| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 <asm/io.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> | 
 | 16 | #include <asm/apic.h> | 
 | 17 |  | 
 | 18 | /* | 
 | 19 |  * Power off function, if any | 
 | 20 |  */ | 
 | 21 | void (*pm_power_off)(void); | 
 | 22 |  | 
 | 23 | static long no_idt[3]; | 
 | 24 | static enum {  | 
 | 25 | 	BOOT_TRIPLE = 't', | 
 | 26 | 	BOOT_KBD = 'k' | 
 | 27 | } reboot_type = BOOT_KBD; | 
 | 28 | static int reboot_mode = 0; | 
 | 29 | int reboot_force; | 
 | 30 |  | 
 | 31 | /* reboot=t[riple] | k[bd] [, [w]arm | [c]old] | 
 | 32 |    warm   Don't set the cold reboot flag | 
 | 33 |    cold   Set the cold reboot flag | 
 | 34 |    triple Force a triple fault (init) | 
 | 35 |    kbd    Use the keyboard controller. cold reset (default) | 
 | 36 |    force  Avoid anything that could hang. | 
 | 37 |  */  | 
 | 38 | static int __init reboot_setup(char *str) | 
 | 39 | { | 
 | 40 | 	for (;;) { | 
 | 41 | 		switch (*str) { | 
 | 42 | 		case 'w':  | 
 | 43 | 			reboot_mode = 0x1234; | 
 | 44 | 			break; | 
 | 45 |  | 
 | 46 | 		case 'c': | 
 | 47 | 			reboot_mode = 0; | 
 | 48 | 			break; | 
 | 49 |  | 
 | 50 | 		case 't': | 
 | 51 | 		case 'b': | 
 | 52 | 		case 'k': | 
 | 53 | 			reboot_type = *str; | 
 | 54 | 			break; | 
 | 55 | 		case 'f': | 
 | 56 | 			reboot_force = 1; | 
 | 57 | 			break; | 
 | 58 | 		} | 
 | 59 | 		if((str = strchr(str,',')) != NULL) | 
 | 60 | 			str++; | 
 | 61 | 		else | 
 | 62 | 			break; | 
 | 63 | 	} | 
 | 64 | 	return 1; | 
 | 65 | } | 
 | 66 |  | 
 | 67 | __setup("reboot=", reboot_setup); | 
 | 68 |  | 
 | 69 | #ifdef CONFIG_SMP | 
 | 70 | static void smp_halt(void) | 
 | 71 | { | 
 | 72 | 	int cpuid = safe_smp_processor_id();  | 
 | 73 | 	static int first_entry = 1; | 
 | 74 |  | 
 | 75 | 	if (reboot_force) | 
 | 76 | 		return; | 
 | 77 |  | 
 | 78 | 	if (first_entry) { | 
 | 79 | 		first_entry = 0; | 
 | 80 | 		smp_call_function((void *)machine_restart, NULL, 1, 0); | 
 | 81 | 	} | 
 | 82 | 			 | 
 | 83 | 	smp_stop_cpu();  | 
 | 84 |  | 
 | 85 | 	/* AP calling this. Just halt */ | 
 | 86 | 	if (cpuid != boot_cpu_id) {  | 
 | 87 | 		for (;;)  | 
 | 88 | 			asm("hlt"); | 
 | 89 | 	} | 
 | 90 |  | 
 | 91 | 	/* Wait for all other CPUs to have run smp_stop_cpu */ | 
 | 92 | 	while (!cpus_empty(cpu_online_map)) | 
 | 93 | 		rep_nop();  | 
 | 94 | } | 
 | 95 | #endif | 
 | 96 |  | 
 | 97 | static inline void kb_wait(void) | 
 | 98 | { | 
 | 99 | 	int i; | 
 | 100 |  | 
 | 101 | 	for (i=0; i<0x10000; i++) | 
 | 102 | 		if ((inb_p(0x64) & 0x02) == 0) | 
 | 103 | 			break; | 
 | 104 | } | 
 | 105 |  | 
 | 106 | void machine_restart(char * __unused) | 
 | 107 | { | 
 | 108 | 	int i; | 
 | 109 |  | 
 | 110 | 	printk("machine restart\n"); | 
 | 111 |  | 
 | 112 | #ifdef CONFIG_SMP | 
 | 113 | 	smp_halt();  | 
 | 114 | #endif | 
 | 115 |  | 
 | 116 | 	if (!reboot_force) { | 
 | 117 | 		local_irq_disable(); | 
 | 118 | #ifndef CONFIG_SMP | 
 | 119 | 		disable_local_APIC(); | 
 | 120 | #endif | 
 | 121 | 		disable_IO_APIC(); | 
 | 122 | 		local_irq_enable(); | 
 | 123 | 	} | 
 | 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<100; i++) { | 
 | 133 | 			kb_wait(); | 
 | 134 | 			udelay(50); | 
 | 135 | 			outb(0xfe,0x64);         /* pulse reset low */ | 
 | 136 | 			udelay(50); | 
 | 137 | 		} | 
 | 138 |  | 
 | 139 | 		case BOOT_TRIPLE:  | 
 | 140 | 			__asm__ __volatile__("lidt (%0)": :"r" (&no_idt)); | 
 | 141 | 			__asm__ __volatile__("int3"); | 
 | 142 |  | 
 | 143 | 			reboot_type = BOOT_KBD; | 
 | 144 | 			break; | 
 | 145 | 		}       | 
 | 146 | 	}       | 
 | 147 | } | 
 | 148 |  | 
 | 149 | EXPORT_SYMBOL(machine_restart); | 
 | 150 |  | 
 | 151 | void machine_halt(void) | 
 | 152 | { | 
 | 153 | } | 
 | 154 |  | 
 | 155 | EXPORT_SYMBOL(machine_halt); | 
 | 156 |  | 
 | 157 | void machine_power_off(void) | 
 | 158 | { | 
 | 159 | 	if (pm_power_off) | 
 | 160 | 		pm_power_off(); | 
 | 161 | } | 
 | 162 |  | 
 | 163 | EXPORT_SYMBOL(machine_power_off); |