arch/sh/include/asm/checksum_64.h

   1 #ifndef __ASM_SH_CHECKSUM_64_H
   2 #define __ASM_SH_CHECKSUM_64_H
   3
   4 /*
   5  * include/asm-sh/checksum_64.h
   6  *
   7  * Copyright (C) 2000, 2001  Paolo Alberelli
   8  *
   9  * This file is subject to the terms and conditions of the GNU General Public
  10  * License.  See the file "COPYING" in the main directory of this archive
  11  * for more details.
  12  */
  13
  14 /*
  15  * computes the checksum of a memory block at buff, length len,
  16  * and adds in "sum" (32-bit)
  17  *
  18  * returns a 32-bit number suitable for feeding into itself
  19  * or csum_tcpudp_magic
  20  *
  21  * this function must be called with even lengths, except
  22  * for the last fragment, which may be odd
  23  *
  24  * it's best to have buff aligned on a 32-bit boundary
  25  */
  26 asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum);
  27
  28 /*
  29  *      Note: when you get a NULL pointer exception here this means someone
  30  *      passed in an incorrect kernel address to one of these functions.
  31  *
  32  *      If you use these functions directly please don't forget the
  33  *      access_ok().
  34  */
  35
  36
  37 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len,
  38                                        __wsum sum);
  39
  40 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  41                                          int len, __wsum sum, int *err_ptr);
  42
  43 static inline __sum16 csum_fold(__wsum csum)
  44 {
  45         u32 sum = (__force u32)csum;
  46         sum = (sum & 0xffff) + (sum >> 16);
  47         sum = (sum & 0xffff) + (sum >> 16);
  48         return (__force __sum16)~sum;
  49 }
  50
  51 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  52
  53 __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
  54                                  unsigned short len, unsigned short proto,
  55                                  __wsum sum);
  56
  57 /*
  58  * computes the checksum of the TCP/UDP pseudo-header
  59  * returns a 16-bit checksum, already complemented
  60  */
  61 static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
  62                                                    unsigned short len,
  63                                                    unsigned short proto,
  64                                                    __wsum sum)
  65 {
  66         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  67 }
  68
  69 /*
  70  * this routine is used for miscellaneous IP-like checksums, mainly
  71  * in icmp.c
  72  */
  73 static inline __sum16 ip_compute_csum(const void *buff, int len)
  74 {
  75         return csum_fold(csum_partial(buff, len, 0));
  76 }
  77
  78 #endif /* __ASM_SH_CHECKSUM_64_H */