[PATCH 05/28] media/v4l2: remove V4L2-FLAG-MEMORY-NON-CONSISTENT
From: Christoph Hellwig
Date: Wed Aug 19 2020 - 03:09:57 EST
The V4L2-FLAG-MEMORY-NON-CONSISTENT flag is entirely unused, and causes
weird gymanstics with the DMA_ATTR_NON_CONSISTENT flag, which is
unimplemented except on PARISC and some MIPS configs, and about to be
removed.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
.../userspace-api/media/v4l/buffer.rst | 17 ---------
.../media/v4l/vidioc-reqbufs.rst | 1 -
.../media/common/videobuf2/videobuf2-core.c | 36 +------------------
.../common/videobuf2/videobuf2-dma-contig.c | 19 ----------
.../media/common/videobuf2/videobuf2-dma-sg.c | 3 +-
.../media/common/videobuf2/videobuf2-v4l2.c | 12 -------
include/media/videobuf2-core.h | 3 +-
include/uapi/linux/videodev2.h | 2 --
8 files changed, 3 insertions(+), 90 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
index 57e752aaf414a7..2044ed13cd9d7d 100644
--- a/Documentation/userspace-api/media/v4l/buffer.rst
+++ b/Documentation/userspace-api/media/v4l/buffer.rst
@@ -701,23 +701,6 @@ Memory Consistency Flags
:stub-columns: 0
:widths: 3 1 4
- * .. _`V4L2-FLAG-MEMORY-NON-CONSISTENT`:
-
- - ``V4L2_FLAG_MEMORY_NON_CONSISTENT``
- - 0x00000001
- - A buffer is allocated either in consistent (it will be automatically
- coherent between the CPU and the bus) or non-consistent memory. The
- latter can provide performance gains, for instance the CPU cache
- sync/flush operations can be avoided if the buffer is accessed by the
- corresponding device only and the CPU does not read/write to/from that
- buffer. However, this requires extra care from the driver -- it must
- guarantee memory consistency by issuing a cache flush/sync when
- consistency is needed. If this flag is set V4L2 will attempt to
- allocate the buffer in non-consistent memory. The flag takes effect
- only if the buffer is used for :ref:`memory mapping <mmap>` I/O and the
- queue reports the :ref:`V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS
- <V4L2-BUF-CAP-SUPPORTS-MMAP-CACHE-HINTS>` capability.
-
.. c:type:: v4l2_memory
enum v4l2_memory
diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
index 75d894d9c36c42..3180c111d368ee 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
@@ -169,7 +169,6 @@ aborting or finishing any DMA in progress, an implicit
- This capability is set by the driver to indicate that the queue supports
cache and memory management hints. However, it's only valid when the
queue is used for :ref:`memory mapping <mmap>` streaming I/O. See
- :ref:`V4L2_FLAG_MEMORY_NON_CONSISTENT <V4L2-FLAG-MEMORY-NON-CONSISTENT>`,
:ref:`V4L2_BUF_FLAG_NO_CACHE_INVALIDATE <V4L2-BUF-FLAG-NO-CACHE-INVALIDATE>` and
:ref:`V4L2_BUF_FLAG_NO_CACHE_CLEAN <V4L2-BUF-FLAG-NO-CACHE-CLEAN>`.
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index f544d3393e9d6b..66a41cef33c1b1 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -721,39 +721,14 @@ 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)
-{
- q->dma_attrs &= ~DMA_ATTR_NON_CONSISTENT;
-
- if (!vb2_queue_allows_cache_hints(q))
- return;
- if (!consistent_mem)
- 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(q, 1, "memory consistency model mismatch\n");
- return false;
- }
- return true;
-}
-
int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
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;
- if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
- consistent_mem = false;
-
if (q->streaming) {
dprintk(q, 1, "streaming active\n");
return -EBUSY;
@@ -765,8 +740,7 @@ 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) ||
- !verify_consistency_attr(q, consistent_mem)) {
+ (q->memory != VB2_MEMORY_UNKNOWN && q->memory != memory)) {
/*
* We already have buffers allocated, so first check if they
* are not in use and can be freed.
@@ -803,7 +777,6 @@ 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.
