271 lines
7.8 KiB
C
271 lines
7.8 KiB
C
/*
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* QEMU 8253/8254 - common bits of emulated and KVM kernel model
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*
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* Copyright (c) 2003-2004 Fabrice Bellard
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* Copyright (c) 2012 Jan Kiszka, Siemens AG
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*
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* Permission is hereby granted, free of charge, to any person obtaining a copy
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* of this software and associated documentation files (the "Software"), to deal
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* in the Software without restriction, including without limitation the rights
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* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
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* copies of the Software, and to permit persons to whom the Software is
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* furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice shall be included in
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* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
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* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
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* THE SOFTWARE.
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*/
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#include "qemu/osdep.h"
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#include "hw/isa/isa.h"
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#include "qemu/module.h"
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#include "qemu/timer.h"
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#include "hw/timer/i8254.h"
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#include "hw/timer/i8254_internal.h"
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#include "migration/vmstate.h"
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/* val must be 0 or 1 */
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void pit_set_gate(ISADevice *dev, int channel, int val)
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{
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PITCommonState *pit = PIT_COMMON(dev);
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PITChannelState *s = &pit->channels[channel];
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PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
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c->set_channel_gate(pit, s, val);
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}
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/* get pit output bit */
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int pit_get_out(PITChannelState *s, int64_t current_time)
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{
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uint64_t d;
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int out;
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d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
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NANOSECONDS_PER_SECOND);
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switch (s->mode) {
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default:
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case 0:
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out = (d >= s->count);
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break;
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case 1:
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out = (d < s->count);
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break;
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case 2:
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if ((d % s->count) == 0 && d != 0) {
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out = 1;
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} else {
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out = 0;
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}
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break;
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case 3:
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out = (d % s->count) < ((s->count + 1) >> 1);
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break;
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case 4:
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case 5:
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out = (d == s->count);
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break;
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}
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return out;
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}
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/* return -1 if no transition will occur. */
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int64_t pit_get_next_transition_time(PITChannelState *s, int64_t current_time)
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{
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uint64_t d, next_time, base;
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int period2;
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d = muldiv64(current_time - s->count_load_time, PIT_FREQ,
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NANOSECONDS_PER_SECOND);
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switch (s->mode) {
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default:
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case 0:
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case 1:
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if (d < s->count) {
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next_time = s->count;
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} else {
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return -1;
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}
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break;
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case 2:
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base = QEMU_ALIGN_DOWN(d, s->count);
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if ((d - base) == 0 && d != 0) {
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next_time = base + s->count;
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} else {
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next_time = base + s->count + 1;
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}
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break;
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case 3:
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base = QEMU_ALIGN_DOWN(d, s->count);
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period2 = ((s->count + 1) >> 1);
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if ((d - base) < period2) {
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next_time = base + period2;
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} else {
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next_time = base + s->count;
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}
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break;
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case 4:
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case 5:
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if (d < s->count) {
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next_time = s->count;
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} else if (d == s->count) {
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next_time = s->count + 1;
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} else {
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return -1;
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}
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break;
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}
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/* convert to timer units */
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next_time = s->count_load_time + muldiv64(next_time, NANOSECONDS_PER_SECOND,
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PIT_FREQ);
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/* fix potential rounding problems */
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/* XXX: better solution: use a clock at PIT_FREQ Hz */
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if (next_time <= current_time) {
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next_time = current_time + 1;
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}
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return next_time;
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}
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void pit_get_channel_info_common(PITCommonState *s, PITChannelState *sc,
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PITChannelInfo *info)
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{
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info->gate = sc->gate;
