hw/timer/i8254_common.c - qemu - Git at Google

 /*
  * 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 "qemu/osdep.h"
 #include "hw/isa/isa.h"
 #include "qemu/module.h"
 #include "qemu/timer.h"
 #include "hw/timer/i8254.h"
 #include "hw/timer/i8254_internal.h"
 #include "migration/vmstate.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,
                  NANOSECONDS_PER_SECOND);
     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,
                  NANOSECONDS_PER_SECOND);
     switch (s->mode) {
     default:
     case 0:
     case 1:
         if (d < s->count) {
             next_time = s->count;
         } else {
             return -1;
         }
         break;
     case 2:
         base = QEMU_ALIGN_DOWN(d, s->count);
         if ((d - base) == 0 && d != 0) {
             next_time = base + s->count;
         } else {
             next_time = base + s->count + 1;
         }
         break;
     case 3:
         base = QEMU_ALIGN_DOWN(d, 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, NANOSECONDS_PER_SECOND,
                                               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_clock_get_ns(QEMU_CLOCK_VIRTUAL));
 }

 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_clock_get_ns(QEMU_CLOCK_VIRTUAL);
         s->count = 0x10000;
         if (i == 0 && !s->irq_disabled) {
             s->next_transition_time =
                 pit_get_next_transition_time(s, s->count_load_time);
         }
     }
 }

 static void pit_common_realize(DeviceState *dev, Error **errp)
 {
     ISADevice *isadev = ISA_DEVICE(dev);
     PITCommonState *pit = PIT_COMMON(dev);

     isa_register_ioport(isadev, &pit->ioports, pit->iobase);

     qdev_set_legacy_instance_id(dev, pit->iobase, 2);
 }

 static const VMStateDescription vmstate_pit_channel = {
     .name = "pit channel",
     .version_id = 2,
     .minimum_version_id = 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_dispatch_pre_save(void *opaque)
 {
     PITCommonState *s = opaque;
     PITCommonClass *c = PIT_COMMON_GET_CLASS(s);

     if (c->pre_save) {
         c->pre_save(s);
     }

     return 0;
 }

 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,
     .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)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->realize = pit_common_realize;
     dc->vmsd = &vmstate_pit_common;
     /*
      * Reason: unlike ordinary ISA devices, the PIT may need to be
      * wired to the HPET, and because of that, some wiring is always
      * done by board code.
      */
     dc->user_creatable = false;
 }

 static const 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);
	/*
	* 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 "qemu/osdep.h"
	#include "hw/isa/isa.h"
	#include "qemu/module.h"
	#include "qemu/timer.h"
	#include "hw/timer/i8254.h"
	#include "hw/timer/i8254_internal.h"
	#include "migration/vmstate.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,
	NANOSECONDS_PER_SECOND);
	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,
	NANOSECONDS_PER_SECOND);
	switch (s->mode) {
	default:
	case 0:
	case 1:
	if (d < s->count) {
	next_time = s->count;
	} else {
	return -1;
	}
	break;
	case 2:
	base = QEMU_ALIGN_DOWN(d, s->count);
	if ((d - base) == 0 && d != 0) {
	next_time = base + s->count;
	} else {
	next_time = base + s->count + 1;
	}
	break;
	case 3:
	base = QEMU_ALIGN_DOWN(d, 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, NANOSECONDS_PER_SECOND,
	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_clock_get_ns(QEMU_CLOCK_VIRTUAL));
	}

	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_clock_get_ns(QEMU_CLOCK_VIRTUAL);
	s->count = 0x10000;
	if (i == 0 && !s->irq_disabled) {
	s->next_transition_time =
	pit_get_next_transition_time(s, s->count_load_time);
	}
	}
	}

	static void pit_common_realize(DeviceState dev, Error *errp)
	{
	ISADevice *isadev = ISA_DEVICE(dev);
	PITCommonState *pit = PIT_COMMON(dev);

	isa_register_ioport(isadev, &pit->ioports, pit->iobase);

	qdev_set_legacy_instance_id(dev, pit->iobase, 2);
	}

	static const VMStateDescription vmstate_pit_channel = {
	.name = "pit channel",
	.version_id = 2,
	.minimum_version_id = 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_dispatch_pre_save(void *opaque)
	{
	PITCommonState *s = opaque;
	PITCommonClass *c = PIT_COMMON_GET_CLASS(s);

	if (c->pre_save) {
	c->pre_save(s);
	}

	return 0;
	}

	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,
	.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)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = pit_common_realize;
	dc->vmsd = &vmstate_pit_common;
	/*
	* Reason: unlike ordinary ISA devices, the PIT may need to be
	* wired to the HPET, and because of that, some wiring is always
	* done by board code.
	*/
	dc->user_creatable = false;
	}

	static const 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);