1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * main.c - Multi purpose firmware loading support
4  *
5  * Copyright (c) 2003 Manuel Estrada Sainz
6  *
7  * Please see Documentation/driver-api/firmware/ for more information.
8  *
9  */
10 
11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12 
13 #include <linux/capability.h>
14 #include <linux/device.h>
15 #include <linux/kernel_read_file.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/initrd.h>
19 #include <linux/timer.h>
20 #include <linux/vmalloc.h>
21 #include <linux/interrupt.h>
22 #include <linux/bitops.h>
23 #include <linux/mutex.h>
24 #include <linux/workqueue.h>
25 #include <linux/highmem.h>
26 #include <linux/firmware.h>
27 #include <linux/slab.h>
28 #include <linux/sched.h>
29 #include <linux/file.h>
30 #include <linux/list.h>
31 #include <linux/fs.h>
32 #include <linux/async.h>
33 #include <linux/pm.h>
34 #include <linux/suspend.h>
35 #include <linux/syscore_ops.h>
36 #include <linux/reboot.h>
37 #include <linux/security.h>
38 #include <linux/xz.h>
39 
40 #include <generated/utsrelease.h>
41 
42 #include "../base.h"
43 #include "firmware.h"
44 #include "fallback.h"
45 
46 MODULE_AUTHOR("Manuel Estrada Sainz");
47 MODULE_DESCRIPTION("Multi purpose firmware loading support");
48 MODULE_LICENSE("GPL");
49 
50 struct firmware_cache {
51 	/* firmware_buf instance will be added into the below list */
52 	spinlock_t lock;
53 	struct list_head head;
54 	int state;
55 
56 #ifdef CONFIG_FW_CACHE
57 	/*
58 	 * Names of firmware images which have been cached successfully
59 	 * will be added into the below list so that device uncache
60 	 * helper can trace which firmware images have been cached
61 	 * before.
62 	 */
63 	spinlock_t name_lock;
64 	struct list_head fw_names;
65 
66 	struct delayed_work work;
67 
68 	struct notifier_block   pm_notify;
69 #endif
70 };
71 
72 struct fw_cache_entry {
73 	struct list_head list;
74 	const char *name;
75 };
76 
77 struct fw_name_devm {
78 	unsigned long magic;
79 	const char *name;
80 };
81 
82 static inline struct fw_priv *to_fw_priv(struct kref *ref)
83 {
84 	return container_of(ref, struct fw_priv, ref);
85 }
86 
87 #define	FW_LOADER_NO_CACHE	0
88 #define	FW_LOADER_START_CACHE	1
89 
90 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
91  * guarding for corner cases a global lock should be OK */
92 DEFINE_MUTEX(fw_lock);
93 
94 static struct firmware_cache fw_cache;
95 
96 /* Builtin firmware support */
97 
98 #ifdef CONFIG_FW_LOADER
99 
100 extern struct builtin_fw __start_builtin_fw[];
101 extern struct builtin_fw __end_builtin_fw[];
102 
103 static void fw_copy_to_prealloc_buf(struct firmware *fw,
104 				    void *buf, size_t size)
105 {
106 	if (!buf || size < fw->size)
107 		return;
108 	memcpy(buf, fw->data, fw->size);
109 }
110 
111 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
112 				    void *buf, size_t size)
113 {
114 	struct builtin_fw *b_fw;
115 
116 	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
117 		if (strcmp(name, b_fw->name) == 0) {
118 			fw->size = b_fw->size;
119 			fw->data = b_fw->data;
120 			fw_copy_to_prealloc_buf(fw, buf, size);
121 
122 			return true;
123 		}
124 	}
125 
126 	return false;
127 }
128 
129 static bool fw_is_builtin_firmware(const struct firmware *fw)
130 {
131 	struct builtin_fw *b_fw;
132 
133 	for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
134 		if (fw->data == b_fw->data)
135 			return true;
136 
137 	return false;
138 }
139 
140 #else /* Module case - no builtin firmware support */
141 
142 static inline bool fw_get_builtin_firmware(struct firmware *fw,
143 					   const char *name, void *buf,
144 					   size_t size)
145 {
146 	return false;
147 }
148 
149 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
150 {
151 	return false;
152 }
153 #endif
154 
155 static void fw_state_init(struct fw_priv *fw_priv)
156 {
157 	struct fw_state *fw_st = &fw_priv->fw_st;
158 
159 	init_completion(&fw_st->completion);
160 	fw_st->status = FW_STATUS_UNKNOWN;
161 }
162 
163 static inline int fw_state_wait(struct fw_priv *fw_priv)
164 {
165 	return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
166 }
167 
168 static int fw_cache_piggyback_on_request(const char *name);
169 
170 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
171 					  struct firmware_cache *fwc,
172 					  void *dbuf,
173 					  size_t size,
174 					  size_t offset,
175 					  u32 opt_flags)
176 {
177 	struct fw_priv *fw_priv;
178 
179 	/* For a partial read, the buffer must be preallocated. */
180 	if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
181 		return NULL;
182 
183 	/* Only partial reads are allowed to use an offset. */
184 	if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
185 		return NULL;
186 
187 	fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
188 	if (!fw_priv)
189 		return NULL;
190 
191 	fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
192 	if (!fw_priv->fw_name) {
193 		kfree(fw_priv);
194 		return NULL;
195 	}
196 
197 	kref_init(&fw_priv->ref);
198 	fw_priv->fwc = fwc;
199 	fw_priv->data = dbuf;
200 	fw_priv->allocated_size = size;
201 	fw_priv->offset = offset;
202 	fw_priv->opt_flags = opt_flags;
203 	fw_state_init(fw_priv);
204 #ifdef CONFIG_FW_LOADER_USER_HELPER
205 	INIT_LIST_HEAD(&fw_priv->pending_list);
206 #endif
207 
208 	pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
209 
210 	return fw_priv;
211 }
212 
213 static struct fw_priv *__lookup_fw_priv(const char *fw_name)
214 {
215 	struct fw_priv *tmp;
216 	struct firmware_cache *fwc = &fw_cache;
217 
218 	list_for_each_entry(tmp, &fwc->head, list)
219 		if (!strcmp(tmp->fw_name, fw_name))
220 			return tmp;
221 	return NULL;
222 }
223 
224 /* Returns 1 for batching firmware requests with the same name */
225 static int alloc_lookup_fw_priv(const char *fw_name,
226 				struct firmware_cache *fwc,
227 				struct fw_priv **fw_priv,
228 				void *dbuf,
229 				size_t size,
230 				size_t offset,
231 				u32 opt_flags)
232 {
233 	struct fw_priv *tmp;
234 
235 	spin_lock(&fwc->lock);
236 	/*
237 	 * Do not merge requests that are marked to be non-cached or
238 	 * are performing partial reads.
