[mirror_edk2.git] / MdePkg / Library / BaseSynchronizationLib / Arm / Synchronization.asm

//  Implementation of synchronization functions for ARM architecture\r
//\r
//  Copyright (c) 2012-2015, ARM Limited. All rights reserved.\r
//  Copyright (c) 2015, Linaro Limited. All rights reserved.\r
//\r
//  SPDX-License-Identifier: BSD-2-Clause-Patent\r
//\r
//\r
\r
    EXPORT  InternalSyncCompareExchange16\r
    EXPORT  InternalSyncCompareExchange32\r
    EXPORT  InternalSyncCompareExchange64\r
    EXPORT  InternalSyncIncrement\r
    EXPORT  InternalSyncDecrement\r
\r
    AREA   ArmSynchronization, CODE, READONLY\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
InternalSyncCompareExchange16\r
  dmb\r
\r
InternalSyncCompareExchange16Again\r
  ldrexh  r3, [r0]\r
  cmp     r3, r1\r
  bne     InternalSyncCompareExchange16Fail\r
\r
InternalSyncCompareExchange16Exchange\r
  strexh  ip, r2, [r0]\r
  cmp     ip, #0\r
  bne     InternalSyncCompareExchange16Again\r
\r
InternalSyncCompareExchange16Fail\r
  dmb\r
  mov     r0, r3\r
  bx      lr\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
InternalSyncCompareExchange32\r
  dmb\r
\r
InternalSyncCompareExchange32Again\r
  ldrex   r3, [r0]\r
  cmp     r3, r1\r
  bne     InternalSyncCompareExchange32Fail\r
\r
InternalSyncCompareExchange32Exchange\r
  strex   ip, r2, [r0]\r
  cmp     ip, #0\r
  bne     InternalSyncCompareExchange32Again\r
\r
InternalSyncCompareExchange32Fail\r
  dmb\r
  mov     r0, r3\r
  bx      lr\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,         // r0\r
//  IN      UINT64                    CompareValue,   // r2-r3\r
//  IN      UINT64                    ExchangeValue   // stack\r
//  )\r
InternalSyncCompareExchange64\r
  push    { r4-r7 }\r
  ldrd    r4, r5, [sp, #16]\r
  dmb\r
\r
InternalSyncCompareExchange64Again\r
  ldrexd  r6, r7, [r0]\r
  cmp     r6, r2\r
  cmpeq   r7, r3\r
  bne     InternalSyncCompareExchange64Fail\r
\r
InternalSyncCompareExchange64Exchange\r
  strexd  ip, r4, r5, [r0]\r
  cmp     ip, #0\r
  bne     InternalSyncCompareExchange64Again\r
\r
InternalSyncCompareExchange64Fail\r
  dmb\r
  mov     r0, r6\r
  mov     r1, r7\r
  pop     { r4-r7 }\r
  bx      lr\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
InternalSyncIncrement\r
  dmb\r
TryInternalSyncIncrement\r
  ldrex   r1, [r0]\r
  add     r1, r1, #1\r
  strex   r2, r1, [r0]\r
  cmp     r2, #0\r
  bne     TryInternalSyncIncrement\r
  dmb\r
  mov     r0, r1\r
  bx      lr\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
InternalSyncDecrement\r
  dmb\r
TryInternalSyncDecrement\r
  ldrex   r1, [r0]\r
  sub     r1, r1, #1\r
  strex   r2, r1, [r0]\r
  cmp     r2, #0\r
  bne     TryInternalSyncDecrement\r
  dmb\r
  mov     r0, r1\r
  bx      lr\r
\r
  END\r
Commit	Line	Data
cc310428 OM	1	// Implementation of synchronization functions for ARM architecture\r
	2	//\r
	3	// Copyright (c) 2012-2015, ARM Limited. All rights reserved.\r
9b89163e	4	// Copyright (c) 2015, Linaro Limited. All rights reserved.\r
cc310428	5	//\r
9344f092	6	// SPDX-License-Identifier: BSD-2-Clause-Patent\r
cc310428 OM	7	//\r
	8	//\r
	9	\r
9b89163e	10	EXPORT InternalSyncCompareExchange16\r
cc310428 OM	11	EXPORT InternalSyncCompareExchange32\r
	12	EXPORT InternalSyncCompareExchange64\r
	13	EXPORT InternalSyncIncrement\r
	14	EXPORT InternalSyncDecrement\r
	15	\r
	16	AREA ArmSynchronization, CODE, READONLY\r
	17	\r
9b89163e AB	18	/**\r
	19	Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	20	\r
	21	Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	22	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	23	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	24	then Value is returned. The compare exchange operation must be performed using\r
	25	MP safe mechanisms.\r
	26	\r
	27	@param Value A pointer to the 16-bit value for the compare exchange\r
	28	operation.\r
	29	@param CompareValue 16-bit value used in compare operation.\r
	30	@param ExchangeValue 16-bit value used in exchange operation.\r
	31	\r
	32	@return The original *Value before exchange.\r
	33	\r
	34	**/\r
	35	//UINT16\r
	36	//EFIAPI\r
	37	//InternalSyncCompareExchange16 (\r
	38	// IN volatile UINT16 *Value,\r
	39	// IN UINT16 CompareValue,\r
	40	// IN UINT16 ExchangeValue\r
