| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <cpu/x86/msr.h> |
| #include <timer.h> |
| #include <timestamp.h> |
| |
| #define CU_PTSC_MSR 0xc0010280 |
| #define PTSC_FREQ_MHZ 100 |
| |
| void timer_monotonic_get(struct mono_time *mt) |
| { |
| mono_time_set_usecs(mt, timestamp_get()); |
| } |
| |
| /* The TSC has a non-constant rate before the microcode update is applied, so it can't be used |
| in timestamp_get before that. Instead, the Performance Time Stamp Counter is used. */ |
| uint64_t timestamp_get(void) |
| { |
| msr_t msr; |
| |
| msr = rdmsr(CU_PTSC_MSR); |
| |
| return msr.raw / PTSC_FREQ_MHZ; |
| } |