Merge tag 'nfs-for-4.10-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
[linux-2.6-block.git] / drivers / base / firmware_class.c
1 /*
2  * firmware_class.c - Multi purpose firmware loading support
3  *
4  * Copyright (c) 2003 Manuel Estrada Sainz
5  *
6  * Please see Documentation/firmware_class/ for more information.
7  *
8  */
9
10 #include <linux/capability.h>
11 #include <linux/device.h>
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/timer.h>
15 #include <linux/vmalloc.h>
16 #include <linux/interrupt.h>
17 #include <linux/bitops.h>
18 #include <linux/mutex.h>
19 #include <linux/workqueue.h>
20 #include <linux/highmem.h>
21 #include <linux/firmware.h>
22 #include <linux/slab.h>
23 #include <linux/sched.h>
24 #include <linux/file.h>
25 #include <linux/list.h>
26 #include <linux/fs.h>
27 #include <linux/async.h>
28 #include <linux/pm.h>
29 #include <linux/suspend.h>
30 #include <linux/syscore_ops.h>
31 #include <linux/reboot.h>
32 #include <linux/security.h>
33 #include <linux/swait.h>
34
35 #include <generated/utsrelease.h>
36
37 #include "base.h"
38
39 MODULE_AUTHOR("Manuel Estrada Sainz");
40 MODULE_DESCRIPTION("Multi purpose firmware loading support");
41 MODULE_LICENSE("GPL");
42
43 /* Builtin firmware support */
44
45 #ifdef CONFIG_FW_LOADER
46
47 extern struct builtin_fw __start_builtin_fw[];
48 extern struct builtin_fw __end_builtin_fw[];
49
50 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name,
51                                     void *buf, size_t size)
52 {
53         struct builtin_fw *b_fw;
54
55         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
56                 if (strcmp(name, b_fw->name) == 0) {
57                         fw->size = b_fw->size;
58                         fw->data = b_fw->data;
59
60                         if (buf && fw->size <= size)
61                                 memcpy(buf, fw->data, fw->size);
62                         return true;
63                 }
64         }
65
66         return false;
67 }
68
69 static bool fw_is_builtin_firmware(const struct firmware *fw)
70 {
71         struct builtin_fw *b_fw;
72
73         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
74                 if (fw->data == b_fw->data)
75                         return true;
76
77         return false;
78 }
79
80 #else /* Module case - no builtin firmware support */
81
82 static inline bool fw_get_builtin_firmware(struct firmware *fw,
83                                            const char *name, void *buf,
84                                            size_t size)
85 {
86         return false;
87 }
88
89 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
90 {
91         return false;
92 }
93 #endif
94
95 enum fw_status {
96         FW_STATUS_UNKNOWN,
97         FW_STATUS_LOADING,
98         FW_STATUS_DONE,
99         FW_STATUS_ABORTED,
100 };
101
102 static int loading_timeout = 60;        /* In seconds */
103
104 static inline long firmware_loading_timeout(void)
105 {
106         return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET;
107 }
108
109 /*
110  * Concurrent request_firmware() for the same firmware need to be
111  * serialized.  struct fw_state is simple state machine which hold the
112  * state of the firmware loading.
113  */
114 struct fw_state {
115         struct swait_queue_head wq;
116         enum fw_status status;
117 };
118
119 static void fw_state_init(struct fw_state *fw_st)
120 {
121         init_swait_queue_head(&fw_st->wq);
122         fw_st->status = FW_STATUS_UNKNOWN;
123 }
124
125 static inline bool __fw_state_is_done(enum fw_status status)
126 {
127         return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED;
128 }
129
130 static int __fw_state_wait_common(struct fw_state *fw_st, long timeout)
131 {
132         long ret;
133
134         ret = swait_event_interruptible_timeout(fw_st->wq,
135                                 __fw_state_is_done(READ_ONCE(fw_st->status)),
136                                 timeout);
137         if (ret != 0 && fw_st->status == FW_STATUS_ABORTED)
138                 return -ENOENT;
139         if (!ret)
140                 return -ETIMEDOUT;
141
142         return ret < 0 ? ret : 0;
143 }
144
145 static void __fw_state_set(struct fw_state *fw_st,
146                            enum fw_status status)
147 {
148         WRITE_ONCE(fw_st->status, status);
149
150         if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED)
151                 swake_up(&fw_st->wq);
152 }
153
154 #define fw_state_start(fw_st)                                   \
155         __fw_state_set(fw_st, FW_STATUS_LOADING)
156 #define fw_state_done(fw_st)                                    \
157         __fw_state_set(fw_st, FW_STATUS_DONE)
158 #define fw_state_wait(fw_st)                                    \
159         __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT)
160
161 #ifndef CONFIG_FW_LOADER_USER_HELPER
162
163 #define fw_state_is_aborted(fw_st)      false
164
165 #else /* CONFIG_FW_LOADER_USER_HELPER */
166
167 static int __fw_state_check(struct fw_state *fw_st, enum fw_status status)
168 {
169         return fw_st->status == status;
170 }
171
172 #define fw_state_aborted(fw_st)                                 \
173         __fw_state_set(fw_st, FW_STATUS_ABORTED)
174 #define fw_state_is_done(fw_st)                                 \
175         __fw_state_check(fw_st, FW_STATUS_DONE)
176 #define fw_state_is_loading(fw_st)                              \
177         __fw_state_check(fw_st, FW_STATUS_LOADING)
178 #define fw_state_is_aborted(fw_st)                              \
179         __fw_state_check(fw_st, FW_STATUS_ABORTED)
180 #define fw_state_wait_timeout(fw_st, timeout)                   \
181         __fw_state_wait_common(fw_st, timeout)
182
183 #endif /* CONFIG_FW_LOADER_USER_HELPER */
184
185 /* firmware behavior options */
186 #define FW_OPT_UEVENT   (1U << 0)
187 #define FW_OPT_NOWAIT   (1U << 1)
188 #ifdef CONFIG_FW_LOADER_USER_HELPER
189 #define FW_OPT_USERHELPER       (1U << 2)
190 #else
191 #define FW_OPT_USERHELPER       0
192 #endif
193 #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK
194 #define FW_OPT_FALLBACK         FW_OPT_USERHELPER
195 #else
196 #define FW_OPT_FALLBACK         0
197 #endif
198 #define FW_OPT_NO_WARN  (1U << 3)
199 #define FW_OPT_NOCACHE  (1U << 4)
200
201 struct firmware_cache {
202         /* firmware_buf instance will be added into the below list */
203         spinlock_t lock;
204         struct list_head head;
205         int state;
206
207 #ifdef CONFIG_PM_SLEEP
208         /*
209          * Names of firmware images which have been cached successfully
210          * will be added into the below list so that device uncache
211          * helper can trace which firmware images have been cached
212          * before.
