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linux-next/arch/m68k/include/asm/checksum.h
Greg Ungerer 7f73bafc46 m68k: simpler m68k and ColdFire CPU's can use generic csum code
We have two implementations of the IP checksuming code for the m68k arch.
One uses the more advanced instructions available in 68020 and above
processors, the other uses the simpler instructions available on the
original 68000 processors and the modern ColdFire processors.

This simpler code is pretty much the same as the generic lib implementation
of the IP csum functions. So lets just switch over to using that. That
means we can completely remove the checksum_no.c file, and only have the
local fast code used for the more complex 68k CPU family members.

Signed-off-by: Greg Ungerer <gerg@uclinux.org>
2011-12-24 21:47:57 +10:00

150 lines
3.4 KiB
C

#ifndef _M68K_CHECKSUM_H
#define _M68K_CHECKSUM_H
#include <linux/in6.h>
#ifdef CONFIG_GENERIC_CSUM
#include <asm-generic/checksum.h>
#else
/*
* 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
*/
extern __wsum csum_partial_copy_from_user(const void __user *src,
void *dst,
int len, __wsum sum,
int *csum_err);
extern __wsum csum_partial_copy_nocheck(const void *src,
void *dst, int len,
__wsum sum);
/*
* This is a version of ip_fast_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*/
static inline __sum16 ip_fast_csum(const void *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 (__force __sum16)~sum;
}
static inline __sum16 csum_fold(__wsum sum)
{
unsigned int tmp = (__force u32)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 (__force __sum16)~sum;
}
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
unsigned short proto, __wsum 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 __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));
}
#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
__u32 len, unsigned short proto, __wsum 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 /* CONFIG_GENERIC_CSUM */
#endif /* _M68K_CHECKSUM_H */