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