[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
//  SPDX-License-Identifier: BSD-2-Clause-Patent\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	5	//\r
9344f092	6	// SPDX-License-Identifier: BSD-2-Clause-Patent\r
cc310428 OM	7	//\r
	8	//\r
	9	\r
	10	.text\r
	11	.align 3\r
	12	\r
9b89163e	13	GCC_ASM_EXPORT(InternalSyncCompareExchange16)\r
cc310428 OM	14	GCC_ASM_EXPORT(InternalSyncCompareExchange32)\r
	15	GCC_ASM_EXPORT(InternalSyncCompareExchange64)\r
	16	GCC_ASM_EXPORT(InternalSyncIncrement)\r
	17	GCC_ASM_EXPORT(InternalSyncDecrement)\r
	18	\r
9b89163e AB	19	/**\r
	20	Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	21	\r
	22	Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	23	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	24	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	25	then Value is returned. The compare exchange operation must be performed using\r
	26	MP safe mechanisms.\r
	27	\r
	28	@param Value A pointer to the 16-bit value for the compare exchange\r
	29	operation.\r
	30	@param CompareValue 16-bit value used in compare operation.\r
	31	@param ExchangeValue 16-bit value used in exchange operation.\r
	32	\r
	33	@return The original *Value before exchange.\r
	34	\r
	35	**/\r
	36	//UINT16\r
	37	//EFIAPI\r
	38	//InternalSyncCompareExchange16 (\r
	39	// IN volatile UINT16 *Value,\r
	40	// IN UINT16 CompareValue,\r
	41	// IN UINT16 ExchangeValue\r
	42	// )\r
	43	ASM_PFX(InternalSyncCompareExchange16):\r
	44	dmb\r
	45	\r
	46	InternalSyncCompareExchange16Again:\r
	47	ldrexh r3, [r0]\r
	48	cmp r3, r1\r
	49	bne InternalSyncCompareExchange16Fail\r
	50	\r
	51	InternalSyncCompareExchange16Exchange:\r
	52	strexh ip, r2, [r0]\r
	53	cmp ip, #0\r
	54	bne InternalSyncCompareExchange16Again\r
	55	\r
	56	InternalSyncCompareExchange16Fail:\r
	57	dmb\r
	58	mov r0, r3\r
	59	bx lr\r
	60	\r
cc310428 OM	61	/**\r
	62	Performs an atomic compare exchange operation on a 32-bit unsigned integer.\r
	63	\r
	64	Performs an atomic compare exchange operation on the 32-bit unsigned integer\r
	65	specified by Value. If Value is equal to CompareValue, then Value is set to\r
	66	ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	67	then Value is returned. The compare exchange operation must be performed using\r
	68	MP safe mechanisms.\r
	69	\r
	70	@param Value A pointer to the 32-bit value for the compare exchange\r
	71	operation.\r
	72	@param CompareValue 32-bit value used in compare operation.\r
	73	@param ExchangeValue 32-bit value used in exchange operation.\r
	74	\r
	75	@return The original *Value before exchange.\r
	76	\r
	77	**/\r
	78	//UINT32\r
	79	//EFIAPI\r
	80	//InternalSyncCompareExchange32 (\r
	81	// IN volatile UINT32 *Value,\r
	82	// IN UINT32 CompareValue,\r
	83	// IN UINT32 ExchangeValue\r
	84	// )\r
	85	ASM_PFX(InternalSyncCompareExchange32):\r
	86	dmb\r
	87	\r
	88	InternalSyncCompareExchange32Again:\r
	89	ldrex r3, [r0]\r
	90	cmp r3, r1\r
	91	bne InternalSyncCompareExchange32Fail\r
	92	\r
	93	InternalSyncCompareExchange32Exchange:\r
	94	strex ip, r2, [r0]\r
	95	cmp ip, #0\r
	96	bne InternalSyncCompareExchange32Again\r
	97	\r
	98	InternalSyncCompareExchange32Fail:\r
	99	dmb\r
	100	mov r0, r3\r
	101	bx lr\r
	102	\r
	103	/**\r
	104	Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
	105	\r
	106	Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
	107	by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
	108	CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
	109	The compare exchange operation must be performed using MP safe mechanisms.\r
	110	\r
	111	@param Value A pointer to the 64-bit value for the compare exchange\r
	112	operation.\r
	113	@param CompareValue 64-bit value used in compare operation.\r
	114	@param ExchangeValue 64-bit value used in exchange operation.\r
	115	\r
	116	@return The original *Value before exchange.\r
	117	\r
	118	**/\r
	119	//UINT64\r
	120	//EFIAPI\r
	121	//InternalSyncCompareExchange64 (\r
	122	// IN volatile UINT64 *Value, // r0\r
	123	// IN UINT64 CompareValue, // r2-r3\r
	124	// IN UINT64 ExchangeValue // stack\r
125	// )\r
126	ASM_PFX(InternalSyncCompareExchange64):\r
127	push { r4-r7 }\r
128	ldrd r4, r5, [sp, #16]\r
129	dmb\r
130	\r
131	InternalSyncCompareExchange64Again:\r
132	ldrexd r6, r7, [r0]\r
133	cmp r6, r2\r
134	cmpeq r7, r3\r
135	bne InternalSyncCompareExchange64Fail\r
136	\r
137	InternalSyncCompareExchange64Exchange:\r
138	strexd ip, r4, r5, [r0]\r
139	cmp ip, #0\r
140	bne InternalSyncCompareExchange64Again\r
141	\r
142	InternalSyncCompareExchange64Fail:\r
143	dmb\r
144	mov r0, r6\r
145	mov r1, r7\r
146	pop { r4-r7 }\r
147	bx lr\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\r
169	TryInternalSyncIncrement:\r
170	ldrex r1, [r0]\r
171	add r1, r1, #1\r
172	strex r2, r1, [r0]\r
173	cmp r2, #0\r
174	bne TryInternalSyncIncrement\r
175	dmb\r
f61762d0	176	mov r0, r1\r
cc310428 OM	177	bx lr\r
	178	\r
	179	/**\r
	180	Performs an atomic decrement of an 32-bit unsigned integer.\r
	181	\r
	182	Performs an atomic decrement of the 32-bit unsigned integer specified by\r
	183	Value and returns the decrement value. The decrement operation must be\r
	184	performed using MP safe mechanisms. The state of the return value is not\r
	185	guaranteed to be MP safe.\r
	186	\r
	187	@param Value A pointer to the 32-bit value to decrement.\r
	188	\r
	189	@return The decrement value.\r
	190	\r
	191	**/\r
	192	//UINT32\r
	193	//EFIAPI\r
	194	//InternalSyncDecrement (\r
	195	// IN volatile UINT32 *Value\r
	196	// )\r
	197	ASM_PFX(InternalSyncDecrement):\r
	198	dmb\r
	199	TryInternalSyncDecrement:\r
	200	ldrex r1, [r0]\r
	201	sub r1, r1, #1\r
	202	strex r2, r1, [r0]\r
	203	cmp r2, #0\r
	204	bne TryInternalSyncDecrement\r
	205	dmb\r
f61762d0	206	mov r0, r1\r
cc310428	207	bx lr\r