code scrub for DebugSpport Module.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@6997 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/DebugSupportDxe/Ipf/PlDebugSupport.h

@@ -15,7 +15,6 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 #ifndef _PLDEBUG_SUPPORT_H_
 #define _PLDEBUG_SUPPORT_H_
 
-
 #include <Uefi.h>
 
 #include <Protocol/DebugSupport.h>
@@ -29,11 +28,13 @@ WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
 
 #define DISABLE_INTERRUPTS  0UL
 
-//
-// The remaining definitions comprise the protocol members.
-//
 #define EFI_ISA IsaIpf
 
+typedef struct {
+  UINT64  low;
+  UINT64  high;
+} BUNDLE;
+
 /**
   IPF specific DebugSupport driver initialization. 
 
@@ -217,4 +218,86 @@ CommonHandler (
   IN EFI_SYSTEM_CONTEXT Context
   );
 
+/**
+  This is the worker function that uninstalls and removes all handlers.
+
+  @param  ExceptionType     Exception Type
+  @param  NewBundles        New Boundles
+  @param  NewCallback       New Callback
+
+  @retval EFI_ALEADY_STARTED Ivt already hooked.
+  @retval others             Indicates the request was not satisfied.
+  @retval EFI_SUCCESS        Successfully uninstalled.
+
+**/
+EFI_STATUS
+ManageIvtEntryTable (
+  IN  EFI_EXCEPTION_TYPE    ExceptionType,
+  IN  BUNDLE                NewBundles[4],
+  IN  VOID                  (*NewCallback) ()
+  );
+
+/**
+  Saves original IVT contents and inserts a few new bundles which are fixed up
+  to store the ExceptionType and then call the common handler.
+
+  @param  ExceptionType      Exception Type
+  @param  NewBundles         New Boundles
+  @param  NewCallback        New Callback
+
+**/
+VOID
+HookEntry (
+  IN  EFI_EXCEPTION_TYPE    ExceptionType,
+  IN  BUNDLE                NewBundles[4],
+  IN  VOID                  (*NewCallback) ()
+  );
+
+/**
+  Restores original IVT contents when unregistering a callback function.
+
+  @param  ExceptionType     Exception Type
+
+**/
+VOID
+UnhookEntry (
+  IN  EFI_EXCEPTION_TYPE    ExceptionType
+  );
+
+/**
+  Sets up cache flush and calls assembly function to chain external interrupt.
+
+  Records new callback in IvtEntryTable.
+
+  @param  NewCallback     New Callback.
+
+**/
+VOID
+ChainExternalInterrupt (
+  IN  VOID                  (*NewCallback) ()
+  );
+
+/**
+  Sets up cache flush and calls assembly function to restore external interrupt.
+  Removes registered callback from IvtEntryTable.
+
+**/
+VOID
+UnchainExternalInterrupt (
+  VOID
+  );
+
+/**
+  Given an integer number, return the physical address of the entry point in the IFT.
+
+  @param  HandlerIndex       Index of the Handler 
+  @param  EntryPoint         IFT Entrypoint
+
+**/
+VOID
+GetHandlerEntryPoint (
+  UINTN                     HandlerIndex,
+  VOID                      **EntryPoint
+  );
+
 #endif