[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
//  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
    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 OM	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
9b89163e	16	EXPORT InternalSyncCompareExchange16\r
cc310428 OM	17	EXPORT InternalSyncCompareExchange32\r
	18	EXPORT InternalSyncCompareExchange64\r
	19	EXPORT InternalSyncIncrement\r
	20	EXPORT InternalSyncDecrement\r
	21	\r
	22	AREA ArmSynchronization, CODE, READONLY\r
	23	\r
9b89163e AB	24	/**\r
	25	Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	26	\r
	27	Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	28	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	29	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	30	then Value is returned. The compare exchange operation must be performed using\r
	31	MP safe mechanisms.\r
	32	\r
	33	@param Value A pointer to the 16-bit value for the compare exchange\r
	34	operation.\r
	35	@param CompareValue 16-bit value used in compare operation.\r
	36	@param ExchangeValue 16-bit value used in exchange operation.\r
	37	\r
	38	@return The original *Value before exchange.\r
	39	\r
	40	**/\r
	41	//UINT16\r
	42	//EFIAPI\r
	43	//InternalSyncCompareExchange16 (\r
	44	// IN volatile UINT16 *Value,\r
	45	// IN UINT16 CompareValue,\r
	46	// IN UINT16 ExchangeValue\r
	47	// )\r
	48	InternalSyncCompareExchange16\r
	49	dmb\r
	50	\r
	51	InternalSyncCompareExchange16Again\r
	52	ldrexh r3, [r0]\r
	53	cmp r3, r1\r
	54	bne InternalSyncCompareExchange16Fail\r
	55	\r
	56	InternalSyncCompareExchange16Exchange\r
	57	strexh ip, r2, [r0]\r
	58	cmp ip, #0\r
	59	bne InternalSyncCompareExchange16Again\r
	60	\r
	61	InternalSyncCompareExchange16Fail\r
	62	dmb\r
	63	mov r0, r3\r
	64	bx lr\r
	65	\r
cc310428 OM	66	/**\r
	67	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	68	\r
	69	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	70	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	71	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	72	then Value is returned. The compare exchange operation must be performed using\r
	73	MP safe mechanisms.\r
	74	\r
	75	@param Value A pointer to the 32-bit value for the compare exchange\r
	76	operation.\r
	77	@param CompareValue 32-bit value used in compare operation.\r
	78	@param ExchangeValue 32-bit value used in exchange operation.\r
	79	\r
	80	@return The original *Value before exchange.\r
	81	\r
	82	**/\r
	83	//UINT32\r
	84	//EFIAPI\r
	85	//InternalSyncCompareExchange32 (\r
	86	// IN volatile UINT32 *Value,\r
	87	// IN UINT32 CompareValue,\r
	88	// IN UINT32 ExchangeValue\r
	89	// )\r
	90	InternalSyncCompareExchange32\r
	91	dmb\r
	92	\r
	93	InternalSyncCompareExchange32Again\r
	94	ldrex r3, [r0]\r
	95	cmp r3, r1\r
	96	bne InternalSyncCompareExchange32Fail\r
	97	\r
	98	InternalSyncCompareExchange32Exchange\r
	99	strex ip, r2, [r0]\r
	100	cmp ip, #0\r
	101	bne InternalSyncCompareExchange32Again\r
	102	\r
	103	InternalSyncCompareExchange32Fail\r
	104	dmb\r
	105	mov r0, r3\r
	106	bx lr\r
	107	\r
	108	/**\r
	109	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	110	\r
	111	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
	112	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
	113	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
	114	The compare exchange operation must be performed using MP safe mechanisms.\r
	115	\r
	116	@param Value A pointer to the 64-bit value for the compare exchange\r
	117	operation.\r
	118	@param CompareValue 64-bit value used in compare operation.\r
	119	@param ExchangeValue 64-bit value used in exchange operation.\r
	120	\r
	121	@return The original *Value before exchange.\r
	122	\r
	123	**/\r
	124	//UINT64\r
	125	//EFIAPI\r
	126	//InternalSyncCompareExchange64 (\r
	127	// IN volatile UINT64 *Value, // r0\r
	128	// IN UINT64 CompareValue, // r2-r3\r
	129	// IN UINT64 ExchangeValue // stack\r
130	// )\r
131	InternalSyncCompareExchange64\r
132	push { r4-r7 }\r
133	ldrd r4, r5, [sp, #16]\r
134	dmb\r
135	\r
136	InternalSyncCompareExchange64Again\r
137	ldrexd r6, r7, [r0]\r
138	cmp r6, r2\r
139	cmpeq r7, r3\r
140	bne InternalSyncCompareExchange64Fail\r
141	\r
142	InternalSyncCompareExchange64Exchange\r
143	strexd ip, r4, r5, [r0]\r
144	cmp ip, #0\r
145	bne InternalSyncCompareExchange64Again\r
146	\r
147	InternalSyncCompareExchange64Fail\r
148	dmb\r
149	mov r0, r6\r
150	mov r1, r7\r
151	pop { r4-r7 }\r
152	bx lr\r
153	\r
154	/**\r
155	Performs an atomic increment of an 32-bit unsigned integer.\r
156	\r
157	Performs an atomic increment of the 32-bit unsigned integer specified by\r
158	Value and returns the incremented value. The increment operation must be\r
159	performed using MP safe mechanisms. The state of the return value is not\r
160	guaranteed to be MP safe.\r
161	\r
162	@param Value A pointer to the 32-bit value to increment.\r
163	\r
164	@return The incremented value.\r
165	\r
166	**/\r
167	//UINT32\r
168	//EFIAPI\r
169	//InternalSyncIncrement (\r
170	// IN volatile UINT32 *Value\r
171	// )\r
172	InternalSyncIncrement\r
173	dmb\r
174	TryInternalSyncIncrement\r
175	ldrex r1, [r0]\r
176	add r1, r1, #1\r
177	strex r2, r1, [r0]\r
178	cmp r2, #0\r
179	bne TryInternalSyncIncrement\r
180	dmb\r
f61762d0	181	mov r0, r1\r
cc310428 OM	182	bx lr\r
	183	\r
	184	/**\r
	185	Performs an atomic decrement of an 32-bit unsigned integer.\r
	186	\r
	187	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	188	Value and returns the decrement value. The decrement operation must be\r
	189	performed using MP safe mechanisms. The state of the return value is not\r
	190	guaranteed to be MP safe.\r
	191	\r
	192	@param Value A pointer to the 32-bit value to decrement.\r
	193	\r
	194	@return The decrement value.\r
	195	\r
	196	**/\r
	197	//UINT32\r
	198	//EFIAPI\r
	199	//InternalSyncDecrement (\r
	200	// IN volatile UINT32 *Value\r
	201	// )\r
	202	InternalSyncDecrement\r
	203	dmb\r
	204	TryInternalSyncDecrement\r
	205	ldrex r1, [r0]\r
	206	sub r1, r1, #1\r
	207	strex r2, r1, [r0]\r
	208	cmp r2, #0\r
	209	bne TryInternalSyncDecrement\r
	210	dmb\r
f61762d0	211	mov r0, r1\r
cc310428 OM	212	bx lr\r
	213	\r
	214	END\r