[coreboot-gerrit] New patch to review for coreboot: soc/intel/common: provide option to invalide MRC cache on recovery

[Aaron Durbin]

Aaron Durbin ([e-mail]) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17870

-gerrit

commit d26a7e70e24a9ab6d7b7fa9204ac64d87242227e
Author: Aaron Durbin 
Date:   Wed Dec 14 15:36:56 2016 -0600

soc/intel/common: provide option to invalide MRC cache on recovery

Allow a board/platform to invalidate the normal MRC cache when
    hardware retraining is requested in recovery mode. A small 4 byte
    payload is used to update the latest data written. It will of course
    fail on MRC cache retreival on next usage.

BUG=chrome-os-partner:60592
    BRANCH=reef

Change-Id: Ic88cd66802664813562d003f50d54e4a4ea375ef
    Signed-off-by: Aaron Durbin 
---
 src/soc/intel/common/Kconfig     |  4 ++++
 src/soc/intel/common/mrc_cache.c | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 38 insertions(+)

diff --git a/src/soc/intel/common/Kconfig b/src/soc/intel/common/Kconfig
index 1cc856e..68bb38a 100644
--- a/src/soc/intel/common/Kconfig
+++ b/src/soc/intel/common/Kconfig
@@ -31,6 +31,10 @@ config HAS_RECOVERY_MRC_CACHE
    bool
    default n

+config MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN
+	bool
+	default n
+
 config MRC_SETTINGS_VARIABLE_DATA
    bool
    default n
diff --git a/src/soc/intel/common/mrc_cache.c b/src/soc/intel/common/mrc_cache.c
index 69e5b00..d515c71 100644
--- a/src/soc/intel/common/mrc_cache.c
+++ b/src/soc/intel/common/mrc_cache.c
@@ -486,6 +486,37 @@ static void protect_mrc_region(void)
    protect_mrc_cache(DEFAULT_MRC_CACHE);
 }

+static void invalidate_normal_cache(void)
+{
+	struct region_file cache_file;
+	struct region_device rdev;
+	const char *name = DEFAULT_MRC_CACHE;
+	const uint32_t invalid = ~MRC_DATA_SIGNATURE;
+
+	/* Invalidate only on recovery mode with retraining enabled. */
+	if (!vboot_recovery_mode_enabled())
+		return;
+	if (!vboot_recovery_mode_memory_retrain())
+		return;
+
+	if (fmap_locate_area_as_rdev_rw(name, &rdev) < 0) {
+		printk(BIOS_ERR, "MRC: Couldn't find '%s' region. Invalidation failed\n",
+			name);
+		return;
+	}
+
+	if (region_file_init(&cache_file, &rdev) < 0) {
+		printk(BIOS_ERR, "MRC: region file invalid for '%s'. Invalidation failed\n",
+		name);
+		return;
+	}
+
+	/* Push an update that consists of 4 bytes that is smaller than the
+	 * MRC metadata as well as an invalid signature. */
+	if (region_file_update_data(&cache_file, &invalid, sizeof(invalid)) < 0)
+		printk(BIOS_ERR, "MRC: invalidation failed for '%s'.\n", name);
+}
+
 static void update_mrc_cache(void *unused)
 {
    update_mrc_cache_by_type(MRC_TRAINING_DATA);
@@ -493,6 +524,9 @@ static void update_mrc_cache(void *unused)
    if (IS_ENABLED(CONFIG_MRC_SETTINGS_VARIABLE_DATA))
    	update_mrc_cache_by_type(MRC_VARIABLE_DATA);

+	if (IS_ENABLED(CONFIG_MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN))
+		invalidate_normal_cache();
+
    protect_mrc_region();
 }