/* * firmware_class.c - Multi purpose firmware loading support * * Copyright (c) 2003 Manuel Estrada Sainz * * Please see Documentation/firmware_class/ for more information. * */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include "base.h" MODULE_AUTHOR("Manuel Estrada Sainz"); MODULE_DESCRIPTION("Multi purpose firmware loading support"); MODULE_LICENSE("GPL"); /* Builtin firmware support */ #ifdef CONFIG_FW_LOADER extern struct builtin_fw __start_builtin_fw[]; extern struct builtin_fw __end_builtin_fw[]; static bool fw_get_builtin_firmware(struct firmware *fw, const char *name, void *buf, size_t size) { struct builtin_fw *b_fw; for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) { if (strcmp(name, b_fw->name) == 0) { fw->size = b_fw->size; fw->data = b_fw->data; if (buf && fw->size <= size) memcpy(buf, fw->data, fw->size); return true; } } return false; } static bool fw_is_builtin_firmware(const struct firmware *fw) { struct builtin_fw *b_fw; for (b_fw = __start_builtin_fw; b_fw != __end_builtin_fw; b_fw++) if (fw->data == b_fw->data) return true; return false; } #else /* Module case - no builtin firmware support */ static inline bool fw_get_builtin_firmware(struct firmware *fw, const char *name, void *buf, size_t size) { return false; } static inline bool fw_is_builtin_firmware(const struct firmware *fw) { return false; } #endif enum fw_status { FW_STATUS_UNKNOWN, FW_STATUS_LOADING, FW_STATUS_DONE, FW_STATUS_ABORTED, }; static int loading_timeout = 60; /* In seconds */ static inline long firmware_loading_timeout(void) { return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET; } /* * Concurrent request_firmware() for the same firmware need to be * serialized. struct fw_state is simple state machine which hold the * state of the firmware loading. */ struct fw_state { struct completion completion; enum fw_status status; }; static void fw_state_init(struct fw_state *fw_st) { init_completion(&fw_st->completion); fw_st->status = FW_STATUS_UNKNOWN; } static inline bool __fw_state_is_done(enum fw_status status) { return status == FW_STATUS_DONE || status == FW_STATUS_ABORTED; } static int __fw_state_wait_common(struct fw_state *fw_st, long timeout) { long ret; ret = wait_for_completion_killable_timeout(&fw_st->completion, timeout); if (ret != 0 && fw_st->status == FW_STATUS_ABORTED) return -ENOENT; if (!ret) return -ETIMEDOUT; return ret < 0 ? ret : 0; } static void __fw_state_set(struct fw_state *fw_st, enum fw_status status) { WRITE_ONCE(fw_st->status, status); if (status == FW_STATUS_DONE || status == FW_STATUS_ABORTED) complete_all(&fw_st->completion); } #define fw_state_start(fw_st) \ __fw_state_set(fw_st, FW_STATUS_LOADING) #define fw_state_done(fw_st) \ __fw_state_set(fw_st, FW_STATUS_DONE) #define fw_state_aborted(fw_st) \ __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_wait(fw_st) \ __fw_state_wait_common(fw_st, MAX_SCHEDULE_TIMEOUT) static int __fw_state_check(struct fw_state *fw_st, enum fw_status status) { return fw_st->status == status; } #define fw_state_is_aborted(fw_st) \ __fw_state_check(fw_st, FW_STATUS_ABORTED) #ifdef CONFIG_FW_LOADER_USER_HELPER #define fw_state_aborted(fw_st) \ __fw_state_set(fw_st, FW_STATUS_ABORTED) #define fw_state_is_done(fw_st) \ __fw_state_check(fw_st, FW_STATUS_DONE) #define fw_state_is_loading(fw_st) \ __fw_state_check(fw_st, FW_STATUS_LOADING) #define fw_state_wait_timeout(fw_st, timeout) \ __fw_state_wait_common(fw_st, timeout) #endif /* CONFIG_FW_LOADER_USER_HELPER */ /* firmware behavior options */ #define FW_OPT_UEVENT (1U << 0) #define FW_OPT_NOWAIT (1U << 1) #ifdef CONFIG_FW_LOADER_USER_HELPER #define FW_OPT_USERHELPER (1U << 2) #else #define FW_OPT_USERHELPER 0 #endif #ifdef CONFIG_FW_LOADER_USER_HELPER_FALLBACK #define FW_OPT_FALLBACK FW_OPT_USERHELPER #else #define FW_OPT_FALLBACK 0 #endif #define FW_OPT_NO_WARN (1U << 3) #define FW_OPT_NOCACHE (1U << 4) struct firmware_cache { /* firmware_buf instance will be added into the below list */ spinlock_t lock; struct list_head head; int state; #ifdef CONFIG_PM_SLEEP /* * Names of firmware images which have been cached successfully * will be added into the below list so that device uncache * helper can trace which firmware images have been cached * before. */ spinlock_t name_lock; struct list_head fw_names; struct delayed_work work; struct notifier_block pm_notify; #endif }; struct firmware_buf { struct kref ref; struct list_head list; struct firmware_cache *fwc; struct fw_state fw_st; void *data; size_t size; size_t allocated_size; #ifdef CONFIG_FW_LOADER_USER_HELPER bool is_paged_buf; bool need_uevent; struct page **pages; int nr_pages; int page_array_size; struct list_head pending_list; #endif const char *fw_id; }; struct fw_cache_entry { struct list_head list; const char *name; }; struct fw_name_devm { unsigned long magic; const char *name; }; #define to_fwbuf(d) container_of(d, struct firmware_buf, ref) #define FW_LOADER_NO_CACHE 0 #define FW_LOADER_START_CACHE 1 static int fw_cache_piggyback_on_request(const char *name); /* fw_lock could be moved to 'struct firmware_priv' but since it is just * guarding for corner cases a global lock should be OK */ static DEFINE_MUTEX(fw_lock); static struct firmware_cache