void timer_monotonic_get(struct mono_time *mt)
{
uint64_t current_tick;
uint64_t ticks_elapsed;
unsigned long ticks_per_usec;
struct monotonic_counter *mono_counter;
mono_counter = get_monotonic_context();
if (!mono_counter->initialized) {
init_timer();
mono_counter->last_value = rdtscll();
mono_counter->initialized = 1;
}
current_tick = rdtscll();
ticks_elapsed = current_tick - mono_counter->last_value;
ticks_per_usec = get_clocks_per_usec();
/* Update current time and tick values only if a full tick occurred. */
if (ticks_elapsed >= ticks_per_usec) {
uint64_t usecs_elapsed;
usecs_elapsed = ticks_elapsed / ticks_per_usec;
mono_time_add_usecs(&mono_counter->time, (long)usecs_elapsed);
mono_counter->last_value = current_tick;
}
/* Save result. */
*mt = mono_counter->time;
}
void udelay(unsigned us)
{
unsigned long long start;
unsigned long long current;
unsigned long long clocks;
if (!thread_yield_microseconds(us))
return;
start = rdtscll();
clocks = us;
clocks *= get_clocks_per_usec();
current = rdtscll();
while((current - start) < clocks) {
cpu_relax();
current = rdtscll();
}
}
