[edk2-devel] [PATCH] StandaloneMmPkg/Core: Remove dead code

["Ni, Ray" <ray.ni@intel.com>]

Load-module-at-fixed-address feature does not work in standalone MM core.

The patch removes the 2 dead functions and related global variables
that are related to the feature.

Signed-off-by: Ray Ni <ray.ni@intel.com>
Cc: Ard Biesheuvel <ardb+tianocore@kernel.org>
Cc: Sami Mujawar <sami.mujawar@arm.com>
---
 StandaloneMmPkg/Core/Dispatcher.c       | 185 +-----------------------
 StandaloneMmPkg/Core/StandaloneMmCore.h |   3 +-
 2 files changed, 2 insertions(+), 186 deletions(-)

diff --git a/StandaloneMmPkg/Core/Dispatcher.c b/StandaloneMmPkg/Core/Dispatcher.c
index 7b4a3c4c55..6d43e53851 100644
--- a/StandaloneMmPkg/Core/Dispatcher.c
+++ b/StandaloneMmPkg/Core/Dispatcher.c
@@ -29,7 +29,7 @@
   Depex - Dependency Expresion.
 
   Copyright (c) 2014, Hewlett-Packard Development Company, L.P.
-  Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2023, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2016 - 2021, Arm Limited. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -97,189 +97,6 @@ BOOLEAN  gDispatcherRunning = FALSE;
 //
 BOOLEAN  gRequestDispatch = FALSE;
 
