[PATCH] ppc64: Fix runlatch code to work on pseries machines

Not all ppc64 CPUs have the CTRL SPR, so we need a cputable feature for it.

Signed-off-by: Anton Blanchard <anton@samba.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 11 insertions, 6 deletions

diff --git a/include/asm-ppc64/processor.h b/include/asm-ppc64/processor.h
index af28aa55d8c1..06aa07c2c71d 100644
--- a/include/asm-ppc64/processor.h
+++ b/include/asm-ppc64/processor.h
@@ -20,6 +20,7 @@
 #include <asm/ptrace.h>
 #include <asm/types.h>
 #include <asm/systemcfg.h>
+#include <asm/cputable.h>
 
 /* Machine State Register (MSR) Fields */
 #define MSR_SF_LG       63              /* Enable 64 bit mode */
@@ -501,18 +502,22 @@ static inline void ppc64_runlatch_on(void)
 {
         unsigned long ctrl;
 
-        ctrl = mfspr(SPRN_CTRLF);
-        ctrl |= CTRL_RUNLATCH;
-        mtspr(SPRN_CTRLT, 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;
 
-        ctrl = mfspr(SPRN_CTRLF);
-        ctrl &= ~CTRL_RUNLATCH;
-        mtspr(SPRN_CTRLT, ctrl);
+        if (cpu_has_feature(CPU_FTR_CTRL)) {
+                ctrl = mfspr(SPRN_CTRLF);
+                ctrl &= ~CTRL_RUNLATCH;
+                mtspr(SPRN_CTRLT, ctrl);
+        }
 }
 
 #endif /* __KERNEL__ */