arch/x86/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 struct task_struct *voyager_thread;
  34 static __u8 set_timeout;
  35
  36 static int execute(const char *string)
  37 {
  38         int ret;
  39
  40         char *envp[] = {
  41                 "HOME=/",
  42                 "TERM=linux",
  43                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  44                 NULL,
  45         };
  46         char *argv[] = {
  47                 "/bin/bash",
  48                 "-c",
  49                 (char *)string,
  50                 NULL,
  51         };
  52
  53         if ((ret =
  54              call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC)) != 0) {
  55                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n", string,
  56                        ret);
  57         }
  58         return ret;
  59 }
  60
  61 static void check_from_kernel(void)
  62 {
  63         if (voyager_status.switch_off) {
  64
  65                 /* FIXME: This should be configurable via proc */
  66                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  67         } else if (voyager_status.power_fail) {
  68                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  69
  70                 /* FIXME: This should be configureable via proc */
  71                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  72                 set_timeout = 1;
  73         }
  74 }
  75
  76 static void check_continuing_condition(void)
  77 {
  78         if (voyager_status.power_fail) {
  79                 __u8 data;
  80                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
  81                                 VOYAGER_PSI_AC_FAIL_REG, &data);
  82                 if ((data & 0x1f) == 0) {
  83                         /* all power restored */
  84                         printk(KERN_NOTICE
  85                                "VOYAGER AC power restored, cancelling shutdown\n");
  86                         /* FIXME: should be user configureable */
  87                         execute
  88                             ("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
  89                         set_timeout = 0;
  90                 }
  91         }
  92 }
  93
  94 static int thread(void *unused)
  95 {
  96         printk(KERN_NOTICE "Voyager starting monitor thread\n");
  97
  98         for (;;) {
  99                 set_current_state(TASK_INTERRUPTIBLE);
 100                 schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
 101
 102                 VDEBUG(("Voyager Daemon awoken\n"));
 103                 if (voyager_status.request_from_kernel == 0) {
 104                         /* probably awoken from timeout */
 105                         check_continuing_condition();
 106                 } else {
 107                         check_from_kernel();
 108                         voyager_status.request_from_kernel = 0;
 109                 }
 110         }
 111 }
 112
 113 static int __init voyager_thread_start(void)
 114 {
 115         voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
 116         if (IS_ERR(voyager_thread)) {
 117                 printk(KERN_ERR
 118                        "Voyager: Failed to create system monitor thread.\n");
 119                 return PTR_ERR(voyager_thread);
 120         }
 121         return 0;
 122 }
 123
 124 static void __exit voyager_thread_stop(void)
 125 {
 126         kthread_stop(voyager_thread);
 127 }
 128
 129 module_init(voyager_thread_start);
 130 module_exit(voyager_thread_stop);