[mirror_edk2.git] / MdePkg / Library / BaseLib / SynchronizationGcc.c

/** @file\r
  Implementation of synchronization functions.\r
\r
  Copyright (c) 2006 - 2007, Intel Corporation<BR>\r
  All rights reserved. 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
  Module Name:  SynchronizationGcc.c\r
\r
**/\r
\r
#include "BaseLibInternals.h"\r
\r
//\r
// GCC inline assembly for Read Write Barrier  \r
//\r
#define _ReadWriteBarrier() do { asm volatile ("": : : "memory"); } while(0)\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 must be a\r
  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
  // @bug May use a PCD entry to determine this alignment.\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\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
InitializeSpinLock (\r
  OUT     SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  ASSERT (SpinLock != NULL);\r
\r
  _ReadWriteBarrier();\r
  *SpinLock = SPIN_LOCK_RELEASED;\r
  _ReadWriteBarrier();\r
\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\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
AcquireSpinLock (\r
  IN OUT  SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  UINT64                            Tick;\r
  UINT64                            Start, End;\r
  UINT64                            Timeout;\r
\r
  Tick = 0;\r
  Start = 0;\r
  End = 0;\r
  if (PcdGet32 (PcdSpinLockTimeout) > 0) {\r
    Tick = GetPerformanceCounter ();\r
    Timeout = DivU64x32 (\r
                MultU64x32 (\r
                  GetPerformanceCounterProperties (&Start, &End),\r
                  PcdGet32 (PcdSpinLockTimeout)\r
                  ),\r
                1000000\r
                );\r
    if (Start < End) {\r
      Tick += Timeout;\r
    } else {\r
      Tick -= Timeout;\r
    }\r
  }\r
\r
  while (!AcquireSpinLockOrFail (SpinLock)) {\r
    CpuPause ();\r
    ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));\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
  VOID  *Result;\r
  \r
  ASSERT (SpinLock != NULL);\r
  ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED);\r
\r
  _ReadWriteBarrier ();\r
  Result = InterlockedCompareExchangePointer (\r
             (VOID**)SpinLock,\r
             (VOID*)SPIN_LOCK_RELEASED,\r
             (VOID*)SPIN_LOCK_ACQUIRED\r
           );\r
\r
  _ReadWriteBarrier ();\r
  return (BOOLEAN) (Result == (VOID*) SPIN_LOCK_RELEASED);\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\r
\r
**/\r
SPIN_LOCK *\r
EFIAPI\r
ReleaseSpinLock (\r
  IN OUT  SPIN_LOCK                 *SpinLock\r
  )\r
{\r
  ASSERT (SpinLock != NULL);\r
  ASSERT (*SpinLock == SPIN_LOCK_ACQUIRED || *SpinLock == SPIN_LOCK_RELEASED);\r
\r
  _ReadWriteBarrier ();\r
  *SpinLock = SPIN_LOCK_RELEASED;\r
  _ReadWriteBarrier ();\r
\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      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      UINT32                    *Value\r
  )\r
{\r
  ASSERT (Value != NULL);\r
  return InternalSyncDecrement (Value);\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  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  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
**/\r
VOID *\r
EFIAPI\r
InterlockedCompareExchangePointer (\r
  IN OUT  VOID                      **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
                             (UINT32*)Value,\r
                             (UINT32)(UINTN)CompareValue,\r
                             (UINT32)(UINTN)ExchangeValue\r
                             );\r
    case sizeof (UINT64):\r
      return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
                             (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
878ddf1f	1	/** @file\r
	2	Implementation of synchronization functions.\r
	3	\r
ef7baf58	4	Copyright (c) 2006 - 2007, Intel Corporation<BR>\r
