5 files changed, 40 insertions, 42 deletions

diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index 2b03a09fe5e9..bb845eed0e98 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -319,7 +319,6 @@ exception_marker:
 label##_pSeries:                                        \
         HMT_MEDIUM;                                     \
         mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
-        RUNLATCH_ON(r13);                               \
         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, label##_common)
 
 #define STD_EXCEPTION_ISERIES(n, label, area)           \
@@ -327,7 +326,6 @@ label##_pSeries:					\
 label##_iSeries:                                        \
         HMT_MEDIUM;                                     \
         mtspr   SPRN_SPRG1,r13;         /* save r13 */  \
-        RUNLATCH_ON(r13);                               \
         EXCEPTION_PROLOG_ISERIES_1(area);               \
         EXCEPTION_PROLOG_ISERIES_2;                     \
         b       label##_common
@@ -337,7 +335,6 @@ label##_iSeries:					\
 label##_iSeries:                                                        \
         HMT_MEDIUM;                                                     \
         mtspr   SPRN_SPRG1,r13;         /* save r13 */                  \
-        RUNLATCH_ON(r13);                                               \
         EXCEPTION_PROLOG_ISERIES_1(PACA_EXGEN);                         \
         lbz     r10,PACAPROCENABLED(r13);                               \
         cmpwi   0,r10,0;                                                \
@@ -390,6 +387,7 @@ label##_common:						\
 label##_common:                                         \
         EXCEPTION_PROLOG_COMMON(trap, PACA_EXGEN);      \
         DISABLE_INTS;                                   \
+        bl      .ppc64_runlatch_on;                     \
         addi    r3,r1,STACK_FRAME_OVERHEAD;             \
         bl      hdlr;                                   \
         b       .ret_from_except_lite
@@ -407,7 +405,6 @@ __start_interrupts:
 _machine_check_pSeries:
         HMT_MEDIUM
         mtspr   SPRN_SPRG1,r13          /* save r13 */
-        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
 
         . = 0x300
@@ -434,7 +431,6 @@ END_FTR_SECTION_IFCLR(CPU_FTR_SLB)
 data_access_slb_pSeries:
         HMT_MEDIUM
         mtspr   SPRN_SPRG1,r13
-        RUNLATCH_ON(r13)
         mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
         std     r3,PACA_EXSLB+EX_R3(r13)
         mfspr   r3,SPRN_DAR
@@ -460,7 +456,6 @@ data_access_slb_pSeries:
 instruction_access_slb_pSeries:
         HMT_MEDIUM
         mtspr   SPRN_SPRG1,r13
-        RUNLATCH_ON(r13)
         mfspr   r13,SPRN_SPRG3          /* get paca address into r13 */
         std     r3,PACA_EXSLB+EX_R3(r13)
         mfspr   r3,SPRN_SRR0            /* SRR0 is faulting address */
@@ -491,7 +486,6 @@ instruction_access_slb_pSeries:
         .globl  system_call_pSeries
 system_call_pSeries:
         HMT_MEDIUM
-        RUNLATCH_ON(r9)
         mr      r9,r13
         mfmsr   r10
         mfspr   r13,SPRN_SPRG3
@@ -575,7 +569,6 @@ slb_miss_user_pseries:
 system_reset_fwnmi:
         HMT_MEDIUM
         mtspr   SPRN_SPRG1,r13          /* save r13 */
-        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common)
 
         .globl machine_check_fwnmi
@@ -583,7 +576,6 @@ system_reset_fwnmi:
 machine_check_fwnmi:
         HMT_MEDIUM
         mtspr   SPRN_SPRG1,r13          /* save r13 */
-        RUNLATCH_ON(r13)
         EXCEPTION_PROLOG_PSERIES(PACA_EXMC, machine_check_common)
 
