[mirror_edk2.git] / MdePkg / Library / BaseSynchronizationLib / Synchronization.c

/** @file\r
  Implementation of synchronization functions.\r
\r
  Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
  This program and the accompanying materials\r
  are licensed and made available under the terms and conditions of the BSD License\r
  which accompanies this distribution.  The full text of the license may be found at\r
  http://opensource.org/licenses/bsd-license.php.\r
\r
  THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
  WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
\r
#include "BaseSynchronizationLibInternals.h"\r
\r
#define SPIN_LOCK_RELEASED          ((UINTN) 1)\r
#define SPIN_LOCK_ACQUIRED          ((UINTN) 2)\r
\r
/**\r
  Retrieves the architecture specific spin lock alignment requirements for\r
  optimal spin lock performance.\r
\r
  This function retrieves the spin lock alignment requirements for optimal\r
  performance on a given CPU architecture. The spin lock alignment is byte alignment.\r
  It must be a power of two and is returned by this function. If there are no alignment\r
  requirements, then 1 must be returned. The spin lock synchronization\r
  functions must function correctly if the spin lock size and alignment values\r
  returned by this function are not used at all. These values are hints to the\r
  consumers of the spin lock synchronization functions to obtain optimal spin\r
  lock performance.\r
\r
  @return The architecture specific spin lock alignment.\r
\r
**/\r
UINTN\r
EFIAPI\r
GetSpinLockProperties (\r
  VOID\r
  )\r
{\r
  return 32;\r
}\r
\r
/**\r
  Initializes a spin lock to the released state and returns the spin lock.\r
\r
  This function initializes the spin lock specified by SpinLock to the released\r
  state, and returns SpinLock. Optimal performance can be achieved by calling\r
  GetSpinLockProperties() to determine the size and alignment requirements for\r
  SpinLock.\r
\r
  If SpinLock is NULL, then ASSERT().\r
\r
  @param  SpinLock  A pointer to the spin lock to initialize to the released\r
                    state.\r
\r
  @return SpinLock is in release state.\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
InitializeSpinLock (\r
  OUT      SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  ASSERT (SpinLock != NULL);\r
  *SpinLock = SPIN_LOCK_RELEASED;\r
  return SpinLock;\r
}\r
\r
/**\r
  Waits until a spin lock can be placed in the acquired state.\r
\r
  This function checks the state of the spin lock specified by SpinLock. If\r
  SpinLock is in the released state, then this function places SpinLock in the\r
  acquired state and returns SpinLock. Otherwise, this function waits\r
  indefinitely for the spin lock to be released, and then places it in the\r
  acquired state and returns SpinLock. All state transitions of SpinLock must\r
  be performed using MP safe mechanisms.\r
\r
  If SpinLock is NULL, then ASSERT().\r
  If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
  If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r
  PcdSpinLockTimeout microseconds, then ASSERT().\r
\r
  @param  SpinLock  A pointer to the spin lock to place in the acquired state.\r
\r
  @return SpinLock acquired the lock.\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
AcquireSpinLock (\r
  IN OUT  SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  UINT64  Current;\r
  UINT64  Previous;\r
  UINT64  Total;\r
  UINT64  Start;\r
  UINT64  End;\r
  UINT64  Timeout;\r
  INT64   Cycle;\r
  INT64   Delta;\r
\r
  if (PcdGet32 (PcdSpinLockTimeout) == 0) {\r
    while (!AcquireSpinLockOrFail (SpinLock)) {\r
      CpuPause ();\r
    }\r
  } else if (!AcquireSpinLockOrFail (SpinLock)) {\r
    //\r
