From: Sumit Semwal sumit.semwal@ti.com

Adds DMABUF memory type to v4l framework. Also adds the related file descriptor in v4l2_plane and v4l2_buffer.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com [original work in the PoC for buffer sharing] Signed-off-by: Sumit Semwal sumit.semwal@ti.com Signed-off-by: Sumit Semwal sumit.semwal@linaro.org --- include/linux/videodev2.h | 7 +++++++ 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index c9c9a46..d884d4a 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -185,6 +185,7 @@ enum v4l2_memory { V4L2_MEMORY_MMAP = 1, V4L2_MEMORY_USERPTR = 2, V4L2_MEMORY_OVERLAY = 3, + V4L2_MEMORY_DMABUF = 4, };

/* see also http://vektor.theorem.ca/graphics/ycbcr/ */ @@ -588,6 +589,8 @@ struct v4l2_requestbuffers { * should be passed to mmap() called on the video node) * @userptr: when memory is V4L2_MEMORY_USERPTR, a userspace pointer * pointing to this plane + * @fd: when memory is V4L2_MEMORY_DMABUF, a userspace file + * descriptor associated with this plane * @data_offset: offset in the plane to the start of data; usually 0, * unless there is a header in front of the data * @@ -602,6 +605,7 @@ struct v4l2_plane { union { __u32 mem_offset; unsigned long userptr; + int fd; } m; __u32 data_offset; __u32 reserved[11]; @@ -624,6 +628,8 @@ struct v4l2_plane { * (or a "cookie" that should be passed to mmap() as offset) * @userptr: for non-multiplanar buffers with memory == V4L2_MEMORY_USERPTR; * a userspace pointer pointing to this buffer + * @fd: for non-multiplanar buffers with memory == V4L2_MEMORY_DMABUF; + * a userspace file descriptor associated with this buffer * @planes: for multiplanar buffers; userspace pointer to the array of plane * info structs for this buffer * @length: size in bytes of the buffer (NOT its payload) for single-plane @@ -650,6 +656,7 @@ struct v4l2_buffer { __u32 offset; unsigned long userptr; struct v4l2_plane *planes; + int fd; } m; __u32 length; __u32 input;

This patch adds description and usage examples for importing DMABUF file descriptor in V4L2.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- Documentation/DocBook/media/v4l/compat.xml | 4 + Documentation/DocBook/media/v4l/io.xml | 179 ++++++++++++++++++++ .../DocBook/media/v4l/vidioc-create-bufs.xml | 1 + Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 15 ++ Documentation/DocBook/media/v4l/vidioc-reqbufs.xml | 47 +++--- 5 files changed, 224 insertions(+), 22 deletions(-)

diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index bce97c5..2a2083d 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2523,6 +2523,10 @@ ioctls.</para> <listitem> <para>Selection API. <xref linkend="selection-api" /></para> </listitem> + <listitem> + <para>Importing DMABUF file descriptors as a new IO method described + in <xref linkend="dmabuf" />.</para> + </listitem> </itemizedlist> </section>

diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index b815929..dc5979d 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -472,6 +472,162 @@ rest should be evident.</para> </footnote></para> </section>

