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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;
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(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(new_array_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(out_size);
332 if (!out_buf)
333 return -ENOMEM;
334 }
335
336 workspace_size = zstd_dctx_workspace_bound();
337 workspace = kvzalloc(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 (!(fw_priv->opt_flags & FW_OPT_NO_WARN)) {
555 if (rc != -ENOENT)
556 dev_warn(device,
557 "loading %s failed with error %d\n",
558 path, rc);
559 else
560 dev_dbg(device,
561 "loading %s failed for no such file or directory.\n",
562 path);
563 }
564 continue;
565 }
566 size = rc;
567 rc = 0;
568
569 dev_dbg(device, "Loading firmware from %s\n", path);
570 if (decompress) {
571 dev_dbg(device, "f/w decompressing %s\n",
572 fw_priv->fw_name);
573 rc = decompress(device, fw_priv, size, buffer);
574 /* discard the superfluous original content */
575 vfree(addr: buffer);
576 buffer = NULL;
577 if (rc) {
578 fw_free_paged_buf(fw_priv);
579 continue;
580 }
581 } else {
582 dev_dbg(device, "direct-loading %s\n",
583 fw_priv->fw_name);
584 if (!fw_priv->data)
585 fw_priv->data = buffer;
586 fw_priv->size = size;
587 }
588 fw_state_done(fw_priv);
589 break;
590 }
591 __putname(path);
592
593 return rc;
594}
595
596/* firmware holds the ownership of pages */
597static void firmware_free_data(const struct firmware *fw)
598{
599 /* Loaded directly? */
600 if (!fw->priv) {
601 vfree(addr: fw->data);
602 return;
603 }
604 free_fw_priv(fw_priv: fw->priv);
605}
606
607/* store the pages buffer info firmware from buf */
608static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw)
609{
610 fw->priv = fw_priv;
611 fw->size = fw_priv->size;
612 fw->data = fw_priv->data;
613
614 pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n",
615 __func__, fw_priv->fw_name, fw_priv, fw_priv->data,
616 (unsigned int)fw_priv->size);
617}
618
619#ifdef CONFIG_FW_CACHE
620static void fw_name_devm_release(struct device *dev, void *res)
621{
622 struct fw_name_devm *fwn = res;
623
624 if (fwn->magic == (unsigned long)&fw_cache)
625 pr_debug("%s: fw_name-%s devm-%p released\n",
626 __func__, fwn->name, res);
627 kfree_const(x: fwn->name);
628}
629
630static int fw_devm_match(struct device *dev, void *res,
631 void *match_data)
632{
633 struct fw_name_devm *fwn = res;
634
635 return (fwn->magic == (unsigned long)&fw_cache) &&
636 !strcmp(fwn->name, match_data);
637}
638
639static struct fw_name_devm *fw_find_devm_name(struct device *dev,
640 const char *name)
641{
642 struct fw_name_devm *fwn;
643
644 fwn = devres_find(dev, release: fw_name_devm_release,
645 match: fw_devm_match, match_data: (void *)name);
646 return fwn;
647}
648
649static bool fw_cache_is_setup(struct device *dev, const char *name)
650{
651 struct fw_name_devm *fwn;
652
653 fwn = fw_find_devm_name(dev, name);
654 if (fwn)
655 return true;
656
657 return false;
658}
659
660/* add firmware name into devres list */
661static int fw_add_devm_name(struct device *dev, const char *name)
662{
663 struct fw_name_devm *fwn;
664
665 if (fw_cache_is_setup(dev, name))
666 return 0;
667
668 fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
669 GFP_KERNEL);
670 if (!fwn)
671 return -ENOMEM;
672 fwn->name = kstrdup_const(s: name, GFP_KERNEL);
673 if (!fwn->name) {
674 devres_free(res: fwn);
675 return -ENOMEM;
676 }
677
678 fwn->magic = (unsigned long)&fw_cache;
679 devres_add(dev, res: fwn);
680
681 return 0;
682}
683#else
684static bool fw_cache_is_setup(struct device *dev, const char *name)
685{
686 return false;
687}
688
689static int fw_add_devm_name(struct device *dev, const char *name)
690{
691 return 0;
692}
693#endif
694
695int assign_fw(struct firmware *fw, struct device *device)
696{
697 struct fw_priv *fw_priv = fw->priv;
698 int ret;
699
700 mutex_lock(&fw_lock);
701 if (!fw_priv->size || fw_state_is_aborted(fw_priv)) {
702 mutex_unlock(lock: &fw_lock);
703 return -ENOENT;
704 }
705
706 /*
707 * add firmware name into devres list so that we can auto cache
708 * and uncache firmware for device.
709 *
710 * device may has been deleted already, but the problem
711 * should be fixed in devres or driver core.