239 	 */
240 	if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
241 		tmp = __lookup_fw_priv(fw_name);
242 		if (tmp) {
243 			kref_get(&tmp->ref);
244 			spin_unlock(&fwc->lock);
245 			*fw_priv = tmp;
246 			pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
247 			return 1;
248 		}
249 	}
250 
251 	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
252 	if (tmp) {
253 		INIT_LIST_HEAD(&tmp->list);
254 		if (!(opt_flags & FW_OPT_NOCACHE))
255 			list_add(&tmp->list, &fwc->head);
256 	}
257 	spin_unlock(&fwc->lock);
258 
259 	*fw_priv = tmp;
260 
261 	return tmp ? 0 : -ENOMEM;
262 }
263 
264 static void __free_fw_priv(struct kref *ref)
265 	__releases(&fwc->lock)
266 {
267 	struct fw_priv *fw_priv = to_fw_priv(ref);
268 	struct firmware_cache *fwc = fw_priv->fwc;
269 
270 	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
271 		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
272 		 (unsigned int)fw_priv->size);
273 
274 	list_del(&fw_priv->list);
275 	spin_unlock(&fwc->lock);
276 
277 	if (fw_is_paged_buf(fw_priv))
278 		fw_free_paged_buf(fw_priv);
279 	else if (!fw_priv->allocated_size)
280 		vfree(fw_priv->data);
281 
282 	kfree_const(fw_priv->fw_name);
283 	kfree(fw_priv);
284 }
285 
286 static void free_fw_priv(struct fw_priv *fw_priv)
287 {
288 	struct firmware_cache *fwc = fw_priv->fwc;
289 	spin_lock(&fwc->lock);
290 	if (!kref_put(&fw_priv->ref, __free_fw_priv))
291 		spin_unlock(&fwc->lock);
292 }
293 
294 #ifdef CONFIG_FW_LOADER_PAGED_BUF
295 bool fw_is_paged_buf(struct fw_priv *fw_priv)
296 {
297 	return fw_priv->is_paged_buf;
298 }
299 
300 void fw_free_paged_buf(struct fw_priv *fw_priv)
301 {
302 	int i;
303 
304 	if (!fw_priv->pages)
305 		return;
306 
307 	vunmap(fw_priv->data);
308 
309 	for (i = 0; i < fw_priv->nr_pages; i++)
310 		__free_page(fw_priv->pages[i]);
311 	kvfree(fw_priv->pages);
312 	fw_priv->pages = NULL;
313 	fw_priv->page_array_size = 0;
314 	fw_priv->nr_pages = 0;
315 }
316 
317 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
318 {
319 	/* If the array of pages is too small, grow it */
320 	if (fw_priv->page_array_size < pages_needed) {
321 		int new_array_size = max(pages_needed,
322 					 fw_priv->page_array_size * 2);
323 		struct page **new_pages;
324 
325 		new_pages = kvmalloc_array(new_array_size, sizeof(void *),
326 					   GFP_KERNEL);
327 		if (!new_pages)
328 			return -ENOMEM;
329 		memcpy(new_pages, fw_priv->pages,
330 		       fw_priv->page_array_size * sizeof(void *));
331 		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
332 		       (new_array_size - fw_priv->page_array_size));
333 		kvfree(fw_priv->pages);
334 		fw_priv->pages = new_pages;
335 		fw_priv->page_array_size = new_array_size;
336 	}
337 
338 	while (fw_priv->nr_pages < pages_needed) {
339 		fw_priv->pages[fw_priv->nr_pages] =
340 			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
341 
342 		if (!fw_priv->pages[fw_priv->nr_pages])
343 			return -ENOMEM;
344 		fw_priv->nr_pages++;
345 	}
346 
347 	return 0;
348 }
349 
350 int fw_map_paged_buf(struct fw_priv *fw_priv)
351 {
352 	/* one pages buffer should be mapped/unmapped only once */
353 	if (!fw_priv->pages)
354 		return 0;
355 
356 	vunmap(fw_priv->data);
357 	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
358 			     PAGE_KERNEL_RO);
359 	if (!fw_priv->data)
360 		return -ENOMEM;
361 
362 	return 0;
363 }
364 #endif
365 
366 /*
367  * XZ-compressed firmware support
368  */
369 #ifdef CONFIG_FW_LOADER_COMPRESS
370 /* show an error and return the standard error code */
371 static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
372 {
373 	if (xz_ret != XZ_STREAM_END) {
374 		dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
375 		return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
376 	}
377 	return 0;
378 }
379 
380 /* single-shot decompression onto the pre-allocated buffer */
381 static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
382 				   size_t in_size, const void *in_buffer)
383 {
384 	struct xz_dec *xz_dec;
385 	struct xz_buf xz_buf;
386 	enum xz_ret xz_ret;
387 
388 	xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
389 	if (!xz_dec)
390 		return -ENOMEM;
391 
392 	xz_buf.in_size = in_size;
393 	xz_buf.in = in_buffer;
394 	xz_buf.in_pos = 0;
395 	xz_buf.out_size = fw_priv->allocated_size;
396 	xz_buf.out = fw_priv->data;
397 	xz_buf.out_pos = 0;
398 
399 	xz_ret = xz_dec_run(xz_dec, &xz_buf);
400 	xz_dec_end(xz_dec);
401 
402 	fw_priv->size = xz_buf.out_pos;
403 	return fw_decompress_xz_error(dev, xz_ret);
404 }
405 
406 /* decompression on paged buffer and map it */
407 static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
408 				  size_t in_size, const void *in_buffer)
409 {
410 	struct xz_dec *xz_dec;
411 	struct xz_buf xz_buf;
412 	enum xz_ret xz_ret;
413 	struct page *page;
414 	int err = 0;
415 
416 	xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
417 	if (!xz_dec)
418 		return -ENOMEM;
419 
420 	xz_buf.in_size = in_size;
421 	xz_buf.in = in_buffer;
422 	xz_buf.in_pos = 0;
423 
424 	fw_priv->is_paged_buf = true;
425 	fw_priv->size = 0;
426 	do {
427 		if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
428 			err = -ENOMEM;
429 			goto out;
430 		}
431 
432 		/* decompress onto the new allocated page */
433 		page = fw_priv->pages[fw_priv->nr_pages - 1];
434 		xz_buf.out = kmap(page);
435 		xz_buf.out_pos = 0;
436 		xz_buf.out_size = PAGE_SIZE;
437 		xz_ret = xz_dec_run(xz_dec, &xz_buf);
438 		kunmap(page);
439 		fw_priv->size += xz_buf.out_pos;
440 		/* partial decompression means either end or error */
441 		if (xz_buf.out_pos != PAGE_SIZE)
442 			break;
443 	} while (xz_ret == XZ_OK);
444 
445 	err = fw_decompress_xz_error(dev, xz_ret);
446 	if (!err)
447 		err = fw_map_paged_buf(fw_priv);
448 
449  out:
450 	xz_dec_end(xz_dec);
451 	return err;
452 }
453 
454 static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
455 			    size_t in_size, const void *in_buffer)
456 {
457 	/* if the buffer is pre-allocated, we can perform in single-shot mode */
458 	if (fw_priv->data)
459 		return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
460 	else
