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/pgalloc.h>
  32 #include <asm/mtrr.h>
  33 #include <asm/msr.h>
  34
  35 #include <linux/irq.h>
  36
  37 #define THREAD_NAME "kvoyagerd"
  38
  39 /* external variables */
  40 int kvoyagerd_running = 0;
  41 DECLARE_MUTEX_LOCKED(kvoyagerd_sem);
  42
  43 static int thread(void *);
  44
  45 static __u8 set_timeout = 0;
  46
  47 /* Start the machine monitor thread.  Return 1 if OK, 0 if fail */
  48 static int __init
  49 voyager_thread_start(void)
  50 {
  51         if(kernel_thread(thread, NULL, CLONE_KERNEL) < 0) {
  52                 /* This is serious, but not fatal */
  53                 printk(KERN_ERR "Voyager: Failed to create system monitor thread!!!\n");
  54                 return 1;
  55         }
  56         return 0;
  57 }
  58
  59 static int
  60 execute(const char *string)
  61 {
  62         int ret;
  63
  64         char *envp[] = {
  65                 "HOME=/",
  66                 "TERM=linux",
  67                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  68                 NULL,
  69         };
  70         char *argv[] = {
  71                 "/bin/bash",
  72                 "-c",
  73                 (char *)string,
  74                 NULL,
  75         };
  76
  77         if ((ret = call_usermodehelper(argv[0], argv, envp, 1)) != 0) {
  78                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
  79                        string, ret);
  80         }
  81         return ret;
  82 }
  83
  84 static void
  85 check_from_kernel(void)
  86 {
  87         if(voyager_status.switch_off) {
  88
  89                 /* FIXME: This should be configureable via proc */
  90                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  91         } else if(voyager_status.power_fail) {
  92                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  93
  94                 /* FIXME: This should be configureable via proc */
  95                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  96                 set_timeout = 1;
  97         }
  98 }
  99
 100 static void
 101 check_continuing_condition(void)
 102 {
 103         if(voyager_status.power_fail) {
 104                 __u8 data;
 105                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
 106                                 VOYAGER_PSI_AC_FAIL_REG, &data);
 107                 if((data & 0x1f) == 0) {
 108                         /* all power restored */
 109                         printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
 110                         /* FIXME: should be user configureable */
 111                         execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
 112                         set_timeout = 0;
 113                 }
 114         }
 115 }
 116
 117 static void
 118 wakeup(unsigned long unused)
 119 {
 120         up(&kvoyagerd_sem);
 121 }
 122
 123 static int
 124 thread(void *unused)
 125 {
 126         struct timer_list wakeup_timer;
 127
 128         kvoyagerd_running = 1;
 129
 130         reparent_to_init();
 131         daemonize(THREAD_NAME);
 132
 133         set_timeout = 0;
 134
 135         init_timer(&wakeup_timer);
 136
 137         sigfillset(&current->blocked);
 138         current->signal->tty = NULL;
 139
 140         printk(KERN_NOTICE "Voyager starting monitor thread\n");
 141
 142         for(;;) {
 143                 down_interruptible(&kvoyagerd_sem);
 144                 VDEBUG(("Voyager Daemon awoken\n"));
 145                 if(voyager_status.request_from_kernel == 0) {
 146                         /* probably awoken from timeout */
 147                         check_continuing_condition();
 148                 } else {
 149                         check_from_kernel();
 150                         voyager_status.request_from_kernel = 0;
 151                 }
 152                 if(set_timeout) {
 153                         del_timer(&wakeup_timer);
 154                         wakeup_timer.expires = HZ + jiffies;
 155                         wakeup_timer.function = wakeup;
 156                         add_timer(&wakeup_timer);
 157                 }
 158         }
 159 }
 160
 161 static void __exit
 162 voyager_thread_stop(void)
 163 {
 164         /* FIXME: do nothing at the moment */
 165 }
 166
 167 module_init(voyager_thread_start);
 168 //module_exit(voyager_thread_stop);