[deliverable/linux.git] / arch / i386 / kernel / reboot.c

/*
 *  linux/arch/i386/kernel/reboot.c
 */

#include <linux/mm.h>
#include <linux/module.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <linux/efi.h>
#include <linux/dmi.h>
#include <linux/ctype.h>
#include <linux/pm.h>
#include <linux/reboot.h>
#include <asm/uaccess.h>
#include <asm/apic.h>
#include <asm/desc.h>
#include "mach_reboot.h"
#include <linux/reboot_fixups.h>

/*
 * Power off function, if any
 */
void (*pm_power_off)(void);
EXPORT_SYMBOL(pm_power_off);

static int reboot_mode;
static int reboot_thru_bios;

#ifdef CONFIG_SMP
static int reboot_cpu = -1;
#endif
static int __init reboot_setup(char *str)
{
	while(1) {
		switch (*str) {
		case 'w': /* "warm" reboot (no memory testing etc) */
			reboot_mode = 0x1234;
			break;
		case 'c': /* "cold" reboot (with memory testing etc) */
			reboot_mode = 0x0;
			break;
		case 'b': /* "bios" reboot by jumping through the BIOS */
			reboot_thru_bios = 1;
			break;
		case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */
			reboot_thru_bios = 0;
			break;
#ifdef CONFIG_SMP
		case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
			if (isdigit(*(str+1))) {
				reboot_cpu = (int) (*(str+1) - '0');
				if (isdigit(*(str+2)))
					reboot_cpu = reboot_cpu*10 + (int)(*(str+2) - '0');
			}
				/* we will leave sorting out the final value 
				when we are ready to reboot, since we might not
 				have set up boot_cpu_id or smp_num_cpu */
			break;
#endif
		}
		if((str = strchr(str,',')) != NULL)
			str++;
		else
			break;
	}
	return 1;
}

__setup("reboot=", reboot_setup);

/*
 * Reboot options and system auto-detection code provided by
 * Dell Inc. so their systems "just work". :-)
 */

/*
 * Some machines require the "reboot=b"  commandline option, this quirk makes that automatic.
 */
static int __init set_bios_reboot(struct dmi_system_id *d)
{
	if (!reboot_thru_bios) {
		reboot_thru_bios = 1;
		printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
	}
	return 0;
}

static struct dmi_system_id __initdata reboot_dmi_table[] = {
	{	/* Handle problems with rebooting on Dell 1300's */
		.callback = set_bios_reboot,
		.ident = "Dell PowerEdge 1300",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
		},
	},
	{	/* Handle problems with rebooting on Dell 300's */
		.callback = set_bios_reboot,
		.ident = "Dell PowerEdge 300",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
		},
	},
	{	/* Handle problems with rebooting on Dell 2400's */
		.callback = set_bios_reboot,
		.ident = "Dell PowerEdge 2400",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
			DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
		},
	},
	{	/* Handle problems with rebooting on HP laptops */
		.callback = set_bios_reboot,
		.ident = "HP Compaq Laptop",
		.matches = {
			DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
			DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
		},
	},
	{ }
};

static int __init reboot_init(void)
{
	dmi_check_system(reboot_dmi_table);
	return 0;
}

core_initcall(reboot_init);

/* The following code and data reboots the machine by switching to real
   mode and jumping to the BIOS reset entry point, as if the CPU has
   really been reset.  The previous version asked the keyboard
   controller to pulse the CPU reset line, which is more thorough, but
   doesn't work with at least one type of 486 motherboard.  It is easy
   to stop this code working; hence the copious comments. */

static unsigned long long
real_mode_gdt_entries [3] =
{
	0x0000000000000000ULL,	/* Null descriptor */
	0x00009a000000ffffULL,	/* 16-bit real-mode 64k code at 0x00000000 */
	0x000092000100ffffULL	/* 16-bit real-mode 64k data at 0x00000100 */
};

static struct Xgt_desc_struct
real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
real_mode_idt = { 0x3ff, 0 },
no_idt = { 0, 0 };


/* This is 16-bit protected mode code to disable paging and the cache,
   switch to real mode and jump to the BIOS reset code.

