1 /* 2 * Copyright (C) 2008 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2006 Atmark Techno, Inc. 4 * 5 * This file is subject to the terms and conditions of the GNU General Public 6 * License. See the file "COPYING" in the main directory of this archive 7 * for more details. 8 */ 9 10 #ifndef _ASM_MICROBLAZE_CHECKSUM_H 11 #define _ASM_MICROBLAZE_CHECKSUM_H 12 13 #include <linux/in6.h> 14 15 /* 16 * computes the checksum of the TCP/UDP pseudo-header 17 * returns a 16-bit checksum, already complemented 18 */ 19 static inline __wsum 20 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, 21 unsigned short proto, __wsum sum) 22 { 23 __asm__("add %0, %0, %1\n\t" 24 "addc %0, %0, %2\n\t" 25 "addc %0, %0, %3\n\t" 26 "addc %0, %0, r0\n\t" 27 : "+&d" (sum) 28 : "d" (saddr), "d" (daddr), "d" (len + proto)); 29 30 return sum; 31 } 32 33 /* 34 * computes the checksum of a memory block at buff, length len, 35 * and adds in "sum" (32-bit) 36 * 37 * returns a 32-bit number suitable for feeding into itself 38 * or csum_tcpudp_magic 39 * 40 * this function must be called with even lengths, except 41 * for the last fragment, which may be odd 42 * 43 * it's best to have buff aligned on a 32-bit boundary 44 */ 45 extern __wsum csum_partial(const void *buff, int len, __wsum sum); 46 47 /* 48 * the same as csum_partial, but copies from src while it 49 * checksums 50 * 51 * here even more important to align src and dst on a 32-bit (or even 52 * better 64-bit) boundary 53 */ 54 extern __wsum csum_partial_copy(const void *src, void *dst, int len, 55 __wsum sum); 56 57 /* 58 * the same as csum_partial_copy, but copies from user space. 59 * 60 * here even more important to align src and dst on a 32-bit (or even 61 * better 64-bit) boundary 62 */ 63 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, 64 int len, __wsum sum, int *csum_err); 65 66 #define csum_partial_copy_nocheck(src, dst, len, sum) \ 67 csum_partial_copy((src), (dst), (len), (sum)) 68 69 /* 70 * This is a version of ip_compute_csum() optimized for IP headers, 71 * which always checksum on 4 octet boundaries. 72 * 73 */ 74 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl); 75 76 /* 77 * Fold a partial checksum 78 */ 79 static inline __sum16 csum_fold(__wsum csum) 80 { 81 u32 sum = (__force u32)csum; 82 sum = (sum & 0xffff) + (sum >> 16); 83 sum = (sum & 0xffff) + (sum >> 16); 84 return (__force __sum16)~sum; 85 } 86 87 static inline __sum16 88 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, 89 unsigned short proto, __wsum sum) 90 { 91 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); 92 } 93 94 /* 95 * this routine is used for miscellaneous IP-like checksums, mainly 96 * in icmp.c 97 */ 98 extern __sum16 ip_compute_csum(const void *buff, int len); 99 100 #endif /* _ASM_MICROBLAZE_CHECKSUM_H */ 101