@@ -54,6 +54,7 @@ typedef struct HPETTimer { /* timers */
uint64_t cmp; /* comparator */
uint64_t fsb; /* FSB route */
/* Hidden register state */
+ uint64_t cmp64; /* comparator (extended to counter width) */
uint64_t period; /* Last value written to comparator */
uint8_t wrap_flag; /* timer pop will indicate wrap for one-shot 32-bit
* mode. Next pop will be actual timer expiration.
@@ -115,11 +116,6 @@ static uint32_t timer_enabled(HPETTimer *t)
}
static uint32_t hpet_time_after(uint64_t a, uint64_t b)
-{
- return ((int32_t)(b - a) < 0);
-}
-
-static uint32_t hpet_time_after64(uint64_t a, uint64_t b)
{
return ((int64_t)(b - a) < 0);
}
@@ -156,29 +152,34 @@ static uint64_t hpet_get_ticks(HPETState *s)
return ns_to_ticks(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + s->hpet_offset);
}
-/*
- * calculate diff between comparator value and current ticks
- */
-static inline uint64_t hpet_calculate_diff(HPETTimer *t, uint64_t current)
+static uint64_t hpet_get_ns(HPETState *s, uint64_t tick)
{
+ return ticks_to_ns(tick) - s->hpet_offset;
+}
+/*
+ * calculate next value of the general counter that matches the
+ * target (either entirely, or the low 32-bit only depending on
+ * the timer mode).
+ */
+static uint64_t hpet_calculate_cmp64(HPETTimer *t, uint64_t cur_tick, uint64_t target)
+{
if (t->config & HPET_TN_32BIT) {
- uint32_t diff, cmp;
-
- cmp = (uint32_t)t->cmp;
- diff = cmp - (uint32_t)current;
- diff = (int32_t)diff > 0 ? diff : (uint32_t)1;
- return (uint64_t)diff;
+ uint64_t result = deposit64(cur_tick, 0, 32, target);
+ if (result < cur_tick) {
+ result += 0x100000000ULL;
+ }
+ return result;
} else {
- uint64_t diff, cmp;
-
- cmp = t->cmp;
- diff = cmp - current;
- diff = (int64_t)diff > 0 ? diff : (uint64_t)1;
- return diff;
+ return target;
}
}
+static uint64_t hpet_next_wrap(uint64_t cur_tick)
+{
+ return (cur_tick | 0xffffffffU) + 1;
+}
+
static void update_irq(struct HPETTimer *timer, int set)
{
uint64_t mask;
@@ -260,7 +261,12 @@ static bool hpet_validate_num_timers(void *opaque, int version_id)
static int hpet_post_load(void *opaque, int version_id)
{
HPETState *s = opaque;
+ int i;
+ for (i = 0; i < s->num_timers; i++) {
+ HPETTimer *t = &s->timer[i];
+ t->cmp64 = hpet_calculate_cmp64(t, s->hpet_counter, t->cmp);
+ }
/* Recalculate the offset between the main counter and guest time */
if (!s->hpet_offset_saved) {
s->hpet_offset = ticks_to_ns(s->hpet_counter)
@@ -356,14 +362,10 @@ static const VMStateDescription vmstate_hpet = {
}
};
-static void hpet_arm(HPETTimer *t, uint64_t ticks)
+static void hpet_arm(HPETTimer *t, uint64_t tick)
{
- if (ticks < ns_to_ticks(INT64_MAX / 2)) {
- timer_mod(t->qemu_timer,
- qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) + ticks_to_ns(ticks));
- } else {
- timer_del(t->qemu_timer);
- }
+ /* FIXME: Clamp period to reasonable min value? */
+ timer_mod(t->qemu_timer, hpet_get_ns(t->state, tick));
}
/*
@@ -372,54 +374,44 @@ static void hpet_arm(HPETTimer *t, uint64_t ticks)
static void hpet_timer(void *opaque)
{
HPETTimer *t = opaque;
- uint64_t diff;
-
uint64_t period = t->period;
uint64_t cur_tick = hpet_get_ticks(t->state);
if (timer_is_periodic(t) && period != 0) {
+ while (hpet_time_after(cur_tick, t->cmp64)) {
+ t->cmp64 += period;
+ }
if (t->config & HPET_TN_32BIT) {
- while (hpet_time_after(cur_tick, t->cmp)) {
- t->cmp = (uint32_t)(t->cmp + t->period);
- }
+ t->cmp = (uint32_t)t->cmp64;
} else {
- while (hpet_time_after64(cur_tick, t->cmp)) {
- t->cmp += period;
- }
- }
- diff = hpet_calculate_diff(t, cur_tick);
- hpet_arm(t, diff);
- } else if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
- if (t->wrap_flag) {
- diff = hpet_calculate_diff(t, cur_tick);
- hpet_arm(t, diff);
- t->wrap_flag = 0;
+ t->cmp = t->cmp64;
}
+ hpet_arm(t, t->cmp64);
+ } else if (t->wrap_flag) {
+ t->wrap_flag = 0;
+ hpet_arm(t, t->cmp64);
}
update_irq(t, 1);
}
static void hpet_set_timer(HPETTimer *t)
{
- uint64_t diff;
- uint32_t wrap_diff; /* how many ticks until we wrap? */
uint64_t cur_tick = hpet_get_ticks(t->state);
- /* whenever new timer is being set up, make sure wrap_flag is 0 */
t->wrap_flag = 0;
- diff = hpet_calculate_diff(t, cur_tick);
+ t->cmp64 = hpet_calculate_cmp64(t, cur_tick, t->cmp);
+ if (t->config & HPET_TN_32BIT) {
- /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
- * counter wraps in addition to an interrupt with comparator match.
- */
- if (t->config & HPET_TN_32BIT && !timer_is_periodic(t)) {
- wrap_diff = 0xffffffff - (uint32_t)cur_tick;
- if (wrap_diff < (uint32_t)diff) {
- diff = wrap_diff;
+ /* hpet spec says in one-shot 32-bit mode, generate an interrupt when
+ * counter wraps in addition to an interrupt with comparator match.
+ */
+ if (!timer_is_periodic(t) && t->cmp64 > hpet_next_wrap(cur_tick)) {
t->wrap_flag = 1;
+ hpet_arm(t, hpet_next_wrap(cur_tick));
+ return;
}
}
- hpet_arm(t, diff);
+ hpet_arm(t, t->cmp64);
}
static void hpet_del_timer(HPETTimer *t)
@@ -550,12 +542,7 @@ static void hpet_ram_write(void *opaque, hwaddr addr,
timer->cmp = deposit64(timer->cmp, shift, len, value);
}
if (timer_is_periodic(timer)) {
- /*
- * FIXME: Clamp period to reasonable min value?
- * Clamp period to reasonable max value
- */
- new_val = deposit64(timer->period, shift, len, value);
- timer->period = MIN(new_val, (timer->config & HPET_TN_32BIT ? ~0u : ~0ull) >> 1);
+ timer->period = deposit64(timer->period, shift, len, value);
}
timer->config &= ~HPET_TN_SETVAL;
if (hpet_enabled(s)) {
Store the full 64-bit value at which the timer should fire. This makes it possible to skip the imprecise hpet_calculate_diff() step, and to remove the clamping of the period to 31 or 63 bits. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> --- hw/timer/hpet.c | 111 +++++++++++++++++++++--------------------------- 1 file changed, 49 insertions(+), 62 deletions(-)