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/zstd.h>
39 #include <linux/xz.h>
40 
41 #include <generated/utsrelease.h>
42 
43 #include "../base.h"
44 #include "firmware.h"
45 #include "fallback.h"
46 
47 MODULE_AUTHOR("Manuel Estrada Sainz");
48 MODULE_DESCRIPTION("Multi purpose firmware loading support");
49 MODULE_LICENSE("GPL");
50 
51 struct firmware_cache {
52 	/* firmware_buf instance will be added into the below list */
53 	spinlock_t lock;
54 	struct list_head head;
55 	int state;
56 
57 #ifdef CONFIG_FW_CACHE
58 	/*
59 	 * Names of firmware images which have been cached successfully
60 	 * will be added into the below list so that device uncache
61 	 * helper can trace which firmware images have been cached
62 	 * before.
63 	 */
64 	spinlock_t name_lock;
65 	struct list_head fw_names;
66 
67 	struct delayed_work work;
68 
69 	struct notifier_block   pm_notify;
70 #endif
71 };
72 
73 struct fw_cache_entry {
74 	struct list_head list;
75 	const char *name;
76 };
77 
78 struct fw_name_devm {
79 	unsigned long magic;
80 	const char *name;
81 };
82 
to_fw_priv(struct kref * ref)83 static inline struct fw_priv *to_fw_priv(struct kref *ref)
84 {
85 	return container_of(ref, struct fw_priv, ref);
86 }
87 
88 #define	FW_LOADER_NO_CACHE	0
89 #define	FW_LOADER_START_CACHE	1
90 
91 /* fw_lock could be moved to 'struct fw_sysfs' but since it is just
92  * guarding for corner cases a global lock should be OK */
93 DEFINE_MUTEX(fw_lock);
94 
95 struct firmware_cache fw_cache;
96 
fw_state_init(struct fw_priv * fw_priv)97 void fw_state_init(struct fw_priv *fw_priv)
98 {
99 	struct fw_state *fw_st = &fw_priv->fw_st;
100 
101 	init_completion(&fw_st->completion);
102 	fw_st->status = FW_STATUS_UNKNOWN;
103 }
104 
fw_state_wait(struct fw_priv * fw_priv)105 static inline int fw_state_wait(struct fw_priv *fw_priv)
106 {
107 	return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
108 }
109 
110 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
111 
__allocate_fw_priv(const char * fw_name,struct firmware_cache * fwc,void * dbuf,size_t size,size_t offset,u32 opt_flags)112 static struct fw_priv *__allocate_fw_priv(const char *fw_name,
113 					  struct firmware_cache *fwc,
114 					  void *dbuf,
115 					  size_t size,
116 					  size_t offset,
117 					  u32 opt_flags)
118 {
119 	struct fw_priv *fw_priv;
120 
121 	/* For a partial read, the buffer must be preallocated. */
122 	if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
123 		return NULL;
124 
125 	/* Only partial reads are allowed to use an offset. */
126 	if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
127 		return NULL;
128 
129 	fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
130 	if (!fw_priv)
131 		return NULL;
132 
133 	fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
134 	if (!fw_priv->fw_name) {
135 		kfree(fw_priv);
136 		return NULL;
137 	}
138 
139 	kref_init(&fw_priv->ref);
140 	fw_priv->fwc = fwc;
141 	fw_priv->data = dbuf;
142 	fw_priv->allocated_size = size;
143 	fw_priv->offset = offset;
144 	fw_priv->opt_flags = opt_flags;
145 	fw_state_init(fw_priv);
146 #ifdef CONFIG_FW_LOADER_USER_HELPER
147 	INIT_LIST_HEAD(&fw_priv->pending_list);
148 #endif
149 
150 	pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
151 
152 	return fw_priv;
153 }
154 
__lookup_fw_priv(const char * fw_name)155 static struct fw_priv *__lookup_fw_priv(const char *fw_name)
156 {
157 	struct fw_priv *tmp;
158 	struct firmware_cache *fwc = &fw_cache;
159 
160 	list_for_each_entry(tmp, &fwc->head, list)
161 		if (!strcmp(tmp->fw_name, fw_name))
162 			return tmp;
163 	return NULL;
164 }
165 
166 /* Returns 1 for batching firmware requests with the same name */
alloc_lookup_fw_priv(const char * fw_name,struct firmware_cache * fwc,struct fw_priv ** fw_priv,void * dbuf,size_t size,size_t offset,u32 opt_flags)167 int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
168 			 struct fw_priv **fw_priv, void *dbuf, size_t size,
169 			 size_t offset, u32 opt_flags)
170 {
171 	struct fw_priv *tmp;
172 
173 	spin_lock(&fwc->lock);
174 	/*
175 	 * Do not merge requests that are marked to be non-cached or
176 	 * are performing partial reads.
177 	 */
178 	if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
179 		tmp = __lookup_fw_priv(fw_name);
180 		if (tmp) {
181 			kref_get(&tmp->ref);
182 			spin_unlock(&fwc->lock);
183 			*fw_priv = tmp;
184 			pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
185 			return 1;
186 		}
187 	}
188 
189 	tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
190 	if (tmp) {
191 		INIT_LIST_HEAD(&tmp->list);
192 		if (!(opt_flags & FW_OPT_NOCACHE))
193 			list_add(&tmp->list, &fwc->head);
194 	}
195 	spin_unlock(&fwc->lock);
196 
197 	*fw_priv = tmp;
198 
199 	return tmp ? 0 : -ENOMEM;
200 }
201 
__free_fw_priv(struct kref * ref)202 static void __free_fw_priv(struct kref *ref)
203 	__releases(&fwc->lock)
204 {
205 	struct fw_priv *fw_priv = to_fw_priv(ref);
206 	struct firmware_cache *fwc = fw_priv->fwc;
207 
208 	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
209 		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
210 		 (unsigned int)fw_priv->size);
211 
212 	list_del(&fw_priv->list);
213 	spin_unlock(&fwc->lock);
214 
215 	if (fw_is_paged_buf(fw_priv))
216 		fw_free_paged_buf(fw_priv);
217 	else if (!fw_priv->allocated_size)
218 		vfree(fw_priv->data);
219 
220 	kfree_const(fw_priv->fw_name);
221 	kfree(fw_priv);
222 }
223 
free_fw_priv(struct fw_priv * fw_priv)224 void free_fw_priv(struct fw_priv *fw_priv)
225 {
226 	struct firmware_cache *fwc = fw_priv->fwc;
227 	spin_lock(&fwc->lock);
228 	if (!kref_put(&fw_priv->ref, __free_fw_priv))
229 		spin_unlock(&fwc->lock);
230 }
231 
232 #ifdef CONFIG_FW_LOADER_PAGED_BUF
fw_is_paged_buf(struct fw_priv * fw_priv)233 bool fw_is_paged_buf(struct fw_priv *fw_priv)
234 {
235 	return fw_priv->is_paged_buf;
236 }
237 
fw_free_paged_buf(struct fw_priv * fw_priv)238 void fw_free_paged_buf(struct fw_priv *fw_priv)
239 {
240 	int i;
241 
242 	if (!fw_priv->pages)
243 		return;
244 
245 	vunmap(fw_priv->data);
246 
247 	for (i = 0; i < fw_priv->nr_pages; i++)
248 		__free_page(fw_priv->pages[i]);
249 	kvfree(fw_priv->pages);
250 	fw_priv->pages = NULL;
251 	fw_priv->page_array_size = 0;
252 	fw_priv->nr_pages = 0;
253 	fw_priv->data = NULL;
254 	fw_priv->size = 0;
255 }
256 
fw_grow_paged_buf(struct fw_priv * fw_priv,int pages_needed)257 int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
258 {
259 	/* If the array of pages is too small, grow it */
260 	if (fw_priv->page_array_size < pages_needed) {
261 		int new_array_size = max(pages_needed,
262 					 fw_priv->page_array_size * 2);
263 		struct page **new_pages;
264 
265 		new_pages = kvmalloc_array(new_array_size, sizeof(void *),
