diff options
Diffstat (limited to 'drivers/media/v4l2-core/videobuf2-core.c')
| -rw-r--r-- | drivers/media/v4l2-core/videobuf2-core.c | 2383 |
1 files changed, 2383 insertions, 0 deletions
diff --git a/drivers/media/v4l2-core/videobuf2-core.c b/drivers/media/v4l2-core/videobuf2-core.c new file mode 100644 index 000000000000..e6a26b433e87 --- /dev/null +++ b/drivers/media/v4l2-core/videobuf2-core.c @@ -0,0 +1,2383 @@ +/* + * 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_STATE_FLAGS (V4L2_BUF_FLAG_MAPPED | V4L2_BUF_FLAG_QUEUED | \ + V4L2_BUF_FLAG_DONE | V4L2_BUF_FLAG_ERROR | \ + V4L2_BUF_FLAG_PREPARED) + +/** + * __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 */ + for (plane = 0; plane < vb->num_planes; ++plane) { + mem_priv = call_memop(q, alloc, q->alloc_ctx[plane], + q->plane_sizes[plane]); + 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; + } +} + +/** + * __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; + } + + __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 + __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) +{ + /* 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; +} + +/** + * __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 int __fill_v4l2_buffer(struct vb2_buffer *vb, struct v4l2_buffer *b) +{ + struct vb2_queue *q = vb->vb2_queue; + int ret; + + /* 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)) { + ret = __verify_planes_array(vb, b); + if (ret) + return ret; + + /* + * Fill in plane-related data if userspace provided an array + * for it. The memory and size is verified above. + */ + 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; + } + + /* + * Clear any buffer state related flags. + */ + b->flags &= ~V4L2_BUFFER_STATE_FLAGS; + + 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; + + return 0; +} + +/** + * 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; + + 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]; + + return __fill_v4l2_buffer(vb, b); +} +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_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) { + 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; + } + + /* + * 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; + + 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, vb->state); + + /* 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 + */ +static int __fill_vb2_buffer(struct vb2_buffer *vb, const struct v4l2_buffer *b, + struct v4l2_plane *v4l2_planes) +{ + unsigned int plane; + int ret; + + if (V4L2_TYPE_IS_MULTIPLANAR(b->type)) { + /* + * Verify that the userspace gave us a valid array for + * plane information. + */ + ret = __verify_planes_array(vb, b); + if (ret) + return ret; + + /* 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; + } + } + } 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; + + if (b->memory == V4L2_MEMORY_USERPTR) { + v4l2_planes[0].m.userptr = b->m.userptr; + v4l2_planes[0].length = b->length; + } + } + + vb->v4l2_buf.field = b->field; + vb->v4l2_buf.timestamp = b->timestamp; + vb->v4l2_buf.flags = b->flags & ~V4L2_BUFFER_STATE_FLAGS; + + return 0; +} + +/** + * __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); + + /* Verify and copy relevant information provided by the userspace */ + ret = __fill_vb2_buffer(vb, b, planes); + if (ret) + return ret; + + for (plane = 0; plane < vb->num_planes; ++plane) { + /* 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]) { + 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) +{ + return __fill_vb2_buffer(vb, b, vb->v4l2_planes); +} + +/** + * __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; + + vb->state = VB2_BUF_STATE_ACTIVE; + atomic_inc(&q->queued_count); + 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; + + switch (q->memory) { + case V4L2_MEMORY_MMAP: + ret = __qbuf_mmap(vb, b); + break; + case V4L2_MEMORY_USERPTR: + ret = __qbuf_userptr(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; +} + +/** + * 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) +{ + struct vb2_buffer *vb; + int ret; + + if (q->fileio) { + dprintk(1, "%s(): file io in progress\n", __func__); + return -EBUSY; + } + + if (b->type != q->type) { + dprintk(1, "%s(): invalid buffer type\n", __func__); + return -EINVAL; + } + + if (b->index >= q->num_buffers) { + dprintk(1, "%s(): buffer index out of range\n", __func__); + return -EINVAL; + } + + vb = q->bufs[b->index]; + if (NULL == vb) { + /* Should never happen */ + dprintk(1, "%s(): buffer is NULL\n", __func__); + return -EINVAL; + } + + if (b->memory != q->memory) { + dprintk(1, "%s(): invalid memory type\n", __func__); + return -EINVAL; + } + + if (vb->state != VB2_BUF_STATE_DEQUEUED) { + dprintk(1, "%s(): invalid buffer state %d\n", __func__, vb->state); + return -EINVAL; + } + + ret = __buf_prepare(vb, b); + if (ret < 0) + return ret; + + __fill_v4l2_buffer(vb, b); + + return 0; +} +EXPORT_SYMBOL_GPL(vb2_prepare_buf); + +/** + * 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) +{ + struct rw_semaphore *mmap_sem = NULL; + struct vb2_buffer *vb; + int ret = 0; + + /* + * In case of user pointer buffers vb2 allocator needs to get direct + * access to userspace pages. This requires getting read access on + * mmap semaphore in the current process structure. The same + * semaphore is taken before calling mmap operation, while both mmap + * and qbuf are called by the driver or v4l2 core with driver's lock + * held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in + * mmap and driver's lock then mmap_sem in qbuf) the videobuf2 core + * release driver's lock, takes mmap_sem and then takes again driver's + * lock. + * + * To avoid race with other vb2 calls, which might be called after + * releasing driver's lock, this operation is performed at the + * beggining of qbuf processing. This way the queue status is + * consistent after getting 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, "qbuf: file io in progress\n"); + ret = -EBUSY; + goto unlock; + } + + if (b->type != q->type) { + dprintk(1, "qbuf: invalid buffer type\n"); + ret = -EINVAL; + goto unlock; + } + + if (b->index >= q->num_buffers) { + dprintk(1, "qbuf: buffer index out of range\n"); + ret = -EINVAL; + goto unlock; + } + + vb = q->bufs[b->index]; + if (NULL == vb) { + /* Should never happen */ + dprintk(1, "qbuf: buffer is NULL\n"); + ret = -EINVAL; + goto unlock; + } + + if (b->memory != q->memory) { + dprintk(1, "qbuf: invalid memory type\n"); + ret = -EINVAL; + goto unlock; + } + + switch (vb->state) { + case VB2_BUF_STATE_DEQUEUED: + ret = __buf_prepare(vb, b); + if (ret) + goto unlock; + case VB2_BUF_STATE_PREPARED: + break; + default: + dprintk(1, "qbuf: buffer already in use\n"); + ret = -EINVAL; + goto unlock; + } + + /* + * 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); + + /* Fill buffer information for the userspace */ + __fill_v4l2_buffer(vb, b); + + dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index); +unlock: + if (mmap_sem) + up_read(mmap_sem); + return ret; +} +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) + 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, + 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); + list_del(&(*vb)->done_entry); + spin_unlock_irqrestore(&q->done_lock, flags); + + return 0; +} + +/** + * 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() - 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, nonblocking); + if (ret < 0) { + dprintk(1, "dqbuf: error getting next done buffer\n"); + 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); + + 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); + +/** + * __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) + q->bufs[i]->state = VB2_BUF_STATE_DEQUEUED; +} + +/** + * 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_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; + + 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]; + + 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); + } + + /* + * 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; + + 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)) + return -EINVAL; + + 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) + 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, char __user *data, size_t count, + loff_t *ppos, int nonblocking) +{ + return __vb2_perform_fileio(q, 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); + +/* v4l2_file_operations helpers */ + +int vb2_fop_mmap(struct file *file, struct vm_area_struct *vma) +{ + struct video_device *vdev = video_devdata(file); + + return vb2_mmap(vdev->queue, vma); +} +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, 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); + + return vb2_get_unmapped_area(vdev->queue, addr, len, pgoff, flags); +} +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"); |