xref: /freebsd/lib/libthr/arch/arm/include/pthread_md.h (revision 0b3105a37d7adcadcb720112fed4dc4e8040be99)
1 /*-
2  * Copyright (c) 2005 David Xu <davidxu@freebsd.org>.
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  *
15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 /*
30  * Machine-dependent thread prototypes/definitions.
31  */
32 #ifndef _PTHREAD_MD_H_
33 #define	_PTHREAD_MD_H_
34 
35 #include <sys/types.h>
36 #include <machine/sysarch.h>
37 #include <stddef.h>
38 
39 #define	CPU_SPINWAIT
40 #define	DTV_OFFSET		offsetof(struct tcb, tcb_dtv)
41 
42 /*
43  * Variant II tcb, first two members are required by rtld.
44  */
45 struct tcb {
46 	void			*tcb_dtv;	/* required by rtld */
47 	struct pthread		*tcb_thread;	/* our hook */
48 };
49 
50 /* Called from the thread to set its private data. */
51 static __inline void
52 _tcb_set(struct tcb *tcb)
53 {
54 #ifdef ARM_TP_ADDRESS
55 	*((struct tcb **)ARM_TP_ADDRESS) = tcb;	/* avoids a system call */
56 #else
57 	sysarch(ARM_SET_TP, tcb);
58 #endif
59 }
60 
61 /*
62  * Get the current tcb.
63  */
64 static __inline struct tcb *
65 _tcb_get(void)
66 {
67 #ifdef ARM_TP_ADDRESS
68 	return (*((struct tcb **)ARM_TP_ADDRESS));
69 #else
70 	struct tcb *tcb;
71 
72 	__asm __volatile("mrc  p15, 0, %0, c13, c0, 3"		\
73 	   		 : "=r" (tcb));
74 	return (tcb);
75 #endif
76 }
77 
78 extern struct pthread *_thr_initial;
79 
80 static __inline struct pthread *
81 _get_curthread(void)
82 {
83 	if (_thr_initial)
84 		return (_tcb_get()->tcb_thread);
85 	return (NULL);
86 }
87 
88 #endif /* _PTHREAD_MD_H_ */
89