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qemu / qemu / 522ece32d214bd4b086821c4350c2aebe5587878 / . / hw / timer / mc146818rtc.c
blob: 35a05a64cc6f40e9a05e5aa429248f33f6c4913d [file] [log] [blame]
/*
* QEMU MC146818 RTC emulation
*
* Copyright (c) 2003-2004 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 "qemu/osdep.h"
#include "qemu/cutils.h"
#include "qemu/bcd.h"
#include "hw/hw.h"
#include "qemu/timer.h"
#include "sysemu/sysemu.h"
#include "sysemu/replay.h"
#include "hw/timer/mc146818rtc.h"
#include "qapi/visitor.h"
#include "qapi-event.h"
#include "qmp-commands.h"
#ifdef TARGET_I386
#include "hw/i386/apic.h"
#endif
//#define DEBUG_CMOS
//#define DEBUG_COALESCED
#ifdef DEBUG_CMOS
# define CMOS_DPRINTF(format, ...) printf(format, ## __VA_ARGS__)
#else
# define CMOS_DPRINTF(format, ...) do { } while (0)
#endif
#ifdef DEBUG_COALESCED
# define DPRINTF_C(format, ...) printf(format, ## __VA_ARGS__)
#else
# define DPRINTF_C(format, ...) do { } while (0)
#endif
#define SEC_PER_MIN 60
#define MIN_PER_HOUR 60
#define SEC_PER_HOUR 3600
#define HOUR_PER_DAY 24
#define SEC_PER_DAY 86400
#define RTC_REINJECT_ON_ACK_COUNT 20
#define RTC_CLOCK_RATE 32768
#define UIP_HOLD_LENGTH (8 * NANOSECONDS_PER_SECOND / 32768)
#define MC146818_RTC(obj) OBJECT_CHECK(RTCState, (obj), TYPE_MC146818_RTC)
typedef struct RTCState {
ISADevice parent_obj;
MemoryRegion io;
uint8_t cmos_data[128];
uint8_t cmos_index;
int32_t base_year;
uint64_t base_rtc;
uint64_t last_update;
int64_t offset;
qemu_irq irq;
int it_shift;
/* periodic timer */
QEMUTimer *periodic_timer;
int64_t next_periodic_time;
/* update-ended timer */
QEMUTimer *update_timer;
uint64_t next_alarm_time;
uint16_t irq_reinject_on_ack_count;
uint32_t irq_coalesced;
uint32_t period;
QEMUTimer *coalesced_timer;
Notifier clock_reset_notifier;
LostTickPolicy lost_tick_policy;
Notifier suspend_notifier;
QLIST_ENTRY(RTCState) link;
} RTCState;
static void rtc_set_time(RTCState *s);
static void rtc_update_time(RTCState *s);
static void rtc_set_cmos(RTCState *s, const struct tm *tm);
static inline int rtc_from_bcd(RTCState *s, int a);
static uint64_t get_next_alarm(RTCState *s);
static inline bool rtc_running(RTCState *s)
{
return (!(s->cmos_data[RTC_REG_B] & REG_B_SET) &&
(s->cmos_data[RTC_REG_A] & 0x70) <= 0x20);
}
static uint64_t get_guest_rtc_ns(RTCState *s)
{
uint64_t guest_clock = qemu_clock_get_ns(rtc_clock);
return s->base_rtc * NANOSECONDS_PER_SECOND +
guest_clock - s->last_update + s->offset;
}
static void rtc_coalesced_timer_update(RTCState *s)
{
if (s->irq_coalesced == 0) {
timer_del(s->coalesced_timer);
} else {
/* divide each RTC interval to 2 - 8 smaller intervals */
int c = MIN(s->irq_coalesced, 7) + 1;
int64_t next_clock = qemu_clock_get_ns(rtc_clock) +
periodic_clock_to_ns(s->period / c);
timer_mod(s->coalesced_timer, next_clock);
}
}
static QLIST_HEAD(, RTCState) rtc_devices =
QLIST_HEAD_INITIALIZER(rtc_devices);
#ifdef TARGET_I386
void qmp_rtc_reset_reinjection(Error **errp)
{
RTCState *s;
QLIST_FOREACH(s, &rtc_devices, link) {
s->irq_coalesced = 0;
}
}
static bool rtc_policy_slew_deliver_irq(RTCState *s)
{
apic_reset_irq_delivered();
qemu_irq_raise(s->irq);
return apic_get_irq_delivered();
}
static void rtc_coalesced_timer(void *opaque)
{
RTCState *s = opaque;
if (s->irq_coalesced != 0) {
s->cmos_data[RTC_REG_C] |= 0xc0;
DPRINTF_C("cmos: injecting from timer\n");
if (rtc_policy_slew_deliver_irq(s)) {
s->irq_coalesced--;
DPRINTF_C("cmos: coalesced irqs decreased to %d\n",
s->irq_coalesced);
}
}
rtc_coalesced_timer_update(s);
}
#else
static bool rtc_policy_slew_deliver_irq(RTCState *s)
{
assert(0);
return false;
}
#endif
static uint32_t rtc_periodic_clock_ticks(RTCState *s)
{
int period_code;
if (!(s->cmos_data[RTC_REG_B] & REG_B_PIE)) {
return 0;
}
period_code = s->cmos_data[RTC_REG_A] & 0x0f;
return periodic_period_to_clock(period_code);
}
/*
* handle periodic timer. @old_period indicates the periodic timer update
* is just due to period adjustment.