461 		return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
462 }
463 #endif /* CONFIG_FW_LOADER_COMPRESS */
464 
465 /* direct firmware loading support */
466 static char fw_path_para[256];
467 static const char * const fw_path[] = {
468 	fw_path_para,
469 	"/lib/firmware/updates/" UTS_RELEASE,
470 	"/lib/firmware/updates",
471 	"/lib/firmware/" UTS_RELEASE,
472 	"/lib/firmware"
473 };
474 
475 /*
476  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
477  * from kernel command line because firmware_class is generally built in
478  * kernel instead of module.
479  */
480 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
481 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
482 
483 static int
484 fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
485 			   const char *suffix,
486 			   int (*decompress)(struct device *dev,
487 					     struct fw_priv *fw_priv,
488 					     size_t in_size,
489 					     const void *in_buffer))
490 {
491 	size_t size;
492 	int i, len;
493 	int rc = -ENOENT;
494 	char *path;
495 	size_t msize = INT_MAX;
496 	void *buffer = NULL;
497 
498 	/* Already populated data member means we're loading into a buffer */
499 	if (!decompress && fw_priv->data) {
500 		buffer = fw_priv->data;
501 		msize = fw_priv->allocated_size;
502 	}
503 
504 	path = __getname();
505 	if (!path)
506 		return -ENOMEM;
507 
508 	wait_for_initramfs();
509 	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
510 		size_t file_size = 0;
511 		size_t *file_size_ptr = NULL;
512 
513 		/* skip the unset customized path */
514 		if (!fw_path[i][0])
515 			continue;
516 
517 		len = snprintf(path, PATH_MAX, "%s/%s%s",
518 			       fw_path[i], fw_priv->fw_name, suffix);
519 		if (len >= PATH_MAX) {
520 			rc = -ENAMETOOLONG;
521 			break;
522 		}
523 
524 		fw_priv->size = 0;
525 
526 		/*
527 		 * The total file size is only examined when doing a partial
528 		 * read; the "full read" case needs to fail if the whole
529 		 * firmware was not completely loaded.
530 		 */
531 		if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
532 			file_size_ptr = &file_size;
533 
534 		/* load firmware files from the mount namespace of init */
535 		rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
536 						       &buffer, msize,
537 						       file_size_ptr,
538 						       READING_FIRMWARE);
539 		if (rc < 0) {
540 			if (rc != -ENOENT)
541 				dev_warn(device, "loading %s failed with error %d\n",
542 					 path, rc);
543 			else
544 				dev_dbg(device, "loading %s failed for no such file or directory.\n",
545 					 path);
546 			continue;
547 		}
548 		size = rc;
549 		rc = 0;
550 
551 		dev_dbg(device, "Loading firmware from %s\n", path);
552 		if (decompress) {
553 			dev_dbg(device, "f/w decompressing %s\n",
554 				fw_priv->fw_name);
555 			rc = decompress(device, fw_priv, size, buffer);
556 			/* discard the superfluous original content */
557 			vfree(buffer);
558 			buffer = NULL;
559 			if (rc) {
560 				fw_free_paged_buf(fw_priv);
561 				continue;
562 			}
563 		} else {
564 			dev_dbg(device, "direct-loading %s\n",
565 				fw_priv->fw_name);
566 			if (!fw_priv->data)
567 				fw_priv->data = buffer;
568 			fw_priv->size = size;
569 		}
570 		fw_state_done(fw_priv);
571 		break;
572 	}
573 	__putname(path);
574 
575 	return rc;
576 }
577 
578 /* firmware holds the ownership of pages */
579 static void firmware_free_data(const struct firmware *fw)
580 {
581 	/* Loaded directly? */
582 	if (!fw->priv) {
583 		vfree(fw->data);
584 		return;
585 	}
586 	free_fw_priv(fw->priv);
587 }
588 
589 /* store the pages buffer info firmware from buf */
590 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
591 {
592 	fw->priv = fw_priv;
593 	fw->size = fw_priv->size;
594 	fw->data = fw_priv->data;
595 
596 	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
597 		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
598 		 (unsigned int)fw_priv->size);
599 }
600 
601 #ifdef CONFIG_FW_CACHE
602 static void fw_name_devm_release(struct device *dev, void *res)
603 {
604 	struct fw_name_devm *fwn = res;
605 
606 	if (fwn->magic == (unsigned long)&fw_cache)
607 		pr_debug("%s: fw_name-%s devm-%p released\n",
608 				__func__, fwn->name, res);
609 	kfree_const(fwn->name);
610 }
611 
612 static int fw_devm_match(struct device *dev, void *res,
613 		void *match_data)
614 {
615 	struct fw_name_devm *fwn = res;
616 
617 	return (fwn->magic == (unsigned long)&fw_cache) &&
618 		!strcmp(fwn->name, match_data);
619 }
620 
621 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
622 		const char *name)
623 {
624 	struct fw_name_devm *fwn;
625 
626 	fwn = devres_find(dev, fw_name_devm_release,
627 			  fw_devm_match, (void *)name);
628 	return fwn;
629 }
630 
631 static bool fw_cache_is_setup(struct device *dev, const char *name)
632 {
633 	struct fw_name_devm *fwn;
634 
635 	fwn = fw_find_devm_name(dev, name);
636 	if (fwn)
637 		return true;
638 
639 	return false;
640 }
641 
642 /* add firmware name into devres list */
643 static int fw_add_devm_name(struct device *dev, const char *name)
644 {
645 	struct fw_name_devm *fwn;
646 
647 	if (fw_cache_is_setup(dev, name))
648 		return 0;
649 
650 	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
651 			   GFP_KERNEL);
652 	if (!fwn)
653 		return -ENOMEM;
654 	fwn->name = kstrdup_const(name, GFP_KERNEL);
655 	if (!fwn->name) {
656 		devres_free(fwn);
657 		return -ENOMEM;
658 	}
659 
660 	fwn->magic = (unsigned long)&fw_cache;
661 	devres_add(dev, fwn);
662 
663 	return 0;
664 }
665 #else
666 static bool fw_cache_is_setup(struct device *dev, const char *name)
667 {
668 	return false;
669 }
670 
671 static int fw_add_devm_name(struct device *dev, const char *name)
672 {
673 	return 0;
674 }
675 #endif
676 
677 int assign_fw(struct firmware *fw, struct device *device)
678 {
679 	struct fw_priv *fw_priv = fw->priv;
680 	int ret;
681 
682 	mutex_lock(&fw_lock);
683 	if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
684 		mutex_unlock(&fw_lock);
685 		return -ENOENT;
686 	}
687 
688 	/*
689 	 * add firmware name into devres list so that we can auto cache
690 	 * and uncache firmware for device.
