// SPDX-License-Identifier: GPL-2.0 /* * main.c - Multi purpose firmware loading support * * Copyright (c) 2003 Manuel Estrada Sainz * * Please see Documentation/driver-api/firmware/ for more information. * */ #define pr_fmt(fmt) … #include <linux/capability.h> #include <linux/device.h> #include <linux/kernel_read_file.h> #include <linux/module.h> #include <linux/init.h> #include <linux/initrd.h> #include <linux/timer.h> #include <linux/vmalloc.h> #include <linux/interrupt.h> #include <linux/bitops.h> #include <linux/mutex.h> #include <linux/workqueue.h> #include <linux/highmem.h> #include <linux/firmware.h> #include <linux/slab.h> #include <linux/sched.h> #include <linux/file.h> #include <linux/list.h> #include <linux/fs.h> #include <linux/async.h> #include <linux/pm.h> #include <linux/suspend.h> #include <linux/syscore_ops.h> #include <linux/reboot.h> #include <linux/security.h> #include <linux/zstd.h> #include <linux/xz.h> #include <generated/utsrelease.h> #include "../base.h" #include "firmware.h" #include "fallback.h" MODULE_AUTHOR(…) …; MODULE_DESCRIPTION(…) …; MODULE_LICENSE(…) …; struct firmware_cache { … }; struct fw_cache_entry { … }; struct fw_name_devm { … }; static inline struct fw_priv *to_fw_priv(struct kref *ref) { … } #define FW_LOADER_NO_CACHE … #define FW_LOADER_START_CACHE … /* fw_lock could be moved to 'struct fw_sysfs' but since it is just * guarding for corner cases a global lock should be OK */ DEFINE_MUTEX(…) …; struct firmware_cache fw_cache; bool fw_load_abort_all; void fw_state_init(struct fw_priv *fw_priv) { … } static inline int fw_state_wait(struct fw_priv *fw_priv) { … } static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv); static struct fw_priv *__allocate_fw_priv(const char *fw_name, struct firmware_cache *fwc, void *dbuf, size_t size, size_t offset, u32 opt_flags) { … } static struct fw_priv *__lookup_fw_priv(const char *fw_name) { … } /* Returns 1 for batching firmware requests with the same name */ int alloc_lookup_fw_priv(const char *fw_name, struct firmware_cache *fwc, struct fw_priv **fw_priv, void *dbuf, size_t size, size_t offset, u32 opt_flags) { … } static void __free_fw_priv(struct kref *ref) __releases(&fwc->lock) { … } void free_fw_priv(struct fw_priv *fw_priv) { … } #ifdef CONFIG_FW_LOADER_PAGED_BUF bool fw_is_paged_buf(struct fw_priv *fw_priv) { … } void fw_free_paged_buf(struct fw_priv *fw_priv) { … } int fw_grow_paged_buf(struct fw_priv *fw_priv, int pages_needed) { … } int fw_map_paged_buf(struct fw_priv *fw_priv) { … } #endif /* * ZSTD-compressed firmware support */ #ifdef CONFIG_FW_LOADER_COMPRESS_ZSTD static int fw_decompress_zstd(struct device *dev, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer) { … } #endif /* CONFIG_FW_LOADER_COMPRESS_ZSTD */ /* * XZ-compressed firmware support */ #ifdef CONFIG_FW_LOADER_COMPRESS_XZ /* show an error and return the standard error code */ static int fw_decompress_xz_error(struct device *dev, enum xz_ret xz_ret) { … } /* single-shot decompression onto the pre-allocated buffer */ static int fw_decompress_xz_single(struct device *dev, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer) { … } /* decompression on paged buffer and map it */ static int fw_decompress_xz_pages(struct device *dev, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer) { … } static int fw_decompress_xz(struct device *dev, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer) { … } #endif /* CONFIG_FW_LOADER_COMPRESS_XZ */ /* direct firmware loading support */ static char fw_path_para[256]; static const char * const fw_path[] = …; /* * 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(…); MODULE_PARM_DESC(…) …; static int fw_get_filesystem_firmware(struct device *device, struct fw_priv *fw_priv, const char *suffix, int (*decompress)(struct device *dev, struct fw_priv *fw_priv, size_t in_size, const void *in_buffer)) { … } /* firmware holds the ownership of pages */ static void firmware_free_data(const struct firmware *fw) { … } /* store the pages buffer info firmware from buf */ static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw) { … } #ifdef CONFIG_FW_CACHE static void fw_name_devm_release(struct device *dev, void *res) { … } static int fw_devm_match(struct device *dev, void *res, void *match_data) { … } static struct fw_name_devm *fw_find_devm_name(struct device *dev, const char *name) { … } static bool fw_cache_is_setup(struct device *dev, const char *name) { … } /* add firmware name into devres list */ static int fw_add_devm_name(struct device *dev, const char *name) { … } #else static bool fw_cache_is_setup(struct device *dev, const char *name) { return false; } static int fw_add_devm_name(struct device *dev, const char *name) { return 0; } #endif int assign_fw(struct firmware *fw, struct device *device) { … } /* 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, size_t offset, u32 opt_flags) { … } /* * 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 fw_priv 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) { … } #if defined(CONFIG_FW_LOADER_DEBUG) #include <crypto/hash.h> #include <crypto/sha2.h> static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device) { … } #else static void fw_log_firmware_info(const struct firmware *fw, const char *name, struct device *device) {} #endif /* 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, size_t offset, u32 opt_flags) { … } /** * 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) { … } EXPORT_SYMBOL(…); /** * firmware_request_nowarn() - request for an optional fw module * @firmware: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded * * This function is similar in behaviour to request_firmware(), except it * doesn't produce warning messages when the file is not found. The sysfs * fallback mechanism is enabled if direct filesystem lookup fails. However, * failures to find the firmware file with it are still suppressed. It is * therefore up to the driver to check for the return value of this call and to * decide when to inform the users of errors. **/ int firmware_request_nowarn(const struct firmware **firmware, const char *name, struct device *device) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL_GPL(…); /** * firmware_request_platform() - request firmware with platform-fw fallback * @firmware: pointer to firmware image * @name: name of firmware file * @device: device for which firmware is being loaded * * This function is similar in behaviour to request_firmware, except that if * direct filesystem lookup fails, it will fallback to looking for a copy of the * requested firmware embedded in the platform's main (e.g. UEFI) firmware. **/ int firmware_request_platform(const struct firmware **firmware, const char *name, struct device *device) { … } EXPORT_SYMBOL_GPL(…); /** * firmware_request_cache() - cache firmware for suspend so resume can use it * @name: name of firmware file * @device: device for which firmware should be cached for * * There are some devices with an optimization that enables the device to not * require loading firmware on system reboot. This optimization may still * require the firmware present on resume from suspend. This routine can be * used to ensure the firmware is present on resume from suspend in these * situations. This helper is not compatible with drivers which use * request_firmware_into_buf() or request_firmware_nowait() with no uevent set. **/ int firmware_request_cache(struct device *device, const char *name) { … } EXPORT_SYMBOL_GPL(…); /** * 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) { … } EXPORT_SYMBOL(…); /** * request_partial_firmware_into_buf() - load partial 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 * @offset: offset into file to read * * This function works pretty much like request_firmware_into_buf except * it allows a partial read of the file. */ int request_partial_firmware_into_buf(const struct firmware **firmware_p, const char *name, struct device *device, void *buf, size_t size, size_t offset) { … } EXPORT_SYMBOL(…); /** * release_firmware() - release the resource associated with a firmware image * @fw: firmware resource to release **/ void release_firmware(const struct firmware *fw) { … } EXPORT_SYMBOL(…); /* Async support */ struct firmware_work { … }; static void request_firmware_work_func(struct work_struct *work) { … } static 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), bool nowarn) { … } /** * 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)) { … } EXPORT_SYMBOL(…); /** * firmware_request_nowait_nowarn() - async version of request_firmware_nowarn * @module: module requesting the firmware * @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. * * Similar in function to request_firmware_nowait(), but doesn't print a warning * when the firmware file could not be found and always sends a uevent to copy * the firmware image. */ int firmware_request_nowait_nowarn( struct module *module, const char *name, struct device *device, gfp_t gfp, void *context, void (*cont)(const struct firmware *fw, void *context)) { … } EXPORT_SYMBOL_GPL(…); #ifdef CONFIG_FW_CACHE 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) { … } static struct fw_priv *lookup_fw_priv(const char *fw_name) { … } /** * 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) { … } static struct fw_cache_entry *alloc_fw_cache_entry(const char *name) { … } static int __fw_entry_found(const char *name) { … } static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv) { … } static void free_fw_cache_entry(struct fw_cache_entry *fce) { … } static void __async_dev_cache_fw_image(void *fw_entry, async_cookie_t cookie) { … } /* called with dev->devres_lock held */ static void dev_create_fw_entry(struct device *dev, void *res, void *data) { … } static int devm_name_match(struct device *dev, void *res, void *match_data) { … } static void dev_cache_fw_image(struct device *dev, void *data) { … } static void __device_uncache_fw_images(void) { … } /** * 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) { … } /** * 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) { … } static void device_uncache_fw_images_work(struct work_struct *work) { … } /** * 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) { … } static int fw_pm_notify(struct notifier_block *notify_block, unsigned long mode, void *unused) { … } /* stop caching firmware once syscore_suspend is reached */ static int fw_suspend(void) { … } static struct syscore_ops fw_syscore_ops = …; static int __init register_fw_pm_ops(void) { … } static inline void unregister_fw_pm_ops(void) { … } #else static void fw_cache_piggyback_on_request(struct fw_priv *fw_priv) { } static inline int register_fw_pm_ops(void) { return 0; } static inline void unregister_fw_pm_ops(void) { } #endif static void __init fw_cache_init(void) { … } static int fw_shutdown_notify(struct notifier_block *unused1, unsigned long unused2, void *unused3) { … } static struct notifier_block fw_shutdown_nb = …; static int __init firmware_class_init(void) { … } static void __exit firmware_class_exit(void) { … } fs_initcall(firmware_class_init); module_exit(firmware_class_exit);
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