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