[mirror_ubuntu-jammy-kernel.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 <asm/reboot_fixups.h>
#include <asm/reboot.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)
{
	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(&rtc_lock);
	CMOS_WRITE(0x00, 0x8f);
	spin_unlock(&rtc_lock);

	/* 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

static void native_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 __attribute__((weak)) mach_reboot_fixups(void)
{
}

static void native_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));
}

static void native_machine_restart(char * __unused)
{
	machine_shutdown();
	machine_emergency_restart();
}

static void native_machine_halt(void)
{
}

static void native_machine_power_off(void)
{
	if (pm_power_off) {
		machine_shutdown();
		pm_power_off();
	}
}


struct machine_ops machine_ops = {
	.power_off = native_machine_power_off,
	.shutdown = native_machine_shutdown,
	.emergency_restart = native_machine_emergency_restart,
	.restart = native_machine_restart,
	.halt = native_machine_halt,
};

void machine_power_off(void)
{
	machine_ops.power_off();
}

void machine_shutdown(void)
{
	machine_ops.shutdown();
}

void machine_emergency_restart(void)
{
	machine_ops.emergency_restart();
}

void machine_restart(char *cmd)
{
	machine_ops.restart(cmd);
}

void machine_halt(void)
{
	machine_ops.halt();
}
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"
973efae2	20	#include <asm/reboot_fixups.h>
07f3331c	21	#include <asm/reboot.h>
1da177e4 LT	22
	23	/*
	24	* Power off function, if any
	25	*/
	26	void (*pm_power_off)(void);
129f6946	27	EXPORT_SYMBOL(pm_power_off);
1da177e4 LT	28
	29	static int reboot_mode;
	30	static int reboot_thru_bios;
	31
	32	#ifdef CONFIG_SMP
1da177e4	33	static int reboot_cpu = -1;
1da177e4 LT	34	#endif
	35	static int __init reboot_setup(char *str)
	36	{
	37	while(1) {
	38	switch (*str) {
	39	case 'w': /* "warm" reboot (no memory testing etc) */
	40	reboot_mode = 0x1234;
	41	break;
	42	case 'c': /* "cold" reboot (with memory testing etc) */
	43	reboot_mode = 0x0;
	44	break;
	45	case 'b': /* "bios" reboot by jumping through the BIOS */
	46	reboot_thru_bios = 1;
	47	break;
	48	case 'h': /* "hard" reboot by toggling RESET and/or crashing the CPU */
	49	reboot_thru_bios = 0;
	50	break;
	51	#ifdef CONFIG_SMP
	52	case 's': /* "smp" reboot by executing reset on BSP or other CPU*/
6f673d83	53	if (isdigit(*(str+1))) {
1da177e4	54	reboot_cpu = (int) (*(str+1) - '0');
6f673d83	55	if (isdigit(*(str+2)))
1da177e4 LT	56	reboot_cpu = reboot_cpu10 + (int)((str+2) - '0');
	57	}
	58	/* we will leave sorting out the final value
	59	when we are ready to reboot, since we might not
	60	have set up boot_cpu_id or smp_num_cpu */
	61	break;
	62	#endif
	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	/*
	75	* Reboot options and system auto-detection code provided by
	76	* Dell Inc. so their systems "just work". :-)
	77	*/
	78
	79	/*
	80	* Some machines require the "reboot=b" commandline option, this quirk makes that automatic.
	81	*/
	82	static int __init set_bios_reboot(struct dmi_system_id *d)
	83	{
	84	if (!reboot_thru_bios) {
	85	reboot_thru_bios = 1;
	86	printk(KERN_INFO "%s series board detected. Selecting BIOS-method for reboots.\n", d->ident);
	87	}
	88	return 0;
	89	}
	90
1da177e4 LT	91	static struct dmi_system_id __initdata reboot_dmi_table[] = {