213          */
214         spinlock_t name_lock;
215         struct list_head fw_names;
216
217         struct delayed_work work;
218
219         struct notifier_block   pm_notify;
220 #endif
221 };
222
223 struct firmware_buf {
224         struct kref ref;
225         struct list_head list;
226         struct firmware_cache *fwc;
227         struct fw_state fw_st;
228         void *data;
229         size_t size;
230         size_t allocated_size;
231 #ifdef CONFIG_FW_LOADER_USER_HELPER
232         bool is_paged_buf;
233         bool need_uevent;
234         struct page **pages;
235         int nr_pages;
236         int page_array_size;
237         struct list_head pending_list;
238 #endif
239         const char *fw_id;
240 };
241
242 struct fw_cache_entry {
243         struct list_head list;
244         const char *name;
245 };
246
247 struct fw_name_devm {
248         unsigned long magic;
249         const char *name;
250 };
251
252 #define to_fwbuf(d) container_of(d, struct firmware_buf, ref)
253
254 #define FW_LOADER_NO_CACHE      0
255 #define FW_LOADER_START_CACHE   1
256
257 static int fw_cache_piggyback_on_request(const char *name);
258
259 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
260  * guarding for corner cases a global lock should be OK */
261 static DEFINE_MUTEX(fw_lock);
262
263 static struct firmware_cache fw_cache;
264
265 static struct firmware_buf *__allocate_fw_buf(const char *fw_name,
266                                               struct firmware_cache *fwc,
267                                               void *dbuf, size_t size)
268 {
269         struct firmware_buf *buf;
270
271         buf = kzalloc(sizeof(*buf), GFP_ATOMIC);
272         if (!buf)
273                 return NULL;
274
275         buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC);
276         if (!buf->fw_id) {
277                 kfree(buf);
278                 return NULL;
279         }
280
281         kref_init(&buf->ref);
282         buf->fwc = fwc;
283         buf->data = dbuf;
284         buf->allocated_size = size;
285         fw_state_init(&buf->fw_st);
286 #ifdef CONFIG_FW_LOADER_USER_HELPER
287         INIT_LIST_HEAD(&buf->pending_list);
288 #endif
289
290         pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf);
291
292         return buf;
293 }
294
295 static struct firmware_buf *__fw_lookup_buf(const char *fw_name)
296 {
297         struct firmware_buf *tmp;
298         struct firmware_cache *fwc = &fw_cache;
299
300         list_for_each_entry(tmp, &fwc->head, list)
301                 if (!strcmp(tmp->fw_id, fw_name))
302                         return tmp;
303         return NULL;
304 }
305
306 static int fw_lookup_and_allocate_buf(const char *fw_name,
307                                       struct firmware_cache *fwc,
308                                       struct firmware_buf **buf, void *dbuf,
309                                       size_t size)
310 {
311         struct firmware_buf *tmp;
312
313         spin_lock(&fwc->lock);
314         tmp = __fw_lookup_buf(fw_name);
315         if (tmp) {
316                 kref_get(&tmp->ref);
317                 spin_unlock(&fwc->lock);
318                 *buf = tmp;
319                 return 1;
320         }
321         tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size);
322         if (tmp)
323                 list_add(&tmp->list, &fwc->head);
324         spin_unlock(&fwc->lock);
325
326         *buf = tmp;
327
328         return tmp ? 0 : -ENOMEM;
329 }
330
331 static void __fw_free_buf(struct kref *ref)
332         __releases(&fwc->lock)
333 {
334         struct firmware_buf *buf = to_fwbuf(ref);
335         struct firmware_cache *fwc = buf->fwc;
336
337         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
338                  __func__, buf->fw_id, buf, buf->data,
339                  (unsigned int)buf->size);
340
341         list_del(&buf->list);
342         spin_unlock(&fwc->lock);
343
344 #ifdef CONFIG_FW_LOADER_USER_HELPER
345         if (buf->is_paged_buf) {
346                 int i;
347                 vunmap(buf->data);
348                 for (i = 0; i < buf->nr_pages; i++)
349                         __free_page(buf->pages[i]);
350                 vfree(buf->pages);
351         } else
352 #endif
353         if (!buf->allocated_size)
354                 vfree(buf->data);
355         kfree_const(buf->fw_id);
356         kfree(buf);
357 }
358
359 static void fw_free_buf(struct firmware_buf *buf)
360 {
361         struct firmware_cache *fwc = buf->fwc;
362         spin_lock(&fwc->lock);
363         if (!kref_put(&buf->ref, __fw_free_buf))
364                 spin_unlock(&fwc->lock);
365 }
366
367 /* direct firmware loading support */
368 static char fw_path_para[256];
369 static const char * const fw_path[] = {
370         fw_path_para,
371         "/lib/firmware/updates/" UTS_RELEASE,
372         "/lib/firmware/updates",
373         "/lib/firmware/" UTS_RELEASE,
374         "/lib/firmware"
375 };
376
377 /*
378  * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH'
379  * from kernel command line because firmware_class is generally built in
380  * kernel instead of module.
381  */
382 module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644);
383 MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path");
384
385 static int
386 fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf)
387 {
388         loff_t size;
389         int i, len;
390         int rc = -ENOENT;
391         char *path;
392         enum kernel_read_file_id id = READING_FIRMWARE;
393         size_t msize = INT_MAX;
394
395         /* Already populated data member means we're loading into a buffer */
396         if (buf->data) {
397                 id = READING_FIRMWARE_PREALLOC_BUFFER;
398                 msize = buf->allocated_size;
399         }
400
401         path = __getname();
402         if (!path)
403                 return -ENOMEM;
404
405         for (i = 0; i < ARRAY_SIZE(fw_path); i++) {
406                 /* skip the unset customized path */
407                 if (!fw_path[i][0])
408                         continue;
409
410                 len = snprintf(path, PATH_MAX, "%s/%s",
411                                fw_path[i], buf->fw_id);
412                 if (len >= PATH_MAX) {
413                         rc = -ENAMETOOLONG;
414                         break;
415                 }
416
417                 buf->size = 0;
418                 rc = kernel_read_file_from_path(path, &buf->data, &size, msize,
419                                                 id);
420                 if (rc) {
421                         if (rc == -ENOENT)
422                                 dev_dbg(device, "loading %s failed with error %d\n",
423                                          path, rc);
424                         else
425                                 dev_warn(device, "loading %s failed with error %d\n",
426                                          path, rc);
427                         continue;
428                 }
429                 dev_dbg(device, "direct-loading %s\n", buf->fw_id);
430                 buf->size = size;
431                 fw_state_done(&buf->fw_st);
432                 break;
433         }
434         __putname(path);
435
436         return rc;
437 }
438
439 /* firmware holds the ownership of pages */
440 static void firmware_free_data(const struct firmware *fw)
441 {
442         /* Loaded directly? */
443         if (!fw->priv) {
444                 vfree(fw->data);
445                 return;
446         }
447         fw_free_buf(fw->priv);
448 }
449
450 /* store the pages buffer info firmware from buf */
451 static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw)
452 {
453         fw->priv = buf;
454 #ifdef CONFIG_FW_LOADER_USER_HELPER
455         fw->pages = buf->pages;
