1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef __ASM_SH_CHECKSUM_H 3 #define __ASM_SH_CHECKSUM_H 4 5 /* 6 * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka 7 */ 8 9 #include <linux/in6.h> 10 11 /* 12 * computes the checksum of a memory block at buff, length len, 13 * and adds in "sum" (32-bit) 14 * 15 * returns a 32-bit number suitable for feeding into itself 16 * or csum_tcpudp_magic 17 * 18 * this function must be called with even lengths, except 19 * for the last fragment, which may be odd 20 * 21 * it's best to have buff aligned on a 32-bit boundary 22 */ 23 asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); 24 25 /* 26 * the same as csum_partial, but copies from src while it 27 * checksums, and handles user-space pointer exceptions correctly, when needed. 28 * 29 * here even more important to align src and dst on a 32-bit (or even 30 * better 64-bit) boundary 31 */ 32 33 asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, 34 int len, __wsum sum, 35 int *src_err_ptr, int *dst_err_ptr); 36 37 /* 38 * Note: when you get a NULL pointer exception here this means someone 39 * passed in an incorrect kernel address to one of these functions. 40 * 41 * If you use these functions directly please don't forget the 42 * access_ok(). 43 */ 44 static inline 45 __wsum csum_partial_copy_nocheck(const void *src, void *dst, 46 int len, __wsum sum) 47 { 48 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 49 } 50 51 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 52 static inline 53 __wsum csum_and_copy_from_user(const void __user *src, void *dst, 54 int len, __wsum sum, int *err_ptr) 55 { 56 if (access_ok(src, len)) 57 return csum_partial_copy_generic((__force const void *)src, dst, 58 len, sum, err_ptr, NULL); 59 if (len) 60 *err_ptr = -EFAULT; 61 return sum; 62 } 63 64 /* 65 * Fold a partial checksum 66 */ 67 68 static inline __sum16 csum_fold(__wsum sum) 69 { 70 unsigned int __dummy; 71 __asm__("swap.w %0, %1\n\t" 72 "extu.w %0, %0\n\t" 73 "extu.w %1, %1\n\t" 74 "add %1, %0\n\t" 75 "swap.w %0, %1\n\t" 76 "add %1, %0\n\t" 77 "not %0, %0\n\t" 78 : "=r" (sum), "=&r" (__dummy) 79 : "0" (sum) 80 : "t"); 81 return (__force __sum16)sum; 82 } 83 84 /* 85 * This is a version of ip_compute_csum() optimized for IP headers, 86 * which always checksum on 4 octet boundaries. 87 * 88 * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted 89 * for linux by * Arnt Gulbrandsen. 90 */ 91 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 92 { 93 unsigned int sum, __dummy0, __dummy1; 94 95 __asm__ __volatile__( 96 "mov.l @%1+, %0\n\t" 97 "mov.l @%1+, %3\n\t" 98 "add #-2, %2\n\t" 99 "clrt\n\t" 100 "1:\t" 101 "addc %3, %0\n\t" 102 "movt %4\n\t" 103 "mov.l @%1+, %3\n\t" 104 "dt %2\n\t" 105 "bf/s 1b\n\t" 106 " cmp/eq #1, %4\n\t" 107 "addc %3, %0\n\t" 108 "addc %2, %0" /* Here %2 is 0, add carry-bit */ 109 /* Since the input registers which are loaded with iph and ihl 110 are modified, we must also specify them as outputs, or gcc 111 will assume they contain their original values. */ 112 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1) 113 : "1" (iph), "2" (ihl) 114 : "t", "memory"); 115 116 return csum_fold(sum); 117 } 118 119 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 120 __u32 len, __u8 proto, 121 __wsum sum) 122 { 123 #ifdef __LITTLE_ENDIAN__ 124 unsigned long len_proto = (proto + len) << 8; 125 #else 126 unsigned long len_proto = proto + len; 127 #endif 128 __asm__("clrt\n\t" 129 "addc %0, %1\n\t" 130 "addc %2, %1\n\t" 131 "addc %3, %1\n\t" 132 "movt %0\n\t" 133 "add %1, %0" 134 : "=r" (sum), "=r" (len_proto) 135 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) 136 : "t"); 137 138 return sum; 139 } 140 141 /* 142 * computes the checksum of the TCP/UDP pseudo-header 143 * returns a 16-bit checksum, already complemented 144 */ 145 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 146 __u32 len, __u8 proto, 147 __wsum sum) 148 { 149 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 150 } 151 152 /* 153 * this routine is used for miscellaneous IP-like checksums, mainly 154 * in icmp.c 155 */ 156 static inline __sum16 ip_compute_csum(const void *buff, int len) 157 { 158 return csum_fold(csum_partial(buff, len, 0)); 159 } 160 161 #define _HAVE_ARCH_IPV6_CSUM 162 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 163 const struct in6_addr *daddr, 164 __u32 len, __u8 proto, __wsum sum) 165 { 166 unsigned int __dummy; 167 __asm__("clrt\n\t" 168 "mov.l @(0,%2), %1\n\t" 169 "addc %1, %0\n\t" 170 "mov.l @(4,%2), %1\n\t" 171 "addc %1, %0\n\t" 172 "mov.l @(8,%2), %1\n\t" 173 "addc %1, %0\n\t" 174 "mov.l @(12,%2), %1\n\t" 175 "addc %1, %0\n\t" 176 "mov.l @(0,%3), %1\n\t" 177 "addc %1, %0\n\t" 178 "mov.l @(4,%3), %1\n\t" 179 "addc %1, %0\n\t" 180 "mov.l @(8,%3), %1\n\t" 181 "addc %1, %0\n\t" 182 "mov.l @(12,%3), %1\n\t" 183 "addc %1, %0\n\t" 184 "addc %4, %0\n\t" 185 "addc %5, %0\n\t" 186 "movt %1\n\t" 187 "add %1, %0\n" 188 : "=r" (sum), "=&r" (__dummy) 189 : "r" (saddr), "r" (daddr), 190 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 191 : "t"); 192 193 return csum_fold(sum); 194 } 195 196 /* 197 * Copy and checksum to user 198 */ 199 #define HAVE_CSUM_COPY_USER 200 static inline __wsum csum_and_copy_to_user(const void *src, 201 void __user *dst, 202 int len, __wsum sum, 203 int *err_ptr) 204 { 205 if (access_ok(dst, len)) 206 return csum_partial_copy_generic((__force const void *)src, 207 dst, len, sum, NULL, err_ptr); 208 209 if (len) 210 *err_ptr = -EFAULT; 211 212 return (__force __wsum)-1; /* invalid checksum */ 213 } 214 #endif /* __ASM_SH_CHECKSUM_H */ 215