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* TI OMAP3 ISP - Video buffers queue handling
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* Copyright (C) 2010 Nokia Corporation
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* Contacts: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
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* Sakari Ailus <sakari.ailus@iki.fi>
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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* This program is distributed in the hope that it will be useful, but
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* WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
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#include <asm/cacheflush.h>
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#include <linux/dma-mapping.h>
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#include <linux/pagemap.h>
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#include <linux/poll.h>
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#include <linux/scatterlist.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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/* -----------------------------------------------------------------------------
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* Video buffers management
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* isp_video_buffer_cache_sync - Keep the buffers coherent between CPU and ISP
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* The typical operation required here is Cache Invalidation across
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* the (user space) buffer address range. And this _must_ be done
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* at QBUF stage (and *only* at QBUF).
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* We try to use optimal cache invalidation function:
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* - used when the number of pages are _low_.
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* - it becomes quite slow as the number of pages increase.
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* - for 648x492 viewfinder (150 pages) it takes 1.3 ms.
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* - for 5 Mpix buffer (2491 pages) it takes between 25-50 ms.
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* - used when the number of pages are _high_.
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* - time taken in the range of 500-900 us.
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* - has a higher penalty but, as whole dcache + icache is invalidated
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* FIXME: dmac_inv_range crashes randomly on the user space buffer
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* address. Fall back to flush_cache_all for now.
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#define ISP_CACHE_FLUSH_PAGES_MAX 0
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static void isp_video_buffer_cache_sync(struct isp_video_buffer *buf)
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if (buf->vbuf.m.userptr == 0 || buf->npages == 0 ||
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buf->npages > ISP_CACHE_FLUSH_PAGES_MAX)
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dmac_map_area((void *)buf->vbuf.m.userptr, buf->vbuf.length,
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outer_inv_range(buf->vbuf.m.userptr,
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buf->vbuf.m.userptr + buf->vbuf.length);
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* isp_video_buffer_lock_vma - Prevent VMAs from being unmapped
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* Lock the VMAs underlying the given buffer into memory. This avoids the
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* userspace buffer mapping from being swapped out, making VIPT cache handling
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* Note that the pages will not be freed as the buffers have been locked to
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* memory using by a call to get_user_pages(), but the userspace mapping could
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* still disappear if the VMAs are not locked. This is caused by the memory
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* management code trying to be as lock-less as possible, which results in the
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* userspace mapping manager not finding out that the pages are locked under
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static int isp_video_buffer_lock_vma(struct isp_video_buffer *buf, int lock)
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struct vm_area_struct *vma;
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if (buf->vbuf.memory == V4L2_MEMORY_MMAP)
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/* We can be called from workqueue context if the current task dies to
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* unlock the VMAs. In that case there's no current memory management
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* context so unlocking can't be performed, but the VMAs have been or
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* are getting destroyed anyway so it doesn't really matter.
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if (!current || !current->mm)
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return lock ? -EINVAL : 0;
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start = buf->vbuf.m.userptr;
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end = buf->vbuf.m.userptr + buf->vbuf.length - 1;
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down_write(¤t->mm->mmap_sem);
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spin_lock(¤t->mm->page_table_lock);
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vma = find_vma(current->mm, start);
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vma->vm_flags |= VM_LOCKED;
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vma->vm_flags &= ~VM_LOCKED;
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start = vma->vm_end + 1;
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} while (vma->vm_end < end);
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buf->vm_flags |= VM_LOCKED;
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buf->vm_flags &= ~VM_LOCKED;
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spin_unlock(¤t->mm->page_table_lock);
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up_write(¤t->mm->mmap_sem);
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* isp_video_buffer_sglist_kernel - Build a scatter list for a vmalloc'ed buffer
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* Iterate over the vmalloc'ed area and create a scatter list entry for every
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static int isp_video_buffer_sglist_kernel(struct isp_video_buffer *buf)
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struct scatterlist *sglist;
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npages = PAGE_ALIGN(buf->vbuf.length) >> PAGE_SHIFT;
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sglist = vmalloc(npages * sizeof(*sglist));
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sg_init_table(sglist, npages);
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for (i = 0; i < npages; ++i, addr += PAGE_SIZE) {
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struct page *page = vmalloc_to_page(addr);
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if (page == NULL || PageHighMem(page)) {
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sg_set_page(&sglist[i], page, PAGE_SIZE, 0);
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buf->sglist = sglist;
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* isp_video_buffer_sglist_user - Build a scatter list for a userspace buffer
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* Walk the buffer pages list and create a 1:1 mapping to a scatter list.
