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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * poll_state.c - Polling idle state4 */5 6#include <linux/cpuidle.h>7#include <linux/sched.h>8#include <linux/sched/clock.h>9#include <linux/sched/idle.h>10 11#define POLL_IDLE_RELAX_COUNT 20012 13static int __cpuidle poll_idle(struct cpuidle_device *dev,14 struct cpuidle_driver *drv, int index)15{16 u64 time_start;17 18 time_start = local_clock_noinstr();19 20 dev->poll_time_limit = false;21 22 raw_local_irq_enable();23 if (!current_set_polling_and_test()) {24 unsigned int loop_count = 0;25 u64 limit;26 27 limit = cpuidle_poll_time(drv, dev);28 29 while (!need_resched()) {30 cpu_relax();31 if (loop_count++ < POLL_IDLE_RELAX_COUNT)32 continue;33 34 loop_count = 0;35 if (local_clock_noinstr() - time_start > limit) {36 dev->poll_time_limit = true;37 break;38 }39 }40 }41 raw_local_irq_disable();42 43 current_clr_polling();44 45 return index;46}47 48void cpuidle_poll_state_init(struct cpuidle_driver *drv)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;56 state->exit_latency_ns = 0;57 state->target_residency_ns = 0;58 state->power_usage = -1;59 state->enter = poll_idle;60 state->flags = CPUIDLE_FLAG_POLLING;61}62EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);63