https://bugzilla.tianocore.org/show_bug.cgi?id=1373 Replace BSD 2-Clause License with BSD+Patent License. This change is based on the following emails: https://lists.01.org/pipermail/edk2-devel/2019-February/036260.html https://lists.01.org/pipermail/edk2-devel/2018-October/030385.html RFCs with detailed process for the license change: V3: https://lists.01.org/pipermail/edk2-devel/2019-March/038116.html V2: https://lists.01.org/pipermail/edk2-devel/2019-March/037669.html V1: https://lists.01.org/pipermail/edk2-devel/2019-March/037500.html Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Michael D Kinney <michael.d.kinney@intel.com> Reviewed-by: Liming Gao <liming.gao@intel.com>
		
			
				
	
	
		
			411 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			411 lines
		
	
	
		
			12 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /** @file
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|   Implementation of synchronization functions.
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| 
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|   Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>
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|   SPDX-License-Identifier: BSD-2-Clause-Patent
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| 
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| **/
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| 
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| #include "BaseSynchronizationLibInternals.h"
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| 
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| #define SPIN_LOCK_RELEASED          ((UINTN) 1)
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| #define SPIN_LOCK_ACQUIRED          ((UINTN) 2)
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| 
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| /**
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|   Retrieves the architecture specific spin lock alignment requirements for
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|   optimal spin lock performance.
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| 
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|   This function retrieves the spin lock alignment requirements for optimal
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|   performance on a given CPU architecture. The spin lock alignment is byte alignment.
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|   It must be a power of two and is returned by this function. If there are no alignment
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|   requirements, then 1 must be returned. The spin lock synchronization
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|   functions must function correctly if the spin lock size and alignment values
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|   returned by this function are not used at all. These values are hints to the
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|   consumers of the spin lock synchronization functions to obtain optimal spin
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|   lock performance.
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| 
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|   @return The architecture specific spin lock alignment.
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| 
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| **/
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| UINTN
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| EFIAPI
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| GetSpinLockProperties (
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|   VOID
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|   )
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| {
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|   return 32;
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| }
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| 
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| /**
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|   Initializes a spin lock to the released state and returns the spin lock.
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| 
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|   This function initializes the spin lock specified by SpinLock to the released
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|   state, and returns SpinLock. Optimal performance can be achieved by calling
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|   GetSpinLockProperties() to determine the size and alignment requirements for
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|   SpinLock.
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| 
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|   If SpinLock is NULL, then ASSERT().
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| 
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|   @param  SpinLock  A pointer to the spin lock to initialize to the released
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|                     state.
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| 
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|   @return SpinLock is in release state.
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| 
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| **/
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| SPIN_LOCK *
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| EFIAPI
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| InitializeSpinLock (
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|   OUT      SPIN_LOCK                 *SpinLock
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|   )
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| {
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|   ASSERT (SpinLock != NULL);
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|   *SpinLock = SPIN_LOCK_RELEASED;
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|   return SpinLock;
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| }
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| 
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| /**
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|   Waits until a spin lock can be placed in the acquired state.
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| 
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|   This function checks the state of the spin lock specified by SpinLock. If
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|   SpinLock is in the released state, then this function places SpinLock in the
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|   acquired state and returns SpinLock. Otherwise, this function waits
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|   indefinitely for the spin lock to be released, and then places it in the
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|   acquired state and returns SpinLock. All state transitions of SpinLock must
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|   be performed using MP safe mechanisms.
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| 
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|   If SpinLock is NULL, then ASSERT().
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|   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
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|   If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
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|   PcdSpinLockTimeout microseconds, then ASSERT().
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| 
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|   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
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| 
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|   @return SpinLock acquired the lock.
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| 
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| **/
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| SPIN_LOCK *
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| EFIAPI
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| AcquireSpinLock (
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|   IN OUT  SPIN_LOCK                 *SpinLock
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|   )
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| {
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|   UINT64  Current;
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|   UINT64  Previous;
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|   UINT64  Total;
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|   UINT64  Start;
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|   UINT64  End;
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|   UINT64  Timeout;
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|   INT64   Cycle;
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|   INT64   Delta;
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| 
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|   if (PcdGet32 (PcdSpinLockTimeout) == 0) {
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|     while (!AcquireSpinLockOrFail (SpinLock)) {
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|       CpuPause ();
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|     }
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|   } else if (!AcquireSpinLockOrFail (SpinLock)) {
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|     //
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|     // Get the current timer value
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|     //
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|     Current = GetPerformanceCounter();
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| 
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|     //
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|     // Initialize local variables
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|     //
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|     Start = 0;
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|     End   = 0;
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|     Total = 0;
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| 
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|     //
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|     // Retrieve the performance counter properties and compute the number of performance
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|     // counter ticks required to reach the timeout
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|     //
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|     Timeout = DivU64x32 (
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|                 MultU64x32 (
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|                   GetPerformanceCounterProperties (&Start, &End),
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|                   PcdGet32 (PcdSpinLockTimeout)
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|                   ),
