/* * videobuf2-core.c - video buffer 2 core framework * * Copyright (C) 2010 Samsung Electronics * * Author: Pawel Osciak * Marek Szyprowski * * The vb2_thread implementation was based on code from videobuf-dvb.c: * (c) 2004 Gerd Knorr [SUSE Labs] * * 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 #include #include #include #include #include #include #include #include #include #include #include static int debug; module_param(debug, int, 0644); #define dprintk(level, fmt, arg...) \ do { \ if (debug >= level) \ pr_info("vb2-core: %s: " fmt, __func__, ## arg); \ } while (0) #ifdef CONFIG_VIDEO_ADV_DEBUG /* * If advanced debugging is on, then count how often each op is called * successfully, which can either be per-buffer or per-queue. * * This makes it easy to check that the 'init' and 'cleanup' * (and variations thereof) stay balanced. */ #define log_memop(vb, op) \ dprintk(2, "call_memop(%p, %d, %s)%s\n", \ (vb)->vb2_queue, (vb)->index, #op, \ (vb)->vb2_queue->mem_ops->op ? "" : " (nop)") #define call_memop(vb, op, args...) \ ({ \ struct vb2_queue *_q = (vb)->vb2_queue; \ int err; \ \ log_memop(vb, op); \ err = _q->mem_ops->op ? _q->mem_ops->op(args) : 0; \ if (!err) \ (vb)->cnt_mem_ ## op++; \ err; \ }) #define call_ptr_memop(vb, op, args...) \ ({ \ struct vb2_queue *_q = (vb)->vb2_queue; \ void *ptr; \ \ log_memop(vb, op); \ ptr = _q->mem_ops->op ? _q->mem_ops->op(args) : NULL; \ if (!IS_ERR_OR_NULL(ptr)) \ (vb)->cnt_mem_ ## op++; \ ptr; \ }) #define call_void_memop(vb, op, args...) \ ({ \ struct vb2_queue *_q = (vb)->vb2_queue; \ \ log_memop(vb, op); \ if (_q->mem_ops->op) \ _q->mem_ops->op(args); \ (vb)->cnt_mem_ ## op++; \ }) #define log_qop(q, op) \ dprintk(2, "call_qop(%p, %s)%s\n", q, #op, \ (q)->ops->op ? "" : " (nop)") #define call_qop(q, op, args...) \ ({ \ int err; \ \ log_qop(q, op); \ err = (q)->ops->op ? (q)->ops->op(args) : 0; \ if (!err) \ (q)->cnt_ ## op++; \ err; \ }) #define call_void_qop(q, op, args...) \ ({ \ log_qop(q, op); \ if ((q)->ops->op) \ (q)->ops->op(args); \ (q)->cnt_ ## op++; \ }) #define log_vb_qop(vb, op, args...) \ dprintk(2, "call_vb_qop(%p, %d, %s)%s\n", \ (vb)->vb2_queue, (vb)->index, #op, \ (vb)->vb2_queue->ops->op ? "" : " (nop)") #define call_vb_qop(vb, op, args...) \ ({ \ int err; \ \ log_vb_qop(vb, op); \ err = (vb)->vb2_queue->ops->op ? \ (vb)->vb2_queue->ops->op(args) : 0; \ if (!err) \ (vb)->cnt_ ## op++; \ err; \ }) #define call_void_vb_qop(vb, op, args...) \ ({ \ log_vb_qop(vb, op); \ if ((vb)->vb2_queue->ops->op) \ (vb)->vb2_queue->ops->op(args); \ (vb)->cnt_ ## op++; \ }) #else #define call_memop(vb, op, args...) \ ((vb)->vb2_queue->mem_ops->op ? \ (vb)->vb2_queue->mem_ops->op(args) : 0) #define call_ptr_memop(vb, op, args...) \ ((vb)->vb2_queue->mem_ops->op ? \ (vb)->vb2_queue->mem_ops->op(args) : NULL) #define call_void_memop(vb, op, args...) \ do { \ if ((vb)->vb2_queue->mem_ops->op) \ (vb)->vb2_queue->mem_ops->op(args); \ } while (0) #define call_qop(q, op, args...) \ ((q)->ops->op ? (q)->ops->op(args) : 0) #define call_void_qop(q, op, args...) \ do { \ if ((q)->ops->op) \ (q)->ops->op(args); \ } while (0) #define call_vb_qop(vb, op, args...) \ ((vb)->vb2_queue->ops->op ? (vb)->vb2_queue->ops->op(args) : 0) #define call_void_vb_qop(vb, op, args...) \ do { \ if ((vb)->vb2_queue->ops->op) \ (vb)->vb2_queue->ops->op(args); \ } while (0) #endif #define call_bufop(q, op, args...) \ ({ \ int ret = 0; \ if (q && q->buf_ops && q->buf_ops->op) \ ret = q->buf_ops->op(args); \ ret; \ }) #define call_void_bufop(q, op, args...) \ ({ \ if (q && q->buf_ops && q->buf_ops->op) \ q->buf_ops->op(args); \ }) static void __vb2_queue_cancel(struct vb2_queue *q); static void __enqueue_in_driver(struct vb2_buffer *vb); /** * __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; enum dma_data_direction dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; void *mem_priv; int plane; int ret = -ENOMEM; /* * Allocate memory for all planes in this buffer * NOTE: mmapped areas should be page aligned */ for (plane = 0; plane < vb->num_planes; ++plane) { unsigned long size = PAGE_ALIGN(vb->planes[plane].length); mem_priv = call_ptr_memop(vb, alloc, q->alloc_devs[plane] ? : q->dev, q->dma_attrs, size, dma_dir, q->gfp_flags); if (IS_ERR(mem_priv)) { if (mem_priv) ret = PTR_ERR(mem_priv); goto free; } /* Associate allocator private data with this plane */ vb->planes[plane].mem_priv = mem_priv; } return 0; free: /* Free already allocated memory if one of the allocations failed */ for (; plane > 0; --plane) { call_void_memop(vb, put, vb->planes[plane - 1].mem_priv); vb->planes[plane - 1].mem_priv = NULL; } return ret; } /** * __vb2_buf_mem_free() - free memory of the given buffer */ static void __vb2_buf_mem_free(struct vb2_buffer *vb) { unsigned int plane; for (plane = 0; plane < vb->num_planes; ++plane) { call_void_memop(vb, put, vb->planes[plane].mem_priv); vb->planes[plane].mem_priv = NULL; dprintk(3, "freed plane %d of buffer %d\n", plane, vb->index); } } /** * __vb2_buf_userptr_put() - release userspace memory associated with * a USERPTR buffer */ static void __vb2_buf_userptr_put(struct vb2_buffer *vb) { unsigned int plane; for (plane = 0; plane < vb->num_planes; ++plane) { if (vb->planes[plane].mem_priv) call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv); vb->planes[plane].mem_priv = NULL; } } /** * __vb2_plane_dmabuf_put() - release memory associated with * a DMABUF shared plane */ static void __vb2_plane_dmabuf_put(struct vb2_buffer *vb, struct vb2_plane *p) { if (!p->mem_priv) return; if (p->dbuf_mapped) call_void_memop(vb, unmap_dmabuf, p->mem_priv); call_void_memop(vb, detach_dmabuf, p->mem_priv); dma_buf_put(p->dbuf); p->mem_priv = NULL; p->dbuf = NULL; p->dbuf_mapped = 0; } /** * __vb2_buf_dmabuf_put() - release memory associated with * a DMABUF shared buffer */ static void __vb2_buf_dmabuf_put(struct vb2_buffer *vb) { unsigned int plane; for (plane = 0; plane < vb->num_planes; ++plane) __vb2_plane_dmabuf_put(vb, &vb->planes[plane]); } /** * __setup_offsets() - setup unique offsets ("cookies") for every plane in * the buffer. */ static void __setup_offsets(struct vb2_buffer *vb) { struct vb2_queue *q = vb->vb2_queue; unsigned int plane; unsigned long off = 0; if (vb->index) { struct vb2_buffer *prev = q->bufs[vb->index - 1]; struct vb2_plane *p = &prev->planes[prev->num_planes - 1]; off = PAGE_ALIGN(p->m.offset + p->length); } for (plane = 0; plane < vb->num_planes; ++plane) { vb->planes[plane].m.offset = off; dprintk(3, "buffer %d, plane %d offset 0x%08lx\n", vb->index, plane, off); off += vb->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 vb2_memory memory, unsigned int num_buffers, unsigned int num_planes, const unsigned plane_sizes[VB2_MAX_PLANES]) { unsigned int buffer, plane; 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; } vb->state = VB2_BUF_STATE_DEQUEUED; vb->vb2_queue = q; vb->num_planes = num_planes; vb->index = q->num_buffers + buffer; vb->type = q->type; vb->memory = memory; for (plane = 0; plane < num_planes; ++plane) { vb->planes[plane].length = plane_sizes[plane]; vb->planes[plane].min_length = plane_sizes[plane]; } q->bufs[vb->index] = vb; /* Allocate video buffer memory for the MMAP type */ if (memory == VB2_MEMORY_MMAP) { ret = __vb2_buf_mem_alloc(vb); if (ret) { dprintk(1, "failed allocating memory for " "buffer %d\n", buffer); q->bufs[vb->index] = NULL; kfree(vb); break; } __setup_offsets(vb); /* * Call the driver-provided buffer initialization * callback, if given. An error in initialization * results in queue setup failure. */ ret = call_vb_qop(vb, buf_init, vb); if (ret) { dprintk(1, "buffer %d %p initialization" " failed\n", buffer, vb); __vb2_buf_mem_free(vb); q->bufs[vb->index] = NULL; kfree(vb); break; } } } 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 == VB2_MEMORY_MMAP) __vb2_buf_mem_free(vb); else if (q->memory == VB2_MEMORY_DMABUF) __vb2_buf_dmabuf_put(vb); else __vb2_buf_userptr_put(vb); } } /** * __vb2_queue_free() - free buffers at the end of the queue - video memory and * related information, if no buffers are left return the queue to an * uninitialized state. Might be called even if the queue has already been freed. */ static int __vb2_queue_free(struct vb2_queue *q, unsigned int buffers) { unsigned int buffer; /* * Sanity check: when preparing a buffer the queue lock is released for * a short while (see __buf_prepare for the details), which would allow * a race with a reqbufs which can call this function. Removing the * buffers from underneath __buf_prepare is obviously a bad idea, so we * check if any of the buffers is in the state PREPARING, and if so we * just return -EAGAIN. */ for (buffer = q->num_buffers - buffers; buffer < q->num_buffers; ++buffer) { if (q->bufs[buffer] == NULL) continue; if (q->bufs[buffer]->state == VB2_BUF_STATE_PREPARING) { dprintk(1, "preparing buffers, cannot free\n"); return -EAGAIN; } } /* Call driver-provided cleanup function for each buffer, if provided */ for (buffer = q->num_buffers - buffers; buffer < q->num_buffers; ++buffer) { struct vb2_buffer *vb = q->bufs[buffer]; if (vb && vb->planes[0].mem_priv) call_void_vb_qop(vb, buf_cleanup, vb); } /* Release video buffer memory */ __vb2_free_mem(q, buffers); #ifdef CONFIG_VIDEO_ADV_DEBUG /* * Check that all the calls were balances during the life-time of this * queue. If not (or if the debug level is 1 or up), then dump the * counters to the kernel log. */ if (q->num_buffers) { bool unbalanced = q->cnt_start_streaming != q->cnt_stop_streaming || q->cnt_wait_prepare != q->cnt_wait_finish; if (unbalanced || debug) { pr_info("vb2: counters for queue %p:%s\n", q, unbalanced ? " UNBALANCED!" : ""); pr_info("vb2: setup: %u start_streaming: %u stop_streaming: %u\n", q->cnt_queue_setup, q->cnt_start_streaming, q->cnt_stop_streaming); pr_info("vb2: wait_prepare: %u wait_finish: %u\n", q->cnt_wait_prepare, q->cnt_wait_finish); } q->cnt_queue_setup = 0; q->cnt_wait_prepare = 0; q->cnt_wait_finish = 0; q->cnt_start_streaming = 0; q->cnt_stop_streaming = 0; } for (buffer = 0; buffer < q->num_buffers; ++buffer) { struct vb2_buffer *vb = q->bufs[buffer]; bool unbalanced = vb->cnt_mem_alloc != vb->cnt_mem_put || vb->cnt_mem_prepare != vb->cnt_mem_finish || vb->cnt_mem_get_userptr != vb->cnt_mem_put_userptr || vb->cnt_mem_attach_dmabuf != vb->cnt_mem_detach_dmabuf || vb->cnt_mem_map_dmabuf != vb->cnt_mem_unmap_dmabuf || vb->cnt_buf_queue != vb->cnt_buf_done || vb->cnt_buf_prepare != vb->cnt_buf_finish || vb->cnt_buf_init != vb->cnt_buf_cleanup; if (unbalanced || debug) { pr_info("vb2: counters for queue %p, buffer %d:%s\n", q, buffer, unbalanced ? " UNBALANCED!" : ""); pr_info("vb2: buf_init: %u buf_cleanup: %u buf_prepare: %u buf_finish: %u\n", vb->cnt_buf_init, vb->cnt_buf_cleanup, vb->cnt_buf_prepare, vb->cnt_buf_finish); pr_info("vb2: buf_queue: %u buf_done: %u\n", vb->cnt_buf_queue, vb->cnt_buf_done); pr_info("vb2: alloc: %u put: %u prepare: %u finish: %u mmap: %u\n", vb->cnt_mem_alloc, vb->cnt_mem_put, vb->cnt_mem_prepare, vb->cnt_mem_finish, vb->cnt_mem_mmap); pr_info("vb2: get_userptr: %u put_userptr: %u\n", vb->cnt_mem_get_userptr, vb->cnt_mem_put_userptr); pr_info("vb2: attach_dmabuf: %u detach_dmabuf: %u map_dmabuf: %u unmap_dmabuf: %u\n", vb->cnt_mem_attach_dmabuf, vb->cnt_mem_detach_dmabuf, vb->cnt_mem_map_dmabuf, vb->cnt_mem_unmap_dmabuf); pr_info("vb2: get_dmabuf: %u num_users: %u vaddr: %u cookie: %u\n", vb->cnt_mem_get_dmabuf, vb->cnt_mem_num_users, vb->cnt_mem_vaddr, vb->cnt_mem_cookie); } } #endif /* 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); } return 0; } /** * vb2_buffer_in_use() - return true if the buffer is in use and * the queue cannot be freed (by the means of REQBUFS(0)) call */ bool vb2_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(vb, num_users, mem_priv) > 1) return true; } return false; } EXPORT_SYMBOL(vb2_buffer_in_use); /** * __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 (vb2_buffer_in_use(q, q->bufs[buffer])) return true; } return false; } /** * vb2_core_querybuf() - query video buffer information * @q: videobuf queue * @index: id number of the buffer * @pb: buffer struct passed from userspace * * Should be called from vidioc_querybuf ioctl handler in driver. * The passed buffer should have been verified. * This function fills the relevant information for the userspace. */ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb) { call_void_bufop(q, fill_user_buffer, q->bufs[index], pb); } EXPORT_SYMBOL_GPL(vb2_core_querybuf); /** * __verify_userptr_ops() - verify that all memory operations required for * USERPTR queue type have been provided */ static int __verify_userptr_ops(struct vb2_queue *q) { if (!(q->io_modes & VB2_USERPTR) || !q->mem_ops->get_userptr || !q->mem_ops->put_userptr) return -EINVAL; return 0; } /** * __verify_mmap_ops() - verify that all memory operations required for * MMAP queue type have been provided */ static int __verify_mmap_ops(struct vb2_queue *q) { if (!(q->io_modes & VB2_MMAP) || !q->mem_ops->alloc || !q->mem_ops->put || !q->mem_ops->mmap) return -EINVAL; return 0; } /** * __verify_dmabuf_ops() - verify that all memory operations required for * DMABUF queue type have been provided */ static int __verify_dmabuf_ops(struct vb2_queue *q) { if (!(q->io_modes & VB2_DMABUF) || !q->mem_ops->attach_dmabuf || !q->mem_ops->detach_dmabuf || !q->mem_ops->map_dmabuf || !q->mem_ops->unmap_dmabuf) return -EINVAL; return 0; } /** * vb2_verify_memory_type() - Check whether the memory type and buffer type * passed to a buffer operation are compatible with the queue. */ int vb2_verify_memory_type(struct vb2_queue *q, enum vb2_memory memory, unsigned int type) { if (memory != VB2_MEMORY_MMAP && memory != VB2_MEMORY_USERPTR && memory != VB2_MEMORY_DMABUF) { dprintk(1, "unsupported memory type\n"); return -EINVAL; } if (type != q->type) { dprintk(1, "requested type is incorrect\n"); return -EINVAL; } /* * Make sure all the required memory ops for given memory type * are available. */ if (memory == VB2_MEMORY_MMAP && __verify_mmap_ops(q)) { dprintk(1, "MMAP for current setup unsupported\n"); return -EINVAL; } if (memory == VB2_MEMORY_USERPTR && __verify_userptr_ops(q)) { dprintk(1, "USERPTR for current setup unsupported\n"); return -EINVAL; } if (memory == VB2_MEMORY_DMABUF && __verify_dmabuf_ops(q)) { dprintk(1, "DMABUF for current setup unsupported\n"); return -EINVAL; } /* * Place the busy tests at the end: -EBUSY can be ignored when * create_bufs is called with count == 0, but count == 0 should still * do the memory and type validation. */ if (vb2_fileio_is_active(q)) { dprintk(1, "file io in progress\n"); return -EBUSY; } return 0; } EXPORT_SYMBOL(vb2_verify_memory_type); /** * vb2_core_reqbufs() - Initiate streaming * @q: videobuf2 queue * @memory: memory type * @count: requested buffer count * * 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. */ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, unsigned int *count) { unsigned int num_buffers, allocated_buffers, num_planes = 0; unsigned plane_sizes[VB2_MAX_PLANES] = { }; int ret; if (q->streaming) { dprintk(1, "streaming active\n"); return -EBUSY; } if (*count == 0 || q->num_buffers != 0 || q->memory != memory) { /* * We already have buffers allocated, so first check if they * are not in use and can be freed. */ mutex_lock(&q->mmap_lock); if (q->memory == VB2_MEMORY_MMAP && __buffers_in_use(q)) { mutex_unlock(&q->mmap_lock); dprintk(1, "memory in use, cannot free\n"); return -EBUSY; } /* * Call queue_cancel to clean up any buffers in the PREPARED or * QUEUED state which is possible if buffers were prepared or * queued without ever calling STREAMON. */ __vb2_queue_cancel(q); ret = __vb2_queue_free(q, q->num_buffers); mutex_unlock(&q->mmap_lock); if (ret) return ret; /* * In case of REQBUFS(0) return immediately without calling * driver's queue_setup() callback and allocating resources. */ if (*count == 0) return 0; } /* * Make sure the requested values and current defaults are sane. */ num_buffers = min_t(unsigned int, *count, VB2_MAX_FRAME); num_buffers = max_t(unsigned int, num_buffers, q->min_buffers_needed); memset(q->alloc_devs, 0, sizeof(q->alloc_devs)); q->memory = 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, &num_buffers, &num_planes, plane_sizes, q->alloc_devs); if (ret) return ret; /* Finally, allocate buffers and video memory */ allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes); if (allocated_buffers == 0) { dprintk(1, "memory allocation failed\n"); return -ENOMEM; } /* * There is no point in continuing if we can't allocate the minimum * number of buffers needed by this vb2_queue. */ if (allocated_buffers < q->min_buffers_needed) ret = -ENOMEM; /* * Check if driver can handle the allocated number of buffers. */ if (!ret && allocated_buffers < num_buffers) { num_buffers = allocated_buffers; /* * num_planes is set by the previous queue_setup(), but since it * signals to queue_setup() whether it is called from create_bufs() * vs reqbufs() we zero it here to signal that queue_setup() is * called for the reqbufs() case. */ num_planes = 0; ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, plane_sizes, q->alloc_devs); if (!ret && allocated_buffers < num_buffers) ret = -ENOMEM; /* * Either the driver has accepted a smaller number of buffers, * or .queue_setup() returned an error */ } mutex_lock(&q->mmap_lock); q->num_buffers = allocated_buffers; if (ret < 0) { /* * Note: __vb2_queue_free() will subtract 'allocated_buffers' * from q->num_buffers. */ __vb2_queue_free(q, allocated_buffers); mutex_unlock(&q->mmap_lock); return ret; } mutex_unlock(&q->mmap_lock); /* * Return the number of successfully allocated buffers * to the userspace. */ *count = allocated_buffers; q->waiting_for_buffers = !q->is_output; return 0; } EXPORT_SYMBOL_GPL(vb2_core_reqbufs); /** * vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs * @q: videobuf2 queue * @memory: memory type * @count: requested buffer count * @parg: parameter passed to device 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. */ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory, unsigned int *count, unsigned requested_planes, const unsigned requested_sizes[]) { unsigned int num_planes = 0, num_buffers, allocated_buffers; unsigned plane_sizes[VB2_MAX_PLANES] = { }; int ret; if (q->num_buffers == VB2_MAX_FRAME) { dprintk(1, "maximum number of buffers already allocated\n"); return -ENOBUFS; } if (!q->num_buffers) { memset(q->alloc_devs, 0, sizeof(q->alloc_devs)); q->memory = memory; q->waiting_for_buffers = !q->is_output; } num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers); if (requested_planes && requested_sizes) { num_planes = requested_planes; memcpy(plane_sizes, requested_sizes, sizeof(plane_sizes)); } /* * Ask the driver, whether the requested number of buffers, planes per * buffer and their sizes are acceptable */ ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, plane_sizes, q->alloc_devs); if (ret) return ret; /* Finally, allocate buffers and video memory */ allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers, num_planes, plane_sizes); if (allocated_buffers == 0) { dprintk(1, "memory allocation failed\n"); return -ENOMEM; } /* * Check if driver can handle the so far allocated number of buffers. */ if (allocated_buffers < num_buffers) { num_buffers = allocated_buffers; /* * q->num_buffers contains the total number of buffers, that the * queue driver has set up */ ret = call_qop(q, queue_setup, q, &num_buffers, &num_planes, plane_sizes, q->alloc_devs); if (!ret && allocated_buffers < num_buffers) ret = -ENOMEM; /* * Either the driver has accepted a smaller number of buffers, * or .queue_setup() returned an error */ } mutex_lock(&q->mmap_lock); q->num_buffers += allocated_buffers; if (ret < 0) { /* * Note: __vb2_queue_free() will subtract 'allocated_buffers' * from q->num_buffers. */ __vb2_queue_free(q, allocated_buffers); mutex_unlock(&q->mmap_lock); return -ENOMEM; } mutex_unlock(&q->mmap_lock); /* * Return the number of successfully allocated buffers * to the userspace. */ *count = allocated_buffers; return 0; } EXPORT_SYMBOL_GPL(vb2_core_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) { if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv) return NULL; return call_ptr_memop(vb, 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) { if (plane_no >= vb->num_planes || !vb->planes[plane_no].mem_priv) return NULL; return call_ptr_memop(vb, 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, * VB2_BUF_STATE_ERROR if the operation finished with an error or * VB2_BUF_STATE_QUEUED if the driver wants to requeue buffers. * If start_streaming fails then it should return buffers with state * VB2_BUF_STATE_QUEUED to put them back into the queue. * * 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. * * While streaming a buffer can only be returned in state DONE or ERROR. * The start_streaming op can also return them in case the DMA engine cannot * be started for some reason. In that case the buffers should be returned with * state QUEUED. */ void vb2_buffer_done(struct vb2_buffer *vb, enum vb2_buffer_state state) { struct vb2_queue *q = vb->vb2_queue; unsigned long flags; unsigned int plane; if (WARN_ON(vb->state != VB2_BUF_STATE_ACTIVE)) return; if (WARN_ON(state != VB2_BUF_STATE_DONE && state != VB2_BUF_STATE_ERROR && state != VB2_BUF_STATE_QUEUED && state != VB2_BUF_STATE_REQUEUEING)) state = VB2_BUF_STATE_ERROR; #ifdef CONFIG_VIDEO_ADV_DEBUG /* * Although this is not a callback, it still does have to balance * with the buf_queue op. So update this counter manually. */ vb->cnt_buf_done++; #endif dprintk(4, "done processing on buffer %d, state: %d\n", vb->index, state); /* sync buffers */ for (plane = 0; plane < vb->num_planes; ++plane) call_void_memop(vb, finish, vb->planes[plane].mem_priv); spin_lock_irqsave(&q->done_lock, flags); if (state == VB2_BUF_STATE_QUEUED || state == VB2_BUF_STATE_REQUEUEING) { vb->state = VB2_BUF_STATE_QUEUED; } else { /* Add the buffer to the done buffers list */ list_add_tail(&vb->done_entry, &q->done_list); vb->state = state; } atomic_dec(&q->owned_by_drv_count); spin_unlock_irqrestore(&q->done_lock, flags); trace_vb2_buf_done(q, vb); switch (state) { case VB2_BUF_STATE_QUEUED: return; case VB2_BUF_STATE_REQUEUEING: if (q->start_streaming_called) __enqueue_in_driver(vb); return; default: /* Inform any processes that may be waiting for