+ <section id="dmabuf"> + <title>Streaming I/O (DMA buffer importing)</title> + + <note> + <title>Experimental</title> + <para>This is an <link linkend="experimental"> experimental </link> + interface and may change in the future.</para> + </note> + +<para>The DMABUF framework provides a generic mean for sharing buffers between + multiple devices. Device drivers that support DMABUF can export a DMA buffer +to userspace as a file descriptor (known as the exporter role), import a DMA +buffer from userspace using a file descriptor previously exported for a +different or the same device (known as the importer role), or both. This +section describes the DMABUF importer role API in V4L2.</para> + +<para>Input and output devices support the streaming I/O method when the +<constant>V4L2_CAP_STREAMING</constant> flag in the +<structfield>capabilities</structfield> field of &v4l2-capability; returned by +the &VIDIOC-QUERYCAP; ioctl is set. Whether importing DMA buffers through +DMABUF file descriptors is supported is determined by calling the +&VIDIOC-REQBUFS; ioctl with the memory type set to +<constant>V4L2_MEMORY_DMABUF</constant>.</para> + + <para>This I/O method is dedicated for sharing DMA buffers between V4L and +other APIs. Buffers (planes) are allocated by a driver on behalf of the +application, and exported to the application as file descriptors using an API +specific to the allocator driver. Only those file descriptor are exchanged, +these files and meta-information are passed in &v4l2-buffer; (or in +&v4l2-plane; in the multi-planar API case). The driver must be switched into +DMABUF I/O mode by calling the &VIDIOC-REQBUFS; with the desired buffer type. +No buffers (planes) are allocated beforehand, consequently they are not indexed +and cannot be queried like mapped buffers with the +<constant>VIDIOC_QUERYBUF</constant> ioctl.</para> + + <example> + <title>Initiating streaming I/O with DMABUF file descriptors</title> + + <programlisting> +&v4l2-requestbuffers; reqbuf; + +memset (&amp;reqbuf, 0, sizeof (reqbuf)); +reqbuf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; +reqbuf.memory = V4L2_MEMORY_DMABUF; + +if (ioctl (fd, &VIDIOC-REQBUFS;, &amp;reqbuf) == -1) { + if (errno == EINVAL) + printf ("Video capturing or DMABUF streaming is not supported\n"); + else + perror ("VIDIOC_REQBUFS"); + + exit (EXIT_FAILURE); +} + </programlisting> + </example> + + <para>Buffer (plane) file is passed on the fly with the &VIDIOC-QBUF; +ioctl. In case of multiplanar buffers, every plane can be associated with a +different DMABUF descriptor.Although buffers are commonly cycled, applications +can pass different DMABUF descriptor at each <constant>VIDIOC_QBUF</constant> +call.</para> + + <example> + <title>Queueing DMABUF using single plane API</title> + + <programlisting> +int buffer_queue(int v4lfd, int index, int dmafd) +{ + &v4l2-buffer; buf; + + memset(&amp;buf, 0, sizeof buf); + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + buf.memory = V4L2_MEMORY_DMABUF; + buf.index = index; + buf.m.fd = dmafd; + + if (ioctl (v4lfd, &VIDIOC-QBUF;, &amp;buf) == -1) { + perror ("VIDIOC_QBUF"); + return -1; + } + + return 0; +} + </programlisting> + </example> + + <example> + <title>Queueing DMABUF using multi plane API</title> + + <programlisting> +int buffer_queue_mp(int v4lfd, int index, int dmafd[], int n_planes) +{ + &v4l2-buffer; buf; + &v4l2-plane; planes[VIDEO_MAX_PLANES]; + int i; + + memset(&amp;buf, 0, sizeof buf); + buf.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; + buf.memory = V4L2_MEMORY_DMABUF; + buf.index = index; + buf.m.planes = planes; + buf.length = n_planes; + + memset(&amp;planes, 0, sizeof planes); + + for (i = 0; i &lt; n_planes; ++i) + buf.m.planes[i].m.fd = dmafd[i]; + + if (ioctl (v4lfd, &VIDIOC-QBUF;, &amp;buf) == -1) { + perror ("VIDIOC_QBUF"); + return -1; + } + + return 0; +} + </programlisting> + </example> + + <para>Filled or displayed buffers are dequeued with the +&VIDIOC-DQBUF; ioctl. The driver can unpin the buffer at any +time between the completion of the DMA and this ioctl. The memory is +also unpinned when &VIDIOC-STREAMOFF; is called, &VIDIOC-REQBUFS;, or +when the device is closed.</para> + + <para>For capturing applications it is customary to enqueue a +number of empty buffers, to start capturing and enter the read loop. +Here the application waits until a filled buffer can be dequeued, and +re-enqueues the buffer when the data is no longer needed. Output +applications fill and enqueue buffers, when enough buffers are stacked +up output is started. In the write loop, when the application +runs out of free buffers it must wait until an empty buffer can be +dequeued and reused. Two methods exist to suspend execution of the +application until one or more buffers can be dequeued. By default +<constant>VIDIOC_DQBUF</constant> blocks when no buffer is in the +outgoing queue. When the <constant>O_NONBLOCK</constant> flag was +given to the &func-open; function, <constant>VIDIOC_DQBUF</constant> +returns immediately with an &EAGAIN; when no buffer is available. The +&func-select; or &func-poll; function are always available.</para> + + <para>To start and stop capturing or output applications call the +&VIDIOC-STREAMON; and &VIDIOC-STREAMOFF; ioctls. Note that +<constant>VIDIOC_STREAMOFF</constant> removes all buffers from both queues and +unlocks/unpins all buffers as a side effect. Since there is no notion of doing +anything "now" on a multitasking system, if an application needs to synchronize +with another event it should examine the &v4l2-buffer; +<structfield>timestamp</structfield> of captured buffers, or set the field +before enqueuing buffers for output.</para> + + <para>Drivers implementing DMABUF importing I/O must support the +<constant>VIDIOC_REQBUFS</constant>, <constant>VIDIOC_QBUF</constant>, +<constant>VIDIOC_DQBUF</constant>, <constant>VIDIOC_STREAMON</constant> and +<constant>VIDIOC_STREAMOFF</constant> ioctl, the <function>select()</function> +and <function>poll()</function> function.</para> + + </section> + <section id="async"> <title>Asynchronous I/O</title>