   The instruction that switches to real mode by writing to CR0 must be
   followed immediately by a far jump instruction, which set CS to a
   valid value for real mode, and flushes the prefetch queue to avoid
   running instructions that have already been decoded in protected
   mode.

   Clears all the flags except ET, especially PG (paging), PE
   (protected-mode enable) and TS (task switch for coprocessor state
   save).  Flushes the TLB after paging has been disabled.  Sets CD and
   NW, to disable the cache on a 486, and invalidates the cache.  This
   is more like the state of a 486 after reset.  I don't know if
   something else should be done for other chips.

   More could be done here to set up the registers as if a CPU reset had
   occurred; hopefully real BIOSs don't assume much. */

static unsigned char real_mode_switch [] =
{
	0x66, 0x0f, 0x20, 0xc0,			/*    movl  %cr0,%eax        */
	0x66, 0x83, 0xe0, 0x11,			/*    andl  $0x00000011,%eax */
	0x66, 0x0d, 0x00, 0x00, 0x00, 0x60,	/*    orl   $0x60000000,%eax */
	0x66, 0x0f, 0x22, 0xc0,			/*    movl  %eax,%cr0        */
	0x66, 0x0f, 0x22, 0xd8,			/*    movl  %eax,%cr3        */
	0x66, 0x0f, 0x20, 0xc3,			/*    movl  %cr0,%ebx        */
	0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60,	/*    andl  $0x60000000,%ebx */
	0x74, 0x02,				/*    jz    f                */
	0x0f, 0x09,				/*    wbinvd                 */
	0x24, 0x10,				/* f: andb  $0x10,al         */
	0x66, 0x0f, 0x22, 0xc0			/*    movl  %eax,%cr0        */
};
static unsigned char jump_to_bios [] =
{
	0xea, 0x00, 0x00, 0xff, 0xff		/*    ljmp  $0xffff,$0x0000  */
};

/*
 * Switch to real mode and then execute the code
 * specified by the code and length parameters.
 * We assume that length will aways be less that 100!
 */
void machine_real_restart(unsigned char *code, int length)
{
	unsigned long flags;

	local_irq_disable();

	/* Write zero to CMOS register number 0x0f, which the BIOS POST
	   routine will recognize as telling it to do a proper reboot.  (Well
	   that's what this book in front of me says -- it may only apply to
	   the Phoenix BIOS though, it's not clear).  At the same time,
	   disable NMIs by setting the top bit in the CMOS address register,
	   as we're about to do peculiar things to the CPU.  I'm not sure if
	   `outb_p' is needed instead of just `outb'.  Use it to be on the
	   safe side.  (Yes, CMOS_WRITE does outb_p's. -  Paul G.)
	 */

	spin_lock_irqsave(&rtc_lock, flags);
	CMOS_WRITE(0x00, 0x8f);
	spin_unlock_irqrestore(&rtc_lock, flags);

	/* Remap the kernel at virtual address zero, as well as offset zero
	   from the kernel segment.  This assumes the kernel segment starts at
	   virtual address PAGE_OFFSET. */

	memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
		sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);

	/*
	 * Use `swapper_pg_dir' as our page directory.
	 */
	load_cr3(swapper_pg_dir);

	/* Write 0x1234 to absolute memory location 0x472.  The BIOS reads
	   this on booting to tell it to "Bypass memory test (also warm
	   boot)".  This seems like a fairly standard thing that gets set by
	   REBOOT.COM programs, and the previous reset routine did this
	   too. */

	*((unsigned short *)0x472) = reboot_mode;

	/* For the switch to real mode, copy some code to low memory.  It has
	   to be in the first 64k because it is running in 16-bit mode, and it
	   has to have the same physical and virtual address, because it turns
	   off paging.  Copy it near the end of the first page, out of the way
	   of BIOS variables. */

	memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),
		real_mode_switch, sizeof (real_mode_switch));
	memcpy ((void *) (0x1000 - 100), code, length);

	/* Set up the IDT for real mode. */

	load_idt(&real_mode_idt);

