diff options
Diffstat (limited to 'drivers/media/platform/omap3isp/ispqueue.c')
| -rw-r--r-- | drivers/media/platform/omap3isp/ispqueue.c | 1158 |
1 files changed, 1158 insertions, 0 deletions
diff --git a/drivers/media/platform/omap3isp/ispqueue.c b/drivers/media/platform/omap3isp/ispqueue.c new file mode 100644 index 000000000000..15bf3eab2224 --- /dev/null +++ b/drivers/media/platform/omap3isp/ispqueue.c @@ -0,0 +1,1158 @@ +/* + * ispqueue.c + * + * TI OMAP3 ISP - Video buffers queue handling + * + * Copyright (C) 2010 Nokia Corporation + * + * Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com> + * Sakari Ailus <sakari.ailus@iki.fi> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA + * 02110-1301 USA + */ + +#include <asm/cacheflush.h> +#include <linux/dma-mapping.h> +#include <linux/mm.h> +#include <linux/pagemap.h> +#include <linux/poll.h> +#include <linux/scatterlist.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> + +#include "ispqueue.h" + +/* ----------------------------------------------------------------------------- + * Video buffers management + */ + +/* + * isp_video_buffer_cache_sync - Keep the buffers coherent between CPU and ISP + * + * The typical operation required here is Cache Invalidation across + * the (user space) buffer address range. And this _must_ be done + * at QBUF stage (and *only* at QBUF). + * + * We try to use optimal cache invalidation function: + * - dmac_map_area: + * - used when the number of pages are _low_. + * - it becomes quite slow as the number of pages increase. + * - for 648x492 viewfinder (150 pages) it takes 1.3 ms. + * - for 5 Mpix buffer (2491 pages) it takes between 25-50 ms. + * + * - flush_cache_all: + * - used when the number of pages are _high_. + * - time taken in the range of 500-900 us. + * - has a higher penalty but, as whole dcache + icache is invalidated + */ +/* + * FIXME: dmac_inv_range crashes randomly on the user space buffer + * address. Fall back to flush_cache_all for now. + */ +#define ISP_CACHE_FLUSH_PAGES_MAX 0 + +static void isp_video_buffer_cache_sync(struct isp_video_buffer *buf) +{ + if (buf->skip_cache) + return; + + if (buf->vbuf.m.userptr == 0 || buf->npages == 0 || + buf->npages > ISP_CACHE_FLUSH_PAGES_MAX) + flush_cache_all(); + else { + dmac_map_area((void *)buf->vbuf.m.userptr, buf->vbuf.length, + DMA_FROM_DEVICE); + outer_inv_range(buf->vbuf.m.userptr, + buf->vbuf.m.userptr + buf->vbuf.length); + } +} + +/* + * isp_video_buffer_lock_vma - Prevent VMAs from being unmapped + * + * Lock the VMAs underlying the given buffer into memory. This avoids the + * userspace buffer mapping from being swapped out, making VIPT cache handling + * easier. + * + * Note that the pages will not be freed as the buffers have been locked to + * memory using by a call to get_user_pages(), but the userspace mapping could + * still disappear if the VMAs are not locked. This is caused by the memory + * management code trying to be as lock-less as possible, which results in the + * userspace mapping manager not finding out that the pages are locked under + * some conditions. + */ +static int isp_video_buffer_lock_vma(struct isp_video_buffer *buf, int lock) +{ + struct vm_area_struct *vma; + unsigned long start; + unsigned long end; + int ret = 0; + + if (buf->vbuf.memory == V4L2_MEMORY_MMAP) + return 0; + + /* We can be called from workqueue context if the current task dies to + * unlock the VMAs. In that case there's no current memory management + * context so unlocking can't be performed, but the VMAs have been or + * are getting destroyed anyway so it doesn't really matter. + */ + if (!current || !current->mm) + return lock ? -EINVAL : 0; + + start = buf->vbuf.m.userptr; + end = buf->vbuf.m.userptr + buf->vbuf.length - 1; + + down_write(¤t->mm->mmap_sem); + spin_lock(¤t->mm->page_table_lock); + + do { + vma = find_vma(current->mm, start); + if (vma == NULL) { + ret = -EFAULT; + goto out; + } + + if (lock) + vma->vm_flags |= VM_LOCKED; + else + vma->vm_flags &= ~VM_LOCKED; + + start = vma->vm_end + 1; + } while (vma->vm_end < end); + + if (lock) + buf->vm_flags |= VM_LOCKED; + else + buf->vm_flags &= ~VM_LOCKED; + +out: + spin_unlock(¤t->mm->page_table_lock); + up_write(¤t->mm->mmap_sem); + return ret; +} + +/* + * isp_video_buffer_sglist_kernel - Build a scatter list for a vmalloc'ed buffer + * + * Iterate over the vmalloc'ed area and create a scatter list entry for every + * page. + */ +static int isp_video_buffer_sglist_kernel(struct isp_video_buffer *buf) +{ + struct scatterlist *sglist; + unsigned int npages; + unsigned int i; + void *addr; + + addr = buf->vaddr; + npages = PAGE_ALIGN(buf->vbuf.length) >> PAGE_SHIFT; + + sglist = vmalloc(npages * sizeof(*sglist)); + if (sglist == NULL) + return -ENOMEM; + + sg_init_table(sglist, npages); + + for (i = 0; i < npages; ++i, addr += PAGE_SIZE) { + struct page *page = vmalloc_to_page(addr); + + if (page == NULL || PageHighMem(page)) { + vfree(sglist); + return -EINVAL; + } + + sg_set_page(&sglist[i], page, PAGE_SIZE, 0); + } + + buf->sglen = npages; + buf->sglist = sglist; + + return 0; +} + +/* + * isp_video_buffer_sglist_user - Build a scatter list for a userspace buffer + * + * Walk the buffer pages list and create a 1:1 mapping to a scatter list. + */ +static int isp_video_buffer_sglist_user(struct isp_video_buffer *buf) +{ + struct scatterlist *sglist; + unsigned int offset = buf->offset; + unsigned int i; + + sglist = vmalloc(buf->npages * sizeof(*sglist)); + if (sglist == NULL) + return -ENOMEM; + + sg_init_table(sglist, buf->npages); + + for (i = 0; i < buf->npages; ++i) { + if (PageHighMem(buf->pages[i])) { + vfree(sglist); + return -EINVAL; + } + + sg_set_page(&sglist[i], buf->pages[i], PAGE_SIZE - offset, + offset); + offset = 0; + } + + buf->sglen = buf->npages; + buf->sglist = sglist; + + return 0; +} + +/* + * isp_video_buffer_sglist_pfnmap - Build a scatter list for a VM_PFNMAP buffer + * + * Create a scatter list of physically contiguous pages starting at the buffer + * memory physical address. + */ +static int isp_video_buffer_sglist_pfnmap(struct isp_video_buffer *buf) +{ + struct scatterlist *sglist; + unsigned int offset = buf->offset; + unsigned long pfn = buf->paddr >> PAGE_SHIFT; + unsigned int i; + + sglist = vmalloc(buf->npages * sizeof(*sglist)); + if (sglist == NULL) + return -ENOMEM; + + sg_init_table(sglist, buf->npages); + + for (i = 0; i < buf->npages; ++i, ++pfn) { + sg_set_page(&sglist[i], pfn_to_page(pfn), PAGE_SIZE - offset, + offset); + /* PFNMAP buffers will not get DMA-mapped, set the DMA address + * manually. + */ + sg_dma_address(&sglist[i]) = (pfn << PAGE_SHIFT) + offset; + offset = 0; + } + + buf->sglen = buf->npages; + buf->sglist = sglist; + + return 0; +} + +/* + * isp_video_buffer_cleanup - Release pages for a userspace VMA. + * + * Release pages locked by a call isp_video_buffer_prepare_user and free the + * pages table. + */ +static void isp_video_buffer_cleanup(struct isp_video_buffer *buf) +{ + enum dma_data_direction direction; + unsigned int i; + + if (buf->queue->ops->buffer_cleanup) + buf->queue->ops->buffer_cleanup(buf); + + if (!