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 CC: linux-doc@vger.kernel.org --- Documentation/DocBook/media/v4l/compat.xml | 4 + Documentation/DocBook/media/v4l/io.xml | 180 +++++++++++++++++++- .../DocBook/media/v4l/vidioc-create-bufs.xml | 16 +- Documentation/DocBook/media/v4l/vidioc-qbuf.xml | 17 ++ Documentation/DocBook/media/v4l/vidioc-reqbufs.xml | 47 ++--- 5 files changed, 234 insertions(+), 30 deletions(-)

diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index faa0fd1..a46f95b 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2621,6 +2621,10 @@ ioctls.</para> <listitem> <para>Support for frequency band enumeration: &VIDIOC-ENUM-FREQ-BANDS; ioctl.</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 1885cc0..5b58657 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -331,7 +331,7 @@ application until one or more buffers can be dequeued. By default 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> +&func-select; or &func-poll; functions are always available.</para>

<para>To start and stop capturing or output applications call the &VIDIOC-STREAMON; and &VIDIOC-STREAMOFF; ioctl. Note @@ -472,6 +472,161 @@ 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 method 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 an +application. Next, these buffers are exported to the application as file +descriptors using an API which is specific for an allocator driver. Only such +file descriptor are exchanged. The descriptors 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.</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; +reqbuf.count = 1; + +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>The buffer (plane) file descriptor 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 a 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 unlock the buffer at any +time between the completion of the DMA and this ioctl. The memory is +also unlocked 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 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> ioctls, and the +<function>select()</function> and <function>poll()</function> functions.</para> + + </section> + <section id="async"> <title>Asynchronous I/O</title>

@@ -673,6 +828,14 @@ 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 +909,15 @@ 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> @@ -973,6 +1145,12 @@ pointer</link> I/O.</entry> <entry>3</entry> <entry>[to do]</entry> </row> + <row> + <entry><constant>V4L2_MEMORY_DMABUF</constant></entry> + <entry>4</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 a8cda1a..cd99436 100644 --- a/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml +++ b/Documentation/DocBook/media/v4l/vidioc-create-bufs.xml @@ -6,7 +6,8 @@

<refnamediv> <refname>VIDIOC_CREATE_BUFS</refname> - <refpurpose>Create buffers for Memory Mapped or User Pointer I/O</refpurpose> + <refpurpose>Create buffers for Memory Mapped or User Pointer or DMA Buffer + I/O</refpurpose> </refnamediv>

<refsynopsisdiv> @@ -55,11 +56,11 @@ </note>

<para>This ioctl is used to create buffers for <link linkend="mmap">memory -mapped</link> or <link linkend="userp">user pointer</link> -I/O. It can be used as an alternative or in addition to the -<constant>VIDIOC_REQBUFS</constant> ioctl, when a tighter control over buffers -is required. This ioctl can be called multiple times to create buffers of -different sizes.</para> +mapped</link> or <link linkend="userp">user pointer</link> or <link +linkend="dmabuf">DMA buffer</link> I/O. It can be used as an alternative or in +addition to the <constant>VIDIOC_REQBUFS</constant> ioctl, when a tighter +control over buffers is required. This ioctl can be called multiple times to +create buffers of different sizes.</para>

<para>To allocate device buffers applications initialize relevant fields of the <structname>v4l2_create_buffers</structname> structure. They set the @@ -109,7 +110,8 @@ information.</para> <entry>__u32</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>. See <xref linkend="v4l2-memory" /></entry> </row> diff --git a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml index 77ff5be..f40dfa0 100644 --- a/Documentation/DocBook/media/v4l/vidioc-qbuf.xml +++ b/Documentation/DocBook/media/v4l/vidioc-qbuf.xml @@ -109,6 +109,23 @@ 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> +field to a file descriptor associated with a DMABUF buffer. When the +multi-planar API is used the <structfield>m.fd</structfield> fields 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. Locking a buffer means passing it to a driver for an +access by hardware. If an application accesses (reads/writes) a locked buffer +then the result is undefined. 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 d7c9505..20f4323 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>__u32</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>. See <xref linkend="v4l2-memory" />.</entry> </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 Acked-by: Laurent Pinchart laurent.pinchart@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 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].m.fd = + b->m.planes[plane].m.fd; + v4l2_planes[plane].length = + b->m.planes[plane].length; + v4l2_planes[plane].data_offset = + b->m.planes[plane].data_offset; + } + } } else { /* * Single-planar buffers do not use planes array, @@ -867,6 +931,12 @@ 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; + v4l2_planes[0].length = b->length; + } + }

vb->v4l2_buf.field = b->field; @@ -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); + 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 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) @@ -993,6 +1166,9 @@ 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; @@ -1301,6 +1477,30 @@ int vb2_wait_for_all_buffers(struct vb2_queue *q) EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers);

/** + * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state + */ +static void __vb2_dqbuf(struct vb2_buffer *vb) +{ + struct vb2_queue *q = vb->vb2_queue; + unsigned int i; + + /* nothing to do if the buffer is already dequeued */ + if (vb->state == VB2_BUF_STATE_DEQUEUED) + return; + + vb->state = VB2_BUF_STATE_DEQUEUED; + + /* unmap DMABUF buffer */ + if (q->memory == V4L2_MEMORY_DMABUF) + for (i = 0; i < vb->num_planes; ++i) { + if (!vb->planes[i].dbuf_mapped) + continue; + call_memop(q, unmap_dmabuf, vb->planes[i].mem_priv); + vb->planes[i].dbuf_mapped = 0; + } +} + +/** * vb2_dqbuf() - Dequeue a buffer to the userspace * @q: videobuf2 queue * @b: buffer structure passed from userspace to vidioc_dqbuf handler @@ -1364,11 +1564,12 @@ int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) __fill_v4l2_buffer(vb, b); /* Remove from videobuf queue */ list_del(&vb->queued_entry); + /* go back to dequeued state */ + __vb2_dqbuf(vb);

dprintk(1, "dqbuf of buffer %d, with state %d\n", vb->v4l2_buf.index, vb->state);

- vb->state = VB2_BUF_STATE_DEQUEUED; return 0; } EXPORT_SYMBOL_GPL(vb2_dqbuf); @@ -1407,7 +1608,7 @@ static void __vb2_queue_cancel(struct vb2_queue *q) * Reinitialize all buffers for next use. */ for (i = 0; i < q->num_buffers; ++i) - q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED; + __vb2_dqbuf(q->bufs[i]); }

/** diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index 8dd9b6c..84f11f2 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 Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/videobuf-core.c | 4 ++++ 1 file changed, 4 insertions(+)

diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c index bf7a326..5449e8a 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; @@ -405,6 +408,7 @@ int __videobuf_mmap_setup(struct videobuf_queue *q, break; case V4L2_MEMORY_USERPTR: case V4L2_MEMORY_OVERLAY: + case V4L2_MEMORY_DMABUF: /* nothing */ break; }

This patch removes a reference to alloc_ctx from an instance of a DMA contiguous buffer. It helps to avoid a risk of a dangling pointer if the context is released while the buffer is still valid. Moreover it removes one dereference step while accessing a device structure.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/videobuf2-dma-contig.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index a05784f..20c95da 100644 --- a/drivers/media/video/videobuf2-dma-contig.c +++ b/drivers/media/video/videobuf2-dma-contig.c @@ -23,7 +23,7 @@ struct vb2_dc_conf { };

struct vb2_dc_buf { - struct vb2_dc_conf *conf; + struct device *dev; void *vaddr; dma_addr_t dma_addr; unsigned long size; @@ -37,22 +37,21 @@ static void vb2_dc_put(void *buf_priv); static void *vb2_dc_alloc(void *alloc_ctx, unsigned long size) { struct vb2_dc_conf *conf = alloc_ctx; + struct device *dev = conf->dev; struct vb2_dc_buf *buf;

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

- buf->vaddr = dma_alloc_coherent(conf->dev, size, &buf->dma_addr, - GFP_KERNEL); + buf->vaddr = dma_alloc_coherent(dev, size, &buf->dma_addr, GFP_KERNEL); if (!buf->vaddr) { - dev_err(conf->dev, "dma_alloc_coherent of size %ld failed\n", - size); + dev_err(dev, "dma_alloc_coherent of size %ld failed\n", size); kfree(buf); return ERR_PTR(-ENOMEM); }

- buf->conf = conf; + buf->dev = dev; buf->size = size;

buf->handler.refcount = &buf->refcount; @@ -69,7 +68,7 @@ static void vb2_dc_put(void *buf_priv) struct vb2_dc_buf *buf = buf_priv;

if (atomic_dec_and_test(&buf->refcount)) { - dma_free_coherent(buf->conf->dev, buf->size, buf->vaddr, + dma_free_coherent(buf->dev, buf->size, buf->vaddr, buf->dma_addr); kfree(buf); }

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

This patch contains some of the code kindly provided by Marek Szyprowski m.szyprowski@samsung.com and Kamil Debski k.debski@samsung.com and Andrzej Pietrasiewicz andrzej.p@samsung.com. Kind thanks for bug reports from Laurent Pinchart laurent.pinchart@ideasonboard.com and Seung-Woo Kim sw0312.kim@samsung.com.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/videobuf2-dma-contig.c | 226 ++++++++++++++++++++++++++-- 1 file changed, 210 insertions(+), 16 deletions(-)

diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index daac2b2..8486e06 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>

@@ -27,6 +29,8 @@ 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; @@ -37,6 +41,44 @@ struct vb2_dc_buf { };

