/* * firmware_class.c - Multi purpose firmware loading support * * Copyright (c) 2003 Manuel Estrada Sainz * * Please see Documentation/firmware_class/ for more information. * */ #include <linux/capability.h> #include <linux/device.h> #include <linux/module.h> #include <linux/init.h> #include <linux/timer.h> #include <linux/vmalloc.h> #include <linux/interrupt.h> #include <linux/bitops.h> #include <linux/mutex.h> #include <linux/kthread.h> #include <linux/highmem.h> #include <linux/firmware.h> #include <linux/slab.h> #define to_dev(obj) container_of(obj, struct device, kobj) 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) { 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; 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) { return false; } static inline bool fw_is_builtin_firmware(const struct firmware *fw) { return false; } #endif enum { FW_STATUS_LOADING, FW_STATUS_DONE, FW_STATUS_ABORT, }; static int loading_timeout = 60; /* In seconds */ /* 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); struct firmware_priv { struct completion completion; struct firmware *fw; unsigned long status; struct page **pages; int nr_pages; int page_array_size; struct timer_list timeout; struct device dev; bool nowait; char fw_id[]; }; 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_priv *fw_priv) { set_bit(FW_STATUS_ABORT, &fw_priv->status); wmb(); complete(&fw_priv->completion); } static ssize_t firmware_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 firmware_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 struct class_attribute firmware_class_attrs[] = { __ATTR(timeout, S_IWUSR | S_IRUGO, firmware_timeout_show, firmware_timeout_store), __ATTR_NULL }; static void fw_dev_release(struct device *dev) { struct firmware_priv *fw_priv = to_firmware_priv(dev); int i; for (i = 0; i < fw_priv->nr_pages; i++) __free_page(fw_priv->pages[i]); kfree(fw_priv->pages); kfree(fw_priv); module_put(THIS_MODULE); } static int firmware_uevent(struct device *dev, struct kobj_uevent_env *env) { struct firmware_priv *fw_priv = to_firmware_priv(dev); if (add_uevent_var(env, "FIRMWARE=%s", fw_priv->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 struct class firmware_class = { .name = "firmware", .class_attrs = firmware_class_attrs, .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 = test_bit(FW_STATUS_LOADING, &fw_priv->status); return sprintf(buf, "%d\n", loading); } static void firmware_free_data(const struct firmware *fw) { int i; vunmap(fw->data); if (fw->pages) { for (i = 0; i < PFN_UP(fw->size); i++) __free_page(fw->pages[i]); kfree(fw->pages); } } /* Some architectures don't have PAGE_KERNEL_RO */ #ifndef PAGE_KERNEL_RO #define PAGE_KERNEL_RO PAGE_KERNEL #endif /** * 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); int loading = simple_strtol(buf, NULL, 10); int i; mutex_lock(&fw_lock); if (!fw_priv->fw) goto out; switch (loading) { case 1: firmware_free_data(fw_priv->fw); memset(fw_priv->fw, 0, sizeof(struct firmware)); /* If the pages are not owned by 'struct firmware' */ for (i = 0; i < fw_priv->nr_pages; i++) __free_page(fw_priv->pages[i]); kfree(fw_priv->pages); fw_priv->pages = NULL; fw_priv->page_array_size = 0; fw_priv->nr_pages = 0; set_bit(FW_STATUS_LOADING, &fw_priv->status); break; case 0: if (test_bit(FW_STATUS_LOADING, &fw_priv->status)) { vunmap(fw_priv->fw->data); fw_priv->fw->data = vmap(fw_priv->pages, fw_priv->nr_pages, 0, PAGE_KERNEL_RO); if (!fw_priv->fw->data) { dev_err(dev, "%s: vmap() failed\n", __func__); goto err; } /* Pages are now owned by 'struct firmware' */ fw_priv->fw->pages = fw_priv->pages; fw_priv->pages = NULL; fw_priv->page_array_size = 0; fw_priv->nr_pages = 0; complete(&fw_priv->completion); clear_bit(FW_STATUS_LOADING, &fw_priv->status); break; } /* fallthrough */ default: dev_err(dev, "%s: unexpected value (%d)\n", __func__, loading); /* fallthrough */ case -1: err: fw_load_abort(fw_priv); break; } out: mutex_unlock(&fw_lock); return count; } static DEVICE_ATTR(loading, 0644, firmware_loading_show, firmware_loading_store); 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 = to_dev(kobj); struct firmware_priv *fw_priv = to_firmware_priv(dev); struct firmware *fw; ssize_t ret_count; mutex_lock(&fw_lock); fw = fw_priv->fw; if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { ret_count = -ENODEV; goto out; } if (offset > fw->size) { ret_count = 0; goto out; } if (count > fw->size - offset) count = fw->size - offset; ret_count = count; 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(fw_priv->pages[page_nr]); memcpy(buffer, page_data + page_ofs, page_cnt); kunmap(fw_priv->pages[page_nr]); buffer += page_cnt; offset += page_cnt; count -= page_cnt; } out: mutex_unlock(&fw_lock); return ret_count; } static int fw_realloc_buffer(struct firmware_priv *fw_priv, int min_size) { int pages_needed = ALIGN(min_size, PAGE_SIZE) >> PAGE_SHIFT; /* If the array of pages is too small, grow it... */ if (fw_priv->page_array_size < pages_needed) { int new_array_size = max(pages_needed, fw_priv->page_array_size * 2); struct page **new_pages; new_pages = kmalloc(new_array_size * sizeof(void *), GFP_KERNEL); if (!new_pages) { fw_load_abort(fw_priv); return -ENOMEM; } memcpy(new_pages, fw_priv->pages, fw_priv->page_array_size * sizeof(void *)); memset(&new_pages[fw_priv->page_array_size], 0, sizeof(void *) * (new_array_size - fw_priv->page_array_size)); kfree(fw_priv->pages); fw_priv->pages = new_pages; fw_priv->page_array_size = new_array_size; } while (fw_priv->nr_pages < pages_needed) { fw_priv->pages[fw_priv->nr_pages] = alloc_page(GFP_KERNEL | __GFP_HIGHMEM); if (!fw_priv->pages[fw_priv->nr_pages]) { fw_load_abort(fw_priv); return -ENOMEM; } fw_priv->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 = to_dev(kobj); struct firmware_priv *fw_priv = to_firmware_priv(dev); struct firmware *fw; ssize_t retval; if (!capable(CAP_SYS_RAWIO)) return -EPERM; mutex_lock(&fw_lock); fw = fw_priv->fw; if (!fw || test_bit(FW_STATUS_DONE, &fw_priv->status)) { retval = -ENODEV; goto out; } retval = fw_realloc_buffer(fw_priv, offset + count); if (retval) goto out; retval = count; 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(fw_priv->pages[page_nr]); memcpy(page_data + page_ofs, buffer, page_cnt); kunmap(fw_priv->pages[page_nr]); buffer += page_cnt; offset += page_cnt; count -= page_cnt; } fw->size = max_t(size_t, offset, fw->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 void firmware_class_timeout(u_long data) { struct firmware_priv *fw_priv = (struct firmware_priv *) data; fw_load_abort(fw_priv); } static struct firmware_priv * fw_create_instance(struct firmware *firmware, const char *fw_name, struct device *device, bool uevent, bool nowait) { struct firmware_priv *fw_priv; struct device *f_dev; int error; fw_priv = kzalloc(sizeof(*fw_priv) + strlen(fw_name) + 1 , GFP_KERNEL); if (!fw_priv) { dev_err(device, "%s: kmalloc failed\n", __func__); error = -ENOMEM; goto err_out; } fw_priv->fw = firmware; fw_priv->nowait = nowait; strcpy(fw_priv->fw_id, fw_name); init_completion(&fw_priv->completion); setup_timer(&fw_priv->timeout, firmware_class_timeout, (u_long) fw_priv); f_dev = &fw_priv->dev; device_initialize(f_dev); dev_set_name(f_dev, "%s", dev_name(device)); f_dev->parent = device; f_dev->class = &firmware_class; dev_set_uevent_suppress(f_dev, true); /* Need to pin this module until class device is destroyed */ __module_get(THIS_MODULE); error = device_add(f_dev); if (error) { dev_err(device, "%s: device_register failed\n", __func__); goto err_put_dev; } error = device_create_bin_file(f_dev, &firmware_attr_data); if (error) { dev_err(device, "%s: sysfs_create_bin_file failed\n", __func__); goto err_del_dev; } error = device_create_file(f_dev, &dev_attr_loading); if (error) { dev_err(device, "%s: device_create_file failed\n", __func__); goto err_del_bin_attr; } if (uevent) dev_set_uevent_suppress(f_dev, false); return fw_priv; err_del_bin_attr: device_remove_bin_file(f_dev, &firmware_attr_data); err_del_dev: device_del(f_dev); err_put_dev: put_device(f_dev); err_out: return ERR_PTR(error); } static void fw_destroy_instance(struct firmware_priv *fw_priv) { struct device *f_dev = &fw_priv->dev; device_remove_file(f_dev, &dev_attr_loading); device_remove_bin_file(f_dev, &firmware_attr_data); device_unregister(f_dev); } static int _request_firmware(const struct firmware **firmware_p, const char *name, struct device *device, bool uevent, bool nowait) { struct firmware_priv *fw_priv; struct firmware *firmware; int retval = 0; if (!firmware_p) return -EINVAL; *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL); if (!firmware) { dev_err(device, "%s: kmalloc(struct firmware) failed\n", __func__); retval = -ENOMEM; goto out; } if (fw_get_builtin_firmware(firmware, name)) { dev_dbg(device, "firmware: using built-in firmware %s\n", name); return 0; } read_lock_usermodehelper(); if (WARN_ON(usermodehelper_is_disabled())) { dev_err(device, "firmware: %s will not be loaded\n", name); retval = -EBUSY; goto out; } if (uevent) dev_dbg(device, "firmware: requesting %s\n", name); fw_priv = fw_create_instance(firmware, name, device, uevent, nowait); if (IS_ERR(fw_priv)) { retval = PTR_ERR(fw_priv); goto out; } if (uevent) { if (loading_timeout > 0) mod_timer(&fw_priv->timeout, round_jiffies_up(jiffies + loading_timeout * HZ)); kobject_uevent(&fw_priv->dev.kobj, KOBJ_ADD); } wait_for_completion(&fw_priv->completion); set_bit(FW_STATUS_DONE, &fw_priv->status); del_timer_sync(&fw_priv->timeout); mutex_lock(&fw_lock); if (!fw_priv->fw->size || test_bit(FW_STATUS_ABORT, &fw_priv->status)) retval = -ENOENT; fw_priv->fw = NULL; mutex_unlock(&fw_lock); fw_destroy_instance(fw_priv); out: read_unlock_usermodehelper(); if (retval) { release_firmware(firmware); *firmware_p = NULL; } return retval; } /** * 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. **/ int request_firmware(const struct firmware **firmware_p, const char *name, struct device *device) { return _request_firmware(firmware_p, name, device, true, false); } /** * 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); } } /* 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); bool uevent; }; static int request_firmware_work_func(void *arg) { struct firmware_work *fw_work = arg; const struct firmware *fw; int ret; if (!arg) { WARN_ON(1); return 0; } ret = _request_firmware(&fw, fw_work->name, fw_work->device, fw_work->uevent, true); fw_work->cont(fw, fw_work->context); module_put(fw_work->module); kfree(fw_work); return ret; } /** * 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. * * Asynchronous variant of request_firmware() for user contexts where * it is not possible to sleep for long time. It can't be called * in atomic contexts. **/ 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 task_struct *task; 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 = name; fw_work->device = device; fw_work->context = context; fw_work->cont = cont; fw_work->uevent = uevent; if (!try_module_get(module)) { kfree(fw_work); return -EFAULT; } task = kthread_run(request_firmware_work_func, fw_work, "firmware/%s", name); if (IS_ERR(task)) { fw_work->cont(NULL, fw_work->context); module_put(fw_work->module); kfree(fw_work); return PTR_ERR(task); } return 0; } static int __init firmware_class_init(void) { return class_register(&firmware_class); } static void __exit firmware_class_exit(void) { class_unregister(&firmware_class); } fs_initcall(firmware_class_init); module_exit(firmware_class_exit); EXPORT_SYMBOL(release_firmware); EXPORT_SYMBOL(request_firmware); EXPORT_SYMBOL(request_firmware_nowait);