fw_cache; static struct firmware_buf *__allocate_fw_buf(const char *fw_name, struct firmware_cache *fwc, void *dbuf, size_t size) { struct firmware_buf *buf; buf = kzalloc(sizeof(*buf), GFP_ATOMIC); if (!buf) return NULL; buf->fw_id = kstrdup_const(fw_name, GFP_ATOMIC); if (!buf->fw_id) { kfree(buf); return NULL; } kref_init(&buf->ref); buf->fwc = fwc; buf->data = dbuf; buf->allocated_size = size; fw_state_init(&buf->fw_st); #ifdef CONFIG_FW_LOADER_USER_HELPER INIT_LIST_HEAD(&buf->pending_list); #endif pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf); return buf; } static struct firmware_buf *__fw_lookup_buf(const char *fw_name) { struct firmware_buf *tmp; struct firmware_cache *fwc = &fw_cache; list_for_each_entry(tmp, &fwc->head, list) if (!strcmp(tmp->fw_id, fw_name)) return tmp; return NULL; } /* Returns 1 for batching firmware requests with the same name */ static int fw_lookup_and_allocate_buf(const char *fw_name, struct firmware_cache *fwc, struct firmware_buf **buf, void *dbuf, size_t size) { struct firmware_buf *tmp; spin_lock(&fwc->lock); tmp = __fw_lookup_buf(fw_name); if (tmp) { kref_get(&tmp->ref); spin_unlock(&fwc->lock); *buf = tmp; pr_debug("batched request - sharing the same struct firmware_buf and lookup for multiple requests\n"); return 1; } tmp = __allocate_fw_buf(fw_name, fwc, dbuf, size); if (tmp) list_add(&tmp->list, &fwc->head); spin_unlock(&fwc->lock); *buf = tmp; return tmp ? 0 : -ENOMEM; } static void __fw_free_buf(struct kref *ref) __releases(&fwc->lock) { struct firmware_buf *buf = to_fwbuf(ref); struct firmware_cache *fwc = buf->fwc; pr_debug("%s: fw-%s buf=%p data=%p size=%u\n", __func__, buf->fw_id, buf, buf->data, (unsigned int)buf->size); list_del(&buf->list); spin_unlock(&fwc->lock); #ifdef CONFIG_FW_LOADER_USER_HELPER if (buf->is_paged_buf) { int i; vunmap(buf->data); for (i = 0; i < buf->nr_pages; i++) __free_page(buf->pages[i]); vfree(buf->pages); } else #endif if (!buf->allocated_size) vfree(buf->data); kfree_const(buf->fw_id); kfree(buf); } static void fw_free_buf(struct firmware_buf *buf) { struct firmware_cache *fwc = buf->fwc; spin_lock(&fwc->lock); if (!kref_put(&buf->ref, __fw_free_buf)) spin_unlock(&fwc->lock); } /* direct firmware loading support */ static char fw_path_para[256]; static const char * const fw_path[] = { fw_path_para, "/lib/firmware/updates/" UTS_RELEASE, "/lib/firmware/updates", "/lib/firmware/" UTS_RELEASE, "/lib/firmware" }; /* * Typical usage is that passing 'firmware_class.path=$CUSTOMIZED_PATH' * from kernel command line because firmware_class is generally built in * kernel instead of module. */ module_param_string(path, fw_path_para, sizeof(fw_path_para), 0644); MODULE_PARM_DESC(path, "customized firmware image search path with a higher priority than default path"); static int fw_get_filesystem_firmware(struct device *device, struct firmware_buf *buf) { loff_t size; int i, len; int rc = -ENOENT; char *path; enum kernel_read_file_id id = READING_FIRMWARE; size_t msize = INT_MAX; if (ROOT_DEV == 0) return -EPROBE_DEFER; /* Already populated data member means we're loading into a buffer */ if (buf->data) { id = READING_FIRMWARE_PREALLOC_BUFFER; msize = buf->allocated_size; } path = __getname(); if (!path) return -ENOMEM; for (i = 0; i < ARRAY_SIZE(fw_path); i++) { /* skip the unset customized path */ if (!fw_path[i][0]) continue; len = snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id); if (len >= PATH_MAX) { rc = -ENAMETOOLONG; break; } buf->size = 0; rc = kernel_read_file_from_path(path, &buf->data, &size, msize, id); if (rc) { if (rc == -ENOENT) dev_dbg(device, "loading %s failed with error %d\n", path, rc); else dev_warn(device, "loading %s failed with error %d\n", path, rc); continue; } dev_dbg(device, "direct-loading %s\n", buf->fw_id); buf->size = size; fw_state_done(&buf->fw_st); break; } __putname(path); return rc; } /* firmware holds the ownership of pages */ static void firmware_free_data(const struct firmware *fw) { /* Loaded directly? */ if (!fw->priv) { vfree(fw->data); return; } fw_free_buf(fw->priv); } /* store the pages buffer info firmware from buf */ static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw) { fw->priv = buf; #ifdef CONFIG_FW_LOADER_USER_HELPER fw->pages = buf->pages; #endif fw->size = buf->size; fw->data = buf->data; pr_debug("%s: fw-%s buf=%p data=%p size=%u\n", __func__, buf->fw_id, buf, buf->data, (unsigned int)buf->size); } #ifdef CONFIG_PM_SLEEP static void fw_name_devm_release(struct device *dev, void *res) { struct fw_name_devm *fwn = res; if (fwn->magic == (unsigned long)&fw_cache) pr_debug("%s: fw_name-%s devm-%p released\n", __func__, fwn->name, res); kfree_const(fwn->name); } static int fw_devm_match(struct device *dev, void *res, void *match_data) { struct fw_name_devm *fwn = res; return (fwn->magic == (unsigned long)&fw_cache) && !strcmp(fwn->name, match_data); } static struct fw_name_devm *fw_find_devm_name(struct device *dev, const char *name) { struct fw_name_devm *fwn; fwn = devres_find(dev, fw_name_devm_release, fw_devm_match, (void *)name); return fwn; } /* add firmware name into devres list */ static int fw_add_devm_name(struct device *dev, const char *name) { struct fw_name_devm *fwn; fwn = fw_find_devm_name(dev, name); if (fwn) return 1; fwn = devres_alloc(fw_name_devm_release, sizeof(struct fw_name_devm), GFP_KERNEL); if (!fwn) return -ENOMEM; fwn->name = kstrdup_const(name, GFP_KERNEL); if (!fwn->name) { devres_free(fwn); return -ENOMEM; } fwn->magic = (unsigned long)&fw_cache; devres_add(dev, fwn); return 0; } #else static int fw_add_devm_name(struct device *dev, const char *name) { return 0; } #endif static int assign_firmware_buf(struct firmware *fw, struct device *device, unsigned int opt_flags) { struct firmware_buf *buf = fw->priv; mutex_lock(&fw_lock); if (!buf->size || fw_state_is_aborted(&buf->fw_st)) { mutex_unlock(&fw_lock); return -ENOENT; } /* * add firmware name into devres list so that we can auto cache * and uncache firmware for device. * * device may has been deleted already, but the problem * should be fixed in devres or driver core. */ /* don't cache firmware handled without uevent */ if (device && (opt_flags & FW_OPT_UEVENT) && !(opt_flags & FW_OPT_NOCACHE)) fw_add_devm_name(device, buf->fw_id); /* * After caching firmware image is started, let it piggyback * on request firmware. */ if (!(opt_flags & FW_OPT_NOCACHE) && buf->fwc->state == FW_LOADER_START_CACHE) { if (fw_cache_piggyback_on_request(buf->fw_id)) kref_get(&buf->ref); } /* pass the pages buffer to driver at the last minute */ fw_set_page_data(buf, fw); mutex_unlock(&fw_lock); return 0; } /* * user-mode helper code */ #ifdef CONFIG_FW_LOADER_USER_HELPER struct firmware_priv { bool nowait; struct device dev; struct firmware_buf *buf; struct firmware *fw; }; static struct firmware_priv *to_firmware_priv(struct device *dev) { return container_of(dev, struct firmware_priv, dev); } static void __fw_load_abort(struct firmware_buf *buf) { /* * There is a small window in which user can write to 'loading' * between loading done and disappearance of 'loading' */ if (fw_state_is_done(&buf->fw_st)) return; list_del_init(&buf->pending_list); fw_state_aborted(&buf->fw_st); } static void fw_load_abort(struct firmware_priv *fw_priv) { struct firmware_buf *buf = fw_priv->buf; __fw_load_abort(buf); } static LIST_HEAD(pending_fw_head); static void kill_pending_fw_fallback_reqs(bool only_kill_custom) { struct firmware_buf *buf; struct firmware_buf *next; mutex_lock(&fw_lock); list_for_each_entry_safe(buf, next, &pending_fw_head, pending_list) { if (!buf->need_uevent || !only_kill_custom) __fw_load_abort(buf); } mutex_unlock(&fw_lock); } static ssize_t timeout_show(struct class *class, struct class_attribute *attr, char *buf) { return sprintf(buf, "%d\n", loading_timeout); } /** * firmware_timeout_store - set number of seconds to wait for firmware * @class: device class pointer * @attr: device attribute pointer * @buf: buffer to scan for timeout value * @count: number of bytes in @buf * * Sets the number of seconds to wait for the firmware. Once * this expires an error will be returned to the driver and no * firmware will be provided. * * Note: zero means 'wait forever'. **/ static ssize_t timeout_store(struct class *class, struct class_attribute *attr, const char *buf, size_t count) { loading_timeout = simple_strtol(buf, NULL, 10); if (loading_timeout < 0) loading_timeout = 0; return count; } static CLASS_ATTR_RW(timeout); static struct attribute *firmware_class_attrs[] = { &class_attr_timeout.attr, NULL, }; ATTRIBUTE_GROUPS(firmware_class); static void fw_dev_release(struct device *dev) { struct firmware_priv *fw_priv = to_firmware_priv(dev); kfree(fw_priv); } static int do_firmware_uevent(struct firmware_priv *fw_priv, struct kobj_uevent_env *env) { if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->buf->fw_id)) return -ENOMEM; if (add_uevent_var(env, "TIMEOUT=%i", loading_timeout)) return -ENOMEM; if (add_uevent_var(env, "ASYNC=%d", fw_priv->nowait)) return -ENOMEM; return 0; } static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) { struct firmware_priv *fw_priv = to_firmware_priv(dev); int err = 0; mutex_lock(&fw_lock); if (fw_priv->buf) err = do_firmware_uevent(fw_priv, env); mutex_unlock(&fw_lock); return err; } static struct class firmware_class = { .name = "firmware", .class_groups = firmware_class_groups, .dev_uevent = firmware_uevent, .dev_release = fw_dev_release, }; static ssize_t firmware_loading_show(struct device *dev, struct device_attribute *attr, char *buf) { struct firmware_priv *fw_priv = to_firmware_priv(dev); int loading = 0; mutex_lock(&fw_lock); if (fw_priv->buf) loading = fw_state_is_loading(&fw_priv->buf->fw_st); mutex_unlock(&fw_lock); return sprintf(buf, "%d\n", loading); } /* Some architectures don't have PAGE_KERNEL_RO */ #ifndef PAGE_KERNEL_RO #define PAGE_KERNEL_RO PAGE_KERNEL #endif /* one pages buffer should be mapped/unmapped only once */ static int fw_map_pages_buf(struct firmware_buf *buf) { if (!buf->is_paged_buf) return 0; vunmap(buf->data); buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO); if (!buf->data) return -ENOMEM; return 0; } /** * firmware_loading_store - set value in the 'loading' control file * @dev: device pointer * @attr: device attribute pointer * @buf: buffer to scan for loading control value * @count: number of bytes in @buf * * The relevant values are: * * 1: Start a load, discarding any previous partial