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1 | /** @file\r |
2 | Implementation of synchronization functions.\r |
3 | \r |
4 | Copyright (c) 2006, Intel Corporation<BR>\r |
5 | All rights reserved. This program and the accompanying materials\r |
6 | are licensed and made available under the terms and conditions of the BSD License\r |
7 | which accompanies this distribution. The full text of the license may be found at\r |
8 | http://opensource.org/licenses/bsd-license.php\r |
9 | \r |
10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r |
11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r |
12 | \r |
13 | Module Name: Synchronization.c\r |
14 | \r |
15 | **/\r |
16 | \r |
27787243 |
17 | #define SPIN_LOCK_RELEASED ((SPIN_LOCK)1)\r |
18 | #define SPIN_LOCK_ACQUIRED ((SPIN_LOCK)2)\r |
878ddf1f |
19 | \r |
1ea5ca46 |
20 | /**\r |
21 | Performs an atomic increment of an 32-bit unsigned integer.\r |
22 | \r |
23 | Performs an atomic increment of the 32-bit unsigned integer specified by\r |
24 | Value and returns the incremented value. The increment operation must be\r |
25 | performed using MP safe mechanisms. The state of the return value is not\r |
26 | guaranteed to be MP safe.\r |
27 | \r |
28 | @param Value A pointer to the 32-bit value to increment.\r |
29 | \r |
30 | @return The incremented value.\r |
31 | \r |
32 | **/\r |
878ddf1f |
33 | UINT32\r |
34 | EFIAPI\r |
35 | InternalSyncIncrement (\r |
36 | IN volatile UINT32 *Value\r |
37 | );\r |
38 | \r |
1ea5ca46 |
39 | /**\r |
40 | Performs an atomic decrement of an 32-bit unsigned integer.\r |
41 | \r |
42 | Performs an atomic decrement of the 32-bit unsigned integer specified by\r |
43 | Value and returns the decrement value. The decrement operation must be\r |
44 | performed using MP safe mechanisms. The state of the return value is not\r |
45 | guaranteed to be MP safe.\r |
46 | \r |
47 | @param Value A pointer to the 32-bit value to decrement.\r |
48 | \r |
49 | @return The decrement value.\r |
50 | \r |
51 | **/\r |
878ddf1f |
52 | UINT32\r |
53 | EFIAPI\r |
54 | InternalSyncDecrement (\r |
55 | IN volatile UINT32 *Value\r |
56 | );\r |
57 | \r |
1ea5ca46 |
58 | /**\r |
59 | Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r |
60 | \r |
61 | Performs an atomic compare exchange operation on the 32-bit unsigned integer\r |
62 | specified by Value. If Value is equal to CompareValue, then Value is set to \r |
63 | ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r |
64 | then Value is returned. The compare exchange operation must be performed using \r |
65 | MP safe mechanisms.\r |
66 | \r |
67 | @param Value A pointer to the 32-bit value for the compare exchange\r |
68 | operation.\r |
69 | @param CompareValue 32-bit value used in compare operation.\r |
70 | @param ExchangeValue 32-bit value used in exchange operation.\r |
71 | \r |
72 | @return The original *Value before exchange.\r |
73 | \r |
74 | **/\r |
878ddf1f |
75 | UINT32\r |
76 | EFIAPI\r |
77 | InternalSyncCompareExchange32 (\r |
78 | IN volatile UINT32 *Value,\r |
79 | IN UINT32 CompareValue,\r |
80 | IN UINT32 ExchangeValue\r |
81 | );\r |
82 | \r |
1ea5ca46 |
83 | /**\r |
84 | Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r |
85 | \r |
86 | Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r |
87 | by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and \r |
88 | CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. \r |
89 | The compare exchange operation must be performed using MP safe mechanisms.\r |
90 | \r |
91 | @param Value A pointer to the 64-bit value for the compare exchange\r |
92 | operation.\r |
93 | @param CompareValue 64-bit value used in compare operation.\r |
94 | @param ExchangeValue 64-bit value used in exchange operation.\r |
95 | \r |
96 | @return The original *Value before exchange.\r |
97 | \r |
98 | **/\r |
878ddf1f |
99 | UINT64\r |
100 | EFIAPI\r |
