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 <acpi/reboot.h>
  13 #include <asm/io.h>
  14 #include <asm/delay.h>
  15 #include <asm/desc.h>
  16 #include <asm/hw_irq.h>
  17 #include <asm/system.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/tlbflush.h>
  20 #include <asm/apic.h>
  21 #include <asm/hpet.h>
  22 #include <asm/gart.h>
  23
  24 /*
  25  * Power off function, if any
  26  */
  27 void (*pm_power_off)(void);
  28 EXPORT_SYMBOL(pm_power_off);
  29
  30 static long no_idt[3];
  31 static enum {
  32         BOOT_TRIPLE = 't',
  33         BOOT_KBD = 'k',
  34         BOOT_ACPI = 'a'
  35 } reboot_type = BOOT_KBD;
  36 static int reboot_mode = 0;
  37 int reboot_force;
  38
  39 /* reboot=t[riple] | k[bd] [, [w]arm | [c]old]
  40    warm   Don't set the cold reboot flag
  41    cold   Set the cold reboot flag
  42    triple Force a triple fault (init)
  43    kbd    Use the keyboard controller. cold reset (default)
  44    acpi   Use the RESET_REG in the FADT
  45    force  Avoid anything that could hang.
  46  */
  47 static int __init reboot_setup(char *str)
  48 {
  49         for (;;) {
  50                 switch (*str) {
  51                 case 'w':
  52                         reboot_mode = 0x1234;
  53                         break;
  54
  55                 case 'c':
  56                         reboot_mode = 0;
  57                         break;
  58
  59                 case 't':
  60                 case 'a':
  61                 case 'b':
  62                 case 'k':
  63                         reboot_type = *str;
  64                         break;
  65                 case 'f':
  66                         reboot_force = 1;
  67                         break;
  68                 }
  69                 if((str = strchr(str,',')) != NULL)
  70                         str++;
  71                 else
  72                         break;
  73         }
  74         return 1;
  75 }
  76
  77 __setup("reboot=", reboot_setup);
  78
  79 static inline void kb_wait(void)
  80 {
  81         int i;
  82
  83         for (i=0; i<0x10000; i++)
  84                 if ((inb_p(0x64) & 0x02) == 0)
  85                         break;
  86 }
  87
  88 void machine_shutdown(void)
  89 {
  90         unsigned long flags;
  91
  92         /* Stop the cpus and apics */
  93 #ifdef CONFIG_SMP
  94         int reboot_cpu_id;
  95
  96         /* The boot cpu is always logical cpu 0 */
  97         reboot_cpu_id = 0;
  98
  99         /* Make certain the cpu I'm about to reboot on is online */
 100         if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
 101                 reboot_cpu_id = smp_processor_id();
 102         }
 103
 104         /* Make certain I only run on the appropriate processor */
 105         set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
 106
 107         /* O.K Now that I'm on the appropriate processor,
 108          * stop all of the others.
 109          */
 110         smp_send_stop();
 111 #endif
 112
 113         local_irq_save(flags);
 114
 115 #ifndef CONFIG_SMP
 116         disable_local_APIC();
 117 #endif
 118
 119         disable_IO_APIC();
 120
 121 #ifdef CONFIG_HPET_TIMER
 122         hpet_disable();
 123 #endif
 124         local_irq_restore(flags);
 125
 126         pci_iommu_shutdown();
 127 }
 128
 129 void machine_emergency_restart(void)
 130 {
 131         int i;
 132
 133         /* Tell the BIOS if we want cold or warm reboot */
 134         *((unsigned short *)__va(0x472)) = reboot_mode;
 135
 136         for (;;) {
 137                 /* Could also try the reset bit in the Hammer NB */
 138                 switch (reboot_type) {
 139                 case BOOT_KBD:
 140                 for (i=0; i<10; i++) {
 141                         kb_wait();
 142                         udelay(50);
 143                         outb(0xfe,0x64);         /* pulse reset low */
 144                         udelay(50);
 145                 }
 146
 147                 case BOOT_TRIPLE:
 148                         load_idt((const struct desc_ptr *)&no_idt);
 149                         __asm__ __volatile__("int3");
 150
 151                         reboot_type = BOOT_KBD;
 152                         break;
 153
 154                 case BOOT_ACPI:
 155                         acpi_reboot();
 156                         reboot_type = BOOT_KBD;
 157                         break;
 158                 }
 159         }
 160 }
 161
 162 void machine_restart(char * __unused)
 163 {
 164         printk("machine restart\n");
 165
 166         if (!reboot_force) {
 167                 machine_shutdown();
 168         }
 169         machine_emergency_restart();
 170 }
 171
 172 void machine_halt(void)
 173 {
 174 }
 175
 176 void machine_power_off(void)
 177 {
 178         if (pm_power_off) {
 179                 if (!reboot_force) {
 180                         machine_shutdown();
 181                 }
 182                 pm_power_off();
 183         }
 184 }
 185