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 __u32 len, __u8 proto, 119 __wsum sum) 120 { 121 #ifdef __LITTLE_ENDIAN__ 122 unsigned long len_proto = (proto + len) << 8; 123 #else 124 unsigned long len_proto = proto + len; 125 #endif 126 __asm__("clrt\n\t" 127 "addc %0, %1\n\t" 128 "addc %2, %1\n\t" 129 "addc %3, %1\n\t" 130 "movt %0\n\t" 131 "add %1, %0" 132 : "=r" (sum), "=r" (len_proto) 133 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) 134 : "t"); 135 136 return sum; 137 } 138 139 /* 140 * computes the checksum of the TCP/UDP pseudo-header 141 * returns a 16-bit checksum, already complemented 142 */ 143 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 144 __u32 len, __u8 proto, 145 __wsum sum) 146 { 147 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 148 } 149 150 /* 151 * this routine is used for miscellaneous IP-like checksums, mainly 152 * in icmp.c 153 */ 154 static inline __sum16 ip_compute_csum(const void *buff, int len) 155 { 156 return csum_fold(csum_partial(buff, len, 0)); 157 } 158 159 #define _HAVE_ARCH_IPV6_CSUM 160 static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 161 const struct in6_addr *daddr, 162 __u32 len, __u8 proto, __wsum sum) 163 { 164 unsigned int __dummy; 165 __asm__("clrt\n\t" 166 "mov.l @(0,%2), %1\n\t" 167 "addc %1, %0\n\t" 168 "mov.l @(4,%2), %1\n\t" 169 "addc %1, %0\n\t" 170 "mov.l @(8,%2), %1\n\t" 171 "addc %1, %0\n\t" 172 "mov.l @(12,%2), %1\n\t" 173 "addc %1, %0\n\t" 174 "mov.l @(0,%3), %1\n\t" 175 "addc %1, %0\n\t" 176 "mov.l @(4,%3), %1\n\t" 177 "addc %1, %0\n\t" 178 "mov.l @(8,%3), %1\n\t" 179 "addc %1, %0\n\t" 180 "mov.l @(12,%3), %1\n\t" 181 "addc %1, %0\n\t" 182 "addc %4, %0\n\t" 183 "addc %5, %0\n\t" 184 "movt %1\n\t" 185 "add %1, %0\n" 186 : "=r" (sum), "=&r" (__dummy) 187 : "r" (saddr), "r" (daddr), 188 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 189 : "t"); 190 191 return csum_fold(sum); 192 } 193 194 /* 195 * Copy and checksum to user 196 */ 197 #define HAVE_CSUM_COPY_USER 198 static inline __wsum csum_and_copy_to_user(const void *src, 199 void __user *dst, 200 int len, __wsum sum, 201 int *err_ptr) 202 { 203 if (access_ok(VERIFY_WRITE, dst, len)) 204 return csum_partial_copy_generic((__force const void *)src, 205 dst, len, sum, NULL, err_ptr); 206 207 if (len) 208 *err_ptr = -EFAULT; 209 210 return (__force __wsum)-1; /* invalid checksum */ 211 } 212 #endif /* __ASM_SH_CHECKSUM_H */ 213