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

/** @file\r
  Implementation of synchronization functions.\r
\r
  Copyright (c) 2006, 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:  Synchronization.c\r
\r
**/\r
\r
#define SPIN_LOCK_RELEASED          ((SPIN_LOCK)1)\r
#define SPIN_LOCK_ACQUIRED          ((SPIN_LOCK)2)\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
  @param  Value A pointer to the 32-bit value to increment.\r
\r
  @return The incremented value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InternalSyncIncrement (\r
  IN      volatile UINT32           *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 decrement 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
  @param  Value A pointer to the 32-bit value to decrement.\r
\r
  @return The decrement value.\r
\r
**/\r
UINT32\r
EFIAPI\r
InternalSyncDecrement (\r
  IN      volatile UINT32           *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
  @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
InternalSyncCompareExchange32 (\r
  IN      volatile UINT32           *Value,\r
  IN      UINT32                    CompareValue,\r
  IN      UINT32                    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
  @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
InternalSyncCompareExchange64 (\r
  IN      volatile UINT64           *Value,\r
  IN      UINT64                    CompareValue,\r
  IN      UINT64                    ExchangeValue\r
  );\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
  *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\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
  volatile SPIN_LOCK    LockValue;\r
\r
  ASSERT (SpinLock != NULL);\r
\r
  LockValue = *SpinLock;\r
  ASSERT (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);\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\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 (LockValue == SPIN_LOCK_ACQUIRED || LockValue == SPIN_LOCK_RELEASED);\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      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
  switch (sizeof (*Value)) {\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
	4	Copyright (c) 2006, Intel Corporation<BR>\r
	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
	13	Module Name: Synchronization.c\r
	14	\r
	15	**/\r
	16	\r
27787243	17	#define SPIN_LOCK_RELEASED ((SPIN_LOCK)1)\r
27787243	18	#define SPIN_LOCK_ACQUIRED ((SPIN_LOCK)2)\r
878ddf1f	19	\r
1ea5ca46	20	/**\r
	21	Performs an atomic increment of an 32-bit unsigned integer.\r
	22	\r
	23	Performs an atomic increment of the 32-bit unsigned integer specified by\r
	24	Value and returns the incremented value. The increment operation must be\r
	25	performed using MP safe mechanisms. The state of the return value is not\r
	26	guaranteed to be MP safe.\r
	27	\r
	28	@param Value A pointer to the 32-bit value to increment.\r
	29	\r
	30	@return The incremented value.\r
	31	\r
	32	**/\r
878ddf1f	33	UINT32\r
	34	EFIAPI\r
	35	InternalSyncIncrement (\r
	36	IN volatile UINT32 *Value\r
	37	);\r
	38	\r
1ea5ca46	39	/**\r
	40	Performs an atomic decrement of an 32-bit unsigned integer.\r
	41	\r
	42	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	43	Value and returns the decrement value. The decrement operation must be\r
	44	performed using MP safe mechanisms. The state of the return value is not\r
	45	guaranteed to be MP safe.\r
	46	\r
	47	@param Value A pointer to the 32-bit value to decrement.\r
	48	\r
	49	@return The decrement value.\r
	50	\r
	51	**/\r
878ddf1f	52	UINT32\r
	53	EFIAPI\r
	54	InternalSyncDecrement (\r
	55	IN volatile UINT32 *Value\r
	56	);\r
	57	\r
1ea5ca46	58	/**\r
	59	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	60	\r
	61	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	62	specified by Value. If Value is equal to CompareValue, then Value is set to \r
	63	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	64	then Value is returned. The compare exchange operation must be performed using \r
	65	MP safe mechanisms.\r
