xref: /freebsd/lib/libthr/arch/arm/include/pthread_md.h (revision ca987d4641cdcd7f27e153db17c5bf064934faf5)
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 I tcb. The structure layout is fixed, don't blindly
44  * change it.
45  */
46 struct tcb {
47 	void			*tcb_dtv;	/* required by rtld */
48 	struct pthread		*tcb_thread;	/* our hook */
49 };
50 
51 /* Called from the thread to set its private data. */
52 static __inline void
53 _tcb_set(struct tcb *tcb)
54 {
55 #ifdef ARM_TP_ADDRESS
56 	*((struct tcb **)ARM_TP_ADDRESS) = tcb;	/* avoids a system call */
57 #else
58 	sysarch(ARM_SET_TP, tcb);
59 #endif
60 }
61 
62 /*
63  * Get the current tcb.
64  */
65 static __inline struct tcb *
66 _tcb_get(void)
67 {
68 #ifdef ARM_TP_ADDRESS
69 	return (*((struct tcb **)ARM_TP_ADDRESS));
70 #else
71 	struct tcb *tcb;
72 
73 	__asm __volatile("mrc  p15, 0, %0, c13, c0, 3"		\
74 	   		 : "=r" (tcb));
75 	return (tcb);
76 #endif
77 }
78 
79 static __inline struct pthread *
80 _get_curthread(void)
81 {
82 	if (_thr_initial)
83 		return (_tcb_get()->tcb_thread);
84 	return (NULL);
85 }
86 
87 #endif /* _PTHREAD_MD_H_ */
88