From c0acf9cfeee061f041fab778dbdcb34b6ca5e2e7 Mon Sep 17 00:00:00 2001 From: Sergey Senozhatsky Date: Thu, 9 Sep 2021 13:24:29 +0200 Subject: [PATCH] media: videobuf2: handle V4L2_MEMORY_FLAG_NON_COHERENT flag This patch lets user-space request a non-coherent 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 byte of a 4 byte ->reserved[1] member of struct v4l2_requestbuffers. The struct, thus, now has reserved 3 bytes. Signed-off-by: Sergey Senozhatsky Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- .../userspace-api/media/v4l/vidioc-create-bufs.rst | 7 ++++- .../userspace-api/media/v4l/vidioc-reqbufs.rst | 11 +++++--- drivers/media/common/videobuf2/videobuf2-core.c | 4 +-- drivers/media/common/videobuf2/videobuf2-v4l2.c | 31 +++++++++++++++++++--- drivers/media/v4l2-core/v4l2-compat-ioctl32.c | 9 ++++++- drivers/media/v4l2-core/v4l2-ioctl.c | 4 +-- include/uapi/linux/videodev2.h | 9 +++++-- 7 files changed, 60 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 f98f18c..a048a9f 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-create-bufs.rst @@ -113,7 +113,12 @@ than the number requested. ``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 e59306a..099fa66 100644 --- a/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst +++ b/Documentation/userspace-api/media/v4l/vidioc-reqbufs.rst @@ -104,10 +104,13 @@ 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. - * - __u32 - - ``reserved``\ [1] - - A place holder for future extensions. Drivers and applications - must set the array to zero. + * - __u8 + - ``flags`` + - Specifies additional buffer management attributes. + See :ref:`memory-flags`. + * - __u8 + - ``reserved``\ [3] + - Reserved for future extensions. .. _v4l2-buf-capabilities: .. _V4L2-BUF-CAP-SUPPORTS-MMAP: diff --git a/drivers/media/common/videobuf2/videobuf2-core.c b/drivers/media/common/videobuf2/videobuf2-core.c index 60fb43b..2266bbd 100644 --- a/drivers/media/common/videobuf2/videobuf2-core.c +++ b/drivers/media/common/videobuf2/videobuf2-core.c @@ -761,7 +761,7 @@ int vb2_core_reqbufs(struct vb2_queue *q, enum vb2_memory memory, { unsigned int num_buffers, allocated_buffers, num_planes = 0; unsigned plane_sizes[VB2_MAX_PLANES] = { }; - bool non_coherent_mem = false; + bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT; unsigned int i; int ret; @@ -905,7 +905,7 @@ 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 non_coherent_mem = false; + bool non_coherent_mem = flags & V4L2_MEMORY_FLAG_NON_COHERENT; int ret; if (q->num_buffers == VB2_MAX_FRAME) { diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index b4f70dd..6edf450 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -692,12 +692,32 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) #endif } +static void validate_memory_flags(struct vb2_queue *q, + int memory, + u32 *flags) +{ + if (!q->allow_cache_hints || memory != V4L2_MEMORY_MMAP) { + /* + * This needs to clear V4L2_MEMORY_FLAG_NON_COHERENT only, + * but in order to avoid bugs we zero out all bits. + */ + *flags = 0; + } else { + /* Clear all unknown flags. */ + *flags &= V4L2_MEMORY_FLAG_NON_COHERENT; + } +} + int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) { int ret = vb2_verify_memory_type(q, req->memory, req->type); + u32 flags = req->flags; fill_buf_caps(q, &req->capabilities); - return ret ? ret : vb2_core_reqbufs(q, req->memory, 0, &req->count); + validate_memory_flags(q, req->memory, &flags); + req->flags = flags; + return ret ? ret : vb2_core_reqbufs(q, req->memory, + req->flags, &req->count); } EXPORT_SYMBOL_GPL(vb2_reqbufs); @@ -729,6 +749,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) unsigned i; fill_buf_caps(q, &create->capabilities); + validate_memory_flags(q, create->memory, &create->flags); create->index = q->num_buffers; if (create->count == 0) return ret != -EBUSY ? ret : 0; @@ -772,7 +793,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) if (requested_sizes[i] == 0) return -EINVAL; return ret ? ret : vb2_core_create_bufs(q, create->memory, - 0, + create->flags, &create->count, requested_planes, requested_sizes); @@ -969,13 +990,16 @@ int vb2_ioctl_reqbufs(struct file *file, void *priv, { struct video_device *vdev = video_devdata(file); int res = vb2_verify_memory_type(vdev->queue, p->memory, p->type); + u32 flags = p->flags; fill_buf_caps(vdev->queue, &p->capabilities); + validate_memory_flags(vdev->queue, p->memory, &flags); + p->flags = flags; if (res) 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); /* 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) @@ -993,6 +1017,7 @@ int vb2_ioctl_create_bufs(struct file *file, void *priv, p->index = vdev->queue->num_buffers; fill_buf_caps(vdev->queue, &p->capabilities); + validate_memory_flags(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/drivers/media/v4l2-core/v4l2-compat-ioctl32.c b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c index 47aff3b..8176769 100644 --- a/drivers/media/v4l2-core/v4l2-compat-ioctl32.c +++ b/drivers/media/v4l2-core/v4l2-compat-ioctl32.c @@ -126,6 +126,9 @@ 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 unless the + * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability and + * configured for MMAP streaming I/O). * @reserved: future extensions */ struct v4l2_create_buffers32 { @@ -134,7 +137,8 @@ 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 get_v4l2_format32(struct v4l2_format *p64, @@ -182,6 +186,8 @@ static int get_v4l2_create32(struct v4l2_create_buffers *p64, if (copy_from_user(p64, p32, offsetof(struct v4l2_create_buffers32, format))) return -EFAULT; + if (copy_from_user(&p64->flags, &p32->flags, sizeof(p32->flags))) + return -EFAULT; return get_v4l2_format32(&p64->format, &p32->format); } @@ -227,6 +233,7 @@ static int put_v4l2_create32(struct v4l2_create_buffers *p64, if (copy_to_user(p32, p64, offsetof(struct v4l2_create_buffers32, format)) || put_user(p64->capabilities, &p32->capabilities) || + put_user(p64->flags, &p32->flags) || copy_to_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 bc83d23..31d0109 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -2024,7 +2024,7 @@ static int v4l_reqbufs(const struct v4l2_ioctl_ops *ops, if (ret) return ret; - CLEAR_AFTER_FIELD(p, capabilities); + CLEAR_AFTER_FIELD(p, flags); return ops->vidioc_reqbufs(file, fh, p); } @@ -2065,7 +2065,7 @@ 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 9b7032a..f118fe7 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -959,7 +959,8 @@ struct v4l2_requestbuffers { __u32 type; /* enum v4l2_buf_type */ __u32 memory; /* enum v4l2_memory */ __u32 capabilities; - __u32 reserved[1]; + __u8 flags; + __u8 reserved[3]; }; #define V4L2_MEMORY_FLAG_NON_COHERENT (1 << 0) @@ -2507,6 +2508,9 @@ 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 unless the + * queue has V4L2_BUF_CAP_SUPPORTS_MMAP_CACHE_HINTS capability + * and configured for MMAP streaming I/O). * @reserved: future extensions */ struct v4l2_create_buffers { @@ -2515,7 +2519,8 @@ struct v4l2_create_buffers { __u32 memory; struct v4l2_format format; __u32 capabilities; - __u32 reserved[7]; + __u32 flags; + __u32 reserved[6]; }; /* -- 2.7.4