LXR linux/include/asm-sparc/checksum.h

   1/* $Id: checksum.h,v 1.33 2002/02/01 22:01:05 davem Exp $ */
   2#ifndef __SPARC_CHECKSUM_H
   3#define __SPARC_CHECKSUM_H
   4
   5/*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
   6 *
   7 *  Copyright(C) 1995 Linus Torvalds
   8 *  Copyright(C) 1995 Miguel de Icaza
   9 *  Copyright(C) 1996 David S. Miller
  10 *  Copyright(C) 1996 Eddie C. Dost
  11 *  Copyright(C) 1997 Jakub Jelinek
  12 *
  13 * derived from:
  14 *      Alpha checksum c-code
  15 *      ix86 inline assembly
  16 *      RFC1071 Computing the Internet Checksum
  17 */
  18 
  19#include <linux/in6.h>
  20#include <asm/uaccess.h>
  21
  22/* computes the checksum of a memory block at buff, length len,
  23 * and adds in "sum" (32-bit)
  24 *
  25 * returns a 32-bit number suitable for feeding into itself
  26 * or csum_tcpudp_magic
  27 *
  28 * this function must be called with even lengths, except
  29 * for the last fragment, which may be odd
  30 *
  31 * it's best to have buff aligned on a 32-bit boundary
  32 */
  33extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  34
  35/* the same as csum_partial, but copies from fs:src while it
  36 * checksums
  37 *
  38 * here even more important to align src and dst on a 32-bit (or even
  39 * better 64-bit) boundary
  40 */
  41
  42extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
  43
  44static inline __wsum
  45csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
  46{
  47        register unsigned int ret asm("o0") = (unsigned int)src;
  48        register char *d asm("o1") = dst;
  49        register int l asm("g1") = len;
  50
  51        __asm__ __volatile__ (
  52                "call __csum_partial_copy_sparc_generic\n\t"
  53                " mov %6, %%g7\n"
  54        : "=&r" (ret), "=&r" (d), "=&r" (l)
  55        : "0" (ret), "1" (d), "2" (l), "r" (sum)
  56        : "o2", "o3", "o4", "o5", "o7",
  57          "g2", "g3", "g4", "g5", "g7",
  58          "memory", "cc");
  59        return (__force __wsum)ret;
  60}
  61
  62static inline __wsum
  63csum_partial_copy_from_user(const void __user *src, void *dst, int len,
  64                            __wsum sum, int *err)
  65  {
  66        register unsigned long ret asm("o0") = (unsigned long)src;
  67        register char *d asm("o1") = dst;
  68        register int l asm("g1") = len;
  69        register __wsum s asm("g7") = sum;
  70
  71        __asm__ __volatile__ (
  72        ".section __ex_table,#alloc\n\t"
  73        ".align 4\n\t"
  74        ".word 1f,2\n\t"
  75        ".previous\n"
  76        "1:\n\t"
  77        "call __csum_partial_copy_sparc_generic\n\t"
  78        " st %8, [%%sp + 64]\n"
  79        : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  80        : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  81        : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
  82          "cc", "memory");
  83        return (__force __wsum)ret;
  84}
  85  
  86static inline __wsum
  87csum_partial_copy_to_user(const void *src, void __user *dst, int len,
  88                          __wsum sum, int *err)
  89{
  90        if (!access_ok (VERIFY_WRITE, dst, len)) {
  91                *err = -EFAULT;
  92                return sum;
  93        } else {
  94                register unsigned long ret asm("o0") = (unsigned long)src;
  95                register char __user *d asm("o1") = dst;
  96                register int l asm("g1") = len;
  97                register __wsum s asm("g7") = sum;
  98
  99                __asm__ __volatile__ (
 100                ".section __ex_table,#alloc\n\t"
 101                ".align 4\n\t"
 102                ".word 1f,1\n\t"
 103                ".previous\n"
 104                "1:\n\t"
 105                "call __csum_partial_copy_sparc_generic\n\t"
 106                " st %8, [%%sp + 64]\n"
 107                : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
 108                : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
 109                : "o2", "o3", "o4", "o5", "o7",
 110                  "g2", "g3", "g4", "g5",
 111                  "cc", "memory");
 112                return (__force __wsum)ret;
 113        }
 114}
 115
 116#define HAVE_CSUM_COPY_USER
 117#define csum_and_copy_to_user csum_partial_copy_to_user
 118
 119/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 120 * the majority of the time.
 121 */
 122static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 123{
 124        __sum16 sum;
 125
 126        /* Note: We must read %2 before we touch %0 for the first time,
 127         *       because GCC can legitimately use the same register for
 128         *       both operands.