/*********************************************/ +/* scatterlist table functions */ +/*********************************************/ + + +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->orig_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 */ /*********************************************/

@@ -122,42 +164,194 @@ 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 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) { + pr_err("no page for address %lu\n", start); + return ret; + } + pages[i] = pfn_to_page(pfn); + } + } else { + int n; + + n = get_user_pages(current, current->mm, start & PAGE_MASK, + n_pages, write, 1, pages, NULL); + /* negative error means that no page was pinned */ + n = max(n, 0); + if (n != n_pages) { + pr_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); + + sg_free_table(sgt); + kfree(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_conf *conf = alloc_ctx; struct vb2_dc_buf *buf; + unsigned long start; + unsigned long end; + unsigned long offset; + struct page **pages; + int n_pages; + int ret = 0; struct vm_area_struct *vma; - dma_addr_t dma_addr = 0; - int ret; + 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 = conf->dev; + 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; + pr_err("failed to allocate pages table\n"); + goto fail_buf; + } + + /* current->mm->mmap_sem is taken by videobuf2 core */ + vma = find_vma(current->mm, vaddr); + if (!vma) { + pr_err("no vma for address %lu\n", vaddr); + ret = -EFAULT; + goto fail_pages; + } + + if (vma->vm_end < vaddr + size) { + pr_err("vma at %lu is too small for %lu bytes\n", vaddr, size); + ret = -EFAULT; + goto fail_pages; + } + + buf->vma = vb2_get_vma(vma); + if (!buf->vma) { + pr_err("failed to copy vma\n"); + ret = -ENOMEM; + goto fail_pages; + } + + /* extract page list from userspace mapping */ + ret = vb2_dc_get_user_pages(start, pages, n_pages, vma, write); if (ret) { - printk(KERN_ERR "Failed acquiring VMA for vaddr 0x%08lx\n", - vaddr); - kfree(buf); - return ERR_PTR(ret); + pr_err("failed to get user pages\n"); + goto fail_vma; + } + + sgt = kzalloc(sizeof(*sgt), GFP_KERNEL); + if (!sgt) { + pr_err("failed to allocate sg table\n"); + ret = -ENOMEM; + goto fail_get_user_pages; + } + + ret = sg_alloc_table_from_pages(sgt, pages, n_pages, + offset, size, GFP_KERNEL); + if (ret) { + pr_err("failed to initialize sg table\n"); + goto fail_sgt; + } + + /* 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) { + pr_err("failed to map scatterlist\n"); + ret = -EIO; + goto fail_sgt_init; + } + + contig_size = vb2_dc_get_contiguous_size(sgt); + if (contig_size < size) { + pr_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->orig_nents, buf->dma_dir);

- if (!buf) - return; +fail_sgt_init: + if (!vma_is_io(buf->vma)) + vb2_dc_sgt_foreach_page(sgt, put_page); + sg_free_table(sgt); + +fail_sgt: + kfree(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] Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/Kconfig | 1 + drivers/media/video/videobuf2-dma-contig.c | 120 +++++++++++++++++++++++++++- 2 files changed, 119 insertions(+), 2 deletions(-)

diff --git a/drivers/media/video/Kconfig b/drivers/media/video/Kconfig index c558d37..ec089da 100644 --- a/drivers/media/video/Kconfig +++ b/drivers/media/video/Kconfig @@ -54,6 +54,7 @@ config VIDEOBUF2_MEMOPS config VIDEOBUF2_DMA_CONTIG select VIDEOBUF2_CORE select VIDEOBUF2_MEMOPS + select DMA_SHARED_BUFFER tristate

config VIDEOBUF2_VMALLOC diff --git a/drivers/media/video/videobuf2-dma-contig.c b/drivers/media/video/videobuf2-dma-contig.c index 494a824..a5804cf 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> @@ -38,6 +39,9 @@ struct vb2_dc_buf {

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

/*********************************************/ @@ -108,7 +112,8 @@ static void vb2_dc_prepare(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt;

- if (!sgt) + /* DMABUF exporter will flush the cache for us */ + if (!sgt || buf->db_attach) return;

dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); @@ -119,7 +124,8 @@ static void vb2_dc_finish(void *buf_priv) struct vb2_dc_buf *buf = buf_priv; struct sg_table *sgt = buf->dma_sgt;

- if (!sgt) + /* DMABUF exporter will flush the cache for us */ + if (!sgt || buf->db_attach) return;

dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir); @@ -377,6 +383,112 @@ 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)) { + pr_err("trying to pin a non attached buffer\n"); + return -EINVAL; + } + + if (WARN_ON(buf->dma_sgt)) { + pr_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)) { + pr_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) { + pr_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)) { + pr_err("trying to unpin a not attached buffer\n"); + return; + } + + if (WARN_ON(!sgt)) { + pr_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 vb2 works correctly you should never detach mapped buffer */ + 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_conf *conf = alloc_ctx; + 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 = conf->dev; + /* create attachment for the dmabuf with the user device */ + dba = dma_buf_attach(dbuf, buf->dev); + if (IS_ERR(dba)) { + pr_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 */ /*********************************************/