266 					   GFP_KERNEL);
267 		if (!new_pages)
268 			return -ENOMEM;
269 		memcpy(new_pages, fw_priv->pages,
270 		       fw_priv->page_array_size * sizeof(void *));
271 		memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
272 		       (new_array_size - fw_priv->page_array_size));
273 		kvfree(fw_priv->pages);
274 		fw_priv->pages = new_pages;
275 		fw_priv->page_array_size = new_array_size;
276 	}
277 
278 	while (fw_priv->nr_pages < pages_needed) {
279 		fw_priv->pages[fw_priv->nr_pages] =
280 			alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
281 
282 		if (!fw_priv->pages[fw_priv->nr_pages])
283 			return -ENOMEM;
284 		fw_priv->nr_pages++;
285 	}
286 
287 	return 0;
288 }
289 
fw_map_paged_buf(struct fw_priv * fw_priv)290 int fw_map_paged_buf(struct fw_priv *fw_priv)
291 {
292 	/* one pages buffer should be mapped/unmapped only once */
293 	if (!fw_priv->pages)
294 		return 0;
295 
296 	vunmap(fw_priv->data);
297 	fw_priv->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0,
298 			     PAGE_KERNEL_RO);
299 	if (!fw_priv->data)
300 		return -ENOMEM;
301 
302 	return 0;
303 }
304 #endif
305 
306 /*
307  * ZSTD-compressed firmware support
308  */
309 #ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
fw_decompress_zstd(struct device * dev,struct fw_priv * fw_priv,size_t in_size,const void * in_buffer)310 static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv,
311 			      size_t in_size, const void *in_buffer)
312 {
313 	size_t len, out_size, workspace_size;
314 	void *workspace, *out_buf;
315 	zstd_dctx *ctx;
316 	int err;
317 
318 	if (fw_priv->allocated_size) {
319 		out_size = fw_priv->allocated_size;
320 		out_buf = fw_priv->data;
321 	} else {
322 		zstd_frame_header params;
323 
324 		if (zstd_get_frame_header(&params, in_buffer, in_size) ||
325 		    params.frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN) {
326 			dev_dbg(dev, "%s: invalid zstd header\n", __func__);
327 			return -EINVAL;
328 		}
329 		out_size = params.frameContentSize;
330 		out_buf = vzalloc(out_size);
331 		if (!out_buf)
332 			return -ENOMEM;
333 	}
334 
335 	workspace_size = zstd_dctx_workspace_bound();
336 	workspace = kvzalloc(workspace_size, GFP_KERNEL);
337 	if (!workspace) {
338 		err = -ENOMEM;
339 		goto error;
340 	}
341 
342 	ctx = zstd_init_dctx(workspace, workspace_size);
343 	if (!ctx) {
344 		dev_dbg(dev, "%s: failed to initialize context\n", __func__);
345 		err = -EINVAL;
346 		goto error;
347 	}
348 
349 	len = zstd_decompress_dctx(ctx, out_buf, out_size, in_buffer, in_size);
350 	if (zstd_is_error(len)) {
351 		dev_dbg(dev, "%s: failed to decompress: %d\n", __func__,
352 			zstd_get_error_code(len));
353 		err = -EINVAL;
354 		goto error;
355 	}
356 
357 	if (!fw_priv->allocated_size)
358 		fw_priv->data = out_buf;
359 	fw_priv->size = len;
360 	err = 0;
361 
362  error:
363 	kvfree(workspace);
364 	if (err && !fw_priv->allocated_size)
365 		vfree(out_buf);
366 	return err;
367 }
368 #endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */
369 
370 /*
371  * XZ-compressed firmware support
372  */
373 #ifdef CONFIG_FW_LOADER_COMPRESS_XZ
374 /* show an error and return the standard error code */
fw_decompress_xz_error(struct device * dev,enum xz_ret xz_ret)375 static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
376 {
377 	if (xz_ret != XZ_STREAM_END) {
378 		dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
379 		return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
380 	}
381 	return 0;
382 }
383 
384 /* single-shot decompression onto the pre-allocated buffer */
fw_decompress_xz_single(struct device * dev,struct fw_priv * fw_priv,size_t in_size,const void * in_buffer)385 static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
386 				   size_t in_size, const void *in_buffer)
387 {
388 	struct xz_dec *xz_dec;
389 	struct xz_buf xz_buf;
390 	enum xz_ret xz_ret;
391 
392 	xz_dec = xz_dec_init(XZ_SINGLE, (u32)-1);
393 	if (!xz_dec)
394 		return -ENOMEM;
395 
396 	xz_buf.in_size = in_size;
397 	xz_buf.in = in_buffer;
398 	xz_buf.in_pos = 0;
399 	xz_buf.out_size = fw_priv->allocated_size;
400 	xz_buf.out = fw_priv->data;
401 	xz_buf.out_pos = 0;
402 
403 	xz_ret = xz_dec_run(xz_dec, &xz_buf);
404 	xz_dec_end(xz_dec);
405 
406 	fw_priv->size = xz_buf.out_pos;
407 	return fw_decompress_xz_error(dev, xz_ret);
408 }
409 
410 /* decompression on paged buffer and map it */
fw_decompress_xz_pages(struct device * dev,struct fw_priv * fw_priv,size_t in_size,const void * in_buffer)411 static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
412 				  size_t in_size, const void *in_buffer)
413 {
414 	struct xz_dec *xz_dec;
415 	struct xz_buf xz_buf;
416 	enum xz_ret xz_ret;
417 	struct page *page;
418 	int err = 0;
419 
420 	xz_dec = xz_dec_init(XZ_DYNALLOC, (u32)-1);
421 	if (!xz_dec)
422 		return -ENOMEM;
423 
424 	xz_buf.in_size = in_size;
425 	xz_buf.in = in_buffer;
426 	xz_buf.in_pos = 0;
427 
428 	fw_priv->is_paged_buf = true;
429 	fw_priv->size = 0;
430 	do {
431 		if (fw_grow_paged_buf(fw_priv, fw_priv->nr_pages + 1)) {
432 			err = -ENOMEM;
433 			goto out;
434 		}
435 
436 		/* decompress onto the new allocated page */
437 		page = fw_priv->pages[fw_priv->nr_pages - 1];
438 		xz_buf.out = kmap(page);
439 		xz_buf.out_pos = 0;
440 		xz_buf.out_size = PAGE_SIZE;
441 		xz_ret = xz_dec_run(xz_dec, &xz_buf);
442 		kunmap(page);
443 		fw_priv->size += xz_buf.out_pos;
444 		/* partial decompression means either end or error */
445 		if (xz_buf.out_pos != PAGE_SIZE)
446 			break;
447 	} while (xz_ret == XZ_OK);
448 
449 	err = fw_decompress_xz_error(dev, xz_ret);
450 	if (!err)
451 		err = fw_map_paged_buf(fw_priv);
452 
453  out:
454 	xz_dec_end(xz_dec);
455 	return err;
456 }
457 
fw_decompress_xz(struct device * dev,struct fw_priv * fw_priv,size_t in_size,const void * in_buffer)458 static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
459 			    size_t in_size, const void *in_buffer)
460 {
461 	/* if the buffer is pre-allocated, we can perform in single-shot mode */
462 	if (fw_priv->data)
463 		return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
464 	else
465 		return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
466 }
467 #endif /* CONFIG_FW_LOADER_COMPRESS_XZ */
468 
469 /* direct firmware loading support */
470 static char fw_path_para[256];
471 static const char * const fw_path[] = {
472 	fw_path_para,
473 	"/lib/firmware/updates/" UTS_RELEASE,
474 	"/lib/firmware/updates",
475 	"/lib/firmware/" UTS_RELEASE,
476 	"/lib/firmware"
477 };
478 
479 /*
480  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
481  * from kernel command line because firmware_class is generally built in
482  * kernel instead of module.