*/
static void
periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period)
{
uint32_t period;
int64_t cur_clock, next_irq_clock, lost_clock = 0;
period = rtc_periodic_clock_ticks(s);
if (period) {
/* compute 32 khz clock */
cur_clock =
muldiv64(current_time, RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND);
/*
* if the periodic timer's update is due to period re-configuration,
* we should count the clock since last interrupt.
*/
if (old_period) {
int64_t last_periodic_clock, next_periodic_clock;
next_periodic_clock = muldiv64(s->next_periodic_time,
RTC_CLOCK_RATE, NANOSECONDS_PER_SECOND);
last_periodic_clock = next_periodic_clock - old_period;
lost_clock = cur_clock - last_periodic_clock;
assert(lost_clock >= 0);
}
/*
* s->irq_coalesced can change for two reasons:
*
* a) if one or more periodic timer interrupts have been lost,
* lost_clock will be more that a period.
*
* b) when the period may be reconfigured, we expect the OS to
* treat delayed tick as the new period. So, when switching
* from a shorter to a longer period, scale down the missing,
* because the OS will treat past delayed ticks as longer
* (leftovers are put back into lost_clock). When switching
* to a shorter period, scale up the missing ticks since the
* OS handler will treat past delayed ticks as shorter.
*/
if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
uint32_t old_irq_coalesced = s->irq_coalesced;
s->period = period;
lost_clock += old_irq_coalesced * old_period;
s->irq_coalesced = lost_clock / s->period;
lost_clock %= s->period;
if (old_irq_coalesced != s->irq_coalesced ||
old_period != s->period) {
DPRINTF_C("cmos: coalesced irqs scaled from %d to %d, "
"period scaled from %d to %d\n", old_irq_coalesced,
s->irq_coalesced, old_period, s->period);
rtc_coalesced_timer_update(s);
}
} else {
/*
* no way to compensate the interrupt if LOST_TICK_POLICY_SLEW
* is not used, we should make the time progress anyway.
*/
lost_clock = MIN(lost_clock, period);
}
assert(lost_clock >= 0 && lost_clock <= period);
next_irq_clock = cur_clock + period - lost_clock;
s->next_periodic_time = periodic_clock_to_ns(next_irq_clock) + 1;
timer_mod(s->periodic_timer, s->next_periodic_time);
} else {
s->irq_coalesced = 0;
timer_del(s->periodic_timer);
}
}
static void rtc_periodic_timer(void *opaque)
{
RTCState *s = opaque;
periodic_timer_update(s, s->next_periodic_time, 0);
s->cmos_data[RTC_REG_C] |= REG_C_PF;
if (s->cmos_data[RTC_REG_B] & REG_B_PIE) {
s->cmos_data[RTC_REG_C] |= REG_C_IRQF;
if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
if (s->irq_reinject_on_ack_count >= RTC_REINJECT_ON_ACK_COUNT)
s->irq_reinject_on_ack_count = 0;
if (!rtc_policy_slew_deliver_irq(s)) {
s->irq_coalesced++;
rtc_coalesced_timer_update(s);
DPRINTF_C("cmos: coalesced irqs increased to %d\n",
s->irq_coalesced);
}
} else
qemu_irq_raise(s->irq);
}
}
/* handle update-ended timer */
static void check_update_timer(RTCState *s)
{
uint64_t next_update_time;
uint64_t guest_nsec;
int next_alarm_sec;
/* From the data sheet: "Holding the dividers in reset prevents
* interrupts from operating, while setting the SET bit allows"
* them to occur.