@@ -390,6 +502,10 @@ 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 VIVI driver with a support for importing a buffer from DMABUF file descriptors.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/vivi.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/video/vivi.c b/drivers/media/video/vivi.c index a05494b..4fb38b9 100644 --- a/drivers/media/video/vivi.c +++ b/drivers/media/video/vivi.c @@ -1284,7 +1284,7 @@ static int __init vivi_create_instance(int inst) q = &dev->vb_vidq; memset(q, 0, sizeof(dev->vb_vidq)); q->type = V4L2_BUF_TYPE_VIDEO_CAPTURE; - q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_READ; + q->io_modes = VB2_MMAP | VB2_USERPTR | VB2_DMABUF | VB2_READ; q->drv_priv = dev; q->buf_struct_size = sizeof(struct vivi_buffer); q->ops = &vivi_video_qops;

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 Acked-by: Sylwester Nawrocki s.nawrocki@samsung.com --- drivers/media/video/s5p-fimc/fimc-capture.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/media/video/s5p-fimc/fimc-capture.c b/drivers/media/video/s5p-fimc/fimc-capture.c index 8e413dd..3fcaf7d 100644 --- a/drivers/media/video/s5p-fimc/fimc-capture.c +++ b/drivers/media/video/s5p-fimc/fimc-capture.c @@ -1634,7 +1634,7 @@ static 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;

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

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com CC: linux-doc@vger.kernel.org --- Documentation/DocBook/media/v4l/compat.xml | 3 + Documentation/DocBook/media/v4l/io.xml | 3 + Documentation/DocBook/media/v4l/v4l2.xml | 1 + Documentation/DocBook/media/v4l/vidioc-expbuf.xml | 212 +++++++++++++++++++++ 4 files changed, 219 insertions(+) create mode 100644 Documentation/DocBook/media/v4l/vidioc-expbuf.xml

diff --git a/Documentation/DocBook/media/v4l/compat.xml b/Documentation/DocBook/media/v4l/compat.xml index a46f95b..f0512aa 100644 --- a/Documentation/DocBook/media/v4l/compat.xml +++ b/Documentation/DocBook/media/v4l/compat.xml @@ -2625,6 +2625,9 @@ ioctls.</para> <para>Importing DMABUF file descriptors as a new IO method described in <xref linkend="dmabuf" />.</para> </listitem> + <listitem> + <para>Exporting DMABUF files using &VIDIOC-EXPBUF; ioctl.</para> + </listitem> </itemizedlist> </section>

