MdePkg/Library/BaseSynchronizationLib/SynchronizationMsc.c

   1 /** @file
   2   Implementation of synchronization functions.
   3
   4   Copyright (c) 2006 - 2018, 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 #include "BaseSynchronizationLibInternals.h"
  16
  17 /**
  18   Microsoft Visual Studio 7.1 Function Prototypes for read write barrier Intrinsics.
  19 **/
  20
  21 void    _ReadWriteBarrier (void);
  22 #pragma intrinsic(_ReadWriteBarrier)
  23
  24
  25 #define SPIN_LOCK_RELEASED          ((UINTN) 1)
  26 #define SPIN_LOCK_ACQUIRED          ((UINTN) 2)
  27
  28 /**
  29   Retrieves the architecture specific spin lock alignment requirements for
  30   optimal spin lock performance.
  31
  32   This function retrieves the spin lock alignment requirements for optimal
  33   performance on a given CPU architecture. The spin lock alignment is byte alignment.
  34   It must be a power of two and is returned by this function. If there are no alignment
  35   requirements, then 1 must be returned. The spin lock synchronization
  36   functions must function correctly if the spin lock size and alignment values
  37   returned by this function are not used at all. These values are hints to the
  38   consumers of the spin lock synchronization functions to obtain optimal spin
  39   lock performance.
  40
  41   @return The architecture specific spin lock alignment.
  42
  43 **/
  44 UINTN
  45 EFIAPI
  46 GetSpinLockProperties (
  47   VOID
  48   )
  49 {
  50   return InternalGetSpinLockProperties ();
  51 }
  52
  53 /**
  54   Initializes a spin lock to the released state and returns the spin lock.
  55
  56   This function initializes the spin lock specified by SpinLock to the released
  57   state, and returns SpinLock. Optimal performance can be achieved by calling
  58   GetSpinLockProperties() to determine the size and alignment requirements for
  59   SpinLock.
  60
  61   If SpinLock is NULL, then ASSERT().
  62
  63   @param  SpinLock  A pointer to the spin lock to initialize to the released
  64                     state.
  65
  66   @return SpinLock is in release state.
  67
  68 **/
  69 SPIN_LOCK *
  70 EFIAPI
  71 InitializeSpinLock (
  72   OUT      SPIN_LOCK                 *SpinLock
  73   )
  74 {
  75   ASSERT (SpinLock != NULL);
  76
  77   _ReadWriteBarrier();
  78   *SpinLock = SPIN_LOCK_RELEASED;
  79   _ReadWriteBarrier();
  80
  81   return SpinLock;
  82 }
  83
  84 /**
  85   Waits until a spin lock can be placed in the acquired state.
  86
  87   This function checks the state of the spin lock specified by SpinLock. If
  88   SpinLock is in the released state, then this function places SpinLock in the
  89   acquired state and returns SpinLock. Otherwise, this function waits
  90   indefinitely for the spin lock to be released, and then places it in the
  91   acquired state and returns SpinLock. All state transitions of SpinLock must
  92   be performed using MP safe mechanisms.
  93
  94   If SpinLock is NULL, then ASSERT().
  95   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
  96   If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in
  97   PcdSpinLockTimeout microseconds, then ASSERT().
  98
  99   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
 100
 101   @return SpinLock acquired the lock.
 102
 103 **/
 104 SPIN_LOCK *
 105 EFIAPI
 106 AcquireSpinLock (
 107   IN OUT  SPIN_LOCK                 *SpinLock
 108   )
 109 {
 110   UINT64  Current;
 111   UINT64  Previous;
 112   UINT64  Total;
 113   UINT64  Start;
 114   UINT64  End;
 115   UINT64  Timeout;
 116   INT64   Cycle;
 117   INT64   Delta;
 118
 119   if (PcdGet32 (PcdSpinLockTimeout) == 0) {
 120     while (!AcquireSpinLockOrFail (SpinLock)) {
 121       CpuPause ();
 122     }
 123   } else if (!AcquireSpinLockOrFail (SpinLock)) {
 124     //
 125     // Get the current timer value
 126     //
 127     Current = GetPerformanceCounter();
 128
 129     //
 130     // Initialize local variables
 131     //
 132     Start = 0;
 133     End   = 0;
 134     Total = 0;
 135
 136     //
 137     // Retrieve the performance counter properties and compute the number of performance
 138     // counter ticks required to reach the timeout
 139     //
 140     Timeout = DivU64x32 (
 141                 MultU64x32 (
 142                   GetPerformanceCounterProperties (&Start, &End),
 143                   PcdGet32 (PcdSpinLockTimeout)
 144                   ),
 145                 1000000
 146                 );
 147     Cycle = End - Start;
 148     if (Cycle < 0) {
 149       Cycle = -Cycle;
 150     }
 151     Cycle++;
 152
 153     while (!AcquireSpinLockOrFail (SpinLock)) {
 154       CpuPause ();
 155       Previous = Current;
 156       Current  = GetPerformanceCounter();
 157       Delta = (INT64) (Current - Previous);
 158       if (Start > End) {
 159         Delta = -Delta;
 160       }
 161       if (Delta < 0) {
 162         Delta += Cycle;
 163       }
 164       Total += Delta;
 165       ASSERT (Total < Timeout);
 166     }
 167   }
 168   return SpinLock;