	/* Set up a GDT from which we can load segment descriptors for real
	   mode.  The GDT is not used in real mode; it is just needed here to
	   prepare the descriptors. */

	load_gdt(&real_mode_gdt);

	/* Load the data segment registers, and thus the descriptors ready for
	   real mode.  The base address of each segment is 0x100, 16 times the
	   selector value being loaded here.  This is so that the segment
	   registers don't have to be reloaded after switching to real mode:
	   the values are consistent for real mode operation already. */

	__asm__ __volatile__ ("movl $0x0010,%%eax\n"
				"\tmovl %%eax,%%ds\n"
				"\tmovl %%eax,%%es\n"
				"\tmovl %%eax,%%fs\n"
				"\tmovl %%eax,%%gs\n"
				"\tmovl %%eax,%%ss" : : : "eax");

	/* Jump to the 16-bit code that we copied earlier.  It disables paging
	   and the cache, switches to real mode, and jumps to the BIOS reset
	   entry point. */

	__asm__ __volatile__ ("ljmp $0x0008,%0"
				:
				: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
}
#ifdef CONFIG_APM_MODULE
EXPORT_SYMBOL(machine_real_restart);
#endif

void machine_shutdown(void)
{
#ifdef CONFIG_SMP
	int reboot_cpu_id;

	/* The boot cpu is always logical cpu 0 */
	reboot_cpu_id = 0;

	/* See if there has been given a command line override */
	if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
		cpu_isset(reboot_cpu, cpu_online_map)) {
		reboot_cpu_id = reboot_cpu;
	}

	/* Make certain the cpu I'm rebooting on is online */
	if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
		reboot_cpu_id = smp_processor_id();
	}

	/* Make certain I only run on the appropriate processor */
	set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));

	/* O.K. Now that I'm on the appropriate processor, stop
	 * all of the others, and disable their local APICs.
	 */

	smp_send_stop();
#endif /* CONFIG_SMP */

	lapic_shutdown();

#ifdef CONFIG_X86_IO_APIC
	disable_IO_APIC();
#endif
}

void machine_emergency_restart(void)
{
	if (!reboot_thru_bios) {
		if (efi_enabled) {
			efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
			load_idt(&no_idt);
			__asm__ __volatile__("int3");
		}
		/* rebooting needs to touch the page at absolute addr 0 */
		*((unsigned short *)__va(0x472)) = reboot_mode;
		for (;;) {
			mach_reboot_fixups(); /* for board specific fixups */
			mach_reboot();
			/* That didn't work - force a triple fault.. */
			load_idt(&no_idt);
			__asm__ __volatile__("int3");
		}
	}
	if (efi_enabled)
		efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL);

	machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
}

void machine_restart(char * __unused)
{
	machine_shutdown();
	machine_emergency_restart();
}