712 */
713 /* don't cache firmware handled without uevent */
714 if (device && (fw_priv->opt_flags & FW_OPT_UEVENT) &&
715 !(fw_priv->opt_flags & FW_OPT_NOCACHE)) {
716 ret = fw_add_devm_name(dev: device, name: fw_priv->fw_name);
717 if (ret) {
718 mutex_unlock(lock: &fw_lock);
719 return ret;
720 }
721 }
722
723 /*
724 * After caching firmware image is started, let it piggyback
725 * on request firmware.
726 */
727 if (!(fw_priv->opt_flags & FW_OPT_NOCACHE) &&
728 fw_priv->fwc->state == FW_LOADER_START_CACHE)
729 fw_cache_piggyback_on_request(fw_priv);
730
731 /* pass the pages buffer to driver at the last minute */
732 fw_set_page_data(fw_priv, fw);
733 mutex_unlock(lock: &fw_lock);
734 return 0;
735}
736
737/* prepare firmware and firmware_buf structs;
738 * return 0 if a firmware is already assigned, 1 if need to load one,
739 * or a negative error code
740 */
741static int
742_request_firmware_prepare(struct firmware **firmware_p, const char *name,
743 struct device *device, void *dbuf, size_t size,
744 size_t offset, u32 opt_flags)
745{
746 struct firmware *firmware;
747 struct fw_priv *fw_priv;
748 int ret;
749
750 *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
751 if (!firmware) {
752 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
753 __func__);
754 return -ENOMEM;
755 }
756
757 if (firmware_request_builtin_buf(fw: firmware, name, buf: dbuf, size)) {
758 dev_dbg(device, "using built-in %s\n", name);
759 return 0; /* assigned */
760 }
761
762 ret = alloc_lookup_fw_priv(fw_name: name, fwc: &fw_cache, fw_priv: &fw_priv, dbuf, size,
763 offset, opt_flags);
764
765 /*
766 * bind with 'priv' now to avoid warning in failure path
767 * of requesting firmware.
768 */
769 firmware->priv = fw_priv;
770
771 if (ret > 0) {
772 ret = fw_state_wait(fw_priv);
773 if (!ret) {
774 fw_set_page_data(fw_priv, fw: firmware);
775 return 0; /* assigned */
776 }
777 }
778
779 if (ret < 0)
780 return ret;
781 return 1; /* need to load */
782}
783
784/*
785 * Batched requests need only one wake, we need to do this step last due to the
786 * fallback mechanism. The buf is protected with kref_get(), and it won't be
787 * released until the last user calls release_firmware().
788 *
789 * Failed batched requests are possible as well, in such cases we just share
790 * the struct fw_priv and won't release it until all requests are woken
791 * and have gone through this same path.
792 */
793static void fw_abort_batch_reqs(struct firmware *fw)
794{
795 struct fw_priv *fw_priv;
796
797 /* Loaded directly? */
798 if (!fw || !fw->priv)
799 return;
800
801 fw_priv = fw->priv;
802 mutex_lock(&fw_lock);
803 if (!fw_state_is_aborted(fw_priv))
804 fw_state_aborted(fw_priv);
805 mutex_unlock(lock: &fw_lock);
806}
807
808#if defined(CONFIG_FW_LOADER_DEBUG)
809#include <crypto/sha2.h>
810
811static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device)
812{
813 u8 digest[SHA256_DIGEST_SIZE];
814
815 sha256(data: fw->data, len: fw->size, out: digest);
816 dev_dbg(device, "Loaded FW: %s, sha256: %*phN\n",
817 name, SHA256_DIGEST_SIZE, digest);
818}
819#else
820static void fw_log_firmware_info(const struct firmware *fw, const char *name,
821 struct device *device)
822{}
823#endif
824
825/* called from request_firmware() and request_firmware_work_func() */
826static int
827_request_firmware(const struct firmware **firmware_p, const char *name,
828 struct device *device, void *buf, size_t size,
829 size_t offset, u32 opt_flags)
830{
831 struct firmware *fw = NULL;
832 bool nondirect = false;
833 int ret;
834
835 if (!firmware_p)
836 return -EINVAL;
837
838 if (!name || name[0] == '\0') {
839 ret = -EINVAL;
840 goto out;
841 }
842
843
844 /*
845 * Reject firmware file names with ".." path components.
846 * There are drivers that construct firmware file names from
847 * device-supplied strings, and we don't want some device to be
848 * able to tell us "I would like to be sent my firmware from
849 * ../../../etc/shadow, please".
850 *
851 * This intentionally only looks at the firmware name, not at
852 * the firmware base directory or at symlink contents.
853 */
854 if (name_contains_dotdot(name)) {
855 dev_warn(device,
856 "Firmware load for '%s' refused, path contains '..' component\n",
857 name);
858 ret = -EINVAL;
859 goto out;
860 }
861
862 ret = _request_firmware_prepare(firmware_p: &fw, name, device, dbuf: buf, size,
863 offset, opt_flags);
864 if (ret <= 0) /* error or already assigned */
865 goto out;
866
867 /*
868 * We are about to try to access the firmware file. Because we may have been
869 * called by a driver when serving an unrelated request from userland, we use
870 * the kernel credentials to read the file.
