/* SPDX-License-Identifier: GPL-2.0-or-later */ #include #include #include #include #include #include #include #include unsigned long tsc_freq_mhz(void) { union pstate_msr pstate_reg; /* * See the Family 15h Models 70h-7Fh BKDG (PID 55072) definition for * MSR0000_0010. The TSC increments at the P0 frequency. According * to the "Software P-state Numbering" section, P0 is the highest * non-boosted state. freq = 100MHz * (CpuFid + 10h) / (2^(CpuDid)). */ pstate_reg.raw = rdmsr(PSTATE_MSR(get_pstate_0_reg())).raw; if (!pstate_reg.pstate_en) die("Unknown error: cannot determine P-state 0\n"); return get_pstate_core_freq(pstate_reg); }