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 <linux/uaccess.h> 16#include <asm/core.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 */ 30asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); 31 32/* 33 * the same as csum_partial, but copies from src while it 34 * checksums, and handles user-space pointer exceptions correctly, when needed. 35 * 36 * here even more important to align src and dst on a 32-bit (or even 37 * better 64-bit) boundary 38 */ 39 40asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len); 41 42#define _HAVE_ARCH_CSUM_AND_COPY 43/* 44 * Note: when you get a NULL pointer exception here this means someone 45 * passed in an incorrect kernel address to one of these functions. 46 */ 47static inline 48__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len) 49{ 50 return csum_partial_copy_generic(src, dst, len); 51} 52 53#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 54static inline 55__wsum csum_and_copy_from_user(const void __user *src, void *dst, 56 int len) 57{ 58 if (!access_ok(src, len)) 59 return 0; 60 return csum_partial_copy_generic((__force const void *)src, dst, len); 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), 116 "=&r" (endaddr) 117 : "1" (iph), "2" (ihl) 118 : "memory"); 119 120 return csum_fold(sum); 121} 122 123static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 124 __u32 len, __u8 proto, 125 __wsum sum) 126{ 127 128#ifdef __XTENSA_EL__ 129 unsigned long len_proto = (len + proto) << 8; 130#elif defined(__XTENSA_EB__) 131 unsigned long len_proto = len + proto; 132#else 133# error processor byte order undefined! 134#endif 135 __asm__("add %0, %0, %1\n\t" 136 "bgeu %0, %1, 1f\n\t" 137 "addi %0, %0, 1\n\t" 138 "1:\t" 139 "add %0, %0, %2\n\t" 140 "bgeu %0, %2, 1f\n\t" 141 "addi %0, %0, 1\n\t" 142 "1:\t" 143 "add %0, %0, %3\n\t" 144 "bgeu %0, %3, 1f\n\t" 145 "addi %0, %0, 1\n\t" 146 "1:\t" 147 : "=r" (sum), "=r" (len_proto) 148 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); 149 return sum; 150} 151 152/* 153 * computes the checksum of the TCP/UDP pseudo-header 154 * returns a 16-bit checksum, already complemented 155 */ 156static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 157 __u32 len, __u8 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, __u8 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 : "memory"); 232 233 return csum_fold(sum); 234} 235 236/* 237 * Copy and checksum to user 238 */ 239#define HAVE_CSUM_COPY_USER 240static __inline__ __wsum csum_and_copy_to_user(const void *src, 241 void __user *dst, int len) 242{ 243 if (!access_ok(dst, len)) 244 return 0; 245 return csum_partial_copy_generic(src, (__force void *)dst, len); 246} 247#endif 248