From: yshang1 Date: Tue, 3 Apr 2007 06:25:25 +0000 (+0000) Subject: Add the ReadWriteBarrier in the Acquire/ReleaseSpin to block the unexpected optimizat... X-Git-Tag: edk2-stable201903~23373 X-Git-Url: https://git.proxmox.com/?p=mirror_edk2.git;a=commitdiff_plain;h=ef7baf58d031adb9aad451f761a1898190f482f5 Add the ReadWriteBarrier in the Acquire/ReleaseSpin to block the unexpected optimization of compiler. git-svn-id: https://edk2.svn.sourceforge.net/svnroot/edk2/trunk/edk2@2524 6f19259b-4bc3-4df7-8a09-765794883524 --- diff --git a/MdePkg/Library/BaseLib/BaseLib.msa b/MdePkg/Library/BaseLib/BaseLib.msa index 99ba05a870..7e1690fefa 100644 --- a/MdePkg/Library/BaseLib/BaseLib.msa +++ b/MdePkg/Library/BaseLib/BaseLib.msa @@ -42,7 +42,6 @@ BaseLibInternals.h String.c LinkedList.c - Synchronization.c Cpu.c CpuDeadLoop.c BitField.c @@ -73,7 +72,9 @@ SwapBytes32.c SwapBytes64.c SwitchStack.c - CheckSum.c + CheckSum.c + SynchronizationGcc.c + SynchronizationMsc.c x86DisablePaging32.c x86DisablePaging64.c x86EnablePaging32.c diff --git a/MdePkg/Library/BaseLib/Synchronization.c b/MdePkg/Library/BaseLib/Synchronization.c deleted file mode 100644 index 59919a7f03..0000000000 --- a/MdePkg/Library/BaseLib/Synchronization.c +++ /dev/null @@ -1,362 +0,0 @@ -/** @file - Implementation of synchronization functions. - - Copyright (c) 2006, Intel Corporation
- 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. - - Module Name: Synchronization.c - -**/ - -#include "BaseLibInternals.h" - -// -// SPIN_LOCK_RELEASED & SPIN_LOCK_ACQUIRED should belong to type "SPIN_LOCK". -// Here we use type-case "UINTN" to avoid "volatile" modifier on const integers. -// -#define SPIN_LOCK_RELEASED ((UINTN) 1) -#define SPIN_LOCK_ACQUIRED ((UINTN) 2) - -/** - Retrieves the architecture specific spin lock alignment requirements for - optimal spin lock performance. - - This function retrieves the spin lock alignment requirements for optimal - performance on a given CPU architecture. The spin lock alignment must be a - power of two and is returned by this function. If there are no alignment - requirements, then 1 must be returned. The spin lock synchronization - functions must function correctly if the spin lock size and alignment values - returned by this function are not used at all. These values are hints to the - consumers of the spin lock synchronization functions to obtain optimal spin - lock performance. - - @return The architecture specific spin lock alignment. - -**/ -UINTN -EFIAPI -GetSpinLockProperties ( - VOID - ) -{ - // @bug May use a PCD entry to determine this alignment. - return 32; -} - -/** - Initializes a spin lock to the released state and returns the spin lock. - - This function initializes the spin lock specified by SpinLock to the released - state, and returns SpinLock. Optimal performance can be achieved by calling - GetSpinLockProperties() to determine the size and alignment requirements for - SpinLock. - - If SpinLock is NULL, then ASSERT(). - - @param SpinLock A pointer to the spin lock to initialize to the released - state. - - @return SpinLock - -**/ -SPIN_LOCK * -EFIAPI -InitializeSpinLock ( - OUT SPIN_LOCK *SpinLock - ) -{ - ASSERT (SpinLock != NULL); - *SpinLock = SPIN_LOCK_RELEASED; - return SpinLock; -} - -/** - Waits until a spin lock can be placed in the acquired state. - - This function checks the state of the spin lock specified by SpinLock. If - SpinLock is in the released state, then this function places SpinLock in the - acquired state and returns SpinLock. Otherwise, this function waits - indefinitely for the spin lock to be released, and then places it in the - acquired state and returns SpinLock. All state transitions of SpinLock must - be performed using MP safe mechanisms. - - If SpinLock is NULL, then ASSERT(). - If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). - If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in - PcdSpinLockTimeout microseconds, then ASSERT(). - - @param SpinLock A pointer to the spin lock to place in the acquired