drivers/cpuidle/poll_state.c

   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>
   9 #include <linux/sched/idle.h>
  10
  11 static int __cpuidle poll_idle(struct cpuidle_device *dev,
  12                                struct cpuidle_driver *drv, int index)
  13 {
  14         local_irq_enable();
  15         if (!current_set_polling_and_test()) {
  16                 while (!need_resched())
  17                         cpu_relax();
  18         }
  19         current_clr_polling();
  20
  21         return index;
  22 }
  23
  24 void cpuidle_poll_state_init(struct cpuidle_driver *drv)
  25 {
  26         struct cpuidle_state *state = &drv->states[0];
  27
  28         snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
  29         snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
  30         state->exit_latency = 0;
  31         state->target_residency = 0;
  32         state->power_usage = -1;
  33         state->enter = poll_idle;
  34         state->disabled = false;
  35         state->flags = CPUIDLE_FLAG_POLLING;
  36 }
  37 EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);