xref: /freebsd/lib/libthr/arch/amd64/include/pthread_md.h (revision 5956d97f4b3204318ceb6aa9c77bd0bc6ea87a41)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (C) 2003 David Xu <davidxu@freebsd.org>
5  * Copyright (c) 2001 Daniel Eischen <deischen@freebsd.org>
6  * All rights reserved.
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. Neither the name of the author nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
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 /*
33  * Machine-dependent thread prototypes/definitions.
34  */
35 #ifndef _PTHREAD_MD_H_
36 #define	_PTHREAD_MD_H_
37 
38 #include <stddef.h>
39 #include <sys/types.h>
40 #include <machine/tls.h>
41 
42 #define	CPU_SPINWAIT		__asm __volatile("pause")
43 
44 /* For use in _Static_assert to check structs will fit in a page */
45 #define	THR_PAGE_SIZE_MIN	PAGE_SIZE
46 
47 static __inline struct pthread *
48 _get_curthread(void)
49 {
50 	struct pthread *thr;
51 
52 	__asm __volatile("movq %%fs:%1, %0" : "=r" (thr)
53 	    : "m" (*(volatile u_long *)offsetof(struct tcb, tcb_thread)));
54 	return (thr);
55 }
56 
57 #define	HAS__UMTX_OP_ERR	1
58 
59 #endif
60