483  */
484 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
485 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
486 
487 static int
fw_get_filesystem_firmware(struct device * device,struct fw_priv * fw_priv,const char * suffix,int (* decompress)(struct device * dev,struct fw_priv * fw_priv,size_t in_size,const void * in_buffer))488 fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
489 			   const char *suffix,
490 			   int (*decompress)(struct device *dev,
491 					     struct fw_priv *fw_priv,
492 					     size_t in_size,
493 					     const void *in_buffer))
494 {
495 	size_t size;
496 	int i, len;
497 	int rc = -ENOENT;
498 	char *path;
499 	size_t msize = INT_MAX;
500 	void *buffer = NULL;
501 
502 	/* Already populated data member means we're loading into a buffer */
503 	if (!decompress && fw_priv->data) {
504 		buffer = fw_priv->data;
505 		msize = fw_priv->allocated_size;
506 	}
507 
508 	path = __getname();
509 	if (!path)
510 		return -ENOMEM;
511 
512 	wait_for_initramfs();
513 	for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
514 		size_t file_size = 0;
515 		size_t *file_size_ptr = NULL;
516 
517 		/* skip the unset customized path */
518 		if (!fw_path[i][0])
519 			continue;
520 
521 		len = snprintf(path, PATH_MAX, "%s/%s%s",
522 			       fw_path[i], fw_priv->fw_name, suffix);
523 		if (len >= PATH_MAX) {
524 			rc = -ENAMETOOLONG;
525 			break;
526 		}
527 
528 		fw_priv->size = 0;
529 
530 		/*
531 		 * The total file size is only examined when doing a partial
532 		 * read; the "full read" case needs to fail if the whole
533 		 * firmware was not completely loaded.
534 		 */
535 		if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
536 			file_size_ptr = &file_size;
537 
538 		/* load firmware files from the mount namespace of init */
539 		rc = kernel_read_file_from_path_initns(path, fw_priv->offset,
540 						       &buffer, msize,
541 						       file_size_ptr,
542 						       READING_FIRMWARE);
543 		if (rc < 0) {
544 			if (rc != -ENOENT)
545 				dev_warn(device, "loading %s failed with error %d\n",
546 					 path, rc);
547 			else
548 				dev_dbg(device, "loading %s failed for no such file or directory.\n",
549 					 path);
550 			continue;
551 		}
552 		size = rc;
553 		rc = 0;
554 
555 		dev_dbg(device, "Loading firmware from %s\n", path);
556 		if (decompress) {
557 			dev_dbg(device, "f/w decompressing %s\n",
558 				fw_priv->fw_name);
559 			rc = decompress(device, fw_priv, size, buffer);
560 			/* discard the superfluous original content */
561 			vfree(buffer);
562 			buffer = NULL;
563 			if (rc) {
564 				fw_free_paged_buf(fw_priv);
565 				continue;
566 			}
567 		} else {
568 			dev_dbg(device, "direct-loading %s\n",
569 				fw_priv->fw_name);
570 			if (!fw_priv->data)
571 				fw_priv->data = buffer;
572 			fw_priv->size = size;
573 		}
574 		fw_state_done(fw_priv);
575 		break;
576 	}
577 	__putname(path);
578 
579 	return rc;
580 }
581 
582 /* firmware holds the ownership of pages */
firmware_free_data(const struct firmware * fw)583 static void firmware_free_data(const struct firmware *fw)
584 {
585 	/* Loaded directly? */
586 	if (!fw->priv) {
587 		vfree(fw->data);
588 		return;
589 	}
590 	free_fw_priv(fw->priv);
591 }
592 
593 /* store the pages buffer info firmware from buf */
fw_set_page_data(struct fw_priv * fw_priv,struct firmware * fw)594 static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
595 {
596 	fw->priv = fw_priv;
597 	fw->size = fw_priv->size;
598 	fw->data = fw_priv->data;
599 
600 	pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
601 		 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
602 		 (unsigned int)fw_priv->size);
603 }
604 
605 #ifdef CONFIG_FW_CACHE
fw_name_devm_release(struct device * dev,void * res)606 static void fw_name_devm_release(struct device *dev, void *res)
607 {
608 	struct fw_name_devm *fwn = res;
609 
610 	if (fwn->magic == (unsigned long)&fw_cache)
611 		pr_debug("%s: fw_name-%s devm-%p released\n",
612 				__func__, fwn->name, res);
613 	kfree_const(fwn->name);
614 }
615 
fw_devm_match(struct device * dev,void * res,void * match_data)616 static int fw_devm_match(struct device *dev, void *res,
617 		void *match_data)
618 {
619 	struct fw_name_devm *fwn = res;
620 
621 	return (fwn->magic == (unsigned long)&fw_cache) &&
622 		!strcmp(fwn->name, match_data);
623 }
624 
fw_find_devm_name(struct device * dev,const char * name)625 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
626 		const char *name)
627 {
628 	struct fw_name_devm *fwn;
629 
630 	fwn = devres_find(dev, fw_name_devm_release,
631 			  fw_devm_match, (void *)name);
632 	return fwn;
633 }
634 
fw_cache_is_setup(struct device * dev,const char * name)635 static bool fw_cache_is_setup(struct device *dev, const char *name)
636 {
637 	struct fw_name_devm *fwn;
638 
639 	fwn = fw_find_devm_name(dev, name);
640 	if (fwn)
641 		return true;
642 
643 	return false;
644 }
645 
646 /* add firmware name into devres list */
fw_add_devm_name(struct device * dev,const char * name)647 static int fw_add_devm_name(struct device *dev, const char *name)
648 {
649 	struct fw_name_devm *fwn;
650 
651 	if (fw_cache_is_setup(dev, name))
652 		return 0;
653 
654 	fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
655 			   GFP_KERNEL);
656 	if (!fwn)
657 		return -ENOMEM;
658 	fwn->name = kstrdup_const(name, GFP_KERNEL);
659 	if (!fwn->name) {
660 		devres_free(fwn);
661 		return -ENOMEM;
662 	}
663 
664 	fwn->magic = (unsigned long)&fw_cache;
665 	devres_add(dev, fwn);
666 
667 	return 0;
668 }
669 #else
fw_cache_is_setup(struct device * dev,const char * name)670 static bool fw_cache_is_setup(struct device *dev, const char *name)
671 {
672 	return false;
673 }
674 
fw_add_devm_name(struct device * dev,const char * name)675 static int fw_add_devm_name(struct device *dev, const char *name)
676 {
677 	return 0;
678 }
679 #endif
680 
assign_fw(struct firmware * fw,struct device * device)681 int assign_fw(struct firmware *fw, struct device *device)
682 {
683 	struct fw_priv *fw_priv = fw->priv;
684 	int ret;
685 
686 	mutex_lock(&fw_lock);
687 	if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
688 		mutex_unlock(&fw_lock);
689 		return -ENOENT;
690 	}
691 
692 	/*
693 	 * add firmware name into devres list so that we can auto cache
694 	 * and uncache firmware for device.
