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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
47MODULE_AUTHOR("Manuel Estrada Sainz");
48MODULE_DESCRIPTION("Multi purpose firmware loading support");
49MODULE_LICENSE("GPL");
50
51struct 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
73struct fw_cache_entry {
74 struct list_head list;
75 const char *name;
76};
77
78struct fw_name_devm {
79 unsigned long magic;
80 const char *name;
81};
82
83static 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 */
93DEFINE_MUTEX(fw_lock);
94
95struct firmware_cache fw_cache;
96
97void 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
105static inline int fw_state_wait(struct fw_priv *fw_priv)
106{
107 return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
108}
109
110static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
111
112static 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
155static 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 */
167int 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
202static 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
224void 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
233bool fw_is_paged_buf(struct fw_priv *fw_priv)
234{
235 return fw_priv->is_paged_buf;
236}
237
238void 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
257int 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
290int 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
310static 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(¶ms, 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 */
375static 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 */
385static 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 */
411static 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_local_page(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_local(xz_buf.out);
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
458static 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 */
470static char fw_path_para[256];
471static 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 */
484module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
485MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
486
487static int
488fw_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 */
583static 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 */
594static 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
606static 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
616static 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
625static 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
635static 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 */
647static 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
670static bool fw_cache_is_setup(struct device *dev, const char *name)
671{
672 return false;
673}
674
675static int fw_add_devm_name(struct device *dev, const char *name)
676{
677 return 0;
678}
679#endif
680
681int 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 */
727static int
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 */
779static 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() */
795static int
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(&init_task);
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 **/
895int
896request_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}
908EXPORT_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 **/
923int 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}
935EXPORT_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 **/
948int 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}
960EXPORT_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 **/
972int 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}
984EXPORT_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 **/
998int 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}
1008EXPORT_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 */
1025int
1026request_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}
1040EXPORT_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 */
1054int
1055request_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}
1071EXPORT_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 **/
1077void 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}
1085EXPORT_SYMBOL(release_firmware);
1086
1087/* Async support */
1088struct 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
1098static 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 **/
1138int
1139request_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}
1179EXPORT_SYMBOL(request_firmware_nowait);
1180
1181#ifdef CONFIG_FW_CACHE
1182static 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 */
1198static 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
1214static 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 */
1237static 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
1256static 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 }
1270exit:
1271 return fce;
1272}
1273
1274static 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
1286static 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 }
1302found:
1303 spin_unlock(&fwc->name_lock);
1304}
1305
1306static void free_fw_cache_entry(struct fw_cache_entry *fce)
1307{
1308 kfree_const(fce->name);
1309 kfree(fce);
1310}
1311
1312static 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 */
1330static 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
1343static 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
1350static 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
1381static 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 */
1411static 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 */
1440static void device_uncache_fw_images(void)
1441{
1442 pr_debug("%s\n", __func__);
1443 __device_uncache_fw_images();
1444}
1445
1446static 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 */
1458static 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
1464static 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 */
1498static int fw_suspend(void)
1499{
1500 fw_cache.state = FW_LOADER_NO_CACHE;
1501 return 0;
1502}
1503
1504static struct syscore_ops fw_syscore_ops = {
1505 .suspend = fw_suspend,
1506};
1507
1508static 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
1528static 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
1534static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1535{
1536}
1537static inline int register_fw_pm_ops(void)
1538{
1539 return 0;
1540}
1541static inline void unregister_fw_pm_ops(void)
1542{
1543}
1544#endif
1545
1546static 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
1553static 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
1565static struct notifier_block fw_shutdown_nb = {
1566 .notifier_call = fw_shutdown_notify,
1567};
1568
1569static 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
1586out:
1587 unregister_fw_pm_ops();
1588 return ret;
1589}
1590
1591static 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
1598fs_initcall(firmware_class_init);
1599module_exit(firmware_class_exit);
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/firmware_class/ 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/module.h>
16#include <linux/init.h>
17#include <linux/timer.h>
18#include <linux/vmalloc.h>
19#include <linux/interrupt.h>
20#include <linux/bitops.h>
21#include <linux/mutex.h>
22#include <linux/workqueue.h>
23#include <linux/highmem.h>
24#include <linux/firmware.h>
25#include <linux/slab.h>
26#include <linux/sched.h>
27#include <linux/file.h>
28#include <linux/list.h>
29#include <linux/fs.h>
30#include <linux/async.h>
31#include <linux/pm.h>
32#include <linux/suspend.h>
33#include <linux/syscore_ops.h>
34#include <linux/reboot.h>
35#include <linux/security.h>
36
37#include <generated/utsrelease.h>
38
39#include "../base.h"
40#include "firmware.h"
41#include "fallback.h"
42
43MODULE_AUTHOR("Manuel Estrada Sainz");
44MODULE_DESCRIPTION("Multi purpose firmware loading support");
45MODULE_LICENSE("GPL");
46
47struct firmware_cache {
48 /* firmware_buf instance will be added into the below list */
49 spinlock_t lock;
50 struct list_head head;
51 int state;
52
53#ifdef CONFIG_PM_SLEEP
54 /*
55 * Names of firmware images which have been cached successfully
56 * will be added into the below list so that device uncache
57 * helper can trace which firmware images have been cached
58 * before.
