Message ID | 20200226111529.180197-6-senozhatsky@chromium.org (mailing list archive) |
---|---|
State | New, archived |
Headers | show |
Series | Implement V4L2_BUF_FLAG_NO_CACHE_* flags | expand |
On 2/26/20 12:15 PM, Sergey Senozhatsky wrote: > 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. > > = 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@chromium.org> > --- > .../media/uapi/v4l/vidioc-create-bufs.rst | 8 ++++- > .../media/uapi/v4l/vidioc-reqbufs.rst | 15 +++++++-- > .../media/common/videobuf2/videobuf2-v4l2.c | 31 +++++++++++++++++-- > drivers/media/v4l2-core/v4l2-ioctl.c | 5 +-- > include/uapi/linux/videodev2.h | 8 +++-- > 5 files changed, 54 insertions(+), 13 deletions(-) > > diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > index bd08e4f77ae4..6a8a4d5de2f1 100644 > --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > @@ -121,7 +121,13 @@ 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`. Old drivers and applications must set it to > + zero. Drop the last sentence, it's not relevant. > + > + * - __u32 > + - ``reserved``\ [6] > - A place holder for future extensions. Drivers and applications > must set the array to zero. Old drivers and applications still think reserved is [7] and will zero this. > > diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > index 917df6fb6486..e52cc4401fba 100644 > --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > @@ -112,10 +112,19 @@ 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 > + * - union > + - (anonymous) Anonymous unions are formatted a bit differently (I made a very recent patch that unified the union formatting in the v4l docs). See e.g. Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst. > + * - > + - __u32 > + - ``flags``\ [1] > + - Specifies additional buffer management attributes. > + See :ref:`memory-flags`. Old drivers and applications must set it to > + zero. Ditto. > + > + * - > + - __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-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c > index cc31629c06dc..4954c9fc678d 100644 > --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c > +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c > @@ -722,9 +722,18 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) > int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) > { > int ret = vb2_verify_memory_type(q, req->memory, req->type); > + bool consistent = true; > + > + if (!vb2_queue_allows_cache_hints(q)) > + req->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; > + > + if (req->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) > + consistent = false; > > fill_buf_caps(q, &req->capabilities); > - return ret ? ret : vb2_core_reqbufs(q, req->memory, true, &req->count); > + if (ret) > + return ret; > + return vb2_core_reqbufs(q, req->memory, consistent, &req->count); > } > EXPORT_SYMBOL_GPL(vb2_reqbufs); > > @@ -753,6 +762,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) > unsigned requested_sizes[VIDEO_MAX_PLANES]; > struct v4l2_format *f = &create->format; > int ret = vb2_verify_memory_type(q, create->memory, f->type); > + bool consistent = true; > unsigned i; > > fill_buf_caps(q, &create->capabilities); > @@ -798,7 +808,14 @@ 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, > + > + if (!vb2_queue_allows_cache_hints(q)) > + create->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; > + > + if (create->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) > + consistent = false; > + > + return ret ? ret : vb2_core_create_bufs(q, create->memory, consistent, > &create->count, requested_planes, requested_sizes); > } > EXPORT_SYMBOL_GPL(vb2_create_bufs); > @@ -968,13 +985,21 @@ 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); > + bool consistent = true; > > fill_buf_caps(vdev->queue, &p->capabilities); > if (res) > return res; > if (vb2_queue_is_busy(vdev, file)) > return -EBUSY; > - res = vb2_core_reqbufs(vdev->queue, p->memory, true, &p->count); > + > + if (!vb2_queue_allows_cache_hints(vdev->queue)) > + p->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; > + > + if (p->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) > + consistent = false; > + > + res = vb2_core_reqbufs(vdev->queue, p->memory, consistent, &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/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c > index fbcc7a20eedf..53b87bfd50d7 100644 > --- a/drivers/media/v4l2-core/v4l2-ioctl.c > +++ b/drivers/media/v4l2-core/v4l2-ioctl.c > @@ -1973,9 +1973,6 @@ 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); > } > > @@ -2015,7 +2012,7 @@ 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 e92c29864730..12b1bd220347 100644 > --- a/include/uapi/linux/videodev2.h > +++ b/include/uapi/linux/videodev2.h > @@ -938,7 +938,10 @@ 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 */ > @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers { > __u32 memory; > struct v4l2_format format; > __u32 capabilities; > - __u32 reserved[7]; > + __u32 flags; > + __u32 reserved[6]; > }; > > /* > Regards, Hans
