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tsc: redo calibration, directly use hpet

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Matheus
2024-10-02 19:42:33 -03:00
parent e9b9242653
commit 65ef516fd8
3 changed files with 37 additions and 17 deletions
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kernel-src/arch/x86-64/tsc.c
+13 -12
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@@ -15,7 +15,11 @@ static bool tsc_probe(void) {
return cpuid_results.edx & (1 << 8);
}
static MUTEX_DEFINE(init_mutex);
static time_t ticks_per_us;
static timekeeper_source_info_t *tsc_init(void) {
MUTEX_ACQUIRE(&init_mutex, false);
__assert(tsc_probe());
timekeeper_source_info_t *timekeeper_source_info = alloc(sizeof(timekeeper_source_info_t));
@@ -23,6 +27,9 @@ static timekeeper_source_info_t *tsc_init(void) {
timekeeper_source_info->private = current_cpu();
if (ticks_per_us)
goto leave;
bool need_calibration = false;
if (cpuid_base_max_leaf() >= 0x15) {
cpuid_results_t cpuid_results;
@@ -38,24 +45,18 @@ static timekeeper_source_info_t *tsc_init(void) {
uint64_t core_denominator = cpuid_results.eax;
uint64_t tsc_frequency = core_frequency * core_numerator / core_denominator;
timekeeper_source_info->ticks_per_us = tsc_frequency / 1000000;
ticks_per_us = tsc_frequency / 1000000;
}
calibrate:
if (need_calibration) {
for (int i = 0; i < 10; ++i) {
long old_ipl = interrupt_raiseipl(IPL_TIMER - 1);
time_t ticks_start = rdtsc_serialized();
timekeeper_wait_us(50000);
time_t ticks_end = rdtsc_serialized();
interrupt_loweripl(old_ipl);
timekeeper_source_info->ticks_per_us = (ticks_end - ticks_start) / 50000;
}
ticks_per_us = arch_hpet_calibrate_tsc(200) / 1000;
__assert(ticks_per_us);
}
leave:
timekeeper_source_info->ticks_per_us = ticks_per_us;
MUTEX_RELEASE(&init_mutex);
return timekeeper_source_info;
}