From: Ming Lei Date: Sat, 4 Aug 2012 04:01:21 +0000 (+0800) Subject: firmware loader: always let firmware_buf own the pages buffer X-Git-Tag: firefly_0821_release~3680^2~1978^2~82 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=1f2b79599ee8f5fc82cc73c6c090eb6cdff881d6;p=firefly-linux-kernel-4.4.55.git firmware loader: always let firmware_buf own the pages buffer This patch always let firmware_buf own the pages buffer allocated inside firmware_data_write, and add all instances of firmware_buf into the firmware cache global list. Also introduce one private field in 'struct firmware', so release_firmware will see the instance of firmware_buf associated with the current firmware instance, then just 'free' the instance of firmware_buf. The firmware_buf instance represents one pages buffer for one firmware image, so lots of firmware loading requests can share the same firmware_buf instance if they request the same firmware image file. This patch will make implementation of the following cache_firmware/ uncache_firmware very easy and simple. In fact, the patch improves request_formware/release_firmware: - only request userspace to write firmware image once if several devices share one same firmware image and its drivers call request_firmware concurrently. Signed-off-by: Ming Lei Cc: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index 5f2076e5d5b1..848ad97e8d79 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -21,6 +21,7 @@ #include #include #include +#include MODULE_AUTHOR("Manuel Estrada Sainz"); MODULE_DESCRIPTION("Multi purpose firmware loading support"); @@ -85,13 +86,17 @@ static inline long firmware_loading_timeout(void) return loading_timeout > 0 ? loading_timeout * HZ : MAX_SCHEDULE_TIMEOUT; } -/* 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_cache { + /* firmware_buf instance will be added into the below list */ + spinlock_t lock; + struct list_head head; +}; struct firmware_buf { + struct kref ref; + struct list_head list; struct completion completion; - struct firmware *fw; + struct firmware_cache *fwc; unsigned long status; void *data; size_t size; @@ -106,8 +111,94 @@ struct firmware_priv { bool nowait; struct device dev; struct firmware_buf *buf; + struct firmware *fw; }; +#define to_fwbuf(d) container_of(d, struct firmware_buf, ref) + +/* 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); + + pr_debug("%s: fw-%s buf=%p\n", __func__, fw_name, buf); + + return buf; +} + +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); + list_for_each_entry(tmp, &fwc->head, list) + if (!strcmp(tmp->fw_id, fw_name)) { + 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) +{ + struct firmware_buf *buf = to_fwbuf(ref); + struct firmware_cache *fwc = buf->fwc; + int i; + + pr_debug("%s: fw-%s buf=%p data=%p size=%u\n", + __func__, buf->fw_id, buf, buf->data, + (unsigned int)buf->size); + + spin_lock(&fwc->lock); + list_del(&buf->list); + spin_unlock(&fwc->lock); + + vunmap(buf->data); + for (i = 0; i < buf->nr_pages; i++) + __free_page(buf->pages[i]); + kfree(buf->pages); + kfree(buf); +} + +static void fw_free_buf(struct firmware_buf *buf) +{ + kref_put(&buf->ref, __fw_free_buf); +} + +static void __init fw_cache_init(void) +{ + spin_lock_init(&fw_cache.lock); + INIT_LIST_HEAD(&fw_cache.head); +} + static struct firmware_priv *to_firmware_priv(struct device *dev) { return container_of(dev, struct firmware_priv, dev); @@ -118,7 +209,7 @@ static void fw_load_abort(struct firmware_priv *fw_priv) struct firmware_buf *buf = fw_priv->buf; set_bit(FW_STATUS_ABORT, &buf->status); - complete(&buf->completion); + complete_all(&buf->completion); } static ssize_t firmware_timeout_show(struct class *class, @@ -158,18 +249,6 @@ static struct class_attribute firmware_class_attrs[] = { __ATTR_NULL }; -static void fw_free_buf(struct firmware_buf *buf) -{ - int i; - - if (!buf) - return; - - for (i = 0; i < buf->nr_pages; i++) - __free_page(buf->pages[i]); - kfree(buf->pages); -} - static void fw_dev_release(struct device *dev) { struct firmware_priv *fw_priv = to_firmware_priv(dev); @@ -212,13 +291,8 @@ static ssize_t firmware_loading_show(struct device *dev, /* firmware holds the ownership of pages */ 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); - } + WARN_ON(!fw->priv); + fw_free_buf(fw->priv); } /* Some architectures don't have PAGE_KERNEL_RO */ @@ -269,7 +343,7 @@ static ssize_t firmware_loading_store(struct device *dev, if (test_bit(FW_STATUS_LOADING, &fw_buf->status)) { set_bit(FW_STATUS_DONE, &fw_buf->status); clear_bit(FW_STATUS_LOADING, &fw_buf->status); - complete(&fw_buf->completion); + complete_all(&fw_buf->completion); break; } /* fallthrough */ @@ -448,7 +522,6 @@ fw_create_instance(struct firmware *firmware, const char *fw_name, struct device *device, bool uevent, bool nowait) { struct firmware_priv *fw_priv; - struct firmware_buf *buf; struct device *f_dev; fw_priv = kzalloc(sizeof(*fw_priv), GFP_KERNEL); @@ -458,21 +531,10 @@ fw_create_instance(struct firmware *firmware, const char *fw_name, goto exit; } - buf = kzalloc(sizeof(*buf) + strlen(fw_name) + 1, GFP_KERNEL); - if (!buf) { - dev_err(device, "%s: kmalloc failed\n", __func__); - kfree(fw_priv); - fw_priv = ERR_PTR(-ENOMEM); - goto exit; - } - - buf->fw = firmware; - fw_priv->buf = buf; fw_priv->nowait = nowait; + fw_priv->fw = firmware; setup_timer(&fw_priv->timeout, firmware_class_timeout, (u_long) fw_priv); - strcpy(buf->fw_id, fw_name); - init_completion(&buf->completion); f_dev = &fw_priv->dev; @@ -484,12 +546,42 @@ exit: return fw_priv; } +/* one pages buffer is mapped/unmapped only once */ +static int fw_map_pages_buf(struct firmware_buf *buf) +{ + buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO); + if (!buf->data) + return -ENOMEM; + return 0; +} + +/* store the pages buffer info firmware from buf */ +static void fw_set_page_data(struct firmware_buf *buf, struct firmware *fw) +{ + fw->priv = buf; + fw->pages = buf->pages; + 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); +} + +static void _request_firmware_cleanup(const struct firmware **firmware_p) +{ + release_firmware(*firmware_p); + *firmware_p = NULL; +} + static struct firmware_priv * _request_firmware_prepare(const struct firmware **firmware_p, const char *name, struct device *device, bool uevent, bool nowait) { struct firmware *firmware; - struct firmware_priv *fw_priv; + struct firmware_priv *fw_priv = NULL; + struct firmware_buf *buf; + int ret; if (!firmware_p) return ERR_PTR(-EINVAL); @@ -506,35 +598,45 @@ _request_firmware_prepare(const struct firmware **firmware_p, const char *name, return NULL; } - fw_priv = fw_create_instance(firmware, name, device, uevent, nowait); - if (IS_ERR(fw_priv)) { - release_firmware(firmware); + ret = fw_lookup_and_allocate_buf(name, &fw_cache, &buf); + if (!ret) + fw_priv = fw_create_instance(firmware, name, device, + uevent, nowait); + + if (IS_ERR(fw_priv) || ret < 0) { + kfree(firmware); *firmware_p = NULL; + return ERR_PTR(-ENOMEM); + } else if (fw_priv) { + fw_priv->buf = buf; + + /* + * bind with 'buf' now to avoid warning in failure path + * of requesting firmware. + */ + firmware->priv = buf; + return fw_priv; } - return fw_priv; -} - -static void _request_firmware_cleanup(const struct firmware **firmware_p) -{ - release_firmware(*firmware_p); - *firmware_p = NULL; -} -/* transfer the ownership of pages to firmware */ -static int fw_set_page_data(struct firmware_buf *buf) -{ - struct firmware *fw = buf->fw; - - buf->data = vmap(buf->pages, buf->nr_pages, 0, PAGE_KERNEL_RO); - if (!buf->data) - return -ENOMEM; - - fw->data = buf->data; - fw->pages = buf->pages; - fw->size = buf->size; - WARN_ON(PFN_UP(fw->size) != buf->nr_pages); + /* share the cached buf, which is inprogessing or completed */ + check_status: + mutex_lock(&fw_lock); + if (test_bit(FW_STATUS_ABORT, &buf->status)) { + fw_priv = ERR_PTR(-ENOENT); + _request_firmware_cleanup(firmware_p); + goto exit; + } else if (test_bit(FW_STATUS_DONE, &buf->status)) { + fw_priv = NULL; + fw_set_page_data(buf, firmware); + goto exit; + } + mutex_unlock(&fw_lock); + wait_for_completion(&buf->completion); + goto check_status; - return 0; +exit: + mutex_unlock(&fw_lock); + return fw_priv; } static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, @@ -585,13 +687,12 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status)) retval = -ENOENT; - /* transfer pages ownership at the last minute */ if (!retval) - retval = fw_set_page_data(buf); - if (retval) - fw_free_buf(buf); /* free untransfered pages buffer */ + retval = fw_map_pages_buf(buf); + + /* pass the pages buffer to driver at the last minute */ + fw_set_page_data(buf, fw_priv->fw); - kfree(buf); fw_priv->buf = NULL; mutex_unlock(&fw_lock); @@ -753,6 +854,7 @@ request_firmware_nowait( static int __init firmware_class_init(void) { + fw_cache_init(); return class_register(&firmware_class); } diff --git a/include/linux/firmware.h b/include/linux/firmware.h index 1e7c01189fa6..e85b771f3d8c 100644 --- a/include/linux/firmware.h +++ b/include/linux/firmware.h @@ -12,6 +12,9 @@ struct firmware { size_t size; const u8 *data; struct page **pages; + + /* firmware loader private fields */ + void *priv; }; struct module;