linux / linux / kernel / git / torvalds / linux / refs/tags/v2.6.25-rc7 / . / include / asm-blackfin / checksum.h

#ifndef _BFIN_CHECKSUM_H | |

#define _BFIN_CHECKSUM_H | |

/* | |

* MODIFIED FOR BFIN April 30, 2001 akbar.hussain@lineo.com | |

* | |

* 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 | |

*/ | |

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 | |

*/ | |

unsigned int csum_partial_copy(const unsigned char *src, unsigned char *dst, | |

int len, int 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 int csum_partial_copy_from_user(const unsigned char *src, | |

unsigned char *dst, int len, | |

int 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 int sum) | |

{ | |

while (sum >> 16) | |

sum = (sum & 0xffff) + (sum >> 16); | |

return ((~(sum << 16)) >> 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) | |

{ | |

__asm__ ("%0 = %0 + %1;\n\t" | |

"CC = AC0;\n\t" | |

"if !CC jump 4;\n\t" | |

"%0 = %0 + %4;\n\t" | |

"%0 = %0 + %2;\n\t" | |

"CC = AC0;\n\t" | |

"if !CC jump 4;\n\t" | |

"%0 = %0 + %4;\n\t" | |

"%0 = %0 + %3;\n\t" | |

"CC = AC0;\n\t" | |

"if !CC jump 4;\n\t" | |

"%0 = %0 + %4;\n\t" | |

"NOP;\n\t" | |

: "=d" (sum) | |

: "d" (daddr), "d" (saddr), "d" ((ntohs(len)<<16)+proto*256), "d" (1), "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 /* _BFIN_CHECKSUM_H */ |