From: Wei Huang <wei.huang2@amd.com> To: linux-kernel@vger.kernel.org Cc: bp@suse.de, tony.luck@intel.com, yazen.ghannam@amd.com, tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, linux-edac@vger.kernel.org, x86@kernel.org, smita.koralahallichannabasappa@amd.com, wei.huang2@amd.com Subject: [PATCH V3 1/1] x86/mce/amd: Add PPIN support for AMD MCE Date: Sat, 21 Mar 2020 14:38:00 -0500 Message-ID: <20200321193800.3666964-1-wei.huang2@amd.com> (raw) Newer AMD CPUs support a feature called protected processor identification number (PPIN). This feature can be detected via CPUID_Fn80000008_EBX[23]. However CPUID alone is not enough to read the processor serial number. MSR_AMD_PPIN_CTL also needs to be configured properly. If for any reason X86_FEATURE_AMD_PPIN[PPIN_EN] can not be turned on, such as disabled in BIOS, we have to clear the CPU capability bit of X86_FEATURE_AMD_PPIN. When the X86_FEATURE_AMD_PPIN capability is available, MCE can read the serial number to keep track the source of MCE errors. Co-developed-by: Smita Koralahalli Channabasappa <smita.koralahallichannabasappa@amd.com> Signed-off-by: Smita Koralahalli Channabasappa <smita.koralahallichannabasappa@amd.com> Signed-off-by: Wei Huang <wei.huang2@amd.com> Acked-by: Tony Luck <tony.luck@intel.com> Cc: Borislav Petkov <bp@suse.de> Cc: Yazen Ghannam <yazen.ghannam@amd.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: linux-edac <linux-edac@vger.kernel.org> Cc: x86-ml <x86@kernel.org> --- arch/x86/include/asm/cpufeatures.h | 1 + arch/x86/kernel/cpu/amd.c | 30 ++++++++++++++++++++++++++++++ arch/x86/kernel/cpu/mce/core.c | 2 ++ 3 files changed, 33 insertions(+) diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index f3327cb56edf..4b263ffb793b 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -299,6 +299,7 @@ #define X86_FEATURE_AMD_IBRS (13*32+14) /* "" Indirect Branch Restricted Speculation */ #define X86_FEATURE_AMD_STIBP (13*32+15) /* "" Single Thread Indirect Branch Predictors */ #define X86_FEATURE_AMD_STIBP_ALWAYS_ON (13*32+17) /* "" Single Thread Indirect Branch Predictors always-on preferred */ +#define X86_FEATURE_AMD_PPIN (13*32+23) /* Protected Processor Inventory Number */ #define X86_FEATURE_AMD_SSBD (13*32+24) /* "" Speculative Store Bypass Disable */ #define X86_FEATURE_VIRT_SSBD (13*32+25) /* Virtualized Speculative Store Bypass Disable */ #define X86_FEATURE_AMD_SSB_NO (13*32+26) /* "" Speculative Store Bypass is fixed in hardware. */ diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 1f875fbe1384..aef06c37d338 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -394,6 +394,35 @@ static void amd_detect_cmp(struct cpuinfo_x86 *c) per_cpu(cpu_llc_id, cpu) = c->phys_proc_id; } +static void amd_detect_ppin(struct cpuinfo_x86 *c) +{ + unsigned long long val; + + if (!cpu_has(c, X86_FEATURE_AMD_PPIN)) + return; + + /* When PPIN is defined in CPUID, still need to check PPIN_CTL MSR */ + if (rdmsrl_safe(MSR_AMD_PPIN_CTL, &val)) + goto clear_ppin; + + /* PPIN is locked in disabled mode, clear feature bit */ + if ((val & 3UL) == 1UL) + goto clear_ppin; + + /* If PPIN is disabled, try to enable it */ + if (!(val & 2UL)) { + wrmsrl_safe(MSR_AMD_PPIN_CTL, val | 2UL); + rdmsrl_safe(MSR_AMD_PPIN_CTL, &val); + } + + /* If PPIN_EN bit is 1, return from here; otherwise fall through */ + if (val & 2UL) + return; + +clear_ppin: + clear_cpu_cap(c, X86_FEATURE_AMD_PPIN); +} + u16 amd_get_nb_id(int cpu) { return per_cpu(cpu_llc_id, cpu); @@ -941,6 +970,7 @@ static void init_amd(struct cpuinfo_x86 *c) amd_detect_cmp(c); amd_get_topology(c); srat_detect_node(c); + amd_detect_ppin(c); init_amd_cacheinfo(c); diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c index 2c4f949611e4..57347e899575 100644 --- a/arch/x86/kernel/cpu/mce/core.c +++ b/arch/x86/kernel/cpu/mce/core.c @@ -142,6 +142,8 @@ void mce_setup(struct mce *m) if (this_cpu_has(X86_FEATURE_INTEL_PPIN)) rdmsrl(MSR_PPIN, m->ppin); + else if (this_cpu_has(X86_FEATURE_AMD_PPIN)) + rdmsrl(MSR_AMD_PPIN, m->ppin); m->microcode = boot_cpu_data.microcode; } -- 2.24.1
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