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;
96bool fw_load_abort_all;
97
98void fw_state_init(struct fw_priv *fw_priv)
99{
100 struct fw_state *fw_st = &fw_priv->fw_st;
101
102 init_completion(x: &fw_st->completion);
103 fw_st->status = FW_STATUS_UNKNOWN;
104}
105
106static inline int fw_state_wait(struct fw_priv *fw_priv)
107{
108 return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT);
109}
110
111static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv);
112
113static struct fw_priv *__allocate_fw_priv(const char *fw_name,
114 struct firmware_cache *fwc,
115 void *dbuf,
116 size_t size,
117 size_t offset,
118 u32 opt_flags)
119{
120 struct fw_priv *fw_priv;
121
122 /* For a partial read, the buffer must be preallocated. */
123 if ((opt_flags & FW_OPT_PARTIAL) && !dbuf)
124 return NULL;
125
126 /* Only partial reads are allowed to use an offset. */
127 if (offset != 0 && !(opt_flags & FW_OPT_PARTIAL))
128 return NULL;
129
130 fw_priv = kzalloc(size: sizeof(*fw_priv), GFP_ATOMIC);
131 if (!fw_priv)
132 return NULL;
133
134 fw_priv->fw_name = kstrdup_const(s: fw_name, GFP_ATOMIC);
135 if (!fw_priv->fw_name) {
136 kfree(objp: fw_priv);
137 return NULL;
138 }
139
140 kref_init(kref: &fw_priv->ref);
141 fw_priv->fwc = fwc;
142 fw_priv->data = dbuf;
143 fw_priv->allocated_size = size;
144 fw_priv->offset = offset;
145 fw_priv->opt_flags = opt_flags;
146 fw_state_init(fw_priv);
147#ifdef CONFIG_FW_LOADER_USER_HELPER
148 INIT_LIST_HEAD(list: &fw_priv->pending_list);
149#endif
150
151 pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv);
152
153 return fw_priv;
154}
155
156static struct fw_priv *__lookup_fw_priv(const char *fw_name)
157{
158 struct fw_priv *tmp;
159 struct firmware_cache *fwc = &fw_cache;
160
161 list_for_each_entry(tmp, &fwc->head, list)
162 if (!strcmp(tmp->fw_name, fw_name))
163 return tmp;
164 return NULL;
165}
166
167/* Returns 1 for batching firmware requests with the same name */
168int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc,
169 struct fw_priv **fw_priv, void *dbuf, size_t size,
170 size_t offset, u32 opt_flags)
171{
172 struct fw_priv *tmp;
173
174 spin_lock(lock: &fwc->lock);
175 /*
176 * Do not merge requests that are marked to be non-cached or
177 * are performing partial reads.
178 */
179 if (!(opt_flags & (FW_OPT_NOCACHE | FW_OPT_PARTIAL))) {
180 tmp = __lookup_fw_priv(fw_name);
181 if (tmp) {
182 kref_get(kref: &tmp->ref);
183 spin_unlock(lock: &fwc->lock);
184 *fw_priv = tmp;
185 pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n");
186 return 1;
187 }
188 }
189
190 tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size, offset, opt_flags);
191 if (tmp) {
192 INIT_LIST_HEAD(list: &tmp->list);
193 if (!(opt_flags & FW_OPT_NOCACHE))
194 list_add(new: &tmp->list, head: &fwc->head);
195 }
196 spin_unlock(lock: &fwc->lock);
197
198 *fw_priv = tmp;
199
200 return tmp ? 0 : -ENOMEM;
201}
202
203static void __free_fw_priv(struct kref *ref)
204 __releases(&fwc->lock)
205{
206 struct fw_priv *fw_priv = to_fw_priv(ref);
207 struct firmware_cache *fwc = fw_priv->fwc;
208
209 pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
210 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
211 (unsigned int)fw_priv->size);
212
213 list_del(entry: &fw_priv->list);
214 spin_unlock(lock: &fwc->lock);
215
216 if (fw_is_paged_buf(fw_priv))
217 fw_free_paged_buf(fw_priv);
218 else if (!fw_priv->allocated_size)
219 vfree(addr: fw_priv->data);
220
221 kfree_const(x: fw_priv->fw_name);
222 kfree(objp: fw_priv);
223}
224
225void free_fw_priv(struct fw_priv *fw_priv)
226{
227 struct firmware_cache *fwc = fw_priv->fwc;
228 spin_lock(lock: &fwc->lock);
229 if (!kref_put(kref: &fw_priv->ref, release: __free_fw_priv))
230 spin_unlock(lock: &fwc->lock);
231}
232
233#ifdef CONFIG_FW_LOADER_PAGED_BUF
234bool fw_is_paged_buf(struct fw_priv *fw_priv)
235{
236 return fw_priv->is_paged_buf;
237}
238
239void fw_free_paged_buf(struct fw_priv *fw_priv)
240{
241 int i;
242
243 if (!fw_priv->pages)
244 return;
245
246 vunmap(addr: fw_priv->data);
247
248 for (i = 0; i < fw_priv->nr_pages; i++)
249 __free_page(fw_priv->pages[i]);
250 kvfree(addr: fw_priv->pages);
251 fw_priv->pages = NULL;
252 fw_priv->page_array_size = 0;
253 fw_priv->nr_pages = 0;
254 fw_priv->data = NULL;
255 fw_priv->size = 0;
256}
257
258int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed)
259{
260 /* If the array of pages is too small, grow it */
261 if (fw_priv->page_array_size < pages_needed) {
262 int new_array_size = max(pages_needed,
263 fw_priv->page_array_size * 2);
264 struct page **new_pages;
265
266 new_pages = kvmalloc_array(n: new_array_size, size: sizeof(void *),
267 GFP_KERNEL);
268 if (!new_pages)
269 return -ENOMEM;
270 memcpy(new_pages, fw_priv->pages,
271 fw_priv->page_array_size * sizeof(void *));
272 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
273 (new_array_size - fw_priv->page_array_size));
274 kvfree(addr: fw_priv->pages);
275 fw_priv->pages = new_pages;
276 fw_priv->page_array_size = new_array_size;
277 }
278
279 while (fw_priv->nr_pages < pages_needed) {
280 fw_priv->pages[fw_priv->nr_pages] =
281 alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
282
283 if (!fw_priv->pages[fw_priv->nr_pages])
284 return -ENOMEM;
285 fw_priv->nr_pages++;
286 }
287
288 return 0;
289}
290
291int fw_map_paged_buf(struct fw_priv *fw_priv)
292{
