[media] v4l: vb2: add support for shared buffer (dma_buf) (c5384048) · Commits · e / devices / android_kernel_teracube_emerald

drivers/media/v4l2-core/Kconfig

+1 −0

Original line number	Diff line number	Diff line
		@@ -59,6 +59,7 @@ config VIDEOBUF_DVB

		# Used by drivers that need Videobuf2 modules
		config VIDEOBUF2_CORE
		select DMA_SHARED_BUFFER
		tristate

		config VIDEOBUF2_MEMOPS

drivers/media/v4l2-core/videobuf2-core.c

+203 −3

Original line number	Diff line number	Diff line
		@@ -108,6 +108,36 @@ 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);
		}
		@@ -362,6 +394,8 @@ static void __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;
		}

		/*
		@@ -453,6 +487,20 @@ static int __verify_mmap_ops(struct vb2_queue *q)
		return 0;
		}

		/**
		* __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.
		@@ -460,7 +508,8 @@ static int __verify_mmap_ops(struct vb2_queue *q)
		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
		@@ -845,6 +899,16 @@ static void __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,
		@@ -859,6 +923,13 @@ static void __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;
		v4l2_planes[0].data_offset = 0;
		}

		}

		vb->v4l2_buf.field = b->field;
		@@ -958,6 +1029,107 @@ static int __qbuf_mmap(struct vb2_buffer vb, const struct v4l2_buffer b)
		return 0;
		}

		/**
		* __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 */
		__fill_vb2_buffer(vb, b, planes);

		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
		*/
		@@ -982,6 +1154,9 @@ 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;
		@@ -1302,6 +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
		@@ -1363,11 +1562,12 @@ 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);
		@@ -1406,7 +1606,7 @@ 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]);
		}

		/**

include/media/videobuf2-core.h

+27 −0

Original line number	Diff line number	Diff line
		@@ -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),
		};

		/**