59 */
60 spinlock_t name_lock;
61 struct list_head fw_names;
62
63 struct delayed_work work;
64
65 struct notifier_block pm_notify;
66#endif
67};
68
69struct fw_cache_entry {
70 struct list_head list;
71 const char *name;
72};
73
74struct fw_name_devm {
75 unsigned long magic;
76 const char *name;
77};
78
79static inline struct fw_priv *to_fw_priv(struct kref *ref)
80{
81 return container_of(ref, struct fw_priv, ref);
82}
83
84#define FW_LOADER_NO_CACHE 0
85#define FW_LOADER_START_CACHE 1
86
87/* fw_lock could be moved to 'struct fw_sysfs' but since it is just
88 * guarding for corner cases a global lock should be OK */
89DEFINE_MUTEX(fw_lock);
90
91static struct firmware_cache fw_cache;
92
93/* Builtin firmware support */
94
95#ifdef CONFIG_FW_LOADER
96
97extern struct builtin_fw __start_builtin_fw[];
98extern struct builtin_fw __end_builtin_fw[];
99
100static void fw_copy_to_prealloc_buf(struct firmware *fw,
101 void *buf, size_t size)
102{
103 if (!buf || size < fw->size)
104 return;
105 memcpy(buf, fw->data, fw->size);
106}
107
108static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
109 void *buf, size_t size)
110{
111 struct builtin_fw *b_fw;
112
113 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
114 if (strcmp(name, b_fw->name) == 0) {
115 fw->size = b_fw->size;
116 fw->data = b_fw->data;
117 fw_copy_to_prealloc_buf(fw, buf, size);
118
119 return true;
120 }
121 }
122
123 return false;
124}
125
126static bool fw_is_builtin_firmware(const struct firmware *fw)
127{
128 struct builtin_fw *b_fw;
129
130 for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
131 if (fw->data == b_fw->data)
132 return true;
133
134 return false;
135}
136
137#else /* Module case - no builtin firmware support */
138
139static inline bool fw_get_builtin_firmware(struct firmware *fw,
140 const char *name, void *buf,
141 size_t size)
142{
143 return false;
144}
145
146static inline bool fw_is_builtin_firmware(const struct firmware *fw)
147{
148 return false;
149}
150#endif
151
152static void fw_state_init(struct fw_priv *fw_priv)
153{
154 struct fw_state *fw_st = &fw_priv->fw_st;
155
156 init_completion(&fw_st->completion);
157 fw_st->status = FW_STATUS_UNKNOWN;
158}
159
160static inline int fw_state_wait(struct fw_priv *fw_priv)
161{
162 return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
163}
164
165static int fw_cache_piggyback_on_request(const char *name);
166
167static struct fw_priv *__allocate_fw_priv(const char *fw_name,
168 struct firmware_cache *fwc,
169 void *dbuf, size_t size)
170{
171 struct fw_priv *fw_priv;
172
173 fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC);
174 if (!fw_priv)
175 return NULL;
176
177 fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC);
178 if (!fw_priv->fw_name) {
179 kfree(fw_priv);
180 return NULL;
181 }
182
183 kref_init(&fw_priv->ref);
184 fw_priv->fwc = fwc;
185 fw_priv->data = dbuf;
186 fw_priv->allocated_size = size;
187 fw_state_init(fw_priv);
188#ifdef CONFIG_FW_LOADER_USER_HELPER
189 INIT_LIST_HEAD(&fw_priv->pending_list);
190#endif
191
192 pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
193
194 return fw_priv;
195}
196
197static struct fw_priv *__lookup_fw_priv(const char *fw_name)
198{
199 struct fw_priv *tmp;
200 struct firmware_cache *fwc = &fw_cache;
201
202 list_for_each_entry(tmp, &fwc->head, list)
203 if (!strcmp(tmp->fw_name, fw_name))
204 return tmp;
205 return NULL;
206}
207
208/* Returns 1 for batching firmware requests with the same name */
209static int alloc_lookup_fw_priv(const char *fw_name,
210 struct firmware_cache *fwc,
211 struct fw_priv **fw_priv, void *dbuf,
212 size_t size)
213{
214 struct fw_priv *tmp;
215
216 spin_lock(&fwc->lock);
217 tmp = __lookup_fw_priv(fw_name);
218 if (tmp) {
219 kref_get(&tmp->ref);
220 spin_unlock(&fwc->lock);
221 *fw_priv = tmp;
222 pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
223 return 1;
224 }
225 tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size);
226 if (tmp)
227 list_add(&tmp->list, &fwc->head);
228 spin_unlock(&fwc->lock);
229
230 *fw_priv = tmp;
231
232 return tmp ? 0 : -ENOMEM;
233}
234
235static void __free_fw_priv(struct kref *ref)
236 __releases(&fwc->lock)
237{
238 struct fw_priv *fw_priv = to_fw_priv(ref);
239 struct firmware_cache *fwc = fw_priv->fwc;
240
241 pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
242 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
243 (unsigned int)fw_priv->size);
244
245 list_del(&fw_priv->list);
246 spin_unlock(&fwc->lock);
247
248#ifdef CONFIG_FW_LOADER_USER_HELPER
249 if (fw_priv->is_paged_buf) {
250 int i;
251 vunmap(fw_priv->data);
252 for (i = 0; i < fw_priv->nr_pages; i++)
253 __free_page(fw_priv->pages[i]);
254 vfree(fw_priv->pages);
255 } else
256#endif
257 if (!fw_priv->allocated_size)
258 vfree(fw_priv->data);
259 kfree_const(fw_priv->fw_name);
260 kfree(fw_priv);
261}
262
263static void free_fw_priv(struct fw_priv *fw_priv)
264{
265 struct firmware_cache *fwc = fw_priv->fwc;
266 spin_lock(&fwc->lock);
267 if (!kref_put(&fw_priv->ref, __free_fw_priv))
268 spin_unlock(&fwc->lock);
269}
270
271/* direct firmware loading support */
272static char fw_path_para[256];
273static const char * const fw_path[] = {
274 fw_path_para,
275 "/lib/firmware/updates/" UTS_RELEASE,
276 "/lib/firmware/updates",
277 "/lib/firmware/" UTS_RELEASE,
278 "/lib/firmware"
279};
280
281/*
282 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
283 * from kernel command line because firmware_class is generally built in
284 * kernel instead of module.
