This patch updates XenBusDxe to use the 16-bit compare and exchange function that was introduced for this purpose to the BaseSynchronizationLib. It also provides a new generic implementation of TestAndClearBit () using the same 16-bit compare and exchange, making this module fully architecture agnostic.
Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org> --- OvmfPkg/XenBusDxe/GrantTable.c | 2 +- .../Ia32/InterlockedCompareExchange16.nasm | 42 -------------------- OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm | 16 -------- OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c | 33 ---------------- OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h | 38 ------------------ OvmfPkg/XenBusDxe/TestAndClearBit.c | 45 ++++++++++++++++++++++ .../X64/InterlockedCompareExchange16.nasm | 41 -------------------- OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm | 15 -------- OvmfPkg/XenBusDxe/XenBusDxe.h | 2 +- OvmfPkg/XenBusDxe/XenBusDxe.inf | 12 +----- 10 files changed, 49 insertions(+), 197 deletions(-) delete mode 100644 OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.nasm delete mode 100644 OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm delete mode 100644 OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c delete mode 100644 OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h create mode 100644 OvmfPkg/XenBusDxe/TestAndClearBit.c delete mode 100644 OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.nasm delete mode 100644 OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm diff --git a/OvmfPkg/XenBusDxe/GrantTable.c b/OvmfPkg/XenBusDxe/GrantTable.c index 19117fbe0373..6e47483f136f 100644 --- a/OvmfPkg/XenBusDxe/GrantTable.c +++ b/OvmfPkg/XenBusDxe/GrantTable.c @@ -35,9 +35,9 @@ #include <IndustryStandard/Xen/memory.h> #include <Library/XenHypercallLib.h> +#include <Library/SynchronizationLib.h> #include "GrantTable.h" -#include "InterlockedCompareExchange16.h" #define NR_RESERVED_ENTRIES 8 diff --git a/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.nasm b/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.nasm deleted file mode 100644 index d45582dd8109..000000000000 --- a/OvmfPkg/XenBusDxe/Ia32/InterlockedCompareExchange16.nasm +++ /dev/null @@ -1,42 +0,0 @@ -;------------------------------------------------------------------------------ -; -; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR> -; 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. -; -; Module Name: -; -; InterlockedCompareExchange16.Asm -; -; Abstract: -; -; InterlockedCompareExchange16 function -; -; Notes: -; -;------------------------------------------------------------------------------ - - SECTION .text - -;------------------------------------------------------------------------------ -; UINT32 -; EFIAPI -; InternalSyncCompareExchange16 ( -; IN UINT16 *Value, -; IN UINT16 CompareValue, -; IN UINT16 ExchangeValue -; ); -;------------------------------------------------------------------------------ -global ASM_PFX(InternalSyncCompareExchange16) -ASM_PFX(InternalSyncCompareExchange16): - mov ecx, [esp + 4] - mov eax, [esp + 8] - mov edx, [esp + 12] - lock cmpxchg [ecx], dx - ret - diff --git a/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm b/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm deleted file mode 100644 index d77f74ef249d..000000000000 --- a/OvmfPkg/XenBusDxe/Ia32/TestAndClearBit.nasm +++ /dev/null @@ -1,16 +0,0 @@ -SECTION .text - -; INT32 -; EFIAPI -; TestAndClearBit ( -; IN INT32 Bit, -; IN volatile VOID* Address -; ); -global ASM_PFX(TestAndClearBit) -ASM_PFX(TestAndClearBit): - mov ecx, [esp + 4] - mov edx, [esp + 8] - lock btr [edx], ecx - sbb eax, eax - ret - diff --git a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c deleted file mode 100644 index 2b0fadd88dd1..000000000000 --- a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.c +++ /dev/null @@ -1,33 +0,0 @@ -#include <Library/DebugLib.h> -#include "InterlockedCompareExchange16.h" - -/** - 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. - - If Value is NULL, then ASSERT(). - - @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 -InterlockedCompareExchange16 ( - IN OUT UINT16 *Value, - IN UINT16 CompareValue, - IN UINT16 ExchangeValue - ) -{ - ASSERT (Value != NULL); - return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue); -} diff --git a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h b/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h deleted file mode 100644 index fd3f15b1c8d6..000000000000 --- a/OvmfPkg/XenBusDxe/InterlockedCompareExchange16.h +++ /dev/null @@ -1,38 +0,0 @@ -/** - Assembly implementation of InterlockedCompareExchange16. - - Look at the documentation of