xref: /freebsd/contrib/ofed/opensm/include/complib/cl_spinlock.h (revision 3078531de10dcae44b253a35125c949ff4235284)
1 /*
2  * Copyright (c) 2004, 2005 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 spin lock object.
39  */
40 
41 #ifndef _CL_SPINLOCK_H_
42 #define _CL_SPINLOCK_H_
43 
44 #include <complib/cl_spinlock_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* Public/Spinlock
56 * NAME
57 *	Spinlock
58 *
59 * DESCRIPTION
60 *	Spinlock provides synchronization between threads for exclusive access to
61 *	a resource.
62 *
63 *	The spinlock functions manipulate a cl_spinlock_t structure which should
64 *	be treated as opaque and should be manipulated only through the provided
65 *	functions.
66 *
67 * SEE ALSO
68 *	Structures:
69 *		cl_spinlock_t
70 *
71 *	Initialization:
72 *		cl_spinlock_construct, cl_spinlock_init, cl_spinlock_destroy
73 *
74 *	Manipulation
75 *		cl_spinlock_acquire, cl_spinlock_release
76 *********/
77 /****f* Component Library: Spinlock/cl_spinlock_construct
78 * NAME
79 *	cl_spinlock_construct
80 *
81 * DESCRIPTION
82 *	The cl_spinlock_construct function initializes the state of a
83 *	spin lock.
84 *
85 * SYNOPSIS
86 */
87 void cl_spinlock_construct(IN cl_spinlock_t * const p_spinlock);
88 /*
89 * PARAMETERS
90 *	p_spin_lock
91 *		[in] Pointer to a spin lock structure whose state to initialize.
92 *
93 * RETURN VALUE
94 *	This function does not return a value.
95 *
96 * NOTES
97 *	Allows calling cl_spinlock_destroy without first calling
98 *	cl_spinlock_init.
99 *
100 *	Calling cl_spinlock_construct is a prerequisite to calling any other
101 *	spin lock function except cl_spinlock_init.
102 *
103 * SEE ALSO
104 *	Spinlock, cl_spinlock_init, cl_spinlock_destroy
105 *********/
106 
107 /****f* Component Library: Spinlock/cl_spinlock_init
108 * NAME
109 *	cl_spinlock_init
110 *
111 * DESCRIPTION
112 *	The cl_spinlock_init function initializes a spin lock for use.
113 *
114 * SYNOPSIS
115 */
116 cl_status_t cl_spinlock_init(IN cl_spinlock_t * const p_spinlock);
117 /*
118 * PARAMETERS
119 *	p_spin_lock
120 *		[in] Pointer to a spin lock structure to initialize.
121 *
122 * RETURN VALUES
123 *	CL_SUCCESS if initialization succeeded.
124 *
125 *	CL_ERROR if initialization failed. Callers should call
126 *	cl_spinlock_destroy to clean up any resources allocated during
127 *	initialization.
128 *
129 * NOTES
130 *	Initialize the spin lock structure. Allows calling cl_spinlock_aquire
131 *	and cl_spinlock_release.
132 *
133 * SEE ALSO
134 *	Spinlock, cl_spinlock_construct, cl_spinlock_destroy,
135 *	cl_spinlock_acquire, cl_spinlock_release
136 *********/
137 
138 /****f* Component Library: Spinlock/cl_spinlock_destroy
139 * NAME
140 *	cl_spinlock_destroy
141 *
142 * DESCRIPTION
143 *	The cl_spinlock_destroy function performs all necessary cleanup of a
144 *	spin lock.
145 *
146 * SYNOPSIS
147 */
148 void cl_spinlock_destroy(IN cl_spinlock_t * const p_spinlock);
149 /*
150 * PARAMETERS
151 *	p_spin_lock
152 *		[in] Pointer to a spin lock structure to destroy.
153 *
154 * RETURN VALUE
155 *	This function does not return a value.
156 *
157 * NOTES
158 *	Performs any necessary cleanup of a spin lock. This function must only
159 *	be called if either cl_spinlock_construct or cl_spinlock_init has been
160 *	called.
161 *
162 * SEE ALSO
163 *	Spinlock, cl_spinlock_construct, cl_spinlock_init
164 *********/
165 
166 /****f* Component Library: Spinlock/cl_spinlock_acquire
167 * NAME
168 *	cl_spinlock_acquire
169 *
170 * DESCRIPTION
171 *	The cl_spinlock_acquire function acquires a spin lock.
172 *	This version of lock does not prevent an interrupt from
173 *	occuring on the processor on which the code is being
174 *	executed.
175 *
176 * SYNOPSIS
177 */
178 void cl_spinlock_acquire(IN cl_spinlock_t * const p_spinlock);
179 /*
180 * PARAMETERS
181 *	p_spin_lock
182 *		[in] Pointer to a spin lock structure to acquire.
183 *
184 * RETURN VALUE
185 *	This function does not return a value.
186 *
187 * SEE ALSO
188 *	Spinlock, cl_spinlock_release
189 *********/
190 
191 /****f* Component Library: Spinlock/cl_spinlock_release
192 * NAME
193 *	cl_spinlock_release
194 *
195 * DESCRIPTION
196 *	The cl_spinlock_release function releases a spin lock object.
197 *
198 * SYNOPSIS
199 */
200 void cl_spinlock_release(IN cl_spinlock_t * const p_spinlock);
201 /*
202 * PARAMETERS
203 *	p_spin_lock
204 *		[in] Pointer to a spin lock structure to release.
205 *
206 * RETURN VALUE
207 *	This function does not return a value.
208 *
209 * NOTES
210 *	Releases a spin lock after a call to cl_spinlock_acquire.
211 *
212 * SEE ALSO
213 *	Spinlock, cl_spinlock_acquire
214 *********/
215 
216 END_C_DECLS
217 #endif				/* _CL_SPINLOCK_H_ */
218