Edit File: checksum_64.h
#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 <asm/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); #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1 #define HAVE_CSUM_COPY_USER 1 /* Do not call this directly. Use the wrappers below */ extern __wsum csum_partial_copy_generic(const void *src, const void *dst, int len, __wsum sum, int *src_err_ptr, int *dst_err_ptr); extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum isum, int *errp); extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst, int len, __wsum isum, int *errp); extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum); /* Old names. To be removed. */ #define csum_and_copy_to_user csum_partial_copy_to_user #define csum_and_copy_from_user csum_partial_copy_from_user /** * 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, unsigned short 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 */