/* SPDX-License-Identifier: GPL-2.0-only */ /* This file is part of the coreboot project. */ #include <cpu/cpu.h> #include <cpu/x86/cache.h> #include <cpu/x86/mtrr.h> #include <cpu/x86/msr.h> /* Get first available variable MTRR. * Returns var# if available, else returns -1. */ int get_free_var_mtrr(void) { msr_t maskm; int vcnt; int i; vcnt = get_var_mtrr_count(); /* Identify the first var mtrr which is not valid. */ for (i = 0; i < vcnt; i++) { maskm = rdmsr(MTRR_PHYS_MASK(i)); if ((maskm.lo & MTRR_PHYS_MASK_VALID) == 0) return i; } /* No free var mtrr. */ return -1; } void set_var_mtrr( unsigned int reg, unsigned int base, unsigned int size, unsigned int type) { /* Bit Bit 32-35 of MTRRphysMask should be set to 1 */ /* FIXME: It only support 4G less range */ msr_t basem, maskm; basem.lo = base | type; basem.hi = 0; wrmsr(MTRR_PHYS_BASE(reg), basem); maskm.lo = ~(size - 1) | MTRR_PHYS_MASK_VALID; maskm.hi = (1 << (cpu_phys_address_size() - 32)) - 1; wrmsr(MTRR_PHYS_MASK(reg), maskm); }