[mirror_ubuntu-artful-kernel.git] / arch / i386 / kernel / reboot.c

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

#include <linux/config.h>
#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 <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
{
	unsigned short       size __attribute__ ((packed));
	unsigned long long * base __attribute__ ((packed));
}
real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, real_mode_gdt_entries },
real_mode_idt = { 0x3ff, NULL },
no_idt = { 0, NULL };


/* 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)
{
	machine_shutdown();

	if (pm_power_off)
		pm_power_off();
}
Commit	Line	Data
1da177e4 LT	1	/*
	2	* linux/arch/i386/kernel/reboot.c
	3	*/
	4
129f6946	5	#include <linux/config.h>
1da177e4 LT	6	#include <linux/mm.h>
	7	#include <linux/module.h>
	8	#include <linux/delay.h>
	9	#include <linux/init.h>
	10	#include <linux/interrupt.h>
	11	#include <linux/mc146818rtc.h>
	12	#include <linux/efi.h>
	13	#include <linux/dmi.h>
6f673d83	14	#include <linux/ctype.h>
1da177e4 LT	15	#include <asm/uaccess.h>
1da177e4 LT	16	#include <asm/apic.h>
4d37e7e3	17	#include <asm/desc.h>
1da177e4	18	#include "mach_reboot.h"
a2f7c354	19	#include <linux/reboot_fixups.h>
1da177e4 LT	20
	21	/*
	22	* Power off function, if any
	23	*/
	24	void (*pm_power_off)(void);
129f6946	25	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	26
	27	static int reboot_mode;
	28	static int reboot_thru_bios;
	29
	30	#ifdef CONFIG_SMP
1da177e4	31	static int reboot_cpu = -1;
1da177e4 LT	32	#endif
	33	static int __init reboot_setup(char *str)
	34	{
	35	while(1) {
	36	switch (*str) {
	37	case 'w': /* "warm" reboot (no memory testing etc) */
	38	reboot_mode = 0x1234;
	39	break;
	40	case 'c': /* "cold" reboot (with memory testing etc) */
	41	reboot_mode = 0x0;
	42	break;
	43	case 'b': /* "bios" reboot by jumping through the BIOS */
	44	reboot_thru_bios = 1;
	45	break;
	46	case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */
	47	reboot_thru_bios = 0;
	48	break;
	49	#ifdef CONFIG_SMP
	50	case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
6f673d83	51	if (isdigit(*(str+1))) {
1da177e4	52	reboot_cpu = (int) (*(str+1) - '0');
6f673d83	53	if (isdigit(*(str+2)))
1da177e4 LT	54	reboot_cpu = reboot_cpu10 + (int)((str+2) - '0');
	55	}
	56	/* we will leave sorting out the final value
	57	when we are ready to reboot, since we might not
	58	have set up boot_cpu_id or smp_num_cpu */
	59	break;
	60	#endif
	61	}
	62	if((str = strchr(str,',')) != NULL)
	63	str++;
	64	else
	65	break;
	66	}
	67	return 1;
	68	}
	69
	70	__setup("reboot=", reboot_setup);
	71
	72	/*
	73	* Reboot options and system auto-detection code provided by
	74	* Dell Inc. so their systems "just work". :-)
	75	*/
	76
	77	/*
	78	* Some machines require the "reboot=b" commandline option, this quirk makes that automatic.