void machine_halt(void)
{
}

void machine_power_off(void)
{
	if (pm_power_off) {
		machine_shutdown();
		pm_power_off();
	}
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/i386/kernel/reboot.c
	3	*/
	4
	5	#include <linux/mm.h>
	6	#include <linux/module.h>
	7	#include <linux/delay.h>
	8	#include <linux/init.h>
	9	#include <linux/interrupt.h>
	10	#include <linux/mc146818rtc.h>
	11	#include <linux/efi.h>
	12	#include <linux/dmi.h>
6f673d83	13	#include <linux/ctype.h>
6e3fbee5	14	#include <linux/pm.h>
cd6ed525	15	#include <linux/reboot.h>
1da177e4 LT	16	#include <asm/uaccess.h>
1da177e4 LT	17	#include <asm/apic.h>
4d37e7e3	18	#include <asm/desc.h>
1da177e4	19	#include "mach_reboot.h"
a2f7c354	20	#include <linux/reboot_fixups.h>
1da177e4 LT	21
	22	/*
	23	* Power off function, if any
	24	*/
	25	void (*pm_power_off)(void);
129f6946	26	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	27
	28	static int reboot_mode;
	29	static int reboot_thru_bios;
	30
	31	#ifdef CONFIG_SMP
1da177e4	32	static int reboot_cpu = -1;
1da177e4 LT	33	#endif
	34	static int __init reboot_setup(char *str)
	35	{
	36	while(1) {
	37	switch (*str) {
	38	case 'w': /* "warm" reboot (no memory testing etc) */
	39	reboot_mode = 0x1234;
	40	break;
	41	case 'c': /* "cold" reboot (with memory testing etc) */
	42	reboot_mode = 0x0;
	43	break;
	44	case 'b': /* "bios" reboot by jumping through the BIOS */
	45	reboot_thru_bios = 1;
	46	break;
	47	case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */
	48	reboot_thru_bios = 0;
	49	break;
	50	#ifdef CONFIG_SMP
	51	case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
6f673d83	52	if (isdigit(*(str+1))) {
1da177e4	53	reboot_cpu = (int) (*(str+1) - '0');
6f673d83	54	if (isdigit(*(str+2)))
1da177e4 LT	55	reboot_cpu = reboot_cpu10 + (int)((str+2) - '0');
	56	}
	57	/* we will leave sorting out the final value
	58	when we are ready to reboot, since we might not
	59	have set up boot_cpu_id or smp_num_cpu */
	60	break;
	61	#endif
	62	}
	63	if((str = strchr(str,',')) != NULL)
	64	str++;
	65	else
	66	break;
	67	}
	68	return 1;
	69	}
	70
	71	__setup("reboot=", reboot_setup);
	72
	73	/*
	74	* Reboot options and system auto-detection code provided by
	75	* Dell Inc. so their systems "just work". :-)
	76	*/
	77
	78	/*
	79	* Some machines require the "reboot=b" commandline option, this quirk makes that automatic.
	80	*/
	81	static int __init set_bios_reboot(struct dmi_system_id *d)
	82	{
	83	if (!reboot_thru_bios) {
	84	reboot_thru_bios = 1;
	85	printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
	86	}
	87	return 0;
	88	}
	89
1da177e4 LT	90	static struct dmi_system_id __initdata reboot_dmi_table[] = {
1da177e4 LT	91	{ /* Handle problems with rebooting on Dell 1300's */
dd2a1305	92	.callback = set_bios_reboot,
1da177e4 LT	93	.ident = "Dell PowerEdge 1300",
	94	.matches = {
	95	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	96	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
	97	},
	98	},
	99	{ /* Handle problems with rebooting on Dell 300's */
	100	.callback = set_bios_reboot,
	101	.ident = "Dell PowerEdge 300",
	102	.matches = {
	103	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	104	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
	105	},
	106	},
	107	{ /* Handle problems with rebooting on Dell 2400's */
	108	.callback = set_bios_reboot,
	109	.ident = "Dell PowerEdge 2400",
	110	.matches = {
	111	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	112	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
	113	},
	114	},
766c3f94	115	{ /* Handle problems with rebooting on HP laptops */
d91b14c4	116	.callback = set_bios_reboot,
766c3f94	117	.ident = "HP Compaq Laptop",
d91b14c4 TV	118	.matches = {
d91b14c4 TV	119	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
766c3f94	120	DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
d91b14c4 TV	121	},
d91b14c4 TV	122	},
1da177e4 LT	123	{ }
	124	};
	125
	126	static int __init reboot_init(void)
	127	{
	128	dmi_check_system(reboot_dmi_table);
	129	return 0;
	130	}
	131
	132	core_initcall(reboot_init);
	133
	134	/* The following code and data reboots the machine by switching to real
	135	mode and jumping to the BIOS reset entry point, as if the CPU has
