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1da177e4 LT |
1 | #ifndef _M68K_CHECKSUM_H |
2 | #define _M68K_CHECKSUM_H | |
3 | ||
4 | #include <linux/in6.h> | |
5 | ||
6 | /* | |
7 | * computes the checksum of a memory block at buff, length len, | |
8 | * and adds in "sum" (32-bit) | |
9 | * | |
10 | * returns a 32-bit number suitable for feeding into itself | |
11 | * or csum_tcpudp_magic | |
12 | * | |
13 | * this function must be called with even lengths, except | |
14 | * for the last fragment, which may be odd | |
15 | * | |
16 | * it's best to have buff aligned on a 32-bit boundary | |
17 | */ | |
18 | unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum); | |
19 | ||
20 | /* | |
21 | * the same as csum_partial, but copies from src while it | |
22 | * checksums | |
23 | * | |
24 | * here even more important to align src and dst on a 32-bit (or even | |
25 | * better 64-bit) boundary | |
26 | */ | |
27 | ||
28 | extern unsigned int csum_partial_copy_from_user(const unsigned char *src, | |
29 | unsigned char *dst, | |
30 | int len, int sum, | |
31 | int *csum_err); | |
32 | ||
33 | extern unsigned int csum_partial_copy_nocheck(const unsigned char *src, | |
34 | unsigned char *dst, int len, | |
35 | int sum); | |
36 | ||
37 | /* | |
38 | * This is a version of ip_compute_csum() optimized for IP headers, | |
39 | * which always checksum on 4 octet boundaries. | |
40 | * | |
41 | */ | |
42 | static inline unsigned short | |
43 | ip_fast_csum(unsigned char *iph, unsigned int ihl) | |
44 | { | |
45 | unsigned int sum = 0; | |
46 | unsigned long tmp; | |
47 | ||
48 | __asm__ ("subqw #1,%2\n" | |
49 | "1:\t" | |
50 | "movel %1@+,%3\n\t" | |
51 | "addxl %3,%0\n\t" | |
52 | "dbra %2,1b\n\t" | |
53 | "movel %0,%3\n\t" | |
54 | "swap %3\n\t" | |
55 | "addxw %3,%0\n\t" | |
56 | "clrw %3\n\t" | |
57 | "addxw %3,%0\n\t" | |
58 | : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp) | |
59 | : "0" (sum), "1" (iph), "2" (ihl) | |
60 | : "memory"); | |
61 | return ~sum; | |
62 | } | |
63 | ||
64 | /* | |
65 | * Fold a partial checksum | |
66 | */ | |
67 | ||
68 | static inline unsigned int csum_fold(unsigned int sum) | |
69 | { | |
70 | unsigned int tmp = sum; | |
71 | __asm__("swap %1\n\t" | |
72 | "addw %1, %0\n\t" | |
73 | "clrw %1\n\t" | |
74 | "addxw %1, %0" | |
75 | : "=&d" (sum), "=&d" (tmp) | |
76 | : "0" (sum), "1" (tmp)); | |
77 | return ~sum; | |
78 | } | |
79 | ||
80 | ||
81 | static inline unsigned int | |
82 | csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len, | |
83 | unsigned short proto, unsigned int sum) | |
84 | { | |
85 | __asm__ ("addl %2,%0\n\t" | |
86 | "addxl %3,%0\n\t" | |
87 | "addxl %4,%0\n\t" | |
88 | "clrl %1\n\t" | |
89 | "addxl %1,%0" | |
90 | : "=&d" (sum), "=d" (saddr) | |
91 | : "g" (daddr), "1" (saddr), "d" (len + proto), | |
92 | "0" (sum)); | |
93 | return sum; | |
94 | } | |
95 | ||
96 | ||
97 | /* | |
98 | * computes the checksum of the TCP/UDP pseudo-header | |
99 | * returns a 16-bit checksum, already complemented | |
100 | */ | |
101 | static inline unsigned short int | |
102 | csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len, | |
103 | unsigned short proto, unsigned int sum) | |
104 | { | |
105 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); | |
106 | } | |
107 | ||
108 | /* | |
109 | * this routine is used for miscellaneous IP-like checksums, mainly | |
110 | * in icmp.c | |
111 | */ | |
112 | ||
113 | static inline unsigned short | |
114 | ip_compute_csum(unsigned char * buff, int len) | |
115 | { | |
116 | return csum_fold (csum_partial(buff, len, 0)); | |
117 | } | |
118 | ||
119 | #define _HAVE_ARCH_IPV6_CSUM | |
120 | static __inline__ unsigned short int | |
121 | csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr, | |
122 | __u32 len, unsigned short proto, unsigned int sum) | |
123 | { | |
124 | register unsigned long tmp; | |
125 | __asm__("addl %2@,%0\n\t" | |
126 | "movel %2@(4),%1\n\t" | |
127 | "addxl %1,%0\n\t" | |
128 | "movel %2@(8),%1\n\t" | |
129 | "addxl %1,%0\n\t" | |
130 | "movel %2@(12),%1\n\t" | |
131 | "addxl %1,%0\n\t" | |
132 | "movel %3@,%1\n\t" | |
133 | "addxl %1,%0\n\t" | |
134 | "movel %3@(4),%1\n\t" | |
135 | "addxl %1,%0\n\t" | |
136 | "movel %3@(8),%1\n\t" | |
137 | "addxl %1,%0\n\t" | |
138 | "movel %3@(12),%1\n\t" | |
139 | "addxl %1,%0\n\t" | |
140 | "addxl %4,%0\n\t" | |
141 | "clrl %1\n\t" | |
142 | "addxl %1,%0" | |
143 | : "=&d" (sum), "=&d" (tmp) | |
144 | : "a" (saddr), "a" (daddr), "d" (len + proto), | |
145 | "0" (sum)); | |
146 | ||
147 | return csum_fold(sum); | |
148 | } | |
149 | ||
150 | #endif /* _M68K_CHECKSUM_H */ |