EdkModulePkg/Library/PeiPerformanceLib/PeiPerformanceLib.c - edk2 - Git at Google

 /*++

 Copyright (c) 2006, Intel Corporation
 All rights reserved. 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.

 Module Name:

   PeiPerformanceLib.c

 Abstract:

   Performance Library

 --*/

 /**
   Gets PEI the GUID HOB for PEI performance.

   This internal function searches for the GUID HOB for PEI performance.
   If that GUID HOB is not found, it will build a new one.
   It returns the data area of that GUID HOB to record performance log.

   @param  Handle                  Pointer to environment specific context used
                                   to identify the component being measured.
   @param  Token                   Pointer to a Null-terminated ASCII string
                                   that identifies the component being measured.
   @param  Module                  Pointer to a Null-terminated ASCII string
                                   that identifies the module being measured.

   @retval The index of log entry in the array.

 **/
 PEI_PERFORMANCE_LOG_HEADER *
 InternalGetPerformanceHobLog (
   VOID
   )
 {
   EFI_HOB_GUID_TYPE           *GuidHob;
   PEI_PERFORMANCE_LOG_HEADER  *PeiPerformanceLog;
   UINTN                       PeiPerformanceLogSize;

   GuidHob = GetFirstGuidHob (&gPeiPerformanceHobGuid);

   if (GuidHob != NULL) {
     //
     // PEI Performance HOB was found, then return the existing one.
     //
     PeiPerformanceLog = GET_GUID_HOB_DATA (GuidHob);
   } else {
     //
     // PEI Performance HOB was not found, then build one.
     //
     PeiPerformanceLogSize = sizeof (PEI_PERFORMANCE_LOG_HEADER) +
                             sizeof (PEI_PERFORMANCE_LOG_ENTRY) * MAX_PEI_PERFORMANCE_LOG_ENTRIES;
     PeiPerformanceLog     = BuildGuidHob (&gPeiPerformanceHobGuid, PeiPerformanceLogSize);
     PeiPerformanceLog     = ZeroMem (PeiPerformanceLog, PeiPerformanceLogSize);
   }

   return PeiPerformanceLog;
 }

 /**
   Searches in the log array with keyword Handle, Token and Module.

   This internal function searches for the log entry in the log array.
   If there is an entry that exactly matches the given key word triple
   and its end time stamp is zero, then the index of that log entry is returned;
   otherwise, the the number of log entries in the array is returned.

   @param  Handle                  Pointer to environment specific context used
                                   to identify the component being measured.
   @param  Token                   Pointer to a Null-terminated ASCII string
                                   that identifies the component being measured.
   @param  Module                  Pointer to a Null-terminated ASCII string
                                   that identifies the module being measured.

   @retval The index of log entry in the array.

 **/
 UINT32
 InternalSearchForLogEntry (
   IN PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog,
   IN CONST VOID                 *Handle,  OPTIONAL
   IN CONST CHAR8                *Token,   OPTIONAL
   IN CONST CHAR8                *Module   OPTIONAL
   )
 {
   UINT32                    Index;
   UINT32                    NumberOfEntries;
   PEI_PERFORMANCE_LOG_ENTRY *LogEntryArray;


   if (Token == NULL) {
     Token = "";
   }
   if (Module == NULL) {
     Module = "";
   }
   NumberOfEntries = PeiPerformanceLog->NumberOfEntries;
   LogEntryArray   = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);

   for (Index = 0; Index < NumberOfEntries; Index++) {
     if ((LogEntryArray[Index].Handle == (EFI_PHYSICAL_ADDRESS) (UINTN) Handle) &&
          AsciiStrnCmp (LogEntryArray[Index].Token, Token, PEI_PERFORMANCE_STRING_LENGTH) == 0 &&
          AsciiStrnCmp (LogEntryArray[Index].Module, Module, PEI_PERFORMANCE_STRING_LENGTH) == 0 &&
          LogEntryArray[Index].EndTimeStamp == 0
        ) {
       break;
     }
   }
   return Index;
 }

 /**
   Creates a record for the beginning of a performance measurement.

   Creates a record that contains the Handle, Token, and Module.
   If TimeStamp is not zero, then TimeStamp is added to the record as the start time.
   If TimeStamp is zero, then this function reads the current time stamp
   and adds that time stamp value to the record as the start time.

