[PATCHv5 05/13] videobuf2: add queue memory consistency parameter

From: Sergey Senozhatsky
Date: Fri Apr 24 2020 - 05:31:03 EST


From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>

Preparations for future V4L2_FLAG_MEMORY_NON_CONSISTENT support.

Extend vb2_core_reqbufs() with queue memory consistency flag
that is applied to the newly allocated buffers.

An attempt to allocate a buffer with consistency requirements
which don't match queue's consistency model will fail.

Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
.../media/common/videobuf2/videobuf2-core.c | 52 +++++++++++++++----
.../media/common/videobuf2/videobuf2-v4l2.c | 6 +--
drivers/media/dvb-core/dvb_vb2.c | 2 +-
include/media/videobuf2-core.h | 8 ++-
4 files changed, 52 insertions(+), 16 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 44d65f5be845..f1a65925bc17 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -664,11 +664,34 @@ int vb2_verify_memory_type(struct vb2_queue *q,
}
EXPORT_SYMBOL(vb2_verify_memory_type);

+static void set_queue_consistency(struct vb2_queue *q, bool consistent_mem)
+{
+ if (!vb2_queue_allows_cache_hints(q))
+ return;
+
+ if (consistent_mem)
+ q->dma_attrs &= ~DMA_ATTR_NON_CONSISTENT;
+ else
+ q->dma_attrs |= DMA_ATTR_NON_CONSISTENT;
+}
+
+static bool verify_consistency_attr(struct vb2_queue *q, bool consistent_mem)
+{
+ bool queue_is_consistent = !(q->dma_attrs & DMA_ATTR_NON_CONSISTENT);
+
+ if (consistent_mem != queue_is_consistent) {
+ dprintk(1, "memory consistency model mismatch\n");
+ return false;
+ }
+ return true;
+}
+
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count)
+ unsigned int flags, unsigned int *count)
{
unsigned int num_buffers, allocated_buffers, num_planes = 0;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
+ bool consistent_mem = true;
unsigned int i;
int ret;

@@ -683,7 +706,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
}

if (*count == 0 || q->num_buffers != 0 ||
- (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
+ (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory) ||
+ !verify_consistency_attr(q, consistent_mem)) {
/*
* We already have buffers allocated, so first check if they
* are not in use and can be freed.
@@ -730,6 +754,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
if (ret)
return ret;

+ set_queue_consistency(q, consistent_mem);
/* Check that driver has set sane values */
if (WARN_ON(!num_planes))
return -EINVAL;
@@ -804,11 +829,13 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
EXPORT_SYMBOL_GPL(vb2_core_reqbufs);

int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count, unsigned requested_planes,
- const unsigned requested_sizes[])
+ unsigned int flags, unsigned int *count,
+ unsigned int requested_planes,
+ const unsigned int requested_sizes[])
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
+ bool consistent_mem = true;
int ret;

if (q->num_buffers == VB2_MAX_FRAME) {
@@ -824,9 +851,13 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
q->memory = memory;
q->waiting_for_buffers = !q->is_output;
- } else if (q->memory != memory) {
- dprintk(1, "memory model mismatch\n");
- return -EINVAL;
+ } else {
+ if (q->memory != memory) {
+ dprintk(1, "memory model mismatch\n");
+ return -EINVAL;
+ }
+ if (!verify_consistency_attr(q, consistent_mem))
+ return -EINVAL;
}

num_buffers = min(*count, VB2_MAX_FRAME - q->num_buffers);
@@ -845,6 +876,7 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
if (ret)
return ret;

+ set_queue_consistency(q, consistent_mem);
/* Finally, allocate buffers and video memory */
allocated_buffers = __vb2_queue_alloc(q, memory, num_buffers,
num_planes, plane_sizes);
@@ -2498,7 +2530,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)
fileio->memory = VB2_MEMORY_MMAP;
fileio->type = q->type;
q->fileio = fileio;
- ret = vb2_core_reqbufs(q, fileio->memory, &fileio->count);
+ ret = vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
if (ret)
goto err_kfree;

