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 #ifdef CONFIG_GENERIC_CSUM 13 #include <asm-generic/checksum.h> 14 #else 15 #include <linux/bitops.h> 16 #include <linux/in6.h> 17 /* 18 * Computes the checksum of a memory block at src, length len, 19 * and adds in "sum" (32-bit), while copying the block to dst. 20 * If an access exception occurs on src or dst, it stores -EFAULT 21 * to *src_err or *dst_err respectively (if that pointer is not 22 * NULL), and, for an error on src, zeroes the rest of dst. 23 * 24 * Like csum_partial, this must be called with even lengths, 25 * except for the last fragment. 26 */ 27 extern __wsum csum_partial_copy_generic(const void *src, void *dst, 28 int len, __wsum sum, 29 int *src_err, int *dst_err); 30 31 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 32 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 33 int len, __wsum sum, int *err_ptr); 34 #define HAVE_CSUM_COPY_USER 35 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 36 int len, __wsum sum, int *err_ptr); 37 38 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 39 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) 40 41 42 /* 43 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 44 * 1's complement 16-bit checksum. 45 */ 46 static inline __sum16 csum_fold(__wsum sum) 47 { 48 unsigned int tmp; 49 50 /* swap the two 16-bit halves of sum */ 51 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); 52 /* if there is a carry from adding the two 16-bit halves, 53 it will carry from the lower half into the upper half, 54 giving us the correct sum in the upper half. */ 55 return (__force __sum16)(~((__force u32)sum + tmp) >> 16); 56 } 57 58 static inline u32 from64to32(u64 x) 59 { 60 return (x + ror64(x, 32)) >> 32; 61 } 62 63 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 64 __u8 proto, __wsum sum) 65 { 66 #ifdef __powerpc64__ 67 u64 s = (__force u32)sum; 68 69 s += (__force u32)saddr; 70 s += (__force u32)daddr; 71 #ifdef __BIG_ENDIAN__ 72 s += proto + len; 73 #else 74 s += (proto + len) << 8; 75 #endif 76 return (__force __wsum) from64to32(s); 77 #else 78 __asm__("\n\ 79 addc %0,%0,%1 \n\ 80 adde %0,%0,%2 \n\ 81 adde %0,%0,%3 \n\ 82 addze %0,%0 \n\ 83 " 84 : "=r" (sum) 85 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 86 return sum; 87 #endif 88 } 89 90 /* 91 * computes the checksum of the TCP/UDP pseudo-header 92 * returns a 16-bit checksum, already complemented 93 */ 94 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 95 __u8 proto, __wsum sum) 96 { 97 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 98 } 99 100 #define HAVE_ARCH_CSUM_ADD 101 static inline __wsum csum_add(__wsum csum, __wsum addend) 102 { 103 #ifdef __powerpc64__ 104 u64 res = (__force u64)csum; 105 #endif 106 if (__builtin_constant_p(csum) && csum == 0) 107 return addend; 108 if (__builtin_constant_p(addend) && addend == 0) 109 return csum; 110 111 #ifdef __powerpc64__ 112 res += (__force u64)addend; 113 return (__force __wsum)((u32)res + (res >> 32)); 114 #else 115 asm("addc %0,%0,%1;" 116 "addze %0,%0;" 117 : "+r" (csum) : "r" (addend) : "xer"); 118 return csum; 119 #endif 120 } 121 122 /* 123 * This is a version of ip_compute_csum() optimized for IP headers, 124 * which always checksum on 4 octet boundaries. ihl is the number 125 * of 32-bit words and is always >= 5. 126 */ 127 static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) 128 { 129 const u32 *ptr = (const u32 *)iph + 1; 130 #ifdef __powerpc64__ 131 unsigned int i; 132 u64 s = *(const u32 *)iph; 133 134 for (i = 0; i < ihl - 1; i++, ptr++) 135 s += *ptr; 136 return (__force __wsum)from64to32(s); 137 #else 138 __wsum sum, tmp; 139 140 asm("mtctr %3;" 141 "addc %0,%4,%5;" 142 "1: lwzu %1, 4(%2);" 143 "adde %0,%0,%1;" 144 "bdnz 1b;" 145 "addze %0,%0;" 146 : "=r" (sum), "=r" (tmp), "+b" (ptr) 147 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 148 : "ctr", "xer", "memory"); 149 150 return sum; 151 #endif 152 } 153 154 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 155 { 156 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 157 } 158 159 /* 160 * computes the checksum of a memory block at buff, length len, 161 * and adds in "sum" (32-bit) 162 * 163 * returns a 32-bit number suitable for feeding into itself 164 * or csum_tcpudp_magic 165 * 166 * this function must be called with even lengths, except 167 * for the last fragment, which may be odd 168 * 169 * it's best to have buff aligned on a 32-bit boundary 170 */ 171 __wsum __csum_partial(const void *buff, int len, __wsum sum); 172 173 static inline __wsum csum_partial(const void *buff, int len, __wsum sum) 174 { 175 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 176 if (len == 2) 177 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 178 if (len >= 4) 179 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 180 if (len == 6) 181 sum = csum_add(sum, (__force __wsum) 182 *(const u16 *)(buff + 4)); 183 if (len >= 8) 184 sum = csum_add(sum, (__force __wsum) 185 *(const u32 *)(buff + 4)); 186 if (len == 10) 187 sum = csum_add(sum, (__force __wsum) 188 *(const u16 *)(buff + 8)); 189 if (len >= 12) 190 sum = csum_add(sum, (__force __wsum) 191 *(const u32 *)(buff + 8)); 192 if (len == 14) 193 sum = csum_add(sum, (__force __wsum) 194 *(const u16 *)(buff + 12)); 195 if (len >= 16) 196 sum = csum_add(sum, (__force __wsum) 197 *(const u32 *)(buff + 12)); 198 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 199 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 200 } else { 201 sum = __csum_partial(buff, len, sum); 202 } 203 return sum; 204 } 205 206 /* 207 * this routine is used for miscellaneous IP-like checksums, mainly 208 * in icmp.c 209 */ 210 static inline __sum16 ip_compute_csum(const void *buff, int len) 211 { 212 return csum_fold(csum_partial(buff, len, 0)); 213 } 214 215 #define _HAVE_ARCH_IPV6_CSUM 216 __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 217 const struct in6_addr *daddr, 218 __u32 len, __u8 proto, __wsum sum); 219 220 #endif 221 #endif /* __KERNEL__ */ 222 #endif 223