   @param  Handle                  Pointer to environment specific context used
                                   to identify the component being measured.
   @param  Token                   Pointer to a Null-terminated ASCII string
                                   that identifies the component being measured.
   @param  Module                  Pointer to a Null-terminated ASCII string
                                   that identifies the module being measured.
   @param  TimeStamp               64-bit time stamp.

   @retval RETURN_SUCCESS          The start of the measurement was recorded.
   @retval RETURN_OUT_OF_RESOURCES There are not enough resources to record the measurement.

 **/
 RETURN_STATUS
 EFIAPI
 StartPerformanceMeasurement (
   IN CONST VOID   *Handle,  OPTIONAL
   IN CONST CHAR8  *Token,   OPTIONAL
   IN CONST CHAR8  *Module,  OPTIONAL
   IN UINT64       TimeStamp
   )
 {
   PEI_PERFORMANCE_LOG_HEADER  *PeiPerformanceLog;
   PEI_PERFORMANCE_LOG_ENTRY   *LogEntryArray;
   UINT32                      Index;

   PeiPerformanceLog = InternalGetPerformanceHobLog ();

   if (PeiPerformanceLog->NumberOfEntries >= MAX_PEI_PERFORMANCE_LOG_ENTRIES) {
     return RETURN_OUT_OF_RESOURCES;
   }
   Index                       = PeiPerformanceLog->NumberOfEntries++;
   LogEntryArray               = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
   LogEntryArray[Index].Handle = (EFI_PHYSICAL_ADDRESS) (UINTN) Handle;

   if (Token != NULL) {
     AsciiStrnCpy (LogEntryArray[Index].Token, Token, PEI_PERFORMANCE_STRING_LENGTH);
   }
   if (Module != NULL) {
     AsciiStrnCpy (LogEntryArray[Index].Module, Module, PEI_PERFORMANCE_STRING_LENGTH);
   }

   if (TimeStamp == 0) {
     TimeStamp = GetPerformanceCounter ();
   }
   LogEntryArray[Index].StartTimeStamp = TimeStamp;

   return RETURN_SUCCESS;
 }

 /**
   Fills in the end time of a performance measurement.

   Looks up the record that matches Handle, Token, and Module.
   If the record can not be found then return RETURN_NOT_FOUND.
   If the record is found and TimeStamp is not zero,
   then TimeStamp is added to the record as the end time.
   If the record is found and TimeStamp is zero, then this function reads
   the current time stamp and adds that time stamp value to the record as the end time.
   If this function is called multiple times for the same record, then the end time is overwritten.

   @param  Handle                  Pointer to environment specific context used
                                   to identify the component being measured.
   @param  Token                   Pointer to a Null-terminated ASCII string
                                   that identifies the component being measured.
   @param  Module                  Pointer to a Null-terminated ASCII string
                                   that identifies the module being measured.
   @param  TimeStamp               64-bit time stamp.

   @retval RETURN_SUCCESS          The end of  the measurement was recorded.
   @retval RETURN_NOT_FOUND        The specified measurement record could not be found.

 **/
 RETURN_STATUS
 EFIAPI
 EndPerformanceMeasurement (
   IN CONST VOID   *Handle,  OPTIONAL
   IN CONST CHAR8  *Token,   OPTIONAL
   IN CONST CHAR8  *Module,  OPTIONAL
   IN UINT64       TimeStamp
   )
 {
   PEI_PERFORMANCE_LOG_HEADER  *PeiPerformanceLog;
   PEI_PERFORMANCE_LOG_ENTRY   *LogEntryArray;
   UINT32                      Index;

   if (TimeStamp == 0) {
     TimeStamp = GetPerformanceCounter ();
   }

   PeiPerformanceLog = InternalGetPerformanceHobLog ();
   Index             = InternalSearchForLogEntry (PeiPerformanceLog, Handle, Token, Module);
   if (Index >= PeiPerformanceLog->NumberOfEntries) {
     return RETURN_NOT_FOUND;
   }
   LogEntryArray     = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
   LogEntryArray[Index].EndTimeStamp = TimeStamp;

   return RETURN_SUCCESS;
 }

 /**
   Attempts to retrieve a performance measurement log entry from the performance measurement log.

