1 /** @file 2 Provides synchronization functions. 3 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 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 **/ 14 15 #ifndef __SYNCHRONIZATION_LIB__ 16 #define __SYNCHRONIZATION_LIB__ 17 18 /// 19 /// Definitions for SPIN_LOCK 20 /// 21 typedef volatile UINTN SPIN_LOCK; 22 23 24 /** 25 Retrieves the architecture-specific spin lock alignment requirements for 26 optimal spin lock performance. 27 28 This function retrieves the spin lock alignment requirements for optimal 29 performance on a given CPU architecture. The spin lock alignment is byte alignment. 30 It must be a power of two and is returned by this function. If there are no alignment 31 requirements, then 1 must be returned. The spin lock synchronization 32 functions must function correctly if the spin lock size and alignment values 33 returned by this function are not used at all. These values are hints to the 34 consumers of the spin lock synchronization functions to obtain optimal spin 35 lock performance. 36 37 @return The architecture-specific spin lock alignment. 38 39 **/ 40 UINTN 41 EFIAPI 42 GetSpinLockProperties ( 43 VOID 44 ); 45 46 47 /** 48 Initializes a spin lock to the released state and returns the spin lock. 49 50 This function initializes the spin lock specified by SpinLock to the released 51 state, and returns SpinLock. Optimal performance can be achieved by calling 52 GetSpinLockProperties() to determine the size and alignment requirements for 53 SpinLock. 54 55 If SpinLock is NULL, then ASSERT(). 56 57 @param SpinLock A pointer to the spin lock to initialize to the released 58 state. 59 60 @return SpinLock in release state. 61 62 **/ 63 SPIN_LOCK * 64 EFIAPI 65 InitializeSpinLock ( 66 OUT SPIN_LOCK *SpinLock 67 ); 68 69 70 /** 71 Waits until a spin lock can be placed in the acquired state. 72 73 This function checks the state of the spin lock specified by SpinLock. If 74 SpinLock is in the released state, then this function places SpinLock in the 75 acquired state and returns SpinLock. Otherwise, this function waits 76 indefinitely for the spin lock to be released, and then places it in the 77 acquired state and returns SpinLock. All state transitions of SpinLock must 78 be performed using MP safe mechanisms. 79 80 If SpinLock is NULL, then ASSERT(). 81 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). 82 If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in 83 PcdSpinLockTimeout microseconds, then ASSERT(). 84 85 @param SpinLock A pointer to the spin lock to place in the acquired state. 86 87 @return SpinLock acquired lock. 88 89 **/ 90 SPIN_LOCK * 91 EFIAPI 92 AcquireSpinLock ( 93 IN OUT SPIN_LOCK *SpinLock 94 ); 95 96 97 /** 98 Attempts to place a spin lock in the acquired state. 99 100 This function checks the state of the spin lock specified by SpinLock. If 101 SpinLock is in the released state, then this function places SpinLock in the 102 acquired state and returns TRUE. Otherwise, FALSE is returned. All state 103 transitions of SpinLock must be performed using MP safe mechanisms. 104 105 If SpinLock is NULL, then ASSERT(). 106 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). 107 108 @param SpinLock A pointer to the spin lock to place in the acquired state. 109 110 @retval TRUE SpinLock was placed in the acquired state. 111 @retval FALSE SpinLock could not be acquired. 112 113 **/ 114 BOOLEAN 115 EFIAPI 116 AcquireSpinLockOrFail ( 117 IN OUT SPIN_LOCK *SpinLock 118 ); 119 120 121 /** 122 Releases a spin lock. 123 124 This function places the spin lock specified by SpinLock in the release state 125 and returns SpinLock. 126 127 If SpinLock is NULL, then ASSERT(). 128 If SpinLock was not initialized with InitializeSpinLock(), then ASSERT(). 129 130 @param SpinLock A pointer to the spin lock to release. 131 132 @return SpinLock released lock. 133 134 **/ 135 SPIN_LOCK * 136 EFIAPI 137 ReleaseSpinLock ( 138 IN OUT SPIN_LOCK *SpinLock 139 ); 140 141 142 /** 143 Performs an atomic increment of a 32-bit unsigned integer. 144 145 Performs an atomic increment of the 32-bit unsigned integer specified by 146 Value and returns the incremented value. The increment operation must be 147 performed using MP safe mechanisms. The state of the return value is not 148 guaranteed to be MP safe. 149 150 If Value is NULL, then ASSERT(). 151 152 @param Value A pointer to the 32-bit value to increment. 