mrc: Add support for separate training cache in recovery mode

1. Re-factor MRC cache driver to properly select RW_MRC_CACHE or
RECOVERY_MRC_CACHE based on the boot mode.
 - If normal mode boot, use RW_MRC_CACHE, if available.
 - If recovery mode boot:
    - Retrain memory if RECOVERY_MRC_CACHE not present, or recovery is
    requested explicity with retrain memory request.
    - Use RECOVERY_MRC_CACHE otherwise.
2. Protect RW and RECOVERY mrc caches in recovery and non-recovery boot
modes. Check if both are present under one unified region and protect
that region as a whole. Else try protecting individual regions.
3. Update training data in appropriate cache:
 - Use RW_MRC_CACHE if normal mode.
 - Use RECOVERY_MRC_CACHE if present in recovery mode. Else use
 RW_MRC_CACHE.
4. Add proper debug logs to indicate which training data cache is used
at any point.

BUG=chrome-os-partner:59352
BRANCH=None
TEST=Verified that correct cache is used in both normal and recovery
mode on reef.

Change-Id: Ie79737a1450bd1ff71543e44a5a3e16950e70fb3
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://review.coreboot.org/17242
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/src/soc/intel/common/mrc_cache.h b/src/soc/intel/common/mrc_cache.h
index 9b14c1efd8..850acd6c0a 100644
--- a/src/soc/intel/common/mrc_cache.h
+++ b/src/soc/intel/common/mrc_cache.h
@@ -19,6 +19,10 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#define DEFAULT_MRC_CACHE	"RW_MRC_CACHE"
+#define RECOVERY_MRC_CACHE	"RECOVERY_MRC_CACHE"
+#define UNIFIED_MRC_CACHE	"UNIFIED_MRC_CACHE"
+
 /* Wrapper object to save MRC information. */
 struct mrc_saved_data {
 	uint32_t signature;
@@ -32,6 +36,9 @@ struct mrc_saved_data {
 int mrc_cache_get_current(const struct mrc_saved_data **cache);
 int mrc_cache_get_current_with_version(const struct mrc_saved_data **cache,
 					uint32_t version);
+int mrc_cache_get_current_from_region(const struct mrc_saved_data **cache,
+				      uint32_t version,
+				      const char *region_name);
 
 /* Stash the resulting MRC data to be saved in non-volatile storage later. */
 int mrc_cache_stash_data(const void *data, size_t size);