@@ -2555,7 +2587,7 @@ static int __vb2_init_fileio(struct vb2_queue *q, int read)

err_reqbufs:
fileio->count = 0;
- vb2_core_reqbufs(q, fileio->memory, &fileio->count);
+ vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);

err_kfree:
q->fileio = NULL;
@@ -2575,7 +2607,7 @@ static int __vb2_cleanup_fileio(struct vb2_queue *q)
vb2_core_streamoff(q, q->type);
q->fileio = NULL;
fileio->count = 0;
- vb2_core_reqbufs(q, fileio->memory, &fileio->count);
+ vb2_core_reqbufs(q, fileio->memory, 0, &fileio->count);
kfree(fileio);
dprintk(3, "file io emulator closed\n");
}
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 26716055d914..04ea332567b1 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -723,7 +723,7 @@ int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req)
int ret = vb2_verify_memory_type(q, req->memory, req->type);

fill_buf_caps(q, &req->capabilities);
- return ret ? ret : vb2_core_reqbufs(q, req->memory, &req->count);
+ return ret ? ret : vb2_core_reqbufs(q, req->memory, 0, &req->count);
}
EXPORT_SYMBOL_GPL(vb2_reqbufs);

@@ -797,7 +797,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
for (i = 0; i < requested_planes; i++)
if (requested_sizes[i] == 0)
return -EINVAL;
- return ret ? ret : vb2_core_create_bufs(q, create->memory,
+ return ret ? ret : vb2_core_create_bufs(q, create->memory, true,
&create->count, requested_planes, requested_sizes);
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);
@@ -973,7 +973,7 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
return res;
if (vb2_queue_is_busy(vdev, file))
return -EBUSY;
- res = vb2_core_reqbufs(vdev->queue, p->memory, &p->count);
+ res = vb2_core_reqbufs(vdev->queue, p->memory, 0, &p->count);
/* If count == 0, then the owner has released all buffers and he
is no longer owner of the queue. Otherwise we have a new owner. */
if (res == 0)
diff --git a/drivers/media/dvb-core/dvb_vb2.c b/drivers/media/dvb-core/dvb_vb2.c
index 6974f1731529..959d110407a4 100644
--- a/drivers/media/dvb-core/dvb_vb2.c
+++ b/drivers/media/dvb-core/dvb_vb2.c
@@ -342,7 +342,7 @@ int dvb_vb2_reqbufs(struct dvb_vb2_ctx *ctx, struct dmx_requestbuffers *req)

ctx->buf_siz = req->size;
ctx->buf_cnt = req->count;
- ret = vb2_core_reqbufs(&ctx->vb_q, VB2_MEMORY_MMAP, &req->count);
+ ret = vb2_core_reqbufs(&ctx->vb_q, VB2_MEMORY_MMAP, 0, &req->count);
if (ret) {
ctx->state = DVB_VB2_STATE_NONE;
dprintk(1, "[%s] count=%d size=%d errno=%d\n", ctx->name,
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index ccc5c498d3e3..9e68fe043a6c 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -740,6 +740,8 @@ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
* vb2_core_reqbufs() - Initiate streaming.
* @q: pointer to &struct vb2_queue with videobuf2 queue.
* @memory: memory type, as defined by &enum vb2_memory.
+ * @flags: auxiliary queue/buffer management flags. Currently, the only
+ * used flag is %V4L2_FLAG_MEMORY_NON_CONSISTENT.
* @count: requested buffer count.
*
* Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
@@ -764,12 +766,13 @@ void vb2_core_querybuf(struct vb2_queue *q, unsigned int index, void *pb);
* Return: returns zero on success; an error code otherwise.
*/
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count);
+ unsigned int flags, unsigned int *count);

/**
* vb2_core_create_bufs() - Allocate buffers and any required auxiliary structs
* @q: pointer to &struct vb2_queue with videobuf2 queue.
* @memory: memory type, as defined by &enum vb2_memory.
+ * @flags: auxiliary queue/buffer management flags.
* @count: requested buffer count.
* @requested_planes: number of planes requested.
* @requested_sizes: array with the size of the planes.
@@ -787,7 +790,8 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
* Return: returns zero on success; an error code otherwise.
*/
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count, unsigned int requested_planes,
+ unsigned int flags, unsigned int *count,
+ unsigned int requested_planes,
const unsigned int requested_sizes[]);

/**
--
2.26.2