285 */
286module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
287MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
288
289static int
290fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv)
291{
292 loff_t size;
293 int i, len;
294 int rc = -ENOENT;
295 char *path;
296 enum kernel_read_file_id id = READING_FIRMWARE;
297 size_t msize = INT_MAX;
298
299 /* Already populated data member means we're loading into a buffer */
300 if (fw_priv->data) {
301 id = READING_FIRMWARE_PREALLOC_BUFFER;
302 msize = fw_priv->allocated_size;
303 }
304
305 path = __getname();
306 if (!path)
307 return -ENOMEM;
308
309 for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
310 /* skip the unset customized path */
311 if (!fw_path[i][0])
312 continue;
313
314 len = snprintf(path, PATH_MAX, "%s/%s",
315 fw_path[i], fw_priv->fw_name);
316 if (len >= PATH_MAX) {
317 rc = -ENAMETOOLONG;
318 break;
319 }
320
321 fw_priv->size = 0;
322 rc = kernel_read_file_from_path(path, &fw_priv->data, &size,
323 msize, id);
324 if (rc) {
325 if (rc == -ENOENT)
326 dev_dbg(device, "loading %s failed with error %d\n",
327 path, rc);
328 else
329 dev_warn(device, "loading %s failed with error %d\n",
330 path, rc);
331 continue;
332 }
333 dev_dbg(device, "direct-loading %s\n", fw_priv->fw_name);
334 fw_priv->size = size;
335 fw_state_done(fw_priv);
336 break;
337 }
338 __putname(path);
339
340 return rc;
341}
342
343/* firmware holds the ownership of pages */
344static void firmware_free_data(const struct firmware *fw)
345{
346 /* Loaded directly? */
347 if (!fw->priv) {
348 vfree(fw->data);
349 return;
350 }
351 free_fw_priv(fw->priv);
352}
353
354/* store the pages buffer info firmware from buf */
355static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
356{
357 fw->priv = fw_priv;
358#ifdef CONFIG_FW_LOADER_USER_HELPER
359 fw->pages = fw_priv->pages;
360#endif
361 fw->size = fw_priv->size;
362 fw->data = fw_priv->data;
363
364 pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
365 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
366 (unsigned int)fw_priv->size);
367}
368
369#ifdef CONFIG_PM_SLEEP
370static void fw_name_devm_release(struct device *dev, void *res)
371{
372 struct fw_name_devm *fwn = res;
373
374 if (fwn->magic == (unsigned long)&fw_cache)
375 pr_debug("%s: fw_name-%s devm-%p released\n",
376 __func__, fwn->name, res);
377 kfree_const(fwn->name);
378}
379
380static int fw_devm_match(struct device *dev, void *res,
381 void *match_data)
382{
383 struct fw_name_devm *fwn = res;
384
385 return (fwn->magic == (unsigned long)&fw_cache) &&
386 !strcmp(fwn->name, match_data);
387}
388
389static struct fw_name_devm *fw_find_devm_name(struct device *dev,
390 const char *name)
391{
392 struct fw_name_devm *fwn;
393
394 fwn = devres_find(dev, fw_name_devm_release,
395 fw_devm_match, (void *)name);
396 return fwn;
397}
398
399static bool fw_cache_is_setup(struct device *dev, const char *name)
400{
401 struct fw_name_devm *fwn;
402
403 fwn = fw_find_devm_name(dev, name);
404 if (fwn)
405 return true;
406
407 return false;
408}
409
410/* add firmware name into devres list */
411static int fw_add_devm_name(struct device *dev, const char *name)
412{
413 struct fw_name_devm *fwn;
414
415 if (fw_cache_is_setup(dev, name))
416 return 0;
417
418 fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
419 GFP_KERNEL);
420 if (!fwn)
421 return -ENOMEM;
422 fwn->name = kstrdup_const(name, GFP_KERNEL);
423 if (!fwn->name) {
424 devres_free(fwn);
425 return -ENOMEM;
426 }
427
428 fwn->magic = (unsigned long)&fw_cache;
429 devres_add(dev, fwn);
430
431 return 0;
432}
433#else
434static bool fw_cache_is_setup(struct device *dev, const char *name)
435{
436 return false;
437}
438
439static int fw_add_devm_name(struct device *dev, const char *name)
440{
441 return 0;
442}
443#endif
444
445int assign_fw(struct firmware *fw, struct device *device,
446 unsigned int opt_flags)
447{
448 struct fw_priv *fw_priv = fw->priv;
449 int ret;
450
451 mutex_lock(&fw_lock);
452 if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
453 mutex_unlock(&fw_lock);
454 return -ENOENT;
455 }
456
457 /*
458 * add firmware name into devres list so that we can auto cache
459 * and uncache firmware for device.
