From 1553d073632e1307950f8648444071a0ec27759f Mon Sep 17 00:00:00 2001
From: vanjeff <vanjeff@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Wed, 14 Jan 2009 03:05:45 +0000
Subject: [PATCH] fixed assumption 32bit Local Apic timer counter.

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@7266 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf     |  1 +
 MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c     | 11 +++++++++--
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf b/MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf
index c2a4199fb0..67a3c2cff8 100644
--- a/MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf
+++ b/MdePkg/Library/SecPeiDxeTimerLibCpu/SecPeiDxeTimerLibCpu.inf
@@ -49,6 +49,7 @@
 [LibraryClasses.IA32, LibraryClasses.X64]
   PcdLib
   IoLib
+  DebugLib
 
 [LibraryClasses.IPF]
   PalLib
diff --git a/MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c b/MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c
index 72c684e236..aff51932f6 100644
--- a/MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c
+++ b/MdePkg/Library/SecPeiDxeTimerLibCpu/X86TimerLib.c
@@ -17,9 +17,10 @@
 #include <Library/BaseLib.h>
 #include <Library/IoLib.h>
 #include <Library/PcdLib.h>
+#include <Library/DebugLib.h>
 
 #define APIC_LVTERR     0x370
-#define APIC_TMICT      0x380   
+#define APIC_TMICT      0x380
 #define APIC_TMCCT      0x390
 #define APIC_TDCR       0x3e0
 
@@ -115,7 +116,9 @@ InternalX86Delay (
   // Delay > 2^31 could not be handled by this function
   // Timer wrap-arounds are handled correctly by this function
   //
-  while (InternalX86GetTimerTick (ApicBase) - Ticks >= 0);
+  while (((UINT32)(InternalX86GetTimerTick (ApicBase) - Ticks) & GetPowerOfTwo32 ((MmioRead32 (ApicBase + APIC_TMICT)))) == 0) {
+    CpuPause ();
+  }
 }
 
 /**
@@ -238,6 +241,10 @@ GetPerformanceCounterProperties (
 
   if (StartValue != NULL) {
     *StartValue = MmioRead32 (ApicBase + APIC_TMICT);
+    //
+    // make sure StartValue is all 1s from High Bit
+    //
+    ASSERT ((*StartValue & (*StartValue + 1)) == 0);
   }
 
   if (EndValue != NULL) {
-- 
2.39.2