soc/amd/common: Add S3 supporting functions

Add functions that the wrapper will call to get and save the S3 data.
The wrapper requires two types of data saved:
 * Non-volatile:  Information that is the minimum required for bringing
   the DRAM controller back online.  This change uses the common
   mrc_cache driver to manage the storage
 * Volatile:  May be stored in DRAM; information required to complete
   the system restoration process.

TEST=Suspend/Resume Kahlee with complete S3 patch stack
BUG=b:69614064

Change-Id: Ie60162ea10f053393bc84e927dbd80c9279e6b63
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/22727
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>
diff --git a/src/soc/amd/common/block/s3/s3_resume.c b/src/soc/amd/common/block/s3/s3_resume.c
new file mode 100644
index 0000000..4883fa5
--- /dev/null
+++ b/src/soc/amd/common/block/s3/s3_resume.c
@@ -0,0 +1,60 @@
+/*
+ * This file is part of the coreboot project.
+ *
+ * Copyright (C) 2012-2017 Advanced Micro Devices, Inc.
+ * 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 <cbmem.h>
+#include <stage_cache.h>
+#include <mrc_cache.h>
+#include <console/console.h>
+#include <amdblocks/s3_resume.h>
+
+/* Training data versioning is not supported or tracked. */
+#define DEFAULT_MRC_VERSION 0
+
+void get_s3nv_info(void **base, size_t *size)
+{
+	struct region_device rdev;
+
+	mrc_cache_get_current(MRC_TRAINING_DATA, DEFAULT_MRC_VERSION, &rdev);
+	*base = rdev_mmap_full(&rdev);
+	*size = region_device_sz(&rdev);
+	if (!*base || !*size)
+		printk(BIOS_ERR, "Error: S3 NV data not found\n");
+	else
+		printk(BIOS_SPEW, "S3 NV data @0x%p 0x%0zx total bytes\n",
+							*base, *size);
+}
+
+void get_s3vol_info(void **base, size_t *size)
+{
+	stage_cache_get_raw(STAGE_S3_DATA, base, size);
+	if (!*base || !*size)
+		printk(BIOS_ERR, "Error: S3 volatile data not found\n");
+	else
+		printk(BIOS_SPEW, "S3 volatile data @0x%p 0x%0zx total bytes\n",
+							*base, *size);
+}
+
+int save_s3_info(void *nv_base, size_t nv_size, void *vol_base, size_t vol_size)
+{
+	if (mrc_cache_stash_data(MRC_TRAINING_DATA, DEFAULT_MRC_VERSION,
+				nv_base, nv_size) < 0) {
+		printk(BIOS_ERR, "Failed to stash MRC data\n");
+		return -1;
+	}
+
+	stage_cache_add_raw(STAGE_S3_DATA, vol_base, vol_size);
+	return 0;
+}