1 /* $NetBSD: pthread_md.h,v 1.13 2023/05/25 14:30:03 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. 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 unsigned long 40 pthread__sp(void) 41 { 42 unsigned 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 50 /* 51 * Set initial, sane values for registers whose values aren't just 52 * "don't care". 53 * 0x23 is GSEL(GUDATA_SEL, SEL_UPL), and 54 * 0x1b is GSEL(GUCODE_SEL, SEL_UPL). 55 * 0x202 is PSL_USERSET. 56 */ 57 #define _INITCONTEXT_U_MD(ucp) \ 58 (ucp)->uc_mcontext.__gregs[_REG_GS] = 0x23, \ 59 (ucp)->uc_mcontext.__gregs[_REG_FS] = 0x23, \ 60 (ucp)->uc_mcontext.__gregs[_REG_ES] = 0x23, \ 61 (ucp)->uc_mcontext.__gregs[_REG_DS] = 0x23, \ 62 (ucp)->uc_mcontext.__gregs[_REG_CS] = 0x1b, \ 63 (ucp)->uc_mcontext.__gregs[_REG_SS] = 0x23, \ 64 (ucp)->uc_mcontext.__gregs[_REG_RFL] = 0x202; 65 66 #define pthread__smt_pause() __asm __volatile("rep; nop" ::: "memory") 67 #define pthread__smt_wait() __asm __volatile("rep; nop" ::: "memory") 68 69 /* Don't need additional memory barriers. */ 70 #define PTHREAD__ATOMIC_IS_MEMBAR 71 72 static inline void * 73 _atomic_cas_ptr(volatile void *ptr, void *old, void *new) 74 { 75 volatile uintptr_t *cast = ptr; 76 void *ret; 77 78 __asm __volatile ("lock; cmpxchgq %2, %1" 79 : "=a" (ret), "=m" (*cast) 80 : "r" (new), "m" (*cast), "0" (old)); 81 82 return ret; 83 } 84 85 static inline void * 86 _atomic_cas_ptr_ni(volatile void *ptr, void *old, void *new) 87 { 88 volatile uintptr_t *cast = ptr; 89 void *ret; 90 91 __asm __volatile ("cmpxchgq %2, %1" 92 : "=a" (ret), "=m" (*cast) 93 : "r" (new), "m" (*cast), "0" (old)); 94 95 return ret; 96 } 97 98 #endif /* _LIB_PTHREAD_X86_64_MD_H */ 99