[mirror_edk2.git] / MdePkg / Library / BaseSynchronizationLib / AArch64 / Synchronization.S

//  Implementation of synchronization functions for ARM architecture (AArch64)\r
//\r
//  Copyright (c) 2012-2015, ARM Limited. All rights reserved.\r
//  Copyright (c) 2015, Linaro Limited. All rights reserved.\r
//\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
.text\r
.align 3\r
\r
GCC_ASM_EXPORT(InternalSyncCompareExchange16)\r
GCC_ASM_EXPORT(InternalSyncCompareExchange32)\r
GCC_ASM_EXPORT(InternalSyncCompareExchange64)\r
GCC_ASM_EXPORT(InternalSyncIncrement)\r
GCC_ASM_EXPORT(InternalSyncDecrement)\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
  @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
//InternalSyncCompareExchange16 (\r
//  IN      volatile UINT16           *Value,\r
//  IN      UINT16                    CompareValue,\r
//  IN      UINT16                    ExchangeValue\r
//  )\r
ASM_PFX(InternalSyncCompareExchange16):\r
  uxth    w1, w1\r
  uxth    w2, w2\r
  dmb     sy\r
\r
InternalSyncCompareExchange16Again:\r
  ldxrh   w3, [x0]\r
  cmp     w3, w1\r
  bne     InternalSyncCompareExchange16Fail\r
\r
InternalSyncCompareExchange16Exchange:\r
  stxrh   w4, w2, [x0]\r
  cbnz    w4, InternalSyncCompareExchange16Again\r
\r
InternalSyncCompareExchange16Fail:\r
  dmb     sy\r
  mov     w0, w3\r
  ret\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
ASM_PFX(InternalSyncCompareExchange32):\r
  dmb     sy\r
\r
InternalSyncCompareExchange32Again:\r
  ldxr    w3, [x0]\r
  cmp     w3, w1\r
  bne     InternalSyncCompareExchange32Fail\r
\r
InternalSyncCompareExchange32Exchange:\r
  stxr    w4, w2, [x0]\r
  cbnz    w4, InternalSyncCompareExchange32Again\r
\r
InternalSyncCompareExchange32Fail:\r
  dmb     sy\r
  mov     w0, w3\r
  ret\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
ASM_PFX(InternalSyncCompareExchange64):\r
  dmb     sy\r
\r
InternalSyncCompareExchange64Again:\r
  ldxr    x3, [x0]\r
  cmp     x3, x1\r
  bne     InternalSyncCompareExchange64Fail\r
\r
InternalSyncCompareExchange64Exchange:\r
  stxr    w4, x2, [x0]\r
  cbnz    w4, InternalSyncCompareExchange64Again\r
\r
InternalSyncCompareExchange64Fail:\r
  dmb     sy\r
  mov     x0, x3\r
  ret\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
ASM_PFX(InternalSyncIncrement):\r
  dmb     sy\r
TryInternalSyncIncrement:\r
  ldxr    w1, [x0]\r
  add     w1, w1, #1\r
  stxr    w2, w1, [x0]\r
  cbnz    w2, TryInternalSyncIncrement\r
  mov     w0, w1\r
  dmb     sy\r
  ret\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
ASM_PFX(InternalSyncDecrement):\r
  dmb     sy\r
TryInternalSyncDecrement:\r
  ldxr    w1, [x0]\r
  sub     w1, w1, #1\r
  stxr    w2, w1, [x0]\r
  cbnz    w2, TryInternalSyncDecrement\r
  mov     w0, w1\r
  dmb     sy\r
  ret\r
Commit	Line	Data
	1	// Implementation of synchronization functions for ARM architecture (AArch64)\r
	2	//\r
	3	// Copyright (c) 2012-2015, ARM Limited. All rights reserved.\r
	4	// Copyright (c) 2015, Linaro Limited. All rights reserved.\r
	5	//\r
	6	// This program and the accompanying materials\r
	7	// are licensed and made available under the terms and conditions of the BSD License\r
	8	// which accompanies this distribution. The full text of the license may be found at\r
	9	// http://opensource.org/licenses/bsd-license.php\r
	10	//\r
	11	// THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,\r
	12	// WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
	13	//\r
	14	//\r
	15	\r
	16	.text\r
	17	.align 3\r
	18	\r
	19	GCC_ASM_EXPORT(InternalSyncCompareExchange16)\r
	20	GCC_ASM_EXPORT(InternalSyncCompareExchange32)\r
	21	GCC_ASM_EXPORT(InternalSyncCompareExchange64)\r
	22	GCC_ASM_EXPORT(InternalSyncIncrement)\r
	23	GCC_ASM_EXPORT(InternalSyncDecrement)\r
	24	\r
	25	/**\r
	26	Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	27	\r
	28	Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	29	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	30	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	31	then Value is returned. The compare exchange operation must be performed using\r
	32	MP safe mechanisms.\r
	33	\r
	34	@param Value A pointer to the 16-bit value for the compare exchange\r
	35	operation.\r
	36	@param CompareValue 16-bit value used in compare operation.\r
	37	@param ExchangeValue 16-bit value used in exchange operation.\r
	38	\r
	39	@return The original *Value before exchange.\r
	40	\r
	41	**/\r
	42	//UINT16\r
	43	//EFIAPI\r
	44	//InternalSyncCompareExchange16 (\r
	45	// IN volatile UINT16 *Value,\r
	46	// IN UINT16 CompareValue,\r
	47	// IN UINT16 ExchangeValue\r
	48	// )\r
	49	ASM_PFX(InternalSyncCompareExchange16):\r
