x86/mce: Add a Scalable MCA vendor flags bit

Scalable MCA (SMCA) is a new feature in AMD Fam17h processors
which indicates presence of MCA extensions.

MCA extensions expands existing register space for the MCE banks
and also introduces a new MSR range to accommodate new banks.

Add the detection bit.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
[ Reformat mce_vendor_flags definitions and save indentation levels. Improve comments. ]
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
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/1446207099-24948-2-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/mce.h

@@ -123,19 +123,27 @@ struct mca_config {
 };
 
 struct mce_vendor_flags {
-			/*
-			 * overflow recovery cpuid bit indicates that overflow
-			 * conditions are not fatal
-			 */
-	__u64		overflow_recov	: 1,
-
-			/*
-			 * SUCCOR stands for S/W UnCorrectable error COntainment
-			 * and Recovery. It indicates support for data poisoning
-			 * in HW and deferred error interrupts.
-			 */
-			succor		: 1,
-			__reserved_0	: 62;
+	/*
+	 * Indicates that overflow conditions are not fatal, when set.
+	 */
+	__u64 overflow_recov	: 1,
+
+	/*
+	 * (AMD) SUCCOR stands for S/W UnCorrectable error COntainment and
+	 * Recovery. It indicates support for data poisoning in HW and deferred
+	 * error interrupts.
+	 */
+	      succor		: 1,
+
+	/*
+	 * (AMD) SMCA: This bit indicates support for Scalable MCA which expands
+	 * the register space for each MCA bank and also increases number of
+	 * banks. Also, to accommodate the new banks and registers, the MCA
+	 * register space is moved to a new MSR range.
+	 */
+	      smca		: 1,
+
+	      __reserved_0	: 61;
 };
 extern struct mce_vendor_flags mce_flags;
 

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

@@ -1605,6 +1605,8 @@ static void __mcheck_cpu_init_vendor(struct cpuinfo_x86 *c)
 		mce_amd_feature_init(c);
 		mce_flags.overflow_recov = !!(ebx & BIT(0));
 		mce_flags.succor	 = !!(ebx & BIT(1));
+		mce_flags.smca		 = !!(ebx & BIT(3));
+
 		break;
 		}