arch/microblaze/include/asm/checksum.h

   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 char *src, char *dst, int len, int sum);
  55
  56 /*
  57  * the same as csum_partial_copy, but copies from user space.
  58  *
  59  * here even more important to align src and dst on a 32-bit (or even
  60  * better 64-bit) boundary
  61  */
  62 extern __wsum csum_partial_copy_from_user(const char *src, char *dst,
  63                                         int len, int sum, int *csum_err);
  64
  65 #define csum_partial_copy_nocheck(src, dst, len, sum)   \
  66         csum_partial_copy((src), (dst), (len), (sum))
  67
  68 /*
  69  *      This is a version of ip_compute_csum() optimized for IP headers,
  70  *      which always checksum on 4 octet boundaries.
  71  *
  72  */
  73 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  74
  75 /*
  76  *      Fold a partial checksum
  77  */
  78 static inline __sum16 csum_fold(unsigned int sum)
  79 {
  80         sum = (sum & 0xffff) + (sum >> 16);
  81         sum = (sum & 0xffff) + (sum >> 16);
  82         return ~sum;
  83 }
  84
  85 static inline __sum16
  86 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
  87                   unsigned short proto, __wsum sum)
  88 {
  89         return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
  90 }
  91
  92 /*
  93  * this routine is used for miscellaneous IP-like checksums, mainly
  94  * in icmp.c
  95  */
  96 extern __sum16 ip_compute_csum(const unsigned char *buff, int len);
  97
  98 #endif /* _ASM_MICROBLAZE_CHECKSUM_H */