[PATCH v3,04/21] v4l: add documentation for secure memory flag

[Jeffrey Kardatzke]

On Mon, Dec 11, 2023 at 3:05 AM Hans Verkuil <hverkuil-cisco at xs4all.nl> wrote:
>
> On 06/12/2023 09:15, Yunfei Dong wrote:
> > From: Jeffrey Kardatzke <jkardatzke at google.com>
> >
> > Adds documentation for V4L2_MEMORY_FLAG_SECURE.
> >
> > Signed-off-by: Jeffrey Kardatzke <jkardatzke at google.com>
> > Signed-off-by: Yunfei Dong <yunfei.dong at mediatek.com>
> > ---
> >  Documentation/userspace-api/media/v4l/buffer.rst | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/Documentation/userspace-api/media/v4l/buffer.rst b/Documentation/userspace-api/media/v4l/buffer.rst
> > index 52bbee81c080..a5a7d1c72d53 100644
> > --- a/Documentation/userspace-api/media/v4l/buffer.rst
> > +++ b/Documentation/userspace-api/media/v4l/buffer.rst
> > @@ -696,7 +696,7 @@ enum v4l2_memory
> >
> >  .. _memory-flags:
> >
> > -Memory Consistency Flags
> > +Memory Flags
> >  ------------------------
> >
> >  .. raw:: latex
> > @@ -728,6 +728,12 @@ Memory Consistency Flags
> >       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.
> > +    * .. _`V4L2-MEMORY-FLAG-SECURE`:
> > +
> > +      - ``V4L2_MEMORY_FLAG_SECURE``
> > +      - 0x00000002
> > +      - DMA bufs passed into the queue will be validated to ensure they were
> > +     allocated from a secure dma-heap.
>
> Hmm, that needs a bit more work. How about:
>
> - The queued buffers are expected to be in secure memory. If not, an error will be
>   returned. This flag can only be used with ``V4L2_MEMORY_DMABUF``. Typically
>   secure buffers are allocated using a secure dma-heap. This flag can only be
>   specified if the ``V4L2_BUF_CAP_SUPPORTS_SECURE_MEM`` is set.
>

Thanks Hans. Yunfei, can you integrate this change into the patch please?

> In addition, the title of this table is currently "Memory Consistency Flags": that
> should be renamed to "Memory Flags".

Hans, the patch is already renaming the table as you suggested. :)
(unless there's some other spot I'm missing)
>
> Regards,
>
>         Hans
>
> >
> >  .. raw:: latex
> >
>