1da177e4 LT	92	{ /* Handle problems with rebooting on Dell 1300's */
dd2a1305	93	.callback = set_bios_reboot,
1da177e4 LT	94	.ident = "Dell PowerEdge 1300",
	95	.matches = {
	96	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	97	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 1300/"),
	98	},
	99	},
	100	{ /* Handle problems with rebooting on Dell 300's */
	101	.callback = set_bios_reboot,
	102	.ident = "Dell PowerEdge 300",
	103	.matches = {
	104	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	105	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 300/"),
	106	},
	107	},
	108	{ /* Handle problems with rebooting on Dell 2400's */
	109	.callback = set_bios_reboot,
	110	.ident = "Dell PowerEdge 2400",
	111	.matches = {
	112	DMI_MATCH(DMI_SYS_VENDOR, "Dell Computer Corporation"),
	113	DMI_MATCH(DMI_PRODUCT_NAME, "PowerEdge 2400"),
	114	},
	115	},
766c3f94	116	{ /* Handle problems with rebooting on HP laptops */
d91b14c4	117	.callback = set_bios_reboot,
766c3f94	118	.ident = "HP Compaq Laptop",
d91b14c4 TV	119	.matches = {
d91b14c4 TV	120	DMI_MATCH(DMI_SYS_VENDOR, "Hewlett-Packard"),
766c3f94	121	DMI_MATCH(DMI_PRODUCT_NAME, "HP Compaq"),
d91b14c4 TV	122	},
d91b14c4 TV	123	},
1da177e4 LT	124	{ }
	125	};
	126
	127	static int __init reboot_init(void)
	128	{
	129	dmi_check_system(reboot_dmi_table);
	130	return 0;
	131	}
	132
	133	core_initcall(reboot_init);
	134
	135	/* The following code and data reboots the machine by switching to real
	136	mode and jumping to the BIOS reset entry point, as if the CPU has
	137	really been reset. The previous version asked the keyboard
	138	controller to pulse the CPU reset line, which is more thorough, but
	139	doesn't work with at least one type of 486 motherboard. It is easy
	140	to stop this code working; hence the copious comments. */
	141
	142	static unsigned long long
	143	real_mode_gdt_entries [3] =
	144	{
	145	0x0000000000000000ULL, /* Null descriptor */
	146	0x00009a000000ffffULL, /* 16-bit real-mode 64k code at 0x00000000 */
	147	0x000092000100ffffULL /* 16-bit real-mode 64k data at 0x00000100 */
	148	};
	149
05f4a3ec RR	150	static struct Xgt_desc_struct
	151	real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
	152	real_mode_idt = { 0x3ff, 0 },
	153	no_idt = { 0, 0 };
1da177e4 LT	154
	155
	156	/* This is 16-bit protected mode code to disable paging and the cache,
	157	switch to real mode and jump to the BIOS reset code.
	158
	159	The instruction that switches to real mode by writing to CR0 must be
	160	followed immediately by a far jump instruction, which set CS to a
	161	valid value for real mode, and flushes the prefetch queue to avoid
	162	running instructions that have already been decoded in protected
	163	mode.
	164
	165	Clears all the flags except ET, especially PG (paging), PE
	166	(protected-mode enable) and TS (task switch for coprocessor state
	167	save). Flushes the TLB after paging has been disabled. Sets CD and
	168	NW, to disable the cache on a 486, and invalidates the cache. This
	169	is more like the state of a 486 after reset. I don't know if
	170	something else should be done for other chips.
	171
	172	More could be done here to set up the registers as if a CPU reset had
	173	occurred; hopefully real BIOSs don't assume much. */
	174
	175	static unsigned char real_mode_switch [] =
	176	{
