1/* 2 * include/asm-xtensa/checksum.h 3 * 4 * This file is subject to the terms and conditions of the GNU General Public 5 * License. See the file "COPYING" in the main directory of this archive 6 * for more details. 7 * 8 * Copyright (C) 2001 - 2005 Tensilica Inc. 9 */ 10 11#ifndef _XTENSA_CHECKSUM_H 12#define _XTENSA_CHECKSUM_H 13 14#include <linux/in6.h> 15#include <asm/variant/core.h> 16 17/* 18 * computes the checksum of a memory block at buff, length len, 19 * and adds in "sum" (32-bit) 20 * 21 * returns a 32-bit number suitable for feeding into itself 22 * or csum_tcpudp_magic 23 * 24 * this function must be called with even lengths, except 25 * for the last fragment, which may be odd 26 * 27 * it's best to have buff aligned on a 32-bit boundary 28 */ 29asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); 30 31/* 32 * the same as csum_partial, but copies from src while it 33 * checksums, and handles user-space pointer exceptions correctly, when needed. 34 * 35 * here even more important to align src and dst on a 32-bit (or even 36 * better 64-bit) boundary 37 */ 38 39asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len, __wsum sum, 40 int *src_err_ptr, int *dst_err_ptr); 41 42/* 43 * Note: when you get a NULL pointer exception here this means someone 44 * passed in an incorrect kernel address to one of these functions. 45 * 46 * If you use these functions directly please don't forget the access_ok(). 47 */ 48static inline 49__wsum csum_partial_copy_nocheck(const void *src, void *dst, 50 int len, __wsum sum) 51{ 52 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 53} 54 55static inline 56__wsum csum_partial_copy_from_user(const void __user *src, void *dst, 57 int len, __wsum sum, int *err_ptr) 58{ 59 return csum_partial_copy_generic((__force const void *)src, dst, 60 len, sum, err_ptr, NULL); 61} 62 63/* 64 * Fold a partial checksum 65 */ 66 67static __inline__ __sum16 csum_fold(__wsum sum) 68{ 69 unsigned int __dummy; 70 __asm__("extui %1, %0, 16, 16\n\t" 71 "extui %0 ,%0, 0, 16\n\t" 72 "add %0, %0, %1\n\t" 73 "slli %1, %0, 16\n\t" 74 "add %0, %0, %1\n\t" 75 "extui %0, %0, 16, 16\n\t" 76 "neg %0, %0\n\t" 77 "addi %0, %0, -1\n\t" 78 "extui %0, %0, 0, 16\n\t" 79 : "=r" (sum), "=&r" (__dummy) 80 : "0" (sum)); 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 */ 88static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 89{ 90 unsigned int sum, tmp, endaddr; 91 92 __asm__ __volatile__( 93 "sub %0, %0, %0\n\t" 94#if XCHAL_HAVE_LOOPS 95 "loopgtz %2, 2f\n\t" 96#else 97 "beqz %2, 2f\n\t" 98 "slli %4, %2, 2\n\t" 99 "add %4, %4, %1\n\t" 100 "0:\t" 101#endif 102 "l32i %3, %1, 0\n\t" 103 "add %0, %0, %3\n\t" 104 "bgeu %0, %3, 1f\n\t" 105 "addi %0, %0, 1\n\t" 106 "1:\t" 107 "addi %1, %1, 4\n\t" 108#if !XCHAL_HAVE_LOOPS 109 "blt %1, %4, 0b\n\t" 110#endif 111 "2:\t" 112 /* Since the input registers which are loaded with iph and ihl 113 are modified, we must also specify them as outputs, or gcc 114 will assume they contain their original values. */ 115 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), "=&r" (endaddr) 116 : "1" (iph), "2" (ihl)); 117 118 return csum_fold(sum); 119} 120 121static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 122 unsigned short len, 123 unsigned short proto, 124 __wsum sum) 125{ 126 127#ifdef __XTENSA_EL__ 128 unsigned long len_proto = (len + proto) << 8; 129#elif defined(__XTENSA_EB__) 130 unsigned long len_proto = len + proto; 131#else 132# error processor byte order undefined! 