xref: /NextBSD/contrib/ofed/management/opensm/include/complib/cl_atomic.h (revision eb1a5f8de9f7ea602c373a710f531abbf81141c4)
1 /*
2  * Copyright (c) 2004-2006 Voltaire, Inc. All rights reserved.
3  * Copyright (c) 2002-2005 Mellanox Technologies LTD. All rights reserved.
4  * Copyright (c) 1996-2003 Intel Corporation. All rights reserved.
5  *
6  * This software is available to you under a choice of one of two
7  * licenses.  You may choose to be licensed under the terms of the GNU
8  * General Public License (GPL) Version 2, available from the file
9  * COPYING in the main directory of this source tree, or the
10  * OpenIB.org BSD license below:
11  *
12  *     Redistribution and use in source and binary forms, with or
13  *     without modification, are permitted provided that the following
14  *     conditions are met:
15  *
16  *      - Redistributions of source code must retain the above
17  *        copyright notice, this list of conditions and the following
18  *        disclaimer.
19  *
20  *      - Redistributions in binary form must reproduce the above
21  *        copyright notice, this list of conditions and the following
22  *        disclaimer in the documentation and/or other materials
23  *        provided with the distribution.
24  *
25  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
26  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
27  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
28  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
29  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
30  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
31  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
32  * SOFTWARE.
33  *
34  */
35 
36 /*
37  * Abstract:
38  *	Declaration of atomic manipulation functions.
39  */
40 
41 #ifndef _CL_ATOMIC_H_
42 #define _CL_ATOMIC_H_
43 
44 #include <complib/cl_atomic_osd.h>
45 
46 #ifdef __cplusplus
47 #  define BEGIN_C_DECLS extern "C" {
48 #  define END_C_DECLS   }
49 #else				/* !__cplusplus */
50 #  define BEGIN_C_DECLS
51 #  define END_C_DECLS
52 #endif				/* __cplusplus */
53 
54 BEGIN_C_DECLS
55 /****h* Component Library/Atomic Operations
56 * NAME
57 *	Atomic Operations
58 *
59 * DESCRIPTION
60 *	The Atomic Operations functions allow callers to operate on
61 *	32-bit signed integers in an atomic fashion.
62 *********/
63 /****f* Component Library: Atomic Operations/cl_atomic_inc
64 * NAME
65 *	cl_atomic_inc
66 *
67 * DESCRIPTION
68 *	The cl_atomic_inc function atomically increments a 32-bit signed
69 *	integer and returns the incremented value.
70 *
71 * SYNOPSIS
72 */
73 int32_t cl_atomic_inc(IN atomic32_t * const p_value);
74 /*
75 * PARAMETERS
76 *	p_value
77 *		[in] Pointer to a 32-bit integer to increment.
78 *
79 * RETURN VALUE
80 *	Returns the incremented value pointed to by p_value.
81 *
82 * NOTES
83 *	The provided value is incremented and its value returned in one atomic
84 *	operation.
85 *
86 *	cl_atomic_inc maintains data consistency without requiring additional
87 *	synchronization mechanisms in multi-threaded environments.
88 *
89 * SEE ALSO
90 *	Atomic Operations, cl_atomic_dec, cl_atomic_add, cl_atomic_sub,
91 *	cl_atomic_xchg, cl_atomic_comp_xchg
92 *********/
93 
94 /****f* Component Library: Atomic Operations/cl_atomic_dec
95 * NAME
96 *	cl_atomic_dec
97 *
98 * DESCRIPTION
99 *	The cl_atomic_dec function atomically decrements a 32-bit signed
100 *	integer and returns the decremented value.
101 *
102 * SYNOPSIS
103 */
104 int32_t cl_atomic_dec(IN atomic32_t * const p_value);
105 /*
106 * PARAMETERS
107 *	p_value
108 *		[in] Pointer to a 32-bit integer to decrement.
109 *
110 * RETURN VALUE
111 *	Returns the decremented value pointed to by p_value.
112 *
113 * NOTES
114 *	The provided value is decremented and its value returned in one atomic
115 *	operation.
116 *
117 *	cl_atomic_dec maintains data consistency without requiring additional
118 *	synchronization mechanisms in multi-threaded environments.
119 *
120 * SEE ALSO
121 *	Atomic Operations, cl_atomic_inc, cl_atomic_add, cl_atomic_sub,
122 *	cl_atomic_xchg, cl_atomic_comp_xchg
123 *********/
124 
125 /****f* Component Library: Atomic Operations/cl_atomic_add
126 * NAME
127 *	cl_atomic_add
128 *
129 * DESCRIPTION
130 *	The cl_atomic_add function atomically adds a value to a
131 *	32-bit signed integer and returns the resulting value.
132 *
133 * SYNOPSIS
134 */
135 int32_t
136 cl_atomic_add(IN atomic32_t * const p_value, IN const int32_t increment);
137 /*
138 * PARAMETERS
139 *	p_value
140 *		[in] Pointer to a 32-bit integer that will be added to.
141 *
142 *	increment
143 *		[in] Value by which to increment the integer pointed to by p_value.
144 *
145 * RETURN VALUE
146 *	Returns the value pointed to by p_value after the addition.
147 *
148 * NOTES
149 *	The provided increment is added to the value and the result returned in
150 *	one atomic operation.
151 *
152 *	cl_atomic_add maintains data consistency without requiring additional
153 *	synchronization mechanisms in multi-threaded environments.
154 *
155 * SEE ALSO
156 *	Atomic Operations, cl_atomic_inc, cl_atomic_dec, cl_atomic_sub,
157 *	cl_atomic_xchg, cl_atomic_comp_xchg
158 *********/
159 
160 /****f* Component Library: Atomic Operations/cl_atomic_sub
161 * NAME
162 *	cl_atomic_sub
163 *
164 * DESCRIPTION
165 *	The cl_atomic_sub function atomically subtracts a value from a
166 *	32-bit signed integer and returns the resulting value.
167 *
168 * SYNOPSIS
169 */
170 int32_t
171 cl_atomic_sub(IN atomic32_t * const p_value, IN const int32_t decrement);
172 /*
173 * PARAMETERS
174 *	p_value
175 *		[in] Pointer to a 32-bit integer that will be subtracted from.
176 *
177 *	decrement
178 *		[in] Value by which to decrement the integer pointed to by p_value.
179 *
180 * RETURN VALUE
181 *	Returns the value pointed to by p_value after the subtraction.
182 *
183 * NOTES
184 *	The provided decrement is subtracted from the value and the result
185 *	returned in one atomic operation.
186 *
187 *	cl_atomic_sub maintains data consistency without requiring additional
188 *	synchronization mechanisms in multi-threaded environments.
189 *
190 * SEE ALSO
191 *	Atomic Operations, cl_atomic_inc, cl_atomic_dec, cl_atomic_add,
192 *	cl_atomic_xchg, cl_atomic_comp_xchg
193 *********/
194 
195 END_C_DECLS
196 #endif				/* _CL_ATOMIC_H_ */
197