From: Takashi Iwai Date: Thu, 31 Jan 2013 10:13:54 +0000 (+0100) Subject: firmware: Refactoring for splitting user-mode helper code X-Git-Tag: upstream/snapshot3+hdmi~5697^2~8 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=4e0c92d015235d1dc65f9668a10cef2cea468ba2;p=platform%2Fadaptation%2Frenesas_rcar%2Frenesas_kernel.git firmware: Refactoring for splitting user-mode helper code Since 3.7 kernel, the firmware loader can read the firmware files directly, and the traditional user-mode helper is invoked only as a fallback. This seems working pretty well, and the next step would be to reduce the redundant user-mode helper stuff in future. This patch is a preparation for that: refactor the code for splitting user-mode helper stuff more easily. No functional change. Acked-by: Ming Lei Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/base/firmware_class.c b/drivers/base/firmware_class.c index b392b35..40ec60a 100644 --- a/drivers/base/firmware_class.c +++ b/drivers/base/firmware_class.c @@ -319,7 +319,8 @@ static bool fw_read_file_contents(struct file *file, struct firmware_buf *fw_buf return true; } -static bool fw_get_filesystem_firmware(struct firmware_buf *buf) +static bool fw_get_filesystem_firmware(struct device *device, + struct firmware_buf *buf) { int i; bool success = false; @@ -343,6 +344,16 @@ static bool fw_get_filesystem_firmware(struct firmware_buf *buf) break; } __putname(path); + + if (success) { + 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 success; } @@ -796,99 +807,112 @@ static int fw_add_devm_name(struct device *dev, const char *name) } #endif -static void _request_firmware_cleanup(const struct firmware **firmware_p) +/* wait until the shared firmware_buf becomes ready (or error) */ +static int sync_cached_firmware_buf(struct firmware_buf *buf) { - release_firmware(*firmware_p); - *firmware_p = NULL; + int ret = 0; + + mutex_lock(&fw_lock); + while (!test_bit(FW_STATUS_DONE, &buf->status)) { + if (test_bit(FW_STATUS_ABORT, &buf->status)) { + ret = -ENOENT; + break; + } + mutex_unlock(&fw_lock); + wait_for_completion(&buf->completion); + mutex_lock(&fw_lock); + } + mutex_unlock(&fw_lock); + return ret; } -static struct firmware_priv * -_request_firmware_prepare(const struct firmware **firmware_p, const char *name, - struct device *device, bool uevent, bool nowait) +/* 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_priv *fw_priv = NULL; struct firmware_buf *buf; int ret; - if (!firmware_p) - return ERR_PTR(-EINVAL); - *firmware_p = firmware = kzalloc(sizeof(*firmware), GFP_KERNEL); if (!firmware) { dev_err(device, "%s: kmalloc(struct firmware) failed\n", __func__); - return ERR_PTR(-ENOMEM); + return -ENOMEM; } if (fw_get_builtin_firmware(firmware, name)) { dev_dbg(device, "firmware: using built-in firmware %s\n", name); - return NULL; + return 0; /* assigned */ } 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; - /* - * bind with 'buf' now to avoid warning in failure path - * of requesting firmware. - */ - firmware->priv = buf; - return fw_priv; + if (ret > 0) { + ret = sync_cached_firmware_buf(buf); + if (!ret) { + fw_set_page_data(buf, firmware); + return 0; /* assigned */ + } } - /* share the cached buf, which is inprogessing or completed */ - check_status: + if (ret < 0) + return ret; + return 1; /* need to load */ +} + +static int assign_firmware_buf(struct firmware *fw, struct device *device) +{ + struct firmware_buf *buf = fw->priv; + mutex_lock(&fw_lock); - if (test_bit(FW_STATUS_ABORT, &buf->status)) { - fw_priv = ERR_PTR(-ENOENT); - firmware->priv = buf; - _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; + if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status)) { + mutex_unlock(&fw_lock); + return -ENOENT; } - mutex_unlock(&fw_lock); - wait_for_completion(&buf->completion); - goto check_status; -exit: + /* + * 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. + */ + if (device) + 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 fw_priv; + return 0; } +/* load a firmware via user helper */ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, long timeout) { int retval = 0; struct device *f_dev = &fw_priv->dev; struct firmware_buf *buf = fw_priv->buf; - struct