	136	really been reset. The previous version asked the keyboard
	137	controller to pulse the CPU reset line, which is more thorough, but
	138	doesn't work with at least one type of 486 motherboard. It is easy
	139	to stop this code working; hence the copious comments. */
	140
	141	static unsigned long long
	142	real_mode_gdt_entries [3] =
	143	{
	144	0x0000000000000000ULL, /* Null descriptor */
	145	0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
	146	0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
	147	};
	148
05f4a3ec RR	149	static struct Xgt_desc_struct
	150	real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
	151	real_mode_idt = { 0x3ff, 0 },
	152	no_idt = { 0, 0 };
1da177e4 LT	153
	154
	155	/* This is 16-bit protected mode code to disable paging and the cache,
	156	switch to real mode and jump to the BIOS reset code.
	157
	158	The instruction that switches to real mode by writing to CR0 must be
	159	followed immediately by a far jump instruction, which set CS to a
	160	valid value for real mode, and flushes the prefetch queue to avoid
	161	running instructions that have already been decoded in protected
	162	mode.
	163
	164	Clears all the flags except ET, especially PG (paging), PE
	165	(protected-mode enable) and TS (task switch for coprocessor state
	166	save). Flushes the TLB after paging has been disabled. Sets CD and
	167	NW, to disable the cache on a 486, and invalidates the cache. This
	168	is more like the state of a 486 after reset. I don't know if
	169	something else should be done for other chips.
	170
	171	More could be done here to set up the registers as if a CPU reset had
	172	occurred; hopefully real BIOSs don't assume much. */
	173
	174	static unsigned char real_mode_switch [] =
	175	{
	176	0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
	177	0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
	178	0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
	179	0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
	180	0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
	181	0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
	182	0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
	183	0x74, 0x02, /* jz f */
	184	0x0f, 0x09, /* wbinvd */
	185	0x24, 0x10, /* f: andb $0x10,al */
	186	0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
	187	};
	188	static unsigned char jump_to_bios [] =
	189	{
	190	0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
	191	};
	192
	193	/*
	194	* Switch to real mode and then execute the code
	195	* specified by the code and length parameters.
	196	* We assume that length will aways be less that 100!
	197	*/
	198	void machine_real_restart(unsigned char *code, int length)
	199	{
	200	unsigned long flags;
	201
	202	local_irq_disable();
	203
	204	/* Write zero to CMOS register number 0x0f, which the BIOS POST
	205	routine will recognize as telling it to do a proper reboot. (Well
	206	that's what this book in front of me says -- it may only apply to
	207	the Phoenix BIOS though, it's not clear). At the same time,
	208	disable NMIs by setting the top bit in the CMOS address register,
	209	as we're about to do peculiar things to the CPU. I'm not sure if
	210	`outb_p' is needed instead of just `outb'. Use it to be on the
	211	safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
	212	*/
	213
	214	spin_lock_irqsave(&rtc_lock, flags);
	215	CMOS_WRITE(0x00, 0x8f);
	216	spin_unlock_irqrestore(&rtc_lock, flags);
217
218	/* Remap the kernel at virtual address zero, as well as offset zero
219	from the kernel segment. This assumes the kernel segment starts at
220	virtual address PAGE_OFFSET. */
221
222	memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
223	sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
224
225	/*
226	* Use `swapper_pg_dir' as our page directory.
227	*/
228	load_cr3(swapper_pg_dir);
229
230	/* Write 0x1234 to absolute memory location 0x472. The BIOS reads
231	this on booting to tell it to "Bypass memory test (also warm
232	boot)". This seems like a fairly standard thing that gets set by
233	REBOOT.COM programs, and the previous reset routine did this
234	too. */
235
236	((unsigned short )0x472) = reboot_mode;
