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/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
  34 struct task_struct *voyager_thread;
  35 static __u8 set_timeout;
  36
  37 static int
  38 execute(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, UMH_WAIT_PROC)) != 0) {
  56                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
  57                        string, ret);
  58         }
  59         return ret;
  60 }
  61
  62 static void
  63 check_from_kernel(void)
  64 {
  65         if(voyager_status.switch_off) {
  66
  67                 /* FIXME: This should be configureable via proc */
  68                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  69         } else if(voyager_status.power_fail) {
  70                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  71
  72                 /* FIXME: This should be configureable via proc */
  73                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  74                 set_timeout = 1;
  75         }
  76 }
  77
  78 static void
  79 check_continuing_condition(void)
  80 {
  81         if(voyager_status.power_fail) {
  82                 __u8 data;
  83                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
  84                                 VOYAGER_PSI_AC_FAIL_REG, &data);
  85                 if((data & 0x1f) == 0) {
  86                         /* all power restored */
  87                         printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
  88                         /* FIXME: should be user configureable */
  89                         execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
  90                         set_timeout = 0;
  91                 }
  92         }
  93 }
  94
  95 static int
  96 thread(void *unused)
  97 {
  98         printk(KERN_NOTICE "Voyager starting monitor thread\n");
  99
 100         for (;;) {
 101                 set_current_state(TASK_INTERRUPTIBLE);
 102                 schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
 103
 104                 VDEBUG(("Voyager Daemon awoken\n"));
 105                 if(voyager_status.request_from_kernel == 0) {
 106                         /* probably awoken from timeout */
 107                         check_continuing_condition();
 108                 } else {
 109                         check_from_kernel();
 110                         voyager_status.request_from_kernel = 0;
 111                 }
 112         }
 113 }
 114
 115 static int __init
 116 voyager_thread_start(void)
 117 {
 118         voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
 119         if (IS_ERR(voyager_thread)) {
 120                 printk(KERN_ERR "Voyager: Failed to create system monitor thread.\n");
 121                 return PTR_ERR(voyager_thread);
 122         }
 123         return 0;
 124 }
 125
 126
 127 static void __exit
 128 voyager_thread_stop(void)
 129 {
 130         kthread_stop(voyager_thread);
 131 }
 132
 133 module_init(voyager_thread_start);
 134 module_exit(voyager_thread_stop);