Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/include/asm-arm/checksum.h | |
3 | * | |
4 | * IP checksum routines | |
5 | * | |
6 | * Copyright (C) Original authors of ../asm-i386/checksum.h | |
7 | * Copyright (C) 1996-1999 Russell King | |
8 | */ | |
9 | #ifndef __ASM_ARM_CHECKSUM_H | |
10 | #define __ASM_ARM_CHECKSUM_H | |
11 | ||
12 | #include <linux/in6.h> | |
13 | ||
14 | /* | |
15 | * computes the checksum of a memory block at buff, length len, | |
16 | * and adds in "sum" (32-bit) | |
17 | * | |
18 | * returns a 32-bit number suitable for feeding into itself | |
19 | * or csum_tcpudp_magic | |
20 | * | |
21 | * this function must be called with even lengths, except | |
22 | * for the last fragment, which may be odd | |
23 | * | |
24 | * it's best to have buff aligned on a 32-bit boundary | |
25 | */ | |
eb5a9658 | 26 | __wsum csum_partial(const void *buff, int len, __wsum sum); |
1da177e4 LT |
27 | |
28 | /* | |
29 | * the same as csum_partial, but copies from src while it | |
30 | * checksums, and handles user-space pointer exceptions correctly, when needed. | |
31 | * | |
32 | * here even more important to align src and dst on a 32-bit (or even | |
33 | * better 64-bit) boundary | |
34 | */ | |
35 | ||
eb5a9658 AV |
36 | __wsum |
37 | csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum); | |
1da177e4 | 38 | |
eb5a9658 AV |
39 | __wsum |
40 | csum_partial_copy_from_user(const void __user *src, void *dst, int len, __wsum sum, int *err_ptr); | |
1da177e4 | 41 | |
7ef416c4 RK |
42 | /* |
43 | * Fold a partial checksum without adding pseudo headers | |
44 | */ | |
45 | static inline __sum16 csum_fold(__wsum sum) | |
46 | { | |
47 | __asm__( | |
48 | "add %0, %1, %1, ror #16 @ csum_fold" | |
49 | : "=r" (sum) | |
50 | : "r" (sum) | |
51 | : "cc"); | |
52 | return (__force __sum16)(~(__force u32)sum >> 16); | |
53 | } | |
54 | ||
1da177e4 LT |
55 | /* |
56 | * This is a version of ip_compute_csum() optimized for IP headers, | |
57 | * which always checksum on 4 octet boundaries. | |
58 | */ | |
eb5a9658 AV |
59 | static inline __sum16 |
60 | ip_fast_csum(const void *iph, unsigned int ihl) | |
1da177e4 | 61 | { |
7ef416c4 RK |
62 | unsigned int tmp1; |
63 | __wsum sum; | |
1da177e4 LT |
64 | |
65 | __asm__ __volatile__( | |
66 | "ldr %0, [%1], #4 @ ip_fast_csum \n\ | |
67 | ldr %3, [%1], #4 \n\ | |
68 | sub %2, %2, #5 \n\ | |
69 | adds %0, %0, %3 \n\ | |
70 | ldr %3, [%1], #4 \n\ | |
71 | adcs %0, %0, %3 \n\ | |
72 | ldr %3, [%1], #4 \n\ | |
73 | 1: adcs %0, %0, %3 \n\ | |
74 | ldr %3, [%1], #4 \n\ | |
75 | tst %2, #15 @ do this carefully \n\ | |
76 | subne %2, %2, #1 @ without destroying \n\ | |
77 | bne 1b @ the carry flag \n\ | |
78 | adcs %0, %0, %3 \n\ | |
7ef416c4 | 79 | adc %0, %0, #0" |
1da177e4 LT |
80 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=r" (tmp1) |
81 | : "1" (iph), "2" (ihl) | |
62500d1f | 82 | : "cc", "memory"); |
7ef416c4 | 83 | return csum_fold(sum); |
1da177e4 LT |
84 | } |
85 | ||
eb5a9658 AV |
86 | static inline __wsum |
87 | csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len, | |
88 | unsigned short proto, __wsum sum) | |
1da177e4 LT |
89 | { |
90 | __asm__( | |
91 | "adds %0, %1, %2 @ csum_tcpudp_nofold \n\ | |
eb5a9658 AV |
92 | adcs %0, %0, %3 \n" |
93 | #ifdef __ARMEB__ | |
94 | "adcs %0, %0, %4 \n" | |
95 | #else | |
96 | "adcs %0, %0, %4, lsl #8 \n" | |
97 | #endif | |
98 | "adcs %0, %0, %5 \n\ | |
1da177e4 LT |
99 | adc %0, %0, #0" |
100 | : "=&r"(sum) | |
eb5a9658 | 101 | : "r" (sum), "r" (daddr), "r" (saddr), "r" (len), "Ir" (htons(proto)) |
1da177e4 LT |
102 | : "cc"); |
103 | return sum; | |
104 | } | |
105 | /* | |
106 | * computes the checksum of the TCP/UDP pseudo-header | |
107 | * returns a 16-bit checksum, already complemented | |
108 | */ | |
eb5a9658 AV |
109 | static inline __sum16 |
110 | csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len, | |
111 | unsigned short proto, __wsum sum) | |
1da177e4 | 112 | { |
7ef416c4 | 113 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
1da177e4 LT |
114 | } |
115 | ||
116 | ||
117 | /* | |
118 | * this routine is used for miscellaneous IP-like checksums, mainly | |
119 | * in icmp.c | |
120 | */ | |
eb5a9658 AV |
121 | static inline __sum16 |
122 | ip_compute_csum(const void *buff, int len) | |
1da177e4 LT |
123 | { |
124 | return csum_fold(csum_partial(buff, len, 0)); | |
125 | } | |
126 | ||
127 | #define _HAVE_ARCH_IPV6_CSUM | |
eb5a9658 AV |
128 | extern __wsum |
129 | __csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __be32 len, | |
130 | __be32 proto, __wsum sum); | |
1da177e4 | 131 | |
eb5a9658 AV |
132 | static inline __sum16 |
133 | csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr, __u32 len, | |
134 | unsigned short proto, __wsum sum) | |
1da177e4 LT |
135 | { |
136 | return csum_fold(__csum_ipv6_magic(saddr, daddr, htonl(len), | |
137 | htonl(proto), sum)); | |
138 | } | |
139 | #endif |