	66	\r
	67	@param Value A pointer to the 32-bit value for the compare exchange\r
	68	operation.\r
	69	@param CompareValue 32-bit value used in compare operation.\r
	70	@param ExchangeValue 32-bit value used in exchange operation.\r
	71	\r
	72	@return The original *Value before exchange.\r
	73	\r
	74	**/\r
878ddf1f	75	UINT32\r
	76	EFIAPI\r
	77	InternalSyncCompareExchange32 (\r
	78	IN volatile UINT32 *Value,\r
	79	IN UINT32 CompareValue,\r
	80	IN UINT32 ExchangeValue\r
	81	);\r
	82	\r
1ea5ca46	83	/**\r
	84	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	85	\r
	86	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r
	87	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and \r
	88	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. \r
	89	The compare exchange operation must be performed using MP safe mechanisms.\r
	90	\r
	91	@param Value A pointer to the 64-bit value for the compare exchange\r
	92	operation.\r
	93	@param CompareValue 64-bit value used in compare operation.\r
	94	@param ExchangeValue 64-bit value used in exchange operation.\r
	95	\r
	96	@return The original *Value before exchange.\r
	97	\r
	98	**/\r
878ddf1f	99	UINT64\r
	100	EFIAPI\r
	101	InternalSyncCompareExchange64 (\r
	102	IN volatile UINT64 *Value,\r
	103	IN UINT64 CompareValue,\r
	104	IN UINT64 ExchangeValue\r
	105	);\r
	106	\r
	107	/**\r
	108	Retrieves the architecture specific spin lock alignment requirements for\r
	109	optimal spin lock performance.\r
	110	\r
	111	This function retrieves the spin lock alignment requirements for optimal\r
	112	performance on a given CPU architecture. The spin lock alignment must be a\r
	113	power of two and is returned by this function. If there are no alignment\r
	114	requirements, then 1 must be returned. The spin lock synchronization\r
	115	functions must function correctly if the spin lock size and alignment values\r
	116	returned by this function are not used at all. These values are hints to the\r
	117	consumers of the spin lock synchronization functions to obtain optimal spin\r
	118	lock performance.\r
	119	\r
	120	@return The architecture specific spin lock alignment.\r
	121	\r
	122	**/\r
	123	UINTN\r
	124	EFIAPI\r
	125	GetSpinLockProperties (\r
	126	VOID\r
	127	)\r
	128	{\r
	129	// @bug May use a PCD entry to determine this alignment.\r
	130	return 32;\r
	131	}\r
	132	\r
	133	/**\r
	134	Initializes a spin lock to the released state and returns the spin lock.\r
	135	\r
	136	This function initializes the spin lock specified by SpinLock to the released\r
	137	state, and returns SpinLock. Optimal performance can be achieved by calling\r
	138	GetSpinLockProperties() to determine the size and alignment requirements for\r
	139	SpinLock.\r
	140	\r
	141	If SpinLock is NULL, then ASSERT().\r
	142	\r
	143	@param SpinLock A pointer to the spin lock to initialize to the released\r
	144	state.\r
	145	\r
	146	@return SpinLock\r
	147	\r
	148	**/\r
	149	SPIN_LOCK *\r
	150	EFIAPI\r
	151	InitializeSpinLock (\r
	152	OUT SPIN_LOCK *SpinLock\r
	153	)\r
	154	{\r
	155	ASSERT (SpinLock != NULL);\r
27787243	156	*SpinLock = SPIN_LOCK_RELEASED;\r
878ddf1f	157	return SpinLock;\r
	158	}\r
	159	\r
	160	/**\r
	161	Waits until a spin lock can be placed in the acquired state.\r
	162	\r
	163	This function checks the state of the spin lock specified by SpinLock. If\r
	164	SpinLock is in the released state, then this function places SpinLock in the\r
	165	acquired state and returns SpinLock. Otherwise, this function waits\r
	166	indefinitely for the spin lock to be released, and then places it in the\r
	167	acquired state and returns SpinLock. All state transitions of SpinLock must\r
	168	be performed using MP safe mechanisms.\r
	169	\r
	170	If SpinLock is NULL, then ASSERT().\r
	171	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	172	If PcdSpinLockTimeout is not zero, and SpinLock is can not be acquired in\r
	173	PcdSpinLockTimeout microseconds, then ASSERT().\r
	174	\r
	175	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	176	\r
	177	@return SpinLock\r
	178	\r