diff --git a/Documentation/DocBook/media/v4l/io.xml b/Documentation/DocBook/media/v4l/io.xml index 5b58657..476f448 100644 --- a/Documentation/DocBook/media/v4l/io.xml +++ b/Documentation/DocBook/media/v4l/io.xml @@ -488,6 +488,9 @@ 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>Refer to <link linked="vidioc-expbuf"> DMABUF exporting </link> for +details about exporting a V4L2 buffers as DMABUF file descriptors.</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 diff --git a/Documentation/DocBook/media/v4l/v4l2.xml b/Documentation/DocBook/media/v4l/v4l2.xml index eee6908..d8c2597 100644 --- a/Documentation/DocBook/media/v4l/v4l2.xml +++ b/Documentation/DocBook/media/v4l/v4l2.xml @@ -543,6 +543,7 @@ and discussions on the V4L mailing list.</revremark> &sub-enuminput; &sub-enumoutput; &sub-enumstd; + &sub-expbuf; &sub-g-audio; &sub-g-audioout; &sub-g-crop; diff --git a/Documentation/DocBook/media/v4l/vidioc-expbuf.xml b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml new file mode 100644 index 0000000..bf28e7d --- /dev/null +++ b/Documentation/DocBook/media/v4l/vidioc-expbuf.xml @@ -0,0 +1,212 @@ +<refentry id="vidioc-expbuf"> + + <refmeta> + <refentrytitle>ioctl VIDIOC_EXPBUF</refentrytitle> + &manvol; + </refmeta> + + <refnamediv> + <refname>VIDIOC_EXPBUF</refname> + <refpurpose>Export a buffer as a DMABUF file descriptor.</refpurpose> + </refnamediv> + + <refsynopsisdiv> + <funcsynopsis> + <funcprototype> + <funcdef>int <function>ioctl</function></funcdef> + <paramdef>int <parameter>fd</parameter></paramdef> + <paramdef>int <parameter>request</parameter></paramdef> + <paramdef>struct v4l2_exportbuffer *<parameter>argp</parameter></paramdef> + </funcprototype> + </funcsynopsis> + </refsynopsisdiv> + + <refsect1> + <title>Arguments</title> + + <variablelist> + <varlistentry> + <term><parameter>fd</parameter></term> + <listitem> + <para>&fd;</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>request</parameter></term> + <listitem> + <para>VIDIOC_EXPBUF</para> + </listitem> + </varlistentry> + <varlistentry> + <term><parameter>argp</parameter></term> + <listitem> + <para></para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + + <refsect1> + <title>Description</title> + + <note> + <title>Experimental</title> + <para>This is an <link linkend="experimental"> experimental </link> + interface and may change in the future.</para> + </note> + +<para>This ioctl is an extension to the <link linkend="mmap">memory +mapping</link> I/O method therefore it is available only for +<constant>V4L2_MEMORY_MMAP</constant> buffers. It can be used to export a +buffer as a DMABUF file at any time after buffers have been allocated with the +&VIDIOC-REQBUFS; ioctl.</para> + +<para> To export a buffer, applicationis fill &v4l2-exportbuffer;. The +<structfield> type </structfield> field is set to the same buffer type as was +previously used with &v4l2-requestbuffers;<structfield> type </structfield>. +Applications must also set the <structfield> index </structfield> field. Valid +index numbers range from zero to the number of buffers allocated with +&VIDIOC-REQBUFS; (&v4l2-requestbuffers;<structfield> count </structfield>) +minus one. For multi plane API, applications set the <structfield> plane +</structfield> field to the index of the plane to be exported. Valid planes +range from zero to the maximal number of valid planes for currently active +format. For single plane API, applications must set <structfield> plane +</structfield> to zero. Additional flags may be posted in the <structfield> +flags </structfield> field. Refer to a manual for open() for details. +Currently only O_CLOEXEC is supported. All other fields must be set to zero. +In a case of multi-planar API, every plane is exported separately using +multiple <constant> VIDIOC_EXPBUF </constant> calls. </para> + +<para> After calling <constant>VIDIOC_EXPBUF</constant> the <structfield> fd +</structfield> field will be set by a driver. This is a DMABUF file +descriptor. The application may pass it to other API. Refer to <link +linkend="dmabuf">DMABUF importing</link> for details about importing DMABUF +files into V4L2 nodes. A developer is encouraged to close a DMABUF file when it +is no longer used to avoid a resource leak. </para> + + </refsect1> + <refsect1> + <section> + <title>Examples</title> + + <example> + <title>Exporting a buffer.</title> + <programlisting> +int buffer_export(int v4lfd, &v4l2-buf-type; bt, int index, int *dmafd) +{ + &v4l2-exportbuffer; expbuf; + + memset(&amp;expbuf, 0, sizeof expbuf); + expbuf.type = bt; + expbuf.index = index; + if (ioctl(v4lfd, &VIDIOC-EXPBUF;, &amp;expbuf) == -1) { + perror("VIDIOC_EXPBUF"); + return -1; + } + + *dmafd = expbuf.fd; + + return 0; +} + </programlisting> + </example> + + <example> + <title>Exporting a buffer using multi plane API.</title> + <programlisting> +int buffer_export_mp(int v4lfd, &v4l2-buf-type; bt, int index, + int dmafd[], int n_planes) +{ + int i; + + for (i = 0; i &lt; n_planes; ++i) { + &v4l2-exportbuffer; expbuf; + + memset(&amp;expbuf, 0, sizeof expbuf); + expbuf.type = bt; + expbuf.index = index; + expbuf.plane = i; + if (ioctl(v4lfd, &VIDIOC-EXPBUF;, &amp;expbuf) == -1) { + perror("VIDIOC_EXPBUF"); + while (i) + close(dmafd[--i]); + return -1; + } + dmafd[i] = expbuf.fd; + } + + return 0; +} + </programlisting> + </example> + </section> + </refsect1> + + <refsect1> + <table pgwide="1" frame="none" id="v4l2-exportbuffer"> + <title>struct <structname>v4l2_exportbuffer</structname></title> + <tgroup cols="3"> + &cs-str; + <tbody valign="top"> + <row> + <entry>__s32</entry> + <entry><structfield>fd</structfield></entry> + <entry>The DMABUF file descriptor associated with a buffer. Set by + a driver.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>flags</structfield></entry> + <entry>Flags for newly created file, currently only <constant> +O_CLOEXEC </constant> is supported, refer to the manual of open() for more +details.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>type</structfield></entry> + <entry>Type of the buffer, same as &v4l2-format; +<structfield>type</structfield> or &v4l2-requestbuffers; +<structfield>type</structfield>, set by the application. See <xref +linkend="v4l2-buf-type" /></entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>index</structfield></entry> + <entry>Number of the buffer, set by the application. This field is +only used for <link linkend="mmap">memory mapping</link> I/O and can range from +zero to the number of buffers allocated with the &VIDIOC-REQBUFS; ioctl +(&v4l2-requestbuffers; <structfield>count</structfield>) minus one.</entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>plane</structfield></entry> + <entry>Index of the plane to be exported when using multi plane +API. Otherwise this value must be set to zero. </entry> + </row> + <row> + <entry>__u32</entry> + <entry><structfield>reserved[11]</structfield></entry> + <entry>Reserved field for future use. Must be set to zero.</entry> + </row> + </tbody> + </tgroup> + </table> + + </refsect1> + + <refsect1> + &return-value; + <variablelist> + <varlistentry> + <term><errorcode>EINVAL</errorcode></term> + <listitem> + <para>A queue is not in MMAP mode or DMABUF exporting is not +supported or <structfield> flags </structfield> or <structfield> type +</structfield> or <structfield> index </structfield> or <structfield> plane +</structfield> fields are invalid.</para> + </listitem> + </varlistentry> + </variablelist> + </refsect1> + +</refentry>