	79	*/
	80	static int __init set_bios_reboot(struct dmi_system_id *d)
	81	{
	82	if (!reboot_thru_bios) {
	83	reboot_thru_bios = 1;
	84	printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
	85	}
	86	return 0;
	87	}
	88
1da177e4 LT	89	static struct dmi_system_id __initdata reboot_dmi_table[] = {
1da177e4 LT	90	{ /* Handle problems with rebooting on Dell 1300's */
dd2a1305	91	.callback = set_bios_reboot,
1da177e4 LT	92	.ident = "Dell PowerEdge 1300",
	93	.matches = {
	94	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	95	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
	96	},
	97	},
	98	{ /* Handle problems with rebooting on Dell 300's */
	99	.callback = set_bios_reboot,
	100	.ident = "Dell PowerEdge 300",
	101	.matches = {
	102	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	103	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
	104	},
	105	},
	106	{ /* Handle problems with rebooting on Dell 2400's */
	107	.callback = set_bios_reboot,
	108	.ident = "Dell PowerEdge 2400",
	109	.matches = {
	110	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	111	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
	112	},
	113	},
766c3f94	114	{ /* Handle problems with rebooting on HP laptops */
d91b14c4	115	.callback = set_bios_reboot,
766c3f94	116	.ident = "HP Compaq Laptop",
d91b14c4 TV	117	.matches = {
d91b14c4 TV	118	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
766c3f94	119	DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
d91b14c4 TV	120	},
d91b14c4 TV	121	},
1da177e4 LT	122	{ }
	123	};
	124
	125	static int __init reboot_init(void)
	126	{
	127	dmi_check_system(reboot_dmi_table);
	128	return 0;
	129	}
	130
	131	core_initcall(reboot_init);
	132
	133	/* The following code and data reboots the machine by switching to real
	134	mode and jumping to the BIOS reset entry point, as if the CPU has
	135	really been reset. The previous version asked the keyboard
	136	controller to pulse the CPU reset line, which is more thorough, but
	137	doesn't work with at least one type of 486 motherboard. It is easy
	138	to stop this code working; hence the copious comments. */
	139
	140	static unsigned long long
	141	real_mode_gdt_entries [3] =
	142	{
	143	0x0000000000000000ULL, /* Null descriptor */
	144	0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
	145	0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
	146	};
	147
	148	static struct
	149	{
	150	unsigned short size __attribute__ ((packed));
	151	unsigned long long * base __attribute__ ((packed));
	152	}
	153	real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, real_mode_gdt_entries },
	154	real_mode_idt = { 0x3ff, NULL },
	155	no_idt = { 0, NULL };
	156
	157
	158	/* This is 16-bit protected mode code to disable paging and the cache,
	159	switch to real mode and jump to the BIOS reset code.
	160
	161	The instruction that switches to real mode by writing to CR0 must be
	162	followed immediately by a far jump instruction, which set CS to a
	163	valid value for real mode, and flushes the prefetch queue to avoid
	164	running instructions that have already been decoded in protected
	165	mode.
	166
	167	Clears all the flags except ET, especially PG (paging), PE
	168	(protected-mode enable) and TS (task switch for coprocessor state
	169	save). Flushes the TLB after paging has been disabled. Sets CD and
	170	NW, to disable the cache on a 486, and invalidates the cache. This
	171	is more like the state of a 486 after reset. I don't know if
	172	something else should be done for other chips.
	173
	174	More could be done here to set up the registers as if a CPU reset had
	175	occurred; hopefully real BIOSs don't assume much. */
	176
	177	static unsigned char real_mode_switch [] =
	178	{
	179	0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
	180	0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
	181	0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
	182	0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
	183	0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
	184	0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
	185	0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
186	0x74, 0x02, /* jz f */
187	0x0f, 0x09, /* wbinvd */
188	0x24, 0x10, /* f: andb $0x10,al */
189	0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
190	};
191	static unsigned char jump_to_bios [] =
192	{
193	0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
194	};
195
196	/*
197	* Switch to real mode and then execute the code
198	* specified by the code and length parameters.
199	* We assume that length will aways be less that 100!
200	*/
201	void machine_real_restart(unsigned char *code, int length)
202	{
203	unsigned long flags;
204
205	local_irq_disable();
206
207	/* Write zero to CMOS register number 0x0f, which the BIOS POST
208	routine will recognize as telling it to do a proper reboot. (Well
209	that's what this book in front of me says -- it may only apply to
210	the Phoenix BIOS though, it's not clear). At the same time,
211	disable NMIs by setting the top bit in the CMOS address register,
212	as we're about to do peculiar things to the CPU. I'm not sure if
213	`outb_p' is needed instead of just `outb'. Use it to be on the
214	safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
215	*/
216
217	spin_lock_irqsave(&rtc_lock, flags);
218	CMOS_WRITE(0x00, 0x8f);
219	spin_unlock_irqrestore(&rtc_lock, flags);
220
221	/* Remap the kernel at virtual address zero, as well as offset zero
222	from the kernel segment. This assumes the kernel segment starts at
223	virtual address PAGE_OFFSET. */
224
225	memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
226	sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
227
228	/*
229	* Use `swapper_pg_dir' as our page directory.
