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
);