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