Re: [PATCHv9 03/25] v4l: vb2: add support for shared buffer (dma_buf)
Just a small heads-up for an upcoming change...
On Tue October 2 2012 16:27:14 Tomasz Stanislawski wrote:
From: Sumit Semwal sumit.sem...@ti.com
This patch adds support for DMABUF memory type in videobuf2. It calls relevant
APIs of dma_buf for v4l reqbuf / qbuf / dqbuf operations.
For this version, the support is for videobuf2 as a user of the shared buffer;
so the allocation of the buffer is done outside of V4L2. [A sample allocator
of
dma-buf shared buffer is given at [1]]
[1]: Rob Clark's DRM:
https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf
Signed-off-by: Tomasz Stanislawski t.stanisl...@samsung.com
[original work in the PoC for buffer sharing]
Signed-off-by: Sumit Semwal sumit.sem...@ti.com
Signed-off-by: Sumit Semwal sumit.sem...@linaro.org
Acked-by: Laurent Pinchart laurent.pinch...@ideasonboard.com
---
drivers/media/video/Kconfig |1 +
drivers/media/video/videobuf2-core.c | 207
+-
include/media/videobuf2-core.h | 27 +
3 files changed, 232 insertions(+), 3 deletions(-)
snip
@@ -970,6 +1040,109 @@ static int __qbuf_mmap(struct vb2_buffer *vb, const
struct v4l2_buffer *b)
}
/**
+ * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer
+ */
+static int __qbuf_dmabuf(struct vb2_buffer *vb, const struct v4l2_buffer *b)
+{
+ struct v4l2_plane planes[VIDEO_MAX_PLANES];
+ struct vb2_queue *q = vb-vb2_queue;
+ void *mem_priv;
+ unsigned int plane;
+ int ret;
+ int write = !V4L2_TYPE_IS_OUTPUT(q-type);
+
+ /* Verify and copy relevant information provided by the userspace */
+ ret = __fill_vb2_buffer(vb, b, planes);
Note that this code will have to change a bit when my multiplanar fixes go in:
http://www.spinics.net/lists/linux-media/msg54601.html
__fill_vb2_buffer is now a void function, so there won't be any need to check
the error.
+ if (ret)
+ return ret;
+
+ for (plane = 0; plane vb-num_planes; ++plane) {
+ struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd);
+
+ if (IS_ERR_OR_NULL(dbuf)) {
+ dprintk(1, qbuf: invalid dmabuf fd for plane %d\n,
+ plane);
+ ret = -EINVAL;
+ goto err;
+ }
+
+ /* use DMABUF size if length is not provided */
+ if (planes[plane].length == 0)
+ planes[plane].length = dbuf-size;
+
+ if (planes[plane].length planes[plane].data_offset +
+ q-plane_sizes[plane]) {
+ ret = -EINVAL;
+ goto err;
+ }
+
+ /* Skip the plane if already verified */
+ if (dbuf == vb-planes[plane].dbuf
+ vb-v4l2_planes[plane].length == planes[plane].length) {
+ dma_buf_put(dbuf);
+ continue;
+ }
+
+ dprintk(1, qbuf: buffer for plane %d changed\n, plane);
+
+ /* Release previously acquired memory if present */
+ __vb2_plane_dmabuf_put(q, vb-planes[plane]);
+ memset(vb-v4l2_planes[plane], 0, sizeof(struct v4l2_plane));
+
+ /* Acquire each plane's memory */
+ mem_priv = call_memop(q, attach_dmabuf, q-alloc_ctx[plane],
+ dbuf, planes[plane].length, write);
+ if (IS_ERR(mem_priv)) {
+ dprintk(1, qbuf: failed to attach dmabuf\n);
+ ret = PTR_ERR(mem_priv);
+ dma_buf_put(dbuf);
+ goto err;
+ }
+
+ vb-planes[plane].dbuf = dbuf;
+ vb-planes[plane].mem_priv = mem_priv;
+ }
+
+ /* TODO: This pins the buffer(s) with dma_buf_map_attachment()).. but
+ * really we want to do this just before the DMA, not while queueing
+ * the buffer(s)..
+ */
+ for (plane = 0; plane vb-num_planes; ++plane) {
+ ret = call_memop(q, map_dmabuf, vb-planes[plane].mem_priv);
+ if (ret) {
+ dprintk(1, qbuf: failed to map dmabuf for plane %d\n,
+ plane);
+ goto err;
+ }
+ vb-planes[plane].dbuf_mapped = 1;
+ }
+
+ /*
+ * Call driver-specific initialization on the newly acquired buffer,
+ * if provided.
+ */
+ ret = call_qop(q, buf_init, vb);
+ if (ret) {
+ dprintk(1, qbuf: buffer initialization failed\n);
+ goto err;
+ }
+
+ /*
+ * Now that everything is in order, copy relevant information
+ * provided by userspace.
+ */
+ for (plane = 0; plane vb-num_planes; ++plane)
+ vb-v4l2_planes[plane] = planes[plane];
+
+ return 0;
+err:
+ /* In case of errors, release planes that were
[PATCHv9 03/25] v4l: vb2: add support for shared buffer (dma_buf)
From: Sumit Semwal sumit.sem...@ti.com
This patch adds support for DMABUF memory type in videobuf2. It calls relevant
APIs of dma_buf for v4l reqbuf / qbuf / dqbuf operations.
