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MdePkg/BaseSynchronizationLib: Add InterlockedCompareExchange16

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This implements the function InterlockedCompareExchange16 () for all
architectures, using architecture and toolchain specific intrinsics
or primitive assembler instructions.

Contributed-under: TianoCore Contribution Agreement 1.0
Reviewed-by: Olivier Martin <olivier.martin@arm.com>
Acked-by: Jordan Justen <jordan.l.justen@intel.com>
Reviewed-by: Michael Kinney <michael.d.kinney@intel.com>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Laszlo Ersek <lersek@redhat.com>

git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@16966 6f19259b-4bc3-4df7-8a09-765794883524
This commit is contained in:
Ard Biesheuvel
2015-02-28 20:31:54 +00:00
committed by lersek
parent cc3104283f
commit 9b89163eea
17 changed files with 622 additions and 0 deletions
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44
MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm
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@@ -1,6 +1,7 @@
// Implementation of synchronization functions for ARM architecture
//
// Copyright (c) 2012-2015, ARM Limited. All rights reserved.
// Copyright (c) 2015, Linaro Limited. All rights reserved.
//
// This program and the accompanying materials
// are licensed and made available under the terms and conditions of the BSD License
@@ -12,6 +13,7 @@
//
//
EXPORT InternalSyncCompareExchange16
EXPORT InternalSyncCompareExchange32
EXPORT InternalSyncCompareExchange64
EXPORT InternalSyncIncrement
@@ -19,6 +21,48 @@
AREA ArmSynchronization, CODE, READONLY
/**
Performs an atomic compare exchange operation on a 16-bit unsigned integer.
Performs an atomic compare exchange operation on the 16-bit unsigned integer
specified by Value. If Value is equal to CompareValue, then Value is set to
ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
then Value is returned. The compare exchange operation must be performed using
MP safe mechanisms.
@param Value A pointer to the 16-bit value for the compare exchange
operation.
@param CompareValue 16-bit value used in compare operation.
@param ExchangeValue 16-bit value used in exchange operation.
@return The original *Value before exchange.
**/
//UINT16
//EFIAPI
//InternalSyncCompareExchange16 (
// IN volatile UINT16 *Value,
// IN UINT16 CompareValue,
// IN UINT16 ExchangeValue
// )
InternalSyncCompareExchange16
dmb
InternalSyncCompareExchange16Again
ldrexh r3, [r0]
cmp r3, r1
bne InternalSyncCompareExchange16Fail
InternalSyncCompareExchange16Exchange
strexh ip, r2, [r0]
cmp ip, #0
bne InternalSyncCompareExchange16Again
InternalSyncCompareExchange16Fail
dmb
mov r0, r3
bx lr
/**
Performs an atomic compare exchange operation on a 32-bit unsigned integer.