arch/score/include/asm/checksum.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_SCORE_CHECKSUM_H
   3 #define _ASM_SCORE_CHECKSUM_H
   4
   5 #include <linux/in6.h>
   6 #include <linux/uaccess.h>
   7
   8 /*
   9  * computes the checksum of a memory block at buff, length len,
  10  * and adds in "sum" (32-bit)
  11  *
  12  * returns a 32-bit number suitable for feeding into itself
  13  * or csum_tcpudp_magic
  14  *
  15  * this function must be called with even lengths, except
  16  * for the last fragment, which may be odd
  17  *
  18  * it's best to have buff aligned on a 32-bit boundary
  19  */
  20 unsigned int csum_partial(const void *buff, int len, __wsum sum);
  21 unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len,
  22                                         unsigned int sum, int *csum_err);
  23 unsigned int csum_partial_copy(const char *src, char *dst,
  24                                         int len, unsigned int sum);
  25
  26 /*
  27  * this is a new version of the above that records errors it finds in *errp,
  28  * but continues and zeros the rest of the buffer.
  29  */
  30
  31 /*
  32  * Copy and checksum to user
  33  */
  34 #define HAVE_CSUM_COPY_USER
  35 static inline
  36 __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len,
  37                         __wsum sum, int *err_ptr)
  38 {
  39         sum = csum_partial(src, len, sum);
  40         if (copy_to_user(dst, src, len)) {
  41                 *err_ptr = -EFAULT;
  42                 return (__force __wsum) -1; /* invalid checksum */
  43         }
  44         return sum;
  45 }
  46
  47
  48 #define csum_partial_copy_nocheck csum_partial_copy
  49 /*
  50  *      Fold a partial checksum without adding pseudo headers
  51  */
  52
  53 static inline __sum16 csum_fold(__wsum sum)
  54 {
  55         /* the while loop is unnecessary really, it's always enough with two
  56            iterations */
  57         __asm__ __volatile__(
  58                 ".set volatile\n\t"
  59                 ".set\tr1\n\t"
  60                 "slli\tr1,%0, 16\n\t"
  61                 "add\t%0,%0, r1\n\t"
  62                 "cmp.c\tr1, %0\n\t"
  63                 "srli\t%0, %0, 16\n\t"
  64                 "bleu\t1f\n\t"
  65                 "addi\t%0, 0x1\n\t"
  66                 "1:ldi\tr30, 0xffff\n\t"
  67                 "xor\t%0, %0, r30\n\t"
  68                 "slli\t%0, %0, 16\n\t"
  69                 "srli\t%0, %0, 16\n\t"
  70                 ".set\tnor1\n\t"
  71                 ".set optimize\n\t"
  72                 : "=r" (sum)
  73                 : "0" (sum));
  74         return sum;
  75 }
  76
  77 /*
  78  *      This is a version of ip_compute_csum() optimized for IP headers,
  79  *      which always checksum on 4 octet boundaries.
  80  *
  81  *      By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
  82  *      Arnt Gulbrandsen.
  83  */
  84 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
  85 {
  86         unsigned int sum;
  87         unsigned long dummy;
  88
  89         __asm__ __volatile__(
  90                 ".set volatile\n\t"
  91                 ".set\tnor1\n\t"
  92                 "lw\t%0, [%1]\n\t"
  93                 "subri\t%2, %2, 4\n\t"
  94                 "slli\t%2, %2, 2\n\t"
  95                 "lw\t%3, [%1, 4]\n\t"
  96                 "add\t%2, %2, %1\n\t"
  97                 "add\t%0, %0, %3\n\t"
  98                 "cmp.c\t%3, %0\n\t"
  99                 "lw\t%3, [%1, 8]\n\t"
 100                 "bleu\t1f\n\t"
 101                 "addi\t%0, 0x1\n\t"
 102                 "1:\n\t"
 103                 "add\t%0, %0, %3\n\t"
 104                 "cmp.c\t%3, %0\n\t"
 105                 "lw\t%3, [%1, 12]\n\t"
 106                 "bleu\t1f\n\t"
 107                 "addi\t%0, 0x1\n\t"
 108                 "1:add\t%0, %0, %3\n\t"
 109                 "cmp.c\t%3, %0\n\t"
 110                 "bleu\t1f\n\t"
 111                 "addi\t%0, 0x1\n"
 112
 113                 "1:\tlw\t%3, [%1, 16]\n\t"
 114                 "addi\t%1, 4\n\t"
 115                 "add\t%0, %0, %3\n\t"
 116                 "cmp.c\t%3, %0\n\t"
 117                 "bleu\t2f\n\t"
 118                 "addi\t%0, 0x1\n"
 119                 "2:cmp.c\t%2, %1\n\t"
 120                 "bne\t1b\n\t"
 121
 122                 ".set\tr1\n\t"
 123                 ".set optimize\n\t"
 124                 : "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (dummy)
