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qemu/hw/mc146818rtc.c
Alex Horn 02c6ccc6dd rtc: Only call rtc_set_cmos when Register B SET flag is disabled. 
This bug occurs when the SET flag of Register B is enabled. When an RTC
data register (i.e. any of the ten time/calender CMOS bytes) is set, the
data is (as expected) correctly stored in the cmos_data array. However,
since the SET flag is enabled, the function rtc_set_time is not invoked.
As a result, the field base_rtc in RTCState remains uninitialized. This
causes a problem on subsequent writes which can end up overwriting data.
To see this, consider writing data to Register A after having written
data to any of the RTC data registers; the following figure illustrates
the call stack for the Register A write operation:

 +- cmos_io_port_write
 +-- check_update_timer
 +---- get_next_alarm
 +------ rtc_update_time

In rtc_update_time, get_guest_rtc calculates the wrong time and
overwrites the previously written RTC data register values.

Signed-off-by: Alex Horn <alex.horn@cs.ox.ac.uk>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
2012-11-27 11:04:33 -06:00

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/*
* 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 "hw.h"
#include "qemu-timer.h"
#include "sysemu.h"
#include "mc146818rtc.h"
#include "qapi/qapi-visit-core.h"
#ifdef TARGET_I386
#include "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 NSEC_PER_SEC 1000000000LL
#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 * NSEC_PER_SEC / 32768)
typedef struct RTCState {
ISADevice dev;
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;
qemu_irq sqw_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;
} 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_rtc;
uint64_t guest_clock = qemu_get_clock_ns(rtc_clock);
guest_rtc = s->base_rtc * NSEC_PER_SEC
+ guest_clock - s->last_update + s->offset;
return guest_rtc;
}
#ifdef TARGET_I386
static void rtc_coalesced_timer_update(RTCState *s)
{
if (s->irq_coalesced == 0) {
qemu_del_timer(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_get_clock_ns(rtc_clock) +
muldiv64(s->period / c, get_ticks_per_sec(), RTC_CLOCK_RATE);
qemu_mod_timer(s->coalesced_timer, next_clock);
}
}
static void rtc_coalesced_timer(void *opaque)
{
RTCState *s = opaque;
if (s->irq_coalesced != 0) {
apic_reset_irq_delivered();
s->cmos_data[RTC_REG_C] |= 0xc0;
DPRINTF_C("cmos: injecting from timer\n");
qemu_irq_raise(s->irq);
if (apic_get_irq_delivered()) {
s->irq_coalesced--;
DPRINTF_C("cmos: coalesced irqs decreased to %d\n",
s->irq_coalesced);
}
}
rtc_coalesced_timer_update(s);
}
#endif
/* handle periodic timer */
static void periodic_timer_update(RTCState *s, int64_t current_time)
{
int period_code, period;
int64_t cur_clock, next_irq_clock;
period_code = s->cmos_data[RTC_REG_A] & 0x0f;
if (period_code != 0
&& ((s->cmos_data[RTC_REG_B] & REG_B_PIE)
|| ((s->cmos_data[RTC_REG_B] & REG_B_SQWE) && s->sqw_irq))) {
if (period_code <= 2)
period_code += 7;
/* period in 32 Khz cycles */
period = 1 << (period_code - 1);
#ifdef TARGET_I386
if (period != s->period) {
s->irq_coalesced = (s->irq_coalesced * s->period) / period;
DPRINTF_C("cmos: coalesced irqs scaled to %d\n", s->irq_coalesced);
}
s->period = period;
#endif
/* compute 32 khz clock */
cur_clock = muldiv64(current_time, RTC_CLOCK_RATE, get_ticks_per_sec());
next_irq_clock = (cur_clock & ~(period - 1)) + period;
s->next_periodic_time =
muldiv64(next_irq_clock, get_ticks_per_sec(), RTC_CLOCK_RATE) + 1;
qemu_mod_timer(s->periodic_timer, s->next_periodic_time);
} else {
#ifdef TARGET_I386
s->irq_coalesced = 0;
#endif
qemu_del_timer(s->periodic_timer);
}
}
static void rtc_periodic_timer(void *opaque)
{
RTCState *s = opaque;
periodic_timer_update(s, s->next_periodic_time);
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;
#ifdef TARGET_I386
if (s->lost_tick_policy == LOST_TICK_SLEW) {
if (s->irq_reinject_on_ack_count >= RTC_REINJECT_ON_ACK_COUNT)
s->irq_reinject_on_ack_count = 0;
apic_reset_irq_delivered();
qemu_irq_raise(s->irq);
if (!apic_get_irq_delivered()) {
s->irq_coalesced++;
rtc_coalesced_timer_update(s);
DPRINTF_C("cmos: coalesced irqs increased to %d\n",
s->irq_coalesced);
}
} else
#endif
qemu_irq_raise(s->irq);
}
if (s->cmos_data[RTC_REG_B] & REG_B_SQWE) {
/* Not square wave at all but we don't want 2048Hz interrupts!
