[linux.git] / drivers / cpuidle / poll_state.c

/*
 * poll_state.c - Polling idle state
 *
 * This file is released under the GPLv2.
 */

#include <linux/cpuidle.h>
#include <linux/sched.h>
#include <linux/sched/clock.h>
#include <linux/sched/idle.h>

#define POLL_IDLE_RELAX_COUNT	200

static int __cpuidle poll_idle(struct cpuidle_device *dev,
			       struct cpuidle_driver *drv, int index)
{
	u64 time_start = local_clock();

	dev->poll_time_limit = false;

	local_irq_enable();
	if (!current_set_polling_and_test()) {
		u64 limit = (u64)drv->states[1].target_residency * NSEC_PER_USEC;
		unsigned int loop_count = 0;

		while (!need_resched()) {
			cpu_relax();
			if (loop_count++ < POLL_IDLE_RELAX_COUNT)
				continue;

			loop_count = 0;
			if (local_clock() - time_start > limit) {
				dev->poll_time_limit = true;
				break;
			}
		}
	}
	current_clr_polling();

	return index;
}

void cpuidle_poll_state_init(struct cpuidle_driver *drv)
{
	struct cpuidle_state *state = &drv->states[0];

	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
	state->exit_latency = 0;
	state->target_residency = 0;
	state->power_usage = -1;
	state->enter = poll_idle;
	state->disabled = false;
	state->flags = CPUIDLE_FLAG_POLLING;
}
EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);
Commit	Line	Data
34c2f65b RW	1	/*
	2	* poll_state.c - Polling idle state
	3	*
	4	* This file is released under the GPLv2.
	5	*/
	6
	7	#include <linux/cpuidle.h>
	8	#include <linux/sched.h>
a37b969a	9	#include <linux/sched/clock.h>
34c2f65b RW	10	#include <linux/sched/idle.h>
34c2f65b RW	11
4dc2375c	12	#define POLL_IDLE_RELAX_COUNT 200
a37b969a	13
34c2f65b RW	14	static int __cpuidle poll_idle(struct cpuidle_device *dev,
	15	struct cpuidle_driver *drv, int index)
	16	{
a37b969a RW	17	u64 time_start = local_clock();
a37b969a RW	18
5f26bdce RW	19	dev->poll_time_limit = false;
5f26bdce RW	20
34c2f65b RW	21	local_irq_enable();
34c2f65b RW	22	if (!current_set_polling_and_test()) {
01bad1c6	23	u64 limit = (u64)drv->states[1].target_residency * NSEC_PER_USEC;
4dc2375c RW	24	unsigned int loop_count = 0;
4dc2375c RW	25
a37b969a	26	while (!need_resched()) {
34c2f65b	27	cpu_relax();
4dc2375c RW	28	if (loop_count++ < POLL_IDLE_RELAX_COUNT)
4dc2375c RW	29	continue;
a37b969a	30
4dc2375c	31	loop_count = 0;
01bad1c6	32	if (local_clock() - time_start > limit) {
5f26bdce	33	dev->poll_time_limit = true;
a37b969a	34	break;
5f26bdce	35	}
a37b969a	36	}
34c2f65b RW	37	}
	38	current_clr_polling();
	39
	40	return index;
	41	}
	42
1b39e3f8	43	void cpuidle_poll_state_init(struct cpuidle_driver *drv)
34c2f65b RW	44	{
	45	struct cpuidle_state *state = &drv->states[0];
	46
	47	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
	48	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
	49	state->exit_latency = 0;
	50	state->target_residency = 0;
	51	state->power_usage = -1;
	52	state->enter = poll_idle;
	53	state->disabled = false;
	54	state->flags = CPUIDLE_FLAG_POLLING;
	55	}
1b39e3f8	56	EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);