@@ -671,6 +827,14 @@ memory, set by the application. See <xref linkend="userp" /> for details. <structname>v4l2_buffer</structname> structure.</entry> </row> <row> + <entry></entry> + <entry>int</entry> + <entry><structfield>fd</structfield></entry> + <entry>For the single-plane API and when +<structfield>memory</structfield> is <constant>V4L2_MEMORY_DMABUF</constant> this +is the file descriptor associated with a DMABUF buffer.</entry> + </row> + <row> <entry>__u32</entry> <entry><structfield>length</structfield></entry> <entry></entry> @@ -746,6 +910,15 @@ should set this to 0.</entry> </entry> </row> <row> + <entry></entry> + <entry>int</entry> + <entry><structfield>fd</structfield></entry> + <entry>When the memory type in the containing &v4l2-buffer; is + <constant>V4L2_MEMORY_DMABUF</constant>, this is a file + descriptor associated with a DMABUF buffer, similar to the + <structfield>fd</structfield> field in &v4l2-buffer;.</entry> + </row> + <row> <entry>__u32</entry> <entry><structfield>data_offset</structfield></entry> <entry></entry> @@ -980,6 +1153,12 @@ pointer</link> I/O.</entry> <entry>3</entry> <entry>[to do]</entry> </row> + <row> + <entry><constant>V4L2_MEMORY_DMABUF</constant></entry> + <entry>2</entry> + <entry>The buffer is used for <link linkend="dmabuf">DMA shared +buffer</link> I/O.</entry> + </row> </tbody> </tgroup> </table> diff --git a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml index 73ae8a6..adc92be 100644 --- a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml +++ b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml @@ -98,6 +98,7 @@ information.</para> <entry><structfield>memory</structfield></entry> <entry>Applications set this field to <constant>V4L2_MEMORY_MMAP</constant> or +<constant>V4L2_MEMORY_DMABUF</constant> or <constant>V4L2_MEMORY_USERPTR</constant>.</entry> </row> <row> diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml index 9caa49a..cb5f5ff 100644 --- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml @@ -112,6 +112,21 @@ they cannot be swapped out to disk. Buffers remain locked until dequeued, until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is called, or until the device is closed.</para>

+ <para>To enqueue a <link linkend="dmabuf">DMABUF</link> buffer applications +set the <structfield>memory</structfield> field to +<constant>V4L2_MEMORY_DMABUF</constant> and the <structfield>m.fd</structfield> +to a file descriptor associated with a DMABUF buffer. When the multi-planar API is +used and <structfield>m.fd</structfield> of the passed array of &v4l2-plane; +have to be used instead. When <constant>VIDIOC_QBUF</constant> is called with a +pointer to this structure the driver sets the +<constant>V4L2_BUF_FLAG_QUEUED</constant> flag and clears the +<constant>V4L2_BUF_FLAG_MAPPED</constant> and +<constant>V4L2_BUF_FLAG_DONE</constant> flags in the +<structfield>flags</structfield> field, or it returns an error code. This +ioctl locks the buffer. Buffers remain locked until dequeued, +until the &VIDIOC-STREAMOFF; or &VIDIOC-REQBUFS; ioctl is called, or until the +device is closed.</para> + <para>Applications call the <constant>VIDIOC_DQBUF</constant> ioctl to dequeue a filled (capturing) or displayed (output) buffer from the driver's outgoing queue. They just set the diff --git a/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml b/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml index 7be4b1d..e3e709b 100644 --- a/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml +++ b/Documentation/DocBook/media/v4l/vidioc-reqbufs.xml @@ -48,28 +48,30 @@ <refsect1> <title>Description</title>

- <para>This ioctl is used to initiate <link linkend="mmap">memory -mapped</link> or <link linkend="userp">user pointer</link> -I/O. Memory mapped buffers are located in device memory and must be -allocated with this ioctl before they can be mapped into the -application's address space. User buffers are allocated by -applications themselves, and this ioctl is merely used to switch the -driver into user pointer I/O mode and to setup some internal structures.</para> +<para>This ioctl is used to initiate <link linkend="mmap">memory mapped</link>, +<link linkend="userp">user pointer</link> or <link +linkend="dmabuf">DMABUF</link> based I/O. Memory mapped buffers are located in +device memory and must be allocated with this ioctl before they can be mapped +into the application's address space. User buffers are allocated by +applications themselves, and this ioctl is merely used to switch the driver +into user pointer I/O mode and to setup some internal structures. +Similarly, DMABUF buffers are allocated by applications through a device +driver, and this ioctl only configures the driver into DMABUF I/O mode without +performing any direct allocation.</para>