 125                 : "1" (iph), "2" (ihl));
 126
 127         return csum_fold(sum);
 128 }
 129
 130 static inline __wsum
 131 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
 132                    __u8 proto, __wsum sum)
 133 {
 134         unsigned long tmp = (len + proto) << 8;
 135         __asm__ __volatile__(
 136                 ".set volatile\n\t"
 137                 "add\t%0, %0, %2\n\t"
 138                 "cmp.c\t%2, %0\n\t"
 139                 "bleu\t1f\n\t"
 140                 "addi\t%0, 0x1\n\t"
 141                 "1:\n\t"
 142                 "add\t%0, %0, %3\n\t"
 143                 "cmp.c\t%3, %0\n\t"
 144                 "bleu\t1f\n\t"
 145                 "addi\t%0, 0x1\n\t"
 146                 "1:\n\t"
 147                 "add\t%0, %0, %4\n\t"
 148                 "cmp.c\t%4, %0\n\t"
 149                 "bleu\t1f\n\t"
 150                 "addi\t%0, 0x1\n\t"
 151                 "1:\n\t"
 152                 ".set optimize\n\t"
 153                 : "=r" (sum)
 154                 : "0" (daddr), "r"(saddr),
 155                 "r" (tmp),
 156                 "r" (sum));
 157         return sum;
 158 }
 159
 160 /*
 161  * computes the checksum of the TCP/UDP pseudo-header
 162  * returns a 16-bit checksum, already complemented
 163  */
 164 static inline __sum16
 165 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
 166                   __u8 proto, __wsum sum)
 167 {
 168         return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
 169 }
 170
 171 /*
 172  * this routine is used for miscellaneous IP-like checksums, mainly
 173  * in icmp.c
 174  */
 175
 176 static inline unsigned short ip_compute_csum(const void *buff, int len)
 177 {
 178         return csum_fold(csum_partial(buff, len, 0));
 179 }
 180
 181 #define _HAVE_ARCH_IPV6_CSUM
 182 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
 183                                       const struct in6_addr *daddr,
 184                                       __u32 len, __u8 proto, __wsum sum)
 185 {
 186         __asm__ __volatile__(
 187                 ".set\tvolatile\t\t\t# csum_ipv6_magic\n\t"
 188                 "add\t%0, %0, %5\t\t\t# proto (long in network byte order)\n\t"
 189                 "cmp.c\t%5, %0\n\t"
 190                 "bleu 1f\n\t"
 191                 "addi\t%0, 0x1\n\t"
 192                 "1:add\t%0, %0, %6\t\t\t# csum\n\t"
 193                 "cmp.c\t%6, %0\n\t"
 194                 "lw\t%1, [%2, 0]\t\t\t# four words source address\n\t"
 195                 "bleu 1f\n\t"
 196                 "addi\t%0, 0x1\n\t"
 197                 "1:add\t%0, %0, %1\n\t"
 198                 "cmp.c\t%1, %0\n\t"
 199                 "1:lw\t%1, [%2, 4]\n\t"
 200                 "bleu 1f\n\t"
 201                 "addi\t%0, 0x1\n\t"
 202                 "1:add\t%0, %0, %1\n\t"
 203                 "cmp.c\t%1, %0\n\t"
 204                 "lw\t%1, [%2,8]\n\t"
 205                 "bleu 1f\n\t"
 206                 "addi\t%0, 0x1\n\t"
 207                 "1:add\t%0, %0, %1\n\t"
 208                 "cmp.c\t%1, %0\n\t"
 209                 "lw\t%1, [%2, 12]\n\t"
 210                 "bleu 1f\n\t"
 211                 "addi\t%0, 0x1\n\t"
 212                 "1:add\t%0, %0,%1\n\t"
 213                 "cmp.c\t%1, %0\n\t"
 214                 "lw\t%1, [%3, 0]\n\t"
 215                 "bleu 1f\n\t"
 216                 "addi\t%0, 0x1\n\t"
 217                 "1:add\t%0, %0, %1\n\t"
 218                 "cmp.c\t%1, %0\n\t"
 219                 "lw\t%1, [%3, 4]\n\t"
 220                 "bleu 1f\n\t"
 221                 "addi\t%0, 0x1\n\t"
 222                 "1:add\t%0, %0, %1\n\t"
 223                 "cmp.c\t%1, %0\n\t"
 224                 "lw\t%1, [%3, 8]\n\t"
 225                 "bleu 1f\n\t"
 226                 "addi\t%0, 0x1\n\t"
 227                 "1:add\t%0, %0, %1\n\t"
 228                 "cmp.c\t%1, %0\n\t"
 229                 "lw\t%1, [%3, 12]\n\t"
 230                 "bleu 1f\n\t"
 231                 "addi\t%0, 0x1\n\t"
 232                 "1:add\t%0, %0, %1\n\t"
 233                 "cmp.c\t%1, %0\n\t"
 234                 "bleu 1f\n\t"
 235                 "addi\t%0, 0x1\n\t"
 236                 "1:\n\t"
 237                 ".set\toptimize"
 238                 : "=r" (sum), "=r" (proto)
 239                 : "r" (saddr), "r" (daddr),
 240                   "0" (htonl(len)), "1" (htonl(proto)), "r" (sum));
 241
 242         return csum_fold(sum);
 243 }
 244 #endif /* _ASM_SCORE_CHECKSUM_H */