usb: dwc3: gadget: fix ep->maxburst for ep0
[linux-2.6.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
25 #define to_dev(obj) container_of(obj, struct device, kobj)
26
27 MODULE_AUTHOR("Manuel Estrada Sainz");
28 MODULE_DESCRIPTION("Multi purpose firmware loading support");
29 MODULE_LICENSE("GPL");
30
31 /* Builtin firmware support */
32
33 #ifdef CONFIG_FW_LOADER
34
35 extern struct builtin_fw __start_builtin_fw[];
36 extern struct builtin_fw __end_builtin_fw[];
37
38 static bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
39 {
40         struct builtin_fw *b_fw;
41
42         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) {
43                 if (strcmp(name, b_fw->name) == 0) {
44                         fw->size = b_fw->size;
45                         fw->data = b_fw->data;
46                         return true;
47                 }
48         }
49
50         return false;
51 }
52
53 static bool fw_is_builtin_firmware(const struct firmware *fw)
54 {
55         struct builtin_fw *b_fw;
56
57         for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++)
58                 if (fw->data == b_fw->data)
59                         return true;
60
61         return false;
62 }
63
64 #else /* Module case - no builtin firmware support */
65
66 static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name)
67 {
68         return false;
69 }
70
71 static inline bool fw_is_builtin_firmware(const struct firmware *fw)
72 {
73         return false;
74 }
75 #endif
76
77 enum {
78         FW_STATUS_LOADING,
79         FW_STATUS_DONE,
80         FW_STATUS_ABORT,
81 };
82
83 static int loading_timeout = 60;        /* In seconds */
84
85 static inline long firmware_loading_timeout(void)
86 {
87         return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT;
88 }
89
90 /* fw_lock could be moved to 'struct firmware_priv' but since it is just
91  * guarding for corner cases a global lock should be OK */
92 static DEFINE_MUTEX(fw_lock);
93
94 struct firmware_priv {
95         struct completion completion;
96         struct firmware *fw;
97         unsigned long status;
98         struct page **pages;
99         int nr_pages;
100         int page_array_size;
101         struct timer_list timeout;
102         struct device dev;
103         bool nowait;
104         char fw_id[];
105 };
106
107 static struct firmware_priv *to_firmware_priv(struct device *dev)
108 {
109         return container_of(dev, struct firmware_priv, dev);
110 }
111
112 static void fw_load_abort(struct firmware_priv *fw_priv)
113 {
114         set_bit(FW_STATUS_ABORT, &fw_priv->status);
115         wmb();
116         complete(&fw_priv->completion);
117 }
118
119 static ssize_t firmware_timeout_show(struct class *class,
120                                      struct class_attribute *attr,
121                                      char *buf)
122 {
123         return sprintf(buf, "%d\n", loading_timeout);
124 }
125
126 /**
127  * firmware_timeout_store - set number of seconds to wait for firmware
128  * @class: device class pointer
129  * @attr: device attribute pointer
130  * @buf: buffer to scan for timeout value
131  * @count: number of bytes in @buf
132  *
133  *      Sets the number of seconds to wait for the firmware.  Once
134  *      this expires an error will be returned to the driver and no
135  *      firmware will be provided.
136  *
137  *      Note: zero means 'wait forever'.
