printk(KERN_DEBUG "vb2: " fmt, ## arg); \
} while (0)
-#define call_memop(q, plane, op, args...) \
+#define call_memop(q, op, args...) \
(((q)->mem_ops->op) ? \
((q)->mem_ops->op(args)) : 0)
/* Allocate memory for all planes in this buffer */
for (plane = 0; plane < vb->num_planes; ++plane) {
- mem_priv = call_memop(q, plane, alloc, q->alloc_ctx[plane],
+ mem_priv = call_memop(q, alloc, q->alloc_ctx[plane],
q->plane_sizes[plane]);
if (IS_ERR_OR_NULL(mem_priv))
goto free;
return 0;
free:
/* Free already allocated memory if one of the allocations failed */
- for (; plane > 0; --plane)
- call_memop(q, plane, put, vb->planes[plane - 1].mem_priv);
+ for (; plane > 0; --plane) {
+ call_memop(q, put, vb->planes[plane - 1].mem_priv);
+ vb->planes[plane - 1].mem_priv = NULL;
+ }
return -ENOMEM;
}
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane) {
- call_memop(q, plane, put, vb->planes[plane].mem_priv);
+ call_memop(q, put, vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
- dprintk(3, "Freed plane %d of buffer %d\n",
- plane, vb->v4l2_buf.index);
+ dprintk(3, "Freed plane %d of buffer %d\n", plane,
+ vb->v4l2_buf.index);
}
}
unsigned int plane;
for (plane = 0; plane < vb->num_planes; ++plane) {
- void *mem_priv = vb->planes[plane].mem_priv;
-
- if (mem_priv) {
- call_memop(q, plane, put_userptr, mem_priv);
- vb->planes[plane].mem_priv = NULL;
- }
+ if (vb->planes[plane].mem_priv)
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
+ vb->planes[plane].mem_priv = NULL;
}
}
* case anyway. If num_users() returns more than 1,
* we are not the only user of the plane's memory.
*/
- if (mem_priv && call_memop(q, plane, num_users, mem_priv) > 1)
+ if (mem_priv && call_memop(q, num_users, mem_priv) > 1)
return true;
}
return false;
{
struct vb2_queue *q = vb->vb2_queue;
- if (plane_no > vb->num_planes)
+ if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
return NULL;
- return call_memop(q, plane_no, vaddr, vb->planes[plane_no].mem_priv);
+ return call_memop(q, vaddr, vb->planes[plane_no].mem_priv);
}
EXPORT_SYMBOL_GPL(vb2_plane_vaddr);
{
struct vb2_queue *q = vb->vb2_queue;
- if (plane_no > vb->num_planes)
+ if (plane_no > vb->num_planes || !vb->planes[plane_no].mem_priv)
return NULL;
- return call_memop(q, plane_no, cookie, vb->planes[plane_no].mem_priv);
+ return call_memop(q, cookie, vb->planes[plane_no].mem_priv);
}
EXPORT_SYMBOL_GPL(vb2_plane_cookie);
for (plane = 0; plane < vb->num_planes; ++plane) {
/* Skip the plane if already verified */
- if (vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
+ if (vb->v4l2_planes[plane].m.userptr &&
+ vb->v4l2_planes[plane].m.userptr == planes[plane].m.userptr
&& vb->v4l2_planes[plane].length == planes[plane].length)
continue;
/* Release previously acquired memory if present */
if (vb->planes[plane].mem_priv)
- call_memop(q, plane, put_userptr,
- vb->planes[plane].mem_priv);
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
vb->v4l2_planes[plane].m.userptr = 0;
vb->v4l2_planes[plane].length = 0;
/* Acquire each plane's memory */
- if (q->mem_ops->get_userptr) {
- mem_priv = q->mem_ops->get_userptr(q->alloc_ctx[plane],
- planes[plane].m.userptr,
- planes[plane].length,
- write);
- if (IS_ERR(mem_priv)) {
- dprintk(1, "qbuf: failed acquiring userspace "
+ mem_priv = call_memop(q, get_userptr, q->alloc_ctx[plane],
+ planes[plane].m.userptr,
+ planes[plane].length, write);
