mirror of
https://github.com/CloverHackyColor/CloverBootloader.git
synced 2024-12-27 16:58:09 +01:00
46 lines
1.3 KiB
C
46 lines
1.3 KiB
C
/** @file
|
|
InterlockedCompareExchange16 function
|
|
|
|
Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
|
|
Copyright (c) 2015, Linaro Ltd. All rights reserved.<BR>
|
|
SPDX-License-Identifier: BSD-2-Clause-Patent
|
|
|
|
**/
|
|
|
|
|
|
|
|
|
|
/**
|
|
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 {
|
|
mov ecx, Value
|
|
mov ax, CompareValue
|
|
mov dx, ExchangeValue
|
|
lock cmpxchg [ecx], dx
|
|
}
|
|
}
|
|
|