695 	 *
696 	 * device may has been deleted already, but the problem
697 	 * should be fixed in devres or driver core.
698 	 */
699 	/* don't cache firmware handled without uevent */
700 	if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
701 	    !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
702 		ret = fw_add_devm_name(device, fw_priv->fw_name);
703 		if (ret) {
704 			mutex_unlock(&fw_lock);
705 			return ret;
706 		}
707 	}
708 
709 	/*
710 	 * After caching firmware image is started, let it piggyback
711 	 * on request firmware.
712 	 */
713 	if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
714 	    fw_priv->fwc->state == FW_LOADER_START_CACHE)
715 		fw_cache_piggyback_on_request(fw_priv);
716 
717 	/* pass the pages buffer to driver at the last minute */
718 	fw_set_page_data(fw_priv, fw);
719 	mutex_unlock(&fw_lock);
720 	return 0;
721 }
722 
723 /* prepare firmware and firmware_buf structs;
724  * return 0 if a firmware is already assigned, 1 if need to load one,
725  * or a negative error code
726  */
727 static int
_request_firmware_prepare(struct firmware ** firmware_p,const char * name,struct device * device,void * dbuf,size_t size,size_t offset,u32 opt_flags)728 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
729 			  struct device *device, void *dbuf, size_t size,
730 			  size_t offset, u32 opt_flags)
731 {
732 	struct firmware *firmware;
733 	struct fw_priv *fw_priv;
734 	int ret;
735 
736 	*firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
737 	if (!firmware) {
738 		dev_err(device, "%s: kmalloc(struct firmware) failed\n",
739 			__func__);
740 		return -ENOMEM;
741 	}
742 
743 	if (firmware_request_builtin_buf(firmware, name, dbuf, size)) {
744 		dev_dbg(device, "using built-in %s\n", name);
745 		return 0; /* assigned */
746 	}
747 
748 	ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size,
749 				   offset, opt_flags);
750 
751 	/*
752 	 * bind with 'priv' now to avoid warning in failure path
753 	 * of requesting firmware.
754 	 */
755 	firmware->priv = fw_priv;
756 
757 	if (ret > 0) {
758 		ret = fw_state_wait(fw_priv);
759 		if (!ret) {
760 			fw_set_page_data(fw_priv, firmware);
761 			return 0; /* assigned */
762 		}
763 	}
764 
765 	if (ret < 0)
766 		return ret;
767 	return 1; /* need to load */
768 }
769 
770 /*
771  * Batched requests need only one wake, we need to do this step last due to the
772  * fallback mechanism. The buf is protected with kref_get(), and it won't be
773  * released until the last user calls release_firmware().
774  *
775  * Failed batched requests are possible as well, in such cases we just share
776  * the struct fw_priv and won't release it until all requests are woken
777  * and have gone through this same path.
778  */
fw_abort_batch_reqs(struct firmware * fw)779 static void fw_abort_batch_reqs(struct firmware *fw)
780 {
781 	struct fw_priv *fw_priv;
782 
783 	/* Loaded directly? */
784 	if (!fw || !fw->priv)
785 		return;
786 
787 	fw_priv = fw->priv;
788 	mutex_lock(&fw_lock);
789 	if (!fw_state_is_aborted(fw_priv))
790 		fw_state_aborted(fw_priv);
791 	mutex_unlock(&fw_lock);
792 }
793 
794 /* called from request_firmware() and request_firmware_work_func() */
795 static int
_request_firmware(const struct firmware ** firmware_p,const char * name,struct device * device,void * buf,size_t size,size_t offset,u32 opt_flags)796 _request_firmware(const struct firmware **firmware_p, const char *name,
797 		  struct device *device, void *buf, size_t size,
798 		  size_t offset, u32 opt_flags)
799 {
800 	struct firmware *fw = NULL;
801 	struct cred *kern_cred = NULL;
802 	const struct cred *old_cred;
803 	bool nondirect = false;
804 	int ret;
805 
806 	if (!firmware_p)
807 		return -EINVAL;
808 
809 	if (!name || name[0] == '\0') {
810 		ret = -EINVAL;
811 		goto out;
812 	}
813 
814 	ret = _request_firmware_prepare(&fw, name, device, buf, size,
815 					offset, opt_flags);
816 	if (ret <= 0) /* error or already assigned */
817 		goto out;
818 
819 	/*
820 	 * We are about to try to access the firmware file. Because we may have been
821 	 * called by a driver when serving an unrelated request from userland, we use
822 	 * the kernel credentials to read the file.
