LXR linux/arch/nios2/include/asm/checksum.h

   1/*
   2 * Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
   3 * Copyright (C) 2004 Microtronix Datacom Ltd.
   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_NIOS_CHECKSUM_H
  11#define _ASM_NIOS_CHECKSUM_H
  12
  13/* Take these from lib/checksum.c */
  14extern __wsum csum_partial(const void *buff, int len, __wsum sum);
  15extern __wsum csum_partial_copy(const void *src, void *dst, int len,
  16                                __wsum sum);
  17extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  18                                        int len, __wsum sum, int *csum_err);
  19#define csum_partial_copy_nocheck(src, dst, len, sum)   \
  20        csum_partial_copy((src), (dst), (len), (sum))
  21
  22extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  23extern __sum16 ip_compute_csum(const void *buff, int len);
  24
  25/*
  26 * Fold a partial checksum
  27 */
  28static inline __sum16 csum_fold(__wsum sum)
  29{
  30        __asm__ __volatile__(
  31                "add    %0, %1, %0\n"
  32                "cmpltu r8, %0, %1\n"
  33                "srli   %0, %0, 16\n"
  34                "add    %0, %0, r8\n"
  35                "nor    %0, %0, %0\n"
  36                : "=r" (sum)
  37                : "r" (sum << 16), "0" (sum)
  38                : "r8");
  39        return (__force __sum16) sum;
  40}
  41
  42/*
  43 * computes the checksum of the TCP/UDP pseudo-header
  44 * returns a 16-bit checksum, already complemented
  45 */
  46#define csum_tcpudp_nofold csum_tcpudp_nofold
  47static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  48                                        __u32 len, __u8 proto,
  49                                        __wsum sum)
  50{
  51        __asm__ __volatile__(
  52                "add    %0, %1, %0\n"
  53                "cmpltu r8, %0, %1\n"
  54                "add    %0, %0, r8\n"   /* add carry */
  55                "add    %0, %2, %0\n"
  56                "cmpltu r8, %0, %2\n"
  57                "add    %0, %0, r8\n"   /* add carry */
  58                "add    %0, %3, %0\n"
  59                "cmpltu r8, %0, %3\n"
  60                "add    %0, %0, r8\n"   /* add carry */
  61                : "=r" (sum), "=r" (saddr)
  62                : "r" (daddr), "r" ((len + proto) << 8),
  63                  "0" (sum),
  64                  "1" (saddr)
  65                : "r8");
  66
  67        return sum;
  68}
  69
  70static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  71                                        __u32 len, __u8 proto,
  72                                        __wsum sum)
  73{
  74        return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
  75}
  76
  77#endif /* _ASM_NIOS_CHECKSUM_H */
  78