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
34struct task_struct *voyager_thread;
35static __u8 set_timeout;
36
37static int
38execute(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, 1)) != 0) {
56		printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
57		       string, ret);
58	}
59	return ret;
60}
61
62static void
63check_from_kernel(void)
64{
65	if(voyager_status.switch_off) {
66
67		execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
68	} else if(voyager_status.power_fail) {
69		VDEBUG(("Voyager daemon detected AC power failure\n"));
70
71		execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
72		set_timeout = 1;
73	}
74}
75
76static void
77check_continuing_condition(void)
78{
79	if(voyager_status.power_fail) {
80		__u8 data;
81		voyager_cat_psi(VOYAGER_PSI_SUBREAD,
82				VOYAGER_PSI_AC_FAIL_REG, &data);
83		if((data & 0x1f) == 0) {
84			/* all power restored */
85			printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
86			execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
87			set_timeout = 0;
88		}
89	}
90}
91
92static int
93thread(void *unused)
94{
95	printk(KERN_NOTICE "Voyager starting monitor thread\n");
96
97	for (;;) {
98		set_current_state(TASK_INTERRUPTIBLE);
99		schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
100
101		VDEBUG(("Voyager Daemon awoken\n"));
102		if(voyager_status.request_from_kernel == 0) {
103			/* probably awoken from timeout */
104			check_continuing_condition();
105		} else {
106			check_from_kernel();
107			voyager_status.request_from_kernel = 0;
108		}
109	}
110}
111
112static int __init
113voyager_thread_start(void)
114{
115	voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
116	if (IS_ERR(voyager_thread)) {
117		printk(KERN_ERR "Voyager: Failed to create system monitor thread.\n");
118		return PTR_ERR(voyager_thread);
119	}
120	return 0;
121}
122
123
124static void __exit
125voyager_thread_stop(void)
126{
127	kthread_stop(voyager_thread);
128}
129
130module_init(voyager_thread_start);
131module_exit(voyager_thread_stop);
132