- 根目录:
- drivers
- media
- platform
- omap3isp
- ispqueue.c
/*
* 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 = 0;
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 uninitialized_var(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.flags = V4L2_BUF_FLAG_TIMESTAMP_MONOTONIC;
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;
}