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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Enclosure Services
4 *
5 * Copyright (C) 2008 James Bottomley <[email protected]>
6 *
7**-----------------------------------------------------------------------------
8**
9**
10**-----------------------------------------------------------------------------
11*/
12#include <linux/device.h>
13#include <linux/enclosure.h>
14#include <linux/err.h>
15#include <linux/list.h>
16#include <linux/kernel.h>
17#include <linux/module.h>
18#include <linux/mutex.h>
19#include <linux/slab.h>
20#include <linux/string_choices.h>
21
22static LIST_HEAD(container_list);
23static DEFINE_MUTEX(container_list_lock);
24static struct class enclosure_class;
25
26/**
27 * enclosure_find - find an enclosure given a parent device
28 * @dev: the parent to match against
29 * @start: Optional enclosure device to start from (NULL if none)
30 *
31 * Looks through the list of registered enclosures to find all those
32 * with @dev as a parent. Returns NULL if no enclosure is
33 * found. @start can be used as a starting point to obtain multiple
34 * enclosures per parent (should begin with NULL and then be set to
35 * each returned enclosure device). Obtains a reference to the
36 * enclosure class device which must be released with put_device().
37 * If @start is not NULL, a reference must be taken on it which is
38 * released before returning (this allows a loop through all
39 * enclosures to exit with only the reference on the enclosure of
40 * interest held). Note that the @dev may correspond to the actual
41 * device housing the enclosure, in which case no iteration via @start
42 * is required.
43 */
44struct enclosure_device *enclosure_find(struct device *dev,
45 struct enclosure_device *start)
46{
47 struct enclosure_device *edev;
48
49 mutex_lock(&container_list_lock);
50 edev = list_prepare_entry(start, &container_list, node);
51 if (start)
52 put_device(&start->edev);
53
54 list_for_each_entry_continue(edev, &container_list, node) {
55 struct device *parent = edev->edev.parent;
56 /* parent might not be immediate, so iterate up to
57 * the root of the tree if necessary */
58 while (parent) {
59 if (parent == dev) {
60 get_device(&edev->edev);
61 mutex_unlock(&container_list_lock);
62 return edev;
63 }
64 parent = parent->parent;
65 }
66 }
67 mutex_unlock(&container_list_lock);
68
69 return NULL;
70}
71EXPORT_SYMBOL_GPL(enclosure_find);
72
73/**
74 * enclosure_for_each_device - calls a function for each enclosure
75 * @fn: the function to call
76 * @data: the data to pass to each call
77 *
78 * Loops over all the enclosures calling the function.
79 *
80 * Note, this function uses a mutex which will be held across calls to
81 * @fn, so it must have non atomic context, and @fn may (although it
82 * should not) sleep or otherwise cause the mutex to be held for
83 * indefinite periods
84 */
85int enclosure_for_each_device(int (*fn)(struct enclosure_device *, void *),
86 void *data)
87{
88 int error = 0;
89 struct enclosure_device *edev;
90
91 mutex_lock(&container_list_lock);
92 list_for_each_entry(edev, &container_list, node) {
93 error = fn(edev, data);
94 if (error)
95 break;
96 }
97 mutex_unlock(&container_list_lock);
98
99 return error;
100}
101EXPORT_SYMBOL_GPL(enclosure_for_each_device);
102
103/**
104 * enclosure_register - register device as an enclosure
105 *
106 * @dev: device containing the enclosure
107 * @name: chosen device name
108 * @components: number of components in the enclosure
109 * @cb: platform call-backs
110 *
111 * This sets up the device for being an enclosure. Note that @dev does
112 * not have to be a dedicated enclosure device. It may be some other type
113 * of device that additionally responds to enclosure services
114 */
115struct enclosure_device *
116enclosure_register(struct device *dev, const char *name, int components,
117 struct enclosure_component_callbacks *cb)
118{
119 struct enclosure_device *edev =
120 kzalloc_flex(*edev, component, components);
121 int err, i;
122
123 BUG_ON(!cb);
124
125 if (!edev)
126 return ERR_PTR(-ENOMEM);
127
