/* * This file is part of the coreboot project. * * Copyright (C) 2011 The ChromiumOS Authors. All rights reserved. * * 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 the Free Software Foundation; version 2 of * the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. */ #include <console/console.h> #include <cpu/intel/turbo.h> #include <cpu/x86/msr.h> #include <arch/cpu.h> #if IS_ENABLED(CONFIG_CPU_INTEL_TURBO_NOT_PACKAGE_SCOPED) static inline int get_global_turbo_state(void) { return TURBO_UNKNOWN; } static inline void set_global_turbo_state(int state) { } #else static int g_turbo_state = TURBO_UNKNOWN; static inline int get_global_turbo_state(void) { return g_turbo_state; } static inline void set_global_turbo_state(int state) { g_turbo_state = state; } #endif static const char * const turbo_state_desc[] = { [TURBO_UNKNOWN] = "unknown", [TURBO_UNAVAILABLE] = "unavailable", [TURBO_DISABLED] = "available but hidden", [TURBO_ENABLED] = "available and visible" }; /* * Determine the current state of Turbo and cache it for later. * Turbo is a package level config so it does not need to be * enabled on every core. */ int get_turbo_state(void) { struct cpuid_result cpuid_regs; int turbo_en, turbo_cap; msr_t msr; int turbo_state = get_global_turbo_state(); /* Return cached state if available */ if (turbo_state != TURBO_UNKNOWN) return turbo_state; cpuid_regs = cpuid(CPUID_LEAF_PM); turbo_cap = !!(cpuid_regs.eax & PM_CAP_TURBO_MODE); msr = rdmsr(MSR_IA32_MISC_ENABLES); turbo_en = !(msr.hi & H_MISC_DISABLE_TURBO); if (!turbo_cap && turbo_en) { /* Unavailable */ turbo_state = TURBO_UNAVAILABLE; } else if (!turbo_cap && !turbo_en) { /* Available but disabled */ turbo_state = TURBO_DISABLED; } else if (turbo_cap && turbo_en) { /* Available */ turbo_state = TURBO_ENABLED; } set_global_turbo_state(turbo_state); printk(BIOS_INFO, "Turbo is %s\n", turbo_state_desc[turbo_state]); return turbo_state; } /* * Try to enable Turbo mode. */ void enable_turbo(void) { msr_t msr; /* Only possible if turbo is available but hidden */ if (get_turbo_state() == TURBO_DISABLED) { /* Clear Turbo Disable bit in Misc Enables */ msr = rdmsr(MSR_IA32_MISC_ENABLES); msr.hi &= ~H_MISC_DISABLE_TURBO; wrmsr(MSR_IA32_MISC_ENABLES, msr); /* Update cached turbo state */ set_global_turbo_state(TURBO_ENABLED); printk(BIOS_INFO, "Turbo has been enabled\n"); } } /* * Try to disable Turbo mode. */ void disable_turbo(void) { msr_t msr; /* Set Turbo Disable bit in Misc Enables */ msr = rdmsr(MSR_IA32_MISC_ENABLES); msr.hi |= H_MISC_DISABLE_TURBO; wrmsr(MSR_IA32_MISC_ENABLES, msr); /* Update cached turbo state */ set_global_turbo_state(TURBO_UNAVAILABLE); printk(BIOS_INFO, "Turbo has been disabled\n"); }