153 154 @return The incremented value. 155 156 **/ 157 UINT32 158 EFIAPI 159 InterlockedIncrement ( 160 IN volatile UINT32 *Value 161 ); 162 163 164 /** 165 Performs an atomic decrement of a 32-bit unsigned integer. 166 167 Performs an atomic decrement of the 32-bit unsigned integer specified by 168 Value and returns the decremented value. The decrement operation must be 169 performed using MP safe mechanisms. The state of the return value is not 170 guaranteed to be MP safe. 171 172 If Value is NULL, then ASSERT(). 173 174 @param Value A pointer to the 32-bit value to decrement. 175 176 @return The decremented value. 177 178 **/ 179 UINT32 180 EFIAPI 181 InterlockedDecrement ( 182 IN volatile UINT32 *Value 183 ); 184 185 186 /** 187 Performs an atomic compare exchange operation on a 16-bit unsigned integer. 188 189 Performs an atomic compare exchange operation on the 16-bit unsigned integer 190 specified by Value. If Value is equal to CompareValue, then Value is set to 191 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue, 192 then Value is returned. The compare exchange operation must be performed using 193 MP safe mechanisms. 194 195 If Value is NULL, then ASSERT(). 196 197 @param Value A pointer to the 16-bit value for the compare exchange 198 operation. 199 @param CompareValue 16-bit value used in compare operation. 200 @param ExchangeValue 16-bit value used in exchange operation. 201 202 @return The original *Value before exchange. 203 **/ 204 UINT16 205 EFIAPI 206 InterlockedCompareExchange16 ( 207 IN OUT volatile UINT16 *Value, 208 IN UINT16 CompareValue, 209 IN UINT16 ExchangeValue 210 ); 211 212 /** 213 Performs an atomic compare exchange operation on a 32-bit unsigned integer. 214 215 Performs an atomic compare exchange operation on the 32-bit unsigned integer 216 specified by Value. If Value is equal to CompareValue, then Value is set to 217 ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue, 218 then Value is returned. The compare exchange operation must be performed using 219 MP safe mechanisms. 220 221 If Value is NULL, then ASSERT(). 222 223 @param Value A pointer to the 32-bit value for the compare exchange 224 operation. 225 @param CompareValue 32-bit value used in compare operation. 226 @param ExchangeValue 32-bit value used in exchange operation. 227 228 @return The original *Value before exchange. 229 230 **/ 231 UINT32 232 EFIAPI 233 InterlockedCompareExchange32 ( 234 IN OUT volatile UINT32 *Value, 235 IN UINT32 CompareValue, 236 IN UINT32 ExchangeValue 237 ); 238 239 240 /** 241 Performs an atomic compare exchange operation on a 64-bit unsigned integer. 242 243 Performs an atomic compare exchange operation on the 64-bit unsigned integer specified 244 by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and 245 CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. 246 The compare exchange operation must be performed using MP safe mechanisms. 247 248 If Value is NULL, then ASSERT(). 249 250 @param Value A pointer to the 64-bit value for the compare exchange 251 operation. 252 @param CompareValue 64-bit value used in compare operation. 253 @param ExchangeValue 64-bit value used in exchange operation. 254 255 @return The original *Value before exchange. 256 257 **/ 258 UINT64 259 EFIAPI 260 InterlockedCompareExchange64 ( 261 IN OUT volatile UINT64 *Value, 262 IN UINT64 CompareValue, 263 IN UINT64 ExchangeValue 264 ); 265 266 267 /** 268 Performs an atomic compare exchange operation on a pointer value. 269 270 Performs an atomic compare exchange operation on the pointer value specified 271 by Value. If Value is equal to CompareValue, then Value is set to 272 ExchangeValue and CompareValue is returned. If Value is not equal to 273 CompareValue, then Value is returned. The compare exchange operation must be 274 performed using MP safe mechanisms. 275 276 If Value is NULL, then ASSERT(). 277 278 @param Value A pointer to the pointer value for the compare exchange 279 operation. 280 @param CompareValue Pointer value used in compare operation. 281 @param ExchangeValue Pointer value used in exchange operation. 282 283 @return The original *Value before exchange. 284 **/ 285 VOID * 286 EFIAPI 287 InterlockedCompareExchangePointer ( 288 IN OUT VOID * volatile *Value, 289 IN VOID *CompareValue, 290 IN VOID *ExchangeValue 291 ); 292 293 #endif 294 295 296