128 edev->components = components;
129
130 edev->edev.class = &enclosure_class;
131 edev->edev.parent = get_device(dev);
132 edev->cb = cb;
133 dev_set_name(&edev->edev, "%s", name);
134 err = device_register(&edev->edev);
135 if (err)
136 goto err;
137
138 for (i = 0; i < components; i++) {
139 edev->component[i].number = -1;
140 edev->component[i].slot = -1;
141 edev->component[i].power_status = -1;
142 }
143
144 mutex_lock(&container_list_lock);
145 list_add_tail(&edev->node, &container_list);
146 mutex_unlock(&container_list_lock);
147
148 return edev;
149
150 err:
151 put_device(edev->edev.parent);
152 kfree(edev);
153 return ERR_PTR(err);
154}
155EXPORT_SYMBOL_GPL(enclosure_register);
156
157static struct enclosure_component_callbacks enclosure_null_callbacks;
158
159/**
160 * enclosure_unregister - remove an enclosure
161 *
162 * @edev: the registered enclosure to remove;
163 */
164void enclosure_unregister(struct enclosure_device *edev)
165{
166 int i;
167
168 mutex_lock(&container_list_lock);
169 list_del(&edev->node);
170 mutex_unlock(&container_list_lock);
171
172 for (i = 0; i < edev->components; i++)
173 if (edev->component[i].number != -1)
174 device_unregister(&edev->component[i].cdev);
175
176 /* prevent any callbacks into service user */
177 edev->cb = &enclosure_null_callbacks;
178 device_unregister(&edev->edev);
179}
180EXPORT_SYMBOL_GPL(enclosure_unregister);
181
182#define ENCLOSURE_NAME_SIZE 64
183#define COMPONENT_NAME_SIZE 64
184
185static void enclosure_link_name(struct enclosure_component *cdev, char *name)
186{
187 snprintf(name, ENCLOSURE_NAME_SIZE, "enclosure_device:%s",
188 dev_name(&cdev->cdev));
189}
190
191static void enclosure_remove_links(struct enclosure_component *cdev)
192{
193 char name[ENCLOSURE_NAME_SIZE];
194
195 enclosure_link_name(cdev, name);
196
197 /*
198 * In odd circumstances, like multipath devices, something else may
199 * already have removed the links, so check for this condition first.
200 */
201 if (cdev->dev->kobj.sd)
202 sysfs_remove_link(&cdev->dev->kobj, name);
203
204 if (cdev->cdev.kobj.sd)
205 sysfs_remove_link(&cdev->cdev.kobj, "device");
206}
207
208static int enclosure_add_links(struct enclosure_component *cdev)
209{
210 int error;
211 char name[ENCLOSURE_NAME_SIZE];
212
213 error = sysfs_create_link(&cdev->cdev.kobj, &cdev->dev->kobj, "device");
214 if (error)
215 return error;
216
217 enclosure_link_name(cdev, name);
218 error = sysfs_create_link(&cdev->dev->kobj, &cdev->cdev.kobj, name);
219 if (error)
220 sysfs_remove_link(&cdev->cdev.kobj, "device");
221
222 return error;
223}
224
225static void enclosure_release(struct device *cdev)
226{
227 struct enclosure_device *edev = to_enclosure_device(cdev);
228
229 put_device(cdev->parent);
230 kfree(edev);
231}
232
233static void enclosure_component_release(struct device *dev)
234{
235 struct enclosure_component *cdev = to_enclosure_component(dev);
236
237 if (cdev->dev) {
238 enclosure_remove_links(cdev);
239 put_device(cdev->dev);
240 }
241 put_device(dev->parent);
242}
243
244static struct enclosure_component *
245enclosure_component_find_by_name(struct enclosure_device *edev,
246 const char *name)
247{
248 int i;
249 const char *cname;
250 struct enclosure_component *ecomp;
251
252 if (!edev || !name || !name[0])
253 return NULL;
254
255 for (i = 0; i < edev->components; i++) {
256 ecomp = &edev->component[i];
257 cname = dev_name(&ecomp->cdev);
258 if (ecomp->number != -1 &&
259 cname && cname[0] &&
260 !strcmp(cname, name))
261 return ecomp;
262 }
263
264 return NULL;
265}
266
267static const struct attribute_group *enclosure_component_groups[];
268
269/**
270 * enclosure_component_alloc - prepare a new enclosure component
271 * @edev: the enclosure to add the component
272 * @number: the device number
273 * @type: the type of component being added
274 * @name: an optional name to appear in sysfs (leave NULL if none)
275 *
276 * The name is optional for enclosures that give their components a unique
277 * name. If not, leave the field NULL and a name will be assigned.
278 *
279 * Returns a pointer to the enclosure component or an error.
