source: rtems/cpukit/libnetworking/netinet/in_cksum_arm.h @ a3dfa39

4.104.114.84.95
Last change on this file since a3dfa39 was 0647cc7, checked in by Joel Sherrill <joel.sherrill@…>, on 10/31/02 at 20:10:40

2002-10-31 Joel Sherrill <joel@…>

  • libc/rcmd.c, netinet/in_cksum_arm.c: Removed warnings.
  • Property mode set to 100644
File size: 7.1 KB
Line 
1/*      $NetBSD: in_cksum_arm.c,v 1.3 2001/12/08 21:18:50 chris Exp $   */
2
3/*
4 * ARM version:
5 *
6 * Copyright (c) 1997 Mark Brinicome
7 * Copyright (c) 1997 Causality Limited
8 *
9 * Based on the sparc version.
10 */
11
12/*
13 * Sparc version:
14 *
15 * Copyright (c) 1995 Zubin Dittia.
16 * Copyright (c) 1995 Matthew R. Green.
17 * Copyright (c) 1994 Charles M. Hannum.
18 * Copyright (c) 1992, 1993
19 *      The Regents of the University of California.  All rights reserved.
20 *
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
23 * are met:
24 * 1. Redistributions of source code must retain the above copyright
25 *    notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 *    notice, this list of conditions and the following disclaimer in the
28 *    documentation and/or other materials provided with the distribution.
29 * 3. All advertising materials mentioning features or use of this software
30 *    must display the following acknowledgement:
31 *      This product includes software developed by the University of
32 *      California, Berkeley and its contributors.
33 * 4. Neither the name of the University nor the names of its contributors
34 *    may be used to endorse or promote products derived from this software
35 *    without specific prior written permission.
36 *
37 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
38 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
39 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
40 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
41 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
42 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
43 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
45 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
46 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47 * SUCH DAMAGE.
48 *
49 *      @(#)in_cksum.c  8.1 (Berkeley) 6/11/93
50 */
51
52#include <sys/param.h>
53#include <sys/systm.h>
54#include <sys/mbuf.h>
55#include <netinet/in.h>
56#include <netinet/in_systm.h>
57#include <netinet/ip.h>
58#include <netinet/ip_var.h>
59
60/*
61 * Checksum routine for Internet Protocol family headers.
62 *
63 * This routine is very heavily used in the network
64 * code and should be modified for each CPU to be as fast as possible.
65 *
66 * ARM version.
67 */
68
69#define ADD64   __asm __volatile("      \n\
70        ldmia   %0!, {%2, %3, %4, %5}   \n\
71        adds    %1,%7,%2; adcs %1,%1,%3 \n\
72        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
73        ldmia   %0!, {%2, %3, %4, %5}   \n\
74        adcs    %1,%1,%2; adcs %1,%1,%3 \n\
75        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
76        ldmia   %0!, {%2, %3, %4, %5}   \n\
77        adcs    %1,%1,%2; adcs %1,%1,%3 \n\
78        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
79        ldmia   %0!, {%2, %3, %4, %5}   \n\
80        adcs    %1,%1,%2; adcs %1,%1,%3 \n\
81        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
82        adcs    %1,%1,#0\n"             \
83        : "=r" (w), "=r" (sum), "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3), "=&r" (tmp4) \
84        : "0" (w), "r" (sum)    \
85        : "cc")
86       
87#define ADD32   __asm __volatile("      \n\
88        ldmia   %0!, {%2, %3, %4, %5}   \n\
89        adds    %1,%7,%2; adcs %1,%1,%3 \n\
90        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
91        ldmia   %0!, {%2, %3, %4, %5}   \n\
92        adcs    %1,%1,%2; adcs %1,%1,%3 \n\
93        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
94        adcs    %1,%1,#0\n"             \
95        : "=r" (w), "=r" (sum), "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3), "=&r" (tmp4) \
96        : "0" (w), "r" (sum)    \
97        : "cc")
98
99#define ADD16   __asm __volatile("      \n\
100        ldmia   %0!, {%2, %3, %4, %5}   \n\
101        adds    %1,%7,%2; adcs %1,%1,%3 \n\
102        adcs    %1,%1,%4; adcs %1,%1,%5 \n\
103        adcs    %1,%1,#0\n"             \
104        : "=r" (w), "=r" (sum), "=&r" (tmp1), "=&r" (tmp2), "=&r" (tmp3), "=&r" (tmp4) \
105        : "0" (w), "r" (sum)    \
106        : "cc")
107
108#define ADD8    __asm __volatile("      \n\
109        ldmia   %0!, {%2, %3}           \n\
110        adds    %1,%5,%2; adcs %1,%1,%3 \n\
111        adcs    %1,%1,#0\n"             \
112        : "=r" (w), "=r" (sum), "=&r" (tmp1), "=&r" (tmp2)      \
113        : "0" (w), "r" (sum)            \
114        : "cc" )
115
116#define ADD4    __asm __volatile("      \n\
117        ldr     %2,[%0],#4              \n\
118        adds    %1,%4,%2                \n\
119        adcs    %1,%1,#0\n"             \
120        : "=r" (w), "=r" (sum), "=&r" (tmp1) \
121        : "0" (w), "r" (sum)            \
122        : "cc")