    // Get the current timer value\r
    //\r
    Current = GetPerformanceCounter();\r
\r
    //\r
    // Initialize local variables\r
    //\r
    Start = 0;\r
    End   = 0;\r
    Total = 0;\r
\r
    //\r
    // Retrieve the performance counter properties and compute the number of performance\r
    // counter ticks required to reach the timeout\r
    //\r
    Timeout = DivU64x32 (\r
                MultU64x32 (\r
                  GetPerformanceCounterProperties (&Start, &End),\r
                  PcdGet32 (PcdSpinLockTimeout)\r
                  ),\r
                1000000\r
                );\r
    Cycle = End - Start;\r
    if (Cycle < 0) {\r
      Cycle = -Cycle;\r
    }\r
    Cycle++;\r
\r
    while (!AcquireSpinLockOrFail (SpinLock)) {\r
      CpuPause ();\r
      Previous = Current;\r
      Current  = GetPerformanceCounter();\r
      Delta = (INT64) (Current - Previous);\r
      if (Start > End) {\r
        Delta = -Delta;\r
      }\r
      if (Delta < 0) {\r
        Delta += Cycle;\r
      }\r
      Total += Delta;\r
      ASSERT (Total < Timeout);\r
    }\r
  }\r
  return SpinLock;\r
}\r
\r
/**\r
  Attempts to place a spin lock in the acquired state.\r
\r
  This function checks the state of the spin lock specified by SpinLock. If\r
  SpinLock is in the released state, then this function places SpinLock in the\r
  acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r
  transitions of SpinLock must be performed using MP safe mechanisms.\r
\r
  If SpinLock is NULL, then ASSERT().\r
  If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
\r
  @param  SpinLock  A pointer to the spin lock to place in the acquired state.\r
\r
  @retval TRUE  SpinLock was placed in the acquired state.\r
  @retval FALSE SpinLock could not be acquired.\r
\r
**/\r
BOOLEAN\r
EFIAPI\r
AcquireSpinLockOrFail (\r
  IN OUT  SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  SPIN_LOCK    LockValue;\r
\r
  ASSERT (SpinLock != NULL);\r
\r
  LockValue = *SpinLock;\r
  ASSERT (SPIN_LOCK_ACQUIRED == LockValue || SPIN_LOCK_RELEASED == LockValue);\r
\r
  return (BOOLEAN)(\r
           InterlockedCompareExchangePointer (\r
             (VOID**)SpinLock,\r
             (VOID*)SPIN_LOCK_RELEASED,\r
             (VOID*)SPIN_LOCK_ACQUIRED\r
             ) == (VOID*)SPIN_LOCK_RELEASED\r
           );\r
}\r
\r
/**\r
  Releases a spin lock.\r
\r
  This function places the spin lock specified by SpinLock in the release state\r
  and returns SpinLock.\r
\r
  If SpinLock is NULL, then ASSERT().\r
  If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
\r
  @param  SpinLock  A pointer to the spin lock to release.\r
\r
  @return SpinLock released lock.\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
ReleaseSpinLock (\r
  IN OUT  SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  SPIN_LOCK    LockValue;\r
\r
  ASSERT (SpinLock != NULL);\r
\r
  LockValue = *SpinLock;\r
  ASSERT (SPIN_LOCK_ACQUIRED == LockValue || SPIN_LOCK_RELEASED == LockValue);\r
\r
  *SpinLock = SPIN_LOCK_RELEASED;\r
  return SpinLock;\r
}\r
\r
/**\r
  Performs an atomic increment of an 32-bit unsigned integer.\r
\r
  Performs an atomic increment of the 32-bit unsigned integer specified by\r
  Value and returns the incremented value. The increment operation must be\r
  performed using MP safe mechanisms. The state of the return value is not\r
  guaranteed to be MP safe.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value A pointer to the 32-bit value to increment.\r
\r
  @return The incremented value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InterlockedIncrement (\r
  IN      volatile UINT32           *Value\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncIncrement (Value);\r
}\r
\r
/**\r