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static int isp_video_buffer_sglist_user(struct isp_video_buffer *buf)
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struct scatterlist *sglist;
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unsigned int offset = buf->offset;
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sglist = vmalloc(buf->npages * sizeof(*sglist));
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sg_init_table(sglist, buf->npages);
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for (i = 0; i < buf->npages; ++i) {
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if (PageHighMem(buf->pages[i])) {
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sg_set_page(&sglist[i], buf->pages[i], PAGE_SIZE - offset,
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buf->sglen = buf->npages;
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buf->sglist = sglist;
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* isp_video_buffer_sglist_pfnmap - Build a scatter list for a VM_PFNMAP buffer
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* Create a scatter list of physically contiguous pages starting at the buffer
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* memory physical address.
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static int isp_video_buffer_sglist_pfnmap(struct isp_video_buffer *buf)
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struct scatterlist *sglist;
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unsigned int offset = buf->offset;
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unsigned long pfn = buf->paddr >> PAGE_SHIFT;
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sglist = vmalloc(buf->npages * sizeof(*sglist));
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sg_init_table(sglist, buf->npages);
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for (i = 0; i < buf->npages; ++i, ++pfn) {
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sg_set_page(&sglist[i], pfn_to_page(pfn), PAGE_SIZE - offset,
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/* PFNMAP buffers will not get DMA-mapped, set the DMA address
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sg_dma_address(&sglist[i]) = (pfn << PAGE_SHIFT) + offset;
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buf->sglen = buf->npages;
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buf->sglist = sglist;
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* isp_video_buffer_cleanup - Release pages for a userspace VMA.
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* Release pages locked by a call isp_video_buffer_prepare_user and free the
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static void isp_video_buffer_cleanup(struct isp_video_buffer *buf)
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enum dma_data_direction direction;
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if (buf->queue->ops->buffer_cleanup)
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buf->queue->ops->buffer_cleanup(buf);
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if (!(buf->vm_flags & VM_PFNMAP)) {
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direction = buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE
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? DMA_FROM_DEVICE : DMA_TO_DEVICE;
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dma_unmap_sg(buf->queue->dev, buf->sglist, buf->sglen,
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if (buf->pages != NULL) {
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isp_video_buffer_lock_vma(buf, 0);
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for (i = 0; i < buf->npages; ++i)
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page_cache_release(buf->pages[i]);
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buf->skip_cache = false;
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* isp_video_buffer_prepare_user - Pin userspace VMA pages to memory.
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* This function creates a list of pages for a userspace VMA. The number of
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* pages is first computed based on the buffer size, and pages are then
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* retrieved by a call to get_user_pages.
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* Pages are pinned to memory by get_user_pages, making them available for DMA
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* transfers. However, due to memory management optimization, it seems the
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* get_user_pages doesn't guarantee that the pinned pages will not be written
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* to swap and removed from the userspace mapping(s). When this happens, a page
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* fault can be generated when accessing those unmapped pages.
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* If the fault is triggered by a page table walk caused by VIPT cache
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* management operations, the page fault handler might oops if the MM semaphore
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* is held, as it can't handle kernel page faults in that case. To fix that, a
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* fixup entry needs to be added to the cache management code, or the userspace
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* VMA must be locked to avoid removing pages from the userspace mapping in the
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* If the number of pages retrieved is smaller than the number required by the
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* buffer size, the function returns -EFAULT.
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static int isp_video_buffer_prepare_user(struct isp_video_buffer *buf)
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data = buf->vbuf.m.userptr;
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first = (data & PAGE_MASK) >> PAGE_SHIFT;
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last = ((data + buf->vbuf.length - 1) & PAGE_MASK) >> PAGE_SHIFT;
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buf->offset = data & ~PAGE_MASK;
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buf->npages = last - first + 1;
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buf->pages = vmalloc(buf->npages * sizeof(buf->pages[0]));
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if (buf->pages == NULL)
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down_read(¤t->mm->mmap_sem);
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ret = get_user_pages(current, current->mm, data & PAGE_MASK,
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buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE, 0,
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up_read(¤t->mm->mmap_sem);
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if (ret != buf->npages) {
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buf->npages = ret < 0 ? 0 : ret;
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isp_video_buffer_cleanup(buf);
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ret = isp_video_buffer_lock_vma(buf, 1);
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isp_video_buffer_cleanup(buf);
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* isp_video_buffer_prepare_pfnmap - Validate a VM_PFNMAP userspace buffer
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* Userspace VM_PFNMAP buffers are supported only if they are contiguous in
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* memory and if they span a single VMA.
