1 /* Various gunk just to reboot the machine. */
2 #include <linux/module.h>
3 #include <linux/reboot.h>
4 #include <linux/init.h>
6 #include <linux/kernel.h>
7 #include <linux/ctype.h>
8 #include <linux/string.h>
10 #include <asm/kdebug.h>
11 #include <asm/delay.h>
12 #include <asm/hw_irq.h>
13 #include <asm/system.h>
14 #include <asm/pgtable.h>
15 #include <asm/tlbflush.h>
19 * Power off function, if any
21 void (*pm_power_off)(void);
23 static long no_idt[3];
28 } reboot_type = BOOT_KBD;
29 static int reboot_mode = 0;
31 /* reboot=b[ios] | t[riple] | k[bd] [, [w]arm | [c]old]
32 bios Use the CPU reboot vector for warm reset
33 warm Don't set the cold reboot flag
34 cold Set the cold reboot flag
35 triple Force a triple fault (init)
36 kbd Use the keyboard controller. cold reset (default)
38 static int __init reboot_setup(char *str)
56 if((str = strchr(str,',')) != NULL)
64 __setup("reboot=", reboot_setup);
66 /* overwrites random kernel memory. Should not be kernel .text */
67 #define WARMBOOT_TRAMP 0x1000UL
69 static void reboot_warm(void)
71 extern unsigned char warm_reboot[], warm_reboot_end[];
72 printk("warm reboot\n");
76 /* restore identity mapping */
77 init_level4_pgt[0] = __pml4(__pa(level3_ident_pgt) | 7);
80 /* Move the trampoline to low memory */
81 memcpy(__va(WARMBOOT_TRAMP), warm_reboot, warm_reboot_end - warm_reboot);
83 /* Start it in compatibility mode. */
84 asm volatile( " pushq $0\n" /* ss */
85 " pushq $0x2000\n" /* rsp */
86 " pushfq\n" /* eflags */
90 [cs] "i" (__KERNEL_COMPAT32_CS),
91 [target] "b" (WARMBOOT_TRAMP));
94 static inline void kb_wait(void)
98 for (i=0; i<0x10000; i++)
99 if ((inb_p(0x64) & 0x02) == 0)
103 void machine_shutdown(void)
105 /* Stop the cpus and apics */
109 /* The boot cpu is always logical cpu 0 */
112 /* Make certain the cpu I'm about to reboot on is online */
113 if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
114 reboot_cpu_id = smp_processor_id();
117 /* Make certain I only run on the appropriate processor */
118 set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
120 /* O.K Now that I'm on the appropriate processor,
121 * stop all of the others.
129 disable_local_APIC();
137 void machine_restart(char * __unused)
146 disable_local_APIC();
153 /* Tell the BIOS if we want cold or warm reboot */
154 *((unsigned short *)__va(0x472)) = reboot_mode;
157 /* Could also try the reset bit in the Hammer NB */
158 switch (reboot_type) {
163 for (i=0; i<100; i++) {
166 outb(0xfe,0x64); /* pulse reset low */
171 __asm__ __volatile__("lidt (%0)": :"r" (&no_idt));
172 __asm__ __volatile__("int3");
174 reboot_type = BOOT_KBD;
180 EXPORT_SYMBOL(machine_restart);
182 void machine_halt(void)
186 EXPORT_SYMBOL(machine_halt);
188 void machine_power_off(void)
194 EXPORT_SYMBOL(machine_power_off);