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

//  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
.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
  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
ASM_PFX(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
ASM_PFX(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
ASM_PFX(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
ASM_PFX(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
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
	16	.text\r
	17	.align 3\r
	18	\r
9b89163e	19	GCC_ASM_EXPORT(InternalSyncCompareExchange16)\r
cc310428 OM	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
9b89163e AB	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	dmb\r
	51	\r
	52	InternalSyncCompareExchange16Again:\r
	53	ldrexh r3, [r0]\r
	54	cmp r3, r1\r
	55	bne InternalSyncCompareExchange16Fail\r
	56	\r
	57	InternalSyncCompareExchange16Exchange:\r
	58	strexh ip, r2, [r0]\r
	59	cmp ip, #0\r
	60	bne InternalSyncCompareExchange16Again\r
	61	\r
	62	InternalSyncCompareExchange16Fail:\r
	63	dmb\r
	64	mov r0, r3\r
	65	bx lr\r
	66	\r
cc310428 OM	67	/**\r
	68	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	69	\r
	70	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	71	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	72	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	73	then Value is returned. The compare exchange operation must be performed using\r
	74	MP safe mechanisms.\r
	75	\r
	76	@param Value A pointer to the 32-bit value for the compare exchange\r
	77	operation.\r
	78	@param CompareValue 32-bit value used in compare operation.\r
	79	@param ExchangeValue 32-bit value used in exchange operation.\r
	80	\r
	81	@return The original *Value before exchange.\r
	82	\r
	83	**/\r
	84	//UINT32\r
	85	//EFIAPI\r
	86	//InternalSyncCompareExchange32 (\r
	87	// IN volatile UINT32 *Value,\r
	88	// IN UINT32 CompareValue,\r
	89	// IN UINT32 ExchangeValue\r
	90	// )\r
	91	ASM_PFX(InternalSyncCompareExchange32):\r
	92	dmb\r
	93	\r
	94	InternalSyncCompareExchange32Again:\r
	95	ldrex r3, [r0]\r
	96	cmp r3, r1\r
	97	bne InternalSyncCompareExchange32Fail\r
	98	\r
	99	InternalSyncCompareExchange32Exchange:\r
	100	strex ip, r2, [r0]\r
	101	cmp ip, #0\r
	102	bne InternalSyncCompareExchange32Again\r
	103	\r
	104	InternalSyncCompareExchange32Fail:\r
	105	dmb\r
	106	mov r0, r3\r
	107	bx lr\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, // r0\r
	129	// IN UINT64 CompareValue, // r2-r3\r
	130	// IN UINT64 ExchangeValue // stack\r
131	// )\r
132	ASM_PFX(InternalSyncCompareExchange64):\r
133	push { r4-r7 }\r
134	ldrd r4, r5, [sp, #16]\r
135	dmb\r
136	\r
137	InternalSyncCompareExchange64Again:\r
138	ldrexd r6, r7, [r0]\r
139	cmp r6, r2\r
140	cmpeq r7, r3\r
141	bne InternalSyncCompareExchange64Fail\r
142	\r
143	InternalSyncCompareExchange64Exchange:\r
144	strexd ip, r4, r5, [r0]\r
145	cmp ip, #0\r
146	bne InternalSyncCompareExchange64Again\r
147	\r
148	InternalSyncCompareExchange64Fail:\r
149	dmb\r
150	mov r0, r6\r
151	mov r1, r7\r
152	pop { r4-r7 }\r
153	bx lr\r
154	\r
155	/**\r
156	Performs an atomic increment of an 32-bit unsigned integer.\r
157	\r
158	Performs an atomic increment of the 32-bit unsigned integer specified by\r
159	Value and returns the incremented value. The increment operation must be\r
160	performed using MP safe mechanisms. The state of the return value is not\r
161	guaranteed to be MP safe.\r
162	\r
163	@param Value A pointer to the 32-bit value to increment.\r
164	\r
165	@return The incremented value.\r
166	\r
167	**/\r
168	//UINT32\r
169	//EFIAPI\r
170	//InternalSyncIncrement (\r
171	// IN volatile UINT32 *Value\r
172	// )\r
173	ASM_PFX(InternalSyncIncrement):\r
174	dmb\r
175	TryInternalSyncIncrement:\r
176	ldrex r1, [r0]\r
177	add r1, r1, #1\r
178	strex r2, r1, [r0]\r
179	cmp r2, #0\r
180	bne TryInternalSyncIncrement\r
181	dmb\r
f61762d0	182	mov r0, r1\r
cc310428 OM	183	bx lr\r
	184	\r
	185	/**\r
	186	Performs an atomic decrement of an 32-bit unsigned integer.\r
	187	\r
	188	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	189	Value and returns the decrement value. The decrement operation must be\r
	190	performed using MP safe mechanisms. The state of the return value is not\r
	191	guaranteed to be MP safe.\r
	192	\r
	193	@param Value A pointer to the 32-bit value to decrement.\r
	194	\r
	195	@return The decrement value.\r
	196	\r
	197	**/\r
	198	//UINT32\r
	199	//EFIAPI\r
	200	//InternalSyncDecrement (\r
	201	// IN volatile UINT32 *Value\r
	202	// )\r
	203	ASM_PFX(InternalSyncDecrement):\r
	204	dmb\r
	205	TryInternalSyncDecrement:\r
	206	ldrex r1, [r0]\r
	207	sub r1, r1, #1\r
	208	strex r2, r1, [r0]\r
	209	cmp r2, #0\r
	210	bne TryInternalSyncDecrement\r
	211	dmb\r
f61762d0	212	mov r0, r1\r
cc310428	213	bx lr\r