[linux.git] / drivers / cpuidle / cpuidle-powernv.c

/*
 *  cpuidle-powernv - idle state cpuidle driver.
 *  Adapted from drivers/cpuidle/cpuidle-pseries
 *
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/moduleparam.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
#include <linux/notifier.h>

#include <asm/machdep.h>
#include <asm/firmware.h>

struct cpuidle_driver powernv_idle_driver = {
	.name             = "powernv_idle",
	.owner            = THIS_MODULE,
};

static int max_idle_state;
static struct cpuidle_state *cpuidle_state_table;

static int snooze_loop(struct cpuidle_device *dev,
			struct cpuidle_driver *drv,
			int index)
{
	local_irq_enable();
	set_thread_flag(TIF_POLLING_NRFLAG);

	while (!need_resched()) {
		HMT_low();
		HMT_very_low();
	}

	HMT_medium();
	clear_thread_flag(TIF_POLLING_NRFLAG);
	smp_mb();
	return index;
}

static int nap_loop(struct cpuidle_device *dev,
			struct cpuidle_driver *drv,
			int index)
{
	power7_idle();
	return index;
}

/*
 * States for dedicated partition case.
 */
static struct cpuidle_state powernv_states[] = {
	{ /* Snooze */
		.name = "snooze",
		.desc = "snooze",
		.flags = CPUIDLE_FLAG_TIME_VALID,
		.exit_latency = 0,
		.target_residency = 0,
		.enter = &snooze_loop },
	{ /* NAP */
		.name = "NAP",
		.desc = "NAP",
		.flags = CPUIDLE_FLAG_TIME_VALID,
		.exit_latency = 10,
		.target_residency = 100,
		.enter = &nap_loop },
};

static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
			unsigned long action, void *hcpu)
{
	int hotcpu = (unsigned long)hcpu;
	struct cpuidle_device *dev =
				per_cpu(cpuidle_devices, hotcpu);

	if (dev && cpuidle_get_driver()) {
		switch (action) {
		case CPU_ONLINE:
		case CPU_ONLINE_FROZEN:
			cpuidle_pause_and_lock();
			cpuidle_enable_device(dev);
			cpuidle_resume_and_unlock();
			break;

		case CPU_DEAD:
		case CPU_DEAD_FROZEN:
			cpuidle_pause_and_lock();
			cpuidle_disable_device(dev);
			cpuidle_resume_and_unlock();
			break;

		default:
			return NOTIFY_DONE;
		}
	}
	return NOTIFY_OK;
}

static struct notifier_block setup_hotplug_notifier = {
	.notifier_call = powernv_cpuidle_add_cpu_notifier,
};

/*
 * powernv_cpuidle_driver_init()
 */
static int powernv_cpuidle_driver_init(void)
{
	int idle_state;
	struct cpuidle_driver *drv = &powernv_idle_driver;

	drv->state_count = 0;

	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
		/* Is the state not enabled? */
		if (cpuidle_state_table[idle_state].enter == NULL)
			continue;

		drv->states[drv->state_count] =	/* structure copy */
			cpuidle_state_table[idle_state];

		drv->state_count += 1;
	}

	return 0;
}

/*
 * powernv_idle_probe()
 * Choose state table for shared versus dedicated partition
 */
static int powernv_idle_probe(void)
{

	if (cpuidle_disable != IDLE_NO_OVERRIDE)
		return -ENODEV;

	if (firmware_has_feature(FW_FEATURE_OPALv3)) {
		cpuidle_state_table = powernv_states;
		max_idle_state = ARRAY_SIZE(powernv_states);
 	} else
 		return -ENODEV;

	return 0;
}

static int __init powernv_processor_idle_init(void)
{
	int retval;

	retval = powernv_idle_probe();
	if (retval)
		return retval;

	powernv_cpuidle_driver_init();
	retval = cpuidle_register(&powernv_idle_driver, NULL);
	if (retval) {
		printk(KERN_DEBUG "Registration of powernv driver failed.\n");
		return retval;
	}

	register_cpu_notifier(&setup_hotplug_notifier);
	printk(KERN_DEBUG "powernv_idle_driver registered\n");
	return 0;
}

