arch/x86/kernel/reboot_64.c

   1 /* Various gunk just to reboot the machine. */
   2 #include <linux/module.h>
   3 #include <linux/reboot.h>
   4 #include <linux/init.h>
   5 #include <linux/smp.h>
   6 #include <linux/kernel.h>
   7 #include <linux/ctype.h>
   8 #include <linux/string.h>
   9 #include <linux/pm.h>
  10 #include <linux/kdebug.h>
  11 #include <linux/sched.h>
  12 #include <asm/io.h>
  13 #include <asm/delay.h>
  14 #include <asm/hw_irq.h>
  15 #include <asm/system.h>
  16 #include <asm/pgtable.h>
  17 #include <asm/tlbflush.h>
  18 #include <asm/apic.h>
  19 #include <asm/iommu.h>
  20
  21 /*
  22  * Power off function, if any
  23  */
  24 void (*pm_power_off)(void);
  25 EXPORT_SYMBOL(pm_power_off);
  26
  27 static long no_idt[3];
  28 static enum {
  29         BOOT_TRIPLE = 't',
  30         BOOT_KBD = 'k'
  31 } reboot_type = BOOT_KBD;
  32 static int reboot_mode = 0;
  33 int reboot_force;
  34
  35 /* reboot=t[riple] | k[bd] [, [w]arm | [c]old]
  36    warm   Don't set the cold reboot flag
  37    cold   Set the cold reboot flag
  38    triple Force a triple fault (init)
  39    kbd    Use the keyboard controller. cold reset (default)
  40    force  Avoid anything that could hang.
  41  */
  42 static int __init reboot_setup(char *str)
  43 {
  44         for (;;) {
  45                 switch (*str) {
  46                 case 'w':
  47                         reboot_mode = 0x1234;
  48                         break;
  49
  50                 case 'c':
  51                         reboot_mode = 0;
  52                         break;
  53
  54                 case 't':
  55                 case 'b':
  56                 case 'k':
  57                         reboot_type = *str;
  58                         break;
  59                 case 'f':
  60                         reboot_force = 1;
  61                         break;
  62                 }
  63                 if((str = strchr(str,',')) != NULL)
  64                         str++;
  65                 else
  66                         break;
  67         }
  68         return 1;
  69 }
  70
  71 __setup("reboot=", reboot_setup);
  72
  73 static inline void kb_wait(void)
  74 {
  75         int i;
  76
  77         for (i=0; i<0x10000; i++)
  78                 if ((inb_p(0x64) & 0x02) == 0)
  79                         break;
  80 }
  81
  82 void machine_shutdown(void)
  83 {
  84         unsigned long flags;
  85
  86         /* Stop the cpus and apics */
  87 #ifdef CONFIG_SMP
  88         int reboot_cpu_id;
  89
  90         /* The boot cpu is always logical cpu 0 */
  91         reboot_cpu_id = 0;
  92
  93         /* Make certain the cpu I'm about to reboot on is online */
  94         if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
  95                 reboot_cpu_id = smp_processor_id();
  96         }
  97
  98         /* Make certain I only run on the appropriate processor */
  99         set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
 100
 101         /* O.K Now that I'm on the appropriate processor,
 102          * stop all of the others.
 103          */
 104         smp_send_stop();
 105 #endif
 106
 107         local_irq_save(flags);
 108
 109 #ifndef CONFIG_SMP
 110         disable_local_APIC();
 111 #endif
 112
 113         disable_IO_APIC();
 114
 115         local_irq_restore(flags);
 116
 117         pci_iommu_shutdown();
 118 }
 119
 120 void machine_emergency_restart(void)
 121 {
 122         int i;
 123
 124         /* Tell the BIOS if we want cold or warm reboot */
 125         *((unsigned short *)__va(0x472)) = reboot_mode;
 126
 127         for (;;) {
 128                 /* Could also try the reset bit in the Hammer NB */
 129                 switch (reboot_type) {
 130                 case BOOT_KBD:
 131                 for (i=0; i<10; i++) {
 132                         kb_wait();
 133                         udelay(50);
 134                         outb(0xfe,0x64);         /* pulse reset low */
 135                         udelay(50);
 136                 }
 137
 138                 case BOOT_TRIPLE:
 139                         __asm__ __volatile__("lidt (%0)": :"r" (&no_idt));
 140                         __asm__ __volatile__("int3");
 141
 142                         reboot_type = BOOT_KBD;
 143                         break;
 144                 }
 145         }
 146 }
 147
 148 void machine_restart(char * __unused)
 149 {
 150         printk("machine restart\n");
 151
 152         if (!reboot_force) {
 153                 machine_shutdown();
 154         }
 155         machine_emergency_restart();
 156 }
 157
 158 void machine_halt(void)
 159 {
 160 }
 161
 162 void machine_power_off(void)
 163 {
 164         if (pm_power_off) {
 165                 if (!reboot_force) {
 166                         machine_shutdown();
 167                 }
 168                 pm_power_off();
 169         }
 170 }
 171