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|                 1000000
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|                 );
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|     Cycle = End - Start;
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|     if (Cycle < 0) {
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|       Cycle = -Cycle;
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|     }
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|     Cycle++;
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| 
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|     while (!AcquireSpinLockOrFail (SpinLock)) {
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|       CpuPause ();
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|       Previous = Current;
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|       Current  = GetPerformanceCounter();
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|       Delta = (INT64) (Current - Previous);
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|       if (Start > End) {
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|         Delta = -Delta;
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|       }
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|       if (Delta < 0) {
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|         Delta += Cycle;
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|       }
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|       Total += Delta;
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|       ASSERT (Total < Timeout);
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|     }
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|   }
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|   return SpinLock;
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| }
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| 
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| /**
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|   Attempts to place a spin lock in the acquired state.
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| 
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|   This function checks the state of the spin lock specified by SpinLock. If
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|   SpinLock is in the released state, then this function places SpinLock in the
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|   acquired state and returns TRUE. Otherwise, FALSE is returned. All state
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|   transitions of SpinLock must be performed using MP safe mechanisms.
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| 
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|   If SpinLock is NULL, then ASSERT().
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|   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
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| 
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|   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
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| 
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|   @retval TRUE  SpinLock was placed in the acquired state.
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|   @retval FALSE SpinLock could not be acquired.
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| 
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| **/
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| BOOLEAN
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| EFIAPI
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| AcquireSpinLockOrFail (
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|   IN OUT  SPIN_LOCK                 *SpinLock
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|   )
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| {
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|   SPIN_LOCK    LockValue;
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| 
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|   ASSERT (SpinLock != NULL);
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| 
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|   LockValue = *SpinLock;
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|   ASSERT (SPIN_LOCK_ACQUIRED == LockValue || SPIN_LOCK_RELEASED == LockValue);
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| 
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|   return (BOOLEAN)(
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|            InterlockedCompareExchangePointer (
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|              (VOID**)SpinLock,
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|              (VOID*)SPIN_LOCK_RELEASED,
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|              (VOID*)SPIN_LOCK_ACQUIRED
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|              ) == (VOID*)SPIN_LOCK_RELEASED
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|            );
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| }
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| 
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| /**
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|   Releases a spin lock.
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| 
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|   This function places the spin lock specified by SpinLock in the release state
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|   and returns SpinLock.
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| 
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|   If SpinLock is NULL, then ASSERT().
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|   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
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| 
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|   @param  SpinLock  A pointer to the spin lock to release.
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| 
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|   @return SpinLock released lock.
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| 
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| **/
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| SPIN_LOCK *
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| EFIAPI
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| ReleaseSpinLock (
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|   IN OUT  SPIN_LOCK                 *SpinLock
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|   )
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| {
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|   SPIN_LOCK    LockValue;
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| 
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|   ASSERT (SpinLock != NULL);
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| 
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|   LockValue = *SpinLock;
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|   ASSERT (SPIN_LOCK_ACQUIRED == LockValue || SPIN_LOCK_RELEASED == LockValue);
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| 
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|   *SpinLock = SPIN_LOCK_RELEASED;
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|   return SpinLock;
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| }
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| 
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| /**
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|   Performs an atomic increment of an 32-bit unsigned integer.
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| 
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|   Performs an atomic increment of the 32-bit unsigned integer specified by
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|   Value and returns the incremented value. The increment operation must be
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|   performed using MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value A pointer to the 32-bit value to increment.
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| 
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|   @return The incremented value.
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| 
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| **/
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| UINT32
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| EFIAPI
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| InterlockedIncrement (
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|   IN      volatile UINT32           *Value
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|   )
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| {
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|   ASSERT (Value != NULL);
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|   return InternalSyncIncrement (Value);
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| }
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| 
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| /**
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|   Performs an atomic decrement of an 32-bit unsigned integer.
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| 
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|   Performs an atomic decrement of the 32-bit unsigned integer specified by
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|   Value and returns the decremented value. The decrement operation must be
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|   performed using MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value A pointer to the 32-bit value to decrement.
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| 
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|   @return The decremented value.
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| 
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| **/
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| UINT32
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| EFIAPI
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| InterlockedDecrement (
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|   IN      volatile UINT32           *Value
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|   )
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| {
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|   ASSERT (Value != NULL);
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|   return InternalSyncDecrement (Value);
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| }
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| 
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| /**
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|   Performs an atomic compare exchange operation on a 16-bit unsigned integer.
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| 
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|   Performs an atomic compare exchange operation on the 16-bit unsigned integer