456 #endif
457         fw->size = buf->size;
458         fw->data = buf->data;
459
460         pr_debug("%s: fw-%s buf=%p data=%p size=%u\n",
461                  __func__, buf->fw_id, buf, buf->data,
462                  (unsigned int)buf->size);
463 }
464
465 #ifdef CONFIG_PM_SLEEP
466 static void fw_name_devm_release(struct device *dev, void *res)
467 {
468         struct fw_name_devm *fwn = res;
469
470         if (fwn->magic == (unsigned long)&fw_cache)
471                 pr_debug("%s: fw_name-%s devm-%p released\n",
472                                 __func__, fwn->name, res);
473         kfree_const(fwn->name);
474 }
475
476 static int fw_devm_match(struct device *dev, void *res,
477                 void *match_data)
478 {
479         struct fw_name_devm *fwn = res;
480
481         return (fwn->magic == (unsigned long)&fw_cache) &&
482                 !strcmp(fwn->name, match_data);
483 }
484
485 static struct fw_name_devm *fw_find_devm_name(struct device *dev,
486                 const char *name)
487 {
488         struct fw_name_devm *fwn;
489
490         fwn = devres_find(dev, fw_name_devm_release,
491                           fw_devm_match, (void *)name);
492         return fwn;
493 }
494
495 /* add firmware name into devres list */
496 static int fw_add_devm_name(struct device *dev, const char *name)
497 {
498         struct fw_name_devm *fwn;
499
500         fwn = fw_find_devm_name(dev, name);
501         if (fwn)
502                 return 1;
503
504         fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm),
505                            GFP_KERNEL);
506         if (!fwn)
507                 return -ENOMEM;
508         fwn->name = kstrdup_const(name, GFP_KERNEL);
509         if (!fwn->name) {
510                 devres_free(fwn);
511                 return -ENOMEM;
512         }
513
514         fwn->magic = (unsigned long)&fw_cache;
515         devres_add(dev, fwn);
516
517         return 0;
518 }
519 #else
520 static int fw_add_devm_name(struct device *dev, const char *name)
521 {
522         return 0;
523 }
524 #endif
525
526
527 /*
528  * user-mode helper code
529  */
530 #ifdef CONFIG_FW_LOADER_USER_HELPER
531 struct firmware_priv {
532         bool nowait;
533         struct device dev;
534         struct firmware_buf *buf;
535         struct firmware *fw;
536 };
537
538 static struct firmware_priv *to_firmware_priv(struct device *dev)
539 {
540         return container_of(dev, struct firmware_priv, dev);
541 }
542
543 static void __fw_load_abort(struct firmware_buf *buf)
544 {
545         /*
546          * There is a small window in which user can write to 'loading'
547          * between loading done and disappearance of 'loading'
548          */
549         if (fw_state_is_done(&buf->fw_st))
550                 return;
551
552         list_del_init(&buf->pending_list);
553         fw_state_aborted(&buf->fw_st);
554 }
555
556 static void fw_load_abort(struct firmware_priv *fw_priv)
557 {
558         struct firmware_buf *buf = fw_priv->buf;
559
560         __fw_load_abort(buf);
561
562         /* avoid user action after loading abort */
563         fw_priv->buf = NULL;
564 }
565
566 static LIST_HEAD(pending_fw_head);
567
568 /* reboot notifier for avoid deadlock with usermode_lock */
569 static int fw_shutdown_notify(struct notifier_block *unused1,
570                               unsigned long unused2, void *unused3)
571 {
572         mutex_lock(&fw_lock);
573         while (!list_empty(&pending_fw_head))
574                 __fw_load_abort(list_first_entry(&pending_fw_head,
575                                                struct firmware_buf,
576                                                pending_list));
577         mutex_unlock(&fw_lock);
578         return NOTIFY_DONE;
579 }
580
581 static struct notifier_block fw_shutdown_nb = {
582         .notifier_call = fw_shutdown_notify,
583 };
584
585 static ssize_t timeout_show(struct class *class, struct class_attribute *attr,
586                             char *buf)
587 {
588         return sprintf(buf, "%d\n", loading_timeout);
589 }
590
591 /**
592  * firmware_timeout_store - set number of seconds to wait for firmware
593  * @class: device class pointer
594  * @attr: device attribute pointer
595  * @buf: buffer to scan for timeout value
596  * @count: number of bytes in @buf
597  *
598  *      Sets the number of seconds to wait for the firmware.  Once
599  *      this expires an error will be returned to the driver and no
600  *      firmware will be provided.
601  *
602  *      Note: zero means 'wait forever'.
603  **/
604 static ssize_t timeout_store(struct class *class, struct class_attribute *attr,
605                              const char *buf, size_t count)
606 {
607         loading_timeout = simple_strtol(buf, NULL, 10);
608         if (loading_timeout < 0)
609                 loading_timeout = 0;
610
611         return count;
612 }
613 static CLASS_ATTR_RW(timeout);
614
615 static struct attribute *firmware_class_attrs[] = {
616         &class_attr_timeout.attr,
617         NULL,
618 };
619 ATTRIBUTE_GROUPS(firmware_class);
620
621 static void fw_dev_release(struct device *dev)
622 {
623         struct firmware_priv *fw_priv = to_firmware_priv(dev);
624
625         kfree(fw_priv);
626 }
627
628 static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env)
629 {
630         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id))
631                 return -ENOMEM;
632         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
633                 return -ENOMEM;
634         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
635                 return -ENOMEM;
636
637         return 0;
638 }
639
640 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
641 {
642         struct firmware_priv *fw_priv = to_firmware_priv(dev);
643         int err = 0;
644
645         mutex_lock(&fw_lock);
646         if (fw_priv->buf)
647                 err = do_firmware_uevent(fw_priv, env);
648         mutex_unlock(&fw_lock);
649         return err;
650 }
651
652 static struct class firmware_class = {
653         .name           = "firmware",
654         .class_groups   = firmware_class_groups,
655         .dev_uevent     = firmware_uevent,
656         .dev_release    = fw_dev_release,
657 };
658
659 static ssize_t firmware_loading_show(struct device *dev,
660                                      struct device_attribute *attr, char *buf)
661 {
662         struct firmware_priv *fw_priv = to_firmware_priv(dev);
663         int loading = 0;
664
665         mutex_lock(&fw_lock);
666         if (fw_priv->buf)
667                 loading = fw_state_is_loading(&fw_priv->buf->fw_st);
668         mutex_unlock(&fw_lock);
669
670         return sprintf(buf, "%d\n", loading);
671 }
672
673 /* Some architectures don't have PAGE_KERNEL_RO */
674 #ifndef PAGE_KERNEL_RO
675 #define PAGE_KERNEL_RO PAGE_KERNEL
676 #endif
677
678 /* one pages buffer should be mapped/unmapped only once */
679 static int fw_map_pages_buf(struct firmware_buf *buf)
680 {
681         if (!buf->is_paged_buf)
682                 return 0;
683
684         vunmap(buf->data);
685         buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO);
686         if (!buf->data)
687                 return -ENOMEM;
688         return 0;
689 }
690
691 /**
692  * firmware_loading_store - set value in the 'loading' control file
693  * @dev: device pointer
694  * @attr: device attribute pointer
695  * @buf: buffer to scan for loading control value
696  * @count: number of bytes in @buf
697  *
698  *      The relevant values are:
699  *
700  *       1: Start a load, discarding any previous partial load.
701  *       0: Conclude the load and hand the data to the driver code.
702  *      -1: Conclude the load with an error and discard any written data.