691 	 *
692 	 * device may has been deleted already, but the problem
693 	 * should be fixed in devres or driver core.
694 	 */
695 	/* don't cache firmware handled without uevent */
696 	if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
697 	    !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
698 		ret = fw_add_devm_name(device, fw_priv->fw_name);
699 		if (ret) {
700 			mutex_unlock(&fw_lock);
701 			return ret;
702 		}
703 	}
704 
705 	/*
706 	 * After caching firmware image is started, let it piggyback
707 	 * on request firmware.
708 	 */
709 	if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
710 	    fw_priv->fwc->state == FW_LOADER_START_CACHE) {
711 		if (fw_cache_piggyback_on_request(fw_priv->fw_name))
712 			kref_get(&fw_priv->ref);
713 	}
714 
715 	/* pass the pages buffer to driver at the last minute */
716 	fw_set_page_data(fw_priv, fw);
717 	mutex_unlock(&fw_lock);
718 	return 0;
719 }
720 
721 /* prepare firmware and firmware_buf structs;
722  * return 0 if a firmware is already assigned, 1 if need to load one,
723  * or a negative error code
724  */
725 static int
726 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
727 			  struct device *device, void *dbuf, size_t size,
728 			  size_t offset, u32 opt_flags)
729 {
730 	struct firmware *firmware;
731 	struct fw_priv *fw_priv;
732 	int ret;
733 
734 	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
735 	if (!firmware) {
736 		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
737 			__func__);
738 		return -ENOMEM;
739 	}
740 
741 	if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
742 		dev_dbg(device, "using built-in %s\n", name);
743 		return 0; /* assigned */
744 	}
745 
746 	ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
747 				   offset, opt_flags);
748 
749 	/*
750 	 * bind with 'priv' now to avoid warning in failure path
751 	 * of requesting firmware.
752 	 */
753 	firmware->priv = fw_priv;
754 
755 	if (ret > 0) {
756 		ret = fw_state_wait(fw_priv);
757 		if (!ret) {
758 			fw_set_page_data(fw_priv, firmware);
759 			return 0; /* assigned */
760 		}
761 	}
762 
763 	if (ret < 0)
764 		return ret;
765 	return 1; /* need to load */
766 }
767 
768 /*
769  * Batched requests need only one wake, we need to do this step last due to the
770  * fallback mechanism. The buf is protected with kref_get(), and it won't be
771  * released until the last user calls release_firmware().
772  *
773  * Failed batched requests are possible as well, in such cases we just share
774  * the struct fw_priv and won't release it until all requests are woken
775  * and have gone through this same path.
776  */
777 static void fw_abort_batch_reqs(struct firmware *fw)
778 {
779 	struct fw_priv *fw_priv;
780 
781 	/* Loaded directly? */
782 	if (!fw || !fw->priv)
783 		return;
784 
785 	fw_priv = fw->priv;
786 	mutex_lock(&fw_lock);
787 	if (!fw_state_is_aborted(fw_priv))
788 		fw_state_aborted(fw_priv);
789 	mutex_unlock(&fw_lock);
790 }
791 
792 /* called from request_firmware() and request_firmware_work_func() */
793 static int
794 _request_firmware(const struct firmware **firmware_p, const char *name,
795 		  struct device *device, void *buf, size_t size,
796 		  size_t offset, u32 opt_flags)
797 {
798 	struct firmware *fw = NULL;
799 	bool nondirect = false;
800 	int ret;
801 
802 	if (!firmware_p)
803 		return -EINVAL;
804 
805 	if (!name || name[0] == '\0') {
806 		ret = -EINVAL;
807 		goto out;
808 	}
809 
810 	ret = _request_firmware_prepare(&fw, name, device, buf, size,
811 					offset, opt_flags);
812 	if (ret <= 0) /* error or already assigned */
813 		goto out;
814 
815 	ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
816 
817 	/* Only full reads can support decompression, platform, and sysfs. */
818 	if (!(opt_flags & FW_OPT_PARTIAL))
819 		nondirect = true;
820 
821 #ifdef CONFIG_FW_LOADER_COMPRESS
822 	if (ret == -ENOENT && nondirect)
823 		ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
824 						 fw_decompress_xz);
825 #endif
826 	if (ret == -ENOENT && nondirect)
827 		ret = firmware_fallback_platform(fw->priv);
828 
829 	if (ret) {
830 		if (!(opt_flags & FW_OPT_NO_WARN))
831 			dev_warn(device,
832 				 "Direct firmware load for %s failed with error %d\n",
833 				 name, ret);
834 		if (nondirect)
835 			ret = firmware_fallback_sysfs(fw, name, device,
836 						      opt_flags, ret);
837 	} else
838 		ret = assign_fw(fw, device);
839 
840  out:
841 	if (ret < 0) {
842 		fw_abort_batch_reqs(fw);
843 		release_firmware(fw);
844 		fw = NULL;
845 	}
846 
847 	*firmware_p = fw;
848 	return ret;
849 }
850 
851 /**
852  * request_firmware() - send firmware request and wait for it
853  * @firmware_p: pointer to firmware image
854  * @name: name of firmware file
855  * @device: device for which firmware is being loaded
856  *
857  *      @firmware_p will be used to return a firmware image by the name
858  *      of @name for device @device.
