xref: /openbmc/linux/arch/m68k/include/asm/checksum.h (revision 94cdda6b)
1 #ifndef _M68K_CHECKSUM_H
2 #define _M68K_CHECKSUM_H
3 
4 #include <linux/in6.h>
5 
6 #ifdef CONFIG_GENERIC_CSUM
7 #include <asm-generic/checksum.h>
8 #else
9 
10 /*
11  * computes the checksum of a memory block at buff, length len,
12  * and adds in "sum" (32-bit)
13  *
14  * returns a 32-bit number suitable for feeding into itself
15  * or csum_tcpudp_magic
16  *
17  * this function must be called with even lengths, except
18  * for the last fragment, which may be odd
19  *
20  * it's best to have buff aligned on a 32-bit boundary
21  */
22 __wsum csum_partial(const void *buff, int len, __wsum sum);
23 
24 /*
25  * the same as csum_partial, but copies from src while it
26  * checksums
27  *
28  * here even more important to align src and dst on a 32-bit (or even
29  * better 64-bit) boundary
30  */
31 
32 extern __wsum csum_partial_copy_from_user(const void __user *src,
33 						void *dst,
34 						int len, __wsum sum,
35 						int *csum_err);
36 
37 extern __wsum csum_partial_copy_nocheck(const void *src,
38 					      void *dst, int len,
39 					      __wsum sum);
40 
41 /*
42  *	This is a version of ip_fast_csum() optimized for IP headers,
43  *	which always checksum on 4 octet boundaries.
44  */
45 static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
46 {
47 	unsigned int sum = 0;
48 	unsigned long tmp;
49 
50 	__asm__ ("subqw #1,%2\n"
51 		 "1:\t"
52 		 "movel %1@+,%3\n\t"
53 		 "addxl %3,%0\n\t"
54 		 "dbra  %2,1b\n\t"
55 		 "movel %0,%3\n\t"
56 		 "swap  %3\n\t"
57 		 "addxw %3,%0\n\t"
58 		 "clrw  %3\n\t"
59 		 "addxw %3,%0\n\t"
60 		 : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
61 		 : "0" (sum), "1" (iph), "2" (ihl)
62 		 : "memory");
63 	return (__force __sum16)~sum;
64 }
65 
66 static inline __sum16 csum_fold(__wsum sum)
67 {
68 	unsigned int tmp = (__force u32)sum;
69 
70 	__asm__("swap %1\n\t"
71 		"addw %1, %0\n\t"
72 		"clrw %1\n\t"
73 		"addxw %1, %0"
74 		: "=&d" (sum), "=&d" (tmp)
75 		: "0" (sum), "1" (tmp));
76 
77 	return (__force __sum16)~sum;
78 }
79 
80 static inline __wsum
81 csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
82 		  unsigned short proto, __wsum sum)
83 {
84 	__asm__ ("addl  %2,%0\n\t"
85 		 "addxl %3,%0\n\t"
86 		 "addxl %4,%0\n\t"
87 		 "clrl %1\n\t"
88 		 "addxl %1,%0"
89 		 : "=&d" (sum), "=d" (saddr)
90 		 : "g" (daddr), "1" (saddr), "d" (len + proto),
91 		   "0" (sum));
92 	return sum;
93 }
94 
95 
96 /*
97  * computes the checksum of the TCP/UDP pseudo-header
98  * returns a 16-bit checksum, already complemented
99  */
100 static inline __sum16
101 csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
102 		  unsigned short proto, __wsum sum)
103 {
104 	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
105 }
106 
107 /*
108  * this routine is used for miscellaneous IP-like checksums, mainly
109  * in icmp.c
110  */
111 
112 static inline __sum16 ip_compute_csum(const void *buff, int len)
113 {
114 	return csum_fold (csum_partial(buff, len, 0));
115 }
116 
117 #define _HAVE_ARCH_IPV6_CSUM
118 static __inline__ __sum16
119 csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
120 		__u32 len, unsigned short proto, __wsum sum)
121 {
122 	register unsigned long tmp;
123 	__asm__("addl %2@,%0\n\t"
124 		"movel %2@(4),%1\n\t"
125 		"addxl %1,%0\n\t"
126 		"movel %2@(8),%1\n\t"
127 		"addxl %1,%0\n\t"
128 		"movel %2@(12),%1\n\t"
129 		"addxl %1,%0\n\t"
130 		"movel %3@,%1\n\t"
131 		"addxl %1,%0\n\t"
132 		"movel %3@(4),%1\n\t"
133 		"addxl %1,%0\n\t"
134 		"movel %3@(8),%1\n\t"
135 		"addxl %1,%0\n\t"
136 		"movel %3@(12),%1\n\t"
137 		"addxl %1,%0\n\t"
138 		"addxl %4,%0\n\t"
139 		"clrl %1\n\t"
140 		"addxl %1,%0"
141 		: "=&d" (sum), "=&d" (tmp)
142 		: "a" (saddr), "a" (daddr), "d" (len + proto),
143 		  "0" (sum));
144 
145 	return csum_fold(sum);
146 }
147 
148 #endif /* CONFIG_GENERIC_CSUM */
149 #endif /* _M68K_CHECKSUM_H */
150