123
124/*#define REDUCE        {sum = (sum & 0xffff) + (sum >> 16);}*/
125#define REDUCE  __asm __volatile("      \n\
126        mov     %2, #0x00ff             \n\
127        orr     %2, %2, #0xff00         \n\
128        and     %2, %0, %2              \n\
129        add     %0, %2, %0, lsr #16\n"  \
130        : "=r" (sum)                    \
131        : "0" (sum), "r" (tmp1))
132
133#define ADDCARRY        {if (sum > 0xffff) sum -= 0xffff;}
134#define ROL             {sum = sum << 8;}       /* depends on recent REDUCE */
135#define ADDBYTE         {ROL; sum += (*w << 8); byte_swapped ^= 1;}
136#define ADDSHORT        {sum += *(u_short *)w;}
137#define ADVANCE(n)      {w += n; mlen -= n;}
138#define ADVANCEML(n)    {mlen -= n;}
139
140static __inline__ int
141in_cksum_internal(struct mbuf *m, int off, int len, u_int sum) 
142{
143        u_char *w;
144        int mlen = 0;
145        int byte_swapped = 0;
146
147        /*
148         * Declare four temporary registers for use by the asm code.  We
149         * allow the compiler to pick which specific machine registers to
150         * use, instead of hard-coding this in the asm code above.
151         */
152        register u_int tmp1=0, tmp2, tmp3, tmp4;
153
154        for (; m && len; m = m->m_next) {
155                if (m->m_len == 0)
156                        continue;
157                w = mtod(m, u_char *) + off;
158                mlen = m->m_len - off;
159                off = 0;
160                if (len < mlen)
161                        mlen = len;
162                len -= mlen;
163
164                /*
165                 * Ensure that we're aligned on a word boundary here so
166                 * that we can do 32 bit operations below.
167                 */
168                if ((3 & (long)w) != 0) {
169                        REDUCE;
170                        if ((1 & (long)w) != 0 && mlen >= 1) {
171                                ADDBYTE;
172                                ADVANCE(1);
173                        }
174                        if ((2 & (long)w) != 0 && mlen >= 2) {
175                                ADDSHORT;
176                                ADVANCE(2);
177                        }
178                }
179
180                /*
181                 * Do as many 32 bit operations as possible using the
182                 * 64/32/16/8/4 macro's above, using as many as possible of
183                 * these.
184                 */
185
186                while (mlen >= 64) {
187                        ADD64;
188                        ADVANCEML(64);
189                }
190                if (mlen >= 32) {
191                        ADD32;
192                        ADVANCEML(32);
193                }
194                if (mlen >= 16) {
195                        ADD16;
196                        ADVANCEML(16);
197                }
198                if (mlen >= 8) {
199                        ADD8;
200                        ADVANCEML(8);
201                }
202                if (mlen >= 4) {
203                        ADD4;
204                        ADVANCEML(4)
205                }
206                if (mlen == 0)
207                        continue;
208
209                REDUCE;
210                if (mlen >= 2) {
211                        ADDSHORT;
212                        ADVANCE(2);
213                }
214                if (mlen == 1) {
215                        ADDBYTE;
216                }
217        }
218        if (byte_swapped) {
219                REDUCE;
220                ROL;
221        }
222        REDUCE;
223        ADDCARRY;
224
225        return (0xffff ^ sum);
226}
227
228int
229in_cksum(m, len)
230    struct mbuf *m;
231    int len;
232{
233    int cksum;
234    cksum =in_cksum_internal(m, 0, len, 0);
235    return cksum;
236}
237
238int
239in4_cksum(m, nxt, off, len)
240    struct mbuf *m;
241    u_int8_t nxt;
242    int off, len;
243{
244        u_int sum = 0;
245       
246        if (nxt != 0) {
247            /* for ADD macros */
248            register u_int tmp1, tmp2, tmp3, tmp4;
249            u_char *w;
250            struct ipovly ipov;
251            /* pseudo header */
252            if (off < sizeof(struct ipovly))
253                panic("in4_cksum: offset too short");
254            if (m->m_len < sizeof(struct ip))
255                panic("in4_cksum: bad mbuf chain");
256           
257            bzero(&ipov, sizeof(ipov));
258            ipov.ih_len = htons(len);
259            ipov.ih_pr = nxt;
260            ipov.ih_src = mtod(m, struct ip *)->ip_src;
261            ipov.ih_dst = mtod(m, struct ip *)->ip_dst;
262            w = (u_char *)&ipov;
263           
264            /* assumes sizeof(ipov) == 20 */
265            ADD16;
266            ADD4;
267        }
268        /* skip unnecessary part */
269        while (m && off > 0) {
270                if (m->m_len > off)
271                        break;
272                off -= m->m_len;
273                m = m->m_next;
274        }
275        return (in_cksum_internal(m, off, len, sum));
276}
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