703  **/
704 static ssize_t firmware_loading_store(struct device *dev,
705                                       struct device_attribute *attr,
706                                       const char *buf, size_t count)
707 {
708         struct firmware_priv *fw_priv = to_firmware_priv(dev);
709         struct firmware_buf *fw_buf;
710         ssize_t written = count;
711         int loading = simple_strtol(buf, NULL, 10);
712         int i;
713
714         mutex_lock(&fw_lock);
715         fw_buf = fw_priv->buf;
716         if (!fw_buf)
717                 goto out;
718
719         switch (loading) {
720         case 1:
721                 /* discarding any previous partial load */
722                 if (!fw_state_is_done(&fw_buf->fw_st)) {
723                         for (i = 0; i < fw_buf->nr_pages; i++)
724                                 __free_page(fw_buf->pages[i]);
725                         vfree(fw_buf->pages);
726                         fw_buf->pages = NULL;
727                         fw_buf->page_array_size = 0;
728                         fw_buf->nr_pages = 0;
729                         fw_state_start(&fw_buf->fw_st);
730                 }
731                 break;
732         case 0:
733                 if (fw_state_is_loading(&fw_buf->fw_st)) {
734                         int rc;
735
736                         /*
737                          * Several loading requests may be pending on
738                          * one same firmware buf, so let all requests
739                          * see the mapped 'buf->data' once the loading
740                          * is completed.
741                          * */
742                         rc = fw_map_pages_buf(fw_buf);
743                         if (rc)
744                                 dev_err(dev, "%s: map pages failed\n",
745                                         __func__);
746                         else
747                                 rc = security_kernel_post_read_file(NULL,
748                                                 fw_buf->data, fw_buf->size,
749                                                 READING_FIRMWARE);
750
751                         /*
752                          * Same logic as fw_load_abort, only the DONE bit
753                          * is ignored and we set ABORT only on failure.
754                          */
755                         list_del_init(&fw_buf->pending_list);
756                         if (rc) {
757                                 fw_state_aborted(&fw_buf->fw_st);
758                                 written = rc;
759                         } else {
760                                 fw_state_done(&fw_buf->fw_st);
761                         }
762                         break;
763                 }
764                 /* fallthrough */
765         default:
766                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
767                 /* fallthrough */
768         case -1:
769                 fw_load_abort(fw_priv);
770                 break;
771         }
772 out:
773         mutex_unlock(&fw_lock);
774         return written;
775 }
776
777 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
778
779 static void firmware_rw_buf(struct firmware_buf *buf, char *buffer,
780                            loff_t offset, size_t count, bool read)
781 {
782         if (read)
783                 memcpy(buffer, buf->data + offset, count);
784         else
785                 memcpy(buf->data + offset, buffer, count);
786 }
787
788 static void firmware_rw(struct firmware_buf *buf, char *buffer,
789                         loff_t offset, size_t count, bool read)
790 {
791         while (count) {
792                 void *page_data;
793                 int page_nr = offset >> PAGE_SHIFT;
794                 int page_ofs = offset & (PAGE_SIZE-1);
795                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
796
797                 page_data = kmap(buf->pages[page_nr]);
798
799                 if (read)
800                         memcpy(buffer, page_data + page_ofs, page_cnt);
801                 else
802                         memcpy(page_data + page_ofs, buffer, page_cnt);
803
804                 kunmap(buf->pages[page_nr]);
805                 buffer += page_cnt;
806                 offset += page_cnt;
807                 count -= page_cnt;
808         }
809 }
810
811 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
812                                   struct bin_attribute *bin_attr,
813                                   char *buffer, loff_t offset, size_t count)
814 {
815         struct device *dev = kobj_to_dev(kobj);
816         struct firmware_priv *fw_priv = to_firmware_priv(dev);
817         struct firmware_buf *buf;
818         ssize_t ret_count;
819
820         mutex_lock(&fw_lock);
821         buf = fw_priv->buf;
822         if (!buf || fw_state_is_done(&buf->fw_st)) {
823                 ret_count = -ENODEV;
824                 goto out;
825         }
826         if (offset > buf->size) {
827                 ret_count = 0;
828                 goto out;
829         }
830         if (count > buf->size - offset)
831                 count = buf->size - offset;
832
833         ret_count = count;
834
835         if (buf->data)
836                 firmware_rw_buf(buf, buffer, offset, count, true);
837         else
838                 firmware_rw(buf, buffer, offset, count, true);
839
840 out:
841         mutex_unlock(&fw_lock);
842         return ret_count;
843 }
844
845 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
846 {
847         struct firmware_buf *buf = fw_priv->buf;
848         int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT;
849
850         /* If the array of pages is too small, grow it... */
851         if (buf->page_array_size < pages_needed) {
852                 int new_array_size = max(pages_needed,
853                                          buf->page_array_size * 2);
854                 struct page **new_pages;
855
856                 new_pages = vmalloc(new_array_size * sizeof(void *));
857                 if (!new_pages) {
858                         fw_load_abort(fw_priv);
859                         return -ENOMEM;
860                 }
861                 memcpy(new_pages, buf->pages,
862                        buf->page_array_size * sizeof(void *));
863                 memset(&new_pages[buf->page_array_size], 0, sizeof(void *) *
864                        (new_array_size - buf->page_array_size));
865                 vfree(buf->pages);
866                 buf->pages = new_pages;
867                 buf->page_array_size = new_array_size;
868         }
869
870         while (buf->nr_pages < pages_needed) {
871                 buf->pages[buf->nr_pages] =
872                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
873
874                 if (!buf->pages[buf->nr_pages]) {
875                         fw_load_abort(fw_priv);
876                         return -ENOMEM;
877                 }
878                 buf->nr_pages++;
879         }
880         return 0;
881 }
882
883 /**
884  * firmware_data_write - write method for firmware
885  * @filp: open sysfs file
886  * @kobj: kobject for the device
887  * @bin_attr: bin_attr structure
888  * @buffer: buffer being written
889  * @offset: buffer offset for write in total data store area
890  * @count: buffer size
891  *
892  *      Data written to the 'data' attribute will be later handed to
893  *      the driver as a firmware image.