- <para>To allocate device buffers applications initialize all -fields of the <structname>v4l2_requestbuffers</structname> structure. -They set the <structfield>type</structfield> field to the respective -stream or buffer type, the <structfield>count</structfield> field to -the desired number of buffers, <structfield>memory</structfield> -must be set to the requested I/O method and the <structfield>reserved</structfield> array -must be zeroed. When the ioctl -is called with a pointer to this structure the driver will attempt to allocate -the requested number of buffers and it stores the actual number -allocated in the <structfield>count</structfield> field. It can be -smaller than the number requested, even zero, when the driver runs out -of free memory. A larger number is also possible when the driver requires -more buffers to function correctly. For example video output requires at least two buffers, -one displayed and one filled by the application.</para> + <para>To allocate device buffers applications initialize all fields of the +<structname>v4l2_requestbuffers</structname> structure. They set the +<structfield>type</structfield> field to the respective stream or buffer type, +the <structfield>count</structfield> field to the desired number of buffers, +<structfield>memory</structfield> must be set to the requested I/O method and +the <structfield>reserved</structfield> array must be zeroed. When the ioctl is +called with a pointer to this structure the driver will attempt to allocate the +requested number of buffers and it stores the actual number allocated in the +<structfield>count</structfield> field. It can be smaller than the number +requested, even zero, when the driver runs out of free memory. A larger number +is also possible when the driver requires more buffers to function correctly. +For example video output requires at least two buffers, one displayed and one +filled by the application.</para> <para>When the I/O method is not supported the ioctl returns an &EINVAL;.</para>

@@ -102,7 +104,8 @@ as the &v4l2-format; <structfield>type</structfield> field. See <xref <entry>&v4l2-memory;</entry> <entry><structfield>memory</structfield></entry> <entry>Applications set this field to -<constant>V4L2_MEMORY_MMAP</constant> or +<constant>V4L2_MEMORY_MMAP</constant>, +<constant>V4L2_MEMORY_DMABUF</constant> or <constant>V4L2_MEMORY_USERPTR</constant>.</entry> </row> <row>

From: Sumit Semwal sumit.semwal@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.stanislaws@samsung.com [original work in the PoC for buffer sharing] Signed-off-by: Sumit Semwal sumit.semwal@ti.com Signed-off-by: Sumit Semwal sumit.semwal@linaro.org --- drivers/media/video/videobuf2-core.c | 196 +++++++++++++++++++++++++++++++++- include/media/videobuf2-core.h | 27 +++++ 2 files changed, 219 insertions(+), 4 deletions(-)

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index 2e8f1df..d26b1cc 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c @@ -106,6 +106,36 @@ 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 */ @@ -227,6 +257,8 @@ 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); } @@ -349,6 +381,12 @@ 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 +398,8 @@ 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 +491,20 @@ 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 @@ -483,8 +537,9 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) return -EBUSY; }

- if (req->memory != V4L2_MEMORY_MMAP - && req->memory != V4L2_MEMORY_USERPTR) { + 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 +568,11 @@ 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 @@ -619,8 +679,9 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) return -EBUSY; }

- if (create->memory != V4L2_MEMORY_MMAP - && create->memory != V4L2_MEMORY_USERPTR) { + if (create->memory != V4L2_MEMORY_MMAP && + create->memory != V4L2_MEMORY_USERPTR && + create->memory != V4L2_MEMORY_DMABUF) { dprintk(1, "%s(): unsupported memory type\n", __func__); return -EINVAL; } @@ -644,6 +705,11 @@ 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 +905,14 @@ 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 +927,10 @@ 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 +1035,100 @@ 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 */ + __vb2_plane_dmabuf_put(q, &vb->planes[plane]); + + /* 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; + } + 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 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 +1152,9 @@ 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; @@ -1335,6 +1510,19 @@ 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 to do this just after DMA, not when the + * buffer is dequeued.. + */ + if (q->memory == V4L2_MEMORY_DMABUF) { + unsigned int i; + + for (i = 0; i < vb->num_planes; ++i) { + call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv); + vb->planes[i].dbuf_mapped = 0; + } + } + 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..859bbaf 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 +82,12 @@ struct vb2_mem_ops { unsigned long size, int write); void (*put_userptr)(void *buf_priv);

+ 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 +98,8 @@ struct vb2_mem_ops {

struct vb2_plane { void *mem_priv; + struct dma_buf *dbuf; + unsigned int dbuf_mapped; };

/** @@ -83,12 +108,14 @@ 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), };

/**

From: Sumit Semwal sumit.semwal@ti.com

Adding DMABUF memory type causes videobuf to complain about not using it in some switch cases. This patch removes these warnings.

Signed-off-by: Sumit Semwal sumit.semwal@ti.com --- drivers/media/video/videobuf-core.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index de4fa4e..b457c8b 100644 --- a/drivers/media/video/videobuf-core.c +++ b/drivers/media/video/videobuf-core.c @@ -335,6 +335,9 @@ static void videobuf_status(struct videobuf_queue *q, struct v4l2_buffer *b, case V4L2_MEMORY_OVERLAY: b->m.offset = vb->boff; break; + case V4L2_MEMORY_DMABUF: + /* DMABUF is not handled in videobuf framework */ + break; }

b->flags = 0; @@ -411,6 +414,7 @@ int __videobuf_mmap_setup(struct videobuf_queue *q, break; case V4L2_MEMORY_USERPTR: case V4L2_MEMORY_OVERLAY: + case V4L2_MEMORY_DMABUF: /* nothing */ break; }

