[go: nahoru, domu]

1/*
2 * firmware_class.c - Multi purpose firmware loading support
3 *
4 * Copyright (c) 2003 Manuel Estrada Sainz
5 *
6 * Please see Documentation/firmware_class/ for more information.
7 *
8 */
9
10#include <linux/capability.h>
11#include <linux/device.h>
12#include <linux/module.h>
13#include <linux/init.h>
14#include <linux/timer.h>
15#include <linux/vmalloc.h>
16#include <linux/interrupt.h>
17#include <linux/bitops.h>
18#include <linux/mutex.h>
19#include <linux/workqueue.h>
20#include <linux/highmem.h>
21#include <linux/firmware.h>
22#include <linux/slab.h>
23#include <linux/sched.h>
24#include <linux/file.h>
25#include <linux/list.h>
26#include <linux/async.h>
27#include <linux/pm.h>
28#include <linux/suspend.h>
29#include <linux/syscore_ops.h>
30#include <linux/reboot.h>
31#include <linux/security.h>
32
33#include <generated/utsrelease.h>
34
35#include "base.h"
36
37MODULE_AUTHOR("Manuel Estrada Sainz");
38MODULE_DESCRIPTION("Multi purpose firmware loading support");
39MODULE_LICENSE("GPL");
40
41/* Builtin firmware support */
42
43#ifdef CONFIG_FW_LOADER
44
45extern struct builtin_fw __start_builtin_fw[];
46extern struct builtin_fw __end_builtin_fw[];
47
48static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
49{
50	struct builtin_fw *b_fw;
51
52	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
53		if (strcmp(name, b_fw->name) == 0) {
54			fw->size = b_fw->size;
55			fw->data = b_fw->data;
56			return true;
57		}
58	}
59
60	return false;
61}
62
63static bool fw_is_builtin_firmware(const struct firmware *fw)
64{
65	struct builtin_fw *b_fw;
66
67	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
68		if (fw->data == b_fw->data)
69			return true;
70
71	return false;
72}
73
74#else /* Module case - no builtin firmware support */
75
76static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
77{
78	return false;
79}
80
81static inline bool fw_is_builtin_firmware(const struct firmware *fw)
82{
83	return false;
84}
85#endif
86
87enum {
88	FW_STATUS_LOADING,
89	FW_STATUS_DONE,
90	FW_STATUS_ABORT,
91};
92
93static int loading_timeout = 60;	/* In seconds */
94
95static inline long firmware_loading_timeout(void)
96{
97	return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
98}
99
100/* firmware behavior options */
101#define FW_OPT_UEVENT	(1U << 0)
102#define FW_OPT_NOWAIT	(1U << 1)
103#ifdef CONFIG_FW_LOADER_USER_HELPER
104#define FW_OPT_USERHELPER	(1U << 2)
105#else
106#define FW_OPT_USERHELPER	0
107#endif
108#ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
109#define FW_OPT_FALLBACK		FW_OPT_USERHELPER
110#else
111#define FW_OPT_FALLBACK		0
112#endif
113#define FW_OPT_NO_WARN	(1U << 3)
114
115struct firmware_cache {
116	/* firmware_buf instance will be added into the below list */
117	spinlock_t lock;
118	struct list_head head;
119	int state;
120
121#ifdef CONFIG_PM_SLEEP
122	/*
123	 * Names of firmware images which have been cached successfully
124	 * will be added into the below list so that device uncache
125	 * helper can trace which firmware images have been cached
126	 * before.
127	 */
128	spinlock_t name_lock;
129	struct list_head fw_names;
130
131	struct delayed_work work;
132
133	struct notifier_block   pm_notify;
134#endif
135};
136
137struct firmware_buf {
138	struct kref ref;
139	struct list_head list;
140	struct completion completion;
141	struct firmware_cache *fwc;
142	unsigned long status;
143	void *data;
144	size_t size;
145#ifdef CONFIG_FW_LOADER_USER_HELPER
146	bool is_paged_buf;
147	bool need_uevent;
148	struct page **pages;
149	int nr_pages;
150	int page_array_size;
151	struct list_head pending_list;
152#endif
153	char fw_id[];
154};
155
156struct fw_cache_entry {
157	struct list_head list;
158	char name[];
159};
160
161struct fw_name_devm {
162	unsigned long magic;
163	char name[];
164};
165
166#define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
167
168#define	FW_LOADER_NO_CACHE	0
169#define	FW_LOADER_START_CACHE	1
170
171static int fw_cache_piggyback_on_request(const char *name);
172
173/* fw_lock could be moved to 'struct firmware_priv' but since it is just
174 * guarding for corner cases a global lock should be OK */
175static DEFINE_MUTEX(fw_lock);
176
177static struct firmware_cache fw_cache;
178
179static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
180					      struct firmware_cache *fwc)
181{
182	struct firmware_buf *buf;
183
184	buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1 , GFP_ATOMIC);
185
186	if (!buf)
187		return buf;
188
189	kref_init(&buf->ref);
190	strcpy(buf->fw_id, fw_name);
191	buf->fwc = fwc;
192	init_completion(&buf->completion);
193#ifdef CONFIG_FW_LOADER_USER_HELPER
194	INIT_LIST_HEAD(&buf->pending_list);
195#endif
196
197	pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
198
199	return buf;
200}
201
202static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
203{
204	struct firmware_buf *tmp;
205	struct firmware_cache *fwc = &fw_cache;
206
207	list_for_each_entry(tmp, &fwc->head, list)
208		if (!strcmp(tmp->fw_id, fw_name))
209			return tmp;
210	return NULL;
211}
212
213static int fw_lookup_and_allocate_buf(const char *fw_name,
214				      struct firmware_cache *fwc,
215				      struct firmware_buf **buf)
216{
217	struct firmware_buf *tmp;
218
219	spin_lock(&fwc->lock);
220	tmp = __fw_lookup_buf(fw_name);
221	if (tmp) {
222		kref_get(&tmp->ref);
223		spin_unlock(&fwc->lock);
224		*buf = tmp;
225		return 1;
226	}
227	tmp = __allocate_fw_buf(fw_name, fwc);
228	if (tmp)
229		list_add(&tmp->list, &fwc->head);
230	spin_unlock(&fwc->lock);
231
232	*buf = tmp;
233
234	return tmp ? 0 : -ENOMEM;
235}
236
237static void __fw_free_buf(struct kref *ref)
238	__releases(&fwc->lock)
239{
240	struct firmware_buf *buf = to_fwbuf(ref);
241	struct firmware_cache *fwc = buf->fwc;
242
243	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
244		 __func__, buf->fw_id, buf, buf->data,
245		 (unsigned int)buf->size);
246
247	list_del(&buf->list);
248	spin_unlock(&fwc->lock);
249
250#ifdef CONFIG_FW_LOADER_USER_HELPER
251	if (buf->is_paged_buf) {
252		int i;
253		vunmap(buf->data);
254		for (i = 0; i < buf->nr_pages; i++)
255			__free_page(buf->pages[i]);
256		kfree(buf->pages);
257	} else
258#endif
259		vfree(buf->data);
260	kfree(buf);
261}
262
263static void fw_free_buf(struct firmware_buf *buf)
264{
265	struct firmware_cache *fwc = buf->fwc;
266	spin_lock(&fwc->lock);
267	if (!kref_put(&buf->ref, __fw_free_buf))
268		spin_unlock(&fwc->lock);
269}
270
271/* direct firmware loading support */
272static char fw_path_para[256];
273static const char * const fw_path[] = {
274	fw_path_para,
275	"/lib/firmware/updates/" UTS_RELEASE,
276	"/lib/firmware/updates",
277	"/lib/firmware/" UTS_RELEASE,
278	"/lib/firmware"
279};
280
281/*
282 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
283 * from kernel command line because firmware_class is generally built in
284 * kernel instead of module.
