[RFC PATCH 06/11] MdeModulePkg/DxeCore: Expose memory mapped FV protocol when possible

["Ard Biesheuvel" <ardb@kernel.org>]

Expose the EDK2 specific memory mapped FV protocol in addition to the
firmware volume protocol defined by PI when the underlying firmware
volume block protocol informs us that the firmware volume is memory
mapped. This permits the image loader to access any FFS files in the
image directly, rather than requiring it to load a cached copy into
memory via the ReadFile() API. This avoids a redundant memcpy().

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 MdeModulePkg/Core/Dxe/FwVol/FwVol.c       | 113 +++++++++++++++++++-
 MdeModulePkg/Core/Dxe/FwVol/FwVolDriver.h |  31 ++++++
 2 files changed, 140 insertions(+), 4 deletions(-)

diff --git a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
index 153bfecafa7772ea..f7f236496686bc36 100644
--- a/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
+++ b/MdeModulePkg/Core/Dxe/FwVol/FwVol.c
@@ -41,7 +41,8 @@ FV_DEVICE  mFvDevice = {
   0,
   0,
   FALSE,
-  FALSE
+  FALSE,
+  { MemoryMappedFvGetLocationAndSize },
 };
 
 //
@@ -676,11 +677,13 @@ NotifyFwVolBlock (
         //
         // Install an New FV protocol on the existing handle
         //
-        Status = CoreInstallProtocolInterface (
+        Status = CoreInstallMultipleProtocolInterfaces (
                    &Handle,
                    &gEfiFirmwareVolume2ProtocolGuid,
-                   EFI_NATIVE_INTERFACE,
-                   &FvDevice->Fv
+                   &FvDevice->Fv,
+                   (FvDevice->IsMemoryMapped ? &gEdkiiMemoryMappedFvProtocolGuid : NULL),
+                   &FvDevice->MemoryMappedFv,
+                   NULL
                    );
         ASSERT_EFI_ERROR (Status);
       } else {
@@ -722,3 +725,105 @@ FwVolDriverInit (
                           );
   return EFI_SUCCESS;
 }
+
+/**
+  Get the physical address and size of a file's section in a memory mapped FV
+
+  @param[in]  This          The protocol pointer
+  @param[in]  NameGuid      The name GUID of the file
+  @param[in]  SectionType   The file section from which to retrieve address and size
+  @param[out] FileAddress   The physical address of the file
+  @param[out] FileSize      The size of the file
+  @param[out] AuthStatus    The authentication status associated with the file
+
+  @retval EFI_SUCCESS            Information about the file was retrieved successfully.
+  @retval EFI_INVALID_PARAMETER  FileAddress was NULL, FileSize was NULL, AuthStatus
+                                 was NULL.
+  @retval EFI_NOT_FOUND          No section of the specified type could be located in
+                                 the specified file.
+
+**/
+EFI_STATUS
+EFIAPI
+MemoryMappedFvGetLocationAndSize (
+  IN  EDKII_MEMORY_MAPPED_FV_PROTOCOL  *This,
+  IN  CONST EFI_GUID                   *NameGuid,
+  IN  EFI_SECTION_TYPE                 SectionType,
+  OUT EFI_PHYSICAL_ADDRESS             *FileAddress,
+  OUT UINTN                            *FileSize,
+  OUT UINT32                           *AuthStatus
+  )
+{
+  FV_DEVICE                  *FvDevice;
+  EFI_STATUS                 Status;
+  EFI_FV_FILETYPE            FileType;
+  EFI_FV_FILE_ATTRIBUTES     FileAttributes;
+  EFI_GUID                   FileNameGuid;
+  FFS_FILE_LIST_ENTRY        *FfsFileEntry;
+  EFI_COMMON_SECTION_HEADER  *Section;
+  UINTN                      FvFileSize;
+  UINTN                      SectionLength;
+  UINTN                      HeaderLength;
+
+  FvDevice     = FV_DEVICE_FROM_MMFV (This);
+  FfsFileEntry = NULL;
+
+  do {
+    FileType = 0;
+    Status   = FvGetNextFile (
+                 &FvDevice->Fv,
+                 &FfsFileEntry,
+                 &FileType,
+                 &FileNameGuid,
+                 &FileAttributes,
+                 &FvFileSize
+                 );
+    if (EFI_ERROR (Status)) {
+      return EFI_NOT_FOUND;
+    }
+  } while (!CompareGuid (&FileNameGuid, NameGuid));
+
+  //
+  // Skip over file header
+  //
+  if (IS_FFS_FILE2 (FfsFileEntry->FfsHeader)) {
+    Section = (VOID *)((UINT8 *)FfsFileEntry->FfsHeader +
+                       sizeof (EFI_FFS_FILE_HEADER2));
+  } else {
+    Section = (VOID *)((UINT8 *)FfsFileEntry->FfsHeader +
+                       sizeof (EFI_FFS_FILE_HEADER));
+  }
+
+  do {
+    if (IS_SECTION2 (Section)) {
+      SectionLength = SECTION2_SIZE (Section);
+      HeaderLength  = sizeof (EFI_COMMON_SECTION_HEADER2);
+    } else {
+      SectionLength = SECTION_SIZE (Section);
+      HeaderLength  = sizeof (EFI_COMMON_SECTION_HEADER);
+    }
+
+    if (SectionLength > FvFileSize) {
+      DEBUG ((DEBUG_WARN, "%a: %x > %x\n", __func__, SectionLength, FvFileSize));
+      break;
+    }
+
+    if (Section->Type == SectionType) {
+      *FileAddress = (UINTN)Section + HeaderLength;
+      *FileSize    = SectionLength - HeaderLength;
+      *AuthStatus  = FvDevice->AuthenticationStatus;
+
+      return EFI_SUCCESS;
+    }
+
+    //
+    // SectionLength is adjusted it is 4 byte aligned.
+    // Go to the next section
+    //
+    SectionLength = ALIGN_VALUE (SectionLength, 4);
+    Section       = (EFI_COMMON_SECTION_HEADER *)((UINT8 *)Section + SectionLength);
+    FvFileSize   -= SectionLength;
+  } while (TRUE);
+
+  return EFI_NOT_FOUND;
+}
diff --git a/MdeModulePkg/Core/Dxe/FwVol/FwVolDriver.h b/MdeModulePkg/Core/Dxe/FwVol/FwVolDriver.h
index 3403c812b2ebcb45..eb1b702c1ee0bd4f 100644
--- a/MdeModulePkg/Core/Dxe/FwVol/FwVolDriver.h
+++ b/MdeModulePkg/Core/Dxe/FwVol/FwVolDriver.h
@@ -40,10 +40,13 @@ typedef struct {
   UINT8                                 ErasePolarity;
   BOOLEAN                               IsFfs3Fv;
   BOOLEAN                               IsMemoryMapped;
+  EDKII_MEMORY_MAPPED_FV_PROTOCOL       MemoryMappedFv;
 } FV_DEVICE;
 
