#include "hw/ptimer.h"
#include "qemu/host-utils.h"
#include "sysemu/replay.h"
+#include "sysemu/qtest.h"
+
+#define DELTA_ADJUST 1
+#define DELTA_NO_ADJUST -1
struct ptimer_state
{
int64_t period;
int64_t last_event;
int64_t next_event;
+ uint8_t policy_mask;
QEMUBH *bh;
QEMUTimer *timer;
};
}
}
-static void ptimer_reload(ptimer_state *s)
+static void ptimer_reload(ptimer_state *s, int delta_adjust)
{
uint32_t period_frac = s->period_frac;
uint64_t period = s->period;
+ uint64_t delta = s->delta;
- if (s->delta == 0) {
+ if (delta == 0 && !(s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)) {
ptimer_trigger(s);
- s->delta = s->limit;
}
- if (s->delta == 0 || s->period == 0) {
- fprintf(stderr, "Timer with period zero, disabling\n");
+
+ if (delta == 0 && !(s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_RELOAD)) {
+ delta = s->delta = s->limit;
+ }
+
+ if (s->period == 0) {
+ if (!qtest_enabled()) {
+ fprintf(stderr, "Timer with period zero, disabling\n");
+ }
+ timer_del(s->timer);
+ s->enabled = 0;
+ return;
+ }
+
+ if (s->policy_mask & PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD) {
+ if (delta_adjust != DELTA_NO_ADJUST) {
+ delta += delta_adjust;
+ }
+ }
+
+ if (delta == 0 && (s->policy_mask & PTIMER_POLICY_CONTINUOUS_TRIGGER)) {
+ if (s->enabled == 1 && s->limit == 0) {
+ delta = 1;
+ }
+ }
+
+ if (delta == 0 && (s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)) {
+ if (delta_adjust != DELTA_NO_ADJUST) {
+ delta = 1;
+ }
+ }
+
+ if (delta == 0 && (s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_RELOAD)) {
+ if (s->enabled == 1 && s->limit != 0) {
+ delta = 1;
+ }
+ }
+
+ if (delta == 0) {
+ if (!qtest_enabled()) {
+ fprintf(stderr, "Timer with delta zero, disabling\n");
+ }
+ timer_del(s->timer);
s->enabled = 0;
return;
}
* on the current generation of host machines.
*/
- if (s->enabled == 1 && (s->delta * period < 10000) && !use_icount) {
- period = 10000 / s->delta;
+ if (s->enabled == 1 && (delta * period < 10000) && !use_icount) {
+ period = 10000 / delta;
period_frac = 0;
}
s->last_event = s->next_event;
- s->next_event = s->last_event + s->delta * period;
+ s->next_event = s->last_event + delta * period;
if (period_frac) {
- s->next_event += ((int64_t)period_frac * s->delta) >> 32;
+ s->next_event += ((int64_t)period_frac * delta) >> 32;
}
timer_mod(s->timer, s->next_event);
}
static void ptimer_tick(void *opaque)
{
ptimer_state *s = (ptimer_state *)opaque;
- ptimer_trigger(s);
- s->delta = 0;
+ bool trigger = true;
+
if (s->enabled == 2) {
+ s->delta = 0;
s->enabled = 0;
} else {
- ptimer_reload(s);
+ int delta_adjust = DELTA_ADJUST;
+
+ if (s->delta == 0 || s->limit == 0) {
+ /* If a "continuous trigger" policy is not used and limit == 0,
+ we should error out. delta == 0 means that this tick is
+ caused by a "no immediate reload" policy, so it shouldn't
+ be adjusted. */
+ delta_adjust = DELTA_NO_ADJUST;
+ }
+
+ if (!(s->policy_mask & PTIMER_POLICY_NO_IMMEDIATE_TRIGGER)) {
+ /* Avoid re-trigger on deferred reload if "no immediate trigger"
+ policy isn't used. */
+ trigger = (delta_adjust == DELTA_ADJUST);
+ }
+
+ s->delta = s->limit;
+
+ ptimer_reload(s, delta_adjust);
+ }
+
+ if (trigger) {
+ ptimer_trigger(s);
}
}
{
uint64_t counter;
- if (s->enabled) {
+ if (s->enabled && s->delta != 0) {
int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
int64_t next = s->next_event;
+ int64_t last = s->last_event;
bool expired = (now - next >= 0);
bool oneshot = (s->enabled == 2);
/* Figure out the current counter value. */
- if (s->period == 0 || (expired && (oneshot || use_icount))) {
+ if (expired) {
/* Prevent timer underflowing if it should already have
triggered. */
counter = 0;
/* We need to divide time by period, where time is stored in
rem (64-bit integer) and period is stored in period/period_frac
(64.32 fixed point).