285 */
286module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
287MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
288
289static int fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf)
290{
291	int size;
292	char *buf;
293	int rc;
294
295	if (!S_ISREG(file_inode(file)->i_mode))
296		return -EINVAL;
297	size = i_size_read(file_inode(file));
298	if (size <= 0)
299		return -EINVAL;
300	buf = vmalloc(size);
301	if (!buf)
302		return -ENOMEM;
303	rc = kernel_read(file, 0, buf, size);
304	if (rc != size) {
305		if (rc > 0)
306			rc = -EIO;
307		goto fail;
308	}
309	rc = security_kernel_fw_from_file(file, buf, size);
310	if (rc)
311		goto fail;
312	fw_buf->data = buf;
313	fw_buf->size = size;
314	return 0;
315fail:
316	vfree(buf);
317	return rc;
318}
319
320static int fw_get_filesystem_firmware(struct device *device,
321				       struct firmware_buf *buf)
322{
323	int i;
324	int rc = -ENOENT;
325	char *path = __getname();
326
327	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
328		struct file *file;
329
330		/* skip the unset customized path */
331		if (!fw_path[i][0])
332			continue;
333
334		snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id);
335
336		file = filp_open(path, O_RDONLY, 0);
337		if (IS_ERR(file))
338			continue;
339		rc = fw_read_file_contents(file, buf);
340		fput(file);
341		if (rc)
342			dev_warn(device, "firmware, attempted to load %s, but failed with error %d\n",
343				path, rc);
344		else
345			break;
346	}
347	__putname(path);
348
349	if (!rc) {
350		dev_dbg(device, "firmware: direct-loading firmware %s\n",
351			buf->fw_id);
352		mutex_lock(&fw_lock);
353		set_bit(FW_STATUS_DONE, &buf->status);
354		complete_all(&buf->completion);
355		mutex_unlock(&fw_lock);
356	}
357
358	return rc;
359}
360
361/* firmware holds the ownership of pages */
362static void firmware_free_data(const struct firmware *fw)
363{
364	/* Loaded directly? */
365	if (!fw->priv) {
366		vfree(fw->data);
367		return;
368	}
369	fw_free_buf(fw->priv);
370}
371
372/* store the pages buffer info firmware from buf */
373static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
374{
375	fw->priv = buf;
376#ifdef CONFIG_FW_LOADER_USER_HELPER
377	fw->pages = buf->pages;
378#endif
379	fw->size = buf->size;
380	fw->data = buf->data;
381
382	pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
383		 __func__, buf->fw_id, buf, buf->data,
384		 (unsigned int)buf->size);
385}
386
387#ifdef CONFIG_PM_SLEEP
388static void fw_name_devm_release(struct device *dev, void *res)
389{
390	struct fw_name_devm *fwn = res;
391
392	if (fwn->magic == (unsigned long)&fw_cache)
393		pr_debug("%s: fw_name-%s devm-%p released\n",
394				__func__, fwn->name, res);
395}
396
397static int fw_devm_match(struct device *dev, void *res,
398		void *match_data)
399{
400	struct fw_name_devm *fwn = res;
401
402	return (fwn->magic == (unsigned long)&fw_cache) &&
403		!strcmp(fwn->name, match_data);
404}
405
406static struct fw_name_devm *fw_find_devm_name(struct device *dev,
407		const char *name)
408{
409	struct fw_name_devm *fwn;
410
411	fwn = devres_find(dev, fw_name_devm_release,
412			  fw_devm_match, (void *)name);
413	return fwn;
414}
415
416/* add firmware name into devres list */
417static int fw_add_devm_name(struct device *dev, const char *name)
418{
419	struct fw_name_devm *fwn;
420
421	fwn = fw_find_devm_name(dev, name);
422	if (fwn)
423		return 1;
424
425	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm) +
426			   strlen(name) + 1, GFP_KERNEL);
427	if (!fwn)
428		return -ENOMEM;
429
430	fwn->magic = (unsigned long)&fw_cache;
431	strcpy(fwn->name, name);
432	devres_add(dev, fwn);
433
434	return 0;
435}
436#else
437static int fw_add_devm_name(struct device *dev, const char *name)
438{
439	return 0;
440}
441#endif
442
443
444/*
445 * user-mode helper code
446 */
447#ifdef CONFIG_FW_LOADER_USER_HELPER
448struct firmware_priv {
449	struct delayed_work timeout_work;
450	bool nowait;
451	struct device dev;
452	struct firmware_buf *buf;
453	struct firmware *fw;
454};
455
456static struct firmware_priv *to_firmware_priv(struct device *dev)
457{
458	return container_of(dev, struct firmware_priv, dev);
459}
460
461static void __fw_load_abort(struct firmware_buf *buf)
462{
463	/*
464	 * There is a small window in which user can write to 'loading'
465	 * between loading done and disappearance of 'loading'
466	 */
467	if (test_bit(FW_STATUS_DONE, &buf->status))
468		return;
469
470	list_del_init(&buf->pending_list);
471	set_bit(FW_STATUS_ABORT, &buf->status);
472	complete_all(&buf->completion);
473}
474
475static void fw_load_abort(struct firmware_priv *fw_priv)
476{
477	struct firmware_buf *buf = fw_priv->buf;
478
479	__fw_load_abort(buf);
480
481	/* avoid user action after loading abort */
482	fw_priv->buf = NULL;
483}
484
485#define is_fw_load_aborted(buf)	\
486	test_bit(FW_STATUS_ABORT, &(buf)->status)
487
488static LIST_HEAD(pending_fw_head);
489
490/* reboot notifier for avoid deadlock with usermode_lock */
491static int fw_shutdown_notify(struct notifier_block *unused1,
492			      unsigned long unused2, void *unused3)
493{
494	mutex_lock(&fw_lock);
495	while (!list_empty(&pending_fw_head))
496		__fw_load_abort(list_first_entry(&pending_fw_head,
497					       struct firmware_buf,
498					       pending_list));
499	mutex_unlock(&fw_lock);
500	return NOTIFY_DONE;
501}
502
503static struct notifier_block fw_shutdown_nb = {
504	.notifier_call = fw_shutdown_notify,
505};
506
507static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
508			    char *buf)
509{
510	return sprintf(buf, "%d\n", loading_timeout);
511}
512
513/**
514 * firmware_timeout_store - set number of seconds to wait for firmware
515 * @class: device class pointer
516 * @attr: device attribute pointer
517 * @buf: buffer to scan for timeout value
518 * @count: number of bytes in @buf
519 *
520 *	Sets the number of seconds to wait for the firmware.  Once
521 *	this expires an error will be returned to the driver and no
522 *	firmware will be provided.
