diff options
Diffstat (limited to 'kernel/drivers/base/firmware_class.c')
| -rw-r--r-- | kernel/drivers/base/firmware_class.c | 1686 |
1 files changed, 1686 insertions, 0 deletions
diff --git a/kernel/drivers/base/firmware_class.c b/kernel/drivers/base/firmware_class.c new file mode 100644 index 000000000..171841ad1 --- /dev/null +++ b/kernel/drivers/base/firmware_class.c @@ -0,0 +1,1686 @@ +/* + * 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/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/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" + +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 */ + +static inline long firmware_loading_timeout(void) +{ + return loading_timeout > 0 ? loading_timeout * HZ : MAX_JIFFY_OFFSET; +} + +/* 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) + +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 completion completion; + struct firmware_cache *fwc; + unsigned long status; + void *data; + size_t 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 + char fw_id[]; +}; + +struct fw_cache_entry { + struct list_head list; + char name[]; +}; + +struct fw_name_devm { + unsigned long magic; + 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) +{ + struct firmware_buf *buf; + + buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1, GFP_ATOMIC); + + if (!buf) + return buf; + + kref_init(&buf->ref); + strcpy(buf->fw_id, fw_name); + buf->fwc = fwc; + init_completion(&buf->completion); +#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; +} + +static int fw_lookup_and_allocate_buf(const char *fw_name, + struct firmware_cache *fwc, + struct firmware_buf **buf) +{ + 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; + return 1; + } + tmp = __allocate_fw_buf(fw_name, fwc); + 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]); + kfree(buf->pages); + } else +#endif + vfree(buf->data); + 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_read_file_contents(struct file *file, struct firmware_buf *fw_buf) +{ + int size; + char *buf; + int rc; + + if (!S_ISREG(file_inode(file)->i_mode)) + return -EINVAL; + size = i_size_read(file_inode(file)); + if (size <= 0) + return -EINVAL; + buf = vmalloc(size); + if (!buf) + return -ENOMEM; + rc = kernel_read(file, 0, buf, size); + if (rc != size) { + if (rc > 0) + rc = -EIO; + goto fail; + } + rc = security_kernel_fw_from_file(file, buf, size); + if (rc) + goto fail; + fw_buf->data = buf; + fw_buf->size = size; + return 0; +fail: + vfree(buf); + return rc; +} + +static int fw_get_filesystem_firmware(struct device *device, + struct firmware_buf *buf) +{ + int i; + int rc = -ENOENT; + char *path = __getname(); + + for (i = 0; i < ARRAY_SIZE(fw_path); i++) { + struct file *file; + + /* skip the unset customized path */ + if (!fw_path[i][0]) + continue; + + snprintf(path, PATH_MAX, "%s/%s", fw_path[i], buf->fw_id); + + file = filp_open(path, O_RDONLY, 0); + if (IS_ERR(file)) + continue; + rc = fw_read_file_contents(file, buf); + fput(file); + if (rc) + dev_warn(device, "firmware, attempted to load %s, but failed with error %d\n", + path, rc); + else + break; + } + __putname(path); + + if (!rc) { + dev_dbg(device, "firmware: direct-loading firmware %s\n", + buf->fw_id); + mutex_lock(&fw_lock); + set_bit(FW_STATUS_DONE, &buf->status); + complete_all(&buf->completion); + mutex_unlock(&fw_lock); + } + + 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); +} + +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) + + strlen(name) + 1, GFP_KERNEL); + if (!fwn) + return -ENOMEM; + + fwn->magic = (unsigned long)&fw_cache; + strcpy(fwn->name, name); + devres_add(dev, fwn); + + return 0; +} +#else +static int fw_add_devm_name(struct device *dev, const char *name) +{ + return 0; +} +#endif + + +/* + * 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 (test_bit(FW_STATUS_DONE, &buf->status)) + return; + + list_del_init(&buf->pending_list); + set_bit(FW_STATUS_ABORT, &buf->status); + complete_all(&buf->completion); +} + +static void fw_load_abort(struct firmware_priv *fw_priv) +{ + struct