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 __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 57 unsigned short len, 58 unsigned short proto, 59 __wsum sum) 60 { 61 #ifdef __powerpc64__ 62 unsigned long s = (__force u32)sum; 63 64 s += (__force u32)saddr; 65 s += (__force u32)daddr; 66 s += proto + len; 67 s += (s >> 32); 68 return (__force __wsum) s; 69 #else 70 __asm__("\n\ 71 addc %0,%0,%1 \n\ 72 adde %0,%0,%2 \n\ 73 adde %0,%0,%3 \n\ 74 addze %0,%0 \n\ 75 " 76 : "=r" (sum) 77 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 78 return sum; 79 #endif 80 } 81 82 /* 83 * computes the checksum of the TCP/UDP pseudo-header 84 * returns a 16-bit checksum, already complemented 85 */ 86 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 87 unsigned short len, 88 unsigned short proto, 89 __wsum sum) 90 { 91 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 92 } 93 94 #define HAVE_ARCH_CSUM_ADD 95 static inline __wsum csum_add(__wsum csum, __wsum addend) 96 { 97 #ifdef __powerpc64__ 98 u64 res = (__force u64)csum; 99 #endif 100 if (__builtin_constant_p(csum) && csum == 0) 101 return addend; 102 if (__builtin_constant_p(addend) && addend == 0) 103 return csum; 104 105 #ifdef __powerpc64__ 106 res += (__force u64)addend; 107 return (__force __wsum)((u32)res + (res >> 32)); 108 #else 109 asm("addc %0,%0,%1;" 110 "addze %0,%0;" 111 : "+r" (csum) : "r" (addend) : "xer"); 112 return csum; 113 #endif 114 } 115 116 /* 117 * This is a version of ip_compute_csum() optimized for IP headers, 118 * which always checksum on 4 octet boundaries. ihl is the number 119 * of 32-bit words and is always >= 5. 120 */ 121 static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) 122 { 123 const u32 *ptr = (const u32 *)iph + 1; 124 #ifdef __powerpc64__ 125 unsigned int i; 126 u64 s = *(const u32 *)iph; 127 128 for (i = 0; i < ihl - 1; i++, ptr++) 129 s += *ptr; 130 s += (s >> 32); 131 return (__force __wsum)s; 132 #else 133 __wsum sum, tmp; 134 135 asm("mtctr %3;" 136 "addc %0,%4,%5;" 137 "1: lwzu %1, 4(%2);" 138 "adde %0,%0,%1;" 139 "bdnz 1b;" 140 "addze %0,%0;" 141 : "=r" (sum), "=r" (tmp), "+b" (ptr) 142 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 143 : "ctr", "xer", "memory"); 144 145 return sum; 146 #endif 147 } 148 149 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 150 { 151 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 152 } 153 154 /* 155 * computes the checksum of a memory block at buff, length len, 156 * and adds in "sum" (32-bit) 157 * 158 * returns a 32-bit number suitable for feeding into itself 159 * or csum_tcpudp_magic 160 * 161 * this function must be called with even lengths, except 162 * for the last fragment, which may be odd 163 * 164 * it's best to have buff aligned on a 32-bit boundary 165 */ 166 __wsum __csum_partial(const void *buff, int len, __wsum sum); 167 168 static inline __wsum csum_partial(const void *buff, int len, __wsum sum) 169 { 170 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 171 if (len == 2) 172 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 173 if (len >= 4) 174 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 175 if (len == 6) 176 sum = csum_add(sum, (__force __wsum) 177 *(const u16 *)(buff + 4)); 178 if (len >= 8) 179 sum = csum_add(sum, (__force __wsum) 180 *(const u32 *)(buff + 4)); 181 if (len == 10) 182 sum = csum_add(sum, (__force __wsum) 183 *(const u16 *)(buff + 8)); 184 if (len >= 12) 185 sum = csum_add(sum, (__force __wsum) 186 *(const u32 *)(buff + 8)); 187 if (len == 14) 188 sum = csum_add(sum, (__force __wsum) 189 *(const u16 *)(buff + 12)); 190 if (len >= 16) 191 sum = csum_add(sum, (__force __wsum) 192 *(const u32 *)(buff + 12)); 193 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 194 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 195 } else { 196 sum = __csum_partial(buff, len, sum); 197 } 198 return sum; 199 } 200 201 /* 202 * this routine is used for miscellaneous IP-like checksums, mainly 203 * in icmp.c 204 */ 205 static inline __sum16 ip_compute_csum(const void *buff, int len) 206 { 207 return csum_fold(csum_partial(buff, len, 0)); 208 } 209 210 #endif 211 #endif /* __KERNEL__ */ 212 #endif 213