media: media-request: add media_request_(un)lock_for_access (6736f4e9) · Commits · 戴 / test

drivers/media/media-request.c

+10 −0

Original line number	Diff line number	Diff line
		@@ -43,6 +43,7 @@ static void media_request_clean(struct media_request *req)
		/* Just a sanity check. No other code path is allowed to change this. */
		WARN_ON(req->state != MEDIA_REQUEST_STATE_CLEANING);
		WARN_ON(req->updating_count);
		WARN_ON(req->access_count);

		list_for_each_entry_safe(obj, obj_safe, &req->objects, list) {
		media_request_object_unbind(obj);
		@@ -50,6 +51,7 @@ static void media_request_clean(struct media_request *req)
		}

		req->updating_count = 0;
		req->access_count = 0;
		WARN_ON(req->num_incomplete_objects);
		req->num_incomplete_objects = 0;
		wake_up_interruptible_all(&req->poll_wait);
		@@ -198,6 +200,13 @@ static long media_request_ioctl_reinit(struct media_request *req)
		spin_unlock_irqrestore(&req->lock, flags);
		return -EBUSY;
		}
		if (req->access_count) {
		dev_dbg(mdev->dev,
		"request: %s is being accessed, cannot reinit\n",
		req->debug_str);
		spin_unlock_irqrestore(&req->lock, flags);
		return -EBUSY;
		}
		req->state = MEDIA_REQUEST_STATE_CLEANING;
		spin_unlock_irqrestore(&req->lock, flags);

		@@ -313,6 +322,7 @@ int media_request_alloc(struct media_device mdev, int alloc_fd)
		spin_lock_init(&req->lock);
		init_waitqueue_head(&req->poll_wait);
		req->updating_count = 0;
		req->access_count = 0;

		*alloc_fd = fd;

include/media/media-request.h

+56 −0

Original line number	Diff line number	Diff line
		@@ -53,6 +53,7 @@ struct media_request_object;
		* @debug_str: Prefix for debug messages (process name:fd)
		* @state: The state of the request
		* @updating_count: count the number of request updates that are in progress
		* @access_count: count the number of request accesses that are in progress
		* @objects: List of @struct media_request_object request objects
		* @num_incomplete_objects: The number of incomplete objects in the request
		* @poll_wait: Wait queue for poll
		@@ -64,6 +65,7 @@ struct media_request {
		char debug_str[TASK_COMM_LEN + 11];
		enum media_request_state state;
		unsigned int updating_count;
		unsigned int access_count;
		struct list_head objects;
		unsigned int num_incomplete_objects;
		struct wait_queue_head poll_wait;
		@@ -72,6 +74,50 @@ struct media_request {

		#ifdef CONFIG_MEDIA_CONTROLLER

		/**
		* media_request_lock_for_access - Lock the request to access its objects
		*
		* @req: The media request
		*
		* Use before accessing a completed request. A reference to the request must
		* be held during the access. This usually takes place automatically through
		* a file handle. Use @media_request_unlock_for_access when done.
		*/
		static inline int __must_check
		media_request_lock_for_access(struct media_request *req)
		{
		unsigned long flags;
		int ret = -EBUSY;

		spin_lock_irqsave(&req->lock, flags);
		if (req->state == MEDIA_REQUEST_STATE_COMPLETE) {
		req->access_count++;
		ret = 0;
		}
		spin_unlock_irqrestore(&req->lock, flags);

		return ret;
		}

		/**
		* media_request_unlock_for_access - Unlock a request previously locked for
		* access
		*
		* @req: The media request
		*
		* Unlock a request that has previously been locked using
		* @media_request_lock_for_access.
		*/
		static inline void media_request_unlock_for_access(struct media_request *req)
		{
		unsigned long flags;

		spin_lock_irqsave(&req->lock, flags);
		if (!WARN_ON(!req->access_count))
		req->access_count--;
		spin_unlock_irqrestore(&req->lock, flags);
		}

		/**
		* media_request_lock_for_update - Lock the request for updating its objects
		*
		@@ -333,6 +379,16 @@ void media_request_object_complete(struct media_request_object *obj);

		#else

		static inline int __must_check
		media_request_lock_for_access(struct media_request *req)
		{
		return -EINVAL;
		}

		static inline void media_request_unlock_for_access(struct media_request *req)
		{
		}

		static inline int __must_check
		media_request_lock_for_update(struct media_request *req)
		{

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