	177	0x66, 0x0f, 0x20, 0xc0, /* movl %cr0,%eax */
	178	0x66, 0x83, 0xe0, 0x11, /* andl $0x00000011,%eax */
	179	0x66, 0x0d, 0x00, 0x00, 0x00, 0x60, /* orl $0x60000000,%eax */
	180	0x66, 0x0f, 0x22, 0xc0, /* movl %eax,%cr0 */
	181	0x66, 0x0f, 0x22, 0xd8, /* movl %eax,%cr3 */
	182	0x66, 0x0f, 0x20, 0xc3, /* movl %cr0,%ebx */
	183	0x66, 0x81, 0xe3, 0x00, 0x00, 0x00, 0x60, /* andl $0x60000000,%ebx */
	184	0x74, 0x02, /* jz f */
	185	0x0f, 0x09, /* wbinvd */
	186	0x24, 0x10, /* f: andb $0x10,al */
	187	0x66, 0x0f, 0x22, 0xc0 /* movl %eax,%cr0 */
	188	};
	189	static unsigned char jump_to_bios [] =
	190	{
	191	0xea, 0x00, 0x00, 0xff, 0xff /* ljmp $0xffff,$0x0000 */
	192	};
	193
	194	/*
	195	* Switch to real mode and then execute the code
	196	* specified by the code and length parameters.
	197	* We assume that length will aways be less that 100!
	198	*/
	199	void machine_real_restart(unsigned char *code, int length)
	200	{
1da177e4 LT	201	local_irq_disable();
	202
	203	/* Write zero to CMOS register number 0x0f, which the BIOS POST
	204	routine will recognize as telling it to do a proper reboot. (Well
	205	that's what this book in front of me says -- it may only apply to
	206	the Phoenix BIOS though, it's not clear). At the same time,
	207	disable NMIs by setting the top bit in the CMOS address register,
	208	as we're about to do peculiar things to the CPU. I'm not sure if
	209	`outb_p' is needed instead of just `outb'. Use it to be on the
	210	safe side. (Yes, CMOS_WRITE does outb_p's. - Paul G.)
	211	*/
	212
62dbc210	213	spin_lock(&rtc_lock);
1da177e4	214	CMOS_WRITE(0x00, 0x8f);
62dbc210	215	spin_unlock(&rtc_lock);
1da177e4 LT	216
	217	/* Remap the kernel at virtual address zero, as well as offset zero
	218	from the kernel segment. This assumes the kernel segment starts at
	219	virtual address PAGE_OFFSET. */
	220
	221	memcpy (swapper_pg_dir, swapper_pg_dir + USER_PGD_PTRS,
	222	sizeof (swapper_pg_dir [0]) * KERNEL_PGD_PTRS);
	223
	224	/*
	225	* Use `swapper_pg_dir' as our page directory.
	226	*/
	227	load_cr3(swapper_pg_dir);
	228
	229	/* Write 0x1234 to absolute memory location 0x472. The BIOS reads
	230	this on booting to tell it to "Bypass memory test (also warm
	231	boot)". This seems like a fairly standard thing that gets set by
	232	REBOOT.COM programs, and the previous reset routine did this
	233	too. */
	234
	235	((unsigned short )0x472) = reboot_mode;
	236
	237	/* For the switch to real mode, copy some code to low memory. It has
	238	to be in the first 64k because it is running in 16-bit mode, and it
	239	has to have the same physical and virtual address, because it turns
	240	off paging. Copy it near the end of the first page, out of the way
	241	of BIOS variables. */
	242
	243	memcpy ((void *) (0x1000 - sizeof (real_mode_switch) - 100),
	244	real_mode_switch, sizeof (real_mode_switch));
	245	memcpy ((void *) (0x1000 - 100), code, length);
	246
	247	/* Set up the IDT for real mode. */
	248
4d37e7e3	249	load_idt(&real_mode_idt);
1da177e4 LT	250
	251	/* Set up a GDT from which we can load segment descriptors for real
	252	mode. The GDT is not used in real mode; it is just needed here to
	253	prepare the descriptors. */
	254
4d37e7e3	255	load_gdt(&real_mode_gdt);
1da177e4 LT	256
	257	/* Load the data segment registers, and thus the descriptors ready for
	258	real mode. The base address of each segment is 0x100, 16 times the
