| /* |
| * 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 <arch/early_variables.h> |
| |
| typedef void (* const car_migration_func_t)(void); |
| |
| extern car_migration_func_t _car_migrate_start; |
| |
| 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]; |
| } |
| |
| /* |
| * Update a CAR_GLOBAL variable var, originally pointing to CAR region, |
| * with the address in migrated CAR region in DRAM. |
| */ |
| void *car_sync_var_ptr(void *var) |
| { |
| void ** mig_var = car_get_var_ptr(var); |
| void * _car_start = &_car_data_start; |
| void * _car_end = &_car_data_end; |
| |
| /* Not moved or migrated yet. */ |
| if (mig_var == var) |
| return mig_var; |
| |
| /* It's already pointing outside car.global_data. */ |
| if (*mig_var < _car_start || *mig_var > _car_end) |
| return mig_var; |
| |
| #if !IS_ENABLED(CONFIG_PLATFORM_USES_FSP) |
| /* Keep console buffer in CAR until cbmemc_reinit() moves it. */ |
| if (*mig_var == _car_end) |
| return mig_var; |
| #endif |
| |
| /* Move the pointer by the same amount the variable storing it was |
| * moved by. |
| */ |
| *mig_var += (char *)mig_var - (char *)var; |
| |
| return mig_var; |
| } |
| |
| static void do_car_migrate_variables(void) |
| { |
| void *migrated_base; |
| 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; |
| } |
| |
| static void do_car_migrate_hooks(void) |
| { |
| car_migration_func_t *migrate_func; |
| /* Call all the migration functions. */ |
| migrate_func = &_car_migrate_start; |
| while (*migrate_func != NULL) { |
| (*migrate_func)(); |
| migrate_func++; |
| } |
| } |
| |
| void car_migrate_variables(void) |
| { |
| if (!IS_ENABLED(CONFIG_BROKEN_CAR_MIGRATE)) |
| do_car_migrate_variables(); |
| |
| if (!IS_ENABLED(CONFIG_BROKEN_CAR_MIGRATE)) |
| do_car_migrate_hooks(); |
| } |