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> |
1da177e4 LT |
27 | |
28 | #include <asm/system.h> | |
29 | #include <asm/processor.h> | |
1da177e4 LT |
30 | #include <asm/cputable.h> |
31 | #include <asm/time.h> | |
fd899c0c | 32 | #include <asm/machdep.h> |
2249ca9d | 33 | #include <asm/smp.h> |
1da177e4 | 34 | |
a0652fc9 | 35 | #ifdef CONFIG_HOTPLUG_CPU |
543b9fd3 JB |
36 | /* this is used for software suspend, and that shuts down |
37 | * CPUs even while the system is still booting... */ | |
a0652fc9 | 38 | #define cpu_should_die() (cpu_is_offline(smp_processor_id()) && \ |
543b9fd3 JB |
39 | (system_state == SYSTEM_RUNNING \ |
40 | || system_state == SYSTEM_BOOTING)) | |
a0652fc9 PM |
41 | #else |
42 | #define cpu_should_die() 0 | |
43 | #endif | |
1da177e4 | 44 | |
302eca18 AB |
45 | static int __init powersave_off(char *arg) |
46 | { | |
47 | ppc_md.power_save = NULL; | |
48 | return 0; | |
49 | } | |
50 | __setup("powersave=off", powersave_off); | |
51 | ||
a0652fc9 PM |
52 | /* |
53 | * The body of the idle task. | |
54 | */ | |
55 | void cpu_idle(void) | |
1da177e4 | 56 | { |
a0652fc9 PM |
57 | if (ppc_md.idle_loop) |
58 | ppc_md.idle_loop(); /* doesn't return */ | |
1da177e4 | 59 | |
a0652fc9 | 60 | set_thread_flag(TIF_POLLING_NRFLAG); |
1da177e4 | 61 | while (1) { |
a0652fc9 | 62 | while (!need_resched() && !cpu_should_die()) { |
ddafddcf AB |
63 | ppc64_runlatch_off(); |
64 | ||
a0652fc9 PM |
65 | if (ppc_md.power_save) { |
66 | clear_thread_flag(TIF_POLLING_NRFLAG); | |
67 | /* | |
68 | * smp_mb is so clearing of TIF_POLLING_NRFLAG | |
69 | * is ordered w.r.t. need_resched() test. | |
70 | */ | |
71 | smp_mb(); | |
72 | local_irq_disable(); | |
73 | ||
74 | /* check again after disabling irqs */ | |
75 | if (!need_resched() && !cpu_should_die()) | |
76 | ppc_md.power_save(); | |
77 | ||
78 | local_irq_enable(); | |
79 | set_thread_flag(TIF_POLLING_NRFLAG); | |
80 | ||
81 | } else { | |
1da177e4 LT |
82 | /* |
83 | * Go into low thread priority and possibly | |
84 | * low power mode. | |
85 | */ | |
86 | HMT_low(); | |
87 | HMT_very_low(); | |
88 | } | |
1da177e4 LT |
89 | } |
90 | ||
a0652fc9 | 91 | HMT_medium(); |
45e75dfb | 92 | ppc64_runlatch_on(); |
a0652fc9 PM |
93 | if (cpu_should_die()) |
94 | cpu_die(); | |
5bfb5d69 | 95 | preempt_enable_no_resched(); |
1da177e4 | 96 | schedule(); |
5bfb5d69 | 97 | preempt_disable(); |
1da177e4 | 98 | } |
1da177e4 LT |
99 | } |
100 | ||
1da177e4 LT |
101 | int powersave_nap; |
102 | ||
103 | #ifdef CONFIG_SYSCTL | |
104 | /* | |
105 | * Register the sysctl to set/clear powersave_nap. | |
106 | */ | |
107 | static ctl_table powersave_nap_ctl_table[]={ | |
108 | { | |
109 | .ctl_name = KERN_PPC_POWERSAVE_NAP, | |
110 | .procname = "powersave-nap", | |
111 | .data = &powersave_nap, | |
112 | .maxlen = sizeof(int), | |
113 | .mode = 0644, | |
114 | .proc_handler = &proc_dointvec, | |
115 | }, | |
f5f10678 | 116 | {} |
1da177e4 LT |
117 | }; |
118 | static ctl_table powersave_nap_sysctl_root[] = { | |
f5f10678 EB |
119 | { |
120 | .ctl_name = CTL_KERN, | |
121 | .procname = "kernel", | |
122 | .mode = 0755, | |
123 | .child = powersave_nap_ctl_table, | |
124 | }, | |
125 | {} | |
1da177e4 LT |
126 | }; |
127 | ||
128 | static int __init | |
129 | register_powersave_nap_sysctl(void) | |
130 | { | |
0b4d4147 | 131 | register_sysctl_table(powersave_nap_sysctl_root); |
1da177e4 LT |
132 | |
133 | return 0; | |
134 | } | |
135 | __initcall(register_powersave_nap_sysctl); | |
136 | #endif |