 #ifdef CONFIG_PPC_ISERIES
@@ -894,7 +886,6 @@ unrecov_fer:
         .align  7
         .globl data_access_common
 data_access_common:
-        RUNLATCH_ON(r10)                /* It wont fit in the 0x300 handler */
         mfspr   r10,SPRN_DAR
         std     r10,PACA_EXGEN+EX_DAR(r13)
         mfspr   r10,SPRN_DSISR
@@ -1042,6 +1033,7 @@ hardware_interrupt_common:
         EXCEPTION_PROLOG_COMMON(0x500, PACA_EXGEN)
 hardware_interrupt_entry:
         DISABLE_INTS
+        bl      .ppc64_runlatch_on
         addi    r3,r1,STACK_FRAME_OVERHEAD
         bl      .do_IRQ
         b       .ret_from_except_lite
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 57703994a063..c225cf154bfe 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -888,3 +888,35 @@ void dump_stack(void)
         show_stack(current, NULL);
 }
 EXPORT_SYMBOL(dump_stack);
+
+#ifdef CONFIG_PPC64
+void ppc64_runlatch_on(void)
+{
+        unsigned long ctrl;
+
+        if (cpu_has_feature(CPU_FTR_CTRL) && !test_thread_flag(TIF_RUNLATCH)) {
+                HMT_medium();
+
+                ctrl = mfspr(SPRN_CTRLF);
+                ctrl |= CTRL_RUNLATCH;
+                mtspr(SPRN_CTRLT, ctrl);
+
+                set_thread_flag(TIF_RUNLATCH);
+        }
+}
+
+void ppc64_runlatch_off(void)
+{
+        unsigned long ctrl;
+
+        if (cpu_has_feature(CPU_FTR_CTRL) && test_thread_flag(TIF_RUNLATCH)) {
+                HMT_medium();
+
+                clear_thread_flag(TIF_RUNLATCH);
+
+                ctrl = mfspr(SPRN_CTRLF);
+                ctrl &= ~CTRL_RUNLATCH;
+                mtspr(SPRN_CTRLT, ctrl);
+        }
+}
+#endif
diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c
index 3f8790146b00..3ecc4a652d82 100644
--- a/arch/powerpc/platforms/iseries/setup.c
+++ b/arch/powerpc/platforms/iseries/setup.c
@@ -648,6 +648,7 @@ static void yield_shared_processor(void)
          * here and let the timer_interrupt code sort out the actual time.
          */
         get_lppaca()->int_dword.fields.decr_int = 1;
+        ppc64_runlatch_on();
         process_iSeries_events();
 }
 
diff --git a/include/asm-powerpc/reg.h b/include/asm-powerpc/reg.h
index 12ecc9b9f285..72bfe3af0460 100644
--- a/include/asm-powerpc/reg.h
+++ b/include/asm-powerpc/reg.h
@@ -615,27 +615,9 @@
 #define proc_trap()     asm volatile("trap")
 
 #ifdef CONFIG_PPC64
-static inline void ppc64_runlatch_on(void)
-{
-        unsigned long ctrl;
-
-        if (cpu_has_feature(CPU_FTR_CTRL)) {
-                ctrl = mfspr(SPRN_CTRLF);
-                ctrl |= CTRL_RUNLATCH;
-                mtspr(SPRN_CTRLT, ctrl);
-        }
-}
-
-static inline void ppc64_runlatch_off(void)
-{
-        unsigned long ctrl;
-
-        if (cpu_has_feature(CPU_FTR_CTRL)) {
-                ctrl = mfspr(SPRN_CTRLF);
-                ctrl &= ~CTRL_RUNLATCH;
-                mtspr(SPRN_CTRLT, ctrl);
-        }
-}
+
+extern void ppc64_runlatch_on(void);
+extern void ppc64_runlatch_off(void);
 
 extern unsigned long scom970_read(unsigned int address);
 extern void scom970_write(unsigned int address, unsigned long value);
@@ -645,15 +627,6 @@ extern void scom970_write(unsigned int address, unsigned long value);
 #define __get_SP()      ({unsigned long sp; \
                         asm volatile("mr %0,1": "=r" (sp)); sp;})
 
-#else /* __ASSEMBLY__ */
-
-#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 /* __ASSEMBLY__ */
 #endif /* __KERNEL__ */
 #endif /* _ASM_POWERPC_REG_H */
diff --git a/include/asm-powerpc/thread_info.h b/include/asm-powerpc/thread_info.h
index c044ec16a879..237fc2b72974 100644
--- a/include/asm-powerpc/thread_info.h
+++ b/include/asm-powerpc/thread_info.h
@@ -113,7 +113,7 @@ static inline struct thread_info *current_thread_info(void)
 #define TIF_POLLING_NRFLAG      4       /* true if poll_idle() is polling
                                            TIF_NEED_RESCHED */
 #define TIF_32BIT               5       /* 32 bit binary */
-/* #define SPARE                6 */
+#define TIF_RUNLATCH            6       /* Is the runlatch enabled? */
 #define TIF_ABI_PENDING         7       /* 32/64 bit switch needed */
 #define TIF_SYSCALL_AUDIT       8       /* syscall auditing active */
 #define TIF_SINGLESTEP          9       /* singlestepping active */
@@ -131,7 +131,7 @@ static inline struct thread_info *current_thread_info(void)
 #define _TIF_NEED_RESCHED       (1<<TIF_NEED_RESCHED)
 #define _TIF_POLLING_NRFLAG     (1<<TIF_POLLING_NRFLAG)
 #define _TIF_32BIT              (1<<TIF_32BIT)
-/* #define _SPARE               (1<<SPARE) */
+#define _TIF_RUNLATCH           (1<<TIF_RUNLATCH)
 #define _TIF_ABI_PENDING        (1<<TIF_ABI_PENDING)
 #define _TIF_SYSCALL_AUDIT      (1<<TIF_SYSCALL_AUDIT)
 #define _TIF_SINGLESTEP         (1<<TIF_SINGLESTEP)