280 */
281struct enclosure_component *
282enclosure_component_alloc(struct enclosure_device *edev,
283 unsigned int number,
284 enum enclosure_component_type type,
285 const char *name)
286{
287 struct enclosure_component *ecomp;
288 struct device *cdev;
289 int i;
290 char newname[COMPONENT_NAME_SIZE];
291
292 if (number >= edev->components)
293 return ERR_PTR(-EINVAL);
294
295 ecomp = &edev->component[number];
296
297 if (ecomp->number != -1)
298 return ERR_PTR(-EINVAL);
299
300 ecomp->type = type;
301 ecomp->number = number;
302 cdev = &ecomp->cdev;
303 cdev->parent = get_device(&edev->edev);
304
305 if (name && name[0]) {
306 /* Some hardware (e.g. enclosure in RX300 S6) has components
307 * with non unique names. Registering duplicates in sysfs
308 * will lead to warnings during bootup. So make the names
309 * unique by appending consecutive numbers -1, -2, ... */
310 i = 1;
311 snprintf(newname, COMPONENT_NAME_SIZE,
312 "%s", name);
313 while (enclosure_component_find_by_name(edev, newname))
314 snprintf(newname, COMPONENT_NAME_SIZE,
315 "%s-%i", name, i++);
316 dev_set_name(cdev, "%s", newname);
317 } else
318 dev_set_name(cdev, "%u", number);
319
320 cdev->release = enclosure_component_release;
321 cdev->groups = enclosure_component_groups;
322
323 return ecomp;
324}
325EXPORT_SYMBOL_GPL(enclosure_component_alloc);
326
327/**
328 * enclosure_component_register - publishes an initialized enclosure component
329 * @ecomp: component to add
330 *
331 * Returns 0 on successful registration, releases the component otherwise
332 */
333int enclosure_component_register(struct enclosure_component *ecomp)
334{
335 struct device *cdev;
336 int err;
337
338 cdev = &ecomp->cdev;
339 err = device_register(cdev);
340 if (err) {
341 ecomp->number = -1;
342 put_device(cdev);
343 return err;
344 }
345
346 return 0;
347}
348EXPORT_SYMBOL_GPL(enclosure_component_register);
349
350/**
351 * enclosure_add_device - add a device as being part of an enclosure
352 * @edev: the enclosure device being added to.
353 * @component: the number of the component
354 * @dev: the device being added
355 *
356 * Declares a real device to reside in slot (or identifier) @num of an
357 * enclosure. This will cause the relevant sysfs links to appear.
358 * This function may also be used to change a device associated with
359 * an enclosure without having to call enclosure_remove_device() in
360 * between.
361 *
362 * Returns zero on success or an error.
363 */
364int enclosure_add_device(struct enclosure_device *edev, int component,
365 struct device *dev)
366{
367 struct enclosure_component *cdev;
368 int err;
369
370 if (!edev || component >= edev->components)
371 return -EINVAL;
372
373 cdev = &edev->component[component];
374
375 if (cdev->dev == dev)
376 return -EEXIST;
377
378 if (cdev->dev) {
379 enclosure_remove_links(cdev);
380 put_device(cdev->dev);
381 }
382 cdev->dev = get_device(dev);
383 err = enclosure_add_links(cdev);
384 if (err) {
385 put_device(cdev->dev);
386 cdev->dev = NULL;
387 }
388 return err;
389}
390EXPORT_SYMBOL_GPL(enclosure_add_device);
391
392/**
393 * enclosure_remove_device - remove a device from an enclosure
394 * @edev: the enclosure device
395 * @dev: device to remove/put
396 *
397 * Returns zero on success or an error.