  Performs an atomic decrement of an 32-bit unsigned integer.\r
\r
  Performs an atomic decrement of the 32-bit unsigned integer specified by\r
  Value and returns the decremented value. The decrement operation must be\r
  performed using MP safe mechanisms. The state of the return value is not\r
  guaranteed to be MP safe.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value A pointer to the 32-bit value to decrement.\r
\r
  @return The decremented value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InterlockedDecrement (\r
  IN      volatile UINT32           *Value\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncDecrement (Value);\r
}\r
\r
/**\r
  Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
\r
  Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
  specified by Value.  If Value is equal to CompareValue, then Value is set to\r
  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,\r
  then Value is returned.  The compare exchange operation must be performed using\r
  MP safe mechanisms.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value         A pointer to the 16-bit value for the compare exchange\r
                        operation.\r
  @param  CompareValue  16-bit value used in compare operation.\r
  @param  ExchangeValue 16-bit value used in exchange operation.\r
\r
  @return The original *Value before exchange.\r
\r
**/\r
UINT16\r
EFIAPI\r
InterlockedCompareExchange16 (\r
  IN OUT  volatile UINT16           *Value,\r
  IN      UINT16                    CompareValue,\r
  IN      UINT16                    ExchangeValue\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);\r
}\r
\r
/**\r
  Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
\r
  Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
  specified by Value.  If Value is equal to CompareValue, then Value is set to\r
  ExchangeValue and CompareValue is returned.  If Value is not equal to CompareValue,\r
  then Value is returned.  The compare exchange operation must be performed using\r
  MP safe mechanisms.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value         A pointer to the 32-bit value for the compare exchange\r
                        operation.\r
  @param  CompareValue  32-bit value used in compare operation.\r
  @param  ExchangeValue 32-bit value used in exchange operation.\r
\r
  @return The original *Value before exchange.\r
\r
**/\r
UINT32\r
EFIAPI\r
InterlockedCompareExchange32 (\r
  IN OUT  volatile UINT32           *Value,\r
  IN      UINT32                    CompareValue,\r
  IN      UINT32                    ExchangeValue\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r
}\r
\r
/**\r
  Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
\r
  Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
  by Value.  If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
  CompareValue is returned.  If Value is not equal to CompareValue, then Value is returned.\r
  The compare exchange operation must be performed using MP safe mechanisms.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value         A pointer to the 64-bit value for the compare exchange\r
                        operation.\r
  @param  CompareValue  64-bit value used in compare operation.\r
  @param  ExchangeValue 64-bit value used in exchange operation.\r
\r
  @return The original *Value before exchange.\r
\r
**/\r
UINT64\r
EFIAPI\r
InterlockedCompareExchange64 (\r
  IN OUT  volatile UINT64           *Value,\r
  IN      UINT64                    CompareValue,\r
  IN      UINT64                    ExchangeValue\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r
}\r
\r
/**\r
  Performs an atomic compare exchange operation on a pointer value.\r
\r
