[PATCHv5 06/13] videobuf2: handle V4L2_FLAG_MEMORY_NON_CONSISTENT flag
From: Sergey Senozhatsky
Date: Fri Apr 24 2020 - 05:31:08 EST
From: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
This patch lets user-space to request a non-consistent memory
allocation during CREATE_BUFS and REQBUFS ioctl calls.
= CREATE_BUFS
struct v4l2_create_buffers has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= CREATE_BUFS32
struct v4l2_create_buffers32 has seven 4-byte reserved areas,
so reserved[0] is renamed to ->flags. The struct, thus, now
has six reserved 4-byte regions.
= REQBUFS
We use one bit of a ->reserved[1] member of struct v4l2_requestbuffers,
which is now renamed to ->flags. Unlike v4l2_create_buffers, struct
v4l2_requestbuffers does not have enough reserved room. Therefore for
backward compatibility ->reserved and ->flags were put into anonymous
union.
Signed-off-by: Sergey Senozhatsky <senozhatsky@xxxxxxxxxxxx>
---
.../media/v4l/vidioc-create-bufs.rst | 7 ++-
.../media/v4l/vidioc-reqbufs.rst | 11 ++++-
.../media/common/videobuf2/videobuf2-core.c | 6 +++
.../media/common/videobuf2/videobuf2-v4l2.c | 43 +++++++++++++++++--
drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 +++-
drivers/media/v4l2-core/v4l2-ioctl.c | 5 +--
include/uapi/linux/videodev2.h | 10 ++++-
7 files changed, 76 insertions(+), 15 deletions(-)
diff --git a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
index bd580232be10..4ece2551b355 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst
@@ -121,7 +121,12 @@ than the number requested.
other changes, then set ``count`` to 0, ``memory`` to
``V4L2_MEMORY_MMAP`` and ``format.type`` to the buffer type.
* - __u32
- - ``reserved``\ [7]
+ - ``flags``
+ - Specifies additional buffer management attributes.
+ See :ref:`memory-flags`.
+
+ * - __u32
+ - ``reserved``\ [6]
- A place holder for future extensions. Drivers and applications
must set the array to zero.
diff --git a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
index 893570af617b..a933a72dab1f 100644
--- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
+++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst
@@ -112,10 +112,17 @@ aborting or finishing any DMA in progress, an implicit
``V4L2_MEMORY_MMAP`` and ``type`` set to the buffer type. This will
free any previously allocated buffers, so this is typically something
that will be done at the start of the application.
+ * - union {
+ - (anonymous)
+ * - __u32
+ - ``flags``
+ - Specifies additional buffer management attributes.
+ See :ref:`memory-flags`.
* - __u32
- ``reserved``\ [1]
- - A place holder for future extensions. Drivers and applications
- must set the array to zero.
+ - Kept for backwards compatibility. Use ``flags`` instead.
+ * - }
+ -
.. tabularcolumns:: |p{6.1cm}|p{2.2cm}|p{8.7cm}|
diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c
index f1a65925bc17..d16f47022552 100644
--- a/drivers/media/common/videobuf2/videobuf2-core.c
+++ b/drivers/media/common/videobuf2/videobuf2-core.c
@@ -695,6 +695,9 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory,
unsigned int i;
int ret;
+ if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
+ consistent_mem = false;
+
if (q->streaming) {
dprintk(1, "streaming active\n");
return -EBUSY;
@@ -838,6 +841,9 @@ int vb2_core_create_bufs(struct vb2_queue *q, enum vb2_memory memory,
bool consistent_mem = true;
int ret;
+ if (flags & V4L2_FLAG_MEMORY_NON_CONSISTENT)
+ consistent_mem = false;
+
if (q->num_buffers == VB2_MAX_FRAME) {
dprintk(1, "maximum number of buffers already allocated\n");
return -ENOBUFS;
diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c
index 04ea332567b1..aeb29c33984e 100644
--- a/drivers/media/common/videobuf2/videobuf2-v4l2.c
+++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c
@@ -718,12 +718,36 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps)
#endif
}
+/*
+ * vb2_core_reqbufs()/vb2_core_create_bufs() can re-initialize the queue,
+ * change its memory, type and invoke driver's ->queue_setup(), so we need
+ * to adjust consistency flag and caps accordingly.
