Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * This file is subject to the terms and conditions of the GNU General Public |
| 3 | * License. See the file "COPYING" in the main directory of this archive |
| 4 | * for more details. |
| 5 | * |
| 6 | * Copyright (C) 1995, 96, 97, 98, 99, 2001 by Ralf Baechle |
| 7 | * Copyright (C) 1999 Silicon Graphics, Inc. |
| 8 | * Copyright (C) 2001 Thiemo Seufer. |
| 9 | * Copyright (C) 2002 Maciej W. Rozycki |
| 10 | */ |
| 11 | #ifndef _ASM_CHECKSUM_H |
| 12 | #define _ASM_CHECKSUM_H |
| 13 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 14 | #include <linux/in6.h> |
| 15 | |
| 16 | #include <asm/uaccess.h> |
| 17 | |
| 18 | /* |
| 19 | * computes the checksum of a memory block at buff, length len, |
| 20 | * and adds in "sum" (32-bit) |
| 21 | * |
| 22 | * returns a 32-bit number suitable for feeding into itself |
| 23 | * or csum_tcpudp_magic |
| 24 | * |
| 25 | * this function must be called with even lengths, except |
| 26 | * for the last fragment, which may be odd |
| 27 | * |
| 28 | * it's best to have buff aligned on a 32-bit boundary |
| 29 | */ |
| 30 | unsigned int csum_partial(const unsigned char *buff, int len, unsigned int sum); |
| 31 | |
| 32 | /* |
| 33 | * this is a new version of the above that records errors it finds in *errp, |
| 34 | * but continues and zeros the rest of the buffer. |
| 35 | */ |
Ralf Baechle | fe00f94 | 2005-03-01 19:22:29 +0000 | [diff] [blame] | 36 | unsigned int csum_partial_copy_from_user(const unsigned char __user *src, |
| 37 | unsigned char *dst, int len, |
| 38 | unsigned int sum, int *errp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
| 40 | /* |
| 41 | * Copy and checksum to user |
| 42 | */ |
| 43 | #define HAVE_CSUM_COPY_USER |
| 44 | static inline unsigned int csum_and_copy_to_user (const unsigned char *src, |
| 45 | unsigned char __user *dst, |
| 46 | int len, int sum, |
| 47 | int *err_ptr) |
| 48 | { |
| 49 | might_sleep(); |
| 50 | sum = csum_partial(src, len, sum); |
| 51 | |
| 52 | if (copy_to_user(dst, src, len)) { |
| 53 | *err_ptr = -EFAULT; |
| 54 | return -1; |
| 55 | } |
| 56 | |
| 57 | return sum; |
| 58 | } |
| 59 | |
| 60 | /* |
| 61 | * the same as csum_partial, but copies from user space (but on MIPS |
| 62 | * we have just one address space, so this is identical to the above) |
| 63 | */ |
| 64 | unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, |
| 65 | int len, unsigned int sum); |
| 66 | |
| 67 | /* |
| 68 | * Fold a partial checksum without adding pseudo headers |
| 69 | */ |
| 70 | static inline unsigned short int csum_fold(unsigned int sum) |
| 71 | { |
| 72 | __asm__( |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 73 | " .set push # csum_fold\n" |
| 74 | " .set noat \n" |
| 75 | " sll $1, %0, 16 \n" |
| 76 | " addu %0, $1 \n" |
| 77 | " sltu $1, %0, $1 \n" |
| 78 | " srl %0, %0, 16 \n" |
| 79 | " addu %0, $1 \n" |
| 80 | " xori %0, 0xffff \n" |
| 81 | " .set pop" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 82 | : "=r" (sum) |
| 83 | : "0" (sum)); |
| 84 | |
| 85 | return sum; |
| 86 | } |
| 87 | |
| 88 | /* |
| 89 | * This is a version of ip_compute_csum() optimized for IP headers, |
| 90 | * which always checksum on 4 octet boundaries. |
| 91 | * |
| 92 | * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by |
| 93 | * Arnt Gulbrandsen. |
| 94 | */ |
| 95 | static inline unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl) |
| 96 | { |
| 97 | unsigned int *word = (unsigned int *) iph; |
| 98 | unsigned int *stop = word + ihl; |
| 99 | unsigned int csum; |
| 100 | int carry; |
| 101 | |
| 102 | csum = word[0]; |
| 103 | csum += word[1]; |
| 104 | carry = (csum < word[1]); |
| 105 | csum += carry; |
| 106 | |
| 107 | csum += word[2]; |
| 108 | carry = (csum < word[2]); |
| 109 | csum += carry; |
| 110 | |
| 111 | csum += word[3]; |
| 112 | carry = (csum < word[3]); |
| 113 | csum += carry; |
| 114 | |
| 115 | word += 4; |
| 116 | do { |
| 117 | csum += *word; |
| 118 | carry = (csum < *word); |
| 119 | csum += carry; |
| 120 | word++; |
| 121 | } while (word != stop); |
| 122 | |
| 123 | return csum_fold(csum); |
| 124 | } |
| 125 | |
| 126 | static inline unsigned int csum_tcpudp_nofold(unsigned long saddr, |
| 127 | unsigned long daddr, unsigned short len, unsigned short proto, |
| 128 | unsigned int sum) |
| 129 | { |
| 130 | __asm__( |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 131 | " .set push # csum_tcpudp_nofold\n" |
| 132 | " .set noat \n" |
Ralf Baechle | 875d43e | 2005-09-03 15:56:16 -0700 | [diff] [blame] | 133 | #ifdef CONFIG_32BIT |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 134 | " addu %0, %2 \n" |
| 135 | " sltu $1, %0, %2 \n" |
