diff options
Diffstat (limited to 'drivers/base/firmware_loader/main.c')
| -rw-r--r-- | drivers/base/firmware_loader/main.c | 1282 |
1 files changed, 1282 insertions, 0 deletions
diff --git a/drivers/base/firmware_loader/main.c b/drivers/base/firmware_loader/main.c new file mode 100644 index 000000000..cfa5e598a --- /dev/null +++ b/drivers/base/firmware_loader/main.c @@ -0,0 +1,1282 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * main.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 <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/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 <generated/utsrelease.h> + +#include "../base.h" +#include "firmware.h" +#include "fallback.h" + +MODULE_AUTHOR("Manuel Estrada Sainz"); +MODULE_DESCRIPTION("Multi purpose firmware loading support"); +MODULE_LICENSE("GPL"); + +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 fw_cache_entry { + struct list_head list; + const char *name; +}; + +struct fw_name_devm { + unsigned long magic; + const char *name; +}; + +static inline struct fw_priv *to_fw_priv(struct kref *ref) +{ + return container_of(ref, struct fw_priv, ref); +} + +#define FW_LOADER_NO_CACHE 0 +#define FW_LOADER_START_CACHE 1 + +/* 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(fw_lock); + +static struct firmware_cache fw_cache; + +/* Builtin firmware support */ + +#ifdef CONFIG_FW_LOADER + +extern struct builtin_fw __start_builtin_fw[]; +extern struct builtin_fw __end_builtin_fw[]; + +static bool fw_copy_to_prealloc_buf(struct firmware *fw, + void *buf, size_t size) +{ + if (!buf) + return true; + if (size < fw->size) + return false; + memcpy(buf, fw->data, fw->size); + return true; +} + +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; + return fw_copy_to_prealloc_buf(fw, buf, size); + } + } + + 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 + +static void fw_state_init(struct fw_priv *fw_priv) +{ + struct fw_state *fw_st = &fw_priv->fw_st; + + init_completion(&fw_st->completion); + fw_st->status = FW_STATUS_UNKNOWN; +} + +static inline int fw_state_wait(struct fw_priv *fw_priv) +{ + return __fw_state_wait_common(fw_priv, MAX_SCHEDULE_TIMEOUT); +} + +static int fw_cache_piggyback_on_request(const char *name); + +static struct fw_priv *__allocate_fw_priv(const char *fw_name, + struct firmware_cache *fwc, + void *dbuf, size_t size) +{ + struct fw_priv *fw_priv; + + fw_priv = kzalloc(sizeof(*fw_priv), GFP_ATOMIC); + if (!fw_priv) + return NULL; + + fw_priv->fw_name = kstrdup_const(fw_name, GFP_ATOMIC); + if (!fw_priv->fw_name) { + kfree(fw_priv); + return NULL; + } + + kref_init(&fw_priv->ref); + fw_priv->fwc = fwc; + fw_priv->data = dbuf; + fw_priv->allocated_size = size; + fw_state_init(fw_priv); +#ifdef CONFIG_FW_LOADER_USER_HELPER + INIT_LIST_HEAD(&fw_priv->pending_list); +#endif + + pr_debug("%s: fw-%s fw_priv=%p\n", __func__, fw_name, fw_priv); + + return fw_priv; +} + +static struct fw_priv *__lookup_fw_priv(const char *fw_name) +{ + struct fw_priv *tmp; + struct firmware_cache *fwc = &fw_cache; + + list_for_each_entry(tmp, &fwc->head, list) + if (!strcmp(tmp->fw_name, fw_name)) + return tmp; + return NULL; +} + +/* Returns 1 for batching firmware requests with the same name */ +static int alloc_lookup_fw_priv(const char *fw_name, + struct firmware_cache *fwc, + struct fw_priv **fw_priv, void *dbuf, + size_t size, enum fw_opt opt_flags) +{ + struct fw_priv *tmp; + + spin_lock(&fwc->lock); + if (!(opt_flags & FW_OPT_NOCACHE)) { + tmp = __lookup_fw_priv(fw_name); + if (tmp) { + kref_get(&tmp->ref); + spin_unlock(&fwc->lock); + *fw_priv = tmp; + pr_debug("batched request - sharing the same struct fw_priv and lookup for multiple requests\n"); + return 1; + } + } + + tmp = __allocate_fw_priv(fw_name, fwc, dbuf, size); + if (tmp) { + INIT_LIST_HEAD(&tmp->list); + if (!(opt_flags & FW_OPT_NOCACHE)) + list_add(&tmp->list, &fwc->head); + } + spin_unlock(&fwc->lock); + + *fw_priv = tmp; + + return tmp ? 