firmware_cache *fwc = &fw_cache; - int direct_load = 0; - - /* try direct loading from fs first */ - if (fw_get_filesystem_firmware(buf)) { - dev_dbg(f_dev->parent, "firmware: direct-loading" - " firmware %s\n", buf->fw_id); - - mutex_lock(&fw_lock); - set_bit(FW_STATUS_DONE, &buf->status); - mutex_unlock(&fw_lock); - complete_all(&buf->completion); - direct_load = 1; - goto handle_fw; - } /* fall back on userspace loading */ buf->fmt = PAGE_BUF; @@ -929,38 +953,7 @@ static int _request_firmware_load(struct firmware_priv *fw_priv, bool uevent, cancel_delayed_work_sync(&fw_priv->timeout_work); -handle_fw: - mutex_lock(&fw_lock); - if (!buf->size || test_bit(FW_STATUS_ABORT, &buf->status)) - retval = -ENOENT; - - /* - * add firmware name into devres list so that we can auto cache - * and uncache firmware for device. - * - * f_dev->parent may has been deleted already, but the problem - * should be fixed in devres or driver core. - */ - if (!retval && f_dev->parent) - fw_add_devm_name(f_dev->parent, buf->fw_id); - - /* - * After caching firmware image is started, let it piggyback - * on request firmware. - */ - if (!retval && 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_priv->fw); - fw_priv->buf = NULL; - mutex_unlock(&fw_lock); - - if (direct_load) - goto err_put_dev; device_remove_file(f_dev, &dev_attr_loading); err_del_bin_attr: @@ -972,6 +965,73 @@ err_put_dev: return retval; } +static int fw_load_from_user_helper(struct firmware *firmware, + const char *name, struct device *device, + bool uevent, bool nowait, long timeout) +{ + struct firmware_priv *fw_priv; + + fw_priv = fw_create_instance(firmware, name, device, uevent, nowait); + if (IS_ERR(fw_priv)) + return PTR_ERR(fw_priv); + + fw_priv->buf = firmware->priv; + return _request_firmware_load(fw_priv, uevent, timeout); +} + +/* called from request_firmware() and request_firmware_work_func() */ +static int +_request_firmware(const struct firmware **firmware_p, const char *name, + struct device *device, bool uevent, bool nowait) +{ + struct firmware *fw; + long timeout; + int ret; + + if (!firmware_p) + 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 (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; + } + } + + if (!fw_get_filesystem_firmware(device, fw->priv)) + ret = fw_load_from_user_helper(fw, name, device, + uevent, nowait, timeout); + if (!ret) + ret = assign_firmware_buf(fw, device); + + 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 @@ -996,26 +1056,7 @@ int request_firmware(const struct firmware **firmware_p, const char *name, struct device *device) { - struct firmware_priv *fw_priv; - int ret; - - fw_priv = _request_firmware_prepare(firmware_p, name, device, true, - false); - if (IS_ERR_OR_NULL(fw_priv)) - return PTR_RET(fw_priv); - - ret = usermodehelper_read_trylock(); - if (WARN_ON(ret)) { - dev_err(device, "firmware: %s will not be loaded\n", name); - } else { - ret = _request_firmware_load(fw_priv, true, - firmware_loading_timeout()); - usermodehelper_read_unlock(); - } - if (ret) - _request_firmware_cleanup(firmware_p); - - return ret; + return _request_firmware(firmware_p, name, device, true, false); } /** @@ -1046,33 +1087,13 @@ static void request_firmware_work_func(struct work_struct *work) { struct firmware_work *fw_work; const struct firmware *fw; - struct firmware_priv *fw_priv; - long timeout; - int ret; fw_work = container_of(work, struct firmware_work, work); - fw_priv = _request_firmware_prepare(&fw, fw_work->name, fw_work->device, - fw_work->uevent, true); - if (IS_ERR_OR_NULL(fw_priv)) { - ret = PTR_RET(fw_priv); - goto out; - } - timeout = usermodehelper_read_lock_wait(firmware_loading_timeout()); - if (timeout) { - ret = _request_firmware_load(fw_priv, fw_work->uevent, timeout); - usermodehelper_read_unlock(); - } else { - dev_dbg(fw_work->device, "firmware: %s loading timed out\n", - fw_work->name); - ret = -EAGAIN; - } - if (ret) - _request_firmware_cleanup(&fw); - - out: + _request_firmware(&fw, fw_work->name, fw_work->device, + fw_work->uevent, true); fw_work->cont(fw, fw_work->context); - put_device(fw_work->device); + put_device(fw_work->device); /* taken in request_firmware_nowait() */ module_put(fw_work->module); kfree(fw_work);