| 136 | " addu %0, $1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 137 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 138 | " addu %0, %3 \n" |
| 139 | " sltu $1, %0, %3 \n" |
| 140 | " addu %0, $1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 142 | " addu %0, %4 \n" |
| 143 | " sltu $1, %0, %4 \n" |
| 144 | " addu %0, $1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 145 | #endif |
Ralf Baechle | 875d43e | 2005-09-03 15:56:16 -0700 | [diff] [blame] | 146 | #ifdef CONFIG_64BIT |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 147 | " daddu %0, %2 \n" |
| 148 | " daddu %0, %3 \n" |
| 149 | " daddu %0, %4 \n" |
| 150 | " dsll32 $1, %0, 0 \n" |
| 151 | " daddu %0, $1 \n" |
Ralf Baechle | e972883 | 2005-09-20 10:56:26 +0000 | [diff] [blame] | 152 | " dsra32 %0, %0, 0 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 153 | #endif |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 154 | " .set pop" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 155 | : "=r" (sum) |
| 156 | : "0" (daddr), "r"(saddr), |
| 157 | #ifdef __MIPSEL__ |
| 158 | "r" (((unsigned long)htons(len)<<16) + proto*256), |
| 159 | #else |
| 160 | "r" (((unsigned long)(proto)<<16) + len), |
| 161 | #endif |
| 162 | "r" (sum)); |
| 163 | |
| 164 | return sum; |
| 165 | } |
| 166 | |
| 167 | /* |
| 168 | * computes the checksum of the TCP/UDP pseudo-header |
| 169 | * returns a 16-bit checksum, already complemented |
| 170 | */ |
| 171 | static inline unsigned short int csum_tcpudp_magic(unsigned long saddr, |
| 172 | unsigned long daddr, |
| 173 | unsigned short len, |
| 174 | unsigned short proto, |
| 175 | unsigned int sum) |
| 176 | { |
| 177 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
| 178 | } |
| 179 | |
| 180 | /* |
| 181 | * this routine is used for miscellaneous IP-like checksums, mainly |
| 182 | * in icmp.c |
| 183 | */ |
| 184 | static inline unsigned short ip_compute_csum(unsigned char * buff, int len) |
| 185 | { |
| 186 | return csum_fold(csum_partial(buff, len, 0)); |
| 187 | } |
| 188 | |
| 189 | #define _HAVE_ARCH_IPV6_CSUM |
| 190 | static __inline__ unsigned short int csum_ipv6_magic(struct in6_addr *saddr, |
| 191 | struct in6_addr *daddr, |
| 192 | __u32 len, |
| 193 | unsigned short proto, |
| 194 | unsigned int sum) |
| 195 | { |
| 196 | __asm__( |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 197 | " .set push # csum_ipv6_magic\n" |
| 198 | " .set noreorder \n" |
| 199 | " .set noat \n" |
| 200 | " addu %0, %5 # proto (long in network byte order)\n" |
| 201 | " sltu $1, %0, %5 \n" |
| 202 | " addu %0, $1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 203 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 204 | " addu %0, %6 # csum\n" |
| 205 | " sltu $1, %0, %6 \n" |
| 206 | " lw %1, 0(%2) # four words source address\n" |
| 207 | " addu %0, $1 \n" |
| 208 | " addu %0, %1 \n" |
| 209 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 210 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 211 | " lw %1, 4(%2) \n" |
| 212 | " addu %0, $1 \n" |
| 213 | " addu %0, %1 \n" |
| 214 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 216 | " lw %1, 8(%2) \n" |
| 217 | " addu %0, $1 \n" |
| 218 | " addu %0, %1 \n" |
| 219 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 220 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 221 | " lw %1, 12(%2) \n" |
| 222 | " addu %0, $1 \n" |
| 223 | " addu %0, %1 \n" |
| 224 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 225 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 226 | " lw %1, 0(%3) \n" |
| 227 | " addu %0, $1 \n" |
| 228 | " addu %0, %1 \n" |
| 229 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 230 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 231 | " lw %1, 4(%3) \n" |
| 232 | " addu %0, $1 \n" |
| 233 | " addu %0, %1 \n" |
| 234 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 235 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 236 | " lw %1, 8(%3) \n" |
| 237 | " addu %0, $1 \n" |
| 238 | " addu %0, %1 \n" |
| 239 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 241 | " lw %1, 12(%3) \n" |
| 242 | " addu %0, $1 \n" |
| 243 | " addu %0, %1 \n" |
| 244 | " sltu $1, %0, %1 \n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 245 | |
Thiemo Seufer | 04988d6f | 2005-07-08 09:17:05 +0000 | [diff] [blame] | 246 | " addu %0, $1 # Add final carry\n" |
| 247 | " .set pop" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 248 | : "=r" (sum), "=r" (proto) |
| 249 | : "r" (saddr), "r" (daddr), |
| 250 | "0" (htonl(len)), "1" (htonl(proto)), "r" (sum)); |
| 251 | |
| 252 | return csum_fold(sum); |
| 253 | } |
| 254 | |
| 255 | #endif /* _ASM_CHECKSUM_H */ |