diff options
Diffstat (limited to 'drivers/media/video/videobuf2-core.c')
| -rw-r--r-- | drivers/media/video/videobuf2-core.c | 2387 |
1 files changed, 0 insertions, 2387 deletions
diff --git a/drivers/media/video/videobuf2-core.c b/drivers/media/video/videobuf2-core.c deleted file mode 100644 index 268c7dd..0000000 --- a/drivers/media/video/videobuf2-core.c +++ /dev/null @@ -1,2387 +0,0 @@ -/* - * 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) -{ - BUG_ON(!q); - BUG_ON(!q->ops); - BUG_ON(!q->mem_ops); - BUG_ON(!q->type); - BUG_ON(!q->io_modes); - - BUG_ON(!q->ops->queue_setup); - BUG_ON(!q->ops->buf_queue); - - 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; - bool must_lock = !test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) && lock; - int err = -EBUSY; - - if (must_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 (err >= 0) - vdev->queue->owner = file->private_data; -exit: - if (must_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; - bool must_lock = !test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags) && vdev->lock; - int err = -EBUSY; - - if (must_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 (err >= 0) - vdev->queue->owner = file->private_data; -exit: - if (must_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; - /* Yuck. We really need to get rid of this flag asap. If it is - set, then the core took the serialization lock before calling - poll(). This is being phased out, but for now we have to handle - this case. */ - bool locked = test_bit(V4L2_FL_LOCK_ALL_FOPS, &vdev->flags); - 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 && !locked && !lock); - - if (must_lock && !locked && 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 && !locked && 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"); |
