From 8c533a4e567dc29eb31cf1d991f31700aad12d45 Mon Sep 17 00:00:00 2001
From: Raghava Gudla <raghava.gudla@intel.com>
Date: Fri, 9 Aug 2019 14:25:33 -0700
Subject: [PATCH] [CFL] MRC data save is ignored after first boot

Current code will check if the first 4 bytes of the existing
MRC training data, if it is 0xFFFFFFFF then MRC training data
will be saved otherwise even though there is change in the
training data, it will not be saved.

Modified the code to compare the incoming training data to the
saved data, if they do not match, save the incoming training data.

Signed-off-by: Raghava Gudla <raghava.gudla@intel.com>
---
 .../Stage2BoardInitLib/Stage2BoardInitLib.c   | 69 +++++++++----------
 1 file changed, 34 insertions(+), 35 deletions(-)

diff --git a/Platform/CoffeelakeBoardPkg/Library/Stage2BoardInitLib/Stage2BoardInitLib.c b/Platform/CoffeelakeBoardPkg/Library/Stage2BoardInitLib/Stage2BoardInitLib.c
index a47b9ea3..8df19cbb 100644
--- a/Platform/CoffeelakeBoardPkg/Library/Stage2BoardInitLib/Stage2BoardInitLib.c
+++ b/Platform/CoffeelakeBoardPkg/Library/Stage2BoardInitLib/Stage2BoardInitLib.c
@@ -1596,54 +1596,53 @@ SaveNvsData (
   UINT32      Address;
   UINT32      BaseAddress;
   UINT32      RegionSize;
-  UINT32      TotalSize;
+  UINT32      MrcDataRegSize;
 
-  Status = GetComponentInfo (FLASH_MAP_SIG_MRCDATA, &Address, NULL);
+  Status = GetComponentInfo (FLASH_MAP_SIG_MRCDATA, &Address, &MrcDataRegSize);
   if (EFI_ERROR(Status)) {
     return EFI_NOT_FOUND;
   }
-  if (*(UINT32 *)Address == 0xFFFFFFFF) {
-    Status = SpiConstructor ();
-    if (EFI_ERROR (Status)) {
-      return Status;
-    }
 
-    Status = SpiGetRegionAddress (FlashRegionAll, NULL,  &TotalSize);
-    if (EFI_ERROR (Status)) {
-      return Status;
-    }
+  if (Length > MrcDataRegSize) {
+    return EFI_INVALID_PARAMETER;
+  }
 
-    Status = SpiGetRegionAddress (FlashRegionBios, &BaseAddress, &RegionSize);
-    if (EFI_ERROR (Status)) {
-      return Status;
-    }
+  //
+  // Compare input data against the stored MRC training data
+  // if they match, no need to update again.
+  //
+  if (CompareMem ((VOID *)Address, Buffer, Length) == 0){
+    return EFI_ALREADY_STARTED;
+  }
 
-    BaseAddress += ((UINT32)(~TotalSize) + 1);
-    if (Address < BaseAddress) {
-      return EFI_ACCESS_DENIED;
-    }
+  Status = SpiGetRegionAddress (FlashRegionBios, &BaseAddress, &RegionSize);
+  if (EFI_ERROR (Status)) {
+    return Status;
+  }
 
-    Address -= BaseAddress;
-    if ((Address + ROUNDED_UP(Length, KB_(4))) > RegionSize) {
-      return EFI_OUT_OF_RESOURCES;
-    }
+  BaseAddress = ((UINT32)(~RegionSize) + 1);
+  if (Address < BaseAddress) {
+    return EFI_ACCESS_DENIED;
+  }
 
+  Address -= BaseAddress;
+  if ((Address + ROUNDED_UP(Length, KB_(4))) > RegionSize) {
+    return EFI_OUT_OF_RESOURCES;
+  }
+
+  if (!EFI_ERROR(Status)) {
+    Status = SpiFlashErase (FlashRegionBios, Address, ROUNDED_UP(Length, KB_(4)));
     if (!EFI_ERROR(Status)) {
-      Status = SpiFlashErase (FlashRegionBios, Address, ROUNDED_UP(Length, KB_(4)));
+      Status = SpiFlashWrite (FlashRegionBios, Address, Length, Buffer);
       if (!EFI_ERROR(Status)) {
-        Status = SpiFlashWrite (FlashRegionBios, Address, Length, Buffer);
-        if (!EFI_ERROR(Status)) {
-          DEBUG ((DEBUG_INFO, "MRC data successfully cached to 0x%X\n", Address));
-          MmioAndThenOr8 (
-            PCH_PWRM_BASE_ADDRESS + R_PMC_PWRM_GEN_PMCON_A + 2,
-            (UINT8) ~((B_PMC_PWRM_GEN_PMCON_A_MS4V | B_PMC_PWRM_GEN_PMCON_A_SUS_PWR_FLR) >> 16),
-            B_PMC_PWRM_GEN_PMCON_A_DISB >> 16
-            );
-        }
+        DEBUG ((DEBUG_INFO, "MRC data successfully cached to 0x%X\n", Address));
+        MmioAndThenOr8 (
+          PCH_PWRM_BASE_ADDRESS + R_PMC_PWRM_GEN_PMCON_A + 2,
+          (UINT8) ~((B_PMC_PWRM_GEN_PMCON_A_MS4V | B_PMC_PWRM_GEN_PMCON_A_SUS_PWR_FLR) >> 16),
+          B_PMC_PWRM_GEN_PMCON_A_DISB >> 16
+          );
       }
     }
-  } else {
-    Status = EFI_ALREADY_STARTED;
   }
 
   return Status;