state. - - @return SpinLock - -**/ -SPIN_LOCK * -EFIAPI -AcquireSpinLock ( - IN OUT SPIN_LOCK *SpinLock - ) -{ - UINT64 Tick; - UINT64 Start, End; - UINT64 Timeout; - - Tick = 0; - Start = 0; - End = 0; - if (PcdGet32 (PcdSpinLockTimeout) > 0) { - Tick = GetPerformanceCounter (); - Timeout = DivU64x32 ( - MultU64x32 ( - GetPerformanceCounterProperties (&Start, &End), - PcdGet32 (PcdSpinLockTimeout) - ), - 1000000 - ); - if (Start < End) { - Tick += Timeout; - } else { - Tick -= Timeout; - } - } - - while (!AcquireSpinLockOrFail (SpinLock)) { - CpuPause (); - ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ())); - } - return SpinLock; -} - -/** - Attempts to place a spin lock in the acquired state. - - This function checks the state of the spin lock specified by SpinLock. If - SpinLock is in the released state, then this function places SpinLock in the - acquired state and returns TRUE. Otherwise, FALSE is returned. All state - transitions of SpinLock must be performed using MP safe mechanisms. - - If SpinLock is NULL, then ASSERT(). - If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). - - @param SpinLock A pointer to the spin lock to place in the acquired state. - - @retval TRUE SpinLock was placed in the acquired state. - @retval FALSE SpinLock could not be acquired. - -**/ -BOOLEAN -EFIAPI -AcquireSpinLockOrFail ( - IN OUT SPIN_LOCK *SpinLock - ) -{ - SPIN_LOCK LockValue; - - ASSERT (SpinLock != NULL); - - LockValue = *SpinLock; - ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED); - - return (BOOLEAN)( - InterlockedCompareExchangePointer ( - (VOID**)SpinLock, - (VOID*)SPIN_LOCK_RELEASED, - (VOID*)SPIN_LOCK_ACQUIRED - ) == (VOID*)SPIN_LOCK_RELEASED - ); -} - -/** - Releases a spin lock. - - This function places the spin lock specified by SpinLock in the release state - and returns SpinLock. - - If SpinLock is NULL, then ASSERT(). - If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). - - @param SpinLock A pointer to the spin lock to release. - - @return SpinLock - -**/ -SPIN_LOCK * -EFIAPI -ReleaseSpinLock ( - IN OUT SPIN_LOCK *SpinLock - ) -{ - SPIN_LOCK LockValue; - - ASSERT (SpinLock != NULL); - - LockValue = *SpinLock; - ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED); - - *SpinLock = SPIN_LOCK_RELEASED; - return SpinLock; -} - -/** - 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. - - If Value is NULL, then ASSERT(). - - @param Value A pointer to the 32-bit value to increment. - - @return The incremented value. - -**/ -UINT32 -EFIAPI -InterlockedIncrement ( - IN UINT32 *Value - ) -{ - ASSERT (Value != NULL); - return InternalSyncIncrement (Value); -} - -/** - 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 decremented value. The decrement operation must be - performed using MP safe mechanisms. The state of the return value is not - guaranteed to be MP safe. - - If Value is NULL, then ASSERT(). - - @param Value A pointer to the 32-bit value to decrement. - - @return The decremented value. - -**/ -UINT32 -EFIAPI -InterlockedDecrement ( - IN UINT32 *Value - ) -{ - ASSERT (Value != NULL); - return InternalSyncDecrement (Value); -} - -/** - 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. - - If Value is NULL, then ASSERT(). - - @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 -InterlockedCompareExchange32 ( - IN OUT UINT32 *Value, - IN UINT32 CompareValue, - IN UINT32 ExchangeValue - ) -{ - ASSERT (Value != NULL); - return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue); -} - -/** - 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. - - If Value is NULL, then ASSERT(). - - @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 -InterlockedCompareExchange64 ( - IN OUT UINT64 *Value, - IN UINT64 CompareValue, - IN UINT64 ExchangeValue - ) -{ - ASSERT (Value != NULL); - return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue); -} - -/** - Performs an atomic compare exchange operation on a pointer value. - - Performs an atomic compare exchange operation on the pointer value 