linux-kernel - [PATCH 1/2] EDAC/mce_amd: Decode MCA

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Date:   Tue, 12 Feb 2019 21:24:28 +0000
From:   "Ghannam, Yazen" <Yazen.Ghannam@....com>
To:     "linux-edac@...r.kernel.org" <linux-edac@...r.kernel.org>
CC:     "Ghannam, Yazen" <Yazen.Ghannam@....com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "bp@...e.de" <bp@...e.de>
Subject: [PATCH 1/2] EDAC/mce_amd: Decode MCA_STATUS[Scrub] bit

From: Yazen Ghannam <yazen.ghannam@....com>

Previous AMD systems have had a bit in MCA_STATUS to indicate that an
error was detected on a scrub operation. However, this bit was defined
differently within different banks and families/models.

Starting with Family 17h, MCA_STATUS[40] is either Reserved/Read-as-Zero
or defined as "Scrub", for all MCA banks and CPU models. Therefore, we
can define this bit as the "Scrub" bit.

Define MCA_STATUS[40] as "Scrub" and decode it in the AMD MCE decoding
module for Family 17h and newer systems.

Signed-off-by: Yazen Ghannam <yazen.ghannam@....com>
---
 arch/x86/include/asm/mce.h | 1 +
 drivers/edac/mce_amd.c     | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 299a38536567..22d05e3835f0 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -48,6 +48,7 @@
 #define MCI_STATUS_SYNDV	BIT_ULL(53)  /* synd reg. valid */
 #define MCI_STATUS_DEFERRED	BIT_ULL(44)  /* uncorrected error, deferred exception */
 #define MCI_STATUS_POISON	BIT_ULL(43)  /* access poisonous data */
+#define MCI_STATUS_SCRUB	BIT_ULL(40)  /* Error detected during scrub operation */
 
 /*
  * McaX field if set indicates a given bank supports MCA extensions:
diff --git a/drivers/edac/mce_amd.c b/drivers/edac/mce_amd.c
index f286b880f981..b349c22bb386 100644
--- a/drivers/edac/mce_amd.c
+++ b/drivers/edac/mce_amd.c
@@ -1078,6 +1078,9 @@ amd_decode_mce(struct notifier_block *nb, unsigned long val, void *data)
 	if (ecc)
 		pr_cont("|%sECC", ((ecc == 2) ? "C" : "U"));
 
+	if (fam >= 0x17)
+		pr_cont("|%s", (m->status & MCI_STATUS_SCRUB ? "Scrub" : "-"));
+
 	pr_cont("]: 0x%016llx\n", m->status);
 
 	if (m->status & MCI_STATUS_ADDRV)
-- 
2.17.1