aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/cpu/idle.c
diff options
context:
space:
mode:
Diffstat (limited to 'kernel/cpu/idle.c')
-rw-r--r--kernel/cpu/idle.c144
1 files changed, 0 insertions, 144 deletions
diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c
deleted file mode 100644
index 277f494c2a9a..000000000000
--- a/kernel/cpu/idle.c
+++ /dev/null
@@ -1,144 +0,0 @@
1/*
2 * Generic entry point for the idle threads
3 */
4#include <linux/sched.h>
5#include <linux/cpu.h>
6#include <linux/tick.h>
7#include <linux/mm.h>
8#include <linux/stackprotector.h>
9
10#include <asm/tlb.h>
11
12#include <trace/events/power.h>
13
14static int __read_mostly cpu_idle_force_poll;
15
16void cpu_idle_poll_ctrl(bool enable)
17{
18 if (enable) {
19 cpu_idle_force_poll++;
20 } else {
21 cpu_idle_force_poll--;
22 WARN_ON_ONCE(cpu_idle_force_poll < 0);
23 }
24}
25
26#ifdef CONFIG_GENERIC_IDLE_POLL_SETUP
27static int __init cpu_idle_poll_setup(char *__unused)
28{
29 cpu_idle_force_poll = 1;
30 return 1;
31}
32__setup("nohlt", cpu_idle_poll_setup);
33
34static int __init cpu_idle_nopoll_setup(char *__unused)
35{
36 cpu_idle_force_poll = 0;
37 return 1;
38}
39__setup("hlt", cpu_idle_nopoll_setup);
40#endif
41
42static inline int cpu_idle_poll(void)
43{
44 rcu_idle_enter();
45 trace_cpu_idle_rcuidle(0, smp_processor_id());
46 local_irq_enable();
47 while (!tif_need_resched())
48 cpu_relax();
49 trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, smp_processor_id());
50 rcu_idle_exit();
51 return 1;
52}
53
54/* Weak implementations for optional arch specific functions */
55void __weak arch_cpu_idle_prepare(void) { }
56void __weak arch_cpu_idle_enter(void) { }
57void __weak arch_cpu_idle_exit(void) { }
58void __weak arch_cpu_idle_dead(void) { }
59void __weak arch_cpu_idle(void)
60{
61 cpu_idle_force_poll = 1;
62 local_irq_enable();
63}
64
65/*
66 * Generic idle loop implementation
67 */
68static void cpu_idle_loop(void)
69{
70 while (1) {
71 tick_nohz_idle_enter();
72
73 while (!need_resched()) {
74 check_pgt_cache();
75 rmb();
76
77 if (cpu_is_offline(smp_processor_id()))
78 arch_cpu_idle_dead();
79
80 local_irq_disable();
81 arch_cpu_idle_enter();
82
83 /*
84 * In poll mode we reenable interrupts and spin.
85 *
86 * Also if we detected in the wakeup from idle
87 * path that the tick broadcast device expired
88 * for us, we don't want to go deep idle as we
89 * know that the IPI is going to arrive right
90 * away
91 */
92 if (cpu_idle_force_poll || tick_check_broadcast_expired()) {
93 cpu_idle_poll();
94 } else {
95 if (!current_clr_polling_and_test()) {
96 stop_critical_timings();
97 rcu_idle_enter();
98 arch_cpu_idle();
99 WARN_ON_ONCE(irqs_disabled());
100 rcu_idle_exit();
101 start_critical_timings();
102 } else {
103 local_irq_enable();
104 }
105 __current_set_polling();
106 }
107 arch_cpu_idle_exit();
108 }
109
110 /*
111 * Since we fell out of the loop above, we know
112 * TIF_NEED_RESCHED must be set, propagate it into
113 * PREEMPT_NEED_RESCHED.
114 *
115 * This is required because for polling idle loops we will
116 * not have had an IPI to fold the state for us.
117 */
118 preempt_set_need_resched();
119 tick_nohz_idle_exit();
120 schedule_preempt_disabled();
121 }
122}
123
124void cpu_startup_entry(enum cpuhp_state state)
125{
126 /*
127 * This #ifdef needs to die, but it's too late in the cycle to
128 * make this generic (arm and sh have never invoked the canary
129 * init for the non boot cpus!). Will be fixed in 3.11
130 */
131#ifdef CONFIG_X86
132 /*
133 * If we're the non-boot CPU, nothing set the stack canary up
134 * for us. The boot CPU already has it initialized but no harm
135 * in doing it again. This is a good place for updating it, as
136 * we wont ever return from this function (so the invalid
137 * canaries already on the stack wont ever trigger).
138 */
139 boot_init_stack_canary();
140#endif
141 __current_set_polling();
142 arch_cpu_idle_prepare();
143 cpu_idle_loop();
144}