871 */
872 scoped_with_kernel_creds() {
873 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: "", NULL);
874
875 /* Only full reads can support decompression, platform, and sysfs. */
876 if (!(opt_flags & FW_OPT_PARTIAL))
877 nondirect = true;
878
879#ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD
880 if (ret == -ENOENT && nondirect)
881 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: ".zst",
882 decompress: fw_decompress_zstd);
883#endif
884#ifdef CONFIG_FW_LOADER_COMPRESS_XZ
885 if (ret == -ENOENT && nondirect)
886 ret = fw_get_filesystem_firmware(device, fw_priv: fw->priv, suffix: ".xz",
887 decompress: fw_decompress_xz);
888#endif
889 if (ret == -ENOENT && nondirect)
890 ret = firmware_fallback_platform(fw_priv: fw->priv);
891
892 if (ret) {
893 if (!(opt_flags & FW_OPT_NO_WARN))
894 dev_warn(device,
895 "Direct firmware load for %s failed with error %d\n",
896 name, ret);
897 if (nondirect)
898 ret = firmware_fallback_sysfs(fw, name, device,
899 opt_flags, ret);
900 } else {
901 ret = assign_fw(fw, device);
902 }
903 }
904
905out:
906 if (ret < 0) {
907 fw_abort_batch_reqs(fw);
908 release_firmware(fw);
909 fw = NULL;
910 } else {
911 fw_log_firmware_info(fw, name, device);
912 }
913
914 *firmware_p = fw;
915 return ret;
916}
917
918/**
919 * request_firmware() - send firmware request and wait for it
920 * @firmware_p: pointer to firmware image
921 * @name: name of firmware file
922 * @device: device for which firmware is being loaded
923 *
924 * @firmware_p will be used to return a firmware image by the name
925 * of @name for device @device.
926 *
927 * Should be called from user context where sleeping is allowed.
928 *
929 * @name will be used as $FIRMWARE in the uevent environment and
930 * should be distinctive enough not to be confused with any other
931 * firmware image for this or any other device.
932 * It must not contain any ".." path components - "foo/bar..bin" is
933 * allowed, but "foo/../bar.bin" is not.
934 *
935 * Caller must hold the reference count of @device.
936 *
937 * The function can be called safely inside device's suspend and
938 * resume callback.
939 **/
940int
941request_firmware(const struct firmware **firmware_p, const char *name,
942 struct device *device)
943{
944 int ret;
945
946 /* Need to pin this module until return */
947 __module_get(THIS_MODULE);
948 ret = _request_firmware(firmware_p, name, device, NULL, size: 0, offset: 0,
949 opt_flags: FW_OPT_UEVENT);
950 module_put(THIS_MODULE);
951 return ret;
952}
953EXPORT_SYMBOL(request_firmware);
954
955/**
956 * firmware_request_nowarn() - request for an optional fw module
957 * @firmware: pointer to firmware image
958 * @name: name of firmware file
959 * @device: device for which firmware is being loaded
960 *
961 * This function is similar in behaviour to request_firmware(), except it
962 * doesn't produce warning messages when the file is not found. The sysfs
963 * fallback mechanism is enabled if direct filesystem lookup fails. However,
964 * failures to find the firmware file with it are still suppressed. It is
965 * therefore up to the driver to check for the return value of this call and to
966 * decide when to inform the users of errors.
967 **/
968int firmware_request_nowarn(const struct firmware **firmware, const char *name,
969 struct device *device)
970{
971 int ret;
972
973 /* Need to pin this module until return */
974 __module_get(THIS_MODULE);
975 ret = _request_firmware(firmware_p: firmware, name, device, NULL, size: 0, offset: 0,
976 opt_flags: FW_OPT_UEVENT | FW_OPT_NO_WARN);
977 module_put(THIS_MODULE);
978 return ret;
979}
980EXPORT_SYMBOL_GPL(firmware_request_nowarn);
981
982/**
983 * request_firmware_direct() - load firmware directly without usermode helper
984 * @firmware_p: pointer to firmware image
985 * @name: name of firmware file
986 * @device: device for which firmware is being loaded
987 *
988 * This function works pretty much like request_firmware(), but this doesn't
989 * fall back to usermode helper even if the firmware couldn't be loaded
990 * directly from fs. Hence it's useful for loading optional firmwares, which
991 * aren't always present, without extra long timeouts of udev.
