1#ifndef _ASM_SCORE_CHECKSUM_H 2#define _ASM_SCORE_CHECKSUM_H 3 4#include <linux/in6.h> 5#include <asm/uaccess.h> 6 7/* 8 * computes the checksum of a memory block at buff, length len, 9 * and adds in "sum" (32-bit) 10 * 11 * returns a 32-bit number suitable for feeding into itself 12 * or csum_tcpudp_magic 13 * 14 * this function must be called with even lengths, except 15 * for the last fragment, which may be odd 16 * 17 * it's best to have buff aligned on a 32-bit boundary 18 */ 19unsigned int csum_partial(const void *buff, int len, __wsum sum); 20unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, 21 unsigned int sum, int *csum_err); 22unsigned int csum_partial_copy(const char *src, char *dst, 23 int len, unsigned int sum); 24 25/* 26 * this is a new version of the above that records errors it finds in *errp, 27 * but continues and zeros the rest of the buffer. 28 */ 29 30/* 31 * Copy and checksum to user 32 */ 33#define HAVE_CSUM_COPY_USER 34static inline 35__wsum csum_and_copy_to_user(const void *src, void __user *dst, int len, 36 __wsum sum, int *err_ptr) 37{ 38 sum = csum_partial(src, len, sum); 39 if (copy_to_user(dst, src, len)) { 40 *err_ptr = -EFAULT; 41 return (__force __wsum) -1; /* invalid checksum */ 42 } 43 return sum; 44} 45 46 47#define csum_partial_copy_nocheck csum_partial_copy 48/* 49 * Fold a partial checksum without adding pseudo headers 50 */ 51 52static inline __sum16 csum_fold(__wsum sum) 53{ 54 /* the while loop is unnecessary really, it's always enough with two 55 iterations */ 56 __asm__ __volatile__( 57 ".set volatile\n\t" 58 ".set\tr1\n\t" 59 "slli\tr1,%0, 16\n\t" 60 "add\t%0,%0, r1\n\t" 61 "cmp.c\tr1, %0\n\t" 62 "srli\t%0, %0, 16\n\t" 63 "bleu\t1f\n\t" 64 "addi\t%0, 0x1\n\t" 65 "1:ldi\tr30, 0xffff\n\t" 66 "xor\t%0, %0, r30\n\t" 67 "slli\t%0, %0, 16\n\t" 68 "srli\t%0, %0, 16\n\t" 69 ".set\tnor1\n\t" 70 ".set optimize\n\t" 71 : "=r" (sum) 72 : "0" (sum)); 73 return sum; 74} 75 76/* 77 * This is a version of ip_compute_csum() optimized for IP headers, 78 * which always checksum on 4 octet boundaries. 79 * 80 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by 81 * Arnt Gulbrandsen. 82 */ 83static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 84{ 85 unsigned int sum; 86 unsigned long dummy; 87 88 __asm__ __volatile__( 89 ".set volatile\n\t" 90 ".set\tnor1\n\t" 91 "lw\t%0, [%1]\n\t" 92 "subri\t%2, %2, 4\n\t" 93 "slli\t%2, %2, 2\n\t" 94 "lw\t%3, [%1, 4]\n\t" 95 "add\t%2, %2, %1\n\t" 96 "add\t%0, %0, %3\n\t" 97 "cmp.c\t%3, %0\n\t" 98 "lw\t%3, [%1, 8]\n\t" 99 "bleu\t1f\n\t" 100 "addi\t%0, 0x1\n\t" 101 "1:\n\t" 102 "add\t%0, %0, %3\n\t" 103 "cmp.c\t%3, %0\n\t" 104 "lw\t%3, [%1, 12]\n\t" 105 "bleu\t1f\n\t" 106 "addi\t%0, 0x1\n\t" 107 "1:add\t%0, %0, %3\n\t" 108 "cmp.c\t%3, %0\n\t" 109 "bleu\t1f\n\t" 110 "addi\t%0, 0x1\n" 111 112 "1:\tlw\t%3, [%1, 16]\n\t" 113 "addi\t%1, 4\n\t" 114 "add\t%0, %0, %3\n\t" 115 "cmp.c\t%3, %0\n\t" 116 "bleu\t2f\n\t" 117 "addi\t%0, 0x1\n" 118 "2:cmp.c\t%2, %1\n\t" 119 "bne\t1b\n\t" 120 121 ".set\tr1\n\t" 122 ".set optimize\n\t" 123 : "=&r" (sum), "=&r" (iph), "=&r" (ihl), "=&r" (dummy) 124 : "1" (iph), "2" (ihl)); 125 126 return csum_fold(sum); 127} 128 129static inline __wsum 130csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, 131 unsigned short proto, __wsum sum) 132{ 133 unsigned long tmp = (ntohs(len) << 16) + proto * 256; 134 __asm__ __volatile__( 135 ".set volatile\n\t" 136 "add\t%0, %0, %2\n\t" 137 "cmp.c\t%2, %0\n\t" 138 "bleu\t1f\n\t" 139 "addi\t%0, 0x1\n\t" 140 "1:\n\t" 141 "add\t%0, %0, %3\n\t" 142 "cmp.c\t%3, %0\n\t" 143 "bleu\t1f\n\t" 144 "addi\t%0, 0x1\n\t" 145 "1:\n\t" 146 "add\t%0, %0, %4\n\t" 147 "cmp.c\t%4, %0\n\t" 148 "bleu\t1f\n\t" 149 "addi\t%0, 0x1\n\t" 150 "1:\n\t" 151 ".set optimize\n\t" 152 : "=r" (sum) 153 : "0" (daddr), "r"(saddr), 154 "r" (tmp), 155 "r" (sum)); 156 return sum; 157} 158 159/* 160 * computes the checksum of the TCP/UDP pseudo-header 161 * returns a 16-bit checksum, already complemented 162 */ 163static inline __sum16 164csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, 165 unsigned short proto, __wsum sum) 166{ 167 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 168} 169 170/* 171 * this routine is used for miscellaneous IP-like checksums, mainly 172 * in icmp.c 173 */ 174 175static inline unsigned short ip_compute_csum(const void *buff, int len) 176{ 177 return csum_fold(csum_partial(buff, len, 0)); 178} 179 180#define _HAVE_ARCH_IPV6_CSUM 181static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 182 const struct in6_addr *daddr, 183 __u32 len, unsigned short proto, 184 __wsum sum) 185{ 186 __asm__ __volatile__( 187 ".set\tnoreorder\t\t\t# csum_ipv6_magic\n\t" 188 ".set\tnoat\n\t" 189 "addu\t%0, %5\t\t\t# proto (long in network byte order)\n\t" 190 "sltu\t$1, %0, %5\n\t" 191 "addu\t%0, $1\n\t" 192 "addu\t%0, %6\t\t\t# csum\n\t" 193 "sltu\t$1, %0, %6\n\t" 194 "lw\t%1, 0(%2)\t\t\t# four words source address\n\t" 195 "addu\t%0, $1\n\t" 196 "addu\t%0, %1\n\t" 197 "sltu\t$1, %0, %1\n\t" 198 "lw\t%1, 4(%2)\n\t" 199 "addu\t%0, $1\n\t" 200 "addu\t%0, %1\n\t" 201 "sltu\t$1, %0, %1\n\t" 202 "lw\t%1, 8(%2)\n\t" 203 "addu\t%0, $1\n\t" 204 "addu\t%0, %1\n\t" 205 "sltu\t$1, %0, %1\n\t" 206 "lw\t%1, 12(%2)\n\t" 207 "addu\t%0, $1\n\t" 208 "addu\t%0, %1\n\t" 209 "sltu\t$1, %0, %1\n\t" 210 "lw\t%1, 0(%3)\n\t" 211 "addu\t%0, $1\n\t" 212 "addu\t%0, %1\n\t" 213 "sltu\t$1, %0, %1\n\t" 214 "lw\t%1, 4(%3)\n\t" 215 "addu\t%0, $1\n\t" 216 "addu\t%0, %1\n\t" 217 "sltu\t$1, %0, %1\n\t" 218 "lw\t%1, 8(%3)\n\t" 219 "addu\t%0, $1\n\t" 220 "addu\t%0, %1\n\t" 221 "sltu\t$1, %0, %1\n\t" 222 "lw\t%1, 12(%3)\n\t" 223 "addu\t%0, $1\n\t" 224 "addu\t%0, %1\n\t" 225 "sltu\t$1, %0, %1\n\t" 226 "addu\t%0, $1\t\t\t# Add final carry\n\t" 227 ".set\tnoat\n\t" 228 ".set\tnoreorder" 229 : "=r" (sum), "=r" (proto) 230 : "r" (saddr), "r" (daddr), 231 "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); 232 233 return csum_fold(sum); 234} 235#endif /* _ASM_SCORE_CHECKSUM_H */ 236