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