| /* |
| * videobuf2-core.c - V4L2 driver helper framework |
| * |
| * Copyright (C) 2010 Samsung Electronics |
| * |
| * Author: Pawel Osciak <pawel@osciak.com> |
| * Marek Szyprowski <m.szyprowski@samsung.com> |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation. |
| */ |
| |
| #include <linux/err.h> |
| #include <linux/kernel.h> |
| #include <linux/module.h> |
| #include <linux/mm.h> |
| #include <linux/poll.h> |
| #include <linux/slab.h> |
| #include <linux/sched.h> |
| |
| #include <media/v4l2-dev.h> |
| #include <media/v4l2-fh.h> |
| #include <media/v4l2-event.h> |
| #include <media/videobuf2-core.h> |
| |
| static int debug; |
| module_param(debug, int, 0644); |
| |
| #define dprintk(level, fmt, arg...) \ |
| do { \ |
| if (debug >= level) \ |
| printk(KERN_DEBUG "vb2: " fmt, ## arg); \ |
| } while (0) |
| |
| #define call_memop(q, op, args...) \ |
| (((q)->mem_ops->op) ? \ |
| ((q)->mem_ops->op(args)) : 0) |
| |
| #define call_qop(q, op, args...) \ |
| (((q)->ops->op) ? ((q)->ops->op(args)) : 0) |
| |
| #define V4L2_BUFFER_MASK_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \ |
| V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \ |
| V4L2_BUF_FLAG_PREPARED | \ |
| V4L2_BUF_FLAG_TIMESTAMP_MASK) |
| |
| /** |
| * __vb2_buf_mem_alloc() - allocate video memory for the given buffer |
| */ |
| static int __vb2_buf_mem_alloc(struct vb2_buffer *vb) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| void *mem_priv; |
| int plane; |
| |
| /* |
| * Allocate memory for all planes in this buffer |
| * NOTE: mmapped areas should be page aligned |
| */ |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| unsigned long size = PAGE_ALIGN(q->plane_sizes[plane]); |
| |
| mem_priv = call_memop(q, alloc, q->alloc_ctx[plane], |
| size, q->gfp_flags); |
| if (IS_ERR_OR_NULL(mem_priv)) |
| goto free; |
| |
| /* Associate allocator private data with this plane */ |
| vb->planes[plane].mem_priv = mem_priv; |
| vb->v4l2_planes[plane].length = q->plane_sizes[plane]; |
| } |
| |
| return 0; |
| free: |
| /* Free already allocated memory if one of the allocations failed */ |
| for (; plane > 0; --plane) { |
| call_memop(q, put, vb->planes[plane - 1].mem_priv); |
| vb->planes[plane - 1].mem_priv = NULL; |
| } |
| |
| return -ENOMEM; |
| } |
| |
| /** |
| * __vb2_buf_mem_free() - free memory of the given buffer |
| */ |
| static void __vb2_buf_mem_free(struct vb2_buffer *vb) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| unsigned int plane; |
| |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| call_memop(q, put, vb->planes[plane].mem_priv); |
| vb->planes[plane].mem_priv = NULL; |
| dprintk(3, "Freed plane %d of buffer %d\n", plane, |
| vb->v4l2_buf.index); |
| } |
| } |
| |
| /** |
| * __vb2_buf_userptr_put() - release userspace memory associated with |
| * a USERPTR buffer |
| */ |
| static void __vb2_buf_userptr_put(struct vb2_buffer *vb) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| unsigned int plane; |
| |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| if (vb->planes[plane].mem_priv) |
| call_memop(q, put_userptr, vb->planes[plane].mem_priv); |
| vb->planes[plane].mem_priv = NULL; |
| } |
| } |
| |
| /** |
| * __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 |
| */ |
| static void __setup_offsets(struct vb2_queue *q, unsigned int n) |
| { |
| unsigned int buffer, plane; |
| struct vb2_buffer *vb; |
| unsigned long off; |
| |
| if (q->num_buffers) { |
| struct v4l2_plane *p; |
| vb = q->bufs[q->num_buffers - 1]; |
| p = &vb->v4l2_planes[vb->num_planes - 1]; |
| off = PAGE_ALIGN(p->m.mem_offset + p->length); |
| } else { |
| off = 0; |
| } |
| |
| for (buffer = q->num_buffers; buffer < q->num_buffers + n; ++buffer) { |
| vb = q->bufs[buffer]; |
| if (!vb) |
| continue; |
| |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| vb->v4l2_planes[plane].length = q->plane_sizes[plane]; |
| vb->v4l2_planes[plane].m.mem_offset = off; |
| |
| dprintk(3, "Buffer %d, plane %d offset 0x%08lx\n", |
| buffer, plane, off); |
| |
| off += vb->v4l2_planes[plane].length; |
| off = PAGE_ALIGN(off); |
| } |
| } |
| } |
| |
| /** |
| * __vb2_queue_alloc() - allocate videobuf buffer structures and (for MMAP type) |
| * video buffer memory for all buffers/planes on the queue and initializes the |
| * queue |
| * |
| * Returns the number of buffers successfully allocated. |
| */ |
| static int __vb2_queue_alloc(struct vb2_queue *q, enum v4l2_memory memory, |
| unsigned int num_buffers, unsigned int num_planes) |
| { |
| unsigned int buffer; |
| struct vb2_buffer *vb; |
| int ret; |
| |
| for (buffer = 0; buffer < num_buffers; ++buffer) { |
| /* Allocate videobuf buffer structures */ |
| vb = kzalloc(q->buf_struct_size, GFP_KERNEL); |
| if (!vb) { |
| dprintk(1, "Memory alloc for buffer struct failed\n"); |
| break; |
| } |
| |
| /* Length stores number of planes for multiplanar buffers */ |
| if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) |
| vb->v4l2_buf.length = num_planes; |
| |
| vb->state = VB2_BUF_STATE_DEQUEUED; |
| vb->vb2_queue = q; |
| vb->num_planes = num_planes; |
| vb->v4l2_buf.index = q->num_buffers + buffer; |
| vb->v4l2_buf.type = q->type; |
| vb->v4l2_buf.memory = memory; |
| |
| /* Allocate video buffer memory for the MMAP type */ |
| if (memory == V4L2_MEMORY_MMAP) { |
| ret = __vb2_buf_mem_alloc(vb); |
| if (ret) { |
| dprintk(1, "Failed allocating memory for " |
| "buffer %d\n", buffer); |
| kfree(vb); |
| break; |
| } |
| /* |
| * Call the driver-provided buffer initialization |
| * callback, if given. An error in initialization |
| * results in queue setup failure. |
| */ |
| ret = call_qop(q, buf_init, vb); |
| if (ret) { |
| dprintk(1, "Buffer %d %p initialization" |
| " failed\n", buffer, vb); |
| __vb2_buf_mem_free(vb); |
| kfree(vb); |
| break; |
| } |
| } |
| |
| q->bufs[q->num_buffers + buffer] = vb; |
| } |
| |
| if (memory == V4L2_MEMORY_MMAP) |
| __setup_offsets(q, buffer); |
| |
| dprintk(1, "Allocated %d buffers, %d plane(s) each\n", |
| buffer, num_planes); |
| |
| return buffer; |
| } |
| |
| /** |
| * __vb2_free_mem() - release all video buffer memory for a given queue |
| */ |
| static void __vb2_free_mem(struct vb2_queue *q, unsigned int buffers) |
| { |
| unsigned int buffer; |
| struct vb2_buffer *vb; |
| |
| for (buffer = q->num_buffers - buffers; buffer < q->num_buffers; |
| ++buffer) { |
| vb = q->bufs[buffer]; |
| if (!vb) |
| continue; |
| |
| /* 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); |
| } |
| } |
| |
| /** |
| * __vb2_queue_free() - free buffers at the end of the queue - video memory and |
| * related information, if no buffers are left return the queue to an |
| * uninitialized state. Might be called even if the queue has already been freed. |
| */ |
| static void __vb2_queue_free(struct vb2_queue *q, unsigned int buffers) |
| { |
| unsigned int buffer; |
| |
| /* Call driver-provided cleanup function for each buffer, if provided */ |
| if (q->ops->buf_cleanup) { |
| for (buffer = q->num_buffers - buffers; buffer < q->num_buffers; |
| ++buffer) { |
| if (NULL == q->bufs[buffer]) |
| continue; |
| q->ops->buf_cleanup(q->bufs[buffer]); |
| } |
| } |
| |
| /* Release video buffer memory */ |
| __vb2_free_mem(q, buffers); |
| |
| /* Free videobuf buffers */ |
| for (buffer = q->num_buffers - buffers; buffer < q->num_buffers; |
| ++buffer) { |
| kfree(q->bufs[buffer]); |
| q->bufs[buffer] = NULL; |
| } |
| |
| q->num_buffers -= buffers; |
| if (!q->num_buffers) |
| q->memory = 0; |
| INIT_LIST_HEAD(&q->queued_list); |
| } |
| |
| /** |
| * __verify_planes_array() - verify that the planes array passed in struct |
| * v4l2_buffer from userspace can be safely used |
| */ |
| static int __verify_planes_array(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| if (!V4L2_TYPE_IS_MULTIPLANAR(b->type)) |
| return 0; |
| |
| /* Is memory for copying plane information present? */ |
| if (NULL == b->m.planes) { |
| dprintk(1, "Multi-planar buffer passed but " |
| "planes array not provided\n"); |
| return -EINVAL; |
| } |
| |
| if (b->length < vb->num_planes || b->length > VIDEO_MAX_PLANES) { |
| dprintk(1, "Incorrect planes array length, " |
| "expected %d, got %d\n", vb->num_planes, b->length); |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * __verify_length() - Verify that the bytesused value for each plane fits in |
| * the plane length and that the data offset doesn't exceed the bytesused value. |
| */ |
| static int __verify_length(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| unsigned int length; |
| unsigned int plane; |
| |
| if (!V4L2_TYPE_IS_OUTPUT(b->type)) |
| return 0; |
| |
| if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| length = (b->memory == V4L2_MEMORY_USERPTR) |