138  **/
139 static ssize_t firmware_timeout_store(struct class *class,
140                                       struct class_attribute *attr,
141                                       const char *buf, size_t count)
142 {
143         loading_timeout = simple_strtol(buf, NULL, 10);
144         if (loading_timeout < 0)
145                 loading_timeout = 0;
146
147         return count;
148 }
149
150 static struct class_attribute firmware_class_attrs[] = {
151         __ATTR(timeout, S_IWUSR | S_IRUGO,
152                 firmware_timeout_show, firmware_timeout_store),
153         __ATTR_NULL
154 };
155
156 static void fw_dev_release(struct device *dev)
157 {
158         struct firmware_priv *fw_priv = to_firmware_priv(dev);
159         int i;
160
161         for (i = 0; i < fw_priv->nr_pages; i++)
162                 __free_page(fw_priv->pages[i]);
163         kfree(fw_priv->pages);
164         kfree(fw_priv);
165
166         module_put(THIS_MODULE);
167 }
168
169 static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env)
170 {
171         struct firmware_priv *fw_priv = to_firmware_priv(dev);
172
173         if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->fw_id))
174                 return -ENOMEM;
175         if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout))
176                 return -ENOMEM;
177         if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait))
178                 return -ENOMEM;
179
180         return 0;
181 }
182
183 static struct class firmware_class = {
184         .name           = "firmware",
185         .class_attrs    = firmware_class_attrs,
186         .dev_uevent     = firmware_uevent,
187         .dev_release    = fw_dev_release,
188 };
189
190 static ssize_t firmware_loading_show(struct device *dev,
191                                      struct device_attribute *attr, char *buf)
192 {
193         struct firmware_priv *fw_priv = to_firmware_priv(dev);
194         int loading = test_bit(FW_STATUS_LOADING, &fw_priv->status);
195
196         return sprintf(buf, "%d\n", loading);
197 }
198
199 static void firmware_free_data(const struct firmware *fw)
200 {
201         int i;
202         vunmap(fw->data);
203         if (fw->pages) {
204                 for (i = 0; i < PFN_UP(fw->size); i++)
205                         __free_page(fw->pages[i]);
206                 kfree(fw->pages);
207         }
208 }
209
210 /* Some architectures don't have PAGE_KERNEL_RO */
211 #ifndef PAGE_KERNEL_RO
212 #define PAGE_KERNEL_RO PAGE_KERNEL
213 #endif
214 /**
215  * firmware_loading_store - set value in the 'loading' control file
216  * @dev: device pointer
217  * @attr: device attribute pointer
218  * @buf: buffer to scan for loading control value
219  * @count: number of bytes in @buf
220  *
221  *      The relevant values are:
222  *
223  *       1: Start a load, discarding any previous partial load.
224  *       0: Conclude the load and hand the data to the driver code.
225  *      -1: Conclude the load with an error and discard any written data.
226  **/
227 static ssize_t firmware_loading_store(struct device *dev,
228                                       struct device_attribute *attr,
229                                       const char *buf, size_t count)
230 {
231         struct firmware_priv *fw_priv = to_firmware_priv(dev);
232         int loading = simple_strtol(buf, NULL, 10);
233         int i;
234
235         mutex_lock(&fw_lock);
236
237         if (!fw_priv->fw)
238                 goto out;
239
240         switch (loading) {
241         case 1:
242                 firmware_free_data(fw_priv->fw);
243                 memset(fw_priv->fw, 0, sizeof(struct firmware));
244                 /* If the pages are not owned by 'struct firmware' */
245                 for (i = 0; i < fw_priv->nr_pages; i++)
246                         __free_page(fw_priv->pages[i]);
247                 kfree(fw_priv->pages);
248                 fw_priv->pages = NULL;
249                 fw_priv->page_array_size = 0;
250                 fw_priv->nr_pages = 0;
251                 set_bit(FW_STATUS_LOADING, &fw_priv->status);
252                 break;
253         case 0:
254                 if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) {
255                         vunmap(fw_priv->fw->data);
256                         fw_priv->fw->data = vmap(fw_priv->pages,
257                                                  fw_priv->nr_pages,
258                                                  0, PAGE_KERNEL_RO);
259                         if (!fw_priv->fw->data) {
260                                 dev_err(dev, "%s: vmap() failed\n", __func__);
261                                 goto err;
262                         }
263                         /* Pages are now owned by 'struct firmware' */
264                         fw_priv->fw->pages = fw_priv->pages;
265                         fw_priv->pages = NULL;
266
267                         fw_priv->page_array_size = 0;
268                         fw_priv->nr_pages = 0;
269                         complete(&fw_priv->completion);
270                         clear_bit(FW_STATUS_LOADING, &fw_priv->status);
271                         break;
272                 }
273                 /* fallthrough */
274         default:
275                 dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading);
276                 /* fallthrough */
277         case -1:
278         err:
