[PATCH 5/5] x86/mcheck/AMD: Set MCAX Enable bit

[Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>]

It is required for OS to acknowledge that it is using
the MCAX register set and its associated fields by setting
the 'McaXEnable' bit in each bank's MCi_CONFIG register. If
it is not set, then all UC errors will cause a system panic.

So setting the bit here and also defining the new MSR range for
SMCA enabled proccessors in msr-index

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
---
 arch/x86/include/asm/msr-index.h     | 23 +++++++++++++++++++++++
 arch/x86/kernel/cpu/mcheck/mce_amd.c | 12 ++++++++++++
 2 files changed, 35 insertions(+)

diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h
index b05402e..88505f8 100644
--- a/arch/x86/include/asm/msr-index.h
+++ b/arch/x86/include/asm/msr-index.h
@@ -264,6 +264,29 @@
 #define MSR_IA32_MC0_CTL2		0x00000280
 #define MSR_IA32_MCx_CTL2(x)		(MSR_IA32_MC0_CTL2 + (x))
 
+/* SMCA defined MSR register set for AMD64 */
+#define MSR_AMD64_SMCA_MC0_CTL		0xc0002000
+#define MSR_AMD64_SMCA_MC0_STATUS	0xc0002001
+#define MSR_AMD64_SMCA_MC0_ADDR		0xc0002002
+#define MSR_AMD64_SMCA_MC0_MISC0	0xc0002003
+#define MSR_AMD64_SMCA_MC0_CONFIG	0xc0002004
+#define MSR_AMD64_SMCA_MC0_IPID		0xc0002005
+#define MSR_AMD64_SMCA_MC0_SYND		0xc0002006
+#define MSR_AMD64_SMCA_MC0_DESTAT	0xc0002008
+#define MSR_AMD64_SMCA_MC0_DEADDR	0xc0002009
+#define MSR_AMD64_SMCA_MC0_MISC1	0xc000200a
+
+#define MSR_AMD64_SMCA_MCx_CTL(x)	(MSR_AMD64_SMCA_MC0_CTL + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_STATUS(x)	(MSR_AMD64_SMCA_MC0_STATUS + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_ADDR(x)	(MSR_AMD64_SMCA_MC0_ADDR + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_MISC(x)	(MSR_AMD64_SMCA_MC0_MISC0 + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_CONFIG(x)	(MSR_AMD64_SMCA_MC0_CONFIG + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_IPID(x)	(MSR_AMD64_SMCA_MC0_IPID + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_SYND(x)	(MSR_AMD64_SMCA_MC0_SYND + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_DESTAT(x)	(MSR_AMD64_SMCA_MC0_DESTAT + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_DEADDR(x)	(MSR_AMD64_SMCA_MC0_DEADDR + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_MISCy(x, y)	((MSR_AMD64_SMCA_MC0_MISC1 + y) + (0x10*(x)))
+
 #define MSR_P6_PERFCTR0			0x000000c1
 #define MSR_P6_PERFCTR1			0x000000c2
 #define MSR_P6_EVNTSEL0			0x00000186
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 4383d75..ae6fcca 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -51,6 +51,7 @@
 
 /* SMCA settings */
 #define SMCA_THR_LVT_OFF	0xF000
+#define SMCA_MCAX_EN_OFF	0x1
 
 static const char * const th_names[] = {
 	"load_store",
@@ -316,6 +317,17 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 
 			if (mce_flags.smca) {
 				u32 smca_low = 0, smca_high = 0;
+				u32 smca_addr = 0;
+
+				/* Set MCAXEnable bit for each bank */
+				smca_addr = MSR_AMD64_SMCA_MCx_CONFIG(bank);
+				if (rdmsr_safe(smca_addr,
+					       &smca_low,
+					       &smca_high))
+					continue;
+
+				smca_high = (smca_high & ~SMCA_MCAX_EN_OFF) | 0x1;
+				wrmsr(smca_addr, smca_low, smca_high);
 
 				/* Gather LVT offset for thresholding */
 				if (rdmsr_safe(MSR_CU_DEF_ERR,
-- 
2.7.0