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authorxdu2 <xdu2@6f19259b-4bc3-4df7-8a09-765794883524>2011-08-25 05:59:17 +0000
committerxdu2 <xdu2@6f19259b-4bc3-4df7-8a09-765794883524>2011-08-25 05:59:17 +0000
commitb9610b9cb5b34b202251d8e08c02a788240e4cdd (patch)
tree09775a466b5315657279f1f51625c6466412af61 /UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c
parent6e5ed099afee619553a1eb1bea79b1f99658ec84 (diff)
downloadedk2-platforms-b9610b9cb5b34b202251d8e08c02a788240e4cdd.tar.xz
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
Diffstat (limited to 'UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c')
-rw-r--r--UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c46
1 files changed, 45 insertions, 1 deletions
diff --git a/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c b/UefiCpuPkg/Library/SecPeiDxeTimerLibUefiCpu/IpfTimerLib.c
index 06d5a3cebc..714b99eec4 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;
+}