279                 fw_load_abort(fw_priv);
280                 break;
281         }
282 out:
283         mutex_unlock(&fw_lock);
284         return count;
285 }
286
287 static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store);
288
289 static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj,
290                                   struct bin_attribute *bin_attr,
291                                   char *buffer, loff_t offset, size_t count)
292 {
293         struct device *dev = to_dev(kobj);
294         struct firmware_priv *fw_priv = to_firmware_priv(dev);
295         struct firmware *fw;
296         ssize_t ret_count;
297
298         mutex_lock(&fw_lock);
299         fw = fw_priv->fw;
300         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
301                 ret_count = -ENODEV;
302                 goto out;
303         }
304         if (offset > fw->size) {
305                 ret_count = 0;
306                 goto out;
307         }
308         if (count > fw->size - offset)
309                 count = fw->size - offset;
310
311         ret_count = count;
312
313         while (count) {
314                 void *page_data;
315                 int page_nr = offset >> PAGE_SHIFT;
316                 int page_ofs = offset & (PAGE_SIZE-1);
317                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
318
319                 page_data = kmap(fw_priv->pages[page_nr]);
320
321                 memcpy(buffer, page_data + page_ofs, page_cnt);
322
323                 kunmap(fw_priv->pages[page_nr]);
324                 buffer += page_cnt;
325                 offset += page_cnt;
326                 count -= page_cnt;
327         }
328 out:
329         mutex_unlock(&fw_lock);
330         return ret_count;
331 }
332
333 static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size)
334 {
335         int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT;
336
337         /* If the array of pages is too small, grow it... */
338         if (fw_priv->page_array_size < pages_needed) {
339                 int new_array_size = max(pages_needed,
340                                          fw_priv->page_array_size * 2);
341                 struct page **new_pages;
342
343                 new_pages = kmalloc(new_array_size * sizeof(void *),
344                                     GFP_KERNEL);
345                 if (!new_pages) {
346                         fw_load_abort(fw_priv);
347                         return -ENOMEM;
348                 }
349                 memcpy(new_pages, fw_priv->pages,
350                        fw_priv->page_array_size * sizeof(void *));
351                 memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) *
352                        (new_array_size - fw_priv->page_array_size));
353                 kfree(fw_priv->pages);
354                 fw_priv->pages = new_pages;
355                 fw_priv->page_array_size = new_array_size;
356         }
357
358         while (fw_priv->nr_pages < pages_needed) {
359                 fw_priv->pages[fw_priv->nr_pages] =
360                         alloc_page(GFP_KERNEL | __GFP_HIGHMEM);
361
362                 if (!fw_priv->pages[fw_priv->nr_pages]) {
363                         fw_load_abort(fw_priv);
364                         return -ENOMEM;
365                 }
366                 fw_priv->nr_pages++;
367         }
368         return 0;
369 }
370
371 /**
372  * firmware_data_write - write method for firmware
373  * @filp: open sysfs file
374  * @kobj: kobject for the device
375  * @bin_attr: bin_attr structure
376  * @buffer: buffer being written
377  * @offset: buffer offset for write in total data store area
378  * @count: buffer size
379  *
380  *      Data written to the 'data' attribute will be later handed to
381  *      the driver as a firmware image.
382  **/
383 static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj,
384                                    struct bin_attribute *bin_attr,
385                                    char *buffer, loff_t offset, size_t count)
386 {
387         struct device *dev = to_dev(kobj);
388         struct firmware_priv *fw_priv = to_firmware_priv(dev);
389         struct firmware *fw;
390         ssize_t retval;
391
392         if (!capable(CAP_SYS_RAWIO))
393                 return -EPERM;
394
395         mutex_lock(&fw_lock);
396         fw = fw_priv->fw;
397         if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) {
398                 retval = -ENODEV;
399                 goto out;
400         }
401         retval = fw_realloc_buffer(fw_priv, offset + count);
402         if (retval)
403                 goto out;
404
405         retval = count;
406
407         while (count) {
408                 void *page_data;
409                 int page_nr = offset >> PAGE_SHIFT;
410                 int page_ofs = offset & (PAGE_SIZE - 1);
411                 int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count);
412
413                 page_data = kmap(fw_priv->pages[page_nr]);
414
415                 memcpy(page_data + page_ofs, buffer, page_cnt);
416
417                 kunmap(fw_priv->pages[page_nr]);
418                 buffer += page_cnt;
419                 offset += page_cnt;
420                 count -= page_cnt;
421         }
422
423         fw->size = max_t(size_t, offset, fw->size);
424 out:
425         mutex_unlock(&fw_lock);
426         return retval;
427 }
428
429 static struct bin_attribute firmware_attr_data = {