| ? b->m.planes[plane].length |
| : vb->v4l2_planes[plane].length; |
| |
| if (b->m.planes[plane].bytesused > length) |
| return -EINVAL; |
| if (b->m.planes[plane].data_offset >= |
| b->m.planes[plane].bytesused) |
| return -EINVAL; |
| } |
| } else { |
| length = (b->memory == V4L2_MEMORY_USERPTR) |
| ? b->length : vb->v4l2_planes[0].length; |
| |
| if (b->bytesused > length) |
| return -EINVAL; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * __buffer_in_use() - return true if the buffer is in use and |
| * the queue cannot be freed (by the means of REQBUFS(0)) call |
| */ |
| static bool __buffer_in_use(struct vb2_queue *q, struct vb2_buffer *vb) |
| { |
| unsigned int plane; |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| void *mem_priv = vb->planes[plane].mem_priv; |
| /* |
| * If num_users() has not been provided, call_memop |
| * will return 0, apparently nobody cares about this |
| * case anyway. If num_users() returns more than 1, |
| * we are not the only user of the plane's memory. |
| */ |
| if (mem_priv && call_memop(q, num_users, mem_priv) > 1) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * __buffers_in_use() - return true if any buffers on the queue are in use and |
| * the queue cannot be freed (by the means of REQBUFS(0)) call |
| */ |
| static bool __buffers_in_use(struct vb2_queue *q) |
| { |
| unsigned int buffer; |
| for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| if (__buffer_in_use(q, q->bufs[buffer])) |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * __fill_v4l2_buffer() - fill in a struct v4l2_buffer with information to be |
| * returned to userspace |
| */ |
| static void __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| |
| /* Copy back data such as timestamp, flags, etc. */ |
| memcpy(b, &vb->v4l2_buf, offsetof(struct v4l2_buffer, m)); |
| b->reserved2 = vb->v4l2_buf.reserved2; |
| b->reserved = vb->v4l2_buf.reserved; |
| |
| if (V4L2_TYPE_IS_MULTIPLANAR(q->type)) { |
| /* |
| * Fill in plane-related data if userspace provided an array |
| * for it. The caller has already verified memory and size. |
| */ |
| b->length = vb->num_planes; |
| memcpy(b->m.planes, vb->v4l2_planes, |
| b->length * sizeof(struct v4l2_plane)); |
| } else { |
| /* |
| * We use length and offset in v4l2_planes array even for |
| * single-planar buffers, but userspace does not. |
| */ |
| b->length = vb->v4l2_planes[0].length; |
| b->bytesused = vb->v4l2_planes[0].bytesused; |
| if (q->memory == V4L2_MEMORY_MMAP) |
| 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; |
| } |
| |
| /* |
| * Clear any buffer state related flags. |
| */ |
| b->flags &= ~V4L2_BUFFER_MASK_FLAGS; |
| b->flags |= q->timestamp_type; |
| |
| switch (vb->state) { |
| case VB2_BUF_STATE_QUEUED: |
| case VB2_BUF_STATE_ACTIVE: |
| b->flags |= V4L2_BUF_FLAG_QUEUED; |
| break; |
| case VB2_BUF_STATE_ERROR: |
| b->flags |= V4L2_BUF_FLAG_ERROR; |
| /* fall through */ |
| case VB2_BUF_STATE_DONE: |
| b->flags |= V4L2_BUF_FLAG_DONE; |
| break; |
| case VB2_BUF_STATE_PREPARED: |
| b->flags |= V4L2_BUF_FLAG_PREPARED; |
| break; |
| case VB2_BUF_STATE_DEQUEUED: |
| /* nothing */ |
| break; |
| } |
| |
| if (__buffer_in_use(q, vb)) |
| b->flags |= V4L2_BUF_FLAG_MAPPED; |
| } |
| |
| /** |
| * vb2_querybuf() - query video buffer information |
| * @q: videobuf queue |
| * @b: buffer struct passed from userspace to vidioc_querybuf handler |
| * in driver |
| * |
| * Should be called from vidioc_querybuf ioctl handler in driver. |
| * This function will verify the passed v4l2_buffer structure and fill the |
| * relevant information for the userspace. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_querybuf handler in driver. |
| */ |
| int vb2_querybuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| struct vb2_buffer *vb; |
| int ret; |
| |
| if (b->type != q->type) { |
| dprintk(1, "querybuf: wrong buffer type\n"); |
| return -EINVAL; |
| } |
| |
| if (b->index >= q->num_buffers) { |
| dprintk(1, "querybuf: buffer index out of range\n"); |
| return -EINVAL; |
| } |
| vb = q->bufs[b->index]; |
| ret = __verify_planes_array(vb, b); |
| if (!ret) |
| __fill_v4l2_buffer(vb, b); |
| return ret; |
| } |
| EXPORT_SYMBOL(vb2_querybuf); |
| |
| /** |
| * __verify_userptr_ops() - verify that all memory operations required for |
| * USERPTR queue type have been provided |
| */ |
| static int __verify_userptr_ops(struct vb2_queue *q) |
| { |
| if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr || |
| !q->mem_ops->put_userptr) |
| return -EINVAL; |
| |
| return 0; |
| } |
| |
| /** |
| * __verify_mmap_ops() - verify that all memory operations required for |
| * MMAP queue type have been provided |
| */ |
| static int __verify_mmap_ops(struct vb2_queue *q) |
| { |
| if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc || |
| !q->mem_ops->put || !q->mem_ops->mmap) |
| return -EINVAL; |
| |
| 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. |
| */ |
| 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 && |
| memory != V4L2_MEMORY_DMABUF) { |
| dprintk(1, "reqbufs: unsupported memory type\n"); |
| return -EINVAL; |
| } |
| |
| if (type != q->type) { |
| dprintk(1, "reqbufs: requested type is incorrect\n"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Make sure all the required memory ops for given memory type |
| * are available. |
| */ |
| if (memory == V4L2_MEMORY_MMAP && __verify_mmap_ops(q)) { |
| dprintk(1, "reqbufs: MMAP for current setup unsupported\n"); |
| return -EINVAL; |
| } |
| |
| if (memory == V4L2_MEMORY_USERPTR && __verify_userptr_ops(q)) { |
| dprintk(1, "reqbufs: USERPTR for current setup unsupported\n"); |
| 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 |
| * do the memory and type validation. |
| */ |
| if (q->fileio) { |
| dprintk(1, "reqbufs: file io in progress\n"); |
| return -EBUSY; |
| } |
| return 0; |
| } |
| |
| /** |
| * __reqbufs() - Initiate streaming |
| * @q: videobuf2 queue |
| * @req: struct passed from userspace to vidioc_reqbufs handler in driver |
| * |
| * Should be called from vidioc_reqbufs ioctl handler of a driver. |
| * This function: |
| * 1) verifies streaming parameters passed from the userspace, |
| * 2) sets up the queue, |
| * 3) negotiates number of buffers and planes per buffer with the driver |
| * to be used during streaming, |
| * 4) allocates internal buffer structures (struct vb2_buffer), according to |
| * the agreed parameters, |
| * 5) for MMAP memory type, allocates actual video memory, using the |
| * memory handling/allocation routines provided during queue initialization |
| * |
| * If req->count is 0, all the memory will be freed instead. |
| * If the queue has been allocated previously (by a previous vb2_reqbufs) call |
| * and the queue is not busy, memory will be reallocated. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_reqbufs handler in driver. |
| */ |
| static int __reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) |
| { |
| unsigned int num_buffers, allocated_buffers, num_planes = 0; |
| int ret; |
| |
| if (q->streaming) { |
| dprintk(1, "reqbufs: streaming active\n"); |
| return -EBUSY; |
| } |
| |
| if (req->count == 0 || q->num_buffers != 0 || q->memory != req->memory) { |
| /* |
| * We already have buffers allocated, so first check if they |
| * are not in use and can be freed. |
| */ |
| if (q->memory == V4L2_MEMORY_MMAP && __buffers_in_use(q)) { |
| dprintk(1, "reqbufs: memory in use, cannot free\n"); |
| return -EBUSY; |
| } |
| |
| __vb2_queue_free(q, q->num_buffers); |
| |
| /* |
| * In case of REQBUFS(0) return immediately without calling |
| * driver's queue_setup() callback and allocating resources. |
| */ |
| if (req->count == 0) |
| return 0; |
| } |
| |
| /* |
| * Make sure the requested values and current defaults are sane. |
| */ |
| num_buffers = min_t(unsigned int, req->count, VIDEO_MAX_FRAME); |
| memset(q->plane_sizes, 0, sizeof(q->plane_sizes)); |
| memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); |
| q->memory = req->memory; |
| |
| /* |
| * Ask the driver how many buffers and planes per buffer it requires. |
| * Driver also sets the size and allocator context for each plane. |
| */ |
| ret = call_qop(q, queue_setup, q, NULL, &num_buffers, &num_planes, |
| q->plane_sizes, q->alloc_ctx); |
| if (ret) |
| return ret; |
| |
| /* Finally, allocate buffers and video memory */ |
| ret = __vb2_queue_alloc(q, req->memory, num_buffers, num_planes); |
| if (ret == 0) { |
| dprintk(1, "Memory allocation failed\n"); |
| return -ENOMEM; |
| } |
| |
| allocated_buffers = ret; |
| |
| /* |
| * Check if driver can handle the allocated number of buffers. |
| */ |
