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1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_CHECKSUM_64_H
3#define _ASM_X86_CHECKSUM_64_H
4
5/*
6 * Checksums for x86-64
7 * Copyright 2002 by Andi Kleen, SuSE Labs
8 * with some code from asm-x86/checksum.h
9 */
10
11#include <linux/compiler.h>
12#include <linux/uaccess.h>
13#include <asm/byteorder.h>
14
15/**
16 * csum_fold - Fold and invert a 32bit checksum.
17 * sum: 32bit unfolded sum
18 *
19 * Fold a 32bit running checksum to 16bit and invert it. This is usually
20 * the last step before putting a checksum into a packet.
21 * Make sure not to mix with 64bit checksums.
22 */
23static inline __sum16 csum_fold(__wsum sum)
24{
25 asm(" addl %1,%0\n"
26 " adcl $0xffff,%0"
27 : "=r" (sum)
28 : "r" ((__force u32)sum << 16),
29 "0" ((__force u32)sum & 0xffff0000));
30 return (__force __sum16)(~(__force u32)sum >> 16);
31}
32
33/*
34 * This is a version of ip_compute_csum() optimized for IP headers,
35 * which always checksum on 4 octet boundaries.
36 *
37 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
38 * Arnt Gulbrandsen.
39 */
40
41/**
42 * ip_fast_csum - Compute the IPv4 header checksum efficiently.
43 * iph: ipv4 header
44 * ihl: length of header / 4
45 */
46static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
47{
48 unsigned int sum;
49
50 asm(" movl (%1), %0\n"
51 " subl $4, %2\n"
52 " jbe 2f\n"
53 " addl 4(%1), %0\n"
54 " adcl 8(%1), %0\n"
55 " adcl 12(%1), %0\n"
56 "1: adcl 16(%1), %0\n"
57 " lea 4(%1), %1\n"
58 " decl %2\n"
59 " jne 1b\n"
60 " adcl $0, %0\n"
61 " movl %0, %2\n"
62 " shrl $16, %0\n"
63 " addw %w2, %w0\n"
64 " adcl $0, %0\n"
65 " notl %0\n"
66 "2:"
67 /* Since the input registers which are loaded with iph and ihl
68 are modified, we must also specify them as outputs, or gcc
69 will assume they contain their original values. */
70 : "=r" (sum), "=r" (iph), "=r" (ihl)
71 : "1" (iph), "2" (ihl)
72 : "memory");
73 return (__force __sum16)sum;
74}
75
76/**
77 * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
78 * @saddr: source address
79 * @daddr: destination address
80 * @len: length of packet
81 * @proto: ip protocol of packet
82 * @sum: initial sum to be added in (32bit unfolded)
83 *
84 * Returns the pseudo header checksum the input data. Result is
85 * 32bit unfolded.
86 */
87static inline __wsum
88csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
89 __u8 proto, __wsum sum)
90{
91 asm(" addl %1, %0\n"
92 " adcl %2, %0\n"
93 " adcl %3, %0\n"
94 " adcl $0, %0\n"
95 : "=r" (sum)
96 : "g" (daddr), "g" (saddr),
97 "g" ((len + proto)<<8), "0" (sum));
98 return sum;
99}
100
101
102/**
103 * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
104 * @saddr: source address
105 * @daddr: destination address
106 * @len: length of packet
107 * @proto: ip protocol of packet
108 * @sum: initial sum to be added in (32bit unfolded)
109 *
110 * Returns the 16bit pseudo header checksum the input data already
111 * complemented and ready to be filled in.
112 */
113static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
114 __u32 len, __u8 proto,
115 __wsum sum)
116{
117 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
118}
119
120/**
121 * csum_partial - Compute an internet checksum.
122 * @buff: buffer to be checksummed
123 * @len: length of buffer.
124 * @sum: initial sum to be added in (32bit unfolded)
125 *
126 * Returns the 32bit unfolded internet checksum of the buffer.
127 * Before filling it in it needs to be csum_fold()'ed.
128 * buff should be aligned to a 64bit boundary if possible.