523 *
524 *	Note: zero means 'wait forever'.
525 **/
526static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
527			     const char *buf, size_t count)
528{
529	loading_timeout = simple_strtol(buf, NULL, 10);
530	if (loading_timeout < 0)
531		loading_timeout = 0;
532
533	return count;
534}
535
536static struct class_attribute firmware_class_attrs[] = {
537	__ATTR_RW(timeout),
538	__ATTR_NULL
539};
540
541static void fw_dev_release(struct device *dev)
542{
543	struct firmware_priv *fw_priv = to_firmware_priv(dev);
544
545	kfree(fw_priv);
546}
547
548static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
549{
550	struct firmware_priv *fw_priv = to_firmware_priv(dev);
551
552	if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
553		return -ENOMEM;
554	if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
555		return -ENOMEM;
556	if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
557		return -ENOMEM;
558
559	return 0;
560}
561
562static struct class firmware_class = {
563	.name		= "firmware",
564	.class_attrs	= firmware_class_attrs,
565	.dev_uevent	= firmware_uevent,
566	.dev_release	= fw_dev_release,
567};
568
569static ssize_t firmware_loading_show(struct device *dev,
570				     struct device_attribute *attr, char *buf)
571{
572	struct firmware_priv *fw_priv = to_firmware_priv(dev);
573	int loading = 0;
574
575	mutex_lock(&fw_lock);
576	if (fw_priv->buf)
577		loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status);
578	mutex_unlock(&fw_lock);
579
580	return sprintf(buf, "%d\n", loading);
581}
582
583/* Some architectures don't have PAGE_KERNEL_RO */
584#ifndef PAGE_KERNEL_RO
585#define PAGE_KERNEL_RO PAGE_KERNEL
586#endif
587
588/* one pages buffer should be mapped/unmapped only once */
589static int fw_map_pages_buf(struct firmware_buf *buf)
590{
591	if (!buf->is_paged_buf)
592		return 0;
593
594	if (buf->data)
595		vunmap(buf->data);
596	buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
597	if (!buf->data)
598		return -ENOMEM;
599	return 0;
600}
601
602/**
603 * firmware_loading_store - set value in the 'loading' control file
604 * @dev: device pointer
605 * @attr: device attribute pointer
606 * @buf: buffer to scan for loading control value
607 * @count: number of bytes in @buf
608 *
609 *	The relevant values are:
610 *
611 *	 1: Start a load, discarding any previous partial load.
612 *	 0: Conclude the load and hand the data to the driver code.
613 *	-1: Conclude the load with an error and discard any written data.
614 **/
615static ssize_t firmware_loading_store(struct device *dev,
616				      struct device_attribute *attr,
617				      const char *buf, size_t count)
618{
619	struct firmware_priv *fw_priv = to_firmware_priv(dev);
620	struct firmware_buf *fw_buf;
621	ssize_t written = count;
622	int loading = simple_strtol(buf, NULL, 10);
623	int i;
624
625	mutex_lock(&fw_lock);
626	fw_buf = fw_priv->buf;
627	if (!fw_buf)
628		goto out;
629
630	switch (loading) {
631	case 1:
632		/* discarding any previous partial load */
633		if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) {
634			for (i = 0; i < fw_buf->nr_pages; i++)
635				__free_page(fw_buf->pages[i]);
636			kfree(fw_buf->pages);
637			fw_buf->pages = NULL;
638			fw_buf->page_array_size = 0;
639			fw_buf->nr_pages = 0;
640			set_bit(FW_STATUS_LOADING, &fw_buf->status);
641		}
642		break;
643	case 0:
644		if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) {
645			int rc;
646
647			set_bit(FW_STATUS_DONE, &fw_buf->status);
648			clear_bit(FW_STATUS_LOADING, &fw_buf->status);
649
650			/*
651			 * Several loading requests may be pending on
652			 * one same firmware buf, so let all requests
653			 * see the mapped 'buf->data' once the loading
654			 * is completed.
655			 * */
656			rc = fw_map_pages_buf(fw_buf);
657			if (rc)
658				dev_err(dev, "%s: map pages failed\n",
659					__func__);
660			else
661				rc = security_kernel_fw_from_file(NULL,
662						fw_buf->data, fw_buf->size);
663
664			/*
665			 * Same logic as fw_load_abort, only the DONE bit
666			 * is ignored and we set ABORT only on failure.