230	*/
231	load_cr3(swapper_pg_dir);
232
233	/* Write 0x1234 to absolute memory location 0x472. The BIOS reads
234	this on booting to tell it to "Bypass memory test (also warm
235	boot)". This seems like a fairly standard thing that gets set by
236	REBOOT.COM programs, and the previous reset routine did this
237	too. */
238
239	((unsigned short )0x472) = reboot_mode;
240
241	/* For the switch to real mode, copy some code to low memory. It has
242	to be in the first 64k because it is running in 16-bit mode, and it
243	has to have the same physical and virtual address, because it turns
244	off paging. Copy it near the end of the first page, out of the way
245	of BIOS variables. */
246
247	memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),
248	real_mode_switch, sizeof (real_mode_switch));
249	memcpy ((void *) (0x1000 - 100), code, length);
250
251	/* Set up the IDT for real mode. */
252
4d37e7e3	253	load_idt(&real_mode_idt);
1da177e4 LT	254
	255	/* Set up a GDT from which we can load segment descriptors for real
	256	mode. The GDT is not used in real mode; it is just needed here to
	257	prepare the descriptors. */
	258
4d37e7e3	259	load_gdt(&real_mode_gdt);
1da177e4 LT	260
	261	/* Load the data segment registers, and thus the descriptors ready for
	262	real mode. The base address of each segment is 0x100, 16 times the
	263	selector value being loaded here. This is so that the segment
	264	registers don't have to be reloaded after switching to real mode:
	265	the values are consistent for real mode operation already. */
	266
	267	__asm__ __volatile__ ("movl $0x0010,%%eax\n"
	268	"\tmovl %%eax,%%ds\n"
	269	"\tmovl %%eax,%%es\n"
	270	"\tmovl %%eax,%%fs\n"
	271	"\tmovl %%eax,%%gs\n"
	272	"\tmovl %%eax,%%ss" : : : "eax");
	273
	274	/* Jump to the 16-bit code that we copied earlier. It disables paging
	275	and the cache, switches to real mode, and jumps to the BIOS reset
	276	entry point. */
	277
	278	__asm__ __volatile__ ("ljmp $0x0008,%0"
	279	:
	280	: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
	281	}
129f6946 AD	282	#ifdef CONFIG_APM_MODULE
	283	EXPORT_SYMBOL(machine_real_restart);
	284	#endif
1da177e4	285
dd2a1305	286	void machine_shutdown(void)
1da177e4 LT	287	{
1da177e4 LT	288	#ifdef CONFIG_SMP
dd2a1305 EB	289	int reboot_cpu_id;
	290
	291	/* The boot cpu is always logical cpu 0 */
	292	reboot_cpu_id = 0;
	293
	294	/* See if there has been given a command line override */
d8e392e7	295	if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
dd2a1305 EB	296	cpu_isset(reboot_cpu, cpu_online_map)) {
dd2a1305 EB	297	reboot_cpu_id = reboot_cpu;
1da177e4 LT	298	}
1da177e4 LT	299
dd2a1305 EB	300	/* Make certain the cpu I'm rebooting on is online */
	301	if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
	302	reboot_cpu_id = smp_processor_id();
1da177e4	303	}
dd2a1305 EB	304
	305	/* Make certain I only run on the appropriate processor */
	306	set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
	307
	308	/* O.K. Now that I'm on the appropriate processor, stop
	309	* all of the others, and disable their local APICs.
1da177e4	310	*/
dd2a1305	311
1da177e4 LT	312	smp_send_stop();
	313	#endif /* CONFIG_SMP */
	314
	315	lapic_shutdown();
	316
	317	#ifdef CONFIG_X86_IO_APIC
	318	disable_IO_APIC();
	319	#endif
dd2a1305 EB	320	}
dd2a1305 EB	321
4a1421f8	322	void machine_emergency_restart(void)
dd2a1305	323	{
1da177e4 LT	324	if (!reboot_thru_bios) {
	325	if (efi_enabled) {
	326	efi.reset_system(EFI_RESET_COLD, EFI_SUCCESS, 0, NULL);
4d37e7e3	327	load_idt(&no_idt);
1da177e4 LT	328	__asm__ __volatile__("int3");
	329	}
	330	/* rebooting needs to touch the page at absolute addr 0 */
	331	((unsigned short )__va(0x472)) = reboot_mode;
	332	for (;;) {
a2f7c354	333	mach_reboot_fixups(); /* for board specific fixups */
1da177e4 LT	334	mach_reboot();
1da177e4 LT	335	/* That didn't work - force a triple fault.. */
4d37e7e3	336	load_idt(&no_idt);
1da177e4 LT	337	__asm__ __volatile__("int3");
	338	}
	339	}
	340	if (efi_enabled)
	341	efi.reset_system(EFI_RESET_WARM, EFI_SUCCESS, 0, NULL);
	342
	343	machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
	344	}
	345
4a1421f8 EB	346	void machine_restart(char * __unused)
	347	{
	348	machine_shutdown();
	349	machine_emergency_restart();
	350	}
	351
1da177e4 LT	352	void machine_halt(void)
	353	{
	354	}
	355
1da177e4 LT	356	void machine_power_off(void)
1da177e4 LT	357	{
4fa2564a	358	machine_shutdown();
1da177e4	359
1da177e4 LT	360	if (pm_power_off)
	361	pm_power_off();
	362	}
	363
1da177e4	364