From: Laurent Pinchart laurent.pinchart@ideasonboard.com

Signed-off-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/videobuf2-dma-contig.c | 36 ++++++++++++++-------------- 1 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index f17ad98..5207eb1 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -31,9 +31,9 @@ struct vb2_dc_buf { struct vb2_vmarea_handler handler; };

-static void vb2_dma_contig_put(void *buf_priv); +static void vb2_dc_put(void *buf_priv);

-static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size) +static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size) { struct vb2_dc_conf *conf = alloc_ctx; struct vb2_dc_buf *buf; @@ -55,7 +55,7 @@ static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size) buf->size = size;

buf->handler.refcount = &buf->refcount; - buf->handler.put = vb2_dma_contig_put; + buf->handler.put = vb2_dc_put; buf->handler.arg = buf;

atomic_inc(&buf->refcount); @@ -63,7 +63,7 @@ static void *vb2_dma_contig_alloc(void *alloc_ctx, unsigned long size) return buf; }

-static void vb2_dma_contig_put(void *buf_priv) +static void vb2_dc_put(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv;

@@ -74,14 +74,14 @@ static void vb2_dma_contig_put(void *buf_priv) } }

-static void *vb2_dma_contig_cookie(void *buf_priv) +static void *vb2_dc_cookie(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv;

return &buf->dma_addr; }

-static void *vb2_dma_contig_vaddr(void *buf_priv) +static void *vb2_dc_vaddr(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv; if (!buf) @@ -90,14 +90,14 @@ static void *vb2_dma_contig_vaddr(void *buf_priv) return buf->vaddr; }

-static unsigned int vb2_dma_contig_num_users(void *buf_priv) +static unsigned int vb2_dc_num_users(void *buf_priv) { struct vb2_dc_buf *buf = buf_priv;

return atomic_read(&buf->refcount); }

-static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma) +static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) { struct vb2_dc_buf *buf = buf_priv;

@@ -110,7 +110,7 @@ static int vb2_dma_contig_mmap(void *buf_priv, struct vm_area_struct *vma) &vb2_common_vm_ops, &buf->handler); }

-static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr, +static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, unsigned long size, int write) { struct vb2_dc_buf *buf; @@ -137,7 +137,7 @@ static void *vb2_dma_contig_get_userptr(void *alloc_ctx, unsigned long vaddr, return buf; }

-static void vb2_dma_contig_put_userptr(void *mem_priv) +static void vb2_dc_put_userptr(void *mem_priv) { struct vb2_dc_buf *buf = mem_priv;

@@ -149,14 +149,14 @@ static void vb2_dma_contig_put_userptr(void *mem_priv) }

const struct vb2_mem_ops vb2_dma_contig_memops = { - .alloc = vb2_dma_contig_alloc, - .put = vb2_dma_contig_put, - .cookie = vb2_dma_contig_cookie, - .vaddr = vb2_dma_contig_vaddr, - .mmap = vb2_dma_contig_mmap, - .get_userptr = vb2_dma_contig_get_userptr, - .put_userptr = vb2_dma_contig_put_userptr, - .num_users = vb2_dma_contig_num_users, + .alloc = vb2_dc_alloc, + .put = vb2_dc_put, + .cookie = vb2_dc_cookie, + .vaddr = vb2_dc_vaddr, + .mmap = vb2_dc_mmap, + .get_userptr = vb2_dc_get_userptr, + .put_userptr = vb2_dc_put_userptr, + .num_users = vb2_dc_num_users, }; EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);

From: Andrzej Pietrasiewicz andrzej.p@samsung.com

This patch introduces usage of dma_map_sg to map memory behind a userspace pointer to a device as dma-contiguous mapping.

Signed-off-by: Andrzej Pietrasiewicz andrzej.p@samsung.com Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com [bugfixing] Signed-off-by: Kamil Debski k.debski@samsung.com [bugfixing] Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com [add sglist subroutines/code refactoring] Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/videobuf2-dma-contig.c | 287 ++++++++++++++++++++++++++-- 1 files changed, 270 insertions(+), 17 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index 476e536..3a1e314 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -11,6 +11,8 @@ */

#include <linux/module.h> +#include <linux/scatterlist.h> +#include <linux/sched.h> #include <linux/slab.h> #include <linux/dma-mapping.h>

@@ -22,6 +24,8 @@ struct vb2_dc_buf { void *vaddr; unsigned long size; dma_addr_t dma_addr; + enum dma_data_direction dma_dir; + struct sg_table *dma_sgt;

/* MMAP related */ struct vb2_vmarea_handler handler; @@ -32,6 +36,103 @@ struct vb2_dc_buf { };

