x86/mce: Save microcode revision in machine check records

["Luck, Tony" <tony.luck@intel.com>]

Updating microcode used to be relatively rare. Now that it has become
more common we should save the microcode version in a machine check
record to make sure that those people looking at the error have this
important information bundled with the rest of the logged information.

Signed-off-by: Tony Luck <tony.luck@intel.com>
---
 arch/x86/include/uapi/asm/mce.h  | 1 +
 arch/x86/kernel/cpu/mcheck/mce.c | 5 +++++
 2 files changed, 6 insertions(+)

diff --git a/arch/x86/include/uapi/asm/mce.h b/arch/x86/include/uapi/asm/mce.h
index 91723461dc1f..435db58a7bad 100644
--- a/arch/x86/include/uapi/asm/mce.h
+++ b/arch/x86/include/uapi/asm/mce.h
@@ -30,6 +30,7 @@ struct mce {
 	__u64 synd;	/* MCA_SYND MSR: only valid on SMCA systems */
 	__u64 ipid;	/* MCA_IPID MSR: only valid on SMCA systems */
 	__u64 ppin;	/* Protected Processor Inventory Number */
+	__u32 microcode;/* Microcode revision */
 };
 
 #define MCE_GET_RECORD_LEN   _IOR('M', 1, int)
diff --git a/arch/x86/kernel/cpu/mcheck/mce.c b/arch/x86/kernel/cpu/mcheck/mce.c
index 8ff94d1e2dce..b9403c446e05 100644
--- a/arch/x86/kernel/cpu/mcheck/mce.c
+++ b/arch/x86/kernel/cpu/mcheck/mce.c
@@ -118,6 +118,8 @@ BLOCKING_NOTIFIER_HEAD(x86_mce_decoder_chain);
 /* Do initial initialization of a struct mce */
 void mce_setup(struct mce *m)
 {
+	struct cpuinfo_x86 *c;
+
 	memset(m, 0, sizeof(struct mce));
 	m->cpu = m->extcpu = smp_processor_id();
 	/* We hope get_seconds stays lockless */
@@ -130,6 +132,9 @@ void mce_setup(struct mce *m)
 
 	if (this_cpu_has(X86_FEATURE_INTEL_PPIN))
 		rdmsrl(MSR_PPIN, m->ppin);
+
+	c = &cpu_data(m->cpu);
+	m->microcode = c->microcode;
 }
 
 DEFINE_PER_CPU(struct mce, injectm);