667			 */
668			list_del_init(&fw_buf->pending_list);
669			if (rc) {
670				set_bit(FW_STATUS_ABORT, &fw_buf->status);
671				written = rc;
672			}
673			complete_all(&fw_buf->completion);
674			break;
675		}
676		/* fallthrough */
677	default:
678		dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
679		/* fallthrough */
680	case -1:
681		fw_load_abort(fw_priv);
682		break;
683	}
684out:
685	mutex_unlock(&fw_lock);
686	return written;
687}
688
689static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
690
691static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
692				  struct bin_attribute *bin_attr,
693				  char *buffer, loff_t offset, size_t count)
694{
695	struct device *dev = kobj_to_dev(kobj);
696	struct firmware_priv *fw_priv = to_firmware_priv(dev);
697	struct firmware_buf *buf;
698	ssize_t ret_count;
699
700	mutex_lock(&fw_lock);
701	buf = fw_priv->buf;
702	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
703		ret_count = -ENODEV;
704		goto out;
705	}
706	if (offset > buf->size) {
707		ret_count = 0;
708		goto out;
709	}
710	if (count > buf->size - offset)
711		count = buf->size - offset;
712
713	ret_count = count;
714
715	while (count) {
716		void *page_data;
717		int page_nr = offset >> PAGE_SHIFT;
718		int page_ofs = offset & (PAGE_SIZE-1);
719		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
720
721		page_data = kmap(buf->pages[page_nr]);
722
723		memcpy(buffer, page_data + page_ofs, page_cnt);
724
725		kunmap(buf->pages[page_nr]);
726		buffer += page_cnt;
727		offset += page_cnt;
728		count -= page_cnt;
729	}
730out:
731	mutex_unlock(&fw_lock);
732	return ret_count;
733}
734
735static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
736{
737	struct firmware_buf *buf = fw_priv->buf;
738	int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
739
740	/* If the array of pages is too small, grow it... */
741	if (buf->page_array_size < pages_needed) {
742		int new_array_size = max(pages_needed,
743					 buf->page_array_size * 2);
744		struct page **new_pages;
745
746		new_pages = kmalloc(new_array_size * sizeof(void *),
747				    GFP_KERNEL);
748		if (!new_pages) {
749			fw_load_abort(fw_priv);
750			return -ENOMEM;
751		}
752		memcpy(new_pages, buf->pages,
753		       buf->page_array_size * sizeof(void *));
754		memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
755		       (new_array_size - buf->page_array_size));
756		kfree(buf->pages);
757		buf->pages = new_pages;
758		buf->page_array_size = new_array_size;
759	}
760
761	while (buf->nr_pages < pages_needed) {
762		buf->pages[buf->nr_pages] =
763			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
764
765		if (!buf->pages[buf->nr_pages]) {
766			fw_load_abort(fw_priv);
767			return -ENOMEM;
768		}
769		buf->nr_pages++;
770	}
771	return 0;
772}
773
774/**
775 * firmware_data_write - write method for firmware
776 * @filp: open sysfs file
777 * @kobj: kobject for the device
778 * @bin_attr: bin_attr structure
779 * @buffer: buffer being written
780 * @offset: buffer offset for write in total data store area
781 * @count: buffer size
782 *
783 *	Data written to the 'data' attribute will be later handed to
784 *	the driver as a firmware image.
785 **/
786static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
787				   struct bin_attribute *bin_attr,
788				   char *buffer, loff_t offset, size_t count)
789{
790	struct device *dev = kobj_to_dev(kobj);
791	struct firmware_priv *fw_priv = to_firmware_priv(dev);
792	struct firmware_buf *buf;
793	ssize_t retval;
794
795	if (!capable(CAP_SYS_RAWIO))
796		return -EPERM;
797
798	mutex_lock(&fw_lock);
799	buf = fw_priv->buf;
800	if (!buf || test_bit(FW_STATUS_DONE, &buf->status)) {
801		retval = -ENODEV;
802		goto out;
803	}
804
805	retval = fw_realloc_buffer(fw_priv, offset + count);
806	if (retval)
807		goto out;
808
809	retval = count;
810
811	while (count) {
812		void *page_data;
813		int page_nr = offset >> PAGE_SHIFT;
814		int page_ofs = offset & (PAGE_SIZE - 1);
815		int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
816
817		page_data = kmap(buf->pages[page_nr]);
818
819		memcpy(page_data + page_ofs, buffer, page_cnt);
820
821		kunmap(buf->pages[page_nr]);
822		buffer += page_cnt;
823		offset += page_cnt;
824		count -= page_cnt;
825	}
826
827	buf->size = max_t(size_t, offset, buf->size);
828out:
829	mutex_unlock(&fw_lock);
830	return retval;
831}
832
833static struct bin_attribute firmware_attr_data = {
834	.attr = { .name = "data", .mode = 0644 },
835	.size = 0,
836	.read = firmware_data_read,
837	.write = firmware_data_write,
838};
839
840static void firmware_class_timeout_work(struct work_struct *work)
841{
842	struct firmware_priv *fw_priv = container_of(work,
843			struct firmware_priv, timeout_work.work);
844
845	mutex_lock(&fw_lock);
846	fw_load_abort(fw_priv);
847	mutex_unlock(&fw_lock);
848}
849
850static struct firmware_priv *
851fw_create_instance(struct firmware *firmware, const char *fw_name,
852		   struct device *device, unsigned int opt_flags)
853{
854	struct firmware_priv *fw_priv;
855	struct device *f_dev;
856
857	fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
858	if (!fw_priv) {
859		dev_err(device, "%s: kmalloc failed\n", __func__);
860		fw_priv = ERR_PTR(-ENOMEM);
861		goto exit;
862	}
863
864	fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
865	fw_priv->fw = firmware;
866	INIT_DELAYED_WORK(&fw_priv->timeout_work,
867		firmware_class_timeout_work);
868
869	f_dev = &fw_priv->dev;
870
871	device_initialize(f_dev);
872	dev_set_name(f_dev, "%s", fw_name);
873	f_dev->parent = device;
874	f_dev->class = &firmware_class;
875exit:
876	return fw_priv;
877}
878
879/* load a firmware via user helper */
