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Commit 65051397 authored by H. Peter Anvin's avatar H. Peter Anvin
Browse files

x86-64, reboot: Allow reboot=bios and reboot-cpu override on x86-64 



With the revamped realmode trampoline code, it is trivial to extend
support for reboot=bios to x86-64.  Furthermore, while we are at it,
remove the restriction that only we can only override the reboot CPU
on 32 bits.

Signed-off-by: default avatarH. Peter Anvin <hpa@zytor.com>
Link: http://lkml.kernel.org/n/tip-jopx7y6g6dbcx4tpal8q0jlr@git.kernel.org
parent cfaf0251

arch/x86/include/asm/emergency-restart.h

+0 −2
Original line number Diff line number Diff line
@@ -4,9 +4,7 @@ 
enum reboot_type {

	BOOT_TRIPLE = 't',

	BOOT_KBD = 'k',

#ifdef CONFIG_X86_32

	BOOT_BIOS = 'b',

#endif

	BOOT_ACPI = 'a',

	BOOT_EFI = 'e',

	BOOT_CF9 = 'p',

arch/x86/include/asm/realmode.h

+2 −1
Original line number Diff line number Diff line
@@ -21,8 +21,9 @@ struct real_mode_header { 
	u32	wakeup_header;

#endif

	/* APM/BIOS reboot */

#ifdef CONFIG_X86_32

	u32	machine_real_restart_asm;

#ifdef CONFIG_X86_64

	u32	machine_real_restart_seg;

#endif

};

arch/x86/include/asm/reboot.h

+2 −2
Original line number Diff line number Diff line
@@ -18,8 +18,8 @@ extern struct machine_ops machine_ops; 


void native_machine_crash_shutdown(struct pt_regs *regs);

void native_machine_shutdown(void);

void machine_real_restart(unsigned int type);

/* These must match dispatch_table in reboot_32.S */

void __noreturn machine_real_restart(unsigned int type);

/* These must match dispatch in arch/x86/realmore/rm/reboot.S */

#define MRR_BIOS	0

#define MRR_APM		1

arch/x86/kernel/reboot.c

+24 −28
Original line number Diff line number Diff line
@@ -20,14 +20,12 @@ 
#include <asm/virtext.h>

#include <asm/cpu.h>

#include <asm/nmi.h>

#include <asm/smp.h>



#ifdef CONFIG_X86_32

#include <linux/ctype.h>

#include <linux/mc146818rtc.h>

#include <asm/realmode.h>

#else

#include <asm/x86_init.h>

#endif



/*

 * Power off function, if any
@@ -49,7 +47,7 @@ int reboot_force; 
 */

static int reboot_default = 1;



#if defined(CONFIG_X86_32) && defined(CONFIG_SMP)

#ifdef CONFIG_SMP

static int reboot_cpu = -1;

#endif
@@ -67,8 +65,8 @@ bool port_cf9_safe = false; 
 * reboot=b[ios] | s[mp] | t[riple] | k[bd] | e[fi] [, [w]arm | [c]old] | p[ci]

 * 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)

 * bios   Reboot by jumping through the BIOS

 * smp    Reboot by executing reset on BSP or other CPU

 * triple Force a triple fault (init)

 * kbd    Use the keyboard controller. cold reset (default)

 * acpi   Use the RESET_REG in the FADT
@@ -95,7 +93,6 @@ static int __init reboot_setup(char *str) 
			reboot_mode = 0;

			break;



#ifdef CONFIG_X86_32

#ifdef CONFIG_SMP

		case 's':

			if (isdigit(*(str+1))) {
@@ -112,7 +109,6 @@ static int __init reboot_setup(char *str) 
#endif /* CONFIG_SMP */



		case 'b':

#endif

		case 'a':

		case 'k':

		case 't':
@@ -138,7 +134,6 @@ static int __init reboot_setup(char *str) 
__setup("reboot=", reboot_setup);