| if (allocated_buffers < num_buffers) { |
| num_buffers = allocated_buffers; |
| |
| ret = call_qop(q, queue_setup, q, NULL, &num_buffers, |
| &num_planes, q->plane_sizes, q->alloc_ctx); |
| |
| if (!ret && allocated_buffers < num_buffers) |
| ret = -ENOMEM; |
| |
| /* |
| * Either the driver has accepted a smaller number of buffers, |
| * or .queue_setup() returned an error |
| */ |
| } |
| |
| q->num_buffers = allocated_buffers; |
| |
| if (ret < 0) { |
| __vb2_queue_free(q, allocated_buffers); |
| return ret; |
| } |
| |
| /* |
| * Return the number of successfully allocated buffers |
| * to the userspace. |
| */ |
| req->count = allocated_buffers; |
| |
| return 0; |
| } |
| |
| /** |
| * vb2_reqbufs() - Wrapper for __reqbufs() that also verifies the memory and |
| * type values. |
| * @q: videobuf2 queue |
| * @req: struct passed from userspace to vidioc_reqbufs handler in driver |
| */ |
| int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) |
| { |
| int ret = __verify_memory_type(q, req->memory, req->type); |
| |
| return ret ? ret : __reqbufs(q, req); |
| } |
| EXPORT_SYMBOL_GPL(vb2_reqbufs); |
| |
| /** |
| * __create_bufs() - Allocate buffers and any required auxiliary structs |
| * @q: videobuf2 queue |
| * @create: creation parameters, passed from userspace to vidioc_create_bufs |
| * handler in driver |
| * |
| * Should be called from vidioc_create_bufs ioctl handler of a driver. |
| * This function: |
| * 1) verifies parameter sanity |
| * 2) calls the .queue_setup() queue operation |
| * 3) performs any necessary memory allocations |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_create_bufs handler in driver. |
| */ |
| static int __create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) |
| { |
| unsigned int num_planes = 0, num_buffers, allocated_buffers; |
| int ret; |
| |
| if (q->num_buffers == VIDEO_MAX_FRAME) { |
| dprintk(1, "%s(): maximum number of buffers already allocated\n", |
| __func__); |
| return -ENOBUFS; |
| } |
| |
| if (!q->num_buffers) { |
| memset(q->plane_sizes, 0, sizeof(q->plane_sizes)); |
| memset(q->alloc_ctx, 0, sizeof(q->alloc_ctx)); |
| q->memory = create->memory; |
| } |
| |
| num_buffers = min(create->count, VIDEO_MAX_FRAME - q->num_buffers); |
| |
| /* |
| * Ask the driver, whether the requested number of buffers, planes per |
| * buffer and their sizes are acceptable |
| */ |
| ret = call_qop(q, queue_setup, q, &create->format, &num_buffers, |
| &num_planes, q->plane_sizes, q->alloc_ctx); |
| if (ret) |
| return ret; |
| |
| /* Finally, allocate buffers and video memory */ |
| ret = __vb2_queue_alloc(q, create->memory, num_buffers, |
| num_planes); |
| if (ret == 0) { |
| dprintk(1, "Memory allocation failed\n"); |
| return -ENOMEM; |
| } |
| |
| allocated_buffers = ret; |
| |
| /* |
| * Check if driver can handle the so far allocated number of buffers. |
| */ |
| if (ret < num_buffers) { |
| num_buffers = ret; |
| |
| /* |
| * q->num_buffers contains the total number of buffers, that the |
| * queue driver has set up |
| */ |
| ret = call_qop(q, queue_setup, q, &create->format, &num_buffers, |
| &num_planes, q->plane_sizes, q->alloc_ctx); |
| |
| if (!ret && allocated_buffers < num_buffers) |
| ret = -ENOMEM; |
| |
| /* |
| * Either the driver has accepted a smaller number of buffers, |
| * or .queue_setup() returned an error |
| */ |
| } |
| |
| q->num_buffers += allocated_buffers; |
| |
| if (ret < 0) { |
| __vb2_queue_free(q, allocated_buffers); |
| return -ENOMEM; |
| } |
| |
| /* |
| * Return the number of successfully allocated buffers |
| * to the userspace. |
| */ |
| create->count = allocated_buffers; |
| |
| return 0; |
| } |
| |
| /** |
| * vb2_create_bufs() - Wrapper for __create_bufs() that also verifies the |
| * memory and type values. |
| * @q: videobuf2 queue |
| * @create: creation parameters, passed from userspace to vidioc_create_bufs |
| * handler in driver |
| */ |
| int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) |
| { |
| int ret = __verify_memory_type(q, create->memory, create->format.type); |
| |
| create->index = q->num_buffers; |
| if (create->count == 0) |
| return ret != -EBUSY ? ret : 0; |
| return ret ? ret : __create_bufs(q, create); |
| } |
| EXPORT_SYMBOL_GPL(vb2_create_bufs); |
| |
| /** |
| * vb2_plane_vaddr() - Return a kernel virtual address of a given plane |
| * @vb: vb2_buffer to which the plane in question belongs to |
| * @plane_no: plane number for which the address is to be returned |
| * |
| * This function returns a kernel virtual address of a given plane if |
| * such a mapping exist, NULL otherwise. |
| */ |
| void *vb2_plane_vaddr(struct vb2_buffer *vb, unsigned int plane_no) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| |
| if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv) |
| return NULL; |
| |
| return call_memop(q, vaddr, vb->planes[plane_no].mem_priv); |
| |
| } |
| EXPORT_SYMBOL_GPL(vb2_plane_vaddr); |
| |
| /** |
| * vb2_plane_cookie() - Return allocator specific cookie for the given plane |
| * @vb: vb2_buffer to which the plane in question belongs to |
| * @plane_no: plane number for which the cookie is to be returned |
| * |
| * This function returns an allocator specific cookie for a given plane if |
| * available, NULL otherwise. The allocator should provide some simple static |
| * inline function, which would convert this cookie to the allocator specific |
| * type that can be used directly by the driver to access the buffer. This can |
| * be for example physical address, pointer to scatter list or IOMMU mapping. |
| */ |
| void *vb2_plane_cookie(struct vb2_buffer *vb, unsigned int plane_no) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| |
| if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv) |
| return NULL; |
| |
| return call_memop(q, cookie, vb->planes[plane_no].mem_priv); |
| } |
| EXPORT_SYMBOL_GPL(vb2_plane_cookie); |
| |
| /** |
| * vb2_buffer_done() - inform videobuf that an operation on a buffer is finished |
| * @vb: vb2_buffer returned from the driver |
| * @state: either VB2_BUF_STATE_DONE if the operation finished successfully |
| * or VB2_BUF_STATE_ERROR if the operation finished with an error |
| * |
| * This function should be called by the driver after a hardware operation on |
| * a buffer is finished and the buffer may be returned to userspace. The driver |
| * cannot use this buffer anymore until it is queued back to it by videobuf |
| * by the means of buf_queue callback. Only buffers previously queued to the |
| * driver by buf_queue can be passed to this function. |
| */ |
| void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| unsigned long flags; |
| unsigned int plane; |
| |
| if (vb->state != VB2_BUF_STATE_ACTIVE) |
| return; |
| |
| if (state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR) |
| return; |
| |
| dprintk(4, "Done processing on buffer %d, state: %d\n", |
| vb->v4l2_buf.index, state); |
| |
| /* sync buffers */ |
| for (plane = 0; plane < vb->num_planes; ++plane) |
| call_memop(q, finish, vb->planes[plane].mem_priv); |
| |
| /* Add the buffer to the done buffers list */ |
| spin_lock_irqsave(&q->done_lock, flags); |
| vb->state = state; |
| list_add_tail(&vb->done_entry, &q->done_list); |
| atomic_dec(&q->queued_count); |
| spin_unlock_irqrestore(&q->done_lock, flags); |
| |
| /* Inform any processes that may be waiting for buffers */ |
| wake_up(&q->done_wq); |
| } |
| EXPORT_SYMBOL_GPL(vb2_buffer_done); |
| |
| /** |
| * __fill_vb2_buffer() - fill a vb2_buffer with information provided in a |
| * v4l2_buffer by the userspace. The caller has already verified that struct |
| * v4l2_buffer has a valid number of planes. |
| */ |
| static void __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b, |
| struct v4l2_plane *v4l2_planes) |
| { |
| unsigned int plane; |
| |
| if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { |
| /* Fill in driver-provided information for OUTPUT types */ |
| if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| /* |
| * Will have to go up to b->length when API starts |
| * accepting variable number of planes. |
| */ |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| v4l2_planes[plane].bytesused = |
| b->m.planes[plane].bytesused; |
| v4l2_planes[plane].data_offset = |
| b->m.planes[plane].data_offset; |
| } |
| } |
| |
| if (b->memory == V4L2_MEMORY_USERPTR) { |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| v4l2_planes[plane].m.userptr = |
| b->m.planes[plane].m.userptr; |
| v4l2_planes[plane].length = |
| 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, |
| * so fill in relevant v4l2_buffer struct fields instead. |
| * In videobuf we use our internal V4l2_planes struct for |