   Attempts to retrieve the performance log entry specified by LogEntryKey.  If LogEntryKey is
   zero on entry, then an attempt is made to retrieve the first entry from the performance log,
   and the key for the second entry in the log is returned.  If the performance log is empty,
   then no entry is retrieved and zero is returned.  If LogEntryKey is not zero, then the performance
   log entry associated with LogEntryKey is retrieved, and the key for the next entry in the log is
   returned.  If LogEntryKey is the key for the last entry in the log, then the last log entry is
   retrieved and an implementation specific non-zero key value that specifies the end of the performance
   log is returned.  If LogEntryKey is equal this implementation specific non-zero key value, then no entry
   is retrieved and zero is returned.  In the cases where a performance log entry can be returned,
   the log entry is returned in Handle, Token, Module, StartTimeStamp, and EndTimeStamp.
   If LogEntryKey is not a valid log entry key for the performance measurement log, then ASSERT().
   If Handle is NULL, then ASSERT().
   If Token is NULL, then ASSERT().
   If Module is NULL, then ASSERT().
   If StartTimeStamp is NULL, then ASSERT().
   If EndTimeStamp is NULL, then ASSERT().

   @param  LogEntryKey             On entry, the key of the performance measurement log entry to retrieve.
                                   0, then the first performance measurement log entry is retrieved.
                                   On exit, the key of the next performance lof entry entry.
   @param  Handle                  Pointer to environment specific context used to identify the component
                                   being measured.
   @param  Token                   Pointer to a Null-terminated ASCII string that identifies the component
                                   being measured.
   @param  Module                  Pointer to a Null-terminated ASCII string that identifies the module
                                   being measured.
   @param  StartTimeStamp          Pointer to the 64-bit time stamp that was recorded when the measurement
                                   was started.
   @param  EndTimeStamp            Pointer to the 64-bit time stamp that was recorded when the measurement
                                   was ended.

   @return The key for the next performance log entry (in general case).

 **/
 UINTN
 EFIAPI
 GetPerformanceMeasurement (
   IN  UINTN       LogEntryKey,
   OUT CONST VOID  **Handle,
   OUT CONST CHAR8 **Token,
   OUT CONST CHAR8 **Module,
   OUT UINT64      *StartTimeStamp,
   OUT UINT64      *EndTimeStamp
   )
 {
   PEI_PERFORMANCE_LOG_HEADER  *PeiPerformanceLog;
   PEI_PERFORMANCE_LOG_ENTRY   *CurrentLogEntry;
   PEI_PERFORMANCE_LOG_ENTRY   *LogEntryArray;
   UINTN                       NumberOfEntries;

   ASSERT (Handle != NULL);
   ASSERT (Token != NULL);
   ASSERT (Module != NULL);
   ASSERT (StartTimeStamp != NULL);
   ASSERT (EndTimeStamp != NULL);

   PeiPerformanceLog = InternalGetPerformanceHobLog ();

   NumberOfEntries   = (UINTN) (PeiPerformanceLog->NumberOfEntries);
   LogEntryArray     = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
   //
   // Make sure that LogEntryKey is a valid log entry key.
   //
   ASSERT (LogEntryKey <= NumberOfEntries);

   if (LogEntryKey == NumberOfEntries) {
     return 0;
   }

   CurrentLogEntry = &(LogEntryArray[LogEntryKey++]);

   *Handle         = (VOID *) (UINTN) (CurrentLogEntry->Handle);
   *Token          = CurrentLogEntry->Token;
   *Module         = CurrentLogEntry->Module;
   *StartTimeStamp = CurrentLogEntry->StartTimeStamp;
   *EndTimeStamp   = CurrentLogEntry->EndTimeStamp;

   return LogEntryKey;
 }

 /**
   Returns TRUE if the performance measurement macros are enabled.

   This function returns TRUE if the PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
   PcdPerformanceLibraryPropertyMask is set.  Otherwise FALSE is returned.

   @retval TRUE                    The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                   PcdPerformanceLibraryPropertyMask is set.
   @retval FALSE                   The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
                                   PcdPerformanceLibraryPropertyMask is clear.