firmware_buf *buf = fw_priv->buf; + + __fw_load_abort(buf); + + /* avoid user action after loading abort */ + fw_priv->buf = NULL; +} + +#define is_fw_load_aborted(buf) \ + test_bit(FW_STATUS_ABORT, &(buf)->status) + +static LIST_HEAD(pending_fw_head); + +/* reboot notifier for avoid deadlock with usermode_lock */ +static int fw_shutdown_notify(struct notifier_block *unused1, + unsigned long unused2, void *unused3) +{ + mutex_lock(&fw_lock); + while (!list_empty(&pending_fw_head)) + __fw_load_abort(list_first_entry(&pending_fw_head, + struct firmware_buf, + pending_list)); + mutex_unlock(&fw_lock); + return NOTIFY_DONE; +} + +static struct notifier_block fw_shutdown_nb = { + .notifier_call = fw_shutdown_notify, +}; + +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 struct class_attribute firmware_class_attrs[] = { + __ATTR_RW(timeout), + __ATTR_NULL +}; + +static void fw_dev_release(struct device *dev) +{ + struct firmware_priv *fw_priv = to_firmware_priv(dev); + + kfree(fw_priv); +} + +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->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 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 = 0; + + mutex_lock(&fw_lock); + if (fw_priv->buf) + loading = test_bit(FW_STATUS_LOADING, &fw_priv->buf->status); + 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_buf) + goto out; + + switch (loading) { + case 1: + /* discarding any previous partial load */ + if (!test_bit(FW_STATUS_DONE, &fw_buf->status)) { + for (i = 0; i < fw_buf->nr_pages; i++) + __free_page(fw_buf->pages[i]); + kfree(fw_buf->pages); + fw_buf->pages = NULL; + fw_buf->page_array_size = 0; + fw_buf->nr_pages = 0; + set_bit(FW_STATUS_LOADING, &fw_buf->status); + } + break; + case 0: + if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) { + int rc; + + set_bit(FW_STATUS_DONE, &fw_buf->status); + clear_bit(FW_STATUS_LOADING, &fw_buf->status); + + /* + * 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_fw_from_file(NULL, + fw_buf->data, fw_buf->size); + + /* + * 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) { + set_bit(FW_STATUS_ABORT, &fw_buf->status); + written = rc; + } + complete_all(&fw_buf->completion); + 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 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 || test_bit(FW_STATUS_DONE, &buf->status)) { + 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; + + 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]); + + memcpy(buffer, page_data + page_ofs, page_cnt); + + kunmap(buf->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) +{ + 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 = kmalloc(new_array_size * sizeof(void *), + GFP_KERNEL); + 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)); + kfree(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 || test_bit(FW_STATUS_DONE, &buf->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(buf->pages[page_nr]); + + memcpy(page_data + page_ofs, buffer, page_cnt); + + kunmap(buf->pages[page_nr]); + buffer += page_cnt; + offset += page_cnt; + count -= page_cnt; + } + + buf->size = max_t(size_t, offset, 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 */ + 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 = wait_for_completion_interruptible_timeout(&buf->completion, + timeout); + if (retval == -ERESTARTSYS || !retval) { + mutex_lock(&fw_lock); + fw_load_abort(fw_priv); + mutex_unlock(&fw_lock); + } else if (retval > 0) { + retval = 0; + } + + if (is_fw_load_aborted(buf)) + retval = -EAGAIN; + else if (!