[PATCHv13 15/28] vb2: store userspace data in vb2_v4l2_buffer

[Hans Verkuil <hverkuil@xs4all.nl>]

From: Hans Verkuil <hans.verkuil@cisco.com>

The userspace-provided plane data needs to be stored in
vb2_v4l2_buffer. Currently this information is applied by
__fill_vb2_buffer() which is called by the core prepare_buf
and qbuf functions, but when using requests these functions
aren't called yet since the buffer won't be prepared until
the media request is actually queued.

In the meantime this information has to be stored somewhere
and vb2_v4l2_buffer is a good place for it.

The __fill_vb2_buffer callback now just copies the relevant
information from vb2_v4l2_buffer into the planes array.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
---
 .../media/common/videobuf2/videobuf2-core.c   |  43 +--
 .../media/common/videobuf2/videobuf2-v4l2.c   | 324 ++++++++++--------
 drivers/media/dvb-core/dvb_vb2.c              |   3 +-
 include/media/videobuf2-core.h                |   3 +-
 include/media/videobuf2-v4l2.h                |   2 +
 5 files changed, 206 insertions(+), 169 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index d3f7bb33a54d..70ba43c5b3e2 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -964,20 +964,19 @@ EXPORT_SYMBOL_GPL(vb2_discard_done);
 /*
  * __prepare_mmap() - prepare an MMAP buffer
  */
-static int __prepare_mmap(struct vb2_buffer *vb, const void *pb)
+static int __prepare_mmap(struct vb2_buffer *vb)
 {
 	int ret = 0;
 
-	if (pb)
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, vb->planes);
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, vb->planes);
 	return ret ? ret : call_vb_qop(vb, buf_prepare, vb);
 }
 
 /*
  * __prepare_userptr() - prepare a USERPTR buffer
  */
-static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
+static int __prepare_userptr(struct vb2_buffer *vb)
 {
 	struct vb2_plane planes[VB2_MAX_PLANES];
 	struct vb2_queue *q = vb->vb2_queue;
@@ -988,12 +987,10 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 	/* Copy relevant information provided by the userspace */
-	if (pb) {
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, planes);
-		if (ret)
-			return ret;
-	}
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
 
 	for (plane = 0; plane < vb->num_planes; ++plane) {
 		/* Skip the plane if already verified */
@@ -1093,7 +1090,7 @@ static int __prepare_userptr(struct vb2_buffer *vb, const void *pb)
 /*
  * __prepare_dmabuf() - prepare a DMABUF buffer
  */
-static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
+static int __prepare_dmabuf(struct vb2_buffer *vb)
 {
 	struct vb2_plane planes[VB2_MAX_PLANES];
 	struct vb2_queue *q = vb->vb2_queue;
@@ -1104,12 +1101,10 @@ static int __prepare_dmabuf(struct vb2_buffer *vb, const void *pb)
 
 	memset(planes, 0, sizeof(planes[0]) * vb->num_planes);
 	/* Copy relevant information provided by the userspace */
-	if (pb) {
-		ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
-				 vb, pb, planes);
-		if (ret)
-			return ret;
-	}
+	ret = call_bufop(vb->vb2_queue, fill_vb2_buffer,
+			 vb, planes);
+	if (ret)
+		return ret;
 
 	for (plane = 0; plane < vb->num_planes; ++plane) {
 		struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
@@ -1238,7 +1233,7 @@ static void __enqueue_in_driver(struct vb2_buffer *vb)
 	call_void_vb_qop(vb, buf_queue, vb);
 }
 
