[RFC][PATCHv2 04/12] videobuf2: add queue memory consistency parameter

From: Sergey Senozhatsky
Date: Mon Feb 03 2020 - 21:57:08 EST


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.

Change-Id: Ia40362553b6bd96fea3b652f4a376e7a3467df0a
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
.../media/common/videobuf2/videobuf2-core.c | 47 +++++++++++++++----
.../media/common/videobuf2/videobuf2-v4l2.c | 6 +--
drivers/media/dvb-core/dvb_vb2.c | 2 +-
include/media/videobuf2-core.h | 7 ++-
4 files changed, 47 insertions(+), 15 deletions(-)

diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index 4489744fbbd9..56fd17eafb6c 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -664,8 +664,19 @@ 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 (!q->allow_cache_hints)
+ return;
+
+ if (consistent_mem)
+ q->dma_attrs &= ~DMA_ATTR_NON_CONSISTENT;
+ else
+ q->dma_attrs |= DMA_ATTR_NON_CONSISTENT;
+}
+
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count)
+ bool consistent_mem, unsigned int *count)
{
unsigned int num_buffers, allocated_buffers, num_planes = 0;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
@@ -720,6 +731,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
num_buffers = min_t(unsigned int, num_buffers, VB2_MAX_FRAME);
memset(q->alloc_devs, 0, sizeof(q->alloc_devs));
q->memory = memory;
+ set_queue_consistency(q, consistent_mem);

/*
* Ask the driver how many buffers and planes per buffer it requires.
@@ -803,9 +815,21 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
}
EXPORT_SYMBOL_GPL(vb2_core_reqbufs);

+static bool verify_consistency_attr(struct vb2_queue *q, bool consistent_mem)
+{
+ bool queue_attr = q->dma_attrs & DMA_ATTR_NON_CONSISTENT;
+
+ if (consistent_mem != queue_attr) {
+ dprintk(1, "memory consistency model mismatch\n");
+ return false;
+ }
+ return true;
+}
+
int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
- unsigned int *count, unsigned requested_planes,
- const unsigned requested_sizes[])
+ bool consistent_mem, unsigned int *count,
+ unsigned requested_planes,
+ const unsigned requested_sizes[])
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
@@ -823,10 +847,15 @@ 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;
+ set_queue_consistency(q, consistent_mem);
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);
@@ -2498,7 +2527,7 @@ 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, true, &fileio->count);
if (ret)
goto err_kfree;

@@ -2555,7 +2584,7 @@ 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, true, &fileio->count);

err_kfree:
q->fileio = NULL;
@@ -2575,7 +2604,7 @@ 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, true, &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 2da06a2ad6c4..7cdfcd1baf82 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -709,7 +709,7 @@ 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, true, &req->count);
}
EXPORT_SYMBOL_GPL(vb2_reqbufs);

@@ -783,7 +783,7 @@ 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);
@@ -959,7 +959,7 @@ 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, true, &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..e60063652164 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, true, &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 026004180440..5e5450bdabbd 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -726,6 +726,7 @@ 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.
+ * @consistent_mem: memory consistency model.
* @count: requested buffer count.
*
* Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
@@ -750,12 +751,13 @@ 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);
+ bool consistent_mem, 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.
+ * @consistent_mem: memory consistency model.
* @count: requested buffer count.
* @requested_planes: number of planes requested.
* @requested_sizes: array with the size of the planes.
@@ -773,7 +775,8 @@ 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,
+ bool consistent_mem, unsigned int *count,
+ unsigned int requested_planes,
const unsigned int requested_sizes[]);

/**
--
2.25.0.341.g760bfbb309-goog