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 <linux/efi.h>
  13 #include <acpi/reboot.h>
  14 #include <asm/io.h>
  15 #include <asm/delay.h>
  16 #include <asm/desc.h>
  17 #include <asm/hw_irq.h>
  18 #include <asm/system.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/tlbflush.h>
  21 #include <asm/apic.h>
  22 #include <asm/hpet.h>
  23 #include <asm/gart.h>
  24
  25 /*
  26  * Power off function, if any
  27  */
  28 void (*pm_power_off)(void);
  29 EXPORT_SYMBOL(pm_power_off);
  30
  31 static long no_idt[3];
  32 enum reboot_type reboot_type = BOOT_KBD;
  33 static int reboot_mode = 0;
  34 int reboot_force;
  35
  36 /* reboot=t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
  37    warm   Don't set the cold reboot flag
  38    cold   Set the cold reboot flag
  39    triple Force a triple fault (init)
  40    kbd    Use the keyboard controller. cold reset (default)
  41    acpi   Use the RESET_REG in the FADT
  42    efi    Use efi reset_system runtime service
  43    force  Avoid anything that could hang.
  44  */
  45 static int __init reboot_setup(char *str)
  46 {
  47         for (;;) {
  48                 switch (*str) {
  49                 case 'w':
  50                         reboot_mode = 0x1234;
  51                         break;
  52
  53                 case 'c':
  54                         reboot_mode = 0;
  55                         break;
  56
  57                 case 't':
  58                 case 'a':
  59                 case 'b':
  60                 case 'k':
  61                 case 'e':
  62                         reboot_type = *str;
  63                         break;
  64                 case 'f':
  65                         reboot_force = 1;
  66                         break;
  67                 }
  68                 if((str = strchr(str,',')) != NULL)
  69                         str++;
  70                 else
  71                         break;
  72         }
  73         return 1;
  74 }
  75
  76 __setup("reboot=", reboot_setup);
  77
  78 static inline void kb_wait(void)
  79 {
  80         int i;
  81
  82         for (i=0; i<0x10000; i++)
  83                 if ((inb_p(0x64) & 0x02) == 0)
  84                         break;
  85 }
  86
  87 void machine_shutdown(void)
  88 {
  89         unsigned long flags;
  90
  91         /* Stop the cpus and apics */
  92 #ifdef CONFIG_SMP
  93         int reboot_cpu_id;
  94
  95         /* The boot cpu is always logical cpu 0 */
  96         reboot_cpu_id = 0;
  97
  98         /* Make certain the cpu I'm about to reboot on is online */
  99         if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
 100                 reboot_cpu_id = smp_processor_id();
 101         }
 102
 103         /* Make certain I only run on the appropriate processor */
 104         set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
 105
 106         /* O.K Now that I'm on the appropriate processor,
 107          * stop all of the others.
 108          */
 109         smp_send_stop();
 110 #endif
 111
 112         local_irq_save(flags);
 113
 114 #ifndef CONFIG_SMP
 115         disable_local_APIC();
 116 #endif
 117
 118         disable_IO_APIC();
 119
 120 #ifdef CONFIG_HPET_TIMER
 121         hpet_disable();
 122 #endif
 123         local_irq_restore(flags);
 124
 125         pci_iommu_shutdown();
 126 }
 127
 128 void machine_emergency_restart(void)
 129 {
 130         int i;
 131
 132         /* Tell the BIOS if we want cold or warm reboot */
 133         *((unsigned short *)__va(0x472)) = reboot_mode;
 134
 135         for (;;) {
 136                 /* Could also try the reset bit in the Hammer NB */
 137                 switch (reboot_type) {
 138                 case BOOT_KBD:
 139                 for (i=0; i<10; i++) {
 140                         kb_wait();
 141                         udelay(50);
 142                         outb(0xfe,0x64);         /* pulse reset low */
 143                         udelay(50);
 144                 }
 145
 146                 case BOOT_TRIPLE:
 147                         load_idt((const struct desc_ptr *)&no_idt);
 148                         __asm__ __volatile__("int3");
 149
 150                         reboot_type = BOOT_KBD;
 151                         break;
 152
 153                 case BOOT_ACPI:
 154                         acpi_reboot();
 155                         reboot_type = BOOT_KBD;
 156                         break;
 157
 158                 case BOOT_EFI:
 159                         if (efi_enabled)
 160                                 efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
 161                                                  EFI_SUCCESS, 0, NULL);
 162                         reboot_type = BOOT_KBD;
 163                         break;
 164                 }
 165         }
 166 }
 167
 168 void machine_restart(char * __unused)
 169 {
 170         printk("machine restart\n");
 171
 172         if (!reboot_force) {
 173                 machine_shutdown();
 174         }
 175         machine_emergency_restart();
 176 }
 177
 178 void machine_halt(void)
 179 {
 180 }
 181
 182 void machine_power_off(void)
 183 {
 184         if (pm_power_off) {
 185                 if (!reboot_force) {
 186                         machine_shutdown();
 187                 }
 188                 pm_power_off();
 189         }
 190 }
 191