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 pointer value for the compare exchange - operation. - @param CompareValue Pointer value used in compare operation. - @param ExchangeValue Pointer value used in exchange operation. - -**/ -VOID * -EFIAPI -InterlockedCompareExchangePointer ( - IN OUT VOID **Value, - IN VOID *CompareValue, - IN VOID *ExchangeValue - ) -{ - UINT8 SizeOfValue; - - SizeOfValue = sizeof (*Value); - - switch (SizeOfValue) { - case sizeof (UINT32): - return (VOID*)(UINTN)InterlockedCompareExchange32 ( - (UINT32*)Value, - (UINT32)(UINTN)CompareValue, - (UINT32)(UINTN)ExchangeValue - ); - case sizeof (UINT64): - return (VOID*)(UINTN)InterlockedCompareExchange64 ( - (UINT64*)Value, - (UINT64)(UINTN)CompareValue, - (UINT64)(UINTN)ExchangeValue - ); - default: - ASSERT (FALSE); - return NULL; - } -} diff --git a/MdePkg/Library/BaseLib/SynchronizationGcc.c b/MdePkg/Library/BaseLib/SynchronizationGcc.c new file mode 100644 index 0000000000..9d57a1f34d --- /dev/null +++ b/MdePkg/Library/BaseLib/SynchronizationGcc.c @@ -0,0 +1,366 @@ +/** @file + Implementation of synchronization functions. + + Copyright (c) 2006 - 2007, Intel Corporation
+ 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. + + Module Name: SynchronizationGcc.c + +**/ + +#include "BaseLibInternals.h" + +// +// GCC inline assembly for Read Write Barrier +// +#define _ReadWriteBarrier() do { asm volatile ("": : : "memory"); } while(0) + +#define SPIN_LOCK_RELEASED ((UINTN) 1) +#define SPIN_LOCK_ACQUIRED ((UINTN) 2) + +/** + Retrieves the architecture specific spin lock alignment requirements for + optimal spin lock performance. + + This function retrieves the spin lock alignment requirements for optimal + performance on a given CPU architecture. The spin lock alignment must be a + power of two and is returned by this function. If there are no alignment + requirements, then 1 must be returned. The spin lock synchronization + functions must function correctly if the spin lock size and alignment values + returned by this function are not used at all. These values are hints to the + consumers of the spin lock synchronization functions to obtain optimal spin + lock performance. + + @return The architecture specific spin lock alignment. + +**/ +UINTN +EFIAPI +GetSpinLockProperties ( + VOID + ) +{ + // @bug May use a PCD entry to determine this alignment. + return 32; +} + +/** + Initializes a spin lock to the released state and returns the spin lock. + + This function initializes the spin lock specified by SpinLock to the released + state, and returns SpinLock. Optimal performance can be achieved by calling + GetSpinLockProperties() to determine the size and alignment requirements for + SpinLock. + + If SpinLock is NULL, then ASSERT(). + + @param SpinLock A pointer to the spin lock to initialize to the released + state. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +InitializeSpinLock ( + OUT SPIN_LOCK *SpinLock + ) +{ + ASSERT (SpinLock != NULL); + + _ReadWriteBarrier(); + *SpinLock = SPIN_LOCK_RELEASED; + _ReadWriteBarrier(); + + return SpinLock; +} + +/** + Waits until a spin lock can be placed in the acquired state. + + This function checks the state of the spin lock specified by SpinLock. If + SpinLock is in the released state, then this function places SpinLock in the + acquired state and returns SpinLock. Otherwise, this function waits + indefinitely for the spin lock to be released, and then places it in the + acquired state and returns SpinLock. All state transitions of SpinLock must + be performed using MP safe mechanisms. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in + PcdSpinLockTimeout microseconds, then ASSERT(). + + @param SpinLock A pointer to the spin lock to place in the acquired state. