linux/arch/nios2/include/asm/checksum.h
Al Viro 6e41c585e3 unify generic instances of csum_partial_copy_nocheck()
quite a few architectures have the same csum_partial_copy_nocheck() -
simply memcpy() the data and then return the csum of the copy.

hexagon, parisc, ia64, s390, um: explicitly spelled out that way.

arc, arm64, csky, h8300, m68k/nommu, microblaze, mips/GENERIC_CSUM, nds32,
nios2, openrisc, riscv, unicore32: end up picking the same thing spelled
out in lib/checksum.h (with varying amounts of perversions along the way).

everybody else (alpha, arm, c6x, m68k/mmu, mips/!GENERIC_CSUM, powerpc,
sh, sparc, x86, xtensa) have non-generic variants.  For all except c6x
the declaration is in their asm/checksum.h.  c6x uses the wrapper
from asm-generic/checksum.h that would normally lead to the lib/checksum.h
instance, but in case of c6x we end up using an asm function from arch/c6x
instead.

Screw that mess - have architectures with private instances define
_HAVE_ARCH_CSUM_AND_COPY in their asm/checksum.h and have the default
one right in net/checksum.h conditional on _HAVE_ARCH_CSUM_AND_COPY
*not* defined.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-08-20 15:45:14 -04:00

71 lines
1.7 KiB
C

/*
* Copyright (C) 2010 Tobias Klauser <tklauser@distanz.ch>
* Copyright (C) 2004 Microtronix Datacom Ltd.
*
* 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.
*/
#ifndef _ASM_NIOS_CHECKSUM_H
#define _ASM_NIOS_CHECKSUM_H
/* Take these from lib/checksum.c */
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
extern __sum16 ip_compute_csum(const void *buff, int len);
/*
* Fold a partial checksum
*/
static inline __sum16 csum_fold(__wsum sum)
{
__asm__ __volatile__(
"add %0, %1, %0\n"
"cmpltu r8, %0, %1\n"
"srli %0, %0, 16\n"
"add %0, %0, r8\n"
"nor %0, %0, %0\n"
: "=r" (sum)
: "r" (sum << 16), "0" (sum)
: "r8");
return (__force __sum16) sum;
}
/*
* computes the checksum of the TCP/UDP pseudo-header
* returns a 16-bit checksum, already complemented
*/
#define csum_tcpudp_nofold csum_tcpudp_nofold
static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
__asm__ __volatile__(
"add %0, %1, %0\n"
"cmpltu r8, %0, %1\n"
"add %0, %0, r8\n" /* add carry */
"add %0, %2, %0\n"
"cmpltu r8, %0, %2\n"
"add %0, %0, r8\n" /* add carry */
"add %0, %3, %0\n"
"cmpltu r8, %0, %3\n"
"add %0, %0, r8\n" /* add carry */
: "=r" (sum), "=r" (saddr)
: "r" (daddr), "r" ((len + proto) << 8),
"0" (sum),
"1" (saddr)
: "r8");
return sum;
}
static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
__u32 len, __u8 proto,
__wsum sum)
{
return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
}
#endif /* _ASM_NIOS_CHECKSUM_H */