101 | InternalSyncCompareExchange64 (\r |
102 | IN volatile UINT64 *Value,\r |
103 | IN UINT64 CompareValue,\r |
104 | IN UINT64 ExchangeValue\r |
105 | );\r |
106 | \r |
107 | /**\r |
108 | Retrieves the architecture specific spin lock alignment requirements for\r |
109 | optimal spin lock performance.\r |
110 | \r |
111 | This function retrieves the spin lock alignment requirements for optimal\r |
112 | performance on a given CPU architecture. The spin lock alignment must be a\r |
113 | power of two and is returned by this function. If there are no alignment\r |
114 | requirements, then 1 must be returned. The spin lock synchronization\r |
115 | functions must function correctly if the spin lock size and alignment values\r |
116 | returned by this function are not used at all. These values are hints to the\r |
117 | consumers of the spin lock synchronization functions to obtain optimal spin\r |
118 | lock performance.\r |
119 | \r |
120 | @return The architecture specific spin lock alignment.\r |
121 | \r |
122 | **/\r |
123 | UINTN\r |
124 | EFIAPI\r |
125 | GetSpinLockProperties (\r |
126 | VOID\r |
127 | )\r |
128 | {\r |
129 | // @bug May use a PCD entry to determine this alignment.\r |
130 | return 32;\r |
131 | }\r |
132 | \r |
133 | /**\r |
134 | Initializes a spin lock to the released state and returns the spin lock.\r |
135 | \r |
136 | This function initializes the spin lock specified by SpinLock to the released\r |
137 | state, and returns SpinLock. Optimal performance can be achieved by calling\r |
138 | GetSpinLockProperties() to determine the size and alignment requirements for\r |
139 | SpinLock.\r |
140 | \r |
141 | If SpinLock is NULL, then ASSERT().\r |
142 | \r |
143 | @param SpinLock A pointer to the spin lock to initialize to the released\r |
144 | state.\r |
145 | \r |
146 | @return SpinLock\r |
147 | \r |
148 | **/\r |
149 | SPIN_LOCK *\r |
150 | EFIAPI\r |
151 | InitializeSpinLock (\r |
152 | OUT SPIN_LOCK *SpinLock\r |
153 | )\r |
154 | {\r |
155 | ASSERT (SpinLock != NULL);\r |
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156 | *SpinLock = SPIN_LOCK_RELEASED;\r |
878ddf1f |
157 | return SpinLock;\r |
158 | }\r |
159 | \r |
160 | /**\r |
161 | Waits until a spin lock can be placed in the acquired state.\r |
162 | \r |
163 | This function checks the state of the spin lock specified by SpinLock. If\r |
164 | SpinLock is in the released state, then this function places SpinLock in the\r |
165 | acquired state and returns SpinLock. Otherwise, this function waits\r |
166 | indefinitely for the spin lock to be released, and then places it in the\r |
167 | acquired state and returns SpinLock. All state transitions of SpinLock must\r |
168 | be performed using MP safe mechanisms.\r |
169 | \r |
170 | If SpinLock is NULL, then ASSERT().\r |
171 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
172 | If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r |
173 | PcdSpinLockTimeout microseconds, then ASSERT().\r |
174 | \r |
175 | @param SpinLock A pointer to the spin lock to place in the acquired state.\r |
176 | \r |
177 | @return SpinLock\r |
178 | \r |
179 | **/\r |
180 | SPIN_LOCK *\r |
181 | EFIAPI\r |
182 | AcquireSpinLock (\r |
183 | IN OUT SPIN_LOCK *SpinLock\r |
184 | )\r |
185 | {\r |
186 | UINT64 Tick;\r |
187 | UINT64 Start, End;\r |
188 | UINT64 Timeout;\r |
189 | \r |
190 | Tick = 0;\r |
191 | Start = 0;\r |
192 | End = 0;\r |
dc530c7b |
193 | if (PcdGet32 (PcdSpinLockTimeout) > 0) {\r |
878ddf1f |
194 | Tick = GetPerformanceCounter ();\r |
195 | Timeout = DivU64x32 (\r |
196 | MultU64x32 (\r |
197 | GetPerformanceCounterProperties (&Start, &End),\r |
dc530c7b |
198 | PcdGet32 (PcdSpinLockTimeout)\r |
878ddf1f |
199 | ),\r |
200 | 1000000\r |
201 | );\r |
202 | if (Start < End) {\r |
203 | Tick += Timeout;\r |
204 | } else {\r |
205 | Tick -= Timeout;\r |
206 | }\r |
207 | }\r |
208 | \r |