Must be seen as a pulse. */
qemu_irq_raise(s->sqw_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. However, it will prevent an alarm interrupt
* from occurring, because the time of day is not updated.
*/
if ((s->cmos_data[RTC_REG_A] & 0x60) == 0x60) {
qemu_del_timer(s->update_timer);
return;
}
if ((s->cmos_data[RTC_REG_C] & REG_C_UF) &&
(s->cmos_data[RTC_REG_B] & REG_B_SET)) {
qemu_del_timer(s->update_timer);
return;
}
if ((s->cmos_data[RTC_REG_C] & REG_C_UF) &&
(s->cmos_data[RTC_REG_C] & REG_C_AF)) {
qemu_del_timer(s->update_timer);
return;
}
guest_nsec = get_guest_rtc_ns(s) % NSEC_PER_SEC;
/* if UF is clear, reprogram to next second */
next_update_time = qemu_get_clock_ns(rtc_clock)
+ NSEC_PER_SEC - 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) * NSEC_PER_SEC;
if (s->cmos_data[RTC_REG_C] & REG_C_UF) {
/* 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 != qemu_timer_expire_time_ns(s->update_timer)) {
qemu_mod_timer(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_get_clock_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;
if ((addr & 1) == 0) {
s->cmos_index = data & 0x7f;
} else {
CMOS_DPRINTF("cmos: write index=0x%02x val=0x%02x\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:
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);
periodic_timer_update(s, qemu_get_clock_ns(rtc_clock));
check_update_timer(s);
break;
case RTC_REG_B:
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) % NSEC_PER_SEC;
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;
periodic_timer_update(s, qemu_get_clock_ns(rtc_clock));
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_get_clock_ns(rtc_clock);
rtc_change_mon_event(&tm);
}
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 / NSEC_PER_SEC;
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 (qemu_timer_pending(s->update_timer)) {
int64_t next_update_time = qemu_timer_expire_time_ns(s->update_timer);
/* Latch UIP until the timer expires. */
if (qemu_get_clock_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 % NSEC_PER_SEC) >= (NSEC_PER_SEC - 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:
if (update_in_progress(s)) {
s->cmos_data[s->cmos_index] |= REG_A_UIP;
} else {
s->cmos_data[s->cmos_index] &= ~REG_A_UIP;
}
ret = s->cmos_data[s->cmos_index];
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);
}
#ifdef TARGET_I386
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;
apic_reset_irq_delivered();
DPRINTF_C("cmos: injecting on ack\n");
qemu_irq_raise(s->irq);
if (apic_get_irq_delivered()) {
s->irq_coalesced--;
DPRINTF_C("cmos: coalesced irqs decreased to %d\n",
s->irq_coalesced);
}
}
#endif
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 = DO_UPCAST(RTCState, dev, dev);
if (addr >= 0 && addr <= 127)
s->cmos_data[addr] = val;
}
static void rtc_set_date_from_host(ISADevice *dev)
{
RTCState *s = DO_UPCAST(RTCState, dev, dev);
struct tm tm;
qemu_get_timedate(&tm, 0);
s->base_rtc = mktimegm(&tm);
s->last_update = qemu_get_clock_ns(rtc_clock);
s->offset = 0;
/* set the CMOS date */
rtc_set_cmos(s, &tm);
}
static int rtc_post_load(void *opaque, int version_id)
{
RTCState *s = opaque;
if (version_id <= 2) {
rtc_set_time(s);
s->offset = 0;
check_update_timer(s);
}
#ifdef TARGET_I386
if (version_id >= 2) {
if (s->lost_tick_policy == LOST_TICK_SLEW) {
rtc_coalesced_timer_update(s);
}
}
#endif
return 0;
}
static const VMStateDescription vmstate_rtc = {
.name = "mc146818rtc",
.version_id = 3,
