diff options
Diffstat (limited to 'hw/core/ptimer.c')
| -rw-r--r-- | hw/core/ptimer.c | 130 |
1 files changed, 112 insertions, 18 deletions
diff --git a/hw/core/ptimer.c b/hw/core/ptimer.c index c45c835a17..3af82afe78 100644 --- a/hw/core/ptimer.c +++ b/hw/core/ptimer.c @@ -13,6 +13,9 @@ #include "sysemu/replay.h" #include "sysemu/qtest.h" +#define DELTA_ADJUST 1 +#define DELTA_NO_ADJUST -1 + struct ptimer_state { uint8_t enabled; /* 0 = disabled, 1 = periodic, 2 = oneshot. */ @@ -35,16 +38,21 @@ static void ptimer_trigger(ptimer_state *s) } } -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) { + + 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"); } @@ -53,6 +61,39 @@ static void ptimer_reload(ptimer_state *s) 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; + } + /* * Artificially limit timeout rate to something * achievable under QEMU. Otherwise, QEMU spends all @@ -62,15 +103,15 @@ static void ptimer_reload(ptimer_state *s) * 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); } @@ -78,12 +119,35 @@ static void ptimer_reload(ptimer_state *s) 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); } } @@ -91,9 +155,10 @@ 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; bool expired = (now - next >= 0); bool oneshot = (s->enabled == 2); @@ -118,7 +183,7 @@ uint64_t ptimer_get_count(ptimer_state *s) /* 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 @@ -145,6 +210,35 @@ uint64_t ptimer_get_count(ptimer_state *s) div += 1; } counter = rem / div; + + 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 { counter = s->delta; @@ -157,7 +251,7 @@ void ptimer_set_count(ptimer_state *s, uint64_t count) s->delta = count; if (s->enabled) { s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - ptimer_reload(s); + ptimer_reload(s, 0); } } @@ -174,7 +268,7 @@ void ptimer_run(ptimer_state *s, int oneshot) 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); } } @@ -198,7 +292,7 @@ void ptimer_set_period(ptimer_state *s, int64_t period) s->period_frac = 0; if (s->enabled) { s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - ptimer_reload(s); + ptimer_reload(s, 0); } } @@ -210,7 +304,7 @@ void ptimer_set_freq(ptimer_state *s, uint32_t freq) 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); } } @@ -223,7 +317,7 @@ void ptimer_set_limit(ptimer_state *s, uint64_t limit, int reload) s->delta = limit; if (s->enabled && reload) { s->next_event = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); - ptimer_reload(s); + ptimer_reload(s, 0); } } |