878ddf1f |
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 |
17 | #define SPIN_LOCK_RELEASED ((SPIN_LOCK)0)\r |
18 | #define SPIN_LOCK_ACQUIRED ((SPIN_LOCK)-1)\r |
19 | \r |
20 | UINT32\r |
21 | EFIAPI\r |
22 | InternalSyncIncrement (\r |
23 | IN volatile UINT32 *Value\r |
24 | );\r |
25 | \r |
26 | UINT32\r |
27 | EFIAPI\r |
28 | InternalSyncDecrement (\r |
29 | IN volatile UINT32 *Value\r |
30 | );\r |
31 | \r |
32 | UINT32\r |
33 | EFIAPI\r |
34 | InternalSyncCompareExchange32 (\r |
35 | IN volatile UINT32 *Value,\r |
36 | IN UINT32 CompareValue,\r |
37 | IN UINT32 ExchangeValue\r |
38 | );\r |
39 | \r |
40 | UINT64\r |
41 | EFIAPI\r |
42 | InternalSyncCompareExchange64 (\r |
43 | IN volatile UINT64 *Value,\r |
44 | IN UINT64 CompareValue,\r |
45 | IN UINT64 ExchangeValue\r |
46 | );\r |
47 | \r |
48 | /**\r |
49 | Retrieves the architecture specific spin lock alignment requirements for\r |
50 | optimal spin lock performance.\r |
51 | \r |
52 | This function retrieves the spin lock alignment requirements for optimal\r |
53 | performance on a given CPU architecture. The spin lock alignment must be a\r |
54 | power of two and is returned by this function. If there are no alignment\r |
55 | requirements, then 1 must be returned. The spin lock synchronization\r |
56 | functions must function correctly if the spin lock size and alignment values\r |
57 | returned by this function are not used at all. These values are hints to the\r |
58 | consumers of the spin lock synchronization functions to obtain optimal spin\r |
59 | lock performance.\r |
60 | \r |
61 | @return The architecture specific spin lock alignment.\r |
62 | \r |
63 | **/\r |
64 | UINTN\r |
65 | EFIAPI\r |
66 | GetSpinLockProperties (\r |
67 | VOID\r |
68 | )\r |
69 | {\r |
70 | // @bug May use a PCD entry to determine this alignment.\r |
71 | return 32;\r |
72 | }\r |
73 | \r |
74 | /**\r |
75 | Initializes a spin lock to the released state and returns the spin lock.\r |
76 | \r |
77 | This function initializes the spin lock specified by SpinLock to the released\r |
78 | state, and returns SpinLock. Optimal performance can be achieved by calling\r |
79 | GetSpinLockProperties() to determine the size and alignment requirements for\r |
80 | SpinLock.\r |
81 | \r |
82 | If SpinLock is NULL, then ASSERT().\r |
83 | \r |
84 | @param SpinLock A pointer to the spin lock to initialize to the released\r |
85 | state.\r |
86 | \r |
87 | @return SpinLock\r |
88 | \r |
89 | **/\r |
90 | SPIN_LOCK *\r |
91 | EFIAPI\r |
92 | InitializeSpinLock (\r |
93 | OUT SPIN_LOCK *SpinLock\r |
94 | )\r |
95 | {\r |
96 | ASSERT (SpinLock != NULL);\r |
97 | *SpinLock = 0;\r |
98 | return SpinLock;\r |
99 | }\r |
100 | \r |
101 | /**\r |
102 | Waits until a spin lock can be placed in the acquired state.\r |
103 | \r |
104 | This function checks the state of the spin lock specified by SpinLock. If\r |
105 | SpinLock is in the released state, then this function places SpinLock in the\r |
106 | acquired state and returns SpinLock. Otherwise, this function waits\r |
107 | indefinitely for the spin lock to be released, and then places it in the\r |
108 | acquired state and returns SpinLock. All state transitions of SpinLock must\r |
109 | be performed using MP safe mechanisms.\r |
110 | \r |
111 | If SpinLock is NULL, then ASSERT().\r |
112 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
113 | If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r |
114 | PcdSpinLockTimeout microseconds, then ASSERT().\r |
115 | \r |
116 | @param SpinLock A pointer to the spin lock to place in the acquired state.\r |
117 | \r |
118 | @return SpinLock\r |
119 | \r |
120 | **/\r |
121 | SPIN_LOCK *\r |
122 | EFIAPI\r |
