[PATCH 1/1] powerpc/traps : Updated MC for E6500 L1D cache err

[Matt Weber]

This patch updates the machine check handler of Linux kernel to
handle the e6500 architecture case. In e6500 core, L1 Data Cache Write
Shadow Mode (DCWS) register is not implemented but L1 data cache always
runs in write shadow mode. So, on L1 data cache parity errors, hardware
will automatically invalidate the data cache but will still log a
machine check interrupt.

Signed-off-by: Ronak Desai 
Signed-off-by: Matthew Weber 
---
 arch/powerpc/kernel/traps.c | 12 ++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 76f6045..f656277 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -504,6 +504,7 @@ int machine_check_47x(struct pt_regs *regs)
 int machine_check_e500mc(struct pt_regs *regs)
 {
unsigned long mcsr = mfspr(SPRN_MCSR);
+   unsigned long pvr = mfspr(SPRN_PVR);
unsigned long reason = mcsr;
int recoverable = 1;
 
@@ -545,8 +546,15 @@ int machine_check_e500mc(struct pt_regs *regs)
 * may still get logged and cause a machine check.  We should
 * only treat the non-write shadow case as non-recoverable.
 */
-   if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
-   recoverable = 0;
+   /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit
+* is not implemented but L1 data cache always runs in write
+* shadow mode. Hence on data cache parity errors HW will
+* automatically invalidate the L1 Data Cache.
+*/
+   if (PVR_VER(pvr) != PVR_VER_E6500) {
+   if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
+   recoverable = 0;
+   }
}
 
if (reason & MCSR_L2MMU_MHIT) {
-- 
1.9.1

[PATCH 1/1] powerpc/traps : Updated MC for E6500 L1D cache err

[Matt Weber]

This patch updates the machine check handler of Linux kernel to
handle the e6500 architecture case. In e6500 core, L1 Data Cache Write
Shadow Mode (DCWS) register is not implemented but L1 data cache always
runs in write shadow mode. So, on L1 data cache parity errors, hardware
will automatically invalidate the data cache but will still log a
machine check interrupt.

Signed-off-by: Ronak Desai 
Signed-off-by: Matthew Weber 
---
 arch/powerpc/include/asm/reg_booke.h |  1 +
 arch/powerpc/kernel/traps.c  | 12 ++--
 2 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/arch/powerpc/include/asm/reg_booke.h 
b/arch/powerpc/include/asm/reg_booke.h
index 737e012..c811128 100644
--- a/arch/powerpc/include/asm/reg_booke.h
+++ b/arch/powerpc/include/asm/reg_booke.h
@@ -196,6 +196,7 @@
 #define SPRN_DEAR  0x03D   /* Data Error Address Register */
 #define SPRN_ESR   0x03E   /* Exception Syndrome Register */
 #define SPRN_PIR   0x11E   /* Processor Identification Register */
+#define SPRN_PVR   0x11F   /* Processor Version Register */
 #define SPRN_DBSR  0x130   /* Debug Status Register */
 #define SPRN_DBCR0 0x134   /* Debug Control Register 0 */
 #define SPRN_DBCR1 0x135   /* Debug Control Register 1 */
diff --git a/arch/powerpc/kernel/traps.c b/arch/powerpc/kernel/traps.c
index 76f6045..d5bc3ab 100644
--- a/arch/powerpc/kernel/traps.c
+++ b/arch/powerpc/kernel/traps.c
@@ -504,6 +504,7 @@ int machine_check_47x(struct pt_regs *regs)
 int machine_check_e500mc(struct pt_regs *regs)
 {
unsigned long mcsr = mfspr(SPRN_MCSR);
+   unsigned long pvr = mfspr(SPRN_PVR);
unsigned long reason = mcsr;
int recoverable = 1;
 
@@ -545,8 +546,15 @@ int machine_check_e500mc(struct pt_regs *regs)
 * may still get logged and cause a machine check.  We should
 * only treat the non-write shadow case as non-recoverable.
 */
-   if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
-   recoverable = 0;
+   /* On e6500 core, L1 DCWS (Data cache write shadow mode) bit is
+* not implemented but L1 data cache is by default configured
+* to run in write shadow mode. Hence on data cache parity 
errors
+* HW will automatically invalidate the L1 Data Cache.
+*/
+   if (PVR_VER(pvr) != PVR_VER_E6500) {
+   if (!(mfspr(SPRN_L1CSR2) & L1CSR2_DCWS))
+   recoverable = 0;
+   }
}
 
if (reason & MCSR_L2MMU_MHIT) {
-- 
1.9.1