From: Michael Ellerman <mpe@ellerman.id.au>
Subject: powerpc: Add a cpu feature CPU_FTR_PMAO_BUG
Git-commit: 68f2f0d431d9ea4fbd373cd31e828b0ceaefea30
Patch-mainline: v3.15-rc2
References: bnc#885935

 powerpc: Add a cpu feature CPU_FTR_PMAO_BUG

Some power8 revisions have a hardware bug where we can lose a
Performance Monitor (PMU) exception under certain circumstances.

We will be adding a workaround for this case, see the next commit for
details. The observed behaviour is that writing PMAO doesn't cause an
exception as we would expect, hence the name of the feature.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Torsten Duwe <duwe@suse.de>

diff --git a/arch/powerpc/include/asm/cputable.h b/arch/powerpc/include/asm/cputable.h
index 617cc76..bc23477 100644
--- a/arch/powerpc/include/asm/cputable.h
+++ b/arch/powerpc/include/asm/cputable.h
@@ -189,6 +189,7 @@ extern const char *powerpc_base_platform;
 #define	CPU_FTR_HAS_PPR			LONG_ASM_CONST(0x0200000000000000)
 #define CPU_FTR_DAWR			LONG_ASM_CONST(0x0400000000000000)
 #define CPU_FTR_DABRX			LONG_ASM_CONST(0x0800000000000000)
+#define CPU_FTR_PMAO_BUG		LONG_ASM_CONST(0x1000000000000000)
 
 #ifndef __ASSEMBLY__
 
@@ -445,6 +446,7 @@ extern const char *powerpc_base_platform;
 	    CPU_FTR_ICSWX | CPU_FTR_CFAR | CPU_FTR_HVMODE | CPU_FTR_VMX_COPY | \
 	    CPU_FTR_DBELL | CPU_FTR_HAS_PPR | CPU_FTR_DAWR | \
 	    CPU_FTR_ARCH_207S | CPU_FTR_TM_COMP)
+#define CPU_FTRS_POWER8E (CPU_FTRS_POWER8 | CPU_FTR_PMAO_BUG)
 #define CPU_FTRS_CELL	(CPU_FTR_USE_TB | CPU_FTR_LWSYNC | \
 	    CPU_FTR_PPCAS_ARCH_V2 | CPU_FTR_CTRL | \
 	    CPU_FTR_ALTIVEC_COMP | CPU_FTR_MMCRA | CPU_FTR_SMT | \
@@ -466,8 +468,8 @@ extern const char *powerpc_base_platform;
 #define CPU_FTRS_POSSIBLE	\
 	    (CPU_FTRS_POWER3 | CPU_FTRS_RS64 | CPU_FTRS_POWER4 |	\
 	    CPU_FTRS_PPC970 | CPU_FTRS_POWER5 | CPU_FTRS_POWER6 |	\
-	    CPU_FTRS_POWER7 | CPU_FTRS_POWER8 | CPU_FTRS_CELL |		\
-	    CPU_FTRS_PA6T | CPU_FTR_VSX)
+	    CPU_FTRS_POWER7 | CPU_FTRS_POWER8E | CPU_FTRS_POWER8 |	\
+	    CPU_FTRS_CELL | CPU_FTRS_PA6T | CPU_FTR_VSX)
 #endif
 #else
 enum {
diff --git a/arch/powerpc/kernel/cputable.c b/arch/powerpc/kernel/cputable.c
index 6c8dd5d..c1faade 100644
--- a/arch/powerpc/kernel/cputable.c
+++ b/arch/powerpc/kernel/cputable.c
@@ -510,7 +510,7 @@ static struct cpu_spec __initdata cpu_specs[] = {
 		.pvr_mask		= 0xffff0000,
 		.pvr_value		= 0x004b0000,
 		.cpu_name		= "POWER8E (raw)",
-		.cpu_features		= CPU_FTRS_POWER8,
+		.cpu_features		= CPU_FTRS_POWER8E,
 		.cpu_user_features	= COMMON_USER_POWER8,
 		.cpu_user_features2	= COMMON_USER2_POWER8,
 		.mmu_features		= MMU_FTRS_POWER8,