This patch adds extension to V4L2 api. It allow to export a mmap buffer as file descriptor. New ioctl VIDIOC_EXPBUF is added. It takes a buffer offset used by mmap and return a file descriptor on success.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/v4l2-compat-ioctl32.c | 1 + drivers/media/video/v4l2-dev.c | 1 + drivers/media/video/v4l2-ioctl.c | 10 ++++++++++ include/linux/videodev2.h | 28 ++++++++++++++++++++++++++++ include/media/v4l2-ioctl.h | 2 ++ 5 files changed, 42 insertions(+)

diff --git a/drivers/media/video/v4l2-compat-ioctl32.c b/drivers/media/video/v4l2-compat-ioctl32.c index f0b5aba..8788000 100644 --- a/drivers/media/video/v4l2-compat-ioctl32.c +++ b/drivers/media/video/v4l2-compat-ioctl32.c @@ -971,6 +971,7 @@ long v4l2_compat_ioctl32(struct file *file, unsigned int cmd, unsigned long arg) case VIDIOC_S_FBUF32: case VIDIOC_OVERLAY32: case VIDIOC_QBUF32: + case VIDIOC_EXPBUF: case VIDIOC_DQBUF32: case VIDIOC_STREAMON32: case VIDIOC_STREAMOFF32: diff --git a/drivers/media/video/v4l2-dev.c b/drivers/media/video/v4l2-dev.c index 07aeafc..c43127c 100644 --- a/drivers/media/video/v4l2-dev.c +++ b/drivers/media/video/v4l2-dev.c @@ -638,6 +638,7 @@ static void determine_valid_ioctls(struct video_device *vdev) SET_VALID_IOCTL(ops, VIDIOC_REQBUFS, vidioc_reqbufs); SET_VALID_IOCTL(ops, VIDIOC_QUERYBUF, vidioc_querybuf); SET_VALID_IOCTL(ops, VIDIOC_QBUF, vidioc_qbuf); + SET_VALID_IOCTL(ops, VIDIOC_EXPBUF, vidioc_expbuf); SET_VALID_IOCTL(ops, VIDIOC_DQBUF, vidioc_dqbuf); SET_VALID_IOCTL(ops, VIDIOC_OVERLAY, vidioc_overlay); SET_VALID_IOCTL(ops, VIDIOC_G_FBUF, vidioc_g_fbuf); diff --git a/drivers/media/video/v4l2-ioctl.c b/drivers/media/video/v4l2-ioctl.c index dffd3c9..f3ec8c0 100644 --- a/drivers/media/video/v4l2-ioctl.c +++ b/drivers/media/video/v4l2-ioctl.c @@ -458,6 +458,15 @@ static void v4l_print_buffer(const void *arg, bool write_only) tc->type, tc->flags, tc->frames, *(__u32 *)tc->userbits); }

+static void v4l_print_exportbuffer(const void *arg, bool write_only) +{ + const struct v4l2_exportbuffer *p = arg; + + pr_cont("fd=%d, type=%s, index=%u, plane=%u, flags=0x%08x\n", + p->fd, prt_names(p->type, v4l2_type_names), + p->index, p->plane, p->flags); +} + static void v4l_print_create_buffers(const void *arg, bool write_only) { const struct v4l2_create_buffers *p = arg; @@ -1947,6 +1956,7 @@ static struct v4l2_ioctl_info v4l2_ioctls[] = { IOCTL_INFO_STD(VIDIOC_S_FBUF, vidioc_s_fbuf, v4l_print_framebuffer, INFO_FL_PRIO), IOCTL_INFO_STD(VIDIOC_OVERLAY, vidioc_overlay, v4l_print_u32, INFO_FL_PRIO), IOCTL_INFO_FNC(VIDIOC_QBUF, v4l_qbuf, v4l_print_buffer, INFO_FL_QUEUE), + IOCTL_INFO_STD(VIDIOC_EXPBUF, vidioc_expbuf, v4l_print_exportbuffer, 0), IOCTL_INFO_FNC(VIDIOC_DQBUF, v4l_dqbuf, v4l_print_buffer, INFO_FL_QUEUE), IOCTL_INFO_FNC(VIDIOC_STREAMON, v4l_streamon, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE), IOCTL_INFO_FNC(VIDIOC_STREAMOFF, v4l_streamoff, v4l_print_buftype, INFO_FL_PRIO | INFO_FL_QUEUE), diff --git a/include/linux/videodev2.h b/include/linux/videodev2.h index e04a73e..f429b6a 100644 --- a/include/linux/videodev2.h +++ b/include/linux/videodev2.h @@ -688,6 +688,33 @@ struct v4l2_buffer { #define V4L2_BUF_FLAG_NO_CACHE_INVALIDATE 0x0800 #define V4L2_BUF_FLAG_NO_CACHE_CLEAN 0x1000