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +AcquireSpinLock ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + UINT64 Tick; + UINT64 Start, End; + UINT64 Timeout; + + Tick = 0; + Start = 0; + End = 0; + if (PcdGet32 (PcdSpinLockTimeout) > 0) { + Tick = GetPerformanceCounter (); + Timeout = DivU64x32 ( + MultU64x32 ( + GetPerformanceCounterProperties (&Start, &End), + PcdGet32 (PcdSpinLockTimeout) + ), + 1000000 + ); + if (Start < End) { + Tick += Timeout; + } else { + Tick -= Timeout; + } + } + + while (!AcquireSpinLockOrFail (SpinLock)) { + CpuPause (); + ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ())); + } + return SpinLock; +} + +/** + Attempts to place a spin lock in the acquired state. + + This function checks the state of the spin lock specified by SpinLock. If + SpinLock is in the released state, then this function places SpinLock in the + acquired state and returns TRUE. Otherwise, FALSE is returned. All state + transitions of SpinLock must be performed using MP safe mechanisms. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + + @param SpinLock A pointer to the spin lock to place in the acquired state. + + @retval TRUE SpinLock was placed in the acquired state. + @retval FALSE SpinLock could not be acquired. + +**/ +BOOLEAN +EFIAPI +AcquireSpinLockOrFail ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + VOID *Result; + + ASSERT (SpinLock != NULL); + ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED); + + _ReadWriteBarrier (); + Result = InterlockedCompareExchangePointer ( + (VOID**)SpinLock, + (VOID*)SPIN_LOCK_RELEASED, + (VOID*)SPIN_LOCK_ACQUIRED + ); + + _ReadWriteBarrier (); + return (BOOLEAN) (Result == (VOID*) SPIN_LOCK_RELEASED); +} + +/** + Releases a spin lock. + + This function places the spin lock specified by SpinLock in the release state + and returns SpinLock. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + + @param SpinLock A pointer to the spin lock to release. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +ReleaseSpinLock ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + ASSERT (SpinLock != NULL); + ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED); + + _ReadWriteBarrier (); + *SpinLock = SPIN_LOCK_RELEASED; + _ReadWriteBarrier (); + + return SpinLock; +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @param Value A pointer to the 32-bit value to increment. + + @return The incremented value. + +**/ +UINT32 +EFIAPI +InterlockedIncrement ( + IN UINT32 *Value + ) +{ + ASSERT (Value != NULL); + return InternalSyncIncrement (Value); +} + +/** + 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 decremented value. The decrement operation must be + performed using MP safe mechanisms. The state of the return value is not + guaranteed to be MP safe. + + If Value is NULL, then ASSERT(). + + @param Value A pointer to the 32-bit value to decrement. + + @return The decremented value. + +**/ +UINT32 +EFIAPI +InterlockedDecrement ( + IN UINT32 *Value + ) +{ + ASSERT (Value != NULL); + return InternalSyncDecrement (Value); +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @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 +InterlockedCompareExchange32 ( + IN OUT UINT32 *Value, + IN UINT32 CompareValue, + IN UINT32 ExchangeValue + ) +{ + ASSERT (Value != NULL); + return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue); +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @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 +InterlockedCompareExchange64 ( + IN OUT UINT64 *Value, + IN UINT64 CompareValue, + IN UINT64 ExchangeValue + ) +{ + ASSERT (Value != NULL); + return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue); +} + +/** + Performs an atomic compare exchange operation on a pointer value. + + Performs an atomic compare exchange operation on the pointer value 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 pointer value for the compare exchange + operation. + @param CompareValue Pointer value used in compare operation. + @param ExchangeValue Pointer value used in exchange operation. + +**/ +VOID * +EFIAPI +InterlockedCompareExchangePointer ( + IN OUT VOID **Value, + IN VOID *CompareValue, + IN VOID *ExchangeValue + ) +{ + UINT8 SizeOfValue; + + SizeOfValue = sizeof (*Value); + + switch (SizeOfValue) { + case sizeof (UINT32): + return (VOID*)(UINTN)InterlockedCompareExchange32 ( + (UINT32*)Value, + (UINT32)(UINTN)CompareValue, + (UINT32)(UINTN)ExchangeValue + ); + case sizeof (UINT64): + return (VOID*)(UINTN)InterlockedCompareExchange64 ( + (UINT64*)Value, + (UINT64)(UINTN)CompareValue, + (UINT64)(UINTN)ExchangeValue + ); + default: + ASSERT (FALSE); + return NULL; + } +} diff --git a/MdePkg/Library/BaseLib/SynchronizationMsc.c b/MdePkg/Library/BaseLib/SynchronizationMsc.c new file mode 100644 index 0000000000..fb10b5d01b --- /dev/null +++ b/MdePkg/Library/BaseLib/SynchronizationMsc.c @@ -0,0 +1,368 @@ +/** @file + Implementation of synchronization functions. + + Copyright (c) 2006 - 2007, Intel Corporation
+ 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. + + Module Name: SynchronizationMsc.c + +**/ + +#include "BaseLibInternals.h" + +// +// Microsoft Visual Studio 7.1 Function Prototypes for read write barrier Intrinsics +// +void _ReadWriteBarrier (void); +#pragma intrinsic(_ReadWriteBarrier) + + +#define SPIN_LOCK_RELEASED ((UINTN) 1) +#define SPIN_LOCK_ACQUIRED ((UINTN) 2) + +/** + Retrieves the architecture specific spin lock alignment requirements for + optimal spin lock performance. + + This function retrieves the spin lock alignment requirements for optimal + performance on a given CPU architecture. The spin lock alignment must be a + power of two and is returned by this function. If there are no alignment + requirements, then 1 must be returned. The spin lock synchronization + functions must function correctly if the spin lock size and alignment values + returned by this function are not used at all. These values are hints to the + consumers of the spin lock synchronization functions to obtain optimal spin + lock performance. + + @return The architecture specific spin lock alignment. + +**/ +UINTN +EFIAPI +GetSpinLockProperties ( + VOID + ) +{ + // @bug May use a PCD entry to determine this alignment. + return 32; +} + +/** + Initializes a spin lock to the released state and returns the spin lock. + + This function initializes the spin lock specified by SpinLock to the released + state, and returns SpinLock. Optimal performance can be achieved by calling + GetSpinLockProperties() to determine the size and alignment requirements for + SpinLock. + + If SpinLock is NULL, then ASSERT(). + + @param SpinLock A pointer to the spin lock to initialize to the released + state. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +InitializeSpinLock ( + OUT SPIN_LOCK *SpinLock + ) +{ + ASSERT (SpinLock != NULL); + + _ReadWriteBarrier(); + *SpinLock = SPIN_LOCK_RELEASED; + _ReadWriteBarrier(); + + return SpinLock; +} + +/** + Waits until a spin lock can be placed in the acquired state. + + This function checks the state of the spin lock specified by SpinLock. If + SpinLock is in the released state, then this function places SpinLock in the + acquired state and returns SpinLock. Otherwise, this function waits + indefinitely for the spin lock to be released, and then places it in the + acquired state and returns SpinLock. All state transitions of SpinLock must + be performed using MP safe mechanisms. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in + PcdSpinLockTimeout microseconds, then ASSERT(). + + @param SpinLock A pointer to the spin lock to place in the acquired state. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +AcquireSpinLock ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + UINT64 Tick; + UINT64 Start, End; + UINT64 Timeout; + + Tick = 0; + Start = 0; + End = 0; + if (PcdGet32 (PcdSpinLockTimeout) > 0) { + Tick = GetPerformanceCounter (); + Timeout = DivU64x32 ( + MultU64x32 ( + GetPerformanceCounterProperties (&Start, &End), + PcdGet32 (PcdSpinLockTimeout) + ), + 1000000 + ); + if (Start < End) { + Tick += Timeout; + } else { + Tick -= Timeout; + } + } + + while (!AcquireSpinLockOrFail (SpinLock)) { + CpuPause (); + ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ())); + } + return SpinLock; +} + +/** + Attempts to place a spin lock in the acquired state. + + This function checks the state of the spin lock specified by SpinLock. If + SpinLock is in the released state, then this function places SpinLock in the + acquired state and returns TRUE. Otherwise, FALSE is returned. All state + transitions of SpinLock must be performed using MP safe mechanisms. