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/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_CHECKSUM_64_H
#define _ASM_X86_CHECKSUM_64_H
/*
* Checksums for x86-64
* Copyright 2002 by Andi Kleen, SuSE Labs
* with some code from asm-x86/checksum.h
*/
#include <linux/compiler.h>
#include <linux/uaccess.h>
#include <asm/byteorder.h>
/**
* csum_fold - Fold and invert a 32bit checksum.
* sum: 32bit unfolded sum
*
* Fold a 32bit running checksum to 16bit and invert it. This is usually
* the last step before putting a checksum into a packet.
* Make sure not to mix with 64bit checksums.
*/
static inline __sum16 csum_fold(__wsum sum)
{
asm(" addl %1,%0\n"
" adcl $0xffff,%0"
: "=r" (sum)
: "r" ((__force u32)sum << 16),
"0" ((__force u32)sum & 0xffff0000));
return (__force __sum16)(~(__force u32)sum >> 16);
}
/*
* This is a version of ip_compute_csum() optimized for IP headers,
* which always checksum on 4 octet boundaries.
*
* By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
* Arnt Gulbrandsen.
*/
/**
* ip_fast_csum - Compute the IPv4 header checksum efficiently.
* iph: ipv4 header
* ihl: length of header / 4
*/
static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
{
unsigned int sum;
asm(" movl (%1), %0\n"
" subl $4, %2\n"
" jbe 2f\n"
" addl 4(%1), %0\n"
" adcl 8(%1), %0\n"
" adcl 12(%1), %0\n"
"1: adcl 16(%1), %0\n"
" lea 4(%1), %1\n"
" decl %2\n"
" jne 1b\n"
" adcl $0, %0\n"
" movl %0, %2\n"
" shrl $16, %0\n"
" addw %w2, %w0\n"
" adcl $0, %0\n"
" notl %0\n"
"2:"
/* Since the input registers which are loaded with iph and ihl
are modified, we must also specify them as outputs, or gcc
will assume they contain their original values. */
: "=r" (sum), "=r" (iph), "=r" (ihl)
: "1" (iph), "2" (ihl)
: "memory");
return (__force __sum16)sum;
}
/**
* csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: ip protocol of packet
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the pseudo header checksum the input data. Result is
* 32bit unfolded.
*/
static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
__u8 proto, __wsum sum)
{
asm(" addl %1, %0\n"
" adcl %2, %0\n"
" adcl %3, %0\n"
" adcl $0, %0\n"
: "=r" (sum)
: "g" (daddr), "g" (saddr),
"g" ((len + proto)<<8), "0" (sum));
return sum;
}
/**
* csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: ip protocol of packet
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the 16bit pseudo header checksum the input data already
* complemented and ready to be filled in.
*/
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));
}
/**
* csum_partial - Compute an internet checksum.
* @buff: buffer to be checksummed
* @len: length of buffer.
* @sum: initial sum to be added in (32bit unfolded)
*
* Returns the 32bit unfolded internet checksum of the buffer.
* Before filling it in it needs to be csum_fold()'ed.
* buff should be aligned to a 64bit boundary if possible.
*/
extern __wsum csum_partial(const void *buff, int len, __wsum sum);
/* Do not call this directly. Use the wrappers below */
extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
/**
* ip_compute_csum - Compute an 16bit IP checksum.
* @buff: buffer address.
* @len: length of buffer.
*
* Returns the 16bit folded/inverted checksum of the passed buffer.
* Ready to fill in.
*/
extern __sum16 ip_compute_csum(const void *buff, int len);
/**
* csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
* @saddr: source address
* @daddr: destination address
* @len: length of packet
* @proto: protocol of packet
* @sum: initial sum (32bit unfolded) to be added in
*
* Computes an IPv6 pseudo header checksum. This sum is added the checksum
* into UDP/TCP packets and contains some link layer information.
* Returns the unfolded 32bit checksum.
*/
struct in6_addr;
#define _HAVE_ARCH_IPV6_CSUM 1
extern __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
__u32 len, __u8 proto, __wsum sum);
static inline unsigned add32_with_carry(unsigned a, unsigned b)
{
asm("addl %2,%0\n\t"
"adcl $0,%0"
: "=r" (a)
: "0" (a), "rm" (b));
return a;
}
#define HAVE_ARCH_CSUM_ADD
static inline __wsum csum_add(__wsum csum, __wsum addend)
{
return (__force __wsum)add32_with_carry((__force unsigned)csum,
(__force unsigned)addend);
}
#endif /* _ASM_X86_CHECKSUM_64_H */
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