1 files changed, 68 insertions, 0 deletions
diff --git a/src/cpu/x86/smm/backup_default_smm.c b/src/cpu/x86/smm/backup_default_smm.c
new file mode 100644
index 0000000000..ef1d3a9e41
--- /dev/null
+++ b/src/cpu/x86/smm/backup_default_smm.c
@@ -0,0 +1,68 @@
+/*
+ * 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.
+ *
+ * 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 <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_slp_type == 3) {
+		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);
+}