Re: [PATCH v3 2/4] i2c: piix4: Move SB800_PIIX4_FCH_PM_ADDR definition to amd_node.h

[Mario Limonciello]

On 4/13/25 03:44, Ingo Molnar wrote:
> * Ingo Molnar <mingo@xxxxxxxxxx> wrote:
>
> > * Borislav Petkov <bp@xxxxxxxxx> wrote:
> >
> > > I was aiming more for a header which contains non-CPU defines -
> > > i.e., platform. But the FCH is only one part of that platform. But
> > > let's start with amd/fch.h - "amd/" subpath element would allow us
> > > to trivially put other headers there too - and see where it gets
> > > us. We can (and will) always refactor later if needed...
> >
> > Yeah, agreed on opening the <asm/amd/> namespace for this.
>
> Here's a tree that establishes <asm/amd/> and moves existing headers
> there:
>
>    git://git.kernel.org/pub/scm/linux/kernel/git/mingo/tip.git WIP.x86/platform
>
> Mario, could you base your series on top of this tree?

Sure.

One problem that I notice though is that by using <asm/amd/fch.h> that 
drivers/i2c/busses/i2c-piix4.c has some compile failures on non-x86.

This is the same problem that lkp robot raised for v3 when it was on 
<asm/amd_node.h>:

https://lore.kernel.org/linux-doc/20250410200202.2974062-1-superm1@xxxxxxxxxx/T/#mc33abfcdc434c85fbc94d03498759db631efcf53

What's the preferred way to handle it?

The three ways that immediately jump out to me:

1) Add '#if CONFIG_X86' around all related code.

2) Move applicable code to drivers/i2c/busses/i2c-amd-fch.c (similar to 
how we have i2c-amd-asf-plat.c) but modify drivers/i2c/busses/Makefile 
to only compile it for x86.

3) Idea two but also add a new Kconfig for CONFIG_I2C_AMD_FCH that 
depends on CONFIG_X86.

I am /leaning/ on the refactor with idea 3.

> Thanks,
>
> 	Ingo
>
> ===============>
> Ingo Molnar (6):
>    x86/platform/amd: Move the <asm/amd-ibs.h> header to <asm/amd/ibs.h>
>    x86/platform/amd: Add standard header guards to <asm/amd/ibs.h>
>    x86/platform/amd: Move the <asm/amd_nb.h> header to <asm/amd/nb.h>
>    x86/platform/amd: Move the <asm/amd_hsmp.h> header to <asm/amd/hsmp.h>
>    x86/platform/amd: Clean up the <asm/amd/hsmp.h> header guards a bit
>    x86/platform/amd: Move the <asm/amd_node.h> header to <asm/amd/node.h>
>
>   Documentation/userspace-api/ioctl/ioctl-number.rst | 2 +-
>   MAINTAINERS                                        | 6 +++---
>   arch/x86/events/amd/ibs.c                          | 2 +-
>   arch/x86/include/asm/{amd_hsmp.h => amd/hsmp.h}    | 4 ++--
>   arch/x86/include/asm/{amd-ibs.h => amd/ibs.h}      | 5 +++++
>   arch/x86/include/asm/{amd_nb.h => amd/nb.h}        | 2 +-
>   arch/x86/include/asm/{amd_node.h => amd/node.h}    | 0
>   arch/x86/kernel/amd_gart_64.c                      | 2 +-
>   arch/x86/kernel/amd_nb.c                           | 2 +-
>   arch/x86/kernel/amd_node.c                         | 2 +-
>   arch/x86/kernel/aperture_64.c                      | 2 +-
>   arch/x86/kernel/cpu/cacheinfo.c                    | 2 +-
>   arch/x86/kernel/cpu/mce/inject.c                   | 2 +-
>   arch/x86/mm/amdtopology.c                          | 2 +-
>   arch/x86/mm/numa.c                                 | 2 +-
>   arch/x86/pci/amd_bus.c                             | 2 +-
>   arch/x86/pci/fixup.c                               | 2 +-
>   drivers/char/agp/amd64-agp.c                       | 2 +-
>   drivers/edac/amd64_edac.c                          | 4 ++--
>   drivers/hwmon/k10temp.c                            | 2 +-
>   drivers/platform/x86/amd/hsmp/acpi.c               | 4 ++--
>   drivers/platform/x86/amd/hsmp/hsmp.c               | 2 +-
>   drivers/platform/x86/amd/hsmp/plat.c               | 4 ++--
>   drivers/platform/x86/amd/pmc/mp1_stb.c             | 2 +-
>   drivers/platform/x86/amd/pmc/pmc.c                 | 2 +-
>   drivers/platform/x86/amd/pmf/core.c                | 2 +-
>   drivers/pnp/quirks.c                               | 2 +-
>   drivers/ras/amd/atl/internal.h                     | 4 ++--
>   sound/soc/amd/acp/acp-rembrandt.c                  | 2 +-
>   sound/soc/amd/acp/acp63.c                          | 2 +-
>   sound/soc/amd/acp/acp70.c                          | 2 +-
>   sound/soc/sof/amd/acp.c                            | 2 +-
>   tools/perf/check-headers.sh                        | 2 +-
>   tools/perf/util/amd-sample-raw.c                   | 2 +-
>   34 files changed, 44 insertions(+), 39 deletions(-)
>   rename arch/x86/include/asm/{amd_hsmp.h => amd/hsmp.h} (91%)
>   rename arch/x86/include/asm/{amd-ibs.h => amd/ibs.h} (98%)
>   rename arch/x86/include/asm/{amd_nb.h => amd/nb.h} (98%)
>   rename arch/x86/include/asm/{amd_node.h => amd/node.h} (100%)