On (20/02/27 13:36), Hans Verkuil wrote: > > diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > > index bd08e4f77ae4..6a8a4d5de2f1 100644 > > --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > > +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst > > @@ -121,7 +121,13 @@ 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`. Old drivers and applications must set it to > > + zero. > > Drop the last sentence, it's not relevant. OK. > > + > > + * - __u32 > > + - ``reserved``\ [6] > > - A place holder for future extensions. Drivers and applications > > must set the array to zero. > > Old drivers and applications still think reserved is [7] and will zero this. OK. Hmm... If those apps use hard-coded size then we might have a problem. If they use sizeof(reserved) then everything is OK. Shall we also have a union here? > > diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > > index 917df6fb6486..e52cc4401fba 100644 > > --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > > +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst > > @@ -112,10 +112,19 @@ 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 > > + * - union > > + - (anonymous) > > Anonymous unions are formatted a bit differently (I made a very recent patch > that unified the union formatting in the v4l docs). See e.g. > Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst. OK, will take a look. -ss
On (20/02/27 13:36), Hans Verkuil wrote: [..] > > 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`. Old drivers and applications must set it to > > + zero. > > Drop the last sentence, it's not relevant. > > > + > > + * - __u32 > > + - ``reserved``\ [6] > > - A place holder for future extensions. Drivers and applications > > must set the array to zero. > > Old drivers and applications still think reserved is [7] and will zero this. Just to make sure, does this mean that you also want me to drop the "Drivers and applications must set the array to zero" sentence? -ss
On 2/28/20 2:38 AM, Sergey Senozhatsky wrote: > On (20/02/27 13:36), Hans Verkuil wrote: >>> diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst >>> index bd08e4f77ae4..6a8a4d5de2f1 100644 >>> --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst >>> +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst >>> @@ -121,7 +121,13 @@ 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`. Old drivers and applications must set it to >>> + zero. >> >> Drop the last sentence, it's not relevant. > > OK. > >>> + >>> + * - __u32 >>> + - ``reserved``\ [6] >>> - A place holder for future extensions. Drivers and applications >>> must set the array to zero. >> >> Old drivers and applications still think reserved is [7] and will zero this. > > OK. > > Hmm... If those apps use hard-coded size then we might have a problem. > If they use sizeof(reserved) then everything is OK. Shall we also have > a union here? No, apps will use sizeof(reserved). Regards, Hans > >>> diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst >>> index 917df6fb6486..e52cc4401fba 100644 >>> --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst >>> +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst >>> @@ -112,10 +112,19 @@ 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 >>> + * - union >>> + - (anonymous) >> >> Anonymous unions are formatted a bit differently (I made a very recent patch >> that unified the union formatting in the v4l docs). See e.g. >> Documentation/media/uapi/v4l/vidioc-g-ext-ctrls.rst. > > OK, will take a look. > > -ss >
On 2/28/20 4:57 AM, Sergey Senozhatsky wrote: > On (20/02/27 13:36), Hans Verkuil wrote: > [..] >>> 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`. Old drivers and applications must set it to >>> + zero. >> >> Drop the last sentence, it's not relevant. >> >>> + >>> + * - __u32 >>> + - ``reserved``\ [6] >>> - A place holder for future extensions. Drivers and applications >>> must set the array to zero. >> >> Old drivers and applications still think reserved is [7] and will zero this. > > Just to make sure, does this mean that you also want me to drop the > "Drivers and applications must set the array to zero" sentence? Not for the reserved field, only for the flags field. Regards, Hans > > -ss >
