linux-kernel - Re: [PATCH 2/4] x86/mce, PCI: Provide quirks to identify Xeon models with machine check recovery

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Date:   Sat, 27 Aug 2016 07:26:34 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     Ingo Molnar <mingo@...nel.org>, Boris Petkov <bp@...e.de>,
        Dan Williams <dan.j.williams@...el.com>,
        "H. Peter Anvin" <hpa@...or.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Linus Torvalds <torvalds@...ux-foundation.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 2/4] x86/mce, PCI: Provide quirks to identify Xeon models
 with machine check recovery

On Fri, Aug 26, 2016 at 02:08:03PM -0700, Tony Luck wrote:
> Each Xeon includes a number of capability registers in PCI space
> that describe some features not enumerated by CPUID.
> 
> Use these to determine that we are running on a model that can recover
> from machine checks. Hooks for Ivybridge ... Skylake provided.
> 
> Signed-off-by: Tony Luck <tony.luck@...el.com>
> ---
>  arch/x86/include/asm/string_64.h |  3 +++
>  arch/x86/kernel/cpu/mcheck/mce.c |  7 +++++++
>  drivers/pci/quirks.c             | 31 +++++++++++++++++++++++++++++++
>  3 files changed, 41 insertions(+)
> 
> diff --git a/arch/x86/include/asm/string_64.h b/arch/x86/include/asm/string_64.h
> index 90dbbd9666d4..877a1dfbf770 100644
> --- a/arch/x86/include/asm/string_64.h
> +++ b/arch/x86/include/asm/string_64.h
> @@ -2,6 +2,7 @@
>  #define _ASM_X86_STRING_64_H
>  
>  #ifdef __KERNEL__
> +#include <linux/jump_label.h>
>  
>  /* Written 2002 by Andi Kleen */
>  
> @@ -78,6 +79,8 @@ int strcmp(const char *cs, const char *ct);
>  #define memset(s, c, n) __memset(s, c, n)
>  #endif
>  
> +DECLARE_STATIC_KEY_FALSE(mcsafe_key);
> +
>  /**
>   * memcpy_mcsafe - copy memory with indication if a machine check happened
>   *
> diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
> index 79d8ec849468..c192fabc3d76 100644
> --- a/arch/x86/kernel/cpu/mcheck/mce.c
> +++ b/arch/x86/kernel/cpu/mcheck/mce.c
> @@ -41,6 +41,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/irq_work.h>
>  #include <linux/export.h>
> +#include <linux/jump_label.h>
>  
>  #include <asm/processor.h>
>  #include <asm/traps.h>
> @@ -2676,8 +2677,14 @@ static int __init mcheck_debugfs_init(void)
>  static int __init mcheck_debugfs_init(void) { return -EINVAL; }
>  #endif
>  
> +DEFINE_STATIC_KEY_FALSE(mcsafe_key);
> +EXPORT_SYMBOL_GPL(mcsafe_key);
> +
>  static int __init mcheck_late_init(void)
>  {
> +	if (mca_cfg.recovery)
> +		static_branch_inc(&mcsafe_key);
> +
>  	mcheck_debugfs_init();
>  
>  	/*
> diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
> index 37ff0158e45f..c88191074879 100644
> --- a/drivers/pci/quirks.c
> +++ b/drivers/pci/quirks.c

Shouldn't all that stuff below be in arch/x86/?

arch/x86/pci/fixup.c maybe, for example?

> @@ -4428,3 +4428,34 @@ static void quirk_intel_qat_vf_cap(struct pci_dev *pdev)
>  	}
>  }
>  DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x443, quirk_intel_qat_vf_cap);
> +
> +#if defined(CONFIG_X86_64) && defined(CONFIG_X86_MCE)
> +#include <linux/jump_label.h>
> +#include <asm/string_64.h>
> +
> +/* Ivy Bridge, Haswell, Broadwell */
> +static void quirk_intel_brickland_xeon_ras_cap(struct pci_dev *pdev)
> +{
> +	u32 capid0;
> +
> +	pci_read_config_dword(pdev, 0x84, &capid0);
> +
> +	if (capid0 & 0x10)
> +		static_branch_inc(&mcsafe_key);
> +}
> +
> +/* Skylake */
> +static void quirk_intel_purley_xeon_ras_cap(struct pci_dev *pdev)
> +{
> +	u32 capid0;
> +
> +	pci_read_config_dword(pdev, 0x84, &capid0);
> +
> +	if ((capid0 & 0xc0) == 0xc0)
> +		static_branch_inc(&mcsafe_key);
> +}
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x0ec3, quirk_intel_brickland_xeon_ras_cap);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2fc0, quirk_intel_brickland_xeon_ras_cap);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x6fc0, quirk_intel_brickland_xeon_ras_cap);
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_INTEL, 0x2083, quirk_intel_purley_xeon_ras_cap);
> +#endif
> -- 
> 2.5.0
> 

-- 
Regards/Gruss,
    Boris.

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