[PATCH] x86: reboot_{32|64}.c unification

["Miguel Botón" <mboton.lkml@gmail.com>]

reboot_{32|64}.c unification patch.

This patch unifies the code from the reboot_32.c and reboot_64.c files.

It has been tested in computers with X86_32 and X86_64 kernels and it
looks like all reboot modes work fine (EFI restart system hasn't been
tested yet).

Probably I made some mistakes (like I usually do) so I hope
we can identify and fix them soon.

Signed-off-by: Miguel Botón <mboton@gmail.com>

diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index 0903bbf..0cd4085 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -30,8 +30,8 @@ obj-y				+= step.o
 obj-$(CONFIG_STACKTRACE)	+= stacktrace.o
 obj-y				+= cpu/
 obj-y				+= acpi/
-obj-$(CONFIG_X86_BIOS_REBOOT)	+= reboot_32.o
-obj-$(CONFIG_X86_64)            += reboot_64.o
+obj-$(CONFIG_X86_BIOS_REBOOT)	+= reboot.o
+obj-$(CONFIG_X86_64)		+= reboot.o
 obj-$(CONFIG_MCA)		+= mca_32.o
 obj-$(CONFIG_X86_MSR)		+= msr.o
 obj-$(CONFIG_X86_CPUID)		+= cpuid.o
diff --git a/arch/x86/kernel/reboot.c b/arch/x86/kernel/reboot.c
new file mode 100644
index 0000000..bf9b106
--- /dev/null
+++ b/arch/x86/kernel/reboot.c
@@ -0,0 +1,441 @@
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/reboot.h>
+#include <linux/init.h>
+#include <linux/pm.h>
+#include <linux/efi.h>
+#include <acpi/reboot.h>
+#include <asm/io.h>
+#include <asm/apic.h>
+#include <asm/desc.h>
+#include <asm/hpet.h>
+#include <asm/reboot_fixups.h>
+#include <asm/reboot.h>
+
+#ifdef CONFIG_X86_32
+# include <linux/dmi.h>
+# include <linux/ctype.h>
+# include <linux/mc146818rtc.h>
+# include <asm/pgtable.h>
+#else
+# include <asm/iommu.h>
+#endif
+
+/*
+ * Power off function, if any
+ */
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+static long no_idt[3];
+static int reboot_mode;
+enum reboot_type reboot_type = BOOT_KBD;
+int reboot_force;
+
+#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)
+static int reboot_cpu = -1;
+#endif
+
+/* reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
+   warm   Don't set the cold reboot flag
+   cold   Set the cold reboot flag
+   bios   Reboot by jumping through the BIOS (only for X86_32)
+   smp    Reboot by executing reset on BSP or other CPU (only for X86_32)
+   triple Force a triple fault (init)
+   kbd    Use the keyboard controller. cold reset (default)
+   acpi   Use the RESET_REG in the FADT
+   efi    Use efi reset_system runtime service
+   force  Avoid anything that could hang.
+ */
+static int __init reboot_setup(char *str)
+{
+	for (;;) {
+		switch (*str) {
+		case 'w':
+			reboot_mode = 0x1234;
+			break;
+
+		case 'c':
+			reboot_mode = 0;
+			break;
+
+#ifdef CONFIG_X86_32
+#ifdef CONFIG_SMP
+		case 's':
+			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 /* CONFIG_SMP */
+
+		case 'b':
+#endif
+		case 'a':
+		case 'k':
+		case 't':
+		case 'e':
+			reboot_type = *str;
+			break;
+
+		case 'f':
+			reboot_force = 1;
+			break;
+		}
+
+		str = strchr(str, ',');
+		if (str)
+			str++;
+		else
+			break;
+	}
+	return 1;
+}
+
+__setup("reboot=", reboot_setup);
+
+
+#ifdef CONFIG_X86_32
+/*
+ * 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(const struct dmi_system_id *d)
+{
+	if (reboot_type != BOOT_BIOS) {
+		reboot_type = BOOT_BIOS;
+		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 E520's */
+		.callback = set_bios_reboot,
+		.ident = "Dell E520",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
+		},
+	},
+	{	/* 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 Optiplex 745's SFF*/
+		.callback = set_bios_reboot,
+		.ident = "Dell OptiPlex 745",
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
+			DMI_MATCH(DMI_BOARD_NAME, "0WF810"),
