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

// SPDX-License-Identifier: GPL-2.0-only
/*
 * poll_state.c - Polling idle state
 */

#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;

	time_start = local_clock();

	dev->poll_time_limit = false;

	raw_local_irq_enable();
	if (!current_set_polling_and_test()) {
		unsigned int loop_count = 0;
		u64 limit;

		limit = cpuidle_poll_time(drv, dev);

		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;
			}
		}
	}
	raw_local_irq_disable();

	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->exit_latency_ns = 0;
	state->target_residency_ns = 0;
	state->power_usage = -1;
	state->enter = poll_idle;
	state->flags = CPUIDLE_FLAG_POLLING;
}
EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);
Commit	Line	Data
55716d26	1	// SPDX-License-Identifier: GPL-2.0-only
34c2f65b RW	2	/*
34c2f65b RW	3	* poll_state.c - Polling idle state
34c2f65b RW	4	*/
	5
	6	#include <linux/cpuidle.h>
	7	#include <linux/sched.h>
a37b969a	8	#include <linux/sched/clock.h>
34c2f65b RW	9	#include <linux/sched/idle.h>
34c2f65b RW	10
4dc2375c	11	#define POLL_IDLE_RELAX_COUNT 200
a37b969a	12
34c2f65b RW	13	static int __cpuidle poll_idle(struct cpuidle_device *dev,
	14	struct cpuidle_driver *drv, int index)
	15	{
00717eb8 PZ	16	u64 time_start;
00717eb8 PZ	17
00717eb8	18	time_start = local_clock();
a37b969a	19
5f26bdce RW	20	dev->poll_time_limit = false;
5f26bdce RW	21
5e26aa93	22	raw_local_irq_enable();
34c2f65b	23	if (!current_set_polling_and_test()) {
4dc2375c	24	unsigned int loop_count = 0;
259231a0	25	u64 limit;
800fb34a	26
259231a0	27	limit = cpuidle_poll_time(drv, dev);
4dc2375c	28
a37b969a	29	while (!need_resched()) {
34c2f65b	30	cpu_relax();
4dc2375c RW	31	if (loop_count++ < POLL_IDLE_RELAX_COUNT)
4dc2375c RW	32	continue;
a37b969a	33
4dc2375c	34	loop_count = 0;
01bad1c6	35	if (local_clock() - time_start > limit) {
5f26bdce	36	dev->poll_time_limit = true;
a37b969a	37	break;
5f26bdce	38	}
a37b969a	39	}
34c2f65b	40	}
5e26aa93 PZ	41	raw_local_irq_disable();
5e26aa93 PZ	42
34c2f65b RW	43	current_clr_polling();
	44
	45	return index;
	46	}
	47
1b39e3f8	48	void cpuidle_poll_state_init(struct cpuidle_driver *drv)
34c2f65b RW	49	{
	50	struct cpuidle_state *state = &drv->states[0];
	51
	52	snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
	53	snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
	54	state->exit_latency = 0;
	55	state->target_residency = 0;
c1d51f68 RW	56	state->exit_latency_ns = 0;
c1d51f68 RW	57	state->target_residency_ns = 0;
34c2f65b RW	58	state->power_usage = -1;
34c2f65b RW	59	state->enter = poll_idle;
34c2f65b RW	60	state->flags = CPUIDLE_FLAG_POLLING;
34c2f65b RW	61	}
1b39e3f8	62	EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);