dev_attr_power_status.attr,
675 &dev_attr_type.attr,
676 &dev_attr_slot.attr,
677 NULL
679 ATTRIBUTE_GROUPS(enclosure_component);
681 static int __init enclosure_init(void)
683 return class_register(&enclosure_class);
686 static void __exit enclosure_exit(void)
688 class_unregister(&enclosure_class);
691 module_init(enclosure_init);
692 module_exit(enclosure_exit);
694 MODULE_AUTHOR("James Bottomley");
695 MODULE_DESCRIPTION("Enclosure Services");
696 MODULE_LICENSE("GPL v2");