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, long timeout) +{ + struct firmware_priv *fw_priv; + + fw_priv = fw_create_instance(firmware, name, device, opt_flags); + if (IS_ERR(fw_priv)) + return PTR_ERR(fw_priv); + + fw_priv->buf = firmware->priv; + return _request_firmware_load(fw_priv, opt_flags, timeout); +} + +#ifdef CONFIG_PM_SLEEP +/* kill pending requests without uevent to avoid blocking suspend */ +static void kill_requests_without_uevent(void) +{ + 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) + __fw_load_abort(buf); + } + mutex_unlock(&fw_lock); +} +#endif + +#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, + long timeout) +{ + return -ENOENT; +} + +/* No abort during direct loading */ +#define is_fw_load_aborted(buf) false + +#ifdef CONFIG_PM_SLEEP +static inline void kill_requests_without_uevent(void) { } +#endif + +#endif /* CONFIG_FW_LOADER_USER_HELPER */ + + +/* wait until the shared firmware_buf becomes ready (or error) */ +static int sync_cached_firmware_buf(struct firmware_buf *buf) +{ + int ret = 0; + + mutex_lock(&fw_lock); + while (!test_bit(FW_STATUS_DONE, &buf->status)) { + if (is_fw_load_aborted(buf)) { + ret = -ENOENT; + break; + } + mutex_unlock(&fw_lock); + ret = wait_for_completion_interruptible(&buf->completion); + mutex_lock(&fw_lock); + } + mutex_unlock(&fw_lock); + return ret; +} + +/* 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) +{ + 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)) { + dev_dbg(device, "firmware: using built-in firmware %s\n", name); + return 0; /* assigned */ + } + + ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf); + + /* + * bind with 'buf' now to avoid warning in failure path + * of requesting firmware. + */ + firmware->priv = buf; + + if (ret > 0) { + ret = sync_cached_firmware_buf(buf); + if (!ret) { + fw_set_page_data(buf, firmware); + return 0; /* assigned */ + } + } + + if (ret < 0) + return ret; + return 1; /* need to load */ +} + +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 || is_fw_load_aborted(buf)) { + 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)) + fw_add_devm_name(device, buf->fw_id); + + /* + * After caching firmware image is started, let it piggyback + * on request firmware. + */ + if (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; +} + +/* called from request_firmware() and request_firmware_work_func() */ +static int +_request_firmware(const struct firmware **firmware_p, const char *name, + struct device *device, unsigned int opt_flags) +{ + struct firmware *fw; + long timeout; + int ret; + + if (!firmware_p) + return -EINVAL; + + if (!name || name[0] == '\0') + return -EINVAL; + + ret = _request_firmware_prepare(&fw, name, device); + if (ret <= 0) /* error or already assigned */ + goto out; + + ret = 0; + 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); + ret = -EBUSY; + goto out; + } + } else { + ret = usermodehelper_read_trylock(); + if (WARN_ON(ret)) { + dev_err(device, "firmware: %s will not be loaded\n", + name); + 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, timeout); + } + } + + if (!ret) + ret = assign_firmware_buf(fw, device, opt_flags); + + usermodehelper_read_unlock(); + + out: + if (ret < 0) { + 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, + 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, + FW_OPT_UEVENT | FW_OPT_NO_WARN); + module_put(THIS_MODULE); + return ret; +} +EXPORT_SYMBOL_GPL(request_firmware_direct); + +/** + * 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; +}; + +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, + 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(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 = name; + 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); + + if (!try_module_get(module)) { + 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)) + 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) + strlen(name) + 1, GFP_ATOMIC); + if (!fce) + goto exit; + + strcpy(fce->name, name); +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(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_requests_without_uevent(); + 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 __init firmware_class_init(void) +{ + fw_cache_init(); +#ifdef CONFIG_FW_LOADER_USER_HELPER + register_reboot_notifier(&fw_shutdown_nb); + 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 +#ifdef CONFIG_FW_LOADER_USER_HELPER + unregister_reboot_notifier(&fw_shutdown_nb); + class_unregister(&firmware_class); +#endif +} + +fs_initcall(firmware_class_init); +module_exit(firmware_class_exit); |