430         .attr = { .name = "data", .mode = 0644 },
431         .size = 0,
432         .read = firmware_data_read,
433         .write = firmware_data_write,
434 };
435
436 static void firmware_class_timeout(u_long data)
437 {
438         struct firmware_priv *fw_priv = (struct firmware_priv *) data;
439
440         fw_load_abort(fw_priv);
441 }
442
443 static struct firmware_priv *
444 fw_create_instance(struct firmware *firmware, const char *fw_name,
445                    struct device *device, bool uevent, bool nowait)
446 {
447         struct firmware_priv *fw_priv;
448         struct device *f_dev;
449
450         fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL);
451         if (!fw_priv) {
452                 dev_err(device, "%s: kmalloc failed\n", __func__);
453                 return ERR_PTR(-ENOMEM);
454         }
455
456         fw_priv->fw = firmware;
457         fw_priv->nowait = nowait;
458         strcpy(fw_priv->fw_id, fw_name);
459         init_completion(&fw_priv->completion);
460         setup_timer(&fw_priv->timeout,
461                     firmware_class_timeout, (u_long) fw_priv);
462
463         f_dev = &fw_priv->dev;
464
465         device_initialize(f_dev);
466         dev_set_name(f_dev, "%s", dev_name(device));
467         f_dev->parent = device;
468         f_dev->class = &firmware_class;
469
470         return fw_priv;
471 }
472
473 static struct firmware_priv *
474 _request_firmware_prepare(const struct firmware **firmware_p, const char *name,
475                           struct device *device, bool uevent, bool nowait)
476 {
477         struct firmware *firmware;
478         struct firmware_priv *fw_priv;
479
480         if (!firmware_p)
481                 return ERR_PTR(-EINVAL);
482
483         *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL);
484         if (!firmware) {
485                 dev_err(device, "%s: kmalloc(struct firmware) failed\n",
486                         __func__);
487                 return ERR_PTR(-ENOMEM);
488         }
489
490         if (fw_get_builtin_firmware(firmware, name)) {
491                 dev_dbg(device, "firmware: using built-in firmware %s\n", name);
492                 return NULL;
493         }
494
495         fw_priv = fw_create_instance(firmware, name, device, uevent, nowait);
496         if (IS_ERR(fw_priv)) {
497                 release_firmware(firmware);
498                 *firmware_p = NULL;
499         }
500         return fw_priv;
501 }
502
503 static void _request_firmware_cleanup(const struct firmware **firmware_p)
504 {
505         release_firmware(*firmware_p);
506         *firmware_p = NULL;
507 }
508
509 static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent,
510                                   long timeout)
511 {
512         int retval = 0;
513         struct device *f_dev = &fw_priv->dev;
514
515         dev_set_uevent_suppress(f_dev, true);
516
517         /* Need to pin this module until class device is destroyed */
518         __module_get(THIS_MODULE);
519
520         retval = device_add(f_dev);
521         if (retval) {
522                 dev_err(f_dev, "%s: device_register failed\n", __func__);
523                 goto err_put_dev;
524         }
525
526         retval = device_create_bin_file(f_dev, &firmware_attr_data);
527         if (retval) {
528                 dev_err(f_dev, "%s: sysfs_create_bin_file failed\n", __func__);
529                 goto err_del_dev;
530         }
531
532         retval = device_create_file(f_dev, &dev_attr_loading);
533         if (retval) {
534                 dev_err(f_dev, "%s: device_create_file failed\n", __func__);
535                 goto err_del_bin_attr;
536         }
537
538         if (uevent) {
539                 dev_set_uevent_suppress(f_dev, false);
540                 dev_dbg(f_dev, "firmware: requesting %s\n", fw_priv->fw_id);
541                 if (timeout != MAX_SCHEDULE_TIMEOUT)
542                         mod_timer(&fw_priv->timeout,
543                                   round_jiffies_up(jiffies + timeout));
544
545                 kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD);
546         }
547
548         wait_for_completion(&fw_priv->completion);
549
550         set_bit(FW_STATUS_DONE, &fw_priv->status);
551         del_timer_sync(&fw_priv->timeout);
552
553         mutex_lock(&fw_lock);
554         if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status))
555                 retval = -ENOENT;
556         fw_priv->fw = NULL;
557         mutex_unlock(&fw_lock);
558
559         device_remove_file(f_dev, &dev_attr_loading);
560 err_del_bin_attr:
561         device_remove_bin_file(f_dev, &firmware_attr_data);
562 err_del_dev:
563         device_del(f_dev);
564 err_put_dev:
565         put_device(f_dev);
566         return retval;
567 }
568
569 /**
570  * request_firmware: - send firmware request and wait for it
571  * @firmware_p: pointer to firmware image
572  * @name: name of firmware file
573  * @device: device for which firmware is being loaded
574  *
575  *      @firmware_p will be used to return a firmware image by the name
576  *      of @name for device @device.
577  *
578  *      Should be called from user context where sleeping is allowed.
579  *
580  *      @name will be used as $FIRMWARE in the uevent environment and
581  *      should be distinctive enough not to be confused with any other
582  *      firmware image for this or any other device.
