| 1 | |
| 2 | |
| 3 | * poll_state.c - Polling idle state
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| 4 |
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| 5 |
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| 6 | #include <linux/cpuidle.h>
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| 7 | #include <linux/export.h>
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| 8 | #include <linux/irqflags.h>
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| 9 | #include <linux/sched.h>
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| 10 | #include <linux/sched/clock.h>
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| 11 | #include <linux/sched/idle.h>
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| 12 | #include <linux/sprintf.h>
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| 13 | #include <linux/types.h>
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| 14 |
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| 15 | #define POLL_IDLE_RELAX_COUNT 200
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| 16 |
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| 17 | static int __cpuidle poll_idle(struct cpuidle_device *dev,
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| 18 | struct cpuidle_driver *drv, int index)
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| 19 | {
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| 20 | u64 time_start;
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| 21 |
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| 22 | time_start = local_clock_noinstr();
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| 23 |
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| 24 | dev->poll_time_limit = false;
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| 25 |
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| 26 | raw_local_irq_enable();
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| 27 | if (!current_set_polling_and_test()) {
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| 28 | unsigned int loop_count = 0;
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| 29 | u64 limit;
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| 30 |
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| 31 | limit = cpuidle_poll_time(drv, dev);
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| 32 |
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| 33 | while (!need_resched()) {
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| 34 | cpu_relax();
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| 35 | if (loop_count++ < POLL_IDLE_RELAX_COUNT)
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| 36 | continue;
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| 37 |
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| 38 | loop_count = 0;
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| 39 | if (local_clock_noinstr() - time_start > limit) {
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| 40 | dev->poll_time_limit = true;
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| 41 | break;
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| 42 | }
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| 43 | }
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| 44 | }
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| 45 | raw_local_irq_disable();
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| 46 |
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| 47 | current_clr_polling();
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| 48 |
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| 49 | return index;
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| 50 | }
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| 51 |
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| 52 | void cpuidle_poll_state_init(struct cpuidle_driver *drv)
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| 53 | {
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| 54 | struct cpuidle_state *state = &drv->states[0];
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| 55 |
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| 56 | snprintf(state->name, CPUIDLE_NAME_LEN, "POLL");
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| 57 | snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE");
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| 58 | state->exit_latency = 0;
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| 59 | state->target_residency = 0;
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| 60 | state->exit_latency_ns = 0;
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| 61 | state->target_residency_ns = 0;
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| 62 | state->power_usage = -1;
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| 63 | state->enter = poll_idle;
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| 64 | state->flags = CPUIDLE_FLAG_POLLING;
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| 65 | }
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| 66 | EXPORT_SYMBOL_GPL(cpuidle_poll_state_init);
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