(buf->vm_flags & VM_PFNMAP)) { + direction = buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE + ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + dma_unmap_sg(buf->queue->dev, buf->sglist, buf->sglen, + direction); + } + + vfree(buf->sglist); + buf->sglist = NULL; + buf->sglen = 0; + + if (buf->pages != NULL) { + isp_video_buffer_lock_vma(buf, 0); + + for (i = 0; i < buf->npages; ++i) + page_cache_release(buf->pages[i]); + + vfree(buf->pages); + buf->pages = NULL; + } + + buf->npages = 0; + buf->skip_cache = false; +} + +/* + * isp_video_buffer_prepare_user - Pin userspace VMA pages to memory. + * + * This function creates a list of pages for a userspace VMA. The number of + * pages is first computed based on the buffer size, and pages are then + * retrieved by a call to get_user_pages. + * + * Pages are pinned to memory by get_user_pages, making them available for DMA + * transfers. However, due to memory management optimization, it seems the + * get_user_pages doesn't guarantee that the pinned pages will not be written + * to swap and removed from the userspace mapping(s). When this happens, a page + * fault can be generated when accessing those unmapped pages. + * + * If the fault is triggered by a page table walk caused by VIPT cache + * management operations, the page fault handler might oops if the MM semaphore + * is held, as it can't handle kernel page faults in that case. To fix that, a + * fixup entry needs to be added to the cache management code, or the userspace + * VMA must be locked to avoid removing pages from the userspace mapping in the + * first place. + * + * If the number of pages retrieved is smaller than the number required by the + * buffer size, the function returns -EFAULT. + */ +static int isp_video_buffer_prepare_user(struct isp_video_buffer *buf) +{ + unsigned long data; + unsigned int first; + unsigned int last; + int ret; + + data = buf->vbuf.m.userptr; + first = (data & PAGE_MASK) >> PAGE_SHIFT; + last = ((data + buf->vbuf.length - 1) & PAGE_MASK) >> PAGE_SHIFT; + + buf->offset = data & ~PAGE_MASK; + buf->npages = last - first + 1; + buf->pages = vmalloc(buf->npages * sizeof(buf->pages[0])); + if (buf->pages == NULL) + return -ENOMEM; + + down_read(¤t->mm->mmap_sem); + ret = get_user_pages(current, current->mm, data & PAGE_MASK, + buf->npages, + buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE, 0, + buf->pages, NULL); + up_read(¤t->mm->mmap_sem); + + if (ret != buf->npages) { + buf->npages = ret < 0 ? 0 : ret; + isp_video_buffer_cleanup(buf); + return -EFAULT; + } + + ret = isp_video_buffer_lock_vma(buf, 1); + if (ret < 0) + isp_video_buffer_cleanup(buf); + + return ret; +} + +/* + * isp_video_buffer_prepare_pfnmap - Validate a VM_PFNMAP userspace buffer + * + * Userspace VM_PFNMAP buffers are supported only if they are contiguous in + * memory and if they span a single VMA. + * + * Return 0 if the buffer is valid, or -EFAULT otherwise. + */ +static int isp_video_buffer_prepare_pfnmap(struct isp_video_buffer *buf) +{ + struct vm_area_struct *vma; + unsigned long prev_pfn; + unsigned long this_pfn; + unsigned long start; + unsigned long end; + dma_addr_t pa; + int ret = -EFAULT; + + start = buf->vbuf.m.userptr; + end = buf->vbuf.m.userptr + buf->vbuf.length - 1; + + buf->offset = start & ~PAGE_MASK; + buf->npages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1; + buf->pages = NULL; + + down_read(¤t->mm->mmap_sem); + vma = find_vma(current->mm, start); + if (vma == NULL || vma->vm_end < end) + goto done; + + for (prev_pfn = 0; start <= end; start += PAGE_SIZE) { + ret = follow_pfn(vma, start, &this_pfn); + if (ret) + goto done; + + if (prev_pfn == 0) + pa = this_pfn << PAGE_SHIFT; + else if (this_pfn != prev_pfn + 1) { + ret = -EFAULT; + goto done; + } + + prev_pfn = this_pfn; + } + + buf->paddr = pa + buf->offset; + ret = 0; + +done: + up_read(¤t->mm->mmap_sem); + return