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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 | #ifndef _S390_CHECKSUM_H #define _S390_CHECKSUM_H /* * include/asm-s390/checksum.h * S390 fast network checksum routines * see also arch/S390/lib/checksum.c * * S390 version * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation * Author(s): Ulrich Hild (first version) * Martin Schwidefsky (heavily optimized CKSM version) * D.J. Barrow (third attempt) */ #include <asm/uaccess.h> /* * computes the checksum of a memory block at buff, length len, * and adds in "sum" (32-bit) * * returns a 32-bit number suitable for feeding into itself * or csum_tcpudp_magic * * this function must be called with even lengths, except * for the last fragment, which may be odd * * it's best to have buff aligned on a 32-bit boundary */ unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); /* * csum_partial as an inline function */ extern inline unsigned int csum_partial_inline(const unsigned char * buff, int len, unsigned int sum) { __asm__ __volatile__ ( " lr 2,%1\n" /* address in gpr 2 */ " lr 3,%2\n" /* length in gpr 3 */ "0: cksm %0,2\n" /* do checksum on longs */ " jo 0b\n" : "+&d" (sum) : "d" (buff), "d" (len) : "cc", "2", "3" ); return sum; } /* * the same as csum_partial, but copies from src while it * checksums * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ extern inline unsigned int csum_partial_copy(const char *src, char *dst, int len,unsigned int sum) { memcpy(dst,src,len); return csum_partial_inline(dst, len, sum); } /* * the same as csum_partial_copy, but copies from user space. * * here even more important to align src and dst on a 32-bit (or even * better 64-bit) boundary */ extern inline unsigned int csum_partial_copy_from_user(const char *src, char *dst, int len, unsigned int sum, int *errp) { if (copy_from_user(dst, src, len)) { *errp = -EFAULT; memset(dst, 0, len); return sum; } return csum_partial(dst, len, sum); } extern inline unsigned int csum_partial_copy_nocheck (const char *src, char *dst, int len, unsigned int sum) { memcpy(dst,src,len); return csum_partial_inline(dst, len, sum); } /* * Fold a partial checksum without adding pseudo headers */ #if 1 unsigned short csum_fold(unsigned int sum); #else extern inline unsigned short csum_fold(unsigned int sum) { __asm__ __volatile__ ( " sr 3,3\n" /* %0 = H*65536 + L */ " lr 2,%0\n" /* %0 = H L, R2/R3 = H L / 0 0 */ " srdl 2,16\n" /* %0 = H L, R2/R3 = 0 H / L 0 */ " alr 2,3\n" /* %0 = H L, R2/R3 = L H / L 0 */ " alr %0,2\n" /* %0 = H+L+C L+H */ " srl %0,16\n" /* %0 = H+L+C */ : "+&d" (sum) : : "cc", "2", "3"); return ((unsigned short) ~sum); } #endif /* * This is a version of ip_compute_csum() optimized for IP headers, * which always checksum on 4 octet boundaries. * */ extern inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) { unsigned long sum; __asm__ __volatile__ ( " sr %0,%0\n" /* set sum to zero */ " lr 2,%1\n" /* address in gpr 2 */ " lr 3,%2\n" /* length in gpr 3 */ "0: cksm %0,2\n" /* do checksum on longs */ " jo 0b\n" : "=&d" (sum) : "d" (iph), "d" (ihl*4) : "cc", "2", "3" ); return csum_fold(sum); } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 32-bit checksum */ extern inline unsigned int csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { __asm__ __volatile__ ( " sll %3,16\n" " or %3,%4\n" /* newproto=proto<<16 in hiword, len in lowword */ " alr %1,%2\n" /* saddr+=daddr */ " brc 12,0f\n" " ahi %1,1\n" /* add carry */ "0: alr %1,%3\n" /* add saddr+=newproto */ " brc 12,1f\n" " ahi %1,1\n" /* add carry again */ "1: alr %0,%1\n" /* sum+=saddr */ " brc 12,2f\n" " ahi %0,1\n" /* add carry again */ "2:" : "+&d" (sum) : "d" (saddr), "d" (daddr), "d" (proto), "d" (len) : "cc" ); return sum; } /* * computes the checksum of the TCP/UDP pseudo-header * returns a 16-bit checksum, already complemented */ extern inline unsigned short int csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, unsigned short proto, unsigned int sum) { return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); } /* * this routine is used for miscellaneous IP-like checksums, mainly * in icmp.c */ extern inline unsigned short ip_compute_csum(unsigned char * buff, int len) { return csum_fold(csum_partial(buff, len, 0)); } #endif /* _S390_CHECKSUM_H */ |