/* Copyright (C) 2005, 2006, 2007, 2008 by Thomas Hillebrandt and Heiko Will
 * This file is subject to the terms and conditions of the GNU Lesser
 * General Public License v2.1. See the file LICENSE in the top level
 * directory for more details.
 */

#include "VIC.h"
#include <stdbool.h>

#define IRQ_MASK 0x00000080

static inline unsigned __get_cpsr(void)
{
    unsigned long retval;
    __asm__ volatile(" mrs  %0, cpsr" : "=r"(retval) : /* no inputs */ : "memory");
    return retval;
}

int irq_is_in(void)
{
    int retval;
    __asm__ volatile(" mrs  %0, cpsr" : "=r"(retval) : /* no inputs */ : "memory");
    return (retval & INTMode) == 18;
}

static inline void __set_cpsr(unsigned val)
{
    __asm__ volatile(" msr  cpsr, %0" : /* no outputs */ : "r"(val) : "memory");
}

unsigned irq_disable(void)
{
    unsigned _cpsr;

    _cpsr = __get_cpsr();
    __set_cpsr(_cpsr | IRQ_MASK);
    return _cpsr;
}

unsigned irq_restore(unsigned oldCPSR)
{
    unsigned _cpsr;

    _cpsr = __get_cpsr();
    __set_cpsr((_cpsr & ~IRQ_MASK) | (oldCPSR & IRQ_MASK));
    return _cpsr;
}

unsigned irq_enable(void)
{
    unsigned _cpsr;

    _cpsr = __get_cpsr();
    __set_cpsr(_cpsr & ~IRQ_MASK);
    return _cpsr;
}