129 */
130extern __wsum csum_partial(const void *buff, int len, __wsum sum);
131
132/* Do not call this directly. Use the wrappers below */
133extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len);
134
135extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
136extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len);
137extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
138
139/**
140 * ip_compute_csum - Compute an 16bit IP checksum.
141 * @buff: buffer address.
142 * @len: length of buffer.
143 *
144 * Returns the 16bit folded/inverted checksum of the passed buffer.
145 * Ready to fill in.
146 */
147extern __sum16 ip_compute_csum(const void *buff, int len);
148
149/**
150 * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
151 * @saddr: source address
152 * @daddr: destination address
153 * @len: length of packet
154 * @proto: protocol of packet
155 * @sum: initial sum (32bit unfolded) to be added in
156 *
157 * Computes an IPv6 pseudo header checksum. This sum is added the checksum
158 * into UDP/TCP packets and contains some link layer information.
159 * Returns the unfolded 32bit checksum.
160 */
161
162struct in6_addr;
163
164#define _HAVE_ARCH_IPV6_CSUM 1
165extern __sum16
166csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
167 __u32 len, __u8 proto, __wsum sum);
168
169static inline unsigned add32_with_carry(unsigned a, unsigned b)
170{
171 asm("addl %2,%0\n\t"
172 "adcl $0,%0"
173 : "=r" (a)
174 : "0" (a), "rm" (b));
175 return a;
176}
177
178#define HAVE_ARCH_CSUM_ADD
179static inline __wsum csum_add(__wsum csum, __wsum addend)
180{
181 return (__force __wsum)add32_with_carry((__force unsigned)csum,
182 (__force unsigned)addend);
183}
184
185#endif /* _ASM_X86_CHECKSUM_64_H */
1#ifndef _ASM_X86_CHECKSUM_64_H
2#define _ASM_X86_CHECKSUM_64_H
3
4/*
5 * Checksums for x86-64
6 * Copyright 2002 by Andi Kleen, SuSE Labs
7 * with some code from asm-x86/checksum.h
8 */
9
10#include <linux/compiler.h>
11#include <asm/uaccess.h>
12#include <asm/byteorder.h>
13
14/**
15 * csum_fold - Fold and invert a 32bit checksum.
16 * sum: 32bit unfolded sum
17 *
18 * Fold a 32bit running checksum to 16bit and invert it. This is usually
19 * the last step before putting a checksum into a packet.
20 * Make sure not to mix with 64bit checksums.
21 */
22static inline __sum16 csum_fold(__wsum sum)
23{
24 asm(" addl %1,%0\n"
25 " adcl $0xffff,%0"
26 : "=r" (sum)
27 : "r" ((__force u32)sum << 16),
28 "0" ((__force u32)sum & 0xffff0000));
29 return (__force __sum16)(~(__force u32)sum >> 16);
30}
31
32/*
33 * This is a version of ip_compute_csum() optimized for IP headers,
34 * which always checksum on 4 octet boundaries.
35 *
36 * By Jorge Cwik <jorge@laser.satlink.net>, adapted for linux by
37 * Arnt Gulbrandsen.
38 */
39
40/**
41 * ip_fast_csum - Compute the IPv4 header checksum efficiently.
42 * iph: ipv4 header
43 * ihl: length of header / 4
44 */
45static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
46{
47 unsigned int sum;
48
49 asm(" movl (%1), %0\n"
50 " subl $4, %2\n"
51 " jbe 2f\n"
52 " addl 4(%1), %0\n"
53 " adcl 8(%1), %0\n"
54 " adcl 12(%1), %0\n"
55 "1: adcl 16(%1), %0\n"
56 " lea 4(%1), %1\n"
57 " decl %2\n"
58 " jne 1b\n"
59 " adcl $0, %0\n"
60 " movl %0, %2\n"
61 " shrl $16, %0\n"
62 " addw %w2, %w0\n"
63 " adcl $0, %0\n"
64 " notl %0\n"
65 "2:"
66 /* Since the input registers which are loaded with iph and ihl
67 are modified, we must also specify them as outputs, or gcc
68 will assume they contain their original values. */
69 : "=r" (sum), "=r" (iph), "=r" (ihl)
70 : "1" (iph), "2" (ihl)
71 : "memory");
72 return (__force __sum16)sum;
73}
74
75/**
76 * csum_tcpup_nofold - Compute an IPv4 pseudo header checksum.
