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 #include <linux/uaccess.h> 12 /* 13 * Computes the checksum of a memory block at src, length len, 14 * and adds in "sum" (32-bit), while copying the block to dst. 15 * If an access exception occurs on src or dst, it stores -EFAULT 16 * to *src_err or *dst_err respectively (if that pointer is not 17 * NULL), and, for an error on src, zeroes the rest of dst. 18 * 19 * Like csum_partial, this must be called with even lengths, 20 * except for the last fragment. 21 */ 22 extern __wsum csum_partial_copy_generic(const void *src, void *dst, int len); 23 24 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 25 static inline __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len) 26 { 27 scoped_user_read_access_size(src, len, efault) 28 return csum_partial_copy_generic((void __force *)src, dst, len); 29 30 efault: 31 return 0; 32 } 33 34 #define HAVE_CSUM_COPY_USER 35 static inline __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len) 36 { 37 scoped_user_write_access_size(dst, len, efault) 38 return csum_partial_copy_generic(src, (void __force *)dst, len); 39 40 efault: 41 return 0; 42 } 43 44 #define _HAVE_ARCH_CSUM_AND_COPY 45 #define csum_partial_copy_nocheck(src, dst, len) \ 46 csum_partial_copy_generic((src), (dst), (len)) 47 48 49 /* 50 * turns a 32-bit partial checksum (e.g. from csum_partial) into a 51 * 1's complement 16-bit checksum. 52 */ 53 static inline __sum16 csum_fold(__wsum sum) 54 { 55 u32 tmp = (__force u32)sum; 56 57 /* 58 * swap the two 16-bit halves of sum 59 * if there is a carry from adding the two 16-bit halves, 60 * it will carry from the lower half into the upper half, 61 * giving us the correct sum in the upper half. 62 */ 63 return (__force __sum16)(~(tmp + rol32(tmp, 16)) >> 16); 64 } 65 66 static inline u32 from64to32(u64 x) 67 { 68 return (x + ror64(x, 32)) >> 32; 69 } 70 71 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len, 72 __u8 proto, __wsum sum) 73 { 74 #ifdef __powerpc64__ 75 u64 s = (__force u32)sum; 76 77 s += (__force u32)saddr; 78 s += (__force u32)daddr; 79 #ifdef __BIG_ENDIAN__ 80 s += proto + len; 81 #else 82 s += (proto + len) << 8; 83 #endif 84 return (__force __wsum) from64to32(s); 85 #else 86 __asm__("\n\ 87 addc %0,%0,%1 \n\ 88 adde %0,%0,%2 \n\ 89 adde %0,%0,%3 \n\ 90 addze %0,%0 \n\ 91 " 92 : "=r" (sum) 93 : "r" (daddr), "r"(saddr), "r"(proto + len), "0"(sum)); 94 return sum; 95 #endif 96 } 97 98 /* 99 * computes the checksum of the TCP/UDP pseudo-header 100 * returns a 16-bit checksum, already complemented 101 */ 102 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len, 103 __u8 proto, __wsum sum) 104 { 105 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 106 } 107 108 #define HAVE_ARCH_CSUM_ADD 109 static __always_inline __wsum csum_add(__wsum csum, __wsum addend) 110 { 111 #ifdef __powerpc64__ 112 u64 res = (__force u64)csum; 113 114 res += (__force u64)addend; 115 return (__force __wsum)((u32)res + (res >> 32)); 116 #else 117 if (__builtin_constant_p(csum) && csum == 0) 118 return addend; 119 if (__builtin_constant_p(addend) && addend == 0) 120 return csum; 121 122 asm("addc %0,%0,%1;" 123 "addze %0,%0;" 124 : "+r" (csum) : "r" (addend) : "xer"); 125 return csum; 126 #endif 127 } 128 129 #define HAVE_ARCH_CSUM_SHIFT 130 static __always_inline __wsum csum_shift(__wsum sum, int offset) 131 { 132 /* rotate sum to align it with a 16b boundary */ 133 return (__force __wsum)rol32((__force u32)sum, (offset & 1) << 3); 134 } 135 136 /* 137 * This is a version of ip_compute_csum() optimized for IP headers, 138 * which always checksum on 4 octet boundaries. ihl is the number 139 * of 32-bit words and is always >= 5. 