xref: /freebsd/lib/libthr/arch/arm/include/pthread_md.h (revision cfd6422a5217410fbd66f7a7a8a64d9d85e61229)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3  *
4  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>.
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  * 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 ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  *
28  * $FreeBSD$
29  */
30 
31 /*
32  * Machine-dependent thread prototypes/definitions.
33  */
34 #ifndef _PTHREAD_MD_H_
35 #define	_PTHREAD_MD_H_
36 
37 #include <sys/types.h>
38 #include <machine/sysarch.h>
39 #include <stddef.h>
40 
41 #define	CPU_SPINWAIT
42 #define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
43 
44 /*
45  * Variant I tcb. The structure layout is fixed, don't blindly
46  * change it.
47  */
48 struct tcb {
49 	void			*tcb_dtv;	/* required by rtld */
50 	struct pthread		*tcb_thread;	/* our hook */
51 };
52 
53 /* Called from the thread to set its private data. */
54 static __inline void
55 _tcb_set(struct tcb *tcb)
56 {
57 #ifdef ARM_TP_ADDRESS
58 	*((struct tcb **)ARM_TP_ADDRESS) = tcb;	/* avoids a system call */
59 #else
60 	sysarch(ARM_SET_TP, tcb);
61 #endif
62 }
63 
64 /*
65  * Get the current tcb.
66  */
67 static __inline struct tcb *
68 _tcb_get(void)
69 {
70 #ifdef ARM_TP_ADDRESS
71 	return (*((struct tcb **)ARM_TP_ADDRESS));
72 #else
73 	struct tcb *tcb;
74 
75 	__asm __volatile("mrc  p15, 0, %0, c13, c0, 3"		\
76 	   		 : "=r" (tcb));
77 	return (tcb);
78 #endif
79 }
80 
81 static __inline struct pthread *
82 _get_curthread(void)
83 {
84 	if (_thr_initial)
85 		return (_tcb_get()->tcb_thread);
86 	return (NULL);
87 }
88 
89 #endif /* _PTHREAD_MD_H_ */
90