hw/ptimer: Add "continuous trigger" policy

Currently, periodic timer that has load = delta = 0 performs trigger
on timer reload and stops, printing a "period zero" error message.
Introduce new policy that makes periodic timer to continuously trigger
with a period interval in case of load = 0.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Message-id: 632b23dd11055d9bd5e338d66b38fac0bd51462e.1475421224.git.digetx@gmail.com
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
This commit is contained in:
Dmitry Osipenko 2016-10-24 16:26:51 +01:00 committed by Peter Maydell
parent 293130aa91
commit ef0a9984aa
2 changed files with 31 additions and 3 deletions

View File

@ -47,7 +47,8 @@ static void ptimer_reload(ptimer_state *s, int delta_adjust)
ptimer_trigger(s);
delta = s->delta = s->limit;
}
if (delta == 0 || s->period == 0) {
if (s->period == 0) {
if (!qtest_enabled()) {
fprintf(stderr, "Timer with period zero, disabling\n");
}
@ -60,6 +61,21 @@ static void ptimer_reload(ptimer_state *s, int delta_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) {
if (!qtest_enabled()) {
fprintf(stderr, "Timer with delta zero, disabling\n");
}
timer_del(s->timer);
s->enabled = 0;
return;
}
/*
* Artificially limit timeout rate to something
* achievable under QEMU. Otherwise, QEMU spends all
@ -90,7 +106,15 @@ static void ptimer_tick(void *opaque)
if (s->enabled == 2) {
s->enabled = 0;
} else {
ptimer_reload(s, DELTA_ADJUST);
int delta_adjust = DELTA_ADJUST;
if (s->limit == 0) {
/* If a "continuous trigger" policy is not used and limit == 0,
we should error out. */
delta_adjust = 0;
}
ptimer_reload(s, delta_adjust);
}
}
@ -98,7 +122,7 @@ uint64_t ptimer_get_count(ptimer_state *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;

View File

@ -39,6 +39,10 @@
* around. */
#define PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD (1 << 0)
/* Running periodic timer that has counter = limit = 0 would continuously
* re-trigger every period. */
#define PTIMER_POLICY_CONTINUOUS_TRIGGER (1 << 1)
/* ptimer.c */
typedef struct ptimer_state ptimer_state;
typedef void (*ptimer_cb)(void *opaque);