From: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx>
It tests the accuracy of rtc periodic timer which is recently
improved & fixed by:
mc146818rtc: precisely count the clock for periodic timer
(commit id has not been decided yet)
Changelog in v2:
integrate it with rtc-test by using clock_step_next() to inquire
the time in QEMU instead of real time (thanks to Paolo's suggestion)
Signed-off-by: Xiao Guangrong <xiaoguangrong@xxxxxxxxxxx>
---
hw/timer/mc146818rtc.c | 15 +++----------
include/hw/timer/mc146818rtc.h | 19 ++++++++++++++++
tests/rtc-test.c | 49 ++++++++++++++++++++++++++++++++++++++++++
3 files changed, 71 insertions(+), 12 deletions(-)
diff --git a/hw/timer/mc146818rtc.c b/hw/timer/mc146818rtc.c
index 6d0a610..0aba66c 100644
--- a/hw/timer/mc146818rtc.c
+++ b/hw/timer/mc146818rtc.c
@@ -120,7 +120,7 @@ static void rtc_coalesced_timer_update(RTCState *s)
/* 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) +
- muldiv64(s->period / c, NANOSECONDS_PER_SECOND, RTC_CLOCK_RATE);
+ periodic_clock_to_ns(s->period / c);
timer_mod(s->coalesced_timer, next_clock);
}
}
@@ -178,16 +178,8 @@ static uint32_t rtc_periodic_clock_ticks(RTCState *s)
}
period_code = s->cmos_data[RTC_REG_A] & 0x0f;
- if (!period_code) {
- return 0;
- }
-
- if (period_code <= 2) {
- period_code += 7;
- }
- /* period in 32 Khz cycles */
- return 1 << (period_code - 1);
+ return periodic_period_to_clock(period_code);
}
/*
@@ -266,8 +258,7 @@ periodic_timer_update(RTCState *s, int64_t current_time, uint32_t old_period)
assert(lost_clock >= 0 && lost_clock <= period);
next_irq_clock = cur_clock + period - lost_clock;
- s->next_periodic_time = muldiv64(next_irq_clock, NANOSECONDS_PER_SECOND,
- RTC_CLOCK_RATE) + 1;
+ 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;
diff --git a/include/hw/timer/mc146818rtc.h b/include/hw/timer/mc146818rtc.h
index 7c8e64b..f23e734 100644
--- a/include/hw/timer/mc146818rtc.h
+++ b/include/hw/timer/mc146818rtc.h
@@ -10,4 +10,23 @@ ISADevice *rtc_init(ISABus *bus, int base_year, qemu_irq intercept_irq);
void rtc_set_memory(ISADevice *dev, int addr, int val);
int rtc_get_memory(ISADevice *dev, int addr);
+static inline uint32_t periodic_period_to_clock(int period_code)
+{
+ if (!period_code) {
+ return 0;
+ }
+
+ if (period_code <= 2) {
+ period_code += 7;
+ }
+ /* period in 32 Khz cycles */
+ return 1 << (period_code - 1);
+}
+
+#define RTC_CLOCK_RATE 32768
+
+static inline int64_t periodic_clock_to_ns(int64_t clocks)
+{
+ return muldiv64(clocks, NANOSECONDS_PER_SECOND, RTC_CLOCK_RATE);
+}
#endif /* MC146818RTC_H */
diff --git a/tests/rtc-test.c b/tests/rtc-test.c
index a086efd..0500686 100644
--- a/tests/rtc-test.c
+++ b/tests/rtc-test.c
@@ -14,6 +14,7 @@
#include "qemu/osdep.h"
#include "libqtest.h"
+#include "hw/timer/mc146818rtc.h"
#include "hw/timer/mc146818rtc_regs.h"
static uint8_t base = 0x70;
@@ -542,6 +543,52 @@ static void register_b_set_flag(void)
g_assert_cmpint(cmos_read(RTC_CENTURY), ==, 0x20);
}
+#define RTC_PERIOD_CODE1 13 /* 8 Hz */
+#define RTC_PERIOD_CODE2 15 /* 2 Hz */
+
+#define RTC_PERIOD_TEST_NR 50
+
+static uint64_t wait_periodic_interrupt(uint64_t real_time)
+{
+ while (!get_irq(RTC_ISA_IRQ)) {
+ real_time = clock_step_next();
+ }
+
+ g_assert((cmos_read(RTC_REG_C) & REG_C_PF) != 0);
+ return real_time;
+}
+
+static void periodic_timer(void)
+{
+ int i;
+ uint64_t period_clocks, period_time, start_time, real_time;
+
+ /* disable all interrupts. */
+ cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) &
+ ~(REG_B_PIE | REG_B_AIE | REG_B_UIE));
+ cmos_write(RTC_REG_A, RTC_PERIOD_CODE1);
+ /* enable periodic interrupt after properly configure the period. */
+ cmos_write(RTC_REG_B, cmos_read(RTC_REG_B) | REG_B_PIE);
+
+ start_time = real_time = clock_step_next();
+
+ for (i = 0; i < RTC_PERIOD_TEST_NR; i++) {
+ cmos_write(RTC_REG_A, RTC_PERIOD_CODE1);
+ real_time = wait_periodic_interrupt(real_time);
+ cmos_write(RTC_REG_A, RTC_PERIOD_CODE2);
+ real_time = wait_periodic_interrupt(real_time);
+ }
+
+ period_clocks = periodic_period_to_clock(RTC_PERIOD_CODE1) +
+ periodic_period_to_clock(RTC_PERIOD_CODE2);
+ period_clocks *= RTC_PERIOD_TEST_NR;
+ period_time = periodic_clock_to_ns(period_clocks);
+
+ real_time -= start_time;
+ g_assert_cmpint(ABS((int64_t)(real_time - period_time)), <=,
+ NANOSECONDS_PER_SECOND * 0.5);
+}
+
int main(int argc, char **argv)
{
QTestState *s = NULL;
@@ -564,6 +611,8 @@ int main(int argc, char **argv)
qtest_add_func("/rtc/set-year/1980", set_year_1980);
qtest_add_func("/rtc/misc/register_b_set_flag", register_b_set_flag);
qtest_add_func("/rtc/misc/fuzz-registers", fuzz_registers);
+ qtest_add_func("/rtc/periodic/interrupt", periodic_timer);
+
ret = g_test_run();
if (s) {
--
2.9.4
