aboutsummaryrefslogtreecommitdiffstats
path: root/include/asm-m68k/checksum.h
blob: 17280ef719f561844a67fe4ffe233f108cdd7867 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
#ifndef _M68K_CHECKSUM_H
#define _M68K_CHECKSUM_H

#include <linux/in6.h>

/*
 * computes the checksum of a memory block at buff, length len,
 * and adds in "sum" (32-bit)
 *
 * returns a 32-bit number suitable for feeding into itself
 * or csum_tcpudp_magic
 *
 * this function must be called with even lengths, except
 * for the last fragment, which may be odd
 *
 * it's best to have buff aligned on a 32-bit boundary
 */
unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);

/*
 * the same as csum_partial, but copies from src while it
 * checksums
 *
 * here even more important to align src and dst on a 32-bit (or even
 * better 64-bit) boundary
 */

extern unsigned int csum_partial_copy_from_user(const unsigned char __user *src,
						unsigned char *dst,
						int len, int sum,
						int *csum_err);

extern unsigned int csum_partial_copy_nocheck(const unsigned char *src,
					      unsigned char *dst, int len,
					      int sum);

/*
 *	This is a version of ip_compute_csum() optimized for IP headers,
 *	which always checksum on 4 octet boundaries.
 *
 */
static inline unsigned short
ip_fast_csum(unsigned char *iph, unsigned int ihl)
{
	unsigned int sum = 0;
	unsigned long tmp;

	__asm__ ("subqw #1,%2\n"
		 "1:\t"
		 "movel %1@+,%3\n\t"
		 "addxl %3,%0\n\t"
		 "dbra  %2,1b\n\t"
		 "movel %0,%3\n\t"
		 "swap  %3\n\t"
		 "addxw %3,%0\n\t"
		 "clrw  %3\n\t"
		 "addxw %3,%0\n\t"
		 : "=d" (sum), "=&a" (iph), "=&d" (ihl), "=&d" (tmp)
		 : "0" (sum), "1" (iph), "2" (ihl)
		 : "memory");
	return ~sum;
}

/*
 *	Fold a partial checksum
 */

static inline unsigned int csum_fold(unsigned int sum)
{
	unsigned int tmp = sum;
	__asm__("swap %1\n\t"
		"addw %1, %0\n\t"
		"clrw %1\n\t"
		"addxw %1, %0"
		: "=&d" (sum), "=&d" (tmp)
		: "0" (sum), "1" (tmp));
	return ~sum;
}


static inline unsigned int
csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
		  unsigned short proto, unsigned int sum)
{
	__asm__ ("addl  %2,%0\n\t"
		 "addxl %3,%0\n\t"
		 "addxl %4,%0\n\t"
		 "clrl %1\n\t"
		 "addxl %1,%0"
		 : "=&d" (sum), "=d" (saddr)
		 : "g" (daddr), "1" (saddr), "d" (len + proto),
		   "0" (sum));
	return sum;
}


/*
 * computes the checksum of the TCP/UDP pseudo-header
 * returns a 16-bit checksum, already complemented
 */
static inline unsigned short int
csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
		  unsigned short proto, unsigned int sum)
{
	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
}

/*
 * this routine is used for miscellaneous IP-like checksums, mainly
 * in icmp.c
 */

static inline unsigned short
ip_compute_csum(unsigned char * buff, int len)
{
	return csum_fold (csum_partial(buff, len, 0));
}

#define _HAVE_ARCH_IPV6_CSUM
static __inline__ unsigned short int
csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
		__u32 len, unsigned short proto, unsigned int sum)
{
	register unsigned long tmp;
	__asm__("addl %2@,%0\n\t"
		"movel %2@(4),%1\n\t"
		"addxl %1,%0\n\t"
		"movel %2@(8),%1\n\t"
		"addxl %1,%0\n\t"
		"movel %2@(12),%1\n\t"
		"addxl %1,%0\n\t"
		"movel %3@,%1\n\t"
		"addxl %1,%0\n\t"
		"movel %3@(4),%1\n\t"
		"addxl %1,%0\n\t"
		"movel %3@(8),%1\n\t"
		"addxl %1,%0\n\t"
		"movel %3@(12),%1\n\t"
		"addxl %1,%0\n\t"
		"addxl %4,%0\n\t"
		"clrl %1\n\t"
		"addxl %1,%0"
		: "=&d" (sum), "=&d" (tmp)
		: "a" (saddr), "a" (daddr), "d" (len + proto),
		  "0" (sum));

	return csum_fold(sum);
}

#endif /* _M68K_CHECKSUM_H */