+ */
+static void fixup_consistency_attr(struct vb2_queue *q, unsigned int *flags)
+{
+ if (!vb2_queue_allows_cache_hints(q))
+ *flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT;
+}
+
+static void fixup_cache_hints_cap(struct vb2_queue *q, unsigned int *caps)
+{
+ if (!vb2_queue_allows_cache_hints(q))
+ *caps &= ~V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS;
+ else
+ *caps |= V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS;
+}
+
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, 0, &req->count);
+ if (ret)
+ return ret;
+ ret = vb2_core_reqbufs(q, req->memory, req->flags, &req->count);
+ fixup_consistency_attr(q, &req->flags);
+ fixup_cache_hints_cap(q, &req->capabilities);
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_reqbufs);
@@ -797,8 +821,16 @@ 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, true,
- &create->count, requested_planes, requested_sizes);
+
+ if (ret)
+ return ret;
+
+ ret = vb2_core_create_bufs(q, create->memory,
+ create->flags, &create->count,
+ requested_planes, requested_sizes);
+ fixup_consistency_attr(q, &create->flags);
+ fixup_cache_hints_cap(q, &create->capabilities);
+ return ret;
}
EXPORT_SYMBOL_GPL(vb2_create_bufs);
@@ -973,7 +1005,10 @@ 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, 0, &p->count);
+
+ res = vb2_core_reqbufs(vdev->queue, p->memory, p->flags, &p->count);
+ fixup_consistency_attr(vdev->queue, &p->flags);
+ fixup_cache_hints_cap(vdev->queue, &p->capabilities);
/* 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/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
index a99e82ec9ab6..aa162ed6d01c 100644
--- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
+++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c
@@ -246,6 +246,8 @@ struct v4l2_format32 {
* @memory: buffer memory type
* @format: frame format, for which buffers are requested
* @capabilities: capabilities of this buffer type.
+ * @flags: additional buffer management attributes (ignored if queue
+ * does not have V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS capability).
* @reserved: future extensions
*/
struct v4l2_create_buffers32 {
@@ -254,7 +256,8 @@ struct v4l2_create_buffers32 {
__u32 memory; /* enum v4l2_memory */
struct v4l2_format32 format;
__u32 capabilities;
- __u32 reserved[7];
+ __u32 flags;
+ __u32 reserved[6];
};
static int __bufsize_v4l2_format(struct v4l2_format32 __user *p32, u32 *size)
@@ -355,7 +358,8 @@ static int get_v4l2_create32(struct v4l2_create_buffers __user *p64,
{
if (!access_ok(p32, sizeof(*p32)) ||
copy_in_user(p64, p32,
- offsetof(struct v4l2_create_buffers32, format)))
+ offsetof(struct v4l2_create_buffers32, format)) ||
+ assign_in_user(&p64->flags, &p32->flags))
return -EFAULT;
return __get_v4l2_format32(&p64->format, &p32->format,
aux_buf, aux_space);
@@ -417,6 +421,7 @@ static int put_v4l2_create32(struct v4l2_create_buffers __user *p64,
copy_in_user(p32, p64,
offsetof(struct v4l2_create_buffers32, format)) ||
assign_in_user(&p32->capabilities, &p64->capabilities) ||
+ assign_in_user(&p32->flags, &p64->flags) ||
copy_in_user(p32->reserved, p64->reserved, sizeof(p64->reserved)))
return -EFAULT;
return __put_v4l2_format32(&p64->format, &p32->format);
diff --git a/drivers/media/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c
index 833e79a2cb98..4c2dadbeefdc 100644
--- a/drivers/media/v4l2-core/v4l2-ioctl.c
+++ b/drivers/media/v4l2-core/v4l2-ioctl.c
@@ -1978,9 +1978,6 @@ static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops,
if (ret)
return ret;
-
- CLEAR_AFTER_FIELD(p, capabilities);
-
return ops->vidioc_reqbufs(file, fh, p);
}
@@ -2020,7 +2017,7 @@ static int v4l_create_bufs(const struct v4l2_ioctl_ops *ops,
if (ret)
return ret;
- CLEAR_AFTER_FIELD(create, capabilities);
+ CLEAR_AFTER_FIELD(create, flags);
v4l_sanitize_format(&create->format);
diff --git a/include/uapi/linux/videodev2.h b/include/uapi/linux/videodev2.h
index 0d4deba8fe30..f0a4694dd7c6 100644
--- a/include/uapi/linux/videodev2.h
+++ b/include/uapi/linux/videodev2.h
@@ -943,7 +943,10 @@ struct v4l2_requestbuffers {
__u32 type; /* enum v4l2_buf_type */
__u32 memory; /* enum v4l2_memory */
__u32 capabilities;
- __u32 reserved[1];
+ union {
+ __u32 flags;
+ __u32 reserved[1];
+ };
};
/* capabilities for struct v4l2_requestbuffers and v4l2_create_buffers */
@@ -2447,6 +2450,8 @@ struct v4l2_dbg_chip_info {
* @memory: enum v4l2_memory; buffer memory type
* @format: frame format, for which buffers are requested
* @capabilities: capabilities of this buffer type.
+ * @flags: additional buffer management attributes (ignored if queue
+ * does not have V4L2_BUF_CAP_SUPPORTS_CACHE_HINTS capability).
* @reserved: future extensions
*/
struct v4l2_create_buffers {
@@ -2455,7 +2460,8 @@ struct v4l2_create_buffers {
__u32 memory;
struct v4l2_format format;
__u32 capabilities;
- __u32 reserved[7];
+ __u32 flags;
+ __u32 reserved[6];
};
/*
--
2.26.2