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