 **/
 BOOLEAN
 EFIAPI
 PerformanceMeasurementEnabled (
   VOID
   )
 {
   return ((PcdGet8(PcdPerformanceLibraryPropertyMask) & PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED) != 0);
 }
	/*++

	Copyright (c) 2006, Intel Corporation
	All rights reserved. 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.

	Module Name:

	PeiPerformanceLib.c

	Abstract:

	Performance Library

	--*/

	/**
	Gets PEI the GUID HOB for PEI performance.

	This internal function searches for the GUID HOB for PEI performance.
	If that GUID HOB is not found, it will build a new one.
	It returns the data area of that GUID HOB to record performance log.

	@param Handle Pointer to environment specific context used
	to identify the component being measured.
	@param Token Pointer to a Null-terminated ASCII string
	that identifies the component being measured.
	@param Module Pointer to a Null-terminated ASCII string
	that identifies the module being measured.

	@retval The index of log entry in the array.

	**/
	PEI_PERFORMANCE_LOG_HEADER *
	InternalGetPerformanceHobLog (
	VOID
	)
	{
	EFI_HOB_GUID_TYPE *GuidHob;
	PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog;
	UINTN PeiPerformanceLogSize;

	GuidHob = GetFirstGuidHob (&gPeiPerformanceHobGuid);

	if (GuidHob != NULL) {
	//
	// PEI Performance HOB was found, then return the existing one.
	//
	PeiPerformanceLog = GET_GUID_HOB_DATA (GuidHob);
	} else {
	//
	// PEI Performance HOB was not found, then build one.
	//
	PeiPerformanceLogSize = sizeof (PEI_PERFORMANCE_LOG_HEADER) +
	sizeof (PEI_PERFORMANCE_LOG_ENTRY) * MAX_PEI_PERFORMANCE_LOG_ENTRIES;
	PeiPerformanceLog = BuildGuidHob (&gPeiPerformanceHobGuid, PeiPerformanceLogSize);
	PeiPerformanceLog = ZeroMem (PeiPerformanceLog, PeiPerformanceLogSize);
	}

	return PeiPerformanceLog;
	}

	/**
	Searches in the log array with keyword Handle, Token and Module.

	This internal function searches for the log entry in the log array.
	If there is an entry that exactly matches the given key word triple
	and its end time stamp is zero, then the index of that log entry is returned;
	otherwise, the the number of log entries in the array is returned.

	@param Handle Pointer to environment specific context used
	to identify the component being measured.
	@param Token Pointer to a Null-terminated ASCII string
	that identifies the component being measured.
	@param Module Pointer to a Null-terminated ASCII string
	that identifies the module being measured.

	@retval The index of log entry in the array.

	**/
	UINT32
	InternalSearchForLogEntry (
	IN PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog,
	IN CONST VOID *Handle, OPTIONAL
	IN CONST CHAR8 *Token, OPTIONAL
	IN CONST CHAR8 *Module OPTIONAL
	)
	{
	UINT32 Index;
	UINT32 NumberOfEntries;
	PEI_PERFORMANCE_LOG_ENTRY *LogEntryArray;


	if (Token == NULL) {
	Token = "";
	}
	if (Module == NULL) {
	Module = "";
	}
	NumberOfEntries = PeiPerformanceLog->NumberOfEntries;
	LogEntryArray = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);

	for (Index = 0; Index < NumberOfEntries; Index++) {
	if ((LogEntryArray[Index].Handle == (EFI_PHYSICAL_ADDRESS) (UINTN) Handle) &&
	AsciiStrnCmp (LogEntryArray[Index].Token, Token, PEI_PERFORMANCE_STRING_LENGTH) == 0 &&
	AsciiStrnCmp (LogEntryArray[Index].Module, Module, PEI_PERFORMANCE_STRING_LENGTH) == 0 &&
	LogEntryArray[Index].EndTimeStamp == 0
	) {
	break;
	}
	}
	return Index;
	}

	/**
	Creates a record for the beginning of a performance measurement.

	Creates a record that contains the Handle, Token, and Module.
	If TimeStamp is not zero, then TimeStamp is added to the record as the start time.
	If TimeStamp is zero, then this function reads the current time stamp
	and adds that time stamp value to the record as the start time.