859  *
860  *      Should be called from user context where sleeping is allowed.
861  *
862  *      @name will be used as $FIRMWARE in the uevent environment and
863  *      should be distinctive enough not to be confused with any other
864  *      firmware image for this or any other device.
865  *
866  *	Caller must hold the reference count of @device.
867  *
868  *	The function can be called safely inside device's suspend and
869  *	resume callback.
870  **/
871 int
872 request_firmware(const struct firmware **firmware_p, const char *name,
873 		 struct device *device)
874 {
875 	int ret;
876 
877 	/* Need to pin this module until return */
878 	__module_get(THIS_MODULE);
879 	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
880 				FW_OPT_UEVENT);
881 	module_put(THIS_MODULE);
882 	return ret;
883 }
884 EXPORT_SYMBOL(request_firmware);
885 
886 /**
887  * firmware_request_nowarn() - request for an optional fw module
888  * @firmware: pointer to firmware image
889  * @name: name of firmware file
890  * @device: device for which firmware is being loaded
891  *
892  * This function is similar in behaviour to request_firmware(), except it
893  * doesn't produce warning messages when the file is not found. The sysfs
894  * fallback mechanism is enabled if direct filesystem lookup fails. However,
895  * failures to find the firmware file with it are still suppressed. It is
896  * therefore up to the driver to check for the return value of this call and to
897  * decide when to inform the users of errors.
898  **/
899 int firmware_request_nowarn(const struct firmware **firmware, const char *name,
900 			    struct device *device)
901 {
902 	int ret;
903 
904 	/* Need to pin this module until return */
905 	__module_get(THIS_MODULE);
906 	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
907 				FW_OPT_UEVENT | FW_OPT_NO_WARN);
908 	module_put(THIS_MODULE);
909 	return ret;
910 }
911 EXPORT_SYMBOL_GPL(firmware_request_nowarn);
912 
913 /**
914  * request_firmware_direct() - load firmware directly without usermode helper
915  * @firmware_p: pointer to firmware image
916  * @name: name of firmware file
917  * @device: device for which firmware is being loaded
918  *
919  * This function works pretty much like request_firmware(), but this doesn't
920  * fall back to usermode helper even if the firmware couldn't be loaded
921  * directly from fs.  Hence it's useful for loading optional firmwares, which
922  * aren't always present, without extra long timeouts of udev.
923  **/
924 int request_firmware_direct(const struct firmware **firmware_p,
925 			    const char *name, struct device *device)
926 {
927 	int ret;
928 
929 	__module_get(THIS_MODULE);
930 	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
931 				FW_OPT_UEVENT | FW_OPT_NO_WARN |
932 				FW_OPT_NOFALLBACK_SYSFS);
933 	module_put(THIS_MODULE);
934 	return ret;
935 }
936 EXPORT_SYMBOL_GPL(request_firmware_direct);
937 
938 /**
939  * firmware_request_platform() - request firmware with platform-fw fallback
940  * @firmware: pointer to firmware image
941  * @name: name of firmware file
942  * @device: device for which firmware is being loaded
943  *
944  * This function is similar in behaviour to request_firmware, except that if
945  * direct filesystem lookup fails, it will fallback to looking for a copy of the
946  * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
947  **/
948 int firmware_request_platform(const struct firmware **firmware,
949 			      const char *name, struct device *device)
950 {
951 	int ret;
952 
953 	/* Need to pin this module until return */
954 	__module_get(THIS_MODULE);
955 	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
956 				FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
957 	module_put(THIS_MODULE);
958 	return ret;
959 }
960 EXPORT_SYMBOL_GPL(firmware_request_platform);
961 
962 /**
963  * firmware_request_cache() - cache firmware for suspend so resume can use it
964  * @name: name of firmware file
965  * @device: device for which firmware should be cached for
966  *
967  * There are some devices with an optimization that enables the device to not
968  * require loading firmware on system reboot. This optimization may still
969  * require the firmware present on resume from suspend. This routine can be
970  * used to ensure the firmware is present on resume from suspend in these
971  * situations. This helper is not compatible with drivers which use
972  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
973  **/
974 int firmware_request_cache(struct device *device, const char *name)
975 {
976 	int ret;
977 
978 	mutex_lock(&fw_lock);
979 	ret = fw_add_devm_name(device, name);
980 	mutex_unlock(&fw_lock);
981 
982 	return ret;
983 }
984 EXPORT_SYMBOL_GPL(firmware_request_cache);
985 
986 /**
987  * request_firmware_into_buf() - load firmware into a previously allocated buffer
988  * @firmware_p: pointer to firmware image
989  * @name: name of firmware file
990  * @device: device for which firmware is being loaded and DMA region allocated
991  * @buf: address of buffer to load firmware into
992  * @size: size of buffer
993  *
994  * This function works pretty much like request_firmware(), but it doesn't
995  * allocate a buffer to hold the firmware data. Instead, the firmware
996  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
997  * data member is pointed at @buf.
998  *
999  * This function doesn't cache firmware either.
1000  */
1001 int
1002 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1003 			  struct device *device, void *buf, size_t size)
1004 {
1005 	int ret;
1006 
1007 	if (fw_cache_is_setup(device, name))
1008 		return -EOPNOTSUPP;
1009 
1010 	__module_get(THIS_MODULE);
1011 	ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1012 				FW_OPT_UEVENT | FW_OPT_NOCACHE);
1013 	module_put(THIS_MODULE);
1014 	return ret;
1015 }
1016 EXPORT_SYMBOL(request_firmware_into_buf);
1017 
1018 /**
1019  * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1020  * @firmware_p: pointer to firmware image
1021  * @name: name of firmware file
1022  * @device: device for which firmware is being loaded and DMA region allocated
1023  * @buf: address of buffer to load firmware into
1024  * @size: size of buffer
1025  * @offset: offset into file to read
1026  *
1027  * This function works pretty much like request_firmware_into_buf except
1028  * it allows a partial read of the file.