123 | AcquireSpinLock (\r |
124 | IN OUT SPIN_LOCK *SpinLock\r |
125 | )\r |
126 | {\r |
127 | UINT64 Tick;\r |
128 | UINT64 Start, End;\r |
129 | UINT64 Timeout;\r |
130 | \r |
131 | Tick = 0;\r |
132 | Start = 0;\r |
133 | End = 0;\r |
134 | if (FixedPcdGet32 (PcdSpinLockTimeout) > 0) {\r |
135 | Tick = GetPerformanceCounter ();\r |
136 | Timeout = DivU64x32 (\r |
137 | MultU64x32 (\r |
138 | GetPerformanceCounterProperties (&Start, &End),\r |
139 | FixedPcdGet32 (PcdSpinLockTimeout)\r |
140 | ),\r |
141 | 1000000\r |
142 | );\r |
143 | if (Start < End) {\r |
144 | Tick += Timeout;\r |
145 | } else {\r |
146 | Tick -= Timeout;\r |
147 | }\r |
148 | }\r |
149 | \r |
150 | while (!AcquireSpinLockOrFail (SpinLock)) {\r |
151 | CpuPause ();\r |
152 | ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));\r |
153 | }\r |
154 | return SpinLock;\r |
155 | }\r |
156 | \r |
157 | /**\r |
158 | Attempts to place a spin lock in the acquired state.\r |
159 | \r |
160 | This function checks the state of the spin lock specified by SpinLock. If\r |
161 | SpinLock is in the released state, then this function places SpinLock in the\r |
162 | acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r |
163 | transitions of SpinLock must be performed using MP safe mechanisms.\r |
164 | \r |
165 | If SpinLock is NULL, then ASSERT().\r |
166 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
167 | \r |
168 | @param SpinLock A pointer to the spin lock to place in the acquired state.\r |
169 | \r |
170 | @retval TRUE SpinLock was placed in the acquired state.\r |
171 | @retval FALSE SpinLock could not be acquired.\r |
172 | \r |
173 | **/\r |
174 | BOOLEAN\r |
175 | EFIAPI\r |
176 | AcquireSpinLockOrFail (\r |
177 | IN OUT SPIN_LOCK *SpinLock\r |
178 | )\r |
179 | {\r |
180 | ASSERT (SpinLock != NULL);\r |
181 | return (BOOLEAN)(\r |
182 | InterlockedCompareExchangePointer (\r |
183 | (VOID**)SpinLock,\r |
184 | (VOID*)SPIN_LOCK_RELEASED,\r |
185 | (VOID*)SPIN_LOCK_ACQUIRED\r |
186 | ) == (VOID*)SPIN_LOCK_RELEASED\r |
187 | );\r |
188 | }\r |
189 | \r |
190 | /**\r |
191 | Releases a spin lock.\r |
192 | \r |
193 | This function places the spin lock specified by SpinLock in the release state\r |
194 | and returns SpinLock.\r |
195 | \r |
196 | If SpinLock is NULL, then ASSERT().\r |
197 | If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r |
198 | \r |
199 | @param SpinLock A pointer to the spin lock to release.\r |
200 | \r |
201 | @return SpinLock\r |
202 | \r |
203 | **/\r |
204 | SPIN_LOCK *\r |
205 | EFIAPI\r |
206 | ReleaseSpinLock (\r |
207 | IN OUT SPIN_LOCK *SpinLock\r |
208 | )\r |
209 | {\r |
210 | ASSERT (SpinLock != NULL);\r |
211 | *SpinLock = 0;\r |
212 | return SpinLock;\r |
213 | }\r |
214 | \r |
215 | /**\r |
216 | Performs an atomic increment of an 32-bit unsigned integer.\r |
217 | \r |
218 | Performs an atomic increment of the 32-bit unsigned integer specified by\r |
219 | Value and returns the incremented value. The increment operation must be\r |
220 | performed using MP safe mechanisms. The state of the return value is not\r |
221 | guaranteed to be MP safe.\r |
222 | \r |
223 | If Value is NULL, then ASSERT().\r |
224 | \r |
225 | @param Value A pointer to the 32-bit value to increment.\r |
226 | \r |
227 | @return The incremented value.\r |
228 | \r |
229 | **/\r |
230 | UINT32\r |
231 | EFIAPI\r |
232 | InterlockedIncrement (\r |
233 | IN UINT32 *Value\r |
234 | )\r |
235 | {\r |
236 | ASSERT (Value != NULL);\r |
237 | return InternalSyncIncrement (Value);\r |
238 | }\r |
239 | \r |
240 | /**\r |
241 | Performs an atomic decrement of an 32-bit unsigned integer.\r |
242 | \r |
243 | Performs an atomic decrement of the 32-bit unsigned integer specified by\r |