992 **/
993int request_firmware_direct(const struct firmware **firmware_p,
994 const char *name, struct device *device)
995{
996 int ret;
997
998 __module_get(THIS_MODULE);
999 ret = _request_firmware(firmware_p, name, device, NULL, size: 0, offset: 0,
1000 opt_flags: FW_OPT_UEVENT | FW_OPT_NO_WARN |
1001 FW_OPT_NOFALLBACK_SYSFS);
1002 module_put(THIS_MODULE);
1003 return ret;
1004}
1005EXPORT_SYMBOL_GPL(request_firmware_direct);
1006
1007/**
1008 * firmware_request_platform() - request firmware with platform-fw fallback
1009 * @firmware: pointer to firmware image
1010 * @name: name of firmware file
1011 * @device: device for which firmware is being loaded
1012 *
1013 * This function is similar in behaviour to request_firmware, except that if
1014 * direct filesystem lookup fails, it will fallback to looking for a copy of the
1015 * requested firmware embedded in the platform's main (e.g. UEFI) firmware.
1016 **/
1017int firmware_request_platform(const struct firmware **firmware,
1018 const char *name, struct device *device)
1019{
1020 int ret;
1021
1022 /* Need to pin this module until return */
1023 __module_get(THIS_MODULE);
1024 ret = _request_firmware(firmware_p: firmware, name, device, NULL, size: 0, offset: 0,
1025 opt_flags: FW_OPT_UEVENT | FW_OPT_FALLBACK_PLATFORM);
1026 module_put(THIS_MODULE);
1027 return ret;
1028}
1029EXPORT_SYMBOL_GPL(firmware_request_platform);
1030
1031/**
1032 * firmware_request_cache() - cache firmware for suspend so resume can use it
1033 * @device: device for which firmware should be cached for
1034 * @name: name of firmware file
1035 *
1036 * There are some devices with an optimization that enables the device to not
1037 * require loading firmware on system reboot. This optimization may still
1038 * require the firmware present on resume from suspend. This routine can be
1039 * used to ensure the firmware is present on resume from suspend in these
1040 * situations. This helper is not compatible with drivers which use
1041 * request_firmware_into_buf() or request_firmware_nowait() with no uevent set.
1042 **/
1043int firmware_request_cache(struct device *device, const char *name)
1044{
1045 int ret;
1046
1047 mutex_lock(&fw_lock);
1048 ret = fw_add_devm_name(dev: device, name);
1049 mutex_unlock(lock: &fw_lock);
1050
1051 return ret;
1052}
1053EXPORT_SYMBOL_GPL(firmware_request_cache);
1054
1055/**
1056 * request_firmware_into_buf() - load firmware into a previously allocated buffer
1057 * @firmware_p: pointer to firmware image
1058 * @name: name of firmware file
1059 * @device: device for which firmware is being loaded and DMA region allocated
1060 * @buf: address of buffer to load firmware into
1061 * @size: size of buffer
1062 *
1063 * This function works pretty much like request_firmware(), but it doesn't
1064 * allocate a buffer to hold the firmware data. Instead, the firmware
1065 * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1066 * data member is pointed at @buf.
1067 *
1068 * This function doesn't cache firmware either.
1069 */
1070int
1071request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1072 struct device *device, void *buf, size_t size)
1073{
1074 int ret;
1075
1076 if (fw_cache_is_setup(dev: device, name))
1077 return -EOPNOTSUPP;
1078
1079 __module_get(THIS_MODULE);
1080 ret = _request_firmware(firmware_p, name, device, buf, size, offset: 0,
1081 opt_flags: FW_OPT_UEVENT | FW_OPT_NOCACHE);
1082 module_put(THIS_MODULE);
1083 return ret;
1084}
1085EXPORT_SYMBOL(request_firmware_into_buf);
1086
1087/**
1088 * request_partial_firmware_into_buf() - load partial firmware into a previously allocated buffer
1089 * @firmware_p: pointer to firmware image
1090 * @name: name of firmware file
1091 * @device: device for which firmware is being loaded and DMA region allocated
1092 * @buf: address of buffer to load firmware into
1093 * @size: size of buffer
1094 * @offset: offset into file to read
1095 *
1096 * This function works pretty much like request_firmware_into_buf except
1097 * it allows a partial read of the file.