	41	// )\r
	42	InternalSyncCompareExchange16\r
	43	dmb\r
	44	\r
	45	InternalSyncCompareExchange16Again\r
	46	ldrexh r3, [r0]\r
	47	cmp r3, r1\r
	48	bne InternalSyncCompareExchange16Fail\r
	49	\r
	50	InternalSyncCompareExchange16Exchange\r
	51	strexh ip, r2, [r0]\r
	52	cmp ip, #0\r
	53	bne InternalSyncCompareExchange16Again\r
	54	\r
	55	InternalSyncCompareExchange16Fail\r
	56	dmb\r
	57	mov r0, r3\r
	58	bx lr\r
	59	\r
cc310428 OM	60	/**\r
	61	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	62	\r
	63	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	64	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	65	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	66	then Value is returned. The compare exchange operation must be performed using\r
	67	MP safe mechanisms.\r
	68	\r
	69	@param Value A pointer to the 32-bit value for the compare exchange\r
	70	operation.\r
	71	@param CompareValue 32-bit value used in compare operation.\r
	72	@param ExchangeValue 32-bit value used in exchange operation.\r
	73	\r
	74	@return The original *Value before exchange.\r
	75	\r
	76	**/\r
	77	//UINT32\r
	78	//EFIAPI\r
	79	//InternalSyncCompareExchange32 (\r
	80	// IN volatile UINT32 *Value,\r
	81	// IN UINT32 CompareValue,\r
	82	// IN UINT32 ExchangeValue\r
	83	// )\r
	84	InternalSyncCompareExchange32\r
	85	dmb\r
	86	\r
	87	InternalSyncCompareExchange32Again\r
	88	ldrex r3, [r0]\r
	89	cmp r3, r1\r
	90	bne InternalSyncCompareExchange32Fail\r
	91	\r
	92	InternalSyncCompareExchange32Exchange\r
	93	strex ip, r2, [r0]\r
	94	cmp ip, #0\r
	95	bne InternalSyncCompareExchange32Again\r
	96	\r
	97	InternalSyncCompareExchange32Fail\r
	98	dmb\r
	99	mov r0, r3\r
	100	bx lr\r
	101	\r
	102	/**\r
	103	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	104	\r
	105	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
	106	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
	107	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
	108	The compare exchange operation must be performed using MP safe mechanisms.\r
	109	\r
	110	@param Value A pointer to the 64-bit value for the compare exchange\r
	111	operation.\r
	112	@param CompareValue 64-bit value used in compare operation.\r
	113	@param ExchangeValue 64-bit value used in exchange operation.\r
	114	\r
	115	@return The original *Value before exchange.\r
	116	\r
	117	**/\r
	118	//UINT64\r
	119	//EFIAPI\r
	120	//InternalSyncCompareExchange64 (\r
	121	// IN volatile UINT64 *Value, // r0\r
	122	// IN UINT64 CompareValue, // r2-r3\r
	123	// IN UINT64 ExchangeValue // stack\r
124	// )\r
125	InternalSyncCompareExchange64\r
126	push { r4-r7 }\r
127	ldrd r4, r5, [sp, #16]\r
128	dmb\r
129	\r
130	InternalSyncCompareExchange64Again\r
131	ldrexd r6, r7, [r0]\r
132	cmp r6, r2\r
133	cmpeq r7, r3\r
134	bne InternalSyncCompareExchange64Fail\r
135	\r
136	InternalSyncCompareExchange64Exchange\r
137	strexd ip, r4, r5, [r0]\r
138	cmp ip, #0\r
139	bne InternalSyncCompareExchange64Again\r
140	\r
141	InternalSyncCompareExchange64Fail\r
142	dmb\r
143	mov r0, r6\r
144	mov r1, r7\r
145	pop { r4-r7 }\r
146	bx lr\r
147	\r
148	/**\r
149	Performs an atomic increment of an 32-bit unsigned integer.\r
150	\r
151	Performs an atomic increment of the 32-bit unsigned integer specified by\r
152	Value and returns the incremented value. The increment operation must be\r
153	performed using MP safe mechanisms. The state of the return value is not\r
154	guaranteed to be MP safe.\r
155	\r
156	@param Value A pointer to the 32-bit value to increment.\r
157	\r
158	@return The incremented value.\r
159	\r
160	**/\r
161	//UINT32\r
162	//EFIAPI\r
163	//InternalSyncIncrement (\r
164	// IN volatile UINT32 *Value\r
165	// )\r
166	InternalSyncIncrement\r
167	dmb\r
168	TryInternalSyncIncrement\r
169	ldrex r1, [r0]\r
170	add r1, r1, #1\r
171	strex r2, r1, [r0]\r
172	cmp r2, #0\r
173	bne TryInternalSyncIncrement\r
174	dmb\r
f61762d0	175	mov r0, r1\r
cc310428 OM	176	bx lr\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	InternalSyncDecrement\r
	197	dmb\r
	198	TryInternalSyncDecrement\r
	199	ldrex r1, [r0]\r
	200	sub r1, r1, #1\r
	201	strex r2, r1, [r0]\r
	202	cmp r2, #0\r
	203	bne TryInternalSyncDecrement\r
	204	dmb\r
f61762d0	205	mov r0, r1\r
cc310428 OM	206	bx lr\r
	207	\r
	208	END\r