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55716d26 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
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2 | /* |
3 | * poll_state.c - Polling idle state | |
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4 | */ |
5 | ||
6 | #include <linux/cpuidle.h> | |
7 | #include <linux/sched.h> | |
a37b969a | 8 | #include <linux/sched/clock.h> |
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9 | #include <linux/sched/idle.h> |
10 | ||
4dc2375c | 11 | #define POLL_IDLE_RELAX_COUNT 200 |
a37b969a | 12 | |
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13 | static int __cpuidle poll_idle(struct cpuidle_device *dev, |
14 | struct cpuidle_driver *drv, int index) | |
15 | { | |
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16 | u64 time_start = local_clock(); |
17 | ||
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18 | dev->poll_time_limit = false; |
19 | ||
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20 | local_irq_enable(); |
21 | if (!current_set_polling_and_test()) { | |
4dc2375c | 22 | unsigned int loop_count = 0; |
1617971c | 23 | u64 limit = TICK_NSEC; |
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24 | int i; |
25 | ||
26 | for (i = 1; i < drv->state_count; i++) { | |
27 | if (drv->states[i].disabled || dev->states_usage[i].disable) | |
28 | continue; | |
29 | ||
30 | limit = (u64)drv->states[i].target_residency * NSEC_PER_USEC; | |
31 | break; | |
32 | } | |
4dc2375c | 33 | |
a37b969a | 34 | while (!need_resched()) { |
34c2f65b | 35 | cpu_relax(); |
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36 | if (loop_count++ < POLL_IDLE_RELAX_COUNT) |
37 | continue; | |
a37b969a | 38 | |
4dc2375c | 39 | loop_count = 0; |
01bad1c6 | 40 | if (local_clock() - time_start > limit) { |
5f26bdce | 41 | dev->poll_time_limit = true; |
a37b969a | 42 | break; |
5f26bdce | 43 | } |
a37b969a | 44 | } |
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45 | } |
46 | current_clr_polling(); | |
47 | ||
48 | return index; | |
49 | } | |
50 | ||
1b39e3f8 | 51 | void cpuidle_poll_state_init(struct cpuidle_driver *drv) |
34c2f65b RW |
52 | { |
53 | struct cpuidle_state *state = &drv->states[0]; | |
54 | ||
55 | snprintf(state->name, CPUIDLE_NAME_LEN, "POLL"); | |
56 | snprintf(state->desc, CPUIDLE_DESC_LEN, "CPUIDLE CORE POLL IDLE"); | |
57 | state->exit_latency = 0; | |
58 | state->target_residency = 0; | |
59 | state->power_usage = -1; | |
60 | state->enter = poll_idle; | |
61 | state->disabled = false; | |
62 | state->flags = CPUIDLE_FLAG_POLLING; | |
63 | } | |
1b39e3f8 | 64 | EXPORT_SYMBOL_GPL(cpuidle_poll_state_init); |