load. * 0: Conclude the load and hand the data to the driver code. * -1: Conclude the load with an error and discard any written data. **/ static ssize_t firmware_loading_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct firmware_priv *fw_priv = to_firmware_priv(dev); struct firmware_buf *fw_buf; ssize_t written = count; int loading = simple_strtol(buf, NULL, 10); int i; mutex_lock(&fw_lock); fw_buf = fw_priv->buf; if (fw_state_is_aborted(&fw_buf->fw_st)) goto out; switch (loading) { case 1: /* discarding any previous partial load */ if (!fw_state_is_done(&fw_buf->fw_st)) { for (i = 0; i < fw_buf->nr_pages; i++) __free_page(fw_buf->pages[i]); vfree(fw_buf->pages); fw_buf->pages = NULL; fw_buf->page_array_size = 0; fw_buf->nr_pages = 0; fw_state_start(&fw_buf->fw_st); } break; case 0: if (fw_state_is_loading(&fw_buf->fw_st)) { int rc; /* * Several loading requests may be pending on * one same firmware buf, so let all requests * see the mapped 'buf->data' once the loading * is completed. * */ rc = fw_map_pages_buf(fw_buf); if (rc) dev_err(dev, "%s: map pages failed\n", __func__); else rc = security_kernel_post_read_file(NULL, fw_buf->data, fw_buf->size, READING_FIRMWARE); /* * Same logic as fw_load_abort, only the DONE bit * is ignored and we set ABORT only on failure. */ list_del_init(&fw_buf->pending_list); if (rc) { fw_state_aborted(&fw_buf->fw_st); written = rc; } else { fw_state_done(&fw_buf->fw_st); } break; } /* fallthrough */ default: dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading); /* fallthrough */ case -1: fw_load_abort(fw_priv); break; } out: mutex_unlock(&fw_lock); return written; } static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store); static void firmware_rw_buf(struct firmware_buf *buf, char *buffer, loff_t offset, size_t count, bool read) { if (read) memcpy(buffer, buf->data + offset, count); else memcpy(buf->data + offset, buffer, count); } static void firmware_rw(struct firmware_buf *buf, char *buffer, loff_t offset, size_t count, bool read) { while (count) { void *page_data; int page_nr = offset >> PAGE_SHIFT; int page_ofs = offset & (PAGE_SIZE-1); int page_cnt = min_t(size_t, PAGE_SIZE - page_ofs, count); page_data = kmap(buf->pages[page_nr]); if (read) memcpy(buffer, page_data + page_ofs, page_cnt); else memcpy(page_data + page_ofs, buffer, page_cnt); kunmap(buf->pages[page_nr]); buffer += page_cnt; offset += page_cnt; count -= page_cnt; } } static ssize_t firmware_data_read(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = kobj_to_dev(kobj); struct firmware_priv *fw_priv = to_firmware_priv(dev); struct firmware_buf *buf; ssize_t ret_count; mutex_lock(&fw_lock); buf = fw_priv->buf; if (!buf || fw_state_is_done(&buf->fw_st)) { ret_count = -ENODEV; goto out; } if (offset > buf->size) { ret_count = 0; goto out; } if (count > buf->size - offset) count = buf->size - offset; ret_count = count; if (buf->data) firmware_rw_buf(buf, buffer, offset, count, true); else firmware_rw(buf, buffer, offset, count, true); out: mutex_unlock(&fw_lock); return ret_count; } static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size) { struct firmware_buf *buf = fw_priv->buf; int pages_needed = PAGE_ALIGN(min_size) >> PAGE_SHIFT; /* If the array of pages is too small, grow it... */ if (buf->page_array_size < pages_needed) { int new_array_size = max(pages_needed, buf->page_array_size * 2); struct page **new_pages; new_pages = vmalloc(new_array_size * sizeof(void *)); if (!new_pages) { fw_load_abort(fw_priv); return -ENOMEM; } memcpy(new_pages, buf->pages, buf->page_array_size * sizeof(void *)); memset(&new_pages[buf->page_array_size], 0, sizeof(void *) * (new_array_size - buf->page_array_size)); vfree(buf->pages); buf->pages = new_pages; buf->page_array_size = new_array_size; } while (buf->nr_pages < pages_needed) { buf->pages[buf->nr_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); if (!buf->pages[buf->nr_pages]) { fw_load_abort(fw_priv); return -ENOMEM; } buf->nr_pages++; } return 0; } /** * firmware_data_write - write method for firmware * @filp: open sysfs file * @kobj: kobject for the device * @bin_attr: bin_attr structure * @buffer: buffer being written * @offset: buffer offset for write in total data store area * @count: buffer size * * Data written to the 'data' attribute will be later handed to * the driver as a firmware image. **/ static ssize_t firmware_data_write(struct file *filp, struct kobject *kobj, struct bin_attribute *bin_attr, char *buffer, loff_t offset, size_t count) { struct device *dev = kobj_to_dev(kobj); struct firmware_priv *fw_priv = to_firmware_priv(dev); struct firmware_buf *buf; ssize_t retval; if (!capable(CAP_SYS_RAWIO)) return -EPERM; mutex_lock(&fw_lock); buf = fw_priv->buf; if (!buf || fw_state_is_done(&buf->fw_st)) { retval = -ENODEV; goto out; } if (buf->data) { if (offset + count > buf->allocated_size) { retval = -ENOMEM; goto out; } firmware_rw_buf(buf, buffer, offset, count, false); retval = count; } else { retval = fw_realloc_buffer(fw_priv, offset + count); if (retval) goto out; retval = count; firmware_rw(buf, buffer, offset, count, false); } buf->size = max_t(size_t, offset + count, buf->size); out: mutex_unlock(&fw_lock); return retval; } static struct