 #define FV_DEVICE_FROM_THIS(a)  CR(a, FV_DEVICE, Fv, FV2_DEVICE_SIGNATURE)
 
+#define FV_DEVICE_FROM_MMFV(a)  CR(a, FV_DEVICE, MemoryMappedFv, FV2_DEVICE_SIGNATURE)
+
 /**
   Retrieves attributes, insures positive polarity of attribute bits, returns
   resulting attributes in output parameter.
@@ -384,4 +387,32 @@ IsValidFfsFile (
   IN EFI_FFS_FILE_HEADER  *FfsHeader
   );
 
+/**
+  Get the physical address and size of a file's section in a memory mapped FV
+
+  @param[in]  This          The protocol pointer
+  @param[in]  NameGuid      The name GUID of the file
+  @param[in]  SectionType   The file section from which to retrieve address and size
+  @param[out] FileAddress   The physical address of the file
+  @param[out] FileSize      The size of the file
+  @param[out] AuthStatus    The authentication status associated with the file
+
+  @retval EFI_SUCCESS            Information about the file was retrieved successfully.
+  @retval EFI_INVALID_PARAMETER  FileAddress was NULL, FileSize was NULL, AuthStatus
+                                 was NULL.
+  @retval EFI_NOT_FOUND          No section of the specified type could be located in
+                                 the specified file.
+
+**/
+EFI_STATUS
+EFIAPI
+MemoryMappedFvGetLocationAndSize (
+  IN  EDKII_MEMORY_MAPPED_FV_PROTOCOL  *This,
+  IN  CONST EFI_GUID                   *NameGuid,
+  IN  EFI_SECTION_TYPE                 SectionType,
+  OUT EFI_PHYSICAL_ADDRESS             *FileAddress,
+  OUT UINTN                            *FileSize,
+  OUT UINT32                           *AuthStatus
+  );
+
 #endif
-- 
2.39.2