[edk2-platforms:PATCH V1] MinPlatformPkg/SaveMemoryConfig: Support NVS Data compression.

[Raghava Gudla <raghava.gudla@intel.com>]

Around 50KB "FspNonVolatileStorageHob" data can be compressed to
approximately 3 KB which can save NVRAM space and enhance life
of the SPI part by decreasing the number of reclaim cycles needed.

This patch added support to compress "FspNonVolatileStorageHob" data
before saving to NVRAM.

A PcdEnableCompressFspNvsHob is introduced to enable/disable this
feature per platform usage.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>

Signed-off-by: Raghava Gudla <raghava.gudla@intel.com>
---
 .../SaveMemoryConfig/SaveMemoryConfig.c       | 34 +++++++++++++++++++
 .../SaveMemoryConfig/SaveMemoryConfig.inf     |  6 +++-
 .../Include/Dsc/CoreCommonLib.dsc             |  1 +
 .../Intel/MinPlatformPkg/MinPlatformPkg.dec   |  5 +++
 4 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c
index 0215e8eed..8aa935b54 100644
--- a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c
+++ b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.c
@@ -21,6 +21,8 @@ SPDX-License-Identifier: BSD-2-Clause-Patent
 #include <Library/LargeVariableWriteLib.h>
 #include <Library/VariableWriteLib.h>
 #include <Guid/FspNonVolatileStorageHob2.h>
+#include <Library/PcdLib.h>
+#include <Library/CompressLib.h>
 
 /**
   This is the standard EFI driver point that detects whether there is a
@@ -45,6 +47,9 @@ SaveMemoryConfigEntryPoint (
   UINTN             DataSize;
   UINTN             BufferSize;
   BOOLEAN           DataIsIdentical;
+  VOID              *CompressedData;
+  UINT64            CompressedSize;
+  UINTN             CompressedAllocationPages;
 
   DataSize        = 0;
   BufferSize      = 0;
@@ -73,6 +78,35 @@ SaveMemoryConfigEntryPoint (
     }
   }
 
+  if (PcdGetBool (PcdEnableCompressFspNvsHob) == 1) {
+    CompressedData            = NULL;
+    CompressedSize            = 0;
+    CompressedAllocationPages = 0;
+
+    DEBUG ((DEBUG_INFO, "compressing mem config nvs variable\n"));
+    if (DataSize > 0) {
+      CompressedAllocationPages = EFI_SIZE_TO_PAGES (DataSize);
+      CompressedData = AllocatePages (CompressedAllocationPages);
+      if (CompressedData == NULL) {
+        DEBUG ((DEBUG_ERROR, "[%a] - Failed to allocate compressed data buffer.\n", __func__));
+        ASSERT_EFI_ERROR (EFI_OUT_OF_RESOURCES);
+        return EFI_OUT_OF_RESOURCES;
+      }
+
+      CompressedSize = EFI_PAGES_TO_SIZE (CompressedAllocationPages);
+      Status = Compress (HobData, DataSize, CompressedData, &CompressedSize);
+      if (EFI_ERROR (Status)) {
+        DEBUG ((DEBUG_ERROR, "[%a] - failed to compress data. Status = %r\n", __func__, Status));
+        ASSERT_EFI_ERROR (Status);
+        FreePool(CompressedData);
+        return Status;
+      } else {
+        HobData  = CompressedData;
+        DataSize = (UINTN) CompressedSize;
+      }
+    }
+  }
+
   if (HobData != NULL) {
     DEBUG ((DEBUG_INFO, "FspNvsHob.NvsDataLength:%d\n", DataSize));
     DEBUG ((DEBUG_INFO, "FspNvsHob.NvsDataPtr   : 0x%x\n", HobData));
diff --git a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
index 61e85a658..77920d031 100644
--- a/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
+++ b/Platform/Intel/MinPlatformPkg/FspWrapper/SaveMemoryConfig/SaveMemoryConfig.inf
@@ -26,6 +26,7 @@
   LargeVariableReadLib
   LargeVariableWriteLib
   BaseLib
+  CompressLib
 
 [Packages]
   MdePkg/MdePkg.dec
@@ -45,6 +46,9 @@
   gFspNonVolatileStorageHob2Guid                ## CONSUMES
   gFspNvsBufferVariableGuid                     ## PRODUCES
 
+[Pcd]
+  gMinPlatformPkgTokenSpaceGuid.PcdEnableCompressFspNvsHob
+
 [Depex]
   gEfiVariableArchProtocolGuid        AND
-  gEfiVariableWriteArchProtocolGuid
\ No newline at end of file
+  gEfiVariableWriteArchProtocolGuid
diff --git a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc
index 5ce21cf31..dfe7d836d 100644
--- a/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc
+++ b/Platform/Intel/MinPlatformPkg/Include/Dsc/CoreCommonLib.dsc
@@ -147,6 +147,7 @@
   BmpSupportLib|MdeModulePkg/Library/BaseBmpSupportLib/BaseBmpSupportLib.inf
   LargeVariableReadLib|MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableReadLib.inf
   LargeVariableWriteLib|MinPlatformPkg/Library/BaseLargeVariableLib/BaseLargeVariableWriteLib.inf
+  CompressLib|MinPlatformPkg/Library/CompressLib/CompressLib.inf
 
   #
   # CryptLib
diff --git a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
index 784abb828..e21d55fb3 100644
--- a/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
+++ b/Platform/Intel/MinPlatformPkg/MinPlatformPkg.dec
@@ -348,6 +348,11 @@
   gMinPlatformPkgTokenSpaceGuid.PcdFadtFlags|0x000086A5|UINT32|0x90000027
   gMinPlatformPkgTokenSpaceGuid.PcdFadtMajorVersion|0x06|UINT8|0x90000030
   gMinPlatformPkgTokenSpaceGuid.PcdFadtMinorVersion|0x03|UINT8|0x90000031
+## Controls whether the Memory Config UEFI Variable is saved as compressed data.
+# Data compression can significantly reduce variable storage usage for FSP NVS buffer data.
+# Platforms that choose to compress the data will need to decompress the variable data upon
+# extraction.
+  gMinPlatformPkgTokenSpaceGuid.PcdEnableCompressFspNvsHob|FALSE|BOOLEAN|0x90000032
 
 [PcdsFixedAtBuild]
 
-- 
2.19.1.windows.1