460 *
461 * device may has been deleted already, but the problem
462 * should be fixed in devres or driver core.
463 */
464 /* don't cache firmware handled without uevent */
465 if (device && (opt_flags & FW_OPT_UEVENT) &&
466 !(opt_flags & FW_OPT_NOCACHE)) {
467 ret = fw_add_devm_name(device, fw_priv->fw_name);
468 if (ret) {
469 mutex_unlock(&fw_lock);
470 return ret;
471 }
472 }
473
474 /*
475 * After caching firmware image is started, let it piggyback
476 * on request firmware.
477 */
478 if (!(opt_flags & FW_OPT_NOCACHE) &&
479 fw_priv->fwc->state == FW_LOADER_START_CACHE) {
480 if (fw_cache_piggyback_on_request(fw_priv->fw_name))
481 kref_get(&fw_priv->ref);
482 }
483
484 /* pass the pages buffer to driver at the last minute */
485 fw_set_page_data(fw_priv, fw);
486 mutex_unlock(&fw_lock);
487 return 0;
488}
489
490/* prepare firmware and firmware_buf structs;
491 * return 0 if a firmware is already assigned, 1 if need to load one,
492 * or a negative error code
493 */
494static int
495_request_firmware_prepare(struct firmware **firmware_p, const char *name,
496 struct device *device, void *dbuf, size_t size)
497{
498 struct firmware *firmware;
499 struct fw_priv *fw_priv;
500 int ret;
501
502 *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
503 if (!firmware) {
504 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
505 __func__);
506 return -ENOMEM;
507 }
508
509 if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
510 dev_dbg(device, "using built-in %s\n", name);
511 return 0; /* assigned */
512 }
513
514 ret = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size);
515
516 /*
517 * bind with 'priv' now to avoid warning in failure path
518 * of requesting firmware.
519 */
520 firmware->priv = fw_priv;
521
522 if (ret > 0) {
523 ret = fw_state_wait(fw_priv);
524 if (!ret) {
525 fw_set_page_data(fw_priv, firmware);
526 return 0; /* assigned */
527 }
528 }
529
530 if (ret < 0)
531 return ret;
532 return 1; /* need to load */
533}
534
535/*
536 * Batched requests need only one wake, we need to do this step last due to the
537 * fallback mechanism. The buf is protected with kref_get(), and it won't be
538 * released until the last user calls release_firmware().
539 *
540 * Failed batched requests are possible as well, in such cases we just share
541 * the struct fw_priv and won't release it until all requests are woken
542 * and have gone through this same path.
543 */
544static void fw_abort_batch_reqs(struct firmware *fw)
545{
546 struct fw_priv *fw_priv;
547
548 /* Loaded directly? */
549 if (!fw || !fw->priv)
550 return;
551
552 fw_priv = fw->priv;
553 if (!fw_state_is_aborted(fw_priv))
554 fw_state_aborted(fw_priv);
555}
556
557/* called from request_firmware() and request_firmware_work_func() */
558static int
559_request_firmware(const struct firmware **firmware_p, const char *name,
560 struct device *device, void *buf, size_t size,
561 unsigned int opt_flags)
562{
563 struct firmware *fw = NULL;
564 int ret;
565
566 if (!firmware_p)
567 return -EINVAL;
568
569 if (!name || name[0] == '\0') {
570 ret = -EINVAL;
571 goto out;
572 }
573
574 ret = _request_firmware_prepare(&fw, name, device, buf, size);
575 if (ret <= 0) /* error or already assigned */
576 goto out;
577
578 ret = fw_get_filesystem_firmware(device, fw->priv);
579 if (ret) {
580 if (!(opt_flags & FW_OPT_NO_WARN))
581 dev_warn(device,
582 "Direct firmware load for %s failed with error %d\n",
583 name, ret);
584 ret = fw_sysfs_fallback(fw, name, device, opt_flags, ret);
585 } else
586 ret = assign_fw(fw, device, opt_flags);
587
588 out:
589 if (ret < 0) {
590 fw_abort_batch_reqs(fw);
591 release_firmware(fw);
592 fw = NULL;
593 }
594
595 *firmware_p = fw;
596 return ret;
597}
598
599/**
600 * request_firmware: - send firmware request and wait for it
601 * @firmware_p: pointer to firmware image
602 * @name: name of firmware file
603 * @device: device for which firmware is being loaded
604 *
605 * @firmware_p will be used to return a firmware image by the name
606 * of @name for device @device.
