[PATCH] ppc64: cleanup iseries runlight support

The iseries has a bar graph on the front panel that shows how busy it is.
The operating system sets and clears a bit in the CTRL register to control
it.

Instead of going to the complexity of using a thread info bit, just set and
clear it in the idle loop.

Also create two helper functions, ppc64_runlatch_on and ppc64_runlatch_off.

Finally don't use the short form of the SPR defines.

Signed-off-by: Anton Blanchard <anton@samba.org>
Acked-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/arch/ppc64/kernel/sysfs.c b/arch/ppc64/kernel/sysfs.c
index 0925694c3ce5..c8fa6569b2fd 100644
--- a/arch/ppc64/kernel/sysfs.c
+++ b/arch/ppc64/kernel/sysfs.c
@@ -113,7 +113,6 @@ void ppc64_enable_pmcs(void)
 #ifdef CONFIG_PPC_PSERIES
         unsigned long set, reset;
         int ret;
-        unsigned int ctrl;
 #endif /* CONFIG_PPC_PSERIES */
 
         /* Only need to enable them once */
@@ -167,11 +166,8 @@ void ppc64_enable_pmcs(void)
          * On SMT machines we have to set the run latch in the ctrl register
          * in order to make PMC6 spin.
          */
-        if (cpu_has_feature(CPU_FTR_SMT)) {
-                ctrl = mfspr(CTRLF);
-                ctrl |= RUNLATCH;
-                mtspr(CTRLT, ctrl);
-        }
+        if (cpu_has_feature(CPU_FTR_SMT))
+                ppc64_runlatch_on();
 #endif /* CONFIG_PPC_PSERIES */
 }