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