2 files changed, 19 insertions, 0 deletions

diff --git a/arch/ppc64/kernel/head.S b/arch/ppc64/kernel/head.S
index 675c2708588f..93ebcac0d5a2 100644
--- a/arch/ppc64/kernel/head.S
+++ b/arch/ppc64/kernel/head.S
@@ -308,6 +308,7 @@ exception_marker:
 label##_pSeries:                                        \
         HMT_MEDIUM;                                     \
         mtspr   SPRG1,r13;              /* save r13 */  \
+        RUNLATCH_ON(r13);                               \
         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
 
 #define STD_EXCEPTION_ISERIES(n, label, area)           \
@@ -315,6 +316,7 @@ label##_pSeries:					\
 label##_iSeries:                                        \
         HMT_MEDIUM;                                     \
         mtspr   SPRG1,r13;              /* save r13 */  \
+        RUNLATCH_ON(r13);                               \
         EXCEPTION_PROLOG_ISERIES_1(area);               \
         EXCEPTION_PROLOG_ISERIES_2;                     \
         b       label##_common
@@ -324,6 +326,7 @@ label##_iSeries:					\
 label##_iSeries:                                                        \
         HMT_MEDIUM;                                                     \
         mtspr   SPRG1,r13;              /* save r13 */                  \
+        RUNLATCH_ON(r13);                                               \
         EXCEPTION_PROLOG_ISERIES_1(PACA_EXGEN);                         \
         lbz     r10,PACAPROCENABLED(r13);                               \
         cmpwi   0,r10,0;                                                \
@@ -393,6 +396,7 @@ __start_interrupts:
 _machine_check_pSeries:
         HMT_MEDIUM
         mtspr   SPRG1,r13               /* save r13 */
+        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
 
         . = 0x300
@@ -419,6 +423,7 @@ END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
 data_access_slb_pSeries:
         HMT_MEDIUM
         mtspr   SPRG1,r13
+        RUNLATCH_ON(r13)
         mfspr   r13,SPRG3               /* get paca address into r13 */
         std     r9,PACA_EXSLB+EX_R9(r13)        /* save r9 - r12 */
         std     r10,PACA_EXSLB+EX_R10(r13)
@@ -439,6 +444,7 @@ data_access_slb_pSeries:
 instruction_access_slb_pSeries:
         HMT_MEDIUM
         mtspr   SPRG1,r13
+        RUNLATCH_ON(r13)
         mfspr   r13,SPRG3               /* get paca address into r13 */
         std     r9,PACA_EXSLB+EX_R9(r13)        /* save r9 - r12 */
         std     r10,PACA_EXSLB+EX_R10(r13)
@@ -464,6 +470,7 @@ instruction_access_slb_pSeries:
         .globl  system_call_pSeries
 system_call_pSeries:
         HMT_MEDIUM
+        RUNLATCH_ON(r9)
         mr      r9,r13
         mfmsr   r10
         mfspr   r13,SPRG3
@@ -707,11 +714,13 @@ fwnmi_data_area:
 system_reset_fwnmi:
         HMT_MEDIUM
         mtspr   SPRG1,r13               /* save r13 */
+        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
         .globl machine_check_fwnmi
 machine_check_fwnmi:
         HMT_MEDIUM
         mtspr   SPRG1,r13               /* save r13 */
+        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
 
         /*
@@ -848,6 +857,7 @@ unrecov_fer:
         .align  7
         .globl data_access_common
 data_access_common:
+        RUNLATCH_ON(r10)                /* It wont fit in the 0x300 handler */
         mfspr   r10,DAR
         std     r10,PACA_EXGEN+EX_DAR(r13)
         mfspr   r10,DSISR
diff --git a/include/asm-ppc64/processor.h b/include/asm-ppc64/processor.h
index 06aa07c2c71d..352306cfb579 100644
--- a/include/asm-ppc64/processor.h
+++ b/include/asm-ppc64/processor.h
@@ -524,6 +524,15 @@ static inline void ppc64_runlatch_off(void)
 
 #endif /* __ASSEMBLY__ */
 
+#ifdef __KERNEL__
+#define RUNLATCH_ON(REG)                        \
+BEGIN_FTR_SECTION                               \
+        mfspr   (REG),SPRN_CTRLF;               \
+        ori     (REG),(REG),CTRL_RUNLATCH;      \
+        mtspr   SPRN_CTRLT,(REG);               \
+END_FTR_SECTION_IFSET(CPU_FTR_CTRL)
+#endif
+
 /*
  * Number of entries in the SLB. If this ever changes we should handle
  * it with a use a cpu feature fixup.