-static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
+static int __buf_prepare(struct vb2_buffer *vb)
 {
 	struct vb2_queue *q = vb->vb2_queue;
 	unsigned int plane;
@@ -1253,13 +1248,13 @@ static int __buf_prepare(struct vb2_buffer *vb, const void *pb)
 
 	switch (q->memory) {
 	case VB2_MEMORY_MMAP:
-		ret = __prepare_mmap(vb, pb);
+		ret = __prepare_mmap(vb);
 		break;
 	case VB2_MEMORY_USERPTR:
-		ret = __prepare_userptr(vb, pb);
+		ret = __prepare_userptr(vb);
 		break;
 	case VB2_MEMORY_DMABUF:
-		ret = __prepare_dmabuf(vb, pb);
+		ret = __prepare_dmabuf(vb);
 		break;
 	default:
 		WARN(1, "Invalid queue type\n");
@@ -1293,7 +1288,7 @@ int vb2_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb)
 		return -EINVAL;
 	}
 
-	ret = __buf_prepare(vb, pb);
+	ret = __buf_prepare(vb);
 	if (ret)
 		return ret;
 
@@ -1378,7 +1373,7 @@ int vb2_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb)
 
 	switch (vb->state) {
 	case VB2_BUF_STATE_DEQUEUED:
-		ret = __buf_prepare(vb, pb);
+		ret = __buf_prepare(vb);
 		if (ret)
 			return ret;
 		break;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 4e9c77f21858..bf7a3ba9fed0 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -154,9 +154,177 @@ static void vb2_warn_zero_bytesused(struct vb2_buffer *vb)
 		pr_warn("use the actual size instead.\n");
 }
 
