mcontext.h revision 1.15 
1/*	$NetBSD: mcontext.h,v 1.15 2024/11/04 15:45:24 christos Exp $	*/
2
3/*-
4 * Copyright (c) 1999 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * Copyright (c) 1999, 2003 Marcel Moolenaar
8 *
9 * This code is derived from software contributed to The NetBSD Foundation
10 * by Klaus Klein.
11 *
12 * Redistribution and use in source and binary forms, with or without
13 * modification, are permitted provided that the following conditions
14 * are met:
15 * 1. Redistributions of source code must retain the above copyright
16 *    notice, this list of conditions and the following disclaimer.
17 * 2. Redistributions in binary form must reproduce the above copyright
18 *    notice, this list of conditions and the following disclaimer in the
19 *    documentation and/or other materials provided with the distribution.
20 * 3. The name of the author may not be used to endorse or promote products
21 *    derived from this software without specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
24 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
25 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
26 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
27 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
30 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
31 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
32 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
33 * POSSIBILITY OF SUCH DAMAGE.
34 */
35
36#ifndef _IA64_MCONTEXT_H_
37#define _IA64_MCONTEXT_H_
38
39#include <machine/_regset.h>
40
41/* XXX fix this, just get to compile for now */
42#define _NGREG	1
43
44#ifndef __ASSEMBLER__
45typedef unsigned long __greg_t;
46typedef __greg_t __gregset_t[_NGREG];
47
48typedef struct {
49  union _ia64_fpreg __fpregs[_NGREG];
50} __fpregset_t;
51
52#endif /* __ASSEMBLER__ */
53
54/*
55 * The mc_flags field provides the necessary clues when dealing with the gory
56 * details of ia64 specific contexts. A comprehensive explanation is added for
57 * everybody's sanity, including the author's.
58 *
59 * The first and foremost variation in the context is synchronous contexts
60 * (= synctx) versus asynchronous contexts (= asynctx). A synctx is created
61 * synchronously WRT program execution and has the advantage that none of the
62 * scratch registers have to be saved. They are assumed to be clobbered by the
63 * call to the function that creates the context. An asynctx needs to have the
64 * scratch registers preserved because it can describe any point in a thread's
65 * (or process') execution.
66 * The second variation is for synchronous contexts. When the kernel creates
67 * a synchronous context if needs to preserve the scratch registers, because
68 * the syscall argument and return values are stored there in the trapframe
69 * and they need to be preserved in order to restart a syscall or return the
70 * proper return values. Also, the IIP and CFM fields need to be preserved
71 * as they point to the syscall stub, which the kernel saves as a favor to
72 * userland (it keeps the stubs small and simple).
73 *
74 * Below a description of the flags and their meaning:
75 *
76 *	_MC_FLAGS_ASYNC_CONTEXT
77 *		If set, indicates that mc_scratch and mc_scratch_fp are both
78 *		valid. IFF not set, _MC_FLAGS_SYSCALL_CONTEXT indicates if the
79 *		synchronous context is one corresponding to a syscall or not.
80 *		Only the kernel is expected to create such a context and it's
81 *		probably wise to let the kernel restore it.
82 *	_MC_FLAGS_HIGHFP_VALID
83 *		If set, indicates that the high FP registers (f32-f127) are
84 *		valid. This flag is very likely not going to be set for any
85 *		sensible synctx, but is not explicitly disallowed. Any synctx
86 *		that has this flag may or may not have the high FP registers
87 *		restored. In short: don't do it.
88 *	_MC_FLAGS_SYSCALL_CONTEXT
89 *		If set (hence _MC_FLAGS_ASYNC_CONTEXT is not set) indicates
90 *		that the scratch registers contain syscall arguments and
91 *		return values and that additionally IIP and CFM are valid.
92 *		Only the kernel is expected to create such a context. It's
93 *		probably wise to let the kernel restore it.
94 */
95
96typedef struct __mcontext {
97	unsigned long		mc_flags;
98#define	_MC_FLAGS_ASYNC_CONTEXT		0x0001
99#define	_MC_FLAGS_HIGHFP_VALID		0x0002
100#define	_MC_FLAGS_SYSCALL_CONTEXT	0x0008
101	unsigned long		_reserved_;
102	struct _special		mc_special;
103	struct _callee_saved	mc_preserved;
104	struct _callee_saved_fp	mc_preserved_fp;
105	struct _caller_saved	mc_scratch;
106	struct _caller_saved_fp	mc_scratch_fp;
107	struct _high_fp		mc_high_fp;
108
109	/* XXX fix */
110	__gregset_t		__gregs;
111	__fpregset_t		__fpregs;
112} mcontext_t;
113
114#define _UC_MACHINE_SP(uc)	((uc)->uc_mcontext.mc_special.sp)  /* gregs[12] */
115#define _UC_MACHINE_FP(uc)	0 /* Not supported in target */
116#define	_UC_MACHINE_PC(uc)	((uc)->uc_mcontext.mc_special.iip)
117#define	_UC_MACHINE_INTRV(uc)	((uc)->uc_mcontext.mc_scratch.gr8) /* gregs[8] */
118#define _UC_MACHINE_SET_PC(uc, pc)	(uc)->uc_mcontext.mc_special.iip = (pc)
119
120#define	_UC_TLSBASE	_UC_MD_BIT16
121#define	_UC_SETSTACK	_UC_MD_BIT17
122#define	_UC_CLRSTACK	_UC_MD_BIT18
123
124
125#if defined(_RTLD_SOURCE) || defined(_LIBC_SOURCE) || \
126    defined(__LIBPTHREAD_SOURCE__)
127#include <sys/tls.h>
128
129__BEGIN_DECLS
130static __inline void *
131__lwp_getprivate_fast(void)
132{
133	return (void*)0;
134}
135__END_DECLS
136
137#endif
138
139#endif	/* !_IA64_MCONTEXT_H_ */
140