	179	**/\r
	180	SPIN_LOCK *\r
	181	EFIAPI\r
	182	AcquireSpinLock (\r
	183	IN OUT SPIN_LOCK *SpinLock\r
	184	)\r
	185	{\r
	186	UINT64 Tick;\r
	187	UINT64 Start, End;\r
	188	UINT64 Timeout;\r
	189	\r
	190	Tick = 0;\r
	191	Start = 0;\r
	192	End = 0;\r
dc530c7b	193	if (PcdGet32 (PcdSpinLockTimeout) > 0) {\r
878ddf1f	194	Tick = GetPerformanceCounter ();\r
	195	Timeout = DivU64x32 (\r
	196	MultU64x32 (\r
	197	GetPerformanceCounterProperties (&Start, &End),\r
dc530c7b	198	PcdGet32 (PcdSpinLockTimeout)\r
878ddf1f	199	),\r
	200	1000000\r
	201	);\r
	202	if (Start < End) {\r
	203	Tick += Timeout;\r
	204	} else {\r
	205	Tick -= Timeout;\r
	206	}\r
	207	}\r
	208	\r
	209	while (!AcquireSpinLockOrFail (SpinLock)) {\r
	210	CpuPause ();\r
	211	ASSERT ((Start < End) ^ (Tick <= GetPerformanceCounter ()));\r
	212	}\r
	213	return SpinLock;\r
	214	}\r
	215	\r
	216	/**\r
	217	Attempts to place a spin lock in the acquired state.\r
	218	\r
	219	This function checks the state of the spin lock specified by SpinLock. If\r
	220	SpinLock is in the released state, then this function places SpinLock in the\r
	221	acquired state and returns TRUE. Otherwise, FALSE is returned. All state\r
	222	transitions of SpinLock must be performed using MP safe mechanisms.\r
	223	\r
	224	If SpinLock is NULL, then ASSERT().\r
	225	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	226	\r
	227	@param SpinLock A pointer to the spin lock to place in the acquired state.\r
	228	\r
	229	@retval TRUE SpinLock was placed in the acquired state.\r
	230	@retval FALSE SpinLock could not be acquired.\r
	231	\r
	232	**/\r
	233	BOOLEAN\r
	234	EFIAPI\r
	235	AcquireSpinLockOrFail (\r
	236	IN OUT SPIN_LOCK *SpinLock\r
	237	)\r
	238	{\r
2d57c546	239	volatile SPIN_LOCK LockValue;\r
c9708ddd	240	\r
878ddf1f	241	ASSERT (SpinLock != NULL);\r
c9708ddd	242	\r
	243	LockValue = *SpinLock;\r
	244	ASSERT (LockValue == SPIN_LOCK_ACQUIRED \|\| LockValue == SPIN_LOCK_RELEASED);\r
	245	\r
878ddf1f	246	return (BOOLEAN)(\r
	247	InterlockedCompareExchangePointer (\r
	248	(VOID**)SpinLock,\r
	249	(VOID*)SPIN_LOCK_RELEASED,\r
	250	(VOID*)SPIN_LOCK_ACQUIRED\r
	251	) == (VOID*)SPIN_LOCK_RELEASED\r
	252	);\r
	253	}\r
	254	\r
	255	/**\r
	256	Releases a spin lock.\r
	257	\r
	258	This function places the spin lock specified by SpinLock in the release state\r
	259	and returns SpinLock.\r
	260	\r
	261	If SpinLock is NULL, then ASSERT().\r
	262	If SpinLock was not initialized with InitializeSpinLock(), then ASSERT().\r
	263	\r
	264	@param SpinLock A pointer to the spin lock to release.\r
	265	\r
	266	@return SpinLock\r
	267	\r
	268	**/\r
	269	SPIN_LOCK *\r
	270	EFIAPI\r
	271	ReleaseSpinLock (\r
	272	IN OUT SPIN_LOCK *SpinLock\r
	273	)\r
	274	{\r
c9708ddd	275	SPIN_LOCK LockValue;\r
c9708ddd	276	\r
878ddf1f	277	ASSERT (SpinLock != NULL);\r
c9708ddd	278	\r
	279	LockValue = *SpinLock;\r
	280	ASSERT (LockValue == SPIN_LOCK_ACQUIRED \|\| LockValue == SPIN_LOCK_RELEASED);\r
	281	\r
27787243	282	*SpinLock = SPIN_LOCK_RELEASED;\r
878ddf1f	283	return SpinLock;\r
	284	}\r
	285	\r
	286	/**\r
	287	Performs an atomic increment of an 32-bit unsigned integer.\r
	288	\r
	289	Performs an atomic increment of the 32-bit unsigned integer specified by\r
	290	Value and returns the incremented value. The increment operation must be\r
	291	performed using MP safe mechanisms. The state of the return value is not\r
	292	guaranteed to be MP safe.\r
	293	\r
	294	If Value is NULL, then ASSERT().\r
	295	\r
	296	@param Value A pointer to the 32-bit value to increment.\r
	297	\r
	298	@return The incremented value.\r
	299	\r
	300	**/\r
	301	UINT32\r
	302	EFIAPI\r
	303	InterlockedIncrement (\r
	304	IN UINT32 *Value\r
	305	)\r
	306	{\r
	307	ASSERT (Value != NULL);\r
	308	return InternalSyncIncrement (Value);\r
	309	}\r
	310	\r
	311	/**\r
	312	Performs an atomic decrement of an 32-bit unsigned integer.\r
	313	\r
	314	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	315	Value and returns the decremented value. The decrement operation must be\r
	316	performed using MP safe mechanisms. The state of the return value is not\r
