Boot Linux faster!

Check our new training course

Boot Linux faster!

Check our new training course
and Creative Commons CC-BY-SA
lecture and lab materials

Bootlin logo

Elixir Cross Referencer

 * Copyright (c) 2010-2014 Wind River Systems, Inc.
 * SPDX-License-Identifier: Apache-2.0

 * @file
 * @brief Interrupt support for IA-32 arch
 * The _idt_base_address symbol is used to determine the base address of the IDT.
 * (It is generated by the linker script, and doesn't correspond to an actual
 * global variable.)

#include <kernel.h>
#include <arch/cpu.h>
#include <kernel_structs.h>
#include <misc/__assert.h>
#include <misc/printk.h>
#include <irq.h>
#include <logging/kernel_event_logger.h>

extern void _SpuriousIntHandler(void *);
extern void _SpuriousIntNoErrCodeHandler(void *);

 * These 'dummy' variables are used in nanoArchInit() to force the inclusion of
 * the spurious interrupt handlers. They *must* be declared in a module other
 * than the one they are used in to get around garbage collection issues and
 * warnings issued some compilers that they aren't used. Therefore care must
 * be taken if they are to be moved. See kernel_structs.h for more information.
void *_dummy_spurious_interrupt;
void *_dummy_exception_vector_stub;

 * Place the addresses of the spurious interrupt handlers into the intList
 * section. The genIdt tool can then populate any unused vectors with
 * these routines.
void *__attribute__((section(".spurIsr"))) MK_ISR_NAME(_SpuriousIntHandler) =
void *__attribute__((section(".spurNoErrIsr")))
	MK_ISR_NAME(_SpuriousIntNoErrCodeHandler) =

/* FIXME: IRQ direct inline functions have to be placed here and not in
 * arch/cpu.h as inline functions due to nasty circular dependency between
 * arch/cpu.h and kernel_structs.h; the inline functions typically need to
 * perform operations on _kernel.  For now, leave as regular functions, a
 * future iteration will resolve this.
 * We have a similar issue with the k_event_logger functions.
 * See

void _arch_irq_direct_pm(void)
	if (_kernel.idle) {
		int32_t idle_val = _kernel.idle;

		_kernel.idle = 0;

void _arch_isr_direct_header(void)

	/* We're not going to unlock IRQs, but we still need to increment this
	 * so that _is_in_isr() works

void _arch_isr_direct_footer(int swap)

	/* Call swap if all the following is true:
	 * 1) swap argument was enabled to this function
	 * 2) We are not in a nested interrupt
	 * 3) Current thread is preemptible
	 * 4) Next thread to run in the ready queue is not this thread
	if (swap && !_kernel.nested &&
	    _current->base.preempt < _NON_PREEMPT_THRESHOLD &&
	    _kernel.ready_q.cache != _current) {
		unsigned int flags;

		/* Fetch EFLAGS argument to _Swap() */
		__asm__ volatile (
			"popl %0\n\t"
			: "=g" (flags)
			: "memory"