linux / linux / kernel / git / klassert / ipsec-next / refs/tags/v2.6.16-rc1 / . / include / asm-v850 / checksum.h

/* | |

* include/asm-v850/checksum.h -- Checksum ops | |

* | |

* Copyright (C) 2001,2005 NEC Corporation | |

* Copyright (C) 2001,2005 Miles Bader <miles@gnu.org> | |

* | |

* This file is subject to the terms and conditions of the GNU General | |

* Public License. See the file COPYING in the main directory of this | |

* archive for more details. | |

* | |

* Written by Miles Bader <miles@gnu.org> | |

*/ | |

#ifndef __V850_CHECKSUM_H__ | |

#define __V850_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 | |

*/ | |

extern unsigned int csum_partial (const unsigned char * buff, int len, | |

unsigned int 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 | |

*/ | |

extern unsigned csum_partial_copy (const unsigned char *src, | |

unsigned char *dst, int len, unsigned sum); | |

/* | |

* the same as csum_partial_copy, but copies from user space. | |

* | |

* here even more important to align src and dst on a 32-bit (or even | |

* better 64-bit) boundary | |

*/ | |

extern unsigned csum_partial_copy_from_user (const unsigned char *src, | |

unsigned char *dst, | |

int len, unsigned sum, | |

int *csum_err); | |

#define csum_partial_copy_nocheck(src, dst, len, sum) \ | |

csum_partial_copy ((src), (dst), (len), (sum)) | |

unsigned short ip_fast_csum (unsigned char *iph, unsigned int ihl); | |

/* | |

* Fold a partial checksum | |

*/ | |

static inline unsigned int csum_fold (unsigned long sum) | |

{ | |

unsigned int result; | |

/* | |

%0 %1 | |

hsw %1, %0 H L L H | |

add %1, %0 H L H+L+C H+L | |

*/ | |

asm ("hsw %1, %0; add %1, %0" : "=&r" (result) : "r" (sum)); | |

return (~result) >> 16; | |

} | |

/* | |

* computes the checksum of the TCP/UDP pseudo-header | |

* returns a 16-bit checksum, already complemented | |

*/ | |

static inline unsigned int | |

csum_tcpudp_nofold (unsigned long saddr, unsigned long daddr, | |

unsigned short len, | |

unsigned short proto, unsigned int sum) | |

{ | |

int __carry; | |

__asm__ ("add %2, %0;" | |

"setf c, %1;" | |

"add %1, %0;" | |

"add %3, %0;" | |

"setf c, %1;" | |

"add %1, %0;" | |

"add %4, %0;" | |

"setf c, %1;" | |

"add %1, %0" | |

: "=&r" (sum), "=&r" (__carry) | |

: "r" (daddr), "r" (saddr), | |

"r" (ntohs (len) + (proto << 8)), | |

"0" (sum)); | |

return sum; | |

} | |

static inline unsigned short int | |

csum_tcpudp_magic (unsigned long saddr, unsigned long daddr, | |

unsigned short len, | |

unsigned short proto, unsigned int 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 | |

*/ | |

extern unsigned short ip_compute_csum (const unsigned char * buff, int len); | |

#endif /* __V850_CHECKSUM_H__ */ |