diff mbox

[v3,1/2] powerpc: Add a cpu feature CPU_FTR_PMAO_BUG

Message ID 1393911093-8248-1-git-send-email-mpe@ellerman.id.au (mailing list archive)
State Accepted
Commit 68f2f0d431d9ea4fbd373cd31e828b0ceaefea30
Delegated to: Michael Ellerman
Headers show

Commit Message

Michael Ellerman March 4, 2014, 5:31 a.m. UTC 
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>
---
 arch/powerpc/include/asm/cputable.h | 6 ++++--
 arch/powerpc/kernel/cputable.c      | 2 +-
 2 files changed, 5 insertions(+), 3 deletions(-)

v3: Add CPU_FTRS_POWER8E to the possible map!
v2: Set the bit directly via the cputable entry for POWER8E.
diff mbox

Patch

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,