66 lines
1.4 KiB
C
66 lines
1.4 KiB
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()) {
|
|
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);
|