Signed-off-by: Shumin Qiu <shumin.qiu@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com> git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14739 6f19259b-4bc3-4df7-8a09-765794883524
		
			
				
	
	
		
			167 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			167 lines
		
	
	
		
			4.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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|   Implementation of Timestamp Protocol using UEFI APIs.
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|   
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| Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>
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| This program and the accompanying materials
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| are licensed and made available under the terms and conditions of the BSD License
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| which accompanies this distribution.  The full text of the license may be found at
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| http://opensource.org/licenses/bsd-license.php
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| 
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| THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 
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| **/
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| 
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| #include <Uefi.h>
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| #include <Library/DebugLib.h>
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| #include <Library/UefiDriverEntryPoint.h>
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| #include <Library/UefiBootServicesTableLib.h>
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| #include <Library/TimerLib.h>
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| #include <Library/BaseMemoryLib.h>
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| #include <Protocol/Timestamp.h>
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| 
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| //
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| // The StartValue in TimerLib
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| //
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| UINT64 mTimerLibStartValue = 0;
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| 
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| //
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| // The EndValue in TimerLib
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| //
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| UINT64 mTimerLibEndValue = 0;
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| 
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| //
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| // The properties of timestamp
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| //
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| EFI_TIMESTAMP_PROPERTIES mTimestampProperties = {
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|   0,
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|   0
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| };
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| 
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| /**
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|   Retrieves the current value of a 64-bit free running timestamp counter.
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| 
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|   The counter shall count up in proportion to the amount of time that has passed. The counter value
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|   will always roll over to zero. The properties of the counter can be retrieved from GetProperties().
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|   The caller should be prepared for the function to return the same value twice across successive calls.
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|   The counter value will not go backwards other than when wrapping, as defined by EndValue in GetProperties().
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|   The frequency of the returned timestamp counter value must remain constant. Power management operations that 
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|   affect clocking must not change the returned counter frequency. The quantization of counter value updates may 
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|   vary as long as the value reflecting time passed remains consistent.           
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| 
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|   @retval The current value of the free running timestamp counter.
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| 
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| **/
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| UINT64
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| EFIAPI
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| TimestampDriverGetTimestamp (
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|   VOID
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|   )
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| {
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|   //
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|   // The timestamp of Timestamp Protocol
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|   //
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|   UINT64  TimestampValue;
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|   TimestampValue = 0;
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|   
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|   //
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|   // Get the timestamp
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|   //
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|   if (mTimerLibStartValue > mTimerLibEndValue) {
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|     TimestampValue = mTimerLibStartValue - GetPerformanceCounter();
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|   } else {
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|     TimestampValue = GetPerformanceCounter() - mTimerLibStartValue;
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|   }
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|     
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|   return TimestampValue;
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| }
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| 
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| /**
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|   Obtains timestamp counter properties including frequency and value limits.
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| 
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|   @param[out]  Properties              The properties of the timestamp counter.
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| 
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|   @retval      EFI_SUCCESS             The properties were successfully retrieved. 
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|   @retval      EFI_DEVICE_ERROR        An error occurred trying to retrieve the properties of the timestamp 
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|                                        counter subsystem. Properties is not pedated.                                
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|   @retval      EFI_INVALID_PARAMETER   Properties is NULL.
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| 
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| **/
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| EFI_STATUS
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| EFIAPI
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| TimestampDriverGetProperties(
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|   OUT   EFI_TIMESTAMP_PROPERTIES       *Properties
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|   )
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| {
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|   if (Properties == NULL) {
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|     return EFI_INVALID_PARAMETER;
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|   }
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|   
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|   //
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|   // Get timestamp properties
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|   //
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|   CopyMem((VOID *) Properties, (VOID *) &mTimestampProperties, sizeof (mTimestampProperties));
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|   
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|   return EFI_SUCCESS;
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| }
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| 
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| //
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| // The Timestamp Protocol instance produced by this driver
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| //
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| EFI_TIMESTAMP_PROTOCOL  mTimestamp = {
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|   TimestampDriverGetTimestamp,
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|   TimestampDriverGetProperties
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| };
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| 
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| /**
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|   Entry point of the Timestamp Protocol driver.
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| 
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|   @param  ImageHandle   The image handle of this driver.
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|   @param  SystemTable   The pointer of EFI_SYSTEM_TABLE.
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| 
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|   @retval EFI_SUCCESS   Watchdog Timer Architectural Protocol successfully installed.
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| 
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| **/
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| EFI_STATUS
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| EFIAPI
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| TimestampDriverInitialize (
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|   IN EFI_HANDLE        ImageHandle,
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|   IN EFI_SYSTEM_TABLE  *SystemTable
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|   )
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| {
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|   EFI_STATUS  Status;
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|   
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|   EFI_HANDLE  TimestampHandle;
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|   TimestampHandle = NULL;
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|   
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|   //
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|   // Get the start value, end value and frequency in Timerlib
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|   //
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|   mTimestampProperties.Frequency = GetPerformanceCounterProperties(&mTimerLibStartValue, &mTimerLibEndValue);
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|   
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|   //
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|   // Set the EndValue 
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|   //
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|   if (mTimerLibEndValue > mTimerLibStartValue) {
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|     mTimestampProperties.EndValue = mTimerLibEndValue - mTimerLibStartValue;
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|   } else {
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|     mTimestampProperties.EndValue = mTimerLibStartValue - mTimerLibEndValue;
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|   }
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|   
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|   DEBUG ((EFI_D_INFO, "TimerFrequency:0x%lx, TimerLibStartTime:0x%lx, TimerLibEndtime:0x%lx\n", mTimestampProperties.Frequency, mTimerLibStartValue, mTimerLibEndValue));
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|   
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|   //
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|   // Install the Timestamp Protocol onto a new handle
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|   //
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|   Status = gBS->InstallMultipleProtocolInterfaces (
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|                   &TimestampHandle,
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|                   &gEfiTimestampProtocolGuid,
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|                   &mTimestamp,
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|                   NULL
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|                   );
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|                   
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|   ASSERT_EFI_ERROR (Status);
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| 
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|   return EFI_SUCCESS;
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| }
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