1 files changed, 48 insertions, 0 deletions
diff --git a/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
new file mode 100644
index 0000000000..6f5c07a4f0
--- /dev/null
+++ b/PcAtChipsetPkg/Library/AcpiTimerLib/DxeAcpiTimerLib.c
@@ -0,0 +1,48 @@
+/** @file
+  ACPI Timer implements one instance of Timer Library.
+
+  Copyright (c) 2013 - 2014, 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 <Base.h>
+#include <Library/TimerLib.h>
+#include <Library/BaseLib.h>
+
+//
+// Cached performance counter frequency
+//
+UINT64  mPerformanceCounterFrequency = 0;
+
+/**
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  Internal function to retrieves the 64-bit frequency in Hz.
+
+  @return The frequency in Hz.
+
+**/
+UINT64
+InternalGetPerformanceCounterFrequency (
+  VOID
+  ) 
+{
+  BOOLEAN  InterruptState;
+  UINT64   Count;
+
+  if (mPerformanceCounterFrequency == 0) {
+    InterruptState = SaveAndDisableInterrupts ();
+    Count = GetPerformanceCounter ();
+    MicroSecondDelay (100);
+    mPerformanceCounterFrequency = MultU64x32 (GetPerformanceCounter () - Count, 10000);
+    SetInterruptState (InterruptState);
+  }
+  return  mPerformanceCounterFrequency;
+}