+/** + * struct v4l2_exportbuffer - export of video buffer as DMABUF file descriptor + * + * @fd: file descriptor associated with DMABUF (set by driver) + * @flags: flags for newly created file, currently only O_CLOEXEC is + * supported, refer to manual of open syscall for more details + * @index: id number of the buffer + * @type: enum v4l2_buf_type; buffer type (type == *_MPLANE for + * multiplanar buffers); + * @plane: index of the plane to be exported, 0 for single plane queues + * + * Contains data used for exporting a video buffer as DMABUF file descriptor. + * The buffer is identified by a 'cookie' returned by VIDIOC_QUERYBUF + * (identical to the cookie used to mmap() the buffer to userspace). All + * reserved fields must be set to zero. The field reserved0 is expected to + * become a structure 'type' allowing an alternative layout of the structure + * content. Therefore this field should not be used for any other extensions. + */ +struct v4l2_exportbuffer { + __s32 fd; + __u32 flags; + __u32 type; /* enum v4l2_buf_type */ + __u32 index; + __u32 plane; + __u32 reserved[11]; +}; + /* * O V E R L A Y P R E V I E W */ @@ -2558,6 +2585,7 @@ struct v4l2_create_buffers { #define VIDIOC_S_FBUF _IOW('V', 11, struct v4l2_framebuffer) #define VIDIOC_OVERLAY _IOW('V', 14, int) #define VIDIOC_QBUF _IOWR('V', 15, struct v4l2_buffer) +#define VIDIOC_EXPBUF _IOWR('V', 16, struct v4l2_exportbuffer) #define VIDIOC_DQBUF _IOWR('V', 17, struct v4l2_buffer) #define VIDIOC_STREAMON _IOW('V', 18, int) #define VIDIOC_STREAMOFF _IOW('V', 19, int) diff --git a/include/media/v4l2-ioctl.h b/include/media/v4l2-ioctl.h index e614c9c..38fb139 100644 --- a/include/media/v4l2-ioctl.h +++ b/include/media/v4l2-ioctl.h @@ -119,6 +119,8 @@ struct v4l2_ioctl_ops { int (*vidioc_reqbufs) (struct file *file, void *fh, struct v4l2_requestbuffers *b); int (*vidioc_querybuf)(struct file *file, void *fh, struct v4l2_buffer *b); int (*vidioc_qbuf) (struct file *file, void *fh, struct v4l2_buffer *b); + int (*vidioc_expbuf) (struct file *file, void *fh, + struct v4l2_exportbuffer *e); int (*vidioc_dqbuf) (struct file *file, void *fh, struct v4l2_buffer *b);

int (*vidioc_create_bufs)(struct file *file, void *fh, struct v4l2_create_buffers *b);

This patch adds extension to videobuf2-core. It allow to export a mmap buffer as a file descriptor.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com Acked-by: Laurent Pinchart laurent.pinchart@ideasonboard.com --- drivers/media/video/videobuf2-core.c | 82 ++++++++++++++++++++++++++++++++++ include/media/videobuf2-core.h | 4 ++ 2 files changed, 86 insertions(+)

diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c index 05da3b4..a97815b 100644 --- a/drivers/media/video/videobuf2-core.c +++ b/drivers/media/video/videobuf2-core.c @@ -1753,6 +1753,79 @@ static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, }