-//
-// The global variable is defined for Loading modules at fixed address feature to track the MM code
-// memory range usage. It is a bit mapped array in which every bit indicates the correspoding
-// memory page available or not.
-//
-GLOBAL_REMOVE_IF_UNREFERENCED    UINT64  *mMmCodeMemoryRangeUsageBitMap = NULL;
-
-/**
-  To check memory usage bit map array to figure out if the memory range in which the image will be loaded
-  is available or not. If memory range is avaliable, the function will mark the corresponding bits to 1
-  which indicates the memory range is used. The function is only invoked when load modules at fixed address
-  feature is enabled.
-
-  @param  ImageBase                The base addres the image will be loaded at.
-  @param  ImageSize                The size of the image
-
-  @retval EFI_SUCCESS              The memory range the image will be loaded in is available
-  @retval EFI_NOT_FOUND            The memory range the image will be loaded in is not available
-**/
-EFI_STATUS
-CheckAndMarkFixLoadingMemoryUsageBitMap (
-  IN  EFI_PHYSICAL_ADDRESS  ImageBase,
-  IN  UINTN                 ImageSize
-  )
-{
-  UINT32                MmCodePageNumber;
-  UINT64                MmCodeSize;
-  EFI_PHYSICAL_ADDRESS  MmCodeBase;
-  UINTN                 BaseOffsetPageNumber;
-  UINTN                 TopOffsetPageNumber;
-  UINTN                 Index;
-
-  //
-  // Build tool will calculate the smm code size and then patch the PcdLoadFixAddressMmCodePageNumber
-  //
-  MmCodePageNumber = 0;
-  MmCodeSize       = EFI_PAGES_TO_SIZE (MmCodePageNumber);
-  MmCodeBase       = gLoadModuleAtFixAddressMmramBase;
-
-  //
-  // If the memory usage bit map is not initialized,  do it. Every bit in the array
-  // indicate the status of the corresponding memory page, available or not
-  //
-  if (mMmCodeMemoryRangeUsageBitMap == NULL) {
-    mMmCodeMemoryRangeUsageBitMap = AllocateZeroPool (((MmCodePageNumber / 64) + 1) * sizeof (UINT64));
-  }
-
-  //
-  // If the Dxe code memory range is not allocated or the bit map array allocation failed, return EFI_NOT_FOUND
-  //
-  if (mMmCodeMemoryRangeUsageBitMap == NULL) {
-    return EFI_NOT_FOUND;
-  }
-
-  //
-  // see if the memory range for loading the image is in the MM code range.
-  //
-  if ((MmCodeBase + MmCodeSize <  ImageBase + ImageSize) || (MmCodeBase >  ImageBase)) {
-    return EFI_NOT_FOUND;
-  }
-
-  //
-  // Test if the memory is available or not.
-  //
-  BaseOffsetPageNumber = (UINTN)EFI_SIZE_TO_PAGES ((UINT32)(ImageBase - MmCodeBase));
-  TopOffsetPageNumber  = (UINTN)EFI_SIZE_TO_PAGES ((UINT32)(ImageBase + ImageSize - MmCodeBase));
-  for (Index = BaseOffsetPageNumber; Index < TopOffsetPageNumber; Index++) {
-    if ((mMmCodeMemoryRangeUsageBitMap[Index / 64] & LShiftU64 (1, (Index % 64))) != 0) {
-      //
-      // This page is already used.
-      //
-      return EFI_NOT_FOUND;
-    }
-  }
-
-  //
-  // Being here means the memory range is available.  So mark the bits for the memory range
-  //
-  for (Index = BaseOffsetPageNumber; Index < TopOffsetPageNumber; Index++) {
-    mMmCodeMemoryRangeUsageBitMap[Index / 64] |= LShiftU64 (1, (Index % 64));
-  }
-
-  return EFI_SUCCESS;
-}
-
-/**
-  Get the fixed loading address from image header assigned by build tool. This function only be called
-  when Loading module at Fixed address feature enabled.
-
-  @param  ImageContext              Pointer to the image context structure that describes the PE/COFF
-                                    image that needs to be examined by this function.
-  @retval EFI_SUCCESS               An fixed loading address is assigned to this image by build tools .
-  @retval EFI_NOT_FOUND             The image has no assigned fixed loadding address.
-
-**/
-EFI_STATUS
-GetPeCoffImageFixLoadingAssignedAddress (
-  IN OUT PE_COFF_LOADER_IMAGE_CONTEXT  *ImageContext
-  )
-{
-  UINTN                            SectionHeaderOffset;
-  EFI_STATUS                       Status;
-  EFI_IMAGE_SECTION_HEADER         SectionHeader;
-  EFI_IMAGE_OPTIONAL_HEADER_UNION  *ImgHdr;
-  EFI_PHYSICAL_ADDRESS             FixLoadingAddress;
-  UINT16                           Index;
-  UINTN                            Size;
-  UINT16                           NumberOfSections;
-  UINT64                           ValueInSectionHeader;
-
-  FixLoadingAddress = 0;
-  Status            = EFI_NOT_FOUND;
-
-  //
-  // Get PeHeader pointer
-  //
-  ImgHdr              = (EFI_IMAGE_OPTIONAL_HEADER_UNION *)((CHAR8 *)ImageContext->Handle + ImageContext->PeCoffHeaderOffset);
-  SectionHeaderOffset = ImageContext->PeCoffHeaderOffset + sizeof (UINT32) + sizeof (EFI_IMAGE_FILE_HEADER) +
-                        ImgHdr->Pe32.FileHeader.SizeOfOptionalHeader;
-  NumberOfSections = ImgHdr->Pe32.FileHeader.NumberOfSections;
-
-  //
-  // Get base address from the first section header that doesn't point to code section.
-  //
-  for (Index = 0; Index < NumberOfSections; Index++) {
-    //
-    // Read section header from file
-    //
-    Size   = sizeof (EFI_IMAGE_SECTION_HEADER);
-    Status = ImageContext->ImageRead (
-                             ImageContext->Handle,
-                             SectionHeaderOffset,
-                             &Size,
-                             &SectionHeader
-                             );
-    if (EFI_ERROR (Status)) {
-      return Status;
-    }
-
-    Status = EFI_NOT_FOUND;
-
-    if ((SectionHeader.Characteristics & EFI_IMAGE_SCN_CNT_CODE) == 0) {
-      //
-      // Build tool will save the address in PointerToRelocations & PointerToLineNumbers fields
-      // in the first section header that doesn't point to code section in image header. So there
-      // is an assumption that when the feature is enabled, if a module with a loading address
-      // assigned by tools, the PointerToRelocations & PointerToLineNumbers fields should not be
-      // Zero, or else, these 2 fields should be set to Zero
-      //
-      ValueInSectionHeader = ReadUnaligned64 ((UINT64 *)&SectionHeader.PointerToRelocations);
-      if (ValueInSectionHeader != 0) {
-        //
-        // Found first section header that doesn't point to code section in which build tool saves the
-        // offset to SMRAM base as image base in PointerToRelocations & PointerToLineNumbers fields
-        //
-        FixLoadingAddress = (EFI_PHYSICAL_ADDRESS)(gLoadModuleAtFixAddressMmramBase + (INT64)ValueInSectionHeader);
-        //
-        // Check if the memory range is available.
-        //
-        Status = CheckAndMarkFixLoadingMemoryUsageBitMap (FixLoadingAddress, (UINTN)(ImageContext->ImageSize + ImageContext->SectionAlignment));
-        if (!EFI_ERROR (Status)) {
-          //
-          // The assigned address is valid. Return the specified loading address
-          //
-          ImageContext->ImageAddress = FixLoadingAddress;
-        }
-      }
-
-      break;
-    }
-
-    SectionHeaderOffset += sizeof (EFI_IMAGE_SECTION_HEADER);
-  }
-
-  DEBUG ((
-    DEBUG_INFO|DEBUG_LOAD,
-    "LOADING MODULE FIXED INFO: Loading module at fixed address %x, Status = %r\n",
-    FixLoadingAddress,
-    Status
-    ));
-  return Status;
-}
-
 /**
   Loads an EFI image into SMRAM.
 
diff --git a/StandaloneMmPkg/Core/StandaloneMmCore.h b/StandaloneMmPkg/Core/StandaloneMmCore.h
index da23b8dc3c..3d71bc84f8 100644
--- a/StandaloneMmPkg/Core/StandaloneMmCore.h
+++ b/StandaloneMmPkg/Core/StandaloneMmCore.h
@@ -2,7 +2,7 @@
   The internal header file includes the common header files, defines
   internal structure and functions used by MmCore module.
 
-  Copyright (c) 2009 - 2014, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2009 - 2023, Intel Corporation. All rights reserved.<BR>
   Copyright (c) 2016 - 2021, Arm Limited. All rights reserved.<BR>
 
   SPDX-License-Identifier: BSD-2-Clause-Patent
@@ -177,7 +177,6 @@ typedef struct {
 extern MM_CORE_PRIVATE_DATA  *gMmCorePrivate;
 extern EFI_MM_SYSTEM_TABLE   gMmCoreMmst;
 extern LIST_ENTRY            gHandleList;
-extern EFI_PHYSICAL_ADDRESS  gLoadModuleAtFixAddressMmramBase;
 
 /**
   Called to initialize the memory service.
-- 
2.39.1.windows.1



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