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qemu/hw/i8254_common.c
Jan Kiszka 3fbc1c0c13 i8254: Open-code timer restore 
Same as for the APIC: To enable migration between accelerated and
non-accelerated models, we need to arm the channel 0 timer only inside
the emulated PIT model. The common code just saves/restores that timer
to the the next_transition_time field.

Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
2012-03-07 12:27:41 +02:00

312 lines
8.7 KiB
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/*
* QEMU 8253/8254 - common bits of emulated and KVM kernel model
*
* Copyright (c) 2003-2004 Fabrice Bellard
* Copyright (c) 2012 Jan Kiszka, Siemens AG
*
* 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 "pc.h"
#include "isa.h"
#include "qemu-timer.h"
#include "i8254.h"
#include "i8254_internal.h"
/* val must be 0 or 1 */
void pit_set_gate(ISADevice *dev, int channel, int val)
{
PITCommonState *pit = PIT_COMMON(dev);
PITChannelState *s = &pit->channels[channel];
PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
c->set_channel_gate(pit, s, val);
}
/* get pit output bit */
int pit_get_out(PITChannelState *s, int64_t current_time)
{
uint64_t d;
int out;
d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
get_ticks_per_sec());
switch (s->mode) {
default:
case 0:
out = (d >= s->count);
break;
case 1:
out = (d < s->count);
break;
case 2:
if ((d % s->count) == 0 && d != 0) {
out = 1;
} else {
out = 0;
}
break;
case 3:
out = (d % s->count) < ((s->count + 1) >> 1);
break;
case 4:
case 5:
out = (d == s->count);
break;
}
return out;
}
/* return -1 if no transition will occur. */
int64_t pit_get_next_transition_time(PITChannelState *s, int64_t current_time)
{
uint64_t d, next_time, base;
int period2;
d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
get_ticks_per_sec());
switch (s->mode) {
default:
case 0:
case 1:
if (d < s->count) {
next_time = s->count;
} else {
return -1;
}
break;
case 2:
base = (d / s->count) * s->count;
if ((d - base) == 0 && d != 0) {
next_time = base + s->count;
} else {
next_time = base + s->count + 1;
}
break;
case 3:
base = (d / s->count) * s->count;
period2 = ((s->count + 1) >> 1);
if ((d - base) < period2) {
next_time = base + period2;
} else {
next_time = base + s->count;
}
break;
case 4:
case 5:
if (d < s->count) {
next_time = s->count;
} else if (d == s->count) {
next_time = s->count + 1;
} else {
return -1;
}
break;
}
/* convert to timer units */
next_time = s->count_load_time + muldiv64(next_time, get_ticks_per_sec(),
PIT_FREQ);
/* fix potential rounding problems */
/* XXX: better solution: use a clock at PIT_FREQ Hz */
if (next_time <= current_time) {
next_time = current_time + 1;
}
return next_time;
}
void pit_get_channel_info_common(PITCommonState *s, PITChannelState *sc,
PITChannelInfo *info)
{
info->gate = sc->gate;
info->mode = sc->mode;
info->initial_count = sc->count;
info->out = pit_get_out(sc, qemu_get_clock_ns(vm_clock));
}
void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info)
{
PITCommonState *pit = PIT_COMMON(dev);
PITChannelState *s = &pit->channels[channel];
PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
c->get_channel_info(pit, s, info);
}
void pit_reset_common(PITCommonState *pit)
{
PITChannelState *s;
int i;
for (i = 0; i < 3; i++) {
s = &pit->channels[i];
s->mode = 3;
s->gate = (i != 2);
s->count_load_time = qemu_get_clock_ns(vm_clock);
s->count = 0x10000;
if (i == 0 && !s->irq_disabled) {
s->next_transition_time =
pit_get_next_transition_time(s, s->count_load_time);