607 *
608 * Should be called from user context where sleeping is allowed.
609 *
610 * @name will be used as $FIRMWARE in the uevent environment and
611 * should be distinctive enough not to be confused with any other
612 * firmware image for this or any other device.
613 *
614 * Caller must hold the reference count of @device.
615 *
616 * The function can be called safely inside device's suspend and
617 * resume callback.
618 **/
619int
620request_firmware(const struct firmware **firmware_p, const char *name,
621 struct device *device)
622{
623 int ret;
624
625 /* Need to pin this module until return */
626 __module_get(THIS_MODULE);
627 ret = _request_firmware(firmware_p, name, device, NULL, 0,
628 FW_OPT_UEVENT);
629 module_put(THIS_MODULE);
630 return ret;
631}
632EXPORT_SYMBOL(request_firmware);
633
634/**
635 * request_firmware_direct: - load firmware directly without usermode helper
636 * @firmware_p: pointer to firmware image
637 * @name: name of firmware file
638 * @device: device for which firmware is being loaded
639 *
640 * This function works pretty much like request_firmware(), but this doesn't
641 * fall back to usermode helper even if the firmware couldn't be loaded
642 * directly from fs. Hence it's useful for loading optional firmwares, which
643 * aren't always present, without extra long timeouts of udev.
644 **/
645int request_firmware_direct(const struct firmware **firmware_p,
646 const char *name, struct device *device)
647{
648 int ret;
649
650 __module_get(THIS_MODULE);
651 ret = _request_firmware(firmware_p, name, device, NULL, 0,
652 FW_OPT_UEVENT | FW_OPT_NO_WARN |
653 FW_OPT_NOFALLBACK);
654 module_put(THIS_MODULE);
655 return ret;
656}
657EXPORT_SYMBOL_GPL(request_firmware_direct);
658
659/**
660 * firmware_request_cache: - cache firmware for suspend so resume can use it
661 * @name: name of firmware file
662 * @device: device for which firmware should be cached for
663 *
664 * There are some devices with an optimization that enables the device to not
665 * require loading firmware on system reboot. This optimization may still
666 * require the firmware present on resume from suspend. This routine can be
667 * used to ensure the firmware is present on resume from suspend in these
668 * situations. This helper is not compatible with drivers which use
669 * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
670 **/
671int firmware_request_cache(struct device *device, const char *name)
672{
673 int ret;
674
675 mutex_lock(&fw_lock);
676 ret = fw_add_devm_name(device, name);
677 mutex_unlock(&fw_lock);
678
679 return ret;
680}
681EXPORT_SYMBOL_GPL(firmware_request_cache);
682
683/**
684 * request_firmware_into_buf - load firmware into a previously allocated buffer
685 * @firmware_p: pointer to firmware image
686 * @name: name of firmware file
687 * @device: device for which firmware is being loaded and DMA region allocated
688 * @buf: address of buffer to load firmware into
689 * @size: size of buffer
690 *
691 * This function works pretty much like request_firmware(), but it doesn't
692 * allocate a buffer to hold the firmware data. Instead, the firmware
693 * is loaded directly into the buffer pointed to by @buf and the @firmware_p
694 * data member is pointed at @buf.
695 *
696 * This function doesn't cache firmware either.
697 */
698int
699request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
700 struct device *device, void *buf, size_t size)
701{
702 int ret;
703
704 if (fw_cache_is_setup(device, name))
705 return -EOPNOTSUPP;
706
707 __module_get(THIS_MODULE);
708 ret = _request_firmware(firmware_p, name, device, buf, size,
709 FW_OPT_UEVENT | FW_OPT_NOCACHE);
710 module_put(THIS_MODULE);
711 return ret;
712}
713EXPORT_SYMBOL(request_firmware_into_buf);
714
715/**
716 * release_firmware: - release the resource associated with a firmware image
717 * @fw: firmware resource to release
718 **/
719void release_firmware(const struct firmware *fw)
720{
721 if (fw) {
722 if (!fw_is_builtin_firmware(fw))
723 firmware_free_data(fw);
724 kfree(fw);
725 }
726}
727EXPORT_SYMBOL(release_firmware);
728
729/* Async support */
730struct firmware_work {
731 struct work_struct work;
732 struct module *module;
733 const char *name;
734 struct device *device;
735 void *context;
736 void (*cont)(const struct firmware *fw, void *context);
737 unsigned int opt_flags;
738};
739
740static void request_firmware_work_func(struct work_struct *work)
741{
742 struct firmware_work *fw_work;
743 const struct firmware *fw;
744
745 fw_work = container_of(work, struct firmware_work, work);
746
747 _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
748 fw_work->opt_flags);
749 fw_work->cont(fw, fw_work->context);
750 put_device(fw_work->device); /* taken in request_firmware_nowait() */
751
752 module_put(fw_work->module);
753 kfree_const(fw_work->name);
754 kfree(fw_work);
755}
756
757/**
758 * request_firmware_nowait - asynchronous version of request_firmware
759 * @module: module requesting the firmware
760 * @uevent: sends uevent to copy the firmware image if this flag
761 * is non-zero else the firmware copy must be done manually.
