From b9610b9cb5b34b202251d8e08c02a788240e4cdd Mon Sep 17 00:00:00 2001
From: xdu2 <xdu2@6f19259b-4bc3-4df7-8a09-765794883524>
Date: Thu, 25 Aug 2011 05:59:17 +0000
Subject: Add new API GetTimeInNanoSecond() to TimerLib to convert elapsed
 ticks to time in unit of nanoseconds.

Signed-off-by: xdu2
Reviewed-by: mdkinney

git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@12206 6f19259b-4bc3-4df7-8a09-765794883524
---
 .../Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c | 46 +++++++++++++++++++++-
 .../Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c | 46 +++++++++++++++++++++-
 2 files changed, 90 insertions(+), 2 deletions(-)

(limited to 'UefiCpuPkg')

diff --git a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c
index 06d5a3ceb..714b99eec 100644
--- a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c
+++ b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c
@@ -1,7 +1,7 @@
 /** @file
   Timer Library functions built upon ITC on IPF.
 
-  Copyright (c) 2006 - 2008, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2006 - 2011, 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
@@ -170,3 +170,47 @@ GetPerformanceCounterProperties (
 
   return BaseFrequence * (PalRet.r11 >> 32) / (UINT32)PalRet.r11;
 }
+
+/**
+  Converts elapsed ticks of performance counter to time in nanoseconds.
+
+  This function converts the elapsed ticks of running performance counter to
+  time value in unit of nanoseconds.
+
+  @param  Ticks     The number of elapsed ticks of running performance counter.
+
+  @return The elapsed time in nanoseconds.
+
+**/
+UINT64
+EFIAPI
+GetTimeInNanoSecond (
+  IN      UINT64                     Ticks
+  )
+{
+  UINT64  Frequency;
+  UINT64  NanoSeconds;
+  UINT64  Remainder;
+  INTN    Shift;
+
+  Frequency = GetPerformanceCounterProperties (NULL, NULL);
+
+  //
+  //          Ticks
+  // Time = --------- x 1,000,000,000
+  //        Frequency
+  //
+  NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
+
+  //
+  // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
+  // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
+  // i.e. highest bit set in Remainder should <= 33.
+  //
+  Shift = MAX (0, HighBitSet64 (Remainder) - 33);
+  Remainder = RShiftU64 (Remainder, (UINTN) Shift);
+  Frequency = RShiftU64 (Frequency, (UINTN) Shift);
+  NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
+
+  return NanoSeconds;
+}
diff --git a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c
index 3ca3ca800..99f8121ee 100644
--- a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c
+++ b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/X86TimerLib.c
@@ -3,7 +3,7 @@
 
   This library uses the local APIC library so that it supports x2APIC mode.
   
-  Copyright (c) 2010, Intel Corporation. All rights reserved.<BR>
+  Copyright (c) 2010 - 2011, 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
@@ -193,3 +193,47 @@ GetPerformanceCounterProperties (
 
   return (UINT64) InternalX86GetTimerFrequency ();
 }
+
+/**
+  Converts elapsed ticks of performance counter to time in nanoseconds.
+
+  This function converts the elapsed ticks of running performance counter to
+  time value in unit of nanoseconds.
+
+  @param  Ticks     The number of elapsed ticks of running performance counter.
+
+  @return The elapsed time in nanoseconds.
+
+**/
+UINT64
+EFIAPI
+GetTimeInNanoSecond (
+  IN      UINT64                     Ticks
+  )
+{
+  UINT64  Frequency;
+  UINT64  NanoSeconds;
+  UINT64  Remainder;
+  INTN    Shift;
+
+  Frequency = GetPerformanceCounterProperties (NULL, NULL);
+
+  //
+  //          Ticks
+  // Time = --------- x 1,000,000,000
+  //        Frequency
+  //
+  NanoSeconds = MultU64x32 (DivU64x64Remainder (Ticks, Frequency, &Remainder), 1000000000u);
+
+  //
+  // Ensure (Remainder * 1,000,000,000) will not overflow 64-bit.
+  // Since 2^29 < 1,000,000,000 = 0x3B9ACA00 < 2^30, Remainder should < 2^(64-30) = 2^34,
+  // i.e. highest bit set in Remainder should <= 33.
+  //
+  Shift = MAX (0, HighBitSet64 (Remainder) - 33);
+  Remainder = RShiftU64 (Remainder, (UINTN) Shift);
+  Frequency = RShiftU64 (Frequency, (UINTN) Shift);
+  NanoSeconds += DivU64x64Remainder (MultU64x32 (Remainder, 1000000000u), Frequency, NULL);
+
+  return NanoSeconds;
+}
-- 
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