xref: /freebsd/lib/libthr/arch/riscv/include/pthread_md.h (revision f7c32ed617858bcd22f8d1b03199099d50125721)
1 /*-
2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3  * Copyright (c) 2015 Ruslan Bukin <br@bsdpad.com>
4  * All rights reserved.
5  *
6  * Portions of this software were developed by SRI International and the
7  * University of Cambridge Computer Laboratory under DARPA/AFRL contract
8  * FA8750-10-C-0237 ("CTSRD"), as part of the DARPA CRASH research programme.
9  *
10  * Portions of this software were developed by the University of Cambridge
11  * Computer Laboratory as part of the CTSRD Project, with support from the
12  * UK Higher Education Innovation Fund (HEIF).
13  *
14  * Redistribution and use in source and binary forms, with or without
15  * modification, are permitted provided that the following conditions
16  * are met:
17  * 1. Redistributions of source code must retain the above copyright
18  *    notice, this list of conditions and the following disclaimer.
19  * 2. Redistributions in binary form must reproduce the above copyright
20  *    notice, this list of conditions and the following disclaimer in the
21  *    documentation and/or other materials provided with the distribution.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  * $FreeBSD$
36  */
37 
38 /*
39  * Machine-dependent thread prototypes/definitions.
40  */
41 #ifndef _PTHREAD_MD_H_
42 #define	_PTHREAD_MD_H_
43 
44 #include <sys/types.h>
45 #include <stddef.h>
46 
47 #define	CPU_SPINWAIT
48 #define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
49 #define	TP_OFFSET		sizeof(struct tcb)
50 
51 /*
52  * Variant I tcb. The structure layout is fixed, don't blindly
53  * change it!
54  */
55 struct tcb {
56 	void			*tcb_dtv;
57 	struct pthread		*tcb_thread;
58 };
59 
60 /* Called from the thread to set its private data. */
61 static __inline void
62 _tcb_set(struct tcb *tcb)
63 {
64 
65 	__asm __volatile("addi tp, %0, %1" :: "r"(tcb), "I"(TP_OFFSET));
66 }
67 
68 /*
69  * Get the current tcb.
70  */
71 static __inline struct tcb *
72 _tcb_get(void)
73 {
74 	struct tcb *_tcb;
75 
76 	__asm __volatile("addi %0, tp, %1" : "=r"(_tcb) : "I"(-TP_OFFSET));
77 
78 	return (_tcb);
79 }
80 
81 static __inline struct pthread *
82 _get_curthread(void)
83 {
84 
85 	if (_thr_initial)
86 		return (_tcb_get()->tcb_thread);
87 	return (NULL);
88 }
89 
90 #endif /* _PTHREAD_MD_H_ */
91