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

;  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
  EXPORT InternalSyncCompareExchange16\r
  EXPORT InternalSyncCompareExchange32\r
  EXPORT InternalSyncCompareExchange64\r
  EXPORT InternalSyncIncrement\r
  EXPORT InternalSyncDecrement\r
  AREA BaseSynchronizationLib_LowLevel, 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
  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
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
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
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
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
\r
  END\r
Commit	Line	Data
37db86ae PB	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	EXPORT InternalSyncCompareExchange16\r
	17	EXPORT InternalSyncCompareExchange32\r
	18	EXPORT InternalSyncCompareExchange64\r
	19	EXPORT InternalSyncIncrement\r
	20	EXPORT InternalSyncDecrement\r
	21	AREA BaseSynchronizationLib_LowLevel, CODE, READONLY\r
	22	\r
	23	;/**\r
	24	; Performs an atomic compare exchange operation on a 16-bit unsigned integer.\r
	25	;\r
	26	; Performs an atomic compare exchange operation on the 16-bit unsigned integer\r
	27	; specified by Value. If Value is equal to CompareValue, then Value is set to\r
	28	; ExchangeValue and CompareValue is returned. If Value is not equal to CompareValue,\r
	29	; then Value is returned. The compare exchange operation must be performed using\r
	30	; MP safe mechanisms.\r
	31	;\r
	32	; @param Value A pointer to the 16-bit value for the compare exchange\r
	33	; operation.\r
	34	; @param CompareValue 16-bit value used in compare operation.\r
	35	; @param ExchangeValue 16-bit value used in exchange operation.\r
	36	;\r
	37	; @return The original *Value before exchange.\r
	38	;\r
	39	;**/\r
	40	;UINT16\r
	41	;EFIAPI\r
	42	;InternalSyncCompareExchange16 (\r
	43	; IN volatile UINT16 *Value,\r
	44	; IN UINT16 CompareValue,\r
	45	; IN UINT16 ExchangeValue\r
	46	; )\r
	47	InternalSyncCompareExchange16\r
	48	uxth w1, w1\r
	49	uxth w2, w2\r
	50	dmb sy\r
	51	\r
	52	InternalSyncCompareExchange16Again\r
	53	ldxrh w3, [x0]\r
	54	cmp w3, w1\r
	55	bne InternalSyncCompareExchange16Fail\r
	56	\r
	57	InternalSyncCompareExchange16Exchange\r
	58	stxrh w4, w2, [x0]\r
	59	cbnz w4, InternalSyncCompareExchange16Again\r
	60	\r
	61	InternalSyncCompareExchange16Fail\r
	62	dmb sy\r
	63	mov w0, w3\r
	64	ret\r
65	\r
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 sy\r
92	\r
93	InternalSyncCompareExchange32Again\r
94	ldxr w3, [x0]\r
95	cmp w3, w1\r
96	bne InternalSyncCompareExchange32Fail\r
97	\r
98	InternalSyncCompareExchange32Exchange\r
99	stxr w4, w2, [x0]\r
100	cbnz w4, InternalSyncCompareExchange32Again\r
101	\r
102	InternalSyncCompareExchange32Fail\r
103	dmb sy\r
104	mov w0, w3\r
105	ret\r
106	\r
107	;/**\r
108	; Performs an atomic compare exchange operation on a 64-bit unsigned integer.\r
109	;\r
110	; Performs an atomic compare exchange operation on the 64-bit unsigned integer specified\r
111	; by Value. If Value is equal to CompareValue, then Value is set to ExchangeValue and\r
112	; CompareValue is returned. If Value is not equal to CompareValue, then Value is returned.\r
113	; The compare exchange operation must be performed using MP safe mechanisms.\r
114	;\r
115	; @param Value A pointer to the 64-bit value for the compare exchange\r
116	; operation.\r
117	; @param CompareValue 64-bit value used in compare operation.\r
118	; @param ExchangeValue 64-bit value used in exchange operation.\r
119	;\r
120	; @return The original *Value before exchange.\r
121	;\r
122	;**/\r
123	;UINT64\r
124	;EFIAPI\r
125	;InternalSyncCompareExchange64 (\r
126	; IN volatile UINT64 *Value,\r
127	; IN UINT64 CompareValue,\r
128	; IN UINT64 ExchangeValue\r
129	; )\r
130	InternalSyncCompareExchange64\r
131	dmb sy\r
132	\r
133	InternalSyncCompareExchange64Again\r
134	ldxr x3, [x0]\r
135	cmp x3, x1\r
136	bne InternalSyncCompareExchange64Fail\r
137	\r
138	InternalSyncCompareExchange64Exchange\r
139	stxr w4, x2, [x0]\r
140	cbnz w4, InternalSyncCompareExchange64Again\r
141	\r
142	InternalSyncCompareExchange64Fail\r
143	dmb sy\r
144	mov x0, x3\r
145	ret\r
146	\r
147	;/**\r
148	; Performs an atomic increment of an 32-bit unsigned integer.\r
149	;\r
150	; Performs an atomic increment of the 32-bit unsigned integer specified by\r
151	; Value and returns the incremented value. The increment operation must be\r
152	; performed using MP safe mechanisms. The state of the return value is not\r
153	; guaranteed to be MP safe.\r
154	;\r
155	; @param Value A pointer to the 32-bit value to increment.\r
156	;\r
157	; @return The incremented value.\r
158	;\r
159	;**/\r
160	;UINT32\r
161	;EFIAPI\r
162	;InternalSyncIncrement (\r
163	; IN volatile UINT32 *Value\r
164	; )\r
165	InternalSyncIncrement\r
166	dmb sy\r
167	TryInternalSyncIncrement\r
168	ldxr w1, [x0]\r
169	add w1, w1, #1\r
170	stxr w2, w1, [x0]\r
171	cbnz w2, TryInternalSyncIncrement\r
172	mov w0, w1\r
173	dmb sy\r
174	ret\r
175	\r
176	;/**\r
177	; Performs an atomic decrement of an 32-bit unsigned integer.\r
178	;\r
179	; Performs an atomic decrement of the 32-bit unsigned integer specified by\r
180	; Value and returns the decrement value. The decrement operation must be\r
181	; performed using MP safe mechanisms. The state of the return value is not\r
182	; guaranteed to be MP safe.\r
183	;\r
184	; @param Value A pointer to the 32-bit value to decrement.\r
185	;\r
186	; @return The decrement value.\r
187	;\r
188	;**/\r
189	;UINT32\r
190	;EFIAPI\r
191	;InternalSyncDecrement (\r
192	; IN volatile UINT32 *Value\r
193	; )\r
194	InternalSyncDecrement\r
195	dmb sy\r
196	TryInternalSyncDecrement\r
197	ldxr w1, [x0]\r
198	sub w1, w1, #1\r
199	stxr w2, w1, [x0]\r
200	cbnz w2, TryInternalSyncDecrement\r
201	mov w0, w1\r
202	dmb sy\r
203	ret\r
204	\r
205	END\r