root/arch/x86/kernel/irqinit_32.c

DEFINITIONS

1. math_error_irq
2. init_ISA_irqs
3. native_init_IRQ

#include <linux/errno.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include <linux/random.h>
#include <linux/init.h>
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>
#include <linux/bitops.h>

#include <asm/atomic.h>
#include <asm/system.h>
#include <asm/io.h>
#include <asm/timer.h>
#include <asm/pgtable.h>
#include <asm/delay.h>
#include <asm/desc.h>
#include <asm/apic.h>
#include <asm/arch_hooks.h>
#include <asm/i8259.h>



/*
 * Note that on a 486, we don't want to do a SIGFPE on an irq13
 * as the irq is unreliable, and exception 16 works correctly
 * (ie as explained in the intel literature). On a 386, you
 * can't use exception 16 due to bad IBM design, so we have to
 * rely on the less exact irq13.
 *
 * Careful.. Not only is IRQ13 unreliable, but it is also
 * leads to races. IBM designers who came up with it should
 * be shot.
 */
 

static irqreturn_t math_error_irq(int cpl, void *dev_id)
{
        extern void math_error(void __user *);
        outb(0,0xF0);
        if (ignore_fpu_irq || !boot_cpu_data.hard_math)
                return IRQ_NONE;
        math_error((void __user *)get_irq_regs()->ip);
        return IRQ_HANDLED;
}

/*
 * New motherboards sometimes make IRQ 13 be a PCI interrupt,
 * so allow interrupt sharing.
 */
static struct irqaction fpu_irq = {
        .handler = math_error_irq,
        .mask = CPU_MASK_NONE,
        .name = "fpu",
};

void __init init_ISA_irqs (void)
{
        int i;

#ifdef CONFIG_X86_LOCAL_APIC
        init_bsp_APIC();
#endif
        init_8259A(0);

        /*
         * 16 old-style INTA-cycle interrupts:
         */
        for (i = 0; i < 16; i++) {
                set_irq_chip_and_handler_name(i, &i8259A_chip,
                                              handle_level_irq, "XT");
        }
}

/*
 * IRQ2 is cascade interrupt to second interrupt controller
 */
static struct irqaction irq2 = {
        .handler = no_action,
        .mask = CPU_MASK_NONE,
        .name = "cascade",
};

/* Overridden in paravirt.c */
void init_IRQ(void) __attribute__((weak, alias("native_init_IRQ")));

void __init native_init_IRQ(void)
{
        int i;

        /* all the set up before the call gates are initialised */
        pre_intr_init_hook();

        /*
         * Cover the whole vector space, no vector can escape
         * us. (some of these will be overridden and become
         * 'special' SMP interrupts)
         */
        for (i = 0; i < (NR_VECTORS - FIRST_EXTERNAL_VECTOR); i++) {
                int vector = FIRST_EXTERNAL_VECTOR + i;
                if (i >= NR_IRQS)
                        break;
                /* SYSCALL_VECTOR was reserved in trap_init. */
                if (!test_bit(vector, used_vectors))
                        set_intr_gate(vector, interrupt[i]);
        }

#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_SMP)
        /*
         * IRQ0 must be given a fixed assignment and initialized,
         * because it's used before the IO-APIC is set up.
         */
        set_intr_gate(FIRST_DEVICE_VECTOR, interrupt[0]);

        /*
         * The reschedule interrupt is a CPU-to-CPU reschedule-helper
         * IPI, driven by wakeup.
         */
        alloc_intr_gate(RESCHEDULE_VECTOR, reschedule_interrupt);

        /* IPI for invalidation */
        alloc_intr_gate(INVALIDATE_TLB_VECTOR, invalidate_interrupt);

        /* IPI for generic function call */
        alloc_intr_gate(CALL_FUNCTION_VECTOR, call_function_interrupt);

        /* IPI for single call function */
        set_intr_gate(CALL_FUNCTION_SINGLE_VECTOR, call_function_single_interrupt);
#endif

#ifdef CONFIG_X86_LOCAL_APIC
        /* self generated IPI for local APIC timer */
        alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);

        /* IPI vectors for APIC spurious and error interrupts */
        alloc_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
        alloc_intr_gate(ERROR_APIC_VECTOR, error_interrupt);
#endif

#if defined(CONFIG_X86_LOCAL_APIC) && defined(CONFIG_X86_MCE_P4THERMAL)
        /* thermal monitor LVT interrupt */
        alloc_intr_gate(THERMAL_APIC_VECTOR, thermal_interrupt);
#endif

        if (!acpi_ioapic)
                setup_irq(2, &irq2);

        /* setup after call gates are initialised (usually add in
         * the architecture specific gates)
         */
        intr_init_hook();

        /*
         * External FPU? Set up irq13 if so, for
         * original braindamaged IBM FERR coupling.
         */
        if (boot_cpu_data.hard_math && !cpu_has_fpu)
                setup_irq(FPU_IRQ, &fpu_irq);

        irq_ctx_init(smp_processor_id());
}