1/* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License, Version 1.0 only 6 * (the "License"). You may not use this file except in compliance 7 * with the License. 8 * 9 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 10 * or http://www.opensolaris.org/os/licensing. 11 * See the License for the specific language governing permissions 12 * and limitations under the License. 13 * 14 * When distributing Covered Code, include this CDDL HEADER in each 15 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 16 * If applicable, add the following below this CDDL HEADER, with the 17 * fields enclosed by brackets "[]" replaced with your own identifying 18 * information: Portions Copyright [yyyy] [name of copyright owner] 19 * 20 * CDDL HEADER END 21 */ 22/* 23 * Copyright 2005 Sun Microsystems, Inc. All rights reserved. 24 * Use is subject to license terms. 25 */ 26 27#ident "%Z%%M% %I% %E% SMI" 28 29#include <sys/asm_linkage.h> 30 31#if defined(lint) 32#include <sys/types.h> 33#endif /* lint */ 34 35/* 36 * ip_ocsum(address, halfword_count, sum) 37 * Do a 16 bit one's complement sum of a given number of (16-bit) 38 * halfwords. The halfword pointer must not be odd. 39 * %o0 address; %o1 count; %o2 sum accumulator; %o4 temp 40 * %g2 and %g3 used in main loop 41 * 42 * (from @(#)ocsum.s 1.3 89/02/24 SMI) 43 * 44 */ 45 46#if defined(lint) 47 48/* ARGSUSED */ 49unsigned int 50ip_ocsum(u_short *address, int halfword_count, unsigned int sum) 51{ return (0); } 52 53#else /* lint */ 54 55 ENTRY(ip_ocsum) 56 cmp %o1, 31 ! less than 62 bytes? 57 bl,a .dohw ! just do halfwords 58 tst %o1 ! delay slot, test count 59 60 btst 31, %o0 ! (delay slot) 61 bz 2f ! if 32 byte aligned, skip 62 nop 63 64 ! 65 ! Do first halfwords until 32-byte aligned 66 ! 671: 68 lduh [%o0], %g2 ! read data 69 add %o0, 2, %o0 ! increment address 70 add %o2, %g2, %o2 ! add to accumulator, don't need carry yet 71 btst 31, %o0 ! 32 byte aligned? 72 bnz 1b 73 sub %o1, 1, %o1 ! decrement count 74 ! 75 ! loop to add in 32 byte chunks 76 ! The loads and adds are staggered to help avoid load/use 77 ! interlocks on highly pipelined implementations, and double 78 ! loads are used for 64-bit wide memory systems. 79 ! 802: 81 sub %o1, 16, %o1 ! decrement count to aid testing 824: 83 ldd [%o0], %g2 ! read data 84 ldd [%o0+8], %o4 ! read more data 85 addcc %o2, %g2, %o2 ! add to accumulator 86 addxcc %o2, %g3, %o2 ! add to accumulator with carry 87 ldd [%o0+16], %g2 ! read more data 88 addxcc %o2, %o4, %o2 ! add to accumulator with carry 89 addxcc %o2, %o5, %o2 ! add to accumulator with carry 90 ldd [%o0+24], %o4 ! read more data 91 addxcc %o2, %g2, %o2 ! add to accumulator with carry 92 addxcc %o2, %g3, %o2 ! add to accumulator with carry 93 addxcc %o2, %o4, %o2 ! add to accumulator 94 addxcc %o2, %o5, %o2 ! add to accumulator with carry 95 addxcc %o2, 0, %o2 ! if final carry, add it in 96 subcc %o1, 16, %o1 ! decrement count (in halfwords) 97 bge 4b 98 add %o0, 32, %o0 ! delay slot, increment address 99 100 add %o1, 16, %o1 ! add back in 101 ! 102 ! Do any remaining halfwords 103 ! 104 b .dohw 105 tst %o1 ! delay slot, for more to do 106 1073: 108 add %o0, 2, %o0 ! increment address 109 addcc %o2, %g2, %o2 ! add to accumulator 110 addxcc %o2, 0, %o2 ! if carry, add it in 111 subcc %o1, 1, %o1 ! decrement count 112.dohw: 113 bg,a 3b ! more to do? 114 lduh [%o0], %g2 ! read data 115 116 ! 117 ! at this point the 32-bit accumulator 118 ! has the result that needs to be returned in 16-bits 119 ! 120 sll %o2, 16, %o4 ! put low halfword in high halfword %o4 121 addcc %o4, %o2, %o2 ! add the 2 halfwords in high %o2, set carry 122 srl %o2, 16, %o2 ! shift to low halfword 123 retl ! return 124 addxcc %o2, 0, %o0 ! add in carry if any. result in %o0 125 SET_SIZE(ip_ocsum) 126 127#endif /* lint */ 128