From 74ac8bd3b5c6ed23308341fa41681db6a3b45c46 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Mon, 29 Oct 2018 17:57:45 +0000
Subject: [PATCH] media: videobuf2: Allow exporting of a struct dmabuf
videobuf2 only allowed exporting a dmabuf as a file descriptor,
but there are instances where having the struct dma_buf is
useful within the kernel.
Split the current implementation into two, one step which
exports a struct dma_buf, and the second which converts that
into an fd.
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
.../media/common/videobuf2/videobuf2-core.c | 21 ++++++++++++++++---
include/media/videobuf2-core.h | 15 +++++++++++++
2 files changed, 33 insertions(+), 3 deletions(-)
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -2084,12 +2084,12 @@ static int __find_plane_by_offset(struct
return -EINVAL;
}
-int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
- unsigned int index, unsigned int plane, unsigned int flags)
+int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,
+ unsigned int index, unsigned int plane,
+ unsigned int flags, struct dma_buf **dmabuf)
{
struct vb2_buffer *vb = NULL;
struct vb2_plane *vb_plane;
- int ret;
struct dma_buf *dbuf;
if (q->memory != VB2_MEMORY_MMAP) {
@@ -2139,6 +2139,21 @@ int vb2_core_expbuf(struct vb2_queue *q,
return -EINVAL;
}
+ *dmabuf = dbuf;
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vb2_core_expbuf_dmabuf);
+
+int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type,
+ unsigned int index, unsigned int plane, unsigned int flags)
+{
+ struct dma_buf *dbuf;
+ int ret;
+
+ ret = vb2_core_expbuf_dmabuf(q, type, index, plane, flags, &dbuf);
+ if (ret)
+ return ret;
+
ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE);
if (ret < 0) {
dprintk(3, "buffer %d, plane %d failed to export (%d)\n",
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -870,6 +870,21 @@ int vb2_core_streamon(struct vb2_queue *
int vb2_core_streamoff(struct vb2_queue *q, unsigned int type);
/**
+ * vb2_core_expbuf_dmabuf() - Export a buffer as a dma_buf structure
+ * @q: videobuf2 queue
+ * @type: buffer type
+ * @index: id number of the buffer
+ * @plane: index of the plane to be exported, 0 for single plane queues
+ * @flags: flags for newly created file, currently only O_CLOEXEC is
+ * supported, refer to manual of open syscall for more details
+ * @dmabuf: Returns the dmabuf pointer
+ *
+ */
+int vb2_core_expbuf_dmabuf(struct vb2_queue *q, unsigned int type,
+ unsigned int index, unsigned int plane,
+ unsigned int flags, struct dma_buf **dmabuf);
+
+/**
* vb2_core_expbuf() - Export a buffer as a file descriptor.
* @q: pointer to &struct vb2_queue with videobuf2 queue.
* @fd: pointer to the file descriptor associated with DMABUF