| * single-planar buffers as well, for simplicity. |
| */ |
| if (V4L2_TYPE_IS_OUTPUT(b->type)) { |
| v4l2_planes[0].bytesused = b->bytesused; |
| v4l2_planes[0].data_offset = 0; |
| } |
| |
| if (b->memory == V4L2_MEMORY_USERPTR) { |
| 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; |
| vb->v4l2_buf.timestamp = b->timestamp; |
| vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_MASK_FLAGS; |
| } |
| |
| /** |
| * __qbuf_userptr() - handle qbuf of a USERPTR buffer |
| */ |
| static int __qbuf_userptr(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); |
| |
| /* Copy relevant information provided by the userspace */ |
| __fill_vb2_buffer(vb, b, planes); |
| |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| /* Skip the plane if already verified */ |
| if (vb->v4l2_planes[plane].m.userptr && |
| vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr |
| && vb->v4l2_planes[plane].length == planes[plane].length) |
| continue; |
| |
| dprintk(3, "qbuf: userspace address for plane %d changed, " |
| "reacquiring memory\n", plane); |
| |
| /* Check if the provided plane buffer is large enough */ |
| if (planes[plane].length < q->plane_sizes[plane]) { |
| dprintk(1, "qbuf: provided buffer size %u is less than " |
| "setup size %u for plane %d\n", |
| planes[plane].length, |
| q->plane_sizes[plane], plane); |
| ret = -EINVAL; |
| goto err; |
| } |
| |
| /* Release previously acquired memory if present */ |
| if (vb->planes[plane].mem_priv) |
| call_memop(q, put_userptr, vb->planes[plane].mem_priv); |
| |
| vb->planes[plane].mem_priv = NULL; |
| vb->v4l2_planes[plane].m.userptr = 0; |
| vb->v4l2_planes[plane].length = 0; |
| |
| /* Acquire each plane's memory */ |
| mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane], |
| planes[plane].m.userptr, |
| planes[plane].length, write); |
| if (IS_ERR_OR_NULL(mem_priv)) { |
| dprintk(1, "qbuf: failed acquiring userspace " |
| "memory for plane %d\n", plane); |
| ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL; |
| goto err; |
| } |
| vb->planes[plane].mem_priv = mem_priv; |
| } |
| |
| /* |
| * 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 */ |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| if (vb->planes[plane].mem_priv) |
| call_memop(q, put_userptr, vb->planes[plane].mem_priv); |
| vb->planes[plane].mem_priv = NULL; |
| vb->v4l2_planes[plane].m.userptr = 0; |
| vb->v4l2_planes[plane].length = 0; |
| } |
| |
| return ret; |
| } |
| |
| /** |
| * __qbuf_mmap() - handle qbuf of an MMAP buffer |
| */ |
| static int __qbuf_mmap(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| __fill_vb2_buffer(vb, b, vb->v4l2_planes); |
| 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 |
| */ |
| static void __enqueue_in_driver(struct vb2_buffer *vb) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| unsigned int plane; |
| |
| vb->state = VB2_BUF_STATE_ACTIVE; |
| atomic_inc(&q->queued_count); |
| |
| /* sync buffers */ |
| for (plane = 0; plane < vb->num_planes; ++plane) |
| call_memop(q, prepare, vb->planes[plane].mem_priv); |
| |
| q->ops->buf_queue(vb); |
| } |
| |
| static int __buf_prepare(struct vb2_buffer *vb, const struct v4l2_buffer *b) |
| { |
| struct vb2_queue *q = vb->vb2_queue; |
| int ret; |
| |
| ret = __verify_length(vb, b); |
| if (ret < 0) { |
| dprintk(1, "%s(): plane parameters verification failed: %d\n", |
| __func__, ret); |
| return ret; |
| } |
| |
| switch (q->memory) { |
| case V4L2_MEMORY_MMAP: |
| ret = __qbuf_mmap(vb, b); |
| break; |
| 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; |
| } |
| |
| if (!ret) |
| ret = call_qop(q, buf_prepare, vb); |
| if (ret) |
| dprintk(1, "qbuf: buffer preparation failed: %d\n", ret); |
| else |
| vb->state = VB2_BUF_STATE_PREPARED; |
| |
| return ret; |
| } |
| |
| static int vb2_queue_or_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b, |
| const char *opname, |
| int (*handler)(struct vb2_queue *, |
| struct v4l2_buffer *, |
| struct vb2_buffer *)) |
| { |
| struct rw_semaphore *mmap_sem = NULL; |
| struct vb2_buffer *vb; |
| int ret; |
| |
| /* |
| * In case of user pointer buffers vb2 allocators need to get direct |
| * access to userspace pages. This requires getting the mmap semaphore |
| * for read access in the current process structure. The same semaphore |
| * is taken before calling mmap operation, while both qbuf/prepare_buf |
| * and mmap are called by the driver or v4l2 core with the driver's lock |
| * held. To avoid an AB-BA deadlock (mmap_sem then driver's lock in mmap |
| * and driver's lock then mmap_sem in qbuf/prepare_buf) the videobuf2 |
| * core releases the driver's lock, takes mmap_sem and then takes the |
| * driver's lock again. |
| * |
| * To avoid racing with other vb2 calls, which might be called after |
| * releasing the driver's lock, this operation is performed at the |
| * beginning of qbuf/prepare_buf processing. This way the queue status |
| * is consistent after getting the driver's lock back. |
| */ |
| if (q->memory == V4L2_MEMORY_USERPTR) { |
| mmap_sem = ¤t->mm->mmap_sem; |
| call_qop(q, wait_prepare, q); |
| down_read(mmap_sem); |
| call_qop(q, wait_finish, q); |
| } |
| |
| if (q->fileio) { |
| dprintk(1, "%s(): file io in progress\n", opname); |
| ret = -EBUSY; |
| goto unlock; |
| } |
| |
| if (b->type != q->type) { |
| dprintk(1, "%s(): invalid buffer type\n", opname); |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| if (b->index >= q->num_buffers) { |
| dprintk(1, "%s(): buffer index out of range\n", opname); |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| vb = q->bufs[b->index]; |
| if (NULL == vb) { |
| /* Should never happen */ |
| dprintk(1, "%s(): buffer is NULL\n", opname); |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| if (b->memory != q->memory) { |
| dprintk(1, "%s(): invalid memory type\n", opname); |
| ret = -EINVAL; |
| goto unlock; |
| } |
| |
| ret = __verify_planes_array(vb, b); |
| if (ret) |
| goto unlock; |
| |
| ret = handler(q, b, vb); |
| if (ret) |
| goto unlock; |
| |
| /* Fill buffer information for the userspace */ |
| __fill_v4l2_buffer(vb, b); |
| |
| dprintk(1, "%s() of buffer %d succeeded\n", opname, vb->v4l2_buf.index); |
| unlock: |
| if (mmap_sem) |
| up_read(mmap_sem); |
| return ret; |
| } |
| |
| static int __vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b, |
| struct vb2_buffer *vb) |
| { |
| if (vb->state != VB2_BUF_STATE_DEQUEUED) { |
| dprintk(1, "%s(): invalid buffer state %d\n", __func__, |
| vb->state); |
| return -EINVAL; |
| } |
| |
| return __buf_prepare(vb, b); |
| } |
| |
| /** |
| * vb2_prepare_buf() - Pass ownership of a buffer from userspace to the kernel |
| * @q: videobuf2 queue |
| * @b: buffer structure passed from userspace to vidioc_prepare_buf |
| * handler in driver |
| * |
| * Should be called from vidioc_prepare_buf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) calls buf_prepare callback in the driver (if provided), in which |
| * driver-specific buffer initialization can be performed, |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_prepare_buf handler in driver. |
| */ |
| int vb2_prepare_buf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| return vb2_queue_or_prepare_buf(q, b, "prepare_buf", __vb2_prepare_buf); |
| } |
| EXPORT_SYMBOL_GPL(vb2_prepare_buf); |
| |
| static int __vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b, |
| struct vb2_buffer *vb) |
| { |
| int ret; |
| |
| switch (vb->state) { |
| case VB2_BUF_STATE_DEQUEUED: |
| ret = __buf_prepare(vb, b); |
| if (ret) |
| return ret; |
| case VB2_BUF_STATE_PREPARED: |
| break; |
| default: |
| dprintk(1, "qbuf: buffer already in use\n"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Add to the queued buffers list, a buffer will stay on it until |
| * dequeued in dqbuf. |
| */ |
| list_add_tail(&vb->queued_entry, &q->queued_list); |
| vb->state = VB2_BUF_STATE_QUEUED; |
| |
| /* |
| * If already streaming, give the buffer to driver for processing. |
| * If not, the buffer will be given to driver on next streamon. |
| */ |
| if (q->streaming) |
| __enqueue_in_driver(vb); |
| |
| return 0; |
| } |
| |
| /** |
| * vb2_qbuf() - Queue a buffer from userspace |
| * @q: videobuf2 queue |
| * @b: buffer structure passed from userspace to vidioc_qbuf handler |
| * in driver |
| * |
| * Should be called from vidioc_qbuf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) if necessary, calls buf_prepare callback in the driver (if provided), in |
| * which driver-specific buffer initialization can be performed, |
| * 3) if streaming is on, queues the buffer in driver by the means of buf_queue |
| * callback for processing. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_qbuf handler in driver. |