For this version, the support is for videobuf2 as a user of the shared buffer;
so the allocation of the buffer is done outside of V4L2. [A sample allocator of
dma-buf shared buffer is given at [1]]
[1]: Rob Clark's DRM:
https://github.com/robclark/kernel-omap4/commits/drmplane-dmabuf
Signed-off-by: Tomasz Stanislawski t.stanisl...@samsung.com
[original work in the PoC for buffer sharing]
Signed-off-by: Sumit Semwal sumit.sem...@ti.com
Signed-off-by: Sumit Semwal sumit.sem...@linaro.org
Acked-by: Laurent Pinchart laurent.pinch...@ideasonboard.com
---
drivers/media/video/Kconfig |1 +
drivers/media/video/videobuf2-core.c | 207 +-
include/media/videobuf2-core.h | 27 +
3 files changed, 232 insertions(+), 3 deletions(-)
diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig
index c128fac..c558d37 100644
--- a/drivers/media/video/Kconfig
+++ b/drivers/media/video/Kconfig
@@ -45,6 +45,7 @@ config V4L2_MEM2MEM_DEV
depends on VIDEOBUF2_CORE
config VIDEOBUF2_CORE
+ select DMA_SHARED_BUFFER
tristate
config VIDEOBUF2_MEMOPS
diff --git a/drivers/media/video/videobuf2-core.c
b/drivers/media/video/videobuf2-core.c
index 268c7dd..901bc56 100644
--- a/drivers/media/video/videobuf2-core.c
+++ b/drivers/media/video/videobuf2-core.c
@@ -109,6 +109,36 @@ static void __vb2_buf_userptr_put(struct vb2_buffer *vb)
}
/**
+ * __vb2_plane_dmabuf_put() - release memory associated with
+ * a DMABUF shared plane
+ */
+static void __vb2_plane_dmabuf_put(struct vb2_queue *q, struct vb2_plane *p)
+{
+ if (!p-mem_priv)
+ return;
+
+ if (p-dbuf_mapped)
+ call_memop(q, unmap_dmabuf, p-mem_priv);
+
+ call_memop(q, detach_dmabuf, p-mem_priv);
+ dma_buf_put(p-dbuf);
+ memset(p, 0, sizeof(*p));
+}
+
+/**
+ * __vb2_buf_dmabuf_put() - release memory associated with
+ * a DMABUF shared buffer
+ */
+static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb)
+{
+ struct vb2_queue *q = vb-vb2_queue;
+ unsigned int plane;
+
+ for (plane = 0; plane vb-num_planes; ++plane)
+ __vb2_plane_dmabuf_put(q, vb-planes[plane]);
+}
+
+/**
* __setup_offsets() - setup unique offsets (cookies) for every plane in
* every buffer on the queue
*/
@@ -230,6 +260,8 @@ static void __vb2_free_mem(struct vb2_queue *q, unsigned
int buffers)
/* Free MMAP buffers or release USERPTR buffers */
if (q-memory == V4L2_MEMORY_MMAP)
__vb2_buf_mem_free(vb);
+ else if (q-memory == V4L2_MEMORY_DMABUF)
+ __vb2_buf_dmabuf_put(vb);
else
__vb2_buf_userptr_put(vb);
}
@@ -363,6 +395,8 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, struct
v4l2_buffer *b)
b-m.offset = vb-v4l2_planes[0].m.mem_offset;
else if (q-memory == V4L2_MEMORY_USERPTR)
b-m.userptr = vb-v4l2_planes[0].m.userptr;
+ else if (q-memory == V4L2_MEMORY_DMABUF)
+ b-m.fd = vb-v4l2_planes[0].m.fd;
}
/*
@@ -454,13 +488,28 @@ static int __verify_mmap_ops(struct vb2_queue *q)
}
/**
+ * __verify_dmabuf_ops() - verify that all memory operations required for
+ * DMABUF queue type have been provided
+ */
+static int __verify_dmabuf_ops(struct vb2_queue *q)
+{
+ if (!(q-io_modes VB2_DMABUF) || !q-mem_ops-attach_dmabuf ||
+ !q-mem_ops-detach_dmabuf || !q-mem_ops-map_dmabuf ||
+ !q-mem_ops-unmap_dmabuf)
+ return -EINVAL;
+
+ return 0;
+}
+
+/**
* __verify_memory_type() - Check whether the memory type and buffer type
* passed to a buffer operation are compatible with the queue.
*/
static int __verify_memory_type(struct vb2_queue *q,
enum v4l2_memory memory, enum v4l2_buf_type type)
{
- if (memory != V4L2_MEMORY_MMAP memory != V4L2_MEMORY_USERPTR) {
+ if (memory != V4L2_MEMORY_MMAP memory != V4L2_MEMORY_USERPTR
+ memory != V4L2_MEMORY_DMABUF) {
dprintk(1, reqbufs: unsupported memory type\n);
return -EINVAL;
}
@@ -484,6 +533,11 @@ static int __verify_memory_type(struct vb2_queue *q,
return -EINVAL;
}
+ if (memory == V4L2_MEMORY_DMABUF __verify_dmabuf_ops(q)) {
+ dprintk(1, reqbufs: DMABUF for current setup unsupported\n);
+ return -EINVAL;
+ }
+
/*
* Place the busy tests at the end: -EBUSY can be ignored when
* create_bufs is called with count == 0, but count == 0 should still
@@ -853,6 +907,16 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, const
struct