293 /* one pages buffer should be mapped/unmapped only once */
294 if (!fw_priv->pages)
295 return 0;
296
297 vunmap(addr: fw_priv->data);
298 fw_priv->data = vmap(pages: fw_priv->pages, count: fw_priv->nr_pages, flags: 0,
299 PAGE_KERNEL_RO);
300 if (!fw_priv->data)
301 return -ENOMEM;
302
303 return 0;
304}
305#endif
306
307/*
308 * ZSTD-compressed firmware support
309 */
310#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
311static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv,
312 size_t in_size, const void *in_buffer)
313{
314 size_t len, out_size, workspace_size;
315 void *workspace, *out_buf;
316 zstd_dctx *ctx;
317 int err;
318
319 if (fw_priv->allocated_size) {
320 out_size = fw_priv->allocated_size;
321 out_buf = fw_priv->data;
322 } else {
323 zstd_frame_header params;
324
325 if (zstd_get_frame_header(params: &params, src: in_buffer, src_size: in_size) ||
326 params.frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN) {
327 dev_dbg(dev, "%s: invalid zstd header\n", __func__);
328 return -EINVAL;
329 }
330 out_size = params.frameContentSize;
331 out_buf = vzalloc(size: out_size);
332 if (!out_buf)
333 return -ENOMEM;
334 }
335
336 workspace_size = zstd_dctx_workspace_bound();
337 workspace = kvzalloc(size: workspace_size, GFP_KERNEL);
338 if (!workspace) {
339 err = -ENOMEM;
340 goto error;
341 }
342
343 ctx = zstd_init_dctx(workspace, workspace_size);
344 if (!ctx) {
345 dev_dbg(dev, "%s: failed to initialize context\n", __func__);
346 err = -EINVAL;
347 goto error;
348 }
349
350 len = zstd_decompress_dctx(dctx: ctx, dst: out_buf, dst_capacity: out_size, src: in_buffer, src_size: in_size);
351 if (zstd_is_error(code: len)) {
352 dev_dbg(dev, "%s: failed to decompress: %d\n", __func__,
353 zstd_get_error_code(len));
354 err = -EINVAL;
355 goto error;
356 }
357
358 if (!fw_priv->allocated_size)
359 fw_priv->data = out_buf;
360 fw_priv->size = len;
361 err = 0;
362
363 error:
364 kvfree(addr: workspace);
365 if (err && !fw_priv->allocated_size)
366 vfree(addr: out_buf);
367 return err;
368}
369#endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */
370
371/*
372 * XZ-compressed firmware support
373 */
374#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
375/* show an error and return the standard error code */
376static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret)
377{
378 if (xz_ret != XZ_STREAM_END) {
379 dev_warn(dev, "xz decompression failed (xz_ret=%d)\n", xz_ret);
380 return xz_ret == XZ_MEM_ERROR ? -ENOMEM : -EINVAL;
381 }
382 return 0;
383}
384
385/* single-shot decompression onto the pre-allocated buffer */
386static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv,
387 size_t in_size, const void *in_buffer)
388{
389 struct xz_dec *xz_dec;
390 struct xz_buf xz_buf;
391 enum xz_ret xz_ret;
392
393 xz_dec = xz_dec_init(mode: XZ_SINGLE, dict_max: (u32)-1);
394 if (!xz_dec)
395 return -ENOMEM;
396
397 xz_buf.in_size = in_size;
398 xz_buf.in = in_buffer;
399 xz_buf.in_pos = 0;
400 xz_buf.out_size = fw_priv->allocated_size;
401 xz_buf.out = fw_priv->data;
402 xz_buf.out_pos = 0;
403
404 xz_ret = xz_dec_run(s: xz_dec, b: &xz_buf);
405 xz_dec_end(s: xz_dec);
406
407 fw_priv->size = xz_buf.out_pos;
408 return fw_decompress_xz_error(dev, xz_ret);
409}
410
411/* decompression on paged buffer and map it */
412static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv,
413 size_t in_size, const void *in_buffer)
414{
415 struct xz_dec *xz_dec;
416 struct xz_buf xz_buf;
417 enum xz_ret xz_ret;
418 struct page *page;
419 int err = 0;
420
421 xz_dec = xz_dec_init(mode: XZ_DYNALLOC, dict_max: (u32)-1);
422 if (!xz_dec)
423 return -ENOMEM;
424
425 xz_buf.in_size = in_size;
426 xz_buf.in = in_buffer;
427 xz_buf.in_pos = 0;
428
429 fw_priv->is_paged_buf = true;
430 fw_priv->size = 0;
431 do {
432 if (fw_grow_paged_buf(fw_priv, pages_needed: fw_priv->nr_pages + 1)) {
433 err = -ENOMEM;
434 goto out;
435 }
436
437 /* decompress onto the new allocated page */
438 page = fw_priv->pages[fw_priv->nr_pages - 1];
439 xz_buf.out = kmap_local_page(page);
440 xz_buf.out_pos = 0;
441 xz_buf.out_size = PAGE_SIZE;
442 xz_ret = xz_dec_run(s: xz_dec, b: &xz_buf);
443 kunmap_local(xz_buf.out);
444 fw_priv->size += xz_buf.out_pos;
445 /* partial decompression means either end or error */
446 if (xz_buf.out_pos != PAGE_SIZE)
447 break;
448 } while (xz_ret == XZ_OK);
449
450 err = fw_decompress_xz_error(dev, xz_ret);
451 if (!err)
452 err = fw_map_paged_buf(fw_priv);
453
454 out:
455 xz_dec_end(s: xz_dec);
456 return err;
457}
458
459static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv,
460 size_t in_size, const void *in_buffer)
461{
462 /* if the buffer is pre-allocated, we can perform in single-shot mode */
463 if (fw_priv->data)
464 return fw_decompress_xz_single(dev, fw_priv, in_size, in_buffer);
465 else
466 return fw_decompress_xz_pages(dev, fw_priv, in_size, in_buffer);
467}
468#endif /* CONFIG_FW_LOADER_COMPRESS_XZ */
469
470/* direct firmware loading support */
471static char fw_path_para[256];
472static const char * const fw_path[] = {
473 fw_path_para,
474 "/lib/firmware/updates/" UTS_RELEASE,
475 "/lib/firmware/updates",
476 "/lib/firmware/" UTS_RELEASE,
477 "/lib/firmware"
478};
479
480/*
481 * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
482 * from kernel command line because firmware_class is generally built in
483 * kernel instead of module.
