x86/mce: Add Zhaoxin CMCI support

All newer Zhaoxin CPUs support CMCI and are compatible with Intel's
Machine-Check Architecture. Add that support for Zhaoxin CPUs.

 [ bp: Massage comments and export intel_init_cmci(). ]
Signed-off-by: Tony W Wang-oc <TonyWWang-oc@zhaoxin.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: CooperYan@zhaoxin.com
Cc: DavidWang@zhaoxin.com
Cc: HerryYang@zhaoxin.com
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Cc: QiyuanWang@zhaoxin.com
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/1568787573-1297-4-git-send-email-TonyWWang-oc@zhaoxin.com

arch/x86/kernel/cpu/mce/core.c

@@ -1777,6 +1777,29 @@ static void mce_centaur_feature_init(struct cpuinfo_x86 *c)
 	}
 }
 
+static void mce_zhaoxin_feature_init(struct cpuinfo_x86 *c)
+{
+	struct mce_bank *mce_banks = this_cpu_ptr(mce_banks_array);
+
+	/*
+	 * These CPUs have MCA bank 8 which reports only one error type called
+	 * SVAD (System View Address Decoder). The reporting of that error is
+	 * controlled by IA32_MC8.CTL.0.
+	 *
+	 * If enabled, prefetching on these CPUs will cause SVAD MCE when
+	 * virtual machines start and result in a system  panic. Always disable
+	 * bank 8 SVAD error by default.
+	 */
+	if ((c->x86 == 7 && c->x86_model == 0x1b) ||
+	    (c->x86_model == 0x19 || c->x86_model == 0x1f)) {
+		if (this_cpu_read(mce_num_banks) > 8)
+			mce_banks[8].ctl = 0;
+	}
+
+	intel_init_cmci();
+	mce_adjust_timer = cmci_intel_adjust_timer;
+}
+
 static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
 {
 	switch (c->x86_vendor) {
@@ -1798,6 +1821,10 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
 		mce_centaur_feature_init(c);
 		break;
 
+	case X86_VENDOR_ZHAOXIN:
+		mce_zhaoxin_feature_init(c);
+		break;
+
 	default:
 		break;
 	}

arch/x86/kernel/cpu/mce/intel.c

@@ -85,8 +85,10 @@ static int cmci_supported(int *banks)
 	 * initialization is vendor keyed and this
 	 * makes sure none of the backdoors are entered otherwise.
 	 */
-	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL)
+	if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL &&
+	    boot_cpu_data.x86_vendor != X86_VENDOR_ZHAOXIN)
 		return 0;
+
 	if (!boot_cpu_has(X86_FEATURE_APIC) || lapic_get_maxlvt() < 6)
 		return 0;
 	rdmsrl(MSR_IA32_MCG_CAP, cap);
@@ -423,7 +425,7 @@ void cmci_disable_bank(int bank)
 	raw_spin_unlock_irqrestore(&cmci_discover_lock, flags);
 }
 
-static void intel_init_cmci(void)
+void intel_init_cmci(void)
 {
 	int banks;
 

arch/x86/kernel/cpu/mce/internal.h

@@ -45,11 +45,13 @@ unsigned long cmci_intel_adjust_timer(unsigned long interval);
 bool mce_intel_cmci_poll(void);
 void mce_intel_hcpu_update(unsigned long cpu);
 void cmci_disable_bank(int bank);
+void intel_init_cmci(void);
 #else
 # define cmci_intel_adjust_timer mce_adjust_timer_default
 static inline bool mce_intel_cmci_poll(void) { return false; }
 static inline void mce_intel_hcpu_update(unsigned long cpu) { }
 static inline void cmci_disable_bank(int bank) { }
+static inline void intel_init_cmci(void) { }
 #endif
 
 void mce_timer_kick(unsigned long interval);