[PATCH 01/12] amdgpu: add UAPI for creating encrypted buffers

[Luben Tuikov]

On 2019-11-19 21:41, Marek Olšák wrote:
> On Tue, Nov 19, 2019 at 8:52 PM Luben Tuikov <luben.tuikov at amd.com <mailto:luben.tuikov at amd.com>> wrote:
> 
>     On 2019-11-14 10:34 p.m., Aaron Liu wrote:
>     > From: Huang Rui <ray.huang at amd.com <mailto:ray.huang at amd.com>>
>     >
>     > To align the kernel uapi change from Alex:
>     >
>     > "Add a flag to the GEM_CREATE ioctl to create encrypted buffers. Buffers with
>     > this flag set will be created with the TMZ bit set in the PTEs or engines
>     > accessing them. This is required in order to properly access the data from the
>     > engines."
>     >
>     > We will use GEM_CREATE_ENCRYPTED flag for secure buffer allocation.
>     >
>     > Signed-off-by: Huang Rui <ray.huang at amd.com <mailto:ray.huang at amd.com>>
>     > Reviewed-by: Alex Deucher <alexander.deucher at amd.com <mailto:alexander.deucher at amd.com>>
>     > ---
>     >  include/drm/amdgpu_drm.h | 5 +++++
>     >  1 file changed, 5 insertions(+)
>     >
>     > diff --git a/include/drm/amdgpu_drm.h b/include/drm/amdgpu_drm.h
>     > index 5c28aa7..1a95e37 100644
>     > --- a/include/drm/amdgpu_drm.h
>     > +++ b/include/drm/amdgpu_drm.h
>     > @@ -141,6 +141,11 @@ extern "C" {
>     >   * releasing the memory
>     >   */
>     >  #define AMDGPU_GEM_CREATE_VRAM_WIPE_ON_RELEASE       (1 << 9)
>     > +/* Flag that BO will be encrypted and that the TMZ bit should be
>     > + * set in the PTEs when mapping this buffer via GPUVM or
>     > + * accessing it with various hw blocks
>     > + */
>     > +#define AMDGPU_GEM_CREATE_ENCRYPTED          (1 << 10)
> 
>     Style!
>     TAB char?!
> 
>     You have a TAB char between ".._ENCRYPTED" and "(1 << 10)"
>     Do NOT add/insert TAB chars instead of space to align colunmns!
>     If when you press Tab key a tab is inserted, as opposed to the line
>     indented, then DO NOT use this editor.
>     The Tab key should "indent according to mode" by inserting TAB chars.
>     If the line is already indented, as this one is, then it should do nothing.
> 
> 
> I disagree with this 100%. Tabs or spaces don't matter here from my perspective. I also disagree with your language. It's overly impolite.

But it's the coding style of Linux: leading tabs only. Try it with Emacs as described and given in

linux/Documentation/process/coding-style.rst

starting at line 589. And press the Tab key on an already indented line--nothing will happen. Linux has traditionally
shunned from loose TAB chars in already indented lines: leading tabs only mode. In a proper code editor
pressing the Tab key only indents according to buffer mode, it shouldn't insert a Tab char willy-nilly.
People may set their tab stops differently for different tab positions and inserting a tab char may display
incorrectly. The most portable way to align columns in an already indented-according-to-mode line, is
using spaces. (Of course this doesn't matter when using spaces to indent, but Linux uses hard TAB chars
to indent: linux/Documentation/process/coding-style.rst. (which also seem to be set to 8 chars))

It's a code review, there is no "language".

Regards,
Luben

> 
> Marek