Re: [PATCH v5 03/13] gunyah: Common types and error codes for Gunyah hypercalls

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

On Tue, Oct 11, 2022 at 11:50:04AM -0700, Trilok Soni wrote:
> On 10/11/2022 11:48 AM, Greg Kroah-Hartman wrote:
> > On Tue, Oct 11, 2022 at 11:21:36AM -0700, Elliot Berman wrote:
> > > 
> > > 
> > > On 10/11/2022 12:21 AM, Greg Kroah-Hartman wrote:
> > > > On Mon, Oct 10, 2022 at 05:08:30PM -0700, Elliot Berman wrote:
> > > > > Add architecture-independent standard error codes, types, and macros for
> > > > > Gunyah hypercalls.
> > > > > 
> > > > > Signed-off-by: Elliot Berman <quic_eberman@quicinc.com>
> > > > > ---
> > > > >    MAINTAINERS                  |  1 +
> > > > >    include/asm-generic/gunyah.h | 74 ++++++++++++++++++++++++++++++++++++
> > > > >    2 files changed, 75 insertions(+)
> > > > >    create mode 100644 include/asm-generic/gunyah.h
> > > > > 
> > > > > diff --git a/MAINTAINERS b/MAINTAINERS
> > > > > index ef6de7599d98..4fe8cec61551 100644
> > > > > --- a/MAINTAINERS
> > > > > +++ b/MAINTAINERS
> > > > > @@ -8886,6 +8886,7 @@ L:	linux-arm-msm@vger.kernel.org
> > > > >    S:	Supported
> > > > >    F:	Documentation/devicetree/bindings/firmware/gunyah-hypervisor.yaml
> > > > >    F:	Documentation/virt/gunyah/
> > > > > +F:	include/asm-generic/gunyah.h
> > > > >    HABANALABS PCI DRIVER
> > > > >    M:	Oded Gabbay <ogabbay@kernel.org>
> > > > > diff --git a/include/asm-generic/gunyah.h b/include/asm-generic/gunyah.h
> > > > > new file mode 100644
> > > > > index 000000000000..64a02dd3b5ad
> > > > > --- /dev/null
> > > > > +++ b/include/asm-generic/gunyah.h
> > > > 
> > > > Why not include/linux/gunyah.h?  Why asm-generic?  This is not an
> > > > architecture.
> > > > 
> > > 
> > > My idea here is to differentiate between code that interacts with hypercalls
> > > and code that uses the abstractions provided on top of those hypercalls.
> > > include/asm-generic/gunyah.h contains architecture-independent definitions
> > > for hypercalls. Hypercalls are architecture-specific.
> > > 
> > > For instance, I wanted to avoid a header file that mixes the definitions for
> > > the message-queue mailbox with the hypercall definitions that the
> > > message-queue mailbox driver itself uses.
> > > 
> > > I can put it all in include/linux/gunyah.h and delineate with some clear
> > > comments, but I initially felt it would be better to have separate header
> > > file.
> > 
> > Please put it all in one place, this is just one tiny driver and should
> > not abuse the asm-generic location at all, no one is only going to want
> > just this one file, they are going to need the whole thing or nothing.
> > 
> 
> Let's say when we do the RISC-V port for Gunyah, we may need to move it back
> to asm-generic then?

If that really happens and the things are arch-specific, yes, we can
worry about that then.  You know better than this, we only do what is
needed now.  We do not add code, or make splits like this, when it is
not needed today.

Keep it simple first, you want to get this merged first, and then you
can iterate on it to make it complex and messy :)

thanks,

greg k-h