On (20/02/28 09:50), Hans Verkuil wrote: > On 2/28/20 4:57 AM, Sergey Senozhatsky wrote: > > On (20/02/27 13:36), Hans Verkuil wrote: > > [..] [..] > >>> + * - __u32 > >>> + - ``reserved``\ [6] > >>> - A place holder for future extensions. Drivers and applications > >>> must set the array to zero. > >> > >> Old drivers and applications still think reserved is [7] and will zero this. > > > > Just to make sure, does this mean that you also want me to drop the > > "Drivers and applications must set the array to zero" sentence? > > Not for the reserved field, only for the flags field. Got it. So V4 is ready. Do you think it'll make sense to send it out now or next week? -ss
diff --git a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst index bd08e4f77ae4..6a8a4d5de2f1 100644 --- a/Documentation/media/uapi/v4l/vidioc-create-bufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-create-bufs.rst @@ -121,7 +121,13 @@ 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`. Old drivers and applications must set it to + zero. + + * - __u32 + - ``reserved``\ [6] - A place holder for future extensions. Drivers and applications must set the array to zero. diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst index 917df6fb6486..e52cc4401fba 100644 --- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst +++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst @@ -112,10 +112,19 @@ 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 + * - union + - (anonymous) + * - + - __u32 + - ``flags``\ [1] + - Specifies additional buffer management attributes. + See :ref:`memory-flags`. Old drivers and applications must set it to + zero. + + * - + - __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-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index cc31629c06dc..4954c9fc678d 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -722,9 +722,18 @@ static void fill_buf_caps(struct vb2_queue *q, u32 *caps) int vb2_reqbufs(struct vb2_queue *q, struct v4l2_requestbuffers *req) { int ret = vb2_verify_memory_type(q, req->memory, req->type); + bool consistent = true; + + if (!vb2_queue_allows_cache_hints(q)) + req->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; + + if (req->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) + consistent = false; fill_buf_caps(q, &req->capabilities); - return ret ? ret : vb2_core_reqbufs(q, req->memory, true, &req->count); + if (ret) + return ret; + return vb2_core_reqbufs(q, req->memory, consistent, &req->count); } EXPORT_SYMBOL_GPL(vb2_reqbufs); @@ -753,6 +762,7 @@ int vb2_create_bufs(struct vb2_queue *q, struct v4l2_create_buffers *create) unsigned requested_sizes[VIDEO_MAX_PLANES]; struct v4l2_format *f = &create->format; int ret = vb2_verify_memory_type(q, create->memory, f->type); + bool consistent = true; unsigned i; fill_buf_caps(q, &create->capabilities); @@ -798,7 +808,14 @@ 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, + + if (!vb2_queue_allows_cache_hints(q)) + create->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; + + if (create->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) + consistent = false; + + return ret ? ret : vb2_core_create_bufs(q, create->memory, consistent, &create->count, requested_planes, requested_sizes); } EXPORT_SYMBOL_GPL(vb2_create_bufs); @@ -968,13 +985,21 @@ 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); + bool consistent = true; fill_buf_caps(vdev->queue, &p->capabilities); if (res) return res; if (vb2_queue_is_busy(vdev, file)) return -EBUSY; - res = vb2_core_reqbufs(vdev->queue, p->memory, true, &p->count); + + if (!vb2_queue_allows_cache_hints(vdev->queue)) + p->flags &= ~V4L2_FLAG_MEMORY_NON_CONSISTENT; + + if (p->flags & V4L2_FLAG_MEMORY_NON_CONSISTENT) + consistent = false; + + res = vb2_core_reqbufs(vdev->queue, p->memory, consistent, &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/v4l2-core/v4l2-ioctl.c b/drivers/media/v4l2-core/v4l2-ioctl.c index fbcc7a20eedf..53b87bfd50d7 100644 --- a/drivers/media/v4l2-core/v4l2-ioctl.c +++ b/drivers/media/v4l2-core/v4l2-ioctl.c @@ -1973,9 +1973,6 @@ 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); } @@ -2015,7 +2012,7 @@ 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 e92c29864730..12b1bd220347 100644 --- a/include/uapi/linux/videodev2.h +++ b/include/uapi/linux/videodev2.h @@ -938,7 +938,10 @@ 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 */ @@ -2446,7 +2449,8 @@ struct v4l2_create_buffers { __u32 memory; struct v4l2_format format; __u32 capabilities; - __u32 reserved[7]; + __u32 flags; + __u32 reserved[6]; }; /*
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. = 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@chromium.org> --- .../media/uapi/v4l/vidioc-create-bufs.rst | 8 ++++- .../media/uapi/v4l/vidioc-reqbufs.rst | 15 +++++++-- .../media/common/videobuf2/videobuf2-v4l2.c | 31 +++++++++++++++++-- drivers/media/v4l2-core/v4l2-ioctl.c | 5 +-- include/uapi/linux/videodev2.h | 8 +++-- 5 files changed, 54 insertions(+), 13 deletions(-)