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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/Arm | |
| 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/Arm')
| -rw-r--r-- | MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S | 44 | ||||
| -rw-r--r-- | MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm | 44 |
2 files changed, 88 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S index 0128f8f016..d699eb40d2 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S +++ b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S @@ -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
@@ -15,12 +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):
+ 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.
Performs an atomic compare exchange operation on the 32-bit unsigned integer
diff --git a/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm index f9f8073777..dbc5991140 100644 --- a/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm +++ b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.asm @@ -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
@@ -20,6 +22,48 @@ 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.
Performs an atomic compare exchange operation on the 32-bit unsigned integer
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