Hi Tomasz, On Thursday 05 April 2012 16:00:00 Tomasz Stanislawski wrote: > From: Sumit Semwal <sumit.semwal@xxxxxx> > > 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.stanislaws@xxxxxxxxxxx> > [original work in the PoC for buffer sharing] > Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxx> > Signed-off-by: Sumit Semwal <sumit.semwal@xxxxxxxxxx> > --- > drivers/media/video/videobuf2-core.c | 184 ++++++++++++++++++++++++++++++- > include/media/videobuf2-core.h | 31 ++++++ > 2 files changed, 214 insertions(+), 1 deletions(-) > > diff --git a/drivers/media/video/videobuf2-core.c > b/drivers/media/video/videobuf2-core.c index 2e8f1df..b37feea 100644 > --- a/drivers/media/video/videobuf2-core.c > +++ b/drivers/media/video/videobuf2-core.c [snip] > @@ -451,6 +482,21 @@ 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) That's pretty strange indentation. What about 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; > +} > + > +/** > * vb2_reqbufs() - Initiate streaming > * @q: videobuf2 queue > * @req: struct passed from userspace to vidioc_reqbufs handler in driver > @@ -484,6 +530,7 @@ int vb2_reqbufs(struct vb2_queue *q, struct > v4l2_requestbuffers *req) } > > if (req->memory != V4L2_MEMORY_MMAP > + && req->memory != V4L2_MEMORY_DMABUF > && req->memory != V4L2_MEMORY_USERPTR) { > dprintk(1, "reqbufs: unsupported memory type\n"); > return -EINVAL; Ditto. [snip] > @@ -620,7 +672,8 @@ int vb2_create_bufs(struct vb2_queue *q, struct > v4l2_create_buffers *create) } > > if (create->memory != V4L2_MEMORY_MMAP > - && create->memory != V4L2_MEMORY_USERPTR) { > + && create->memory != V4L2_MEMORY_USERPTR > + && create->memory != V4L2_MEMORY_DMABUF) { > dprintk(1, "%s(): unsupported memory type\n", __func__); > return -EINVAL; > } And here too. [snip] > diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h > index a15d1f1..665e846 100644 > --- a/include/media/videobuf2-core.h > +++ b/include/media/videobuf2-core.h [snip] > @@ -65,6 +82,17 @@ struct vb2_mem_ops { > unsigned long size, int write); > void (*put_userptr)(void *buf_priv); > > + /* > + * Comment from Rob Clark: XXX: I think the attach / detach could be > + * handled in the vb2 core, and vb2_mem_ops really just need to get/put > + * the sglist (and make sure that the sglist fits it's needs..) > + */ I think we should address this now. We've previously discussed the question, but haven't reached an agreement. Quoting my reply to "[RFCv2 PATCH 3/9] v4l: vb2: Add dma-contig allocator as dma_buf user" on 28/03/2012: > > Calling dma_buf_attach could be moved to vb2-core. But it gives little > > gain. First, the pointer of dma_buf_attachment would have to be added to > > struct vb2_plane. Second, the allocator would have to keep in the copy of > > this pointer in its context structure for use of vb2_dc_(un)map_dmabuf > > functions. > > Right. Would it make sense to pass the vb2_plane pointer, or possibly the > dma_buf_attachment pointer, to the mmap_dmabuf and unmap_dmabuf operations ? > > > Third, dma_buf_attach requires a pointer to 'struct device' which is not > > available in the vb2-core layer. > > OK, that's a problem. > > > Because of the mentioned reasons I decided to keep attach_dmabuf in > > allocator-specific code. > > Maybe it would make sense to create a vb2_mem_buf structure from which > vb2_dc_buf (and other allocator-specific buffer descriptors) would inherit ? > That structure would store the dma_buf_attach pointer, and common dma-buf > code could be put in videobuf2-memops.c and shared between allocators. Just > an idea. If we find out that the best course of action is to leave the code as-is, we should remove the above comment. > + void *(*attach_dmabuf)(void *alloc_ctx, struct dma_buf *dbuf, > + unsigned long size, int write); > + void (*detach_dmabuf)(void *buf_priv); > + int (*map_dmabuf)(void *buf_priv); > + void (*unmap_dmabuf)(void *buf_priv); > + > void *(*vaddr)(void *buf_priv); > void *(*cookie)(void *buf_priv); -- Regards, Laurent Pinchart -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