 129         */
 130        __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
 131                             "ld\t[%1 + 0x00], %0\n\t"
 132                             "ld\t[%1 + 0x04], %%g2\n\t"
 133                             "ld\t[%1 + 0x08], %%g3\n\t"
 134                             "addcc\t%%g2, %0, %0\n\t"
 135                             "addxcc\t%%g3, %0, %0\n\t"
 136                             "ld\t[%1 + 0x0c], %%g2\n\t"
 137                             "ld\t[%1 + 0x10], %%g3\n\t"
 138                             "addxcc\t%%g2, %0, %0\n\t"
 139                             "addx\t%0, %%g0, %0\n"
 140                             "1:\taddcc\t%%g3, %0, %0\n\t"
 141                             "add\t%1, 4, %1\n\t"
 142                             "addxcc\t%0, %%g0, %0\n\t"
 143                             "subcc\t%%g4, 1, %%g4\n\t"
 144                             "be,a\t2f\n\t"
 145                             "sll\t%0, 16, %%g2\n\t"
 146                             "b\t1b\n\t"
 147                             "ld\t[%1 + 0x10], %%g3\n"
 148                             "2:\taddcc\t%0, %%g2, %%g2\n\t"
 149                             "srl\t%%g2, 16, %0\n\t"
 150                             "addx\t%0, %%g0, %0\n\t"
 151                             "xnor\t%%g0, %0, %0"
 152                             : "=r" (sum), "=&r" (iph)
 153                             : "r" (ihl), "1" (iph)
 154                             : "g2", "g3", "g4", "cc", "memory");
 155        return sum;
 156}
 157
 158/* Fold a partial checksum without adding pseudo headers. */
 159static inline __sum16 csum_fold(__wsum sum)
 160{
 161        unsigned int tmp;
 162
 163        __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
 164                             "srl\t%1, 16, %1\n\t"
 165                             "addx\t%1, %%g0, %1\n\t"
 166                             "xnor\t%%g0, %1, %0"
 167                             : "=&r" (sum), "=r" (tmp)
 168                             : "0" (sum), "1" ((__force u32)sum<<16)
 169                             : "cc");
 170        return (__force __sum16)sum;
 171}
 172
 173static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 174                                               unsigned short len,
 175                                               unsigned short proto,
 176                                               __wsum sum)
 177{
 178        __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
 179                             "addxcc\t%2, %0, %0\n\t"
 180                             "addxcc\t%3, %0, %0\n\t"
 181                             "addx\t%0, %%g0, %0\n\t"
 182                             : "=r" (sum), "=r" (saddr)
 183                             : "r" (daddr), "r" (proto + len), "0" (sum),
 184                               "1" (saddr)
 185                             : "cc");
 186        return sum;
 187}
 188
 189/*
 190 * computes the checksum of the TCP/UDP pseudo-header
 191 * returns a 16-bit checksum, already complemented
 192 */
 193static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 194                                                   unsigned short len,
 195                                                   unsigned short proto,
 196                                                   __wsum sum)
 197{
 198        return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 199}
 200
 201#define _HAVE_ARCH_IPV6_CSUM
 202
 203static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 204                                      const struct in6_addr *daddr,
 205                                      __u32 len, unsigned short proto,
 206                                      __wsum sum)
 207{
 208        __asm__ __volatile__ (
 209                "addcc  %3, %4, %%g4\n\t"
 210                "addxcc %5, %%g4, %%g4\n\t"
 211                "ld     [%2 + 0x0c], %%g2\n\t"
 212                "ld     [%2 + 0x08], %%g3\n\t"
 213                "addxcc %%g2, %%g4, %%g4\n\t"
 214                "ld     [%2 + 0x04], %%g2\n\t"
 215                "addxcc %%g3, %%g4, %%g4\n\t"
 216                "ld     [%2 + 0x00], %%g3\n\t"
 217                "addxcc %%g2, %%g4, %%g4\n\t"
 218                "ld     [%1 + 0x0c], %%g2\n\t"
 219                "addxcc %%g3, %%g4, %%g4\n\t"
 220                "ld     [%1 + 0x08], %%g3\n\t"
 221                "addxcc %%g2, %%g4, %%g4\n\t"
 222                "ld     [%1 + 0x04], %%g2\n\t"
 223                "addxcc %%g3, %%g4, %%g4\n\t"
 224                "ld     [%1 + 0x00], %%g3\n\t"
 225                "addxcc %%g2, %%g4, %%g4\n\t"
 226                "addxcc %%g3, %%g4, %0\n\t"
 227                "addx   0, %0, %0\n"
 228                : "=&r" (sum)
 229                : "r" (saddr), "r" (daddr), 
 230                  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
 231                : "g2", "g3", "g4", "cc");
 232
 233        return csum_fold(sum);
 234}
 235
 236/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 237static inline __sum16 ip_compute_csum(const void *buff, int len)
 238{
 239        return csum_fold(csum_partial(buff, len, 0));
 240}
 241
 242#endif /* !(__SPARC_CHECKSUM_H) */
 243