drm: rework flip-work helpers to avoid calling func when the FIFO is full

[firefly-linux-kernel-4.4.55.git] / include / drm / drm_flip_work.h

diff --git a/include/drm/drm_flip_work.h b/include/drm/drm_flip_work.h
index 9eed34dcd6afea74a8438f5571552cd472191a45..3fcb4c44c9e0cf46d10ce0d38edd7a8f40d797b9 100644 (file)
--- a/include/drm/drm_flip_work.h
+++ b/include/drm/drm_flip_work.h
@@ -25,6 +25,7 @@
 #define DRM_FLIP_WORK_H
 
 #include <linux/kfifo.h>
+#include <linux/spinlock.h>
 #include <linux/workqueue.h>
 
 /**
@@ -32,9 +33,9 @@
  *
  * Util to queue up work to run from work-queue context after flip/vblank.
  * Typically this can be used to defer unref of framebuffer's, cursor
- * bo's, etc until after vblank.  The APIs are all safe (and lockless)
- * for up to one producer and once consumer at a time.  The single-consumer
- * aspect is ensured by committing the queued work to a single work-queue.
+ * bo's, etc until after vblank.  The APIs are all thread-safe.
+ * Moreover, drm_flip_work_queue_task and drm_flip_work_queue can be called
+ * in atomic context.
  */
 
 struct drm_flip_work;
@@ -50,23 +51,37 @@ struct drm_flip_work;
  */
 typedef void (*drm_flip_func_t)(struct drm_flip_work *work, void *val);
 
+/**
+ * struct drm_flip_task - flip work task
+ * @node: list entry element
+ * @data: data to pass to work->func
+ */
+struct drm_flip_task {
+       struct list_head node;
+       void *data;
+};
+
 /**
  * struct drm_flip_work - flip work queue
  * @name: debug name
- * @pending: number of queued but not committed items
- * @count: number of committed items
  * @func: callback fxn called for each committed item
  * @worker: worker which calls @func
- * @fifo: queue of committed items
+ * @queued: queued tasks
+ * @commited: commited tasks
+ * @lock: lock to access queued and commited lists
  */
 struct drm_flip_work {
        const char *name;
-       atomic_t pending, count;
        drm_flip_func_t func;
        struct work_struct worker;
-       DECLARE_KFIFO_PTR(fifo, void *);
+       struct list_head queued;
+       struct list_head commited;
+       spinlock_t lock;
 };
 
+struct drm_flip_task *drm_flip_work_allocate_task(void *data, gfp_t flags);
+void drm_flip_work_queue_task(struct drm_flip_work *work,
+                             struct drm_flip_task *task);
 void drm_flip_work_queue(struct drm_flip_work *work, void *val);
 void drm_flip_work_commit(struct drm_flip_work *work,
                struct workqueue_struct *wq);