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, int len); 22 23 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 24 extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, 25 int len); 26 #define HAVE_CSUM_COPY_USER 27 extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, 28 int len); 29 30 #define _HAVE_ARCH_CSUM_AND_COPY 31 #define csum_partial_copy_nocheck(src, dst, len) \ 32 csum_partial_copy_generic((src), (dst), (len)) 33 34 35 /* 36 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 37 * 1's complement 16-bit checksum. 38 */ 39 static inline __sum16 csum_fold(__wsum sum) 40 { 41 u32 tmp = (__force u32)sum; 42 43 /* 44 * swap the two 16-bit halves of sum 45 * if there is a carry from adding the two 16-bit halves, 46 * it will carry from the lower half into the upper half, 47 * giving us the correct sum in the upper half. 48 */ 49 return (__force __sum16)(~(tmp + rol32(tmp, 16)) >> 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 __always_inline __wsum csum_add(__wsum csum, __wsum addend) 96 { 97 #ifdef __powerpc64__ 98 u64 res = (__force u64)csum; 99 100 res += (__force u64)addend; 101 return (__force __wsum)((u32)res + (res >> 32)); 102 #else 103 if (__builtin_constant_p(csum) && csum == 0) 104 return addend; 105 if (__builtin_constant_p(addend) && addend == 0) 106 return csum; 107 108 asm("addc %0,%0,%1;" 109 "addze %0,%0;" 110 : "+r" (csum) : "r" (addend) : "xer"); 111 return csum; 112 #endif 113 } 114 115 #define HAVE_ARCH_CSUM_SHIFT 116 static __always_inline __wsum csum_shift(__wsum sum, int offset) 117 { 118 /* rotate sum to align it with a 16b boundary */ 119 return (__force __wsum)rol32((__force u32)sum, (offset & 1) << 3); 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 __always_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 /* __KERNEL__ */ 221 #endif 222