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, 40 int len, __wsum sum, 41 int *src_err_ptr, int *dst_err_ptr); 42 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 * 47 * If you use these functions directly please don't forget the access_ok(). 48 */ 49 static inline 50 __wsum csum_partial_copy_nocheck(const void *src, void *dst, 51 int len, __wsum sum) 52 { 53 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 54 } 55 56 static inline 57 __wsum csum_partial_copy_from_user(const void __user *src, void *dst, 58 int len, __wsum sum, int *err_ptr) 59 { 60 return csum_partial_copy_generic((__force const void *)src, dst, 61 len, sum, err_ptr, NULL); 62 } 63 64 /* 65 * Fold a partial checksum 66 */ 67 68 static __inline__ __sum16 csum_fold(__wsum sum) 69 { 70 unsigned int __dummy; 71 __asm__("extui %1, %0, 16, 16\n\t" 72 "extui %0 ,%0, 0, 16\n\t" 73 "add %0, %0, %1\n\t" 74 "slli %1, %0, 16\n\t" 75 "add %0, %0, %1\n\t" 76 "extui %0, %0, 16, 16\n\t" 77 "neg %0, %0\n\t" 78 "addi %0, %0, -1\n\t" 79 "extui %0, %0, 0, 16\n\t" 80 : "=r" (sum), "=&r" (__dummy) 81 : "0" (sum)); 82 return (__force __sum16)sum; 83 } 84 85 /* 86 * This is a version of ip_compute_csum() optimized for IP headers, 87 * which always checksum on 4 octet boundaries. 88 */ 89 static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 90 { 91 unsigned int sum, tmp, endaddr; 92 93 __asm__ __volatile__( 94 "sub %0, %0, %0\n\t" 95 #if XCHAL_HAVE_LOOPS 96 "loopgtz %2, 2f\n\t" 97 #else 98 "beqz %2, 2f\n\t" 99 "slli %4, %2, 2\n\t" 100 "add %4, %4, %1\n\t" 101 "0:\t" 102 #endif 103 "l32i %3, %1, 0\n\t" 104 "add %0, %0, %3\n\t" 105 "bgeu %0, %3, 1f\n\t" 106 "addi %0, %0, 1\n\t" 107 "1:\t" 108 "addi %1, %1, 4\n\t" 109 #if !XCHAL_HAVE_LOOPS 110 "blt %1, %4, 0b\n\t" 111 #endif 112 "2:\t" 113 /* Since the input registers which are loaded with iph and ihl 114 are modified, we must also specify them as outputs, or gcc 115 will assume they contain their original values. */ 116 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), 117 "=&r" (endaddr) 118 : "1" (iph), "2" (ihl) 119 : "memory"); 120 121 return csum_fold(sum); 122 } 123 124 static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 125 unsigned short len, 126 unsigned short proto, 127 __wsum sum) 128 { 129 130 #ifdef __XTENSA_EL__ 131 unsigned long len_proto = (len + proto) << 8; 132 #elif defined(__XTENSA_EB__) 133 unsigned long len_proto = len + proto; 134 #else 135 # error processor byte order undefined! 136 #endif 137 __asm__("add %0, %0, %1\n\t" 138 "bgeu %0, %1, 1f\n\t" 139 "addi %0, %0, 1\n\t" 140 "1:\t" 141 "add %0, %0, %2\n\t" 142 "bgeu %0, %2, 1f\n\t" 143 "addi %0, %0, 1\n\t" 144 "1:\t" 145 "add %0, %0, %3\n\t" 146 "bgeu %0, %3, 1f\n\t" 147 "addi %0, %0, 1\n\t" 148 "1:\t" 149 : "=r" (sum), "=r" (len_proto) 150 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); 151 return sum; 152 } 153 154 /* 155 * computes the checksum of the TCP/UDP pseudo-header 156 * returns a 16-bit checksum, already complemented 157 */ 158 static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 159 unsigned short len, 160 unsigned short proto, 161 __wsum sum) 162 { 163 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 164 } 165 166 /* 167 * this routine is used for miscellaneous IP-like checksums, mainly 168 * in icmp.c 169 */ 170 171 static __inline__ __sum16 ip_compute_csum(const void *buff, int len) 172 { 173 return csum_fold (csum_partial(buff, len, 0)); 174 } 175 176 #define _HAVE_ARCH_IPV6_CSUM 177 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 178 const struct in6_addr *daddr, 179 __u32 len, unsigned short proto, 180 __wsum sum) 181 { 182 unsigned int __dummy; 183 __asm__("l32i %1, %2, 0\n\t" 184 "add %0, %0, %1\n\t" 185 "bgeu %0, %1, 1f\n\t" 186 "addi %0, %0, 1\n\t" 187 "1:\t" 188 "l32i %1, %2, 4\n\t" 189 "add %0, %0, %1\n\t" 190 "bgeu %0, %1, 1f\n\t" 191 "addi %0, %0, 1\n\t" 192 "1:\t" 193 "l32i %1, %2, 8\n\t" 194 "add %0, %0, %1\n\t" 195 "bgeu %0, %1, 1f\n\t" 196 "addi %0, %0, 1\n\t" 197 "1:\t" 198 "l32i %1, %2, 12\n\t" 199 "add %0, %0, %1\n\t" 200 "bgeu %0, %1, 1f\n\t" 201 "addi %0, %0, 1\n\t" 202 "1:\t" 203 "l32i %1, %3, 0\n\t" 204 "add %0, %0, %1\n\t" 205 "bgeu %0, %1, 1f\n\t" 206 "addi %0, %0, 1\n\t" 207 "1:\t" 208 "l32i %1, %3, 4\n\t" 209 "add %0, %0, %1\n\t" 210 "bgeu %0, %1, 1f\n\t" 211 "addi %0, %0, 1\n\t" 212 "1:\t" 213 "l32i %1, %3, 8\n\t" 214 "add %0, %0, %1\n\t" 215 "bgeu %0, %1, 1f\n\t" 216 "addi %0, %0, 1\n\t" 217 "1:\t" 218 "l32i %1, %3, 12\n\t" 219 "add %0, %0, %1\n\t" 220 "bgeu %0, %1, 1f\n\t" 221 "addi %0, %0, 1\n\t" 222 "1:\t" 223 "add %0, %0, %4\n\t" 224 "bgeu %0, %4, 1f\n\t" 225 "addi %0, %0, 1\n\t" 226 "1:\t" 227 "add %0, %0, %5\n\t" 228 "bgeu %0, %5, 1f\n\t" 229 "addi %0, %0, 1\n\t" 230 "1:\t" 231 : "=r" (sum), "=&r" (__dummy) 232 : "r" (saddr), "r" (daddr), 233 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 234 : "memory"); 235 236 return csum_fold(sum); 237 } 238 239 /* 240 * Copy and checksum to user 241 */ 242 #define HAVE_CSUM_COPY_USER 243 static __inline__ __wsum csum_and_copy_to_user(const void *src, 244 void __user *dst, int len, 245 __wsum sum, int *err_ptr) 246 { 247 if (access_ok(VERIFY_WRITE, dst, len)) 248 return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr); 249 250 if (len) 251 *err_ptr = -EFAULT; 252 253 return (__force __wsum)-1; /* invalid checksum */ 254 } 255 #endif 256