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info->mode = sc->mode;
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info->initial_count = sc->count;
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info->out = pit_get_out(sc, qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
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}
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void pit_get_channel_info(ISADevice *dev, int channel, PITChannelInfo *info)
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{
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PITCommonState *pit = PIT_COMMON(dev);
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PITChannelState *s = &pit->channels[channel];
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PITCommonClass *c = PIT_COMMON_GET_CLASS(pit);
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c->get_channel_info(pit, s, info);
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}
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void pit_reset_common(PITCommonState *pit)
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{
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PITChannelState *s;
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int i;
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for (i = 0; i < 3; i++) {
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s = &pit->channels[i];
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s->mode = 3;
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s->gate = (i != 2);
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s->count_load_time = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
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s->count = 0x10000;
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if (i == 0 && !s->irq_disabled) {
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s->next_transition_time =
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pit_get_next_transition_time(s, s->count_load_time);
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}
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}
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}
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static void pit_common_realize(DeviceState *dev, Error **errp)
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{
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ISADevice *isadev = ISA_DEVICE(dev);
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PITCommonState *pit = PIT_COMMON(dev);
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isa_register_ioport(isadev, &pit->ioports, pit->iobase);
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qdev_set_legacy_instance_id(dev, pit->iobase, 2);
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}
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static const VMStateDescription vmstate_pit_channel = {
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.name = "pit channel",
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.version_id = 2,
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.minimum_version_id = 2,
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.fields = (VMStateField[]) {
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VMSTATE_INT32(count, PITChannelState),
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VMSTATE_UINT16(latched_count, PITChannelState),
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VMSTATE_UINT8(count_latched, PITChannelState),
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VMSTATE_UINT8(status_latched, PITChannelState),
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VMSTATE_UINT8(status, PITChannelState),
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VMSTATE_UINT8(read_state, PITChannelState),
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VMSTATE_UINT8(write_state, PITChannelState),
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VMSTATE_UINT8(write_latch, PITChannelState),
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VMSTATE_UINT8(rw_mode, PITChannelState),
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VMSTATE_UINT8(mode, PITChannelState),
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VMSTATE_UINT8(bcd, PITChannelState),
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VMSTATE_UINT8(gate, PITChannelState),
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VMSTATE_INT64(count_load_time, PITChannelState),
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VMSTATE_INT64(next_transition_time, PITChannelState),
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VMSTATE_END_OF_LIST()
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}
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};
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static int pit_dispatch_pre_save(void *opaque)
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{
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PITCommonState *s = opaque;
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PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
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if (c->pre_save) {
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c->pre_save(s);
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}
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return 0;
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}
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static int pit_dispatch_post_load(void *opaque, int version_id)
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{
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PITCommonState *s = opaque;
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PITCommonClass *c = PIT_COMMON_GET_CLASS(s);
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if (c->post_load) {
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c->post_load(s);
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}
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return 0;
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}
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static const VMStateDescription vmstate_pit_common = {
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.name = "i8254",
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.version_id = 3,
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.minimum_version_id = 2,
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.pre_save = pit_dispatch_pre_save,
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.post_load = pit_dispatch_post_load,
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.fields = (VMStateField[]) {
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VMSTATE_UINT32_V(channels[0].irq_disabled, PITCommonState, 3),
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VMSTATE_STRUCT_ARRAY(channels, PITCommonState, 3, 2,
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vmstate_pit_channel, PITChannelState),
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VMSTATE_INT64(channels[0].next_transition_time,
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PITCommonState), /* formerly irq_timer */
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VMSTATE_END_OF_LIST()
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}
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};
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static void pit_common_class_init(ObjectClass *klass, void *data)
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{
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DeviceClass *dc = DEVICE_CLASS(klass);
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dc->realize = pit_common_realize;
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dc->vmsd = &vmstate_pit_common;
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/*
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* Reason: unlike ordinary ISA devices, the PIT may need to be
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* wired to the HPET, and because of that, some wiring is always
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* done by board code.
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*/
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dc->user_creatable = false;
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}
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static const TypeInfo pit_common_type = {
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.name = TYPE_PIT_COMMON,
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.parent = TYPE_ISA_DEVICE,
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.instance_size = sizeof(PITCommonState),
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.class_size = sizeof(PITCommonClass),
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.class_init = pit_common_class_init,
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.abstract = true,
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};
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static void register_devices(void)
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{
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type_register_static(&pit_common_type);
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}
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type_init(register_devices);
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