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|   specified by Value.  If Value is equal to CompareValue, then Value is set to
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|   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
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|   then Value is returned.  The compare exchange operation must be performed using
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|   MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value         A pointer to the 16-bit value for the compare exchange
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|                         operation.
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|   @param  CompareValue  16-bit value used in compare operation.
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|   @param  ExchangeValue 16-bit value used in exchange operation.
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| 
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|   @return The original *Value before exchange.
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| 
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| **/
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| UINT16
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| EFIAPI
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| InterlockedCompareExchange16 (
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|   IN OUT  volatile UINT16           *Value,
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|   IN      UINT16                    CompareValue,
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|   IN      UINT16                    ExchangeValue
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|   )
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| {
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|   ASSERT (Value != NULL);
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|   return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);
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| }
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| 
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| /**
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|   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
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| 
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|   Performs an atomic compare exchange operation on the 32-bit unsigned integer
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|   specified by Value.  If Value is equal to CompareValue, then Value is set to
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|   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
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|   then Value is returned.  The compare exchange operation must be performed using
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|   MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value         A pointer to the 32-bit value for the compare exchange
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|                         operation.
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|   @param  CompareValue  32-bit value used in compare operation.
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|   @param  ExchangeValue 32-bit value used in exchange operation.
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| 
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|   @return The original *Value before exchange.
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| 
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| **/
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| UINT32
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| EFIAPI
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| InterlockedCompareExchange32 (
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|   IN OUT  volatile UINT32           *Value,
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|   IN      UINT32                    CompareValue,
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|   IN      UINT32                    ExchangeValue
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|   )
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| {
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|   ASSERT (Value != NULL);
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|   return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);
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| }
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| 
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| /**
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|   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
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| 
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|   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
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|   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
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|   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
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|   The compare exchange operation must be performed using MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value         A pointer to the 64-bit value for the compare exchange
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|                         operation.
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|   @param  CompareValue  64-bit value used in compare operation.
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|   @param  ExchangeValue 64-bit value used in exchange operation.
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| 
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|   @return The original *Value before exchange.
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| 
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| **/
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| UINT64
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| EFIAPI
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| InterlockedCompareExchange64 (
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|   IN OUT  volatile UINT64           *Value,
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|   IN      UINT64                    CompareValue,
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|   IN      UINT64                    ExchangeValue
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|   )
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| {
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|   ASSERT (Value != NULL);
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|   return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);
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| }
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| 
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| /**
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|   Performs an atomic compare exchange operation on a pointer value.
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| 
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|   Performs an atomic compare exchange operation on the pointer value specified
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|   by Value. If Value is equal to CompareValue, then Value is set to
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|   ExchangeValue and CompareValue is returned. If Value is not equal to
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|   CompareValue, then Value is returned. The compare exchange operation must be
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|   performed using MP safe mechanisms.
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| 
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|   If Value is NULL, then ASSERT().
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| 
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|   @param  Value         A pointer to the pointer value for the compare exchange
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|                         operation.
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|   @param  CompareValue  Pointer value used in compare operation.
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|   @param  ExchangeValue Pointer value used in exchange operation.
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| 
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|   @return The original *Value before exchange.
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| **/
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| VOID *
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| EFIAPI
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| InterlockedCompareExchangePointer (
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|   IN OUT  VOID                      * volatile *Value,
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|   IN      VOID                      *CompareValue,
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|   IN      VOID                      *ExchangeValue
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|   )
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| {
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|   UINT8  SizeOfValue;
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| 
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|   SizeOfValue = sizeof (*Value);
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| 
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|   switch (SizeOfValue) {
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|     case sizeof (UINT32):
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|       return (VOID*)(UINTN)InterlockedCompareExchange32 (
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|                              (volatile UINT32 *)Value,
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|                              (UINT32)(UINTN)CompareValue,
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|                              (UINT32)(UINTN)ExchangeValue
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|                              );
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|     case sizeof (UINT64):
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|       return (VOID*)(UINTN)InterlockedCompareExchange64 (
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|                              (volatile UINT64 *)Value,
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|                              (UINT64)(UINTN)CompareValue,
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|                              (UINT64)(UINTN)ExchangeValue
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|                              );
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|     default:
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|       ASSERT (FALSE);
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|       return NULL;
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|   }
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| }
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