| */ |
| int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b) |
| { |
| return vb2_queue_or_prepare_buf(q, b, "qbuf", __vb2_qbuf); |
| } |
| EXPORT_SYMBOL_GPL(vb2_qbuf); |
| |
| /** |
| * __vb2_wait_for_done_vb() - wait for a buffer to become available |
| * for dequeuing |
| * |
| * Will sleep if required for nonblocking == false. |
| */ |
| static int __vb2_wait_for_done_vb(struct vb2_queue *q, int nonblocking) |
| { |
| /* |
| * All operations on vb_done_list are performed under done_lock |
| * spinlock protection. However, buffers may be removed from |
| * it and returned to userspace only while holding both driver's |
| * lock and the done_lock spinlock. Thus we can be sure that as |
| * long as we hold the driver's lock, the list will remain not |
| * empty if list_empty() check succeeds. |
| */ |
| |
| for (;;) { |
| int ret; |
| |
| if (!q->streaming) { |
| dprintk(1, "Streaming off, will not wait for buffers\n"); |
| return -EINVAL; |
| } |
| |
| if (!list_empty(&q->done_list)) { |
| /* |
| * Found a buffer that we were waiting for. |
| */ |
| break; |
| } |
| |
| if (nonblocking) { |
| dprintk(1, "Nonblocking and no buffers to dequeue, " |
| "will not wait\n"); |
| return -EAGAIN; |
| } |
| |
| /* |
| * We are streaming and blocking, wait for another buffer to |
| * become ready or for streamoff. Driver's lock is released to |
| * allow streamoff or qbuf to be called while waiting. |
| */ |
| call_qop(q, wait_prepare, q); |
| |
| /* |
| * All locks have been released, it is safe to sleep now. |
| */ |
| dprintk(3, "Will sleep waiting for buffers\n"); |
| ret = wait_event_interruptible(q->done_wq, |
| !list_empty(&q->done_list) || !q->streaming); |
| |
| /* |
| * We need to reevaluate both conditions again after reacquiring |
| * the locks or return an error if one occurred. |
| */ |
| call_qop(q, wait_finish, q); |
| if (ret) { |
| dprintk(1, "Sleep was interrupted\n"); |
| return ret; |
| } |
| } |
| return 0; |
| } |
| |
| /** |
| * __vb2_get_done_vb() - get a buffer ready for dequeuing |
| * |
| * Will sleep if required for nonblocking == false. |
| */ |
| static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, |
| struct v4l2_buffer *b, int nonblocking) |
| { |
| unsigned long flags; |
| int ret; |
| |
| /* |
| * Wait for at least one buffer to become available on the done_list. |
| */ |
| ret = __vb2_wait_for_done_vb(q, nonblocking); |
| if (ret) |
| return ret; |
| |
| /* |
| * Driver's lock has been held since we last verified that done_list |
| * is not empty, so no need for another list_empty(done_list) check. |
| */ |
| spin_lock_irqsave(&q->done_lock, flags); |
| *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); |
| /* |
| * Only remove the buffer from done_list if v4l2_buffer can handle all |
| * the planes. |
| */ |
| ret = __verify_planes_array(*vb, b); |
| if (!ret) |
| list_del(&(*vb)->done_entry); |
| spin_unlock_irqrestore(&q->done_lock, flags); |
| |
| return ret; |
| } |
| |
| /** |
| * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2 |
| * @q: videobuf2 queue |
| * |
| * This function will wait until all buffers that have been given to the driver |
| * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call |
| * wait_prepare, wait_finish pair. It is intended to be called with all locks |
| * taken, for example from stop_streaming() callback. |
| */ |
| int vb2_wait_for_all_buffers(struct vb2_queue *q) |
| { |
| if (!q->streaming) { |
| dprintk(1, "Streaming off, will not wait for buffers\n"); |
| return -EINVAL; |
| } |
| |
| wait_event(q->done_wq, !atomic_read(&q->queued_count)); |
| return 0; |
| } |
| 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 |
| * in driver |
| * @nonblocking: if true, this call will not sleep waiting for a buffer if no |
| * buffers ready for dequeuing are present. Normally the driver |
| * would be passing (file->f_flags & O_NONBLOCK) here |
| * |
| * Should be called from vidioc_dqbuf ioctl handler of a driver. |
| * This function: |
| * 1) verifies the passed buffer, |
| * 2) calls buf_finish callback in the driver (if provided), in which |
| * driver can perform any additional operations that may be required before |
| * returning the buffer to userspace, such as cache sync, |
| * 3) the buffer struct members are filled with relevant information for |
| * the userspace. |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_dqbuf handler in driver. |
| */ |
| int vb2_dqbuf(struct vb2_queue *q, struct v4l2_buffer *b, bool nonblocking) |
| { |
| struct vb2_buffer *vb = NULL; |
| int ret; |
| |
| if (q->fileio) { |
| dprintk(1, "dqbuf: file io in progress\n"); |
| return -EBUSY; |
| } |
| |
| if (b->type != q->type) { |
| dprintk(1, "dqbuf: invalid buffer type\n"); |
| return -EINVAL; |
| } |
| ret = __vb2_get_done_vb(q, &vb, b, nonblocking); |
| if (ret < 0) |
| return ret; |
| |
| ret = call_qop(q, buf_finish, vb); |
| if (ret) { |
| dprintk(1, "dqbuf: buffer finish failed\n"); |
| return ret; |
| } |
| |
| switch (vb->state) { |
| case VB2_BUF_STATE_DONE: |
| dprintk(3, "dqbuf: Returning done buffer\n"); |
| break; |
| case VB2_BUF_STATE_ERROR: |
| dprintk(3, "dqbuf: Returning done buffer with errors\n"); |
| break; |
| default: |
| dprintk(1, "dqbuf: Invalid buffer state\n"); |
| return -EINVAL; |
| } |
| |
| /* Fill buffer information for the userspace */ |
| __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); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vb2_dqbuf); |
| |
| /** |
| * __vb2_queue_cancel() - cancel and stop (pause) streaming |
| * |
| * Removes all queued buffers from driver's queue and all buffers queued by |
| * userspace from videobuf's queue. Returns to state after reqbufs. |
| */ |
| static void __vb2_queue_cancel(struct vb2_queue *q) |
| { |
| unsigned int i; |
| |
| /* |
| * Tell driver to stop all transactions and release all queued |
| * buffers. |
| */ |
| if (q->streaming) |
| call_qop(q, stop_streaming, q); |
| q->streaming = 0; |
| |
| /* |
| * Remove all buffers from videobuf's list... |
| */ |
| INIT_LIST_HEAD(&q->queued_list); |
| /* |
| * ...and done list; userspace will not receive any buffers it |
| * has not already dequeued before initiating cancel. |
| */ |
| INIT_LIST_HEAD(&q->done_list); |
| atomic_set(&q->queued_count, 0); |
| wake_up_all(&q->done_wq); |
| |
| /* |
| * Reinitialize all buffers for next use. |
| */ |
| for (i = 0; i < q->num_buffers; ++i) |
| __vb2_dqbuf(q->bufs[i]); |
| } |
| |
| /** |
| * vb2_streamon - start streaming |
| * @q: videobuf2 queue |
| * @type: type argument passed from userspace to vidioc_streamon handler |
| * |
| * Should be called from vidioc_streamon handler of a driver. |
| * This function: |
| * 1) verifies current state |
| * 2) passes any previously queued buffers to the driver and starts streaming |
| * |
| * The return values from this function are intended to be directly returned |
| * from vidioc_streamon handler in the driver. |
| */ |
| int vb2_streamon(struct vb2_queue *q, enum v4l2_buf_type type) |
| { |
| struct vb2_buffer *vb; |
| int ret; |
| |
| if (q->fileio) { |
| dprintk(1, "streamon: file io in progress\n"); |
| return -EBUSY; |
| } |
| |
| if (type != q->type) { |
| dprintk(1, "streamon: invalid stream type\n"); |
| return -EINVAL; |
| } |
| |
| if (q->streaming) { |
| dprintk(1, "streamon: already streaming\n"); |
| return -EBUSY; |
| } |
| |
| /* |
| * If any buffers were queued before streamon, |
| * we can now pass them to driver for processing. |
| */ |
| list_for_each_entry(vb, &q->queued_list, queued_entry) |
| __enqueue_in_driver(vb); |
| |
| /* |
| * Let driver notice that streaming state has been enabled. |
| */ |
| ret = call_qop(q, start_streaming, q, atomic_read(&q->queued_count)); |
| if (ret) { |
| dprintk(1, "streamon: driver refused to start streaming\n"); |
| __vb2_queue_cancel(q); |
| return ret; |
| } |
| |
| q->streaming = 1; |
| |
| dprintk(3, "Streamon successful\n"); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vb2_streamon); |
| |
| |
| /** |
| * vb2_streamoff - stop streaming |
| * @q: videobuf2 queue |
| * @type: type argument passed from userspace to vidioc_streamoff handler |
| * |
| * Should be called from vidioc_streamoff handler of a driver. |
| * This function: |
| * 1) verifies current state, |
| * 2) stop streaming and dequeues any queued buffers, including those previously |
| * passed to the driver (after waiting for the driver to finish). |
| * |
| * This call can be used for pausing playback. |
| * The return values from this function are intended to be directly returned |
| * from vidioc_streamoff handler in the driver |
| */ |
