V4L/DVB (13429): cx18: Add Memory Descriptor List (MDL) layer to buffer handling

Add a Memory Descriptor List (MDL) layer to buffer handling to implement
scatter-gather I/O.  Currently there is still only 1 buffer per MDL.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 47 insertions, 7 deletions

diff --git a/drivers/media/video/cx18/cx18-queue.h b/drivers/media/video/cx18/cx18-queue.h
index 4de06269d88f..96747e5e7c3c 100644
--- a/drivers/media/video/cx18/cx18-queue.h
+++ b/drivers/media/video/cx18/cx18-queue.h
@@ -33,6 +33,19 @@ static inline void cx18_buf_sync_for_cpu(struct cx18_stream *s,
 				s->buf_size, s->dma);
 }
 
+void _cx18_mdl_sync_for_cpu(struct cx18_stream *s, struct cx18_mdl *mdl);
+
+static inline void cx18_mdl_sync_for_cpu(struct cx18_stream *s,
+					 struct cx18_mdl *mdl)
+{
+	if (list_is_singular(&mdl->buf_list))
+		cx18_buf_sync_for_cpu(s, list_first_entry(&mdl->buf_list,
+							  struct cx18_buffer,
+							  list));
+	else
+		_cx18_mdl_sync_for_cpu(s, mdl);
+}
+
 static inline void cx18_buf_sync_for_device(struct cx18_stream *s,
 	struct cx18_buffer *buf)
 {
@@ -40,32 +53,59 @@ static inline void cx18_buf_sync_for_device(struct cx18_stream *s,
 				s->buf_size, s->dma);
 }
 
+void _cx18_mdl_sync_for_device(struct cx18_stream *s, struct cx18_mdl *mdl);
+
+static inline void cx18_mdl_sync_for_device(struct cx18_stream *s,
+					    struct cx18_mdl *mdl)
+{
+	if (list_is_singular(&mdl->buf_list))
+		cx18_buf_sync_for_device(s, list_first_entry(&mdl->buf_list,
+							     struct cx18_buffer,
+							     list));
+	else
+		_cx18_mdl_sync_for_device(s, mdl);
+}
+
 void cx18_buf_swap(struct cx18_buffer *buf);
+void _cx18_mdl_swap(struct cx18_mdl *mdl);
+
+static inline void cx18_mdl_swap(struct cx18_mdl *mdl)
+{
+	if (list_is_singular(&mdl->buf_list))
+		cx18_buf_swap(list_first_entry(&mdl->buf_list,
+					       struct cx18_buffer, list));
+	else
+		_cx18_mdl_swap(mdl);
+}
 
 /* cx18_queue utility functions */
-struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+struct cx18_queue *_cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
 				 struct cx18_queue *q, int to_front);
 
 static inline
-struct cx18_queue *cx18_enqueue(struct cx18_stream *s, struct cx18_buffer *buf,
+struct cx18_queue *cx18_enqueue(struct cx18_stream *s, struct cx18_mdl *mdl,
 				struct cx18_queue *q)
 {
-	return _cx18_enqueue(s, buf, q, 0); /* FIFO */
+	return _cx18_enqueue(s, mdl, q, 0); /* FIFO */
 }
 
 static inline
-struct cx18_queue *cx18_push(struct cx18_stream *s, struct cx18_buffer *buf,
+struct cx18_queue *cx18_push(struct cx18_stream *s, struct cx18_mdl *mdl,
 			     struct cx18_queue *q)
 {
-	return _cx18_enqueue(s, buf, q, 1); /* LIFO */
+	return _cx18_enqueue(s, mdl, q, 1); /* LIFO */
 }
 
 void cx18_queue_init(struct cx18_queue *q);
-struct cx18_buffer *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q);
-struct cx18_buffer *cx18_queue_get_buf(struct cx18_stream *s, u32 id,
+struct cx18_mdl *cx18_dequeue(struct cx18_stream *s, struct cx18_queue *q);
+struct cx18_mdl *cx18_queue_get_mdl(struct cx18_stream *s, u32 id,
 	u32 bytesused);
 void cx18_flush_queues(struct cx18_stream *s);
 
+/* queue MDL reconfiguration helpers */
+void cx18_unload_queues(struct cx18_stream *s);
+void cx18_load_queues(struct cx18_stream *s);
+
 /* cx18_stream utility functions */
 int cx18_stream_alloc(struct cx18_stream *s);
 void cx18_stream_free(struct cx18_stream *s);