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2 Implementation of synchronization functions.
4 Copyright (c) 2006 - 2016, Intel Corporation. All rights reserved.<BR>
5 This program and the accompanying materials
6 are licensed and made available under the terms and conditions of the BSD License
7 which accompanies this distribution. The full text of the license may be found at
8 http://opensource.org/licenses/bsd-license.php.
10 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
11 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
15 #include "BaseSynchronizationLibInternals.h"
17 #define SPIN_LOCK_RELEASED ((UINTN) 1)
18 #define SPIN_LOCK_ACQUIRED ((UINTN) 2)
21 Retrieves the architecture specific spin lock alignment requirements for
22 optimal spin lock performance.
24 This function retrieves the spin lock alignment requirements for optimal
25 performance on a given CPU architecture. The spin lock alignment is byte alignment.
26 It must be a power of two and is returned by this function. If there are no alignment
27 requirements, then 1 must be returned. The spin lock synchronization
28 functions must function correctly if the spin lock size and alignment values
29 returned by this function are not used at all. These values are hints to the
30 consumers of the spin lock synchronization functions to obtain optimal spin
33 @return The architecture specific spin lock alignment.
38 GetSpinLockProperties (
46 Initializes a spin lock to the released state and returns the spin lock.
48 This function initializes the spin lock specified by SpinLock to the released
49 state, and returns SpinLock. Optimal performance can be achieved by calling
50 GetSpinLockProperties() to determine the size and alignment requirements for
53 If SpinLock is NULL, then ASSERT().
55 @param SpinLock A pointer to the spin lock to initialize to the released
58 @return SpinLock is in release state.
64 OUT SPIN_LOCK
*SpinLock
67 ASSERT (SpinLock
!= NULL
);
68 *SpinLock
= SPIN_LOCK_RELEASED
;
73 Waits until a spin lock can be placed in the acquired state.
75 This function checks the state of the spin lock specified by SpinLock. If
76 SpinLock is in the released state, then this function places SpinLock in the
77 acquired state and returns SpinLock. Otherwise, this function waits
78 indefinitely for the spin lock to be released, and then places it in the
79 acquired state and returns SpinLock. All state transitions of SpinLock must
80 be performed using MP safe mechanisms.
82 If SpinLock is NULL, then ASSERT().
83 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
84 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
85 PcdSpinLockTimeout microseconds, then ASSERT().
87 @param SpinLock A pointer to the spin lock to place in the acquired state.
89 @return SpinLock acquired the lock.
95 IN OUT SPIN_LOCK
*SpinLock
107 if (PcdGet32 (PcdSpinLockTimeout
) == 0) {
108 while (!AcquireSpinLockOrFail (SpinLock
)) {
111 } else if (!AcquireSpinLockOrFail (SpinLock
)) {
113 // Get the current timer value
115 Current
= GetPerformanceCounter();
118 // Initialize local variables
125 // Retrieve the performance counter properties and compute the number of performance
126 // counter ticks required to reach the timeout
128 Timeout
= DivU64x32 (
130 GetPerformanceCounterProperties (&Start
, &End
),
131 PcdGet32 (PcdSpinLockTimeout
)
141 while (!AcquireSpinLockOrFail (SpinLock
)) {
144 Current
= GetPerformanceCounter();
145 Delta
= (INT64
) (Current
- Previous
);
153 ASSERT (Total
< Timeout
);
160 Attempts to place a spin lock in the acquired state.
162 This function checks the state of the spin lock specified by SpinLock. If
163 SpinLock is in the released state, then this function places SpinLock in the
164 acquired state and returns TRUE. Otherwise, FALSE is returned. All state
165 transitions of SpinLock must be performed using MP safe mechanisms.
167 If SpinLock is NULL, then ASSERT().
168 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
170 @param SpinLock A pointer to the spin lock to place in the acquired state.
172 @retval TRUE SpinLock was placed in the acquired state.
173 @retval FALSE SpinLock could not be acquired.
178 AcquireSpinLockOrFail (
179 IN OUT SPIN_LOCK
*SpinLock
184 ASSERT (SpinLock
!= NULL
);
186 LockValue
= *SpinLock
;
187 ASSERT (SPIN_LOCK_ACQUIRED
== LockValue
|| SPIN_LOCK_RELEASED
== LockValue
);
190 InterlockedCompareExchangePointer (
192 (VOID
*)SPIN_LOCK_RELEASED
,
193 (VOID
*)SPIN_LOCK_ACQUIRED
194 ) == (VOID
*)SPIN_LOCK_RELEASED
199 Releases a spin lock.
201 This function places the spin lock specified by SpinLock in the release state
202 and returns SpinLock.
204 If SpinLock is NULL, then ASSERT().
205 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
207 @param SpinLock A pointer to the spin lock to release.
209 @return SpinLock released lock.
