Le jeudi 5 avril 2012 17:00:00 Tomasz Stanislawski, vous avez écrit : > 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 > @@ -106,6 +106,27 @@ static void __vb2_buf_userptr_put(struct vb2_buffer > *vb) } > > /** > + * __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) { > + void *mem_priv = vb->planes[plane].mem_priv; > + > + if (mem_priv) { > + call_memop(q, detach_dmabuf, mem_priv); > + dma_buf_put(vb->planes[plane].dbuf); > + vb->planes[plane].dbuf = NULL; > + vb->planes[plane].mem_priv = NULL; > + } > + } > +} > + > +/** > * __setup_offsets() - setup unique offsets ("cookies") for every plane in > * every buffer on the queue > */ > @@ -227,6 +248,8 @@ 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); Missing 'else' here? A switch() statement might be better? > + if (q->memory == V4L2_MEMORY_DMABUF) > + __vb2_buf_dmabuf_put(vb); > else > __vb2_buf_userptr_put(vb); > } > @@ -349,6 +372,12 @@ static int __fill_v4l2_buffer(struct vb2_buffer *vb, > struct v4l2_buffer *b) */ > memcpy(b->m.planes, vb->v4l2_planes, > b->length * sizeof(struct v4l2_plane)); > + > + if (q->memory == V4L2_MEMORY_DMABUF) { > + unsigned int plane; > + for (plane = 0; plane < vb->num_planes; ++plane) > + b->m.planes[plane].m.fd = 0; > + } > } else { > /* > * We use length and offset in v4l2_planes array even for > @@ -360,6 +389,8 @@ 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 = 0; > } > > /* > @@ -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) > + 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; > @@ -513,6 +560,11 @@ int vb2_reqbufs(struct vb2_queue *q, struct > v4l2_requestbuffers *req) return -EINVAL; > } > > + if (req->memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) { > + dprintk(1, "reqbufs: DMABUF for current setup unsupported\n"); > + return -EINVAL; > + } > + > if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) { > /* > * We already have buffers allocated, so first check if they > @@ -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; > } > @@ -644,6 +697,11 @@ int vb2_create_bufs(struct vb2_queue *q, struct > v4l2_create_buffers *create) return -EINVAL; > } > > + if (create->memory == V4L2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) { > + dprintk(1, "%s(): DMABUF for current setup unsupported\n", __func__); > + return -EINVAL; > + } > + > if (q->num_buffers == VIDEO_MAX_FRAME) { > dprintk(1, "%s(): maximum number of buffers already allocated\n", > __func__); > @@ -839,6 +897,14 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, > const struct v4l2_buffer *b, b->m.planes[plane].length; > } > } > + if (b->memory == V4L2_MEMORY_DMABUF) { > + for (plane = 0; plane < vb->num_planes; ++plane) { > + v4l2_planes[plane].bytesused = > + b->m.planes[plane].bytesused; > + v4l2_planes[plane].m.fd = > + b->m.planes[plane].m.fd; > + } > + } > } else { > /* > * Single-planar buffers do not use planes array, > @@ -853,6 +919,10 @@ static int __fill_vb2_buffer(struct vb2_buffer *vb, > const struct v4l2_buffer *b, v4l2_planes[0].m.userptr = b->m.userptr; > v4l2_planes[0].length = b->length; > } > + > + if (b->memory == V4L2_MEMORY_DMABUF) > + v4l2_planes[0].m.fd = b->m.fd; > + > } > > vb->v4l2_buf.field = b->field; > @@ -957,6 +1027,105 @@ 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); > + 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; > + } > + > + /* Skip the plane if already verified */ > + if (dbuf == vb->planes[plane].dbuf) { > + planes[plane].length = dbuf->size; > + dma_buf_put(dbuf); > + continue; > + } > + > + dprintk(3, "qbuf: buffer description for plane %d changed, " > + "reattaching dma buf\n", plane); > + > + /* Release previously acquired memory if present */ > + if (vb->planes[plane].mem_priv) { > + call_memop(q, detach_dmabuf, > + vb->planes[plane].mem_priv); > + dma_buf_put(vb->planes[plane].dbuf); > + } > + > + vb->planes[plane].mem_priv = NULL; > + > + /* Acquire each plane's memory */ > + mem_priv = call_memop(q, attach_dmabuf, q->alloc_ctx[plane], > + dbuf, q->plane_sizes[plane], write); > + if (IS_ERR(mem_priv)) { > + dprintk(1, "qbuf: failed acquiring dmabuf " > + "memory for plane %d\n", plane); > + ret = PTR_ERR(mem_priv); > + goto err; > + } > + > + planes[plane].length = dbuf->size; > + 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 mapping dmabuf " > + "memory for plane %d\n", plane); > + goto err; > + } > + } > + > + /* > + * 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 already acquired */ > + __vb2_buf_dmabuf_put(vb); > + > + return ret; > +} > + > +/** > * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing > */ > static void __enqueue_in_driver(struct vb2_buffer *vb) > @@ -980,6 +1149,9 @@ static int __buf_prepare(struct vb2_buffer *vb, const > struct v4l2_buffer *b) case V4L2_MEMORY_USERPTR: > ret = __qbuf_userptr(vb, b); > break; > + case V4L2_MEMORY_DMABUF: > + ret = __qbuf_dmabuf(vb, b); > + break; > default: > WARN(1, "Invalid queue type\n"); > ret = -EINVAL; > @@ -1312,6 +1484,7 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer > *b, bool nonblocking) { > struct vb2_buffer *vb = NULL; > int ret; > + unsigned int plane; > > if (q->fileio) { > dprintk(1, "dqbuf: file io in progress\n"); > @@ -1335,6 +1508,15 @@ int vb2_dqbuf(struct vb2_queue *q, struct > v4l2_buffer *b, bool nonblocking) return ret; > } > > + /* TODO: this unpins the buffer(dma_buf_unmap_attachment()).. but > + * really we want tot do this just after DMA, not when the Typo. > + * buffer is dequeued.. > + */ > + if (q->memory == V4L2_MEMORY_DMABUF) > + for (plane = 0; plane < vb->num_planes; ++plane) > + call_memop(q, unmap_dmabuf, > + vb->planes[plane].mem_priv); > + > switch (vb->state) { > case VB2_BUF_STATE_DONE: > dprintk(3, "dqbuf: Returning done buffer\n"); > 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 > @@ -16,6 +16,7 @@ > #include <linux/mutex.h> > #include <linux/poll.h> > #include <linux/videodev2.h> > +#include <linux/dma-buf.h> > > struct vb2_alloc_ctx; > struct vb2_fileio_data; > @@ -41,6 +42,20 @@ struct vb2_fileio_data; > * argument to other ops in this structure > * @put_userptr: inform the allocator that a USERPTR buffer will no longer > * be used > + * @attach_dmabuf: attach a shared struct dma_buf for a hardware > operation; + * used for DMABUF memory types; alloc_ctx is the alloc > context + * dbuf is the shared dma_buf; returns NULL on failure; > + * allocator private per-buffer structure on success; > + * this needs to be used for further accesses to the buffer > + * @detach_dmabuf: inform the exporter of the buffer that the current > DMABUF + * buffer is no longer used; the buf_priv argument is the > + * allocator private per-buffer structure previously returned > + * from the attach_dmabuf callback > + * @map_dmabuf: request for access to the dmabuf from allocator; the > allocator + * of dmabuf is informed that this driver is going to use the > + * dmabuf > + * @unmap_dmabuf: releases access control to the dmabuf - allocator is > notified + * that this driver is done using the dmabuf for now > * @vaddr: return a kernel virtual address to a given memory buffer > * associated with the passed private structure or NULL if no > * such mapping exists > @@ -56,6 +71,8 @@ struct vb2_fileio_data; > * Required ops for USERPTR types: get_userptr, put_userptr. > * Required ops for MMAP types: alloc, put, num_users, mmap. > * Required ops for read/write access types: alloc, put, num_users, vaddr > + * Required ops for DMABUF types: attach_dmabuf, detach_dmabuf, > map_dmabuf, + * unmap_dmabuf. > */ > struct vb2_mem_ops { > void *(*alloc)(void *alloc_ctx, unsigned long size); > @@ -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..) > + */ > + 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); > > @@ -75,6 +103,7 @@ struct vb2_mem_ops { > > struct vb2_plane { > void *mem_priv; > + struct dma_buf *dbuf; > }; > > /** > @@ -83,12 +112,14 @@ struct vb2_plane { > * @VB2_USERPTR: driver supports USERPTR with streaming API > * @VB2_READ: driver supports read() style access > * @VB2_WRITE: driver supports write() style access > + * @VB2_DMABUF: driver supports DMABUF with streaming API > */ > enum vb2_io_modes { > VB2_MMAP = (1 << 0), > VB2_USERPTR = (1 << 1), > VB2_READ = (1 << 2), > VB2_WRITE = (1 << 3), > + VB2_DMABUF = (1 << 4), > }; > > /** -- Rémi Denis-Courmont http://www.remlab.net/ http://fi.linkedin.com/in/remidenis -- 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