0 : -ENOMEM; +} + +static void __free_fw_priv(struct kref *ref) + __releases(&fwc->lock) +{ + struct fw_priv *fw_priv = to_fw_priv(ref); + struct firmware_cache *fwc = fw_priv->fwc; + + pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n", + __func__, fw_priv->fw_name, fw_priv, fw_priv->data, + (unsigned int)fw_priv->size); + + list_del(&fw_priv->list); + spin_unlock(&fwc->lock); + +#ifdef CONFIG_FW_LOADER_USER_HELPER + if (fw_priv->is_paged_buf) { + int i; + vunmap(fw_priv->data); + for (i = 0; i < fw_priv->nr_pages; i++) + __free_page(fw_priv->pages[i]); + vfree(fw_priv->pages); + } else +#endif + if (!fw_priv->allocated_size) + vfree(fw_priv->data); + kfree_const(fw_priv->fw_name); + kfree(fw_priv); +} + +static void free_fw_priv(struct fw_priv *fw_priv) +{ + struct firmware_cache *fwc = fw_priv->fwc; + spin_lock(&fwc->lock); + if (!kref_put(&fw_priv->ref, __free_fw_priv)) + 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 fw_priv *fw_priv) +{ + loff_t size; + int i, len; + int rc = -ENOENT; + char *path; + enum kernel_read_file_id id = READING_FIRMWARE; + size_t msize = INT_MAX; + + /* Already populated data member means we're loading into a buffer */ + if (fw_priv->data) { + id = READING_FIRMWARE_PREALLOC_BUFFER; + msize = fw_priv->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], fw_priv->fw_name); + if (len >= PATH_MAX) { + rc = -ENAMETOOLONG; + break; + } + + fw_priv->size = 0; + rc = kernel_read_file_from_path(path, &fw_priv->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", fw_priv->fw_name); + fw_priv->size = size; + fw_state_done(fw_priv); + 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; + } + free_fw_priv(fw->priv); +} + +/* store the pages buffer info firmware from buf */ +static void fw_set_page_data(struct fw_priv *fw_priv, struct firmware *fw) +{ + fw->priv = fw_priv; +#ifdef CONFIG_FW_LOADER_USER_HELPER + fw->pages = fw_priv->pages; +#endif + fw->size = fw_priv->size; + fw->data = fw_priv->data; + + pr_debug("%s: fw-%s fw_priv=%p data=%p size=%u\n", + __func__, fw_priv->fw_name, fw_priv, fw_priv->data, + (unsigned int)fw_priv->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; +} + +static bool fw_cache_is_setup(struct device *dev, const char *name) +{ + struct fw_name_devm *fwn; + + fwn = fw_find_devm_name(dev, name); + if (fwn) + return true; + + return false; +} + +/* add firmware name into devres list */ +static int fw_add_devm_name(struct device *dev, const char *name) +{ + struct fw_name_devm *fwn; + + if (fw_cache_is_setup(dev, name)) + return 0; + + 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 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, + enum fw_opt opt_flags) +{ + struct fw_priv *fw_priv = fw->priv; + int ret; + + mutex_lock(&fw_lock); + if (!fw_priv->size || fw_state_is_aborted(fw_priv)) { + 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)) { + ret = fw_add_devm_name(device, fw_priv->fw_name); + if (ret) { + mutex_unlock(&fw_lock); + return ret; + } + } + + /* + * After caching firmware image is started, let it piggyback + * on request firmware. + */ + if (!(opt_flags & FW_OPT_NOCACHE) && + fw_priv->fwc->state == FW_LOADER_START_CACHE) { + if (fw_cache_piggyback_on_request(fw_priv->fw_name)) + kref_get(&fw_priv->ref); + } + + /* pass the pages buffer to driver at the last minute */ + fw_set_page_data(fw_priv, fw); + mutex_unlock(&fw_lock); + return 0; +} + +/* 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, + enum fw_opt opt_flags) +{ + struct firmware *firmware; + struct fw_priv *fw_priv; + 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 = alloc_lookup_fw_priv(name, &fw_cache, &fw_priv, dbuf, size, + opt_flags); + + /* + * bind with 'priv' now to avoid warning in failure path + * of requesting firmware. + */ + firmware->priv = fw_priv; + + if (ret > 0) { + ret = fw_state_wait(fw_priv); + if (!ret) { + fw_set_page_data(fw_priv, 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 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) +{ + struct fw_priv *fw_priv; + + /* Loaded directly? */ + if (!fw || !fw->priv) + return; + + fw_priv = fw->priv; + mutex_lock(&fw_lock); + if (!fw_state_is_aborted(fw_priv)) + fw_state_aborted(fw_priv); + mutex_unlock(&fw_lock); +} + +/* 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, + enum fw_opt 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, + opt_flags); + 