1 #ifndef _ASM_POWERPC_CHECKSUM_H 2 #define _ASM_POWERPC_CHECKSUM_H 3 #ifdef __KERNEL__ 4 5 /* 6 * This program is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU General Public License 8 * as published by the Free Software Foundation; either version 9 * 2 of the License, or (at your option) any later version. 10 */ 11 12 #include <linux/bitops.h> 13 #include <linux/in6.h> 14 /* 15 * Computes the checksum of a memory block at src, length len, 16 * and adds in "sum" (32-bit), while copying the block to dst. 17 * If an access exception occurs on src or dst, it stores -EFAULT 18 * to *src_err or *dst_err respectively (if that pointer is not 19 * NULL), and, for an error on src, zeroes the rest of dst. 20 * 21 * Like csum_partial, this must be called with even lengths, 22 * except for the last fragment. 23 */ 24 extern __wsum csum_partial_copy_generic(const void *src, void *dst, 25 int len, __wsum sum, 26 int *src_err, int *dst_err); 27 28 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 29 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 30 int len, __wsum sum, int *err_ptr); 31 #define HAVE_CSUM_COPY_USER 32 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 33 int len, __wsum sum, int *err_ptr); 34 35 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 36 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) 37 38 39 /* 40 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 41 * 1's complement 16-bit checksum. 42 */ 43 static inline __sum16 csum_fold(__wsum sum) 44 { 45 unsigned int tmp; 46 47 /* swap the two 16-bit halves of sum */ 48 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); 49 /* if there is a carry from adding the two 16-bit halves, 50 it will carry from the lower half into the upper half, 51 giving us the correct sum in the upper half. */ 52 return (__force __sum16)(~((__force u32)sum + tmp) >> 16); 53 } 54 55 static inline u32 from64to32(u64 x) 56 { 57 return (x + ror64(x, 32)) >> 32; 58 } 59 60 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 61 __u8 proto, __wsum sum) 62 { 63 #ifdef __powerpc64__ 64 u64 s = (__force u32)sum; 65 66 s += (__force u32)saddr; 67 s += (__force u32)daddr; 68 #ifdef __BIG_ENDIAN__ 69 s += proto + len; 70 #else 71 s += (proto + len) << 8; 72 #endif 73 return (__force __wsum) from64to32(s); 74 #else 75 __asm__("\n\ 76 addc %0,%0,%1 \n\ 77 adde %0,%0,%2 \n\ 78 adde %0,%0,%3 \n\ 79 addze %0,%0 \n\ 80 " 81 : "=r" (sum) 82 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 83 return sum; 84 #endif 85 } 86 87 /* 88 * computes the checksum of the TCP/UDP pseudo-header 89 * returns a 16-bit checksum, already complemented 90 */ 91 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 92 __u8 proto, __wsum sum) 93 { 94 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 95 } 96 97 #define HAVE_ARCH_CSUM_ADD 98 static inline __wsum csum_add(__wsum csum, __wsum addend) 99 { 100 #ifdef __powerpc64__ 101 u64 res = (__force u64)csum; 102 #endif 103 if (__builtin_constant_p(csum) && csum == 0) 104 return addend; 105 if (__builtin_constant_p(addend) && addend == 0) 106 return csum; 107 108 #ifdef __powerpc64__ 109 res += (__force u64)addend; 110 return (__force __wsum)((u32)res + (res >> 32)); 111 #else 112 asm("addc %0,%0,%1;" 113 "addze %0,%0;" 114 : "+r" (csum) : "r" (addend) : "xer"); 115 return csum; 116 #endif 117 } 118 119 /* 120 * This is a version of ip_compute_csum() optimized for IP headers, 121 * which always checksum on 4 octet boundaries. ihl is the number 122 * of 32-bit words and is always >= 5. 123 */ 124 static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) 125 { 126 const u32 *ptr = (const u32 *)iph + 1; 127 #ifdef __powerpc64__ 128 unsigned int i; 129 u64 s = *(const u32 *)iph; 130 131 for (i = 0; i < ihl - 1; i++, ptr++) 132 s += *ptr; 133 return (__force __wsum)from64to32(s); 134 #else 135 __wsum sum, tmp; 136 137 asm("mtctr %3;" 138 "addc %0,%4,%5;" 139 "1: lwzu %1, 4(%2);" 140 "adde %0,%0,%1;" 141 "bdnz 1b;" 142 "addze %0,%0;" 143 : "=r" (sum), "=r" (tmp), "+b" (ptr) 144 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 145 : "ctr", "xer", "memory"); 146 147 return sum; 148 #endif 149 } 150 151 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 152 { 153 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 154 } 155 156 /* 157 * computes the checksum of a memory block at buff, length len, 158 * and adds in "sum" (32-bit) 159 * 160 * returns a 32-bit number suitable for feeding into itself 161 * or csum_tcpudp_magic 162 * 163 * this function must be called with even lengths, except 164 * for the last fragment, which may be odd 165 * 166 * it's best to have buff aligned on a 32-bit boundary 167 */ 168 __wsum __csum_partial(const void *buff, int len, __wsum sum); 169 170 static inline __wsum csum_partial(const void *buff, int len, __wsum sum) 171 { 172 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 173 if (len == 2) 174 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 175 if (len >= 4) 176 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 177 if (len == 6) 178 sum = csum_add(sum, (__force __wsum) 179 *(const u16 *)(buff + 4)); 180 if (len >= 8) 181 sum = csum_add(sum, (__force __wsum) 182 *(const u32 *)(buff + 4)); 183 if (len == 10) 184 sum = csum_add(sum, (__force __wsum) 185 *(const u16 *)(buff + 8)); 186 if (len >= 12) 187 sum = csum_add(sum, (__force __wsum) 188 *(const u32 *)(buff + 8)); 189 if (len == 14) 190 sum = csum_add(sum, (__force __wsum) 191 *(const u16 *)(buff + 12)); 192 if (len >= 16) 193 sum = csum_add(sum, (__force __wsum) 194 *(const u32 *)(buff + 12)); 195 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 196 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 197 } else { 198 sum = __csum_partial(buff, len, sum); 199 } 200 return sum; 201 } 202 203 /* 204 * this routine is used for miscellaneous IP-like checksums, mainly 205 * in icmp.c 206 */ 207 static inline __sum16 ip_compute_csum(const void *buff, int len) 208 { 209 return csum_fold(csum_partial(buff, len, 0)); 210 } 211 212 #define _HAVE_ARCH_IPV6_CSUM 213 __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 214 const struct in6_addr *daddr, 215 __u32 len, __u8 proto, __wsum sum); 216 217 #endif /* __KERNEL__ */ 218 #endif 219