	50	uxth w1, w1\r
	51	uxth w2, w2\r
	52	dmb sy\r
	53	\r
	54	InternalSyncCompareExchange16Again:\r
	55	ldxrh w3, [x0]\r
	56	cmp w3, w1\r
	57	bne InternalSyncCompareExchange16Fail\r
	58	\r
	59	InternalSyncCompareExchange16Exchange:\r
	60	stxrh w4, w2, [x0]\r
	61	cbnz w4, InternalSyncCompareExchange16Again\r
	62	\r
	63	InternalSyncCompareExchange16Fail:\r
	64	dmb sy\r
	65	mov w0, w3\r
	66	ret\r
	67	\r
	68	/**\r
	69	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	70	\r
	71	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	72	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	73	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	74	then Value is returned. The compare exchange operation must be performed using\r
	75	MP safe mechanisms.\r
	76	\r
	77	@param Value A pointer to the 32-bit value for the compare exchange\r
	78	operation.\r
	79	@param CompareValue 32-bit value used in compare operation.\r
	80	@param ExchangeValue 32-bit value used in exchange operation.\r
	81	\r
	82	@return The original *Value before exchange.\r
	83	\r
	84	**/\r
	85	//UINT32\r
	86	//EFIAPI\r
	87	//InternalSyncCompareExchange32 (\r
	88	// IN volatile UINT32 *Value,\r
	89	// IN UINT32 CompareValue,\r
	90	// IN UINT32 ExchangeValue\r
	91	// )\r
	92	ASM_PFX(InternalSyncCompareExchange32):\r
	93	dmb sy\r
	94	\r
	95	InternalSyncCompareExchange32Again:\r
	96	ldxr w3, [x0]\r
	97	cmp w3, w1\r
	98	bne InternalSyncCompareExchange32Fail\r
	99	\r
	100	InternalSyncCompareExchange32Exchange:\r
	101	stxr w4, w2, [x0]\r
	102	cbnz w4, InternalSyncCompareExchange32Again\r
	103	\r
	104	InternalSyncCompareExchange32Fail:\r
	105	dmb sy\r
	106	mov w0, w3\r
	107	ret\r
	108	\r
	109	/**\r
	110	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	111	\r
	112	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
	113	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
	114	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
	115	The compare exchange operation must be performed using MP safe mechanisms.\r
	116	\r
	117	@param Value A pointer to the 64-bit value for the compare exchange\r
	118	operation.\r
	119	@param CompareValue 64-bit value used in compare operation.\r
	120	@param ExchangeValue 64-bit value used in exchange operation.\r
	121	\r
	122	@return The original *Value before exchange.\r
	123	\r
	124	**/\r
	125	//UINT64\r
	126	//EFIAPI\r
	127	//InternalSyncCompareExchange64 (\r
	128	// IN volatile UINT64 *Value,\r
	129	// IN UINT64 CompareValue,\r
	130	// IN UINT64 ExchangeValue\r
	131	// )\r
	132	ASM_PFX(InternalSyncCompareExchange64):\r
	133	dmb sy\r
	134	\r
	135	InternalSyncCompareExchange64Again:\r
	136	ldxr x3, [x0]\r
	137	cmp x3, x1\r
	138	bne InternalSyncCompareExchange64Fail\r
	139	\r
	140	InternalSyncCompareExchange64Exchange:\r
	141	stxr w4, x2, [x0]\r
	142	cbnz w4, InternalSyncCompareExchange64Again\r
	143	\r
	144	InternalSyncCompareExchange64Fail:\r
	145	dmb sy\r
	146	mov x0, x3\r
	147	ret\r
	148	\r
	149	/**\r
	150	Performs an atomic increment of an 32-bit unsigned integer.\r
	151	\r
	152	Performs an atomic increment of the 32-bit unsigned integer specified by\r
	153	Value and returns the incremented value. The increment operation must be\r
	154	performed using MP safe mechanisms. The state of the return value is not\r
	155	guaranteed to be MP safe.\r
	156	\r
	157	@param Value A pointer to the 32-bit value to increment.\r
	158	\r
	159	@return The incremented value.\r
	160	\r
	161	**/\r
	162	//UINT32\r
	163	//EFIAPI\r
	164	//InternalSyncIncrement (\r
	165	// IN volatile UINT32 *Value\r
	166	// )\r
	167	ASM_PFX(InternalSyncIncrement):\r
	168	dmb sy\r
	169	TryInternalSyncIncrement:\r
	170	ldxr w1, [x0]\r
	171	add w1, w1, #1\r
	172	stxr w2, w1, [x0]\r
	173	cbnz w2, TryInternalSyncIncrement\r
	174	mov w0, w1\r
	175	dmb sy\r
	176	ret\r
	177	\r
	178	/**\r
	179	Performs an atomic decrement of an 32-bit unsigned integer.\r
	180	\r
	181	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	182	Value and returns the decrement value. The decrement operation must be\r
	183	performed using MP safe mechanisms. The state of the return value is not\r
	184	guaranteed to be MP safe.\r
	185	\r
	186	@param Value A pointer to the 32-bit value to decrement.\r
	187	\r
	188	@return The decrement value.\r
	189	\r
	190	**/\r
	191	//UINT32\r
	192	//EFIAPI\r
	193	//InternalSyncDecrement (\r
	194	// IN volatile UINT32 *Value\r
	195	// )\r
	196	ASM_PFX(InternalSyncDecrement):\r
	197	dmb sy\r
	198	TryInternalSyncDecrement:\r
	199	ldxr w1, [x0]\r
	200	sub w1, w1, #1\r
	201	stxr w2, w1, [x0]\r
	202	cbnz w2, TryInternalSyncDecrement\r
	203	mov w0, w1\r
	204	dmb sy\r
	205	ret\r