xref: /freebsd/sys/x86/include/ifunc.h (revision f39bffc62c1395bde25d152c7f68fdf7cbaab414)
1 /*-
2  * Copyright (c) 2015, 2017 The FreeBSD Foundation
3  * All rights reserved.
4  *
5  * This software was developed by Konstantin Belousov <kib@FreeBSD.org>
6  * under sponsorship from the FreeBSD Foundation.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
13  * 2. Redistributions in binary form must reproduce the above copyright
14  *    notice, this list of conditions and the following disclaimer in the
15  *    documentation and/or other materials provided with the distribution.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  * $FreeBSD$
30  */
31 
32 #ifndef __X86_IFUNC_H
33 #define	__X86_IFUNC_H
34 
35 #define	DECLARE_LIFUNC(ret_type, name, args)				\
36 ret_type name args
37 
38 #define	DEFINE_LIFUNC(scope, selector_qual, ret_type, name, args)	\
39 __asm__ (scope "\t" #name "\n"						\
40 	 "\t.type\t" #name ",@function\n"				\
41 	 #name ":\n"							\
42 	 "\tjmp	*" #name "_selector\n"					\
43 	 "\t.size\t" #name ",\t. - "#name);				\
44 selector_qual ret_type (*name##_selector)args  __used;			\
45 DECLARE_LIFUNC(ret_type, name, args)
46 
47 #define	DEFINE_STATIC_LIFUNC(ret_type, name, args)			\
48 	DEFINE_LIFUNC(".local", static, ret_type, name, args)
49 
50 #define	DEFINE_GLOBAL_LIFUNC(ret_type, name, args)			\
51 	DEFINE_LIFUNC(".globl", , ret_type, name, args)
52 
53 #define	DEFINE_IFUNC(qual, ret_type, name, args, resolver_qual)	\
54     resolver_qual ret_type (*name##_resolver(void))args __used;		\
55     qual ret_type name args __attribute__((ifunc(#name "_resolver")));	\
56     resolver_qual ret_type (*name##_resolver(void))args
57 
58 #endif
59