360
* Return 0 if the buffer is valid, or -EFAULT otherwise.
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static int isp_video_buffer_prepare_pfnmap(struct isp_video_buffer *buf)
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struct vm_area_struct *vma;
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unsigned long prev_pfn;
366
unsigned long this_pfn;
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start = buf->vbuf.m.userptr;
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end = buf->vbuf.m.userptr + buf->vbuf.length - 1;
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buf->offset = start & ~PAGE_MASK;
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buf->npages = (end >> PAGE_SHIFT) - (start >> PAGE_SHIFT) + 1;
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down_read(¤t->mm->mmap_sem);
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vma = find_vma(current->mm, start);
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if (vma == NULL || vma->vm_end < end)
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for (prev_pfn = 0; start <= end; start += PAGE_SIZE) {
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ret = follow_pfn(vma, start, &this_pfn);
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pa = this_pfn << PAGE_SHIFT;
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else if (this_pfn != prev_pfn + 1) {
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buf->paddr = pa + buf->offset;
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up_read(¤t->mm->mmap_sem);
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* isp_video_buffer_prepare_vm_flags - Get VMA flags for a userspace address
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* This function locates the VMAs for the buffer's userspace address and checks
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* that their flags match. The only flag that we need to care for at the moment
414
* The buffer vm_flags field is set to the first VMA flags.
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* Return -EFAULT if no VMA can be found for part of the buffer, or if the VMAs
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* have incompatible flags.
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static int isp_video_buffer_prepare_vm_flags(struct isp_video_buffer *buf)
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struct vm_area_struct *vma;
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pgprot_t vm_page_prot;
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start = buf->vbuf.m.userptr;
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end = buf->vbuf.m.userptr + buf->vbuf.length - 1;
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down_read(¤t->mm->mmap_sem);
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vma = find_vma(current->mm, start);
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if (start == buf->vbuf.m.userptr) {
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buf->vm_flags = vma->vm_flags;
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vm_page_prot = vma->vm_page_prot;
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if ((buf->vm_flags ^ vma->vm_flags) & VM_PFNMAP)
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if (vm_page_prot != vma->vm_page_prot)
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start = vma->vm_end + 1;
449
} while (vma->vm_end < end);
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/* Skip cache management to enhance performances for non-cached or
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* write-combining buffers.
454
if (vm_page_prot == pgprot_noncached(vm_page_prot) ||
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vm_page_prot == pgprot_writecombine(vm_page_prot))
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buf->skip_cache = true;
461
up_read(¤t->mm->mmap_sem);
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* isp_video_buffer_prepare - Make a buffer ready for operation
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* Preparing a buffer involves:
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* - validating VMAs (userspace buffers only)
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* - locking pages and VMAs into memory (userspace buffers only)
472
* - building page and scatter-gather lists
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* - mapping buffers for DMA operation
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* - performing driver-specific preparation
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* The function must be called in userspace context with a valid mm context
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* (this excludes cleanup paths such as sys_close when the userspace process
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static int isp_video_buffer_prepare(struct isp_video_buffer *buf)
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enum dma_data_direction direction;
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switch (buf->vbuf.memory) {
486
case V4L2_MEMORY_MMAP:
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ret = isp_video_buffer_sglist_kernel(buf);
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case V4L2_MEMORY_USERPTR:
491
ret = isp_video_buffer_prepare_vm_flags(buf);
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if (buf->vm_flags & VM_PFNMAP) {
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ret = isp_video_buffer_prepare_pfnmap(buf);
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ret = isp_video_buffer_sglist_pfnmap(buf);
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ret = isp_video_buffer_prepare_user(buf);
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ret = isp_video_buffer_sglist_user(buf);
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if (!(buf->vm_flags & VM_PFNMAP)) {
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direction = buf->vbuf.type == V4L2_BUF_TYPE_VIDEO_CAPTURE
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? DMA_FROM_DEVICE : DMA_TO_DEVICE;
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ret = dma_map_sg(buf->queue->dev, buf->sglist, buf->sglen,
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if (ret != buf->sglen) {
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if (buf->queue->ops->buffer_prepare)
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ret = buf->queue->ops->buffer_prepare(buf);
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isp_video_buffer_cleanup(buf);
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* isp_video_queue_query - Query the status of a given buffer
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* Locking: must be called with the queue lock held.
