[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, 3 insertions, 5 deletions

diff --git a/arch/ppc64/kernel/idle.c b/arch/ppc64/kernel/idle.c
index 6abc621d3ba0..f24ce2b87200 100644
--- a/arch/ppc64/kernel/idle.c
+++ b/arch/ppc64/kernel/idle.c
@@ -75,13 +75,9 @@ static int iSeries_idle(void)
 {
         struct paca_struct *lpaca;
         long oldval;
-        unsigned long CTRL;
 
         /* ensure iSeries run light will be out when idle */
-        clear_thread_flag(TIF_RUN_LIGHT);
-        CTRL = mfspr(CTRLF);
-        CTRL &= ~RUNLATCH;
-        mtspr(CTRLT, CTRL);
+        ppc64_runlatch_off();
 
         lpaca = get_paca();
 
@@ -111,7 +107,9 @@ static int iSeries_idle(void)
                         }
                 }
 
+                ppc64_runlatch_on();
                 schedule();
+                ppc64_runlatch_off();
         }
 
         return 0;