880static int _request_firmware_load(struct firmware_priv *fw_priv,
881				  unsigned int opt_flags, long timeout)
882{
883	int retval = 0;
884	struct device *f_dev = &fw_priv->dev;
885	struct firmware_buf *buf = fw_priv->buf;
886
887	/* fall back on userspace loading */
888	buf->is_paged_buf = true;
889
890	dev_set_uevent_suppress(f_dev, true);
891
892	retval = device_add(f_dev);
893	if (retval) {
894		dev_err(f_dev, "%s: device_register failed\n", __func__);
895		goto err_put_dev;
896	}
897
898	retval = device_create_bin_file(f_dev, &firmware_attr_data);
899	if (retval) {
900		dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
901		goto err_del_dev;
902	}
903
904	mutex_lock(&fw_lock);
905	list_add(&buf->pending_list, &pending_fw_head);
906	mutex_unlock(&fw_lock);
907
908	retval = device_create_file(f_dev, &dev_attr_loading);
909	if (retval) {
910		mutex_lock(&fw_lock);
911		list_del_init(&buf->pending_list);
912		mutex_unlock(&fw_lock);
913		dev_err(f_dev, "%s: device_create_file failed\n", __func__);
914		goto err_del_bin_attr;
915	}
916
917	if (opt_flags & FW_OPT_UEVENT) {
918		buf->need_uevent = true;
919		dev_set_uevent_suppress(f_dev, false);
920		dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
921		if (timeout != MAX_SCHEDULE_TIMEOUT)
922			queue_delayed_work(system_power_efficient_wq,
923					   &fw_priv->timeout_work, timeout);
924
925		kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
926	}
927
928	wait_for_completion(&buf->completion);
929
930	cancel_delayed_work_sync(&fw_priv->timeout_work);
931	if (is_fw_load_aborted(buf))
932		retval = -EAGAIN;
933	else if (!buf->data)
934		retval = -ENOMEM;
935
936	device_remove_file(f_dev, &dev_attr_loading);
937err_del_bin_attr:
938	device_remove_bin_file(f_dev, &firmware_attr_data);
939err_del_dev:
940	device_del(f_dev);
941err_put_dev:
942	put_device(f_dev);
943	return retval;
944}
945
946static int fw_load_from_user_helper(struct firmware *firmware,
947				    const char *name, struct device *device,
948				    unsigned int opt_flags, long timeout)
949{
950	struct firmware_priv *fw_priv;
951
952	fw_priv = fw_create_instance(firmware, name, device, opt_flags);
953	if (IS_ERR(fw_priv))
954		return PTR_ERR(fw_priv);
955
956	fw_priv->buf = firmware->priv;
957	return _request_firmware_load(fw_priv, opt_flags, timeout);
958}
959
960#ifdef CONFIG_PM_SLEEP
961/* kill pending requests without uevent to avoid blocking suspend */
962static void kill_requests_without_uevent(void)
963{
964	struct firmware_buf *buf;
965	struct firmware_buf *next;
966
967	mutex_lock(&fw_lock);
968	list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
969		if (!buf->need_uevent)
970			 __fw_load_abort(buf);
971	}
972	mutex_unlock(&fw_lock);
973}
974#endif
975
976#else /* CONFIG_FW_LOADER_USER_HELPER */
977static inline int
978fw_load_from_user_helper(struct firmware *firmware, const char *name,
979			 struct device *device, unsigned int opt_flags,
980			 long timeout)
981{
982	return -ENOENT;
983}
984
985/* No abort during direct loading */
986#define is_fw_load_aborted(buf) false
987
988#ifdef CONFIG_PM_SLEEP
989static inline void kill_requests_without_uevent(void) { }
990#endif
991
992#endif /* CONFIG_FW_LOADER_USER_HELPER */
993
994
995/* wait until the shared firmware_buf becomes ready (or error) */
996static int sync_cached_firmware_buf(struct firmware_buf *buf)
997{
998	int ret = 0;
999
1000	mutex_lock(&fw_lock);
1001	while (!test_bit(FW_STATUS_DONE, &buf->status)) {
1002		if (is_fw_load_aborted(buf)) {
1003			ret = -ENOENT;
1004			break;
1005		}
1006		mutex_unlock(&fw_lock);
1007		wait_for_completion(&buf->completion);
1008		mutex_lock(&fw_lock);
1009	}
1010	mutex_unlock(&fw_lock);
1011	return ret;
1012}
1013
1014/* prepare firmware and firmware_buf structs;
1015 * return 0 if a firmware is already assigned, 1 if need to load one,
1016 * or a negative error code
1017 */
1018static int
1019_request_firmware_prepare(struct firmware **firmware_p, const char *name,
1020			  struct device *device)
1021{
1022	struct firmware *firmware;
1023	struct firmware_buf *buf;
1024	int ret;
1025
1026	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1027	if (!firmware) {
1028		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1029			__func__);
1030		return -ENOMEM;
1031	}
1032
1033	if (fw_get_builtin_firmware(firmware, name)) {
1034		dev_dbg(device, "firmware: using built-in firmware %s\n", name);
1035		return 0; /* assigned */
1036	}
1037
1038	ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf);
1039
1040	/*
1041	 * bind with 'buf' now to avoid warning in failure path
1042	 * of requesting firmware.
1043	 */
1044	firmware->priv = buf;
1045
1046	if (ret > 0) {
1047		ret = sync_cached_firmware_buf(buf);
1048		if (!ret) {
1049			fw_set_page_data(buf, firmware);
1050			return 0; /* assigned */
1051		}
1052	}
1053
1054	if (ret < 0)
1055		return ret;
1056	return 1; /* need to load */
1057}
1058
1059static int assign_firmware_buf(struct firmware *fw, struct device *device,
1060			       unsigned int opt_flags)
1061{
1062	struct firmware_buf *buf = fw->priv;
1063
1064	mutex_lock(&fw_lock);
1065	if (!buf->size || is_fw_load_aborted(buf)) {
1066		mutex_unlock(&fw_lock);
1067		return -ENOENT;
1068	}
1069
1070	/*
1071	 * add firmware name into devres list so that we can auto cache
1072	 * and uncache firmware for device.
1073	 *
1074	 * device may has been deleted already, but the problem
1075	 * should be fixed in devres or driver core.
1076	 */
1077	/* don't cache firmware handled without uevent */
1078	if (device && (opt_flags & FW_OPT_UEVENT))
1079		fw_add_devm_name(device, buf->fw_id);
1080
1081	/*
1082	 * After caching firmware image is started, let it piggyback
1083	 * on request firmware.