| int vb2_streamoff(struct vb2_queue *q, enum v4l2_buf_type type) |
| { |
| if (q->fileio) { |
| dprintk(1, "streamoff: file io in progress\n"); |
| return -EBUSY; |
| } |
| |
| if (type != q->type) { |
| dprintk(1, "streamoff: invalid stream type\n"); |
| return -EINVAL; |
| } |
| |
| if (!q->streaming) { |
| dprintk(1, "streamoff: not streaming\n"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Cancel will pause streaming and remove all buffers from the driver |
| * and videobuf, effectively returning control over them to userspace. |
| */ |
| __vb2_queue_cancel(q); |
| |
| dprintk(3, "Streamoff successful\n"); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vb2_streamoff); |
| |
| /** |
| * __find_plane_by_offset() - find plane associated with the given offset off |
| */ |
| static int __find_plane_by_offset(struct vb2_queue *q, unsigned long off, |
| unsigned int *_buffer, unsigned int *_plane) |
| { |
| struct vb2_buffer *vb; |
| unsigned int buffer, plane; |
| |
| /* |
| * Go over all buffers and their planes, comparing the given offset |
| * with an offset assigned to each plane. If a match is found, |
| * return its buffer and plane numbers. |
| */ |
| for (buffer = 0; buffer < q->num_buffers; ++buffer) { |
| vb = q->bufs[buffer]; |
| |
| for (plane = 0; plane < vb->num_planes; ++plane) { |
| if (vb->v4l2_planes[plane].m.mem_offset == off) { |
| *_buffer = buffer; |
| *_plane = plane; |
| return 0; |
| } |
| } |
| } |
| |
| return -EINVAL; |
| } |
| |
| /** |
| * 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 |
| * |
| * Should be called from mmap file operation handler of a driver. |
| * This function maps one plane of one of the available video buffers to |
| * userspace. To map whole video memory allocated on reqbufs, this function |
| * has to be called once per each plane per each buffer previously allocated. |
| * |
| * When the userspace application calls mmap, it passes to it an offset returned |
| * to it earlier by the means of vidioc_querybuf handler. That offset acts as |
| * a "cookie", which is then used to identify the plane to be mapped. |
| * This function finds a plane with a matching offset and a mapping is performed |
| * by the means of a provided memory operation. |
| * |
| * The return values from this function are intended to be directly returned |
| * from the mmap handler in driver. |
| */ |
| int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) |
| { |
| unsigned long off = vma->vm_pgoff << PAGE_SHIFT; |
| struct vb2_buffer *vb; |
| unsigned int buffer, plane; |
| int ret; |
| unsigned long length; |
| |
| if (q->memory != V4L2_MEMORY_MMAP) { |
| dprintk(1, "Queue is not currently set up for mmap\n"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Check memory area access mode. |
| */ |
| if (!(vma->vm_flags & VM_SHARED)) { |
| dprintk(1, "Invalid vma flags, VM_SHARED needed\n"); |
| return -EINVAL; |
| } |
| if (V4L2_TYPE_IS_OUTPUT(q->type)) { |
| if (!(vma->vm_flags & VM_WRITE)) { |
| dprintk(1, "Invalid vma flags, VM_WRITE needed\n"); |
| return -EINVAL; |
| } |
| } else { |
| if (!(vma->vm_flags & VM_READ)) { |
| dprintk(1, "Invalid vma flags, VM_READ needed\n"); |
| return -EINVAL; |
| } |
| } |
| |
| /* |
| * Find the plane corresponding to the offset passed by userspace. |
| */ |
| ret = __find_plane_by_offset(q, off, &buffer, &plane); |
| if (ret) |
| return ret; |
| |
| vb = q->bufs[buffer]; |
| |
| /* |
| * MMAP requires page_aligned buffers. |
| * The buffer length was page_aligned at __vb2_buf_mem_alloc(), |
| * so, we need to do the same here. |
| */ |
| length = PAGE_ALIGN(vb->v4l2_planes[plane].length); |
| if (length < (vma->vm_end - vma->vm_start)) { |
| dprintk(1, |
| "MMAP invalid, as it would overflow buffer length\n"); |
| return -EINVAL; |
| } |
| |
| ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma); |
| if (ret) |
| return ret; |
| |
| dprintk(3, "Buffer %d, plane %d successfully mapped\n", buffer, plane); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vb2_mmap); |
| |
| #ifndef CONFIG_MMU |
| unsigned long vb2_get_unmapped_area(struct vb2_queue *q, |
| unsigned long addr, |
| unsigned long len, |
| unsigned long pgoff, |
| unsigned long flags) |
| { |
| unsigned long off = pgoff << PAGE_SHIFT; |
| struct vb2_buffer *vb; |
| unsigned int buffer, plane; |
| int ret; |
| |
| if (q->memory != V4L2_MEMORY_MMAP) { |
| dprintk(1, "Queue is not currently set up for mmap\n"); |
| return -EINVAL; |
| } |
| |
| /* |
| * Find the plane corresponding to the offset passed by userspace. |
| */ |
| ret = __find_plane_by_offset(q, off, &buffer, &plane); |
| if (ret) |
| return ret; |
| |
| vb = q->bufs[buffer]; |
| |
| return (unsigned long)vb2_plane_vaddr(vb, plane); |
| } |
| EXPORT_SYMBOL_GPL(vb2_get_unmapped_area); |
| #endif |
| |
| static int __vb2_init_fileio(struct vb2_queue *q, int read); |
| static int __vb2_cleanup_fileio(struct vb2_queue *q); |
| |
| /** |
| * vb2_poll() - implements poll userspace operation |
| * @q: videobuf2 queue |
| * @file: file argument passed to the poll file operation handler |
| * @wait: wait argument passed to the poll file operation handler |
| * |
| * This function implements poll file operation handler for a driver. |
| * For CAPTURE queues, if a buffer is ready to be dequeued, the userspace will |
| * be informed that the file descriptor of a video device is available for |
| * reading. |
| * For OUTPUT queues, if a buffer is ready to be dequeued, the file descriptor |
| * will be reported as available for writing. |
| * |
| * If the driver uses struct v4l2_fh, then vb2_poll() will also check for any |
| * pending events. |
| * |
| * The return values from this function are intended to be directly returned |
| * from poll handler in driver. |
| */ |
| unsigned int vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) |
| { |
| struct video_device *vfd = video_devdata(file); |
| unsigned long req_events = poll_requested_events(wait); |
| struct vb2_buffer *vb = NULL; |
| unsigned int res = 0; |
| unsigned long flags; |
| |
| if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) { |
| struct v4l2_fh *fh = file->private_data; |
| |
| if (v4l2_event_pending(fh)) |
| res = POLLPRI; |
| else if (req_events & POLLPRI) |
| poll_wait(file, &fh->wait, wait); |
| } |
| |
| if (!V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLIN | POLLRDNORM))) |
| return res; |
| if (V4L2_TYPE_IS_OUTPUT(q->type) && !(req_events & (POLLOUT | POLLWRNORM))) |
| return res; |
| |
| /* |
| * Start file I/O emulator only if streaming API has not been used yet. |
| */ |
| if (q->num_buffers == 0 && q->fileio == NULL) { |
| if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) && |
| (req_events & (POLLIN | POLLRDNORM))) { |
| if (__vb2_init_fileio(q, 1)) |
| return res | POLLERR; |
| } |
| if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) && |
| (req_events & (POLLOUT | POLLWRNORM))) { |
| if (__vb2_init_fileio(q, 0)) |
| return res | POLLERR; |
| /* |
| * Write to OUTPUT queue can be done immediately. |
| */ |
| return res | POLLOUT | POLLWRNORM; |
| } |
| } |
| |
| /* |
| * There is nothing to wait for if no buffers have already been queued. |
| */ |
| if (list_empty(&q->queued_list)) |
| return res | POLLERR; |
| |
| if (list_empty(&q->done_list)) |
| poll_wait(file, &q->done_wq, wait); |
| |
| /* |
| * Take first buffer available for dequeuing. |
| */ |
| spin_lock_irqsave(&q->done_lock, flags); |
| if (!list_empty(&q->done_list)) |
| vb = list_first_entry(&q->done_list, struct vb2_buffer, |
| done_entry); |
| spin_unlock_irqrestore(&q->done_lock, flags); |
| |
| if (vb && (vb->state == VB2_BUF_STATE_DONE |
| || vb->state == VB2_BUF_STATE_ERROR)) { |
| return (V4L2_TYPE_IS_OUTPUT(q->type)) ? |
| res | POLLOUT | POLLWRNORM : |
| res | POLLIN | POLLRDNORM; |
| } |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_poll); |
| |
| /** |
| * vb2_queue_init() - initialize a videobuf2 queue |
| * @q: videobuf2 queue; this structure should be allocated in driver |
| * |
| * The vb2_queue structure should be allocated by the driver. The driver is |
| * responsible of clearing it's content and setting initial values for some |
| * required entries before calling this function. |
| * q->ops, q->mem_ops, q->type and q->io_modes are mandatory. Please refer |
| * to the struct vb2_queue description in include/media/videobuf2-core.h |
| * for more information. |
| */ |
| int vb2_queue_init(struct vb2_queue *q) |
| { |
| /* |
| * Sanity check |
| */ |
| if (WARN_ON(!q) || |
| WARN_ON(!q->ops) || |
| WARN_ON(!q->mem_ops) || |
| WARN_ON(!q->type) || |
| WARN_ON(!q->io_modes) || |
| WARN_ON(!q->ops->queue_setup) || |
| WARN_ON(!q->ops->buf_queue) || |
