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[mirror_edk2.git] / MdePkg / Library / BaseLib / Synchronization.c
1 /** @file
2 Implementation of synchronization functions.
3
4 Copyright (c) 2006, Intel Corporation<BR>
5 All rights reserved. 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
9
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.
12
13 Module Name: Synchronization.c
14
15 **/
16
17 #define SPIN_LOCK_RELEASED ((SPIN_LOCK)1)
18 #define SPIN_LOCK_ACQUIRED ((SPIN_LOCK)2)
19
20 /**
21 Performs an atomic increment of an 32-bit unsigned integer.
22
23 Performs an atomic increment of the 32-bit unsigned integer specified by
24 Value and returns the incremented value. The increment operation must be
25 performed using MP safe mechanisms. The state of the return value is not
26 guaranteed to be MP safe.
27
28 @param Value A pointer to the 32-bit value to increment.
29
30 @return The incremented value.
31
32 **/
33 UINT32
34 EFIAPI
35 InternalSyncIncrement (
36 IN volatile UINT32 *Value
37 );
38
39 /**
40 Performs an atomic decrement of an 32-bit unsigned integer.
41
42 Performs an atomic decrement of the 32-bit unsigned integer specified by
43 Value and returns the decrement value. The decrement operation must be
44 performed using MP safe mechanisms. The state of the return value is not
45 guaranteed to be MP safe.
46
47 @param Value A pointer to the 32-bit value to decrement.
48
49 @return The decrement value.
50
51 **/
52 UINT32
53 EFIAPI
54 InternalSyncDecrement (
55 IN volatile UINT32 *Value
56 );
57
58 /**
59 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
60
61 Performs an atomic compare exchange operation on the 32-bit unsigned integer
62 specified by Value. If Value is equal to CompareValue, then Value is set to
63 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
64 then Value is returned. The compare exchange operation must be performed using
65 MP safe mechanisms.
66
67 @param Value A pointer to the 32-bit value for the compare exchange
68 operation.
69 @param CompareValue 32-bit value used in compare operation.
70 @param ExchangeValue 32-bit value used in exchange operation.
71
72 @return The original *Value before exchange.
73
74 **/
75 UINT32
76 EFIAPI
77 InternalSyncCompareExchange32 (
78 IN volatile UINT32 *Value,
79 IN UINT32 CompareValue,
80 IN UINT32 ExchangeValue
81 );
82
83 /**
84 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
85
86 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
87 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
88 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
89 The compare exchange operation must be performed using MP safe mechanisms.
90
91 @param Value A pointer to the 64-bit value for the compare exchange
92 operation.
93 @param CompareValue 64-bit value used in compare operation.
94 @param ExchangeValue 64-bit value used in exchange operation.
95
96 @return The original *Value before exchange.
97
98 **/
99 UINT64
100 EFIAPI
101 InternalSyncCompareExchange64 (
102 IN volatile UINT64 *Value,
103 IN UINT64 CompareValue,
104 IN UINT64 ExchangeValue
105 );
106
107 /**
108 Retrieves the architecture specific spin lock alignment requirements for
109 optimal spin lock performance.
110
111 This function retrieves the spin lock alignment requirements for optimal
112 performance on a given CPU architecture. The spin lock alignment must be a
113 power of two and is returned by this function. If there are no alignment
114 requirements, then 1 must be returned. The spin lock synchronization
115 functions must function correctly if the spin lock size and alignment values
116 returned by this function are not used at all. These values are hints to the
117 consumers of the spin lock synchronization functions to obtain optimal spin
118 lock performance.
119
120 @return The architecture specific spin lock alignment.
121
122 **/
123 UINTN
124 EFIAPI
125 GetSpinLockProperties (
126 VOID
127 )
128 {
129 // @bug May use a PCD entry to determine this alignment.
130 return 32;
131 }
132
133 /**
134 Initializes a spin lock to the released state and returns the spin lock.
135
136 This function initializes the spin lock specified by SpinLock to the released
137 state, and returns SpinLock. Optimal performance can be achieved by calling
138 GetSpinLockProperties() to determine the size and alignment requirements for
139 SpinLock.
140
141 If SpinLock is NULL, then ASSERT().
142
143 @param SpinLock A pointer to the spin lock to initialize to the released
144 state.