484 */
485module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
486MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
487
488static int
489fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv,
490 const char *suffix,
491 int (*decompress)(struct device *dev,
492 struct fw_priv *fw_priv,
493 size_t in_size,
494 const void *in_buffer))
495{
496 size_t size;
497 int i, len, maxlen = 0;
498 int rc = -ENOENT;
499 char *path, *nt = NULL;
500 size_t msize = INT_MAX;
501 void *buffer = NULL;
502
503 /* Already populated data member means we're loading into a buffer */
504 if (!decompress && fw_priv->data) {
505 buffer = fw_priv->data;
506 msize = fw_priv->allocated_size;
507 }
508
509 path = __getname();
510 if (!path)
511 return -ENOMEM;
512
513 wait_for_initramfs();
514 for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
515 size_t file_size = 0;
516 size_t *file_size_ptr = NULL;
517
518 /* skip the unset customized path */
519 if (!fw_path[i][0])
520 continue;
521
522 /* strip off \n from customized path */
523 maxlen = strlen(fw_path[i]);
524 if (i == 0) {
525 nt = strchr(fw_path[i], '\n');
526 if (nt)
527 maxlen = nt - fw_path[i];
528 }
529
530 len = snprintf(buf: path, PATH_MAX, fmt: "%.*s/%s%s",
531 maxlen, fw_path[i],
532 fw_priv->fw_name, suffix);
533 if (len >= PATH_MAX) {
534 rc = -ENAMETOOLONG;
535 break;
536 }
537
538 fw_priv->size = 0;
539
540 /*
541 * The total file size is only examined when doing a partial
542 * read; the "full read" case needs to fail if the whole
543 * firmware was not completely loaded.
544 */
545 if ((fw_priv->opt_flags & FW_OPT_PARTIAL) && buffer)
546 file_size_ptr = &file_size;
547
548 /* load firmware files from the mount namespace of init */
549 rc = kernel_read_file_from_path_initns(path, offset: fw_priv->offset,
550 buf: &buffer, buf_size: msize,
551 file_size: file_size_ptr,
552 id: READING_FIRMWARE);
553 if (rc < 0) {
554 if (rc != -ENOENT)
555 dev_warn(device, "loading %s failed with error %d\n",
556 path, rc);
557 else
558 dev_dbg(device, "loading %s failed for no such file or directory.\n",
559 path);
560 continue;
561 }
562 size = rc;
563 rc = 0;
564
565 dev_dbg(device, "Loading firmware from %s\n", path);
566 if (decompress) {
567 dev_dbg(device, "f/w decompressing %s\n",
568 fw_priv->fw_name);
569 rc = decompress(device, fw_priv, size, buffer);
570 /* discard the superfluous original content */
571 vfree(addr: buffer);
572 buffer = NULL;
573 if (rc) {
574 fw_free_paged_buf(fw_priv);
575 continue;
576 }
577 } else {
578 dev_dbg(device, "direct-loading %s\n",
579 fw_priv->fw_name);
580 if (!fw_priv->data)
581 fw_priv->data = buffer;
582 fw_priv->size = size;
583 }
584 fw_state_done(fw_priv);
585 break;
586 }
587 __putname(path);
588
589 return rc;
590}
591
592/* firmware holds the ownership of pages */
593static void firmware_free_data(const struct firmware *fw)
594{
595 /* Loaded directly? */
596 if (!fw->priv) {
597 vfree(addr: fw->data);
598 return;
599 }
600 free_fw_priv(fw_priv: fw->priv);
601}
602
603/* store the pages buffer info firmware from buf */
604static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
605{
606 fw->priv = fw_priv;
607 fw->size = fw_priv->size;
608 fw->data = fw_priv->data;
609
610 pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
611 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
612 (unsigned int)fw_priv->size);
613}
614
615#ifdef CONFIG_FW_CACHE
616static void fw_name_devm_release(struct device *dev, void *res)
617{
618 struct fw_name_devm *fwn = res;
619
620 if (fwn->magic == (unsigned long)&fw_cache)
621 pr_debug("%s: fw_name-%s devm-%p released\n",
622 __func__, fwn->name, res);
623 kfree_const(x: fwn->name);
624}
625
626static int fw_devm_match(struct device *dev, void *res,
627 void *match_data)
628{
629 struct fw_name_devm *fwn = res;
630
631 return (fwn->magic == (unsigned long)&fw_cache) &&
632 !strcmp(fwn->name, match_data);
633}
634
635static struct fw_name_devm *fw_find_devm_name(struct device *dev,
636 const char *name)
637{
638 struct fw_name_devm *fwn;
639
640 fwn = devres_find(dev, release: fw_name_devm_release,
641 match: fw_devm_match, match_data: (void *)name);
642 return fwn;
643}
644
645static bool fw_cache_is_setup(struct device *dev, const char *name)
646{
647 struct fw_name_devm *fwn;
648
649 fwn = fw_find_devm_name(dev, name);
650 if (fwn)
651 return true;
652
653 return false;
654}
655
656/* add firmware name into devres list */
657static int fw_add_devm_name(struct device *dev, const char *name)
658{
659 struct fw_name_devm *fwn;
660
661 if (fw_cache_is_setup(dev, name))
662 return 0;
663
664 fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
665 GFP_KERNEL);
666 if (!fwn)
667 return -ENOMEM;
668 fwn->name = kstrdup_const(s: name, GFP_KERNEL);
669 if (!fwn->name) {
670 devres_free(res: fwn);
671 return -ENOMEM;
672 }
673
674 fwn->magic = (unsigned long)&fw_cache;
675 devres_add(dev, res: fwn);
676
677 return 0;
678}
679#else
680static bool fw_cache_is_setup(struct device *dev, const char *name)
681{
682 return false;
683}
684
685static int fw_add_devm_name(struct device *dev, const char *name)
686{
687 return 0;
688}
689#endif
690
691int assign_fw(struct firmware *fw, struct device *device)
692{
693 struct fw_priv *fw_priv = fw->priv;
694 int ret;
695
696 mutex_lock(&fw_lock);
697 if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
698 mutex_unlock(lock: &fw_lock);
699 return -ENOENT;
700 }
701
702 /*
703 * add firmware name into devres list so that we can auto cache
704 * and uncache firmware for device.
705 *
706 * device may has been deleted already, but the problem
707 * should be fixed in devres or driver core.
