linux/arch/sparc/include/asm/checksum_32.h
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   1#ifndef __SPARC_CHECKSUM_H
   2#define __SPARC_CHECKSUM_H
   3
   4/*  checksum.h:  IP/UDP/TCP checksum routines on the Sparc.
   5 *
   6 *  Copyright(C) 1995 Linus Torvalds
   7 *  Copyright(C) 1995 Miguel de Icaza
   8 *  Copyright(C) 1996 David S. Miller
   9 *  Copyright(C) 1996 Eddie C. Dost
  10 *  Copyright(C) 1997 Jakub Jelinek
  11 *
  12 * derived from:
  13 *      Alpha checksum c-code
  14 *      ix86 inline assembly
  15 *      RFC1071 Computing the Internet Checksum
  16 */
  17
  18#include <linux/in6.h>
  19#include <asm/uaccess.h>
  20
  21/* computes the checksum of a memory block at buff, length len,
  22 * and adds in "sum" (32-bit)
  23 *
  24 * returns a 32-bit number suitable for feeding into itself
  25 * or csum_tcpudp_magic
  26 *
  27 * this function must be called with even lengths, except
  28 * for the last fragment, which may be odd
  29 *
  30 * it's best to have buff aligned on a 32-bit boundary
  31 */
  32extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  33
  34/* the same as csum_partial, but copies from fs:src while it
  35 * checksums
  36 *
  37 * here even more important to align src and dst on a 32-bit (or even
  38 * better 64-bit) boundary
  39 */
  40
  41extern unsigned int __csum_partial_copy_sparc_generic (const unsigned char *, unsigned char *);
  42
  43static inline __wsum
  44csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
  45{
  46        register unsigned int ret asm("o0") = (unsigned int)src;
  47        register char *d asm("o1") = dst;
  48        register int l asm("g1") = len;
  49
  50        __asm__ __volatile__ (
  51                "call __csum_partial_copy_sparc_generic\n\t"
  52                " mov %6, %%g7\n"
  53        : "=&r" (ret), "=&r" (d), "=&r" (l)
  54        : "0" (ret), "1" (d), "2" (l), "r" (sum)
  55        : "o2", "o3", "o4", "o5", "o7",
  56          "g2", "g3", "g4", "g5", "g7",
  57          "memory", "cc");
  58        return (__force __wsum)ret;
  59}
  60
  61static inline __wsum
  62csum_partial_copy_from_user(const void __user *src, void *dst, int len,
  63                            __wsum sum, int *err)
  64  {
  65        register unsigned long ret asm("o0") = (unsigned long)src;
  66        register char *d asm("o1") = dst;
  67        register int l asm("g1") = len;
  68        register __wsum s asm("g7") = sum;
  69
  70        __asm__ __volatile__ (
  71        ".section __ex_table,#alloc\n\t"
  72        ".align 4\n\t"
  73        ".word 1f,2\n\t"
  74        ".previous\n"
  75        "1:\n\t"
  76        "call __csum_partial_copy_sparc_generic\n\t"
  77        " st %8, [%%sp + 64]\n"
  78        : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
  79        : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
  80        : "o2", "o3", "o4", "o5", "o7", "g2", "g3", "g4", "g5",
  81          "cc", "memory");
  82        return (__force __wsum)ret;
  83}
  84
  85static inline __wsum
  86csum_partial_copy_to_user(const void *src, void __user *dst, int len,
  87                          __wsum sum, int *err)
  88{
  89        if (!access_ok (VERIFY_WRITE, dst, len)) {
  90                *err = -EFAULT;
  91                return sum;
  92        } else {
  93                register unsigned long ret asm("o0") = (unsigned long)src;
  94                register char __user *d asm("o1") = dst;
  95                register int l asm("g1") = len;
  96                register __wsum s asm("g7") = sum;
  97
  98                __asm__ __volatile__ (
  99                ".section __ex_table,#alloc\n\t"
 100                ".align 4\n\t"
 101                ".word 1f,1\n\t"
 102                ".previous\n"
 103                "1:\n\t"
 104                "call __csum_partial_copy_sparc_generic\n\t"
 105                " st %8, [%%sp + 64]\n"
 106                : "=&r" (ret), "=&r" (d), "=&r" (l), "=&r" (s)
 107                : "0" (ret), "1" (d), "2" (l), "3" (s), "r" (err)
 108                : "o2", "o3", "o4", "o5", "o7",
 109                  "g2", "g3", "g4", "g5",
 110                  "cc", "memory");
 111                return (__force __wsum)ret;
 112        }
 113}
 114
 115#define HAVE_CSUM_COPY_USER
 116#define csum_and_copy_to_user csum_partial_copy_to_user
 117
 118/* ihl is always 5 or greater, almost always is 5, and iph is word aligned
 119 * the majority of the time.
 120 */
 121static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
 122{
 123        __sum16 sum;
 124
 125        /* Note: We must read %2 before we touch %0 for the first time,
 126         *       because GCC can legitimately use the same register for
 127         *       both operands.