762 * @name: name of firmware file
763 * @device: device for which firmware is being loaded
764 * @gfp: allocation flags
765 * @context: will be passed over to @cont, and
766 * @fw may be %NULL if firmware request fails.
767 * @cont: function will be called asynchronously when the firmware
768 * request is over.
769 *
770 * Caller must hold the reference count of @device.
771 *
772 * Asynchronous variant of request_firmware() for user contexts:
773 * - sleep for as small periods as possible since it may
774 * increase kernel boot time of built-in device drivers
775 * requesting firmware in their ->probe() methods, if
776 * @gfp is GFP_KERNEL.
777 *
778 * - can't sleep at all if @gfp is GFP_ATOMIC.
779 **/
780int
781request_firmware_nowait(
782 struct module *module, bool uevent,
783 const char *name, struct device *device, gfp_t gfp, void *context,
784 void (*cont)(const struct firmware *fw, void *context))
785{
786 struct firmware_work *fw_work;
787
788 fw_work = kzalloc(sizeof(struct firmware_work), gfp);
789 if (!fw_work)
790 return -ENOMEM;
791
792 fw_work->module = module;
793 fw_work->name = kstrdup_const(name, gfp);
794 if (!fw_work->name) {
795 kfree(fw_work);
796 return -ENOMEM;
797 }
798 fw_work->device = device;
799 fw_work->context = context;
800 fw_work->cont = cont;
801 fw_work->opt_flags = FW_OPT_NOWAIT |
802 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
803
804 if (!uevent && fw_cache_is_setup(device, name)) {
805 kfree_const(fw_work->name);
806 kfree(fw_work);
807 return -EOPNOTSUPP;
808 }
809
810 if (!try_module_get(module)) {
811 kfree_const(fw_work->name);
812 kfree(fw_work);
813 return -EFAULT;
814 }
815
816 get_device(fw_work->device);
817 INIT_WORK(&fw_work->work, request_firmware_work_func);
818 schedule_work(&fw_work->work);
819 return 0;
820}
821EXPORT_SYMBOL(request_firmware_nowait);
822
823#ifdef CONFIG_PM_SLEEP
824static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
825
826/**
827 * cache_firmware - cache one firmware image in kernel memory space
828 * @fw_name: the firmware image name
829 *
830 * Cache firmware in kernel memory so that drivers can use it when
831 * system isn't ready for them to request firmware image from userspace.
832 * Once it returns successfully, driver can use request_firmware or its
833 * nowait version to get the cached firmware without any interacting
834 * with userspace
835 *
836 * Return 0 if the firmware image has been cached successfully
837 * Return !0 otherwise
838 *
839 */
840static int cache_firmware(const char *fw_name)
841{
842 int ret;
843 const struct firmware *fw;
844
845 pr_debug("%s: %s\n", __func__, fw_name);
846
847 ret = request_firmware(&fw, fw_name, NULL);
848 if (!ret)
849 kfree(fw);
850
851 pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
852
853 return ret;
854}
855
856static struct fw_priv *lookup_fw_priv(const char *fw_name)
857{
858 struct fw_priv *tmp;
859 struct firmware_cache *fwc = &fw_cache;
860
861 spin_lock(&fwc->lock);
862 tmp = __lookup_fw_priv(fw_name);
863 spin_unlock(&fwc->lock);
864
865 return tmp;
866}
867
868/**
869 * uncache_firmware - remove one cached firmware image
870 * @fw_name: the firmware image name
871 *
872 * Uncache one firmware image which has been cached successfully
873 * before.