894  **/
895 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
896                                    struct bin_attribute *bin_attr,
897                                    char *buffer, loff_t offset, size_t count)
898 {
899         struct device *dev = kobj_to_dev(kobj);
900         struct firmware_priv *fw_priv = to_firmware_priv(dev);
901         struct firmware_buf *buf;
902         ssize_t retval;
903
904         if (!capable(CAP_SYS_RAWIO))
905                 return -EPERM;
906
907         mutex_lock(&fw_lock);
908         buf = fw_priv->buf;
909         if (!buf || fw_state_is_done(&buf->fw_st)) {
910                 retval = -ENODEV;
911                 goto out;
912         }
913
914         if (buf->data) {
915                 if (offset + count > buf->allocated_size) {
916                         retval = -ENOMEM;
917                         goto out;
918                 }
919                 firmware_rw_buf(buf, buffer, offset, count, false);
920                 retval = count;
921         } else {
922                 retval = fw_realloc_buffer(fw_priv, offset + count);
923                 if (retval)
924                         goto out;
925
926                 retval = count;
927                 firmware_rw(buf, buffer, offset, count, false);
928         }
929
930         buf->size = max_t(size_t, offset + count, buf->size);
931 out:
932         mutex_unlock(&fw_lock);
933         return retval;
934 }
935
936 static struct bin_attribute firmware_attr_data = {
937         .attr = { .name = "data", .mode = 0644 },
938         .size = 0,
939         .read = firmware_data_read,
940         .write = firmware_data_write,
941 };
942
943 static struct attribute *fw_dev_attrs[] = {
944         &dev_attr_loading.attr,
945         NULL
946 };
947
948 static struct bin_attribute *fw_dev_bin_attrs[] = {
949         &firmware_attr_data,
950         NULL
951 };
952
953 static const struct attribute_group fw_dev_attr_group = {
954         .attrs = fw_dev_attrs,
955         .bin_attrs = fw_dev_bin_attrs,
956 };
957
958 static const struct attribute_group *fw_dev_attr_groups[] = {
959         &fw_dev_attr_group,
960         NULL
961 };
962
963 static struct firmware_priv *
964 fw_create_instance(struct firmware *firmware, const char *fw_name,
965                    struct device *device, unsigned int opt_flags)
966 {
967         struct firmware_priv *fw_priv;
968         struct device *f_dev;
969
970         fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL);
971         if (!fw_priv) {
972                 fw_priv = ERR_PTR(-ENOMEM);
973                 goto exit;
974         }
975
976         fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT);
977         fw_priv->fw = firmware;
978         f_dev = &fw_priv->dev;
979
980         device_initialize(f_dev);
981         dev_set_name(f_dev, "%s", fw_name);
982         f_dev->parent = device;
983         f_dev->class = &firmware_class;
984         f_dev->groups = fw_dev_attr_groups;
985 exit:
986         return fw_priv;
987 }
988
989 /* load a firmware via user helper */
990 static int _request_firmware_load(struct firmware_priv *fw_priv,
991                                   unsigned int opt_flags, long timeout)
992 {
993         int retval = 0;
994         struct device *f_dev = &fw_priv->dev;
995         struct firmware_buf *buf = fw_priv->buf;
996
997         /* fall back on userspace loading */
998         if (!buf->data)
999                 buf->is_paged_buf = true;
1000
1001         dev_set_uevent_suppress(f_dev, true);
1002
1003         retval = device_add(f_dev);
1004         if (retval) {
1005                 dev_err(f_dev, "%s: device_register failed\n", __func__);
1006                 goto err_put_dev;
1007         }
1008
1009         mutex_lock(&fw_lock);
1010         list_add(&buf->pending_list, &pending_fw_head);
1011         mutex_unlock(&fw_lock);
1012
1013         if (opt_flags & FW_OPT_UEVENT) {
1014                 buf->need_uevent = true;
1015                 dev_set_uevent_suppress(f_dev, false);
1016                 dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id);
1017                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
1018         } else {
1019                 timeout = MAX_JIFFY_OFFSET;
1020         }
1021
1022         retval = fw_state_wait_timeout(&buf->fw_st, timeout);
1023         if (retval < 0) {
1024                 mutex_lock(&fw_lock);
1025                 fw_load_abort(fw_priv);
1026                 mutex_unlock(&fw_lock);
1027         }
1028
1029         if (fw_state_is_aborted(&buf->fw_st))
1030                 retval = -EAGAIN;
1031         else if (buf->is_paged_buf && !buf->data)
1032                 retval = -ENOMEM;
1033
1034         device_del(f_dev);
1035 err_put_dev:
1036         put_device(f_dev);
1037         return retval;
1038 }
1039
1040 static int fw_load_from_user_helper(struct firmware *firmware,
1041                                     const char *name, struct device *device,
1042                                     unsigned int opt_flags, long timeout)
1043 {
1044         struct firmware_priv *fw_priv;
1045
1046         fw_priv = fw_create_instance(firmware, name, device, opt_flags);
1047         if (IS_ERR(fw_priv))
1048                 return PTR_ERR(fw_priv);
1049
1050         fw_priv->buf = firmware->priv;
1051         return _request_firmware_load(fw_priv, opt_flags, timeout);
1052 }
1053
1054 #ifdef CONFIG_PM_SLEEP
1055 /* kill pending requests without uevent to avoid blocking suspend */
1056 static void kill_requests_without_uevent(void)
1057 {
1058         struct firmware_buf *buf;
1059         struct firmware_buf *next;
1060
1061         mutex_lock(&fw_lock);
1062         list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) {
1063                 if (!buf->need_uevent)
1064                          __fw_load_abort(buf);
1065         }
1066         mutex_unlock(&fw_lock);
1067 }
1068 #endif
1069
1070 #else /* CONFIG_FW_LOADER_USER_HELPER */
1071 static inline int
1072 fw_load_from_user_helper(struct firmware *firmware, const char *name,
1073                          struct device *device, unsigned int opt_flags,
1074                          long timeout)
1075 {
1076         return -ENOENT;
1077 }
1078
1079 #ifdef CONFIG_PM_SLEEP
1080 static inline void kill_requests_without_uevent(void) { }
1081 #endif
1082
1083 #endif /* CONFIG_FW_LOADER_USER_HELPER */
1084
1085 /* prepare firmware and firmware_buf structs;
1086  * return 0 if a firmware is already assigned, 1 if need to load one,
1087  * or a negative error code
1088  */
1089 static int
1090 _request_firmware_prepare(struct firmware **firmware_p, const char *name,
1091                           struct device *device, void *dbuf, size_t size)
1092 {
1093         struct firmware *firmware;
1094         struct firmware_buf *buf;
1095         int ret;
1096
1097         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
1098         if (!firmware) {
1099                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
1100                         __func__);
1101                 return -ENOMEM;
1102         }
1103
1104         if (fw_get_builtin_firmware(firmware, name, dbuf, size)) {
1105                 dev_dbg(device, "using built-in %s\n", name);
1106                 return 0; /* assigned */
1107         }
1108
1109         ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size);
1110
1111         /*
1112          * bind with 'buf' now to avoid warning in failure path
1113          * of requesting firmware.
1114          */
1115         firmware->priv = buf;
1116
1117         if (ret > 0) {
1118                 ret = fw_state_wait(&buf->fw_st);
1119                 if (!ret) {
1120                         fw_set_page_data(buf, firmware);
1121                         return 0; /* assigned */
1122                 }
1123         }
1124
1125         if (ret < 0)
1126                 return ret;
1127         return 1; /* need to load */
1128 }
1129
1130 static int assign_firmware_buf(struct firmware *fw, struct device *device,
1131                                unsigned int opt_flags)
1132 {
1133         struct firmware_buf *buf = fw->priv;
1134
1135         mutex_lock(&fw_lock);
1136         if (!buf->size || fw_state_is_aborted(&buf->fw_st)) {
1137                 mutex_unlock(&fw_lock);
1138                 return -ENOENT;
1139         }
1140
1141         /*
1142          * add firmware name into devres list so that we can auto cache
1143          * and uncache firmware for device.
1144          *
1145          * device may has been deleted already, but the problem
1146          * should be fixed in devres or driver core.
1147          */
1148         /* don't cache firmware handled without uevent */
1149         if (device && (opt_flags & FW_OPT_UEVENT) &&
1150             !(opt_flags & FW_OPT_NOCACHE))
1151                 fw_add_devm_name(device, buf->fw_id);
1152
1153         /*
1154          * After caching firmware image is started, let it piggyback
1155          * on request firmware.