1029  */
1030 int
1031 request_partial_firmware_into_buf(const struct firmware **firmware_p,
1032 				  const char *name, struct device *device,
1033 				  void *buf, size_t size, size_t offset)
1034 {
1035 	int ret;
1036 
1037 	if (fw_cache_is_setup(device, name))
1038 		return -EOPNOTSUPP;
1039 
1040 	__module_get(THIS_MODULE);
1041 	ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1042 				FW_OPT_UEVENT | FW_OPT_NOCACHE |
1043 				FW_OPT_PARTIAL);
1044 	module_put(THIS_MODULE);
1045 	return ret;
1046 }
1047 EXPORT_SYMBOL(request_partial_firmware_into_buf);
1048 
1049 /**
1050  * release_firmware() - release the resource associated with a firmware image
1051  * @fw: firmware resource to release
1052  **/
1053 void release_firmware(const struct firmware *fw)
1054 {
1055 	if (fw) {
1056 		if (!fw_is_builtin_firmware(fw))
1057 			firmware_free_data(fw);
1058 		kfree(fw);
1059 	}
1060 }
1061 EXPORT_SYMBOL(release_firmware);
1062 
1063 /* Async support */
1064 struct firmware_work {
1065 	struct work_struct work;
1066 	struct module *module;
1067 	const char *name;
1068 	struct device *device;
1069 	void *context;
1070 	void (*cont)(const struct firmware *fw, void *context);
1071 	u32 opt_flags;
1072 };
1073 
1074 static void request_firmware_work_func(struct work_struct *work)
1075 {
1076 	struct firmware_work *fw_work;
1077 	const struct firmware *fw;
1078 
1079 	fw_work = container_of(work, struct firmware_work, work);
1080 
1081 	_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1082 			  fw_work->opt_flags);
1083 	fw_work->cont(fw, fw_work->context);
1084 	put_device(fw_work->device); /* taken in request_firmware_nowait() */
1085 
1086 	module_put(fw_work->module);
1087 	kfree_const(fw_work->name);
1088 	kfree(fw_work);
1089 }
1090 
1091 /**
1092  * request_firmware_nowait() - asynchronous version of request_firmware
1093  * @module: module requesting the firmware
1094  * @uevent: sends uevent to copy the firmware image if this flag
1095  *	is non-zero else the firmware copy must be done manually.
1096  * @name: name of firmware file
1097  * @device: device for which firmware is being loaded
1098  * @gfp: allocation flags
1099  * @context: will be passed over to @cont, and
1100  *	@fw may be %NULL if firmware request fails.
1101  * @cont: function will be called asynchronously when the firmware
1102  *	request is over.
1103  *
1104  *	Caller must hold the reference count of @device.
1105  *
1106  *	Asynchronous variant of request_firmware() for user contexts:
1107  *		- sleep for as small periods as possible since it may
1108  *		  increase kernel boot time of built-in device drivers
1109  *		  requesting firmware in their ->probe() methods, if
1110  *		  @gfp is GFP_KERNEL.
1111  *
1112  *		- can't sleep at all if @gfp is GFP_ATOMIC.
1113  **/
1114 int
1115 request_firmware_nowait(
1116 	struct module *module, bool uevent,
1117 	const char *name, struct device *device, gfp_t gfp, void *context,
1118 	void (*cont)(const struct firmware *fw, void *context))
1119 {
1120 	struct firmware_work *fw_work;
1121 
1122 	fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1123 	if (!fw_work)
1124 		return -ENOMEM;
1125 
1126 	fw_work->module = module;
1127 	fw_work->name = kstrdup_const(name, gfp);
1128 	if (!fw_work->name) {
1129 		kfree(fw_work);
1130 		return -ENOMEM;
1131 	}
1132 	fw_work->device = device;
1133 	fw_work->context = context;
1134 	fw_work->cont = cont;
1135 	fw_work->opt_flags = FW_OPT_NOWAIT |
1136 		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1137 
1138 	if (!uevent && fw_cache_is_setup(device, name)) {
1139 		kfree_const(fw_work->name);
1140 		kfree(fw_work);
1141 		return -EOPNOTSUPP;
1142 	}
1143 
1144 	if (!try_module_get(module)) {
1145 		kfree_const(fw_work->name);
1146 		kfree(fw_work);
1147 		return -EFAULT;
1148 	}
1149 
1150 	get_device(fw_work->device);
1151 	INIT_WORK(&fw_work->work, request_firmware_work_func);
1152 	schedule_work(&fw_work->work);
1153 	return 0;
1154 }
1155 EXPORT_SYMBOL(request_firmware_nowait);
1156 
1157 #ifdef CONFIG_FW_CACHE
1158 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1159 
1160 /**
1161  * cache_firmware() - cache one firmware image in kernel memory space
1162  * @fw_name: the firmware image name
1163  *
1164  * Cache firmware in kernel memory so that drivers can use it when
1165  * system isn't ready for them to request firmware image from userspace.
1166  * Once it returns successfully, driver can use request_firmware or its
1167  * nowait version to get the cached firmware without any interacting
1168  * with userspace
1169  *
1170  * Return 0 if the firmware image has been cached successfully
1171  * Return !0 otherwise
1172  *
1173  */
1174 static int cache_firmware(const char *fw_name)
1175 {
1176 	int ret;
1177 	const struct firmware *fw;
1178 
1179 	pr_debug("%s: %s\n", __func__, fw_name);
1180 
1181 	ret = request_firmware(&fw, fw_name, NULL);
1182 	if (!ret)
1183 		kfree(fw);
1184 
1185 	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1186 
1187 	return ret;
1188 }
1189 
1190 static struct fw_priv *lookup_fw_priv(const char *fw_name)
1191 {
1192 	struct fw_priv *tmp;
1193 	struct firmware_cache *fwc = &fw_cache;
1194 
1195 	spin_lock(&fwc->lock);
1196 	tmp = __lookup_fw_priv(fw_name);
1197 	spin_unlock(&fwc->lock);
1198 
1199 	return tmp;
1200 }
1201 
1202 /**
1203  * uncache_firmware() - remove one cached firmware image
1204  * @fw_name: the firmware image name
1205  *
1206  * Uncache one firmware image which has been cached successfully
1207  * before.
