diff options
Diffstat (limited to 'arch/x86/kernel/tsc_msr.c')
| -rw-r--r-- | arch/x86/kernel/tsc_msr.c | 96 |
1 files changed, 51 insertions, 45 deletions
diff --git a/arch/x86/kernel/tsc_msr.c b/arch/x86/kernel/tsc_msr.c index 19afdbd7d0a7..27ef714d886c 100644 --- a/arch/x86/kernel/tsc_msr.c +++ b/arch/x86/kernel/tsc_msr.c @@ -1,17 +1,19 @@ +// SPDX-License-Identifier: GPL-2.0 /* - * tsc_msr.c - TSC frequency enumeration via MSR + * TSC frequency enumeration via MSR * - * Copyright (C) 2013 Intel Corporation + * Copyright (C) 2013, 2018 Intel Corporation * Author: Bin Gao <bin.gao@intel.com> - * - * This file is released under the GPLv2. */ #include <linux/kernel.h> -#include <asm/processor.h> -#include <asm/setup.h> + #include <asm/apic.h> +#include <asm/cpu_device_id.h> +#include <asm/intel-family.h> +#include <asm/msr.h> #include <asm/param.h> +#include <asm/tsc.h> #define MAX_NUM_FREQS 9 @@ -23,44 +25,48 @@ * field msr_plat does. */ struct freq_desc { - u8 x86_family; /* CPU family */ - u8 x86_model; /* model */ u8 msr_plat; /* 1: use MSR_PLATFORM_INFO, 0: MSR_IA32_PERF_STATUS */ u32 freqs[MAX_NUM_FREQS]; }; -static struct freq_desc freq_desc_tables[] = { - /* PNW */ - { 6, 0x27, 0, { 0, 0, 0, 0, 0, 99840, 0, 83200 } }, - /* CLV+ */ - { 6, 0x35, 0, { 0, 133200, 0, 0, 0, 99840, 0, 83200 } }, - /* TNG - Intel Atom processor Z3400 series */ - { 6, 0x4a, 1, { 0, 100000, 133300, 0, 0, 0, 0, 0 } }, - /* VLV2 - Intel Atom processor E3000, Z3600, Z3700 series */ - { 6, 0x37, 1, { 83300, 100000, 133300, 116700, 80000, 0, 0, 0 } }, - /* ANN - Intel Atom processor Z3500 series */ - { 6, 0x5a, 1, { 83300, 100000, 133300, 100000, 0, 0, 0, 0 } }, - /* AMT - Intel Atom processor X7-Z8000 and X5-Z8000 series */ - { 6, 0x4c, 1, { 83300, 100000, 133300, 116700, - 80000, 93300, 90000, 88900, 87500 } }, +/* + * Penwell and Clovertrail use spread spectrum clock, + * so the freq number is not exactly the same as reported + * by MSR based on SDM. + */ +static const struct freq_desc freq_desc_pnw = { + 0, { 0, 0, 0, 0, 0, 99840, 0, 83200 } }; -static int match_cpu(u8 family, u8 model) -{ - int i; +static const struct freq_desc freq_desc_clv = { + 0, { 0, 133200, 0, 0, 0, 99840, 0, 83200 } +}; - for (i = 0; i < ARRAY_SIZE(freq_desc_tables); i++) { - if ((family == freq_desc_tables[i].x86_family) && - (model == freq_desc_tables[i].x86_model)) - return i; - } +static const struct freq_desc freq_desc_byt = { + 1, { 83300, 100000, 133300, 116700, 80000, 0, 0, 0 } +}; - return -1; -} +static const struct freq_desc freq_desc_cht = { + 1, { 83300, 100000, 133300, 116700, 80000, 93300, 90000, 88900, 87500 } +}; -/* Map CPU reference clock freq ID(0-7) to CPU reference clock freq(KHz) */ -#define id_to_freq(cpu_index, freq_id) \ - (freq_desc_tables[cpu_index].freqs[freq_id]) +static const struct freq_desc freq_desc_tng = { + 1, { 0, 100000, 133300, 0, 0, 0, 0, 0 } +}; + +static const struct freq_desc freq_desc_ann = { + 1, { 83300, 100000, 133300, 100000, 0, 0, 0, 0 } +}; + +static const struct x86_cpu_id tsc_msr_cpu_ids[] = { + INTEL_CPU_FAM6(ATOM_PENWELL, freq_desc_pnw), + INTEL_CPU_FAM6(ATOM_CLOVERVIEW, freq_desc_clv), + INTEL_CPU_FAM6(ATOM_SILVERMONT1, freq_desc_byt), + INTEL_CPU_FAM6(ATOM_AIRMONT, freq_desc_cht), + INTEL_CPU_FAM6(ATOM_MERRIFIELD, freq_desc_tng), + INTEL_CPU_FAM6(ATOM_MOOREFIELD, freq_desc_ann), + {} +}; /* * MSR-based CPU/TSC frequency discovery for certain CPUs. @@ -70,18 +76,17 @@ static int match_cpu(u8 family, u8 model) */ unsigned long cpu_khz_from_msr(void) { - u32 lo, hi, ratio, freq_id, freq; + u32 lo, hi, ratio, freq; + const struct freq_desc *freq_desc; + const struct x86_cpu_id *id; unsigned long res; - int cpu_index; - - if (boot_cpu_data.x86_vendor != X86_VENDOR_INTEL) - return 0; - cpu_index = match_cpu(boot_cpu_data.x86, boot_cpu_data.x86_model); - if (cpu_index < 0) + id = x86_match_cpu(tsc_msr_cpu_ids); + if (!id) return 0; - if (freq_desc_tables[cpu_index].msr_plat) { + freq_desc = (struct freq_desc *)id->driver_data; + if (freq_desc->msr_plat) { rdmsr(MSR_PLATFORM_INFO, lo, hi); ratio = (lo >> 8) & 0xff; } else { @@ -91,8 +96,9 @@ unsigned long cpu_khz_from_msr(void) /* Get FSB FREQ ID */ rdmsr(MSR_FSB_FREQ, lo, hi); - freq_id = lo & 0x7; - freq = id_to_freq(cpu_index, freq_id); + + /* Map CPU reference clock freq ID(0-7) to CPU reference clock freq(KHz) */ + freq = freq_desc->freqs[lo & 0x7]; /* TSC frequency = maximum resolved freq * maximum resolved bus ratio */ res = freq * ratio; |