1156          */
1157         if (!(opt_flags & FW_OPT_NOCACHE) &&
1158             buf->fwc->state == FW_LOADER_START_CACHE) {
1159                 if (fw_cache_piggyback_on_request(buf->fw_id))
1160                         kref_get(&buf->ref);
1161         }
1162
1163         /* pass the pages buffer to driver at the last minute */
1164         fw_set_page_data(buf, fw);
1165         mutex_unlock(&fw_lock);
1166         return 0;
1167 }
1168
1169 /* called from request_firmware() and request_firmware_work_func() */
1170 static int
1171 _request_firmware(const struct firmware **firmware_p, const char *name,
1172                   struct device *device, void *buf, size_t size,
1173                   unsigned int opt_flags)
1174 {
1175         struct firmware *fw = NULL;
1176         long timeout;
1177         int ret;
1178
1179         if (!firmware_p)
1180                 return -EINVAL;
1181
1182         if (!name || name[0] == '\0') {
1183                 ret = -EINVAL;
1184                 goto out;
1185         }
1186
1187         ret = _request_firmware_prepare(&fw, name, device, buf, size);
1188         if (ret <= 0) /* error or already assigned */
1189                 goto out;
1190
1191         ret = 0;
1192         timeout = firmware_loading_timeout();
1193         if (opt_flags & FW_OPT_NOWAIT) {
1194                 timeout = usermodehelper_read_lock_wait(timeout);
1195                 if (!timeout) {
1196                         dev_dbg(device, "firmware: %s loading timed out\n",
1197                                 name);
1198                         ret = -EBUSY;
1199                         goto out;
1200                 }
1201         } else {
1202                 ret = usermodehelper_read_trylock();
1203                 if (WARN_ON(ret)) {
1204                         dev_err(device, "firmware: %s will not be loaded\n",
1205                                 name);
1206                         goto out;
1207                 }
1208         }
1209
1210         ret = fw_get_filesystem_firmware(device, fw->priv);
1211         if (ret) {
1212                 if (!(opt_flags & FW_OPT_NO_WARN))
1213                         dev_warn(device,
1214                                  "Direct firmware load for %s failed with error %d\n",
1215                                  name, ret);
1216                 if (opt_flags & FW_OPT_USERHELPER) {
1217                         dev_warn(device, "Falling back to user helper\n");
1218                         ret = fw_load_from_user_helper(fw, name, device,
1219                                                        opt_flags, timeout);
1220                 }
1221         }
1222
1223         if (!ret)
1224                 ret = assign_firmware_buf(fw, device, opt_flags);
1225
1226         usermodehelper_read_unlock();
1227
1228  out:
1229         if (ret < 0) {
1230                 release_firmware(fw);
1231                 fw = NULL;
1232         }
1233
1234         *firmware_p = fw;
1235         return ret;
1236 }
1237
1238 /**
1239  * request_firmware: - send firmware request and wait for it
1240  * @firmware_p: pointer to firmware image
1241  * @name: name of firmware file
1242  * @device: device for which firmware is being loaded
1243  *
1244  *      @firmware_p will be used to return a firmware image by the name
1245  *      of @name for device @device.
1246  *
1247  *      Should be called from user context where sleeping is allowed.
1248  *
1249  *      @name will be used as $FIRMWARE in the uevent environment and
1250  *      should be distinctive enough not to be confused with any other
1251  *      firmware image for this or any other device.
1252  *
1253  *      Caller must hold the reference count of @device.
1254  *
1255  *      The function can be called safely inside device's suspend and
1256  *      resume callback.
1257  **/
1258 int
1259 request_firmware(const struct firmware **firmware_p, const char *name,
1260                  struct device *device)
1261 {
1262         int ret;
1263
1264         /* Need to pin this module until return */
1265         __module_get(THIS_MODULE);
1266         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1267                                 FW_OPT_UEVENT | FW_OPT_FALLBACK);
1268         module_put(THIS_MODULE);
1269         return ret;
1270 }
1271 EXPORT_SYMBOL(request_firmware);
1272
1273 /**
1274  * request_firmware_direct: - load firmware directly without usermode helper
1275  * @firmware_p: pointer to firmware image
1276  * @name: name of firmware file
1277  * @device: device for which firmware is being loaded
1278  *
1279  * This function works pretty much like request_firmware(), but this doesn't
1280  * fall back to usermode helper even if the firmware couldn't be loaded
1281  * directly from fs.  Hence it's useful for loading optional firmwares, which
1282  * aren't always present, without extra long timeouts of udev.
1283  **/
1284 int request_firmware_direct(const struct firmware **firmware_p,
1285                             const char *name, struct device *device)
1286 {
1287         int ret;
1288
1289         __module_get(THIS_MODULE);
1290         ret = _request_firmware(firmware_p, name, device, NULL, 0,
1291                                 FW_OPT_UEVENT | FW_OPT_NO_WARN);
1292         module_put(THIS_MODULE);
1293         return ret;
1294 }
1295 EXPORT_SYMBOL_GPL(request_firmware_direct);
1296
1297 /**
1298  * request_firmware_into_buf - load firmware into a previously allocated buffer
1299  * @firmware_p: pointer to firmware image
1300  * @name: name of firmware file
1301  * @device: device for which firmware is being loaded and DMA region allocated
1302  * @buf: address of buffer to load firmware into
1303  * @size: size of buffer
1304  *
1305  * This function works pretty much like request_firmware(), but it doesn't
1306  * allocate a buffer to hold the firmware data. Instead, the firmware
1307  * is loaded directly into the buffer pointed to by @buf and the @firmware_p
1308  * data member is pointed at @buf.
1309  *
1310  * This function doesn't cache firmware either.
1311  */
1312 int
1313 request_firmware_into_buf(const struct firmware **firmware_p, const char *name,
1314                           struct device *device, void *buf, size_t size)
1315 {
1316         int ret;
1317
1318         __module_get(THIS_MODULE);
1319         ret = _request_firmware(firmware_p, name, device, buf, size,
1320                                 FW_OPT_UEVENT | FW_OPT_FALLBACK |
1321                                 FW_OPT_NOCACHE);
1322         module_put(THIS_MODULE);
1323         return ret;
1324 }
1325 EXPORT_SYMBOL(request_firmware_into_buf);
1326
1327 /**
1328  * release_firmware: - release the resource associated with a firmware image
1329  * @fw: firmware resource to release
1330  **/
1331 void release_firmware(const struct firmware *fw)
1332 {
1333         if (fw) {
1334                 if (!fw_is_builtin_firmware(fw))
1335                         firmware_free_data(fw);
1336                 kfree(fw);
1337         }
1338 }
1339 EXPORT_SYMBOL(release_firmware);
1340
1341 /* Async support */
1342 struct firmware_work {
1343         struct work_struct work;
1344         struct module *module;
1345         const char *name;
1346         struct device *device;
1347         void *context;
1348         void (*cont)(const struct firmware *fw, void *context);
1349         unsigned int opt_flags;
1350 };
1351
1352 static void request_firmware_work_func(struct work_struct *work)
1353 {
1354         struct firmware_work *fw_work;
1355         const struct firmware *fw;
1356
1357         fw_work = container_of(work, struct firmware_work, work);
1358
1359         _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0,
1360                           fw_work->opt_flags);
1361         fw_work->cont(fw, fw_work->context);
1362         put_device(fw_work->device); /* taken in request_firmware_nowait() */
1363
1364         module_put(fw_work->module);
1365         kfree_const(fw_work->name);
1366         kfree(fw_work);
1367 }
1368
1369 /**
1370  * request_firmware_nowait - asynchronous version of request_firmware
1371  * @module: module requesting the firmware
1372  * @uevent: sends uevent to copy the firmware image if this flag
1373  *      is non-zero else the firmware copy must be done manually.
1374  * @name: name of firmware file
1375  * @device: device for which firmware is being loaded
1376  * @gfp: allocation flags
1377  * @context: will be passed over to @cont, and
1378  *      @fw may be %NULL if firmware request fails.
1379  * @cont: function will be called asynchronously when the firmware
1380  *      request is over.
