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5f97f7f9 HS |
1 | /* |
2 | * Copyright (C) 2004-2006 Atmel Corporation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License version 2 as | |
6 | * published by the Free Software Foundation. | |
7 | */ | |
8 | #ifndef __ASM_AVR32_CHECKSUM_H | |
9 | #define __ASM_AVR32_CHECKSUM_H | |
10 | ||
11 | /* | |
12 | * computes the checksum of a memory block at buff, length len, | |
13 | * and adds in "sum" (32-bit) | |
14 | * | |
15 | * returns a 32-bit number suitable for feeding into itself | |
16 | * or csum_tcpudp_magic | |
17 | * | |
18 | * this function must be called with even lengths, except | |
19 | * for the last fragment, which may be odd | |
20 | * | |
21 | * it's best to have buff aligned on a 32-bit boundary | |
22 | */ | |
475b8f31 | 23 | __wsum csum_partial(const void *buff, int len, __wsum sum); |
5f97f7f9 HS |
24 | |
25 | /* | |
26 | * the same as csum_partial, but copies from src while it | |
27 | * checksums, and handles user-space pointer exceptions correctly, when needed. | |
28 | * | |
29 | * here even more important to align src and dst on a 32-bit (or even | |
30 | * better 64-bit) boundary | |
31 | */ | |
475b8f31 AV |
32 | __wsum csum_partial_copy_generic(const void *src, void *dst, int len, |
33 | __wsum sum, int *src_err_ptr, | |
5f97f7f9 HS |
34 | int *dst_err_ptr); |
35 | ||
36 | /* | |
37 | * Note: when you get a NULL pointer exception here this means someone | |
38 | * passed in an incorrect kernel address to one of these functions. | |
39 | * | |
40 | * If you use these functions directly please don't forget the | |
31321bc9 | 41 | * access_ok(). |
5f97f7f9 HS |
42 | */ |
43 | static inline | |
475b8f31 AV |
44 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, |
45 | int len, __wsum sum) | |
5f97f7f9 HS |
46 | { |
47 | return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL); | |
48 | } | |
49 | ||
50 | static inline | |
475b8f31 AV |
51 | __wsum csum_partial_copy_from_user(const void __user *src, void *dst, |
52 | int len, __wsum sum, int *err_ptr) | |
5f97f7f9 | 53 | { |
475b8f31 | 54 | return csum_partial_copy_generic((const void __force *)src, dst, len, |
5f97f7f9 HS |
55 | sum, err_ptr, NULL); |
56 | } | |
57 | ||
58 | /* | |
59 | * This is a version of ip_compute_csum() optimized for IP headers, | |
60 | * which always checksum on 4 octet boundaries. | |
61 | */ | |
475b8f31 | 62 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
5f97f7f9 HS |
63 | { |
64 | unsigned int sum, tmp; | |
65 | ||
66 | __asm__ __volatile__( | |
67 | " ld.w %0, %1++\n" | |
68 | " ld.w %3, %1++\n" | |
69 | " sub %2, 4\n" | |
70 | " add %0, %3\n" | |
71 | " ld.w %3, %1++\n" | |
72 | " adc %0, %0, %3\n" | |
73 | " ld.w %3, %1++\n" | |
74 | " adc %0, %0, %3\n" | |
75 | " acr %0\n" | |
76 | "1: ld.w %3, %1++\n" | |
77 | " add %0, %3\n" | |
78 | " acr %0\n" | |
79 | " sub %2, 1\n" | |
80 | " brne 1b\n" | |
81 | " lsl %3, %0, 16\n" | |
82 | " andl %0, 0\n" | |
83 | " mov %2, 0xffff\n" | |
84 | " add %0, %3\n" | |
85 | " adc %0, %0, %2\n" | |
86 | " com %0\n" | |
87 | " lsr %0, 16\n" | |
88 | : "=r"(sum), "=r"(iph), "=r"(ihl), "=r"(tmp) | |
89 | : "1"(iph), "2"(ihl) | |
90 | : "memory", "cc"); | |
475b8f31 | 91 | return (__force __sum16)sum; |
5f97f7f9 HS |
92 | } |
93 | ||
94 | /* | |
95 | * Fold a partial checksum | |
96 | */ | |
97 | ||
475b8f31 | 98 | static inline __sum16 csum_fold(__wsum sum) |
5f97f7f9 HS |
99 | { |
100 | unsigned int tmp; | |
101 | ||
102 | asm(" bfextu %1, %0, 0, 16\n" | |
103 | " lsr %0, 16\n" | |
104 | " add %0, %1\n" | |
105 | " bfextu %1, %0, 16, 16\n" | |
106 | " add %0, %1" | |
107 | : "=&r"(sum), "=&r"(tmp) | |
108 | : "0"(sum)); | |
109 | ||
475b8f31 | 110 | return (__force __sum16)~sum; |
5f97f7f9 HS |
111 | } |
112 | ||
475b8f31 | 113 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, |
01cfbad7 AD |
114 | __u32 len, __u8 proto, |
115 | __wsum sum) | |
5f97f7f9 HS |
116 | { |
117 | asm(" add %0, %1\n" | |
118 | " adc %0, %0, %2\n" | |
119 | " adc %0, %0, %3\n" | |
120 | " acr %0" | |
121 | : "=r"(sum) | |
475b8f31 | 122 | : "r"(daddr), "r"(saddr), "r"(len + proto), |
5f97f7f9 HS |
123 | "0"(sum) |
124 | : "cc"); | |
125 | ||
126 | return sum; | |
127 | } | |
128 | ||
129 | /* | |
130 | * computes the checksum of the TCP/UDP pseudo-header | |
131 | * returns a 16-bit checksum, already complemented | |
132 | */ | |
475b8f31 | 133 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
01cfbad7 AD |
134 | __u32 len, __u8 proto, |
135 | __wsum sum) | |
5f97f7f9 HS |
136 | { |
137 | return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum)); | |
138 | } | |
139 | ||
140 | /* | |
141 | * this routine is used for miscellaneous IP-like checksums, mainly | |
142 | * in icmp.c | |
143 | */ | |
144 | ||
475b8f31 | 145 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
5f97f7f9 HS |
146 | { |
147 | return csum_fold(csum_partial(buff, len, 0)); | |
148 | } | |
149 | ||
150 | #endif /* __ASM_AVR32_CHECKSUM_H */ |