140 */ 141 static inline __wsum ip_fast_csum_nofold(const void *iph, unsigned int ihl) 142 { 143 const u32 *ptr = (const u32 *)iph + 1; 144 #ifdef __powerpc64__ 145 unsigned int i; 146 u64 s = *(const u32 *)iph; 147 148 for (i = 0; i < ihl - 1; i++, ptr++) 149 s += *ptr; 150 return (__force __wsum)from64to32(s); 151 #else 152 __wsum sum, tmp; 153 154 asm("mtctr %3;" 155 "addc %0,%4,%5;" 156 "1: lwzu %1, 4(%2);" 157 "adde %0,%0,%1;" 158 "bdnz 1b;" 159 "addze %0,%0;" 160 : "=r" (sum), "=r" (tmp), "+b" (ptr) 161 : "r" (ihl - 2), "r" (*(const u32 *)iph), "r" (*ptr) 162 : "ctr", "xer", "memory"); 163 164 return sum; 165 #endif 166 } 167 168 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 169 { 170 return csum_fold(ip_fast_csum_nofold(iph, ihl)); 171 } 172 173 /* 174 * computes the checksum of a memory block at buff, length len, 175 * and adds in "sum" (32-bit) 176 * 177 * returns a 32-bit number suitable for feeding into itself 178 * or csum_tcpudp_magic 179 * 180 * this function must be called with even lengths, except 181 * for the last fragment, which may be odd 182 * 183 * it's best to have buff aligned on a 32-bit boundary 184 */ 185 __wsum __csum_partial(const void *buff, int len, __wsum sum); 186 187 static __always_inline __wsum csum_partial(const void *buff, int len, __wsum sum) 188 { 189 if (__builtin_constant_p(len) && len <= 16 && (len & 1) == 0) { 190 if (len == 2) 191 sum = csum_add(sum, (__force __wsum)*(const u16 *)buff); 192 if (len >= 4) 193 sum = csum_add(sum, (__force __wsum)*(const u32 *)buff); 194 if (len == 6) 195 sum = csum_add(sum, (__force __wsum) 196 *(const u16 *)(buff + 4)); 197 if (len >= 8) 198 sum = csum_add(sum, (__force __wsum) 199 *(const u32 *)(buff + 4)); 200 if (len == 10) 201 sum = csum_add(sum, (__force __wsum) 202 *(const u16 *)(buff + 8)); 203 if (len >= 12) 204 sum = csum_add(sum, (__force __wsum) 205 *(const u32 *)(buff + 8)); 206 if (len == 14) 207 sum = csum_add(sum, (__force __wsum) 208 *(const u16 *)(buff + 12)); 209 if (len >= 16) 210 sum = csum_add(sum, (__force __wsum) 211 *(const u32 *)(buff + 12)); 212 } else if (__builtin_constant_p(len) && (len & 3) == 0) { 213 sum = csum_add(sum, ip_fast_csum_nofold(buff, len >> 2)); 214 } else { 215 sum = __csum_partial(buff, len, sum); 216 } 217 return sum; 218 } 219 220 /* 221 * this routine is used for miscellaneous IP-like checksums, mainly 222 * in icmp.c 223 */ 224 static inline __sum16 ip_compute_csum(const void *buff, int len) 225 { 226 return csum_fold(csum_partial(buff, len, 0)); 227 } 228 229 #define _HAVE_ARCH_IPV6_CSUM 230 __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 231 const struct in6_addr *daddr, 232 __u32 len, __u8 proto, __wsum sum); 233 234 #endif /* __KERNEL__ */ 235 #endif 236