+		},
+	},
+	{	/* 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 desc_ptr
+real_mode_gdt = { sizeof (real_mode_gdt_entries) - 1, (long)real_mode_gdt_entries },
+real_mode_idt = { 0x3ff, 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
+
+#endif /* CONFIG_X86_32 */
+
+static inline void kb_wait(void)
+{
+	int i;
+
+	for (i = 0; i < 0x10000; i++)
+		if ((inb_p(0x64) & 0x02) == 0)
+			break;
+}
+
+void machine_emergency_restart(void)
+{
+	int i;
+
+	/* Tell the BIOS if we want cold or warm reboot */
+	*((unsigned short *)__va(0x472)) = reboot_mode;
+
+	for (;;) {
+		/* Could also try the reset bit in the Hammer NB */
+		switch (reboot_type) {
+		case BOOT_KBD:
+			for (i = 0; i < 10; i++) {
+				kb_wait();
+				udelay(50);
+				outb(0xfe, 0x64); /* pulse reset low */
+				udelay(50);
+			}
+
+		case BOOT_TRIPLE:
+			load_idt((const struct desc_ptr *)&no_idt);
+			__asm__ __volatile__("int3");
+
+			reboot_type = BOOT_KBD;
+			break;
+
+#ifdef CONFIG_X86_32
+		case BOOT_BIOS:
+			machine_real_restart(jump_to_bios, sizeof(jump_to_bios));
+
+			reboot_type = BOOT_KBD;
+			break;
+#endif
+
+		case BOOT_ACPI:
+			acpi_reboot();
+			reboot_type = BOOT_KBD;
+			break;
+
+
+		case BOOT_EFI:
+			if (efi_enabled)
+				efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
+						 EFI_SUCCESS, 0, NULL);
+
+			reboot_type = BOOT_KBD;
+			break;
+		}
+	}
+}
+
+void machine_shutdown(void)
+{
+	/* Stop the cpus and apics */
+#ifdef CONFIG_SMP
+	int reboot_cpu_id;
+
+	/* The boot cpu is always logical cpu 0 */
+	reboot_cpu_id = 0;
+
+#ifdef CONFIG_X86_32
+	/* 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;
+#endif
+
+	/* Make certain the cpu I'm about to reboot 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.
+	 */
+	smp_send_stop();
+#endif
+
+	lapic_shutdown();
+
+#ifdef CONFIG_X86_IO_APIC
+	disable_IO_APIC();
+#endif
+
+#ifdef CONFIG_HPET_TIMER
+	hpet_disable();
+#endif
+
+#ifdef CONFIG_X86_64
+	pci_iommu_shutdown();
+#endif
+}
+
+void machine_restart(char *__unused)
+{
+	printk("machine restart\n");
+
+	if (!reboot_force)
+		machine_shutdown();
+	machine_emergency_restart();
+}
+
+void machine_halt(void)
+{
+}
+
+void machine_power_off(void)
+{
+	if (pm_power_off) {
+		if (!reboot_force)
+			machine_shutdown();
+		pm_power_off();
+	}
+}
diff --git a/arch/x86/kernel/reboot_32.c b/arch/x86/kernel/reboot_32.c
deleted file mode 100644
index c3376fa..0000000
--- a/arch/x86/kernel/reboot_32.c
+++ /dev/null
@@ -1,413 +0,0 @@
-#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/hpet.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(const 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 E520's */
-		.callback = set_bios_reboot,
-		.ident = "Dell E520",
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "Dell DM061"),
-		},
-	},
-	{	/* 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 Optiplex 745's SFF*/
-		.callback = set_bios_reboot,
-		.ident = "Dell OptiPlex 745",
-		.matches = {
-			DMI_MATCH(DMI_SYS_VENDOR, "Dell Inc."),
-			DMI_MATCH(DMI_PRODUCT_NAME, "OptiPlex 745"),
-			DMI_MATCH(DMI_BOARD_NAME, "0WF810"),
-		},
-	},
-	{	/* 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 desc_ptr
-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
-#ifdef CONFIG_HPET_TIMER
-	hpet_disable();
-#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();
-}
diff --git a/arch/x86/kernel/reboot_64.c b/arch/x86/kernel/reboot_64.c
deleted file mode 100644
index d6bdf93..0000000
--- a/arch/x86/kernel/reboot_64.c
+++ /dev/null
@@ -1,191 +0,0 @@
-/* Various gunk just to reboot the machine. */ 
-#include <linux/module.h>
-#include <linux/reboot.h>
-#include <linux/init.h>
-#include <linux/smp.h>
-#include <linux/kernel.h>
