1 /* $NetBSD: pthread_md.h,v 1.21 2023/05/25 14:30:02 riastradh 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 static inline void 50 _initcontext_u_md(ucontext_t *ucp) 51 { 52 __asm ("pushfl; popl %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_EFL])); 53 __asm ("pushl %%cs; popl %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_CS])); 54 __asm ("movl %%ds, %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_DS])); 55 __asm ("movl %%es, %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_ES])); 56 __asm ("movl %%fs, %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_FS])); 57 __asm ("movl %%gs, %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_GS])); 58 __asm ("movl %%ss, %0" : "=a" (ucp->uc_mcontext.__gregs[_REG_SS])); 59 } 60 61 #define _INITCONTEXT_U_MD(ucp) _initcontext_u_md(ucp); 62 63 #define pthread__smt_pause() __asm __volatile("rep; nop" ::: "memory") 64 #define pthread__smt_wait() __asm __volatile("rep; nop" ::: "memory") 65 66 /* Don't need additional memory barriers. */ 67 #define PTHREAD__ATOMIC_IS_MEMBAR 68 69 static inline void * 70 _atomic_cas_ptr(volatile void *ptr, void *old, void *new) 71 { 72 volatile uintptr_t *cast = ptr; 73 void *ret; 74 75 __asm __volatile ("lock; cmpxchgl %2, %1" 76 : "=a" (ret), "=m" (*cast) 77 : "r" (new), "m" (*cast), "0" (old)); 78 79 return ret; 80 } 81 82 static inline void * 83 _atomic_cas_ptr_ni(volatile void *ptr, void *old, void *new) 84 { 85 volatile uintptr_t *cast = ptr; 86 void *ret; 87 88 __asm __volatile ("cmpxchgl %2, %1" 89 : "=a" (ret), "=m" (*cast) 90 : "r" (new), "m" (*cast), "0" (old)); 91 92 return ret; 93 } 94 95 #endif /* _LIB_PTHREAD_I386_MD_H */ 96