874 *
875 * Return 0 if the firmware cache has been removed successfully
876 * Return !0 otherwise
877 *
878 */
879static int uncache_firmware(const char *fw_name)
880{
881 struct fw_priv *fw_priv;
882 struct firmware fw;
883
884 pr_debug("%s: %s\n", __func__, fw_name);
885
886 if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
887 return 0;
888
889 fw_priv = lookup_fw_priv(fw_name);
890 if (fw_priv) {
891 free_fw_priv(fw_priv);
892 return 0;
893 }
894
895 return -EINVAL;
896}
897
898static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
899{
900 struct fw_cache_entry *fce;
901
902 fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
903 if (!fce)
904 goto exit;
905
906 fce->name = kstrdup_const(name, GFP_ATOMIC);
907 if (!fce->name) {
908 kfree(fce);
909 fce = NULL;
910 goto exit;
911 }
912exit:
913 return fce;
914}
915
916static int __fw_entry_found(const char *name)
917{
918 struct firmware_cache *fwc = &fw_cache;
919 struct fw_cache_entry *fce;
920
921 list_for_each_entry(fce, &fwc->fw_names, list) {
922 if (!strcmp(fce->name, name))
923 return 1;
924 }
925 return 0;
926}
927
928static int fw_cache_piggyback_on_request(const char *name)
929{
930 struct firmware_cache *fwc = &fw_cache;
931 struct fw_cache_entry *fce;
932 int ret = 0;
933
934 spin_lock(&fwc->name_lock);
935 if (__fw_entry_found(name))
936 goto found;
937
938 fce = alloc_fw_cache_entry(name);
939 if (fce) {
940 ret = 1;
941 list_add(&fce->list, &fwc->fw_names);
942 pr_debug("%s: fw: %s\n", __func__, name);
943 }
944found:
945 spin_unlock(&fwc->name_lock);
946 return ret;
947}
948
949static void free_fw_cache_entry(struct fw_cache_entry *fce)
950{
951 kfree_const(fce->name);
952 kfree(fce);
953}
954
955static void __async_dev_cache_fw_image(void *fw_entry,
956 async_cookie_t cookie)
957{
958 struct fw_cache_entry *fce = fw_entry;
959 struct firmware_cache *fwc = &fw_cache;
960 int ret;
961
962 ret = cache_firmware(fce->name);
963 if (ret) {
964 spin_lock(&fwc->name_lock);
965 list_del(&fce->list);
966 spin_unlock(&fwc->name_lock);
967
968 free_fw_cache_entry(fce);
969 }
970}
971
972/* called with dev->devres_lock held */
973static void dev_create_fw_entry(struct device *dev, void *res,
974 void *data)
975{
976 struct fw_name_devm *fwn = res;
977 const char *fw_name = fwn->name;
978 struct list_head *head = data;
979 struct fw_cache_entry *fce;
980
981 fce = alloc_fw_cache_entry(fw_name);
982 if (fce)
983 list_add(&fce->list, head);
984}
985
986static int devm_name_match(struct device *dev, void *res,
987 void *match_data)
988{
989 struct fw_name_devm *fwn = res;
990 return (fwn->magic == (unsigned long)match_data);
991}
992
993static void dev_cache_fw_image(struct device *dev, void *data)
994{
995 LIST_HEAD(todo);
996 struct fw_cache_entry *fce;
997 struct fw_cache_entry *fce_next;
998 struct firmware_cache *fwc = &fw_cache;
999
1000 devres_for_each_res(dev, fw_name_devm_release,
1001 devm_name_match, &fw_cache,
1002 dev_create_fw_entry, &todo);
1003
1004 list_for_each_entry_safe(fce, fce_next, &todo, list) {
1005 list_del(&fce->list);
1006
1007 spin_lock(&fwc->name_lock);
1008 /* only one cache entry for one firmware */
1009 if (!__fw_entry_found(fce->name)) {
1010 list_add(&fce->list, &fwc->fw_names);
1011 } else {
1012 free_fw_cache_entry(fce);
1013 fce = NULL;
1014 }
1015 spin_unlock(&fwc->name_lock);
1016
1017 if (fce)
1018 async_schedule_domain(__async_dev_cache_fw_image,
1019 (void *)fce,
1020 &fw_cache_domain);
1021 }
1022}
1023
1024static void __device_uncache_fw_images(void)
1025{
1026 struct firmware_cache *fwc = &fw_cache;
1027 struct fw_cache_entry *fce;
1028
1029 spin_lock(&fwc->name_lock);
1030 while (!list_empty(&fwc->fw_names)) {
1031 fce = list_entry(fwc->fw_names.next,
1032 struct fw_cache_entry, list);
1033 list_del(&fce->list);
1034 spin_unlock(&fwc->name_lock);
1035
1036 uncache_firmware(fce->name);
1037 free_fw_cache_entry(fce);
1038
1039 spin_lock(&fwc->name_lock);
1040 }
1041 spin_unlock(&fwc->name_lock);
1042}
1043
1044/**
1045 * device_cache_fw_images - cache devices' firmware
1046 *
1047 * If one device called request_firmware or its nowait version
1048 * successfully before, the firmware names are recored into the
1049 * device's devres link list, so device_cache_fw_images can call
1050 * cache_firmware() to cache these firmwares for the device,
1051 * then the device driver can load its firmwares easily at
1052 * time when system is not ready to complete loading firmware.
1053 */
1054static void device_cache_fw_images(void)
1055{
1056 struct firmware_cache *fwc = &fw_cache;
1057 DEFINE_WAIT(wait);
1058
1059 pr_debug("%s\n", __func__);
1060
1061 /* cancel uncache work */
1062 cancel_delayed_work_sync(&fwc->work);
1063
1064 fw_fallback_set_cache_timeout();
1065
1066 mutex_lock(&fw_lock);
1067 fwc->state = FW_LOADER_START_CACHE;
1068 dpm_for_each_dev(NULL, dev_cache_fw_image);
1069 mutex_unlock(&fw_lock);
1070
1071 /* wait for completion of caching firmware for all devices */
1072 async_synchronize_full_domain(&fw_cache_domain);
1073
1074 fw_fallback_set_default_timeout();
1075}
1076
1077/**
1078 * device_uncache_fw_images - uncache devices' firmware
1079 *
1080 * uncache all firmwares which have been cached successfully
1081 * by device_uncache_fw_images earlier
1082 */
1083static void device_uncache_fw_images(void)
1084{
1085 pr_debug("%s\n", __func__);
1086 __device_uncache_fw_images();
1087}
1088
1089static void device_uncache_fw_images_work(struct work_struct *work)
1090{
1091 device_uncache_fw_images();
1092}
1093
1094/**
1095 * device_uncache_fw_images_delay - uncache devices firmwares
1096 * @delay: number of milliseconds to delay uncache device firmwares
1097 *
1098 * uncache all devices's firmwares which has been cached successfully
1099 * by device_cache_fw_images after @delay milliseconds.