*/
if ((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) {
assert((s->cmos_data[RTC_REG_A] & REG_A_UIP) == 0);
timer_del(s->update_timer);
return;
}
guest_nsec = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND;
next_update_time = qemu_clock_get_ns(rtc_clock)
+ NANOSECONDS_PER_SECOND - guest_nsec;
/* Compute time of next alarm. One second is already accounted
* for in next_update_time.
*/
next_alarm_sec = get_next_alarm(s);
s->next_alarm_time = next_update_time +
(next_alarm_sec - 1) * NANOSECONDS_PER_SECOND;
/* If update_in_progress latched the UIP bit, we must keep the timer
* programmed to the next second, so that UIP is cleared. Otherwise,
* if UF is already set, we might be able to optimize.
*/
if (!(s->cmos_data[RTC_REG_A] & REG_A_UIP) &&
(s->cmos_data[RTC_REG_C] & REG_C_UF)) {
/* If AF cannot change (i.e. either it is set already, or
* SET=1 and then the time is not updated), nothing to do.
*/
if ((s->cmos_data[RTC_REG_B] & REG_B_SET) ||
(s->cmos_data[RTC_REG_C] & REG_C_AF)) {
timer_del(s->update_timer);
return;
}
/* UF is set, but AF is clear. Program the timer to target
* the alarm time. */
next_update_time = s->next_alarm_time;
}
if (next_update_time != timer_expire_time_ns(s->update_timer)) {
timer_mod(s->update_timer, next_update_time);
}
}
static inline uint8_t convert_hour(RTCState *s, uint8_t hour)
{
if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) {
hour %= 12;
if (s->cmos_data[RTC_HOURS] & 0x80) {
hour += 12;
}
}
return hour;
}
static uint64_t get_next_alarm(RTCState *s)
{
int32_t alarm_sec, alarm_min, alarm_hour, cur_hour, cur_min, cur_sec;
int32_t hour, min, sec;
rtc_update_time(s);
alarm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS_ALARM]);
alarm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES_ALARM]);
alarm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS_ALARM]);
alarm_hour = alarm_hour == -1 ? -1 : convert_hour(s, alarm_hour);
cur_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]);
cur_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]);
cur_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS]);
cur_hour = convert_hour(s, cur_hour);
if (alarm_hour == -1) {
alarm_hour = cur_hour;
if (alarm_min == -1) {
alarm_min = cur_min;
if (alarm_sec == -1) {
alarm_sec = cur_sec + 1;
} else if (cur_sec > alarm_sec) {
alarm_min++;
}
} else if (cur_min == alarm_min) {
if (alarm_sec == -1) {
alarm_sec = cur_sec + 1;
} else {
if (cur_sec > alarm_sec) {
alarm_hour++;
}
}
if (alarm_sec == SEC_PER_MIN) {
/* wrap to next hour, minutes is not in don't care mode */
alarm_sec = 0;
alarm_hour++;
}
} else if (cur_min > alarm_min) {
alarm_hour++;
}
} else if (cur_hour == alarm_hour) {
if (alarm_min == -1) {
alarm_min = cur_min;
if (alarm_sec == -1) {
