qemu/hw/i386/port92.c
Philippe Mathieu-Daudé d3e07dc83e hw/i386/pc: Extract the port92 device
This device is only used by the PC machines. The pc.c file is
already big enough, with 2255 lines. By removing 113 lines of
it, we reduced it by 5%. It is now a bit easier to navigate
the file.

Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:33:51 +01:00

127 lines
2.8 KiB
C

/*
* QEMU I/O port 0x92 (System Control Port A, to handle Fast Gate A20)
*
* Copyright (c) 2003-2004 Fabrice Bellard
*
* SPDX-License-Identifier: MIT
*/
#include "qemu/osdep.h"
#include "sysemu/runstate.h"
#include "migration/vmstate.h"
#include "hw/irq.h"
#include "hw/i386/pc.h"
#include "trace.h"
#define PORT92(obj) OBJECT_CHECK(Port92State, (obj), TYPE_PORT92)
typedef struct Port92State {
ISADevice parent_obj;
MemoryRegion io;
uint8_t outport;
qemu_irq a20_out;
} Port92State;
static void port92_write(void *opaque, hwaddr addr, uint64_t val,
unsigned size)
{
Port92State *s = opaque;
int oldval = s->outport;
trace_port92_write(val);
s->outport = val;
qemu_set_irq(s->a20_out, (val >> 1) & 1);
if ((val & 1) && !(oldval & 1)) {
qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
}
}
static uint64_t port92_read(void *opaque, hwaddr addr,
unsigned size)
{
Port92State *s = opaque;
uint32_t ret;
ret = s->outport;
trace_port92_read(ret);
return ret;
}
static const VMStateDescription vmstate_port92_isa = {
.name = "port92",
.version_id = 1,
.minimum_version_id = 1,
.fields = (VMStateField[]) {
VMSTATE_UINT8(outport, Port92State),
VMSTATE_END_OF_LIST()
}
};
static void port92_reset(DeviceState *d)
{
Port92State *s = PORT92(d);
s->outport &= ~1;
}
static const MemoryRegionOps port92_ops = {
.read = port92_read,
.write = port92_write,
.impl = {
.min_access_size = 1,
.max_access_size = 1,
},
.endianness = DEVICE_LITTLE_ENDIAN,
};
static void port92_initfn(Object *obj)
{
Port92State *s = PORT92(obj);
memory_region_init_io(&s->io, OBJECT(s), &port92_ops, s, "port92", 1);
s->outport = 0;
qdev_init_gpio_out_named(DEVICE(obj), &s->a20_out, PORT92_A20_LINE, 1);
}
static void port92_realizefn(DeviceState *dev, Error **errp)
{
ISADevice *isadev = ISA_DEVICE(dev);
Port92State *s = PORT92(dev);
isa_register_ioport(isadev, &s->io, 0x92);
}
static void port92_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = port92_realizefn;
dc->reset = port92_reset;
dc->vmsd = &vmstate_port92_isa;
/*
* Reason: unlike ordinary ISA devices, this one needs additional
* wiring: its A20 output line needs to be wired up with
* qdev_connect_gpio_out_named().
*/
dc->user_creatable = false;
}
static const TypeInfo port92_info = {
.name = TYPE_PORT92,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(Port92State),
.instance_init = port92_initfn,
.class_init = port92_class_initfn,
};
static void port92_register_types(void)
{
type_register_static(&port92_info);
}
type_init(port92_register_types)