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atomic_nand_32_cas.c revision 1.1.8.2 
      1 /*	$NetBSD: atomic_nand_32_cas.c,v 1.1.8.2 2014/08/19 23:45:14 tls Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 2014 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Jason R. Thorpe.
      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 #include <sys/atomic.h>
     33 
     34 uint32_t fetch_and_nand_4(volatile uint32_t *, uint32_t, ...)
     35     asm("__sync_fetch_and_nand_4");
     36 uint32_t nand_and_fetch_4(volatile uint32_t *, uint32_t, ...)
     37     asm("__sync_nand_and_fetch_4");
     38 
     39 uint32_t
     40 fetch_and_nand_4(volatile uint32_t *addr, uint32_t val, ...)
     41 {
     42 	uint32_t old, new;
     43 
     44 	do {
     45 		old = *addr;
     46 		new = ~(old & val);
     47 	} while (atomic_cas_32(addr, old, new) != old);
     48 	return old;
     49 }
     50 
     51 uint32_t
     52 nand_and_fetch_4(volatile uint32_t *addr, uint32_t val, ...)
     53 {
     54 	uint32_t old, new;
     55 
     56 	do {
     57 		old = *addr;
     58 		new = ~(old & val);
     59 	} while (atomic_cas_32(addr, old, new) != old);
     60 	return new;
     61 }
     62