1381  *
1382  *      Caller must hold the reference count of @device.
1383  *
1384  *      Asynchronous variant of request_firmware() for user contexts:
1385  *              - sleep for as small periods as possible since it may
1386  *                increase kernel boot time of built-in device drivers
1387  *                requesting firmware in their ->probe() methods, if
1388  *                @gfp is GFP_KERNEL.
1389  *
1390  *              - can't sleep at all if @gfp is GFP_ATOMIC.
1391  **/
1392 int
1393 request_firmware_nowait(
1394         struct module *module, bool uevent,
1395         const char *name, struct device *device, gfp_t gfp, void *context,
1396         void (*cont)(const struct firmware *fw, void *context))
1397 {
1398         struct firmware_work *fw_work;
1399
1400         fw_work = kzalloc(sizeof(struct firmware_work), gfp);
1401         if (!fw_work)
1402                 return -ENOMEM;
1403
1404         fw_work->module = module;
1405         fw_work->name = kstrdup_const(name, gfp);
1406         if (!fw_work->name) {
1407                 kfree(fw_work);
1408                 return -ENOMEM;
1409         }
1410         fw_work->device = device;
1411         fw_work->context = context;
1412         fw_work->cont = cont;
1413         fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK |
1414                 (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER);
1415
1416         if (!try_module_get(module)) {
1417                 kfree_const(fw_work->name);
1418                 kfree(fw_work);
1419                 return -EFAULT;
1420         }
1421
1422         get_device(fw_work->device);
1423         INIT_WORK(&fw_work->work, request_firmware_work_func);
1424         schedule_work(&fw_work->work);
1425         return 0;
1426 }
1427 EXPORT_SYMBOL(request_firmware_nowait);
1428
1429 #ifdef CONFIG_PM_SLEEP
1430 static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain);
1431
1432 /**
1433  * cache_firmware - cache one firmware image in kernel memory space
1434  * @fw_name: the firmware image name
1435  *
1436  * Cache firmware in kernel memory so that drivers can use it when
1437  * system isn't ready for them to request firmware image from userspace.
1438  * Once it returns successfully, driver can use request_firmware or its
1439  * nowait version to get the cached firmware without any interacting
1440  * with userspace
1441  *
1442  * Return 0 if the firmware image has been cached successfully
1443  * Return !0 otherwise
1444  *
1445  */
1446 static int cache_firmware(const char *fw_name)
1447 {
1448         int ret;
1449         const struct firmware *fw;
1450
1451         pr_debug("%s: %s\n", __func__, fw_name);
1452
1453         ret = request_firmware(&fw, fw_name, NULL);
1454         if (!ret)
1455                 kfree(fw);
1456
1457         pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret);
1458
1459         return ret;
1460 }
1461
1462 static struct firmware_buf *fw_lookup_buf(const char *fw_name)
1463 {
1464         struct firmware_buf *tmp;
1465         struct firmware_cache *fwc = &fw_cache;
1466
1467         spin_lock(&fwc->lock);
1468         tmp = __fw_lookup_buf(fw_name);
1469         spin_unlock(&fwc->lock);
1470
1471         return tmp;
1472 }
1473
1474 /**
1475  * uncache_firmware - remove one cached firmware image
1476  * @fw_name: the firmware image name
1477  *
1478  * Uncache one firmware image which has been cached successfully
1479  * before.
1480  *
1481  * Return 0 if the firmware cache has been removed successfully
1482  * Return !0 otherwise
1483  *
1484  */
1485 static int uncache_firmware(const char *fw_name)
1486 {
1487         struct firmware_buf *buf;
1488         struct firmware fw;
1489
1490         pr_debug("%s: %s\n", __func__, fw_name);
1491
1492         if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0))
1493                 return 0;
1494
1495         buf = fw_lookup_buf(fw_name);
1496         if (buf) {
1497                 fw_free_buf(buf);
1498                 return 0;
1499         }
1500
1501         return -EINVAL;
1502 }
1503
1504 static struct fw_cache_entry *alloc_fw_cache_entry(const char *name)
1505 {
1506         struct fw_cache_entry *fce;
1507
1508         fce = kzalloc(sizeof(*fce), GFP_ATOMIC);
1509         if (!fce)
1510                 goto exit;
1511
1512         fce->name = kstrdup_const(name, GFP_ATOMIC);
1513         if (!fce->name) {
1514                 kfree(fce);
1515                 fce = NULL;
1516                 goto exit;
1517         }
1518 exit:
1519         return fce;
1520 }
1521
1522 static int __fw_entry_found(const char *name)
1523 {
1524         struct firmware_cache *fwc = &fw_cache;
1525         struct fw_cache_entry *fce;
1526
1527         list_for_each_entry(fce, &fwc->fw_names, list) {
1528                 if (!strcmp(fce->name, name))
1529                         return 1;
1530         }
1531         return 0;
1532 }
1533
1534 static int fw_cache_piggyback_on_request(const char *name)
1535 {
1536         struct firmware_cache *fwc = &fw_cache;
1537         struct fw_cache_entry *fce;
1538         int ret = 0;
1539
1540         spin_lock(&fwc->name_lock);
1541         if (__fw_entry_found(name))
1542                 goto found;
1543
1544         fce = alloc_fw_cache_entry(name);
1545         if (fce) {
1546                 ret = 1;
1547                 list_add(&fce->list, &fwc->fw_names);
1548                 pr_debug("%s: fw: %s\n", __func__, name);
1549         }
1550 found:
1551         spin_unlock(&fwc->name_lock);
1552         return ret;
1553 }
1554
1555 static void free_fw_cache_entry(struct fw_cache_entry *fce)
1556 {
1557         kfree_const(fce->name);
1558         kfree(fce);
1559 }
1560
1561 static void __async_dev_cache_fw_image(void *fw_entry,
1562                                        async_cookie_t cookie)
1563 {
1564         struct fw_cache_entry *fce = fw_entry;
1565         struct firmware_cache *fwc = &fw_cache;
1566         int ret;
1567
1568         ret = cache_firmware(fce->name);
1569         if (ret) {
1570                 spin_lock(&fwc->name_lock);
1571                 list_del(&fce->list);
1572                 spin_unlock(&fwc->name_lock);
1573
1574                 free_fw_cache_entry(fce);
1575         }
1576 }
1577
1578 /* called with dev->devres_lock held */
1579 static void dev_create_fw_entry(struct device *dev, void *res,
1580                                 void *data)
1581 {
1582         struct fw_name_devm *fwn = res;
1583         const char *fw_name = fwn->name;
1584         struct list_head *head = data;
1585         struct fw_cache_entry *fce;
1586
1587         fce = alloc_fw_cache_entry(fw_name);
1588         if (fce)
1589                 list_add(&fce->list, head);
1590 }
1591
1592 static int devm_name_match(struct device *dev, void *res,
1593                            void *match_data)
1594 {
1595         struct fw_name_devm *fwn = res;
1596         return (fwn->magic == (unsigned long)match_data);
1597 }
1598
1599 static void dev_cache_fw_image(struct device *dev, void *data)
1600 {
1601         LIST_HEAD(todo);
1602         struct fw_cache_entry *fce;
1603         struct fw_cache_entry *fce_next;
1604         struct firmware_cache *fwc = &fw_cache;
1605
1606         devres_for_each_res(dev, fw_name_devm_release,
1607                             devm_name_match, &fw_cache,
1608                             dev_create_fw_entry, &todo);
1609
1610         list_for_each_entry_safe(fce, fce_next, &todo, list) {
1611                 list_del(&fce->list);
1612
1613                 spin_lock(&fwc->name_lock);
1614                 /* only one cache entry for one firmware */
1615                 if (!__fw_entry_found(fce->name)) {
1616                         list_add(&fce->list, &fwc->fw_names);
1617                 } else {
1618                         free_fw_cache_entry(fce);
1619                         fce = NULL;
1620                 }
1621                 spin_unlock(&fwc->name_lock);
1622
1623                 if (fce)
1624                         async_schedule_domain(__async_dev_cache_fw_image,
1625                                               (void *)fce,
1626                                               &fw_cache_domain);
1627         }
1628 }
1629
1630 static void __device_uncache_fw_images(void)
1631 {
1632         struct firmware_cache *fwc = &fw_cache;
1633         struct fw_cache_entry *fce;
1634
1635         spin_lock(&fwc->name_lock);
1636         while (!list_empty(&fwc->fw_names)) {
1637                 fce = list_entry(fwc->fw_names.next,
1638                                 struct fw_cache_entry, list);
1639                 list_del(&fce->list);
1640                 spin_unlock(&fwc->name_lock);
1641
1642                 uncache_firmware(fce->name);
1643                 free_fw_cache_entry(fce);
1644
1645                 spin_lock(&fwc->name_lock);
1646         }
1647         spin_unlock(&fwc->name_lock);
1648 }
1649
1650 /**
1651  * device_cache_fw_images - cache devices' firmware
1652  *
1653  * If one device called request_firmware or its nowait version
1654  * successfully before, the firmware names are recored into the
1655  * device's devres link list, so device_cache_fw_images can call
1656  * cache_firmware() to cache these firmwares for the device,
1657  * then the device driver can load its firmwares easily at
1658  * time when system is not ready to complete loading firmware.
