MdePkg/Include/Library/SynchronizationLib.h

   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