145
146 @return SpinLock
147
148 **/
149 SPIN_LOCK *
150 EFIAPI
151 InitializeSpinLock (
152 OUT SPIN_LOCK *SpinLock
153 )
154 {
155 ASSERT (SpinLock != NULL);
156 *SpinLock = SPIN_LOCK_RELEASED;
157 return SpinLock;
158 }
159
160 /**
161 Waits until a spin lock can be placed in the acquired state.
162
163 This function checks the state of the spin lock specified by SpinLock. If
164 SpinLock is in the released state, then this function places SpinLock in the
165 acquired state and returns SpinLock. Otherwise, this function waits
166 indefinitely for the spin lock to be released, and then places it in the
167 acquired state and returns SpinLock. All state transitions of SpinLock must
168 be performed using MP safe mechanisms.
169
170 If SpinLock is NULL, then ASSERT().
171 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
172 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
173 PcdSpinLockTimeout microseconds, then ASSERT().
174
175 @param SpinLock A pointer to the spin lock to place in the acquired state.
176
177 @return SpinLock
178
179 **/
180 SPIN_LOCK *
181 EFIAPI
182 AcquireSpinLock (
183 IN OUT SPIN_LOCK *SpinLock
184 )
185 {
186 UINT64 Tick;
187 UINT64 Start, End;
188 UINT64 Timeout;
189
190 Tick = 0;
191 Start = 0;
192 End = 0;
193 if (PcdGet32 (PcdSpinLockTimeout) > 0) {
194 Tick = GetPerformanceCounter ();
195 Timeout = DivU64x32 (
196 MultU64x32 (
197 GetPerformanceCounterProperties (&Start, &End),
198 PcdGet32 (PcdSpinLockTimeout)
199 ),
200 1000000
201 );
202 if (Start < End) {
203 Tick += Timeout;
204 } else {
205 Tick -= Timeout;
206 }
207 }
208
209 while (!AcquireSpinLockOrFail (SpinLock)) {
210 CpuPause ();
211 ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));
212 }
213 return SpinLock;
214 }
215
216 /**
217 Attempts to place a spin lock in the acquired state.
218
219 This function checks the state of the spin lock specified by SpinLock. If
220 SpinLock is in the released state, then this function places SpinLock in the
221 acquired state and returns TRUE. Otherwise, FALSE is returned. All state
222 transitions of SpinLock must be performed using MP safe mechanisms.
223
224 If SpinLock is NULL, then ASSERT().
225 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
226
227 @param SpinLock A pointer to the spin lock to place in the acquired state.
228
229 @retval TRUE SpinLock was placed in the acquired state.
230 @retval FALSE SpinLock could not be acquired.
231
232 **/
233 BOOLEAN
234 EFIAPI
235 AcquireSpinLockOrFail (
236 IN OUT SPIN_LOCK *SpinLock
237 )
238 {
239 SPIN_LOCK LockValue;
240
241 ASSERT (SpinLock != NULL);
242
243 LockValue = *SpinLock;
244 ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);
245
246 return (BOOLEAN)(
247 InterlockedCompareExchangePointer (
248 (VOID**)SpinLock,
249 (VOID*)SPIN_LOCK_RELEASED,
250 (VOID*)SPIN_LOCK_ACQUIRED
251 ) == (VOID*)SPIN_LOCK_RELEASED
252 );
253 }
254
255 /**
256 Releases a spin lock.
257
258 This function places the spin lock specified by SpinLock in the release state
259 and returns SpinLock.
260
261 If SpinLock is NULL, then ASSERT().
262 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
263
264 @param SpinLock A pointer to the spin lock to release.
265
266 @return SpinLock
267
268 **/
269 SPIN_LOCK *
270 EFIAPI
271 ReleaseSpinLock (
272 IN OUT SPIN_LOCK *SpinLock
273 )
274 {
275 SPIN_LOCK LockValue;
276
277 ASSERT (SpinLock != NULL);
278
279 LockValue = *SpinLock;
280 ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);
281
282 *SpinLock = SPIN_LOCK_RELEASED;
283 return SpinLock;
284 }
285
286 /**
287 Performs an atomic increment of an 32-bit unsigned integer.
288
289 Performs an atomic increment of the 32-bit unsigned integer specified by
290 Value and returns the incremented value. The increment operation must be
291 performed using MP safe mechanisms. The state of the return value is not
292 guaranteed to be MP safe.
