Re: [PATCH V8 2/5] mfd: Intel Platform Monitoring Technology support

[Geert Uytterhoeven]

Hi David,

On Sat, Oct 3, 2020 at 3:32 AM David E. Box <david.e.box@xxxxxxxxxxxxxxx> wrote:
> Intel Platform Monitoring Technology (PMT) is an architecture for
> enumerating and accessing hardware monitoring facilities. PMT supports
> multiple types of monitoring capabilities. This driver creates platform
> devices for each type so that they may be managed by capability specific
> drivers (to be introduced). Capabilities are discovered using PCIe DVSEC
> ids. Support is included for the 3 current capability types, Telemetry,
> Watcher, and Crashlog. The features are available on new Intel platforms
> starting from Tiger Lake for which support is added. This patch adds
> support for Tiger Lake (TGL), Alder Lake (ADL), and Out-of-Band Management
> Services Module (OOBMSM).
>
> Also add a quirk mechanism for several early hardware differences and bugs.
> For Tiger Lake and Alder Lake, do not support Watcher and Crashlog
> capabilities since they will not be compatible with future product. Also,
> fix use a quirk to fix the discovery table offset.
>
> Co-developed-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Signed-off-by: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
> Signed-off-by: David E. Box <david.e.box@xxxxxxxxxxxxxxx>
> Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>

Thanks for your patch, which is now commit 4f8217d5b0ca8ace ("mfd: Intel
Platform Monitoring Technology support") in the mfd/for-mfd-next.

> --- a/drivers/mfd/Kconfig
> +++ b/drivers/mfd/Kconfig
> @@ -670,6 +670,16 @@ config MFD_INTEL_PMC_BXT
>           Register and P-unit access. In addition this creates devices
>           for iTCO watchdog and telemetry that are part of the PMC.
>
> +config MFD_INTEL_PMT
> +       tristate "Intel Platform Monitoring Technology (PMT) support"
> +       depends on PCI

Does this need a "depend on X86 || COMPILE_TEST", to prevent the
question from showing up on platforms where the PMT cannot be present?

I see the TGL and ADL PCI IDs are also referenced from
drivers/platform/x86/intel_pmt_telemetry.c, which suggests this is X86-only.
Perhaps the OOBMSM is a PCI device that can be used on non-X86 platforms?

> +       select MFD_CORE
> +       help
> +         The Intel Platform Monitoring Technology (PMT) is an interface that
> +         provides access to hardware monitor registers. This driver supports
> +         Telemetry, Watcher, and Crashlog PMT capabilities/devices for
> +         platforms starting from Tiger Lake.
> +

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds