include/asm-m68knommu/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 __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  29         int len, __wsum sum);
  30
  31
  32 /*
  33  * the same as csum_partial_copy, but copies from user space.
  34  *
  35  * here even more important to align src and dst on a 32-bit (or even
  36  * better 64-bit) boundary
  37  */
  38
  39 extern __wsum csum_partial_copy_from_user(const void __user *src,
  40         void *dst, int len, __wsum sum, int *csum_err);
  41
  42 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  43
  44 /*
  45  *      Fold a partial checksum
  46  */
  47
  48 static inline __sum16 csum_fold(__wsum sum)
  49 {
  50         unsigned int tmp = (__force u32)sum;
  51 #ifdef CONFIG_COLDFIRE
  52         tmp = (tmp & 0xffff) + (tmp >> 16);
  53         tmp = (tmp & 0xffff) + (tmp >> 16);
  54         return (__force __sum16)~tmp;
  55 #else
  56         __asm__("swap %1\n\t"
  57                 "addw %1, %0\n\t"
  58                 "clrw %1\n\t"
  59                 "addxw %1, %0"
  60                 : "=&d" (sum), "=&d" (tmp)
  61                 : "0" (sum), "1" (sum));
  62         return (__force __sum16)~sum;
  63 #endif
  64 }
  65
  66
  67 /*
  68  * computes the checksum of the TCP/UDP pseudo-header
  69  * returns a 16-bit checksum, already complemented
  70  */
  71
  72 static inline __wsum
  73 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
  74                   unsigned short proto, __wsum sum)
  75 {
  76         __asm__ ("addl  %1,%0\n\t"
  77                  "addxl %4,%0\n\t"
  78                  "addxl %5,%0\n\t"
  79                  "clrl %1\n\t"
  80                  "addxl %1,%0"
  81                  : "=&d" (sum), "=&d" (saddr)
  82                  : "0" (daddr), "1" (saddr), "d" (len + proto),
  83                    "d"(sum));
  84         return 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
  99 extern __sum16 ip_compute_csum(const void *buff, int len);
 100
 101 #define _HAVE_ARCH_IPV6_CSUM
 102 static __inline__ __sum16
 103 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
 104                 __u32 len, unsigned short proto, __wsum sum)
 105 {
 106         register unsigned long tmp;
 107         __asm__("addl %2@,%0\n\t"
 108                 "movel %2@(4),%1\n\t"
 109                 "addxl %1,%0\n\t"
 110                 "movel %2@(8),%1\n\t"
 111                 "addxl %1,%0\n\t"
 112                 "movel %2@(12),%1\n\t"
 113                 "addxl %1,%0\n\t"
 114                 "movel %3@,%1\n\t"
 115                 "addxl %1,%0\n\t"
 116                 "movel %3@(4),%1\n\t"
 117                 "addxl %1,%0\n\t"
 118                 "movel %3@(8),%1\n\t"
 119                 "addxl %1,%0\n\t"
 120                 "movel %3@(12),%1\n\t"
 121                 "addxl %1,%0\n\t"
 122                 "addxl %4,%0\n\t"
 123                 "clrl %1\n\t"
 124                 "addxl %1,%0"
 125                 : "=&d" (sum), "=&d" (tmp)
 126                 : "a" (saddr), "a" (daddr), "d" (len + proto),
 127                   "0" (sum));
 128
 129         return csum_fold(sum);
 130 }
 131
 132 #endif /* _M68K_CHECKSUM_H */