1084	 */
1085	if (buf->fwc->state == FW_LOADER_START_CACHE) {
1086		if (fw_cache_piggyback_on_request(buf->fw_id))
1087			kref_get(&buf->ref);
1088	}
1089
1090	/* pass the pages buffer to driver at the last minute */
1091	fw_set_page_data(buf, fw);
1092	mutex_unlock(&fw_lock);
1093	return 0;
1094}
1095
1096/* called from request_firmware() and request_firmware_work_func() */
1097static int
1098_request_firmware(const struct firmware **firmware_p, const char *name,
1099		  struct device *device, unsigned int opt_flags)
1100{
1101	struct firmware *fw;
1102	long timeout;
1103	int ret;
1104
1105	if (!firmware_p)
1106		return -EINVAL;
1107
1108	if (!name || name[0] == '\0')
1109		return -EINVAL;
1110
1111	ret = _request_firmware_prepare(&fw, name, device);
1112	if (ret <= 0) /* error or already assigned */
1113		goto out;
1114
1115	ret = 0;
1116	timeout = firmware_loading_timeout();
1117	if (opt_flags & FW_OPT_NOWAIT) {
1118		timeout = usermodehelper_read_lock_wait(timeout);
1119		if (!timeout) {
1120			dev_dbg(device, "firmware: %s loading timed out\n",
1121				name);
1122			ret = -EBUSY;
1123			goto out;
1124		}
1125	} else {
1126		ret = usermodehelper_read_trylock();
1127		if (WARN_ON(ret)) {
1128			dev_err(device, "firmware: %s will not be loaded\n",
1129				name);
1130			goto out;
1131		}
1132	}
1133
1134	ret = fw_get_filesystem_firmware(device, fw->priv);
1135	if (ret) {
1136		if (!(opt_flags & FW_OPT_NO_WARN))
1137			dev_warn(device,
1138				 "Direct firmware load for %s failed with error %d\n",
1139				 name, ret);
1140		if (opt_flags & FW_OPT_USERHELPER) {
1141			dev_warn(device, "Falling back to user helper\n");
1142			ret = fw_load_from_user_helper(fw, name, device,
1143						       opt_flags, timeout);
1144		}
1145	}
1146
1147	if (!ret)
1148		ret = assign_firmware_buf(fw, device, opt_flags);
1149
1150	usermodehelper_read_unlock();
1151
1152 out:
1153	if (ret < 0) {
1154		release_firmware(fw);
1155		fw = NULL;
1156	}
1157
1158	*firmware_p = fw;
1159	return ret;
1160}
1161
1162/**
1163 * request_firmware: - send firmware request and wait for it
1164 * @firmware_p: pointer to firmware image
1165 * @name: name of firmware file
1166 * @device: device for which firmware is being loaded
1167 *
1168 *      @firmware_p will be used to return a firmware image by the name
1169 *      of @name for device @device.
1170 *
1171 *      Should be called from user context where sleeping is allowed.
1172 *
1173 *      @name will be used as $FIRMWARE in the uevent environment and
1174 *      should be distinctive enough not to be confused with any other
1175 *      firmware image for this or any other device.
1176 *
1177 *	Caller must hold the reference count of @device.
1178 *
1179 *	The function can be called safely inside device's suspend and
1180 *	resume callback.
1181 **/
1182int
1183request_firmware(const struct firmware **firmware_p, const char *name,
1184                 struct device *device)
1185{
1186	int ret;
1187
1188	/* Need to pin this module until return */
1189	__module_get(THIS_MODULE);
1190	ret = _request_firmware(firmware_p, name, device,
1191				FW_OPT_UEVENT | FW_OPT_FALLBACK);
1192	module_put(THIS_MODULE);
1193	return ret;
1194}
1195EXPORT_SYMBOL(request_firmware);
1196
1197/**
1198 * request_firmware: - load firmware directly without usermode helper
1199 * @firmware_p: pointer to firmware image
1200 * @name: name of firmware file
1201 * @device: device for which firmware is being loaded
1202 *
1203 * This function works pretty much like request_firmware(), but this doesn't
1204 * fall back to usermode helper even if the firmware couldn't be loaded
1205 * directly from fs.  Hence it's useful for loading optional firmwares, which
1206 * aren't always present, without extra long timeouts of udev.
1207 **/
1208int request_firmware_direct(const struct firmware **firmware_p,
1209			    const char *name, struct device *device)
1210{
1211	int ret;
1212	__module_get(THIS_MODULE);
1213	ret = _request_firmware(firmware_p, name, device,
1214				FW_OPT_UEVENT | FW_OPT_NO_WARN);
1215	module_put(THIS_MODULE);
1216	return ret;
1217}
1218EXPORT_SYMBOL_GPL(request_firmware_direct);
1219
1220/**
1221 * release_firmware: - release the resource associated with a firmware image
1222 * @fw: firmware resource to release
1223 **/
1224void release_firmware(const struct firmware *fw)
1225{
1226	if (fw) {
1227		if (!fw_is_builtin_firmware(fw))
1228			firmware_free_data(fw);
1229		kfree(fw);
1230	}
1231}
1232EXPORT_SYMBOL(release_firmware);
1233
1234/* Async support */
1235struct firmware_work {
1236	struct work_struct work;
1237	struct module *module;
1238	const char *name;
1239	struct device *device;
1240	void *context;
1241	void (*cont)(const struct firmware *fw, void *context);
1242	unsigned int opt_flags;
1243};
1244
1245static void request_firmware_work_func(struct work_struct *work)
1246{
1247	struct firmware_work *fw_work;
1248	const struct firmware *fw;
1249
1250	fw_work = container_of(work, struct firmware_work, work);
1251
1252	_request_firmware(&fw, fw_work->name, fw_work->device,
1253			  fw_work->opt_flags);
1254	fw_work->cont(fw, fw_work->context);
1255	put_device(fw_work->device); /* taken in request_firmware_nowait() */
1256
1257	module_put(fw_work->module);
1258	kfree(fw_work);
1259}
1260
1261/**
1262 * request_firmware_nowait - asynchronous version of request_firmware
1263 * @module: module requesting the firmware
1264 * @uevent: sends uevent to copy the firmware image if this flag
1265 *	is non-zero else the firmware copy must be done manually.
1266 * @name: name of firmware file
1267 * @device: device for which firmware is being loaded
1268 * @gfp: allocation flags
1269 * @context: will be passed over to @cont, and
1270 *	@fw may be %NULL if firmware request fails.
1271 * @cont: function will be called asynchronously when the firmware
1272 *	request is over.
1273 *
1274 *	Caller must hold the reference count of @device.
1275 *
1276 *	Asynchronous variant of request_firmware() for user contexts:
1277 *		- sleep for as small periods as possible since it may
1278 *		increase kernel boot time of built-in device drivers
1279 *		requesting firmware in their ->probe() methods, if
1280 *		@gfp is GFP_KERNEL.
1281 *
1282 *		- can't sleep at all if @gfp is GFP_ATOMIC.