708 */
709 /* don't cache firmware handled without uevent */
710 if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
711 !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
712 ret = fw_add_devm_name(dev: device, name: fw_priv->fw_name);
713 if (ret) {
714 mutex_unlock(lock: &fw_lock);
715 return ret;
716 }
717 }
718
719 /*
720 * After caching firmware image is started, let it piggyback
721 * on request firmware.
722 */
723 if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
724 fw_priv->fwc->state == FW_LOADER_START_CACHE)
725 fw_cache_piggyback_on_request(fw_priv);
726
727 /* pass the pages buffer to driver at the last minute */
728 fw_set_page_data(fw_priv, fw);
729 mutex_unlock(lock: &fw_lock);
730 return 0;
731}
732
733/* prepare firmware and firmware_buf structs;
734 * return 0 if a firmware is already assigned, 1 if need to load one,
735 * or a negative error code
736 */
737static int
738_request_firmware_prepare(struct firmware **firmware_p, const char *name,
739 struct device *device, void *dbuf, size_t size,
740 size_t offset, u32 opt_flags)
741{
742 struct firmware *firmware;
743 struct fw_priv *fw_priv;
744 int ret;
745
746 *firmware_p = firmware = kzalloc(size: sizeof(*firmware), GFP_KERNEL);
747 if (!firmware) {
748 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
749 __func__);
750 return -ENOMEM;
751 }
752
753 if (firmware_request_builtin_buf(fw: firmware, name, buf: dbuf, size)) {
754 dev_dbg(device, "using built-in %s\n", name);
755 return 0; /* assigned */
756 }
757
758 ret = alloc_lookup_fw_priv(fw_name: name, fwc: &fw_cache, fw_priv: &fw_priv, dbuf, size,
759 offset, opt_flags);
760
761 /*
762 * bind with 'priv' now to avoid warning in failure path
763 * of requesting firmware.
764 */
765 firmware->priv = fw_priv;
766
767 if (ret > 0) {
768 ret = fw_state_wait(fw_priv);
769 if (!ret) {
770 fw_set_page_data(fw_priv, fw: firmware);
771 return 0; /* assigned */
772 }
773 }
774
775 if (ret < 0)
776 return ret;
777 return 1; /* need to load */
778}
779
780/*
781 * Batched requests need only one wake, we need to do this step last due to the
782 * fallback mechanism. The buf is protected with kref_get(), and it won't be
783 * released until the last user calls release_firmware().
784 *
785 * Failed batched requests are possible as well, in such cases we just share
786 * the struct fw_priv and won't release it until all requests are woken
787 * and have gone through this same path.
788 */
789static void fw_abort_batch_reqs(struct firmware *fw)
790{
791 struct fw_priv *fw_priv;
792
793 /* Loaded directly? */
794 if (!fw || !fw->priv)
795 return;
796
797 fw_priv = fw->priv;
798 mutex_lock(&fw_lock);
799 if (!fw_state_is_aborted(fw_priv))
800 fw_state_aborted(fw_priv);
801 mutex_unlock(lock: &fw_lock);
802}
803
804#if defined(CONFIG_FW_LOADER_DEBUG)
805#include <crypto/hash.h>
806#include <crypto/sha2.h>
807
808static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device)
809{
810 struct shash_desc *shash;
811 struct crypto_shash *alg;
812 u8 *sha256buf;
813 char *outbuf;
814
815 alg = crypto_alloc_shash(alg_name: "sha256", type: 0, mask: 0);
816 if (IS_ERR(ptr: alg))
817 return;
818
819 sha256buf = kmalloc(SHA256_DIGEST_SIZE, GFP_KERNEL);
820 outbuf = kmalloc(SHA256_BLOCK_SIZE + 1, GFP_KERNEL);
821 shash = kmalloc(size: sizeof(*shash) + crypto_shash_descsize(tfm: alg), GFP_KERNEL);
822 if (!sha256buf || !outbuf || !shash)
823 goto out_free;
824
825 shash->tfm = alg;
826
827 if (crypto_shash_digest(desc: shash, data: fw->data, len: fw->size, out: sha256buf) < 0)
828 goto out_shash;
829
830 for (int i = 0; i < SHA256_DIGEST_SIZE; i++)
831 sprintf(buf: &outbuf[i * 2], fmt: "%02x", sha256buf[i]);
832 outbuf[SHA256_BLOCK_SIZE] = 0;
833 dev_dbg(device, "Loaded FW: %s, sha256: %s\n", name, outbuf);
834
835out_shash:
836 crypto_free_shash(tfm: alg);
837out_free:
838 kfree(objp: shash);
839 kfree(objp: outbuf);
840 kfree(objp: sha256buf);
841}
842#else
843static void fw_log_firmware_info(const struct firmware *fw, const char *name,
844 struct device *device)
845{}
846#endif
847
848/* called from request_firmware() and request_firmware_work_func() */
849static int
850_request_firmware(const struct firmware **firmware_p, const char *name,
851 struct device *device, void *buf, size_t size,
852 size_t offset, u32 opt_flags)
853{
854 struct firmware *fw = NULL;
855 struct cred *kern_cred = NULL;
856 const struct cred *old_cred;
857 bool nondirect = false;
858 int ret;
859
860 if (!firmware_p)
861 return -EINVAL;
862
863 if (!name || name[0] == '\0') {
864 ret = -EINVAL;
865 goto out;
866 }
867
868 ret = _request_firmware_prepare(firmware_p: &fw, name, device, dbuf: buf, size,
869 offset, opt_flags);
870 if (ret <= 0) /* error or already assigned */
871 goto out;
872
873 /*
874 * We are about to try to access the firmware file. Because we may have been
875 * called by a driver when serving an unrelated request from userland, we use
876 * the kernel credentials to read the file.
