1290001Sglebius/* 2290001Sglebius * Copyright (C) 2005, 2007 Internet Systems Consortium, Inc. ("ISC") 3290001Sglebius * 4290001Sglebius * Permission to use, copy, modify, and/or distribute this software for any 5290001Sglebius * purpose with or without fee is hereby granted, provided that the above 6290001Sglebius * copyright notice and this permission notice appear in all copies. 7290001Sglebius * 8290001Sglebius * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH 9290001Sglebius * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY 10290001Sglebius * AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, 11290001Sglebius * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 12290001Sglebius * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE 13290001Sglebius * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR 14290001Sglebius * PERFORMANCE OF THIS SOFTWARE. 15290001Sglebius */ 16290001Sglebius 17290001Sglebius/* $Id: atomic.h,v 1.3 2007/06/19 23:47:18 tbox Exp $ */ 18290001Sglebius 19290001Sglebius#ifndef ISC_ATOMIC_H 20290001Sglebius#define ISC_ATOMIC_H 1 21290001Sglebius 22290001Sglebius#include <isc/platform.h> 23290001Sglebius#include <isc/types.h> 24290001Sglebius 25290001Sglebius#ifdef ISC_PLATFORM_USEGCCASM 26290001Sglebius/* 27290001Sglebius * This routine atomically increments the value stored in 'p' by 'val', and 28290001Sglebius * returns the previous value. 29290001Sglebius */ 30290001Sglebiusstatic inline isc_int32_t 31290001Sglebiusisc_atomic_xadd(isc_int32_t *p, int val) { 32290001Sglebius isc_int32_t orig; 33290001Sglebius 34290001Sglebius /* add is a cheat, since MIPS has no mov instruction */ 35290001Sglebius __asm__ volatile ( 36290001Sglebius "1:" 37290001Sglebius "ll $3, %1\n" 38290001Sglebius "add %0, $0, $3\n" 39290001Sglebius "add $3, $3, %2\n" 40290001Sglebius "sc $3, %1\n" 41290001Sglebius "beq $3, 0, 1b" 42290001Sglebius : "=&r"(orig) 43290001Sglebius : "m"(*p), "r"(val) 44290001Sglebius : "memory", "$3" 45290001Sglebius ); 46290001Sglebius 47290001Sglebius return (orig); 48290001Sglebius} 49290001Sglebius 50290001Sglebius/* 51290001Sglebius * This routine atomically stores the value 'val' in 'p'. 52290001Sglebius */ 53290001Sglebiusstatic inline void 54290001Sglebiusisc_atomic_store(isc_int32_t *p, isc_int32_t val) { 55290001Sglebius __asm__ volatile ( 56290001Sglebius "1:" 57290001Sglebius "ll $3, %0\n" 58290001Sglebius "add $3, $0, %1\n" 59290001Sglebius "sc $3, %0\n" 60290001Sglebius "beq $3, 0, 1b" 61290001Sglebius : 62290001Sglebius : "m"(*p), "r"(val) 63290001Sglebius : "memory", "$3" 64290001Sglebius ); 65290001Sglebius} 66290001Sglebius 67290001Sglebius/* 68290001Sglebius * This routine atomically replaces the value in 'p' with 'val', if the 69290001Sglebius * original value is equal to 'cmpval'. The original value is returned in any 70290001Sglebius * case. 71290001Sglebius */ 72290001Sglebiusstatic inline isc_int32_t 73290001Sglebiusisc_atomic_cmpxchg(isc_int32_t *p, int cmpval, int val) { 74290001Sglebius isc_int32_t orig; 75290001Sglebius 76290001Sglebius __asm__ volatile( 77290001Sglebius "1:" 78290001Sglebius "ll $3, %1\n" 79290001Sglebius "add %0, $0, $3\n" 80290001Sglebius "bne $3, %2, 2f\n" 81290001Sglebius "add $3, $0, %3\n" 82290001Sglebius "sc $3, %1\n" 83290001Sglebius "beq $3, 0, 1b\n" 84290001Sglebius "2:" 85290001Sglebius : "=&r"(orig) 86290001Sglebius : "m"(*p), "r"(cmpval), "r"(val) 87290001Sglebius : "memory", "$3" 88290001Sglebius ); 89290001Sglebius 90290001Sglebius return (orig); 91290001Sglebius} 92290001Sglebius 93290001Sglebius#else /* !ISC_PLATFORM_USEGCCASM */ 94290001Sglebius 95290001Sglebius#error "unsupported compiler. disable atomic ops by --disable-atomic" 96290001Sglebius 97290001Sglebius#endif 98290001Sglebius#endif /* ISC_ATOMIC_H */ 99