]>
Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * Idle daemon for PowerPC. Idle daemon will handle any action | |
3 | * that needs to be taken when the system becomes idle. | |
4 | * | |
a0652fc9 PM |
5 | * Originally written by Cort Dougan (cort@cs.nmt.edu). |
6 | * Subsequent 32-bit hacking by Tom Rini, Armin Kuster, | |
7 | * Paul Mackerras and others. | |
1da177e4 LT |
8 | * |
9 | * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com> | |
10 | * | |
11 | * Additional shared processor, SMT, and firmware support | |
12 | * Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com> | |
13 | * | |
a0652fc9 PM |
14 | * 32-bit and 64-bit versions merged by Paul Mackerras <paulus@samba.org> |
15 | * | |
1da177e4 LT |
16 | * This program is free software; you can redistribute it and/or |
17 | * modify it under the terms of the GNU General Public License | |
18 | * as published by the Free Software Foundation; either version | |
19 | * 2 of the License, or (at your option) any later version. | |
20 | */ | |
21 | ||
1da177e4 LT |
22 | #include <linux/sched.h> |
23 | #include <linux/kernel.h> | |
24 | #include <linux/smp.h> | |
25 | #include <linux/cpu.h> | |
1da177e4 | 26 | #include <linux/sysctl.h> |
1ad74998 | 27 | #include <linux/tick.h> |
1da177e4 | 28 | |
1da177e4 | 29 | #include <asm/processor.h> |
1da177e4 LT |
30 | #include <asm/cputable.h> |
31 | #include <asm/time.h> | |
fd899c0c | 32 | #include <asm/machdep.h> |
ae3a197e | 33 | #include <asm/runlatch.h> |
2249ca9d | 34 | #include <asm/smp.h> |
1da177e4 | 35 | |
a0652fc9 | 36 | #ifdef CONFIG_HOTPLUG_CPU |
61e9916e | 37 | #define cpu_should_die() cpu_is_offline(smp_processor_id()) |
a0652fc9 PM |
38 | #else |
39 | #define cpu_should_die() 0 | |
40 | #endif | |
1da177e4 | 41 | |
771dae81 DD |
42 | unsigned long cpuidle_disable = IDLE_NO_OVERRIDE; |
43 | EXPORT_SYMBOL(cpuidle_disable); | |
44 | ||
302eca18 AB |
45 | static int __init powersave_off(char *arg) |
46 | { | |
47 | ppc_md.power_save = NULL; | |
771dae81 | 48 | cpuidle_disable = IDLE_POWERSAVE_OFF; |
302eca18 AB |
49 | return 0; |
50 | } | |
51 | __setup("powersave=off", powersave_off); | |
52 | ||
a0652fc9 PM |
53 | /* |
54 | * The body of the idle task. | |
55 | */ | |
56 | void cpu_idle(void) | |
1da177e4 | 57 | { |
a0652fc9 | 58 | set_thread_flag(TIF_POLLING_NRFLAG); |
1da177e4 | 59 | while (1) { |
1268fbc7 | 60 | tick_nohz_idle_enter(); |
a5ccfee0 | 61 | rcu_idle_enter(); |
1268fbc7 | 62 | |
a0652fc9 | 63 | while (!need_resched() && !cpu_should_die()) { |
ddafddcf AB |
64 | ppc64_runlatch_off(); |
65 | ||
a0652fc9 PM |
66 | if (ppc_md.power_save) { |
67 | clear_thread_flag(TIF_POLLING_NRFLAG); | |
68 | /* | |
69 | * smp_mb is so clearing of TIF_POLLING_NRFLAG | |
70 | * is ordered w.r.t. need_resched() test. | |
71 | */ | |
72 | smp_mb(); | |
73 | local_irq_disable(); | |
74 | ||
6d07bb47 SR |
75 | /* Don't trace irqs off for idle */ |
76 | stop_critical_timings(); | |
77 | ||
a0652fc9 PM |
78 | /* check again after disabling irqs */ |
79 | if (!need_resched() && !cpu_should_die()) | |
80 | ppc_md.power_save(); | |
81 | ||
6d07bb47 SR |
82 | start_critical_timings(); |
83 | ||
7230c564 BH |
84 | /* Some power_save functions return with |
85 | * interrupts enabled, some don't. | |
86 | */ | |
87 | if (irqs_disabled()) | |
88 | local_irq_enable(); | |
a0652fc9 PM |
89 | set_thread_flag(TIF_POLLING_NRFLAG); |
90 | ||
91 | } else { | |
1da177e4 LT |
92 | /* |
93 | * Go into low thread priority and possibly | |
94 | * low power mode. | |
95 | */ | |
96 | HMT_low(); | |
97 | HMT_very_low(); | |
98 | } | |
1da177e4 LT |
99 | } |
100 | ||
a0652fc9 | 101 | HMT_medium(); |
45e75dfb | 102 | ppc64_runlatch_on(); |
a5ccfee0 | 103 | rcu_idle_exit(); |
1268fbc7 | 104 | tick_nohz_idle_exit(); |
bd2f5536 | 105 | if (cpu_should_die()) { |
ba74c144 | 106 | sched_preempt_enable_no_resched(); |
a0652fc9 | 107 | cpu_die(); |
bd2f5536 TG |
108 | } |
109 | schedule_preempt_disabled(); | |
1da177e4 | 110 | } |
1da177e4 LT |
111 | } |
112 | ||
1da177e4 LT |
113 | int powersave_nap; |
114 | ||
115 | #ifdef CONFIG_SYSCTL | |
116 | /* | |
117 | * Register the sysctl to set/clear powersave_nap. | |
118 | */ | |
119 | static ctl_table powersave_nap_ctl_table[]={ | |
120 | { | |
1da177e4 LT |
121 | .procname = "powersave-nap", |
122 | .data = &powersave_nap, | |
123 | .maxlen = sizeof(int), | |
124 | .mode = 0644, | |
6d456111 | 125 | .proc_handler = proc_dointvec, |
1da177e4 | 126 | }, |
f5f10678 | 127 | {} |
1da177e4 LT |
128 | }; |
129 | static ctl_table powersave_nap_sysctl_root[] = { | |
f5f10678 | 130 | { |
f5f10678 | 131 | .procname = "kernel", |
fb293ae1 | 132 | .mode = 0555, |
f5f10678 EB |
133 | .child = powersave_nap_ctl_table, |
134 | }, | |
135 | {} | |
1da177e4 LT |
136 | }; |
137 | ||
138 | static int __init | |
139 | register_powersave_nap_sysctl(void) | |
140 | { | |
0b4d4147 | 141 | register_sysctl_table(powersave_nap_sysctl_root); |
1da177e4 LT |
142 | |
143 | return 0; | |
144 | } | |
145 | __initcall(register_powersave_nap_sysctl); | |
146 | #endif |