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 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int 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 unsigned int csum_partial_copy_from_user(const unsigned char *src,
  29                                                 unsigned char *dst,
  30                                                 int len, int sum,
  31                                                 int *csum_err);
  32
  33 extern unsigned int csum_partial_copy_nocheck(const unsigned char *src,
  34                                               unsigned char *dst, int len,
  35                                               int 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 unsigned short
  43 ip_fast_csum(unsigned char *iph, unsigned int ihl)
  44 {
  45         unsigned int sum = 0;
  46
  47         __asm__ ("subqw #1,%2\n"
  48                  "1:\t"
  49                  "movel %1@+,%/d0\n\t"
  50                  "addxl %/d0,%0\n\t"
  51                  "dbra  %2,1b\n\t"
  52                  "movel %0,%/d0\n\t"
  53                  "swap  %/d0\n\t"
  54                  "addxw %/d0,%0\n\t"
  55                  "clrw  %/d0\n\t"
  56                  "addxw %/d0,%0\n\t"
  57                  : "=d" (sum), "=a" (iph), "=d" (ihl)
  58                  : "0" (sum), "1" (iph), "2" (ihl)
  59                  : "d0");
  60         return ~sum;
  61 }
  62
  63 /*
  64  *      Fold a partial checksum
  65  */
  66
  67 static inline unsigned int csum_fold(unsigned int sum)
  68 {
  69         unsigned int tmp = 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" (sum));
  76         return ~sum;
  77 }
  78
  79
  80 /*
  81  * computes the checksum of the TCP/UDP pseudo-header
  82  * returns a 16-bit checksum, already complemented
  83  */
  84
  85 static inline unsigned int
  86 csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
  87                   unsigned short proto, unsigned int sum)
  88 {
  89         __asm__ ("addl  %1,%0\n\t"
  90                  "addxl %4,%0\n\t"
  91                  "addxl %5,%0\n\t"
  92                  "clrl %1\n\t"
  93                  "addxl %1,%0"
  94                  : "=&d" (sum), "=&d" (saddr)
  95                  : "0" (daddr), "1" (saddr), "d" (len + proto),
  96                    "d"(sum));
  97         return sum;
  98 }
  99
 100 static inline unsigned short int
 101 csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
 102                   unsigned short proto, unsigned int 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 unsigned short
 113 ip_compute_csum(unsigned char * buff, int len)
 114 {
 115         return csum_fold (csum_partial(buff, len, 0));
 116 }
 117
 118 #define _HAVE_ARCH_IPV6_CSUM
 119 static __inline__ unsigned short int
 120 csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
 121                 __u32 len, unsigned short proto, unsigned int sum)
 122 {
 123         register unsigned long tmp;
 124         __asm__("addl %2@,%0\n\t"
 125                 "movel %2@(4),%1\n\t"
 126                 "addxl %1,%0\n\t"
 127                 "movel %2@(8),%1\n\t"
 128                 "addxl %1,%0\n\t"
 129                 "movel %2@(12),%1\n\t"
 130                 "addxl %1,%0\n\t"
 131                 "movel %3@,%1\n\t"
 132                 "addxl %1,%0\n\t"
 133                 "movel %3@(4),%1\n\t"
 134                 "addxl %1,%0\n\t"
 135                 "movel %3@(8),%1\n\t"
 136                 "addxl %1,%0\n\t"
 137                 "movel %3@(12),%1\n\t"
 138                 "addxl %1,%0\n\t"
 139                 "addxl %4,%0\n\t"
 140                 "clrl %1\n\t"
 141                 "addxl %1,%0"
 142                 : "=&d" (sum), "=&d" (tmp)
 143                 : "a" (saddr), "a" (daddr), "d" (len + proto),
 144                   "0" (sum));
 145
 146         return csum_fold(sum);
 147 }
 148
 149 #endif /* _M68K_CHECKSUM_H */