diff options
Diffstat (limited to 'arch/powerpc/kernel/idle_64.c')
-rw-r--r-- | arch/powerpc/kernel/idle_64.c | 121 |
1 files changed, 121 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/idle_64.c b/arch/powerpc/kernel/idle_64.c new file mode 100644 index 000000000000..b879d3057ef8 --- /dev/null +++ b/arch/powerpc/kernel/idle_64.c | |||
@@ -0,0 +1,121 @@ | |||
1 | /* | ||
2 | * Idle daemon for PowerPC. Idle daemon will handle any action | ||
3 | * that needs to be taken when the system becomes idle. | ||
4 | * | ||
5 | * Originally Written by Cort Dougan (cort@cs.nmt.edu) | ||
6 | * | ||
7 | * iSeries supported added by Mike Corrigan <mikejc@us.ibm.com> | ||
8 | * | ||
9 | * Additional shared processor, SMT, and firmware support | ||
10 | * Copyright (c) 2003 Dave Engebretsen <engebret@us.ibm.com> | ||
11 | * | ||
12 | * This program is free software; you can redistribute it and/or | ||
13 | * modify it under the terms of the GNU General Public License | ||
14 | * as published by the Free Software Foundation; either version | ||
15 | * 2 of the License, or (at your option) any later version. | ||
16 | */ | ||
17 | |||
18 | #include <linux/config.h> | ||
19 | #include <linux/sched.h> | ||
20 | #include <linux/kernel.h> | ||
21 | #include <linux/smp.h> | ||
22 | #include <linux/cpu.h> | ||
23 | #include <linux/sysctl.h> | ||
24 | |||
25 | #include <asm/system.h> | ||
26 | #include <asm/processor.h> | ||
27 | #include <asm/cputable.h> | ||
28 | #include <asm/time.h> | ||
29 | #include <asm/machdep.h> | ||
30 | #include <asm/smp.h> | ||
31 | |||
32 | extern void power4_idle(void); | ||
33 | |||
34 | void default_idle(void) | ||
35 | { | ||
36 | unsigned int cpu = smp_processor_id(); | ||
37 | set_thread_flag(TIF_POLLING_NRFLAG); | ||
38 | |||
39 | while (1) { | ||
40 | if (!need_resched()) { | ||
41 | while (!need_resched() && !cpu_is_offline(cpu)) { | ||
42 | ppc64_runlatch_off(); | ||
43 | |||
44 | /* | ||
45 | * Go into low thread priority and possibly | ||
46 | * low power mode. | ||
47 | */ | ||
48 | HMT_low(); | ||
49 | HMT_very_low(); | ||
50 | } | ||
51 | |||
52 | HMT_medium(); | ||
53 | } | ||
54 | |||
55 | ppc64_runlatch_on(); | ||
56 | preempt_enable_no_resched(); | ||
57 | schedule(); | ||
58 | preempt_disable(); | ||
59 | if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING) | ||
60 | cpu_die(); | ||
61 | } | ||
62 | } | ||
63 | |||
64 | void native_idle(void) | ||
65 | { | ||
66 | while (1) { | ||
67 | ppc64_runlatch_off(); | ||
68 | |||
69 | if (!need_resched()) | ||
70 | power4_idle(); | ||
71 | |||
72 | if (need_resched()) { | ||
73 | ppc64_runlatch_on(); | ||
74 | preempt_enable_no_resched(); | ||
75 | schedule(); | ||
76 | preempt_disable(); | ||
77 | } | ||
78 | |||
79 | if (cpu_is_offline(smp_processor_id()) && | ||
80 | system_state == SYSTEM_RUNNING) | ||
81 | cpu_die(); | ||
82 | } | ||
83 | } | ||
84 | |||
85 | void cpu_idle(void) | ||
86 | { | ||
87 | BUG_ON(NULL == ppc_md.idle_loop); | ||
88 | ppc_md.idle_loop(); | ||
89 | } | ||
90 | |||
91 | int powersave_nap; | ||
92 | |||
93 | #ifdef CONFIG_SYSCTL | ||
94 | /* | ||
95 | * Register the sysctl to set/clear powersave_nap. | ||
96 | */ | ||
97 | static ctl_table powersave_nap_ctl_table[]={ | ||
98 | { | ||
99 | .ctl_name = KERN_PPC_POWERSAVE_NAP, | ||
100 | .procname = "powersave-nap", | ||
101 | .data = &powersave_nap, | ||
102 | .maxlen = sizeof(int), | ||
103 | .mode = 0644, | ||
104 | .proc_handler = &proc_dointvec, | ||
105 | }, | ||
106 | { 0, }, | ||
107 | }; | ||
108 | static ctl_table powersave_nap_sysctl_root[] = { | ||
109 | { 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, }, | ||
110 | { 0,}, | ||
111 | }; | ||
112 | |||
113 | static int __init | ||
114 | register_powersave_nap_sysctl(void) | ||
115 | { | ||
116 | register_sysctl_table(powersave_nap_sysctl_root, 0); | ||
117 | |||
118 | return 0; | ||
119 | } | ||
120 | __initcall(register_powersave_nap_sysctl); | ||
121 | #endif | ||