209 | while (!AcquireSpinLockOrFail (SpinLock)) {\r |
210 | CpuPause ();\r |
211 | ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));\r |
212 | }\r |
213 | return SpinLock;\r |
214 | }\r |
215 | \r |
216 | /**\r |
217 | Attempts to place a spin lock in the acquired state.\r |
218 | \r |
219 | This function checks the state of the spin lock specified by SpinLock. If\r |
220 | SpinLock is in the released state, then this function places SpinLock in the\r |
221 | acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r |
222 | transitions of SpinLock must be performed using MP safe mechanisms.\r |
223 | \r |
224 | If SpinLock is NULL, then ASSERT().\r |
225 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
226 | \r |
227 | @param SpinLock A pointer to the spin lock to place in the acquired state.\r |
228 | \r |
229 | @retval TRUE SpinLock was placed in the acquired state.\r |
230 | @retval FALSE SpinLock could not be acquired.\r |
231 | \r |
232 | **/\r |
233 | BOOLEAN\r |
234 | EFIAPI\r |
235 | AcquireSpinLockOrFail (\r |
236 | IN OUT SPIN_LOCK *SpinLock\r |
237 | )\r |
238 | {\r |
239 | ASSERT (SpinLock != NULL);\r |
27787243 |
240 | ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED);\r |
878ddf1f |
241 | return (BOOLEAN)(\r |
242 | InterlockedCompareExchangePointer (\r |
243 | (VOID**)SpinLock,\r |
244 | (VOID*)SPIN_LOCK_RELEASED,\r |
245 | (VOID*)SPIN_LOCK_ACQUIRED\r |
246 | ) == (VOID*)SPIN_LOCK_RELEASED\r |
247 | );\r |
248 | }\r |
249 | \r |
250 | /**\r |
251 | Releases a spin lock.\r |
252 | \r |
253 | This function places the spin lock specified by SpinLock in the release state\r |
254 | and returns SpinLock.\r |
255 | \r |
256 | If SpinLock is NULL, then ASSERT().\r |
257 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
258 | \r |
259 | @param SpinLock A pointer to the spin lock to release.\r |
260 | \r |
261 | @return SpinLock\r |
262 | \r |
263 | **/\r |
264 | SPIN_LOCK *\r |
265 | EFIAPI\r |
266 | ReleaseSpinLock (\r |
267 | IN OUT SPIN_LOCK *SpinLock\r |
268 | )\r |
269 | {\r |
270 | ASSERT (SpinLock != NULL);\r |
27787243 |
271 | ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED);\r |
272 | *SpinLock = SPIN_LOCK_RELEASED;\r |
878ddf1f |
273 | return SpinLock;\r |
274 | }\r |
275 | \r |
276 | /**\r |
277 | Performs an atomic increment of an 32-bit unsigned integer.\r |
278 | \r |
279 | Performs an atomic increment of the 32-bit unsigned integer specified by\r |
280 | Value and returns the incremented value. The increment operation must be\r |
281 | performed using MP safe mechanisms. The state of the return value is not\r |
282 | guaranteed to be MP safe.\r |
283 | \r |
284 | If Value is NULL, then ASSERT().\r |
285 | \r |
286 | @param Value A pointer to the 32-bit value to increment.\r |
287 | \r |
288 | @return The incremented value.\r |
289 | \r |
290 | **/\r |
291 | UINT32\r |
292 | EFIAPI\r |
293 | InterlockedIncrement (\r |
294 | IN UINT32 *Value\r |
295 | )\r |
296 | {\r |
297 | ASSERT (Value != NULL);\r |
298 | return InternalSyncIncrement (Value);\r |
299 | }\r |
300 | \r |
301 | /**\r |
302 | Performs an atomic decrement of an 32-bit unsigned integer.\r |
303 | \r |
304 | Performs an atomic decrement of the 32-bit unsigned integer specified by\r |
305 | Value and returns the decremented value. The decrement operation must be\r |
306 | performed using MP safe mechanisms. The state of the return value is not\r |
307 | guaranteed to be MP safe.\r |
308 | \r |
309 | If Value is NULL, then ASSERT().\r |
310 | \r |
311 | @param Value A pointer to the 32-bit value to decrement.\r |
312 | \r |
313 | @return The decremented value.\r |
314 | \r |
315 | **/\r |
316 | UINT32\r |
317 | EFIAPI\r |
318 | InterlockedDecrement (\r |
319 | IN UINT32 *Value\r |
320 | )\r |
321 | {\r |
322 | ASSERT (Value != NULL);\r |
323 | return InternalSyncDecrement (Value);\r |
324 | }\r |
325 | \r |
326 | /**\r |
