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 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
34 #define _HAVE_ARCH_CSUM_AND_COPY
35 extern __wsum csum_and_copy_from_user(const void __user *src,
36 						void *dst,
37 						int len);
38 
39 extern __wsum csum_partial_copy_nocheck(const void *src,
40 					      void *dst, int len);
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