1098 */
1099int
1100request_partial_firmware_into_buf(const struct firmware **firmware_p,
1101 const char *name, struct device *device,
1102 void *buf, size_t size, size_t offset)
1103{
1104 int ret;
1105
1106 if (fw_cache_is_setup(dev: device, name))
1107 return -EOPNOTSUPP;
1108
1109 __module_get(THIS_MODULE);
1110 ret = _request_firmware(firmware_p, name, device, buf, size, offset,
1111 opt_flags: FW_OPT_UEVENT | FW_OPT_NOCACHE |
1112 FW_OPT_PARTIAL);
1113 module_put(THIS_MODULE);
1114 return ret;
1115}
1116EXPORT_SYMBOL(request_partial_firmware_into_buf);
1117
1118/**
1119 * release_firmware() - release the resource associated with a firmware image
1120 * @fw: firmware resource to release
1121 **/
1122void release_firmware(const struct firmware *fw)
1123{
1124 if (fw) {
1125 if (!firmware_is_builtin(fw))
1126 firmware_free_data(fw);
1127 kfree(objp: fw);
1128 }
1129}
1130EXPORT_SYMBOL(release_firmware);
1131
1132/* Async support */
1133struct firmware_work {
1134 struct work_struct work;
1135 struct module *module;
1136 const char *name;
1137 struct device *device;
1138 void *context;
1139 void (*cont)(const struct firmware *fw, void *context);
1140 u32 opt_flags;
1141};
1142
1143static void request_firmware_work_func(struct work_struct *work)
1144{
1145 struct firmware_work *fw_work;
1146 const struct firmware *fw;
1147
1148 fw_work = container_of(work, struct firmware_work, work);
1149
1150 _request_firmware(firmware_p: &fw, name: fw_work->name, device: fw_work->device, NULL, size: 0, offset: 0,
1151 opt_flags: fw_work->opt_flags);
1152 fw_work->cont(fw, fw_work->context);
1153 put_device(dev: fw_work->device); /* taken in request_firmware_nowait() */
1154
1155 module_put(module: fw_work->module);
1156 kfree_const(x: fw_work->name);
1157 kfree(objp: fw_work);
1158}
1159
1160
1161static int _request_firmware_nowait(
1162 struct module *module, bool uevent,
1163 const char *name, struct device *device, gfp_t gfp, void *context,
1164 void (*cont)(const struct firmware *fw, void *context), bool nowarn)
1165{
1166 struct firmware_work *fw_work;
1167
1168 fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1169 if (!fw_work)
1170 return -ENOMEM;
1171
1172 fw_work->module = module;
1173 fw_work->name = kstrdup_const(s: name, gfp);
1174 if (!fw_work->name) {
1175 kfree(objp: fw_work);
1176 return -ENOMEM;
1177 }
1178 fw_work->device = device;
1179 fw_work->context = context;
1180 fw_work->cont = cont;
1181 fw_work->opt_flags = FW_OPT_NOWAIT |
1182 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER) |
1183 (nowarn ? FW_OPT_NO_WARN : 0);
1184
1185 if (!uevent && fw_cache_is_setup(dev: device, name)) {
1186 kfree_const(x: fw_work->name);
1187 kfree(objp: fw_work);
1188 return -EOPNOTSUPP;
1189 }
1190
1191 if (!try_module_get(module)) {
1192 kfree_const(x: fw_work->name);
1193 kfree(objp: fw_work);
1194 return -EFAULT;
1195 }
1196
1197 get_device(dev: fw_work->device);
1198 INIT_WORK(&fw_work->work, request_firmware_work_func);
1199 schedule_work(work: &fw_work->work);
1200 return 0;
1201}
1202
1203/**
1204 * request_firmware_nowait() - asynchronous version of request_firmware
1205 * @module: module requesting the firmware
1206 * @uevent: sends uevent to copy the firmware image if this flag
1207 * is non-zero else the firmware copy must be done manually.
1208 * @name: name of firmware file
1209 * @device: device for which firmware is being loaded
1210 * @gfp: allocation flags
1211 * @context: will be passed over to @cont, and
1212 * @fw may be %NULL if firmware request fails.
1213 * @cont: function will be called asynchronously when the firmware
1214 * request is over.
1215 *
1216 * Caller must hold the reference count of @device.
1217 *
1218 * Asynchronous variant of request_firmware() for user contexts:
1219 * - sleep for as small periods as possible since it may
1220 * increase kernel boot time of built-in device drivers
1221 * requesting firmware in their ->probe() methods, if
1222 * @gfp is GFP_KERNEL.
1223 *
1224 * - can't sleep at all if @gfp is GFP_ATOMIC.
1225 **/
1226int request_firmware_nowait(
1227 struct module *module, bool uevent,
1228 const char *name, struct device *device, gfp_t gfp, void *context,
1229 void (*cont)(const struct firmware *fw, void *context))
1230{
1231 return _request_firmware_nowait(module, uevent, name, device, gfp,
1232 context, cont, nowarn: false);
1233
1234}
1235EXPORT_SYMBOL(request_firmware_nowait);
1236
1237/**
1238 * firmware_request_nowait_nowarn() - async version of request_firmware_nowarn
1239 * @module: module requesting the firmware
1240 * @name: name of firmware file
1241 * @device: device for which firmware is being loaded
1242 * @gfp: allocation flags
1243 * @context: will be passed over to @cont, and
1244 * @fw may be %NULL if firmware request fails.
1245 * @cont: function will be called asynchronously when the firmware
1246 * request is over.
