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 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 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 56 static inline 57 __wsum csum_and_copy_from_user(const void __user *src, void *dst, 58 int len, __wsum sum, int *err_ptr) 59 { 60 if (access_ok(src, len)) 61 return csum_partial_copy_generic((__force const void *)src, dst, 62 len, sum, err_ptr, NULL); 63 if (len) 64 *err_ptr = -EFAULT; 65 return sum; 66 } 67 68 /* 69 * Fold a partial checksum 70 */ 71 72 static __inline__ __sum16 csum_fold(__wsum sum) 73 { 74 unsigned int __dummy; 75 __asm__("extui %1, %0, 16, 16\n\t" 76 "extui %0 ,%0, 0, 16\n\t" 77 "add %0, %0, %1\n\t" 78 "slli %1, %0, 16\n\t" 79 "add %0, %0, %1\n\t" 80 "extui %0, %0, 16, 16\n\t" 81 "neg %0, %0\n\t" 82 "addi %0, %0, -1\n\t" 83 "extui %0, %0, 0, 16\n\t" 84 : "=r" (sum), "=&r" (__dummy) 85 : "0" (sum)); 86 return (__force __sum16)sum; 87 } 88 89 /* 90 * This is a version of ip_compute_csum() optimized for IP headers, 91 * which always checksum on 4 octet boundaries. 92 */ 93 static __inline__ __sum16 ip_fast_csum(const void *iph, unsigned int ihl) 94 { 95 unsigned int sum, tmp, endaddr; 96 97 __asm__ __volatile__( 98 "sub %0, %0, %0\n\t" 99 #if XCHAL_HAVE_LOOPS 100 "loopgtz %2, 2f\n\t" 101 #else 102 "beqz %2, 2f\n\t" 103 "slli %4, %2, 2\n\t" 104 "add %4, %4, %1\n\t" 105 "0:\t" 106 #endif 107 "l32i %3, %1, 0\n\t" 108 "add %0, %0, %3\n\t" 109 "bgeu %0, %3, 1f\n\t" 110 "addi %0, %0, 1\n\t" 111 "1:\t" 112 "addi %1, %1, 4\n\t" 113 #if !XCHAL_HAVE_LOOPS 114 "blt %1, %4, 0b\n\t" 115 #endif 116 "2:\t" 117 /* Since the input registers which are loaded with iph and ihl 118 are modified, we must also specify them as outputs, or gcc 119 will assume they contain their original values. */ 120 : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (tmp), 121 "=&r" (endaddr) 122 : "1" (iph), "2" (ihl) 123 : "memory"); 124 125 return csum_fold(sum); 126 } 127 128 static __inline__ __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, 129 __u32 len, __u8 proto, 130 __wsum sum) 131 { 132 133 #ifdef __XTENSA_EL__ 134 unsigned long len_proto = (len + proto) << 8; 135 #elif defined(__XTENSA_EB__) 136 unsigned long len_proto = len + proto; 137 #else 138 # error processor byte order undefined! 139 #endif 140 __asm__("add %0, %0, %1\n\t" 141 "bgeu %0, %1, 1f\n\t" 142 "addi %0, %0, 1\n\t" 143 "1:\t" 144 "add %0, %0, %2\n\t" 145 "bgeu %0, %2, 1f\n\t" 146 "addi %0, %0, 1\n\t" 147 "1:\t" 148 "add %0, %0, %3\n\t" 149 "bgeu %0, %3, 1f\n\t" 150 "addi %0, %0, 1\n\t" 151 "1:\t" 152 : "=r" (sum), "=r" (len_proto) 153 : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum)); 154 return sum; 155 } 156 157 /* 158 * computes the checksum of the TCP/UDP pseudo-header 159 * returns a 16-bit checksum, already complemented 160 */ 161 static __inline__ __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, 162 __u32 len, __u8 proto, 163 __wsum sum) 164 { 165 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); 166 } 167 168 /* 169 * this routine is used for miscellaneous IP-like checksums, mainly 170 * in icmp.c 171 */ 172 173 static __inline__ __sum16 ip_compute_csum(const void *buff, int len) 174 { 175 return csum_fold (csum_partial(buff, len, 0)); 176 } 177 178 #define _HAVE_ARCH_IPV6_CSUM 179 static __inline__ __sum16 csum_ipv6_magic(const struct in6_addr *saddr, 180 const struct in6_addr *daddr, 181 __u32 len, __u8 proto, 182 __wsum sum) 183 { 184 unsigned int __dummy; 185 __asm__("l32i %1, %2, 0\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, 4\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, 8\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, %2, 12\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, 0\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, 4\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, 8\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 "l32i %1, %3, 12\n\t" 221 "add %0, %0, %1\n\t" 222 "bgeu %0, %1, 1f\n\t" 223 "addi %0, %0, 1\n\t" 224 "1:\t" 225 "add %0, %0, %4\n\t" 226 "bgeu %0, %4, 1f\n\t" 227 "addi %0, %0, 1\n\t" 228 "1:\t" 229 "add %0, %0, %5\n\t" 230 "bgeu %0, %5, 1f\n\t" 231 "addi %0, %0, 1\n\t" 232 "1:\t" 233 : "=r" (sum), "=&r" (__dummy) 234 : "r" (saddr), "r" (daddr), 235 "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) 236 : "memory"); 237 238 return csum_fold(sum); 239 } 240 241 /* 242 * Copy and checksum to user 243 */ 244 #define HAVE_CSUM_COPY_USER 245 static __inline__ __wsum csum_and_copy_to_user(const void *src, 246 void __user *dst, int len, 247 __wsum sum, int *err_ptr) 248 { 249 if (access_ok(dst, len)) 250 return csum_partial_copy_generic(src,dst,len,sum,NULL,err_ptr); 251 252 if (len) 253 *err_ptr = -EFAULT; 254 255 return (__force __wsum)-1; /* invalid checksum */ 256 } 257 #endif 258