Merge git://git.kernel.org/pub/scm/linux/kernel/git/bunk/trivial
[linux-2.6.git] / arch / x86 / mach-voyager / voyager_thread.c
1 /* -*- mode: c; c-basic-offset: 8 -*- */
2
3 /* Copyright (C) 2001
4  *
5  * Author: J.E.J.Bottomley@HansenPartnership.com
6  *
7  * linux/arch/i386/kernel/voyager_thread.c
8  *
9  * This module provides the machine status monitor thread for the
10  * voyager architecture.  This allows us to monitor the machine
11  * environment (temp, voltage, fan function) and the front panel and
12  * internal UPS.  If a fault is detected, this thread takes corrective
13  * action (usually just informing init)
14  * */
15
16 #include <linux/module.h>
17 #include <linux/mm.h>
18 #include <linux/kernel_stat.h>
19 #include <linux/delay.h>
20 #include <linux/mc146818rtc.h>
21 #include <linux/init.h>
22 #include <linux/bootmem.h>
23 #include <linux/kmod.h>
24 #include <linux/completion.h>
25 #include <linux/sched.h>
26 #include <linux/kthread.h>
27 #include <asm/desc.h>
28 #include <asm/voyager.h>
29 #include <asm/vic.h>
30 #include <asm/mtrr.h>
31 #include <asm/msr.h>
32
33
34 struct task_struct *voyager_thread;
35 static __u8 set_timeout;
36
37 static int
38 execute(const char *string)
39 {
40         int ret;
41
42         char *envp[] = {
43                 "HOME=/",
44                 "TERM=linux",
45                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
46                 NULL,
47         };
48         char *argv[] = {
49                 "/bin/bash",
50                 "-c",
51                 (char *)string,
52                 NULL,
53         };
54
55         if ((ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC)) != 0) {
56                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
57                        string, ret);
58         }
59         return ret;
60 }
61
62 static void
63 check_from_kernel(void)
64 {
65         if(voyager_status.switch_off) {
66                 
67                 /* FIXME: This should be configurable via proc */
68                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
69         } else if(voyager_status.power_fail) {
70                 VDEBUG(("Voyager daemon detected AC power failure\n"));
71                 
72                 /* FIXME: This should be configureable via proc */
73                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
74                 set_timeout = 1;
75         }
76 }
77
78 static void
79 check_continuing_condition(void)
80 {
81         if(voyager_status.power_fail) {
82                 __u8 data;
83                 voyager_cat_psi(VOYAGER_PSI_SUBREAD, 
84                                 VOYAGER_PSI_AC_FAIL_REG, &data);
85                 if((data & 0x1f) == 0) {
86                         /* all power restored */
87                         printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
88                         /* FIXME: should be user configureable */
89                         execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
90                         set_timeout = 0;
91                 }
92         }
93 }
94
95 static int
96 thread(void *unused)
97 {
98         printk(KERN_NOTICE "Voyager starting monitor thread\n");
99
100         for (;;) {
101                 set_current_state(TASK_INTERRUPTIBLE);
102                 schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
103
104                 VDEBUG(("Voyager Daemon awoken\n"));
105                 if(voyager_status.request_from_kernel == 0) {
106                         /* probably awoken from timeout */
107                         check_continuing_condition();
108                 } else {
109                         check_from_kernel();
110                         voyager_status.request_from_kernel = 0;
111                 }
112         }
113 }
114
115 static int __init
116 voyager_thread_start(void)
117 {
118         voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
119         if (IS_ERR(voyager_thread)) {
120                 printk(KERN_ERR "Voyager: Failed to create system monitor thread.\n");
121                 return PTR_ERR(voyager_thread);
122         }
123         return 0;
124 }
125
126
127 static void __exit
128 voyager_thread_stop(void)
129 {
130         kthread_stop(voyager_thread);
131 }
132
133 module_init(voyager_thread_start);
134 module_exit(voyager_thread_stop);