mirror of
https://github.com/Mathewnd/Astral.git
synced 2026-10-27 20:58:22 +00:00
Matheus
86 lines
2.1 KiB
C
86 lines
2.1 KiB
C
#include <kernel/timekeeper.h>
|
|
#include <arch/tsc.h>
|
|
#include <arch/cpuid.h>
|
|
#include <logging.h>
|
|
#include <kernel/alloc.h>
|
|
#include <arch/hpet.h>
|
|
#include <kernel/kernel_args.h>
|
|
|
|
DEFINE_KERNEL_ARGUMENT(notsc, bool);
|
|
|
|
static bool tsc_probe(void) {
|
|
if (GET_KERNEL_ARGUMENT(notsc, bool))
|
|
return false;
|
|
|
|
cpuid_results_t cpuid_results;
|
|
|
|
uint32_t max_extended_leaf = cpuid_extended_max_leaf();
|
|
if (max_extended_leaf < 0x80000007)
|
|
return false;
|
|
|
|
cpuid(0x80000007, &cpuid_results);
|
|
return cpuid_results.edx & (1 << 8);
|
|
}
|
|
|
|
static MUTEX_DEFINE(init_mutex);
|
|
// keeping this here in a multisocket machine could possibly result in completely wrong
|
|
// tsc measurements for the other sokets. disable the tsc in these using the "notsc" commandline option.
|
|
static time_t hz;
|
|
|
|
static timekeeper_source_info_t *tsc_init(void) {
|
|
MUTEX_ACQUIRE(&init_mutex);
|
|
__assert(tsc_probe());
|
|
|
|
timekeeper_source_info_t *timekeeper_source_info = alloc(sizeof(timekeeper_source_info_t));
|
|
__assert(timekeeper_source_info);
|
|
|
|
timekeeper_source_info->private = current_cpu();
|
|
|
|
if (hz)
|
|
goto leave;
|
|
|
|
bool need_calibration = true;
|
|
if (cpuid_base_max_leaf() >= 0x15) {
|
|
cpuid_results_t cpuid_results;
|
|
cpuid(0x15, &cpuid_results);
|
|
|
|
if (cpuid_results.eax == 0 || cpuid_results.ebx == 0 || cpuid_results.ecx == 0)
|
|
goto calibrate;
|
|
|
|
uint64_t core_frequency = cpuid_results.ecx;
|
|
uint64_t core_numerator = cpuid_results.ebx;
|
|
uint64_t core_denominator = cpuid_results.eax;
|
|
|
|
uint64_t tsc_frequency = core_frequency * core_numerator / core_denominator;
|
|
hz = tsc_frequency;
|
|
need_calibration = false;
|
|
}
|
|
|
|
calibrate:
|
|
if (need_calibration) {
|
|
hz = arch_hpet_calibrate_tsc(200) * 1000;
|
|
__assert(hz);
|
|
}
|
|
|
|
leave:
|
|
timekeeper_source_info->hz = hz;
|
|
MUTEX_RELEASE(&init_mutex);
|
|
return timekeeper_source_info;
|
|
}
|
|
|
|
// ran in at least IPL_DPC
|
|
static time_t tsc_ticks(timekeeper_source_info_t *timekeeper_source_info) {
|
|
__assert(timekeeper_source_info->private == current_cpu());
|
|
|
|
return rdtsc_serialized();
|
|
}
|
|
|
|
TIMEKEEPER_SOURCE(kvmtimer_source,
|
|
.name = "Invariant TSC",
|
|
.priority = 990,
|
|
.probe = tsc_probe,
|
|
.init = tsc_init,
|
|
.ticks = tsc_ticks,
|
|
.flags = 0
|
|
);
|