| WARN_ON(q->timestamp_type & ~V4L2_BUF_FLAG_TIMESTAMP_MASK)) |
| return -EINVAL; |
| |
| /* Warn that the driver should choose an appropriate timestamp type */ |
| WARN_ON(q->timestamp_type == V4L2_BUF_FLAG_TIMESTAMP_UNKNOWN); |
| |
| INIT_LIST_HEAD(&q->queued_list); |
| INIT_LIST_HEAD(&q->done_list); |
| spin_lock_init(&q->done_lock); |
| init_waitqueue_head(&q->done_wq); |
| |
| if (q->buf_struct_size == 0) |
| q->buf_struct_size = sizeof(struct vb2_buffer); |
| |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(vb2_queue_init); |
| |
| /** |
| * vb2_queue_release() - stop streaming, release the queue and free memory |
| * @q: videobuf2 queue |
| * |
| * This function stops streaming and performs necessary clean ups, including |
| * freeing video buffer memory. The driver is responsible for freeing |
| * the vb2_queue structure itself. |
| */ |
| void vb2_queue_release(struct vb2_queue *q) |
| { |
| __vb2_cleanup_fileio(q); |
| __vb2_queue_cancel(q); |
| __vb2_queue_free(q, q->num_buffers); |
| } |
| EXPORT_SYMBOL_GPL(vb2_queue_release); |
| |
| /** |
| * struct vb2_fileio_buf - buffer context used by file io emulator |
| * |
| * vb2 provides a compatibility layer and emulator of file io (read and |
| * write) calls on top of streaming API. This structure is used for |
| * tracking context related to the buffers. |
| */ |
| struct vb2_fileio_buf { |
| void *vaddr; |
| unsigned int size; |
| unsigned int pos; |
| unsigned int queued:1; |
| }; |
| |
| /** |
| * struct vb2_fileio_data - queue context used by file io emulator |
| * |
| * vb2 provides a compatibility layer and emulator of file io (read and |
| * write) calls on top of streaming API. For proper operation it required |
| * this structure to save the driver state between each call of the read |
| * or write function. |
| */ |
| struct vb2_fileio_data { |
| struct v4l2_requestbuffers req; |
| struct v4l2_buffer b; |
| struct vb2_fileio_buf bufs[VIDEO_MAX_FRAME]; |
| unsigned int index; |
| unsigned int q_count; |
| unsigned int dq_count; |
| unsigned int flags; |
| }; |
| |
| /** |
| * __vb2_init_fileio() - initialize file io emulator |
| * @q: videobuf2 queue |
| * @read: mode selector (1 means read, 0 means write) |
| */ |
| static int __vb2_init_fileio(struct vb2_queue *q, int read) |
| { |
| struct vb2_fileio_data *fileio; |
| int i, ret; |
| unsigned int count = 0; |
| |
| /* |
| * Sanity check |
| */ |
| if ((read && !(q->io_modes & VB2_READ)) || |
| (!read && !(q->io_modes & VB2_WRITE))) |
| BUG(); |
| |
| /* |
| * Check if device supports mapping buffers to kernel virtual space. |
| */ |
| if (!q->mem_ops->vaddr) |
| return -EBUSY; |
| |
| /* |
| * Check if streaming api has not been already activated. |
| */ |
| if (q->streaming || q->num_buffers > 0) |
| return -EBUSY; |
| |
| /* |
| * Start with count 1, driver can increase it in queue_setup() |
| */ |
| count = 1; |
| |
| dprintk(3, "setting up file io: mode %s, count %d, flags %08x\n", |
| (read) ? "read" : "write", count, q->io_flags); |
| |
| fileio = kzalloc(sizeof(struct vb2_fileio_data), GFP_KERNEL); |
| if (fileio == NULL) |
| return -ENOMEM; |
| |
| fileio->flags = q->io_flags; |
| |
| /* |
| * Request buffers and use MMAP type to force driver |
| * to allocate buffers by itself. |
| */ |
| fileio->req.count = count; |
| fileio->req.memory = V4L2_MEMORY_MMAP; |
| fileio->req.type = q->type; |
| ret = vb2_reqbufs(q, &fileio->req); |
| if (ret) |
| goto err_kfree; |
| |
| /* |
| * Check if plane_count is correct |
| * (multiplane buffers are not supported). |
| */ |
| if (q->bufs[0]->num_planes != 1) { |
| ret = -EBUSY; |
| goto err_reqbufs; |
| } |
| |
| /* |
| * Get kernel address of each buffer. |
| */ |
| for (i = 0; i < q->num_buffers; i++) { |
| fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0); |
| if (fileio->bufs[i].vaddr == NULL) { |
| ret = -EINVAL; |
| goto err_reqbufs; |
| } |
| fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0); |
| } |
| |
| /* |
| * Read mode requires pre queuing of all buffers. |
| */ |
| if (read) { |
| /* |
| * Queue all buffers. |
| */ |
| for (i = 0; i < q->num_buffers; i++) { |
| struct v4l2_buffer *b = &fileio->b; |
| memset(b, 0, sizeof(*b)); |
| b->type = q->type; |
| b->memory = q->memory; |
| b->index = i; |
| ret = vb2_qbuf(q, b); |
| if (ret) |
| goto err_reqbufs; |
| fileio->bufs[i].queued = 1; |
| } |
| |
| /* |
| * Start streaming. |
| */ |
| ret = vb2_streamon(q, q->type); |
| if (ret) |
| goto err_reqbufs; |
| } |
| |
| q->fileio = fileio; |
| |
| return ret; |
| |
| err_reqbufs: |
| fileio->req.count = 0; |
| vb2_reqbufs(q, &fileio->req); |
| |
| err_kfree: |
| kfree(fileio); |
| return ret; |
| } |
| |
| /** |
| * __vb2_cleanup_fileio() - free resourced used by file io emulator |
| * @q: videobuf2 queue |
| */ |
| static int __vb2_cleanup_fileio(struct vb2_queue *q) |
| { |
| struct vb2_fileio_data *fileio = q->fileio; |
| |
| if (fileio) { |
| /* |
| * Hack fileio context to enable direct calls to vb2 ioctl |
| * interface. |
| */ |
| q->fileio = NULL; |
| |
| vb2_streamoff(q, q->type); |
| fileio->req.count = 0; |
| vb2_reqbufs(q, &fileio->req); |
| kfree(fileio); |
| dprintk(3, "file io emulator closed\n"); |
| } |
| return 0; |
| } |
| |
| /** |
| * __vb2_perform_fileio() - perform a single file io (read or write) operation |
| * @q: videobuf2 queue |
| * @data: pointed to target userspace buffer |
| * @count: number of bytes to read or write |
| * @ppos: file handle position tracking pointer |
| * @nonblock: mode selector (1 means blocking calls, 0 means nonblocking) |
| * @read: access mode selector (1 means read, 0 means write) |
| */ |
| static size_t __vb2_perform_fileio(struct vb2_queue *q, char __user *data, size_t count, |
| loff_t *ppos, int nonblock, int read) |
| { |
| struct vb2_fileio_data *fileio; |
| struct vb2_fileio_buf *buf; |
| int ret, index; |
| |
| dprintk(3, "file io: mode %s, offset %ld, count %zd, %sblocking\n", |
| read ? "read" : "write", (long)*ppos, count, |
| nonblock ? "non" : ""); |
| |
| if (!data) |
| return -EINVAL; |
| |
| /* |
| * Initialize emulator on first call. |
| */ |
| if (!q->fileio) { |
| ret = __vb2_init_fileio(q, read); |
| dprintk(3, "file io: vb2_init_fileio result: %d\n", ret); |
| if (ret) |
| return ret; |
| } |
| fileio = q->fileio; |
| |
| /* |
| * Hack fileio context to enable direct calls to vb2 ioctl interface. |
| * The pointer will be restored before returning from this function. |
| */ |
| q->fileio = NULL; |
| |
| index = fileio->index; |
| buf = &fileio->bufs[index]; |
| |
| /* |
| * Check if we need to dequeue the buffer. |
| */ |
| if (buf->queued) { |
| struct vb2_buffer *vb; |
| |
| /* |
| * Call vb2_dqbuf to get buffer back. |
| */ |
| memset(&fileio->b, 0, sizeof(fileio->b)); |
| fileio->b.type = q->type; |
| fileio->b.memory = q->memory; |
| fileio->b.index = index; |
| ret = vb2_dqbuf(q, &fileio->b, nonblock); |
| dprintk(5, "file io: vb2_dqbuf result: %d\n", ret); |
| if (ret) |
| goto end; |
| fileio->dq_count += 1; |
| |
| /* |
| * Get number of bytes filled by the driver |
| */ |
| vb = q->bufs[index]; |
| buf->size = vb2_get_plane_payload(vb, 0); |
| buf->queued = 0; |
| } |
| |
| /* |
| * Limit count on last few bytes of the buffer. |
| */ |
| if (buf->pos + count > buf->size) { |
| count = buf->size - buf->pos; |
| dprintk(5, "reducing read count: %zd\n", count); |
| } |
| |
| /* |
| * Transfer data to userspace. |
| */ |
| dprintk(3, "file io: copying %zd bytes - buffer %d, offset %u\n", |
| count, index, buf->pos); |
| if (read) |
| ret = copy_to_user(data, buf->vaddr + buf->pos, count); |
| else |
| ret = copy_from_user(buf->vaddr + buf->pos, data, count); |
| if (ret) { |
| dprintk(3, "file io: error copying data\n"); |
| ret = -EFAULT; |
| goto end; |
| } |
| |
| /* |
| * Update counters. |
| */ |
| buf->pos += count; |
| *ppos += count; |
| |
| /* |
| * Queue next buffer if required. |
| */ |
| if (buf->pos == buf->size || |
| (!read && (fileio->flags & VB2_FILEIO_WRITE_IMMEDIATELY))) { |
| /* |
| * Check if this is the last buffer to read. |
| */ |
| if (read && (fileio->flags & VB2_FILEIO_READ_ONCE) && |
| fileio->dq_count == 1) { |
| dprintk(3, "file io: read limit reached\n"); |
| /* |
| * Restore fileio pointer and release the context. |
| */ |
| q->fileio = fileio; |
| return __vb2_cleanup_fileio(q); |
| } |
| |
| /* |
| * Call vb2_qbuf and give buffer to the driver. |
| */ |
| memset(&fileio->b, 0, sizeof(fileio->b)); |
| fileio->b.type = q->type; |
| fileio->b.memory = q->memory; |
| fileio->b.index = index; |
| fileio->b.bytesused = buf->pos; |
| ret = vb2_qbuf(q, &fileio->b); |
| dprintk(5, "file io: vb2_dbuf result: %d\n", ret); |
| if (ret) |
| goto end; |
| |
| /* |