/*********************************************/ +/* scatterlist table functions */ +/*********************************************/ + +static struct sg_table *vb2_dc_pages_to_sgt(struct page **pages, + unsigned int n_pages, unsigned long offset, unsigned long size) +{ + struct sg_table *sgt; + unsigned int chunks; + unsigned int i; + unsigned int cur_page; + int ret; + struct scatterlist *s; + unsigned int offset_end = n_pages * PAGE_SIZE - size; + + sgt = kzalloc(sizeof *sgt, GFP_KERNEL); + if (!sgt) + return ERR_PTR(-ENOMEM); + + /* compute number of chunks */ + chunks = 1; + for (i = 1; i < n_pages; ++i) + if (pages[i] != pages[i - 1] + 1) + ++chunks; + + ret = sg_alloc_table(sgt, chunks, GFP_KERNEL); + if (ret) { + kfree(sgt); + return ERR_PTR(-ENOMEM); + } + + /* merging chunks and putting them into the scatterlist */ + cur_page = 0; + for_each_sg(sgt->sgl, s, sgt->orig_nents, i) { + size_t size = PAGE_SIZE; + unsigned int j; + + for (j = cur_page + 1; j < n_pages; ++j) { + if (pages[j] != pages[j - 1] + 1) + break; + size += PAGE_SIZE; + } + + /* cut offset if chunk starts at the first page */ + if (cur_page == 0) + size -= offset; + /* cut offset_end if chunk ends at the last page */ + if (j == n_pages) + size -= offset_end; + + sg_set_page(s, pages[cur_page], size, offset); + offset = 0; + cur_page = j; + } + + return sgt; +} + +static void vb2_dc_release_sgtable(struct sg_table *sgt) +{ + sg_free_table(sgt); + kfree(sgt); +} + +static void vb2_dc_sgt_foreach_page(struct sg_table *sgt, + void (*cb)(struct page *pg)) +{ + struct scatterlist *s; + unsigned int i; + + for_each_sg(sgt->sgl, s, sgt->nents, i) { + struct page *page = sg_page(s); + unsigned int n_pages = PAGE_ALIGN(s->offset + s->length) + >> PAGE_SHIFT; + unsigned int j; + + for (j = 0; j < n_pages; ++j, ++page) + cb(page); + } +} + +static unsigned long vb2_dc_get_contiguous_size(struct sg_table *sgt) +{ + struct scatterlist *s; + dma_addr_t expected = sg_dma_address(sgt->sgl); + unsigned int i; + unsigned long size = 0; + + for_each_sg(sgt->sgl, s, sgt->nents, i) { + if (sg_dma_address(s) != expected) + break; + expected = sg_dma_address(s) + sg_dma_len(s); + size += sg_dma_len(s); + } + return size; +} + +/*********************************************/ /* callbacks for all buffers */ /*********************************************/

@@ -116,42 +217,194 @@ static int vb2_dc_mmap(void *buf_priv, struct vm_area_struct *vma) /* callbacks for USERPTR buffers */ /*********************************************/

+static inline int vma_is_io(struct vm_area_struct *vma) +{ + return !!(vma->vm_flags & (VM_IO | VM_PFNMAP)); +} + +static struct vm_area_struct *vb2_dc_get_user_vma( + unsigned long start, unsigned long size) +{ + struct vm_area_struct *vma; + + /* current->mm->mmap_sem is taken by videobuf2 core */ + vma = find_vma(current->mm, start); + if (!vma) { + printk(KERN_ERR "no vma for address %lu\n", start); + return ERR_PTR(-EFAULT); + } + + if (vma->vm_end - vma->vm_start < size) { + printk(KERN_ERR "vma at %lu is too small for %lu bytes\n", + start, size); + return ERR_PTR(-EFAULT); + } + + vma = vb2_get_vma(vma); + if (!vma) { + printk(KERN_ERR "failed to copy vma\n"); + return ERR_PTR(-ENOMEM); + } + + return vma; +} + +static int vb2_dc_get_user_pages(unsigned long start, struct page **pages, + int n_pages, struct vm_area_struct *vma, int write) +{ + if (vma_is_io(vma)) { + unsigned int i; + + for (i = 0; i < n_pages; ++i, start += PAGE_SIZE) { + unsigned long pfn; + int ret = follow_pfn(vma, start, &pfn); + + if (ret) { + printk(KERN_ERR "no page for address %lu\n", + start); + return ret; + } + pages[i] = pfn_to_page(pfn); + } + } else { + unsigned int n; + + n = get_user_pages(current, current->mm, start & PAGE_MASK, + n_pages, write, 1, pages, NULL); + if (n != n_pages) { + printk(KERN_ERR "got only %d of %d user pages\n", + n, n_pages); + while (n) + put_page(pages[--n]); + return -EFAULT; + } + } + + return 0; +} + +static void vb2_dc_put_dirty_page(struct page *page) +{ + set_page_dirty_lock(page); + put_page(page); +} + +static void vb2_dc_put_userptr(void *buf_priv) +{ + struct vb2_dc_buf *buf = buf_priv; + struct sg_table *sgt = buf->dma_sgt; + + dma_unmap_sg(buf->dev, sgt->sgl, sgt->orig_nents, buf->dma_dir); + if (!vma_is_io(buf->vma)) + vb2_dc_sgt_foreach_page(sgt, vb2_dc_put_dirty_page); + + vb2_dc_release_sgtable(sgt); + vb2_put_vma(buf->vma); + kfree(buf); +} + static void *vb2_dc_get_userptr(void *alloc_ctx, unsigned long vaddr, - unsigned long size, int write) + unsigned long size, int write) { struct vb2_dc_buf *buf; - struct vm_area_struct *vma; - dma_addr_t dma_addr = 0; - int ret; + unsigned long start; + unsigned long end; + unsigned long offset; + struct page **pages; + int n_pages; + int ret = 0; + struct sg_table *sgt; + unsigned long contig_size;

buf = kzalloc(sizeof *buf, GFP_KERNEL); if (!buf) return ERR_PTR(-ENOMEM);