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + + @param SpinLock A pointer to the spin lock to place in the acquired state. + + @retval TRUE SpinLock was placed in the acquired state. + @retval FALSE SpinLock could not be acquired. + +**/ +BOOLEAN +EFIAPI +AcquireSpinLockOrFail ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + VOID *Result; + + ASSERT (SpinLock != NULL); + ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED); + + _ReadWriteBarrier (); + Result = InterlockedCompareExchangePointer ( + (VOID**)SpinLock, + (VOID*)SPIN_LOCK_RELEASED, + (VOID*)SPIN_LOCK_ACQUIRED + ); + + _ReadWriteBarrier (); + return (BOOLEAN) (Result == (VOID*) SPIN_LOCK_RELEASED); +} + +/** + Releases a spin lock. + + This function places the spin lock specified by SpinLock in the release state + and returns SpinLock. + + If SpinLock is NULL, then ASSERT(). + If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). + + @param SpinLock A pointer to the spin lock to release. + + @return SpinLock + +**/ +SPIN_LOCK * +EFIAPI +ReleaseSpinLock ( + IN OUT SPIN_LOCK *SpinLock + ) +{ + ASSERT (SpinLock != NULL); + ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED); + + _ReadWriteBarrier (); + *SpinLock = SPIN_LOCK_RELEASED; + _ReadWriteBarrier (); + + return SpinLock; +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @param Value A pointer to the 32-bit value to increment. + + @return The incremented value. + +**/ +UINT32 +EFIAPI +InterlockedIncrement ( + IN UINT32 *Value + ) +{ + ASSERT (Value != NULL); + return InternalSyncIncrement (Value); +} + +/** + 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 decremented value. The decrement operation must be + performed using MP safe mechanisms. The state of the return value is not + guaranteed to be MP safe. + + If Value is NULL, then ASSERT(). + + @param Value A pointer to the 32-bit value to decrement. + + @return The decremented value. + +**/ +UINT32 +EFIAPI +InterlockedDecrement ( + IN UINT32 *Value + ) +{ + ASSERT (Value != NULL); + return InternalSyncDecrement (Value); +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @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 +InterlockedCompareExchange32 ( + IN OUT UINT32 *Value, + IN UINT32 CompareValue, + IN UINT32 ExchangeValue + ) +{ + ASSERT (Value != NULL); + return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue); +} + +/** + 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. + + If Value is NULL, then ASSERT(). + + @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 +InterlockedCompareExchange64 ( + IN OUT UINT64 *Value, + IN UINT64 CompareValue, + IN UINT64 ExchangeValue + ) +{ + ASSERT (Value != NULL); + return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue); +} + +/** + Performs an atomic compare exchange operation on a pointer value. + + Performs an atomic compare exchange operation on the pointer value 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 pointer value for the compare exchange + operation. + @param CompareValue Pointer value used in compare operation. + @param ExchangeValue Pointer value used in exchange operation. + +**/ +VOID * +EFIAPI +InterlockedCompareExchangePointer ( + IN OUT VOID **Value, + IN VOID *CompareValue, + IN VOID *ExchangeValue + ) +{ + UINT8 SizeOfValue; + + SizeOfValue = sizeof (*Value); + + switch (SizeOfValue) { + case sizeof (UINT32): + return (VOID*)(UINTN)InterlockedCompareExchange32 ( + (UINT32*)Value, + (UINT32)(UINTN)CompareValue, + (UINT32)(UINTN)ExchangeValue + ); + case sizeof (UINT64): + return (VOID*)(UINTN)InterlockedCompareExchange64 ( + (UINT64*)Value, + (UINT64)(UINTN)CompareValue, + (UINT64)(UINTN)ExchangeValue + ); + default: + ASSERT (FALSE); + return NULL; + } +}