	259	selector value being loaded here. This is so that the segment
	260	registers don't have to be reloaded after switching to real mode:
	261	the values are consistent for real mode operation already. */
	262
	263	__asm__ __volatile__ ("movl $0x0010,%%eax\n"
	264	"\tmovl %%eax,%%ds\n"
	265	"\tmovl %%eax,%%es\n"
	266	"\tmovl %%eax,%%fs\n"
	267	"\tmovl %%eax,%%gs\n"
	268	"\tmovl %%eax,%%ss" : : : "eax");
	269
	270	/* Jump to the 16-bit code that we copied earlier. It disables paging
	271	and the cache, switches to real mode, and jumps to the BIOS reset
	272	entry point. */
	273
	274	__asm__ __volatile__ ("ljmp $0x0008,%0"
	275	:
	276	: "i" ((void *) (0x1000 - sizeof (real_mode_switch) - 100)));
	277	}
129f6946 AD	278	#ifdef CONFIG_APM_MODULE
	279	EXPORT_SYMBOL(machine_real_restart);
	280	#endif
1da177e4	281
07f3331c	282	static void native_machine_shutdown(void)
1da177e4 LT	283	{
1da177e4 LT	284	#ifdef CONFIG_SMP
dd2a1305 EB	285	int reboot_cpu_id;
	286
	287	/* The boot cpu is always logical cpu 0 */
	288	reboot_cpu_id = 0;
	289
	290	/* See if there has been given a command line override */
d8e392e7	291	if ((reboot_cpu != -1) && (reboot_cpu < NR_CPUS) &&
dd2a1305 EB	292	cpu_isset(reboot_cpu, cpu_online_map)) {
dd2a1305 EB	293	reboot_cpu_id = reboot_cpu;
1da177e4 LT	294	}
1da177e4 LT	295
dd2a1305 EB	296	/* Make certain the cpu I'm rebooting on is online */
	297	if (!cpu_isset(reboot_cpu_id, cpu_online_map)) {
	298	reboot_cpu_id = smp_processor_id();
1da177e4	299	}
dd2a1305 EB	300
	301	/* Make certain I only run on the appropriate processor */
	302	set_cpus_allowed(current, cpumask_of_cpu(reboot_cpu_id));
	303
	304	/* O.K. Now that I'm on the appropriate processor, stop
	305	* all of the others, and disable their local APICs.
1da177e4	306	*/
dd2a1305	307
1da177e4 LT	308	smp_send_stop();
	309	#endif /* CONFIG_SMP */
	310
	311	lapic_shutdown();
	312
	313	#ifdef CONFIG_X86_IO_APIC
	314	disable_IO_APIC();
	315	#endif
dd2a1305 EB	316	}
dd2a1305 EB	317
973efae2 JF	318	void __attribute__((weak)) mach_reboot_fixups(void)
	319	{
	320	}
	321
07f3331c	322	static void native_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
07f3331c	346	static void native_machine_restart(char * __unused)
4a1421f8 EB	347	{
	348	machine_shutdown();
	349	machine_emergency_restart();
	350	}
	351
07f3331c	352	static void native_machine_halt(void)
1da177e4 LT	353	{
	354	}
	355
07f3331c	356	static void native_machine_power_off(void)
1da177e4	357	{
6e3fbee5 EB	358	if (pm_power_off) {
6e3fbee5 EB	359	machine_shutdown();
1da177e4	360	pm_power_off();
6e3fbee5	361	}
1da177e4 LT	362	}
1da177e4 LT	363
1da177e4	364
07f3331c JF	365	struct machine_ops machine_ops = {
	366	.power_off = native_machine_power_off,
	367	.shutdown = native_machine_shutdown,
	368	.emergency_restart = native_machine_emergency_restart,
	369	.restart = native_machine_restart,
	370	.halt = native_machine_halt,
	371	};
	372
	373	void machine_power_off(void)
	374	{
	375	machine_ops.power_off();
	376	}
	377
	378	void machine_shutdown(void)
	379	{
	380	machine_ops.shutdown();
	381	}
	382
	383	void machine_emergency_restart(void)
	384	{
	385	machine_ops.emergency_restart();
	386	}
	387
	388	void machine_restart(char *cmd)
	389	{
	390	machine_ops.restart(cmd);
	391	}
	392
	393	void machine_halt(void)
	394	{
	395	machine_ops.halt();
	396	}