823 	 */
824 	kern_cred = prepare_kernel_cred(NULL);
825 	if (!kern_cred) {
826 		ret = -ENOMEM;
827 		goto out;
828 	}
829 	old_cred = override_creds(kern_cred);
830 
831 	ret = fw_get_filesystem_firmware(device, fw->priv, "", NULL);
832 
833 	/* Only full reads can support decompression, platform, and sysfs. */
834 	if (!(opt_flags & FW_OPT_PARTIAL))
835 		nondirect = true;
836 
837 #ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
838 	if (ret == -ENOENT && nondirect)
839 		ret = fw_get_filesystem_firmware(device, fw->priv, ".zst",
840 						 fw_decompress_zstd);
841 #endif
842 #ifdef CONFIG_FW_LOADER_COMPRESS_XZ
843 	if (ret == -ENOENT && nondirect)
844 		ret = fw_get_filesystem_firmware(device, fw->priv, ".xz",
845 						 fw_decompress_xz);
846 #endif
847 	if (ret == -ENOENT && nondirect)
848 		ret = firmware_fallback_platform(fw->priv);
849 
850 	if (ret) {
851 		if (!(opt_flags & FW_OPT_NO_WARN))
852 			dev_warn(device,
853 				 "Direct firmware load for %s failed with error %d\n",
854 				 name, ret);
855 		if (nondirect)
856 			ret = firmware_fallback_sysfs(fw, name, device,
857 						      opt_flags, ret);
858 	} else
859 		ret = assign_fw(fw, device);
860 
861 	revert_creds(old_cred);
862 	put_cred(kern_cred);
863 
864  out:
865 	if (ret < 0) {
866 		fw_abort_batch_reqs(fw);
867 		release_firmware(fw);
868 		fw = NULL;
869 	}
870 
871 	*firmware_p = fw;
872 	return ret;
873 }
874 
875 /**
876  * request_firmware() - send firmware request and wait for it
877  * @firmware_p: pointer to firmware image
878  * @name: name of firmware file
879  * @device: device for which firmware is being loaded
880  *
881  *      @firmware_p will be used to return a firmware image by the name
882  *      of @name for device @device.
883  *
884  *      Should be called from user context where sleeping is allowed.
885  *
886  *      @name will be used as $FIRMWARE in the uevent environment and
887  *      should be distinctive enough not to be confused with any other
888  *      firmware image for this or any other device.
889  *
890  *	Caller must hold the reference count of @device.
891  *
892  *	The function can be called safely inside device's suspend and
893  *	resume callback.
894  **/
895 int
request_firmware(const struct firmware ** firmware_p,const char * name,struct device * device)896 request_firmware(const struct firmware **firmware_p, const char *name,
897 		 struct device *device)
898 {
899 	int ret;
900 
901 	/* Need to pin this module until return */
902 	__module_get(THIS_MODULE);
903 	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
904 				FW_OPT_UEVENT);
905 	module_put(THIS_MODULE);
906 	return ret;
907 }
908 EXPORT_SYMBOL(request_firmware);
909 
910 /**
911  * firmware_request_nowarn() - request for an optional fw module
912  * @firmware: pointer to firmware image
913  * @name: name of firmware file
914  * @device: device for which firmware is being loaded
915  *
916  * This function is similar in behaviour to request_firmware(), except it
917  * doesn't produce warning messages when the file is not found. The sysfs
918  * fallback mechanism is enabled if direct filesystem lookup fails. However,
919  * failures to find the firmware file with it are still suppressed. It is
920  * therefore up to the driver to check for the return value of this call and to
921  * decide when to inform the users of errors.
922  **/
firmware_request_nowarn(const struct firmware ** firmware,const char * name,struct device * device)923 int firmware_request_nowarn(const struct firmware **firmware, const char *name,
924 			    struct device *device)
925 {
926 	int ret;
927 
928 	/* Need to pin this module until return */
929 	__module_get(THIS_MODULE);
930 	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
931 				FW_OPT_UEVENT | FW_OPT_NO_WARN);
932 	module_put(THIS_MODULE);
933 	return ret;
934 }
935 EXPORT_SYMBOL_GPL(firmware_request_nowarn);
936 
937 /**
938  * request_firmware_direct() - load firmware directly without usermode helper
939  * @firmware_p: pointer to firmware image
940  * @name: name of firmware file
941  * @device: device for which firmware is being loaded
942  *
943  * This function works pretty much like request_firmware(), but this doesn't
944  * fall back to usermode helper even if the firmware couldn't be loaded
945  * directly from fs.  Hence it's useful for loading optional firmwares, which
946  * aren't always present, without extra long timeouts of udev.
947  **/
request_firmware_direct(const struct firmware ** firmware_p,const char * name,struct device * device)948 int request_firmware_direct(const struct firmware **firmware_p,
949 			    const char *name, struct device *device)
950 {
951 	int ret;
952 
953 	__module_get(THIS_MODULE);
954 	ret = _request_firmware(firmware_p, name, device, NULL, 0, 0,
955 				FW_OPT_UEVENT | FW_OPT_NO_WARN |
956 				FW_OPT_NOFALLBACK_SYSFS);
957 	module_put(THIS_MODULE);
958 	return ret;
959 }
960 EXPORT_SYMBOL_GPL(request_firmware_direct);
961 
962 /**
963  * firmware_request_platform() - request firmware with platform-fw fallback
964  * @firmware: pointer to firmware image
965  * @name: name of firmware file
966  * @device: device for which firmware is being loaded
967  *
968  * This function is similar in behaviour to request_firmware, except that if
969  * direct filesystem lookup fails, it will fallback to looking for a copy of the
970  * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
971  **/
firmware_request_platform(const struct firmware ** firmware,const char * name,struct device * device)972 int firmware_request_platform(const struct firmware **firmware,
973 			      const char *name, struct device *device)
974 {
975 	int ret;
976 
977 	/* Need to pin this module until return */
978 	__module_get(THIS_MODULE);
979 	ret = _request_firmware(firmware, name, device, NULL, 0, 0,
980 				FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
981 	module_put(THIS_MODULE);
982 	return ret;
983 }
984 EXPORT_SYMBOL_GPL(firmware_request_platform);
985 
986 /**
987  * firmware_request_cache() - cache firmware for suspend so resume can use it
988  * @name: name of firmware file
989  * @device: device for which firmware should be cached for
990  *
991  * There are some devices with an optimization that enables the device to not
992  * require loading firmware on system reboot. This optimization may still
993  * require the firmware present on resume from suspend. This routine can be
994  * used to ensure the firmware is present on resume from suspend in these
995  * situations. This helper is not compatible with drivers which use
996  * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
997  **/
firmware_request_cache(struct device * device,const char * name)998 int firmware_request_cache(struct device *device, const char *name)
999 {
1000 	int ret;
1001 
1002 	mutex_lock(&fw_lock);
1003 	ret = fw_add_devm_name(device, name);
1004 	mutex_unlock(&fw_lock);
1005 
1006 	return ret;
1007 }
1008 EXPORT_SYMBOL_GPL(firmware_request_cache);
1009 
1010 /**
1011  * request_firmware_into_buf() - load firmware into a previously allocated buffer
1012  * @firmware_p: pointer to firmware image
1013  * @name: name of firmware file
1014  * @device: device for which firmware is being loaded and DMA region allocated
1015  * @buf: address of buffer to load firmware into
1016  * @size: size of buffer
1017  *
1018  * This function works pretty much like request_firmware(), but it doesn't
1019  * allocate a buffer to hold the firmware data. Instead, the firmware
1020  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1021  * data member is pointed at @buf.
1022  *
1023  * This function doesn't cache firmware either.
