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 <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 */ 29 asmlinkage __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 39 asmlinkage __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 */ 48 static 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 55 static 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 67 static __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 */ 88 static __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 : "memory"); 118 119 return csum_fold(sum); 120 } 121 122 static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 123 unsigned short len, 124 unsigned short 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 */ 156 static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 157 unsigned short len, 158 unsigned short proto, 159 __wsum sum) 160 { 161 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 162 } 163 164 /* 165 * this routine is used for miscellaneous IP-like checksums, mainly 166 * in icmp.c 167 */ 168 169 static __inline__ __sum16 ip_compute_csum(const void *buff, int len) 170 { 171 return csum_fold (csum_partial(buff, len, 0)); 172 } 173 174 #define _HAVE_ARCH_IPV6_CSUM 175 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 176 const struct in6_addr *daddr, 177 __u32 len, unsigned short proto, 178 __wsum sum) 179 { 180 unsigned int __dummy; 181 __asm__("l32i %1, %2, 0\n\t" 182 "add %0, %0, %1\n\t" 183 "bgeu %0, %1, 1f\n\t" 184 "addi %0, %0, 1\n\t" 185 "1:\t" 186 "l32i %1, %2, 4\n\t" 187 "add %0, %0, %1\n\t" 188 "bgeu %0, %1, 1f\n\t" 189 "addi %0, %0, 1\n\t" 190 "1:\t" 191 "l32i %1, %2, 8\n\t" 192 "add %0, %0, %1\n\t" 193 "bgeu %0, %1, 1f\n\t" 194 "addi %0, %0, 1\n\t" 195 "1:\t" 196 "l32i %1, %2, 12\n\t" 197 "add %0, %0, %1\n\t" 198 "bgeu %0, %1, 1f\n\t" 199 "addi %0, %0, 1\n\t" 200 "1:\t" 201 "l32i %1, %3, 0\n\t" 202 "add %0, %0, %1\n\t" 203 "bgeu %0, %1, 1f\n\t" 204 "addi %0, %0, 1\n\t" 205 "1:\t" 206 "l32i %1, %3, 4\n\t" 207 "add %0, %0, %1\n\t" 208 "bgeu %0, %1, 1f\n\t" 209 "addi %0, %0, 1\n\t" 210 "1:\t" 211 "l32i %1, %3, 8\n\t" 212 "add %0, %0, %1\n\t" 213 "bgeu %0, %1, 1f\n\t" 214 "addi %0, %0, 1\n\t" 215 "1:\t" 216 "l32i %1, %3, 12\n\t" 217 "add %0, %0, %1\n\t" 218 "bgeu %0, %1, 1f\n\t" 219 "addi %0, %0, 1\n\t" 220 "1:\t" 221 "add %0, %0, %4\n\t" 222 "bgeu %0, %4, 1f\n\t" 223 "addi %0, %0, 1\n\t" 224 "1:\t" 225 "add %0, %0, %5\n\t" 226 "bgeu %0, %5, 1f\n\t" 227 "addi %0, %0, 1\n\t" 228 "1:\t" 229 : "=r" (sum), "=&r" (__dummy) 230 : "r" (saddr), "r" (daddr), 231 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 232 : "memory"); 233 234 return csum_fold(sum); 235 } 236 237 /* 238 * Copy and checksum to user 239 */ 240 #define HAVE_CSUM_COPY_USER 241 static __inline__ __wsum csum_and_copy_to_user(const void *src, void __user *dst, 242 int len, __wsum sum, int *err_ptr) 243 { 244 if (access_ok(VERIFY_WRITE, dst, len)) 245 return csum_partial_copy_generic(src, dst, len, sum, NULL, err_ptr); 246 247 if (len) 248 *err_ptr = -EFAULT; 249 250 return (__force __wsum)-1; /* invalid checksum */ 251 } 252 #endif 253