[PATCH 2.6.21-rt2] PowerPC: enable HRT and dynticks support

[Sergei Shtylyov <sshtylyov@ru.mvista.com>]

Enable HRT and dynamic ticks support for PowerPC.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>

---
This patch has been reworked against the 2.6.21 clockevents framework.
It has only been tested on the Book E 32-bit CPU this time, so re-testing on
"classic" PowerPC CPUs is needed (there have been issues as of 2.6.18-rt7 but
those should now be fixed)...

 arch/powerpc/Kconfig       |    1 +
 arch/powerpc/kernel/idle.c |    3 +++
 2 files changed, 4 insertions(+)

Index: linux-2.6/arch/powerpc/Kconfig
===================================================================
--- linux-2.6.orig/arch/powerpc/Kconfig
+++ linux-2.6/arch/powerpc/Kconfig
@@ -770,6 +770,7 @@ config GENERIC_CLOCKEVENTS
 	  NOTE: This is not compatible with the deterministic time accounting
 	  option on PPC64.
 
+source kernel/time/Kconfig
 source kernel/Kconfig.preempt
 
 config RWSEM_GENERIC_SPINLOCK
Index: linux-2.6/arch/powerpc/kernel/idle.c
===================================================================
--- linux-2.6.orig/arch/powerpc/kernel/idle.c
+++ linux-2.6/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>
@@ -56,6 +57,7 @@ void cpu_idle(void)
 
 	set_thread_flag(TIF_POLLING_NRFLAG);
 	while (1) {
+		tick_nohz_stop_sched_tick();
 		while (!need_resched() && !need_resched_delayed() &&
 				!cpu_should_die()) {
 			ppc64_runlatch_off();
@@ -92,6 +94,7 @@ void cpu_idle(void)
 		ppc64_runlatch_on();
 		if (cpu_should_die())
 			cpu_die();
+		tick_nohz_restart_sched_tick();
 		__preempt_enable_no_resched();
 		schedule();
 		preempt_disable();