1024  */
1025 int
request_firmware_into_buf(const struct firmware ** firmware_p,const char * name,struct device * device,void * buf,size_t size)1026 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1027 			  struct device *device, void *buf, size_t size)
1028 {
1029 	int ret;
1030 
1031 	if (fw_cache_is_setup(device, name))
1032 		return -EOPNOTSUPP;
1033 
1034 	__module_get(THIS_MODULE);
1035 	ret = _request_firmware(firmware_p, name, device, buf, size, 0,
1036 				FW_OPT_UEVENT | FW_OPT_NOCACHE);
1037 	module_put(THIS_MODULE);
1038 	return ret;
1039 }
1040 EXPORT_SYMBOL(request_firmware_into_buf);
1041 
1042 /**
1043  * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1044  * @firmware_p: pointer to firmware image
1045  * @name: name of firmware file
1046  * @device: device for which firmware is being loaded and DMA region allocated
1047  * @buf: address of buffer to load firmware into
1048  * @size: size of buffer
1049  * @offset: offset into file to read
1050  *
1051  * This function works pretty much like request_firmware_into_buf except
1052  * it allows a partial read of the file.
1053  */
1054 int
request_partial_firmware_into_buf(const struct firmware ** firmware_p,const char * name,struct device * device,void * buf,size_t size,size_t offset)1055 request_partial_firmware_into_buf(const struct firmware **firmware_p,
1056 				  const char *name, struct device *device,
1057 				  void *buf, size_t size, size_t offset)
1058 {
1059 	int ret;
1060 
1061 	if (fw_cache_is_setup(device, name))
1062 		return -EOPNOTSUPP;
1063 
1064 	__module_get(THIS_MODULE);
1065 	ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1066 				FW_OPT_UEVENT | FW_OPT_NOCACHE |
1067 				FW_OPT_PARTIAL);
1068 	module_put(THIS_MODULE);
1069 	return ret;
1070 }
1071 EXPORT_SYMBOL(request_partial_firmware_into_buf);
1072 
1073 /**
1074  * release_firmware() - release the resource associated with a firmware image
1075  * @fw: firmware resource to release
1076  **/
release_firmware(const struct firmware * fw)1077 void release_firmware(const struct firmware *fw)
1078 {
1079 	if (fw) {
1080 		if (!firmware_is_builtin(fw))
1081 			firmware_free_data(fw);
1082 		kfree(fw);
1083 	}
1084 }
1085 EXPORT_SYMBOL(release_firmware);
1086 
1087 /* Async support */
1088 struct firmware_work {
1089 	struct work_struct work;
1090 	struct module *module;
1091 	const char *name;
1092 	struct device *device;
1093 	void *context;
1094 	void (*cont)(const struct firmware *fw, void *context);
1095 	u32 opt_flags;
1096 };
1097 
request_firmware_work_func(struct work_struct * work)1098 static void request_firmware_work_func(struct work_struct *work)
1099 {
1100 	struct firmware_work *fw_work;
1101 	const struct firmware *fw;
1102 
1103 	fw_work = container_of(work, struct firmware_work, work);
1104 
1105 	_request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, 0,
1106 			  fw_work->opt_flags);
1107 	fw_work->cont(fw, fw_work->context);
1108 	put_device(fw_work->device); /* taken in request_firmware_nowait() */
1109 
1110 	module_put(fw_work->module);
1111 	kfree_const(fw_work->name);
1112 	kfree(fw_work);
1113 }
1114 
1115 /**
1116  * request_firmware_nowait() - asynchronous version of request_firmware
1117  * @module: module requesting the firmware
1118  * @uevent: sends uevent to copy the firmware image if this flag
1119  *	is non-zero else the firmware copy must be done manually.
1120  * @name: name of firmware file
1121  * @device: device for which firmware is being loaded
1122  * @gfp: allocation flags
1123  * @context: will be passed over to @cont, and
1124  *	@fw may be %NULL if firmware request fails.
1125  * @cont: function will be called asynchronously when the firmware
1126  *	request is over.
1127  *
1128  *	Caller must hold the reference count of @device.
1129  *
1130  *	Asynchronous variant of request_firmware() for user contexts:
1131  *		- sleep for as small periods as possible since it may
1132  *		  increase kernel boot time of built-in device drivers
1133  *		  requesting firmware in their ->probe() methods, if
1134  *		  @gfp is GFP_KERNEL.
1135  *
1136  *		- can't sleep at all if @gfp is GFP_ATOMIC.
1137  **/
1138 int
request_firmware_nowait(struct module * module,bool uevent,const char * name,struct device * device,gfp_t gfp,void * context,void (* cont)(const struct firmware * fw,void * context))1139 request_firmware_nowait(
1140 	struct module *module, bool uevent,
1141 	const char *name, struct device *device, gfp_t gfp, void *context,
1142 	void (*cont)(const struct firmware *fw, void *context))
1143 {
1144 	struct firmware_work *fw_work;
1145 
1146 	fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1147 	if (!fw_work)
1148 		return -ENOMEM;
1149 
1150 	fw_work->module = module;
1151 	fw_work->name = kstrdup_const(name, gfp);
1152 	if (!fw_work->name) {
1153 		kfree(fw_work);
1154 		return -ENOMEM;
1155 	}
1156 	fw_work->device = device;
1157 	fw_work->context = context;
1158 	fw_work->cont = cont;
1159 	fw_work->opt_flags = FW_OPT_NOWAIT |
1160 		(uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1161 
1162 	if (!uevent && fw_cache_is_setup(device, name)) {
1163 		kfree_const(fw_work->name);
1164 		kfree(fw_work);
1165 		return -EOPNOTSUPP;
1166 	}
1167 
1168 	if (!try_module_get(module)) {
1169 		kfree_const(fw_work->name);
1170 		kfree(fw_work);
1171 		return -EFAULT;
1172 	}
1173 
1174 	get_device(fw_work->device);
1175 	INIT_WORK(&fw_work->work, request_firmware_work_func);
1176 	schedule_work(&fw_work->work);
1177 	return 0;
1178 }
1179 EXPORT_SYMBOL(request_firmware_nowait);
1180 
1181 #ifdef CONFIG_FW_CACHE
1182 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1183 
1184 /**
1185  * cache_firmware() - cache one firmware image in kernel memory space
1186  * @fw_name: the firmware image name
1187  *
1188  * Cache firmware in kernel memory so that drivers can use it when
1189  * system isn't ready for them to request firmware image from userspace.
1190  * Once it returns successfully, driver can use request_firmware or its
1191  * nowait version to get the cached firmware without any interacting
1192  * with userspace
1193  *
1194  * Return 0 if the firmware image has been cached successfully
1195  * Return !0 otherwise
1196  *
1197  */
cache_firmware(const char * fw_name)1198 static int cache_firmware(const char *fw_name)
1199 {
1200 	int ret;
1201 	const struct firmware *fw;
1202 
1203 	pr_debug("%s: %s\n", __func__, fw_name);
1204 
1205 	ret = request_firmware(&fw, fw_name, NULL);
1206 	if (!ret)
1207 		kfree(fw);
1208 
1209 	pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1210 
1211 	return ret;
1212 }
1213 
lookup_fw_priv(const char * fw_name)1214 static struct fw_priv *lookup_fw_priv(const char *fw_name)
1215 {
1216 	struct fw_priv *tmp;
1217 	struct firmware_cache *fwc = &fw_cache;
1218 
1219 	spin_lock(&fwc->lock);
1220 	tmp = __lookup_fw_priv(fw_name);
1221 	spin_unlock(&fwc->lock);
1222 
1223 	return tmp;
1224 }
1225 
1226 /**
1227  * uncache_firmware() - remove one cached firmware image
1228  * @fw_name: the firmware image name
1229  *
1230  * Uncache one firmware image which has been cached successfully
1231  * before.
