[PATCH v3 4/4] x86/mce: Add Zhaoxin LMCE support

[Tony W Wang-oc]

Zhaoxin newer CPUs support LMCE that compatible with Intel's
"Machine-Check Architecture", so add support for Zhaoxin LMCE
in mce/core.c.

Signed-off-by: Tony W Wang-oc <TonyWWang-oc@xxxxxxxxxxx>
---
v2->v3:
 - Rework mce_zhaoxin_feature_clear() as static
 - Add comment and change coding style

v1->v2:
 - Fix redefinition of "mce_zhaoxin_feature_clear"

 arch/x86/kernel/cpu/mce/core.c | 35 +++++++++++++++++++++++++++++++++--
 1 file changed, 33 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/mce/core.c b/arch/x86/kernel/cpu/mce/core.c
index 65c5a1f..acdd76b 100644
--- a/arch/x86/kernel/cpu/mce/core.c
+++ b/arch/x86/kernel/cpu/mce/core.c
@@ -1132,6 +1132,27 @@ static bool __mc_check_crashing_cpu(int cpu)
 		u64 mcgstatus;
 
 		mcgstatus = mce_rdmsrl(MSR_IA32_MCG_STATUS);
+
+		if (boot_cpu_data.x86_vendor == X86_VENDOR_ZHAOXIN) {
+			if (mcgstatus & MCG_STATUS_LMCES)
+				return false;
+
+			if (!(mcgstatus & MCG_STATUS_LMCES)) {
+				/*
+				 * Clear the MCG_STATUS_RIPV valid status
+				 * bit so that a second MCE won't cause a
+				 * shutdown.
+				 */
+				if (mcgstatus & MCG_STATUS_RIPV)
+					mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
+				/*
+				 * On this CPU, skip synchronize regardless
+				 * of MCG_STATUS_RIPV status.
+				 */
+				return true;
+			}
+		}
+
 		if (mcgstatus & MCG_STATUS_RIPV) {
 			mce_wrmsrl(MSR_IA32_MCG_STATUS, 0);
 			return true;
@@ -1282,9 +1303,10 @@ void do_machine_check(struct pt_regs *regs, long error_code)
 
 	/*
 	 * Check if this MCE is signaled to only this logical processor,
-	 * on Intel only.
+	 * on Intel, Zhaoxin only.
 	 */
-	if (m.cpuvendor == X86_VENDOR_INTEL)
+	if (m.cpuvendor == X86_VENDOR_INTEL ||
+	    m.cpuvendor == X86_VENDOR_ZHAOXIN)
 		lmce = m.mcgstatus & MCG_STATUS_LMCES;
 
 	/*
@@ -1795,9 +1817,15 @@ static void mce_zhaoxin_feature_init(struct cpuinfo_x86 *c)
 	}
 
 	intel_init_cmci();
+	intel_init_lmce();
 	mce_adjust_timer = cmci_intel_adjust_timer;
 }
 
+static void mce_zhaoxin_feature_clear(struct cpuinfo_x86 *c)
+{
+	intel_clear_lmce();
+}
+
 static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
 {
 	switch (c->x86_vendor) {
@@ -1834,6 +1862,9 @@ static void __mcheck_cpu_clear_vendor(struct cpuinfo_x86 *c)
 	case X86_VENDOR_INTEL:
 		mce_intel_feature_clear(c);
 		break;
+	case X86_VENDOR_ZHAOXIN:
+		mce_zhaoxin_feature_clear(c);
+		break;
 	default:
 		break;
 	}
-- 
2.7.4