V4L/DVB: v4l videobuf: move video_copy_to_user and copy_stream to core

The video_copy_to_user and copy_stream ops are almost identical for all
videobuf memtype variants. All that is needed is to use the new vaddr
op and these functions can be moved into the core, ensuring we have just
one single implementation instead of three.

Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 45 insertions, 2 deletions

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index fabe45c4163e..f1dfcff44e1b 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -793,6 +793,49 @@ done:
 	return retval;
 }
 
+static int __videobuf_copy_to_user(struct videobuf_queue *q,
+				   struct videobuf_buffer *buf,
+				   char __user *data, size_t count,
+				   int nonblocking)
+{
+	void *vaddr = CALL(q, vaddr, buf);
+
+	/* copy to userspace */
+	if (count > buf->size - q->read_off)
+		count = buf->size - q->read_off;
+
+	if (copy_to_user(data, vaddr + q->read_off, count))
+		return -EFAULT;
+
+	return count;
+}
+
+static int __videobuf_copy_stream(struct videobuf_queue *q,
+				  struct videobuf_buffer *buf,
+				  char __user *data, size_t count, size_t pos,
+				  int vbihack, int nonblocking)
+{
+	unsigned int *fc = CALL(q, vaddr, buf);
+
+	if (vbihack) {
+		/* dirty, undocumented hack -- pass the frame counter
+			* within the last four bytes of each vbi data block.
+			* We need that one to maintain backward compatibility
+			* to all vbi decoding software out there ... */
+		fc += (buf->size >> 2) - 1;
+		*fc = buf->field_count >> 1;
+		dprintk(1, "vbihack: %d\n", *fc);
+	}
+
+	/* copy stuff using the common method */
+	count = __videobuf_copy_to_user(q, buf, data, count, nonblocking);
+
+	if ((count == -EFAULT) && (pos == 0))
+		return -EFAULT;
+
+	return count;
+}
+
 ssize_t videobuf_read_one(struct videobuf_queue *q,
 			  char __user *data, size_t count, loff_t *ppos,
 			  int nonblocking)
@@ -861,7 +904,7 @@ ssize_t videobuf_read_one(struct videobuf_queue *q,
 	}
 
 	/* Copy to userspace */
-	retval = CALL(q, video_copy_to_user, q, data, count, nonblocking);
+	retval = __videobuf_copy_to_user(q, q->read_buf, data, count, nonblocking);
 	if (retval < 0)
 		goto done;
 
@@ -1003,7 +1046,7 @@ ssize_t videobuf_read_stream(struct videobuf_queue *q,
 		}
 
 		if (q->read_buf->state == VIDEOBUF_DONE) {
-			rc = CALL(q, copy_stream, q, data + retval, count,
+			rc = __videobuf_copy_stream(q, q->read_buf, data + retval, count,
 					retval, vbihack, nonblocking);
 			if (rc < 0) {
 				retval = rc;