- ret = vb2_get_contig_userptr(vaddr, size, &vma, &dma_addr); + buf->dev = alloc_ctx; + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + + start = vaddr & PAGE_MASK; + offset = vaddr & ~PAGE_MASK; + end = PAGE_ALIGN(vaddr + size); + n_pages = (end - start) >> PAGE_SHIFT; + + pages = kmalloc(n_pages * sizeof pages[0], GFP_KERNEL); + if (!pages) { + ret = -ENOMEM; + printk(KERN_ERR "failed to allocate pages table\n"); + goto fail_buf; + } + + buf->vma = vb2_dc_get_user_vma(start, size); + if (IS_ERR(buf->vma)) { + printk(KERN_ERR "failed to get VMA\n"); + ret = PTR_ERR(buf->vma); + goto fail_pages; + } + + /* extract page list from userspace mapping */ + ret = vb2_dc_get_user_pages(start, pages, n_pages, buf->vma, write); if (ret) { - printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n", - vaddr); - kfree(buf); - return ERR_PTR(ret); + printk(KERN_ERR "failed to get user pages\n"); + goto fail_vma; + } + + sgt = vb2_dc_pages_to_sgt(pages, n_pages, offset, size); + if (IS_ERR(sgt)) { + printk(KERN_ERR "failed to create scatterlist table\n"); + ret = -ENOMEM; + goto fail_get_user_pages; + } + + /* pages are no longer needed */ + kfree(pages); + pages = NULL; + + sgt->nents = dma_map_sg(buf->dev, sgt->sgl, sgt->orig_nents, + buf->dma_dir); + if (sgt->nents <= 0) { + printk(KERN_ERR "failed to map scatterlist\n"); + ret = -EIO; + goto fail_sgt; }

+ contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < size) { + printk(KERN_ERR "contiguous mapping is too small %lu/%lu\n", + contig_size, size); + ret = -EFAULT; + goto fail_map_sg; + } + + buf->dma_addr = sg_dma_address(sgt->sgl); buf->size = size; - buf->dma_addr = dma_addr; - buf->vma = vma; + buf->dma_sgt = sgt;

return buf; -}

-static void vb2_dc_put_userptr(void *mem_priv) -{ - struct vb2_dc_buf *buf = mem_priv; +fail_map_sg: + dma_unmap_sg(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);

- if (!buf) - return; +fail_sgt: + if (!vma_is_io(buf->vma)) + vb2_dc_sgt_foreach_page(sgt, put_page); + vb2_dc_release_sgtable(sgt); + +fail_get_user_pages: + if (pages && !vma_is_io(buf->vma)) + while (n_pages) + put_page(pages[--n_pages]);

+fail_vma: vb2_put_vma(buf->vma); + +fail_pages: + kfree(pages); /* kfree is NULL-proof */ + +fail_buf: kfree(buf); + + return ERR_PTR(ret); }

/*********************************************/

From: Sumit Semwal sumit.semwal@ti.com

This patch makes changes for adding dma-contig as a dma_buf user. It provides function implementations for the {attach, detach, map, unmap}_dmabuf() mem_ops of DMABUF memory type.

Signed-off-by: Sumit Semwal sumit.semwal@ti.com Signed-off-by: Sumit Semwal sumit.semwal@linaro.org [author of the original patch] Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com [integration with refactored dma-contig allocator] --- drivers/media/video/videobuf2-dma-contig.c | 112 ++++++++++++++++++++++++++++ 1 files changed, 112 insertions(+), 0 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index 3b1ac77d..a829e7d 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -10,6 +10,7 @@ * the Free Software Foundation. */

+#include <linux/dma-buf.h> #include <linux/module.h> #include <linux/scatterlist.h> #include <linux/sched.h> @@ -33,6 +34,9 @@ struct vb2_dc_buf {

/* USERPTR related */ struct vm_area_struct *vma; + + /* DMABUF related */ + struct dma_buf_attachment *db_attach; };

/*********************************************/ @@ -430,6 +434,110 @@ fail_buf: }

