x86/mce/AMD: Disable LogDeferredInMcaStat for SMCA systems

Disable Deferred Error logging in MCA_{STATUS,ADDR} additionally for
SMCA systems as this information will retrieved from MCA_DE{STAT,ADDR}
on those systems.

Signed-off-by: Yazen Ghannam <Yazen.Ghannam@amd.com>
[ Simplify, drop SMCA_MCAX_EN_OFF define too. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Aravind Gopalakrishnan <aravindksg.lkml@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1462971509-3856-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index d1b1e62f7cb9bc1f420c8e3b7dc7fcf2d8fcb22e..527ddae3017b8500c1d58f585df5d4b437471ff7 100644 (file)
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -54,14 +54,6 @@
 /* Threshold LVT offset is at MSR0xC0000410[15:12] */
 #define SMCA_THR_LVT_OFF       0xF000
 
-/*
- * OS is required to set the MCAX bit to acknowledge that it is now using the
- * new MSR ranges and new registers under each bank. It also means that the OS
- * will configure deferred errors in the new MCx_CONFIG register. If the bit is
- * not set, uncorrectable errors will cause a system panic.
- */
-#define SMCA_MCAX_EN_OFF       0x1
-
 static const char * const th_names[] = {
        "load_store",
        "insn_fetch",
@@ -374,7 +366,35 @@ prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
                u32 smca_addr = MSR_AMD64_SMCA_MCx_CONFIG(bank);
 
                if (!rdmsr_safe(smca_addr, &smca_low, &smca_high)) {
-                       smca_high |= SMCA_MCAX_EN_OFF;
+                       /*
+                        * OS is required to set the MCAX bit to acknowledge
+                        * that it is now using the new MSR ranges and new
+                        * registers under each bank. It also means that the OS
+                        * will configure deferred errors in the new MCx_CONFIG
+                        * register. If the bit is not set, uncorrectable errors
+                        * will cause a system panic.
+                        *
+                        * MCA_CONFIG[MCAX] is bit 32 (0 in the high portion of
+                        * the MSR.)
+                        */
+                       smca_high |= BIT(0);
+
+                       /*
+                        * SMCA logs Deferred Error information in
+                        * MCA_DE{STAT,ADDR} registers with the option of
+                        * additionally logging to MCA_{STATUS,ADDR} if
+                        * MCA_CONFIG[LogDeferredInMcaStat] is set.
+                        *
+                        * This bit is usually set by BIOS to retain the old
+                        * behavior for OSes that don't use the new registers.
+                        * Linux supports the new registers so let's disable
+                        * that additional logging here.
+                        *
+                        * MCA_CONFIG[LogDeferredInMcaStat] is bit 34 (bit 2 in
+                        * the high portion of the MSR).
+                        */
+                       smca_high &= ~BIT(2);
+
                        wrmsr(smca_addr, smca_low, smca_high);
                }