878ddf1f	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
ef7baf58	13	Module Name: SynchronizationGcc.c\r
878ddf1f	14	\r
	15	**/\r
	16	\r
58251024	17	#include "BaseLibInternals.h"\r
58251024	18	\r
eb9603a0	19	//\r
ef7baf58	20	// GCC inline assembly for Read Write Barrier \r
eb9603a0	21	//\r
ef7baf58	22	#define _ReadWriteBarrier() do { asm volatile ("": : : "memory"); } while(0)\r
ef7baf58	23	\r
46dd23b8	24	#define SPIN_LOCK_RELEASED ((UINTN) 1)\r
46dd23b8	25	#define SPIN_LOCK_ACQUIRED ((UINTN) 2)\r
878ddf1f	26	\r
878ddf1f	27	/**\r
	28	Retrieves the architecture specific spin lock alignment requirements for\r
	29	optimal spin lock performance.\r
	30	\r
	31	This function retrieves the spin lock alignment requirements for optimal\r
	32	performance on a given CPU architecture. The spin lock alignment must be a\r
	33	power of two and is returned by this function. If there are no alignment\r
	34	requirements, then 1 must be returned. The spin lock synchronization\r
	35	functions must function correctly if the spin lock size and alignment values\r
	36	returned by this function are not used at all. These values are hints to the\r
	37	consumers of the spin lock synchronization functions to obtain optimal spin\r
	38	lock performance.\r
	39	\r
	40	@return The architecture specific spin lock alignment.\r
	41	\r
	42	**/\r
	43	UINTN\r
	44	EFIAPI\r
	45	GetSpinLockProperties (\r
	46	VOID\r
	47	)\r
	48	{\r
	49	// @bug May use a PCD entry to determine this alignment.\r
	50	return 32;\r
	51	}\r
	52	\r
	53	/**\r
	54	Initializes a spin lock to the released state and returns the spin lock.\r
	55	\r
	56	This function initializes the spin lock specified by SpinLock to the released\r
	57	state, and returns SpinLock. Optimal performance can be achieved by calling\r
	58	GetSpinLockProperties() to determine the size and alignment requirements for\r
	59	SpinLock.\r
	60	\r
	61	If SpinLock is NULL, then ASSERT().\r
	62	\r
	63	@param SpinLock A pointer to the spin lock to initialize to the released\r
	64	state.\r
	65	\r
	66	@return SpinLock\r
	67	\r
	68	**/\r
	69	SPIN_LOCK *\r
	70	EFIAPI\r
	71	InitializeSpinLock (\r
	72	OUT SPIN_LOCK *SpinLock\r
	73	)\r
	74	{\r
	75	ASSERT (SpinLock != NULL);\r
ef7baf58	76	\r
ef7baf58	77	_ReadWriteBarrier();\r
27787243	78	*SpinLock = SPIN_LOCK_RELEASED;\r
ef7baf58	79	_ReadWriteBarrier();\r
ef7baf58	80	\r
878ddf1f	81	return SpinLock;\r
	82	}\r
	83	\r
	84	/**\r
	85	Waits until a spin lock can be placed in the acquired state.\r
	86	\r
	87	This function checks the state of the spin lock specified by SpinLock. If\r
	88	SpinLock is in the released state, then this function places SpinLock in the\r
	89	acquired state and returns SpinLock. Otherwise, this function waits\r
	90	indefinitely for the spin lock to be released, and then places it in the\r
	91	acquired state and returns SpinLock. All state transitions of SpinLock must\r
	92	be performed using MP safe mechanisms.\r
	93	\r
	94	If SpinLock is NULL, then ASSERT().\r
	95	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	96	If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r
	97	PcdSpinLockTimeout microseconds, then ASSERT().\r
	98	\r
	99	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	100	\r
	101	@return SpinLock\r
	102	\r
	103	**/\r
	104	SPIN_LOCK *\r
	105	EFIAPI\r
	106	AcquireSpinLock (\r
	107	IN OUT SPIN_LOCK *SpinLock\r
	108	)\r
	109	{\r
	110	UINT64 Tick;\r
	111	UINT64 Start, End;\r
	112	UINT64 Timeout;\r
	113	\r
	114	Tick = 0;\r
	115	Start = 0;\r
	116	End = 0;\r
dc530c7b	117	if (PcdGet32 (PcdSpinLockTimeout) > 0) {\r
878ddf1f	118	Tick = GetPerformanceCounter ();\r
	119	Timeout = DivU64x32 (\r
	120	MultU64x32 (\r
	121	GetPerformanceCounterProperties (&Start, &End),\r
dc530c7b	122	PcdGet32 (PcdSpinLockTimeout)\r
878ddf1f	123	),\r
	124	1000000\r