327 | Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r |
328 | \r |
1ea5ca46 |
329 | Performs an atomic compare exchange operation on the 32-bit unsigned integer\r |
330 | specified by Value. If Value is equal to CompareValue, then Value is set to \r |
331 | ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r |
332 | then Value is returned. The compare exchange operation must be performed using \r |
333 | MP safe mechanisms.\r |
334 | \r |
335 | If Value is NULL, then ASSERT().\r |
336 | \r |
878ddf1f |
337 | @param Value A pointer to the 32-bit value for the compare exchange\r |
338 | operation.\r |
339 | @param CompareValue 32-bit value used in compare operation.\r |
340 | @param ExchangeValue 32-bit value used in exchange operation.\r |
341 | \r |
342 | @return The original *Value before exchange.\r |
343 | \r |
344 | **/\r |
345 | UINT32\r |
346 | EFIAPI\r |
347 | InterlockedCompareExchange32 (\r |
0ffa1286 |
348 | IN OUT UINT32 *Value,\r |
878ddf1f |
349 | IN UINT32 CompareValue,\r |
350 | IN UINT32 ExchangeValue\r |
351 | )\r |
352 | {\r |
353 | ASSERT (Value != NULL);\r |
354 | return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r |
355 | }\r |
356 | \r |
357 | /**\r |
358 | Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r |
359 | \r |
1ea5ca46 |
360 | Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r |
361 | by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and \r |
362 | CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. \r |
363 | The compare exchange operation must be performed using MP safe mechanisms.\r |
364 | \r |
365 | If Value is NULL, then ASSERT().\r |
366 | \r |
878ddf1f |
367 | @param Value A pointer to the 64-bit value for the compare exchange\r |
368 | operation.\r |
369 | @param CompareValue 64-bit value used in compare operation.\r |
370 | @param ExchangeValue 64-bit value used in exchange operation.\r |
371 | \r |
372 | @return The original *Value before exchange.\r |
373 | \r |
374 | **/\r |
375 | UINT64\r |
376 | EFIAPI\r |
377 | InterlockedCompareExchange64 (\r |
0ffa1286 |
378 | IN OUT UINT64 *Value,\r |
878ddf1f |
379 | IN UINT64 CompareValue,\r |
380 | IN UINT64 ExchangeValue\r |
381 | )\r |
382 | {\r |
383 | ASSERT (Value != NULL);\r |
384 | return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r |
385 | }\r |
386 | \r |
387 | /**\r |
388 | Performs an atomic compare exchange operation on a pointer value.\r |
389 | \r |
390 | Performs an atomic compare exchange operation on the pointer value specified\r |
391 | by Value. If Value is equal to CompareValue, then Value is set to\r |
392 | ExchangeValue and CompareValue is returned. If Value is not equal to\r |
393 | CompareValue, then Value is returned. The compare exchange operation must be\r |
394 | performed using MP safe mechanisms.\r |
395 | \r |
396 | If Value is NULL, then ASSERT().\r |
397 | \r |
398 | @param Value A pointer to the pointer value for the compare exchange\r |
399 | operation.\r |
400 | @param CompareValue Pointer value used in compare operation.\r |
401 | @param ExchangeValue Pointer value used in exchange operation.\r |
402 | \r |
403 | **/\r |
404 | VOID *\r |
405 | EFIAPI\r |
406 | InterlockedCompareExchangePointer (\r |
0ffa1286 |
407 | IN OUT VOID **Value,\r |
878ddf1f |
408 | IN VOID *CompareValue,\r |
409 | IN VOID *ExchangeValue\r |
410 | )\r |
411 | {\r |
412 | switch (sizeof (*Value)) {\r |
413 | case sizeof (UINT32):\r |
414 | return (VOID*)(UINTN)InterlockedCompareExchange32 (\r |
415 | (UINT32*)Value,\r |
416 | (UINT32)(UINTN)CompareValue,\r |
417 | (UINT32)(UINTN)ExchangeValue\r |
418 | );\r |
419 | case sizeof (UINT64):\r |
420 | return (VOID*)(UINTN)InterlockedCompareExchange64 (\r |
421 | (UINT64*)Value,\r |
422 | (UINT64)(UINTN)CompareValue,\r |
423 | (UINT64)(UINTN)ExchangeValue\r |
424 | );\r |
425 | default:\r |
426 | ASSERT (FALSE);\r |
427 | return NULL;\r |
428 | }\r |
429 | }\r |