linux/include/asm-blackfin/checksum.h
Al Viro 45b3947c2d [Blackfin] arch: Blackfin checksum annotations
FSVOtest in this case, since I don't have the hardware...
However, all changes seen by gcc are actually
 - explicit cast to unsigned short in return expression of functions
    returning unsigned short
 - csum_fold() return type changed from unsigned int to __sum16
   (unsigned short), same as for all other architecture and as net/* expects;
   expression actually returned is ((~(sum << 16)) >> 16) with sum being
   unsigned 32bit, so it's (a) going to fit into the range of unsigned short
   and (b) had been unsigned all along, so no sign expansion mess happened.

Tested-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: David Miller <davem@davemloft.net>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
2008-05-12 11:55:10 +08:00

100 lines
2.5 KiB
C

#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
*/
__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(const void *src, void *dst,
int len, __wsum 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 __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
int len, __wsum sum, int *csum_err);
#define csum_partial_copy_nocheck(src, dst, len, sum) \
csum_partial_copy((src), (dst), (len), (sum))
__sum16 ip_fast_csum(unsigned char *iph, unsigned int ihl);
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum 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 __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum 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 __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
*/
extern __sum16 ip_compute_csum(const void *buff, int len);
#endif /* _BFIN_CHECKSUM_H */