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 __wsum csum_partial(const void *buff, int len, __wsum 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 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum 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 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  37                                                 int len, __wsum sum, int *csum_err);
  38
  39 __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
  40
  41
  42 /*
  43  *      Fold a partial checksum
  44  */
  45
  46 static inline __sum16 csum_fold(__wsum sum)
  47 {
  48         __asm__("mov.l %0,er0\n\t"
  49                 "add.w e0,r0\n\t"
  50                 "xor.w e0,e0\n\t"
  51                 "rotxl.w e0\n\t"
  52                 "add.w e0,r0\n\t"
  53                 "sub.w e0,e0\n\t"
  54                 "mov.l er0,%0"
  55                 : "=r"(sum)
  56                 : "0"(sum)
  57                 : "er0");
  58         return (__force __sum16)~sum;
  59 }
  60
  61
  62 /*
  63  * computes the checksum of the TCP/UDP pseudo-header
  64  * returns a 16-bit checksum, already complemented
  65  */
  66
  67 static inline __wsum
  68 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
  69                   unsigned short proto, __wsum sum)
  70 {
  71         __asm__ ("sub.l er0,er0\n\t"
  72                  "add.l %2,%0\n\t"
  73                  "addx  #0,r0l\n\t"
  74                  "add.l %3,%0\n\t"
  75                  "addx  #0,r0l\n\t"
  76                  "add.l %4,%0\n\t"
  77                  "addx  #0,r0l\n\t"
  78                  "add.l er0,%0\n\t"
  79                  "bcc   1f\n\t"
  80                  "inc.l #1,%0\n"
  81                  "1:"
  82                  : "=&r" (sum)
  83                  : "0" (sum), "r" (daddr), "r" (saddr), "r" (len + proto)
  84                  :"er0");
  85         return sum;
  86 }
  87
  88 static inline __sum16
  89 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
  90                   unsigned short proto, __wsum sum)
  91 {
  92         return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  93 }
  94
  95 /*
  96  * this routine is used for miscellaneous IP-like checksums, mainly
  97  * in icmp.c
  98  */
  99
 100 extern __sum16 ip_compute_csum(const void *buff, int len);
 101
 102 #endif /* _H8300_CHECKSUM_H */