linux / linux / kernel / git / gregkh / tty / refs/tags/v2.6.19-rc3 / . / include / asm-m68k / checksum.h

#ifndef _M68K_CHECKSUM_H | |

#define _M68K_CHECKSUM_H | |

#include <linux/in6.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 | |

*/ | |

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

unsigned char *dst, | |

int len, int sum, | |

int *csum_err); | |

extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, | |

unsigned char *dst, int len, | |

int sum); | |

/* | |

* This is a version of ip_compute_csum() optimized for IP headers, | |

* which always checksum on 4 octet boundaries. | |

* | |

*/ | |

static inline unsigned short | |

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

{ | |

unsigned int sum = 0; | |

unsigned long tmp; | |

__asm__ ("subqw #1,%2\n" | |

"1:\t" | |

"movel %1@+,%3\n\t" | |

"addxl %3,%0\n\t" | |

"dbra %2,1b\n\t" | |

"movel %0,%3\n\t" | |

"swap %3\n\t" | |

"addxw %3,%0\n\t" | |

"clrw %3\n\t" | |

"addxw %3,%0\n\t" | |

: "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp) | |

: "0" (sum), "1" (iph), "2" (ihl) | |

: "memory"); | |

return ~sum; | |

} | |

/* | |

* Fold a partial checksum | |

*/ | |

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

{ | |

unsigned int tmp = sum; | |

__asm__("swap %1\n\t" | |

"addw %1, %0\n\t" | |

"clrw %1\n\t" | |

"addxw %1, %0" | |

: "=&d" (sum), "=&d" (tmp) | |

: "0" (sum), "1" (tmp)); | |

return ~sum; | |

} | |

static inline unsigned int | |

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

unsigned short proto, unsigned int sum) | |

{ | |

__asm__ ("addl %2,%0\n\t" | |

"addxl %3,%0\n\t" | |

"addxl %4,%0\n\t" | |

"clrl %1\n\t" | |

"addxl %1,%0" | |

: "=&d" (sum), "=d" (saddr) | |

: "g" (daddr), "1" (saddr), "d" (len + proto), | |

"0" (sum)); | |

return sum; | |

} | |

/* | |

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

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

*/ | |

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 | |

*/ | |

static inline unsigned short | |

ip_compute_csum(unsigned char * buff, int len) | |

{ | |

return csum_fold (csum_partial(buff, len, 0)); | |

} | |

#define _HAVE_ARCH_IPV6_CSUM | |

static __inline__ unsigned short int | |

csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, | |

__u32 len, unsigned short proto, unsigned int sum) | |

{ | |

register unsigned long tmp; | |

__asm__("addl %2@,%0\n\t" | |

"movel %2@(4),%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %2@(8),%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %2@(12),%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %3@,%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %3@(4),%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %3@(8),%1\n\t" | |

"addxl %1,%0\n\t" | |

"movel %3@(12),%1\n\t" | |

"addxl %1,%0\n\t" | |

"addxl %4,%0\n\t" | |

"clrl %1\n\t" | |

"addxl %1,%0" | |

: "=&d" (sum), "=&d" (tmp) | |

: "a" (saddr), "a" (daddr), "d" (len + proto), | |

"0" (sum)); | |

return csum_fold(sum); | |

} | |

#endif /* _M68K_CHECKSUM_H */ |