powerpc/pseries/cpuidle: Use cpuidle_register() for initialisation.

This patch replaces the cpuidle driver and devices initialisation
calls with a single generic cpuidle_register() call
and also includes minor refactoring of the code around it.

Remove the cpu online check in snooze loop, as this code can
only locally run on a cpu only if it is online. Therefore,
this check is not required.

Signed-off-by: Deepthi Dharwar <deepthi@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

diff --git a/drivers/cpuidle/cpuidle-pseries.c b/drivers/cpuidle/cpuidle-pseries.c
index 2115478..32d86bc 100644 (file)
--- a/drivers/cpuidle/cpuidle-pseries.c
+++ b/drivers/cpuidle/cpuidle-pseries.c
@@ -27,7 +27,6 @@ struct cpuidle_driver pseries_idle_driver = {
 #define MAX_IDLE_STATE_COUNT   2
 
 static int max_idle_state = MAX_IDLE_STATE_COUNT - 1;
-static struct cpuidle_device __percpu *pseries_cpuidle_devices;
 static struct cpuidle_state *cpuidle_state_table;
 
 static inline void idle_loop_prolog(unsigned long *in_purr)
@@ -55,13 +54,12 @@ static int snooze_loop(struct cpuidle_device *dev,
                        int index)
 {
        unsigned long in_purr;
-       int cpu = dev->cpu;
 
        idle_loop_prolog(&in_purr);
        local_irq_enable();
        set_thread_flag(TIF_POLLING_NRFLAG);
 
-       while ((!need_resched()) && cpu_online(cpu)) {
+       while (!need_resched()) {
                HMT_low();
                HMT_very_low();
        }
@@ -188,7 +186,7 @@ static int pseries_cpuidle_add_cpu_notifier(struct notifier_block *n,
 {
        int hotcpu = (unsigned long)hcpu;
        struct cpuidle_device *dev =
-                       per_cpu_ptr(pseries_cpuidle_devices, hotcpu);
+                               per_cpu(cpuidle_devices, hotcpu);
 
        if (dev && cpuidle_get_driver()) {
                switch (action) {
@@ -245,50 +243,6 @@ static int pseries_cpuidle_driver_init(void)
        return 0;
 }
 
-/* pseries_idle_devices_uninit(void)
- * unregister cpuidle devices and de-allocate memory
- */
-static void pseries_idle_devices_uninit(void)
-{
-       int i;
-       struct cpuidle_device *dev;
-
-       for_each_possible_cpu(i) {
-               dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-               cpuidle_unregister_device(dev);
-       }
-
-       free_percpu(pseries_cpuidle_devices);
-       return;
-}
-
-/* pseries_idle_devices_init()
- * allocate, initialize and register cpuidle device
- */
-static int pseries_idle_devices_init(void)
-{
-       int i;
-       struct cpuidle_driver *drv = &pseries_idle_driver;
-       struct cpuidle_device *dev;
-
-       pseries_cpuidle_devices = alloc_percpu(struct cpuidle_device);
-       if (pseries_cpuidle_devices == NULL)
-               return -ENOMEM;
-
-       for_each_possible_cpu(i) {
-               dev = per_cpu_ptr(pseries_cpuidle_devices, i);
-               dev->state_count = drv->state_count;
-               dev->cpu = i;
-               if (cpuidle_register_device(dev)) {
-                       printk(KERN_DEBUG \
-                               "cpuidle_register_device %d failed!\n", i);
-                       return -EIO;
-               }
-       }
-
-       return 0;
-}
-
 /*
  * pseries_idle_probe()
  * Choose state table for shared versus dedicated partition
@@ -296,9 +250,6 @@ static int pseries_idle_devices_init(void)
 static int pseries_idle_probe(void)
 {
 
-       if (!firmware_has_feature(FW_FEATURE_SPLPAR))
-               return -ENODEV;
-
        if (cpuidle_disable != IDLE_NO_OVERRIDE)
                return -ENODEV;
 
@@ -307,10 +258,13 @@ static int pseries_idle_probe(void)
                return -EPERM;
        }
 
-       if (lppaca_shared_proc(get_lppaca()))
-               cpuidle_state_table = shared_states;
-       else
-               cpuidle_state_table = dedicated_states;
+       if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
+               if (lppaca_shared_proc(get_lppaca()))
+                       cpuidle_state_table = shared_states;
+               else
+                       cpuidle_state_table = dedicated_states;
+       } else
+               return -ENODEV;
 
        return 0;
 }
@@ -324,22 +278,14 @@ static int __init pseries_processor_idle_init(void)
                return retval;
 
        pseries_cpuidle_driver_init();
-       retval = cpuidle_register_driver(&pseries_idle_driver);
+       retval = cpuidle_register(&pseries_idle_driver, NULL);
        if (retval) {
                printk(KERN_DEBUG "Registration of pseries driver failed.\n");
                return retval;
        }
 
-       retval = pseries_idle_devices_init();
-       if (retval) {
-               pseries_idle_devices_uninit();
-               cpuidle_unregister_driver(&pseries_idle_driver);
-               return retval;
-       }
-
        register_cpu_notifier(&setup_hotplug_notifier);
        printk(KERN_DEBUG "pseries_idle_driver registered\n");
-
        return 0;
 }
 
@@ -347,9 +293,7 @@ static void __exit pseries_processor_idle_exit(void)
 {
 
        unregister_cpu_notifier(&setup_hotplug_notifier);
-       pseries_idle_devices_uninit();
-       cpuidle_unregister_driver(&pseries_idle_driver);
-
+       cpuidle_unregister(&pseries_idle_driver);
        return;
 }