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1 | /* SPDX-License-Identifier: GPL-2.0 */ |
---|---|
2 | #ifndef __ASM_SH_CHECKSUM_H |
3 | #define __ASM_SH_CHECKSUM_H |
4 | |
5 | /* |
6 | * Copyright (C) 1999 by Kaz Kojima & Niibe Yutaka |
7 | */ |
8 | |
9 | #include <linux/in6.h> |
10 | #include <linux/uaccess.h> |
11 | |
12 | /* |
13 | * computes the checksum of a memory block at buff, length len, |
14 | * and adds in "sum" (32-bit) |
15 | * |
16 | * returns a 32-bit number suitable for feeding into itself |
17 | * or csum_tcpudp_magic |
18 | * |
19 | * this function must be called with even lengths, except |
20 | * for the last fragment, which may be odd |
21 | * |
22 | * it's best to have buff aligned on a 32-bit boundary |
23 | */ |
24 | asmlinkage __wsum csum_partial(const void *buff, int len, __wsum sum); |
25 | |
26 | /* |
27 | * the same as csum_partial, but copies from src while it |
28 | * checksums, and handles user-space pointer exceptions correctly, when needed. |
29 | * |
30 | * here even more important to align src and dst on a 32-bit (or even |
31 | * better 64-bit) boundary |
32 | */ |
33 | |
34 | asmlinkage __wsum csum_partial_copy_generic(const void *src, void *dst, int len); |
35 | |
36 | #define _HAVE_ARCH_CSUM_AND_COPY |
37 | /* |
38 | * Note: when you get a NULL pointer exception here this means someone |
39 | * passed in an incorrect kernel address to one of these functions. |
40 | * |
41 | * If you use these functions directly please don't forget the |
42 | * access_ok(). |
43 | */ |
44 | static inline |
45 | __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len) |
46 | { |
47 | return csum_partial_copy_generic(src, dst, len); |
48 | } |
49 | |
50 | #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER |
51 | static inline |
52 | __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len) |
53 | { |
54 | if (!access_ok(src, len)) |
55 | return 0; |
56 | return csum_partial_copy_generic((__force const void *)src, dst, len); |
57 | } |
58 | |
59 | /* |
60 | * Fold a partial checksum |
61 | */ |
62 | |
63 | static inline __sum16 csum_fold(__wsum sum) |
64 | { |
65 | unsigned int __dummy; |
66 | __asm__("swap.w %0, %1\n\t" |
67 | "extu.w %0, %0\n\t" |
68 | "extu.w %1, %1\n\t" |
69 | "add %1, %0\n\t" |
70 | "swap.w %0, %1\n\t" |
71 | "add %1, %0\n\t" |
72 | "not %0, %0\n\t" |
73 | : "=r" (sum), "=&r" (__dummy) |
74 | : "0" (sum) |
75 | : "t"); |
76 | return (__force __sum16)sum; |
77 | } |
78 | |
79 | /* |
80 | * This is a version of ip_compute_csum() optimized for IP headers, |
81 | * which always checksum on 4 octet boundaries. |
82 | * |
83 | * i386 version by Jorge Cwik <jorge@laser.satlink.net>, adapted |
84 | * for linux by * Arnt Gulbrandsen. |
85 | */ |
86 | static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl) |
87 | { |
88 | __wsum sum; |
89 | unsigned int __dummy0, __dummy1; |
90 | |
91 | __asm__ __volatile__( |
92 | "mov.l @%1+, %0\n\t" |
93 | "mov.l @%1+, %3\n\t" |
94 | "add #-2, %2\n\t" |
95 | "clrt\n\t" |
96 | "1:\t" |
97 | "addc %3, %0\n\t" |
98 | "movt %4\n\t" |
99 | "mov.l @%1+, %3\n\t" |
100 | "dt %2\n\t" |
101 | "bf/s 1b\n\t" |
102 | " cmp/eq #1, %4\n\t" |
103 | "addc %3, %0\n\t" |
