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