	125	);\r
	126	if (Start < End) {\r
	127	Tick += Timeout;\r
	128	} else {\r
	129	Tick -= Timeout;\r
	130	}\r
	131	}\r
	132	\r
	133	while (!AcquireSpinLockOrFail (SpinLock)) {\r
	134	CpuPause ();\r
	135	ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));\r
	136	}\r
	137	return SpinLock;\r
	138	}\r
	139	\r
	140	/**\r
	141	Attempts to place a spin lock in the acquired state.\r
	142	\r
	143	This function checks the state of the spin lock specified by SpinLock. If\r
	144	SpinLock is in the released state, then this function places SpinLock in the\r
	145	acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r
	146	transitions of SpinLock must be performed using MP safe mechanisms.\r
	147	\r
	148	If SpinLock is NULL, then ASSERT().\r
	149	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	150	\r
	151	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	152	\r
	153	@retval TRUE SpinLock was placed in the acquired state.\r
	154	@retval FALSE SpinLock could not be acquired.\r
	155	\r
	156	**/\r
	157	BOOLEAN\r
	158	EFIAPI\r
	159	AcquireSpinLockOrFail (\r
	160	IN OUT SPIN_LOCK *SpinLock\r
	161	)\r
	162	{\r
ef7baf58	163	VOID *Result;\r
ef7baf58	164	\r
878ddf1f	165	ASSERT (SpinLock != NULL);\r
ef7baf58	166	ASSERT (SpinLock == SPIN_LOCK_ACQUIRED \|\| SpinLock == SPIN_LOCK_RELEASED);\r
c9708ddd	167	\r
ef7baf58	168	_ReadWriteBarrier ();\r
ef7baf58	169	Result = InterlockedCompareExchangePointer (\r
878ddf1f	170	(VOID**)SpinLock,\r
	171	(VOID*)SPIN_LOCK_RELEASED,\r
	172	(VOID*)SPIN_LOCK_ACQUIRED\r
878ddf1f	173	);\r
ef7baf58	174	\r
	175	_ReadWriteBarrier ();\r
	176	return (BOOLEAN) (Result == (VOID*) SPIN_LOCK_RELEASED);\r
878ddf1f	177	}\r
	178	\r
	179	/**\r
	180	Releases a spin lock.\r
	181	\r
	182	This function places the spin lock specified by SpinLock in the release state\r
	183	and returns SpinLock.\r
	184	\r
	185	If SpinLock is NULL, then ASSERT().\r
	186	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	187	\r
	188	@param SpinLock A pointer to the spin lock to release.\r
	189	\r
	190	@return SpinLock\r
	191	\r
	192	**/\r
	193	SPIN_LOCK *\r
	194	EFIAPI\r
	195	ReleaseSpinLock (\r
	196	IN OUT SPIN_LOCK *SpinLock\r
	197	)\r
	198	{\r
	199	ASSERT (SpinLock != NULL);\r
ef7baf58	200	ASSERT (SpinLock == SPIN_LOCK_ACQUIRED \|\| SpinLock == SPIN_LOCK_RELEASED);\r
c9708ddd	201	\r
ef7baf58	202	_ReadWriteBarrier ();\r
27787243	203	*SpinLock = SPIN_LOCK_RELEASED;\r
ef7baf58	204	_ReadWriteBarrier ();\r
ef7baf58	205	\r
878ddf1f	206	return SpinLock;\r
	207	}\r
	208	\r
	209	/**\r
	210	Performs an atomic increment of an 32-bit unsigned integer.\r
	211	\r
	212	Performs an atomic increment of the 32-bit unsigned integer specified by\r
	213	Value and returns the incremented value. The increment operation must be\r
	214	performed using MP safe mechanisms. The state of the return value is not\r
	215	guaranteed to be MP safe.\r
	216	\r
	217	If Value is NULL, then ASSERT().\r
	218	\r
	219	@param Value A pointer to the 32-bit value to increment.\r
	220	\r
	221	@return The incremented value.\r
	222	\r
	223	**/\r
	224	UINT32\r
	225	EFIAPI\r
	226	InterlockedIncrement (\r
	227	IN UINT32 *Value\r
	228	)\r
	229	{\r
	230	ASSERT (Value != NULL);\r
	231	return InternalSyncIncrement (Value);\r
	232	}\r
	233	\r
	234	/**\r
	235	Performs an atomic decrement of an 32-bit unsigned integer.\r
	236	\r
	237	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	238	Value and returns the decremented value. The decrement operation must be\r
	239	performed using MP safe mechanisms. The state of the return value is not\r
	240	guaranteed to be MP safe.\r
	241	\r
	242	If Value is NULL, then ASSERT().\r
	243	\r
	244	@param Value A pointer to the 32-bit value to decrement.\r
	245	\r
	246	@return The decremented value.\r
	247	\r
	248	**/\r
	249	UINT32\r
	250	EFIAPI\r
	251	InterlockedDecrement (\r
