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>
		
			
				
	
	
		
			208 lines
		
	
	
		
			6.0 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
			
		
		
	
	
			208 lines
		
	
	
		
			6.0 KiB
		
	
	
	
		
			ArmAsm
		
	
	
	
	
	
| //  Implementation of synchronization functions for ARM architecture
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| //
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| //  Copyright (c) 2012-2015, ARM Limited. All rights reserved.
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| //  Copyright (c) 2015, Linaro Limited. All rights reserved.
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| //
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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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| .text
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| .align 3
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| 
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| GCC_ASM_EXPORT(InternalSyncCompareExchange16)
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| GCC_ASM_EXPORT(InternalSyncCompareExchange32)
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| GCC_ASM_EXPORT(InternalSyncCompareExchange64)
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| GCC_ASM_EXPORT(InternalSyncIncrement)
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| GCC_ASM_EXPORT(InternalSyncDecrement)
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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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|   @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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| //InternalSyncCompareExchange16 (
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| //  IN      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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| ASM_PFX(InternalSyncCompareExchange16):
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|   dmb
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| 
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| InternalSyncCompareExchange16Again:
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|   ldrexh  r3, [r0]
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|   cmp     r3, r1
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|   bne     InternalSyncCompareExchange16Fail
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| 
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| InternalSyncCompareExchange16Exchange:
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|   strexh  ip, r2, [r0]
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|   cmp     ip, #0
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|   bne     InternalSyncCompareExchange16Again
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| 
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| InternalSyncCompareExchange16Fail:
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|   dmb
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|   mov     r0, r3
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|   bx      lr
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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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|   @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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| //InternalSyncCompareExchange32 (
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| //  IN      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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| ASM_PFX(InternalSyncCompareExchange32):
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|   dmb
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| 
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| InternalSyncCompareExchange32Again:
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|   ldrex   r3, [r0]
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|   cmp     r3, r1
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|   bne     InternalSyncCompareExchange32Fail
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| 
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| InternalSyncCompareExchange32Exchange:
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|   strex   ip, r2, [r0]
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|   cmp     ip, #0
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|   bne     InternalSyncCompareExchange32Again
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| 
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| InternalSyncCompareExchange32Fail:
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|   dmb
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|   mov     r0, r3
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|   bx      lr
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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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|   @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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| //InternalSyncCompareExchange64 (
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| //  IN      volatile UINT64           *Value,         // r0
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| //  IN      UINT64                    CompareValue,   // r2-r3
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| //  IN      UINT64                    ExchangeValue   // stack
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| //  )
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| ASM_PFX(InternalSyncCompareExchange64):
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|   push    { r4-r7 }
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|   ldrd    r4, r5, [sp, #16]
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|   dmb
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| 
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| InternalSyncCompareExchange64Again:
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|   ldrexd  r6, r7, [r0]
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|   cmp     r6, r2
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|   cmpeq   r7, r3
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|   bne     InternalSyncCompareExchange64Fail
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| 
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| InternalSyncCompareExchange64Exchange:
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|   strexd  ip, r4, r5, [r0]
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|   cmp     ip, #0
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|   bne     InternalSyncCompareExchange64Again
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| 
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| InternalSyncCompareExchange64Fail:
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|   dmb
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|   mov     r0, r6
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|   mov     r1, r7
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|   pop     { r4-r7 }
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|   bx      lr
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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. The state of the return value is not
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|   guaranteed to be MP safe.
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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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| //InternalSyncIncrement (
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| //  IN      volatile UINT32           *Value
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| //  )
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| ASM_PFX(InternalSyncIncrement):
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|   dmb
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| TryInternalSyncIncrement:
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|   ldrex   r1, [r0]
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|   add     r1, r1, #1
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|   strex   r2, r1, [r0]
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|   cmp     r2, #0
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|   bne     TryInternalSyncIncrement
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|   dmb
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|   mov     r0, r1
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|   bx      lr
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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 decrement value. The decrement operation must be
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|   performed using MP safe mechanisms. The state of the return value is not
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|   guaranteed to be MP safe.
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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 decrement value.
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| 
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| **/
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| //UINT32
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| //EFIAPI
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| //InternalSyncDecrement (
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| //  IN      volatile UINT32           *Value
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| //  )
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| ASM_PFX(InternalSyncDecrement):
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|   dmb
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| TryInternalSyncDecrement:
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|   ldrex   r1, [r0]
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|   sub     r1, r1, #1
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|   strex   r2, r1, [r0]
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|   cmp     r2, #0
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|   bne     TryInternalSyncDecrement
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|   dmb
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|   mov     r0, r1
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|   bx      lr
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