bin_attribute firmware_attr_data = { .attr = { .name = "data", .mode = 0644 }, .size = 0, .read = firmware_data_read, .write = firmware_data_write, }; static struct attribute *fw_dev_attrs[] = { &dev_attr_loading.attr, NULL }; static struct bin_attribute *fw_dev_bin_attrs[] = { &firmware_attr_data, NULL }; static const struct attribute_group fw_dev_attr_group = { .attrs = fw_dev_attrs, .bin_attrs = fw_dev_bin_attrs, }; static const struct attribute_group *fw_dev_attr_groups[] = { &fw_dev_attr_group, NULL }; static struct firmware_priv * fw_create_instance(struct firmware *firmware, const char *fw_name, struct device *device, unsigned int opt_flags) { struct firmware_priv *fw_priv; struct device *f_dev; fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL); if (!fw_priv) { fw_priv = ERR_PTR(-ENOMEM); goto exit; } fw_priv->nowait = !!(opt_flags & FW_OPT_NOWAIT); fw_priv->fw = firmware; f_dev = &fw_priv->dev; device_initialize(f_dev); dev_set_name(f_dev, "%s", fw_name); f_dev->parent = device; f_dev->class = &firmware_class; f_dev->groups = fw_dev_attr_groups; exit: return fw_priv; } /* load a firmware via user helper */ static int _request_firmware_load(struct firmware_priv *fw_priv, unsigned int opt_flags, long timeout) { int retval = 0; struct device *f_dev = &fw_priv->dev; struct firmware_buf *buf = fw_priv->buf; /* fall back on userspace loading */ if (!buf->data) buf->is_paged_buf = true; dev_set_uevent_suppress(f_dev, true); retval = device_add(f_dev); if (retval) { dev_err(f_dev, "%s: device_register failed\n", __func__); goto err_put_dev; } mutex_lock(&fw_lock); list_add(&buf->pending_list, &pending_fw_head); mutex_unlock(&fw_lock); if (opt_flags & FW_OPT_UEVENT) { buf->need_uevent = true; dev_set_uevent_suppress(f_dev, false); dev_dbg(f_dev, "firmware: requesting %s\n", buf->fw_id); kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD); } else { timeout = MAX_JIFFY_OFFSET; } retval = fw_state_wait_timeout(&buf->fw_st, timeout); if (retval < 0) { mutex_lock(&fw_lock); fw_load_abort(fw_priv); mutex_unlock(&fw_lock); } if (fw_state_is_aborted(&buf->fw_st)) { if (retval == -ERESTARTSYS) retval = -EINTR; else retval = -EAGAIN; } else if (buf->is_paged_buf && !buf->data) retval = -ENOMEM; device_del(f_dev); err_put_dev: put_device(f_dev); return retval; } static int fw_load_from_user_helper(struct firmware *firmware, const char *name, struct device *device, unsigned int opt_flags) { struct firmware_priv *fw_priv; long timeout; int ret; timeout = firmware_loading_timeout(); if (opt_flags & FW_OPT_NOWAIT) { timeout = usermodehelper_read_lock_wait(timeout); if (!timeout) { dev_dbg(device, "firmware: %s loading timed out\n", name); return -EBUSY; } } else { ret = usermodehelper_read_trylock(); if (WARN_ON(ret)) { dev_err(device, "firmware: %s will not be loaded\n", name); return ret; } } fw_priv = fw_create_instance(firmware, name, device, opt_flags); if (IS_ERR(fw_priv)) { ret = PTR_ERR(fw_priv); goto out_unlock; } fw_priv->buf = firmware->priv; ret = _request_firmware_load(fw_priv, opt_flags, timeout); if (!ret) ret = assign_firmware_buf(firmware, device, opt_flags); out_unlock: usermodehelper_read_unlock(); return ret; } #else /* CONFIG_FW_LOADER_USER_HELPER */ static inline int fw_load_from_user_helper(struct firmware *firmware, const char *name, struct device *device, unsigned int opt_flags) { return -ENOENT; } static inline void kill_pending_fw_fallback_reqs(bool only_kill_custom) { } #endif /* CONFIG_FW_LOADER_USER_HELPER */ /* prepare firmware and firmware_buf structs; * return 0 if a firmware is already assigned, 1 if need to load one, * or a negative error code */ static int _request_firmware_prepare(struct firmware **firmware_p, const char *name, struct device *device, void *dbuf, size_t size) { struct firmware *firmware; struct firmware_buf *buf; int ret; *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL); if (!firmware) { dev_err(device, "%s: kmalloc(struct firmware) failed\n", __func__); return -ENOMEM; } if (fw_get_builtin_firmware(firmware, name, dbuf, size)) { dev_dbg(device, "using built-in %s\n", name); return 0; /* assigned */ } ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf, dbuf, size); /* * bind with 'buf' now to avoid warning in failure path * of requesting firmware. */ firmware->priv = buf; if (ret > 0) { ret = fw_state_wait(&buf->fw_st); if (!ret) { fw_set_page_data(buf, firmware); return 0; /* assigned */ } } if (ret < 0) return ret; return 1; /* need to load */ } /* * Batched requests need only one wake, we need to do this step last due to the * fallback mechanism. The buf is protected with kref_get(), and it won't be * released until the last user calls release_firmware(). * * Failed batched requests are possible as well, in such cases we just share * the struct firmware_buf and won't release it until all requests are woken * and have gone through this same path. */ static void fw_abort_batch_reqs(struct firmware *fw) { struct firmware_buf *buf; /* Loaded directly? */ if (!fw || !fw->priv) return; buf = fw->priv; if (!fw_state_is_aborted(&buf->fw_st)) fw_state_aborted(&buf->fw_st); } /* called from request_firmware() and request_firmware_work_func() */ static int _request_firmware(const struct firmware **firmware_p, const char *name, struct device *device, void *buf, size_t size, unsigned int opt_flags) { struct firmware *fw = NULL; int ret; if (!firmware_p) return -EINVAL; if (!name || name[0] == '\0') { ret = -EINVAL; goto out; } ret = _request_firmware_prepare(&fw, name, device, buf, size); if (ret <= 0) /* error or already assigned */ goto out; ret = fw_get_filesystem_firmware(device, fw->priv); if (ret) { if (!