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