/* * This file is part of the coreboot project. * * Copyright (C) 2013 Google, Inc. * * 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. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include <string.h> #include <stddef.h> #include <console/console.h> #include <cbmem.h> #include <cpu/x86/car.h> typedef void (* const car_migration_func_t)(void); extern car_migration_func_t _car_migrate_start; extern car_migration_func_t _car_migrate_end; extern char _car_data_start[]; extern char _car_data_end[]; /* * The car_migrated global variable determines if the cache-as-ram space has * been migrated to real RAM. It does this by assuming the following things: * 1. cache-as-ram space is zero'd out once it is set up. * 2. Either the cache-as-ram space is memory-backed after getting torn down * or the space returns 0xff's for each byte read. * Based on these 2 attributes there is the ability to tell when the * cache-as-ram region has been migrated. */ static int car_migrated CAR_GLOBAL; void *car_get_var_ptr(void *var) { char *migrated_base; int offset; void * _car_start = &_car_data_start; void * _car_end = &_car_data_end; /* If the cache-as-ram has not been migrated return the pointer * passed in. */ if (!car_migrated) return var; if (var < _car_start || var >= _car_end) { printk(BIOS_ERR, "Requesting CAR variable outside of CAR region: %p\n", var); return var; } migrated_base = cbmem_find(CBMEM_ID_CAR_GLOBALS); if (migrated_base == NULL) { printk(BIOS_ERR, "CAR: Could not find migration base!\n"); return var; } offset = (char *)var - (char *)_car_start; return &migrated_base[offset]; } void car_migrate_variables(void) { void *migrated_base; car_migration_func_t *migrate_func; size_t car_data_size = &_car_data_end[0] - &_car_data_start[0]; /* Check if already migrated. */ if (car_migrated) return; migrated_base = cbmem_add(CBMEM_ID_CAR_GLOBALS, car_data_size); if (migrated_base == NULL) { printk(BIOS_ERR, "Could not migrate CAR data!\n"); return; } memcpy(migrated_base, &_car_data_start[0], car_data_size); /* Mark that the data has been moved. */ car_migrated = ~0; /* Call all the migration functions. */ migrate_func = &_car_migrate_start; while (migrate_func != &_car_migrate_end) { (*migrate_func)(); migrate_func++; } }