215 IN OUT SPIN_LOCK
*SpinLock
220 ASSERT (SpinLock
!= NULL
);
222 LockValue
= *SpinLock
;
223 ASSERT (SPIN_LOCK_ACQUIRED
== LockValue
|| SPIN_LOCK_RELEASED
== LockValue
);
225 *SpinLock
= SPIN_LOCK_RELEASED
;
230 Performs an atomic increment of an 32-bit unsigned integer.
232 Performs an atomic increment of the 32-bit unsigned integer specified by
233 Value and returns the incremented value. The increment operation must be
234 performed using MP safe mechanisms. The state of the return value is not
235 guaranteed to be MP safe.
237 If Value is NULL, then ASSERT().
239 @param Value A pointer to the 32-bit value to increment.
241 @return The incremented value.
246 InterlockedIncrement (
250 ASSERT (Value
!= NULL
);
251 return InternalSyncIncrement (Value
);
255 Performs an atomic decrement of an 32-bit unsigned integer.
257 Performs an atomic decrement of the 32-bit unsigned integer specified by
258 Value and returns the decremented value. The decrement operation must be
259 performed using MP safe mechanisms. The state of the return value is not
260 guaranteed to be MP safe.
262 If Value is NULL, then ASSERT().
264 @param Value A pointer to the 32-bit value to decrement.
266 @return The decremented value.
271 InterlockedDecrement (
275 ASSERT (Value
!= NULL
);
276 return InternalSyncDecrement (Value
);
280 Performs an atomic compare exchange operation on a 16-bit unsigned integer.
282 Performs an atomic compare exchange operation on the 16-bit unsigned integer
283 specified by Value. If Value is equal to CompareValue, then Value is set to
284 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
285 then Value is returned. The compare exchange operation must be performed using
288 If Value is NULL, then ASSERT().
290 @param Value A pointer to the 16-bit value for the compare exchange
292 @param CompareValue 16-bit value used in compare operation.
293 @param ExchangeValue 16-bit value used in exchange operation.
295 @return The original *Value before exchange.
300 InterlockedCompareExchange16 (
301 IN OUT UINT16
*Value
,
302 IN UINT16 CompareValue
,
303 IN UINT16 ExchangeValue
306 ASSERT (Value
!= NULL
);
307 return InternalSyncCompareExchange16 (Value
, CompareValue
, ExchangeValue
);
311 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
313 Performs an atomic compare exchange operation on the 32-bit unsigned integer
314 specified by Value. If Value is equal to CompareValue, then Value is set to
315 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
316 then Value is returned. The compare exchange operation must be performed using
319 If Value is NULL, then ASSERT().
321 @param Value A pointer to the 32-bit value for the compare exchange
323 @param CompareValue 32-bit value used in compare operation.
324 @param ExchangeValue 32-bit value used in exchange operation.
326 @return The original *Value before exchange.
331 InterlockedCompareExchange32 (
332 IN OUT UINT32
*Value
,
333 IN UINT32 CompareValue
,
334 IN UINT32 ExchangeValue
337 ASSERT (Value
!= NULL
);
338 return InternalSyncCompareExchange32 (Value
, CompareValue
, ExchangeValue
);
342 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
344 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
345 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
346 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
347 The compare exchange operation must be performed using MP safe mechanisms.
349 If Value is NULL, then ASSERT().
351 @param Value A pointer to the 64-bit value for the compare exchange
353 @param CompareValue 64-bit value used in compare operation.
354 @param ExchangeValue 64-bit value used in exchange operation.
356 @return The original *Value before exchange.
361 InterlockedCompareExchange64 (
362 IN OUT UINT64
*Value
,
363 IN UINT64 CompareValue
,
364 IN UINT64 ExchangeValue
367 ASSERT (Value
!= NULL
);
368 return InternalSyncCompareExchange64 (Value
, CompareValue
, ExchangeValue
);
372 Performs an atomic compare exchange operation on a pointer value.
374 Performs an atomic compare exchange operation on the pointer value specified
375 by Value. If Value is equal to CompareValue, then Value is set to
376 ExchangeValue and CompareValue is returned. If Value is not equal to
377 CompareValue, then Value is returned. The compare exchange operation must be
378 performed using MP safe mechanisms.
380 If Value is NULL, then ASSERT().
382 @param Value A pointer to the pointer value for the compare exchange
384 @param CompareValue Pointer value used in compare operation.
385 @param ExchangeValue Pointer value used in exchange operation.
387 @return The original *Value before exchange.
391 InterlockedCompareExchangePointer (
393 IN VOID
*CompareValue
,
394 IN VOID
*ExchangeValue
399 SizeOfValue
= sizeof (*Value
);
401 switch (SizeOfValue
) {
402 case sizeof (UINT32
):
403 return (VOID
*)(UINTN
)InterlockedCompareExchange32 (
405 (UINT32
)(UINTN
)CompareValue
,
406 (UINT32
)(UINTN
)ExchangeValue
408 case sizeof (UINT64
):
409 return (VOID
*)(UINTN
)InterlockedCompareExchange64 (
411 (UINT64
)(UINTN
)CompareValue
,
412 (UINT64
)(UINTN
)ExchangeValue