104 | "addc %2, %0" /* Here %2 is 0, add carry-bit */ |
105 | /* Since the input registers which are loaded with iph and ihl |
106 | are modified, we must also specify them as outputs, or gcc |
107 | will assume they contain their original values. */ |
108 | : "=r" (sum), "=r" (iph), "=r" (ihl), "=&r" (__dummy0), "=&z" (__dummy1) |
109 | : "1" (iph), "2" (ihl) |
110 | : "t", "memory"); |
111 | |
112 | return csum_fold(sum); |
113 | } |
114 | |
115 | static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, |
116 | __u32 len, __u8 proto, |
117 | __wsum sum) |
118 | { |
119 | #ifdef __LITTLE_ENDIAN__ |
120 | unsigned long len_proto = (proto + len) << 8; |
121 | #else |
122 | unsigned long len_proto = proto + len; |
123 | #endif |
124 | __asm__("clrt\n\t" |
125 | "addc %0, %1\n\t" |
126 | "addc %2, %1\n\t" |
127 | "addc %3, %1\n\t" |
128 | "movt %0\n\t" |
129 | "add %1, %0" |
130 | : "=r" (sum), "=r" (len_proto) |
131 | : "r" (daddr), "r" (saddr), "1" (len_proto), "0" (sum) |
132 | : "t"); |
133 | |
134 | return sum; |
135 | } |
136 | |
137 | /* |
138 | * computes the checksum of the TCP/UDP pseudo-header |
139 | * returns a 16-bit checksum, already complemented |
140 | */ |
141 | static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, |
142 | __u32 len, __u8 proto, |
143 | __wsum sum) |
144 | { |
145 | return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum)); |
146 | } |
147 | |
148 | /* |
149 | * this routine is used for miscellaneous IP-like checksums, mainly |
150 | * in icmp.c |
151 | */ |
152 | static inline __sum16 ip_compute_csum(const void *buff, int len) |
153 | { |
154 | return csum_fold(csum_partial(buff, len, 0)); |
155 | } |
156 | |
157 | #define _HAVE_ARCH_IPV6_CSUM |
158 | static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr, |
159 | const struct in6_addr *daddr, |
160 | __u32 len, __u8 proto, __wsum sum) |
161 | { |
162 | unsigned int __dummy; |
163 | __asm__("clrt\n\t" |
164 | "mov.l @(0,%2), %1\n\t" |
165 | "addc %1, %0\n\t" |
166 | "mov.l @(4,%2), %1\n\t" |
167 | "addc %1, %0\n\t" |
168 | "mov.l @(8,%2), %1\n\t" |
169 | "addc %1, %0\n\t" |
170 | "mov.l @(12,%2), %1\n\t" |
171 | "addc %1, %0\n\t" |
172 | "mov.l @(0,%3), %1\n\t" |
173 | "addc %1, %0\n\t" |
174 | "mov.l @(4,%3), %1\n\t" |
175 | "addc %1, %0\n\t" |
176 | "mov.l @(8,%3), %1\n\t" |
177 | "addc %1, %0\n\t" |
178 | "mov.l @(12,%3), %1\n\t" |
179 | "addc %1, %0\n\t" |
180 | "addc %4, %0\n\t" |
181 | "addc %5, %0\n\t" |
182 | "movt %1\n\t" |
183 | "add %1, %0\n" |
184 | : "=r" (sum), "=&r" (__dummy) |
185 | : "r" (saddr), "r" (daddr), |
186 | "r" (htonl(len)), "r" (htonl(proto)), "0" (sum) |
187 | : "t"); |
188 | |
189 | return csum_fold(sum); |
190 | } |
191 | |
192 | /* |
193 | * Copy and checksum to user |
194 | */ |
195 | #define HAVE_CSUM_COPY_USER |
196 | static inline __wsum csum_and_copy_to_user(const void *src, |
197 | void __user *dst, |
198 | int len) |
199 | { |
200 | if (!access_ok(dst, len)) |
201 | return 0; |
202 | return csum_partial_copy_generic(src, (__force void *)dst, len); |
203 | } |
204 | #endif /* __ASM_SH_CHECKSUM_H */ |
205 |
Warning: This file is not a C or C++ file. It does not have highlighting.