buffers */ wake_up(&q->done_wq); break; } } EXPORT_SYMBOL_GPL(vb2_buffer_done); /** * vb2_discard_done() - discard all buffers marked as DONE * @q: videobuf2 queue * * This function is intended to be used with suspend/resume operations. It * discards all 'done' buffers as they would be too old to be requested after * resume. * * Drivers must stop the hardware and synchronize with interrupt handlers and/or * delayed works before calling this function to make sure no buffer will be * touched by the driver and/or hardware. */ void vb2_discard_done(struct vb2_queue *q) { struct vb2_buffer *vb; unsigned long flags; spin_lock_irqsave(&q->done_lock, flags); list_for_each_entry(vb, &q->done_list, done_entry) vb->state = VB2_BUF_STATE_ERROR; spin_unlock_irqrestore(&q->done_lock, flags); } EXPORT_SYMBOL_GPL(vb2_discard_done); /** * __qbuf_mmap() - handle qbuf of an MMAP buffer */ static int __qbuf_mmap(struct vb2_buffer *vb, const void *pb) { int ret = 0; if (pb) ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, vb->planes); return ret ? ret : call_vb_qop(vb, buf_prepare, vb); } /** * __qbuf_userptr() - handle qbuf of a USERPTR buffer */ static int __qbuf_userptr(struct vb2_buffer *vb, const void *pb) { struct vb2_plane planes[VB2_MAX_PLANES]; struct vb2_queue *q = vb->vb2_queue; void *mem_priv; unsigned int plane; int ret = 0; enum dma_data_direction dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; bool reacquired = vb->planes[0].mem_priv == NULL; memset(planes, 0, sizeof(planes[0]) * vb->num_planes); /* Copy relevant information provided by the userspace */ if (pb) ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes); if (ret) return ret; for (plane = 0; plane < vb->num_planes; ++plane) { /* Skip the plane if already verified */ if (vb->planes[plane].m.userptr && vb->planes[plane].m.userptr == planes[plane].m.userptr && vb->planes[plane].length == planes[plane].length) continue; dprintk(3, "userspace address for plane %d changed, " "reacquiring memory\n", plane); /* Check if the provided plane buffer is large enough */ if (planes[plane].length < vb->planes[plane].min_length) { dprintk(1, "provided buffer size %u is less than " "setup size %u for plane %d\n", planes[plane].length, vb->planes[plane].min_length, plane); ret = -EINVAL; goto err; } /* Release previously acquired memory if present */ if (vb->planes[plane].mem_priv) { if (!reacquired) { reacquired = true; call_void_vb_qop(vb, buf_cleanup, vb); } call_void_memop(vb, put_userptr, vb->planes[plane].mem_priv); } vb->planes[plane].mem_priv = NULL; vb->planes[plane].bytesused = 0; vb->planes[plane].length = 0; vb->planes[plane].m.userptr = 0; vb->planes[plane].data_offset = 0; /* Acquire each plane's memory */ mem_priv = call_ptr_memop(vb, get_userptr, q->alloc_devs[plane] ? : q->dev, planes[plane].m.userptr, planes[plane].length, dma_dir); if (IS_ERR(mem_priv)) { dprintk(1, "failed acquiring userspace " "memory for plane %d\n", plane); ret = PTR_ERR(mem_priv); goto err; } vb->planes[plane].mem_priv = mem_priv; } /* * Now that everything is in order, copy relevant information * provided by userspace. */ for (plane = 0; plane < vb->num_planes; ++plane) { vb->planes[plane].bytesused = planes[plane].bytesused; vb->planes[plane].length = planes[plane].length; vb->planes[plane].m.userptr = planes[plane].m.userptr; vb->planes[plane].data_offset = planes[plane].data_offset; } if (reacquired) { /* * One or more planes changed, so we must call buf_init to do * the driver-specific initialization on the newly acquired * buffer, if provided. */ ret = call_vb_qop(vb, buf_init, vb); if (ret) { dprintk(1, "buffer initialization failed\n"); goto err; } } ret = call_vb_qop(vb, buf_prepare, vb); if (ret) { dprintk(1, "buffer preparation failed\n"); call_void_vb_qop(vb, buf_cleanup, vb); goto err; } 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_void_memop(vb, put_userptr, vb->planes[plane].mem_priv); vb->planes[plane].mem_priv = NULL; vb->planes[plane].m.userptr = 0; vb->planes[plane].length = 0; } return ret; } /** * __qbuf_dmabuf() - handle qbuf of a DMABUF buffer */ static int __qbuf_dmabuf(struct vb2_buffer *vb, const void *pb) { struct vb2_plane planes[VB2_MAX_PLANES]; struct vb2_queue *q = vb->vb2_queue; void *mem_priv; unsigned int plane; int ret = 0; enum dma_data_direction dma_dir = q->is_output ? DMA_TO_DEVICE : DMA_FROM_DEVICE; bool reacquired = vb->planes[0].mem_priv == NULL; memset(planes, 0, sizeof(planes[0]) * vb->num_planes); /* Copy relevant information provided by the userspace */ if (pb) ret = call_bufop(vb->vb2_queue, fill_vb2_buffer, vb, pb, planes); if (ret) return ret; for (plane = 0; plane < vb->num_planes; ++plane) { struct dma_buf *dbuf = dma_buf_get(planes[plane].m.fd); if (IS_ERR_OR_NULL(dbuf)) { dprintk(1, "invalid dmabuf fd for plane %d\n", plane); ret = -EINVAL; goto err; } /* use DMABUF size if length is not provided */ if (planes[plane].length == 0) planes[plane].length = dbuf->size; if (planes[plane].length < vb->planes[plane].min_length) { dprintk(1, "invalid dmabuf length %u for plane %d, " "minimum length %u\n", planes[plane].length, plane, vb->planes[plane].min_length); dma_buf_put(dbuf); ret = -EINVAL; goto err; } /* Skip the plane if already verified */ if (dbuf == vb->planes[plane].dbuf && vb->planes[plane].length == planes[plane].length) { dma_buf_put(dbuf); continue; } dprintk(1, "buffer for plane %d changed\n", plane); if (!reacquired) { reacquired = true; call_void_vb_qop(vb, buf_cleanup, vb); } /* Release previously acquired memory if present */ __vb2_plane_dmabuf_put(vb, &vb->planes[plane]); vb->planes[plane].bytesused = 0; vb->planes[plane].length = 0; vb->planes[plane].m.fd = 0; vb->planes[plane].data_offset = 0; /* Acquire each plane's memory */ mem_priv = call_ptr_memop(vb, attach_dmabuf, q->alloc_devs[plane] ? : q->dev, dbuf, planes[plane].length, dma_dir); if (IS_ERR(mem_priv)) { dprintk(1, "failed to attach dmabuf\n"); ret = PTR_ERR(mem_priv); dma_buf_put(dbuf); goto err; } vb->planes[plane].dbuf = dbuf; vb->planes[plane].mem_priv = mem_priv; } /* * This pins the buffer(s) with dma_buf_map_attachment()). It's done * here instead just before the DMA, while queueing the buffer(s) so * userspace knows sooner rather than later if the dma-buf map fails. */ for (plane = 0; plane < vb->num_planes; ++plane) { ret = call_memop(vb, map_dmabuf, vb->planes[plane].mem_priv); if (ret) { dprintk(1, "failed to map dmabuf for plane %d\n", plane); goto err; } vb->planes[plane].dbuf_mapped = 1; } /* * Now that everything is in order, copy relevant information * provided by userspace. */ for (plane = 0; plane < vb->num_planes; ++plane) { vb->planes[plane].bytesused = planes[plane].bytesused; vb->planes[plane].length = planes[plane].length; vb->planes[plane].m.fd = planes[plane].m.fd; vb->planes[plane].data_offset = planes[plane].data_offset; } if (reacquired) { /* * Call driver-specific initialization on the newly acquired buffer, * if provided. */ ret = call_vb_qop(vb, buf_init, vb); if (ret) { dprintk(1, "buffer initialization failed\n"); goto err; } } ret = call_vb_qop(vb, buf_prepare, vb); if (ret) { dprintk(1, "buffer preparation failed\n"); call_void_vb_qop(vb, buf_cleanup, vb); goto err; } return 0; err: /* In case of errors, release planes that were already acquired */ __vb2_buf_dmabuf_put(vb); return ret; } /** * __enqueue_in_driver() - enqueue a vb2_buffer in driver for processing */ static void __enqueue_in_driver(struct vb2_buffer *vb) { struct