1283 **/
1284int
1285request_firmware_nowait(
1286	struct module *module, bool uevent,
1287	const char *name, struct device *device, gfp_t gfp, void *context,
1288	void (*cont)(const struct firmware *fw, void *context))
1289{
1290	struct firmware_work *fw_work;
1291
1292	fw_work = kzalloc(sizeof (struct firmware_work), gfp);
1293	if (!fw_work)
1294		return -ENOMEM;
1295
1296	fw_work->module = module;
1297	fw_work->name = name;
1298	fw_work->device = device;
1299	fw_work->context = context;
1300	fw_work->cont = cont;
1301	fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1302		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1303
1304	if (!try_module_get(module)) {
1305		kfree(fw_work);
1306		return -EFAULT;
1307	}
1308
1309	get_device(fw_work->device);
1310	INIT_WORK(&fw_work->work, request_firmware_work_func);
1311	schedule_work(&fw_work->work);
1312	return 0;
1313}
1314EXPORT_SYMBOL(request_firmware_nowait);
1315
1316#ifdef CONFIG_PM_SLEEP
1317static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1318
1319/**
1320 * cache_firmware - cache one firmware image in kernel memory space
1321 * @fw_name: the firmware image name
1322 *
1323 * Cache firmware in kernel memory so that drivers can use it when
1324 * system isn't ready for them to request firmware image from userspace.
1325 * Once it returns successfully, driver can use request_firmware or its
1326 * nowait version to get the cached firmware without any interacting
1327 * with userspace
1328 *
1329 * Return 0 if the firmware image has been cached successfully
1330 * Return !0 otherwise
1331 *
1332 */
1333static int cache_firmware(const char *fw_name)
1334{
1335	int ret;
1336	const struct firmware *fw;
1337
1338	pr_debug("%s: %s\n", __func__, fw_name);
1339
1340	ret = request_firmware(&fw, fw_name, NULL);
1341	if (!ret)
1342		kfree(fw);
1343
1344	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1345
1346	return ret;
1347}
1348
1349static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1350{
1351	struct firmware_buf *tmp;
1352	struct firmware_cache *fwc = &fw_cache;
1353
1354	spin_lock(&fwc->lock);
1355	tmp = __fw_lookup_buf(fw_name);
1356	spin_unlock(&fwc->lock);
1357
1358	return tmp;
1359}
1360
1361/**
1362 * uncache_firmware - remove one cached firmware image
1363 * @fw_name: the firmware image name
1364 *
1365 * Uncache one firmware image which has been cached successfully
1366 * before.
1367 *
1368 * Return 0 if the firmware cache has been removed successfully
1369 * Return !0 otherwise
1370 *
1371 */
1372static int uncache_firmware(const char *fw_name)
1373{
1374	struct firmware_buf *buf;
1375	struct firmware fw;
1376
1377	pr_debug("%s: %s\n", __func__, fw_name);
1378
1379	if (fw_get_builtin_firmware(&fw, fw_name))
1380		return 0;
1381
1382	buf = fw_lookup_buf(fw_name);
1383	if (buf) {
1384		fw_free_buf(buf);
1385		return 0;
1386	}
1387
1388	return -EINVAL;
1389}
1390
1391static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1392{
1393	struct fw_cache_entry *fce;
1394
1395	fce = kzalloc(sizeof(*fce) + strlen(name) + 1, GFP_ATOMIC);
1396	if (!fce)
1397		goto exit;
1398
1399	strcpy(fce->name, name);
1400exit:
1401	return fce;
1402}
1403
1404static int __fw_entry_found(const char *name)
1405{
1406	struct firmware_cache *fwc = &fw_cache;
1407	struct fw_cache_entry *fce;
1408
1409	list_for_each_entry(fce, &fwc->fw_names, list) {
1410		if (!strcmp(fce->name, name))
1411			return 1;
1412	}
1413	return 0;
1414}
1415
1416static int fw_cache_piggyback_on_request(const char *name)
1417{
1418	struct firmware_cache *fwc = &fw_cache;
1419	struct fw_cache_entry *fce;
1420	int ret = 0;
1421
1422	spin_lock(&fwc->name_lock);
1423	if (__fw_entry_found(name))
1424		goto found;
1425
1426	fce = alloc_fw_cache_entry(name);
1427	if (fce) {
1428		ret = 1;
1429		list_add(&fce->list, &fwc->fw_names);
1430		pr_debug("%s: fw: %s\n", __func__, name);
1431	}
1432found:
1433	spin_unlock(&fwc->name_lock);
1434	return ret;
1435}
1436
1437static void free_fw_cache_entry(struct fw_cache_entry *fce)
1438{
1439	kfree(fce);
1440}
1441
1442static void __async_dev_cache_fw_image(void *fw_entry,
1443				       async_cookie_t cookie)
1444{
1445	struct fw_cache_entry *fce = fw_entry;
1446	struct firmware_cache *fwc = &fw_cache;
1447	int ret;
1448
1449	ret = cache_firmware(fce->name);
1450	if (ret) {
1451		spin_lock(&fwc->name_lock);
1452		list_del(&fce->list);
1453		spin_unlock(&fwc->name_lock);
1454
1455		free_fw_cache_entry(fce);
1456	}
1457}
1458
1459/* called with dev->devres_lock held */
1460static void dev_create_fw_entry(struct device *dev, void *res,
1461				void *data)
1462{
1463	struct fw_name_devm *fwn = res;
1464	const char *fw_name = fwn->name;
1465	struct list_head *head = data;
1466	struct fw_cache_entry *fce;
1467
1468	fce = alloc_fw_cache_entry(fw_name);
1469	if (fce)
1470		list_add(&fce->list, head);
1471}
1472
1473static int devm_name_match(struct device *dev, void *res,
1474			   void *match_data)
1475{
1476	struct fw_name_devm *fwn = res;
1477	return (fwn->magic == (unsigned long)match_data);
1478}
1479
1480static void dev_cache_fw_image(struct device *dev, void *data)
1481{
1482	LIST_HEAD(todo);
1483	struct fw_cache_entry *fce;
1484	struct fw_cache_entry *fce_next;
1485	struct firmware_cache *fwc = &fw_cache;
1486
1487	devres_for_each_res(dev, fw_name_devm_release,
1488			    devm_name_match, &fw_cache,
1489			    dev_create_fw_entry, &todo);
1490
1491	list_for_each_entry_safe(fce, fce_next, &todo, list) {
1492		list_del(&fce->list);
1493
1494		spin_lock(&fwc->name_lock);
1495		/* only one cache entry for one firmware */
1496		if (!__fw_entry_found(fce->name)) {
1497			list_add(&fce->list, &fwc->fw_names);
1498		} else {
1499			free_fw_cache_entry(fce);
1500			fce = NULL;
1501		}
1502		spin_unlock(&fwc->name_lock);
1503
1504		if (fce)
1505			async_schedule_domain(__async_dev_cache_fw_image,
1506					      (void *)fce,
1507					      &fw_cache_domain);
1508	}
1509}
1510
1511static void __device_uncache_fw_images(void)
1512{
1513	struct firmware_cache *fwc = &fw_cache;
1514	struct fw_cache_entry *fce;
1515
1516	spin_lock(&fwc->name_lock);
1517	while (!list_empty(&fwc->fw_names)) {
1518		fce = list_entry(fwc->fw_names.next,
1519				struct fw_cache_entry, list);
1520		list_del(&fce->list);
1521		spin_unlock(&fwc->name_lock);
1522
1523		uncache_firmware(fce->name);
1524		free_fw_cache_entry(fce);
1525
1526		spin_lock(&fwc->name_lock);
1527	}
1528	spin_unlock(&fwc->name_lock);
1529}
1530
1531/**
1532 * device_cache_fw_images - cache devices' firmware
1533 *
1534 * If one device called request_firmware or its nowait version
1535 * successfully before, the firmware names are recored into the
1536 * device's devres link list, so device_cache_fw_images can call
1537 * cache_firmware() to cache these firmwares for the device,
1538 * then the device driver can load its firmwares easily at
1539 * time when system is not ready to complete loading firmware.
