aboutsummaryrefslogtreecommitdiffstats
path: root/arch/m68k/include/asm/checksum.h
blob: ec514485c8b6557bc18804c8f53589d4ed6eaefe (plain)
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
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
#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
 */
__wsum csum_partial(const void *buff, int len, __wsum 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 __wsum csum_partial_copy_from_user(const void __user *src,
						void *dst,
						int len, __wsum sum,
						int *csum_err);

extern __wsum csum_partial_copy_nocheck(const void *src,
					      void *dst, int len,
					      __wsum sum);


#ifdef CONFIG_COLDFIRE

/*
 *	The ColdFire cores don't support all the 68k instructions used
 *	in the optimized checksum code below. So it reverts back to using
 *	more standard C coded checksums. The fast checksum code is
 *	significantly larger than the optimized version, so it is not
 *	inlined here.
 */
__sum16 ip_fast_csum(const void *iph, unsigned int ihl);

static inline __sum16 csum_fold(__wsum sum)
{
	unsigned int tmp = (__force u32)sum;

	tmp = (tmp & 0xffff) + (tmp >> 16);
	tmp = (tmp & 0xffff) + (tmp >> 16);

	return (__force __sum16)~tmp;
}

#else

/*
 *	This is a version of ip_fast_csum() optimized for IP headers,
 *	which always checksum on 4 octet boundaries.
 */
static inline __sum16 ip_fast_csum(const void *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 (__force __sum16)~sum;
}

static inline __sum16 csum_fold(__wsum sum)
{
	unsigned int tmp = (__force u32)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 (__force __sum16)~sum;
}

#endif /* CONFIG_COLDFIRE */

static inline __wsum
csum_tcpudp_nofold(__be32 saddr, __be32 daddr, unsigned short len,
		  unsigned short proto, __wsum 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 __sum16
csum_tcpudp_magic(__be32 saddr, __be32 daddr, unsigned short len,
		  unsigned short proto, __wsum 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 __sum16 ip_compute_csum(const void *buff, int len)
{
	return csum_fold (csum_partial(buff, len, 0));
}

#define _HAVE_ARCH_IPV6_CSUM
static __inline__ __sum16
csum_ipv6_magic(const struct in6_addr *saddr, const struct in6_addr *daddr,
		__u32 len, unsigned short proto, __wsum 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 */