mrc_cache: Move code for triggering memory training into mrc_cache

Currently the decision of whether or not to use mrc_cache in recovery
mode is made within the individual platforms' drivers (ie: fsp2.0,
fsp1.1, etc.).  As this is not platform specific, but uses common
vboot infrastructure, the code can be unified and moved into
mrc_cache.  The conditions are as follows:

  1.  If HAS_RECOVERY_MRC_CACHE, use mrc_cache data (unless retrain
      switch is true)
  2.  If !HAS_RECOVERY_MRC_CACHE && VBOOT_STARTS_IN_BOOTBLOCK, this
      means that memory training will occur after verified boot,
      meaning that mrc_cache will be filled with data from executing
      RW code.  So in this case, we never want to use the training
      data in the mrc_cache for recovery mode.
  3.  If !HAS_RECOVERY_MRC_CACHE && VBOOT_STARTS_IN_ROMSTAGE, this
      means that memory training happens before verfied boot, meaning
      that the mrc_cache data is generated by RO code, so it is safe
      to use for a recovery boot.
  4.  Any platform that does not use vboot should be unaffected.

Additionally, we have removed the
MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN config because the
mrc_cache driver takes care of invalidating the mrc_cache data for
normal mode.  If the platform:
  1.  !HAS_RECOVERY_MRC_CACHE, always invalidate mrc_cache data
  2.  HAS_RECOVERY_MRC_CACHE, only invalidate if retrain switch is set

BUG=b:150502246
BRANCH=None
TEST=1. run dut-control power_state:rec_force_mrc twice on lazor
        ensure that memory retraining happens both times
        run dut-control power_state:rec twice on lazor
        ensure that memory retraining happens only first time
     2. remove HAS_RECOVERY_MRC_CACHE from lazor Kconfig
        boot twice to ensure caching of memory training occurred
	on each boot.

Change-Id: I3875a7b4a4ba3c1aa8a3c1507b3993036a7155fc
Signed-off-by: Shelley Chen <shchen@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/46855
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

2 files changed, 16 insertions, 23 deletions

diff --git a/src/soc/intel/broadwell/raminit.c b/src/soc/intel/broadwell/raminit.c
index 7020ddfe0d..e51b4f7b66 100644
--- a/src/soc/intel/broadwell/raminit.c
+++ b/src/soc/intel/broadwell/raminit.c
@@ -85,29 +85,23 @@ void raminit(struct pei_data *pei_data)
 
 	broadwell_fill_pei_data(pei_data);
 
-	if (CONFIG(BROADWELL_VBOOT_IN_BOOTBLOCK) &&
-	    vboot_recovery_mode_enabled()) {
-		/* Recovery mode does not use MRC cache */
-		printk(BIOS_DEBUG, "Recovery mode: not using MRC cache.\n");
+	/* Assume boot device is memory mapped. */
+	assert(CONFIG(BOOT_DEVICE_MEMORY_MAPPED));
+
+	pei_data->saved_data =
+		mrc_cache_current_mmap_leak(MRC_TRAINING_DATA, 0,
+					    &mrc_size);
+	if (pei_data->saved_data) {
+		/* MRC cache found */
+		pei_data->saved_data_size = mrc_size;
+	} else if (pei_data->boot_mode == ACPI_S3) {
+		/* Waking from S3 and no cache. */
+		printk(BIOS_DEBUG,
+		       "No MRC cache found in S3 resume path.\n");
+		post_code(POST_RESUME_FAILURE);
+		system_reset();
 	} else {
-		/* Assume boot device is memory mapped. */
-		assert(CONFIG(BOOT_DEVICE_MEMORY_MAPPED));
-
-		pei_data->saved_data =
-			mrc_cache_current_mmap_leak(MRC_TRAINING_DATA, 0,
-						    &mrc_size);
-		if (pei_data->saved_data) {
-			/* MRC cache found */
-			pei_data->saved_data_size = mrc_size;
-		} else if (pei_data->boot_mode == ACPI_S3) {
-			/* Waking from S3 and no cache. */
-			printk(BIOS_DEBUG,
-			       "No MRC cache found in S3 resume path.\n");
-			post_code(POST_RESUME_FAILURE);
-			system_reset();
-		} else {
-			printk(BIOS_DEBUG, "No MRC cache found.\n");
-		}
+		printk(BIOS_DEBUG, "No MRC cache found.\n");
 	}
 
 	/*
diff --git a/src/soc/qualcomm/sc7180/Kconfig b/src/soc/qualcomm/sc7180/Kconfig
index 4cd1c41cac..066ff5db1c 100644
--- a/src/soc/qualcomm/sc7180/Kconfig
+++ b/src/soc/qualcomm/sc7180/Kconfig
@@ -33,7 +33,6 @@ config VBOOT
 	select VBOOT_RETURN_FROM_VERSTAGE
 	select VBOOT_MUST_REQUEST_DISPLAY
 	select VBOOT_STARTS_IN_BOOTBLOCK
-	select MRC_CLEAR_NORMAL_CACHE_ON_RECOVERY_RETRAIN
 
 config SC7180_QSPI
 	bool