openpic: don't crash on a register access without a CPU context

[qemu.git] / hw / isa_mmio.c

/*
 * Memory mapped access to ISA IO space.
 *
 * Copyright (c) 2006 Fabrice Bellard
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

#include "hw.h"
#include "isa.h"
#include "exec/address-spaces.h"

static void isa_mmio_writeb (void *opaque, hwaddr addr,
                                  uint32_t val)
{
    cpu_outb(addr & IOPORTS_MASK, val);
}

static void isa_mmio_writew(void *opaque, hwaddr addr,
                               uint32_t val)
{
    cpu_outw(addr & IOPORTS_MASK, val);
}

static void isa_mmio_writel(void *opaque, hwaddr addr,
                               uint32_t val)
{
    cpu_outl(addr & IOPORTS_MASK, val);
}

static uint32_t isa_mmio_readb (void *opaque, hwaddr addr)
{
    return cpu_inb(addr & IOPORTS_MASK);
}

static uint32_t isa_mmio_readw(void *opaque, hwaddr addr)
{
    return cpu_inw(addr & IOPORTS_MASK);
}

static uint32_t isa_mmio_readl(void *opaque, hwaddr addr)
{
    return cpu_inl(addr & IOPORTS_MASK);
}

static const MemoryRegionOps isa_mmio_ops = {
    .old_mmio = {
        .write = { isa_mmio_writeb, isa_mmio_writew, isa_mmio_writel },
        .read = { isa_mmio_readb, isa_mmio_readw, isa_mmio_readl, },
    },
    .endianness = DEVICE_LITTLE_ENDIAN,
};

void isa_mmio_setup(MemoryRegion *mr, hwaddr size)
{
    memory_region_init_io(mr, &isa_mmio_ops, NULL, "isa-mmio", size);
}

void isa_mmio_init(hwaddr base, hwaddr size)
{
    MemoryRegion *mr = g_malloc(sizeof(*mr));

    isa_mmio_setup(mr, size);
    memory_region_add_subregion(get_system_memory(), base, mr);
}