| /* |
| * This file is part of the coreboot project. |
| * |
| * Copyright (C) 2014 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. |
| */ |
| |
| #include <string.h> |
| #include <arch/acpi.h> |
| #include <console/console.h> |
| #include <cbmem.h> |
| #include <cpu/x86/smm.h> |
| |
| void *backup_default_smm_area(void) |
| { |
| void *save_area; |
| const void *default_smm = (void *)SMM_DEFAULT_BASE; |
| |
| if (!IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)) |
| return NULL; |
| |
| /* |
| * The buffer needs to be preallocated regardless. In the non-resume |
| * path it will be allocated for handling resume. Note that cbmem_add() |
| * does a find before the addition. |
| */ |
| save_area = cbmem_add(CBMEM_ID_SMM_SAVE_SPACE, SMM_DEFAULT_SIZE); |
| |
| if (save_area == NULL) { |
| printk(BIOS_DEBUG, "SMM save area not added.\n"); |
| return NULL; |
| } |
| |
| /* Only back up the area on S3 resume. */ |
| if (acpi_is_wakeup_s3()) { |
| memcpy(save_area, default_smm, SMM_DEFAULT_SIZE); |
| return save_area; |
| } |
| |
| /* |
| * Not the S3 resume path. No need to restore memory contents after |
| * SMM relocation. |
| */ |
| return NULL; |
| } |
| |
| void restore_default_smm_area(void *smm_save_area) |
| { |
| void *default_smm = (void *)SMM_DEFAULT_BASE; |
| |
| if (smm_save_area == NULL) |
| return; |
| |
| memcpy(default_smm, smm_save_area, SMM_DEFAULT_SIZE); |
| } |