+static int vb2_fill_vb2_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b)
+{
+	struct vb2_queue *q = vb->vb2_queue;
+	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
+	struct vb2_plane *planes = vbuf->planes;
+	unsigned int plane;
+	int ret;
+
+	ret = __verify_length(vb, b);
+	if (ret < 0) {
+		dprintk(1, "plane parameters verification failed: %d\n", ret);
+		return ret;
+	}
+	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
+		/*
+		 * If the format's field is ALTERNATE, then the buffer's field
+		 * should be either TOP or BOTTOM, not ALTERNATE since that
+		 * makes no sense. The driver has to know whether the
+		 * buffer represents a top or a bottom field in order to
+		 * program any DMA correctly. Using ALTERNATE is wrong, since
+		 * that just says that it is either a top or a bottom field,
+		 * but not which of the two it is.
+		 */
+		dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
+		return -EINVAL;
+	}
+	vbuf->sequence = 0;
+
+	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
+		switch (b->memory) {
+		case VB2_MEMORY_USERPTR:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.userptr =
+					b->m.planes[plane].m.userptr;
+				planes[plane].length =
+					b->m.planes[plane].length;
+			}
+			break;
+		case VB2_MEMORY_DMABUF:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.fd =
+					b->m.planes[plane].m.fd;
+				planes[plane].length =
+					b->m.planes[plane].length;
+			}
+			break;
+		default:
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				planes[plane].m.offset =
+					vb->planes[plane].m.offset;
+				planes[plane].length =
+					vb->planes[plane].length;
+			}
+			break;
+		}
+
+		/* Fill in driver-provided information for OUTPUT types */
+		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			/*
+			 * Will have to go up to b->length when API starts
+			 * accepting variable number of planes.
+			 *
+			 * If bytesused == 0 for the output buffer, then fall
+			 * back to the full buffer size. In that case
+			 * userspace clearly never bothered to set it and
+			 * it's a safe assumption that they really meant to
+			 * use the full plane sizes.
+			 *
+			 * Some drivers, e.g. old codec drivers, use bytesused == 0
+			 * as a way to indicate that streaming is finished.
+			 * In that case, the driver should use the
+			 * allow_zero_bytesused flag to keep old userspace
+			 * applications working.
+			 */
+			for (plane = 0; plane < vb->num_planes; ++plane) {
+				struct vb2_plane *pdst = &planes[plane];
+				struct v4l2_plane *psrc = &b->m.planes[plane];
+
+				if (psrc->bytesused == 0)
+					vb2_warn_zero_bytesused(vb);
+
+				if (vb->vb2_queue->allow_zero_bytesused)
+					pdst->bytesused = psrc->bytesused;
+				else
+					pdst->bytesused = psrc->bytesused ?
+						psrc->bytesused : pdst->length;
+				pdst->data_offset = psrc->data_offset;
+			}
+		}
+	} else {
+		/*
+		 * Single-planar buffers do not use planes array,
+		 * so fill in relevant v4l2_buffer struct fields instead.
+		 * In videobuf we use our internal V4l2_planes struct for
+		 * single-planar buffers as well, for simplicity.
+		 *
+		 * If bytesused == 0 for the output buffer, then fall back
+		 * to the full buffer size as that's a sensible default.
+		 *
+		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
+		 * a way to indicate that streaming is finished. In that case,
+		 * the driver should use the allow_zero_bytesused flag to keep
+		 * old userspace applications working.
+		 */
+		switch (b->memory) {
+		case VB2_MEMORY_USERPTR:
+			planes[0].m.userptr = b->m.userptr;
+			planes[0].length = b->length;
+			break;
+		case VB2_MEMORY_DMABUF:
+			planes[0].m.fd = b->m.fd;
+			planes[0].length = b->length;
+			break;
+		default:
+			planes[0].m.offset = vb->planes[0].m.offset;
+			planes[0].length = vb->planes[0].length;
+			break;
+		}
+
+		planes[0].data_offset = 0;
+		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+			if (b->bytesused == 0)
+				vb2_warn_zero_bytesused(vb);
+
+			if (vb->vb2_queue->allow_zero_bytesused)
+				planes[0].bytesused = b->bytesused;
+			else
+				planes[0].bytesused = b->bytesused ?
+					b->bytesused : planes[0].length;
+		} else
+			planes[0].bytesused = 0;
+
+	}
+
+	/* Zero flags that we handle */
+	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
+	if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) {
+		/*
+		 * Non-COPY timestamps and non-OUTPUT queues will get
+		 * their timestamp and timestamp source flags from the
+		 * queue.
+		 */
+		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
+	}
+
+	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
+		/*
+		 * For output buffers mask out the timecode flag:
+		 * this will be handled later in vb2_qbuf().
+		 * The 'field' is valid metadata for this output buffer
+		 * and so that needs to be copied here.
+		 */
+		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
+		vbuf->field = b->field;
+	} else {
+		/* Zero any output buffer flags as this is a capture buffer */
+		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
+		/* Zero last flag, this is a signal from driver to userspace */
+		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
+	}
+
+	return 0;
+}
+
 static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
 				    const char *opname)
 {
+	struct vb2_v4l2_buffer *vbuf;
+	struct vb2_buffer *vb;
+	int ret;
+
 	if (b->type != q->type) {
 		dprintk(1, "%s: invalid buffer type\n", opname);
 		return -EINVAL;
@@ -178,7 +346,15 @@ static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b,
 		return -EINVAL;
 	}
 
-	return __verify_planes_array(q->bufs[b->index], b);
+	vb = q->bufs[b->index];
+	vbuf = to_vb2_v4l2_buffer(vb);
+	ret = __verify_planes_array(vb, b);
+	if (ret)
+		return ret;
+
+	/* Copy relevant information provided by the userspace */
+	memset(vbuf->planes, 0, sizeof(vbuf->planes[0]) * vb->num_planes);
+	return vb2_fill_vb2_v4l2_buffer(vb, b);
 }
 
 /*
@@ -291,153 +467,19 @@ static void __fill_v4l2_buffer(struct vb2_buffer *vb, void *pb)
  * v4l2_buffer by the userspace. It also verifies that struct
  * v4l2_buffer has a valid number of planes.
  */
-static int __fill_vb2_buffer(struct vb2_buffer *vb,
-		const void *pb, struct vb2_plane *planes)
+static int __fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
 {
-	struct vb2_queue *q = vb->vb2_queue;
-	const struct v4l2_buffer *b = pb;
 	struct vb2_v4l2_buffer *vbuf = to_vb2_v4l2_buffer(vb);
 	unsigned int plane;
-	int ret;
 