77 * @saddr: source address
78 * @daddr: destination address
79 * @len: length of packet
80 * @proto: ip protocol of packet
81 * @sum: initial sum to be added in (32bit unfolded)
82 *
83 * Returns the pseudo header checksum the input data. Result is
84 * 32bit unfolded.
85 */
86static inline __wsum
87csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
88 __u8 proto, __wsum sum)
89{
90 asm(" addl %1, %0\n"
91 " adcl %2, %0\n"
92 " adcl %3, %0\n"
93 " adcl $0, %0\n"
94 : "=r" (sum)
95 : "g" (daddr), "g" (saddr),
96 "g" ((len + proto)<<8), "0" (sum));
97 return sum;
98}
99
100
101/**
102 * csum_tcpup_magic - Compute an IPv4 pseudo header checksum.
103 * @saddr: source address
104 * @daddr: destination address
105 * @len: length of packet
106 * @proto: ip protocol of packet
107 * @sum: initial sum to be added in (32bit unfolded)
108 *
109 * Returns the 16bit pseudo header checksum the input data already
110 * complemented and ready to be filled in.
111 */
112static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
113 __u32 len, __u8 proto,
114 __wsum sum)
115{
116 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
117}
118
119/**
120 * csum_partial - Compute an internet checksum.
121 * @buff: buffer to be checksummed
122 * @len: length of buffer.
123 * @sum: initial sum to be added in (32bit unfolded)
124 *
125 * Returns the 32bit unfolded internet checksum of the buffer.
126 * Before filling it in it needs to be csum_fold()'ed.
127 * buff should be aligned to a 64bit boundary if possible.
128 */
129extern __wsum csum_partial(const void *buff, int len, __wsum sum);
130
131#define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER 1
132#define HAVE_CSUM_COPY_USER 1
133
134
135/* Do not call this directly. Use the wrappers below */
136extern __visible __wsum csum_partial_copy_generic(const void *src, const void *dst,
137 int len, __wsum sum,
138 int *src_err_ptr, int *dst_err_ptr);
139
140
141extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
142 int len, __wsum isum, int *errp);
143extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
144 int len, __wsum isum, int *errp);
145extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
146 int len, __wsum sum);
147
148/* Old names. To be removed. */
149#define csum_and_copy_to_user csum_partial_copy_to_user
150#define csum_and_copy_from_user csum_partial_copy_from_user
151
152/**
153 * ip_compute_csum - Compute an 16bit IP checksum.
154 * @buff: buffer address.
155 * @len: length of buffer.
156 *
157 * Returns the 16bit folded/inverted checksum of the passed buffer.
158 * Ready to fill in.
159 */
160extern __sum16 ip_compute_csum(const void *buff, int len);
161
162/**
163 * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header.
164 * @saddr: source address
165 * @daddr: destination address
166 * @len: length of packet
167 * @proto: protocol of packet
168 * @sum: initial sum (32bit unfolded) to be added in
169 *
170 * Computes an IPv6 pseudo header checksum. This sum is added the checksum
171 * into UDP/TCP packets and contains some link layer information.
172 * Returns the unfolded 32bit checksum.
173 */
174
175struct in6_addr;
176
177#define _HAVE_ARCH_IPV6_CSUM 1
178extern __sum16
179csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
180 __u32 len, __u8 proto, __wsum sum);
181
182static inline unsigned add32_with_carry(unsigned a, unsigned b)
183{
184 asm("addl %2,%0\n\t"
185 "adcl $0,%0"
186 : "=r" (a)
187 : "0" (a), "rm" (b));
188 return a;
189}
190
191#define HAVE_ARCH_CSUM_ADD
192static inline __wsum csum_add(__wsum csum, __wsum addend)
193{
194 return (__force __wsum)add32_with_carry((__force unsigned)csum,
195 (__force unsigned)addend);
196}
197
198#endif /* _ASM_X86_CHECKSUM_64_H */