	@param Handle Pointer to environment specific context used
	to identify the component being measured.
	@param Token Pointer to a Null-terminated ASCII string
	that identifies the component being measured.
	@param Module Pointer to a Null-terminated ASCII string
	that identifies the module being measured.
	@param TimeStamp 64-bit time stamp.

	@retval RETURN_SUCCESS The start of the measurement was recorded.
	@retval RETURN_OUT_OF_RESOURCES There are not enough resources to record the measurement.

	**/
	RETURN_STATUS
	EFIAPI
	StartPerformanceMeasurement (
	IN CONST VOID *Handle, OPTIONAL
	IN CONST CHAR8 *Token, OPTIONAL
	IN CONST CHAR8 *Module, OPTIONAL
	IN UINT64 TimeStamp
	)
	{
	PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog;
	PEI_PERFORMANCE_LOG_ENTRY *LogEntryArray;
	UINT32 Index;

	PeiPerformanceLog = InternalGetPerformanceHobLog ();

	if (PeiPerformanceLog->NumberOfEntries >= MAX_PEI_PERFORMANCE_LOG_ENTRIES) {
	return RETURN_OUT_OF_RESOURCES;
	}
	Index = PeiPerformanceLog->NumberOfEntries++;
	LogEntryArray = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
	LogEntryArray[Index].Handle = (EFI_PHYSICAL_ADDRESS) (UINTN) Handle;

	if (Token != NULL) {
	AsciiStrnCpy (LogEntryArray[Index].Token, Token, PEI_PERFORMANCE_STRING_LENGTH);
	}
	if (Module != NULL) {
	AsciiStrnCpy (LogEntryArray[Index].Module, Module, PEI_PERFORMANCE_STRING_LENGTH);
	}

	if (TimeStamp == 0) {
	TimeStamp = GetPerformanceCounter ();
	}
	LogEntryArray[Index].StartTimeStamp = TimeStamp;

	return RETURN_SUCCESS;
	}

	/**
	Fills in the end time of a performance measurement.

	Looks up the record that matches Handle, Token, and Module.
	If the record can not be found then return RETURN_NOT_FOUND.
	If the record is found and TimeStamp is not zero,
	then TimeStamp is added to the record as the end time.
	If the record is found and TimeStamp is zero, then this function reads
	the current time stamp and adds that time stamp value to the record as the end time.
	If this function is called multiple times for the same record, then the end time is overwritten.

	@param Handle Pointer to environment specific context used
	to identify the component being measured.
	@param Token Pointer to a Null-terminated ASCII string
	that identifies the component being measured.
	@param Module Pointer to a Null-terminated ASCII string
	that identifies the module being measured.
	@param TimeStamp 64-bit time stamp.

	@retval RETURN_SUCCESS The end of the measurement was recorded.
	@retval RETURN_NOT_FOUND The specified measurement record could not be found.

	**/
	RETURN_STATUS
	EFIAPI
	EndPerformanceMeasurement (
	IN CONST VOID *Handle, OPTIONAL
	IN CONST CHAR8 *Token, OPTIONAL
	IN CONST CHAR8 *Module, OPTIONAL
	IN UINT64 TimeStamp
	)
	{
	PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog;
	PEI_PERFORMANCE_LOG_ENTRY *LogEntryArray;
	UINT32 Index;

	if (TimeStamp == 0) {
	TimeStamp = GetPerformanceCounter ();
	}

	PeiPerformanceLog = InternalGetPerformanceHobLog ();
	Index = InternalSearchForLogEntry (PeiPerformanceLog, Handle, Token, Module);
	if (Index >= PeiPerformanceLog->NumberOfEntries) {
	return RETURN_NOT_FOUND;
	}
	LogEntryArray = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
	LogEntryArray[Index].EndTimeStamp = TimeStamp;

	return RETURN_SUCCESS;
	}

	/**
	Attempts to retrieve a performance measurement log entry from the performance measurement log.