+ if (IS_ERR_OR_NULL(mem_priv)) {
+ dprintk(1, "qbuf: failed acquiring userspace "
"memory for plane %d\n", plane);
- ret = PTR_ERR(mem_priv);
- goto err;
- }
- vb->planes[plane].mem_priv = mem_priv;
+ ret = mem_priv ? PTR_ERR(mem_priv) : -EINVAL;
+ goto err;
}
+ vb->planes[plane].mem_priv = mem_priv;
}
/*
/* In case of errors, release planes that were already acquired */
for (plane = 0; plane < vb->num_planes; ++plane) {
if (vb->planes[plane].mem_priv)
- call_memop(q, plane, put_userptr,
- vb->planes[plane].mem_priv);
+ call_memop(q, put_userptr, vb->planes[plane].mem_priv);
vb->planes[plane].mem_priv = NULL;
vb->v4l2_planes[plane].m.userptr = 0;
vb->v4l2_planes[plane].length = 0;
*/
int vb2_qbuf(struct vb2_queue *q, struct v4l2_buffer *b)
{
+ struct rw_semaphore *mmap_sem = NULL;
struct vb2_buffer *vb;
- int ret;
+ int ret = 0;
+
+ /*
+ * In case of user pointer buffers vb2 allocator needs to get direct
+ * access to userspace pages. This requires getting read access on
+ * mmap semaphore in the current process structure. The same
+ * semaphore is taken before calling mmap operation, while both mmap
+ * and qbuf are called by the driver or v4l2 core with driver's lock
+ * held. To avoid a AB-BA deadlock (mmap_sem then driver's lock in
+ * mmap and driver's lock then mmap_sem in qbuf) the videobuf2 core
+ * release driver's lock, takes mmap_sem and then takes again driver's
+ * lock.
+ *
+ * To avoid race with other vb2 calls, which might be called after
+ * releasing driver's lock, this operation is performed at the
+ * beggining of qbuf processing. This way the queue status is
+ * consistent after getting driver's lock back.
+ */
+ if (q->memory == V4L2_MEMORY_USERPTR) {
+ mmap_sem = ¤t->mm->mmap_sem;
+ call_qop(q, wait_prepare, q);
+ down_read(mmap_sem);
+ call_qop(q, wait_finish, q);
+ }
if (q->fileio) {
dprintk(1, "qbuf: file io in progress\n");
- return -EBUSY;
+ ret = -EBUSY;
+ goto unlock;
}
if (b->type != q->type) {
dprintk(1, "qbuf: invalid buffer type\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
if (b->index >= q->num_buffers) {
dprintk(1, "qbuf: buffer index out of range\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
vb = q->bufs[b->index];
if (NULL == vb) {
/* Should never happen */
dprintk(1, "qbuf: buffer is NULL\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
if (b->memory != q->memory) {
dprintk(1, "qbuf: invalid memory type\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
switch (vb->state) {
case VB2_BUF_STATE_DEQUEUED:
ret = __buf_prepare(vb, b);
if (ret)
- return ret;
+ goto unlock;
case VB2_BUF_STATE_PREPARED:
break;
default:
dprintk(1, "qbuf: buffer already in use\n");
- return -EINVAL;
+ ret = -EINVAL;
+ goto unlock;
}
/*
__fill_v4l2_buffer(vb, b);
dprintk(1, "qbuf of buffer %d succeeded\n", vb->v4l2_buf.index);
- return 0;
+unlock:
+ if (mmap_sem)
+ up_read(mmap_sem);
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_qbuf);
int vb2_mmap(struct vb2_queue *q, struct vm_area_struct *vma)
{
unsigned long off = vma->vm_pgoff << PAGE_SHIFT;
- struct vb2_plane *vb_plane;
struct vb2_buffer *vb;
unsigned int buffer, plane;
int ret;
return ret;
vb = q->bufs[buffer];
- vb_plane = &vb->planes[plane];
- ret = q->mem_ops->mmap(vb_plane->mem_priv, vma);
+ ret = call_memop(q, mmap, vb->planes[plane].mem_priv, vma);
if (ret)
return ret;
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