1247 *
1248 * Similar in function to request_firmware_nowait(), but doesn't print a warning
1249 * when the firmware file could not be found and always sends a uevent to copy
1250 * the firmware image.
1251 */
1252int firmware_request_nowait_nowarn(
1253 struct module *module, const char *name,
1254 struct device *device, gfp_t gfp, void *context,
1255 void (*cont)(const struct firmware *fw, void *context))
1256{
1257 return _request_firmware_nowait(module, FW_ACTION_UEVENT, name, device,
1258 gfp, context, cont, nowarn: true);
1259}
1260EXPORT_SYMBOL_GPL(firmware_request_nowait_nowarn);
1261
1262#ifdef CONFIG_FW_CACHE
1263static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1264
1265/**
1266 * cache_firmware() - cache one firmware image in kernel memory space
1267 * @fw_name: the firmware image name
1268 *
1269 * Cache firmware in kernel memory so that drivers can use it when
1270 * system isn't ready for them to request firmware image from userspace.
1271 * Once it returns successfully, driver can use request_firmware or its
1272 * nowait version to get the cached firmware without any interacting
1273 * with userspace
1274 *
1275 * Return 0 if the firmware image has been cached successfully
1276 * Return !0 otherwise
1277 *
1278 */
1279static int cache_firmware(const char *fw_name)
1280{
1281 int ret;
1282 const struct firmware *fw;
1283
1284 pr_debug("%s: %s\n", __func__, fw_name);
1285
1286 ret = request_firmware(&fw, fw_name, NULL);
1287 if (!ret)
1288 kfree(objp: fw);
1289
1290 pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1291
1292 return ret;
1293}
1294
1295static struct fw_priv *lookup_fw_priv(const char *fw_name)
1296{
1297 struct fw_priv *tmp;
1298 struct firmware_cache *fwc = &fw_cache;
1299
1300 spin_lock(lock: &fwc->lock);
1301 tmp = __lookup_fw_priv(fw_name);
1302 spin_unlock(lock: &fwc->lock);
1303
1304 return tmp;
1305}
1306
1307/**
1308 * uncache_firmware() - remove one cached firmware image
1309 * @fw_name: the firmware image name
1310 *
1311 * Uncache one firmware image which has been cached successfully
1312 * before.
1313 *
1314 * Return 0 if the firmware cache has been removed successfully
1315 * Return !0 otherwise
1316 *
1317 */
1318static int uncache_firmware(const char *fw_name)
1319{
1320 struct fw_priv *fw_priv;
1321 struct firmware fw;
1322
1323 pr_debug("%s: %s\n", __func__, fw_name);
1324
1325 if (firmware_request_builtin(fw: &fw, name: fw_name))
1326 return 0;
1327
1328 fw_priv = lookup_fw_priv(fw_name);
1329 if (fw_priv) {
1330 free_fw_priv(fw_priv);
1331 return 0;
1332 }
1333
1334 return -EINVAL;
1335}
1336
1337static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1338{
1339 struct fw_cache_entry *fce;
1340
1341 fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1342 if (!fce)
1343 goto exit;
1344
1345 fce->name = kstrdup_const(s: name, GFP_ATOMIC);
1346 if (!fce->name) {
1347 kfree(objp: fce);
1348 fce = NULL;
1349 goto exit;
1350 }
1351exit:
1352 return fce;
1353}
1354
1355static int __fw_entry_found(const char *name)
1356{
1357 struct firmware_cache *fwc = &fw_cache;
1358 struct fw_cache_entry *fce;
1359
1360 list_for_each_entry(fce, &fwc->fw_names, list) {
1361 if (!strcmp(fce->name, name))
1362 return 1;
1363 }
1364 return 0;
1365}
1366
1367static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1368{
1369 const char *name = fw_priv->fw_name;
1370 struct firmware_cache *fwc = fw_priv->fwc;
1371 struct fw_cache_entry *fce;
1372
1373 spin_lock(lock: &fwc->name_lock);
1374 if (__fw_entry_found(name))
1375 goto found;
1376
1377 fce = alloc_fw_cache_entry(name);
1378 if (fce) {
1379 list_add(new: &fce->list, head: &fwc->fw_names);
1380 kref_get(kref: &fw_priv->ref);
1381 pr_debug("%s: fw: %s\n", __func__, name);
1382 }
1383found:
1384 spin_unlock(lock: &fwc->name_lock);
1385}
1386
1387static void free_fw_cache_entry(struct fw_cache_entry *fce)
1388{
1389 kfree_const(x: fce->name);
1390 kfree(objp: fce);
1391}
1392
1393static void __async_dev_cache_fw_image(void *fw_entry,
1394 async_cookie_t cookie)
1395{
1396 struct fw_cache_entry *fce = fw_entry;
1397 struct firmware_cache *fwc = &fw_cache;
1398 int ret;
1399