| * Buffer has been queued, update the status |
| */ |
| buf->pos = 0; |
| buf->queued = 1; |
| buf->size = q->bufs[0]->v4l2_planes[0].length; |
| fileio->q_count += 1; |
| |
| /* |
| * Switch to the next buffer |
| */ |
| fileio->index = (index + 1) % q->num_buffers; |
| |
| /* |
| * Start streaming if required. |
| */ |
| if (!read && !q->streaming) { |
| ret = vb2_streamon(q, q->type); |
| if (ret) |
| goto end; |
| } |
| } |
| |
| /* |
| * Return proper number of bytes processed. |
| */ |
| if (ret == 0) |
| ret = count; |
| end: |
| /* |
| * Restore the fileio context and block vb2 ioctl interface. |
| */ |
| q->fileio = fileio; |
| return ret; |
| } |
| |
| size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, |
| loff_t *ppos, int nonblocking) |
| { |
| return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1); |
| } |
| EXPORT_SYMBOL_GPL(vb2_read); |
| |
| size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, |
| loff_t *ppos, int nonblocking) |
| { |
| return __vb2_perform_fileio(q, (char __user *) data, count, |
| ppos, nonblocking, 0); |
| } |
| EXPORT_SYMBOL_GPL(vb2_write); |
| |
| |
| /* |
| * The following functions are not part of the vb2 core API, but are helper |
| * functions that plug into struct v4l2_ioctl_ops, struct v4l2_file_operations |
| * and struct vb2_ops. |
| * They contain boilerplate code that most if not all drivers have to do |
| * and so they simplify the driver code. |
| */ |
| |
| /* The queue is busy if there is a owner and you are not that owner. */ |
| static inline bool vb2_queue_is_busy(struct video_device *vdev, struct file *file) |
| { |
| return vdev->queue->owner && vdev->queue->owner != file->private_data; |
| } |
| |
| /* vb2 ioctl helpers */ |
| |
| int vb2_ioctl_reqbufs(struct file *file, void *priv, |
| struct v4l2_requestbuffers *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| int res = __verify_memory_type(vdev->queue, p->memory, p->type); |
| |
| if (res) |
| return res; |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| res = __reqbufs(vdev->queue, p); |
| /* If count == 0, then the owner has released all buffers and he |
| is no longer owner of the queue. Otherwise we have a new owner. */ |
| if (res == 0) |
| vdev->queue->owner = p->count ? file->private_data : NULL; |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_reqbufs); |
| |
| int vb2_ioctl_create_bufs(struct file *file, void *priv, |
| struct v4l2_create_buffers *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| int res = __verify_memory_type(vdev->queue, p->memory, p->format.type); |
| |
| p->index = vdev->queue->num_buffers; |
| /* If count == 0, then just check if memory and type are valid. |
| Any -EBUSY result from __verify_memory_type can be mapped to 0. */ |
| if (p->count == 0) |
| return res != -EBUSY ? res : 0; |
| if (res) |
| return res; |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| res = __create_bufs(vdev->queue, p); |
| if (res == 0) |
| vdev->queue->owner = file->private_data; |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_create_bufs); |
| |
| int vb2_ioctl_prepare_buf(struct file *file, void *priv, |
| struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_prepare_buf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_prepare_buf); |
| |
| int vb2_ioctl_querybuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| /* No need to call vb2_queue_is_busy(), anyone can query buffers. */ |
| return vb2_querybuf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_querybuf); |
| |
| int vb2_ioctl_qbuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_qbuf(vdev->queue, p); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_qbuf); |
| |
| int vb2_ioctl_dqbuf(struct file *file, void *priv, struct v4l2_buffer *p) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_dqbuf(vdev->queue, p, file->f_flags & O_NONBLOCK); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_dqbuf); |
| |
| int vb2_ioctl_streamon(struct file *file, void *priv, enum v4l2_buf_type i) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_streamon(vdev->queue, i); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ioctl_streamon); |
| |
| int vb2_ioctl_streamoff(struct file *file, void *priv, enum v4l2_buf_type i) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| return vb2_streamoff(vdev->queue, 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); |
| |
| if (vb2_queue_is_busy(vdev, file)) |
| return -EBUSY; |
| 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) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int err; |
| |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| err = vb2_mmap(vdev->queue, vma); |
| if (lock) |
| mutex_unlock(lock); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_mmap); |
| |
| int vb2_fop_release(struct file *file) |
| { |
| struct video_device *vdev = video_devdata(file); |
| |
| if (file->private_data == vdev->queue->owner) { |
| vb2_queue_release(vdev->queue); |
| vdev->queue->owner = NULL; |
| } |
| return v4l2_fh_release(file); |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_release); |
| |
| ssize_t vb2_fop_write(struct file *file, const char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int err = -EBUSY; |
| |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| if (vb2_queue_is_busy(vdev, file)) |
| goto exit; |
| err = vb2_write(vdev->queue, buf, count, ppos, |
| file->f_flags & O_NONBLOCK); |
| if (vdev->queue->fileio) |
| vdev->queue->owner = file->private_data; |
| exit: |
| if (lock) |
| mutex_unlock(lock); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_write); |
| |
| ssize_t vb2_fop_read(struct file *file, char __user *buf, |
| size_t count, loff_t *ppos) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int err = -EBUSY; |
| |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| if (vb2_queue_is_busy(vdev, file)) |
| goto exit; |
| err = vb2_read(vdev->queue, buf, count, ppos, |
| file->f_flags & O_NONBLOCK); |
| if (vdev->queue->fileio) |
| vdev->queue->owner = file->private_data; |
| exit: |
| if (lock) |
| mutex_unlock(lock); |
| return err; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_read); |
| |
| unsigned int vb2_fop_poll(struct file *file, poll_table *wait) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct vb2_queue *q = vdev->queue; |
| struct mutex *lock = q->lock ? q->lock : vdev->lock; |
| unsigned long req_events = poll_requested_events(wait); |
| unsigned res; |
| void *fileio; |
| bool must_lock = false; |
| |
| /* Try to be smart: only lock if polling might start fileio, |
| otherwise locking will only introduce unwanted delays. */ |
| if (q->num_buffers == 0 && q->fileio == NULL) { |
| if (!V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_READ) && |
| (req_events & (POLLIN | POLLRDNORM))) |
| must_lock = true; |
| else if (V4L2_TYPE_IS_OUTPUT(q->type) && (q->io_modes & VB2_WRITE) && |
| (req_events & (POLLOUT | POLLWRNORM))) |
| must_lock = true; |
| } |
| |
| /* If locking is needed, but this helper doesn't know how, then you |
| shouldn't be using this helper but you should write your own. */ |
| WARN_ON(must_lock && !lock); |
| |
| if (must_lock && lock && mutex_lock_interruptible(lock)) |
| return POLLERR; |
| |
| fileio = q->fileio; |
| |
| res = vb2_poll(vdev->queue, file, wait); |
| |
| /* If fileio was started, then we have a new queue owner. */ |
| if (must_lock && !fileio && q->fileio) |
| q->owner = file->private_data; |
| if (must_lock && lock) |
| mutex_unlock(lock); |
| return res; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_poll); |
| |
| #ifndef CONFIG_MMU |
| unsigned long vb2_fop_get_unmapped_area(struct file *file, unsigned long addr, |
| unsigned long len, unsigned long pgoff, unsigned long flags) |
| { |
| struct video_device *vdev = video_devdata(file); |
| struct mutex *lock = vdev->queue->lock ? vdev->queue->lock : vdev->lock; |
| int ret; |
| |
| if (lock && mutex_lock_interruptible(lock)) |
| return -ERESTARTSYS; |
| ret = vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); |
| if (lock) |
| mutex_unlock(lock); |
| return ret; |
| } |
| EXPORT_SYMBOL_GPL(vb2_fop_get_unmapped_area); |
| #endif |
| |
| /* vb2_ops helpers. Only use if vq->lock is non-NULL. */ |
| |
| void vb2_ops_wait_prepare(struct vb2_queue *vq) |
| { |
| mutex_unlock(vq->lock); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ops_wait_prepare); |
| |
| void vb2_ops_wait_finish(struct vb2_queue *vq) |
| { |
| mutex_lock(vq->lock); |
| } |
| EXPORT_SYMBOL_GPL(vb2_ops_wait_finish); |
| |
| MODULE_DESCRIPTION("Driver helper framework for Video for Linux 2"); |
| MODULE_AUTHOR("Pawel Osciak <pawel@osciak.com>, Marek Szyprowski"); |
| MODULE_LICENSE("GPL"); |