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 */ 30 asmlinkage __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 40 asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, 41 int len, __wsum sum, 42 int *src_err_ptr, int *dst_err_ptr); 43 44 /* 45 * Note: when you get a NULL pointer exception here this means someone 46 * passed in an incorrect kernel address to one of these functions. 47 * 48 * If you use these functions directly please don't forget the access_ok(). 49 */ 50 static inline 51 __wsum csum_partial_copy_nocheck(const void *src, void *dst, 52 int len, __wsum sum) 53 { 54 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); 55 } 56 57 static inline 58 __wsum csum_partial_copy_from_user(const void __user *src, void *dst, 59 int len, __wsum sum, int *err_ptr) 60 { 61 return csum_partial_copy_generic((__force const void *)src, dst, 62 len, sum, err_ptr, NULL); 63 } 64 65 /* 66 * Fold a partial checksum 67 */ 68 69 static __inline__ __sum16 csum_fold(__wsum sum) 70 { 71 unsigned int __dummy; 72 __asm__("extui %1, %0, 16, 16\n\t" 73 "extui %0 ,%0, 0, 16\n\t" 74 "add %0, %0, %1\n\t" 75 "slli %1, %0, 16\n\t" 76 "add %0, %0, %1\n\t" 77 "extui %0, %0, 16, 16\n\t" 78 "neg %0, %0\n\t" 79 "addi %0, %0, -1\n\t" 80 "extui %0, %0, 0, 16\n\t" 81 : "=r" (sum), "=&r" (__dummy) 82 : "0" (sum)); 83 return (__force __sum16)sum; 84 } 85 86 /* 87 * This is a version of ip_compute_csum() optimized for IP headers, 88 * which always checksum on 4 octet boundaries. 89 */ 90 static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 91 { 92 unsigned int sum, tmp, endaddr; 93 94 __asm__ __volatile__( 95 "sub %0, %0, %0\n\t" 96 #if XCHAL_HAVE_LOOPS 97 "loopgtz %2, 2f\n\t" 98 #else 99 "beqz %2, 2f\n\t" 100 "slli %4, %2, 2\n\t" 101 "add %4, %4, %1\n\t" 102 "0:\t" 103 #endif 104 "l32i %3, %1, 0\n\t" 105 "add %0, %0, %3\n\t" 106 "bgeu %0, %3, 1f\n\t" 107 "addi %0, %0, 1\n\t" 108 "1:\t" 109 "addi %1, %1, 4\n\t" 110 #if !XCHAL_HAVE_LOOPS 111 "blt %1, %4, 0b\n\t" 112 #endif 113 "2:\t" 114 /* Since the input registers which are loaded with iph and ihl 115 are modified, we must also specify them as outputs, or gcc 116 will assume they contain their original values. */ 117 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), 118 "=&r" (endaddr) 119 : "1" (iph), "2" (ihl) 120 : "memory"); 121 122 return csum_fold(sum); 123 } 124 125 static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 126 __u32 len, __u8 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 __u32 len, __u8 proto, 160 __wsum sum) 161 { 162 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 163 } 164 165 /* 166 * this routine is used for miscellaneous IP-like checksums, mainly 167 * in icmp.c 168 */ 169 170 static __inline__ __sum16 ip_compute_csum(const void *buff, int len) 171 { 172 return csum_fold (csum_partial(buff, len, 0)); 173 } 174 175 #define _HAVE_ARCH_IPV6_CSUM 176 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 177 const struct in6_addr *daddr, 178 __u32 len, __u8 proto, 179 __wsum sum) 180 { 181 unsigned int __dummy; 182 __asm__("l32i %1, %2, 0\n\t" 183 "add %0, %0, %1\n\t" 184 "bgeu %0, %1, 1f\n\t" 185 "addi %0, %0, 1\n\t" 186 "1:\t" 187 "l32i %1, %2, 4\n\t" 188 "add %0, %0, %1\n\t" 189 "bgeu %0, %1, 1f\n\t" 190 "addi %0, %0, 1\n\t" 191 "1:\t" 192 "l32i %1, %2, 8\n\t" 193 "add %0, %0, %1\n\t" 194 "bgeu %0, %1, 1f\n\t" 195 "addi %0, %0, 1\n\t" 196 "1:\t" 197 "l32i %1, %2, 12\n\t" 198 "add %0, %0, %1\n\t" 199 "bgeu %0, %1, 1f\n\t" 200 "addi %0, %0, 1\n\t" 201 "1:\t" 202 "l32i %1, %3, 0\n\t" 203 "add %0, %0, %1\n\t" 204 "bgeu %0, %1, 1f\n\t" 205 "addi %0, %0, 1\n\t" 206 "1:\t" 207 "l32i %1, %3, 4\n\t" 208 "add %0, %0, %1\n\t" 209 "bgeu %0, %1, 1f\n\t" 210 "addi %0, %0, 1\n\t" 211 "1:\t" 212 "l32i %1, %3, 8\n\t" 213 "add %0, %0, %1\n\t" 214 "bgeu %0, %1, 1f\n\t" 215 "addi %0, %0, 1\n\t" 216 "1:\t" 217 "l32i %1, %3, 12\n\t" 218 "add %0, %0, %1\n\t" 219 "bgeu %0, %1, 1f\n\t" 220 "addi %0, %0, 1\n\t" 221 "1:\t" 222 "add %0, %0, %4\n\t" 223 "bgeu %0, %4, 1f\n\t" 224 "addi %0, %0, 1\n\t" 225 "1:\t" 226 "add %0, %0, %5\n\t" 227 "bgeu %0, %5, 1f\n\t" 228 "addi %0, %0, 1\n\t" 229 "1:\t" 230 : "=r" (sum), "=&r" (__dummy) 231 : "r" (saddr), "r" (daddr), 232 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 233 : "memory"); 234 235 return csum_fold(sum); 236 } 237 238 /* 239 * Copy and checksum to user 240 */ 241 #define HAVE_CSUM_COPY_USER 242 static __inline__ __wsum csum_and_copy_to_user(const void *src, 243 void __user *dst, int len, 244 __wsum sum, int *err_ptr) 245 { 246 if (access_ok(dst, len)) 247 return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr); 248 249 if (len) 250 *err_ptr = -EFAULT; 251 252 return (__force __wsum)-1; /* invalid checksum */ 253 } 254 #endif 255