1232  *
1233  * Return 0 if the firmware cache has been removed successfully
1234  * Return !0 otherwise
1235  *
1236  */
uncache_firmware(const char * fw_name)1237 static int uncache_firmware(const char *fw_name)
1238 {
1239 	struct fw_priv *fw_priv;
1240 	struct firmware fw;
1241 
1242 	pr_debug("%s: %s\n", __func__, fw_name);
1243 
1244 	if (firmware_request_builtin(&fw, fw_name))
1245 		return 0;
1246 
1247 	fw_priv = lookup_fw_priv(fw_name);
1248 	if (fw_priv) {
1249 		free_fw_priv(fw_priv);
1250 		return 0;
1251 	}
1252 
1253 	return -EINVAL;
1254 }
1255 
alloc_fw_cache_entry(const char * name)1256 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1257 {
1258 	struct fw_cache_entry *fce;
1259 
1260 	fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1261 	if (!fce)
1262 		goto exit;
1263 
1264 	fce->name = kstrdup_const(name, GFP_ATOMIC);
1265 	if (!fce->name) {
1266 		kfree(fce);
1267 		fce = NULL;
1268 		goto exit;
1269 	}
1270 exit:
1271 	return fce;
1272 }
1273 
__fw_entry_found(const char * name)1274 static int __fw_entry_found(const char *name)
1275 {
1276 	struct firmware_cache *fwc = &fw_cache;
1277 	struct fw_cache_entry *fce;
1278 
1279 	list_for_each_entry(fce, &fwc->fw_names, list) {
1280 		if (!strcmp(fce->name, name))
1281 			return 1;
1282 	}
1283 	return 0;
1284 }
1285 
fw_cache_piggyback_on_request(struct fw_priv * fw_priv)1286 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1287 {
1288 	const char *name = fw_priv->fw_name;
1289 	struct firmware_cache *fwc = fw_priv->fwc;
1290 	struct fw_cache_entry *fce;
1291 
1292 	spin_lock(&fwc->name_lock);
1293 	if (__fw_entry_found(name))
1294 		goto found;
1295 
1296 	fce = alloc_fw_cache_entry(name);
1297 	if (fce) {
1298 		list_add(&fce->list, &fwc->fw_names);
1299 		kref_get(&fw_priv->ref);
1300 		pr_debug("%s: fw: %s\n", __func__, name);
1301 	}
1302 found:
1303 	spin_unlock(&fwc->name_lock);
1304 }
1305 
free_fw_cache_entry(struct fw_cache_entry * fce)1306 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1307 {
1308 	kfree_const(fce->name);
1309 	kfree(fce);
1310 }
1311 
__async_dev_cache_fw_image(void * fw_entry,async_cookie_t cookie)1312 static void __async_dev_cache_fw_image(void *fw_entry,
1313 				       async_cookie_t cookie)
1314 {
1315 	struct fw_cache_entry *fce = fw_entry;
1316 	struct firmware_cache *fwc = &fw_cache;
1317 	int ret;
1318 
1319 	ret = cache_firmware(fce->name);
1320 	if (ret) {
1321 		spin_lock(&fwc->name_lock);
1322 		list_del(&fce->list);
1323 		spin_unlock(&fwc->name_lock);
1324 
1325 		free_fw_cache_entry(fce);
1326 	}
1327 }
1328 
1329 /* called with dev->devres_lock held */
dev_create_fw_entry(struct device * dev,void * res,void * data)1330 static void dev_create_fw_entry(struct device *dev, void *res,
1331 				void *data)
1332 {
1333 	struct fw_name_devm *fwn = res;
1334 	const char *fw_name = fwn->name;
1335 	struct list_head *head = data;
1336 	struct fw_cache_entry *fce;
1337 
1338 	fce = alloc_fw_cache_entry(fw_name);
1339 	if (fce)
1340 		list_add(&fce->list, head);
1341 }
1342 
devm_name_match(struct device * dev,void * res,void * match_data)1343 static int devm_name_match(struct device *dev, void *res,
1344 			   void *match_data)
1345 {
1346 	struct fw_name_devm *fwn = res;
1347 	return (fwn->magic == (unsigned long)match_data);
1348 }
1349 
dev_cache_fw_image(struct device * dev,void * data)1350 static void dev_cache_fw_image(struct device *dev, void *data)
1351 {
1352 	LIST_HEAD(todo);
1353 	struct fw_cache_entry *fce;
1354 	struct fw_cache_entry *fce_next;
1355 	struct firmware_cache *fwc = &fw_cache;
1356 
1357 	devres_for_each_res(dev, fw_name_devm_release,
1358 			    devm_name_match, &fw_cache,
1359 			    dev_create_fw_entry, &todo);
1360 
1361 	list_for_each_entry_safe(fce, fce_next, &todo, list) {
1362 		list_del(&fce->list);
1363 
1364 		spin_lock(&fwc->name_lock);
1365 		/* only one cache entry for one firmware */
1366 		if (!__fw_entry_found(fce->name)) {
1367 			list_add(&fce->list, &fwc->fw_names);
1368 		} else {
1369 			free_fw_cache_entry(fce);
1370 			fce = NULL;
1371 		}
1372 		spin_unlock(&fwc->name_lock);
1373 
1374 		if (fce)
1375 			async_schedule_domain(__async_dev_cache_fw_image,
1376 					      (void *)fce,
1377 					      &fw_cache_domain);
1378 	}
1379 }
1380 
__device_uncache_fw_images(void)1381 static void __device_uncache_fw_images(void)
1382 {
1383 	struct firmware_cache *fwc = &fw_cache;
1384 	struct fw_cache_entry *fce;
1385 
1386 	spin_lock(&fwc->name_lock);
1387 	while (!list_empty(&fwc->fw_names)) {
1388 		fce = list_entry(fwc->fw_names.next,
1389 				struct fw_cache_entry, list);
1390 		list_del(&fce->list);
1391 		spin_unlock(&fwc->name_lock);
1392 
1393 		uncache_firmware(fce->name);
1394 		free_fw_cache_entry(fce);
1395 
1396 		spin_lock(&fwc->name_lock);
1397 	}
1398 	spin_unlock(&fwc->name_lock);
1399 }
1400 
1401 /**
1402  * device_cache_fw_images() - cache devices' firmware
1403  *
1404  * If one device called request_firmware or its nowait version
1405  * successfully before, the firmware names are recored into the
1406  * device's devres link list, so device_cache_fw_images can call
1407  * cache_firmware() to cache these firmwares for the device,
1408  * then the device driver can load its firmwares easily at
1409  * time when system is not ready to complete loading firmware.