-	ret = __verify_length(vb, b);
-	if (ret < 0) {
-		dprintk(1, "plane parameters verification failed: %d\n", ret);
-		return ret;
-	}
-	if (b->field == V4L2_FIELD_ALTERNATE && q->is_output) {
-		/*
-		 * If the format's field is ALTERNATE, then the buffer's field
-		 * should be either TOP or BOTTOM, not ALTERNATE since that
-		 * makes no sense. The driver has to know whether the
-		 * buffer represents a top or a bottom field in order to
-		 * program any DMA correctly. Using ALTERNATE is wrong, since
-		 * that just says that it is either a top or a bottom field,
-		 * but not which of the two it is.
-		 */
-		dprintk(1, "the field is incorrectly set to ALTERNATE for an output buffer\n");
-		return -EINVAL;
-	}
 	vb->timestamp = 0;
-	vbuf->sequence = 0;
-
-	if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) {
-		if (b->memory == VB2_MEMORY_USERPTR) {
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				planes[plane].m.userptr =
-					b->m.planes[plane].m.userptr;
-				planes[plane].length =
-					b->m.planes[plane].length;
-			}
-		}
-		if (b->memory == VB2_MEMORY_DMABUF) {
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				planes[plane].m.fd =
-					b->m.planes[plane].m.fd;
-				planes[plane].length =
-					b->m.planes[plane].length;
-			}
-		}
-
-		/* Fill in driver-provided information for OUTPUT types */
-		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-			/*
-			 * Will have to go up to b->length when API starts
-			 * accepting variable number of planes.
-			 *
-			 * If bytesused == 0 for the output buffer, then fall
-			 * back to the full buffer size. In that case
-			 * userspace clearly never bothered to set it and
-			 * it's a safe assumption that they really meant to
-			 * use the full plane sizes.
-			 *
-			 * Some drivers, e.g. old codec drivers, use bytesused == 0
-			 * as a way to indicate that streaming is finished.
-			 * In that case, the driver should use the
-			 * allow_zero_bytesused flag to keep old userspace
-			 * applications working.
-			 */
-			for (plane = 0; plane < vb->num_planes; ++plane) {
-				struct vb2_plane *pdst = &planes[plane];
-				struct v4l2_plane *psrc = &b->m.planes[plane];
-
-				if (psrc->bytesused == 0)
-					vb2_warn_zero_bytesused(vb);
 