  Performs an atomic compare exchange operation on the pointer value specified\r
  by Value. If Value is equal to CompareValue, then Value is set to\r
  ExchangeValue and CompareValue is returned. If Value is not equal to\r
  CompareValue, then Value is returned. The compare exchange operation must be\r
  performed using MP safe mechanisms.\r
\r
  If Value is NULL, then ASSERT().\r
\r
  @param  Value         A pointer to the pointer value for the compare exchange\r
                        operation.\r
  @param  CompareValue  Pointer value used in compare operation.\r
  @param  ExchangeValue Pointer value used in exchange operation.\r
\r
  @return The original *Value before exchange.\r
**/\r
VOID *\r
EFIAPI\r
InterlockedCompareExchangePointer (\r
  IN OUT  VOID                      * volatile *Value,\r
  IN      VOID                      *CompareValue,\r
  IN      VOID                      *ExchangeValue\r
  )\r
{\r
  UINT8  SizeOfValue;\r
\r
  SizeOfValue = sizeof (*Value);\r
\r
  switch (SizeOfValue) {\r
    case sizeof (UINT32):\r
      return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
                             (volatile UINT32 *)Value,\r
                             (UINT32)(UINTN)CompareValue,\r
                             (UINT32)(UINTN)ExchangeValue\r
                             );\r
    case sizeof (UINT64):\r
      return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
                             (volatile UINT64 *)Value,\r
                             (UINT64)(UINTN)CompareValue,\r
                             (UINT64)(UINTN)ExchangeValue\r
                             );\r
    default:\r
      ASSERT (FALSE);\r
      return NULL;\r
  }\r
}\r
Commit	Line	Data
720d3c5f	1	/** @file\r
	2	Implementation of synchronization functions.\r
	3	\r
9095d37b	4	Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.<BR>\r
e2d9bfb2	5	This program and the accompanying materials\r
720d3c5f	6	are licensed and made available under the terms and conditions of the BSD License\r
720d3c5f	7	which accompanies this distribution. The full text of the license may be found at\r
2fc59a00	8	http://opensource.org/licenses/bsd-license.php.\r
720d3c5f	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	**/\r
	14	\r
	15	#include "BaseSynchronizationLibInternals.h"\r
	16	\r
	17	#define SPIN_LOCK_RELEASED ((UINTN) 1)\r
	18	#define SPIN_LOCK_ACQUIRED ((UINTN) 2)\r
	19	\r
	20	/**\r
	21	Retrieves the architecture specific spin lock alignment requirements for\r
	22	optimal spin lock performance.\r
	23	\r
	24	This function retrieves the spin lock alignment requirements for optimal\r
9095d37b	25	performance on a given CPU architecture. The spin lock alignment is byte alignment.\r
744265eb	26	It must be a power of two and is returned by this function. If there are no alignment\r
720d3c5f	27	requirements, then 1 must be returned. The spin lock synchronization\r
	28	functions must function correctly if the spin lock size and alignment values\r
	29	returned by this function are not used at all. These values are hints to the\r
	30	consumers of the spin lock synchronization functions to obtain optimal spin\r
	31	lock performance.\r
	32	\r
	33	@return The architecture specific spin lock alignment.\r
	34	\r
	35	**/\r
	36	UINTN\r
	37	EFIAPI\r
	38	GetSpinLockProperties (\r
	39	VOID\r
	40	)\r
	41	{\r
	42	return 32;\r
	43	}\r
	44	\r
	45	/**\r
	46	Initializes a spin lock to the released state and returns the spin lock.\r
	47	\r
	48	This function initializes the spin lock specified by SpinLock to the released\r
	49	state, and returns SpinLock. Optimal performance can be achieved by calling\r
	50	GetSpinLockProperties() to determine the size and alignment requirements for\r
	51	SpinLock.\r
	52	\r