1100 */
1101static void device_uncache_fw_images_delay(unsigned long delay)
1102{
1103 queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1104 msecs_to_jiffies(delay));
1105}
1106
1107static int fw_pm_notify(struct notifier_block *notify_block,
1108 unsigned long mode, void *unused)
1109{
1110 switch (mode) {
1111 case PM_HIBERNATION_PREPARE:
1112 case PM_SUSPEND_PREPARE:
1113 case PM_RESTORE_PREPARE:
1114 /*
1115 * kill pending fallback requests with a custom fallback
1116 * to avoid stalling suspend.
1117 */
1118 kill_pending_fw_fallback_reqs(true);
1119 device_cache_fw_images();
1120 break;
1121
1122 case PM_POST_SUSPEND:
1123 case PM_POST_HIBERNATION:
1124 case PM_POST_RESTORE:
1125 /*
1126 * In case that system sleep failed and syscore_suspend is
1127 * not called.
1128 */
1129 mutex_lock(&fw_lock);
1130 fw_cache.state = FW_LOADER_NO_CACHE;
1131 mutex_unlock(&fw_lock);
1132
1133 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1134 break;
1135 }
1136
1137 return 0;
1138}
1139
1140/* stop caching firmware once syscore_suspend is reached */
1141static int fw_suspend(void)
1142{
1143 fw_cache.state = FW_LOADER_NO_CACHE;
1144 return 0;
1145}
1146
1147static struct syscore_ops fw_syscore_ops = {
1148 .suspend = fw_suspend,
1149};
1150
1151static int __init register_fw_pm_ops(void)
1152{
1153 int ret;
1154
1155 spin_lock_init(&fw_cache.name_lock);
1156 INIT_LIST_HEAD(&fw_cache.fw_names);
1157
1158 INIT_DELAYED_WORK(&fw_cache.work,
1159 device_uncache_fw_images_work);
1160
1161 fw_cache.pm_notify.notifier_call = fw_pm_notify;
1162 ret = register_pm_notifier(&fw_cache.pm_notify);
1163 if (ret)
1164 return ret;
1165
1166 register_syscore_ops(&fw_syscore_ops);
1167
1168 return ret;
1169}
1170
1171static inline void unregister_fw_pm_ops(void)
1172{
1173 unregister_syscore_ops(&fw_syscore_ops);
1174 unregister_pm_notifier(&fw_cache.pm_notify);
1175}
1176#else
1177static int fw_cache_piggyback_on_request(const char *name)
1178{
1179 return 0;
1180}
1181static inline int register_fw_pm_ops(void)
1182{
1183 return 0;
1184}
1185static inline void unregister_fw_pm_ops(void)
1186{
1187}
1188#endif
1189
1190static void __init fw_cache_init(void)
1191{
1192 spin_lock_init(&fw_cache.lock);
1193 INIT_LIST_HEAD(&fw_cache.head);
1194 fw_cache.state = FW_LOADER_NO_CACHE;
1195}
1196
1197static int fw_shutdown_notify(struct notifier_block *unused1,
1198 unsigned long unused2, void *unused3)
1199{
1200 /*
1201 * Kill all pending fallback requests to avoid both stalling shutdown,
1202 * and avoid a deadlock with the usermode_lock.
1203 */
1204 kill_pending_fw_fallback_reqs(false);
1205
1206 return NOTIFY_DONE;
1207}
1208
1209static struct notifier_block fw_shutdown_nb = {
1210 .notifier_call = fw_shutdown_notify,
1211};
1212
1213static int __init firmware_class_init(void)
1214{
1215 int ret;
1216
1217 /* No need to unfold these on exit */
1218 fw_cache_init();
1219
1220 ret = register_fw_pm_ops();
1221 if (ret)
1222 return ret;
1223
1224 ret = register_reboot_notifier(&fw_shutdown_nb);
1225 if (ret)
1226 goto out;
1227
1228 return register_sysfs_loader();
1229
1230out:
1231 unregister_fw_pm_ops();
1232 return ret;
1233}
1234
1235static void __exit firmware_class_exit(void)
1236{
1237 unregister_fw_pm_ops();
1238 unregister_reboot_notifier(&fw_shutdown_nb);
1239 unregister_sysfs_loader();
1240}
1241
1242fs_initcall(firmware_class_init);
1243module_exit(firmware_class_exit);