alarm_sec = cur_sec + 1;
} else if (cur_sec > alarm_sec) {
alarm_min++;
}
if (alarm_sec == SEC_PER_MIN) {
alarm_sec = 0;
alarm_min++;
}
/* wrap to next day, hour is not in don't care mode */
alarm_min %= MIN_PER_HOUR;
} else if (cur_min == alarm_min) {
if (alarm_sec == -1) {
alarm_sec = cur_sec + 1;
}
/* wrap to next day, hours+minutes not in don't care mode */
alarm_sec %= SEC_PER_MIN;
}
}
/* values that are still don't care fire at the next min/sec */
if (alarm_min == -1) {
alarm_min = 0;
}
if (alarm_sec == -1) {
alarm_sec = 0;
}
/* keep values in range */
if (alarm_sec == SEC_PER_MIN) {
alarm_sec = 0;
alarm_min++;
}
if (alarm_min == MIN_PER_HOUR) {
alarm_min = 0;
alarm_hour++;
}
alarm_hour %= HOUR_PER_DAY;
hour = alarm_hour - cur_hour;
min = hour * MIN_PER_HOUR + alarm_min - cur_min;
sec = min * SEC_PER_MIN + alarm_sec - cur_sec;
return sec <= 0 ? sec + SEC_PER_DAY : sec;
}
static void rtc_update_timer(void *opaque)
{
RTCState *s = opaque;
int32_t irqs = REG_C_UF;
int32_t new_irqs;
assert((s->cmos_data[RTC_REG_A] & 0x60) != 0x60);
/* UIP might have been latched, update time and clear it. */
rtc_update_time(s);
s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
if (qemu_clock_get_ns(rtc_clock) >= s->next_alarm_time) {
irqs |= REG_C_AF;
if (s->cmos_data[RTC_REG_B] & REG_B_AIE) {
qemu_system_wakeup_request(QEMU_WAKEUP_REASON_RTC);
}
}
new_irqs = irqs & ~s->cmos_data[RTC_REG_C];
s->cmos_data[RTC_REG_C] |= irqs;
if ((new_irqs & s->cmos_data[RTC_REG_B]) != 0) {
s->cmos_data[RTC_REG_C] |= REG_C_IRQF;
qemu_irq_raise(s->irq);
}
check_update_timer(s);
}
static void cmos_ioport_write(void *opaque, hwaddr addr,
uint64_t data, unsigned size)
{
RTCState *s = opaque;
uint32_t old_period;
bool update_periodic_timer;
if ((addr & 1) == 0) {
s->cmos_index = data & 0x7f;
} else {
CMOS_DPRINTF("cmos: write index=0x%02x val=0x%02" PRIx64 "\n",
s->cmos_index, data);
switch(s->cmos_index) {
case RTC_SECONDS_ALARM:
case RTC_MINUTES_ALARM:
case RTC_HOURS_ALARM:
s->cmos_data[s->cmos_index] = data;
check_update_timer(s);
break;
case RTC_IBM_PS2_CENTURY_BYTE:
s->cmos_index = RTC_CENTURY;
/* fall through */
case RTC_CENTURY:
case RTC_SECONDS:
case RTC_MINUTES:
case RTC_HOURS:
case RTC_DAY_OF_WEEK:
case RTC_DAY_OF_MONTH:
case RTC_MONTH:
case RTC_YEAR:
s->cmos_data[s->cmos_index] = data;
/* if in set mode, do not update the time */
if (rtc_running(s)) {
rtc_set_time(s);
check_update_timer(s);
}
break;
case RTC_REG_A:
update_periodic_timer = (s->cmos_data[RTC_REG_A] ^ data) & 0x0f;
old_period = rtc_periodic_clock_ticks(s);
if ((data & 0x60) == 0x60) {
if (rtc_running(s)) {
rtc_update_time(s);
}
/* What happens to UIP when divider reset is enabled is
* unclear from the datasheet. Shouldn't matter much
* though.
