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Diffstat (limited to 'arch/x86/include/asm/checksum_64.h')
| -rw-r--r-- | arch/x86/include/asm/checksum_64.h | 185 |
1 files changed, 185 insertions, 0 deletions
diff --git a/arch/x86/include/asm/checksum_64.h b/arch/x86/include/asm/checksum_64.h new file mode 100644 index 000000000..407beebad --- /dev/null +++ b/arch/x86/include/asm/checksum_64.h @@ -0,0 +1,185 @@ +/* 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 */ |