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, __u32 len, 57 __u8 proto, __wsum sum) 58 { 59 #ifdef __powerpc64__ 60 unsigned long s = (__force u32)sum; 61 62 s += (__force u32)saddr; 63 s += (__force u32)daddr; 64 s += proto + len; 65 s += (s >> 32); 66 return (__force __wsum) s; 67 #else 68 __asm__("\n\ 69 addc %0,%0,%1 \n\ 70 adde %0,%0,%2 \n\ 71 adde %0,%0,%3 \n\ 72 addze %0,%0 \n\ 73 " 74 : "=r" (sum) 75 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 76 return sum; 77 #endif 78 } 79 80 /* 81 * computes the checksum of the TCP/UDP pseudo-header 82 * returns a 16-bit checksum, already complemented 83 */ 84 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 85 __u8 proto, __wsum sum) 86 { 87 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 88 } 89 90 #define HAVE_ARCH_CSUM_ADD 91 static inline __wsum csum_add(__wsum csum, __wsum addend) 92 { 93 #ifdef __powerpc64__ 94 u64 res = (__force u64)csum; 95 #endif 96 if (__builtin_constant_p(csum) && csum == 0) 97 return addend; 98 if (__builtin_constant_p(addend) && addend == 0) 99 return csum; 100 101 #ifdef __powerpc64__ 102 res += (__force u64)addend; 103 return (__force __wsum)((u32)res + (res >> 32)); 104 #else 105 asm("addc %0,%0,%1;" 106 "addze %0,%0;" 107 : "+r" (csum) : "r" (addend) : "xer"); 108 return csum; 109 #endif 110 } 111 112 /* 113 * This is a version of ip_compute_csum() optimized for IP headers, 114 * which always checksum on 4 octet boundaries. ihl is the number 115 * of 32-bit words and is always >= 5. 116 */ 117 static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) 118 { 119 const u32 *ptr = (const u32 *)iph + 1; 120 #ifdef __powerpc64__ 121 unsigned int i; 122 u64 s = *(const u32 *)iph; 123 124 for (i = 0; i < ihl - 1; i++, ptr++) 125 s += *ptr; 126 s += (s >> 32); 127 return (__force __wsum)s; 128 #else 129 __wsum sum, tmp; 130 131 asm("mtctr %3;" 132 "addc %0,%4,%5;" 133 "1: lwzu %1, 4(%2);" 134 "adde %0,%0,%1;" 135 "bdnz 1b;" 136 "addze %0,%0;" 137 : "=r" (sum), "=r" (tmp), "+b" (ptr) 138 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 139 : "ctr", "xer", "memory"); 140 141 return sum; 142 #endif 143 } 144 145 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 146 { 147 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 148 } 149 150 /* 151 * computes the checksum of a memory block at buff, length len, 152 * and adds in "sum" (32-bit) 153 * 154 * returns a 32-bit number suitable for feeding into itself 155 * or csum_tcpudp_magic 156 * 157 * this function must be called with even lengths, except 158 * for the last fragment, which may be odd 159 * 160 * it's best to have buff aligned on a 32-bit boundary 161 */ 162 __wsum __csum_partial(const void *buff, int len, __wsum sum); 163 164 static inline __wsum csum_partial(const void *buff, int len, __wsum sum) 165 { 166 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 167 if (len == 2) 168 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 169 if (len >= 4) 170 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 171 if (len == 6) 172 sum = csum_add(sum, (__force __wsum) 173 *(const u16 *)(buff + 4)); 174 if (len >= 8) 175 sum = csum_add(sum, (__force __wsum) 176 *(const u32 *)(buff + 4)); 177 if (len == 10) 178 sum = csum_add(sum, (__force __wsum) 179 *(const u16 *)(buff + 8)); 180 if (len >= 12) 181 sum = csum_add(sum, (__force __wsum) 182 *(const u32 *)(buff + 8)); 183 if (len == 14) 184 sum = csum_add(sum, (__force __wsum) 185 *(const u16 *)(buff + 12)); 186 if (len >= 16) 187 sum = csum_add(sum, (__force __wsum) 188 *(const u32 *)(buff + 12)); 189 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 190 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 191 } else { 192 sum = __csum_partial(buff, len, sum); 193 } 194 return sum; 195 } 196 197 /* 198 * this routine is used for miscellaneous IP-like checksums, mainly 199 * in icmp.c 200 */ 201 static inline __sum16 ip_compute_csum(const void *buff, int len) 202 { 203 return csum_fold(csum_partial(buff, len, 0)); 204 } 205 206 #endif 207 #endif /* __KERNEL__ */ 208 #endif 209