877 */
878 kern_cred = prepare_kernel_cred(&init_task);
879 if (!kern_cred) {
880 ret = -ENOMEM;
881 goto out;
882 }
883 old_cred = override_creds(kern_cred);
884
885 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: "", NULL);
886
887 /* Only full reads can support decompression, platform, and sysfs. */
888 if (!(opt_flags & FW_OPT_PARTIAL))
889 nondirect = true;
890
891#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
892 if (ret == -ENOENT && nondirect)
893 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: ".zst",
894 decompress: fw_decompress_zstd);
895#endif
896#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
897 if (ret == -ENOENT && nondirect)
898 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: ".xz",
899 decompress: fw_decompress_xz);
900#endif
901 if (ret == -ENOENT && nondirect)
902 ret = firmware_fallback_platform(fw_priv: fw->priv);
903
904 if (ret) {
905 if (!(opt_flags & FW_OPT_NO_WARN))
906 dev_warn(device,
907 "Direct firmware load for %s failed with error %d\n",
908 name, ret);
909 if (nondirect)
910 ret = firmware_fallback_sysfs(fw, name, device,
911 opt_flags, ret);
912 } else
913 ret = assign_fw(fw, device);
914
915 revert_creds(old_cred);
916 put_cred(cred: kern_cred);
917
918out:
919 if (ret < 0) {
920 fw_abort_batch_reqs(fw);
921 release_firmware(fw);
922 fw = NULL;
923 } else {
924 fw_log_firmware_info(fw, name, device);
925 }
926
927 *firmware_p = fw;
928 return ret;
929}
930
931/**
932 * request_firmware() - send firmware request and wait for it
933 * @firmware_p: pointer to firmware image
934 * @name: name of firmware file
935 * @device: device for which firmware is being loaded
936 *
937 * @firmware_p will be used to return a firmware image by the name
938 * of @name for device @device.
939 *
940 * Should be called from user context where sleeping is allowed.
941 *
942 * @name will be used as $FIRMWARE in the uevent environment and
943 * should be distinctive enough not to be confused with any other
944 * firmware image for this or any other device.
945 *
946 * Caller must hold the reference count of @device.
947 *
948 * The function can be called safely inside device's suspend and
949 * resume callback.
950 **/
951int
952request_firmware(const struct firmware **firmware_p, const char *name,
953 struct device *device)
954{
955 int ret;
956
957 /* Need to pin this module until return */
958 __module_get(THIS_MODULE);
959 ret = _request_firmware(firmware_p, name, device, NULL, size: 0, offset: 0,
960 opt_flags: FW_OPT_UEVENT);
961 module_put(THIS_MODULE);
962 return ret;
963}
964EXPORT_SYMBOL(request_firmware);
965
966/**
967 * firmware_request_nowarn() - request for an optional fw module
968 * @firmware: pointer to firmware image
969 * @name: name of firmware file
970 * @device: device for which firmware is being loaded
971 *
972 * This function is similar in behaviour to request_firmware(), except it
973 * doesn't produce warning messages when the file is not found. The sysfs
974 * fallback mechanism is enabled if direct filesystem lookup fails. However,
975 * failures to find the firmware file with it are still suppressed. It is
976 * therefore up to the driver to check for the return value of this call and to
977 * decide when to inform the users of errors.
978 **/
979int firmware_request_nowarn(const struct firmware **firmware, const char *name,
980 struct device *device)
981{
982 int ret;
983
984 /* Need to pin this module until return */
985 __module_get(THIS_MODULE);
986 ret = _request_firmware(firmware_p: firmware, name, device, NULL, size: 0, offset: 0,
987 opt_flags: FW_OPT_UEVENT | FW_OPT_NO_WARN);
988 module_put(THIS_MODULE);
989 return ret;
990}
991EXPORT_SYMBOL_GPL(firmware_request_nowarn);
992
993/**
994 * request_firmware_direct() - load firmware directly without usermode helper
995 * @firmware_p: pointer to firmware image
996 * @name: name of firmware file
997 * @device: device for which firmware is being loaded
998 *
999 * This function works pretty much like request_firmware(), but this doesn't
1000 * fall back to usermode helper even if the firmware couldn't be loaded
1001 * directly from fs. Hence it's useful for loading optional firmwares, which
1002 * aren't always present, without extra long timeouts of udev.
1003 **/
1004int request_firmware_direct(const struct firmware **firmware_p,
1005 const char *name, struct device *device)
1006{
1007 int ret;
1008
1009 __module_get(THIS_MODULE);
1010 ret = _request_firmware(firmware_p, name, device, NULL, size: 0, offset: 0,
1011 opt_flags: FW_OPT_UEVENT | FW_OPT_NO_WARN |
1012 FW_OPT_NOFALLBACK_SYSFS);
1013 module_put(THIS_MODULE);
1014 return ret;
1015}
1016EXPORT_SYMBOL_GPL(request_firmware_direct);
1017
1018/**
1019 * firmware_request_platform() - request firmware with platform-fw fallback
1020 * @firmware: pointer to firmware image
1021 * @name: name of firmware file
1022 * @device: device for which firmware is being loaded
1023 *
1024 * This function is similar in behaviour to request_firmware, except that if
1025 * direct filesystem lookup fails, it will fallback to looking for a copy of the
1026 * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
1027 **/
1028int firmware_request_platform(const struct firmware **firmware,
1029 const char *name, struct device *device)
1030{
1031 int ret;
1032
1033 /* Need to pin this module until return */
1034 __module_get(THIS_MODULE);
1035 ret = _request_firmware(firmware_p: firmware, name, device, NULL, size: 0, offset: 0,
1036 opt_flags: FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
1037 module_put(THIS_MODULE);
1038 return ret;
1039}
1040EXPORT_SYMBOL_GPL(firmware_request_platform);
1041
1042/**
1043 * firmware_request_cache() - cache firmware for suspend so resume can use it
1044 * @name: name of firmware file
1045 * @device: device for which firmware should be cached for
1046 *
1047 * There are some devices with an optimization that enables the device to not
1048 * require loading firmware on system reboot. This optimization may still
1049 * require the firmware present on resume from suspend. This routine can be
1050 * used to ensure the firmware is present on resume from suspend in these
1051 * situations. This helper is not compatible with drivers which use
1052 * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
1053 **/
1054int firmware_request_cache(struct device *device, const char *name)
1055{
1056 int ret;
1057
1058 mutex_lock(&fw_lock);
1059 ret = fw_add_devm_name(dev: device, name);
1060 mutex_unlock(lock: &fw_lock);
1061
1062 return ret;
1063}
1064EXPORT_SYMBOL_GPL(firmware_request_cache);
1065
1066/**
1067 * request_firmware_into_buf() - load firmware into a previously allocated buffer
1068 * @firmware_p: pointer to firmware image
1069 * @name: name of firmware file
1070 * @device: device for which firmware is being loaded and DMA region allocated
1071 * @buf: address of buffer to load firmware into
1072 * @size: size of buffer
1073 *
1074 * This function works pretty much like request_firmware(), but it doesn't
1075 * allocate a buffer to hold the firmware data. Instead, the firmware
1076 * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1077 * data member is pointed at @buf.
1078 *
1079 * This function doesn't cache firmware either.