1410  */
device_cache_fw_images(void)1411 static void device_cache_fw_images(void)
1412 {
1413 	struct firmware_cache *fwc = &fw_cache;
1414 	DEFINE_WAIT(wait);
1415 
1416 	pr_debug("%s\n", __func__);
1417 
1418 	/* cancel uncache work */
1419 	cancel_delayed_work_sync(&fwc->work);
1420 
1421 	fw_fallback_set_cache_timeout();
1422 
1423 	mutex_lock(&fw_lock);
1424 	fwc->state = FW_LOADER_START_CACHE;
1425 	dpm_for_each_dev(NULL, dev_cache_fw_image);
1426 	mutex_unlock(&fw_lock);
1427 
1428 	/* wait for completion of caching firmware for all devices */
1429 	async_synchronize_full_domain(&fw_cache_domain);
1430 
1431 	fw_fallback_set_default_timeout();
1432 }
1433 
1434 /**
1435  * device_uncache_fw_images() - uncache devices' firmware
1436  *
1437  * uncache all firmwares which have been cached successfully
1438  * by device_uncache_fw_images earlier
1439  */
device_uncache_fw_images(void)1440 static void device_uncache_fw_images(void)
1441 {
1442 	pr_debug("%s\n", __func__);
1443 	__device_uncache_fw_images();
1444 }
1445 
device_uncache_fw_images_work(struct work_struct * work)1446 static void device_uncache_fw_images_work(struct work_struct *work)
1447 {
1448 	device_uncache_fw_images();
1449 }
1450 
1451 /**
1452  * device_uncache_fw_images_delay() - uncache devices firmwares
1453  * @delay: number of milliseconds to delay uncache device firmwares
1454  *
1455  * uncache all devices's firmwares which has been cached successfully
1456  * by device_cache_fw_images after @delay milliseconds.
1457  */
device_uncache_fw_images_delay(unsigned long delay)1458 static void device_uncache_fw_images_delay(unsigned long delay)
1459 {
1460 	queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1461 			   msecs_to_jiffies(delay));
1462 }
1463 
fw_pm_notify(struct notifier_block * notify_block,unsigned long mode,void * unused)1464 static int fw_pm_notify(struct notifier_block *notify_block,
1465 			unsigned long mode, void *unused)
1466 {
1467 	switch (mode) {
1468 	case PM_HIBERNATION_PREPARE:
1469 	case PM_SUSPEND_PREPARE:
1470 	case PM_RESTORE_PREPARE:
1471 		/*
1472 		 * kill pending fallback requests with a custom fallback
1473 		 * to avoid stalling suspend.
1474 		 */
1475 		kill_pending_fw_fallback_reqs(true);
1476 		device_cache_fw_images();
1477 		break;
1478 
1479 	case PM_POST_SUSPEND:
1480 	case PM_POST_HIBERNATION:
1481 	case PM_POST_RESTORE:
1482 		/*
1483 		 * In case that system sleep failed and syscore_suspend is
1484 		 * not called.
1485 		 */
1486 		mutex_lock(&fw_lock);
1487 		fw_cache.state = FW_LOADER_NO_CACHE;
1488 		mutex_unlock(&fw_lock);
1489 
1490 		device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1491 		break;
1492 	}
1493 
1494 	return 0;
1495 }
1496 
1497 /* stop caching firmware once syscore_suspend is reached */
fw_suspend(void)1498 static int fw_suspend(void)
1499 {
1500 	fw_cache.state = FW_LOADER_NO_CACHE;
1501 	return 0;
1502 }
1503 
1504 static struct syscore_ops fw_syscore_ops = {
1505 	.suspend = fw_suspend,
1506 };
1507 
register_fw_pm_ops(void)1508 static int __init register_fw_pm_ops(void)
1509 {
1510 	int ret;
1511 
1512 	spin_lock_init(&fw_cache.name_lock);
1513 	INIT_LIST_HEAD(&fw_cache.fw_names);
1514 
1515 	INIT_DELAYED_WORK(&fw_cache.work,
1516 			  device_uncache_fw_images_work);
1517 
1518 	fw_cache.pm_notify.notifier_call = fw_pm_notify;
1519 	ret = register_pm_notifier(&fw_cache.pm_notify);
1520 	if (ret)
1521 		return ret;
1522 
1523 	register_syscore_ops(&fw_syscore_ops);
1524 
1525 	return ret;
1526 }
1527 
unregister_fw_pm_ops(void)1528 static inline void unregister_fw_pm_ops(void)
1529 {
1530 	unregister_syscore_ops(&fw_syscore_ops);
1531 	unregister_pm_notifier(&fw_cache.pm_notify);
1532 }
1533 #else
fw_cache_piggyback_on_request(struct fw_priv * fw_priv)1534 static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1535 {
1536 }
register_fw_pm_ops(void)1537 static inline int register_fw_pm_ops(void)
1538 {
1539 	return 0;
1540 }
unregister_fw_pm_ops(void)1541 static inline void unregister_fw_pm_ops(void)
1542 {
1543 }
1544 #endif
1545 
fw_cache_init(void)1546 static void __init fw_cache_init(void)
1547 {
1548 	spin_lock_init(&fw_cache.lock);
1549 	INIT_LIST_HEAD(&fw_cache.head);
1550 	fw_cache.state = FW_LOADER_NO_CACHE;
1551 }
1552 
fw_shutdown_notify(struct notifier_block * unused1,unsigned long unused2,void * unused3)1553 static int fw_shutdown_notify(struct notifier_block *unused1,
1554 			      unsigned long unused2, void *unused3)
1555 {
1556 	/*
1557 	 * Kill all pending fallback requests to avoid both stalling shutdown,
1558 	 * and avoid a deadlock with the usermode_lock.
1559 	 */
1560 	kill_pending_fw_fallback_reqs(false);
1561 
1562 	return NOTIFY_DONE;
1563 }
1564 
1565 static struct notifier_block fw_shutdown_nb = {
1566 	.notifier_call = fw_shutdown_notify,
1567 };
1568 
firmware_class_init(void)1569 static int __init firmware_class_init(void)
1570 {
1571 	int ret;
1572 
1573 	/* No need to unfold these on exit */
1574 	fw_cache_init();
1575 
1576 	ret = register_fw_pm_ops();
1577 	if (ret)
1578 		return ret;
1579 
1580 	ret = register_reboot_notifier(&fw_shutdown_nb);
1581 	if (ret)
1582 		goto out;
1583 
1584 	return register_sysfs_loader();
1585 
1586 out:
1587 	unregister_fw_pm_ops();
1588 	return ret;
1589 }
1590 
firmware_class_exit(void)1591 static void __exit firmware_class_exit(void)
1592 {
1593 	unregister_fw_pm_ops();
1594 	unregister_reboot_notifier(&fw_shutdown_nb);
1595 	unregister_sysfs_loader();
1596 }
1597 
1598 fs_initcall(firmware_class_init);
1599 module_exit(firmware_class_exit);
1600