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  * This module provides the machine status monitor thread for the
   8  * voyager architecture.  This allows us to monitor the machine
   9  * environment (temp, voltage, fan function) and the front panel and
  10  * internal UPS.  If a fault is detected, this thread takes corrective
  11  * action (usually just informing init)
  12  * */
  13
  14 #include <linux/module.h>
  15 #include <linux/mm.h>
  16 #include <linux/kernel_stat.h>
  17 #include <linux/delay.h>
  18 #include <linux/mc146818rtc.h>
  19 #include <linux/init.h>
  20 #include <linux/bootmem.h>
  21 #include <linux/kmod.h>
  22 #include <linux/completion.h>
  23 #include <linux/sched.h>
  24 #include <linux/kthread.h>
  25 #include <asm/desc.h>
  26 #include <asm/voyager.h>
  27 #include <asm/vic.h>
  28 #include <asm/mtrr.h>
  29 #include <asm/msr.h>
  30
  31 struct task_struct *voyager_thread;
  32 static __u8 set_timeout;
  33
  34 static int execute(const char *string)
  35 {
  36         int ret;
  37
  38         char *envp[] = {
  39                 "HOME=/",
  40                 "TERM=linux",
  41                 "PATH=/sbin:/usr/sbin:/bin:/usr/bin",
  42                 NULL,
  43         };
  44         char *argv[] = {
  45                 "/bin/bash",
  46                 "-c",
  47                 (char *)string,
  48                 NULL,
  49         };
  50
  51         if ((ret =
  52              call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC)) != 0) {
  53                 printk(KERN_ERR "Voyager failed to run \"%s\": %i\n", string,
  54                        ret);
  55         }
  56         return ret;
  57 }
  58
  59 static void check_from_kernel(void)
  60 {
  61         if (voyager_status.switch_off) {
  62
  63                 /* FIXME: This should be configurable via proc */
  64                 execute("umask 600; echo 0 > /etc/initrunlvl; kill -HUP 1");
  65         } else if (voyager_status.power_fail) {
  66                 VDEBUG(("Voyager daemon detected AC power failure\n"));
  67
  68                 /* FIXME: This should be configureable via proc */
  69                 execute("umask 600; echo F > /etc/powerstatus; kill -PWR 1");
  70                 set_timeout = 1;
  71         }
  72 }
  73
  74 static void check_continuing_condition(void)
  75 {
  76         if (voyager_status.power_fail) {
  77                 __u8 data;
  78                 voyager_cat_psi(VOYAGER_PSI_SUBREAD,
  79                                 VOYAGER_PSI_AC_FAIL_REG, &data);
  80                 if ((data & 0x1f) == 0) {
  81                         /* all power restored */
  82                         printk(KERN_NOTICE
  83                                "VOYAGER AC power restored, cancelling shutdown\n");
  84                         /* FIXME: should be user configureable */
  85                         execute
  86                             ("umask 600; echo O > /etc/powerstatus; kill -PWR 1");
  87                         set_timeout = 0;
  88                 }
  89         }
  90 }
  91
  92 static int thread(void *unused)
  93 {
  94         printk(KERN_NOTICE "Voyager starting monitor thread\n");
  95
  96         for (;;) {
  97                 set_current_state(TASK_INTERRUPTIBLE);
  98                 schedule_timeout(set_timeout ? HZ : MAX_SCHEDULE_TIMEOUT);
  99
 100                 VDEBUG(("Voyager Daemon awoken\n"));
 101                 if (voyager_status.request_from_kernel == 0) {
 102                         /* probably awoken from timeout */
 103                         check_continuing_condition();
 104                 } else {
 105                         check_from_kernel();
 106                         voyager_status.request_from_kernel = 0;
 107                 }
 108         }
 109 }
 110
 111 static int __init voyager_thread_start(void)
 112 {
 113         voyager_thread = kthread_run(thread, NULL, "kvoyagerd");
 114         if (IS_ERR(voyager_thread)) {
 115                 printk(KERN_ERR
 116                        "Voyager: Failed to create system monitor thread.\n");
 117                 return PTR_ERR(voyager_thread);
 118         }
 119         return 0;
 120 }
 121
 122 static void __exit voyager_thread_stop(void)
 123 {
 124         kthread_stop(voyager_thread);
 125 }
 126
 127 module_init(voyager_thread_start);
 128 module_exit(voyager_thread_stop);