583  **/
584 int
585 request_firmware(const struct firmware **firmware_p, const char *name,
586                  struct device *device)
587 {
588         struct firmware_priv *fw_priv;
589         int ret;
590
591         fw_priv = _request_firmware_prepare(firmware_p, name, device, true,
592                                             false);
593         if (IS_ERR_OR_NULL(fw_priv))
594                 return PTR_RET(fw_priv);
595
596         ret = usermodehelper_read_trylock();
597         if (WARN_ON(ret)) {
598                 dev_err(device, "firmware: %s will not be loaded\n", name);
599         } else {
600                 ret = _request_firmware_load(fw_priv, true,
601                                         firmware_loading_timeout());
602                 usermodehelper_read_unlock();
603         }
604         if (ret)
605                 _request_firmware_cleanup(firmware_p);
606
607         return ret;
608 }
609
610 /**
611  * release_firmware: - release the resource associated with a firmware image
612  * @fw: firmware resource to release
613  **/
614 void release_firmware(const struct firmware *fw)
615 {
616         if (fw) {
617                 if (!fw_is_builtin_firmware(fw))
618                         firmware_free_data(fw);
619                 kfree(fw);
620         }
621 }
622
623 /* Async support */
624 struct firmware_work {
625         struct work_struct work;
626         struct module *module;
627         const char *name;
628         struct device *device;
629         void *context;
630         void (*cont)(const struct firmware *fw, void *context);
631         bool uevent;
632 };
633
634 static void request_firmware_work_func(struct work_struct *work)
635 {
636         struct firmware_work *fw_work;
637         const struct firmware *fw;
638         struct firmware_priv *fw_priv;
639         long timeout;
640         int ret;
641
642         fw_work = container_of(work, struct firmware_work, work);
643         fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device,
644                         fw_work->uevent, true);
645         if (IS_ERR_OR_NULL(fw_priv)) {
646                 ret = PTR_RET(fw_priv);
647                 goto out;
648         }
649
650         timeout = usermodehelper_read_lock_wait(firmware_loading_timeout());
651         if (timeout) {
652                 ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout);
653                 usermodehelper_read_unlock();
654         } else {
655                 dev_dbg(fw_work->device, "firmware: %s loading timed out\n",
656                         fw_work->name);
657                 ret = -EAGAIN;
658         }
659         if (ret)
660                 _request_firmware_cleanup(&fw);
661
662  out:
663         fw_work->cont(fw, fw_work->context);
664
665         module_put(fw_work->module);
666         kfree(fw_work);
667 }
668
669 /**
670  * request_firmware_nowait - asynchronous version of request_firmware
671  * @module: module requesting the firmware
672  * @uevent: sends uevent to copy the firmware image if this flag
673  *      is non-zero else the firmware copy must be done manually.
674  * @name: name of firmware file
675  * @device: device for which firmware is being loaded
676  * @gfp: allocation flags
677  * @context: will be passed over to @cont, and
678  *      @fw may be %NULL if firmware request fails.
679  * @cont: function will be called asynchronously when the firmware
680  *      request is over.
681  *
682  *      Asynchronous variant of request_firmware() for user contexts where
683  *      it is not possible to sleep for long time. It can't be called
684  *      in atomic contexts.
685  **/
686 int
687 request_firmware_nowait(
688         struct module *module, bool uevent,
689         const char *name, struct device *device, gfp_t gfp, void *context,
690         void (*cont)(const struct firmware *fw, void *context))
691 {
692         struct firmware_work *fw_work;
693
694         fw_work = kzalloc(sizeof (struct firmware_work), gfp);
695         if (!fw_work)
696                 return -ENOMEM;
697
698         fw_work->module = module;
699         fw_work->name = name;
700         fw_work->device = device;
701         fw_work->context = context;
702         fw_work->cont = cont;
703         fw_work->uevent = uevent;
704
705         if (!try_module_get(module)) {
706                 kfree(fw_work);
707                 return -EFAULT;
708         }
709
710         INIT_WORK(&fw_work->work, request_firmware_work_func);
711         schedule_work(&fw_work->work);
712         return 0;
713 }
714
715 static int __init firmware_class_init(void)
716 {
717         return class_register(&firmware_class);
718 }
719
720 static void __exit firmware_class_exit(void)
721 {
722         class_unregister(&firmware_class);
723 }
724
725 fs_initcall(firmware_class_init);
726 module_exit(firmware_class_exit);
727
728 EXPORT_SYMBOL(release_firmware);
729 EXPORT_SYMBOL(request_firmware);
730 EXPORT_SYMBOL(request_firmware_nowait);