ret; +} + +/* + * isp_video_buffer_prepare_vm_flags - Get VMA flags for a userspace address + * + * This function locates the VMAs for the buffer's userspace address and checks + * that their flags match. The only flag that we need to care for at the moment + * is VM_PFNMAP. + * + * The buffer vm_flags field is set to the first VMA flags. + * + * Return -EFAULT if no VMA can be found for part of the buffer, or if the VMAs + * have incompatible flags. + */ +static int isp_video_buffer_prepare_vm_flags(struct isp_video_buffer *buf) +{ + struct vm_area_struct *vma; + pgprot_t vm_page_prot; + unsigned long start; + unsigned long end; + int ret = -EFAULT; + + start = buf->vbuf.m.userptr; + end = buf->vbuf.m.userptr + buf->vbuf.length - 1; + + down_read(¤t->mm->mmap_sem); + + do { + vma = find_vma(current->mm, start); + if (vma == NULL) + goto done; + + if (start == buf->vbuf.m.userptr) { + buf->vm_flags = vma->vm_flags; + vm_page_prot = vma->vm_page_prot; + } + + if ((buf->vm_flags ^ vma->vm_flags) & VM_PFNMAP) + goto done; + + if (vm_page_prot != vma->vm_page_prot) + goto done; + + start = vma->vm_end + 1; + } while (vma->vm_end < end); + + /* Skip cache management to enhance performances for non-cached or + * write-combining buffers. + */ + if (vm_page_prot == pgprot_noncached(vm_page_prot) || + vm_page_prot == pgprot_writecombine(vm_page_prot)) + buf->skip_cache = true; + + ret = 0; + +done: + up_read(¤t->mm->mmap_sem); + return ret; +} + +/* + * isp_video_buffer_prepare - Make a buffer ready for operation + * + * Preparing a buffer involves: + * + * - validating VMAs (userspace buffers only) + * - locking pages and VMAs into memory (userspace buffers only) + * - building page and scatter-gather lists + * - mapping buffers for DMA operation + * - performing driver-specific preparation + * + * The function must be called in userspace context with a valid mm context + * (this excludes cleanup paths such as sys_close when the userspace process + * segfaults). + */ +static int isp_video_buffer_prepare(struct isp_video_buffer *buf) +{ + enum dma_data_direction direction; + int ret; + + switch (buf->vbuf.memory) { + case V4L2_MEMORY_MMAP: + ret = isp_video_buffer_sglist_kernel(buf); + break; + + case V4L2_MEMORY_USERPTR: + ret = isp_video_buffer_prepare_vm_flags(buf); + if (ret < 0) + return ret; + + if (buf->vm_flags & VM_PFNMAP) { + ret = isp_video_buffer_prepare_pfnmap(buf); + if (ret < 0) + return ret; + + ret = isp_video_buffer_sglist_pfnmap(buf); + } else { + ret = isp_video_buffer_prepare_user(buf); + if (ret < 0) + return ret; + + ret = isp_video_buffer_sglist_user(buf); + } + break; + + default: + return -EINVAL; + } + + if (ret < 0) + goto done; + + if (!(buf->vm_flags & VM_PFNMAP)) { + direction = buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE + ? DMA_FROM_DEVICE : DMA_TO_DEVICE; + ret = dma_map_sg(buf->queue->dev, buf->sglist, buf->sglen, + direction); + if (ret != buf->sglen) { + ret = -EFAULT; + goto done; + } + } + + if (buf->queue->ops->buffer_prepare) + ret = buf->queue->ops->buffer_prepare(buf); + +done: + if (ret < 0) { + isp_video_buffer_cleanup(buf); + return ret; + } + + return ret; +} + +/* + * isp_video_queue_query - Query the status of a given buffer + * + * Locking: must be called with the queue lock held. + */ +static void isp_video_buffer_query(struct isp_video_buffer *buf, + struct v4l2_buffer *vbuf) +{ + memcpy(vbuf, &buf->vbuf, sizeof(*vbuf)); + + if (buf->vma_use_count) + vbuf->flags |= V4L2_BUF_FLAG_MAPPED; + + switch (buf->state) { + case ISP_BUF_STATE_ERROR: + vbuf->flags |= V4L2_BUF_FLAG_ERROR; + case ISP_BUF_STATE_DONE: + vbuf->flags |= V4L2_BUF_FLAG_DONE; + case ISP_BUF_STATE_QUEUED: + case ISP_BUF_STATE_ACTIVE: + vbuf->flags |= V4L2_BUF_FLAG_QUEUED; + break; + case ISP_BUF_STATE_IDLE: + default: + break; + } +} + +/* + * isp_video_buffer_wait - Wait for a buffer to be ready + * + * In non-blocking mode, return immediately with 0 if the buffer is ready or + * -EAGAIN if the buffer is in the QUEUED or ACTIVE state. + * + * In blocking mode, wait (interruptibly but with no timeout) on the buffer wait + * queue using the same condition. + */ +static int isp_video_buffer_wait(struct isp_video_buffer *buf, int nonblocking) +{ + if (nonblocking) { + return (buf->state != ISP_BUF_STATE_QUEUED && + buf->state != ISP_BUF_STATE_ACTIVE) + ? 0 : -EAGAIN; + } + + return wait_event_interruptible(buf->wait, + buf->state != ISP_BUF_STATE_QUEUED && + buf->state != ISP_BUF_STATE_ACTIVE); +} + +/* ----------------------------------------------------------------------------- + * Queue management + */ + +/* + * isp_video_queue_free - Free video buffers memory + * + * Buffers can only be freed if the queue isn't streaming and if no buffer is + * mapped to userspace. Return -EBUSY if those conditions aren't statisfied. + * + * This function must be called with the queue lock held. + */ +static int isp_video_queue_free(struct isp_video_queue *queue) +{ + unsigned int i; + + if (queue->streaming) + return -EBUSY; + + for (i = 0; i < queue->count; ++i) { + if (queue->buffers[i]->vma_use_count != 0) + return -EBUSY; + } + + for (i = 0; i < queue->count; ++i) { + struct isp_video_buffer *buf = queue->buffers[i]; + + isp_video_buffer_cleanup(buf); + + vfree(buf->vaddr); + buf->vaddr = NULL; + + kfree(buf); + queue->buffers[i] = NULL; + } + + INIT_LIST_HEAD(&queue->queue); + queue->count = 0; + return 0; +} + +/* + * isp_video_queue_alloc - Allocate video buffers memory + * + * This function must be called with the queue lock held. + */ +static int isp_video_queue_alloc(struct isp_video_queue *queue, + unsigned int nbuffers, + unsigned int size, enum v4l2_memory memory) +{ + struct isp_video_buffer *buf; + unsigned int i; + void *mem; + int ret; + + /* Start by freeing the buffers. */ + ret = isp_video_queue_free(queue); + if (ret < 0) + return ret; + + /* Bail out if no buffers should be allocated. */ + if (nbuffers == 0) + return 0; + + /* Initialize the allocated buffers. */ + for (i = 0; i < nbuffers; ++i) { + buf = kzalloc(queue->bufsize, GFP_KERNEL); + if (buf == NULL) + break; + + if (memory == V4L2_MEMORY_MMAP) { + /* Allocate video buffers memory for mmap mode. Align + * the size to the page size. + */ + mem = vmalloc_32_user(PAGE_ALIGN(size)); + if (mem == NULL) { + kfree(buf); + break; + } + + buf->vbuf.m.offset = i * PAGE_ALIGN(size); + buf->vaddr = mem; + } + + buf->vbuf.index = i; + buf->vbuf.length = size; + buf->vbuf.type = queue->type; + buf->vbuf.field = V4L2_FIELD_NONE; + buf->vbuf.memory = memory; + + buf->queue = queue; + init_waitqueue_head(&buf->wait); + + queue->buffers[i] = buf; + } + + if (i == 0) + return -ENOMEM; + + queue->count = i; + return nbuffers; +} + +/** + * omap3isp_video_queue_cleanup - Clean up the video buffers queue + * @queue: Video buffers queue + * + * Free all allocated resources and clean up the video buffers queue. The queue + * must not be busy (no ongoing video stream) and buffers must have been + * unmapped. + * + * Return 0 on success or -EBUSY if the queue is busy or buffers haven't been + * unmapped. + */ +int omap3isp_video_queue_cleanup(struct isp_video_queue *queue) +{ + return isp_video_queue_free(queue); +} + +/** + * omap3isp_video_queue_init - Initialize the video buffers queue + * @queue: Video buffers queue + * @type: V4L2 buffer type (capture or output) + * @ops: Driver-specific queue