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| -rw-r--r-- | lib/isc/alpha/include/isc/atomic.h | 180 |
1 files changed, 180 insertions, 0 deletions
diff --git a/lib/isc/alpha/include/isc/atomic.h b/lib/isc/alpha/include/isc/atomic.h new file mode 100644 index 0000000..e704fef --- /dev/null +++ b/lib/isc/alpha/include/isc/atomic.h @@ -0,0 +1,180 @@ +/* + * Copyright (C) Internet Systems Consortium, Inc. ("ISC") + * + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. + * + * See the COPYRIGHT file distributed with this work for additional + * information regarding copyright ownership. + */ + + +/* + * This code was written based on FreeBSD's kernel source whose copyright + * follows: + */ + +/*- + * Copyright (c) 1998 Doug Rabson + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * $FreeBSD: src/sys/alpha/include/atomic.h,v 1.18.6.1 2004/09/13 21:52:04 wilko Exp $ + */ + +#ifndef ISC_ATOMIC_H +#define ISC_ATOMIC_H 1 + +#include <inttypes.h> + +#include <isc/platform.h> +#include <isc/types.h> + +#ifdef ISC_PLATFORM_USEOSFASM +#include <c_asm.h> + +#pragma intrinsic(asm) + +/* + * This routine atomically increments the value stored in 'p' by 'val', and + * returns the previous value. Memory access ordering around this function + * can be critical, so we add explicit memory block instructions at the + * beginning and the end of it (same for other functions). + */ +static inline int32_t +isc_atomic_xadd(int32_t *p, int32_t val) { + return (asm("mb;" + "1:" + "ldl_l %t0, 0(%a0);" /* load old value */ + "mov %t0, %v0;" /* copy the old value */ + "addl %t0, %a1, %t0;" /* calculate new value */ + "stl_c %t0, 0(%a0);" /* attempt to store */ + "beq %t0, 1b;" /* spin if failed */ + "mb;", + p, val)); +} + +/* + * This routine atomically stores the value 'val' in 'p'. + */ +static inline void +isc_atomic_store(int32_t *p, int32_t val) { + (void)asm("mb;" + "1:" + "ldl_l %t0, 0(%a0);" /* load old value */ + "mov %a1, %t0;" /* value to store */ + "stl_c %t0, 0(%a0);" /* attempt to store */ + "beq %t0, 1b;" /* spin if failed */ + "mb;", + p, val); +} + +/* + * This routine atomically replaces the value in 'p' with 'val', if the + * original value is equal to 'cmpval'. The original value is returned in any + * case. + */ +static inline int32_t +isc_atomic_cmpxchg(int32_t *p, int32_t cmpval, int32_t val) { + + return(asm("mb;" + "1:" + "ldl_l %t0, 0(%a0);" /* load old value */ + "mov %t0, %v0;" /* copy the old value */ + "cmpeq %t0, %a1, %t0;" /* compare */ + "beq %t0, 2f;" /* exit if not equal */ + "mov %a2, %t0;" /* value to store */ + "stl_c %t0, 0(%a0);" /* attempt to store */ + "beq %t0, 1b;" /* if it failed, spin */ + "2:" + "mb;", + p, cmpval, val)); +} +#elif defined (ISC_PLATFORM_USEGCCASM) +static inline int32_t +isc_atomic_xadd(int32_t *p, int32_t val) { + int32_t temp, prev; + + __asm__ volatile( + "mb;" + "1:" + "ldl_l %0, %1;" /* load old value */ + "mov %0, %2;" /* copy the old value */ + "addl %0, %3, %0;" /* calculate new value */ + "stl_c %0, %1;" /* attempt to store */ + "beq %0, 1b;" /* spin if failed */ + "mb;" + : "=&r"(temp), "+m"(*p), "=&r"(prev) + : "r"(val) + : "memory"); + + return (prev); +} + +static inline void +isc_atomic_store(int32_t *p, int32_t val) { + int32_t temp; + + __asm__ volatile( + "mb;" + "1:" + "ldl_l %0, %1;" /* load old value */ + "mov %2, %0;" /* value to store */ + "stl_c %0, %1;" /* attempt to store */ + "beq %0, 1b;" /* if it failed, spin */ + "mb;" + : "=&r"(temp), "+m"(*p) + : "r"(val) + : "memory"); +} + +static inline int32_t +isc_atomic_cmpxchg(int32_t *p, int32_t cmpval, int32_t val) { + int32_t temp, prev; + + __asm__ volatile( + "mb;" + "1:" + "ldl_l %0, %1;" /* load old value */ + "mov %0, %2;" /* copy the old value */ + "cmpeq %0, %3, %0;" /* compare */ + "beq %0, 2f;" /* exit if not equal */ + "mov %4, %0;" /* value to store */ + "stl_c %0, %1;" /* attempt to store */ + "beq %0, 1b;" /* if it failed, spin */ + "2:" + "mb;" + : "=&r"(temp), "+m"(*p), "=&r"(prev) + : "r"(cmpval), "r"(val) + : "memory"); + + return (prev); +} +#else + +#error "unsupported compiler. disable atomic ops by --disable-atomic" + +#endif + +#endif /* ISC_ATOMIC_H */ |