244 | Value and returns the decremented value. The decrement operation must be\r |
245 | performed using MP safe mechanisms. The state of the return value is not\r |
246 | guaranteed to be MP safe.\r |
247 | \r |
248 | If Value is NULL, then ASSERT().\r |
249 | \r |
250 | @param Value A pointer to the 32-bit value to decrement.\r |
251 | \r |
252 | @return The decremented value.\r |
253 | \r |
254 | **/\r |
255 | UINT32\r |
256 | EFIAPI\r |
257 | InterlockedDecrement (\r |
258 | IN UINT32 *Value\r |
259 | )\r |
260 | {\r |
261 | ASSERT (Value != NULL);\r |
262 | return InternalSyncDecrement (Value);\r |
263 | }\r |
264 | \r |
265 | /**\r |
266 | Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r |
267 | \r |
268 | @param Value A pointer to the 32-bit value for the compare exchange\r |
269 | operation.\r |
270 | @param CompareValue 32-bit value used in compare operation.\r |
271 | @param ExchangeValue 32-bit value used in exchange operation.\r |
272 | \r |
273 | @return The original *Value before exchange.\r |
274 | \r |
275 | **/\r |
276 | UINT32\r |
277 | EFIAPI\r |
278 | InterlockedCompareExchange32 (\r |
279 | IN UINT32 *Value,\r |
280 | IN UINT32 CompareValue,\r |
281 | IN UINT32 ExchangeValue\r |
282 | )\r |
283 | {\r |
284 | ASSERT (Value != NULL);\r |
285 | return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r |
286 | }\r |
287 | \r |
288 | /**\r |
289 | Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r |
290 | \r |
291 | @param Value A pointer to the 64-bit value for the compare exchange\r |
292 | operation.\r |
293 | @param CompareValue 64-bit value used in compare operation.\r |
294 | @param ExchangeValue 64-bit value used in exchange operation.\r |
295 | \r |
296 | @return The original *Value before exchange.\r |
297 | \r |
298 | **/\r |
299 | UINT64\r |
300 | EFIAPI\r |
301 | InterlockedCompareExchange64 (\r |
302 | IN UINT64 *Value,\r |
303 | IN UINT64 CompareValue,\r |
304 | IN UINT64 ExchangeValue\r |
305 | )\r |
306 | {\r |
307 | ASSERT (Value != NULL);\r |
308 | return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r |
309 | }\r |
310 | \r |
311 | /**\r |
312 | Performs an atomic compare exchange operation on a pointer value.\r |
313 | \r |
314 | Performs an atomic compare exchange operation on the pointer value specified\r |
315 | by Value. If Value is equal to CompareValue, then Value is set to\r |
316 | ExchangeValue and CompareValue is returned. If Value is not equal to\r |
317 | CompareValue, then Value is returned. The compare exchange operation must be\r |
318 | performed using MP safe mechanisms.\r |
319 | \r |
320 | If Value is NULL, then ASSERT().\r |
321 | \r |
322 | @param Value A pointer to the pointer value for the compare exchange\r |
323 | operation.\r |
324 | @param CompareValue Pointer value used in compare operation.\r |
325 | @param ExchangeValue Pointer value used in exchange operation.\r |
326 | \r |
327 | **/\r |
328 | VOID *\r |
329 | EFIAPI\r |
330 | InterlockedCompareExchangePointer (\r |
331 | IN VOID **Value,\r |
332 | IN VOID *CompareValue,\r |
333 | IN VOID *ExchangeValue\r |
334 | )\r |
335 | {\r |
336 | switch (sizeof (*Value)) {\r |
337 | case sizeof (UINT32):\r |
338 | return (VOID*)(UINTN)InterlockedCompareExchange32 (\r |
339 | (UINT32*)Value,\r |
340 | (UINT32)(UINTN)CompareValue,\r |
341 | (UINT32)(UINTN)ExchangeValue\r |
342 | );\r |
343 | case sizeof (UINT64):\r |
344 | return (VOID*)(UINTN)InterlockedCompareExchange64 (\r |
345 | (UINT64*)Value,\r |
346 | (UINT64)(UINTN)CompareValue,\r |
347 | (UINT64)(UINTN)ExchangeValue\r |
348 | );\r |
349 | default:\r |
350 | ASSERT (FALSE);\r |
351 | return NULL;\r |
352 | }\r |
353 | }\r |