237
238	/* For the switch to real mode, copy some code to low memory. It has
239	to be in the first 64k because it is running in 16-bit mode, and it
240	has to have the same physical and virtual address, because it turns
241	off paging. Copy it near the end of the first page, out of the way
242	of BIOS variables. */
243
244	memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),
245	real_mode_switch, sizeof (real_mode_switch));
246	memcpy ((void *) (0x1000 - 100), code, length);
247
248	/* Set up the IDT for real mode. */
249
4d37e7e3	250	load_idt(&real_mode_idt);
1da177e4 LT	251
	252	/* Set up a GDT from which we can load segment descriptors for real
	253	mode. The GDT is not used in real mode; it is just needed here to
	254	prepare the descriptors. */
	255
4d37e7e3	256	load_gdt(&real_mode_gdt);
1da177e4 LT	257
	258	/* Load the data segment registers, and thus the descriptors ready for
	259	real mode. The base address of each segment is 0x100, 16 times the
	260	selector value being loaded here. This is so that the segment
	261	registers don't have to be reloaded after switching to real mode:
	262	the values are consistent for real mode operation already. */
	263
	264	__asm__ __volatile__ ("movl $0x0010,%%eax\n"
	265	"\tmovl %%eax,%%ds\n"
	266	"\tmovl %%eax,%%es\n"
	267	"\tmovl %%eax,%%fs\n"
	268	"\tmovl %%eax,%%gs\n"
	269	"\tmovl %%eax,%%ss" : : : "eax");
	270
	271	/* Jump to the 16-bit code that we copied earlier. It disables paging
	272	and the cache, switches to real mode, and jumps to the BIOS reset
	273	entry point. */
	274
	275	__asm__ __volatile__ ("ljmp $0x0008,%0"
	276	:
	277	: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
	278	}
129f6946 AD	279	#ifdef CONFIG_APM_MODULE
	280	EXPORT_SYMBOL(machine_real_restart);
	281	#endif
1da177e4	282
dd2a1305	283	void machine_shutdown(void)
1da177e4 LT	284	{
1da177e4 LT	285	#ifdef CONFIG_SMP
dd2a1305 EB	286	int reboot_cpu_id;
	287
	288	/* The boot cpu is always logical cpu 0 */
	289	reboot_cpu_id = 0;
	290
	291	/* See if there has been given a command line override */
d8e392e7	292	if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
dd2a1305 EB	293	cpu_isset(reboot_cpu, cpu_online_map)) {
dd2a1305 EB	294	reboot_cpu_id = reboot_cpu;
1da177e4 LT	295	}
1da177e4 LT	296
dd2a1305 EB	297	/* Make certain the cpu I'm rebooting on is online */
	298	if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
	299	reboot_cpu_id = smp_processor_id();
1da177e4	300	}
dd2a1305 EB	301
	302	/* Make certain I only run on the appropriate processor */
	303	set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
	304
	305	/* O.K. Now that I'm on the appropriate processor, stop
	306	* all of the others, and disable their local APICs.
1da177e4	307	*/
dd2a1305	308
1da177e4 LT	309	smp_send_stop();
	310	#endif /* CONFIG_SMP */
	311
	312	lapic_shutdown();
	313
	314	#ifdef CONFIG_X86_IO_APIC
	315	disable_IO_APIC();
	316	#endif
dd2a1305 EB	317	}
dd2a1305 EB	318
4a1421f8	319	void machine_emergency_restart(void)
dd2a1305	320	{
1da177e4 LT	321	if (!reboot_thru_bios) {
	322	if (efi_enabled) {
	323	efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
4d37e7e3	324	load_idt(&no_idt);
1da177e4 LT	325	__asm__ __volatile__("int3");
	326	}
	327	/* rebooting needs to touch the page at absolute addr 0 */
	328	((unsigned short )__va(0x472)) = reboot_mode;
	329	for (;;) {
a2f7c354	330	mach_reboot_fixups(); /* for board specific fixups */
1da177e4 LT	331	mach_reboot();
1da177e4 LT	332	/* That didn't work - force a triple fault.. */
4d37e7e3	333	load_idt(&no_idt);
1da177e4 LT	334	__asm__ __volatile__("int3");
	335	}
	336	}
	337	if (efi_enabled)
	338	efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL);
	339
	340	machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
	341	}
	342
4a1421f8 EB	343	void machine_restart(char * __unused)
	344	{
	345	machine_shutdown();
	346	machine_emergency_restart();
	347	}
	348
1da177e4 LT	349	void machine_halt(void)
	350	{
	351	}
	352
1da177e4 LT	353	void machine_power_off(void)
1da177e4 LT	354	{
6e3fbee5 EB	355	if (pm_power_off) {
6e3fbee5 EB	356	machine_shutdown();
1da177e4	357	pm_power_off();
6e3fbee5	358	}
1da177e4 LT	359	}
1da177e4 LT	360
1da177e4	361