1080 */
1081int
1082request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1083 struct device *device, void *buf, size_t size)
1084{
1085 int ret;
1086
1087 if (fw_cache_is_setup(dev: device, name))
1088 return -EOPNOTSUPP;
1089
1090 __module_get(THIS_MODULE);
1091 ret = _request_firmware(firmware_p, name, device, buf, size, offset: 0,
1092 opt_flags: FW_OPT_UEVENT | FW_OPT_NOCACHE);
1093 module_put(THIS_MODULE);
1094 return ret;
1095}
1096EXPORT_SYMBOL(request_firmware_into_buf);
1097
1098/**
1099 * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1100 * @firmware_p: pointer to firmware image
1101 * @name: name of firmware file
1102 * @device: device for which firmware is being loaded and DMA region allocated
1103 * @buf: address of buffer to load firmware into
1104 * @size: size of buffer
1105 * @offset: offset into file to read
1106 *
1107 * This function works pretty much like request_firmware_into_buf except
1108 * it allows a partial read of the file.
1109 */
1110int
1111request_partial_firmware_into_buf(const struct firmware **firmware_p,
1112 const char *name, struct device *device,
1113 void *buf, size_t size, size_t offset)
1114{
1115 int ret;
1116
1117 if (fw_cache_is_setup(dev: device, name))
1118 return -EOPNOTSUPP;
1119
1120 __module_get(THIS_MODULE);
1121 ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1122 opt_flags: FW_OPT_UEVENT | FW_OPT_NOCACHE |
1123 FW_OPT_PARTIAL);
1124 module_put(THIS_MODULE);
1125 return ret;
1126}
1127EXPORT_SYMBOL(request_partial_firmware_into_buf);
1128
1129/**
1130 * release_firmware() - release the resource associated with a firmware image
1131 * @fw: firmware resource to release
1132 **/
1133void release_firmware(const struct firmware *fw)
1134{
1135 if (fw) {
1136 if (!firmware_is_builtin(fw))
1137 firmware_free_data(fw);
1138 kfree(objp: fw);
1139 }
1140}
1141EXPORT_SYMBOL(release_firmware);
1142
1143/* Async support */
1144struct firmware_work {
1145 struct work_struct work;
1146 struct module *module;
1147 const char *name;
1148 struct device *device;
1149 void *context;
1150 void (*cont)(const struct firmware *fw, void *context);
1151 u32 opt_flags;
1152};
1153
1154static void request_firmware_work_func(struct work_struct *work)
1155{
1156 struct firmware_work *fw_work;
1157 const struct firmware *fw;
1158
1159 fw_work = container_of(work, struct firmware_work, work);
1160
1161 _request_firmware(firmware_p: &fw, name: fw_work->name, device: fw_work->device, NULL, size: 0, offset: 0,
1162 opt_flags: fw_work->opt_flags);
1163 fw_work->cont(fw, fw_work->context);
1164 put_device(dev: fw_work->device); /* taken in request_firmware_nowait() */
1165
1166 module_put(module: fw_work->module);
1167 kfree_const(x: fw_work->name);
1168 kfree(objp: fw_work);
1169}
1170
1171/**
1172 * request_firmware_nowait() - asynchronous version of request_firmware
1173 * @module: module requesting the firmware
1174 * @uevent: sends uevent to copy the firmware image if this flag
1175 * is non-zero else the firmware copy must be done manually.
1176 * @name: name of firmware file
1177 * @device: device for which firmware is being loaded
1178 * @gfp: allocation flags
1179 * @context: will be passed over to @cont, and
1180 * @fw may be %NULL if firmware request fails.
1181 * @cont: function will be called asynchronously when the firmware
1182 * request is over.
1183 *
1184 * Caller must hold the reference count of @device.
1185 *
1186 * Asynchronous variant of request_firmware() for user contexts:
1187 * - sleep for as small periods as possible since it may
1188 * increase kernel boot time of built-in device drivers
1189 * requesting firmware in their ->probe() methods, if
1190 * @gfp is GFP_KERNEL.
1191 *
1192 * - can't sleep at all if @gfp is GFP_ATOMIC.
1193 **/
1194int
1195request_firmware_nowait(
1196 struct module *module, bool uevent,
1197 const char *name, struct device *device, gfp_t gfp, void *context,
1198 void (*cont)(const struct firmware *fw, void *context))
1199{
1200 struct firmware_work *fw_work;
1201
1202 fw_work = kzalloc(size: sizeof(struct firmware_work), flags: gfp);
1203 if (!fw_work)
1204 return -ENOMEM;
1205
1206 fw_work->module = module;
1207 fw_work->name = kstrdup_const(s: name, gfp);
1208 if (!fw_work->name) {
1209 kfree(objp: fw_work);
1210 return -ENOMEM;
1211 }
1212 fw_work->device = device;
1213 fw_work->context = context;
1214 fw_work->cont = cont;
1215 fw_work->opt_flags = FW_OPT_NOWAIT |
1216 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1217
1218 if (!uevent && fw_cache_is_setup(dev: device, name)) {
1219 kfree_const(x: fw_work->name);
1220 kfree(objp: fw_work);
1221 return -EOPNOTSUPP;
1222 }
1223
1224 if (!try_module_get(module)) {
1225 kfree_const(x: fw_work->name);
1226 kfree(objp: fw_work);
1227 return -EFAULT;
1228 }
1229
1230 get_device(dev: fw_work->device);
1231 INIT_WORK(&fw_work->work, request_firmware_work_func);
1232 schedule_work(work: &fw_work->work);
1233 return 0;
1234}
1235EXPORT_SYMBOL(request_firmware_nowait);
1236
1237#ifdef CONFIG_FW_CACHE
1238static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1239
1240/**
1241 * cache_firmware() - cache one firmware image in kernel memory space
1242 * @fw_name: the firmware image name
1243 *
1244 * Cache firmware in kernel memory so that drivers can use it when
1245 * system isn't ready for them to request firmware image from userspace.