vb2_queue *q = vb->vb2_queue; unsigned int plane; vb->state = VB2_BUF_STATE_ACTIVE; atomic_inc(&q->owned_by_drv_count); trace_vb2_buf_queue(q, vb); /* sync buffers */ for (plane = 0; plane < vb->num_planes; ++plane) call_void_memop(vb, prepare, vb->planes[plane].mem_priv); call_void_vb_qop(vb, buf_queue, vb); } static int __buf_prepare(struct vb2_buffer *vb, const void *pb) { struct vb2_queue *q = vb->vb2_queue; int ret; if (q->error) { dprintk(1, "fatal error occurred on queue\n"); return -EIO; } vb->state = VB2_BUF_STATE_PREPARING; switch (q->memory) { case VB2_MEMORY_MMAP: ret = __qbuf_mmap(vb, pb); break; case VB2_MEMORY_USERPTR: ret = __qbuf_userptr(vb, pb); break; case VB2_MEMORY_DMABUF: ret = __qbuf_dmabuf(vb, pb); break; default: WARN(1, "Invalid queue type\n"); ret = -EINVAL; } if (ret) dprintk(1, "buffer preparation failed: %d\n", ret); vb->state = ret ? VB2_BUF_STATE_DEQUEUED : VB2_BUF_STATE_PREPARED; return ret; } /** * vb2_core_prepare_buf() - Pass ownership of a buffer from userspace * to the kernel * @q: videobuf2 queue * @index: id number of the buffer * @pb: buffer structure passed from userspace to vidioc_prepare_buf * handler in driver * * Should be called from vidioc_prepare_buf ioctl handler of a driver. * The passed buffer should have been verified. * This function 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_core_prepare_buf(struct vb2_queue *q, unsigned int index, void *pb) { struct vb2_buffer *vb; int ret; vb = q->bufs[index]; if (vb->state != VB2_BUF_STATE_DEQUEUED) { dprintk(1, "invalid buffer state %d\n", vb->state); return -EINVAL; } ret = __buf_prepare(vb, pb); if (ret) return ret; /* Fill buffer information for the userspace */ call_void_bufop(q, fill_user_buffer, vb, pb); dprintk(1, "prepare of buffer %d succeeded\n", vb->index); return ret; } EXPORT_SYMBOL_GPL(vb2_core_prepare_buf); /** * vb2_start_streaming() - Attempt to start streaming. * @q: videobuf2 queue * * Attempt to start streaming. When this function is called there must be * at least q->min_buffers_needed buffers queued up (i.e. the minimum * number of buffers required for the DMA engine to function). If the * @start_streaming op fails it is supposed to return all the driver-owned * buffers back to vb2 in state QUEUED. Check if that happened and if * not warn and reclaim them forcefully. */ static int vb2_start_streaming(struct vb2_queue *q) { struct vb2_buffer *vb; int ret; /* * 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); /* Tell the driver to start streaming */ q->start_streaming_called = 1; ret = call_qop(q, start_streaming, q, atomic_read(&q->owned_by_drv_count)); if (!ret) return 0; q->start_streaming_called = 0; dprintk(1, "driver refused to start streaming\n"); /* * If you see this warning, then the driver isn't cleaning up properly * after a failed start_streaming(). See the start_streaming() * documentation in videobuf2-core.h for more information how buffers * should be returned to vb2 in start_streaming(). */ if (WARN_ON(atomic_read(&q->owned_by_drv_count))) { unsigned i; /* * Forcefully reclaim buffers if the driver did not * correctly return them to vb2. */ for (i = 0; i < q->num_buffers; ++i) { vb = q->bufs[i]; if (vb->state == VB2_BUF_STATE_ACTIVE) vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED); } /* Must be zero now */ WARN_ON(atomic_read(&q->owned_by_drv_count)); } /* * If done_list is not empty, then start_streaming() didn't call * vb2_buffer_done(vb, VB2_BUF_STATE_QUEUED) but STATE_ERROR or * STATE_DONE. */ WARN_ON(!list_empty(&q->done_list)); return ret; } /** * vb2_core_qbuf() - Queue a buffer from userspace * @q: videobuf2 queue * @index: id number of the buffer * @pb: buffer structure passed from userspace to vidioc_qbuf handler * in driver * * Should be called from vidioc_qbuf ioctl handler of a driver. * The passed buffer should have been verified. * This function: * 1) if necessary, calls buf_prepare callback in the driver (if provided), in * which driver-specific buffer initialization can be performed, * 2) 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_core_qbuf(struct vb2_queue *q, unsigned int index, void *pb) { struct vb2_buffer *vb; int ret; vb = q->bufs[index]; switch (vb->state) { case VB2_BUF_STATE_DEQUEUED: ret = __buf_prepare(vb, pb); if (ret) return ret; break; case VB2_BUF_STATE_PREPARED: break; case VB2_BUF_STATE_PREPARING: dprintk(1, "buffer still being prepared\n"); return -EINVAL; default: dprintk(1, "invalid buffer state %d\n", vb->state); return -EINVAL; } /* * Add to the queued buffers list, a buffer will stay on it until * dequeued in dqbuf. */ list_add_tail(&vb->queued_entry, &q->queued_list); q->queued_count++; q->waiting_for_buffers = false; vb->state = VB2_BUF_STATE_QUEUED; if (pb) call_void_bufop(q, copy_timestamp, vb, pb); trace_vb2_qbuf(q, vb); /* * If already streaming, give the buffer to driver for processing. * If not, the buffer will be given to driver on next streamon. */ if (q->start_streaming_called) __enqueue_in_driver(vb); /* Fill buffer information for the userspace */ if (pb) call_void_bufop(q, fill_user_buffer, vb, pb); /* * If streamon has been called, and we haven't yet called * start_streaming() since not enough buffers were queued, and * we now have reached the minimum number of queued buffers, * then we can finally call start_streaming(). */ if (q->streaming && !q->start_streaming_called && q->queued_count >= q->min_buffers_needed) { ret = vb2_start_streaming(q); if (ret) return ret; } dprintk(1, "qbuf of buffer %d succeeded\n", vb->index); return 0; } EXPORT_SYMBOL_GPL(vb2_core_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 (q->error) { dprintk(1, "Queue in error state, will not wait for buffers\n"); return -EIO; } if (q->last_buffer_dequeued) { dprintk(3, "last buffer dequeued already, will not wait for buffers\n"); return -EPIPE; } 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_void_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 || q->error); /* * We need to reevaluate both conditions again after reacquiring * the locks or return an error if one occurred. */ call_void_qop(q, wait_finish, q); if (ret) { dprintk(1, "sleep was interrupted\n"); return ret; } } return 0; } /** * __vb2_get_done_vb() - get a buffer ready for dequeuing * * Will sleep if required for nonblocking == false. */ static int __vb2_get_done_vb(struct vb2_queue *q, struct vb2_buffer **vb, void *pb, int nonblocking) { unsigned long flags; int ret = 0; /* * Wait for at least one buffer to become available on the done_list. */ ret = __vb2_wait_for_done_vb(q, nonblocking); if (ret) return ret; /* * Driver's lock has been held since we last verified that done_list * is not empty, so no need for another list_empty(done_list) check. */ spin_lock_irqsave(&q->done_lock, flags); *vb = list_first_entry(&q->done_list, struct vb2_buffer, done_entry); /* * Only remove the buffer from done_list if all planes can be * handled. Some cases such as V4L2 file I/O and DVB have pb * == NULL; skip the check then as there's nothing to verify. */ if (pb) ret = call_bufop(q, verify_planes_array, *vb, pb); if (!ret) list_del(&(*vb)->done_entry); spin_unlock_irqrestore(&q->done_lock, flags); return ret; } /** * vb2_wait_for_all_buffers() - wait until all buffers are given back to vb2 * @q: videobuf2 queue * * This function will wait until all buffers that have been given to the driver * by buf_queue() are given back to vb2 with vb2_buffer_done(). It doesn't call * wait_prepare, wait_finish pair. It is intended to be called with all locks * taken, for example from stop_streaming() callback. */ int vb2_wait_for_all_buffers(struct vb2_queue *q) { if (!q->streaming) { dprintk(1, "streaming off, will not wait for buffers\n"); return -EINVAL; } if (q->start_streaming_called) wait_event(q->done_wq, !atomic_read(&q->owned_by_drv_count)); return 0; } EXPORT_SYMBOL_GPL(vb2_wait_for_all_buffers); /** * __vb2_dqbuf() - bring back the buffer to the DEQUEUED state */ static void __vb2_dqbuf(struct vb2_buffer *vb) { struct vb2_queue *q = vb->vb2_queue; unsigned int i; /* nothing to do if the buffer is already dequeued */ if (vb->state == VB2_BUF_STATE_DEQUEUED) return; vb->state = VB2_BUF_STATE_DEQUEUED; /* unmap DMABUF buffer */ if (q->memory == VB2_MEMORY_DMABUF) for (i = 0; i < vb->num_planes; ++i) { if (!vb->planes[i].dbuf_mapped) continue; call_void_memop(vb, unmap_dmabuf, vb->planes[i].mem_priv); vb->planes[i].dbuf_mapped = 0; } } /** * vb2_dqbuf() - Dequeue a buffer to the userspace * @q: videobuf2 queue * @pb: 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. * The passed buffer should have been verified. * This function: * 1) 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, * 2) 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_core_dqbuf(struct vb2_queue *q, unsigned int *pindex, void *pb, bool nonblocking) { struct vb2_buffer *vb = NULL; int ret; ret = __vb2_get_done_vb(q, &vb, pb, nonblocking); if (ret < 0) return ret; switch (vb->state) { case VB2_BUF_STATE_DONE: dprintk(3, "returning done buffer\n"); break; case VB2_BUF_STATE_ERROR: dprintk(3, "returning done buffer with errors\n"); break; default: dprintk(1, "invalid buffer state\n"); return -EINVAL; } call_void_vb_qop(vb, buf_finish, vb); if (pindex) *pindex = vb->index; /* Fill buffer information for the userspace */ if (pb) call_void_bufop(q, fill_user_buffer, vb, pb); /* Remove from videobuf queue */ list_del(&vb->queued_entry); q->queued_count--; trace_vb2_dqbuf(q, vb); /* go back to dequeued state */ __vb2_dqbuf(vb); dprintk(1, "dqbuf of buffer %d, with state %d\n", vb->index, vb->state); return 0; } EXPORT_SYMBOL_GPL(vb2_core_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->start_streaming_called) call_void_qop(q, stop_streaming, q); /* * If you see this warning, then the driver isn't cleaning up properly * in stop_streaming(). See the stop_streaming() documentation in * videobuf2-core.h for more information how buffers should be returned * to vb2 in stop_streaming(). */ if (WARN_ON(atomic_read(&q->owned_by_drv_count))) { for (i = 0; i < q->num_buffers; ++i) if (q->bufs[i]->state == VB2_BUF_STATE_ACTIVE) vb2_buffer_done(q->bufs[i], VB2_BUF_STATE_ERROR); /* Must be zero now */ WARN_ON(atomic_read(&q->owned_by_drv_count)); } q->streaming = 0; q->start_streaming_called = 0; q->queued_count = 0; q->error = 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->owned_by_drv_count, 0); wake_up_all(&q->done_wq); /* * Reinitialize all buffers for next use. * Make sure to call buf_finish for any queued buffers. Normally * that's done in dqbuf, but that's not going to happen when we * cancel the whole queue. Note: this code belongs here, not in * __vb2_dqbuf() since in vb2_core_dqbuf() there is a critical * call to __fill_user_buffer() after buf_finish(). That order can't * be changed, so we can't move the buf_finish() to __vb2_dqbuf(). */ for (i = 0; i < q->num_buffers; ++i) { struct vb2_buffer *vb = q->bufs[i]; if (vb->state != VB2_BUF_STATE_DEQUEUED) { vb->state = VB2_BUF_STATE_PREPARED; call_void_vb_qop(vb, buf_finish, vb); } __vb2_dqbuf(vb); } } int vb2_core_streamon(struct vb2_queue *q, unsigned int type) { int ret; if (type != q->type) { dprintk(1, "invalid stream type\n"); return -EINVAL; } if (q->streaming) { dprintk(3, "already streaming\n"); return 0; } if (!q->num_buffers) { dprintk(1, "no buffers have been allocated\n"); return -EINVAL; } if (q->num_buffers < q->min_buffers_needed) { dprintk(1, "need at least %u allocated buffers\n", q->min_buffers_needed); return -EINVAL; } /* * Tell driver to start streaming provided sufficient buffers * are available. */ if (q->queued_count >= q->min_buffers_needed) { ret = v4l_vb2q_enable_media_source(q); if (ret) return ret; ret = vb2_start_streaming(q); if (ret) { __vb2_queue_cancel(q); return ret; } } q->streaming = 1; dprintk(3, "successful\n"); return 0; } EXPORT_SYMBOL_GPL(vb2_core_streamon); /** * vb2_queue_error() - signal a fatal error on the queue * @q: videobuf2 queue * * Flag that a fatal unrecoverable error has occurred and wake up all processes * waiting on the queue. Polling will now set POLLERR and queuing and dequeuing * buffers will return -EIO. * * The error flag will be cleared when cancelling the queue, either from * vb2_streamoff or vb2_queue_release. Drivers should thus not call this * function before starting the stream, otherwise the error flag will remain set * until the queue is released when closing the device node. */ void vb2_queue_error(struct vb2_queue *q) { q->error = 1; wake_up_all(&q->done_wq); } EXPORT_SYMBOL_GPL(vb2_queue_error); int vb2_core_streamoff(struct vb2_queue *q, unsigned int type) { if (type != q->type) { dprintk(1, "invalid stream type\n"); return -EINVAL; } /* * Cancel will pause streaming and remove all buffers from the driver * and videobuf, effectively returning control over them to userspace. * * Note that we do this even if q->streaming == 0: if you prepare or * queue buffers, and then call streamoff without ever having called * streamon, you would still expect those buffers to be returned to * their normal dequeued state. */ __vb2_queue_cancel(q); q->waiting_for_buffers = !q->is_output; q->last_buffer_dequeued = false; dprintk(3, "successful\n"); return 0; } EXPORT_SYMBOL_GPL(vb2_core_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->planes[plane].m.offset == off) { *_buffer = buffer; *_plane = plane; return 0; } } } return -EINVAL; } /** * vb2_core_expbuf() - Export a buffer as a file descriptor * @q: videobuf2 queue * @fd: file descriptor associated with DMABUF (set by driver) * * @type: buffer type * @index: id number of the buffer * @plane: index of the plane to be exported, 0 for single plane queues * @flags: flags for newly created file, currently only O_CLOEXEC is * supported, refer to manual of open syscall for more details * * The return values from this function are intended to be directly returned * from vidioc_expbuf handler in driver. */ int vb2_core_expbuf(struct vb2_queue *q, int *fd, unsigned int type, unsigned int index, unsigned int plane, unsigned int flags) { struct vb2_buffer *vb = NULL; struct vb2_plane *vb_plane; int ret; struct dma_buf *dbuf; if (q->memory != VB2_MEMORY_MMAP) { dprintk(1, "queue is not currently set up for mmap\n"); return -EINVAL; } if (!q->mem_ops->get_dmabuf) { dprintk(1, "queue does not support DMA buffer exporting\n"); return -EINVAL; } if (flags & ~(O_CLOEXEC | O_ACCMODE)) { dprintk(1, "queue does support only O_CLOEXEC and access mode flags\n"); return -EINVAL; } if (type != q->type) { dprintk(1, "invalid buffer type\n"); return -EINVAL; } if (index >= q->num_buffers) { dprintk(1, "buffer index out of range\n"); return -EINVAL; } vb = q->bufs[index]; if (plane >= vb->num_planes) { dprintk(1, "buffer plane out of range\n"); return -EINVAL; } if (vb2_fileio_is_active(q)) { dprintk(1, "expbuf: file io in progress\n"); return -EBUSY; } vb_plane = &vb->planes[plane]; dbuf = call_ptr_memop(vb, get_dmabuf, vb_plane->mem_priv, flags & O_ACCMODE); if (IS_ERR_OR_NULL(dbuf)) { dprintk(1, "failed to export buffer %d, plane %d\n", index, plane); return -EINVAL; } ret = dma_buf_fd(dbuf, flags & ~O_ACCMODE); if (ret < 0) { dprintk(3, "buffer %d, plane %d failed to export (%d)\n", index, plane, ret); dma_buf_put(dbuf); return ret; } dprintk(3, "buffer %d, plane %d exported as %d descriptor\n", index, plane, ret); *fd = ret; return 0; } EXPORT_SYMBOL_GPL(vb2_core_expbuf); /** * vb2_mmap() - map video buffers into application address space * @q: videobuf2 queue * @vma: vma passed to the mmap file operation handler in the driver * * Should be called from mmap file operation handler of a driver. * This function maps one plane of one of the available video buffers to * userspace. To map whole video memory allocated on reqbufs, this function * has to be called once per each plane per each buffer previously allocated. * * When the userspace application calls mmap, it passes to it an offset returned * to it earlier by the means of vidioc_querybuf handler. That offset acts as * a "cookie", which is then used to identify the plane to be mapped. * This function finds a plane with a matching offset and a mapping is performed * by the means of a provided memory operation. * * The return values from this function are intended to be directly returned * from the mmap handler in driver. */ int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma) { unsigned long off = vma->vm_pgoff << PAGE_SHIFT; struct vb2_buffer *vb; unsigned int buffer = 0, plane = 0; int ret; unsigned long length; if (q->memory != VB2_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 (q->is_output) { 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; } } if (vb2_fileio_is_active(q)) { dprintk(1, "mmap: file io in progress\n"); return -EBUSY; } /* * Find the plane corresponding to the offset passed by userspace. */ ret = __find_plane_by_offset(q, off, &buffer, &plane); if (ret) return ret; vb = q->bufs[buffer]; /* * MMAP requires page_aligned buffers. * The buffer length was page_aligned at __vb2_buf_mem_alloc(), * so, we need to do the same here. */ length = PAGE_ALIGN(vb->planes[plane].length); if (length < (vma->vm_end - vma->vm_start)) { dprintk(1, "MMAP invalid, as it would overflow buffer length\n"); return -EINVAL; } mutex_lock(&q->mmap_lock); ret = call_memop(vb, mmap, vb->planes[plane].mem_priv, vma); mutex_unlock(&q->mmap_lock); 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; void *vaddr; int ret; if (q->memory != VB2_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]; vaddr = vb2_plane_vaddr(vb, plane); return vaddr ? (unsigned long)vaddr : -EINVAL; } EXPORT_SYMBOL_GPL(vb2_get_unmapped_area); #endif /** * vb2_core_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_core_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); mutex_init(&q->mmap_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_core_queue_init); static int __vb2_init_fileio(struct vb2_queue *q, int read); static int __vb2_cleanup_fileio(struct vb2_queue *q); /** * vb2_core_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_core_queue_release(struct vb2_queue *q) { __vb2_cleanup_fileio(q); __vb2_queue_cancel(q); mutex_lock(&q->mmap_lock); __vb2_queue_free(q, q->num_buffers); mutex_unlock(&q->mmap_lock); } EXPORT_SYMBOL_GPL(vb2_core_queue_release); /** * vb2_core_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. * * The return values from this function are intended to be directly returned * from poll handler in driver. */ unsigned int vb2_core_poll(struct vb2_queue *q, struct file *file, poll_table *wait) { unsigned long req_events = poll_requested_events(wait); struct vb2_buffer *vb = NULL; unsigned long flags; if (!q->is_output && !(req_events & (POLLIN | POLLRDNORM))) return 0; if (q->is_output && !(req_events & (POLLOUT | POLLWRNORM))) return 0; /* * Start file I/O emulator only if streaming API has not been used yet. */ if (q->num_buffers == 0 && !vb2_fileio_is_active(q)) { if (!q->is_output && (q->io_modes & VB2_READ) && (req_events & (POLLIN | POLLRDNORM))) { if (__vb2_init_fileio(q, 1)) return POLLERR; } if (q->is_output && (q->io_modes & VB2_WRITE) && (req_events & (POLLOUT | POLLWRNORM))) { if (__vb2_init_fileio(q, 0)) return POLLERR; /* * Write to OUTPUT queue can be done immediately. */ return POLLOUT | POLLWRNORM; } } /* * There is nothing to wait for if the queue isn't streaming, or if the * error flag is set. */ if (!vb2_is_streaming(q) || q->error) return POLLERR; /* * If this quirk is set and QBUF hasn't been called yet then * return POLLERR as well. This only affects capture queues, output * queues will always initialize waiting_for_buffers to false. * This quirk is set by V4L2 for backwards compatibility reasons. */ if (q->quirk_poll_must_check_waiting_for_buffers && q->waiting_for_buffers && (req_events & (POLLIN | POLLRDNORM))) return POLLERR; /* * For output streams you can call write() as long as there are fewer * buffers queued than there are buffers available. */ if (q->is_output && q->fileio && q->queued_count < q->num_buffers) return POLLOUT | POLLWRNORM; if (list_empty(&q->done_list)) { /* * If the last buffer was dequeued from a capture queue, * return immediately. DQBUF will return -EPIPE. */ if (q->last_buffer_dequeued) return POLLIN | POLLRDNORM; 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 (q->is_output) ? POLLOUT | POLLWRNORM : POLLIN | POLLRDNORM; } return 0; } EXPORT_SYMBOL_GPL(vb2_core_poll); /** * 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 * * @cur_index: the index of the buffer currently being read from or * written to. If equal to q->num_buffers then a new buffer * must be dequeued. * @initial_index: in the read() case all buffers are queued up immediately * in __vb2_init_fileio() and __vb2_perform_fileio() just cycles * buffers. However, in the write() case no buffers are initially * queued, instead whenever a buffer is full it is queued up by * __vb2_perform_fileio(). Only once all available buffers have * been queued up will __vb2_perform_fileio() start to dequeue * buffers. This means that initially __vb2_perform_fileio() * needs to know what buffer index to use when it is queuing up * the buffers for the first time. That initial index is stored * in this field. Once it is equal to q->num_buffers all * available buffers have been queued and __vb2_perform_fileio() * should start the normal dequeue/queue cycle. * * 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 { unsigned int count; unsigned int type; unsigned int memory; struct vb2_fileio_buf bufs[VB2_MAX_FRAME]; unsigned int cur_index; unsigned int initial_index; unsigned int q_count; unsigned int dq_count; unsigned read_once:1; unsigned write_immediately:1; }; /** * __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 (WARN_ON((read && !(q->io_modes & VB2_READ)) || (!read && !