(opt_flags & FW_OPT_NO_WARN)) dev_warn(device, "Direct firmware load for %s failed with error %d\n", name, ret); if (opt_flags & FW_OPT_USERHELPER) { dev_warn(device, "Falling back to user helper\n"); ret = fw_load_from_user_helper(fw, name, device, opt_flags); } } else ret = assign_firmware_buf(fw, device, opt_flags); out: if (ret < 0) { fw_abort_batch_reqs(fw); release_firmware(fw); fw = NULL; } *firmware_p = fw; return ret; } /** * request_firmware: - send firmware request and wait for it * @firmware_p: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded * * @firmware_p will be used to return a firmware image by the name * of @name for device @device. * * Should be called from user context where sleeping is allowed. * * @name will be used as $FIRMWARE in the uevent environment and * should be distinctive enough not to be confused with any other * firmware image for this or any other device. * * Caller must hold the reference count of @device. * * The function can be called safely inside device's suspend and * resume callback. **/ int request_firmware(const struct firmware **firmware_p, const char *name, struct device *device) { int ret; /* Need to pin this module until return */ __module_get(THIS_MODULE); ret = _request_firmware(firmware_p, name, device, NULL, 0, FW_OPT_UEVENT | FW_OPT_FALLBACK); module_put(THIS_MODULE); return ret; } EXPORT_SYMBOL(request_firmware); /** * request_firmware_direct: - load firmware directly without usermode helper * @firmware_p: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded * * This function works pretty much like request_firmware(), but this doesn't * fall back to usermode helper even if the firmware couldn't be loaded * directly from fs. Hence it's useful for loading optional firmwares, which * aren't always present, without extra long timeouts of udev. **/ int request_firmware_direct(const struct firmware **firmware_p, const char *name, struct device *device) { int ret; __module_get(THIS_MODULE); ret = _request_firmware(firmware_p, name, device, NULL, 0, FW_OPT_UEVENT | FW_OPT_NO_WARN); module_put(THIS_MODULE); return ret; } EXPORT_SYMBOL_GPL(request_firmware_direct); /** * request_firmware_into_buf - load firmware into a previously allocated buffer * @firmware_p: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded and DMA region allocated * @buf: address of buffer to load firmware into * @size: size of buffer * * This function works pretty much like request_firmware(), but it doesn't * allocate a buffer to hold the firmware data. Instead, the firmware * is loaded directly into the buffer pointed to by @buf and the @firmware_p * data member is pointed at @buf. * * This function doesn't cache firmware either. */ int request_firmware_into_buf(const struct firmware **firmware_p, const char *name, struct device *device, void *buf, size_t size) { int ret; __module_get(THIS_MODULE); ret = _request_firmware(firmware_p, name, device, buf, size, FW_OPT_UEVENT | FW_OPT_FALLBACK | FW_OPT_NOCACHE); module_put(THIS_MODULE); return ret; } EXPORT_SYMBOL(request_firmware_into_buf); /** * release_firmware: - release the resource associated with a firmware image * @fw: firmware resource to release **/ void release_firmware(const struct firmware *fw) { if (fw) { if (!fw_is_builtin_firmware(fw)) firmware_free_data(fw); kfree(fw); } } EXPORT_SYMBOL(release_firmware); /* Async support */ struct firmware_work { struct work_struct work; struct module *module; const char *name; struct device *device; void *context; void (*cont)(const struct firmware *fw, void *context); unsigned int opt_flags; struct list_head node; }; static LIST_HEAD(firmware_work_list); static DEFINE_SPINLOCK(firmware_work_list_lock); static void request_firmware_work_func(struct work_struct *work) { struct firmware_work *fw_work; const struct firmware *fw; int err = 0; fw_work = container_of(work, struct firmware_work, work); err = _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, fw_work->opt_flags); if (err == -EPROBE_DEFER) { spin_lock(&firmware_work_list_lock); list_add_tail(&fw_work->node, &firmware_work_list); spin_unlock(&firmware_work_list_lock); return; } fw_work->cont(fw, fw_work->context); put_device(fw_work->device); /* taken in request_firmware_nowait() */ module_put(fw_work->module); kfree_const(fw_work->name); kfree(fw_work); } void retry_request_firmware(void) { struct firmware_work *fw_work; spin_lock(&firmware_work_list_lock); while (!list_empty(&firmware_work_list)) { fw_work = list_first_entry(&firmware_work_list, struct firmware_work, node); list_del(&fw_work->node); spin_unlock(&firmware_work_list_lock); request_firmware_work_func(&fw_work->work); spin_lock(&firmware_work_list_lock); } spin_unlock(&firmware_work_list_lock); } /** * request_firmware_nowait - asynchronous version of request_firmware * @module: module requesting the firmware * @uevent: sends uevent to copy the firmware image if this flag * is non-zero else the firmware copy must be done manually. * @name: name of firmware file * @device: device for which firmware is being loaded * @gfp: allocation flags * @context: will be passed over to @cont, and * @fw may be %NULL if firmware request fails. * @cont: function will be called asynchronously when the firmware * request is over. * * Caller must hold the reference count of @device. * * Asynchronous variant of request_firmware() for user contexts: * - sleep for as small periods as possible since it may * increase kernel boot time of built-in device drivers * requesting firmware in their ->probe() methods, if * @gfp is GFP_KERNEL. * * - can't sleep at all if @gfp is GFP_ATOMIC. **/ 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)) { struct firmware_work *fw_work; fw_work = kzalloc(sizeof(struct firmware_work), gfp); if (!fw_work) return -ENOMEM; fw_work->module = module; fw_work->name = kstrdup_const(name, gfp); if (!fw_work->name) { kfree(fw_work); return -ENOMEM; } fw_work->device = device; fw_work->context = context; fw_work->cont = cont; fw_work->opt_flags = FW_OPT_NOWAIT | FW_OPT_FALLBACK | (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER); INIT_LIST_HEAD(&fw_work->node); if (!try_module_get(module)) { kfree_const(fw_work->name); kfree(fw_work); return -EFAULT; } get_device(fw_work->device); INIT_WORK(&fw_work->work, request_firmware_work_func); schedule_work(&fw_work->work); return 0; } EXPORT_SYMBOL(request_firmware_nowait); #ifdef CONFIG_PM_SLEEP static ASYNC_DOMAIN_EXCLUSIVE(fw_cache_domain); /** * cache_firmware - cache one firmware image in kernel memory space * @fw_name: the firmware image name * * Cache firmware in kernel memory so that drivers can use it when * system isn't ready for them to request firmware image from userspace. * Once it returns successfully, driver can use request_firmware or its * nowait version to get the cached firmware without any interacting * with userspace * * Return 0 if the firmware image has been cached successfully * Return !0 otherwise * */ static int cache_firmware(const char *fw_name) { int ret; const struct firmware *fw; pr_debug("%s: %s\n", __func__, fw_name); ret = request_firmware(&fw, fw_name, NULL); if (!ret) kfree(fw); pr_debug("%s: %s ret=%d\n", __func__, fw_name, ret); return ret; } static struct firmware_buf *fw_lookup_buf(const char *fw_name) { struct firmware_buf *tmp; struct firmware_cache *fwc = &fw_cache; spin_lock(&fwc->lock); tmp = __fw_lookup_buf(fw_name); spin_unlock(&fwc->lock); return tmp; } /** * uncache_firmware - remove one cached firmware image * @fw_name: the firmware image name * * Uncache one firmware image which has been cached successfully * before. * * Return 0 if the firmware cache has been removed successfully * Return !0 otherwise * */ static int uncache_firmware(const char *fw_name) { struct firmware_buf *buf; struct firmware fw; pr_debug("%s: %s\n", __func__, fw_name); if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0)) return 0; buf = fw_lookup_buf(fw_name); if (buf) { fw_free_buf(buf); return 0; } return -EINVAL; } static struct fw_cache_entry *alloc_fw_cache_entry(const char *name) { struct fw_cache_entry *fce; fce = kzalloc(sizeof(*fce), GFP_ATOMIC); if (!fce) goto exit; fce->name = kstrdup_const(name, GFP_ATOMIC); if (!fce->name) { kfree(fce); fce = NULL; goto exit; } exit: return fce; } static int __fw_entry_found(const char *name) { struct firmware_cache *fwc = &fw_cache; struct fw_cache_entry *fce; list_for_each_entry(fce, &fwc->fw_names, list) { if (!strcmp(fce->name, name)) return 1; } return 0; } static int fw_cache_piggyback_on_request(const char *name) { struct firmware_cache *fwc = &fw_cache; struct fw_cache_entry *fce; int ret = 0; spin_lock(&fwc->name_lock); if (__fw_entry_found(name)) goto found; fce = alloc_fw_cache_entry(name); if (fce) { ret = 1; list_add(&fce->list, &fwc->fw_names); pr_debug("%s: fw: %s\n", __func__, name); } found: spin_unlock(&fwc->name_lock); return ret; } static void free_fw_cache_entry(struct fw_cache_entry *fce) { kfree_const(fce->name); kfree(fce); } static void __async_dev_cache_fw_image(void *fw_entry, async_cookie_t cookie) { struct fw_cache_entry *fce = fw_entry; struct firmware_cache *fwc = &fw_cache; int ret; ret = cache_firmware(fce->name); if (ret) { spin_lock(&fwc->name_lock); list_del(&fce->list); spin_unlock(&fwc->name_lock); free_fw_cache_entry(fce); } } /* called with dev->devres_lock held */ static void dev_create_fw_entry(struct device *dev, void *res, void *data) { struct fw_name_devm *fwn = res; const char *fw_name = fwn->name; struct list_head *head = data; struct fw_cache_entry *fce; fce = alloc_fw_cache_entry(fw_name); if (fce) list_add(&fce->list, head); } static int devm_name_match(struct device *dev, void *res, void *match_data) { struct fw_name_devm *fwn = res; return (fwn->magic == (unsigned long)match_data); } static void dev_cache_fw_image(struct device *dev, void *data) { LIST_HEAD(todo); struct fw_cache_entry *fce; struct fw_cache_entry *fce_next; struct firmware_cache *fwc = &fw_cache; devres_for_each_res(dev, fw_name_devm_release, devm_name_match, &fw_cache, dev_create_fw_entry, &todo); list_for_each_entry_safe(fce, fce_next, &todo, list) { list_del(&fce->list); spin_lock(&fwc->name_lock); /* only one cache entry for one firmware */ if (!