398 *
399 */
400int enclosure_remove_device(struct enclosure_device *edev, struct device *dev)
401{
402 struct enclosure_component *cdev;
403 int i;
404
405 if (!edev || !dev)
406 return -EINVAL;
407
408 for (i = 0; i < edev->components; i++) {
409 cdev = &edev->component[i];
410 if (cdev->dev == dev) {
411 enclosure_remove_links(cdev);
412 put_device(dev);
413 cdev->dev = NULL;
414 return 0;
415 }
416 }
417 return -ENODEV;
418}
419EXPORT_SYMBOL_GPL(enclosure_remove_device);
420
421/*
422 * sysfs pieces below
423 */
424
425static ssize_t components_show(struct device *cdev,
426 struct device_attribute *attr, char *buf)
427{
428 struct enclosure_device *edev = to_enclosure_device(cdev);
429
430 return sysfs_emit(buf, "%d\n", edev->components);
431}
432static DEVICE_ATTR_RO(components);
433
434static ssize_t id_show(struct device *cdev,
435 struct device_attribute *attr,
436 char *buf)
437{
438 struct enclosure_device *edev = to_enclosure_device(cdev);
439
440 if (edev->cb->show_id)
441 return edev->cb->show_id(edev, buf);
442 return -EINVAL;
443}
444static DEVICE_ATTR_RO(id);
445
446static struct attribute *enclosure_class_attrs[] = {
447 &dev_attr_components.attr,
448 &dev_attr_id.attr,
449 NULL,
450};
451ATTRIBUTE_GROUPS(enclosure_class);
452
453static struct class enclosure_class = {
454 .name = "enclosure",
455 .dev_release = enclosure_release,
456 .dev_groups = enclosure_class_groups,
457};
458
459static const char *const enclosure_status[] = {
460 [ENCLOSURE_STATUS_UNSUPPORTED] = "unsupported",
461 [ENCLOSURE_STATUS_OK] = "OK",
462 [ENCLOSURE_STATUS_CRITICAL] = "critical",
463 [ENCLOSURE_STATUS_NON_CRITICAL] = "non-critical",
464 [ENCLOSURE_STATUS_UNRECOVERABLE] = "unrecoverable",
465 [ENCLOSURE_STATUS_NOT_INSTALLED] = "not installed",
466 [ENCLOSURE_STATUS_UNKNOWN] = "unknown",
467 [ENCLOSURE_STATUS_UNAVAILABLE] = "unavailable",
468 [ENCLOSURE_STATUS_MAX] = NULL,
469};
470
471static const char *const enclosure_type[] = {
472 [ENCLOSURE_COMPONENT_DEVICE] = "device",
473 [ENCLOSURE_COMPONENT_ARRAY_DEVICE] = "array device",
474};
475
476static ssize_t get_component_fault(struct device *cdev,
477 struct device_attribute *attr, char *buf)
478{
479 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
480 struct enclosure_component *ecomp = to_enclosure_component(cdev);
481
482 if (edev->cb->get_fault)
483 edev->cb->get_fault(edev, ecomp);
484 return sysfs_emit(buf, "%d\n", ecomp->fault);
485}
486
487static ssize_t set_component_fault(struct device *cdev,
488 struct device_attribute *attr,
489 const char *buf, size_t count)
490{
491 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
492 struct enclosure_component *ecomp = to_enclosure_component(cdev);
493 int val = simple_strtoul(buf, NULL, 0);
494
495 if (edev->cb->set_fault)
496 edev->cb->set_fault(edev, ecomp, val);
497 return count;
498}
499
500static ssize_t get_component_status(struct device *cdev,
501 struct device_attribute *attr,char *buf)
502{
503 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
504 struct enclosure_component *ecomp = to_enclosure_component(cdev);
505
506 if (edev->cb->get_status)
507 edev->cb->get_status(edev, ecomp);
508 return sysfs_emit(buf, "%s\n", enclosure_status[ecomp->status]);
509}
510
511static ssize_t set_component_status(struct device *cdev,
512 struct device_attribute *attr,
513 const char *buf, size_t count)
514{
515 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
516 struct enclosure_component *ecomp = to_enclosure_component(cdev);
517 int i;
518
519 for (i = 0; enclosure_status[i]; i++) {
520 if (strncmp(buf, enclosure_status[i],
521 strlen(enclosure_status[i])) == 0 &&
522 (buf[strlen(enclosure_status[i])] == '\n' ||
523 buf[strlen(enclosure_status[i])] == '\0'))
524 break;
525 }
526
527 if (enclosure_status[i] && edev->cb->set_status) {
528 edev->cb->set_status(edev, ecomp, i);
529 return count;
530 } else
531 return -EINVAL;
532}
533
534static ssize_t get_component_active(struct device *cdev,
535 struct device_attribute *attr, char *buf)
536{
537 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
538 struct enclosure_component *ecomp = to_enclosure_component(cdev);
539
540 if (edev->cb->get_active)
541 edev->cb->get_active(edev, ecomp);
542 return sysfs_emit(buf, "%d\n", ecomp->active);
543}
544
545static ssize_t set_component_active(struct device *cdev,
