* Arun R Bharadwaj <a...@linux.vnet.ibm.com> [2009-09-22 16:55:27]:

This patch cleans up drivers/cpuidle/cpuidle.c
Earlier cpuidle assumed pm_idle as the default idle loop. Break that
assumption and make it more generic. cpuidle_idle_call() which is the
main idle loop of cpuidle is to be called by architectures which have
registered to cpuidle.

Remove routines cpuidle_install/uninstall_idle_handler() and
cpuidle_kick_cpus() which are not needed anymore.

Signed-off-by: Arun R Bharadwaj <a...@linux.vnet.ibm.com>
---
 drivers/cpuidle/cpuidle.c  |   48 +++++++--------------------------------------
 drivers/cpuidle/cpuidle.h  |    1 
 drivers/cpuidle/governor.c |    3 --
 include/linux/cpuidle.h    |    3 ++
 4 files changed, 11 insertions(+), 44 deletions(-)

Index: linux.trees.git/drivers/cpuidle/cpuidle.c
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/cpuidle.c
+++ linux.trees.git/drivers/cpuidle/cpuidle.c
@@ -24,9 +24,6 @@ DEFINE_PER_CPU(struct cpuidle_device *, 
 
 DEFINE_MUTEX(cpuidle_lock);
 LIST_HEAD(cpuidle_detected_devices);
-static void (*pm_idle_old)(void);
-
-static int enabled_devices;
 
 #if defined(CONFIG_ARCH_HAS_CPU_IDLE_WAIT)
 static void cpuidle_kick_cpus(void)
@@ -46,7 +43,7 @@ static int __cpuidle_register_device(str
  *
  * NOTE: no locks or semaphores should be used here
  */
-static void cpuidle_idle_call(void)
+void cpuidle_idle_call(void)
 {
        struct cpuidle_device *dev = __get_cpu_var(cpuidle_devices);
        struct cpuidle_state *target_state;
@@ -54,13 +51,10 @@ static void cpuidle_idle_call(void)
 
        /* check if the device is ready */
        if (!dev || !dev->enabled) {
-               if (pm_idle_old)
-                       pm_idle_old();
-               else
 #if defined(CONFIG_ARCH_HAS_DEFAULT_IDLE)
-                       default_idle();
+               default_idle();
 #else
-                       local_irq_enable();
+               local_irq_enable();
 #endif
                return;
        }
@@ -74,7 +68,11 @@ static void cpuidle_idle_call(void)
        hrtimer_peek_ahead_timers();
 #endif
        /* ask the governor for the next state */
-       next_state = cpuidle_curr_governor->select(dev);
+       if (dev->state_count > 1)
+               next_state = cpuidle_curr_governor->select(dev);
+       else
+               next_state = 0;
+
        if (need_resched())
                return;
        target_state = &dev->states[next_state];
@@ -94,35 +92,11 @@ static void cpuidle_idle_call(void)
 }
 
 /**
- * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
- */
-void cpuidle_install_idle_handler(void)
-{
-       if (enabled_devices && (pm_idle != cpuidle_idle_call)) {
-               /* Make sure all changes finished before we switch to new idle 
*/
-               smp_wmb();
-               pm_idle = cpuidle_idle_call;
-       }
-}
-
-/**
- * cpuidle_uninstall_idle_handler - uninstalls the cpuidle idle loop handler
- */
-void cpuidle_uninstall_idle_handler(void)
-{
-       if (enabled_devices && pm_idle_old && (pm_idle != pm_idle_old)) {
-               pm_idle = pm_idle_old;
-               cpuidle_kick_cpus();
-       }
-}
-
-/**
  * cpuidle_pause_and_lock - temporarily disables CPUIDLE
  */
 void cpuidle_pause_and_lock(void)
 {
        mutex_lock(&cpuidle_lock);
-       cpuidle_uninstall_idle_handler();
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock);
@@ -132,7 +106,6 @@ EXPORT_SYMBOL_GPL(cpuidle_pause_and_lock
  */
 void cpuidle_resume_and_unlock(void)
 {
-       cpuidle_install_idle_handler();
        mutex_unlock(&cpuidle_lock);
 }
 
@@ -180,7 +153,6 @@ int cpuidle_enable_device(struct cpuidle
 
        dev->enabled = 1;
 
-       enabled_devices++;
        return 0;
 
 fail_sysfs:
@@ -211,7 +183,6 @@ void cpuidle_disable_device(struct cpuid
                cpuidle_curr_governor->disable(dev);
 
        cpuidle_remove_state_sysfs(dev);
-       enabled_devices--;
 }
 
 EXPORT_SYMBOL_GPL(cpuidle_disable_device);
@@ -303,7 +274,6 @@ int cpuidle_register_device(struct cpuid
        }
 
        cpuidle_enable_device(dev);
-       cpuidle_install_idle_handler();
 
        mutex_unlock(&cpuidle_lock);
 
@@ -382,8 +352,6 @@ static int __init cpuidle_init(void)
 {
        int ret;
 
-       pm_idle_old = pm_idle;
-
        ret = cpuidle_add_class_sysfs(&cpu_sysdev_class);
        if (ret)
                return ret;
Index: linux.trees.git/drivers/cpuidle/governor.c
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/governor.c
+++ linux.trees.git/drivers/cpuidle/governor.c
@@ -48,8 +48,6 @@ int cpuidle_switch_governor(struct cpuid
        if (gov == cpuidle_curr_governor)
                return 0;
 
-       cpuidle_uninstall_idle_handler();
-
        if (cpuidle_curr_governor) {
                list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
                        cpuidle_disable_device(dev);
@@ -63,7 +61,6 @@ int cpuidle_switch_governor(struct cpuid
                        return -EINVAL;
                list_for_each_entry(dev, &cpuidle_detected_devices, device_list)
                        cpuidle_enable_device(dev);
-               cpuidle_install_idle_handler();
                printk(KERN_INFO "cpuidle: using governor %s\n", gov->name);
        }
 
Index: linux.trees.git/include/linux/cpuidle.h
===================================================================
--- linux.trees.git.orig/include/linux/cpuidle.h
+++ linux.trees.git/include/linux/cpuidle.h
@@ -112,6 +112,9 @@ static inline int cpuidle_get_last_resid
        return dev->last_residency;
 }
 
+extern void cpuidle_idle_call(void);
+extern struct cpuidle_driver *cpuidle_curr_driver;
+
 
 /****************************
  * CPUIDLE DRIVER INTERFACE *
Index: linux.trees.git/drivers/cpuidle/cpuidle.h
===================================================================
--- linux.trees.git.orig/drivers/cpuidle/cpuidle.h
+++ linux.trees.git/drivers/cpuidle/cpuidle.h
@@ -9,7 +9,6 @@
 
 /* For internal use only */
 extern struct cpuidle_governor *cpuidle_curr_governor;
-extern struct cpuidle_driver *cpuidle_curr_driver;
 extern struct list_head cpuidle_governors;
 extern struct list_head cpuidle_detected_devices;
 extern struct mutex cpuidle_lock;
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