x86/mce: Add support for deferred errors on AMD

Deferred errors indicate error conditions that were not corrected, but
those errors have not been consumed yet. They require no action from
S/W (or action is optional). These errors provide info about a latent
uncorrectable MCE that can occur when a poisoned data is consumed by the
processor.

Newer AMD processors can generate deferred errors and can be configured
to generate APIC interrupts on such events.

SUCCOR stands for S/W UnCorrectable error COntainment and Recovery.
It indicates support for data poisoning in HW and deferred error
interrupts.

Add new bitfield to mce_vendor_flags for this. We use this to verify
presence of deferred error interrupts before we enable them in mce_amd.c

While at it, clarify comments in mce_vendor_flags to provide an
indication of usages of the bitfields.

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: x86-ml <x86@kernel.org>
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/1430913538-1415-4-git-send-email-Aravind.Gopalakrishnan@amd.com
[ beef up commit message, do CPUID(8000_0007) only once. ]
Signed-off-by: Borislav Petkov <bp@suse.de>

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 1f5a86d518db..407ced642ac1 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -117,8 +117,19 @@ struct mca_config {
 };
 
 struct mce_vendor_flags {
-	__u64		overflow_recov	: 1, /* cpuid_ebx(80000007) */
-			__reserved_0	: 63;
+			/*
+			 * 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;
 };
 extern struct mce_vendor_flags mce_flags;