[ceph.git] / ceph / src / seastar / dpdk / lib / librte_compat / rte_compat.h

/*-
 *   BSD LICENSE
 *
 *   Copyright(c) 2015 Neil Horman <nhorman@tuxdriver.com>.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#ifndef _RTE_COMPAT_H_
#define _RTE_COMPAT_H_
#include <rte_common.h>

#ifdef RTE_BUILD_SHARED_LIB

/*
 * Provides backwards compatibility when updating exported functions.
 * When a symol is exported from a library to provide an API, it also provides a
 * calling convention (ABI) that is embodied in its name, return type,
 * arguments, etc.  On occasion that function may need to change to accommodate
 * new functionality, behavior, etc.  When that occurs, it is desireable to
 * allow for backwards compatibility for a time with older binaries that are
 * dynamically linked to the dpdk.  To support that, the __vsym and
 * VERSION_SYMBOL macros are created.  They, in conjunction with the
 * <library>_version.map file for a given library allow for multiple versions of
 * a symbol to exist in a shared library so that older binaries need not be
 * immediately recompiled.
 *
 * Refer to the guidelines document in the docs subdirectory for details on the
 * use of these macros
 */

/*
 * Macro Parameters:
 * b - function base name
 * e - function version extension, to be concatenated with base name
 * n - function symbol version string to be applied
 * f - function prototype
 * p - full function symbol name
 */

/*
 * VERSION_SYMBOL
 * Creates a symbol version table entry binding symbol <b>@DPDK_<n> to the internal
 * function name <b>_<e>
 */
#define VERSION_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@DPDK_" RTE_STR(n))

/*
 * BIND_DEFAULT_SYMBOL
 * Creates a symbol version entry instructing the linker to bind references to
 * symbol <b> to the internal symbol <b>_<e>
 */
#define BIND_DEFAULT_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@@DPDK_" RTE_STR(n))
#define __vsym __attribute__((used))

/*
 * MAP_STATIC_SYMBOL
 * If a function has been bifurcated into multiple versions, none of which
 * are defined as the exported symbol name in the map file, this macro can be
 * used to alias a specific version of the symbol to its exported name.  For
 * example, if you have 2 versions of a function foo_v1 and foo_v2, where the
 * former is mapped to foo@DPDK_1 and the latter is mapped to foo@DPDK_2 when
 * building a shared library, this macro can be used to map either foo_v1 or
 * foo_v2 to the symbol foo when building a static library, e.g.:
 * MAP_STATIC_SYMBOL(void foo(), foo_v2);
 */
#define MAP_STATIC_SYMBOL(f, p)

#else
/*
 * No symbol versioning in use
 */
#define VERSION_SYMBOL(b, e, n)
#define __vsym
#define BIND_DEFAULT_SYMBOL(b, e, n)
#define MAP_STATIC_SYMBOL(f, p) f __attribute__((alias(RTE_STR(p))))
/*
 * RTE_BUILD_SHARED_LIB=n
 */
#endif


#endif /* _RTE_COMPAT_H_ */
Commit	Line	Data
7c673cae FG	1	/*-
	2	* BSD LICENSE
	3	*
	4	* Copyright(c) 2015 Neil Horman <nhorman@tuxdriver.com>.
	5	* All rights reserved.
	6	*
	7	* Redistribution and use in source and binary forms, with or without
	8	* modification, are permitted provided that the following conditions
	9	* are met:
	10	*
	11	* * Redistributions of source code must retain the above copyright
	12	* notice, this list of conditions and the following disclaimer.
	13	* * Redistributions in binary form must reproduce the above copyright
	14	* notice, this list of conditions and the following disclaimer in
	15	* the documentation and/or other materials provided with the
	16	* distribution.
	17	*
	18	* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
	19	* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
	20	* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
	21	* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
	22	* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
	23	* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
	24	* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
	25	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
	26	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
	27	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
	28	* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
	29	*/
	30
	31	#ifndef _RTE_COMPAT_H_
	32	#define _RTE_COMPAT_H_
	33	#include <rte_common.h>
	34
	35	#ifdef RTE_BUILD_SHARED_LIB
	36
	37	/*
	38	* Provides backwards compatibility when updating exported functions.
	39	* When a symol is exported from a library to provide an API, it also provides a
	40	* calling convention (ABI) that is embodied in its name, return type,
	41	* arguments, etc. On occasion that function may need to change to accommodate
	42	* new functionality, behavior, etc. When that occurs, it is desireable to
	43	* allow for backwards compatibility for a time with older binaries that are
	44	* dynamically linked to the dpdk. To support that, the __vsym and
	45	* VERSION_SYMBOL macros are created. They, in conjunction with the
	46	* <library>_version.map file for a given library allow for multiple versions of
	47	* a symbol to exist in a shared library so that older binaries need not be
	48	* immediately recompiled.
	49	*
	50	* Refer to the guidelines document in the docs subdirectory for details on the
	51	* use of these macros
	52	*/
	53
	54	/*
	55	* Macro Parameters:
	56	* b - function base name
	57	* e - function version extension, to be concatenated with base name
	58	* n - function symbol version string to be applied
	59	* f - function prototype
	60	* p - full function symbol name
	61	*/
	62
	63	/*
	64	* VERSION_SYMBOL
65	* Creates a symbol version table entry binding symbol <b>@DPDK_<n> to the internal
66	* function name <b>_<e>
67	*/
68	#define VERSION_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@DPDK_" RTE_STR(n))
69
70	/*
71	* BIND_DEFAULT_SYMBOL
72	* Creates a symbol version entry instructing the linker to bind references to
73	* symbol <b> to the internal symbol <b>_<e>
74	*/
75	#define BIND_DEFAULT_SYMBOL(b, e, n) __asm__(".symver " RTE_STR(b) RTE_STR(e) ", " RTE_STR(b) "@@DPDK_" RTE_STR(n))
76	#define __vsym __attribute__((used))
77
78	/*
79	* MAP_STATIC_SYMBOL
80	* If a function has been bifurcated into multiple versions, none of which
81	* are defined as the exported symbol name in the map file, this macro can be
82	* used to alias a specific version of the symbol to its exported name. For
83	* example, if you have 2 versions of a function foo_v1 and foo_v2, where the
84	* former is mapped to foo@DPDK_1 and the latter is mapped to foo@DPDK_2 when
85	* building a shared library, this macro can be used to map either foo_v1 or
86	* foo_v2 to the symbol foo when building a static library, e.g.:
87	* MAP_STATIC_SYMBOL(void foo(), foo_v2);
88	*/
89	#define MAP_STATIC_SYMBOL(f, p)
90
91	#else
92	/*
93	* No symbol versioning in use
94	*/
95	#define VERSION_SYMBOL(b, e, n)
96	#define __vsym
97	#define BIND_DEFAULT_SYMBOL(b, e, n)
98	#define MAP_STATIC_SYMBOL(f, p) f __attribute__((alias(RTE_STR(p))))
99	/*
100	* RTE_BUILD_SHARED_LIB=n
101	*/
102	#endif
103
104
105	#endif /* _RTE_COMPAT_H_ */