*/
s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
} else if (((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) &&
(data & 0x70) <= 0x20) {
/* when the divider reset is removed, the first update cycle
* begins one-half second later*/
if (!(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
s->offset = 500000000;
rtc_set_time(s);
}
s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
}
/* UIP bit is read only */
s->cmos_data[RTC_REG_A] = (data & ~REG_A_UIP) |
(s->cmos_data[RTC_REG_A] & REG_A_UIP);
if (update_periodic_timer) {
periodic_timer_update(s, qemu_clock_get_ns(rtc_clock),
old_period);
}
check_update_timer(s);
break;
case RTC_REG_B:
update_periodic_timer = (s->cmos_data[RTC_REG_B] ^ data)
& REG_B_PIE;
old_period = rtc_periodic_clock_ticks(s);
if (data & REG_B_SET) {
/* update cmos to when the rtc was stopping */
if (rtc_running(s)) {
rtc_update_time(s);
}
/* set mode: reset UIP mode */
s->cmos_data[RTC_REG_A] &= ~REG_A_UIP;
data &= ~REG_B_UIE;
} else {
/* if disabling set mode, update the time */
if ((s->cmos_data[RTC_REG_B] & REG_B_SET) &&
(s->cmos_data[RTC_REG_A] & 0x70) <= 0x20) {
s->offset = get_guest_rtc_ns(s) % NANOSECONDS_PER_SECOND;
rtc_set_time(s);
}
}
/* if an interrupt flag is already set when the interrupt
* becomes enabled, raise an interrupt immediately. */
if (data & s->cmos_data[RTC_REG_C] & REG_C_MASK) {
s->cmos_data[RTC_REG_C] |= REG_C_IRQF;
qemu_irq_raise(s->irq);
} else {
s->cmos_data[RTC_REG_C] &= ~REG_C_IRQF;
qemu_irq_lower(s->irq);
}
s->cmos_data[RTC_REG_B] = data;
if (update_periodic_timer) {
periodic_timer_update(s, qemu_clock_get_ns(rtc_clock),
old_period);
}
check_update_timer(s);
break;
case RTC_REG_C:
case RTC_REG_D:
/* cannot write to them */
break;
default:
s->cmos_data[s->cmos_index] = data;
break;
}
}
}
static inline int rtc_to_bcd(RTCState *s, int a)
{
if (s->cmos_data[RTC_REG_B] & REG_B_DM) {
return a;
} else {
return ((a / 10) << 4) | (a % 10);
}
}
static inline int rtc_from_bcd(RTCState *s, int a)
{
if ((a & 0xc0) == 0xc0) {
return -1;
}
if (s->cmos_data[RTC_REG_B] & REG_B_DM) {
return a;
} else {
return ((a >> 4) * 10) + (a & 0x0f);
}
}
static void rtc_get_time(RTCState *s, struct tm *tm)
{
tm->tm_sec = rtc_from_bcd(s, s->cmos_data[RTC_SECONDS]);
tm->tm_min = rtc_from_bcd(s, s->cmos_data[RTC_MINUTES]);
tm->tm_hour = rtc_from_bcd(s, s->cmos_data[RTC_HOURS] & 0x7f);
if (!(s->cmos_data[RTC_REG_B] & REG_B_24H)) {
tm->tm_hour %= 12;
if (s->cmos_data[RTC_HOURS] & 0x80) {
tm->tm_hour += 12;
}
}
tm->tm_wday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_WEEK]) - 1;
tm->tm_mday = rtc_from_bcd(s, s->cmos_data[RTC_DAY_OF_MONTH]);
tm->tm_mon = rtc_from_bcd(s, s->cmos_data[RTC_MONTH]) - 1;
tm->tm_year =
rtc_from_bcd(s, s->cmos_data[RTC_YEAR]) + s->base_year +
rtc_from_bcd(s, s->cmos_data[RTC_CENTURY]) * 100 - 1900;
}
static void rtc_set_time(RTCState *s)
{
struct tm tm;
rtc_get_time(s, &tm);
s->base_rtc = mktimegm(&tm);
s->last_update = qemu_clock_get_ns(rtc_clock);
qapi_event_send_rtc_change(qemu_timedate_diff(&tm), &error_abort);
}
static void rtc_set_cmos(RTCState *s, const struct tm *tm)
{
int year;
s->cmos_data[RTC_SECONDS] = rtc_to_bcd(s, tm->tm_sec);
s->cmos_data[RTC_MINUTES] = rtc_to_bcd(s, tm->tm_min);
if (s->cmos_data[RTC_REG_B] & REG_B_24H) {
/* 24 hour format */
s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, tm->tm_hour);
} else {
/* 12 hour format */
int h = (tm->tm_hour % 12) ? tm->tm_hour % 12 : 12;
s->cmos_data[RTC_HOURS] = rtc_to_bcd(s, h);
if (tm->tm_hour >= 12)
s->cmos_data[RTC_HOURS] |= 0x80;
}
