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| author | Ard Biesheuvel <ard.biesheuvel@linaro.org> | 2015-02-28 20:31:54 +0000 |
|---|---|---|
| committer | lersek <lersek@Edk2> | 2015-02-28 20:31:54 +0000 |
| commit | 9b89163eea30762f7ab91dcdc414820173cbf858 (patch) | |
| tree | fb413e3b86023d358593766371ee0341b9c7368d /MdePkg/Library/BaseSynchronizationLib/AArch64 | |
| parent | cc3104283f47d99a68e555582a3298a26735eb84 (diff) | |
| download | edk2-platforms-9b89163eea30762f7ab91dcdc414820173cbf858.tar.xz | |
MdePkg/BaseSynchronizationLib: Add InterlockedCompareExchange16
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
Diffstat (limited to 'MdePkg/Library/BaseSynchronizationLib/AArch64')
| -rw-r--r-- | MdePkg/Library/BaseSynchronizationLib/AArch64/Synchronization.S | 44 |
1 files changed, 44 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseSynchronizationLib/AArch64/Synchronization.S b/MdePkg/Library/BaseSynchronizationLib/AArch64/Synchronization.S index 601b00495f..ecb87fc127 100644 --- a/MdePkg/Library/BaseSynchronizationLib/AArch64/Synchronization.S +++ b/MdePkg/Library/BaseSynchronizationLib/AArch64/Synchronization.S @@ -16,12 +16,56 @@ .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.
Performs an atomic compare exchange operation on the 32-bit unsigned integer
|