	252	IN UINT32 *Value\r
	253	)\r
	254	{\r
	255	ASSERT (Value != NULL);\r
	256	return InternalSyncDecrement (Value);\r
	257	}\r
	258	\r
	259	/**\r
	260	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	261	\r
1ea5ca46	262	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	263	specified by Value. If Value is equal to CompareValue, then Value is set to \r
	264	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	265	then Value is returned. The compare exchange operation must be performed using \r
	266	MP safe mechanisms.\r
	267	\r
	268	If Value is NULL, then ASSERT().\r
	269	\r
878ddf1f	270	@param Value A pointer to the 32-bit value for the compare exchange\r
	271	operation.\r
	272	@param CompareValue 32-bit value used in compare operation.\r
	273	@param ExchangeValue 32-bit value used in exchange operation.\r
	274	\r
	275	@return The original *Value before exchange.\r
	276	\r
	277	**/\r
	278	UINT32\r
	279	EFIAPI\r
	280	InterlockedCompareExchange32 (\r
0ffa1286	281	IN OUT UINT32 *Value,\r
878ddf1f	282	IN UINT32 CompareValue,\r
	283	IN UINT32 ExchangeValue\r
	284	)\r
	285	{\r
	286	ASSERT (Value != NULL);\r
	287	return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r
	288	}\r
	289	\r
	290	/**\r
	291	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	292	\r
1ea5ca46	293	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r
	294	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and \r
	295	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. \r
	296	The compare exchange operation must be performed using MP safe mechanisms.\r
	297	\r
	298	If Value is NULL, then ASSERT().\r
	299	\r
878ddf1f	300	@param Value A pointer to the 64-bit value for the compare exchange\r
	301	operation.\r
	302	@param CompareValue 64-bit value used in compare operation.\r
	303	@param ExchangeValue 64-bit value used in exchange operation.\r
	304	\r
	305	@return The original *Value before exchange.\r
	306	\r
	307	**/\r
	308	UINT64\r
	309	EFIAPI\r
	310	InterlockedCompareExchange64 (\r
0ffa1286	311	IN OUT UINT64 *Value,\r
878ddf1f	312	IN UINT64 CompareValue,\r
	313	IN UINT64 ExchangeValue\r
	314	)\r
	315	{\r
	316	ASSERT (Value != NULL);\r
	317	return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r
	318	}\r
	319	\r
	320	/**\r
	321	Performs an atomic compare exchange operation on a pointer value.\r
	322	\r
	323	Performs an atomic compare exchange operation on the pointer value specified\r
	324	by Value. If Value is equal to CompareValue, then Value is set to\r
	325	ExchangeValue and CompareValue is returned. If Value is not equal to\r
	326	CompareValue, then Value is returned. The compare exchange operation must be\r
	327	performed using MP safe mechanisms.\r
	328	\r
	329	If Value is NULL, then ASSERT().\r
	330	\r
	331	@param Value A pointer to the pointer value for the compare exchange\r
	332	operation.\r
	333	@param CompareValue Pointer value used in compare operation.\r
	334	@param ExchangeValue Pointer value used in exchange operation.\r
	335	\r
	336	**/\r
	337	VOID *\r
	338	EFIAPI\r
	339	InterlockedCompareExchangePointer (\r
0ffa1286	340	IN OUT VOID **Value,\r
878ddf1f	341	IN VOID *CompareValue,\r
	342	IN VOID *ExchangeValue\r
	343	)\r
	344	{\r
58251024	345	UINT8 SizeOfValue;\r
	346	\r
	347	SizeOfValue = sizeof (*Value);\r
	348	\r
	349	switch (SizeOfValue) {\r
878ddf1f	350	case sizeof (UINT32):\r
	351	return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
	352	(UINT32*)Value,\r
	353	(UINT32)(UINTN)CompareValue,\r
	354	(UINT32)(UINTN)ExchangeValue\r
	355	);\r
	356	case sizeof (UINT64):\r
	357	return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
	358	(UINT64*)Value,\r
	359	(UINT64)(UINTN)CompareValue,\r
	360	(UINT64)(UINTN)ExchangeValue\r
	361	);\r
	362	default:\r
	363	ASSERT (FALSE);\r
	364	return NULL;\r
	365	}\r
	366	}\r