include/asm-h8300/checksum.h

   1 #ifndef _H8300_CHECKSUM_H
   2 #define _H8300_CHECKSUM_H
   3
   4 /*
   5  * computes the checksum of a memory block at buff, length len,
   6  * and adds in "sum" (32-bit)
   7  *
   8  * returns a 32-bit number suitable for feeding into itself
   9  * or csum_tcpudp_magic
  10  *
  11  * this function must be called with even lengths, except
  12  * for the last fragment, which may be odd
  13  *
  14  * it's best to have buff aligned on a 32-bit boundary
  15  */
  16 unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
  17
  18 /*
  19  * the same as csum_partial, but copies from src while it
  20  * checksums
  21  *
  22  * here even more important to align src and dst on a 32-bit (or even
  23  * better 64-bit) boundary
  24  */
  25
  26 unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);
  27
  28
  29 /*
  30  * the same as csum_partial_copy, but copies from user space.
  31  *
  32  * here even more important to align src and dst on a 32-bit (or even
  33  * better 64-bit) boundary
  34  */
  35
  36 extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
  37                                                 int len, int sum, int *csum_err);
  38
  39 #define csum_partial_copy_nocheck(src, dst, len, sum)   \
  40         csum_partial_copy((src), (dst), (len), (sum))
  41
  42 unsigned short ip_fast_csum(unsigned char *iph, unsigned int ihl);
  43
  44
  45 /*
  46  *      Fold a partial checksum
  47  */
  48
  49 static inline unsigned int csum_fold(unsigned int sum)
  50 {
  51         __asm__("mov.l %0,er0\n\t"
  52                 "add.w e0,r0\n\t"
  53                 "xor.w e0,e0\n\t"
  54                 "rotxl.w e0\n\t"
  55                 "add.w e0,r0\n\t"
  56                 "sub.w e0,e0\n\t"
  57                 "mov.l er0,%0"
  58                 : "=r"(sum)
  59                 : "0"(sum)
  60                 : "er0");
  61         return ~sum;
  62 }
  63
  64
  65 /*
  66  * computes the checksum of the TCP/UDP pseudo-header
  67  * returns a 16-bit checksum, already complemented
  68  */
  69
  70 static inline unsigned int
  71 csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
  72                   unsigned short proto, unsigned int sum)
  73 {
  74         __asm__ ("sub.l er0,er0\n\t"
  75                  "add.l %2,%0\n\t"
  76                  "addx  #0,r0l\n\t"
  77                  "add.l %3,%0\n\t"
  78                  "addx  #0,r0l\n\t"
  79                  "add.l %4,%0\n\t"
  80                  "addx  #0,r0l\n\t"
  81                  "add.l er0,%0\n\t"
  82                  "bcc   1f\n\t"
  83                  "inc.l #1,%0\n"
  84                  "1:"
  85                  : "=&r" (sum)
  86                  : "0" (sum), "r" (daddr), "r" (saddr), "r" (len + proto)
  87                  :"er0");
  88         return sum;
  89 }
  90
  91 static inline unsigned short int
  92 csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
  93                   unsigned short proto, unsigned int sum)
  94 {
  95         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  96 }
  97
  98 /*
  99  * this routine is used for miscellaneous IP-like checksums, mainly
 100  * in icmp.c
 101  */
 102
 103 extern unsigned short ip_compute_csum(const unsigned char * buff, int len);
 104
 105 #endif /* _H8300_CHECKSUM_H */