; Implementation of synchronization functions for ARM architecture (AArch64) | |
; | |
; Copyright (c) 2012-2015, ARM Limited. All rights reserved. | |
; Copyright (c) 2015, Linaro Limited. All rights reserved. | |
; | |
; SPDX-License-Identifier: BSD-2-Clause-Patent | |
; | |
; | |
EXPORT InternalSyncCompareExchange16 | |
EXPORT InternalSyncCompareExchange32 | |
EXPORT InternalSyncCompareExchange64 | |
EXPORT InternalSyncIncrement | |
EXPORT InternalSyncDecrement | |
AREA BaseSynchronizationLib_LowLevel, 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 | |
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. | |
; | |
; Performs an atomic compare exchange operation on the 32-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 32-bit value for the compare exchange | |
; operation. | |
; @param CompareValue 32-bit value used in compare operation. | |
; @param ExchangeValue 32-bit value used in exchange operation. | |
; | |
; @return The original *Value before exchange. | |
; | |
;**/ | |
;UINT32 | |
;EFIAPI | |
;InternalSyncCompareExchange32 ( | |
; IN volatile UINT32 *Value, | |
; IN UINT32 CompareValue, | |
; IN UINT32 ExchangeValue | |
; ) | |
InternalSyncCompareExchange32 | |
dmb sy | |
InternalSyncCompareExchange32Again | |
ldxr w3, [x0] | |
cmp w3, w1 | |
bne InternalSyncCompareExchange32Fail | |
InternalSyncCompareExchange32Exchange | |
stxr w4, w2, [x0] | |
cbnz w4, InternalSyncCompareExchange32Again | |
InternalSyncCompareExchange32Fail | |
dmb sy | |
mov w0, w3 | |
ret | |
;/** | |
; Performs an atomic compare exchange operation on a 64-bit unsigned integer. | |
; | |
; Performs an atomic compare exchange operation on the 64-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 64-bit value for the compare exchange | |
; operation. | |
; @param CompareValue 64-bit value used in compare operation. | |
; @param ExchangeValue 64-bit value used in exchange operation. | |
; | |
; @return The original *Value before exchange. | |
; | |
;**/ | |
;UINT64 | |
;EFIAPI | |
;InternalSyncCompareExchange64 ( | |
; IN volatile UINT64 *Value, | |
; IN UINT64 CompareValue, | |
; IN UINT64 ExchangeValue | |
; ) | |
InternalSyncCompareExchange64 | |
dmb sy | |
InternalSyncCompareExchange64Again | |
ldxr x3, [x0] | |
cmp x3, x1 | |
bne InternalSyncCompareExchange64Fail | |
InternalSyncCompareExchange64Exchange | |
stxr w4, x2, [x0] | |
cbnz w4, InternalSyncCompareExchange64Again | |
InternalSyncCompareExchange64Fail | |
dmb sy | |
mov x0, x3 | |
ret | |
;/** | |
; Performs an atomic increment of an 32-bit unsigned integer. | |
; | |
; Performs an atomic increment of the 32-bit unsigned integer specified by | |
; Value and returns the incremented value. The increment operation must be | |
; performed using MP safe mechanisms. The state of the return value is not | |
; guaranteed to be MP safe. | |
; | |
; @param Value A pointer to the 32-bit value to increment. | |
; | |
; @return The incremented value. | |
; | |
;**/ | |
;UINT32 | |
;EFIAPI | |
;InternalSyncIncrement ( | |
; IN volatile UINT32 *Value | |
; ) | |
InternalSyncIncrement | |
dmb sy | |
TryInternalSyncIncrement | |
ldxr w1, [x0] | |
add w1, w1, #1 | |
stxr w2, w1, [x0] | |
cbnz w2, TryInternalSyncIncrement | |
mov w0, w1 | |
dmb sy | |
ret | |
;/** | |
; Performs an atomic decrement of an 32-bit unsigned integer. | |
; | |
; Performs an atomic decrement of the 32-bit unsigned integer specified by | |
; Value and returns the decrement value. The decrement operation must be | |
; performed using MP safe mechanisms. The state of the return value is not | |
; guaranteed to be MP safe. | |
; | |
; @param Value A pointer to the 32-bit value to decrement. | |
; | |
; @return The decrement value. | |
; | |
;**/ | |
;UINT32 | |
;EFIAPI | |
;InternalSyncDecrement ( | |
; IN volatile UINT32 *Value | |
; ) | |
InternalSyncDecrement | |
dmb sy | |
TryInternalSyncDecrement | |
ldxr w1, [x0] | |
sub w1, w1, #1 | |
stxr w2, w1, [x0] | |
cbnz w2, TryInternalSyncDecrement | |
mov w0, w1 | |
dmb sy | |
ret | |
END |