1540 */
1541static void device_cache_fw_images(void)
1542{
1543	struct firmware_cache *fwc = &fw_cache;
1544	int old_timeout;
1545	DEFINE_WAIT(wait);
1546
1547	pr_debug("%s\n", __func__);
1548
1549	/* cancel uncache work */
1550	cancel_delayed_work_sync(&fwc->work);
1551
1552	/*
1553	 * use small loading timeout for caching devices' firmware
1554	 * because all these firmware images have been loaded
1555	 * successfully at lease once, also system is ready for
1556	 * completing firmware loading now. The maximum size of
1557	 * firmware in current distributions is about 2M bytes,
1558	 * so 10 secs should be enough.
1559	 */
1560	old_timeout = loading_timeout;
1561	loading_timeout = 10;
1562
1563	mutex_lock(&fw_lock);
1564	fwc->state = FW_LOADER_START_CACHE;
1565	dpm_for_each_dev(NULL, dev_cache_fw_image);
1566	mutex_unlock(&fw_lock);
1567
1568	/* wait for completion of caching firmware for all devices */
1569	async_synchronize_full_domain(&fw_cache_domain);
1570
1571	loading_timeout = old_timeout;
1572}
1573
1574/**
1575 * device_uncache_fw_images - uncache devices' firmware
1576 *
1577 * uncache all firmwares which have been cached successfully
1578 * by device_uncache_fw_images earlier
1579 */
1580static void device_uncache_fw_images(void)
1581{
1582	pr_debug("%s\n", __func__);
1583	__device_uncache_fw_images();
1584}
1585
1586static void device_uncache_fw_images_work(struct work_struct *work)
1587{
1588	device_uncache_fw_images();
1589}
1590
1591/**
1592 * device_uncache_fw_images_delay - uncache devices firmwares
1593 * @delay: number of milliseconds to delay uncache device firmwares
1594 *
1595 * uncache all devices's firmwares which has been cached successfully
1596 * by device_cache_fw_images after @delay milliseconds.
1597 */
1598static void device_uncache_fw_images_delay(unsigned long delay)
1599{
1600	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1601			   msecs_to_jiffies(delay));
1602}
1603
1604static int fw_pm_notify(struct notifier_block *notify_block,
1605			unsigned long mode, void *unused)
1606{
1607	switch (mode) {
1608	case PM_HIBERNATION_PREPARE:
1609	case PM_SUSPEND_PREPARE:
1610	case PM_RESTORE_PREPARE:
1611		kill_requests_without_uevent();
1612		device_cache_fw_images();
1613		break;
1614
1615	case PM_POST_SUSPEND:
1616	case PM_POST_HIBERNATION:
1617	case PM_POST_RESTORE:
1618		/*
1619		 * In case that system sleep failed and syscore_suspend is
1620		 * not called.
1621		 */
1622		mutex_lock(&fw_lock);
1623		fw_cache.state = FW_LOADER_NO_CACHE;
1624		mutex_unlock(&fw_lock);
1625
1626		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1627		break;
1628	}
1629
1630	return 0;
1631}
1632
1633/* stop caching firmware once syscore_suspend is reached */
1634static int fw_suspend(void)
1635{
1636	fw_cache.state = FW_LOADER_NO_CACHE;
1637	return 0;
1638}
1639
1640static struct syscore_ops fw_syscore_ops = {
1641	.suspend = fw_suspend,
1642};
1643#else
1644static int fw_cache_piggyback_on_request(const char *name)
1645{
1646	return 0;
1647}
1648#endif
1649
1650static void __init fw_cache_init(void)
1651{
1652	spin_lock_init(&fw_cache.lock);
1653	INIT_LIST_HEAD(&fw_cache.head);
1654	fw_cache.state = FW_LOADER_NO_CACHE;
1655
1656#ifdef CONFIG_PM_SLEEP
1657	spin_lock_init(&fw_cache.name_lock);
1658	INIT_LIST_HEAD(&fw_cache.fw_names);
1659
1660	INIT_DELAYED_WORK(&fw_cache.work,
1661			  device_uncache_fw_images_work);
1662
1663	fw_cache.pm_notify.notifier_call = fw_pm_notify;
1664	register_pm_notifier(&fw_cache.pm_notify);
1665
1666	register_syscore_ops(&fw_syscore_ops);
1667#endif
1668}
1669
1670static int __init firmware_class_init(void)
1671{
1672	fw_cache_init();
1673#ifdef CONFIG_FW_LOADER_USER_HELPER
1674	register_reboot_notifier(&fw_shutdown_nb);
1675	return class_register(&firmware_class);
1676#else
1677	return 0;
1678#endif
1679}
1680
1681static void __exit firmware_class_exit(void)
1682{
1683#ifdef CONFIG_PM_SLEEP
1684	unregister_syscore_ops(&fw_syscore_ops);
1685	unregister_pm_notifier(&fw_cache.pm_notify);
1686#endif
1687#ifdef CONFIG_FW_LOADER_USER_HELPER
1688	unregister_reboot_notifier(&fw_shutdown_nb);
1689	class_unregister(&firmware_class);
1690#endif
1691}
1692
1693fs_initcall(firmware_class_init);
1694module_exit(firmware_class_exit);
1695