@@ -894,12 +867,8 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
{
unsigned int num_planes = 0, num_buffers, allocated_buffers;
unsigned plane_sizes[VB2_MAX_PLANES] = { };
- bool consistent_mem = true;
int ret;
- if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
- consistent_mem = false;
-
if (q->num_buffers == VB2_MAX_FRAME) {
dprintk(q, 1, "maximum number of buffers already allocated\n");
return -ENOBUFS;
@@ -912,15 +881,12 @@ 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(q, 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);
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-contig.c b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
index ec3446cc45b8da..7b1b86ec942d7d 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-contig.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-contig.c
@@ -42,11 +42,6 @@ struct vb2_dc_buf {
struct dma_buf_attachment *db_attach;
};
-static inline bool vb2_dc_buffer_consistent(unsigned long attr)
-{
- return !(attr & DMA_ATTR_NON_CONSISTENT);
-}
-
/*********************************************/
/* scatterlist table functions */
/*********************************************/
@@ -341,13 +336,6 @@ static int
vb2_dc_dmabuf_ops_begin_cpu_access(struct dma_buf *dbuf,
enum dma_data_direction direction)
{
- struct vb2_dc_buf *buf = dbuf->priv;
- struct sg_table *sgt = buf->dma_sgt;
-
- if (vb2_dc_buffer_consistent(buf->attrs))
- return 0;
-
- dma_sync_sg_for_cpu(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
return 0;
}
@@ -355,13 +343,6 @@ static int
vb2_dc_dmabuf_ops_end_cpu_access(struct dma_buf *dbuf,
enum dma_data_direction direction)
{
- struct vb2_dc_buf *buf = dbuf->priv;
- struct sg_table *sgt = buf->dma_sgt;
-
- if (vb2_dc_buffer_consistent(buf->attrs))
- return 0;
-
- dma_sync_sg_for_device(buf->dev, sgt->sgl, sgt->nents, buf->dma_dir);
return 0;
}
diff --git a/drivers/media/common/videobuf2/videobuf2-dma-sg.c b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
index 0a40e00f0d7e5c..a86fce5d8ea8bf 100644
--- a/drivers/media/common/videobuf2/videobuf2-dma-sg.c
+++ b/drivers/media/common/videobuf2/videobuf2-dma-sg.c
@@ -123,8 +123,7 @@ static void *vb2_dma_sg_alloc(struct device *dev, unsigned long dma_attrs,
/*
* NOTE: dma-sg allocates memory using the page allocator directly, so
* there is no memory consistency guarantee, hence dma-sg ignores DMA
- * attributes passed from the upper layer. That means that
- * V4L2_FLAG_MEMORY_NON_CONSISTENT has no effect on dma-sg buffers.
+ * attributes passed from the upper layer.
*/
buf->pages = kvmalloc_array(buf->num_pages, sizeof(struct page *),
GFP_KERNEL | __GFP_ZERO);
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 30caad27281e1a..de83ad48783821 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -722,20 +722,11 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
#endif
}
-static void clear_consistency_attr(struct vb2_queue *q,
- int memory,
- unsigned int *flags)
-{
- if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP)
- *flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
-}
-
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);
- clear_consistency_attr(q, req->memory, &req->flags);
return ret ? ret : vb2_core_reqbufs(q, req->memory,
req->flags, &req->count);
}
@@ -769,7 +760,6 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create)
unsigned i;
fill_buf_caps(q, &create->capabilities);
- clear_consistency_attr(q, create->memory, &create->flags);
create->index = q->num_buffers;
if (create->count == 0)
return ret != -EBUSY ? ret : 0;
@@ -998,7 +988,6 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv,
int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type);
fill_buf_caps(vdev->queue, &p->capabilities);
- clear_consistency_attr(vdev->queue, p->memory, &p->flags);
if (res)
return res;
if (vb2_queue_is_busy(vdev, file))
@@ -1021,7 +1010,6 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv,
p->index = vdev->queue->num_buffers;
fill_buf_caps(vdev->queue, &p->capabilities);
- clear_consistency_attr(vdev->queue, p->memory, &p->flags);
/*
* If count == 0, then just check if memory and type are valid.
* Any -EBUSY result from vb2_verify_memory_type can be mapped to 0.
diff --git a/include/media/videobuf2-core.h b/include/media/videobuf2-core.h
index 52ef92049073e3..4c7f25b07e9375 100644
--- a/include/media/videobuf2-core.h
+++ b/include/media/videobuf2-core.h
@@ -744,8 +744,7 @@ 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.
- * @flags: auxiliary queue/buffer management flags. Currently, the only
- * used flag is %V4L2_FLAG_MEMORY_NON_CONSISTENT.
+ * @flags: auxiliary queue/buffer management flags.
* @count: requested buffer count.
*
* Videobuf2 core helper to implement VIDIOC_REQBUF() operation. It is called
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index c7b70ff53bc1dd..5c00f63d9c1b58 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -191,8 +191,6 @@ enum v4l2_memory {
V4L2_MEMORY_DMABUF = 4,
};
-#define V4L2_FLAG_MEMORY_NON_CONSISTENT (1 << 0)
-
/* see also http://vektor.theorem.ca/graphics/ycbcr/ */
enum v4l2_colorspace {
/*
--
2.28.0