1246 * Once it returns successfully, driver can use request_firmware or its
1247 * nowait version to get the cached firmware without any interacting
1248 * with userspace
1249 *
1250 * Return 0 if the firmware image has been cached successfully
1251 * Return !0 otherwise
1252 *
1253 */
1254static int cache_firmware(const char *fw_name)
1255{
1256 int ret;
1257 const struct firmware *fw;
1258
1259 pr_debug("%s: %s\n", __func__, fw_name);
1260
1261 ret = request_firmware(&fw, fw_name, NULL);
1262 if (!ret)
1263 kfree(objp: fw);
1264
1265 pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1266
1267 return ret;
1268}
1269
1270static struct fw_priv *lookup_fw_priv(const char *fw_name)
1271{
1272 struct fw_priv *tmp;
1273 struct firmware_cache *fwc = &fw_cache;
1274
1275 spin_lock(lock: &fwc->lock);
1276 tmp = __lookup_fw_priv(fw_name);
1277 spin_unlock(lock: &fwc->lock);
1278
1279 return tmp;
1280}
1281
1282/**
1283 * uncache_firmware() - remove one cached firmware image
1284 * @fw_name: the firmware image name
1285 *
1286 * Uncache one firmware image which has been cached successfully
1287 * before.
1288 *
1289 * Return 0 if the firmware cache has been removed successfully
1290 * Return !0 otherwise
1291 *
1292 */
1293static int uncache_firmware(const char *fw_name)
1294{
1295 struct fw_priv *fw_priv;
1296 struct firmware fw;
1297
1298 pr_debug("%s: %s\n", __func__, fw_name);
1299
1300 if (firmware_request_builtin(fw: &fw, name: fw_name))
1301 return 0;
1302
1303 fw_priv = lookup_fw_priv(fw_name);
1304 if (fw_priv) {
1305 free_fw_priv(fw_priv);
1306 return 0;
1307 }
1308
1309 return -EINVAL;
1310}
1311
1312static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1313{
1314 struct fw_cache_entry *fce;
1315
1316 fce = kzalloc(size: sizeof(*fce), GFP_ATOMIC);
1317 if (!fce)
1318 goto exit;
1319
1320 fce->name = kstrdup_const(s: name, GFP_ATOMIC);
1321 if (!fce->name) {
1322 kfree(objp: fce);
1323 fce = NULL;
1324 goto exit;
1325 }
1326exit:
1327 return fce;
1328}
1329
1330static int __fw_entry_found(const char *name)
1331{
1332 struct firmware_cache *fwc = &fw_cache;
1333 struct fw_cache_entry *fce;
1334
1335 list_for_each_entry(fce, &fwc->fw_names, list) {
1336 if (!strcmp(fce->name, name))
1337 return 1;
1338 }
1339 return 0;
1340}
1341
1342static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1343{
1344 const char *name = fw_priv->fw_name;
1345 struct firmware_cache *fwc = fw_priv->fwc;
1346 struct fw_cache_entry *fce;
1347
1348 spin_lock(lock: &fwc->name_lock);
1349 if (__fw_entry_found(name))
1350 goto found;
1351
1352 fce = alloc_fw_cache_entry(name);
1353 if (fce) {
1354 list_add(new: &fce->list, head: &fwc->fw_names);
1355 kref_get(kref: &fw_priv->ref);
1356 pr_debug("%s: fw: %s\n", __func__, name);
1357 }
1358found:
1359 spin_unlock(lock: &fwc->name_lock);
1360}
1361
1362static void free_fw_cache_entry(struct fw_cache_entry *fce)
1363{
1364 kfree_const(x: fce->name);
1365 kfree(objp: fce);
1366}
1367
1368static void __async_dev_cache_fw_image(void *fw_entry,
1369 async_cookie_t cookie)
1370{
1371 struct fw_cache_entry *fce = fw_entry;
1372 struct firmware_cache *fwc = &fw_cache;
1373 int ret;
1374
1375 ret = cache_firmware(fw_name: fce->name);
1376 if (ret) {
1377 spin_lock(lock: &fwc->name_lock);
1378 list_del(entry: &fce->list);
1379 spin_unlock(lock: &fwc->name_lock);
1380
1381 free_fw_cache_entry(fce);
1382 }
1383}
1384
1385/* called with dev->devres_lock held */
1386static void dev_create_fw_entry(struct device *dev, void *res,
1387 void *data)
1388{
1389 struct fw_name_devm *fwn = res;
1390 const char *fw_name = fwn->name;
1391 struct list_head *head = data;
1392 struct fw_cache_entry *fce;
1393
1394 fce = alloc_fw_cache_entry(name: fw_name);
1395 if (fce)
1396 list_add(new: &fce->list, head);
1397}
1398
1399static int devm_name_match(struct device *dev, void *res,
1400 void *match_data)
1401{
1402 struct fw_name_devm *fwn = res;
1403 return (fwn->magic == (unsigned long)match_data);
1404}
1405
1406static void dev_cache_fw_image(struct device *dev, void *data)
1407{
1408 LIST_HEAD(todo);
1409 struct fw_cache_entry *fce;
1410 struct fw_cache_entry *fce_next;
1411 struct firmware_cache *fwc = &fw_cache;
1412
1413 devres_for_each_res(dev, release: fw_name_devm_release,
1414 match: devm_name_match, match_data: &fw_cache,
1415 fn: dev_create_fw_entry, data: &todo);
1416
1417 list_for_each_entry_safe(fce, fce_next, &todo, list) {
1418 list_del(entry: &fce->list);
1419
1420 spin_lock(lock: &fwc->name_lock);
1421 /* only one cache entry for one firmware */
1422 if (!__fw_entry_found(name: fce->name)) {
1423 list_add(new: &fce->list, head: &fwc->fw_names);
1424 } else {
1425 free_fw_cache_entry(fce);
1426 fce = NULL;
1427 }
1428 spin_unlock(lock: &fwc->name_lock);
1429
1430 if (fce)
1431 async_schedule_domain(func: __async_dev_cache_fw_image,
1432 data: (void *)fce,
1433 domain: &fw_cache_domain);
1434 }
1435}
1436
1437static void __device_uncache_fw_images(void)
1438{
1439 struct firmware_cache *fwc = &fw_cache;
1440 struct fw_cache_entry *fce;
1441
1442 spin_lock(lock: &fwc->name_lock);
1443 while (!list_empty(head: &fwc->fw_names)) {
1444 fce = list_entry(fwc->fw_names.next,
1445 struct fw_cache_entry, list);
1446 list_del(entry: &fce->list);
1447 spin_unlock(lock: &fwc->name_lock);
1448
1449 uncache_firmware(fw_name: fce->name);
1450 free_fw_cache_entry(fce);
1451
1452 spin_lock(lock: &fwc->name_lock);
1453 }
1454 spin_unlock(lock: &fwc->name_lock);
1455}
1456
1457/**
1458 * device_cache_fw_images() - cache devices' firmware
1459 *
1460 * If one device called request_firmware or its nowait version
1461 * successfully before, the firmware names are recored into the
1462 * device's devres link list, so device_cache_fw_images can call
1463 * cache_firmware() to cache these firmwares for the device,
1464 * then the device driver can load its firmwares easily at
1465 * time when system is not ready to complete loading firmware.
