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1 | #ifndef _X86_64_CHECKSUM_H |
2 | #define _X86_64_CHECKSUM_H | |
3 | ||
4 | /* | |
5 | * Checksums for x86-64 | |
6 | * Copyright 2002 by Andi Kleen, SuSE Labs | |
7 | * with some code from asm-i386/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 unsigned int csum_fold(unsigned int sum) | |
23 | { | |
24 | __asm__( | |
25 | " addl %1,%0\n" | |
26 | " adcl $0xffff,%0" | |
27 | : "=r" (sum) | |
28 | : "r" (sum << 16), "0" (sum & 0xffff0000) | |
29 | ); | |
30 | return (~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 | */ | |
46 | static inline unsigned short ip_fast_csum(unsigned char *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:" | |
2c656491 | 67 | /* Since the input registers which are loaded with iph and ihl |
1da177e4 LT |
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(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 | */ | |
87 | static inline unsigned long | |
88 | csum_tcpudp_nofold(unsigned saddr, unsigned daddr, unsigned short len, | |
89 | unsigned short proto, unsigned int 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), "g" ((ntohs(len)<<16)+proto*256), "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 unsigned short int | |
113 | csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, | |
114 | unsigned short len, unsigned short proto, unsigned int 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 unsigned int csum_partial(const unsigned char *buff, unsigned len, unsigned int 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 unsigned long csum_partial_copy_generic(const unsigned char *src, const unsigned char *dst, | |
137 | unsigned len, | |
138 | unsigned sum, | |
139 | int *src_err_ptr, int *dst_err_ptr); | |
140 | ||
141 | ||
142 | extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src, unsigned char *dst, | |
143 | int len, unsigned int isum, int *errp); | |
144 | extern unsigned int csum_partial_copy_to_user(const unsigned char *src, unsigned char __user *dst, | |
145 | int len, unsigned int isum, int *errp); | |
146 | extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, unsigned char *dst, int len, | |
147 | unsigned int sum); | |
148 | ||
149 | /* Old names. To be removed. */ | |
150 | #define csum_and_copy_to_user csum_partial_copy_to_user | |
151 | #define csum_and_copy_from_user csum_partial_copy_from_user | |
152 | ||
153 | /** | |
154 | * ip_compute_csum - Compute an 16bit IP checksum. | |
155 | * @buff: buffer address. | |
156 | * @len: length of buffer. | |
157 | * | |
158 | * Returns the 16bit folded/inverted checksum of the passed buffer. | |
159 | * Ready to fill in. | |
160 | */ | |
161 | extern unsigned short ip_compute_csum(unsigned char * buff, int len); | |
162 | ||
163 | /** | |
164 | * csum_ipv6_magic - Compute checksum of an IPv6 pseudo header. | |
165 | * @saddr: source address | |
166 | * @daddr: destination address | |
167 | * @len: length of packet | |
168 | * @proto: protocol of packet | |
169 | * @sum: initial sum (32bit unfolded) to be added in | |
170 | * | |
171 | * Computes an IPv6 pseudo header checksum. This sum is added the checksum | |
172 | * into UDP/TCP packets and contains some link layer information. | |
173 | * Returns the unfolded 32bit checksum. | |
174 | */ | |
175 | ||
176 | struct in6_addr; | |
177 | ||
178 | #define _HAVE_ARCH_IPV6_CSUM 1 | |
179 | extern unsigned short | |
180 | csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, | |
181 | __u32 len, unsigned short proto, unsigned int sum); | |
182 | ||
183 | static inline unsigned add32_with_carry(unsigned a, unsigned b) | |
184 | { | |
185 | asm("addl %2,%0\n\t" | |
186 | "adcl $0,%0" | |
187 | : "=r" (a) | |
188 | : "0" (a), "r" (b)); | |
189 | return a; | |
190 | } | |
191 | ||
192 | #endif | |
193 |