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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 : */
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, unsigned short len,
88 : unsigned short 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 : unsigned short len,
114 : unsigned short proto, __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 : */
129 : extern __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 */
136 : extern __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 :
141 : extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
142 : int len, __wsum isum, int *errp);
143 : extern __wsum csum_partial_copy_to_user(const void *src, void __user *dst,
144 : int len, __wsum isum, int *errp);
145 : extern __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 : */
160 : extern __sum16 ip_compute_csum(const void *buff, int len);
161 1 :
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 :
175 : struct in6_addr;
176 :
177 : #define _HAVE_ARCH_IPV6_CSUM 1
178 : extern __sum16
179 : csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
180 : __u32 len, unsigned short proto, __wsum sum);
181 :
182 : static 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), "r" (b));
188 : return a;
189 : }
190 :
191 : #endif /* _ASM_X86_CHECKSUM_64_H */
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