-				if (vb->vb2_queue->allow_zero_bytesused)
-					pdst->bytesused = psrc->bytesused;
-				else
-					pdst->bytesused = psrc->bytesused ?
-						psrc->bytesused : pdst->length;
-				pdst->data_offset = psrc->data_offset;
-			}
-		}
-	} else {
-		/*
-		 * Single-planar buffers do not use planes array,
-		 * so fill in relevant v4l2_buffer struct fields instead.
-		 * In videobuf we use our internal V4l2_planes struct for
-		 * single-planar buffers as well, for simplicity.
-		 *
-		 * If bytesused == 0 for the output buffer, then fall back
-		 * to the full buffer size as that's a sensible default.
-		 *
-		 * Some drivers, e.g. old codec drivers, use bytesused == 0 as
-		 * a way to indicate that streaming is finished. In that case,
-		 * the driver should use the allow_zero_bytesused flag to keep
-		 * old userspace applications working.
-		 */
-		if (b->memory == VB2_MEMORY_USERPTR) {
-			planes[0].m.userptr = b->m.userptr;
-			planes[0].length = b->length;
-		}
-
-		if (b->memory == VB2_MEMORY_DMABUF) {
-			planes[0].m.fd = b->m.fd;
-			planes[0].length = b->length;
-		}
-
-		if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-			if (b->bytesused == 0)
-				vb2_warn_zero_bytesused(vb);
-
-			if (vb->vb2_queue->allow_zero_bytesused)
-				planes[0].bytesused = b->bytesused;
-			else
-				planes[0].bytesused = b->bytesused ?
-					b->bytesused : planes[0].length;
-		} else
-			planes[0].bytesused = 0;
-
-	}
-
-	/* Zero flags that the vb2 core handles */
-	vbuf->flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS;
-	if (!vb->vb2_queue->copy_timestamp || !V4L2_TYPE_IS_OUTPUT(b->type)) {
-		/*
-		 * Non-COPY timestamps and non-OUTPUT queues will get
-		 * their timestamp and timestamp source flags from the
-		 * queue.
-		 */
-		vbuf->flags &= ~V4L2_BUF_FLAG_TSTAMP_SRC_MASK;
+	for (plane = 0; plane < vb->num_planes; ++plane) {
+		planes[plane].m = vbuf->planes[plane].m;
+		planes[plane].length = vbuf->planes[plane].length;
+		planes[plane].bytesused = vbuf->planes[plane].bytesused;
+		planes[plane].data_offset = vbuf->planes[plane].data_offset;
 	}
-
-	if (V4L2_TYPE_IS_OUTPUT(b->type)) {
-		/*
-		 * For output buffers mask out the timecode flag:
-		 * this will be handled later in vb2_qbuf().
-		 * The 'field' is valid metadata for this output buffer
-		 * and so that needs to be copied here.
-		 */
-		vbuf->flags &= ~V4L2_BUF_FLAG_TIMECODE;
-		vbuf->field = b->field;
-	} else {
-		/* Zero any output buffer flags as this is a capture buffer */
-		vbuf->flags &= ~V4L2_BUFFER_OUT_FLAGS;
-		/* Zero last flag, this is a signal from driver to userspace */
-		vbuf->flags &= ~V4L2_BUF_FLAG_LAST;
-	}
-
 	return 0;
 }
 
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index b811adf88afa..da6a8cec7d42 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -146,8 +146,7 @@ static void _fill_dmx_buffer(struct vb2_buffer *vb, void *pb)
 	dprintk(3, "[%s]\n", ctx->name);
 }
 
-static int _fill_vb2_buffer(struct vb2_buffer *vb,
-			    const void *pb, struct vb2_plane *planes)
+static int _fill_vb2_buffer(struct vb2_buffer *vb, struct vb2_plane *planes)
 {
 	struct dvb_vb2_ctx *ctx = vb2_get_drv_priv(vb->vb2_queue);
 
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index f6818f732f34..224c4820a044 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -417,8 +417,7 @@ struct vb2_ops {
 struct vb2_buf_ops {
 	int (*verify_planes_array)(struct vb2_buffer *vb, const void *pb);
 	void (*fill_user_buffer)(struct vb2_buffer *vb, void *pb);
-	int (*fill_vb2_buffer)(struct vb2_buffer *vb, const void *pb,
-				struct vb2_plane *planes);
+	int (*fill_vb2_buffer)(struct vb2_buffer *vb, struct vb2_plane *planes);
 	void (*copy_timestamp)(struct vb2_buffer *vb, const void *pb);
 };
 
diff --git a/include/media/videobuf2-v4l2.h b/include/media/videobuf2-v4l2.h
index 3d5e2d739f05..097bf3e6951d 100644
--- a/include/media/videobuf2-v4l2.h
+++ b/include/media/videobuf2-v4l2.h
@@ -32,6 +32,7 @@
  *		&enum v4l2_field.
  * @timecode:	frame timecode.
  * @sequence:	sequence count of this frame.
+ * @planes:	plane information (userptr/fd, length, bytesused, data_offset).
  *
  * Should contain enough information to be able to cover all the fields
  * of &struct v4l2_buffer at ``videodev2.h``.
@@ -43,6 +44,7 @@ struct vb2_v4l2_buffer {
 	__u32			field;
 	struct v4l2_timecode	timecode;
 	__u32			sequence;
+	struct vb2_plane	planes[VB2_MAX_PLANES];
 };
 
 /*
-- 
2.17.0