linux/arch/x86/kernel/idt.c

/*
 * Interrupt descriptor table related code
 *
 * This file is licensed under the GPL V2
 */
#include <linux/interrupt.h>

#include <asm/desc.h>

/* Must be page-aligned because the real IDT is used in a fixmap. */
gate_desc idt_table[IDT_ENTRIES] __page_aligned_bss;

struct desc_ptr idt_descr __ro_after_init = {
	.size		= (IDT_ENTRIES * 2 * sizeof(unsigned long)) - 1,
	.address	= (unsigned long) idt_table,
};

#ifdef CONFIG_X86_64
/* No need to be aligned, but done to keep all IDTs defined the same way. */
gate_desc debug_idt_table[IDT_ENTRIES] __page_aligned_bss;

const struct desc_ptr debug_idt_descr = {
	.size		= IDT_ENTRIES * 16 - 1,
	.address	= (unsigned long) debug_idt_table,
};
#endif

/**
 * idt_setup_early_handler - Initializes the idt table with early handlers
 */
void __init idt_setup_early_handler(void)
{
	int i;

	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);
}

/**
 * idt_invalidate - Invalidate interrupt descriptor table
 * @addr:	The virtual address of the 'invalid' IDT
 */
void idt_invalidate(void *addr)
{
	struct desc_ptr idt = { .address = (unsigned long) addr, .size = 0 };

	load_idt(&idt);
}