/*********************************************/ +/* callbacks for DMABUF buffers */ +/*********************************************/ + +static int vb2_dc_map_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + struct sg_table *sgt; + unsigned long contig_size; + + if (WARN_ON(!buf->db_attach)) { + printk(KERN_ERR "trying to pin a non attached buffer\n"); + return -EINVAL; + } + + if (WARN_ON(buf->dma_sgt)) { + printk(KERN_ERR "dmabuf buffer is already pinned\n"); + return 0; + } + + /* get the associated scatterlist for this buffer */ + sgt = dma_buf_map_attachment(buf->db_attach, buf->dma_dir); + if (IS_ERR_OR_NULL(sgt)) { + printk(KERN_ERR "Error getting dmabuf scatterlist\n"); + return -EINVAL; + } + + /* checking if dmabuf is big enough to store contiguous chunk */ + contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < buf->size) { + printk(KERN_ERR "contiguous chunk is too small %lu/%lu b\n", + contig_size, buf->size); + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + return -EFAULT; + } + + buf->dma_addr = sg_dma_address(sgt->sgl); + buf->dma_sgt = sgt; + + return 0; +} + +static void vb2_dc_unmap_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + struct sg_table *sgt = buf->dma_sgt; + + if (WARN_ON(!buf->db_attach)) { + printk(KERN_ERR "trying to unpin a not attached buffer\n"); + return; + } + + if (WARN_ON(!sgt)) { + printk(KERN_ERR "dmabuf buffer is already unpinned\n"); + return; + } + + dma_buf_unmap_attachment(buf->db_attach, sgt, buf->dma_dir); + + buf->dma_addr = 0; + buf->dma_sgt = NULL; +} + +static void vb2_dc_detach_dmabuf(void *mem_priv) +{ + struct vb2_dc_buf *buf = mem_priv; + + if (WARN_ON(buf->dma_addr)) + vb2_dc_unmap_dmabuf(buf); + + /* detach this attachment */ + dma_buf_detach(buf->db_attach->dmabuf, buf->db_attach); + kfree(buf); +} + +static void *vb2_dc_attach_dmabuf(void *alloc_ctx, struct dma_buf *dbuf, + unsigned long size, int write) +{ + struct vb2_dc_buf *buf; + struct dma_buf_attachment *dba; + + if (dbuf->size < size) + return ERR_PTR(-EFAULT); + + buf = kzalloc(sizeof *buf, GFP_KERNEL); + if (!buf) + return ERR_PTR(-ENOMEM); + + buf->dev = alloc_ctx; + /* create attachment for the dmabuf with the user device */ + dba = dma_buf_attach(dbuf, buf->dev); + if (IS_ERR(dba)) { + printk(KERN_ERR "failed to attach dmabuf\n"); + kfree(buf); + return dba; + } + + buf->dma_dir = write ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + buf->size = size; + buf->db_attach = dba; + + return buf; +} + +/*********************************************/ /* DMA CONTIG exported functions */ /*********************************************/

@@ -443,6 +551,10 @@ const struct vb2_mem_ops vb2_dma_contig_memops = { .put_userptr = vb2_dc_put_userptr, .prepare = vb2_dc_prepare, .finish = vb2_dc_finish, + .map_dmabuf = vb2_dc_map_dmabuf, + .unmap_dmabuf = vb2_dc_unmap_dmabuf, + .attach_dmabuf = vb2_dc_attach_dmabuf, + .detach_dmabuf = vb2_dc_detach_dmabuf, .num_users = vb2_dc_num_users, }; EXPORT_SYMBOL_GPL(vb2_dma_contig_memops);

This patch enhances s5p-fimc with support for DMABUF importing via V4L2_MEMORY_DMABUF memory type.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/Kconfig | 1 + drivers/media/video/s5p-fimc/fimc-capture.c | 2 +- 2 files changed, 2 insertions(+), 1 deletions(-)

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig index f2479c5..9de9ddc 100644 --- a/drivers/media/video/Kconfig +++ b/drivers/media/video/Kconfig @@ -1133,6 +1133,7 @@ config VIDEO_SAMSUNG_S5P_FIMC VIDEO_V4L2_SUBDEV_API && EXPERIMENTAL select VIDEOBUF2_DMA_CONTIG select V4L2_MEM2MEM_DEV + select DMA_SHARED_BUFFER ---help--- This is a v4l2 driver for Samsung S5P and EXYNOS4 camera host interface and video postprocessor. diff --git a/drivers/media/video/s5p-fimc/fimc-capture.c b/drivers/media/video/s5p-fimc/fimc-capture.c index b06efd2..38fb39e 100644 --- a/drivers/media/video/s5p-fimc/fimc-capture.c +++ b/drivers/media/video/s5p-fimc/fimc-capture.c @@ -1530,7 +1530,7 @@ int fimc_register_capture_device(struct fimc_dev *fimc, q = &fimc->vid_cap.vbq; memset(q, 0, sizeof(*q)); q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; - q->io_modes = VB2_MMAP | VB2_USERPTR; + q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF; q->drv_priv = fimc->vid_cap.ctx; q->ops = &fimc_capture_qops; q->mem_ops = &vb2_dma_contig_memops;