1 #ifndef __ASM_SH_CHECKSUM_H 2 #define __ASM_SH_CHECKSUM_H 3 4 /* 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 * 9 * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka 10 */ 11 12 #include <linux/in6.h> 13 14 /* 15 * computes the checksum of a memory block at buff, length len, 16 * and adds in "sum" (32-bit) 17 * 18 * returns a 32-bit number suitable for feeding into itself 19 * or csum_tcpudp_magic 20 * 21 * this function must be called with even lengths, except 22 * for the last fragment, which may be odd 23 * 24 * it's best to have buff aligned on a 32-bit boundary 25 */ 26 asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); 27 28 /* 29 * the same as csum_partial, but copies from src while it 30 * checksums, and handles user-space pointer exceptions correctly, when needed. 31 * 32 * here even more important to align src and dst on a 32-bit (or even 33 * better 64-bit) boundary 34 */ 35 36 asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, 37 int len, __wsum sum, 38 int *src_err_ptr, int *dst_err_ptr); 39 40 /* 41 * Note: when you get a NULL pointer exception here this means someone 42 * passed in an incorrect kernel address to one of these functions. 43 * 44 * If you use these functions directly please don't forget the 45 * access_ok(). 46 */ 47 static inline 48 __wsum csum_partial_copy_nocheck(const void *src, void *dst, 49 int len, __wsum sum) 50 { 51 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 52 } 53 54 static inline 55 __wsum csum_partial_copy_from_user(const void __user *src, void *dst, 56 int len, __wsum sum, int *err_ptr) 57 { 58 return csum_partial_copy_generic((__force const void *)src, dst, 59 len, sum, err_ptr, NULL); 60 } 61 62 /* 63 * Fold a partial checksum 64 */ 65 66 static inline __sum16 csum_fold(__wsum sum) 67 { 68 unsigned int __dummy; 69 __asm__("swap.w %0, %1\n\t" 70 "extu.w %0, %0\n\t" 71 "extu.w %1, %1\n\t" 72 "add %1, %0\n\t" 73 "swap.w %0, %1\n\t" 74 "add %1, %0\n\t" 75 "not %0, %0\n\t" 76 : "=r" (sum), "=&r" (__dummy) 77 : "0" (sum) 78 : "t"); 79 return (__force __sum16)sum; 80 } 81 82 /* 83 * This is a version of ip_compute_csum() optimized for IP headers, 84 * which always checksum on 4 octet boundaries. 85 * 86 * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted 87 * for linux by * Arnt Gulbrandsen. 88 */ 89 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 90 { 91 unsigned int sum, __dummy0, __dummy1; 92 93 __asm__ __volatile__( 94 "mov.l @%1+, %0\n\t" 95 "mov.l @%1+, %3\n\t" 96 "add #-2, %2\n\t" 97 "clrt\n\t" 98 "1:\t" 99 "addc %3, %0\n\t" 100 "movt %4\n\t" 101 "mov.l @%1+, %3\n\t" 102 "dt %2\n\t" 103 "bf/s 1b\n\t" 104 " cmp/eq #1, %4\n\t" 105 "addc %3, %0\n\t" 106 "addc %2, %0" /* Here %2 is 0, add carry-bit */ 107 /* Since the input registers which are loaded with iph and ihl 108 are modified, we must also specify them as outputs, or gcc 109 will assume they contain their original values. */ 110 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1) 111 : "1" (iph), "2" (ihl) 112 : "t", "memory"); 113 114 return csum_fold(sum); 115 } 116 117 static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 118 unsigned short len, 119 unsigned short proto, 120 __wsum sum) 121 { 122 #ifdef __LITTLE_ENDIAN__ 123 unsigned long len_proto = (proto + len) << 8; 124 #else 125 unsigned long len_proto = proto + len; 126 #endif 127 __asm__("clrt\n\t" 128 "addc %0, %1\n\t" 129 "addc %2, %1\n\t" 130 "addc %3, %1\n\t" 131 "movt %0\n\t" 132 "add %1, %0" 133 : "=r" (sum), "=r" (len_proto) 134 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) 135 : "t"); 136 137 return sum; 138 } 139 140 /* 141 * computes the checksum of the TCP/UDP pseudo-header 142 * returns a 16-bit checksum, already complemented 143 */ 144 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 145 unsigned short len, 146 unsigned short 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, unsigned short proto, 165 __wsum sum) 166 { 167 unsigned int __dummy; 168 __asm__("clrt\n\t" 169 "mov.l @(0,%2), %1\n\t" 170 "addc %1, %0\n\t" 171 "mov.l @(4,%2), %1\n\t" 172 "addc %1, %0\n\t" 173 "mov.l @(8,%2), %1\n\t" 174 "addc %1, %0\n\t" 175 "mov.l @(12,%2), %1\n\t" 176 "addc %1, %0\n\t" 177 "mov.l @(0,%3), %1\n\t" 178 "addc %1, %0\n\t" 179 "mov.l @(4,%3), %1\n\t" 180 "addc %1, %0\n\t" 181 "mov.l @(8,%3), %1\n\t" 182 "addc %1, %0\n\t" 183 "mov.l @(12,%3), %1\n\t" 184 "addc %1, %0\n\t" 185 "addc %4, %0\n\t" 186 "addc %5, %0\n\t" 187 "movt %1\n\t" 188 "add %1, %0\n" 189 : "=r" (sum), "=&r" (__dummy) 190 : "r" (saddr), "r" (daddr), 191 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 192 : "t"); 193 194 return csum_fold(sum); 195 } 196 197 /* 198 * Copy and checksum to user 199 */ 200 #define HAVE_CSUM_COPY_USER 201 static inline __wsum csum_and_copy_to_user(const void *src, 202 void __user *dst, 203 int len, __wsum sum, 204 int *err_ptr) 205 { 206 if (access_ok(VERIFY_WRITE, dst, len)) 207 return csum_partial_copy_generic((__force const void *)src, 208 dst, len, sum, NULL, err_ptr); 209 210 if (len) 211 *err_ptr = -EFAULT; 212 213 return (__force __wsum)-1; /* invalid checksum */ 214 } 215 #endif /* __ASM_SH_CHECKSUM_H */ 216