Re: [PATCH 1/5] ACPI: NUMA: Add 'nohmat' option

From: Dan Williams <dan.j.williams@intel.com>
To: Linux ACPI <linux-acpi@vger.kernel.org>
Cc: X86 ML <x86@kernel.org>, "Rafael J. Wysocki" <rjw@rjwysocki.net>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	Ard Biesheuvel <ard.biesheuvel@linaro.org>,
	linux-nvdimm <linux-nvdimm@lists.01.org>,
	Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/5] ACPI: NUMA: Add 'nohmat' option
Date: Tue, 17 Mar 2020 17:08:58 -0700	[thread overview]
Message-ID: <CAPcyv4hjgNruY84Kr9S5HZ6P03fNcPcmL7H2DN19Z+CbPZ7d+Q@mail.gmail.com> (raw)
In-Reply-To: <158318760361.2216124.13612198312947463590.stgit@dwillia2-desk3.amr.corp.intel.com>

On Mon, Mar 2, 2020 at 2:36 PM Dan Williams <dan.j.williams@intel.com> wrote:
>
> Disable parsing of the HMAT for debug, to workaround broken platform
> instances, or cases where it is otherwise not wanted.

Rafael, any heartburn with this change to the numa= option?

...as I look at this I realize I failed to also update
Documentation/x86/x86_64/boot-options.rst, will fix.

>
> Cc: x86@kernel.org
> Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
> Cc: Dave Hansen <dave.hansen@linux.intel.com>
> Cc: Andy Lutomirski <luto@kernel.org>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Ingo Molnar <mingo@redhat.com>
> Cc: Borislav Petkov <bp@alien8.de>
> Cc: "H. Peter Anvin" <hpa@zytor.com>
> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
> ---
>  arch/x86/mm/numa.c       |    4 ++++
>  drivers/acpi/numa/hmat.c |    3 ++-
>  include/acpi/acpi_numa.h |    1 +
>  3 files changed, 7 insertions(+), 1 deletion(-)
>
> diff --git a/arch/x86/mm/numa.c b/arch/x86/mm/numa.c
> index 59ba008504dc..22de2e2610c1 100644
> --- a/arch/x86/mm/numa.c
> +++ b/arch/x86/mm/numa.c
> @@ -44,6 +44,10 @@ static __init int numa_setup(char *opt)
>  #ifdef CONFIG_ACPI_NUMA
>         if (!strncmp(opt, "noacpi", 6))
>                 acpi_numa = -1;
> +#ifdef CONFIG_ACPI_HMAT
> +       if (!strncmp(opt, "nohmat", 6))
> +               hmat_disable = 1;
> +#endif
>  #endif
>         return 0;
>  }
> diff --git a/drivers/acpi/numa/hmat.c b/drivers/acpi/numa/hmat.c
> index 2c32cfb72370..d3db121e393a 100644
> --- a/drivers/acpi/numa/hmat.c
> +++ b/drivers/acpi/numa/hmat.c
> @@ -26,6 +26,7 @@
>  #include <linux/sysfs.h>
>
>  static u8 hmat_revision;
> +int hmat_disable __initdata;
>
>  static LIST_HEAD(targets);
>  static LIST_HEAD(initiators);
> @@ -814,7 +815,7 @@ static __init int hmat_init(void)
>         enum acpi_hmat_type i;
>         acpi_status status;
>
> -       if (srat_disabled())
> +       if (srat_disabled() || hmat_disable)
>                 return 0;
>
>         status = acpi_get_table(ACPI_SIG_SRAT, 0, &tbl);
> diff --git a/include/acpi/acpi_numa.h b/include/acpi/acpi_numa.h
> index fdebcfc6c8df..48ca468e9b61 100644
> --- a/include/acpi/acpi_numa.h
> +++ b/include/acpi/acpi_numa.h
> @@ -18,6 +18,7 @@ extern int node_to_pxm(int);
>  extern int acpi_map_pxm_to_node(int);
>  extern unsigned char acpi_srat_revision;
>  extern int acpi_numa __initdata;
> +extern int hmat_disable __initdata;
>
>  extern void bad_srat(void);
>  extern int srat_disabled(void);
>