s->cmos_data[RTC_DAY_OF_WEEK] = rtc_to_bcd(s, tm->tm_wday + 1);
s->cmos_data[RTC_DAY_OF_MONTH] = rtc_to_bcd(s, tm->tm_mday);
s->cmos_data[RTC_MONTH] = rtc_to_bcd(s, tm->tm_mon + 1);
year = tm->tm_year + 1900 - s->base_year;
s->cmos_data[RTC_YEAR] = rtc_to_bcd(s, year % 100);
s->cmos_data[RTC_CENTURY] = rtc_to_bcd(s, year / 100);
}
static void rtc_update_time(RTCState *s)
{
struct tm ret;
time_t guest_sec;
int64_t guest_nsec;
guest_nsec = get_guest_rtc_ns(s);
guest_sec = guest_nsec / NANOSECONDS_PER_SECOND;
gmtime_r(&guest_sec, &ret);
/* Is SET flag of Register B disabled? */
if ((s->cmos_data[RTC_REG_B] & REG_B_SET) == 0) {
rtc_set_cmos(s, &ret);
}
}
static int update_in_progress(RTCState *s)
{
int64_t guest_nsec;
if (!rtc_running(s)) {
return 0;
}
if (timer_pending(s->update_timer)) {
int64_t next_update_time = timer_expire_time_ns(s->update_timer);
/* Latch UIP until the timer expires. */
if (qemu_clock_get_ns(rtc_clock) >=
(next_update_time - UIP_HOLD_LENGTH)) {
s->cmos_data[RTC_REG_A] |= REG_A_UIP;
return 1;
}
}
guest_nsec = get_guest_rtc_ns(s);
/* UIP bit will be set at last 244us of every second. */
if ((guest_nsec % NANOSECONDS_PER_SECOND) >=
(NANOSECONDS_PER_SECOND - UIP_HOLD_LENGTH)) {
return 1;
}
return 0;
}
static uint64_t cmos_ioport_read(void *opaque, hwaddr addr,
unsigned size)
{
RTCState *s = opaque;
int ret;
if ((addr & 1) == 0) {
return 0xff;
} else {
switch(s->cmos_index) {
case RTC_IBM_PS2_CENTURY_BYTE:
s->cmos_index = RTC_CENTURY;
/* fall through */
case RTC_CENTURY:
case RTC_SECONDS:
case RTC_MINUTES:
case RTC_HOURS:
case RTC_DAY_OF_WEEK:
case RTC_DAY_OF_MONTH:
case RTC_MONTH:
case RTC_YEAR:
/* if not in set mode, calibrate cmos before
* reading*/
if (rtc_running(s)) {
rtc_update_time(s);
}
ret = s->cmos_data[s->cmos_index];
break;
case RTC_REG_A:
ret = s->cmos_data[s->cmos_index];
if (update_in_progress(s)) {
ret |= REG_A_UIP;
}
break;
case RTC_REG_C:
ret = s->cmos_data[s->cmos_index];
qemu_irq_lower(s->irq);
s->cmos_data[RTC_REG_C] = 0x00;
if (ret & (REG_C_UF | REG_C_AF)) {
check_update_timer(s);
}
if(s->irq_coalesced &&
(s->cmos_data[RTC_REG_B] & REG_B_PIE) &&
s->irq_reinject_on_ack_count < RTC_REINJECT_ON_ACK_COUNT) {
s->irq_reinject_on_ack_count++;
s->cmos_data[RTC_REG_C] |= REG_C_IRQF | REG_C_PF;
DPRINTF_C("cmos: injecting on ack\n");
if (rtc_policy_slew_deliver_irq(s)) {
s->irq_coalesced--;
DPRINTF_C("cmos: coalesced irqs decreased to %d\n",
s->irq_coalesced);
}
}
break;
default:
ret = s->cmos_data[s->cmos_index];
break;
}
CMOS_DPRINTF("cmos: read index=0x%02x val=0x%02x\n",
s->cmos_index, ret);
return ret;
}
}
void rtc_set_memory(ISADevice *dev, int addr, int val)
{
RTCState *s = MC146818_RTC(dev);
if (addr >= 0 && addr <= 127)
s->cmos_data[addr] = val;
}
int rtc_get_memory(ISADevice *dev, int addr)
{
RTCState *s = MC146818_RTC(dev);
assert(addr >= 0 && addr <= 127);
return s->cmos_data[addr];
}
static void rtc_set_date_from_host(ISADevice *dev)
{
RTCState *s = MC146818_RTC(dev);
struct tm tm;
qemu_get_timedate(&tm, 0);
s->base_rtc = mktimegm(&tm);
s->last_update = qemu_clock_get_ns(rtc_clock);
s->offset = 0;
/* set the CMOS date */
rtc_set_cmos(s, &tm);
}
static int rtc_pre_save(void *opaque)
{
RTCState *s = opaque;
rtc_update_time(s);
return 0;
}
static int rtc_post_load(void *opaque, int version_id)
{
RTCState *s = opaque;
if (version_id <= 2 || rtc_clock == QEMU_CLOCK_REALTIME) {
rtc_set_time(s);
s->offset = 0;
check_update_timer(s);
}
/* The periodic timer is deterministic in record/replay mode,
* so there is no need to update it after loading the vmstate.