	Attempts to retrieve the performance log entry specified by LogEntryKey. If LogEntryKey is
	zero on entry, then an attempt is made to retrieve the first entry from the performance log,
	and the key for the second entry in the log is returned. If the performance log is empty,
	then no entry is retrieved and zero is returned. If LogEntryKey is not zero, then the performance
	log entry associated with LogEntryKey is retrieved, and the key for the next entry in the log is
	returned. If LogEntryKey is the key for the last entry in the log, then the last log entry is
	retrieved and an implementation specific non-zero key value that specifies the end of the performance
	log is returned. If LogEntryKey is equal this implementation specific non-zero key value, then no entry
	is retrieved and zero is returned. In the cases where a performance log entry can be returned,
	the log entry is returned in Handle, Token, Module, StartTimeStamp, and EndTimeStamp.
	If LogEntryKey is not a valid log entry key for the performance measurement log, then ASSERT().
	If Handle is NULL, then ASSERT().
	If Token is NULL, then ASSERT().
	If Module is NULL, then ASSERT().
	If StartTimeStamp is NULL, then ASSERT().
	If EndTimeStamp is NULL, then ASSERT().

	@param LogEntryKey On entry, the key of the performance measurement log entry to retrieve.
	0, then the first performance measurement log entry is retrieved.
	On exit, the key of the next performance lof entry entry.
	@param Handle Pointer to environment specific context used to identify the component
	being measured.
	@param Token Pointer to a Null-terminated ASCII string that identifies the component
	being measured.
	@param Module Pointer to a Null-terminated ASCII string that identifies the module
	being measured.
	@param StartTimeStamp Pointer to the 64-bit time stamp that was recorded when the measurement
	was started.
	@param EndTimeStamp Pointer to the 64-bit time stamp that was recorded when the measurement
	was ended.

	@return The key for the next performance log entry (in general case).

	**/
	UINTN
	EFIAPI
	GetPerformanceMeasurement (
	IN UINTN LogEntryKey,
	OUT CONST VOID **Handle,
	OUT CONST CHAR8 **Token,
	OUT CONST CHAR8 **Module,
	OUT UINT64 *StartTimeStamp,
	OUT UINT64 *EndTimeStamp
	)
	{
	PEI_PERFORMANCE_LOG_HEADER *PeiPerformanceLog;
	PEI_PERFORMANCE_LOG_ENTRY *CurrentLogEntry;
	PEI_PERFORMANCE_LOG_ENTRY *LogEntryArray;
	UINTN NumberOfEntries;

	ASSERT (Handle != NULL);
	ASSERT (Token != NULL);
	ASSERT (Module != NULL);
	ASSERT (StartTimeStamp != NULL);
	ASSERT (EndTimeStamp != NULL);

	PeiPerformanceLog = InternalGetPerformanceHobLog ();

	NumberOfEntries = (UINTN) (PeiPerformanceLog->NumberOfEntries);
	LogEntryArray = (PEI_PERFORMANCE_LOG_ENTRY *) (PeiPerformanceLog + 1);
	//
	// Make sure that LogEntryKey is a valid log entry key.
	//
	ASSERT (LogEntryKey <= NumberOfEntries);

	if (LogEntryKey == NumberOfEntries) {
	return 0;
	}

	CurrentLogEntry = &(LogEntryArray[LogEntryKey++]);

	Handle = (VOID ) (UINTN) (CurrentLogEntry->Handle);
	*Token = CurrentLogEntry->Token;
	*Module = CurrentLogEntry->Module;
	*StartTimeStamp = CurrentLogEntry->StartTimeStamp;
	*EndTimeStamp = CurrentLogEntry->EndTimeStamp;

	return LogEntryKey;
	}

	/**
	Returns TRUE if the performance measurement macros are enabled.

	This function returns TRUE if the PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
	PcdPerformanceLibraryPropertyMask is set. Otherwise FALSE is returned.

	@retval TRUE The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
	PcdPerformanceLibraryPropertyMask is set.
	@retval FALSE The PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED bit of
	PcdPerformanceLibraryPropertyMask is clear.

	**/
	BOOLEAN
	EFIAPI
	PerformanceMeasurementEnabled (
	VOID
	)
	{
	return ((PcdGet8(PcdPerformanceLibraryPropertyMask) & PERFORMANCE_LIBRARY_PROPERTY_MEASUREMENT_ENABLED) != 0);
	}