diff options
Diffstat (limited to 'src/soc/intel/common/block')
| -rw-r--r-- | src/soc/intel/common/block/timer/timer.c | 64 |
1 files changed, 61 insertions, 3 deletions
diff --git a/src/soc/intel/common/block/timer/timer.c b/src/soc/intel/common/block/timer/timer.c index 12988856e4..e60ac4d26d 100644 --- a/src/soc/intel/common/block/timer/timer.c +++ b/src/soc/intel/common/block/timer/timer.c @@ -1,7 +1,7 @@ /* * This file is part of the coreboot project. * - * Copyright (C) 2017 Intel Corporation. + * Copyright (C) 2017-2019 Intel Corporation. * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by @@ -13,12 +13,70 @@ * GNU General Public License for more details. */ +#include <arch/cpu.h> +#include <arch/intel-family.h> +#include <cpu/cpu.h> #include <cpu/x86/msr.h> #include <cpu/x86/tsc.h> #include <intelblocks/msr.h> +static int get_processor_model(void) +{ + struct cpuinfo_x86 c; + + get_fms(&c, cpuid_eax(1)); + + return c.x86_model; +} + +/* + * Nominal TSC frequency = "core crystal clock frequency" * EBX/EAX + * + * Time Stamp Counter + * CPUID Initial EAX value = 0x15 + * EAX Bit 31-0 : An unsigned integer which is the denominator of the + * TSC/"core crystal clock" ratio + * EBX Bit 31-0 : An unsigned integer which is the numerator of the + * TSC/"core crystal clock" ratio + * ECX Bit 31-0 : An unsigned integer which is the nominal frequency of the + * core crystal clock in Hz. + * EDX Bit 31-0 : Reserved = 0 + * + * Refer to Intel SDM Jan 2019 Vol 3B Section 18.7.3 + */ unsigned long tsc_freq_mhz(void) { - msr_t msr = rdmsr(MSR_PLATFORM_INFO); - return (CONFIG_CPU_BCLK_MHZ * ((msr.lo >> 8) & 0xff)); + unsigned int core_crystal_nominal_freq_khz; + struct cpuid_result cpuidr; + + /* CPUID 15H TSC/Crystal ratio, plus optionally Crystal Hz */ + cpuidr = cpuid(0x15); + + if (!cpuidr.ebx || !cpuidr.eax) + return 0; + + core_crystal_nominal_freq_khz = cpuidr.ecx / 1000; + + if (!core_crystal_nominal_freq_khz) { + switch (get_processor_model()) { + case CPU_MODEL_INTEL_SKYLAKE_MOBILE: + case CPU_MODEL_INTEL_SKYLAKE_DESKTOP: + case CPU_MODEL_INTEL_KABYLAKE_MOBILE: + case CPU_MODEL_INTEL_KABYLAKE_DESKTOP: + case CPU_MODEL_INTEL_CANNONLAKE_MOBILE: + case CPU_MODEL_INTEL_ICELAKE_MOBILE: + core_crystal_nominal_freq_khz = 24000; + break; + case CPU_MODEL_INTEL_ATOM_DENVERTON: + core_crystal_nominal_freq_khz = 25000; + break; + case CPU_MODEL_INTEL_ATOM_GOLDMONT: + case CPU_MODEL_INTEL_ATOM_GEMINI_LAKE: + core_crystal_nominal_freq_khz = 19200; + break; + } + } + + return (core_crystal_nominal_freq_khz * cpuidr.ebx / cpuidr.eax) / + 1000; } |