device_initcall(powernv_processor_idle_init);
Commit	Line	Data
2c2e6ecf DD	1	/*
	2	* cpuidle-powernv - idle state cpuidle driver.
	3	* Adapted from drivers/cpuidle/cpuidle-pseries
	4	*
	5	*/
	6
	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>
	14
	15	#include <asm/machdep.h>
	16	#include <asm/firmware.h>
	17
	18	struct cpuidle_driver powernv_idle_driver = {
	19	.name = "powernv_idle",
	20	.owner = THIS_MODULE,
	21	};
	22
	23	static int max_idle_state;
	24	static struct cpuidle_state *cpuidle_state_table;
	25
	26	static int snooze_loop(struct cpuidle_device *dev,
	27	struct cpuidle_driver *drv,
	28	int index)
	29	{
	30	local_irq_enable();
	31	set_thread_flag(TIF_POLLING_NRFLAG);
	32
	33	while (!need_resched()) {
	34	HMT_low();
	35	HMT_very_low();
	36	}
	37
	38	HMT_medium();
	39	clear_thread_flag(TIF_POLLING_NRFLAG);
	40	smp_mb();
	41	return index;
	42	}
	43
	44	static int nap_loop(struct cpuidle_device *dev,
	45	struct cpuidle_driver *drv,
	46	int index)
	47	{
	48	power7_idle();
	49	return index;
	50	}
	51
	52	/*
	53	* States for dedicated partition case.
	54	*/
	55	static struct cpuidle_state powernv_states[] = {
	56	{ /* Snooze */
	57	.name = "snooze",
	58	.desc = "snooze",
	59	.flags = CPUIDLE_FLAG_TIME_VALID,
	60	.exit_latency = 0,
	61	.target_residency = 0,
	62	.enter = &snooze_loop },
	63	{ /* NAP */
	64	.name = "NAP",
65	.desc = "NAP",
66	.flags = CPUIDLE_FLAG_TIME_VALID,
67	.exit_latency = 10,
68	.target_residency = 100,
69	.enter = &nap_loop },
70	};
71
72	static int powernv_cpuidle_add_cpu_notifier(struct notifier_block *n,
73	unsigned long action, void *hcpu)
74	{
75	int hotcpu = (unsigned long)hcpu;
76	struct cpuidle_device *dev =
77	per_cpu(cpuidle_devices, hotcpu);
78
79	if (dev && cpuidle_get_driver()) {
80	switch (action) {
81	case CPU_ONLINE:
82	case CPU_ONLINE_FROZEN:
83	cpuidle_pause_and_lock();
84	cpuidle_enable_device(dev);
85	cpuidle_resume_and_unlock();
86	break;
87
88	case CPU_DEAD:
89	case CPU_DEAD_FROZEN:
90	cpuidle_pause_and_lock();
91	cpuidle_disable_device(dev);
92	cpuidle_resume_and_unlock();
93	break;
94
95	default:
96	return NOTIFY_DONE;
97	}
98	}
99	return NOTIFY_OK;
100	}
101
102	static struct notifier_block setup_hotplug_notifier = {
103	.notifier_call = powernv_cpuidle_add_cpu_notifier,
104	};
105
106	/*
107	* powernv_cpuidle_driver_init()
108	*/
109	static int powernv_cpuidle_driver_init(void)
110	{
111	int idle_state;
112	struct cpuidle_driver *drv = &powernv_idle_driver;
113
114	drv->state_count = 0;
115
116	for (idle_state = 0; idle_state < max_idle_state; ++idle_state) {
117	/* Is the state not enabled? */
118	if (cpuidle_state_table[idle_state].enter == NULL)
119	continue;
120
121	drv->states[drv->state_count] = /* structure copy */
122	cpuidle_state_table[idle_state];
123
124	drv->state_count += 1;
125	}
126
127	return 0;
128	}
129
130	/*
131	* powernv_idle_probe()
132	* Choose state table for shared versus dedicated partition
133	*/
134	static int powernv_idle_probe(void)
135	{
136
137	if (cpuidle_disable != IDLE_NO_OVERRIDE)
138	return -ENODEV;
139
140	if (firmware_has_feature(FW_FEATURE_OPALv3)) {
141	cpuidle_state_table = powernv_states;
142	max_idle_state = ARRAY_SIZE(powernv_states);
143	} else
144	return -ENODEV;
145
146	return 0;
147	}
148
149	static int __init powernv_processor_idle_init(void)
150	{
151	int retval;
152
153	retval = powernv_idle_probe();
154	if (retval)
155	return retval;
156
157	powernv_cpuidle_driver_init();
158	retval = cpuidle_register(&powernv_idle_driver, NULL);
159	if (retval) {
160	printk(KERN_DEBUG "Registration of powernv driver failed.\n");
161	return retval;
162	}
163
164	register_cpu_notifier(&setup_hotplug_notifier);
165	printk(KERN_DEBUG "powernv_idle_driver registered\n");
166	return 0;
167	}
168
169	device_initcall(powernv_processor_idle_init);