	317	guaranteed to be MP safe.\r
	318	\r
	319	If Value is NULL, then ASSERT().\r
	320	\r
	321	@param Value A pointer to the 32-bit value to decrement.\r
	322	\r
	323	@return The decremented value.\r
	324	\r
	325	**/\r
	326	UINT32\r
	327	EFIAPI\r
	328	InterlockedDecrement (\r
	329	IN UINT32 *Value\r
	330	)\r
	331	{\r
	332	ASSERT (Value != NULL);\r
	333	return InternalSyncDecrement (Value);\r
	334	}\r
	335	\r
	336	/**\r
	337	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	338	\r
1ea5ca46	339	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	340	specified by Value. If Value is equal to CompareValue, then Value is set to \r
	341	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	342	then Value is returned. The compare exchange operation must be performed using \r
	343	MP safe mechanisms.\r
	344	\r
	345	If Value is NULL, then ASSERT().\r
	346	\r
878ddf1f	347	@param Value A pointer to the 32-bit value for the compare exchange\r
	348	operation.\r
	349	@param CompareValue 32-bit value used in compare operation.\r
	350	@param ExchangeValue 32-bit value used in exchange operation.\r
	351	\r
	352	@return The original *Value before exchange.\r
	353	\r
	354	**/\r
	355	UINT32\r
	356	EFIAPI\r
	357	InterlockedCompareExchange32 (\r
0ffa1286	358	IN OUT UINT32 *Value,\r
878ddf1f	359	IN UINT32 CompareValue,\r
	360	IN UINT32 ExchangeValue\r
	361	)\r
	362	{\r
	363	ASSERT (Value != NULL);\r
	364	return InternalSyncCompareExchange32 (Value, CompareValue, ExchangeValue);\r
	365	}\r
	366	\r
	367	/**\r
	368	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	369	\r
1ea5ca46	370	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified \r
	371	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and \r
	372	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned. \r
	373	The compare exchange operation must be performed using MP safe mechanisms.\r
	374	\r
	375	If Value is NULL, then ASSERT().\r
	376	\r
878ddf1f	377	@param Value A pointer to the 64-bit value for the compare exchange\r
	378	operation.\r
	379	@param CompareValue 64-bit value used in compare operation.\r
	380	@param ExchangeValue 64-bit value used in exchange operation.\r
	381	\r
	382	@return The original *Value before exchange.\r
	383	\r
	384	**/\r
	385	UINT64\r
	386	EFIAPI\r
	387	InterlockedCompareExchange64 (\r
0ffa1286	388	IN OUT UINT64 *Value,\r
878ddf1f	389	IN UINT64 CompareValue,\r
	390	IN UINT64 ExchangeValue\r
	391	)\r
	392	{\r
	393	ASSERT (Value != NULL);\r
	394	return InternalSyncCompareExchange64 (Value, CompareValue, ExchangeValue);\r
	395	}\r
	396	\r
	397	/**\r
	398	Performs an atomic compare exchange operation on a pointer value.\r
	399	\r
	400	Performs an atomic compare exchange operation on the pointer value specified\r
	401	by Value. If Value is equal to CompareValue, then Value is set to\r
	402	ExchangeValue and CompareValue is returned. If Value is not equal to\r
	403	CompareValue, then Value is returned. The compare exchange operation must be\r
	404	performed using MP safe mechanisms.\r
	405	\r
	406	If Value is NULL, then ASSERT().\r
	407	\r
	408	@param Value A pointer to the pointer value for the compare exchange\r
	409	operation.\r
	410	@param CompareValue Pointer value used in compare operation.\r
	411	@param ExchangeValue Pointer value used in exchange operation.\r
	412	\r
	413	**/\r
	414	VOID *\r
	415	EFIAPI\r
	416	InterlockedCompareExchangePointer (\r
0ffa1286	417	IN OUT VOID **Value,\r
878ddf1f	418	IN VOID *CompareValue,\r
	419	IN VOID *ExchangeValue\r
	420	)\r
	421	{\r
	422	switch (sizeof (*Value)) {\r
	423	case sizeof (UINT32):\r
	424	return (VOID*)(UINTN)InterlockedCompareExchange32 (\r
	425	(UINT32*)Value,\r
	426	(UINT32)(UINTN)CompareValue,\r
	427	(UINT32)(UINTN)ExchangeValue\r
	428	);\r
	429	case sizeof (UINT64):\r
	430	return (VOID*)(UINTN)InterlockedCompareExchange64 (\r
	431	(UINT64*)Value,\r
	432	(UINT64)(UINTN)CompareValue,\r
	433	(UINT64)(UINTN)ExchangeValue\r
	434	);\r
	435	default:\r
	436	ASSERT (FALSE);\r
	437	return NULL;\r
	438	}\r
	439	}\r