5 files changed, 112 insertions, 0 deletions
diff --git a/MdePkg/Include/Library/BaseLib.h b/MdePkg/Include/Library/BaseLib.h
index 8cc086983d..1eb842384e 100644
--- a/MdePkg/Include/Library/BaseLib.h
+++ b/MdePkg/Include/Library/BaseLib.h
@@ -5111,6 +5111,21 @@ CpuDeadLoop (
   VOID
   );
 
+
+/**
+  Uses as a barrier to stop speculative execution.
+
+  Ensures that no later instruction will execute speculatively, until all prior
+  instructions have completed.
+
+**/
+VOID
+EFIAPI
+SpeculationBarrier (
+  VOID
+  );
+
+
 #if defined (MDE_CPU_IA32) || defined (MDE_CPU_X64)
 ///
 /// IA32 and x64 Specific Functions.
diff --git a/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c
new file mode 100644
index 0000000000..8a6165a102
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Arm/SpeculationBarrier.c
@@ -0,0 +1,30 @@
+/** @file
+  SpeculationBarrier() function for ARM.
+
+  Copyright (C) 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
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+/**
+  Uses as a barrier to stop speculative execution.
+
+  Ensures that no later instruction will execute speculatively, until all prior
+  instructions have completed.
+
+**/
+VOID
+EFIAPI
+SpeculationBarrier (
+  VOID
+  )
+{
+}
diff --git a/MdePkg/Library/BaseLib/BaseLib.inf b/MdePkg/Library/BaseLib/BaseLib.inf
index b84e58324c..d195c5417b 100644
--- a/MdePkg/Library/BaseLib/BaseLib.inf
+++ b/MdePkg/Library/BaseLib/BaseLib.inf
@@ -336,6 +336,7 @@
   X86DisablePaging32.c
   X86RdRand.c
   X86PatchInstruction.c
+  X86SpeculationBarrier.c
 
 [Sources.X64]
   X64/Thunk16.nasm
@@ -515,6 +516,7 @@
   X86DisablePaging32.c
   X86RdRand.c
   X86PatchInstruction.c
+  X86SpeculationBarrier.c
   X64/GccInline.c | GCC
   X64/Thunk16.S | XCODE
   X64/SwitchStack.nasm| GCC
@@ -543,12 +545,14 @@
   Ebc/CpuBreakpoint.c
   Ebc/SetJumpLongJump.c
   Ebc/SwitchStack.c
+  Ebc/SpeculationBarrier.c
   Unaligned.c
   Math64.c
 
 [Sources.ARM]
   Arm/InternalSwitchStack.c
   Arm/Unaligned.c
+  Arm/SpeculationBarrier.c
   Math64.c                   | RVCT
   Math64.c                   | MSFT
 
@@ -582,6 +586,7 @@
 [Sources.AARCH64]
   Arm/InternalSwitchStack.c
   Arm/Unaligned.c
+  Arm/SpeculationBarrier.c
   Math64.c
 
   AArch64/MemoryFence.S             | GCC
diff --git a/MdePkg/Library/BaseLib/Ebc/SpeculationBarrier.c b/MdePkg/Library/BaseLib/Ebc/SpeculationBarrier.c
new file mode 100644
index 0000000000..8fa4c204f8
--- /dev/null
+++ b/MdePkg/Library/BaseLib/Ebc/SpeculationBarrier.c
@@ -0,0 +1,30 @@
+/** @file
+  SpeculationBarrier() function for EBC.
+
+  Copyright (C) 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
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+
+/**
+  Uses as a barrier to stop speculative execution.
+
+  Ensures that no later instruction will execute speculatively, until all prior
+  instructions have completed.
+
+**/
+VOID
+EFIAPI
+SpeculationBarrier (
+  VOID
+  )
+{
+}
diff --git a/MdePkg/Library/BaseLib/X86SpeculationBarrier.c b/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
new file mode 100644
index 0000000000..03deca8489
--- /dev/null
+++ b/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
@@ -0,0 +1,32 @@
+/** @file
+  SpeculationBarrier() function for IA32 and x64.
+
+  Copyright (C) 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
+  http://opensource.org/licenses/bsd-license.php.
+
+  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, WITHOUT
+  WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
+
+**/
+
+#include <Library/BaseLib.h>
+
+/**
+  Uses as a barrier to stop speculative execution.
+
+  Ensures that no later instruction will execute speculatively, until all prior
+  instructions have completed.
+
+**/
+VOID
+EFIAPI
+SpeculationBarrier (
+  VOID
+  )
+{
+  AsmLfence ();
+}