-
+
Doing full precision division is hard, so scale values and
do a 64-bit division. The result should be rounded down,
so that the rounding error never causes the timer to go
backwards.
*/
- rem = expired ? now - next : next - now;
+ rem = next - now;
div = period;
clz1 = clz64(rem);
}
counter = rem / div;
- if (expired && counter != 0) {
- /* Wrap around periodic counter. */
- counter = s->limit - (counter - 1) % s->limit;
+ if (s->policy_mask & PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD) {
+ /* Before wrapping around, timer should stay with counter = 0
+ for a one period. */
+ if (!oneshot && s->delta == s->limit) {
+ if (now == last) {
+ /* Counter == delta here, check whether it was
+ adjusted and if it was, then right now it is
+ that "one period". */
+ if (counter == s->limit + DELTA_ADJUST) {
+ return 0;
+ }
+ } else if (counter == s->limit) {
+ /* Since the counter is rounded down and now != last,
+ the counter == limit means that delta was adjusted
+ by +1 and right now it is that adjusted period. */
+ return 0;
+ }
+ }
+ }
+ }
+
+ if (s->policy_mask & PTIMER_POLICY_NO_COUNTER_ROUND_DOWN) {
+ /* If now == last then delta == limit, i.e. the counter already
+ represents the correct value. It would be rounded down a 1ns
+ later. */
+ if (now != last) {
+ counter += 1;
}
}
} else {
s->delta = count;
if (s->enabled) {
s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- ptimer_reload(s);
+ ptimer_reload(s, 0);
}
}
bool was_disabled = !s->enabled;
if (was_disabled && s->period == 0) {
- fprintf(stderr, "Timer with period zero, disabling\n");
+ if (!qtest_enabled()) {
+ fprintf(stderr, "Timer with period zero, disabling\n");
+ }
return;
}
s->enabled = oneshot ? 2 : 1;
if (was_disabled) {
s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- ptimer_reload(s);
+ ptimer_reload(s, 0);
}
}
s->period_frac = 0;
if (s->enabled) {
s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- ptimer_reload(s);
+ ptimer_reload(s, 0);
}
}
s->period_frac = (1000000000ll << 32) / freq;
if (s->enabled) {
s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- ptimer_reload(s);
+ ptimer_reload(s, 0);
}
}
s->delta = limit;
if (s->enabled && reload) {
s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
- ptimer_reload(s);
+ ptimer_reload(s, 0);
}
}
+uint64_t ptimer_get_limit(ptimer_state *s)
+{
+ return s->limit;
+}
+
const VMStateDescription vmstate_ptimer = {
.name = "ptimer",
.version_id = 1,
}
};
-ptimer_state *ptimer_init(QEMUBH *bh)
+ptimer_state *ptimer_init(QEMUBH *bh, uint8_t policy_mask)
{
ptimer_state *s;
s = (ptimer_state *)g_malloc0(sizeof(ptimer_state));
s->bh = bh;
s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, ptimer_tick, s);
+ s->policy_mask = policy_mask;
return s;
}
projects / qemu.git / blobdiff