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static void isp_video_buffer_query(struct isp_video_buffer *buf,
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struct v4l2_buffer *vbuf)
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memcpy(vbuf, &buf->vbuf, sizeof(*vbuf));
550
if (buf->vma_use_count)
551
vbuf->flags |= V4L2_BUF_FLAG_MAPPED;
553
switch (buf->state) {
554
case ISP_BUF_STATE_ERROR:
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vbuf->flags |= V4L2_BUF_FLAG_ERROR;
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case ISP_BUF_STATE_DONE:
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vbuf->flags |= V4L2_BUF_FLAG_DONE;
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case ISP_BUF_STATE_QUEUED:
559
case ISP_BUF_STATE_ACTIVE:
560
vbuf->flags |= V4L2_BUF_FLAG_QUEUED;
562
case ISP_BUF_STATE_IDLE:
569
* isp_video_buffer_wait - Wait for a buffer to be ready
571
* In non-blocking mode, return immediately with 0 if the buffer is ready or
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* -EAGAIN if the buffer is in the QUEUED or ACTIVE state.
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* In blocking mode, wait (interruptibly but with no timeout) on the buffer wait
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* queue using the same condition.
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static int isp_video_buffer_wait(struct isp_video_buffer *buf, int nonblocking)
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return (buf->state != ISP_BUF_STATE_QUEUED &&
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buf->state != ISP_BUF_STATE_ACTIVE)
585
return wait_event_interruptible(buf->wait,
586
buf->state != ISP_BUF_STATE_QUEUED &&
587
buf->state != ISP_BUF_STATE_ACTIVE);
590
/* -----------------------------------------------------------------------------
595
* isp_video_queue_free - Free video buffers memory
597
* Buffers can only be freed if the queue isn't streaming and if no buffer is
598
* mapped to userspace. Return -EBUSY if those conditions aren't statisfied.
600
* This function must be called with the queue lock held.
602
static int isp_video_queue_free(struct isp_video_queue *queue)
606
if (queue->streaming)
609
for (i = 0; i < queue->count; ++i) {
610
if (queue->buffers[i]->vma_use_count != 0)
614
for (i = 0; i < queue->count; ++i) {
615
struct isp_video_buffer *buf = queue->buffers[i];
617
isp_video_buffer_cleanup(buf);
623
queue->buffers[i] = NULL;
626
INIT_LIST_HEAD(&queue->queue);
632
* isp_video_queue_alloc - Allocate video buffers memory
634
* This function must be called with the queue lock held.
636
static int isp_video_queue_alloc(struct isp_video_queue *queue,
637
unsigned int nbuffers,
638
unsigned int size, enum v4l2_memory memory)
640
struct isp_video_buffer *buf;
645
/* Start by freeing the buffers. */
646
ret = isp_video_queue_free(queue);
650
/* Bail out of no buffers should be allocated. */
654
/* Initialize the allocated buffers. */
655
for (i = 0; i < nbuffers; ++i) {
656
buf = kzalloc(queue->bufsize, GFP_KERNEL);
660
if (memory == V4L2_MEMORY_MMAP) {
661
/* Allocate video buffers memory for mmap mode. Align
662
* the size to the page size.