1208  *
1209  * Return 0 if the firmware cache has been removed successfully
1210  * Return !0 otherwise
1211  *
1212  */
1213 static int uncache_firmware(const char *fw_name)
1214 {
1215 	struct fw_priv *fw_priv;
1216 	struct firmware fw;
1217 
1218 	pr_debug("%s: %s\n", __func__, fw_name);
1219 
1220 	if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1221 		return 0;
1222 
1223 	fw_priv = lookup_fw_priv(fw_name);
1224 	if (fw_priv) {
1225 		free_fw_priv(fw_priv);
1226 		return 0;
1227 	}
1228 
1229 	return -EINVAL;
1230 }
1231 
1232 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1233 {
1234 	struct fw_cache_entry *fce;
1235 
1236 	fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1237 	if (!fce)
1238 		goto exit;
1239 
1240 	fce->name = kstrdup_const(name, GFP_ATOMIC);
1241 	if (!fce->name) {
1242 		kfree(fce);
1243 		fce = NULL;
1244 		goto exit;
1245 	}
1246 exit:
1247 	return fce;
1248 }
1249 
1250 static int __fw_entry_found(const char *name)
1251 {
1252 	struct firmware_cache *fwc = &fw_cache;
1253 	struct fw_cache_entry *fce;
1254 
1255 	list_for_each_entry(fce, &fwc->fw_names, list) {
1256 		if (!strcmp(fce->name, name))
1257 			return 1;
1258 	}
1259 	return 0;
1260 }
1261 
1262 static int fw_cache_piggyback_on_request(const char *name)
1263 {
1264 	struct firmware_cache *fwc = &fw_cache;
1265 	struct fw_cache_entry *fce;
1266 	int ret = 0;
1267 
1268 	spin_lock(&fwc->name_lock);
1269 	if (__fw_entry_found(name))
1270 		goto found;
1271 
1272 	fce = alloc_fw_cache_entry(name);
1273 	if (fce) {
1274 		ret = 1;
1275 		list_add(&fce->list, &fwc->fw_names);
1276 		pr_debug("%s: fw: %s\n", __func__, name);
1277 	}
1278 found:
1279 	spin_unlock(&fwc->name_lock);
1280 	return ret;
1281 }
1282 
1283 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1284 {
1285 	kfree_const(fce->name);
1286 	kfree(fce);
1287 }
1288 
1289 static void __async_dev_cache_fw_image(void *fw_entry,
1290 				       async_cookie_t cookie)
1291 {
1292 	struct fw_cache_entry *fce = fw_entry;
1293 	struct firmware_cache *fwc = &fw_cache;
1294 	int ret;
1295 
1296 	ret = cache_firmware(fce->name);
1297 	if (ret) {
1298 		spin_lock(&fwc->name_lock);
1299 		list_del(&fce->list);
1300 		spin_unlock(&fwc->name_lock);
1301 
1302 		free_fw_cache_entry(fce);
1303 	}
1304 }
1305 
1306 /* called with dev->devres_lock held */
1307 static void dev_create_fw_entry(struct device *dev, void *res,
1308 				void *data)
1309 {
1310 	struct fw_name_devm *fwn = res;
1311 	const char *fw_name = fwn->name;
1312 	struct list_head *head = data;
1313 	struct fw_cache_entry *fce;
1314 
1315 	fce = alloc_fw_cache_entry(fw_name);
1316 	if (fce)
1317 		list_add(&fce->list, head);
1318 }
1319 
1320 static int devm_name_match(struct device *dev, void *res,
1321 			   void *match_data)
1322 {
1323 	struct fw_name_devm *fwn = res;
1324 	return (fwn->magic == (unsigned long)match_data);
1325 }
1326 
1327 static void dev_cache_fw_image(struct device *dev, void *data)
1328 {
1329 	LIST_HEAD(todo);
1330 	struct fw_cache_entry *fce;
1331 	struct fw_cache_entry *fce_next;
1332 	struct firmware_cache *fwc = &fw_cache;
1333 
1334 	devres_for_each_res(dev, fw_name_devm_release,
1335 			    devm_name_match, &fw_cache,
1336 			    dev_create_fw_entry, &todo);
1337 
1338 	list_for_each_entry_safe(fce, fce_next, &todo, list) {
1339 		list_del(&fce->list);
1340 
1341 		spin_lock(&fwc->name_lock);
1342 		/* only one cache entry for one firmware */
1343 		if (!__fw_entry_found(fce->name)) {
1344 			list_add(&fce->list, &fwc->fw_names);
1345 		} else {
1346 			free_fw_cache_entry(fce);
1347 			fce = NULL;
1348 		}
1349 		spin_unlock(&fwc->name_lock);
1350 
1351 		if (fce)
1352 			async_schedule_domain(__async_dev_cache_fw_image,
1353 					      (void *)fce,
1354 					      &fw_cache_domain);
1355 	}
1356 }
1357 
1358 static void __device_uncache_fw_images(void)
1359 {
1360 	struct firmware_cache *fwc = &fw_cache;
1361 	struct fw_cache_entry *fce;
1362 
1363 	spin_lock(&fwc->name_lock);
1364 	while (!list_empty(&fwc->fw_names)) {
1365 		fce = list_entry(fwc->fw_names.next,
1366 				struct fw_cache_entry, list);
1367 		list_del(&fce->list);
1368 		spin_unlock(&fwc->name_lock);
1369 
1370 		uncache_firmware(fce->name);
1371 		free_fw_cache_entry(fce);
1372 
1373 		spin_lock(&fwc->name_lock);
1374 	}
1375 	spin_unlock(&fwc->name_lock);
1376 }
1377 
1378 /**
1379  * device_cache_fw_images() - cache devices' firmware
1380  *
1381  * If one device called request_firmware or its nowait version
1382  * successfully before, the firmware names are recored into the
1383  * device's devres link list, so device_cache_fw_images can call
1384  * cache_firmware() to cache these firmwares for the device,
1385  * then the device driver can load its firmwares easily at
1386  * time when system is not ready to complete loading firmware.
