Annotation of sys/arch/hppa/hppa/in_cksum.c, Revision 1.1
1.1 ! nbrk 1: /* $OpenBSD: in_cksum.c,v 1.3 2004/04/07 18:24:19 mickey Exp $ */
! 2:
! 3: /*
! 4: * Copyright (c) 2000 Michael Shalayeff
! 5: * All rights reserved.
! 6: *
! 7: * based on a sparc version of Zubin Dittia.
! 8: * Copyright (c) 1995 Zubin Dittia.
! 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 AUTHOR ``AS IS'' AND ANY EXPRESS OR
! 20: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
! 21: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
! 22: * IN NO EVENT SHALL THE AUTHOR OR HIS RELATIVES BE LIABLE FOR ANY DIRECT,
! 23: * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
! 24: * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
! 25: * SERVICES; LOSS OF MIND, USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
! 26: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
! 27: * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
! 28: * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
! 29: * THE POSSIBILITY OF SUCH DAMAGE.
! 30: */
! 31:
! 32: #include <sys/param.h>
! 33: #include <sys/systm.h>
! 34: #include <sys/mbuf.h>
! 35: #include <netinet/in.h>
! 36:
! 37: /*
! 38: * Checksum routine for Internet Protocol family headers.
! 39: *
! 40: * This routine is very heavily used in the network
! 41: * code and should be modified for each CPU to be as fast as possible.
! 42: *
! 43: * HPPA version.
! 44: */
! 45:
! 46: #define ADD32 asm volatile( "ldw 0x00(%1), %%r19! ldw 0x04(%1), %%r20\n\t" \
! 47: "add %0, %%r19, %0 ! addc %0, %%r20, %0\n\t" \
! 48: "ldw 0x08(%1), %%r19! ldw 0x0c(%1), %%r20\n\t" \
! 49: "addc %0, %%r19, %0 ! addc %0, %%r20, %0\n\t" \
! 50: "ldw 0x10(%1), %%r19! ldw 0x14(%1), %%r20\n\t" \
! 51: "addc %0, %%r19, %0 ! addc %0, %%r20, %0\n\t" \
! 52: "ldw 0x18(%1), %%r19! ldw 0x1c(%1), %%r20\n\t" \
! 53: "addc %0, %%r19, %0 ! addc %0, %%r20, %0\n\t" \
! 54: "ldo 0x20(%1), %1 ! addc %0, %%r0 , %0" \
! 55: : "+r" (sum), "+r" (w) :: "r20", "r19")
! 56: #define ADD16 asm volatile( "ldw 0x00(%1), %%r19! ldw 0x04(%1), %%r20\n\t" \
! 57: "add %0, %%r19, %0! addc %0, %%r20, %0\n\t" \
! 58: "ldw 0x08(%1), %%r19! ldw 0x0c(%1), %%r20\n\t" \
! 59: "addc %0, %%r19, %0! addc %0, %%r20, %0\n\t" \
! 60: "ldo 0x10(%1), %1 ! addc %0, %%r0 , %0" \
! 61: : "+r" (sum), "+r" (w) :: "r20", "r19")
! 62:
! 63: #define ADDCARRY {if (sum > 0xffff) sum -= 0xffff;}
! 64: #define REDUCE {sum = (sum & 0xffff) + (sum >> 16); ADDCARRY}
! 65: #define ROL asm volatile ("shd %0, %0, 8, %0" : "+r" (sum))
! 66: #define ADDBYTE {ROL; sum += *w++; bins++; mlen--;}
! 67: #define ADDSHORT {sum += *((u_short *)w)++; mlen -= 2;}
! 68: #define ADDWORD asm volatile( "ldwm 4(%1), %%r19! add %0, %%r19, %0\n\t" \
! 69: "ldo -4(%2), %2 ! addc %0, 0, %0" \
! 70: : "+r" (sum), "+r" (w), "+r" (mlen) :: "r19")
! 71:
! 72: int
! 73: in_cksum(m, len)
! 74: register struct mbuf *m;
! 75: register int len;
! 76: {
! 77: register u_int sum = 0;
! 78: register u_int bins = 0;
! 79:
! 80: for (; m && len; m = m->m_next) {
! 81: register int mlen = m->m_len;
! 82: register u_char *w;
! 83:
! 84: if (!mlen)
! 85: continue;
! 86: if (len < mlen)
! 87: mlen = len;
! 88: len -= mlen;
! 89: w = mtod(m, u_char *);
! 90:
! 91: if (mlen > 16) {
! 92: /*
! 93: * If we are aligned on a doubleword boundary
! 94: * do 32 bit bundled operations
! 95: */
! 96: if ((7 & (u_long)w) != 0) {
! 97: if ((1 & (u_long)w) != 0)
! 98: ADDBYTE;
! 99: if ((2 & (u_long)w) != 0)
! 100: ADDSHORT;
! 101: if ((4 & (u_long)w) != 0)
! 102: ADDWORD;
! 103: }
! 104:
! 105: while ((mlen -= 32) >= 0)
! 106: ADD32;
! 107:
! 108: mlen += 32;
! 109: if (mlen >= 16) {
! 110: ADD16;
! 111: mlen -= 16;
! 112: }
! 113: }
! 114:
! 115: while (mlen > 0)
! 116: ADDBYTE;
! 117: }
! 118: if (bins & 1)
! 119: ROL;
! 120: REDUCE;
! 121:
! 122: return (0xffff ^ sum);
! 123: }
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