664
mem = vmalloc_32_user(PAGE_ALIGN(size));
670
buf->vbuf.m.offset = i * PAGE_ALIGN(size);
675
buf->vbuf.length = size;
676
buf->vbuf.type = queue->type;
677
buf->vbuf.field = V4L2_FIELD_NONE;
678
buf->vbuf.memory = memory;
681
init_waitqueue_head(&buf->wait);
683
queue->buffers[i] = buf;
694
* omap3isp_video_queue_cleanup - Clean up the video buffers queue
695
* @queue: Video buffers queue
697
* Free all allocated resources and clean up the video buffers queue. The queue
698
* must not be busy (no ongoing video stream) and buffers must have been
701
* Return 0 on success or -EBUSY if the queue is busy or buffers haven't been
704
int omap3isp_video_queue_cleanup(struct isp_video_queue *queue)
706
return isp_video_queue_free(queue);
710
* omap3isp_video_queue_init - Initialize the video buffers queue
711
* @queue: Video buffers queue
712
* @type: V4L2 buffer type (capture or output)
713
* @ops: Driver-specific queue operations
714
* @dev: Device used for DMA operations
715
* @bufsize: Size of the driver-specific buffer structure
717
* Initialize the video buffers queue with the supplied parameters.
719
* The queue type must be one of V4L2_BUF_TYPE_VIDEO_CAPTURE or
720
* V4L2_BUF_TYPE_VIDEO_OUTPUT. Other buffer types are not supported yet.
722
* Buffer objects will be allocated using the given buffer size to allow room
723
* for driver-specific fields. Driver-specific buffer structures must start
724
* with a struct isp_video_buffer field. Drivers with no driver-specific buffer
725
* structure must pass the size of the isp_video_buffer structure in the bufsize
728
* Return 0 on success.
730
int omap3isp_video_queue_init(struct isp_video_queue *queue,
731
enum v4l2_buf_type type,
732
const struct isp_video_queue_operations *ops,
733
struct device *dev, unsigned int bufsize)
735
INIT_LIST_HEAD(&queue->queue);
736
mutex_init(&queue->lock);
737
spin_lock_init(&queue->irqlock);
742
queue->bufsize = bufsize;
747
/* -----------------------------------------------------------------------------
752
* omap3isp_video_queue_reqbufs - Allocate video buffers memory
754
* This function is intended to be used as a VIDIOC_REQBUFS ioctl handler. It
755
* allocated video buffer objects and, for MMAP buffers, buffer memory.
757
* If the number of buffers is 0, all buffers are freed and the function returns
758
* without performing any allocation.
760
* If the number of buffers is not 0, currently allocated buffers (if any) are
761
* freed and the requested number of buffers are allocated. Depending on
762
* driver-specific requirements and on memory availability, a number of buffer
763
* smaller or bigger than requested can be allocated. This isn't considered as
766
* Return 0 on success or one of the following error codes:
768
* -EINVAL if the buffer type or index are invalid
769
* -EBUSY if the queue is busy (streaming or buffers mapped)
770
* -ENOMEM if the buffers can't be allocated due to an out-of-memory condition
772
int omap3isp_video_queue_reqbufs(struct isp_video_queue *queue,
773
struct v4l2_requestbuffers *rb)
775
unsigned int nbuffers = rb->count;
779
if (rb->type != queue->type)
782
queue->ops->queue_prepare(queue, &nbuffers, &size);
786
nbuffers = min_t(unsigned int, nbuffers, ISP_VIDEO_MAX_BUFFERS);
788
mutex_lock(&queue->lock);
790
ret = isp_video_queue_alloc(queue, nbuffers, size, rb->memory);
798
mutex_unlock(&queue->lock);
803
* omap3isp_video_queue_querybuf - Query the status of a buffer in a queue
805
* This function is intended to be used as a VIDIOC_QUERYBUF ioctl handler. It
806
* returns the status of a given video buffer.
808
* Return 0 on success or -EINVAL if the buffer type or index are invalid.
810
int omap3isp_video_queue_querybuf(struct isp_video_queue *queue,
811
struct v4l2_buffer *vbuf)
813
struct isp_video_buffer *buf;
816
if (vbuf->type != queue->type)
819
mutex_lock(&queue->lock);
821
if (vbuf->index >= queue->count) {
826
buf = queue->buffers[vbuf->index];
827
isp_video_buffer_query(buf, vbuf);
830
mutex_unlock(&queue->lock);
835
* omap3isp_video_queue_qbuf - Queue a buffer
837
* This function is intended to be used as a VIDIOC_QBUF ioctl handler.
839
* The v4l2_buffer structure passed from userspace is first sanity tested. If
840
* sane, the buffer is then processed and added to the main queue and, if the
841
* queue is streaming, to the IRQ queue.
