blob: 23a1b27579a54d5e35ea373421aec47597d9f241 [file] [log] [blame]
/*
* 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()) {
unsigned int loop_count = 0;
u64 limit = TICK_NSEC;
int i;
for (i = 1; i < drv->state_count; i++) {
if (drv->states[i].disabled || dev->states_usage[i].disable)
continue;
limit = (u64)drv->states[i].target_residency * NSEC_PER_USEC;
break;
}
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);