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Diffstat (limited to 'MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S')
| -rw-r--r-- | MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S new file mode 100644 index 000000000000..b63feba411a9 --- /dev/null +++ b/MdePkg/Library/BaseSynchronizationLib/Arm/Synchronization.S @@ -0,0 +1,213 @@ +// 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 +// which accompanies this distribution. The full text of the license may be found at +// http://opensource.org/licenses/bsd-license.php +// +// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, +// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. +// +// + +.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 + 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 +// ) +ASM_PFX(InternalSyncCompareExchange32): + dmb + +InternalSyncCompareExchange32Again: + ldrex r3, [r0] + cmp r3, r1 + bne InternalSyncCompareExchange32Fail + +InternalSyncCompareExchange32Exchange: + strex ip, r2, [r0] + cmp ip, #0 + bne InternalSyncCompareExchange32Again + +InternalSyncCompareExchange32Fail: + dmb + mov r0, r3 + bx lr + +/** + 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, // r0 +// IN UINT64 CompareValue, // r2-r3 +// IN UINT64 ExchangeValue // stack +// ) +ASM_PFX(InternalSyncCompareExchange64): + push { r4-r7 } + ldrd r4, r5, [sp, #16] + dmb + +InternalSyncCompareExchange64Again: + ldrexd r6, r7, [r0] + cmp r6, r2 + cmpeq r7, r3 + bne InternalSyncCompareExchange64Fail + +InternalSyncCompareExchange64Exchange: + strexd ip, r4, r5, [r0] + cmp ip, #0 + bne InternalSyncCompareExchange64Again + +InternalSyncCompareExchange64Fail: + dmb + mov r0, r6 + mov r1, r7 + pop { r4-r7 } + bx lr + +/** + 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 +// ) +ASM_PFX(InternalSyncIncrement): + dmb +TryInternalSyncIncrement: + ldrex r1, [r0] + add r1, r1, #1 + strex r2, r1, [r0] + cmp r2, #0 + bne TryInternalSyncIncrement + dmb + mov r0, r1 + bx lr + +/** + 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 +// ) +ASM_PFX(InternalSyncDecrement): + dmb +TryInternalSyncDecrement: + ldrex r1, [r0] + sub r1, r1, #1 + strex r2, r1, [r0] + cmp r2, #0 + bne TryInternalSyncDecrement + dmb + mov r0, r1 + bx lr |