1400 ret = cache_firmware(fw_name: fce->name);
1401 if (ret) {
1402 spin_lock(lock: &fwc->name_lock);
1403 list_del(entry: &fce->list);
1404 spin_unlock(lock: &fwc->name_lock);
1405
1406 free_fw_cache_entry(fce);
1407 }
1408}
1409
1410/* called with dev->devres_lock held */
1411static void dev_create_fw_entry(struct device *dev, void *res,
1412 void *data)
1413{
1414 struct fw_name_devm *fwn = res;
1415 const char *fw_name = fwn->name;
1416 struct list_head *head = data;
1417 struct fw_cache_entry *fce;
1418
1419 fce = alloc_fw_cache_entry(name: fw_name);
1420 if (fce)
1421 list_add(new: &fce->list, head);
1422}
1423
1424static int devm_name_match(struct device *dev, void *res,
1425 void *match_data)
1426{
1427 struct fw_name_devm *fwn = res;
1428 return (fwn->magic == (unsigned long)match_data);
1429}
1430
1431static void dev_cache_fw_image(struct device *dev, void *data)
1432{
1433 LIST_HEAD(todo);
1434 struct fw_cache_entry *fce;
1435 struct fw_cache_entry *fce_next;
1436 struct firmware_cache *fwc = &fw_cache;
1437
1438 devres_for_each_res(dev, release: fw_name_devm_release,
1439 match: devm_name_match, match_data: &fw_cache,
1440 fn: dev_create_fw_entry, data: &todo);
1441
1442 list_for_each_entry_safe(fce, fce_next, &todo, list) {
1443 list_del(entry: &fce->list);
1444
1445 spin_lock(lock: &fwc->name_lock);
1446 /* only one cache entry for one firmware */
1447 if (!__fw_entry_found(name: fce->name)) {
1448 list_add(new: &fce->list, head: &fwc->fw_names);
1449 } else {
1450 free_fw_cache_entry(fce);
1451 fce = NULL;
1452 }
1453 spin_unlock(lock: &fwc->name_lock);
1454
1455 if (fce)
1456 async_schedule_domain(func: __async_dev_cache_fw_image,
1457 data: (void *)fce,
1458 domain: &fw_cache_domain);
1459 }
1460}
1461
1462static void __device_uncache_fw_images(void)
1463{
1464 struct firmware_cache *fwc = &fw_cache;
1465 struct fw_cache_entry *fce;
1466
1467 spin_lock(lock: &fwc->name_lock);
1468 while (!list_empty(head: &fwc->fw_names)) {
1469 fce = list_entry(fwc->fw_names.next,
1470 struct fw_cache_entry, list);
1471 list_del(entry: &fce->list);
1472 spin_unlock(lock: &fwc->name_lock);
1473
1474 uncache_firmware(fw_name: fce->name);
1475 free_fw_cache_entry(fce);
1476
1477 spin_lock(lock: &fwc->name_lock);
1478 }
1479 spin_unlock(lock: &fwc->name_lock);
1480}
1481
1482/**
1483 * device_cache_fw_images() - cache devices' firmware
1484 *
1485 * If one device called request_firmware or its nowait version
1486 * successfully before, the firmware names are recored into the
1487 * device's devres link list, so device_cache_fw_images can call
1488 * cache_firmware() to cache these firmwares for the device,
1489 * then the device driver can load its firmwares easily at
1490 * time when system is not ready to complete loading firmware.
1491 */
1492static void device_cache_fw_images(void)
1493{
1494 struct firmware_cache *fwc = &fw_cache;
1495 DEFINE_WAIT(wait);
1496
1497 pr_debug("%s\n", __func__);
1498
1499 /* cancel uncache work */
1500 cancel_delayed_work_sync(dwork: &fwc->work);
1501
1502 fw_fallback_set_cache_timeout();
1503
1504 mutex_lock(&fw_lock);
1505 fwc->state = FW_LOADER_START_CACHE;
1506 dpm_for_each_dev(NULL, fn: dev_cache_fw_image);
1507 mutex_unlock(lock: &fw_lock);
1508
1509 /* wait for completion of caching firmware for all devices */
1510 async_synchronize_full_domain(domain: &fw_cache_domain);
1511
1512 fw_fallback_set_default_timeout();
1513}
1514
1515/**
1516 * device_uncache_fw_images() - uncache devices' firmware
1517 *
1518 * uncache all firmwares which have been cached successfully
1519 * by device_uncache_fw_images earlier
1520 */
1521static void device_uncache_fw_images(void)
1522{
1523 pr_debug("%s\n", __func__);
1524 __device_uncache_fw_images();
1525}
1526
1527static void device_uncache_fw_images_work(struct work_struct *work)
1528{
1529 device_uncache_fw_images();
1530}
1531
1532/**
1533 * device_uncache_fw_images_delay() - uncache devices firmwares
1534 * @delay: number of milliseconds to delay uncache device firmwares
1535 *
1536 * uncache all devices's firmwares which has been cached successfully
1537 * by device_cache_fw_images after @delay milliseconds.