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); + ret = firmware_fallback_sysfs(fw, name, device, opt_flags, ret); + } else + ret = assign_fw(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); + module_put(THIS_MODULE); + return ret; +} +EXPORT_SYMBOL(request_firmware); + +/** + * 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, 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) +{ + int ret; + + /* Need to pin this module until return */ + __module_get(THIS_MODULE); + ret = _request_firmware(firmware, name, device, NULL, 0, + FW_OPT_UEVENT | FW_OPT_NO_WARN); + module_put(THIS_MODULE); + return ret; +} +EXPORT_SYMBOL_GPL(firmware_request_nowarn); + +/** + * 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 | + FW_OPT_NOFALLBACK); + module_put(THIS_MODULE); + return ret; +} +EXPORT_SYMBOL_GPL(request_firmware_direct); + +/** + * 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) +{ + int ret; + + mutex_lock(&fw_lock); + ret = fw_add_devm_name(device, name); + mutex_unlock(&fw_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(firmware_request_cache); + +/** + * 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; + + if (fw_cache_is_setup(device, name)) + return -EOPNOTSUPP; + + __module_get(THIS_MODULE); + ret = _request_firmware(firmware_p, name, device, buf, size, + FW_OPT_UEVENT | 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); + enum fw_opt opt_flags; +}; + +static void request_firmware_work_func(struct work_struct *work) +{ + struct firmware_work *fw_work; + const struct firmware *fw; + + fw_work = container_of(work, struct firmware_work, work); + + _request_firmware(&fw, fw_work->name, fw_work->device, NULL, 0, + fw_work->opt_flags); + 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); +} + +/** + * 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 | + (uevent ? FW_OPT_UEVENT : FW_OPT_USERHELPER); + + if (!uevent && fw_cache_is_setup(device, name)) { + kfree_const(fw_work->name); + kfree(fw_work); + return -EOPNOTSUPP; + } + + 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 fw_priv *lookup_fw_priv(const char *fw_name) +{ + struct fw_priv *tmp; + struct firmware_cache *fwc = &fw_cache; + + spin_lock(&fwc->lock); + tmp = __lookup_fw_priv(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 fw_priv *fw_priv; + struct firmware fw; + + pr_debug("%s: %s\n", __func__, fw_name); + + if (fw_get_builtin_firmware(&fw, fw_name, NULL, 0)) + return 0; + + fw_priv = lookup_fw_priv(fw_name); + if (fw_priv) { + free_fw_priv(fw_priv); + 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; + DEFINE_WAIT(wait); + + pr_debug("%s\n", __func__); + + /* cancel uncache work */ + cancel_delayed_work_sync(&fwc->work); + + fw_fallback_set_cache_timeout(); + + 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); + + fw_fallback_set_default_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, +}; + +static int __init register_fw_pm_ops(void) +{ + int ret; + + 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; + ret = register_pm_notifier(&fw_cache.pm_notify); + if (ret) + return ret; + + register_syscore_ops(&fw_syscore_ops); + + return ret; +} + +static inline void unregister_fw_pm_ops(void) +{ + unregister_syscore_ops(&fw_syscore_ops); + unregister_pm_notifier(&fw_cache.pm_notify); +} +#else +static int fw_cache_piggyback_on_request(const char *name) +{ + return 0; +} +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) +{ + spin_lock_init(&fw_cache.lock); + INIT_LIST_HEAD(&fw_cache.head); + fw_cache.state = FW_LOADER_NO_CACHE; +} + +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) +{ + int ret; + + /* No need to unfold these on exit */ + fw_cache_init(); + + ret = register_fw_pm_ops(); + if (ret) + return ret; + + ret = register_reboot_notifier(&fw_shutdown_nb); + if (ret) + goto out; + + return register_sysfs_loader(); + +out: + unregister_fw_pm_ops(); + return ret; +} + +static void __exit firmware_class_exit(void) +{ + unregister_fw_pm_ops(); + unregister_reboot_notifier(&fw_shutdown_nb); + unregister_sysfs_loader(); +} + +fs_initcall(firmware_class_init); +module_exit(firmware_class_exit); |