soc/amd/stoneyridge: Reboot if missing MRC cache info

AGESA doesn't detect invalid NV data during AmdInitResume(). In
cases where the data has been erased, or cannot be found, reboot
the system.  Otherwise the user will experience a hang when cbmem
isn't recovered and the postcar frame cannot be initialized.

BUG=b:122725586
TEST=Write S3 NV save data with 0xff and force reboot

Change-Id: Ib3cf2515f300decd3de198f7741660d95ee4c744
Signed-off-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-on: https://review.coreboot.org/c/31160
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

1 files changed, 24 insertions, 8 deletions

diff --git a/src/soc/amd/common/block/s3/s3_resume.c b/src/soc/amd/common/block/s3/s3_resume.c
index 04414e8a2e..eb0148f964 100644
--- a/src/soc/amd/common/block/s3/s3_resume.c
+++ b/src/soc/amd/common/block/s3/s3_resume.c
@@ -16,28 +16,44 @@
 
 #include <stage_cache.h>
 #include <mrc_cache.h>
+#include <reset.h>
 #include <console/console.h>
+#include <soc/southbridge.h>
 #include <amdblocks/s3_resume.h>
 
 /* Training data versioning is not supported or tracked. */
 #define DEFAULT_MRC_VERSION 0
 
+static void reboot_from_resume(const char *message) /* Does not return */
+{
+	printk(BIOS_ERR, "%s", message);
+	set_pm1cnt_s5();
+	board_reset();
+}
+
 void get_s3nv_info(void **base, size_t *size)
 {
 	struct region_device rdev;
 
 	if (mrc_cache_get_current(MRC_TRAINING_DATA, DEFAULT_MRC_VERSION,
-					&rdev)) {
-		printk(BIOS_ERR, "mrc_cache_get_current returned error\n");
-		return;
-	}
+					&rdev))
+		reboot_from_resume("mrc_cache_get_current error, rebooting.\n");
+
 	*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);
+		reboot_from_resume("Error: S3 NV data not found, rebooting.\n");
+
+	/* Read 16 bytes to infer if the NV has been erased from flash. */
+	int i;
+	uint32_t erased = 0xffffffff;
+	for (i = 0; i < 4; i++)
+		erased &= read32((uint32_t *)*base + i);
+
+	if (erased == 0xffffffff)
+		reboot_from_resume("Error: S3 NV data invalid, rebooting.\n");
+
+	printk(BIOS_SPEW, "S3 NV data @0x%p, 0x%0zx bytes\n", *base, *size);
 }
 
 void get_s3vol_info(void **base, size_t *size)