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atomic_nand_32.S revision 1.4 
      1 /* $NetBSD: atomic_nand_32.S,v 1.4 2021/07/05 08:50:31 skrll 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 Matt Thomas of 3am Software Foundry.
      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 "atomic_op_asm.h"
     33 
     34 /*
     35  * { tmp = *ptr; *ptr = ~(tmp & value); return tmp; }   // nand
     36  */
     37 ENTRY_NP(_atomic_nand_32)
     38 	mov	x4, x0
     39 1:	ldxr	w0, [x4]		/* load old value (to be returned) */
     40 	and	w3, w0, w1		/* w3 =  (*ptr & value) */
     41 	mvn	w3, w3			/* x3 = ~(*ptr & value) */
     42 	stxr	w2, w3, [x4]		/* try to store */
     43 	cbnz	w2, 2f			/*   succeed? no, try again */
     44 	ret				/* return old value */
     45 2:	b	1b
     46 END(_atomic_nand_32)
     47 
     48 ATOMIC_OP_ALIAS(atomic_nand_32,_atomic_nand_32)
     49 ATOMIC_OP_ALIAS(atomic_nand_uint,_atomic_nand_32)
     50 STRONG_ALIAS(__sync_fetch_and_nand_4,_atomic_nand_32)
     51 STRONG_ALIAS(_atomic_nand_uint,_atomic_nand_32)
     52 
     53 
     54 /*
     55  * { tmp = ~(*ptr & value); *ptr = tmp; return *ptr; }   // nand
     56  */
     57 ENTRY_NP(_atomic_nand_32_nv)
     58 	mov	x4, x0			/* need r0 for return value */
     59 1:	ldxr	w0, [x4]		/* load old value (*ptr) */
     60 	and	w0, w0, w1		/* x0 =  (*ptr & value) */
     61 	mvn	w0, w0			/* x0 = ~(*ptr & value), return value */
     62 	stxr	w2, w0, [x4]		/* try to store */
     63 	cbnz	w2, 2f			/*   succeed? no, try again? */
     64 	ret				/* return new value */
     65 2:	b	1b
     66 END(_atomic_nand_32_nv)
     67 
     68 ATOMIC_OP_ALIAS(atomic_nand_32_nv,_atomic_nand_32_nv)
     69 ATOMIC_OP_ALIAS(atomic_nand_uint_nv,_atomic_nand_32_nv)
     70 STRONG_ALIAS(__sync_nand_and_fetch_4,_atomic_nand_32_nv)
     71 STRONG_ALIAS(_atomic_nand_uint_nv,_atomic_nand_32_nv)
     72