1659  */
1660 static void device_cache_fw_images(void)
1661 {
1662         struct firmware_cache *fwc = &fw_cache;
1663         int old_timeout;
1664         DEFINE_WAIT(wait);
1665
1666         pr_debug("%s\n", __func__);
1667
1668         /* cancel uncache work */
1669         cancel_delayed_work_sync(&fwc->work);
1670
1671         /*
1672          * use small loading timeout for caching devices' firmware
1673          * because all these firmware images have been loaded
1674          * successfully at lease once, also system is ready for
1675          * completing firmware loading now. The maximum size of
1676          * firmware in current distributions is about 2M bytes,
1677          * so 10 secs should be enough.
1678          */
1679         old_timeout = loading_timeout;
1680         loading_timeout = 10;
1681
1682         mutex_lock(&fw_lock);
1683         fwc->state = FW_LOADER_START_CACHE;
1684         dpm_for_each_dev(NULL, dev_cache_fw_image);
1685         mutex_unlock(&fw_lock);
1686
1687         /* wait for completion of caching firmware for all devices */
1688         async_synchronize_full_domain(&fw_cache_domain);
1689
1690         loading_timeout = old_timeout;
1691 }
1692
1693 /**
1694  * device_uncache_fw_images - uncache devices' firmware
1695  *
1696  * uncache all firmwares which have been cached successfully
1697  * by device_uncache_fw_images earlier
1698  */
1699 static void device_uncache_fw_images(void)
1700 {
1701         pr_debug("%s\n", __func__);
1702         __device_uncache_fw_images();
1703 }
1704
1705 static void device_uncache_fw_images_work(struct work_struct *work)
1706 {
1707         device_uncache_fw_images();
1708 }
1709
1710 /**
1711  * device_uncache_fw_images_delay - uncache devices firmwares
1712  * @delay: number of milliseconds to delay uncache device firmwares
1713  *
1714  * uncache all devices's firmwares which has been cached successfully
1715  * by device_cache_fw_images after @delay milliseconds.
1716  */
1717 static void device_uncache_fw_images_delay(unsigned long delay)
1718 {
1719         queue_delayed_work(system_power_efficient_wq, &fw_cache.work,
1720                            msecs_to_jiffies(delay));
1721 }
1722
1723 static int fw_pm_notify(struct notifier_block *notify_block,
1724                         unsigned long mode, void *unused)
1725 {
1726         switch (mode) {
1727         case PM_HIBERNATION_PREPARE:
1728         case PM_SUSPEND_PREPARE:
1729         case PM_RESTORE_PREPARE:
1730                 kill_requests_without_uevent();
1731                 device_cache_fw_images();
1732                 break;
1733
1734         case PM_POST_SUSPEND:
1735         case PM_POST_HIBERNATION:
1736         case PM_POST_RESTORE:
1737                 /*
1738                  * In case that system sleep failed and syscore_suspend is
1739                  * not called.
1740                  */
1741                 mutex_lock(&fw_lock);
1742                 fw_cache.state = FW_LOADER_NO_CACHE;
1743                 mutex_unlock(&fw_lock);
1744
1745                 device_uncache_fw_images_delay(10 * MSEC_PER_SEC);
1746                 break;
1747         }
1748
1749         return 0;
1750 }
1751
1752 /* stop caching firmware once syscore_suspend is reached */
1753 static int fw_suspend(void)
1754 {
1755         fw_cache.state = FW_LOADER_NO_CACHE;
1756         return 0;
1757 }
1758
1759 static struct syscore_ops fw_syscore_ops = {
1760         .suspend = fw_suspend,
1761 };
1762 #else
1763 static int fw_cache_piggyback_on_request(const char *name)
1764 {
1765         return 0;
1766 }
1767 #endif
1768
1769 static void __init fw_cache_init(void)
1770 {
1771         spin_lock_init(&fw_cache.lock);
1772         INIT_LIST_HEAD(&fw_cache.head);
1773         fw_cache.state = FW_LOADER_NO_CACHE;
1774
1775 #ifdef CONFIG_PM_SLEEP
1776         spin_lock_init(&fw_cache.name_lock);
1777         INIT_LIST_HEAD(&fw_cache.fw_names);
1778
1779         INIT_DELAYED_WORK(&fw_cache.work,
1780                           device_uncache_fw_images_work);
1781
1782         fw_cache.pm_notify.notifier_call = fw_pm_notify;
1783         register_pm_notifier(&fw_cache.pm_notify);
1784
1785         register_syscore_ops(&fw_syscore_ops);
1786 #endif
1787 }
1788
1789 static int __init firmware_class_init(void)
1790 {
1791         fw_cache_init();
1792 #ifdef CONFIG_FW_LOADER_USER_HELPER
1793         register_reboot_notifier(&fw_shutdown_nb);
1794         return class_register(&firmware_class);
1795 #else
1796         return 0;
1797 #endif
1798 }
1799
1800 static void __exit firmware_class_exit(void)
1801 {
1802 #ifdef CONFIG_PM_SLEEP
1803         unregister_syscore_ops(&fw_syscore_ops);
1804         unregister_pm_notifier(&fw_cache.pm_notify);
1805 #endif
1806 #ifdef CONFIG_FW_LOADER_USER_HELPER
1807         unregister_reboot_notifier(&fw_shutdown_nb);
1808         class_unregister(&firmware_class);
1809 #endif
1810 }
1811
1812 fs_initcall(firmware_class_init);
1813 module_exit(firmware_class_exit);