1466 */
1467static void device_cache_fw_images(void)
1468{
1469 struct firmware_cache *fwc = &fw_cache;
1470 DEFINE_WAIT(wait);
1471
1472 pr_debug("%s\n", __func__);
1473
1474 /* cancel uncache work */
1475 cancel_delayed_work_sync(dwork: &fwc->work);
1476
1477 fw_fallback_set_cache_timeout();
1478
1479 mutex_lock(&fw_lock);
1480 fwc->state = FW_LOADER_START_CACHE;
1481 dpm_for_each_dev(NULL, fn: dev_cache_fw_image);
1482 mutex_unlock(lock: &fw_lock);
1483
1484 /* wait for completion of caching firmware for all devices */
1485 async_synchronize_full_domain(domain: &fw_cache_domain);
1486
1487 fw_fallback_set_default_timeout();
1488}
1489
1490/**
1491 * device_uncache_fw_images() - uncache devices' firmware
1492 *
1493 * uncache all firmwares which have been cached successfully
1494 * by device_uncache_fw_images earlier
1495 */
1496static void device_uncache_fw_images(void)
1497{
1498 pr_debug("%s\n", __func__);
1499 __device_uncache_fw_images();
1500}
1501
1502static void device_uncache_fw_images_work(struct work_struct *work)
1503{
1504 device_uncache_fw_images();
1505}
1506
1507/**
1508 * device_uncache_fw_images_delay() - uncache devices firmwares
1509 * @delay: number of milliseconds to delay uncache device firmwares
1510 *
1511 * uncache all devices's firmwares which has been cached successfully
1512 * by device_cache_fw_images after @delay milliseconds.
1513 */
1514static void device_uncache_fw_images_delay(unsigned long delay)
1515{
1516 queue_delayed_work(wq: system_power_efficient_wq, dwork: &fw_cache.work,
1517 delay: msecs_to_jiffies(m: delay));
1518}
1519
1520static int fw_pm_notify(struct notifier_block *notify_block,
1521 unsigned long mode, void *unused)
1522{
1523 switch (mode) {
1524 case PM_HIBERNATION_PREPARE:
1525 case PM_SUSPEND_PREPARE:
1526 case PM_RESTORE_PREPARE:
1527 /*
1528 * Here, kill pending fallback requests will only kill
1529 * non-uevent firmware request to avoid stalling suspend.
1530 */
1531 kill_pending_fw_fallback_reqs(kill_all: false);
1532 device_cache_fw_images();
1533 break;
1534
1535 case PM_POST_SUSPEND:
1536 case PM_POST_HIBERNATION:
1537 case PM_POST_RESTORE:
1538 /*
1539 * In case that system sleep failed and syscore_suspend is
1540 * not called.
1541 */
1542 mutex_lock(&fw_lock);
1543 fw_cache.state = FW_LOADER_NO_CACHE;
1544 mutex_unlock(lock: &fw_lock);
1545
1546 device_uncache_fw_images_delay(delay: 10 * MSEC_PER_SEC);
1547 break;
1548 }
1549
1550 return 0;
1551}
1552
1553/* stop caching firmware once syscore_suspend is reached */
1554static int fw_suspend(void)
1555{
1556 fw_cache.state = FW_LOADER_NO_CACHE;
1557 return 0;
1558}
1559
1560static struct syscore_ops fw_syscore_ops = {
1561 .suspend = fw_suspend,
1562};
1563
1564static int __init register_fw_pm_ops(void)
1565{
1566 int ret;
1567
1568 spin_lock_init(&fw_cache.name_lock);
1569 INIT_LIST_HEAD(list: &fw_cache.fw_names);
1570
1571 INIT_DELAYED_WORK(&fw_cache.work,
1572 device_uncache_fw_images_work);
1573
1574 fw_cache.pm_notify.notifier_call = fw_pm_notify;
1575 ret = register_pm_notifier(nb: &fw_cache.pm_notify);
1576 if (ret)
1577 return ret;
1578
1579 register_syscore_ops(ops: &fw_syscore_ops);
1580
1581 return ret;
1582}
1583
1584static inline void unregister_fw_pm_ops(void)
1585{
1586 unregister_syscore_ops(ops: &fw_syscore_ops);
1587 unregister_pm_notifier(nb: &fw_cache.pm_notify);
1588}
1589#else
1590static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1591{
1592}
1593static inline int register_fw_pm_ops(void)
1594{
1595 return 0;
1596}
1597static inline void unregister_fw_pm_ops(void)
1598{
1599}
1600#endif
1601
1602static void __init fw_cache_init(void)
1603{
1604 spin_lock_init(&fw_cache.lock);
1605 INIT_LIST_HEAD(list: &fw_cache.head);
1606 fw_cache.state = FW_LOADER_NO_CACHE;
1607}
1608
1609static int fw_shutdown_notify(struct notifier_block *unused1,
1610 unsigned long unused2, void *unused3)
1611{
1612 /*
1613 * Kill all pending fallback requests to avoid both stalling shutdown,
1614 * and avoid a deadlock with the usermode_lock.
1615 */
1616 kill_pending_fw_fallback_reqs(kill_all: true);
1617
1618 return NOTIFY_DONE;
1619}
1620
1621static struct notifier_block fw_shutdown_nb = {
1622 .notifier_call = fw_shutdown_notify,
1623};
1624
1625static int __init firmware_class_init(void)
1626{
1627 int ret;
1628
1629 /* No need to unfold these on exit */
1630 fw_cache_init();
1631
1632 ret = register_fw_pm_ops();
1633 if (ret)
1634 return ret;
1635
1636 ret = register_reboot_notifier(&fw_shutdown_nb);
1637 if (ret)
1638 goto out;
1639
1640 return register_sysfs_loader();
1641
1642out:
1643 unregister_fw_pm_ops();
1644 return ret;
1645}
1646
1647static void __exit firmware_class_exit(void)
1648{
1649 unregister_fw_pm_ops();
1650 unregister_reboot_notifier(&fw_shutdown_nb);
1651 unregister_sysfs_loader();
1652}
1653
1654fs_initcall(firmware_class_init);
1655module_exit(firmware_class_exit);
1656

source code of linux/drivers/base/firmware_loader/main.c