xref: /netbsd-src/lib/libpthread/arch/x86_64/pthread_md.h (revision cd22f25e6f6d1cc1f197fe8c5468a80f51d1c4e1)
1 /*	$NetBSD: pthread_md.h,v 1.10 2008/04/28 20:23:02 martin Exp $	*/
2 
3 /*-
4  * Copyright (c) 2001, 2007, 2008 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Nathan J. Williams.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  *
31  * Adapted for x86_64 by fvdl@NetBSD.org
32  */
33 
34 #ifndef _LIB_PTHREAD_X86_64_MD_H
35 #define _LIB_PTHREAD_X86_64_MD_H
36 
37 #include <sys/ucontext.h>
38 
39 static inline long
40 pthread__sp(void)
41 {
42 	long ret;
43 	__asm("movq %%rsp, %0" : "=g" (ret));
44 
45 	return ret;
46 }
47 
48 #define pthread__uc_sp(ucp) ((ucp)->uc_mcontext.__gregs[_REG_URSP])
49 #define pthread__uc_pc(ucp) ((ucp)->uc_mcontext.__gregs[_REG_RIP])
50 
51 /*
52  * Set initial, sane values for registers whose values aren't just
53  * "don't care".
54  * 0x23 is GSEL(GUDATA_SEL, SEL_UPL), and
55  * 0x1b is GSEL(GUCODE_SEL, SEL_UPL).
56  * 0x202 is PSL_USERSET.
57  */
58 #define _INITCONTEXT_U_MD(ucp)						\
59 	(ucp)->uc_mcontext.__gregs[_REG_GS] = 0x23,			\
60 	(ucp)->uc_mcontext.__gregs[_REG_FS] = 0x23,			\
61 	(ucp)->uc_mcontext.__gregs[_REG_ES] = 0x23,			\
62 	(ucp)->uc_mcontext.__gregs[_REG_DS] = 0x23,			\
63 	(ucp)->uc_mcontext.__gregs[_REG_CS] = 0x1b,			\
64 	(ucp)->uc_mcontext.__gregs[_REG_SS] = 0x23,			\
65 	(ucp)->uc_mcontext.__gregs[_REG_RFL] = 0x202;
66 
67 /*
68  * Usable stack space below the ucontext_t.
69  * See comment in pthread_switch.S about STACK_SWITCH.
70  */
71 #define STACKSPACE	64	/* room for 8 long values */
72 
73 /*
74  * Conversions between struct reg and struct mcontext. Used by
75  * libpthread_dbg.
76  */
77 
78 #define PTHREAD_UCONTEXT_TO_REG(reg, uc) \
79 	memcpy(reg, (uc)->uc_mcontext.__gregs, _NGREG * sizeof (long));
80 
81 #define PTHREAD_REG_TO_UCONTEXT(uc, reg) do {				\
82 	memcpy((uc)->uc_mcontext.__gregs, reg, _NGREG * sizeof (long)); \
83 	(uc)->uc_flags = ((uc)->uc_flags | _UC_CPU) & ~_UC_USER; 	\
84 	} while (/*CONSTCOND*/0)
85 
86 
87 #define PTHREAD_UCONTEXT_TO_FPREG(freg, uc)		       		\
88 	(void)memcpy(&(freg)->fxstate,					\
89         (uc)->uc_mcontext.__fpregs, sizeof(struct fpreg))
90 
91 #define PTHREAD_FPREG_TO_UCONTEXT(uc, freg) do {       	       		\
92 	(void)memcpy(							\
93         (uc)->uc_mcontext.__fpregs,					\
94 	&(freg)->fxstate, sizeof(struct fpreg));			\
95 	/*LINTED precision loss */					\
96 	(uc)->uc_flags = ((uc)->uc_flags | _UC_FPU) & ~_UC_USER;	\
97 	} while (/*CONSTCOND*/0)
98 
99 #define	pthread__smt_pause()	__asm __volatile("rep; nop" ::: "memory")
100 
101 /* Don't need additional memory barriers. */
102 #define	PTHREAD__ATOMIC_IS_MEMBAR
103 
104 static inline void *
105 _atomic_cas_ptr(volatile void *ptr, void *old, void *new)
106 {
107 	volatile uintptr_t *cast = ptr;
108 	void *ret;
109 
110 	__asm __volatile ("lock; cmpxchgq %2, %1"
111 		: "=a" (ret), "=m" (*cast)
112 		: "r" (new), "m" (*cast), "0" (old));
113 
114 	return ret;
115 }
116 
117 static inline void *
118 _atomic_cas_ptr_ni(volatile void *ptr, void *old, void *new)
119 {
120 	volatile uintptr_t *cast = ptr;
121 	void *ret;
122 
123 	__asm __volatile ("cmpxchgq %2, %1"
124 		: "=a" (ret), "=m" (*cast)
125 		: "r" (new), "m" (*cast), "0" (old));
126 
127 	return ret;
128 }
129 
130 #endif /* _LIB_PTHREAD_X86_64_MD_H */
131