[tip:ras/core] x86/mce/AMD: Fix logic to obtain block address

[tip-bot for Aravind Gopalakrishnan]

Commit-ID:  8dd1e17a55b0bb1206c71c7a4344c5e3037cdf65
Gitweb:     http://git.kernel.org/tip/8dd1e17a55b0bb1206c71c7a4344c5e3037cdf65
Author:     Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
AuthorDate: Mon, 7 Mar 2016 14:02:19 +0100
Committer:  Ingo Molnar <mingo@xxxxxxxxxx>
CommitDate: Tue, 8 Mar 2016 11:48:14 +0100

x86/mce/AMD: Fix logic to obtain block address

In upcoming processors, the BLKPTR field is no longer used to indicate
the MSR number of the additional register. Insted, it simply indicates
the prescence of additional MSRs.

Fix the logic here to gather MSR address from MSR_AMD64_SMCA_MCx_MISC()
for newer processors and fall back to existing logic for older
processors.

[ Drop nextaddr_out label; style cleanups. ]
Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
Signed-off-by: Borislav Petkov <bp@xxxxxxx>
Cc: Borislav Petkov <bp@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Cc: Tony Luck <tony.luck@xxxxxxxxx>
Cc: linux-edac <linux-edac@xxxxxxxxxxxxxxx>
Link: http://lkml.kernel.org/r/1457021458-2522-4-git-send-email-Aravind.Gopalakrishnan@xxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
---
 arch/x86/include/asm/mce.h           |  4 ++
 arch/x86/kernel/cpu/mcheck/mce_amd.c | 84 +++++++++++++++++++++++-------------
 2 files changed, 59 insertions(+), 29 deletions(-)

diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index 9c467fe..72f8688 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -104,10 +104,14 @@
 #define MCE_LOG_SIGNATURE	"MACHINECHECK"
 
 /* AMD Scalable MCA */
+#define MSR_AMD64_SMCA_MC0_MISC0	0xc0002003
 #define MSR_AMD64_SMCA_MC0_CONFIG	0xc0002004
 #define MSR_AMD64_SMCA_MC0_IPID		0xc0002005
+#define MSR_AMD64_SMCA_MC0_MISC1	0xc000200a
+#define MSR_AMD64_SMCA_MCx_MISC(x)	(MSR_AMD64_SMCA_MC0_MISC0 + 0x10*(x))
 #define MSR_AMD64_SMCA_MCx_CONFIG(x)	(MSR_AMD64_SMCA_MC0_CONFIG + 0x10*(x))
 #define MSR_AMD64_SMCA_MCx_IPID(x)	(MSR_AMD64_SMCA_MC0_IPID + 0x10*(x))
+#define MSR_AMD64_SMCA_MCx_MISCy(x, y)	((MSR_AMD64_SMCA_MC0_MISC1 + y) + (0x10*(x)))
 
 /*
  * This structure contains all data related to the MCE log.  Also
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index ee487a9..a53eb1b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -304,6 +304,51 @@ static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
 	wrmsr(MSR_CU_DEF_ERR, low, high);
 }
 
+static u32 get_block_address(u32 current_addr, u32 low, u32 high,
+			     unsigned int bank, unsigned int block)
+{
+	u32 addr = 0, offset = 0;
+
+	if (mce_flags.smca) {
+		if (!block) {
+			addr = MSR_AMD64_SMCA_MCx_MISC(bank);
+		} else {
+			/*
+			 * For SMCA enabled processors, BLKPTR field of the
+			 * first MISC register (MCx_MISC0) indicates presence of
+			 * additional MISC register set (MISC1-4).
+			 */
+			u32 low, high;
+
+			if (rdmsr_safe(MSR_AMD64_SMCA_MCx_CONFIG(bank), &low, &high))
+				return addr;
+
+			if (!(low & MCI_CONFIG_MCAX))
+				return addr;
+
+			if (!rdmsr_safe(MSR_AMD64_SMCA_MCx_MISC(bank), &low, &high) &&
+			    (low & MASK_BLKPTR_LO))
+				addr = MSR_AMD64_SMCA_MCx_MISCy(bank, block - 1);
+		}
+		return addr;
+	}
+
+	/* Fall back to method we used for older processors: */
+	switch (block) {
+	case 0:
+		addr = MSR_IA32_MCx_MISC(bank);
+		break;
+	case 1:
+		offset = ((low & MASK_BLKPTR_LO) >> 21);
+		if (offset)
+			addr = MCG_XBLK_ADDR + offset;
+		break;
+	default:
+		addr = ++current_addr;
+	}
+	return addr;
+}
+
 static int
 prepare_threshold_block(unsigned int bank, unsigned int block, u32 addr,
 			int offset, u32 misc_high)
@@ -366,16 +411,9 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c)
 
 	for (bank = 0; bank < mca_cfg.banks; ++bank) {
 		for (block = 0; block < NR_BLOCKS; ++block) {
-			if (block == 0)
-				address = MSR_IA32_MCx_MISC(bank);
-			else if (block == 1) {
-				address = (low & MASK_BLKPTR_LO) >> 21;
-				if (!address)
-					break;
-
-				address += MCG_XBLK_ADDR;
-			} else
-				++address;
+			address = get_block_address(address, low, high, bank, block);
+			if (!address)
+				break;
 
 			if (rdmsr_safe(address, &low, &high))
 				break;
@@ -480,16 +518,9 @@ static void amd_threshold_interrupt(void)
 		if (!(per_cpu(bank_map, cpu) & (1 << bank)))
 			continue;
 		for (block = 0; block < NR_BLOCKS; ++block) {
-			if (block == 0) {
-				address = MSR_IA32_MCx_MISC(bank);
-			} else if (block == 1) {
-				address = (low & MASK_BLKPTR_LO) >> 21;
-				if (!address)
-					break;
-				address += MCG_XBLK_ADDR;
-			} else {
-				++address;
-			}
+			address = get_block_address(address, low, high, bank, block);
+			if (!address)
+				break;
 
 			if (rdmsr_safe(address, &low, &high))
 				break;
@@ -709,16 +740,11 @@ static int allocate_threshold_blocks(unsigned int cpu, unsigned int bank,
 	if (err)
 		goto out_free;
 recurse:
-	if (!block) {
-		address = (low & MASK_BLKPTR_LO) >> 21;
-		if (!address)
-			return 0;
-		address += MCG_XBLK_ADDR;
-	} else {
-		++address;
-	}
+	address = get_block_address(address, low, high, bank, ++block);
+	if (!address)
+		return 0;
 
-	err = allocate_threshold_blocks(cpu, bank, ++block, address);
+	err = allocate_threshold_blocks(cpu, bank, block, address);
 	if (err)
 		goto out_free;