/** + * vb2_expbuf() - Export a buffer as a file descriptor + * @q: videobuf2 queue + * @eb: export buffer structure passed from userspace to vidioc_expbuf + * handler in driver + * + * The return values from this function are intended to be directly returned + * from vidioc_expbuf handler in driver. + */ +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb) +{ + struct vb2_buffer *vb = NULL; + struct vb2_plane *vb_plane; + int ret; + struct dma_buf *dbuf; + + if (q->memory != V4L2_MEMORY_MMAP) { + dprintk(1, "Queue is not currently set up for mmap\n"); + return -EINVAL; + } + + if (!q->mem_ops->get_dmabuf) { + dprintk(1, "Queue does not support DMA buffer exporting\n"); + return -EINVAL; + } + + if (eb->flags & ~O_CLOEXEC) { + dprintk(1, "Queue does support only O_CLOEXEC flag\n"); + return -EINVAL; + } + + if (eb->type != q->type) { + dprintk(1, "qbuf: invalid buffer type\n"); + return -EINVAL; + } + + if (eb->index >= q->num_buffers) { + dprintk(1, "buffer index out of range\n"); + return -EINVAL; + } + + vb = q->bufs[eb->index]; + + if (eb->plane >= vb->num_planes) { + dprintk(1, "buffer plane out of range\n"); + return -EINVAL; + } + + vb_plane = &vb->planes[eb->plane]; + + dbuf = call_memop(q, get_dmabuf, vb_plane->mem_priv); + if (IS_ERR_OR_NULL(dbuf)) { + dprintk(1, "Failed to export buffer %d, plane %d\n", + eb->index, eb->plane); + return -EINVAL; + } + + ret = dma_buf_fd(dbuf, eb->flags); + if (ret < 0) { + dprintk(3, "buffer %d, plane %d failed to export (%d)\n", + eb->index, eb->plane, ret); + dma_buf_put(dbuf); + return ret; + } + + dprintk(3, "buffer %d, plane %d exported as %d descriptor\n", + eb->index, eb->plane, ret); + eb->fd = ret; + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_expbuf); + +/** * vb2_mmap() - map video buffers into application address space * @q: videobuf2 queue * @vma: vma passed to the mmap file operation handler in the driver @@ -2455,6 +2528,15 @@ int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) } EXPORT_SYMBOL_GPL(vb2_ioctl_streamoff);

+int vb2_ioctl_expbuf(struct file *file, void *priv, struct v4l2_exportbuffer *p) +{ + struct video_device *vdev = video_devdata(file); + + /* No need to call vb2_queue_is_busy(), anyone can export buffers. */ + return vb2_expbuf(vdev->queue, p); +} +EXPORT_SYMBOL_GPL(vb2_ioctl_expbuf); + /* v4l2_file_operations helpers */

int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h index c306fec..3f57ccb 100644 --- a/include/media/videobuf2-core.h +++ b/include/media/videobuf2-core.h @@ -81,6 +81,7 @@ struct vb2_fileio_data; struct vb2_mem_ops { void *(*alloc)(void *alloc_ctx, unsigned long size); void (*put)(void *buf_priv); + struct dma_buf *(*get_dmabuf)(void *buf_priv);

void *(*get_userptr)(void *alloc_ctx, unsigned long vaddr, unsigned long size, int write); @@ -363,6 +364,7 @@ int vb2_queue_init(struct vb2_queue *q); void vb2_queue_release(struct vb2_queue *q);

int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b); +int vb2_expbuf(struct vb2_queue *q, struct v4l2_exportbuffer *eb); int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking);

int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type); @@ -472,6 +474,8 @@ int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p); int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i); int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i); +int vb2_ioctl_expbuf(struct file *file, void *priv, + struct v4l2_exportbuffer *p);

/* struct v4l2_file_operations helpers */

This patch enhances s5p-tv with support for DMABUF exporting via VIDIOC_EXPBUF ioctl.

Signed-off-by: Tomasz Stanislawski t.stanislaws@samsung.com Signed-off-by: Kyungmin Park kyungmin.park@samsung.com --- drivers/media/video/s5p-tv/mixer_video.c | 10 ++++++++++ 1 file changed, 10 insertions(+)

diff --git a/drivers/media/video/s5p-tv/mixer_video.c b/drivers/media/video/s5p-tv/mixer_video.c index 2c299db..d1641b6 100644 --- a/drivers/media/video/s5p-tv/mixer_video.c +++ b/drivers/media/video/s5p-tv/mixer_video.c @@ -697,6 +697,15 @@ static int mxr_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) return vb2_dqbuf(&layer->vb_queue, p, file->f_flags & O_NONBLOCK); }

+static int mxr_expbuf(struct file *file, void *priv, + struct v4l2_exportbuffer *eb) +{ + struct mxr_layer *layer = video_drvdata(file); + + mxr_dbg(layer->mdev, "%s:%d\n", __func__, __LINE__); + return vb2_expbuf(&layer->vb_queue, eb); +} + static int mxr_streamon(struct file *file, void *priv, enum v4l2_buf_type i) { struct mxr_layer *layer = video_drvdata(file); @@ -724,6 +733,7 @@ static const struct v4l2_ioctl_ops mxr_ioctl_ops = { .vidioc_querybuf = mxr_querybuf, .vidioc_qbuf = mxr_qbuf, .vidioc_dqbuf = mxr_dqbuf, + .vidioc_expbuf = mxr_expbuf, /* Streaming control */ .vidioc_streamon = mxr_streamon, .vidioc_streamoff = mxr_streamoff,