operations + * @dev: Device used for DMA operations + * @bufsize: Size of the driver-specific buffer structure + * + * Initialize the video buffers queue with the supplied parameters. + * + * The queue type must be one of V4L2_BUF_TYPE_VIDEO_CAPTURE or + * V4L2_BUF_TYPE_VIDEO_OUTPUT. Other buffer types are not supported yet. + * + * Buffer objects will be allocated using the given buffer size to allow room + * for driver-specific fields. Driver-specific buffer structures must start + * with a struct isp_video_buffer field. Drivers with no driver-specific buffer + * structure must pass the size of the isp_video_buffer structure in the bufsize + * parameter. + * + * Return 0 on success. + */ +int omap3isp_video_queue_init(struct isp_video_queue *queue, + enum v4l2_buf_type type, + const struct isp_video_queue_operations *ops, + struct device *dev, unsigned int bufsize) +{ + INIT_LIST_HEAD(&queue->queue); + mutex_init(&queue->lock); + spin_lock_init(&queue->irqlock); + + queue->type = type; + queue->ops = ops; + queue->dev = dev; + queue->bufsize = bufsize; + + return 0; +} + +/* ----------------------------------------------------------------------------- + * V4L2 operations + */ + +/** + * omap3isp_video_queue_reqbufs - Allocate video buffers memory + * + * This function is intended to be used as a VIDIOC_REQBUFS ioctl handler. It + * allocated video buffer objects and, for MMAP buffers, buffer memory. + * + * If the number of buffers is 0, all buffers are freed and the function returns + * without performing any allocation. + * + * If the number of buffers is not 0, currently allocated buffers (if any) are + * freed and the requested number of buffers are allocated. Depending on + * driver-specific requirements and on memory availability, a number of buffer + * smaller or bigger than requested can be allocated. This isn't considered as + * an error. + * + * Return 0 on success or one of the following error codes: + * + * -EINVAL if the buffer type or index are invalid + * -EBUSY if the queue is busy (streaming or buffers mapped) + * -ENOMEM if the buffers can't be allocated due to an out-of-memory condition + */ +int omap3isp_video_queue_reqbufs(struct isp_video_queue *queue, + struct v4l2_requestbuffers *rb) +{ + unsigned int nbuffers = rb->count; + unsigned int size; + int ret; + + if (rb->type != queue->type) + return -EINVAL; + + queue->ops->queue_prepare(queue, &nbuffers, &size); + if (size == 0) + return -EINVAL; + + nbuffers = min_t(unsigned int, nbuffers, ISP_VIDEO_MAX_BUFFERS); + + mutex_lock(&queue->lock); + + ret = isp_video_queue_alloc(queue, nbuffers, size, rb->memory); + if (ret < 0) + goto done; + + rb->count = ret; + ret = 0; + +done: + mutex_unlock(&queue->lock); + return ret; +} + +/** + * omap3isp_video_queue_querybuf - Query the status of a buffer in a queue + * + * This function is intended to be used as a VIDIOC_QUERYBUF ioctl handler. It + * returns the status of a given video buffer. + * + * Return 0 on success or -EINVAL if the buffer type or index are invalid. + */ +int omap3isp_video_queue_querybuf(struct isp_video_queue *queue, + struct v4l2_buffer *vbuf) +{ + struct isp_video_buffer *buf; + int ret = 0; + + if (vbuf->type != queue->type) + return -EINVAL; + + mutex_lock(&queue->lock); + + if (vbuf->index >= queue->count) { + ret = -EINVAL; + goto done; + } + + buf = queue->buffers[vbuf->index]; + isp_video_buffer_query(buf, vbuf); + +done: + mutex_unlock(&queue->lock); + return ret; +} + +/** + * omap3isp_video_queue_qbuf - Queue a buffer + * + * This function is intended to be used as a VIDIOC_QBUF ioctl handler. + * + * The v4l2_buffer structure passed from userspace is first sanity tested. If + * sane, the buffer is then processed and added to the main queue and, if the + * queue is streaming, to the IRQ queue. + * + * Before being enqueued, USERPTR buffers are checked for address changes. If + * the buffer has a different userspace address, the old memory area is unlocked + * and the new memory area is locked. + */ +int omap3isp_video_queue_qbuf(struct isp_video_queue *queue, + struct v4l2_buffer *vbuf) +{ + struct isp_video_buffer *buf; + unsigned long flags; + int ret = -EINVAL; + + if (vbuf->type != queue->type) + goto done; + + mutex_lock(&queue->lock); + + if (vbuf->index >= queue->count) + goto done; + + buf = queue->buffers[vbuf->index]; + + if (vbuf->memory != buf->vbuf.memory) + goto done; + + if (buf->state != ISP_BUF_STATE_IDLE) + goto done; + + if (vbuf->memory == V4L2_MEMORY_USERPTR && + vbuf->length < buf->vbuf.length) + goto done; + + if (vbuf->memory == V4L2_MEMORY_USERPTR && + vbuf->m.userptr != buf->vbuf.m.userptr) { + isp_video_buffer_cleanup(buf); + buf->vbuf.m.userptr = vbuf->m.userptr; + buf->prepared = 0; + } + + if (!buf->prepared) { + ret = isp_video_buffer_prepare(buf); + if (ret < 0) + goto done; + buf->prepared = 1; + } + + isp_video_buffer_cache_sync(buf); + + buf->state = ISP_BUF_STATE_QUEUED; + list_add_tail(&buf->stream, &queue->queue); + + if (queue->streaming) { + spin_lock_irqsave(&queue->irqlock, flags); + queue->ops->buffer_queue(buf); + spin_unlock_irqrestore(&queue->irqlock, flags); + } + + ret = 0; + +done: + mutex_unlock(&queue->lock); + return ret; +} + +/** + * omap3isp_video_queue_dqbuf - Dequeue a buffer + * + * This function is intended to be used as a VIDIOC_DQBUF ioctl handler. + * + * Wait until a buffer is ready to be dequeued, remove it from the queue and + * copy its information to the v4l2_buffer structure. + * + * If the nonblocking argument is not zero and no buffer is ready, return + * -EAGAIN immediately instead of waiting. + * + * If no buffer has been enqueued, or if the requested buffer type doesn't match + * the queue type, return -EINVAL. + */ +int omap3isp_video_queue_dqbuf(struct isp_video_queue *queue, + struct v4l2_buffer *vbuf, int nonblocking) +{ + struct isp_video_buffer *buf; + int ret; + + if (vbuf->type != queue->type) + return -EINVAL; + + mutex_lock(&queue->lock); + + if (list_empty(&queue->queue)) { + ret = -EINVAL; + goto done; + } + + buf = list_first_entry(&queue->queue, struct isp_video_buffer, stream); + ret = isp_video_buffer_wait(buf, nonblocking); + if (ret < 0) + goto done; + + list_del(&buf->stream); + + isp_video_buffer_query(buf, vbuf); + buf->state = ISP_BUF_STATE_IDLE; + vbuf->flags &= ~V4L2_BUF_FLAG_QUEUED; + +done: + mutex_unlock(&queue->lock); + return ret; +} + +/** + * omap3isp_video_queue_streamon - Start streaming + * + * This function is intended to be used as a VIDIOC_STREAMON ioctl handler. It + * starts streaming on the queue and calls the buffer_queue operation for all + * queued buffers. + * + * Return 0 on success. + */ +int omap3isp_video_queue_streamon(struct isp_video_queue *queue) +{ + struct isp_video_buffer *buf; + unsigned long flags; + + mutex_lock(&queue->lock); + + if (queue->streaming) + goto done; + + queue->streaming = 1; + + spin_lock_irqsave(&queue->irqlock, flags); + list_for_each_entry(buf, &queue->queue, stream) + queue->ops->buffer_queue(buf); + spin_unlock_irqrestore(&queue->irqlock, flags); + +done: + mutex_unlock(&queue->lock); + return 0; +} + +/** + * omap3isp_video_queue_streamoff - Stop streaming + * + * This function is intended to be used as a VIDIOC_STREAMOFF ioctl handler. It + * stops streaming on the queue and wakes up all the buffers. + * + * 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 