1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _M68K_CHECKSUM_H
3 #define _M68K_CHECKSUM_H
4
5 #include <linux/in6.h>
6
7 #ifdef CONFIG_GENERIC_CSUM
8 #include <asm-generic/checksum.h>
9 #else
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 */
23 __wsum csum_partial(const void *buff, int len, __wsum sum);
24
25 /*
26 * the same as csum_partial, but copies from src while it
27 * checksums
28 *
29 * here even more important to align src and dst on a 32-bit (or even
30 * better 64-bit) boundary
31 */
32
33 extern __wsum csum_partial_copy_from_user(const void __user *src,
34 void *dst,
35 int len, __wsum sum,
36 int *csum_err);
37
38 extern __wsum csum_partial_copy_nocheck(const void *src,
39 void *dst, int len,
40 __wsum sum);
41
42 /*
43 * This is a version of ip_fast_csum() optimized for IP headers,
44 * which always checksum on 4 octet boundaries.
45 */
ip_fast_csum(const void * iph,unsigned int ihl)46 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
47 {
48 unsigned int sum = 0;
49 unsigned long tmp;
50
51 __asm__ ("subqw #1,%2\n"
52 "1:\t"
53 "movel %1@+,%3\n\t"
54 "addxl %3,%0\n\t"
55 "dbra %2,1b\n\t"
56 "movel %0,%3\n\t"
57 "swap %3\n\t"
58 "addxw %3,%0\n\t"
59 "clrw %3\n\t"
60 "addxw %3,%0\n\t"
61 : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
62 : "0" (sum), "1" (iph), "2" (ihl)
63 : "memory");
64 return (__force __sum16)~sum;
65 }
66
csum_fold(__wsum sum)67 static inline __sum16 csum_fold(__wsum sum)
68 {
69 unsigned int tmp = (__force u32)sum;
70
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
78 return (__force __sum16)~sum;
79 }
80
81 static inline __wsum
csum_tcpudp_nofold(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)82 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
83 unsigned short proto, __wsum 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 __sum16
csum_tcpudp_magic(__be32 saddr,__be32 daddr,unsigned short len,unsigned short proto,__wsum sum)102 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
103 unsigned short proto, __wsum 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
ip_compute_csum(const void * buff,int len)113 static inline __sum16 ip_compute_csum(const void *buff, int len)
114 {
115 return csum_fold (csum_partial(buff, len, 0));
116 }
117
118 #define _HAVE_ARCH_IPV6_CSUM
119 static __inline__ __sum16
csum_ipv6_magic(const struct in6_addr * saddr,const struct in6_addr * daddr,__u32 len,__u8 proto,__wsum sum)120 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
121 __u32 len, __u8 proto, __wsum sum)
122 {
123 register unsigned long tmp;
124 __asm__("addl %2@,%0\n\t"
125 "movel %2@(4),%1\n\t"
126 "addxl %1,%0\n\t"
127 "movel %2@(8),%1\n\t"
128 "addxl %1,%0\n\t"
129 "movel %2@(12),%1\n\t"
130 "addxl %1,%0\n\t"
131 "movel %3@,%1\n\t"
132 "addxl %1,%0\n\t"
133 "movel %3@(4),%1\n\t"
134 "addxl %1,%0\n\t"
135 "movel %3@(8),%1\n\t"
136 "addxl %1,%0\n\t"
137 "movel %3@(12),%1\n\t"
138 "addxl %1,%0\n\t"
139 "addxl %4,%0\n\t"
140 "clrl %1\n\t"
141 "addxl %1,%0"
142 : "=&d" (sum), "=&d" (tmp)
143 : "a" (saddr), "a" (daddr), "d" (len + proto),
144 "0" (sum));
145
146 return csum_fold(sum);
147 }
148
149 #endif /* CONFIG_GENERIC_CSUM */
150 #endif /* _M68K_CHECKSUM_H */
151