From 1ad749980a5fda46f7ec920d8409ddcc89b38714 Mon Sep 17 00:00:00 2001
From: Tony Breeds <tony@bakeyournoodle.com>
Date: Fri, 21 Sep 2007 13:26:03 +1000
Subject: [PATCH] [POWERPC] Enable tickless idle and high res timers for
 powerpc

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
---
 arch/powerpc/Kconfig                   | 1 +
 arch/powerpc/kernel/idle.c             | 3 +++
 arch/powerpc/platforms/iseries/setup.c | 6 ++++++
 3 files changed, 10 insertions(+)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a46f8116f4..b387e1ed51 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -173,6 +173,7 @@ config HIGHMEM
 	bool "High memory support"
 	depends on PPC32
 
+source kernel/time/Kconfig
 source kernel/Kconfig.hz
 source kernel/Kconfig.preempt
 source "fs/Kconfig.binfmt"
diff --git a/arch/powerpc/kernel/idle.c b/arch/powerpc/kernel/idle.c
index a9e9cbd329..abd2957fe5 100644
--- a/arch/powerpc/kernel/idle.c
+++ b/arch/powerpc/kernel/idle.c
@@ -24,6 +24,7 @@
 #include <linux/smp.h>
 #include <linux/cpu.h>
 #include <linux/sysctl.h>
+#include <linux/tick.h>
 
 #include <asm/system.h>
 #include <asm/processor.h>
@@ -59,6 +60,7 @@ void cpu_idle(void)
 
 	set_thread_flag(TIF_POLLING_NRFLAG);
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		while (!need_resched() && !cpu_should_die()) {
 			ppc64_runlatch_off();
 
@@ -90,6 +92,7 @@ void cpu_idle(void)
 
 		HMT_medium();
 		ppc64_runlatch_on();
+		tick_nohz_restart_sched_tick();
 		if (cpu_should_die())
 			cpu_die();
 		preempt_enable_no_resched();
diff --git a/arch/powerpc/platforms/iseries/setup.c b/arch/powerpc/platforms/iseries/setup.c
index fad493e29d..37ae07ee54 100644
--- a/arch/powerpc/platforms/iseries/setup.c
+++ b/arch/powerpc/platforms/iseries/setup.c
@@ -26,6 +26,8 @@
 #include <linux/major.h>
 #include <linux/root_dev.h>
 #include <linux/kernel.h>
+#include <linux/hrtimer.h>
+#include <linux/tick.h>
 
 #include <asm/processor.h>
 #include <asm/machdep.h>
@@ -561,6 +563,7 @@ static void yield_shared_processor(void)
 static void iseries_shared_idle(void)
 {
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		while (!need_resched() && !hvlpevent_is_pending()) {
 			local_irq_disable();
 			ppc64_runlatch_off();
@@ -574,6 +577,7 @@ static void iseries_shared_idle(void)
 		}
 
 		ppc64_runlatch_on();
+		tick_nohz_restart_sched_tick();
 
 		if (hvlpevent_is_pending())
 			process_iSeries_events();
@@ -589,6 +593,7 @@ static void iseries_dedicated_idle(void)
 	set_thread_flag(TIF_POLLING_NRFLAG);
 
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		if (!need_resched()) {
 			while (!need_resched()) {
 				ppc64_runlatch_off();
@@ -605,6 +610,7 @@ static void iseries_dedicated_idle(void)
 		}
 
 		ppc64_runlatch_on();
+		tick_nohz_restart_sched_tick();
 		preempt_enable_no_resched();
 		schedule();
 		preempt_disable();
-- 
2.39.5