__fw_entry_found(fce->name)) { list_add(&fce->list, &fwc->fw_names); } else { free_fw_cache_entry(fce); fce = NULL; } spin_unlock(&fwc->name_lock); if (fce) async_schedule_domain(__async_dev_cache_fw_image, (void *)fce, &fw_cache_domain); } } static void __device_uncache_fw_images(void) { struct firmware_cache *fwc = &fw_cache; struct fw_cache_entry *fce; spin_lock(&fwc->name_lock); while (!list_empty(&fwc->fw_names)) { fce = list_entry(fwc->fw_names.next, struct fw_cache_entry, list); list_del(&fce->list); spin_unlock(&fwc->name_lock); uncache_firmware(fce->name); free_fw_cache_entry(fce); spin_lock(&fwc->name_lock); } spin_unlock(&fwc->name_lock); } /** * device_cache_fw_images - cache devices' firmware * * If one device called request_firmware or its nowait version * successfully before, the firmware names are recored into the * device's devres link list, so device_cache_fw_images can call * cache_firmware() to cache these firmwares for the device, * then the device driver can load its firmwares easily at * time when system is not ready to complete loading firmware. */ static void device_cache_fw_images(void) { struct firmware_cache *fwc = &fw_cache; int old_timeout; DEFINE_WAIT(wait); pr_debug("%s\n", __func__); /* cancel uncache work */ cancel_delayed_work_sync(&fwc->work); /* * use small loading timeout for caching devices' firmware * because all these firmware images have been loaded * successfully at lease once, also system is ready for * completing firmware loading now. The maximum size of * firmware in current distributions is about 2M bytes, * so 10 secs should be enough. */ old_timeout = loading_timeout; loading_timeout = 10; mutex_lock(&fw_lock); fwc->state = FW_LOADER_START_CACHE; dpm_for_each_dev(NULL, dev_cache_fw_image); mutex_unlock(&fw_lock); /* wait for completion of caching firmware for all devices */ async_synchronize_full_domain(&fw_cache_domain); loading_timeout = old_timeout; } /** * device_uncache_fw_images - uncache devices' firmware * * uncache all firmwares which have been cached successfully * by device_uncache_fw_images earlier */ static void device_uncache_fw_images(void) { pr_debug("%s\n", __func__); __device_uncache_fw_images(); } static void device_uncache_fw_images_work(struct work_struct *work) { device_uncache_fw_images(); } /** * device_uncache_fw_images_delay - uncache devices firmwares * @delay: number of milliseconds to delay uncache device firmwares * * uncache all devices's firmwares which has been cached successfully * by device_cache_fw_images after @delay milliseconds. */ static void device_uncache_fw_images_delay(unsigned long delay) { queue_delayed_work(system_power_efficient_wq, &fw_cache.work, msecs_to_jiffies(delay)); } static int fw_pm_notify(struct notifier_block *notify_block, unsigned long mode, void *unused) { switch (mode) { case PM_HIBERNATION_PREPARE: case PM_SUSPEND_PREPARE: case PM_RESTORE_PREPARE: /* * kill pending fallback requests with a custom fallback * to avoid stalling suspend. */ kill_pending_fw_fallback_reqs(true); device_cache_fw_images(); break; case PM_POST_SUSPEND: case PM_POST_HIBERNATION: case PM_POST_RESTORE: /* * In case that system sleep failed and syscore_suspend is * not called. */ mutex_lock(&fw_lock); fw_cache.state = FW_LOADER_NO_CACHE; mutex_unlock(&fw_lock); device_uncache_fw_images_delay(10 * MSEC_PER_SEC); break; } return 0; } /* stop caching firmware once syscore_suspend is reached */ static int fw_suspend(void) { fw_cache.state = FW_LOADER_NO_CACHE; return 0; } static struct syscore_ops fw_syscore_ops = { .suspend = fw_suspend, }; #else static int fw_cache_piggyback_on_request(const char *name) { return 0; } #endif static void __init fw_cache_init(void) { spin_lock_init(&fw_cache.lock); INIT_LIST_HEAD(&fw_cache.head); fw_cache.state = FW_LOADER_NO_CACHE; #ifdef CONFIG_PM_SLEEP spin_lock_init(&fw_cache.name_lock); INIT_LIST_HEAD(&fw_cache.fw_names); INIT_DELAYED_WORK(&fw_cache.work, device_uncache_fw_images_work); fw_cache.pm_notify.notifier_call = fw_pm_notify; register_pm_notifier(&fw_cache.pm_notify); register_syscore_ops(&fw_syscore_ops); #endif } static int fw_shutdown_notify(struct notifier_block *unused1, unsigned long unused2, void *unused3) { /* * Kill all pending fallback requests to avoid both stalling shutdown, * and avoid a deadlock with the usermode_lock. */ kill_pending_fw_fallback_reqs(false); return NOTIFY_DONE; } static struct notifier_block fw_shutdown_nb = { .notifier_call = fw_shutdown_notify, }; static int __init firmware_class_init(void) { fw_cache_init(); register_reboot_notifier(&fw_shutdown_nb); #ifdef CONFIG_FW_LOADER_USER_HELPER return class_register(&firmware_class); #else return 0; #endif } static void __exit firmware_class_exit(void) { #ifdef CONFIG_PM_SLEEP unregister_syscore_ops(&fw_syscore_ops); unregister_pm_notifier(&fw_cache.pm_notify); #endif unregister_reboot_notifier(&fw_shutdown_nb); #ifdef CONFIG_FW_LOADER_USER_HELPER class_unregister(&firmware_class); #endif } fs_initcall(firmware_class_init); module_exit(firmware_class_exit);