843
* Before being enqueued, USERPTR buffers are checked for address changes. If
844
* the buffer has a different userspace address, the old memory area is unlocked
845
* and the new memory area is locked.
847
int omap3isp_video_queue_qbuf(struct isp_video_queue *queue,
848
struct v4l2_buffer *vbuf)
850
struct isp_video_buffer *buf;
854
if (vbuf->type != queue->type)
857
mutex_lock(&queue->lock);
859
if (vbuf->index >= queue->count)
862
buf = queue->buffers[vbuf->index];
864
if (vbuf->memory != buf->vbuf.memory)
867
if (buf->state != ISP_BUF_STATE_IDLE)
870
if (vbuf->memory == V4L2_MEMORY_USERPTR &&
871
vbuf->m.userptr != buf->vbuf.m.userptr) {
872
isp_video_buffer_cleanup(buf);
873
buf->vbuf.m.userptr = vbuf->m.userptr;
877
if (!buf->prepared) {
878
ret = isp_video_buffer_prepare(buf);
884
isp_video_buffer_cache_sync(buf);
886
buf->state = ISP_BUF_STATE_QUEUED;
887
list_add_tail(&buf->stream, &queue->queue);
889
if (queue->streaming) {
890
spin_lock_irqsave(&queue->irqlock, flags);
891
queue->ops->buffer_queue(buf);
892
spin_unlock_irqrestore(&queue->irqlock, flags);
898
mutex_unlock(&queue->lock);
903
* omap3isp_video_queue_dqbuf - Dequeue a buffer
905
* This function is intended to be used as a VIDIOC_DQBUF ioctl handler.
907
* The v4l2_buffer structure passed from userspace is first sanity tested. If
908
* sane, the buffer is then processed and added to the main queue and, if the
909
* queue is streaming, to the IRQ queue.
911
* Before being enqueued, USERPTR buffers are checked for address changes. If
912
* the buffer has a different userspace address, the old memory area is unlocked
913
* and the new memory area is locked.
915
int omap3isp_video_queue_dqbuf(struct isp_video_queue *queue,
916
struct v4l2_buffer *vbuf, int nonblocking)
918
struct isp_video_buffer *buf;
921
if (vbuf->type != queue->type)
924
mutex_lock(&queue->lock);
926
if (list_empty(&queue->queue)) {
931
buf = list_first_entry(&queue->queue, struct isp_video_buffer, stream);
932
ret = isp_video_buffer_wait(buf, nonblocking);
936
list_del(&buf->stream);
938
isp_video_buffer_query(buf, vbuf);
939
buf->state = ISP_BUF_STATE_IDLE;
940
vbuf->flags &= ~V4L2_BUF_FLAG_QUEUED;
943
mutex_unlock(&queue->lock);
948
* omap3isp_video_queue_streamon - Start streaming
950
* This function is intended to be used as a VIDIOC_STREAMON ioctl handler. It
951
* starts streaming on the queue and calls the buffer_queue operation for all
954
* Return 0 on success.
956
int omap3isp_video_queue_streamon(struct isp_video_queue *queue)
958
struct isp_video_buffer *buf;
961
mutex_lock(&queue->lock);
963
if (queue->streaming)
966
queue->streaming = 1;
968
spin_lock_irqsave(&queue->irqlock, flags);
969
list_for_each_entry(buf, &queue->queue, stream)
970
queue->ops->buffer_queue(buf);
971
spin_unlock_irqrestore(&queue->irqlock, flags);
974
mutex_unlock(&queue->lock);
979
* omap3isp_video_queue_streamoff - Stop streaming
981
* This function is intended to be used as a VIDIOC_STREAMOFF ioctl handler. It
982
* stops streaming on the queue and wakes up all the buffers.
984
* Drivers must stop the hardware and synchronize with interrupt handlers and/or
985
* delayed works before calling this function to make sure no buffer will be
986
* touched by the driver and/or hardware.
