/* TODO: csum_tcpudp_magic could be speeded up, and csum_fold as well */
  
  #ifndef _CRIS_CHECKSUM_H
  #define _CRIS_CHECKSUM_H

  #include <arch/checksum.h>

  
  /*
   * computes the checksum of a memory block at buff, length len,
   * and adds in "sum" (32-bit)
   *
   * returns a 32-bit number suitable for feeding into itself
   * or csum_tcpudp_magic
   *
   * this function must be called with even lengths, except
   * for the last fragment, which may be odd
   *
   * it's best to have buff aligned on a 32-bit boundary
   */

  __wsum csum_partial(const void *buff, int len, __wsum sum);

  
  /*
   * the same as csum_partial, but copies from src while it
   * checksums
   *
   * here even more important to align src and dst on a 32-bit (or even
   * better 64-bit) boundary
   */

  __wsum csum_partial_copy_nocheck(const void *src, void *dst,
  				       int len, __wsum sum);

  
  /*
   *	Fold a partial checksum into a word
   */

  static inline __sum16 csum_fold(__wsum csum)

  {

  	u32 sum = (__force u32)csum;
  	sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
  	sum = (sum & 0xffff) + (sum >> 16); /* add in end-around carry */
  	return (__force __sum16)~sum;

  }

  extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
  						int len, __wsum sum,

  						int *errptr);
  
  /*
   *	This is a version of ip_compute_csum() optimized for IP headers,
   *	which always checksum on 4 octet boundaries.
   *
   */

  static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)

  {
  	return csum_fold(csum_partial(iph, ihl * 4, 0));
  }
   
  /*
   * computes the checksum of the TCP/UDP pseudo-header
   * returns a 16-bit checksum, already complemented
   */

  static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,

  						   unsigned short len,
  						   unsigned short proto,

  						   __wsum sum)

  {
  	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
  }
  
  /*
   * this routine is used for miscellaneous IP-like checksums, mainly
   * in icmp.c
   */

  static inline __sum16 ip_compute_csum(const void *buff, int len)
  {

  	return csum_fold (csum_partial(buff, len, 0));
  }
  
  #endif