powerpc: Various UP build fixes
[linux-2.6.git] / arch / ppc64 / kernel / idle.c
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/systemcfg.h>
30 #include <asm/machdep.h>
31 #include <asm/smp.h>
32
33 extern void power4_idle(void);
34
35 void default_idle(void)
36 {
37         long oldval;
38         unsigned int cpu = smp_processor_id();
39
40         while (1) {
41                 oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
42
43                 if (!oldval) {
44                         set_thread_flag(TIF_POLLING_NRFLAG);
45
46                         while (!need_resched() && !cpu_is_offline(cpu)) {
47                                 ppc64_runlatch_off();
48
49                                 /*
50                                  * Go into low thread priority and possibly
51                                  * low power mode.
52                                  */
53                                 HMT_low();
54                                 HMT_very_low();
55                         }
56
57                         HMT_medium();
58                         clear_thread_flag(TIF_POLLING_NRFLAG);
59                 } else {
60                         set_need_resched();
61                 }
62
63                 ppc64_runlatch_on();
64                 schedule();
65                 if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
66                         cpu_die();
67         }
68 }
69
70 void native_idle(void)
71 {
72         while (1) {
73                 ppc64_runlatch_off();
74
75                 if (!need_resched())
76                         power4_idle();
77
78                 if (need_resched()) {
79                         ppc64_runlatch_on();
80                         schedule();
81                 }
82
83                 if (cpu_is_offline(smp_processor_id()) &&
84                     system_state == SYSTEM_RUNNING)
85                         cpu_die();
86         }
87 }
88
89 void cpu_idle(void)
90 {
91         BUG_ON(NULL == ppc_md.idle_loop);
92         ppc_md.idle_loop();
93 }
94
95 int powersave_nap;
96
97 #ifdef CONFIG_SYSCTL
98 /*
99  * Register the sysctl to set/clear powersave_nap.
100  */
101 static ctl_table powersave_nap_ctl_table[]={
102         {
103                 .ctl_name       = KERN_PPC_POWERSAVE_NAP,
104                 .procname       = "powersave-nap",
105                 .data           = &powersave_nap,
106                 .maxlen         = sizeof(int),
107                 .mode           = 0644,
108                 .proc_handler   = &proc_dointvec,
109         },
110         { 0, },
111 };
112 static ctl_table powersave_nap_sysctl_root[] = {
113         { 1, "kernel", NULL, 0, 0755, powersave_nap_ctl_table, },
114         { 0,},
115 };
116
117 static int __init
118 register_powersave_nap_sysctl(void)
119 {
120         register_sysctl_table(powersave_nap_sysctl_root, 0);
121
122         return 0;
123 }
124 __initcall(register_powersave_nap_sysctl);
125 #endif