546 struct device_attribute *attr,
547 const char *buf, size_t count)
548{
549 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
550 struct enclosure_component *ecomp = to_enclosure_component(cdev);
551 int val = simple_strtoul(buf, NULL, 0);
552
553 if (edev->cb->set_active)
554 edev->cb->set_active(edev, ecomp, val);
555 return count;
556}
557
558static ssize_t get_component_locate(struct device *cdev,
559 struct device_attribute *attr, char *buf)
560{
561 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
562 struct enclosure_component *ecomp = to_enclosure_component(cdev);
563
564 if (edev->cb->get_locate)
565 edev->cb->get_locate(edev, ecomp);
566 return sysfs_emit(buf, "%d\n", ecomp->locate);
567}
568
569static ssize_t set_component_locate(struct device *cdev,
570 struct device_attribute *attr,
571 const char *buf, size_t count)
572{
573 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
574 struct enclosure_component *ecomp = to_enclosure_component(cdev);
575 int val = simple_strtoul(buf, NULL, 0);
576
577 if (edev->cb->set_locate)
578 edev->cb->set_locate(edev, ecomp, val);
579 return count;
580}
581
582static ssize_t get_component_power_status(struct device *cdev,
583 struct device_attribute *attr,
584 char *buf)
585{
586 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
587 struct enclosure_component *ecomp = to_enclosure_component(cdev);
588
589 if (edev->cb->get_power_status)
590 edev->cb->get_power_status(edev, ecomp);
591
592 /* If still uninitialized, the callback failed or does not exist. */
593 if (ecomp->power_status == -1)
594 return (edev->cb->get_power_status) ? -EIO : -ENOTTY;
595
596 return sysfs_emit(buf, "%s\n", str_on_off(ecomp->power_status));
597}
598
599static ssize_t set_component_power_status(struct device *cdev,
600 struct device_attribute *attr,
601 const char *buf, size_t count)
602{
603 struct enclosure_device *edev = to_enclosure_device(cdev->parent);
604 struct enclosure_component *ecomp = to_enclosure_component(cdev);
605 int val;
606
607 if (strncmp(buf, "on", 2) == 0 &&
608 (buf[2] == '\n' || buf[2] == '\0'))
609 val = 1;
610 else if (strncmp(buf, "off", 3) == 0 &&
611 (buf[3] == '\n' || buf[3] == '\0'))
612 val = 0;
613 else
614 return -EINVAL;
615
616 if (edev->cb->set_power_status)
617 edev->cb->set_power_status(edev, ecomp, val);
618 return count;
619}
620
621static ssize_t get_component_type(struct device *cdev,
622 struct device_attribute *attr, char *buf)
623{
624 struct enclosure_component *ecomp = to_enclosure_component(cdev);
625
626 return sysfs_emit(buf, "%s\n", enclosure_type[ecomp->type]);
627}
628
629static ssize_t get_component_slot(struct device *cdev,
630 struct device_attribute *attr, char *buf)
631{
632 struct enclosure_component *ecomp = to_enclosure_component(cdev);
633 int slot;
634
635 /* if the enclosure does not override then use 'number' as a stand-in */
636 if (ecomp->slot >= 0)
637 slot = ecomp->slot;
638 else
639 slot = ecomp->number;
640
641 return sysfs_emit(buf, "%d\n", slot);
642}
643
644static DEVICE_ATTR(fault, S_IRUGO | S_IWUSR, get_component_fault,
645 set_component_fault);
646static DEVICE_ATTR(status, S_IRUGO | S_IWUSR, get_component_status,
647 set_component_status);
648static DEVICE_ATTR(active, S_IRUGO | S_IWUSR, get_component_active,
649 set_component_active);
650static DEVICE_ATTR(locate, S_IRUGO | S_IWUSR, get_component_locate,
651 set_component_locate);
652static DEVICE_ATTR(power_status, S_IRUGO | S_IWUSR, get_component_power_status,
653 set_component_power_status);
654static DEVICE_ATTR(type, S_IRUGO, get_component_type, NULL);
655static DEVICE_ATTR(slot, S_IRUGO, get_component_slot, NULL);
656
657static struct attribute *enclosure_component_attrs[] = {
658 &dev_attr_fault.attr,
659 &dev_attr_status.attr,
660 &dev_attr_active.attr,
661 &dev_attr_locate.attr,
662 &dev_attr_power_status.attr,
663 &dev_attr_type.attr,
664 &dev_attr_slot.attr,
665 NULL
666};
667ATTRIBUTE_GROUPS(enclosure_component);
668
669static int __init enclosure_init(void)
670{
671 return class_register(&enclosure_class);
672}
673
674static void __exit enclosure_exit(void)
675{
676 class_unregister(&enclosure_class);
677}
678
679module_init(enclosure_init);
680module_exit(enclosure_exit);
681
682MODULE_AUTHOR("James Bottomley");
683MODULE_DESCRIPTION("Enclosure Services");
684MODULE_LICENSE("GPL v2");