*
* Copyright (c) 2007 CodeSourcery.
*
- * This code is licenced under the GNU LGPL.
+ * This code is licensed under the GNU LGPL.
*/
-#include "hw.h"
-#include "qemu-timer.h"
-
+#include "hw/hw.h"
+#include "qemu/timer.h"
+#include "hw/ptimer.h"
+#include "qemu/host-utils.h"
struct ptimer_state
{
- int enabled; /* 0 = disabled, 1 = periodic, 2 = oneshot. */
+ uint8_t enabled; /* 0 = disabled, 1 = periodic, 2 = oneshot. */
uint64_t limit;
uint64_t delta;
uint32_t period_frac;
uint64_t counter;
if (s->enabled) {
- now = qemu_get_clock(vm_clock);
+ now = qemu_get_clock_ns(vm_clock);
/* Figure out the current counter value. */
if (now - s->next_event > 0
|| s->period == 0) {
} else {
uint64_t rem;
uint64_t div;
+ int clz1, clz2;
+ int shift;
+
+ /* 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 = s->next_event - now;
div = s->period;
+
+ clz1 = clz64(rem);
+ clz2 = clz64(div);
+ shift = clz1 < clz2 ? clz1 : clz2;
+
+ rem <<= shift;
+ div <<= shift;
+ if (shift >= 32) {
+ div |= ((uint64_t)s->period_frac << (shift - 32));
+ } else {
+ if (shift != 0)
+ div |= (s->period_frac >> (32 - shift));
+ /* Look at remaining bits of period_frac and round div up if
+ necessary. */
+ if ((uint32_t)(s->period_frac << shift))
+ div += 1;
+ }
counter = rem / div;
}
} else {
{
s->delta = count;
if (s->enabled) {
- s->next_event = qemu_get_clock(vm_clock);
+ s->next_event = qemu_get_clock_ns(vm_clock);
ptimer_reload(s);
}
}
void ptimer_run(ptimer_state *s, int oneshot)
{
+ if (s->enabled) {
+ return;
+ }
if (s->period == 0) {
fprintf(stderr, "Timer with period zero, disabling\n");
return;
}
s->enabled = oneshot ? 2 : 1;
- s->next_event = qemu_get_clock(vm_clock);
+ s->next_event = qemu_get_clock_ns(vm_clock);
ptimer_reload(s);
}
s->period = period;
s->period_frac = 0;
if (s->enabled) {
- s->next_event = qemu_get_clock(vm_clock);
+ s->next_event = qemu_get_clock_ns(vm_clock);
ptimer_reload(s);
}
}
s->period = 1000000000ll / freq;
s->period_frac = (1000000000ll << 32) / freq;
if (s->enabled) {
- s->next_event = qemu_get_clock(vm_clock);
+ s->next_event = qemu_get_clock_ns(vm_clock);
ptimer_reload(s);
}
}
count = limit. */
void ptimer_set_limit(ptimer_state *s, uint64_t limit, int reload)
{
+ /*
+ * Artificially limit timeout rate to something
+ * achievable under QEMU. Otherwise, QEMU spends all
+ * its time generating timer interrupts, and there
+ * is no forward progress.
+ * About ten microseconds is the fastest that really works
+ * on the current generation of host machines.
+ */
+
+ if (limit * s->period < 10000 && s->period) {
+ limit = 10000 / s->period;
+ }
+
s->limit = limit;
if (reload)
s->delta = limit;
if (s->enabled && reload) {
- s->next_event = qemu_get_clock(vm_clock);
+ s->next_event = qemu_get_clock_ns(vm_clock);
ptimer_reload(s);
}
}
-void qemu_put_ptimer(QEMUFile *f, ptimer_state *s)
-{
- qemu_put_byte(f, s->enabled);
- qemu_put_be64s(f, &s->limit);
- qemu_put_be64s(f, &s->delta);
- qemu_put_be32s(f, &s->period_frac);
- qemu_put_be64s(f, &s->period);
- qemu_put_be64s(f, &s->last_event);
- qemu_put_be64s(f, &s->next_event);
- qemu_put_timer(f, s->timer);
-}
-
-void qemu_get_ptimer(QEMUFile *f, ptimer_state *s)
-{
- s->enabled = qemu_get_byte(f);
- qemu_get_be64s(f, &s->limit);
- qemu_get_be64s(f, &s->delta);
- qemu_get_be32s(f, &s->period_frac);
- qemu_get_be64s(f, &s->period);
- qemu_get_be64s(f, &s->last_event);
- qemu_get_be64s(f, &s->next_event);
- qemu_get_timer(f, s->timer);
-}
+const VMStateDescription vmstate_ptimer = {
+ .name = "ptimer",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT8(enabled, ptimer_state),
+ VMSTATE_UINT64(limit, ptimer_state),
+ VMSTATE_UINT64(delta, ptimer_state),
+ VMSTATE_UINT32(period_frac, ptimer_state),
+ VMSTATE_INT64(period, ptimer_state),
+ VMSTATE_INT64(last_event, ptimer_state),
+ VMSTATE_INT64(next_event, ptimer_state),
+ VMSTATE_TIMER(timer, ptimer_state),
+ VMSTATE_END_OF_LIST()
+ }
+};
ptimer_state *ptimer_init(QEMUBH *bh)
{
ptimer_state *s;
- s = (ptimer_state *)qemu_mallocz(sizeof(ptimer_state));
+ s = (ptimer_state *)g_malloc0(sizeof(ptimer_state));
s->bh = bh;
- s->timer = qemu_new_timer(vm_clock, ptimer_tick, s);
+ s->timer = qemu_new_timer_ns(vm_clock, ptimer_tick, s);
return s;
}
-
projects / qemu.git / blobdiff