1 /* SPDX-License-Identifier: GPL-2.0-or-later */ 2 #ifndef _ASM_POWERPC_CHECKSUM_H 3 #define _ASM_POWERPC_CHECKSUM_H 4 #ifdef __KERNEL__ 5 6 /* 7 */ 8 9 #include <linux/bitops.h> 10 #include <linux/in6.h> 11 /* 12 * Computes the checksum of a memory block at src, length len, 13 * and adds in "sum" (32-bit), while copying the block to dst. 14 * If an access exception occurs on src or dst, it stores -EFAULT 15 * to *src_err or *dst_err respectively (if that pointer is not 16 * NULL), and, for an error on src, zeroes the rest of dst. 17 * 18 * Like csum_partial, this must be called with even lengths, 19 * except for the last fragment. 20 */ 21 extern __wsum csum_partial_copy_generic(const void *src, void *dst, 22 int len, __wsum sum, 23 int *src_err, int *dst_err); 24 25 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 26 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 27 int len, __wsum sum, int *err_ptr); 28 #define HAVE_CSUM_COPY_USER 29 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 30 int len, __wsum sum, int *err_ptr); 31 32 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 33 csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) 34 35 36 /* 37 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 38 * 1's complement 16-bit checksum. 39 */ 40 static inline __sum16 csum_fold(__wsum sum) 41 { 42 unsigned int tmp; 43 44 /* swap the two 16-bit halves of sum */ 45 __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); 46 /* if there is a carry from adding the two 16-bit halves, 47 it will carry from the lower half into the upper half, 48 giving us the correct sum in the upper half. */ 49 return (__force __sum16)(~((__force u32)sum + tmp) >> 16); 50 } 51 52 static inline u32 from64to32(u64 x) 53 { 54 return (x + ror64(x, 32)) >> 32; 55 } 56 57 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 58 __u8 proto, __wsum sum) 59 { 60 #ifdef __powerpc64__ 61 u64 s = (__force u32)sum; 62 63 s += (__force u32)saddr; 64 s += (__force u32)daddr; 65 #ifdef __BIG_ENDIAN__ 66 s += proto + len; 67 #else 68 s += (proto + len) << 8; 69 #endif 70 return (__force __wsum) from64to32(s); 71 #else 72 __asm__("\n\ 73 addc %0,%0,%1 \n\ 74 adde %0,%0,%2 \n\ 75 adde %0,%0,%3 \n\ 76 addze %0,%0 \n\ 77 " 78 : "=r" (sum) 79 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 80 return sum; 81 #endif 82 } 83 84 /* 85 * computes the checksum of the TCP/UDP pseudo-header 86 * returns a 16-bit checksum, already complemented 87 */ 88 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 89 __u8 proto, __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 return (__force __wsum)from64to32(s); 131 #else 132 __wsum sum, tmp; 133 134 asm("mtctr %3;" 135 "addc %0,%4,%5;" 136 "1: lwzu %1, 4(%2);" 137 "adde %0,%0,%1;" 138 "bdnz 1b;" 139 "addze %0,%0;" 140 : "=r" (sum), "=r" (tmp), "+b" (ptr) 141 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 142 : "ctr", "xer", "memory"); 143 144 return sum; 145 #endif 146 } 147 148 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 149 { 150 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 151 } 152 153 /* 154 * computes the checksum of a memory block at buff, length len, 155 * and adds in "sum" (32-bit) 156 * 157 * returns a 32-bit number suitable for feeding into itself 158 * or csum_tcpudp_magic 159 * 160 * this function must be called with even lengths, except 161 * for the last fragment, which may be odd 162 * 163 * it's best to have buff aligned on a 32-bit boundary 164 */ 165 __wsum __csum_partial(const void *buff, int len, __wsum sum); 166 167 static inline __wsum csum_partial(const void *buff, int len, __wsum sum) 168 { 169 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 170 if (len == 2) 171 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 172 if (len >= 4) 173 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 174 if (len == 6) 175 sum = csum_add(sum, (__force __wsum) 176 *(const u16 *)(buff + 4)); 177 if (len >= 8) 178 sum = csum_add(sum, (__force __wsum) 179 *(const u32 *)(buff + 4)); 180 if (len == 10) 181 sum = csum_add(sum, (__force __wsum) 182 *(const u16 *)(buff + 8)); 183 if (len >= 12) 184 sum = csum_add(sum, (__force __wsum) 185 *(const u32 *)(buff + 8)); 186 if (len == 14) 187 sum = csum_add(sum, (__force __wsum) 188 *(const u16 *)(buff + 12)); 189 if (len >= 16) 190 sum = csum_add(sum, (__force __wsum) 191 *(const u32 *)(buff + 12)); 192 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 193 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 194 } else { 195 sum = __csum_partial(buff, len, sum); 196 } 197 return sum; 198 } 199 200 /* 201 * this routine is used for miscellaneous IP-like checksums, mainly 202 * in icmp.c 203 */ 204 static inline __sum16 ip_compute_csum(const void *buff, int len) 205 { 206 return csum_fold(csum_partial(buff, len, 0)); 207 } 208 209 #define _HAVE_ARCH_IPV6_CSUM 210 __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 211 const struct in6_addr *daddr, 212 __u32 len, __u8 proto, __wsum sum); 213 214 #endif /* __KERNEL__ */ 215 #endif 216