[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>
diff --git a/arch/ppc64/kernel/sysfs.c b/arch/ppc64/kernel/sysfs.c
index 0925694..c8fa656 100644
--- a/arch/ppc64/kernel/sysfs.c
+++ b/arch/ppc64/kernel/sysfs.c
@@ -113,7 +113,6 @@
 #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 @@
 	 * 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 */
 }