1 /* $NetBSD: pthread_md.h,v 1.18 2011/01/25 19:12:05 christos 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, and by Andrew Doran. 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 32 #ifndef _LIB_PTHREAD_I386_MD_H 33 #define _LIB_PTHREAD_I386_MD_H 34 35 #include <sys/ucontext.h> 36 #include <ucontext.h> 37 38 static inline unsigned long 39 pthread__sp(void) 40 { 41 unsigned long ret; 42 __asm("movl %%esp, %0" : "=g" (ret)); 43 44 return ret; 45 } 46 47 #define pthread__uc_sp(ucp) ((ucp)->uc_mcontext.__gregs[_REG_UESP]) 48 49 /* 50 * Set initial, sane values for registers whose values aren't just 51 * "don't care". 52 * 53 * We use the current context instead of a guessed one because we cannot 54 * assume how the GDT entries are ordered: what is true on i386 is not 55 * true anymore on amd64. 56 */ 57 #define _INITCONTEXT_U_MD(ucp) \ 58 do { \ 59 ucontext_t ucur; \ 60 (void)getcontext(&ucur); \ 61 (ucp)->uc_mcontext.__gregs[_REG_GS] = \ 62 ucur.uc_mcontext.__gregs[_REG_GS], \ 63 (ucp)->uc_mcontext.__gregs[_REG_FS] = \ 64 ucur.uc_mcontext.__gregs[_REG_FS], \ 65 (ucp)->uc_mcontext.__gregs[_REG_ES] = \ 66 ucur.uc_mcontext.__gregs[_REG_ES], \ 67 (ucp)->uc_mcontext.__gregs[_REG_DS] = \ 68 ucur.uc_mcontext.__gregs[_REG_DS], \ 69 (ucp)->uc_mcontext.__gregs[_REG_CS] = \ 70 ucur.uc_mcontext.__gregs[_REG_CS], \ 71 (ucp)->uc_mcontext.__gregs[_REG_SS] = \ 72 ucur.uc_mcontext.__gregs[_REG_SS], \ 73 (ucp)->uc_mcontext.__gregs[_REG_EFL] = \ 74 ucur.uc_mcontext.__gregs[_REG_EFL]; \ 75 } while (/*CONSTCOND*/0); 76 77 #define pthread__smt_pause() __asm __volatile("rep; nop" ::: "memory") 78 /* #define PTHREAD__HAVE_THREADREG */ 79 80 /* Don't need additional memory barriers. */ 81 #define PTHREAD__ATOMIC_IS_MEMBAR 82 83 static inline pthread_t 84 #ifdef __GNUC__ 85 __attribute__ ((__const__)) 86 #endif 87 pthread__threadreg_get(void) 88 { 89 pthread_t self; 90 91 __asm volatile("movl %%gs:0, %0" 92 : "=r" (self) 93 :); 94 95 return self; 96 } 97 98 static inline void * 99 _atomic_cas_ptr(volatile void *ptr, void *old, void *new) 100 { 101 volatile uintptr_t *cast = ptr; 102 void *ret; 103 104 __asm __volatile ("lock; cmpxchgl %2, %1" 105 : "=a" (ret), "=m" (*cast) 106 : "r" (new), "m" (*cast), "0" (old)); 107 108 return ret; 109 } 110 111 static inline void * 112 _atomic_cas_ptr_ni(volatile void *ptr, void *old, void *new) 113 { 114 volatile uintptr_t *cast = ptr; 115 void *ret; 116 117 __asm __volatile ("cmpxchgl %2, %1" 118 : "=a" (ret), "=m" (*cast) 119 : "r" (new), "m" (*cast), "0" (old)); 120 121 return ret; 122 } 123 124 #endif /* _LIB_PTHREAD_I386_MD_H */ 125