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