	53	If SpinLock is NULL, then ASSERT().\r
	54	\r
	55	@param SpinLock A pointer to the spin lock to initialize to the released\r
	56	state.\r
	57	\r
2fc59a00	58	@return SpinLock is in release state.\r
720d3c5f	59	\r
	60	**/\r
	61	SPIN_LOCK *\r
	62	EFIAPI\r
	63	InitializeSpinLock (\r
	64	OUT SPIN_LOCK *SpinLock\r
	65	)\r
	66	{\r
	67	ASSERT (SpinLock != NULL);\r
	68	*SpinLock = SPIN_LOCK_RELEASED;\r
	69	return SpinLock;\r
	70	}\r
	71	\r
	72	/**\r
	73	Waits until a spin lock can be placed in the acquired state.\r
	74	\r
	75	This function checks the state of the spin lock specified by SpinLock. If\r
	76	SpinLock is in the released state, then this function places SpinLock in the\r
	77	acquired state and returns SpinLock. Otherwise, this function waits\r
	78	indefinitely for the spin lock to be released, and then places it in the\r
	79	acquired state and returns SpinLock. All state transitions of SpinLock must\r
	80	be performed using MP safe mechanisms.\r
	81	\r
	82	If SpinLock is NULL, then ASSERT().\r
	83	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	84	If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r
	85	PcdSpinLockTimeout microseconds, then ASSERT().\r
	86	\r
	87	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	88	\r
2fc59a00	89	@return SpinLock acquired the lock.\r
720d3c5f	90	\r
	91	**/\r
	92	SPIN_LOCK *\r
	93	EFIAPI\r
	94	AcquireSpinLock (\r
	95	IN OUT SPIN_LOCK *SpinLock\r
	96	)\r
	97	{\r
	98	UINT64 Current;\r
	99	UINT64 Previous;\r
	100	UINT64 Total;\r
	101	UINT64 Start;\r
	102	UINT64 End;\r
	103	UINT64 Timeout;\r
	104	INT64 Cycle;\r
	105	INT64 Delta;\r
	106	\r
0f18e1ed JF	107	if (PcdGet32 (PcdSpinLockTimeout) == 0) {\r
	108	while (!AcquireSpinLockOrFail (SpinLock)) {\r
	109	CpuPause ();\r
	110	}\r
	111	} else if (!AcquireSpinLockOrFail (SpinLock)) {\r
720d3c5f	112	//\r
	113	// Get the current timer value\r
	114	//\r
	115	Current = GetPerformanceCounter();\r
	116	\r
	117	//\r
	118	// Initialize local variables\r
	119	//\r
	120	Start = 0;\r
	121	End = 0;\r
	122	Total = 0;\r
	123	\r
	124	//\r
	125	// Retrieve the performance counter properties and compute the number of performance\r
	126	// counter ticks required to reach the timeout\r
	127	//\r
	128	Timeout = DivU64x32 (\r
	129	MultU64x32 (\r
	130	GetPerformanceCounterProperties (&Start, &End),\r
	131	PcdGet32 (PcdSpinLockTimeout)\r
	132	),\r
	133	1000000\r
	134	);\r
	135	Cycle = End - Start;\r
	136	if (Cycle < 0) {\r
	137	Cycle = -Cycle;\r
	138	}\r
	139	Cycle++;\r
	140	\r
	141	while (!AcquireSpinLockOrFail (SpinLock)) {\r
	142	CpuPause ();\r
	143	Previous = Current;\r
	144	Current = GetPerformanceCounter();\r
	145	Delta = (INT64) (Current - Previous);\r
	146	if (Start > End) {\r
	147	Delta = -Delta;\r
	148	}\r
	149	if (Delta < 0) {\r
	150	Delta += Cycle;\r
	151	}\r
	152	Total += Delta;\r
	153	ASSERT (Total < Timeout);\r
	154	}\r
720d3c5f	155	}\r
	156	return SpinLock;\r
	157	}\r
	158	\r
	159	/**\r
	160	Attempts to place a spin lock in the acquired state.\r
	161	\r
	162	This function checks the state of the spin lock specified by SpinLock. If\r
	163	SpinLock is in the released state, then this function places SpinLock in the\r
	164	acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r
	165	transitions of SpinLock must be performed using MP safe mechanisms.\r
	166	\r
	167	If SpinLock is NULL, then ASSERT().\r
	168	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	169	\r
	170	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	171	\r
	172	@retval TRUE SpinLock was placed in the acquired state.\r
	173	@retval FALSE SpinLock could not be acquired.\r
	174	\r
	175	**/\r
	176	BOOLEAN\r
	177	EFIAPI\r
	178	AcquireSpinLockOrFail (\r
	179	IN OUT SPIN_LOCK *SpinLock\r
	180	)\r
	181	{\r
	182	SPIN_LOCK LockValue;\r