* Reading RTC here would misalign record and replay.
*/
if (replay_mode == REPLAY_MODE_NONE) {
uint64_t now = qemu_clock_get_ns(rtc_clock);
if (now < s->next_periodic_time ||
now > (s->next_periodic_time + get_max_clock_jump())) {
periodic_timer_update(s, qemu_clock_get_ns(rtc_clock), 0);
}
}
if (version_id >= 2) {
if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
rtc_coalesced_timer_update(s);
}
}
return 0;
}
static bool rtc_irq_reinject_on_ack_count_needed(void *opaque)
{
RTCState *s = (RTCState *)opaque;
return s->irq_reinject_on_ack_count != 0;
}
static const VMStateDescription vmstate_rtc_irq_reinject_on_ack_count = {
.name = "mc146818rtc/irq_reinject_on_ack_count",
.version_id = 1,
.minimum_version_id = 1,
.needed = rtc_irq_reinject_on_ack_count_needed,
.fields = (VMStateField[]) {
VMSTATE_UINT16(irq_reinject_on_ack_count, RTCState),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_rtc = {
.name = "mc146818rtc",
.version_id = 3,
.minimum_version_id = 1,
.pre_save = rtc_pre_save,
.post_load = rtc_post_load,
.fields = (VMStateField[]) {
VMSTATE_BUFFER(cmos_data, RTCState),
VMSTATE_UINT8(cmos_index, RTCState),
VMSTATE_UNUSED(7*4),
VMSTATE_TIMER_PTR(periodic_timer, RTCState),
VMSTATE_INT64(next_periodic_time, RTCState),
VMSTATE_UNUSED(3*8),
VMSTATE_UINT32_V(irq_coalesced, RTCState, 2),
VMSTATE_UINT32_V(period, RTCState, 2),
VMSTATE_UINT64_V(base_rtc, RTCState, 3),
VMSTATE_UINT64_V(last_update, RTCState, 3),
VMSTATE_INT64_V(offset, RTCState, 3),
VMSTATE_TIMER_PTR_V(update_timer, RTCState, 3),
VMSTATE_UINT64_V(next_alarm_time, RTCState, 3),
VMSTATE_END_OF_LIST()
},
.subsections = (const VMStateDescription*[]) {
&vmstate_rtc_irq_reinject_on_ack_count,
NULL
}
};
static void rtc_notify_clock_reset(Notifier *notifier, void *data)
{
RTCState *s = container_of(notifier, RTCState, clock_reset_notifier);
int64_t now = *(int64_t *)data;
rtc_set_date_from_host(ISA_DEVICE(s));
periodic_timer_update(s, now, 0);
check_update_timer(s);
if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
rtc_coalesced_timer_update(s);
}
}
/* set CMOS shutdown status register (index 0xF) as S3_resume(0xFE)
BIOS will read it and start S3 resume at POST Entry */
static void rtc_notify_suspend(Notifier *notifier, void *data)
{
RTCState *s = container_of(notifier, RTCState, suspend_notifier);
rtc_set_memory(ISA_DEVICE(s), 0xF, 0xFE);
}
static void rtc_reset(void *opaque)
{
RTCState *s = opaque;
s->cmos_data[RTC_REG_B] &= ~(REG_B_PIE | REG_B_AIE | REG_B_SQWE);
s->cmos_data[RTC_REG_C] &= ~(REG_C_UF | REG_C_IRQF | REG_C_PF | REG_C_AF);
check_update_timer(s);
qemu_irq_lower(s->irq);
if (s->lost_tick_policy == LOST_TICK_POLICY_SLEW) {
s->irq_coalesced = 0;
s->irq_reinject_on_ack_count = 0;
}
}
static const MemoryRegionOps cmos_ops = {
.read = cmos_ioport_read,
.write = cmos_ioport_write,
.impl = {
.min_access_size = 1,
.max_access_size = 1,
},
.endianness = DEVICE_LITTLE_ENDIAN,
};
static void rtc_get_date(Object *obj, struct tm *current_tm, Error **errp)
{
RTCState *s = MC146818_RTC(obj);
rtc_update_time(s);
rtc_get_time(s, current_tm);
}
static void rtc_realizefn(DeviceState *dev, Error **errp)
{
ISADevice *isadev = ISA_DEVICE(dev);
RTCState *s = MC146818_RTC(dev);
int base = 0x70;
s->cmos_data[RTC_REG_A] = 0x26;
s->cmos_data[RTC_REG_B] = 0x02;
s->cmos_data[RTC_REG_C] = 0x00;
s->cmos_data[RTC_REG_D] = 0x80;
/* This is for historical reasons. The default base year qdev property
* was set to 2000 for most machine types before the century byte was
* implemented.