#ifdef CONFIG_X86_32

/*

 * Reboot options and system auto-detection code provided by

 * Dell Inc. so their systems "just work". :-)
@@ -157,11 +152,8 @@ static int __init set_bios_reboot(const struct dmi_system_id *d) 
	return 0;

}



void machine_real_restart(unsigned int type)

void __noreturn machine_real_restart(unsigned int type)

{

	void (*restart_lowmem)(unsigned int) = (void (*)(unsigned int))

		real_mode_header->machine_real_restart_asm;



	local_irq_disable();



	/*
@@ -181,7 +173,11 @@ void machine_real_restart(unsigned int type) 
	/*

	 * Switch back to the initial page table.

	 */

#ifdef CONFIG_X86_32

	load_cr3(initial_page_table);

#else

	write_cr3(real_mode_header->trampoline_pgd);

#endif



	/*

	 * Write 0x1234 to absolute memory location 0x472.  The BIOS reads
@@ -192,14 +188,21 @@ void machine_real_restart(unsigned int type) 
	*((unsigned short *)0x472) = reboot_mode;



	/* Jump to the identity-mapped low memory code */

	restart_lowmem(type);

#ifdef CONFIG_X86_32

	asm volatile("jmpl *%0" : :

		     "rm" (real_mode_header->machine_real_restart_asm),

		     "a" (type));

#else

	asm volatile("ljmpl *%0" : :

		     "m" (real_mode_header->machine_real_restart_asm),

		     "D" (type));

#endif

	unreachable();

}

#ifdef CONFIG_APM_MODULE

EXPORT_SYMBOL(machine_real_restart);

#endif



#endif /* CONFIG_X86_32 */



/*

 * Some Apple MacBook and MacBookPro's needs reboot=p to be able to reboot

 */
@@ -223,11 +226,9 @@ static int __init set_kbd_reboot(const struct dmi_system_id *d) 
}



/*

 * This is a single dmi_table handling all reboot quirks.  Note that

 * REBOOT_BIOS is only available for 32bit

 * This is a single dmi_table handling all reboot quirks.

 */

static struct dmi_system_id __initdata reboot_dmi_table[] = {

#ifdef CONFIG_X86_32

	{	/* Handle problems with rebooting on Dell E520's */

		.callback = set_bios_reboot,

		.ident = "Dell E520",
@@ -377,7 +378,6 @@ static struct dmi_system_id __initdata reboot_dmi_table[] = { 
			DMI_MATCH(DMI_BOARD_NAME, "P4S800"),

		},

	},

#endif /* CONFIG_X86_32 */



	{	/* Handle reboot issue on Acer Aspire one */

		.callback = set_kbd_reboot,
@@ -576,13 +576,11 @@ static void native_machine_emergency_restart(void) 
			reboot_type = BOOT_KBD;

			break;



#ifdef CONFIG_X86_32

		case BOOT_BIOS:

			machine_real_restart(MRR_BIOS);



			reboot_type = BOOT_KBD;

			break;

#endif



		case BOOT_ACPI:

			acpi_reboot();
@@ -624,12 +622,10 @@ void native_machine_shutdown(void) 
	/* The boot cpu is always logical cpu 0 */

	int 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_cpu_ids) &&

		cpu_online(reboot_cpu))

		reboot_cpu_id = reboot_cpu;

#endif



	/* Make certain the cpu I'm about to reboot on is online */

	if (!cpu_online(reboot_cpu_id))

arch/x86/realmode/rm/Makefile

+1 −1
Original line number Diff line number Diff line
@@ -22,7 +22,7 @@ wakeup-objs += video-bios.o 
realmode-y			+= header.o

realmode-y			+= trampoline_$(BITS).o

realmode-y			+= stack.o

realmode-$(CONFIG_X86_32)	+= reboot_32.o

realmode-y			+= reboot.o

realmode-$(CONFIG_ACPI_SLEEP)	+= $(wakeup-objs)



targets	+= $(realmode-y)