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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/AArch64/Synchronization.S
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@ -16,11 +16,55 @@
.text
.align 3
GCC_ASM_EXPORT(InternalSyncCompareExchange16)
GCC_ASM_EXPORT(InternalSyncCompareExchange32)
GCC_ASM_EXPORT(InternalSyncCompareExchange64)
GCC_ASM_EXPORT(InternalSyncIncrement)
GCC_ASM_EXPORT(InternalSyncDecrement)
/**
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
// )
ASM_PFX(InternalSyncCompareExchange16):
uxth w1, w1
uxth w2, w2
dmb sy
InternalSyncCompareExchange16Again:
ldxrh w3, [x0]
cmp w3, w1
bne InternalSyncCompareExchange16Fail
InternalSyncCompareExchange16Exchange:
stxrh w4, w2, [x0]
cbnz w4, InternalSyncCompareExchange16Again
InternalSyncCompareExchange16Fail:
dmb sy
mov w0, w3
ret
/**
Performs an atomic compare exchange operation on a 32-bit unsigned integer.