enclosure.c

  1// SPDX-License-Identifier: GPL-2.0-only
  2/*
  3 * Enclosure Services
  4 *
  5 * Copyright (C) 2008 James Bottomley <James.Bottomley@HansenPartnership.com>
  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(struct_size(edev, component, components), GFP_KERNEL);
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	strcpy(name, "enclosure_device:");
188	strcat(name, 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");