From a27520904f54643c9e55f5672f005a207c911f32 Mon Sep 17 00:00:00 2001 From: Simon Glass Date: Wed, 25 Sep 2019 08:56:40 -0600 Subject: [PATCH] x86: Add new common CPU functions for turbo/burst mode Add a few more CPU functions that are common on Intel CPUs. Also add attribution for the code source. Signed-off-by: Simon Glass Reviewed-by: Bin Meng [bmeng: add missing MSR_IA32_MISC_ENABLE write back in cpu_set_eist(); fix 2 typos in cpu_get_burst_mode_state() comments] Signed-off-by: Bin Meng --- arch/x86/cpu/intel_common/cpu.c | 61 +++++++++++++++++++++++++++++++ arch/x86/include/asm/cpu_common.h | 49 +++++++++++++++++++++++++ 2 files changed, 110 insertions(+) diff --git a/arch/x86/cpu/intel_common/cpu.c b/arch/x86/cpu/intel_common/cpu.c index 1898903853..4d093a5391 100644 --- a/arch/x86/cpu/intel_common/cpu.c +++ b/arch/x86/cpu/intel_common/cpu.c @@ -1,12 +1,17 @@ // SPDX-License-Identifier: GPL-2.0 /* + * Copyright (C) 2014 Google Inc. * Copyright (c) 2016 Google, Inc + * Copyright (C) 2015-2018 Intel Corporation. + * Copyright (C) 2018 Siemens AG + * Some code taken from coreboot cpulib.c */ #include #include #include #include +#include #include #include #include @@ -165,3 +170,59 @@ bool cpu_config_tdp_levels(void) return ((platform_info.hi >> 1) & 3) != 0; } + +void cpu_set_p_state_to_turbo_ratio(void) +{ + msr_t msr; + + msr = msr_read(MSR_TURBO_RATIO_LIMIT); + cpu_set_perf_control(msr.lo); +} + +enum burst_mode_t cpu_get_burst_mode_state(void) +{ + enum burst_mode_t state; + int burst_en, burst_cap; + msr_t msr; + uint eax; + + eax = cpuid_eax(0x6); + burst_cap = eax & 0x2; + msr = msr_read(MSR_IA32_MISC_ENABLE); + burst_en = !(msr.hi & BURST_MODE_DISABLE); + + if (!burst_cap && burst_en) + state = BURST_MODE_UNAVAILABLE; + else if (burst_cap && !burst_en) + state = BURST_MODE_DISABLED; + else if (burst_cap && burst_en) + state = BURST_MODE_ENABLED; + else + state = BURST_MODE_UNKNOWN; + + return state; +} + +void cpu_set_burst_mode(bool burst_mode) +{ + msr_t msr; + + msr = msr_read(MSR_IA32_MISC_ENABLE); + if (burst_mode) + msr.hi &= ~BURST_MODE_DISABLE; + else + msr.hi |= BURST_MODE_DISABLE; + msr_write(MSR_IA32_MISC_ENABLE, msr); +} + +void cpu_set_eist(bool eist_status) +{ + msr_t msr; + + msr = msr_read(MSR_IA32_MISC_ENABLE); + if (eist_status) + msr.lo |= MISC_ENABLE_ENHANCED_SPEEDSTEP; + else + msr.lo &= ~MISC_ENABLE_ENHANCED_SPEEDSTEP; + msr_write(MSR_IA32_MISC_ENABLE, msr); +} diff --git a/arch/x86/include/asm/cpu_common.h b/arch/x86/include/asm/cpu_common.h index c61d74e4a0..cdd99a90b7 100644 --- a/arch/x86/include/asm/cpu_common.h +++ b/arch/x86/include/asm/cpu_common.h @@ -79,4 +79,53 @@ void cpu_set_perf_control(uint clk_ratio); */ bool cpu_config_tdp_levels(void); +/** enum burst_mode_t - Burst-mode states */ +enum burst_mode_t { + BURST_MODE_UNKNOWN, + BURST_MODE_UNAVAILABLE, + BURST_MODE_DISABLED, + BURST_MODE_ENABLED +}; + +/* + * cpu_get_burst_mode_state() - Get the Burst/Turbo Mode State + * + * This reads MSR IA32_MISC_ENABLE 0x1A0 + * Bit 38 - TURBO_MODE_DISABLE Bit to get state ENABLED / DISABLED. + * Also checks cpuid 0x6 to see whether burst mode is supported. + * + * @return current burst mode status + */ +enum burst_mode_t cpu_get_burst_mode_state(void); + +/** + * cpu_set_burst_mode() - Set CPU burst mode + * + * @burst_mode: true to enable burst mode, false to disable + */ +void cpu_set_burst_mode(bool burst_mode); + +/** + * cpu_set_eist() - Enable Enhanced Intel Speed Step Technology + * + * @eist_status: true to enable EIST, false to disable + */ +void cpu_set_eist(bool eist_status); + +/** + * cpu_set_p_state_to_turbo_ratio() - Set turbo ratio + * + * TURBO_RATIO_LIMIT MSR (0x1AD) Bits 31:0 indicates the + * factory configured values for of 1-core, 2-core, 3-core + * and 4-core turbo ratio limits for all processors. + * + * 7:0 - MAX_TURBO_1_CORE + * 15:8 - MAX_TURBO_2_CORES + * 23:16 - MAX_TURBO_3_CORES + * 31:24 - MAX_TURBO_4_CORES + * + * Set PERF_CTL MSR (0x199) P_Req with that value. + */ +void cpu_set_p_state_to_turbo_ratio(void); + #endif -- 2.25.1