(q->io_modes & VB2_WRITE)))) return -EINVAL; /* * 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, read_once %d, write_immediately %d\n", (read) ? "read" : "write", count, q->fileio_read_once, q->fileio_write_immediately); fileio = kzalloc(sizeof(*fileio), GFP_KERNEL); if (fileio == NULL) return -ENOMEM; fileio->read_once = q->fileio_read_once; fileio->write_immediately = q->fileio_write_immediately; /* * Request buffers and use MMAP type to force driver * to allocate buffers by itself. */ fileio->count = count; fileio->memory = VB2_MEMORY_MMAP; fileio->type = q->type; q->fileio = fileio; ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count); if (ret) goto err_kfree; /* * Check if plane_count is correct * (multiplane buffers are not supported). */ if (q->bufs[0]->num_planes != 1) { ret = -EBUSY; goto err_reqbufs; } /* * Get kernel address of each buffer. */ for (i = 0; i < q->num_buffers; i++) { fileio->bufs[i].vaddr = vb2_plane_vaddr(q->bufs[i], 0); if (fileio->bufs[i].vaddr == NULL) { ret = -EINVAL; goto err_reqbufs; } fileio->bufs[i].size = vb2_plane_size(q->bufs[i], 0); } /* * Read mode requires pre queuing of all buffers. */ if (read) { /* * Queue all buffers. */ for (i = 0; i < q->num_buffers; i++) { ret = vb2_core_qbuf(q, i, NULL); if (ret) goto err_reqbufs; fileio->bufs[i].queued = 1; } /* * All buffers have been queued, so mark that by setting * initial_index to q->num_buffers */ fileio->initial_index = q->num_buffers; fileio->cur_index = q->num_buffers; } /* * Start streaming. */ ret = vb2_core_streamon(q, q->type); if (ret) goto err_reqbufs; return ret; err_reqbufs: fileio->count = 0; vb2_core_reqbufs(q, fileio->memory, &fileio->count); err_kfree: q->fileio = NULL; 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) { vb2_core_streamoff(q, q->type); q->fileio = NULL; fileio->count = 0; vb2_core_reqbufs(q, fileio->memory, &fileio->count); 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; bool is_multiplanar = q->is_multiplanar; /* * When using write() to write data to an output video node the vb2 core * should copy timestamps if V4L2_BUF_FLAG_TIMESTAMP_COPY is set. Nobody * else is able to provide this information with the write() operation. */ bool copy_timestamp = !read && q->copy_timestamp; unsigned index; int ret; dprintk(3, "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 (!vb2_fileio_is_active(q)) { ret = __vb2_init_fileio(q, read); dprintk(3, "vb2_init_fileio result: %d\n", ret); if (ret) return ret; } fileio = q->fileio; /* * Check if we need to dequeue the buffer. */ index = fileio->cur_index; if (index >= q->num_buffers) { struct vb2_buffer *b; /* * Call vb2_dqbuf to get buffer back. */ ret = vb2_core_dqbuf(q, &index, NULL, nonblock); dprintk(5, "vb2_dqbuf result: %d\n", ret); if (ret) return ret; fileio->dq_count += 1; fileio->cur_index = index; buf = &fileio->bufs[index]; b = q->bufs[index]; /* * Get number of bytes filled by the driver */ buf->pos = 0; buf->queued = 0; buf->size = read ? vb2_get_plane_payload(q->bufs[index], 0) : vb2_plane_size(q->bufs[index], 0); /* Compensate for data_offset on read in the multiplanar case. */ if (is_multiplanar && read && b->planes[0].data_offset < buf->size) { buf->pos = b->planes[0].data_offset; buf->size -= buf->pos; } } else { buf = &fileio->bufs[index]; } /* * 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, "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, "error copying data\n"); return -EFAULT; } /* * Update counters. */ buf->pos += count; *ppos += count; /* * Queue next buffer if required. */ if (buf->pos == buf->size || (!read && fileio->write_immediately)) { struct vb2_buffer *b = q->bufs[index]; /* * Check if this is the last buffer to read. */ if (read && fileio->read_once && fileio->dq_count == 1) { dprintk(3, "read limit reached\n"); return __vb2_cleanup_fileio(q); } /* * Call vb2_qbuf and give buffer to the driver. */ b->planes[0].bytesused = buf->pos; if (copy_timestamp) b->timestamp = ktime_get_ns(); ret = vb2_core_qbuf(q, index, NULL); dprintk(5, "vb2_dbuf result: %d\n", ret); if (ret) return ret; /* * Buffer has been queued, update the status */ buf->pos = 0; buf->queued = 1; buf->size = vb2_plane_size(q->bufs[index], 0); fileio->q_count += 1; /* * If we are queuing up buffers for the first time, then * increase initial_index by one. */ if (fileio->initial_index < q->num_buffers) fileio->initial_index++; /* * The next buffer to use is either a buffer that's going to be * queued for the first time (initial_index < q->num_buffers) * or it is equal to q->num_buffers, meaning that the next * time we need to dequeue a buffer since we've now queued up * all the 'first time' buffers. */ fileio->cur_index = fileio->initial_index; } /* * Return proper number of bytes processed. */ if (ret == 0) ret = count; return ret; } size_t vb2_read(struct vb2_queue *q, char __user *data, size_t count, loff_t *ppos, int nonblocking) { return __vb2_perform_fileio(q, data, count, ppos, nonblocking, 1); } EXPORT_SYMBOL_GPL(vb2_read); size_t vb2_write(struct vb2_queue *q, const char __user *data, size_t count, loff_t *ppos, int nonblocking) { return __vb2_perform_fileio(q, (char __user *) data, count, ppos, nonblocking, 0); } EXPORT_SYMBOL_GPL(vb2_write); struct vb2_threadio_data { struct task_struct *thread; vb2_thread_fnc fnc; void *priv; bool stop; }; static int vb2_thread(void *data) { struct vb2_queue *q = data; struct vb2_threadio_data *threadio = q->threadio; bool copy_timestamp = false; unsigned prequeue = 0; unsigned index = 0; int ret = 0; if (q->is_output) { prequeue = q->num_buffers; copy_timestamp = q->copy_timestamp; } set_freezable(); for (;;) { struct vb2_buffer *vb; /* * Call vb2_dqbuf to get buffer back. */ if (prequeue) { vb = q->bufs[index++]; prequeue--; } else { call_void_qop(q, wait_finish, q); if (!threadio->stop) ret = vb2_core_dqbuf(q, &index, NULL, 0); call_void_qop(q, wait_prepare, q); dprintk(5, "file io: vb2_dqbuf result: %d\n", ret); if (!ret) vb = q->bufs[index]; } if (ret || threadio->stop) break; try_to_freeze(); if (vb->state != VB2_BUF_STATE_ERROR) if (threadio->fnc(vb, threadio->priv)) break; call_void_qop(q, wait_finish, q); if (copy_timestamp) vb->timestamp = ktime_get_ns();; if (!threadio->stop) ret = vb2_core_qbuf(q, vb->index, NULL); call_void_qop(q, wait_prepare, q); if (ret || threadio->stop) break; } /* Hmm, linux becomes *very* unhappy without this ... */ while (!kthread_should_stop()) { set_current_state(TASK_INTERRUPTIBLE); schedule(); } return 0; } /* * This function should not be used for anything else but the videobuf2-dvb * support. If you think you have another good use-case for this, then please * contact the linux-media mailinglist first. */ int vb2_thread_start(struct vb2_queue *q, vb2_thread_fnc fnc, void *priv, const char *thread_name) { struct vb2_threadio_data *threadio; int ret = 0; if (q->threadio) return -EBUSY; if (vb2_is_busy(q)) return -EBUSY; if (WARN_ON(q->fileio)) return -EBUSY; threadio = kzalloc(sizeof(*threadio), GFP_KERNEL); if (threadio == NULL) return -ENOMEM; threadio->fnc = fnc; threadio->priv = priv; ret = __vb2_init_fileio(q, !q->is_output); dprintk(3, "file io: vb2_init_fileio result: %d\n", ret); if (ret) goto nomem; q->threadio = threadio; threadio->thread = kthread_run(vb2_thread, q, "vb2-%s", thread_name); if (IS_ERR(threadio->thread)) { ret = PTR_ERR(threadio->thread); threadio->thread = NULL; goto nothread; } return 0; nothread: __vb2_cleanup_fileio(q); nomem: kfree(threadio); return ret; } EXPORT_SYMBOL_GPL(vb2_thread_start); int vb2_thread_stop(struct vb2_queue *q) { struct vb2_threadio_data *threadio = q->threadio; int err; if (threadio == NULL) return 0; threadio->stop = true; /* Wake up all pending sleeps in the thread */ vb2_queue_error(q); err = kthread_stop(threadio->thread); __vb2_cleanup_fileio(q); threadio->thread = NULL; kfree(threadio); q->threadio = NULL; return err; } EXPORT_SYMBOL_GPL(vb2_thread_stop); MODULE_DESCRIPTION("Media buffer core framework"); MODULE_AUTHOR("Pawel Osciak , Marek Szyprowski"); MODULE_LICENSE("GPL");