include/asm-m68k/checksum.h

   1 #ifndef _M68K_CHECKSUM_H
   2 #define _M68K_CHECKSUM_H
   3
   4 #include <linux/in6.h>
   5
   6 /*
   7  * computes the checksum of a memory block at buff, length len,
   8  * and adds in "sum" (32-bit)
   9  *
  10  * returns a 32-bit number suitable for feeding into itself
  11  * or csum_tcpudp_magic
  12  *
  13  * this function must be called with even lengths, except
  14  * for the last fragment, which may be odd
  15  *
  16  * it's best to have buff aligned on a 32-bit boundary
  17  */
  18 __wsum csum_partial(const void *buff, int len, __wsum sum);
  19
  20 /*
  21  * the same as csum_partial, but copies from src while it
  22  * checksums
  23  *
  24  * here even more important to align src and dst on a 32-bit (or even
  25  * better 64-bit) boundary
  26  */
  27
  28 extern __wsum csum_partial_copy_from_user(const void __user *src,
  29                                                 void *dst,
  30                                                 int len, __wsum sum,
  31                                                 int *csum_err);
  32
  33 extern __wsum csum_partial_copy_nocheck(const void *src,
  34                                               void *dst, int len,
  35                                               __wsum sum);
  36
  37 /*
  38  *      This is a version of ip_compute_csum() optimized for IP headers,
  39  *      which always checksum on 4 octet boundaries.
  40  *
  41  */
  42 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
  43 {
  44         unsigned int sum = 0;
  45         unsigned long tmp;
  46
  47         __asm__ ("subqw #1,%2\n"
  48                  "1:\t"
  49                  "movel %1@+,%3\n\t"
  50                  "addxl %3,%0\n\t"
  51                  "dbra  %2,1b\n\t"
  52                  "movel %0,%3\n\t"
  53                  "swap  %3\n\t"
  54                  "addxw %3,%0\n\t"
  55                  "clrw  %3\n\t"
  56                  "addxw %3,%0\n\t"
  57                  : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
  58                  : "0" (sum), "1" (iph), "2" (ihl)
  59                  : "memory");
  60         return (__force __sum16)~sum;
  61 }
  62
  63 /*
  64  *      Fold a partial checksum
  65  */
  66
  67 static inline __sum16 csum_fold(__wsum sum)
  68 {
  69         unsigned int tmp = (__force u32)sum;
  70         __asm__("swap %1\n\t"
  71                 "addw %1, %0\n\t"
  72                 "clrw %1\n\t"
  73                 "addxw %1, %0"
  74                 : "=&d" (sum), "=&d" (tmp)
  75                 : "0" (sum), "1" (tmp));
  76         return (__force __sum16)~sum;
  77 }
  78
  79
  80 static inline __wsum
  81 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
  82                   unsigned short proto, __wsum sum)
  83 {
  84         __asm__ ("addl  %2,%0\n\t"
  85                  "addxl %3,%0\n\t"
  86                  "addxl %4,%0\n\t"
  87                  "clrl %1\n\t"
  88                  "addxl %1,%0"
  89                  : "=&d" (sum), "=d" (saddr)
  90                  : "g" (daddr), "1" (saddr), "d" (len + proto),
  91                    "0" (sum));
  92         return sum;
  93 }
  94
  95
  96 /*
  97  * computes the checksum of the TCP/UDP pseudo-header
  98  * returns a 16-bit checksum, already complemented
  99  */
 100 static inline __sum16
 101 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
 102                   unsigned short proto, __wsum sum)
 103 {
 104         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
 105 }
 106
 107 /*
 108  * this routine is used for miscellaneous IP-like checksums, mainly
 109  * in icmp.c
 110  */
 111
 112 static inline __sum16 ip_compute_csum(const void *buff, int len)
 113 {
 114         return csum_fold (csum_partial(buff, len, 0));
 115 }
 116
 117 #define _HAVE_ARCH_IPV6_CSUM
 118 static __inline__ __sum16
 119 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
 120                 __u32 len, unsigned short proto, __wsum sum)
 121 {
 122         register unsigned long tmp;
 123         __asm__("addl %2@,%0\n\t"
 124                 "movel %2@(4),%1\n\t"
 125                 "addxl %1,%0\n\t"
 126                 "movel %2@(8),%1\n\t"
 127                 "addxl %1,%0\n\t"
 128                 "movel %2@(12),%1\n\t"
 129                 "addxl %1,%0\n\t"
 130                 "movel %3@,%1\n\t"
 131                 "addxl %1,%0\n\t"
 132                 "movel %3@(4),%1\n\t"
 133                 "addxl %1,%0\n\t"
 134                 "movel %3@(8),%1\n\t"
 135                 "addxl %1,%0\n\t"
 136                 "movel %3@(12),%1\n\t"
 137                 "addxl %1,%0\n\t"
 138                 "addxl %4,%0\n\t"
 139                 "clrl %1\n\t"
 140                 "addxl %1,%0"
 141                 : "=&d" (sum), "=&d" (tmp)
 142                 : "a" (saddr), "a" (daddr), "d" (len + proto),
 143                   "0" (sum));
 144
 145         return csum_fold(sum);
 146 }
 147
 148 #endif /* _M68K_CHECKSUM_H */