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Commit 87e81786 authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Ingo Molnar
Browse files

x86/idt: Move early IDT setup out of 32-bit asm 



The early IDT setup can be done in C code like it's done on 64-bit kernels.
Reuse the 64-bit version.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Link: http://lkml.kernel.org/r/20170828064958.757980775@linutronix.de


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 588787fd

arch/x86/include/asm/segment.h

+1 −0
Original line number Diff line number Diff line
@@ -238,6 +238,7 @@ 
#ifndef __ASSEMBLY__



extern const char early_idt_handler_array[NUM_EXCEPTION_VECTORS][EARLY_IDT_HANDLER_SIZE];

extern void early_ignore_irq(void);



/*

 * Load a segment. Fall back on loading the zero segment if something goes

arch/x86/kernel/head32.c

+4 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ 
#include <linux/mm.h>

#include <linux/memblock.h>



#include <asm/desc.h>

#include <asm/setup.h>

#include <asm/sections.h>

#include <asm/e820/api.h>
@@ -30,6 +31,9 @@ static void __init i386_default_early_setup(void) 
asmlinkage __visible void __init i386_start_kernel(void)

{

	cr4_init_shadow();



	idt_setup_early_handler();



	sanitize_boot_params(&boot_params);



	x86_early_init_platform_quirks();

arch/x86/kernel/head_32.S

+2 −34
Original line number Diff line number Diff line
@@ -345,7 +345,6 @@ ENTRY(startup_32_smp) 
	movl %eax,%cr0



	lgdt early_gdt_descr

	lidt idt_descr

	ljmp $(__KERNEL_CS),$1f

1:	movl $(__KERNEL_DS),%eax	# reload all the segment registers

	movl %eax,%ss			# after changing gdt.
@@ -378,37 +377,6 @@ ENDPROC(startup_32_smp) 
 */

__INIT

setup_once:

	/*

	 * Set up a idt with 256 interrupt gates that push zero if there

	 * is no error code and then jump to early_idt_handler_common.

	 * It doesn't actually load the idt - that needs to be done on

	 * each CPU. Interrupts are enabled elsewhere, when we can be

	 * relatively sure everything is ok.

	 */



	movl $idt_table,%edi

	movl $early_idt_handler_array,%eax

	movl $NUM_EXCEPTION_VECTORS,%ecx

1:

	movl %eax,(%edi)

	movl %eax,4(%edi)

	/* interrupt gate, dpl=0, present */

	movl $(0x8E000000 + __KERNEL_CS),2(%edi)

	addl $EARLY_IDT_HANDLER_SIZE,%eax

	addl $8,%edi

	loop 1b



	movl $256 - NUM_EXCEPTION_VECTORS,%ecx

	movl $ignore_int,%edx

	movl $(__KERNEL_CS << 16),%eax

	movw %dx,%ax		/* selector = 0x0010 = cs */

	movw $0x8E00,%dx	/* interrupt gate - dpl=0, present */

2:

	movl %eax,(%edi)

	movl %edx,4(%edi)

	addl $8,%edi

	loop 2b



#ifdef CONFIG_CC_STACKPROTECTOR

	/*

	 * Configure the stack canary. The linker can't handle this by
@@ -498,7 +466,7 @@ ENDPROC(early_idt_handler_common) 


/* This is the default interrupt "handler" :-) */

	ALIGN

ignore_int:

ENTRY(early_ignore_irq)

	cld

#ifdef CONFIG_PRINTK

	pushl %eax
@@ -533,7 +501,7 @@ ignore_int: 
hlt_loop:

	hlt

	jmp hlt_loop

ENDPROC(ignore_int)

ENDPROC(early_ignore_irq)

__INITDATA

	.align 4

GLOBAL(early_recursion_flag)

arch/x86/kernel/idt.c

+4 −0
Original line number Diff line number Diff line
@@ -34,6 +34,10 @@ void __init idt_setup_early_handler(void) 


	for (i = 0; i < NUM_EXCEPTION_VECTORS; i++)

		set_intr_gate(i, early_idt_handler_array[i]);

#ifdef CONFIG_X86_32

	for ( ; i < NR_VECTORS; i++)

		set_intr_gate(i, early_ignore_irq);

#endif

	load_idt(&idt_descr);

}