1538 */
1539static void device_uncache_fw_images_delay(unsigned long delay)
1540{
1541 queue_delayed_work(wq: system_power_efficient_wq, dwork: &fw_cache.work,
1542 delay: msecs_to_jiffies(m: delay));
1543}
1544
1545static int fw_pm_notify(struct notifier_block *notify_block,
1546 unsigned long mode, void *unused)
1547{
1548 switch (mode) {
1549 case PM_HIBERNATION_PREPARE:
1550 case PM_SUSPEND_PREPARE:
1551 case PM_RESTORE_PREPARE:
1552 /*
1553 * Here, kill pending fallback requests will only kill
1554 * non-uevent firmware request to avoid stalling suspend.
1555 */
1556 kill_pending_fw_fallback_reqs(kill_all: false);
1557 device_cache_fw_images();
1558 break;
1559
1560 case PM_POST_SUSPEND:
1561 case PM_POST_HIBERNATION:
1562 case PM_POST_RESTORE:
1563 /*
1564 * In case that system sleep failed and syscore_suspend is
1565 * not called.
1566 */
1567 mutex_lock(&fw_lock);
1568 fw_cache.state = FW_LOADER_NO_CACHE;
1569 mutex_unlock(lock: &fw_lock);
1570
1571 device_uncache_fw_images_delay(delay: 10 * MSEC_PER_SEC);
1572 break;
1573 }
1574
1575 return 0;
1576}
1577
1578/* stop caching firmware once syscore_suspend is reached */
1579static int fw_suspend(void *data)
1580{
1581 fw_cache.state = FW_LOADER_NO_CACHE;
1582 return 0;
1583}
1584
1585static const struct syscore_ops fw_syscore_ops = {
1586 .suspend = fw_suspend,
1587};
1588
1589static struct syscore fw_syscore = {
1590 .ops = &fw_syscore_ops,
1591};
1592
1593static int __init register_fw_pm_ops(void)
1594{
1595 int ret;
1596
1597 spin_lock_init(&fw_cache.name_lock);
1598 INIT_LIST_HEAD(list: &fw_cache.fw_names);
1599
1600 INIT_DELAYED_WORK(&fw_cache.work,
1601 device_uncache_fw_images_work);
1602
1603 fw_cache.pm_notify.notifier_call = fw_pm_notify;
1604 ret = register_pm_notifier(nb: &fw_cache.pm_notify);
1605 if (ret)
1606 return ret;
1607
1608 register_syscore(syscore: &fw_syscore);
1609
1610 return ret;
1611}
1612
1613static inline void unregister_fw_pm_ops(void)
1614{
1615 unregister_syscore(syscore: &fw_syscore);
1616 unregister_pm_notifier(nb: &fw_cache.pm_notify);
1617}
1618#else
1619static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv)
1620{
1621}
1622static inline int register_fw_pm_ops(void)
1623{
1624 return 0;
1625}
1626static inline void unregister_fw_pm_ops(void)
1627{
1628}
1629#endif
1630
1631static void __init fw_cache_init(void)
1632{
1633 spin_lock_init(&fw_cache.lock);
1634 INIT_LIST_HEAD(list: &fw_cache.head);
1635 fw_cache.state = FW_LOADER_NO_CACHE;
1636}
1637
1638static int fw_shutdown_notify(struct notifier_block *unused1,
1639 unsigned long unused2, void *unused3)
1640{
1641 /*
1642 * Kill all pending fallback requests to avoid both stalling shutdown,
1643 * and avoid a deadlock with the usermode_lock.
1644 */
1645 kill_pending_fw_fallback_reqs(kill_all: true);
1646
1647 return NOTIFY_DONE;
1648}
1649
1650static struct notifier_block fw_shutdown_nb = {
1651 .notifier_call = fw_shutdown_notify,
1652};
1653
1654static int __init firmware_class_init(void)
1655{
1656 int ret;
1657
1658 /* No need to unfold these on exit */
1659 fw_cache_init();
1660
1661 ret = register_fw_pm_ops();
1662 if (ret)
1663 return ret;
1664
1665 ret = register_reboot_notifier(&fw_shutdown_nb);
1666 if (ret)
1667 goto out;
1668
1669 return register_sysfs_loader();
1670
1671out:
1672 unregister_fw_pm_ops();
1673 return ret;
1674}
1675
1676static void __exit firmware_class_exit(void)
1677{
1678 unregister_fw_pm_ops();
1679 unregister_reboot_notifier(&fw_shutdown_nb);
1680 unregister_sysfs_loader();
1681}
1682
1683fs_initcall(firmware_class_init);
1684module_exit(firmware_class_exit);
1685

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