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d95bbcb3 KG |
1 | #ifndef _ASM_POWERPC_CHECKSUM_H |
2 | #define _ASM_POWERPC_CHECKSUM_H | |
1da177e4 LT |
3 | |
4 | /* | |
5 | * This program is free software; you can redistribute it and/or | |
6 | * modify it under the terms of the GNU General Public License | |
7 | * as published by the Free Software Foundation; either version | |
8 | * 2 of the License, or (at your option) any later version. | |
9 | */ | |
10 | ||
11 | /* | |
12 | * This is a version of ip_compute_csum() optimized for IP headers, | |
13 | * which always checksum on 4 octet boundaries. ihl is the number | |
14 | * of 32-bit words and is always >= 5. | |
15 | */ | |
16 | extern unsigned short ip_fast_csum(unsigned char * iph, unsigned int ihl); | |
17 | ||
18 | /* | |
19 | * computes the checksum of the TCP/UDP pseudo-header | |
20 | * returns a 16-bit checksum, already complemented | |
21 | */ | |
22 | extern unsigned short csum_tcpudp_magic(unsigned long saddr, | |
23 | unsigned long daddr, | |
24 | unsigned short len, | |
25 | unsigned short proto, | |
26 | unsigned int sum); | |
27 | ||
28 | /* | |
29 | * computes the checksum of a memory block at buff, length len, | |
30 | * and adds in "sum" (32-bit) | |
31 | * | |
32 | * returns a 32-bit number suitable for feeding into itself | |
33 | * or csum_tcpudp_magic | |
34 | * | |
35 | * this function must be called with even lengths, except | |
36 | * for the last fragment, which may be odd | |
37 | * | |
38 | * it's best to have buff aligned on a 32-bit boundary | |
39 | */ | |
40 | extern unsigned int csum_partial(const unsigned char * buff, int len, | |
41 | unsigned int sum); | |
42 | ||
43 | /* | |
d95bbcb3 KG |
44 | * Computes the checksum of a memory block at src, length len, |
45 | * and adds in "sum" (32-bit), while copying the block to dst. | |
46 | * If an access exception occurs on src or dst, it stores -EFAULT | |
47 | * to *src_err or *dst_err respectively (if that pointer is not | |
48 | * NULL), and, for an error on src, zeroes the rest of dst. | |
49 | * | |
50 | * Like csum_partial, this must be called with even lengths, | |
51 | * except for the last fragment. | |
1da177e4 LT |
52 | */ |
53 | extern unsigned int csum_partial_copy_generic(const char *src, char *dst, | |
54 | int len, unsigned int sum, | |
55 | int *src_err, int *dst_err); | |
56 | /* | |
57 | * the same as csum_partial, but copies from src to dst while it | |
58 | * checksums. | |
59 | */ | |
1da177e4 LT |
60 | unsigned int csum_partial_copy_nocheck(const char *src, |
61 | char *dst, | |
62 | int len, | |
63 | unsigned int sum); | |
64 | ||
d95bbcb3 KG |
65 | #define csum_partial_copy_from_user(src, dst, len, sum, errp) \ |
66 | csum_partial_copy_generic((src), (dst), (len), (sum), (errp), NULL) | |
67 | ||
68 | #define csum_partial_copy_nocheck(src, dst, len, sum) \ | |
69 | csum_partial_copy_generic((src), (dst), (len), (sum), NULL, NULL) | |
70 | ||
71 | ||
1da177e4 LT |
72 | /* |
73 | * turns a 32-bit partial checksum (e.g. from csum_partial) into a | |
74 | * 1's complement 16-bit checksum. | |
75 | */ | |
76 | static inline unsigned int csum_fold(unsigned int sum) | |
77 | { | |
78 | unsigned int tmp; | |
79 | ||
80 | /* swap the two 16-bit halves of sum */ | |
81 | __asm__("rlwinm %0,%1,16,0,31" : "=r" (tmp) : "r" (sum)); | |
82 | /* if there is a carry from adding the two 16-bit halves, | |
83 | it will carry from the lower half into the upper half, | |
84 | giving us the correct sum in the upper half. */ | |
85 | sum = ~(sum + tmp) >> 16; | |
86 | return sum; | |
87 | } | |
88 | ||
89 | /* | |
90 | * this routine is used for miscellaneous IP-like checksums, mainly | |
91 | * in icmp.c | |
92 | */ | |
93 | static inline unsigned short ip_compute_csum(unsigned char * buff, int len) | |
94 | { | |
95 | return csum_fold(csum_partial(buff, len, 0)); | |
96 | } | |
97 | ||
d95bbcb3 | 98 | #ifdef __powerpc64__ |
1da177e4 LT |
99 | static inline u32 csum_tcpudp_nofold(u32 saddr, |
100 | u32 daddr, | |
101 | unsigned short len, | |
102 | unsigned short proto, | |
103 | unsigned int sum) | |
104 | { | |
105 | unsigned long s = sum; | |
106 | ||
107 | s += saddr; | |
108 | s += daddr; | |
109 | s += (proto << 16) + len; | |
110 | s += (s >> 32); | |
111 | return (u32) s; | |
112 | } | |
d95bbcb3 KG |
113 | #else |
114 | static inline unsigned long csum_tcpudp_nofold(unsigned long saddr, | |
115 | unsigned long daddr, | |
116 | unsigned short len, | |
117 | unsigned short proto, | |
118 | unsigned int sum) | |
119 | { | |
120 | __asm__("\n\ | |
121 | addc %0,%0,%1 \n\ | |
122 | adde %0,%0,%2 \n\ | |
123 | adde %0,%0,%3 \n\ | |
124 | addze %0,%0 \n\ | |
125 | " | |
126 | : "=r" (sum) | |
127 | : "r" (daddr), "r"(saddr), "r"((proto<<16)+len), "0"(sum)); | |
128 | return sum; | |
129 | } | |
1da177e4 LT |
130 | |
131 | #endif | |
d95bbcb3 | 132 | #endif |