.minimum_version_id = 1,
.minimum_version_id_old = 1,
.post_load = rtc_post_load,
.fields = (VMStateField []) {
VMSTATE_BUFFER(cmos_data, RTCState),
VMSTATE_UINT8(cmos_index, RTCState),
VMSTATE_UNUSED(7*4),
VMSTATE_TIMER(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_V(update_timer, RTCState, 3),
VMSTATE_UINT64_V(next_alarm_time, RTCState, 3),
VMSTATE_END_OF_LIST()
}
};
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(&s->dev);
periodic_timer_update(s, now);
check_update_timer(s);
#ifdef TARGET_I386
if (s->lost_tick_policy == LOST_TICK_SLEW) {
rtc_coalesced_timer_update(s);
}
#endif
}
/* 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(&s->dev, 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);
#ifdef TARGET_I386
if (s->lost_tick_policy == LOST_TICK_SLEW) {
s->irq_coalesced = 0;
}
#endif
}
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, Visitor *v, void *opaque,
const char *name, Error **errp)
{
ISADevice *isa = ISA_DEVICE(obj);
RTCState *s = DO_UPCAST(RTCState, dev, isa);
struct tm current_tm;
rtc_update_time(s);
rtc_get_time(s, &current_tm);
visit_start_struct(v, NULL, "struct tm", name, 0, errp);
visit_type_int32(v, &current_tm.tm_year, "tm_year", errp);
visit_type_int32(v, &current_tm.tm_mon, "tm_mon", errp);
visit_type_int32(v, &current_tm.tm_mday, "tm_mday", errp);
visit_type_int32(v, &current_tm.tm_hour, "tm_hour", errp);
visit_type_int32(v, &current_tm.tm_min, "tm_min", errp);
visit_type_int32(v, &current_tm.tm_sec, "tm_sec", errp);
visit_end_struct(v, errp);
}
static int rtc_initfn(ISADevice *dev)
{
RTCState *s = DO_UPCAST(RTCState, dev, 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(dev);
#ifdef TARGET_I386
switch (s->lost_tick_policy) {
case LOST_TICK_SLEW:
s->coalesced_timer =
qemu_new_timer_ns(rtc_clock, rtc_coalesced_timer, s);
break;
case LOST_TICK_DISCARD:
break;
default:
return -EINVAL;
}
#endif
s->periodic_timer = qemu_new_timer_ns(rtc_clock, rtc_periodic_timer, s);
s->update_timer = qemu_new_timer_ns(rtc_clock, rtc_update_timer, s);
check_update_timer(s);
s->clock_reset_notifier.notify = rtc_notify_clock_reset;
qemu_register_clock_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, &cmos_ops, s, "rtc", 2);
isa_register_ioport(dev, &s->io, base);
qdev_set_legacy_instance_id(&dev->qdev, base, 3);
qemu_register_reset(rtc_reset, s);
object_property_add(OBJECT(s), "date", "struct tm",
rtc_get_date, NULL, NULL, s, NULL);
return 0;
}
ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq)
{
ISADevice *dev;
RTCState *s;
dev = isa_create(bus, "mc146818rtc");
s = DO_UPCAST(RTCState, dev, dev);
qdev_prop_set_int32(&dev->qdev, "base_year", base_year);
qdev_init_nofail(&dev->qdev);
if (intercept_irq) {
s->irq = intercept_irq;
} else {
isa_init_irq(dev, &s->irq, RTC_ISA_IRQ);
}
return dev;
}
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_DISCARD),
DEFINE_PROP_END_OF_LIST(),
};
static void rtc_class_initfn(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
ISADeviceClass *ic = ISA_DEVICE_CLASS(klass);
ic->init = rtc_initfn;
dc->no_user = 1;
dc->vmsd = &vmstate_rtc;
dc->props = mc146818rtc_properties;
}
static TypeInfo mc146818rtc_info = {
.name = "mc146818rtc",
.parent = TYPE_ISA_DEVICE,
.instance_size = sizeof(RTCState),
.class_init = rtc_class_initfn,
};
static void mc146818rtc_register_types(void)
{
type_register_static(&mc146818rtc_info);
}
type_init(mc146818rtc_register_types)
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