1387  */
1388 static void device_cache_fw_images(void)
1389 {
1390 	struct firmware_cache *fwc = &fw_cache;
1391 	DEFINE_WAIT(wait);
1392 
1393 	pr_debug("%s\n", __func__);
1394 
1395 	/* cancel uncache work */
1396 	cancel_delayed_work_sync(&fwc->work);
1397 
1398 	fw_fallback_set_cache_timeout();
1399 
1400 	mutex_lock(&fw_lock);
1401 	fwc->state = FW_LOADER_START_CACHE;
1402 	dpm_for_each_dev(NULL, dev_cache_fw_image);
1403 	mutex_unlock(&fw_lock);
1404 
1405 	/* wait for completion of caching firmware for all devices */
1406 	async_synchronize_full_domain(&fw_cache_domain);
1407 
1408 	fw_fallback_set_default_timeout();
1409 }
1410 
1411 /**
1412  * device_uncache_fw_images() - uncache devices' firmware
1413  *
1414  * uncache all firmwares which have been cached successfully
1415  * by device_uncache_fw_images earlier
1416  */
1417 static void device_uncache_fw_images(void)
1418 {
1419 	pr_debug("%s\n", __func__);
1420 	__device_uncache_fw_images();
1421 }
1422 
1423 static void device_uncache_fw_images_work(struct work_struct *work)
1424 {
1425 	device_uncache_fw_images();
1426 }
1427 
1428 /**
1429  * device_uncache_fw_images_delay() - uncache devices firmwares
1430  * @delay: number of milliseconds to delay uncache device firmwares
1431  *
1432  * uncache all devices's firmwares which has been cached successfully
1433  * by device_cache_fw_images after @delay milliseconds.
1434  */
1435 static void device_uncache_fw_images_delay(unsigned long delay)
1436 {
1437 	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1438 			   msecs_to_jiffies(delay));
1439 }
1440 
1441 static int fw_pm_notify(struct notifier_block *notify_block,
1442 			unsigned long mode, void *unused)
1443 {
1444 	switch (mode) {
1445 	case PM_HIBERNATION_PREPARE:
1446 	case PM_SUSPEND_PREPARE:
1447 	case PM_RESTORE_PREPARE:
1448 		/*
1449 		 * kill pending fallback requests with a custom fallback
1450 		 * to avoid stalling suspend.
1451 		 */
1452 		kill_pending_fw_fallback_reqs(true);
1453 		device_cache_fw_images();
1454 		break;
1455 
1456 	case PM_POST_SUSPEND:
1457 	case PM_POST_HIBERNATION:
1458 	case PM_POST_RESTORE:
1459 		/*
1460 		 * In case that system sleep failed and syscore_suspend is
1461 		 * not called.
1462 		 */
1463 		mutex_lock(&fw_lock);
1464 		fw_cache.state = FW_LOADER_NO_CACHE;
1465 		mutex_unlock(&fw_lock);
1466 
1467 		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1468 		break;
1469 	}
1470 
1471 	return 0;
1472 }
1473 
1474 /* stop caching firmware once syscore_suspend is reached */
1475 static int fw_suspend(void)
1476 {
1477 	fw_cache.state = FW_LOADER_NO_CACHE;
1478 	return 0;
1479 }
1480 
1481 static struct syscore_ops fw_syscore_ops = {
1482 	.suspend = fw_suspend,
1483 };
1484 
1485 static int __init register_fw_pm_ops(void)
1486 {
1487 	int ret;
1488 
1489 	spin_lock_init(&fw_cache.name_lock);
1490 	INIT_LIST_HEAD(&fw_cache.fw_names);
1491 
1492 	INIT_DELAYED_WORK(&fw_cache.work,
1493 			  device_uncache_fw_images_work);
1494 
1495 	fw_cache.pm_notify.notifier_call = fw_pm_notify;
1496 	ret = register_pm_notifier(&fw_cache.pm_notify);
1497 	if (ret)
1498 		return ret;
1499 
1500 	register_syscore_ops(&fw_syscore_ops);
1501 
1502 	return ret;
1503 }
1504 
1505 static inline void unregister_fw_pm_ops(void)
1506 {
1507 	unregister_syscore_ops(&fw_syscore_ops);
1508 	unregister_pm_notifier(&fw_cache.pm_notify);
1509 }
1510 #else
1511 static int fw_cache_piggyback_on_request(const char *name)
1512 {
1513 	return 0;
1514 }
1515 static inline int register_fw_pm_ops(void)
1516 {
1517 	return 0;
1518 }
1519 static inline void unregister_fw_pm_ops(void)
1520 {
1521 }
1522 #endif
1523 
1524 static void __init fw_cache_init(void)
1525 {
1526 	spin_lock_init(&fw_cache.lock);
1527 	INIT_LIST_HEAD(&fw_cache.head);
1528 	fw_cache.state = FW_LOADER_NO_CACHE;
1529 }
1530 
1531 static int fw_shutdown_notify(struct notifier_block *unused1,
1532 			      unsigned long unused2, void *unused3)
1533 {
1534 	/*
1535 	 * Kill all pending fallback requests to avoid both stalling shutdown,
1536 	 * and avoid a deadlock with the usermode_lock.
1537 	 */
1538 	kill_pending_fw_fallback_reqs(false);
1539 
1540 	return NOTIFY_DONE;
1541 }
1542 
1543 static struct notifier_block fw_shutdown_nb = {
1544 	.notifier_call = fw_shutdown_notify,
1545 };
1546 
1547 static int __init firmware_class_init(void)
1548 {
1549 	int ret;
1550 
1551 	/* No need to unfold these on exit */
1552 	fw_cache_init();
1553 
1554 	ret = register_fw_pm_ops();
1555 	if (ret)
1556 		return ret;
1557 
1558 	ret = register_reboot_notifier(&fw_shutdown_nb);
1559 	if (ret)
1560 		goto out;
1561 
1562 	return register_sysfs_loader();
1563 
1564 out:
1565 	unregister_fw_pm_ops();
1566 	return ret;
1567 }
1568 
1569 static void __exit firmware_class_exit(void)
1570 {
1571 	unregister_fw_pm_ops();
1572 	unregister_reboot_notifier(&fw_shutdown_nb);
1573 	unregister_sysfs_loader();
1574 }
1575 
1576 fs_initcall(firmware_class_init);
1577 module_exit(firmware_class_exit);
1578