1 files changed, 30 insertions, 0 deletions
diff --git a/roms/edk2/MdePkg/Library/BaseLib/X86SpeculationBarrier.c b/roms/edk2/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
new file mode 100644
index 000000000..b28fd8de9
--- /dev/null
+++ b/roms/edk2/MdePkg/Library/BaseLib/X86SpeculationBarrier.c
@@ -0,0 +1,30 @@
+/** @file
+  SpeculationBarrier() function for IA32 and x64.
+
+  Copyright (C) 2018 - 2019, Intel Corporation. All rights reserved.<BR>
+
+  SPDX-License-Identifier: BSD-2-Clause-Patent
+
+**/
+
+#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
+  )
+{
+  if (PcdGet8 (PcdSpeculationBarrierType) == 0x01) {
+    AsmLfence ();
+  } else if (PcdGet8 (PcdSpeculationBarrierType) == 0x02) {
+    AsmCpuid (0x01, NULL, NULL, NULL, NULL);
+  }
+}