}
}
}
static int pit_init_common(ISADevice *dev)
{
PITCommonState *pit = PIT_COMMON(dev);
PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
int ret;
ret = c->init(pit);
if (ret < 0) {
return ret;
}
isa_register_ioport(dev, &pit->ioports, pit->iobase);
qdev_set_legacy_instance_id(&dev->qdev, pit->iobase, 2);
return 0;
}
static const VMStateDescription vmstate_pit_channel = {
.name = "pit channel",
.version_id = 2,
.minimum_version_id = 2,
.minimum_version_id_old = 2,
.fields = (VMStateField[]) {
VMSTATE_INT32(count, PITChannelState),
VMSTATE_UINT16(latched_count, PITChannelState),
VMSTATE_UINT8(count_latched, PITChannelState),
VMSTATE_UINT8(status_latched, PITChannelState),
VMSTATE_UINT8(status, PITChannelState),
VMSTATE_UINT8(read_state, PITChannelState),
VMSTATE_UINT8(write_state, PITChannelState),
VMSTATE_UINT8(write_latch, PITChannelState),
VMSTATE_UINT8(rw_mode, PITChannelState),
VMSTATE_UINT8(mode, PITChannelState),
VMSTATE_UINT8(bcd, PITChannelState),
VMSTATE_UINT8(gate, PITChannelState),
VMSTATE_INT64(count_load_time, PITChannelState),
VMSTATE_INT64(next_transition_time, PITChannelState),
VMSTATE_END_OF_LIST()
}
};
static int pit_load_old(QEMUFile *f, void *opaque, int version_id)
{
PITCommonState *pit = opaque;
PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
PITChannelState *s;
int i;
if (version_id != 1) {
return -EINVAL;
}
for (i = 0; i < 3; i++) {
s = &pit->channels[i];
s->count = qemu_get_be32(f);
qemu_get_be16s(f, &s->latched_count);
qemu_get_8s(f, &s->count_latched);
qemu_get_8s(f, &s->status_latched);
qemu_get_8s(f, &s->status);
qemu_get_8s(f, &s->read_state);
qemu_get_8s(f, &s->write_state);
qemu_get_8s(f, &s->write_latch);
qemu_get_8s(f, &s->rw_mode);
qemu_get_8s(f, &s->mode);
qemu_get_8s(f, &s->bcd);
qemu_get_8s(f, &s->gate);
s->count_load_time = qemu_get_be64(f);
s->irq_disabled = 0;
if (i == 0) {
s->next_transition_time = qemu_get_be64(f);
}
}
if (c->post_load) {
c->post_load(pit);
}
return 0;
}
static void pit_dispatch_pre_save(void *opaque)
{
PITCommonState *s = opaque;
PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
if (c->pre_save) {
c->pre_save(s);
}
}
static int pit_dispatch_post_load(void *opaque, int version_id)
{
PITCommonState *s = opaque;
PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
if (c->post_load) {
c->post_load(s);
}
return 0;
}
static const VMStateDescription vmstate_pit_common = {
.name = "i8254",
.version_id = 3,
.minimum_version_id = 2,
.minimum_version_id_old = 1,
.load_state_old = pit_load_old,
.pre_save = pit_dispatch_pre_save,
.post_load = pit_dispatch_post_load,
.fields = (VMStateField[]) {
VMSTATE_UINT32_V(channels[0].irq_disabled, PITCommonState, 3),
VMSTATE_STRUCT_ARRAY(channels, PITCommonState, 3, 2,
vmstate_pit_channel, PITChannelState),
VMSTATE_INT64(channels[0].next_transition_time,
PITCommonState), /* formerly irq_timer */
VMSTATE_END_OF_LIST()
}
};
static void pit_common_class_init(ObjectClass *klass, void *data)
{
ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
DeviceClass *dc = DEVICE_CLASS(klass);
ic->init = pit_init_common;
dc->vmsd = &vmstate_pit_common;
dc->no_user = 1;
}
static TypeInfo pit_common_type = {
.name = TYPE_PIT_COMMON,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(PITCommonState),
.class_size = sizeof(PITCommonClass),
.class_init = pit_common_class_init,
.abstract = true,
};
static void register_devices(void)
{
type_register_static(&pit_common_type);
}
type_init(register_devices);
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