293
294 If Value is NULL, then ASSERT().
295
296 @param Value A pointer to the 32-bit value to increment.
297
298 @return The incremented value.
299
300 **/
301 UINT32
302 EFIAPI
303 InterlockedIncrement (
304 IN UINT32 *Value
305 )
306 {
307 ASSERT (Value != NULL);
308 return InternalSyncIncrement (Value);
309 }
310
311 /**
312 Performs an atomic decrement of an 32-bit unsigned integer.
313
314 Performs an atomic decrement of the 32-bit unsigned integer specified by
315 Value and returns the decremented value. The decrement operation must be
316 performed using MP safe mechanisms. The state of the return value is not
317 guaranteed to be MP safe.
318
319 If Value is NULL, then ASSERT().
320
321 @param Value A pointer to the 32-bit value to decrement.
322
323 @return The decremented value.
324
325 **/
326 UINT32
327 EFIAPI
328 InterlockedDecrement (
329 IN UINT32 *Value
330 )
331 {
332 ASSERT (Value != NULL);
333 return InternalSyncDecrement (Value);
334 }
335
336 /**
337 Performs an atomic compare exchange operation on a 32-bit unsigned integer.
338
339 Performs an atomic compare exchange operation on the 32-bit unsigned integer
340 specified by Value. If Value is equal to CompareValue, then Value is set to
341 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,
342 then Value is returned. The compare exchange operation must be performed using
343 MP safe mechanisms.
344
345 If Value is NULL, then ASSERT().
346
347 @param Value A pointer to the 32-bit value for the compare exchange
348 operation.
349 @param CompareValue 32-bit value used in compare operation.
350 @param ExchangeValue 32-bit value used in exchange operation.
351
352 @return The original *Value before exchange.
353
354 **/
355 UINT32
356 EFIAPI
357 InterlockedCompareExchange32 (
358 IN OUT UINT32 *Value,
359 IN UINT32 CompareValue,
360 IN UINT32 ExchangeValue
361 )
362 {
363 ASSERT (Value != NULL);
364 return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);
365 }
366
367 /**
368 Performs an atomic compare exchange operation on a 64-bit unsigned integer.
369
370 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
371 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and
372 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.
373 The compare exchange operation must be performed using MP safe mechanisms.
374
375 If Value is NULL, then ASSERT().
376
377 @param Value A pointer to the 64-bit value for the compare exchange
378 operation.
379 @param CompareValue 64-bit value used in compare operation.
380 @param ExchangeValue 64-bit value used in exchange operation.
381
382 @return The original *Value before exchange.
383
384 **/
385 UINT64
386 EFIAPI
387 InterlockedCompareExchange64 (
388 IN OUT UINT64 *Value,
389 IN UINT64 CompareValue,
390 IN UINT64 ExchangeValue
391 )
392 {
393 ASSERT (Value != NULL);
394 return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);
395 }
396
397 /**
398 Performs an atomic compare exchange operation on a pointer value.
399
400 Performs an atomic compare exchange operation on the pointer value specified
401 by Value. If Value is equal to CompareValue, then Value is set to
402 ExchangeValue and CompareValue is returned. If Value is not equal to
403 CompareValue, then Value is returned. The compare exchange operation must be
404 performed using MP safe mechanisms.
405
406 If Value is NULL, then ASSERT().
407
408 @param Value A pointer to the pointer value for the compare exchange
409 operation.
410 @param CompareValue Pointer value used in compare operation.
411 @param ExchangeValue Pointer value used in exchange operation.
412
413 **/
414 VOID *
415 EFIAPI
416 InterlockedCompareExchangePointer (
417 IN OUT VOID **Value,
418 IN VOID *CompareValue,
419 IN VOID *ExchangeValue
420 )
421 {
422 switch (sizeof (*Value)) {
423 case sizeof (UINT32):
424 return (VOID*)(UINTN)InterlockedCompareExchange32 (
425 (UINT32*)Value,
426 (UINT32)(UINTN)CompareValue,
427 (UINT32)(UINTN)ExchangeValue
428 );
429 case sizeof (UINT64):
430 return (VOID*)(UINTN)InterlockedCompareExchange64 (
431 (UINT64*)Value,
432 (UINT64)(UINTN)CompareValue,
433 (UINT64)(UINTN)ExchangeValue
434 );
435 default:
436 ASSERT (FALSE);
437 return NULL;
438 }
439 }