106 lines
2.9 KiB
C
106 lines
2.9 KiB
C
/*
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* This file is part of the coreboot project.
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*
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* Copyright (C) 2013 Google, Inc.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; version 2 of the License.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include <string.h>
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#include <stddef.h>
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#include <console/console.h>
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#include <cbmem.h>
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#include <arch/early_variables.h>
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typedef void (* const car_migration_func_t)(void);
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extern car_migration_func_t _car_migrate_start;
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extern car_migration_func_t _car_migrate_end;
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extern char _car_data_start[];
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extern char _car_data_end[];
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/*
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* The car_migrated global variable determines if the cache-as-ram space has
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* been migrated to real RAM. It does this by assuming the following things:
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* 1. cache-as-ram space is zero'd out once it is set up.
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* 2. Either the cache-as-ram space is memory-backed after getting torn down
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* or the space returns 0xff's for each byte read.
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* Based on these 2 attributes there is the ability to tell when the
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* cache-as-ram region has been migrated.
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*/
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static int car_migrated CAR_GLOBAL;
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void *car_get_var_ptr(void *var)
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{
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char *migrated_base;
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int offset;
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void * _car_start = &_car_data_start;
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void * _car_end = &_car_data_end;
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/* If the cache-as-ram has not been migrated return the pointer
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* passed in. */
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if (!car_migrated)
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return var;
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if (var < _car_start || var >= _car_end) {
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printk(BIOS_ERR,
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"Requesting CAR variable outside of CAR region: %p\n",
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var);
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return var;
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}
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migrated_base = cbmem_find(CBMEM_ID_CAR_GLOBALS);
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if (migrated_base == NULL) {
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printk(BIOS_ERR, "CAR: Could not find migration base!\n");
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return var;
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}
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offset = (char *)var - (char *)_car_start;
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return &migrated_base[offset];
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}
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void car_migrate_variables(void)
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{
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void *migrated_base;
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car_migration_func_t *migrate_func;
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size_t car_data_size = &_car_data_end[0] - &_car_data_start[0];
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/* Check if already migrated. */
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if (car_migrated)
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return;
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migrated_base = cbmem_add(CBMEM_ID_CAR_GLOBALS, car_data_size);
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if (migrated_base == NULL) {
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printk(BIOS_ERR, "Could not migrate CAR data!\n");
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return;
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}
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memcpy(migrated_base, &_car_data_start[0], car_data_size);
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/* Mark that the data has been moved. */
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car_migrated = ~0;
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/* Call all the migration functions. */
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migrate_func = &_car_migrate_start;
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while (migrate_func != &_car_migrate_end) {
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(*migrate_func)();
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migrate_func++;
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}
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}
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