*
* This if statement means that the century byte will be always 0
* (at least until 2079...) for base_year = 1980, but will be set
* correctly for base_year = 2000.
*/
if (s->base_year == 2000) {
s->base_year = 0;
}
rtc_set_date_from_host(isadev);
switch (s->lost_tick_policy) {
#ifdef TARGET_I386
case LOST_TICK_POLICY_SLEW:
s->coalesced_timer =
timer_new_ns(rtc_clock, rtc_coalesced_timer, s);
break;
#endif
case LOST_TICK_POLICY_DISCARD:
break;
default:
error_setg(errp, "Invalid lost tick policy.");
return;
}
s->periodic_timer = timer_new_ns(rtc_clock, rtc_periodic_timer, s);
s->update_timer = timer_new_ns(rtc_clock, rtc_update_timer, s);
check_update_timer(s);
s->clock_reset_notifier.notify = rtc_notify_clock_reset;
qemu_clock_register_reset_notifier(rtc_clock,
&s->clock_reset_notifier);
s->suspend_notifier.notify = rtc_notify_suspend;
qemu_register_suspend_notifier(&s->suspend_notifier);
memory_region_init_io(&s->io, OBJECT(s), &cmos_ops, s, "rtc", 2);
isa_register_ioport(isadev, &s->io, base);
qdev_set_legacy_instance_id(dev, base, 3);
qemu_register_reset(rtc_reset, s);
object_property_add_tm(OBJECT(s), "date", rtc_get_date, NULL);
object_property_add_alias(qdev_get_machine(), "rtc-time",
OBJECT(s), "date", NULL);
qdev_init_gpio_out(dev, &s->irq, 1);
}
ISADevice *mc146818_rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq)
{
DeviceState *dev;
ISADevice *isadev;
RTCState *s;
isadev = isa_create(bus, TYPE_MC146818_RTC);
dev = DEVICE(isadev);
s = MC146818_RTC(isadev);
qdev_prop_set_int32(dev, "base_year", base_year);
qdev_init_nofail(dev);
if (intercept_irq) {
qdev_connect_gpio_out(dev, 0, intercept_irq);
} else {
isa_connect_gpio_out(isadev, 0, RTC_ISA_IRQ);
}
QLIST_INSERT_HEAD(&rtc_devices, s, link);
return isadev;
}
static Property mc146818rtc_properties[] = {
DEFINE_PROP_INT32("base_year", RTCState, base_year, 1980),
DEFINE_PROP_LOSTTICKPOLICY("lost_tick_policy", RTCState,
lost_tick_policy, LOST_TICK_POLICY_DISCARD),
DEFINE_PROP_END_OF_LIST(),
};
static void rtc_resetdev(DeviceState *d)
{
RTCState *s = MC146818_RTC(d);
/* Reason: VM do suspend self will set 0xfe
* Reset any values other than 0xfe(Guest suspend case) */
if (s->cmos_data[0x0f] != 0xfe) {
s->cmos_data[0x0f] = 0x00;
}
}
static void rtc_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = rtc_realizefn;
dc->reset = rtc_resetdev;
dc->vmsd = &vmstate_rtc;
dc->props = mc146818rtc_properties;
/* Reason: needs to be wired up by rtc_init() */
dc->user_creatable = false;
}
static void rtc_finalize(Object *obj)
{
object_property_del(qdev_get_machine(), "rtc", NULL);
}
static const TypeInfo mc146818rtc_info = {
.name = TYPE_MC146818_RTC,
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(RTCState),
.class_init = rtc_class_initfn,
.instance_finalize = rtc_finalize,
};
static void mc146818rtc_register_types(void)
{
type_register_static(&mc146818rtc_info);
}
type_init(mc146818rtc_register_types)