-#include <linux/ctype.h>
-#include <linux/string.h>
-#include <linux/pm.h>
-#include <linux/kdebug.h>
-#include <linux/sched.h>
-#include <linux/efi.h>
-#include <acpi/reboot.h>
-#include <asm/io.h>
-#include <asm/delay.h>
-#include <asm/desc.h>
-#include <asm/hw_irq.h>
-#include <asm/system.h>
-#include <asm/pgtable.h>
-#include <asm/tlbflush.h>
-#include <asm/apic.h>
-#include <asm/hpet.h>
-#include <asm/gart.h>
-
-/*
- * Power off function, if any
- */
-void (*pm_power_off)(void);
-EXPORT_SYMBOL(pm_power_off);
-
-static long no_idt[3];
-enum reboot_type reboot_type = BOOT_KBD;
-static int reboot_mode = 0;
-int reboot_force;
-
-/* reboot=t[riple] | k[bd] | e[fi] [, [w]arm | [c]old]
-   warm   Don't set the cold reboot flag
-   cold   Set the cold reboot flag
-   triple Force a triple fault (init)
-   kbd    Use the keyboard controller. cold reset (default)
-   acpi   Use the RESET_REG in the FADT
-   efi    Use efi reset_system runtime service
-   force  Avoid anything that could hang.
- */ 
-static int __init reboot_setup(char *str)
-{
-	for (;;) {
-		switch (*str) {
-		case 'w': 
-			reboot_mode = 0x1234;
-			break;
-
-		case 'c':
-			reboot_mode = 0;
-			break;
-
-		case 't':
-		case 'a':
-		case 'b':
-		case 'k':
-		case 'e':
-			reboot_type = *str;
-			break;
-		case 'f':
-			reboot_force = 1;
-			break;
-		}
-		if((str = strchr(str,',')) != NULL)
-			str++;
-		else
-			break;
-	}
-	return 1;
-}
-
-__setup("reboot=", reboot_setup);
-
-static inline void kb_wait(void)
-{
-	int i;
-
-	for (i=0; i<0x10000; i++)
-		if ((inb_p(0x64) & 0x02) == 0)
-			break;
-}
-
-void machine_shutdown(void)
-{
-	unsigned long flags;
-
-	/* Stop the cpus and apics */
-#ifdef CONFIG_SMP
-	int reboot_cpu_id;
-
-	/* The boot cpu is always logical cpu 0 */
-	reboot_cpu_id = 0;
-
-	/* Make certain the cpu I'm about to reboot 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.
-	 */
-	smp_send_stop();
-#endif
-
-	local_irq_save(flags);
-
-#ifndef CONFIG_SMP
-	disable_local_APIC();
-#endif
-
-	disable_IO_APIC();
-
-#ifdef CONFIG_HPET_TIMER
-	hpet_disable();
-#endif
-	local_irq_restore(flags);
-
-	pci_iommu_shutdown();
-}
-
-void machine_emergency_restart(void)
-{
-	int i;
-
-	/* Tell the BIOS if we want cold or warm reboot */
-	*((unsigned short *)__va(0x472)) = reboot_mode;
-       
-	for (;;) {
-		/* Could also try the reset bit in the Hammer NB */
-		switch (reboot_type) { 
-		case BOOT_KBD:
-		for (i=0; i<10; i++) {
-			kb_wait();
-			udelay(50);
-			outb(0xfe,0x64);         /* pulse reset low */
-			udelay(50);
-		}
-
-		case BOOT_TRIPLE: 
-			load_idt((const struct desc_ptr *)&no_idt);
-			__asm__ __volatile__("int3");
-
-			reboot_type = BOOT_KBD;
-			break;
-
-		case BOOT_ACPI:
-			acpi_reboot();
-			reboot_type = BOOT_KBD;
-			break;
-
-		case BOOT_EFI:
-			if (efi_enabled)
-				efi.reset_system(reboot_mode ? EFI_RESET_WARM : EFI_RESET_COLD,
-						 EFI_SUCCESS, 0, NULL);
-			reboot_type = BOOT_KBD;
-			break;
-		}
-	}      
-}
-
-void machine_restart(char * __unused)
-{
-	printk("machine restart\n");
-
-	if (!reboot_force) {
-		machine_shutdown();
-	}
-	machine_emergency_restart();
-}
-
-void machine_halt(void)
-{
-}
-
-void machine_power_off(void)
-{
-	if (pm_power_off) {
-		if (!reboot_force) {
-			machine_shutdown();
-		}
-		pm_power_off();
-	}
-}
-
diff --git a/include/asm-x86/emergency-restart.h b/include/asm-x86/emergency-restart.h
index 5418908..8e6aef1 100644
--- a/include/asm-x86/emergency-restart.h
+++ b/include/asm-x86/emergency-restart.h
@@ -4,6 +4,9 @@
 enum reboot_type {
 	BOOT_TRIPLE = 't',
 	BOOT_KBD = 'k',
+#ifdef CONFIG_X86_32
+	BOOT_BIOS = 'b',
+#endif
 	BOOT_ACPI = 'a',
 	BOOT_EFI = 'e'
 };

-- 
	Miguel Botón