2 * cpuidle-powernv - idle state cpuidle driver.
3 * Adapted from drivers/cpuidle/cpuidle-pseries
7 #include <linux/kernel.h>
8 #include <linux/module.h>
9 #include <linux/init.h>
10 #include <linux/moduleparam.h>
11 #include <linux/cpuidle.h>
12 #include <linux/cpu.h>
13 #include <linux/notifier.h>
15 #include <asm/machdep.h>
16 #include <asm/firmware.h>
17 #include <asm/runlatch.h>
19 struct cpuidle_driver powernv_idle_driver = {
20 .name = "powernv_idle",
24 static int max_idle_state;
25 static struct cpuidle_state *cpuidle_state_table;
27 static int snooze_loop(struct cpuidle_device *dev,
28 struct cpuidle_driver *drv,
32 set_thread_flag(TIF_POLLING_NRFLAG);
35 while (!need_resched()) {
42 clear_thread_flag(TIF_POLLING_NRFLAG);
47 static int nap_loop(struct cpuidle_device *dev,
48 struct cpuidle_driver *drv,
58 * States for dedicated partition case.
60 static struct cpuidle_state powernv_states[] = {
64 .flags = CPUIDLE_FLAG_TIME_VALID,
66 .target_residency = 0,
67 .enter = &snooze_loop },
71 .flags = CPUIDLE_FLAG_TIME_VALID,
73 .target_residency = 100,
77 static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
78 unsigned long action, void *hcpu)
80 int hotcpu = (unsigned long)hcpu;
81 struct cpuidle_device *dev =
82 per_cpu(cpuidle_devices, hotcpu);
84 if (dev && cpuidle_get_driver()) {
87 case CPU_ONLINE_FROZEN:
88 cpuidle_pause_and_lock();
89 cpuidle_enable_device(dev);
90 cpuidle_resume_and_unlock();
95 cpuidle_pause_and_lock();
96 cpuidle_disable_device(dev);
97 cpuidle_resume_and_unlock();
107 static struct notifier_block setup_hotplug_notifier = {
108 .notifier_call = powernv_cpuidle_add_cpu_notifier,
112 * powernv_cpuidle_driver_init()
114 static int powernv_cpuidle_driver_init(void)
117 struct cpuidle_driver *drv = &powernv_idle_driver;
119 drv->state_count = 0;
121 for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
122 /* Is the state not enabled? */
123 if (cpuidle_state_table[idle_state].enter == NULL)
126 drv->states[drv->state_count] = /* structure copy */
127 cpuidle_state_table[idle_state];
129 drv->state_count += 1;
136 * powernv_idle_probe()
137 * Choose state table for shared versus dedicated partition
139 static int powernv_idle_probe(void)
142 if (cpuidle_disable != IDLE_NO_OVERRIDE)
145 if (firmware_has_feature(FW_FEATURE_OPALv3)) {
146 cpuidle_state_table = powernv_states;
147 max_idle_state = ARRAY_SIZE(powernv_states);
154 static int __init powernv_processor_idle_init(void)
158 retval = powernv_idle_probe();
162 powernv_cpuidle_driver_init();
163 retval = cpuidle_register(&powernv_idle_driver, NULL);
165 printk(KERN_DEBUG "Registration of powernv driver failed.\n");
169 register_cpu_notifier(&setup_hotplug_notifier);
170 printk(KERN_DEBUG "powernv_idle_driver registered\n");
174 device_initcall(powernv_processor_idle_init);