omap3isp_video_queue_streamoff(struct isp_video_queue *queue) +{ + struct isp_video_buffer *buf; + unsigned long flags; + unsigned int i; + + mutex_lock(&queue->lock); + + if (!queue->streaming) + goto done; + + queue->streaming = 0; + + spin_lock_irqsave(&queue->irqlock, flags); + for (i = 0; i < queue->count; ++i) { + buf = queue->buffers[i]; + + if (buf->state == ISP_BUF_STATE_ACTIVE) + wake_up(&buf->wait); + + buf->state = ISP_BUF_STATE_IDLE; + } + spin_unlock_irqrestore(&queue->irqlock, flags); + + INIT_LIST_HEAD(&queue->queue); + +done: + mutex_unlock(&queue->lock); +} + +/** + * omap3isp_video_queue_discard_done - Discard all buffers marked as DONE + * + * 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 omap3isp_video_queue_discard_done(struct isp_video_queue *queue) +{ + struct isp_video_buffer *buf; + unsigned int i; + + mutex_lock(&queue->lock); + + if (!queue->streaming) + goto done; + + for (i = 0; i < queue->count; ++i) { + buf = queue->buffers[i]; + + if (buf->state == ISP_BUF_STATE_DONE) + buf->state = ISP_BUF_STATE_ERROR; + } + +done: + mutex_unlock(&queue->lock); +} + +static void isp_video_queue_vm_open(struct vm_area_struct *vma) +{ + struct isp_video_buffer *buf = vma->vm_private_data; + + buf->vma_use_count++; +} + +static void isp_video_queue_vm_close(struct vm_area_struct *vma) +{ + struct isp_video_buffer *buf = vma->vm_private_data; + + buf->vma_use_count--; +} + +static const struct vm_operations_struct isp_video_queue_vm_ops = { + .open = isp_video_queue_vm_open, + .close = isp_video_queue_vm_close, +}; + +/** + * omap3isp_video_queue_mmap - Map buffers to userspace + * + * This function is intended to be used as an mmap() file operation handler. It + * maps a buffer to userspace based on the VMA offset. + * + * Only buffers of memory type MMAP are supported. + */ +int omap3isp_video_queue_mmap(struct isp_video_queue *queue, + struct vm_area_struct *vma) +{ + struct isp_video_buffer *uninitialized_var(buf); + unsigned long size; + unsigned int i; + int ret = 0; + + mutex_lock(&queue->lock); + + for (i = 0; i < queue->count; ++i) { + buf = queue->buffers[i]; + if ((buf->vbuf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff) + break; + } + + if (i == queue->count) { + ret = -EINVAL; + goto done; + } + + size = vma->vm_end - vma->vm_start; + + if (buf->vbuf.memory != V4L2_MEMORY_MMAP || + size != PAGE_ALIGN(buf->vbuf.length)) { + ret = -EINVAL; + goto done; + } + + ret = remap_vmalloc_range(vma, buf->vaddr, 0); + if (ret < 0) + goto done; + + vma->vm_ops = &isp_video_queue_vm_ops; + vma->vm_private_data = buf; + isp_video_queue_vm_open(vma); + +done: + mutex_unlock(&queue->lock); + return ret; +} + +/** + * omap3isp_video_queue_poll - Poll video queue state + * + * This function is intended to be used as a poll() file operation handler. It + * polls the state of the video buffer at the front of the queue and returns an + * events mask. + * + * If no buffer is present at the front of the queue, POLLERR is returned. + */ +unsigned int omap3isp_video_queue_poll(struct isp_video_queue *queue, + struct file *file, poll_table *wait) +{ + struct isp_video_buffer *buf; + unsigned int mask = 0; + + mutex_lock(&queue->lock); + if (list_empty(&queue->queue)) { + mask |= POLLERR; + goto done; + } + buf = list_first_entry(&queue->queue, struct isp_video_buffer, stream); + + poll_wait(file, &buf->wait, wait); + if (buf->state == ISP_BUF_STATE_DONE || + buf->state == ISP_BUF_STATE_ERROR) { + if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE) + mask |= POLLIN | POLLRDNORM; + else + mask |= POLLOUT | POLLWRNORM; + } + +done: + mutex_unlock(&queue->lock); + return mask; +} |