arch/i386/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/config.h>
  18 #include <linux/mm.h>
  19 #include <linux/kernel_stat.h>
  20 #include <linux/delay.h>
  21 #include <linux/mc146818rtc.h>
  22 #include <linux/smp_lock.h>
  23 #include <linux/init.h>
  24 #include <linux/bootmem.h>
  25 #include <linux/kmod.h>
  26 #include <linux/completion.h>
  27 #include <linux/sched.h>
  28 #include <asm/desc.h>
  29 #include <asm/voyager.h>
  30 #include <asm/vic.h>
  31 #include <asm/mtrr.h>
  32 #include <asm/msr.h>
  33
  34 #define THREAD_NAME "kvoyagerd"
  35
  36 /* external variables */
  37 int kvoyagerd_running = 0;
  38 DECLARE_MUTEX_LOCKED(kvoyagerd_sem);
  39
  40 static int thread(void *);
  41
  42 static __u8 set_timeout = 0;
  43
  44 /* Start the machine monitor thread.  Return 1 if OK, 0 if fail */
  45 static int __init
  46 voyager_thread_start(void)
  47 {
  48         if(kernel_thread(thread, NULL, CLONE_KERNEL) < 0) {
  49                 /* This is serious, but not fatal */
  50                 printk(KERN_ERR "Voyager: Failed to create system monitor thread!!!\n");
  51                 return 1;
  52         }
  53         return 0;
  54 }
  55
  56 static int
  57 execute(const char *string)
  58 {
  59         int ret;
  60
  61         char *envp[] = {
  62                 "HOME=/",
  63                 "TERM=linux",
  64                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  65                 NULL,
  66         };
  67         char *argv[] = {
  68                 "/bin/bash",
  69                 "-c",
  70                 (char *)string,
  71                 NULL,
  72         };
  73
  74         if ((ret = call_usermodehelper(argv[0], argv, envp, 1)) != 0) {
  75                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
  76                        string, ret);
  77         }
  78         return ret;
  79 }
  80
  81 static void
  82 check_from_kernel(void)
  83 {
  84         if(voyager_status.switch_off) {
  85
  86                 /* FIXME: This should be configureable via proc */
  87                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  88         } else if(voyager_status.power_fail) {
  89                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  90
  91                 /* FIXME: This should be configureable via proc */
  92                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  93                 set_timeout = 1;
  94         }
  95 }
  96
  97 static void
  98 check_continuing_condition(void)
  99 {
 100         if(voyager_status.power_fail) {
 101                 __u8 data;
 102                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
 103                                 VOYAGER_PSI_AC_FAIL_REG, &data);
 104                 if((data & 0x1f) == 0) {
 105                         /* all power restored */
 106                         printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
 107                         /* FIXME: should be user configureable */
 108                         execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
 109                         set_timeout = 0;
 110                 }
 111         }
 112 }
 113
 114 static void
 115 wakeup(unsigned long unused)
 116 {
 117         up(&kvoyagerd_sem);
 118 }
 119
 120 static int
 121 thread(void *unused)
 122 {
 123         struct timer_list wakeup_timer;
 124
 125         kvoyagerd_running = 1;
 126
 127         daemonize(THREAD_NAME);
 128
 129         set_timeout = 0;
 130
 131         init_timer(&wakeup_timer);
 132
 133         sigfillset(&current->blocked);
 134         current->signal->tty = NULL;
 135
 136         printk(KERN_NOTICE "Voyager starting monitor thread\n");
 137
 138         for(;;) {
 139                 down_interruptible(&kvoyagerd_sem);
 140                 VDEBUG(("Voyager Daemon awoken\n"));
 141                 if(voyager_status.request_from_kernel == 0) {
 142                         /* probably awoken from timeout */
 143                         check_continuing_condition();
 144                 } else {
 145                         check_from_kernel();
 146                         voyager_status.request_from_kernel = 0;
 147                 }
 148                 if(set_timeout) {
 149                         del_timer(&wakeup_timer);
 150                         wakeup_timer.expires = HZ + jiffies;
 151                         wakeup_timer.function = wakeup;
 152                         add_timer(&wakeup_timer);
 153                 }
 154         }
 155 }
 156
 157 static void __exit
 158 voyager_thread_stop(void)
 159 {
 160         /* FIXME: do nothing at the moment */
 161 }
 162
 163 module_init(voyager_thread_start);
 164 //module_exit(voyager_thread_stop);