988
void omap3isp_video_queue_streamoff(struct isp_video_queue *queue)
990
struct isp_video_buffer *buf;
994
mutex_lock(&queue->lock);
996
if (!queue->streaming)
999
queue->streaming = 0;
1001
spin_lock_irqsave(&queue->irqlock, flags);
1002
for (i = 0; i < queue->count; ++i) {
1003
buf = queue->buffers[i];
1005
if (buf->state == ISP_BUF_STATE_ACTIVE)
1006
wake_up(&buf->wait);
1008
buf->state = ISP_BUF_STATE_IDLE;
1010
spin_unlock_irqrestore(&queue->irqlock, flags);
1012
INIT_LIST_HEAD(&queue->queue);
1015
mutex_unlock(&queue->lock);
1019
* omap3isp_video_queue_discard_done - Discard all buffers marked as DONE
1021
* This function is intended to be used with suspend/resume operations. It
1022
* discards all 'done' buffers as they would be too old to be requested after
1025
* Drivers must stop the hardware and synchronize with interrupt handlers and/or
1026
* delayed works before calling this function to make sure no buffer will be
1027
* touched by the driver and/or hardware.
1029
void omap3isp_video_queue_discard_done(struct isp_video_queue *queue)
1031
struct isp_video_buffer *buf;
1034
mutex_lock(&queue->lock);
1036
if (!queue->streaming)
1039
for (i = 0; i < queue->count; ++i) {
1040
buf = queue->buffers[i];
1042
if (buf->state == ISP_BUF_STATE_DONE)
1043
buf->state = ISP_BUF_STATE_ERROR;
1047
mutex_unlock(&queue->lock);
1050
static void isp_video_queue_vm_open(struct vm_area_struct *vma)
1052
struct isp_video_buffer *buf = vma->vm_private_data;
1054
buf->vma_use_count++;
1057
static void isp_video_queue_vm_close(struct vm_area_struct *vma)
1059
struct isp_video_buffer *buf = vma->vm_private_data;
1061
buf->vma_use_count--;
1064
static const struct vm_operations_struct isp_video_queue_vm_ops = {
1065
.open = isp_video_queue_vm_open,
1066
.close = isp_video_queue_vm_close,
1070
* omap3isp_video_queue_mmap - Map buffers to userspace
1072
* This function is intended to be used as an mmap() file operation handler. It
1073
* maps a buffer to userspace based on the VMA offset.
1075
* Only buffers of memory type MMAP are supported.
1077
int omap3isp_video_queue_mmap(struct isp_video_queue *queue,
1078
struct vm_area_struct *vma)
1080
struct isp_video_buffer *uninitialized_var(buf);
1085
mutex_lock(&queue->lock);
1087
for (i = 0; i < queue->count; ++i) {
1088
buf = queue->buffers[i];
1089
if ((buf->vbuf.m.offset >> PAGE_SHIFT) == vma->vm_pgoff)
1093
if (i == queue->count) {
1098
size = vma->vm_end - vma->vm_start;
1100
if (buf->vbuf.memory != V4L2_MEMORY_MMAP ||
1101
size != PAGE_ALIGN(buf->vbuf.length)) {
1106
ret = remap_vmalloc_range(vma, buf->vaddr, 0);
1110
vma->vm_ops = &isp_video_queue_vm_ops;
1111
vma->vm_private_data = buf;
1112
isp_video_queue_vm_open(vma);
1115
mutex_unlock(&queue->lock);
1120
* omap3isp_video_queue_poll - Poll video queue state
1122
* This function is intended to be used as a poll() file operation handler. It
1123
* polls the state of the video buffer at the front of the queue and returns an
1126
* If no buffer is present at the front of the queue, POLLERR is returned.
1128
unsigned int omap3isp_video_queue_poll(struct isp_video_queue *queue,
1129
struct file *file, poll_table *wait)
1131
struct isp_video_buffer *buf;
1132
unsigned int mask = 0;
1134
mutex_lock(&queue->lock);
1135
if (list_empty(&queue->queue)) {
1139
buf = list_first_entry(&queue->queue, struct isp_video_buffer, stream);
1141
poll_wait(file, &buf->wait, wait);
1142
if (buf->state == ISP_BUF_STATE_DONE ||
1143
buf->state == ISP_BUF_STATE_ERROR) {
1144
if (queue->type == V4L2_BUF_TYPE_VIDEO_CAPTURE)
1145
mask |= POLLIN | POLLRDNORM;
1147
mask |= POLLOUT | POLLWRNORM;
1151
mutex_unlock(&queue->lock);
added
removed
drivers/media/video/omap3isp/ispqueue.c