 169 }
 170
 171 /**
 172   Attempts to place a spin lock in the acquired state.
 173
 174   This function checks the state of the spin lock specified by SpinLock. If
 175   SpinLock is in the released state, then this function places SpinLock in the
 176   acquired state and returns TRUE. Otherwise, FALSE is returned. All state
 177   transitions of SpinLock must be performed using MP safe mechanisms.
 178
 179   If SpinLock is NULL, then ASSERT().
 180   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
 181
 182   @param  SpinLock  A pointer to the spin lock to place in the acquired state.
 183
 184   @retval TRUE  SpinLock was placed in the acquired state.
 185   @retval FALSE SpinLock could not be acquired.
 186
 187 **/
 188 BOOLEAN
 189 EFIAPI
 190 AcquireSpinLockOrFail (
 191   IN OUT  SPIN_LOCK                 *SpinLock
 192   )
 193 {
 194   SPIN_LOCK   LockValue;
 195   VOID        *Result;
 196
 197   ASSERT (SpinLock != NULL);
 198
 199   LockValue = *SpinLock;
 200   ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);
 201
 202   _ReadWriteBarrier ();
 203   Result = InterlockedCompareExchangePointer (
 204              (VOID**)SpinLock,
 205              (VOID*)SPIN_LOCK_RELEASED,
 206              (VOID*)SPIN_LOCK_ACQUIRED
 207            );
 208
 209   _ReadWriteBarrier ();
 210   return (BOOLEAN) (Result == (VOID*) SPIN_LOCK_RELEASED);
 211 }
 212
 213 /**
 214   Releases a spin lock.
 215
 216   This function places the spin lock specified by SpinLock in the release state
 217   and returns SpinLock.
 218
 219   If SpinLock is NULL, then ASSERT().
 220   If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().
 221
 222   @param  SpinLock  A pointer to the spin lock to release.
 223
 224   @return SpinLock released the lock.
 225
 226 **/
 227 SPIN_LOCK *
 228 EFIAPI
 229 ReleaseSpinLock (
 230   IN OUT  SPIN_LOCK                 *SpinLock
 231   )
 232 {
 233   SPIN_LOCK    LockValue;
 234
 235   ASSERT (SpinLock != NULL);
 236
 237   LockValue = *SpinLock;
 238   ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);
 239
 240   _ReadWriteBarrier ();
 241   *SpinLock = SPIN_LOCK_RELEASED;
 242   _ReadWriteBarrier ();
 243
 244   return SpinLock;
 245 }
 246
 247 /**
 248   Performs an atomic increment of an 32-bit unsigned integer.
 249
 250   Performs an atomic increment of the 32-bit unsigned integer specified by
 251   Value and returns the incremented value. The increment operation must be
 252   performed using MP safe mechanisms.
 253
 254   If Value is NULL, then ASSERT().
 255
 256   @param  Value A pointer to the 32-bit value to increment.
 257
 258   @return The incremented value.
 259
 260 **/
 261 UINT32
 262 EFIAPI
 263 InterlockedIncrement (
 264   IN      volatile UINT32           *Value
 265   )
 266 {
 267   ASSERT (Value != NULL);
 268   return InternalSyncIncrement (Value);
 269 }
 270
 271 /**
 272   Performs an atomic decrement of an 32-bit unsigned integer.
 273
 274   Performs an atomic decrement of the 32-bit unsigned integer specified by
 275   Value and returns the decremented value. The decrement operation must be
 276   performed using MP safe mechanisms.
 277
 278   If Value is NULL, then ASSERT().
 279
 280   @param  Value A pointer to the 32-bit value to decrement.
 281
 282   @return The decremented value.
 283
 284 **/
 285 UINT32
 286 EFIAPI
 287 InterlockedDecrement (
 288   IN      volatile UINT32           *Value
 289   )
 290 {
 291   ASSERT (Value != NULL);
 292   return InternalSyncDecrement (Value);
 293 }
 294
 295 /**
 296   Performs an atomic compare exchange operation on a 16-bit unsigned integer.
 297
 298   Performs an atomic compare exchange operation on the 16-bit unsigned integer
 299   specified by Value.  If Value is equal to CompareValue, then Value is set to
 300   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 301   then Value is returned.  The compare exchange operation must be performed using
 302   MP safe mechanisms.
 303
 304   If Value is NULL, then ASSERT().
 305
 306   @param  Value         A pointer to the 16-bit value for the compare exchange
 307                         operation.
