[PATCH v2] IntelFsp2Pkg: FSP should not override IDT

["Chasel, Chiu" <chasel.chiu@intel.com>]

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=1265

FSP should not override IDT table when it is initialized
by boot loader. IDT should be re-initialized in FSP only
when it is invalid.
To mitigate temporary memory usage a PCD
PcdFspMaxInterruptSupported created for platform to decide
how many interrupts the FSP IDT table can support.

Test: Verified on internal platform and boots successfully.

Cc: Jiewen Yao <Jiewen.yao@intel.com>
Cc: Desimone Nathaniel L <nathaniel.l.desimone@intel.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Chasel Chiu <chasel.chiu@intel.com>
---
 IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf |  1 +
 IntelFsp2Pkg/FspSecCore/SecMain.c       | 24 +++++++++++++++++++-----
 IntelFsp2Pkg/FspSecCore/SecMain.h       |  6 ++----
 IntelFsp2Pkg/IntelFsp2Pkg.dec           |  4 ++++
 4 files changed, 26 insertions(+), 9 deletions(-)

diff --git a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
index c61af10b8a..dafe6f5993 100644
--- a/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
+++ b/IntelFsp2Pkg/FspSecCore/FspSecCoreM.inf
@@ -62,6 +62,7 @@
   gIntelFsp2PkgTokenSpaceGuid.PcdTemporaryRamSize              ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspTemporaryRamSize           ## CONSUMES
   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage         ## CONSUMES
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported      ## CONSUMES
 
 [Ppis]
   gEfiTemporaryRamSupportPpiGuid                              ## PRODUCES
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.c b/IntelFsp2Pkg/FspSecCore/SecMain.c
index 37fd4dfdeb..ddbfc4fcdf 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.c
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.c
@@ -70,6 +70,7 @@ SecStartup (
   UINT32                      Index;
   FSP_GLOBAL_DATA             PeiFspData;
   UINT64                      ExceptionHandler;
+  UINTN                       IdtSize;
 
   //
   // Process all libraries constructor function linked to SecCore.
@@ -98,13 +99,26 @@ SecStartup (
   // |                   |
   // |-------------------|---->  TempRamBase
   IdtTableInStack.PeiService  = NULL;
-  ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
-  for (Index = 0; Index < SEC_IDT_ENTRY_COUNT; Index ++) {
-    CopyMem ((VOID*)&IdtTableInStack.IdtTable[Index], (VOID*)&ExceptionHandler, sizeof (UINT64));
+  AsmReadIdtr (&IdtDescriptor);
+  if ((IdtDescriptor.Base == 0) && (IdtDescriptor.Limit == 0xFFFF)) {
+    ExceptionHandler = FspGetExceptionHandler(mIdtEntryTemplate);
+    for (Index = 0; Index < FixedPcdGet8(PcdFspMaxInterruptSupported); Index ++) {
+      CopyMem ((VOID*)&IdtTableInStack.IdtTable[Index], (VOID*)&ExceptionHandler, sizeof (UINT64));
+    }
+    IdtSize = sizeof (IdtTableInStack.IdtTable);
+  } else {
+    if (IdtDescriptor.Limit + 1 > sizeof (IdtTableInStack.IdtTable)) {
+      //
+      // ERROR: IDT table size from boot loader is larger than FSP can support, DeadLoop here!
+      //
+      CpuDeadLoop();
+    } else {
+      IdtSize = IdtDescriptor.Limit + 1;
+    }
+    CopyMem ((VOID *) (UINTN) &IdtTableInStack.IdtTable, (VOID *) IdtDescriptor.Base, IdtSize);
   }
-
   IdtDescriptor.Base  = (UINTN) &IdtTableInStack.IdtTable;
-  IdtDescriptor.Limit = (UINT16)(sizeof (IdtTableInStack.IdtTable) - 1);
+  IdtDescriptor.Limit = (UINT16)(IdtSize - 1);
 
   AsmWriteIdtr (&IdtDescriptor);
 
diff --git a/IntelFsp2Pkg/FspSecCore/SecMain.h b/IntelFsp2Pkg/FspSecCore/SecMain.h
index 291bc5ca5c..19ac2fbfc1 100644
--- a/IntelFsp2Pkg/FspSecCore/SecMain.h
+++ b/IntelFsp2Pkg/FspSecCore/SecMain.h
@@ -1,6 +1,6 @@
 /** @file
 
-  Copyright (c) 2014 - 2016, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2014 - 2018, Intel Corporation. All rights reserved.<BR>
   This program and the accompanying materials
   are licensed and made available under the terms and conditions of the BSD License
   which accompanies this distribution.  The full text of the license may be found at
@@ -29,8 +29,6 @@
 #include <Library/FspCommonLib.h>
 #include <FspEas.h>
 
-#define SEC_IDT_ENTRY_COUNT    34
-
 typedef VOID (*PEI_CORE_ENTRY) ( \
   IN CONST  EFI_SEC_PEI_HAND_OFF    *SecCoreData, \
   IN CONST  EFI_PEI_PPI_DESCRIPTOR  *PpiList \
@@ -38,7 +36,7 @@ typedef VOID (*PEI_CORE_ENTRY) ( \
 
 typedef struct _SEC_IDT_TABLE {
   EFI_PEI_SERVICES  *PeiService;
-  UINT64            IdtTable[SEC_IDT_ENTRY_COUNT];
+  UINT64            IdtTable[FixedPcdGet8 (PcdFspMaxInterruptSupported)];
 } SEC_IDT_TABLE;
 
 /**
diff --git a/IntelFsp2Pkg/IntelFsp2Pkg.dec b/IntelFsp2Pkg/IntelFsp2Pkg.dec
index 5b037d65e2..50496241da 100644
--- a/IntelFsp2Pkg/IntelFsp2Pkg.dec
+++ b/IntelFsp2Pkg/IntelFsp2Pkg.dec
@@ -86,6 +86,10 @@
   # x % of FSP temporary memory will be used for heap
   # (100 - x) % of FSP temporary memory will be used for stack
   gIntelFsp2PkgTokenSpaceGuid.PcdFspHeapSizePercentage    |        50| UINT8|0x10000004
+  #
+  # Maximal Interrupt supported in IDT table.
+  #
+  gIntelFsp2PkgTokenSpaceGuid.PcdFspMaxInterruptSupported |        34| UINT8|0x10000005
 
 [PcdsFixedAtBuild,PcdsDynamic,PcdsDynamicEx]
   gIntelFsp2PkgTokenSpaceGuid.PcdFspReservedMemoryLength |0x00100000|UINT32|0x46530000
-- 
2.13.3.windows.1