 128         */
 129        __asm__ __volatile__("sub\t%2, 4, %%g4\n\t"
 130                             "ld\t[%1 + 0x00], %0\n\t"
 131                             "ld\t[%1 + 0x04], %%g2\n\t"
 132                             "ld\t[%1 + 0x08], %%g3\n\t"
 133                             "addcc\t%%g2, %0, %0\n\t"
 134                             "addxcc\t%%g3, %0, %0\n\t"
 135                             "ld\t[%1 + 0x0c], %%g2\n\t"
 136                             "ld\t[%1 + 0x10], %%g3\n\t"
 137                             "addxcc\t%%g2, %0, %0\n\t"
 138                             "addx\t%0, %%g0, %0\n"
 139                             "1:\taddcc\t%%g3, %0, %0\n\t"
 140                             "add\t%1, 4, %1\n\t"
 141                             "addxcc\t%0, %%g0, %0\n\t"
 142                             "subcc\t%%g4, 1, %%g4\n\t"
 143                             "be,a\t2f\n\t"
 144                             "sll\t%0, 16, %%g2\n\t"
 145                             "b\t1b\n\t"
 146                             "ld\t[%1 + 0x10], %%g3\n"
 147                             "2:\taddcc\t%0, %%g2, %%g2\n\t"
 148                             "srl\t%%g2, 16, %0\n\t"
 149                             "addx\t%0, %%g0, %0\n\t"
 150                             "xnor\t%%g0, %0, %0"
 151                             : "=r" (sum), "=&r" (iph)
 152                             : "r" (ihl), "1" (iph)
 153                             : "g2", "g3", "g4", "cc", "memory");
 154        return sum;
 155}
 156
 157/* Fold a partial checksum without adding pseudo headers. */
 158static inline __sum16 csum_fold(__wsum sum)
 159{
 160        unsigned int tmp;
 161
 162        __asm__ __volatile__("addcc\t%0, %1, %1\n\t"
 163                             "srl\t%1, 16, %1\n\t"
 164                             "addx\t%1, %%g0, %1\n\t"
 165                             "xnor\t%%g0, %1, %0"
 166                             : "=&r" (sum), "=r" (tmp)
 167                             : "0" (sum), "1" ((__force u32)sum<<16)
 168                             : "cc");
 169        return (__force __sum16)sum;
 170}
 171
 172static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
 173                                               unsigned short len,
 174                                               unsigned short proto,
 175                                               __wsum sum)
 176{
 177        __asm__ __volatile__("addcc\t%1, %0, %0\n\t"
 178                             "addxcc\t%2, %0, %0\n\t"
 179                             "addxcc\t%3, %0, %0\n\t"
 180                             "addx\t%0, %%g0, %0\n\t"
 181                             : "=r" (sum), "=r" (saddr)
 182                             : "r" (daddr), "r" (proto + len), "0" (sum),
 183                               "1" (saddr)
 184                             : "cc");
 185        return sum;
 186}
 187
 188/*
 189 * computes the checksum of the TCP/UDP pseudo-header
 190 * returns a 16-bit checksum, already complemented
 191 */
 192static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
 193                                                   unsigned short len,
 194                                                   unsigned short proto,
 195                                                   __wsum sum)
 196{
 197        return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 198}
 199
 200#define _HAVE_ARCH_IPV6_CSUM
 201
 202static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 203                                      const struct in6_addr *daddr,
 204                                      __u32 len, unsigned short proto,
 205                                      __wsum sum)
 206{
 207        __asm__ __volatile__ (
 208                "addcc  %3, %4, %%g4\n\t"
 209                "addxcc %5, %%g4, %%g4\n\t"
 210                "ld     [%2 + 0x0c], %%g2\n\t"
 211                "ld     [%2 + 0x08], %%g3\n\t"
 212                "addxcc %%g2, %%g4, %%g4\n\t"
 213                "ld     [%2 + 0x04], %%g2\n\t"
 214                "addxcc %%g3, %%g4, %%g4\n\t"
 215                "ld     [%2 + 0x00], %%g3\n\t"
 216                "addxcc %%g2, %%g4, %%g4\n\t"
 217                "ld     [%1 + 0x0c], %%g2\n\t"
 218                "addxcc %%g3, %%g4, %%g4\n\t"
 219                "ld     [%1 + 0x08], %%g3\n\t"
 220                "addxcc %%g2, %%g4, %%g4\n\t"
 221                "ld     [%1 + 0x04], %%g2\n\t"
 222                "addxcc %%g3, %%g4, %%g4\n\t"
 223                "ld     [%1 + 0x00], %%g3\n\t"
 224                "addxcc %%g2, %%g4, %%g4\n\t"
 225                "addxcc %%g3, %%g4, %0\n\t"
 226                "addx   0, %0, %0\n"
 227                : "=&r" (sum)
 228                : "r" (saddr), "r" (daddr),
 229                  "r"(htonl(len)), "r"(htonl(proto)), "r"(sum)
 230                : "g2", "g3", "g4", "cc");
 231
 232        return csum_fold(sum);
 233}
 234
 235/* this routine is used for miscellaneous IP-like checksums, mainly in icmp.c */
 236static inline __sum16 ip_compute_csum(const void *buff, int len)
 237{
 238        return csum_fold(csum_partial(buff, len, 0));
 239}
 240
 241#endif /* !(__SPARC_CHECKSUM_H) */
 242
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