133#endif 134 __asm__("add %0, %0, %1\n\t" 135 "bgeu %0, %1, 1f\n\t" 136 "addi %0, %0, 1\n\t" 137 "1:\t" 138 "add %0, %0, %2\n\t" 139 "bgeu %0, %2, 1f\n\t" 140 "addi %0, %0, 1\n\t" 141 "1:\t" 142 "add %0, %0, %3\n\t" 143 "bgeu %0, %3, 1f\n\t" 144 "addi %0, %0, 1\n\t" 145 "1:\t" 146 : "=r" (sum), "=r" (len_proto) 147 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); 148 return sum; 149} 150 151/* 152 * computes the checksum of the TCP/UDP pseudo-header 153 * returns a 16-bit checksum, already complemented 154 */ 155static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 156 unsigned short len, 157 unsigned short proto, 158 __wsum sum) 159{ 160 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 161} 162 163/* 164 * this routine is used for miscellaneous IP-like checksums, mainly 165 * in icmp.c 166 */ 167 168static __inline__ __sum16 ip_compute_csum(const void *buff, int len) 169{ 170 return csum_fold (csum_partial(buff, len, 0)); 171} 172 173#define _HAVE_ARCH_IPV6_CSUM 174static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 175 const struct in6_addr *daddr, 176 __u32 len, unsigned short proto, 177 __wsum sum) 178{ 179 unsigned int __dummy; 180 __asm__("l32i %1, %2, 0\n\t" 181 "add %0, %0, %1\n\t" 182 "bgeu %0, %1, 1f\n\t" 183 "addi %0, %0, 1\n\t" 184 "1:\t" 185 "l32i %1, %2, 4\n\t" 186 "add %0, %0, %1\n\t" 187 "bgeu %0, %1, 1f\n\t" 188 "addi %0, %0, 1\n\t" 189 "1:\t" 190 "l32i %1, %2, 8\n\t" 191 "add %0, %0, %1\n\t" 192 "bgeu %0, %1, 1f\n\t" 193 "addi %0, %0, 1\n\t" 194 "1:\t" 195 "l32i %1, %2, 12\n\t" 196 "add %0, %0, %1\n\t" 197 "bgeu %0, %1, 1f\n\t" 198 "addi %0, %0, 1\n\t" 199 "1:\t" 200 "l32i %1, %3, 0\n\t" 201 "add %0, %0, %1\n\t" 202 "bgeu %0, %1, 1f\n\t" 203 "addi %0, %0, 1\n\t" 204 "1:\t" 205 "l32i %1, %3, 4\n\t" 206 "add %0, %0, %1\n\t" 207 "bgeu %0, %1, 1f\n\t" 208 "addi %0, %0, 1\n\t" 209 "1:\t" 210 "l32i %1, %3, 8\n\t" 211 "add %0, %0, %1\n\t" 212 "bgeu %0, %1, 1f\n\t" 213 "addi %0, %0, 1\n\t" 214 "1:\t" 215 "l32i %1, %3, 12\n\t" 216 "add %0, %0, %1\n\t" 217 "bgeu %0, %1, 1f\n\t" 218 "addi %0, %0, 1\n\t" 219 "1:\t" 220 "add %0, %0, %4\n\t" 221 "bgeu %0, %4, 1f\n\t" 222 "addi %0, %0, 1\n\t" 223 "1:\t" 224 "add %0, %0, %5\n\t" 225 "bgeu %0, %5, 1f\n\t" 226 "addi %0, %0, 1\n\t" 227 "1:\t" 228 : "=r" (sum), "=&r" (__dummy) 229 : "r" (saddr), "r" (daddr), 230 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum)); 231 232 return csum_fold(sum); 233} 234 235/* 236 * Copy and checksum to user 237 */ 238#define HAVE_CSUM_COPY_USER 239static __inline__ __wsum csum_and_copy_to_user(const void *src, void __user *dst, 240 int len, __wsum sum, int *err_ptr) 241{ 242 if (access_ok(VERIFY_WRITE, dst, len)) 243 return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); 244 245 if (len) 246 *err_ptr = -EFAULT; 247 248 return (__force __wsum)-1; /* invalid checksum */ 249} 250#endif 251