[RFC PATCH V4 1/5] cpuidle: Remove pm_idle pointer for x86

From: Trinabh Gupta
Date: Tue Mar 22 2011 - 08:32:47 EST


This patch removes pm_idle function pointer and directly calls
cpuidle_idle_call from the idle loop on x86. Hence, CPUIdle has
to be built into the kernel for x86 and optional for other
archs.

Archs that still use pm_idle can continue to set
pm_idle=cpuidle_idle_call() and co-exist. The
cpuidle_(un)install_idle_handler() is defined per arch in
cpuidle.c and would set pm_idle pointer on non-x86 architectures
until they are incrementally converted to directly call
cpuidle_idle_call() and not use the pm_idle pointer.

Signed-off-by: Trinabh Gupta <trinabh@xxxxxxxxxxxxxxxxxx>
---

arch/x86/kernel/process_32.c | 4 +++-
arch/x86/kernel/process_64.c | 4 +++-
drivers/cpuidle/Kconfig | 3 ++-
drivers/cpuidle/cpuidle.c | 2 +-
4 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 8d12878..17b7101 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -74,6 +74,8 @@ static inline void play_dead(void)
}
#endif

+extern void cpuidle_idle_call(void);
+
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
@@ -109,7 +111,7 @@ void cpu_idle(void)
local_irq_disable();
/* Don't trace irqs off for idle */
stop_critical_timings();
- pm_idle();
+ cpuidle_idle_call();
start_critical_timings();
}
tick_nohz_restart_sched_tick();
diff --git a/arch/x86/kernel/process_64.c b/arch/x86/kernel/process_64.c
index bd387e8..c736bf3 100644
--- a/arch/x86/kernel/process_64.c
+++ b/arch/x86/kernel/process_64.c
@@ -99,6 +99,8 @@ static inline void play_dead(void)
}
#endif

+extern void cpuidle_idle_call(void);
+
/*
* The idle thread. There's no useful work to be
* done, so just try to conserve power and have a
@@ -136,7 +138,7 @@ void cpu_idle(void)
enter_idle();
/* Don't trace irqs off for idle */
stop_critical_timings();
- pm_idle();
+ cpuidle_idle_call();
start_critical_timings();

/* In many cases the interrupt that ended idle
diff --git a/drivers/cpuidle/Kconfig b/drivers/cpuidle/Kconfig
index 7dbc4a8..e67c258 100644
--- a/drivers/cpuidle/Kconfig
+++ b/drivers/cpuidle/Kconfig
@@ -1,7 +1,8 @@

config CPU_IDLE
bool "CPU idle PM support"
- default ACPI
+ default y if X86
+ default y if ACPI
help
CPU idle is a generic framework for supporting software-controlled
idle processor power management. It includes modular cross-platform
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index bf50924..8baaa04 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -47,7 +47,7 @@ static int __cpuidle_register_device(struct cpuidle_device *dev);
*
* NOTE: no locks or semaphores should be used here
*/
-static void cpuidle_idle_call(void)
+void cpuidle_idle_call(void)
{
struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
struct cpuidle_state *target_state;

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