InterlockedCompareExchange16. -**/ -UINT16 -EFIAPI -InternalSyncCompareExchange16 ( - IN volatile UINT16 *Value, - IN UINT16 CompareValue, - IN UINT16 ExchangeValue - ); - -/** - 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. - - If Value is NULL, then ASSERT(). - - @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 -InterlockedCompareExchange16 ( - IN OUT UINT16 *Value, - IN UINT16 CompareValue, - IN UINT16 ExchangeValue - ); diff --git a/OvmfPkg/XenBusDxe/TestAndClearBit.c b/OvmfPkg/XenBusDxe/TestAndClearBit.c new file mode 100644 index 000000000000..410677ee8acd --- /dev/null +++ b/OvmfPkg/XenBusDxe/TestAndClearBit.c @@ -0,0 +1,45 @@ +/** @file + Implementation of TestAndClearBit using compare-exchange primitive + + Copyright (C) 2015, Linaro Ltd. + + 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. + +**/ + +#include <Base.h> +#include <Library/SynchronizationLib.h> + +INT32 +EFIAPI +TestAndClearBit ( + IN INT32 Bit, + IN VOID *Address + ) +{ + UINT16 Word, Read; + UINT16 Mask; + + // + // Calculate the effective address relative to 'Address' based on the + // higher order bits of 'Bit'. Use signed shift instead of division to + // ensure we round towards -Inf, and end up with a positive shift in + // 'Bit', even if 'Bit' itself is negative. + // + Address += (Bit >> 4) * sizeof(UINT16); + Mask = 1U << (Bit & 15); + + for (Word = *(UINT16 *) Address; Word & Mask; Word = Read) { + Read = InterlockedCompareExchange16 (Address, Word, Word & ~Mask); + if (Read == Word) { + return 1; + } + } + return 0; +} diff --git a/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.nasm b/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.nasm deleted file mode 100644 index 048d1f32f6b9..000000000000 --- a/OvmfPkg/XenBusDxe/X64/InterlockedCompareExchange16.nasm +++ /dev/null @@ -1,41 +0,0 @@ -;------------------------------------------------------------------------------ -; -; Copyright (c) 2006, Intel Corporation. All rights reserved.<BR> -; 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. -; -; Module Name: -; -; InterlockedCompareExchange16.Asm -; -; Abstract: -; -; InterlockedCompareExchange16 function -; -; Notes: -; -;------------------------------------------------------------------------------ - - DEFAULT REL - SECTION .text - -;------------------------------------------------------------------------------ -; UINT16 -; EFIAPI -; InterlockedCompareExchange16 ( -; IN UINT16 *Value, -; IN UINT16 CompareValue, -; IN UINT16 ExchangeValue -; ); -;------------------------------------------------------------------------------ -global ASM_PFX(InternalSyncCompareExchange16) -ASM_PFX(InternalSyncCompareExchange16): - mov eax, edx - lock cmpxchg [rcx], r8w - ret - diff --git a/OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm b/OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm deleted file mode 100644 index a4859a62a250..000000000000 --- a/OvmfPkg/XenBusDxe/X64/TestAndClearBit.nasm +++ /dev/null @@ -1,15 +0,0 @@ -DEFAULT REL -SECTION .text - -; INT32 -; EFIAPI -; TestAndClearBit ( -; IN INT32 Bit, // rcx -; IN volatile VOID* Address // rdx -; ); -global ASM_PFX(TestAndClearBit) -ASM_PFX(TestAndClearBit): - lock btr [rdx], ecx - sbb eax, eax - ret - diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.h b/OvmfPkg/XenBusDxe/XenBusDxe.h index 6c306e017b07..953e4b72e85e 100644 --- a/OvmfPkg/XenBusDxe/XenBusDxe.h +++ b/OvmfPkg/XenBusDxe/XenBusDxe.h @@ -122,7 +122,7 @@ INT32 EFIAPI TestAndClearBit ( IN INT32 Bit, - IN volatile VOID *Address + IN VOID *Address ); CHAR8* diff --git a/OvmfPkg/XenBusDxe/XenBusDxe.inf b/OvmfPkg/XenBusDxe/XenBusDxe.inf index 31553ac5a64a..f0c5db98b1f4 100644 --- a/OvmfPkg/XenBusDxe/XenBusDxe.inf +++ b/OvmfPkg/XenBusDxe/XenBusDxe.inf @@ -34,8 +34,6 @@ DriverBinding.h ComponentName.c ComponentName.h - InterlockedCompareExchange16.c - InterlockedCompareExchange16.h GrantTable.c GrantTable.h EventChannel.c @@ -45,14 +43,7 @@ XenBus.c XenBus.h Helpers.c - -[Sources.IA32] - Ia32/InterlockedCompareExchange16.nasm - Ia32/TestAndClearBit.nasm - -[Sources.X64] - X64/InterlockedCompareExchange16.nasm - X64/TestAndClearBit.nasm + TestAndClearBit.c [LibraryClasses] UefiDriverEntryPoint @@ -64,6 +55,7 @@ DevicePathLib DebugLib XenHypercallLib + SynchronizationLib [Protocols] gEfiDriverBindingProtocolGuid -- 1.8.3.2 ------------------------------------------------------------------------------ Dive into the World of Parallel Programming The Go Parallel Website, sponsored by Intel and developed in partnership with Slashdot Media, is your hub for all things parallel software development, from weekly thought leadership blogs to news, videos, case studies, tutorials and more. 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