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 <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 | */ |
22 | static 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 | */ |
45 | static 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 | */ |
86 | static inline __wsum |
87 | csum_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 | */ |
112 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
113 | __u32 len, __u8 proto, |
114 | __wsum sum) |
115 | { |
116 | return csum_fold(sum: 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 | */ |
129 | extern __wsum csum_partial(const void *buff, int len, __wsum sum); |
130 | |
131 | /* Do not call this directly. Use the wrappers below */ |
132 | extern __visible __wsum csum_partial_copy_generic(const void *src, void *dst, int len); |
133 | |
134 | extern __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len); |
135 | extern __wsum csum_and_copy_to_user(const void *src, void __user *dst, int len); |
136 | extern __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len); |
137 | |
138 | /** |
139 | * ip_compute_csum - Compute an 16bit IP checksum. |
140 | * @buff: buffer address. |
141 | * @len: length of buffer. |
142 | * |
143 | * Returns the 16bit folded/inverted checksum of the passed buffer. |
144 | * Ready to fill in. |
145 | */ |
146 | extern __sum16 ip_compute_csum(const void *buff, int len); |
147 | |
148 | /** |
149 | * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header. |
150 | * @saddr: source address |
151 | * @daddr: destination address |
152 | * @len: length of packet |
153 | * @proto: protocol of packet |
154 | * @sum: initial sum (32bit unfolded) to be added in |
155 | * |
156 | * Computes an IPv6 pseudo header checksum. This sum is added the checksum |
157 | * into UDP/TCP packets and contains some link layer information. |
158 | * Returns the unfolded 32bit checksum. |
159 | */ |
160 | |
161 | struct in6_addr; |
162 | |
163 | #define _HAVE_ARCH_IPV6_CSUM 1 |
164 | extern __sum16 |
165 | csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, |
166 | __u32 len, __u8 proto, __wsum sum); |
167 | |
168 | static inline unsigned add32_with_carry(unsigned a, unsigned b) |
169 | { |
170 | asm("addl %2,%0\n\t" |
171 | "adcl $0,%0" |
172 | : "=r" (a) |
173 | : "0" (a), "rm" (b)); |
174 | return a; |
175 | } |
176 | |
177 | #define HAVE_ARCH_CSUM_ADD |
178 | static inline __wsum csum_add(__wsum csum, __wsum addend) |
179 | { |
180 | return (__force __wsum)add32_with_carry(a: (__force unsigned)csum, |
181 | b: (__force unsigned)addend); |
182 | } |
183 | |
184 | #endif /* _ASM_X86_CHECKSUM_64_H */ |
185 | |