 308   @param  CompareValue  A 16-bit value used in a compare operation.
 309   @param  ExchangeValue A 16-bit value used in an exchange operation.
 310
 311   @return The original *Value before exchange.
 312
 313 **/
 314 UINT16
 315 EFIAPI
 316 InterlockedCompareExchange16 (
 317   IN OUT  volatile UINT16           *Value,
 318   IN      UINT16                    CompareValue,
 319   IN      UINT16                    ExchangeValue
 320   )
 321 {
 322   ASSERT (Value != NULL);
 323   return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);
 324 }
 325
 326 /**
 327   Performs an atomic compare exchange operation on a 32-bit unsigned integer.
 328
 329   Performs an atomic compare exchange operation on the 32-bit unsigned integer
 330   specified by Value.  If Value is equal to CompareValue, then Value is set to
 331   ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,
 332   then Value is returned.  The compare exchange operation must be performed using
 333   MP safe mechanisms.
 334
 335   If Value is NULL, then ASSERT().
 336
 337   @param  Value         A pointer to the 32-bit value for the compare exchange
 338                         operation.
 339   @param  CompareValue  A 32-bit value used in a compare operation.
 340   @param  ExchangeValue A 32-bit value used in an exchange operation.
 341
 342   @return The original *Value before exchange.
 343
 344 **/
 345 UINT32
 346 EFIAPI
 347 InterlockedCompareExchange32 (
 348   IN OUT  volatile UINT32           *Value,
 349   IN      UINT32                    CompareValue,
 350   IN      UINT32                    ExchangeValue
 351   )
 352 {
 353   ASSERT (Value != NULL);
 354   return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);
 355 }
 356
 357 /**
 358   Performs an atomic compare exchange operation on a 64-bit unsigned integer.
 359
 360   Performs an atomic compare exchange operation on the 64-bit unsigned integer specified
 361   by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and
 362   CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.
 363   The compare exchange operation must be performed using MP safe mechanisms.
 364
 365   If Value is NULL, then ASSERT().
 366
 367   @param  Value         A pointer to the 64-bit value for the compare exchange
 368                         operation.
 369   @param  CompareValue  A 64-bit value used in a compare operation.
 370   @param  ExchangeValue A 64-bit value used in an exchange operation.
 371
 372   @return The original *Value before exchange.
 373
 374 **/
 375 UINT64
 376 EFIAPI
 377 InterlockedCompareExchange64 (
 378   IN OUT  volatile UINT64           *Value,
 379   IN      UINT64                    CompareValue,
 380   IN      UINT64                    ExchangeValue
 381   )
 382 {
 383   ASSERT (Value != NULL);
 384   return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);
 385 }
 386
 387 /**
 388   Performs an atomic compare exchange operation on a pointer value.
 389
 390   Performs an atomic compare exchange operation on the pointer value specified
 391   by Value. If Value is equal to CompareValue, then Value is set to
 392   ExchangeValue and CompareValue is returned. If Value is not equal to
 393   CompareValue, then Value is returned. The compare exchange operation must be
 394   performed using MP safe mechanisms.
 395
 396   If Value is NULL, then ASSERT().
 397
 398   @param  Value         A pointer to the pointer value for the compare exchange
 399                         operation.
 400   @param  CompareValue  A pointer value used in a compare operation.
 401   @param  ExchangeValue A pointer value used in an exchange operation.
 402
 403   @return The original *Value before exchange.
 404 **/
 405 VOID *
 406 EFIAPI
 407 InterlockedCompareExchangePointer (
 408   IN OUT  VOID                      * volatile *Value,
 409   IN      VOID                      *CompareValue,
 410   IN      VOID                      *ExchangeValue
 411   )
 412 {
 413   UINT8  SizeOfValue;
 414
 415   SizeOfValue = (UINT8) sizeof (*Value);
 416
 417   switch (SizeOfValue) {
 418     case sizeof (UINT32):
 419       return (VOID*)(UINTN)InterlockedCompareExchange32 (
 420                              (volatile UINT32*)Value,
 421                              (UINT32)(UINTN)CompareValue,
 422                              (UINT32)(UINTN)ExchangeValue
 423                              );
 424     case sizeof (UINT64):
 425       return (VOID*)(UINTN)InterlockedCompareExchange64 (
 426                              (volatile UINT64*)Value,
 427                              (UINT64)(UINTN)CompareValue,
 428                              (UINT64)(UINTN)ExchangeValue
 429                              );
 430     default:
 431       ASSERT (FALSE);
 432       return NULL;
 433   }
 434 }