	183	\r
	184	ASSERT (SpinLock != NULL);\r
	185	\r
	186	LockValue = *SpinLock;\r
	187	ASSERT (SPIN_LOCK_ACQUIRED == LockValue \|\| SPIN_LOCK_RELEASED == LockValue);\r
	188	\r
	189	return (BOOLEAN)(\r
	190	InterlockedCompareExchangePointer (\r
	191	(VOID**)SpinLock,\r
	192	(VOID*)SPIN_LOCK_RELEASED,\r
	193	(VOID*)SPIN_LOCK_ACQUIRED\r
	194	) == (VOID*)SPIN_LOCK_RELEASED\r
	195	);\r
	196	}\r
	197	\r
	198	/**\r
	199	Releases a spin lock.\r
	200	\r
	201	This function places the spin lock specified by SpinLock in the release state\r
	202	and returns SpinLock.\r
	203	\r
	204	If SpinLock is NULL, then ASSERT().\r
	205	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	206	\r
	207	@param SpinLock A pointer to the spin lock to release.\r
	208	\r
	209	@return SpinLock released lock.\r
	210	\r
	211	**/\r
	212	SPIN_LOCK *\r
	213	EFIAPI\r
	214	ReleaseSpinLock (\r
	215	IN OUT SPIN_LOCK *SpinLock\r
	216	)\r
	217	{\r
	218	SPIN_LOCK LockValue;\r
219	\r
220	ASSERT (SpinLock != NULL);\r
221	\r
222	LockValue = *SpinLock;\r
223	ASSERT (SPIN_LOCK_ACQUIRED == LockValue \|\| SPIN_LOCK_RELEASED == LockValue);\r
224	\r
225	*SpinLock = SPIN_LOCK_RELEASED;\r
226	return SpinLock;\r
227	}\r
228	\r
229	/**\r
230	Performs an atomic increment of an 32-bit unsigned integer.\r
231	\r
232	Performs an atomic increment of the 32-bit unsigned integer specified by\r
233	Value and returns the incremented value. The increment operation must be\r
234	performed using MP safe mechanisms. The state of the return value is not\r
235	guaranteed to be MP safe.\r
236	\r
237	If Value is NULL, then ASSERT().\r
238	\r
239	@param Value A pointer to the 32-bit value to increment.\r
240	\r
241	@return The incremented value.\r
242	\r
243	**/\r
244	UINT32\r
245	EFIAPI\r
246	InterlockedIncrement (\r
4cee954e	247	IN volatile UINT32 *Value\r
720d3c5f	248	)\r
	249	{\r
	250	ASSERT (Value != NULL);\r
	251	return InternalSyncIncrement (Value);\r
	252	}\r
	253	\r
	254	/**\r
	255	Performs an atomic decrement of an 32-bit unsigned integer.\r
	256	\r
	257	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	258	Value and returns the decremented value. The decrement operation must be\r
	259	performed using MP safe mechanisms. The state of the return value is not\r
	260	guaranteed to be MP safe.\r
	261	\r
	262	If Value is NULL, then ASSERT().\r
	263	\r
	264	@param Value A pointer to the 32-bit value to decrement.\r
	265	\r
	266	@return The decremented value.\r
	267	\r
	268	**/\r
	269	UINT32\r
	270	EFIAPI\r
	271	InterlockedDecrement (\r
4cee954e	272	IN volatile UINT32 *Value\r
720d3c5f	273	)\r
	274	{\r
	275	ASSERT (Value != NULL);\r
	276	return InternalSyncDecrement (Value);\r
	277	}\r
	278	\r
9b89163e AB	279	/**\r
	280	Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	281	\r
	282	Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	283	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	284	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	285	then Value is returned. The compare exchange operation must be performed using\r
	286	MP safe mechanisms.\r
	287	\r
	288	If Value is NULL, then ASSERT().\r
	289	\r
	290	@param Value A pointer to the 16-bit value for the compare exchange\r
	291	operation.\r
	292	@param CompareValue 16-bit value used in compare operation.\r
	293	@param ExchangeValue 16-bit value used in exchange operation.\r
	294	\r
	295	@return The original *Value before exchange.\r
	296	\r
	297	**/\r
	298	UINT16\r
	299	EFIAPI\r
	300	InterlockedCompareExchange16 (\r
4cee954e	301	IN OUT volatile UINT16 *Value,\r
9b89163e AB	302	IN UINT16 CompareValue,\r
	303	IN UINT16 ExchangeValue\r
	304	)\r
	305	{\r
	306	ASSERT (Value != NULL);\r
	307	return InternalSyncCompareExchange16 (Value, CompareValue, ExchangeValue);\r
