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 <linux/kthread.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
  35 struct task_struct *voyager_thread;
  36 static __u8 set_timeout;
  37
  38 static int
  39 execute(const char *string)
  40 {
  41         int ret;
  42
  43         char *envp[] = {
  44                 "HOME=/",
  45                 "TERM=linux",
  46                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  47                 NULL,
  48         };
  49         char *argv[] = {
  50                 "/bin/bash",
  51                 "-c",
  52                 (char *)string,
  53                 NULL,
  54         };
  55
  56         if ((ret = call_usermodehelper(argv[0], argv, envp, 1)) != 0) {
  57                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n",
  58                        string, ret);
  59         }
  60         return ret;
  61 }
  62
  63 static void
  64 check_from_kernel(void)
  65 {
  66         if(voyager_status.switch_off) {
  67
  68                 /* FIXME: This should be configureable via proc */
  69                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  70         } else if(voyager_status.power_fail) {
  71                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  72
  73                 /* FIXME: This should be configureable via proc */
  74                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  75                 set_timeout = 1;
  76         }
  77 }
  78
  79 static void
  80 check_continuing_condition(void)
  81 {
  82         if(voyager_status.power_fail) {
  83                 __u8 data;
  84                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
  85                                 VOYAGER_PSI_AC_FAIL_REG, &data);
  86                 if((data & 0x1f) == 0) {
  87                         /* all power restored */
  88                         printk(KERN_NOTICE "VOYAGER AC power restored, cancelling shutdown\n");
  89                         /* FIXME: should be user configureable */
  90                         execute("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
  91                         set_timeout = 0;
  92                 }
  93         }
  94 }
  95
  96 static int
  97 thread(void *unused)
  98 {
  99         printk(KERN_NOTICE "Voyager starting monitor thread\n");
 100
 101         for (;;) {
 102                 set_current_state(TASK_INTERRUPTIBLE);
 103                 schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
 104
 105                 VDEBUG(("Voyager Daemon awoken\n"));
 106                 if(voyager_status.request_from_kernel == 0) {
 107                         /* probably awoken from timeout */
 108                         check_continuing_condition();
 109                 } else {
 110                         check_from_kernel();
 111                         voyager_status.request_from_kernel = 0;
 112                 }
 113         }
 114 }
 115
 116 static int __init
 117 voyager_thread_start(void)
 118 {
 119         voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
 120         if (IS_ERR(voyager_thread)) {
 121                 printk(KERN_ERR "Voyager: Failed to create system monitor thread.\n");
 122                 return PTR_ERR(voyager_thread);
 123         }
 124         return 0;
 125 }
 126
 127
 128 static void __exit
 129 voyager_thread_stop(void)
 130 {
 131         kthread_stop(voyager_thread);
 132 }
 133
 134 module_init(voyager_thread_start);
 135 module_exit(voyager_thread_stop);