	308	}\r
	309	\r
720d3c5f	310	/**\r
	311	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	312	\r
	313	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	314	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	315	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	316	then Value is returned. The compare exchange operation must be performed using\r
	317	MP safe mechanisms.\r
	318	\r
	319	If Value is NULL, then ASSERT().\r
	320	\r
	321	@param Value A pointer to the 32-bit value for the compare exchange\r
	322	operation.\r
	323	@param CompareValue 32-bit value used in compare operation.\r
	324	@param ExchangeValue 32-bit value used in exchange operation.\r
	325	\r
	326	@return The original *Value before exchange.\r
	327	\r
	328	**/\r
	329	UINT32\r
	330	EFIAPI\r
	331	InterlockedCompareExchange32 (\r
4cee954e	332	IN OUT volatile UINT32 *Value,\r
720d3c5f	333	IN UINT32 CompareValue,\r
	334	IN UINT32 ExchangeValue\r
	335	)\r
	336	{\r
	337	ASSERT (Value != NULL);\r
	338	return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r
	339	}\r
	340	\r
	341	/**\r
	342	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	343	\r
	344	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
	345	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
	346	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
	347	The compare exchange operation must be performed using MP safe mechanisms.\r
	348	\r
	349	If Value is NULL, then ASSERT().\r
	350	\r
	351	@param Value A pointer to the 64-bit value for the compare exchange\r
	352	operation.\r
	353	@param CompareValue 64-bit value used in compare operation.\r
	354	@param ExchangeValue 64-bit value used in exchange operation.\r
	355	\r
	356	@return The original *Value before exchange.\r
	357	\r
	358	**/\r
	359	UINT64\r
	360	EFIAPI\r
	361	InterlockedCompareExchange64 (\r
4cee954e	362	IN OUT volatile UINT64 *Value,\r
720d3c5f	363	IN UINT64 CompareValue,\r
	364	IN UINT64 ExchangeValue\r
	365	)\r
	366	{\r
	367	ASSERT (Value != NULL);\r
	368	return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r
	369	}\r
	370	\r
	371	/**\r
	372	Performs an atomic compare exchange operation on a pointer value.\r
	373	\r
	374	Performs an atomic compare exchange operation on the pointer value specified\r
	375	by Value. If Value is equal to CompareValue, then Value is set to\r
	376	ExchangeValue and CompareValue is returned. If Value is not equal to\r
	377	CompareValue, then Value is returned. The compare exchange operation must be\r
	378	performed using MP safe mechanisms.\r
	379	\r
	380	If Value is NULL, then ASSERT().\r
	381	\r
	382	@param Value A pointer to the pointer value for the compare exchange\r
	383	operation.\r
	384	@param CompareValue Pointer value used in compare operation.\r
	385	@param ExchangeValue Pointer value used in exchange operation.\r
	386	\r
	387	@return The original *Value before exchange.\r
	388	**/\r
	389	VOID *\r
	390	EFIAPI\r
	391	InterlockedCompareExchangePointer (\r
4cee954e	392	IN OUT VOID * volatile *Value,\r
720d3c5f	393	IN VOID *CompareValue,\r
	394	IN VOID *ExchangeValue\r
	395	)\r
	396	{\r
	397	UINT8 SizeOfValue;\r
	398	\r
	399	SizeOfValue = sizeof (*Value);\r
	400	\r
	401	switch (SizeOfValue) {\r
	402	case sizeof (UINT32):\r
	403	return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
4cee954e	404	(volatile UINT32 *)Value,\r
720d3c5f	405	(UINT32)(UINTN)CompareValue,\r
	406	(UINT32)(UINTN)ExchangeValue\r
	407	);\r
	408	case sizeof (UINT64):\r
	409	return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
4cee954e	410	(volatile UINT64 *)Value,\r
720d3c5f	411	(UINT64)(UINTN)CompareValue,\r
	412	(UINT64)(UINTN)ExchangeValue\r
	413	);\r
	414	default:\r
	415	ASSERT (FALSE);\r
	416	return NULL;\r
	417	}\r
	418	}\r