1#ifndef _M68K_CHECKSUM_H
2#define _M68K_CHECKSUM_H
3
4/*
5 * computes the checksum of a memory block at buff, length len,
6 * and adds in "sum" (32-bit)
7 *
8 * returns a 32-bit number suitable for feeding into itself
9 * or csum_tcpudp_magic
10 *
11 * this function must be called with even lengths, except
12 * for the last fragment, which may be odd
13 *
14 * it's best to have buff aligned on a 32-bit boundary
15 */
16unsigned int csum_partial(const unsigned char * buff, int len, unsigned int sum);
17
18/*
19 * the same as csum_partial, but copies from src while it
20 * checksums
21 *
22 * here even more important to align src and dst on a 32-bit (or even
23 * better 64-bit) boundary
24 */
25
26unsigned int csum_partial_copy(const char *src, char *dst, int len, int sum);
27
28
29/*
30 * the same as csum_partial_copy, but copies from user space.
31 *
32 * here even more important to align src and dst on a 32-bit (or even
33 * better 64-bit) boundary
34 */
35
36extern unsigned int csum_partial_copy_from_user(const char *src, char *dst,
37						int len, int sum, int *csum_err);
38
39#define csum_partial_copy_nocheck(src, dst, len, sum)	\
40	csum_partial_copy((src), (dst), (len), (sum))
41
42/*
43 *	This is a version of ip_compute_csum() optimized for IP headers,
44 *	which always checksum on 4 octet boundaries.
45 *
46 */
47static inline unsigned short
48ip_fast_csum(unsigned char *iph, unsigned int ihl)
49{
50	unsigned int sum = 0;
51
52	__asm__ ("subqw #1,%2\n"
53		 "1:\t"
54		 "movel %1@+,%/d0\n\t"
55		 "addxl %/d0,%0\n\t"
56		 "dbra  %2,1b\n\t"
57		 "movel %0,%/d0\n\t"
58		 "swap  %/d0\n\t"
59		 "addxw %/d0,%0\n\t"
60		 "clrw  %/d0\n\t"
61		 "addxw %/d0,%0\n\t"
62		 : "=d" (sum), "=a" (iph), "=d" (ihl)
63		 : "0" (sum), "1" (iph), "2" (ihl)
64		 : "d0");
65	return ~sum;
66}
67
68/*
69 *	Fold a partial checksum
70 */
71
72static inline unsigned int csum_fold(unsigned int sum)
73{
74	unsigned int tmp = sum;
75	__asm__("swap %1\n\t"
76		"addw %1, %0\n\t"
77		"clrw %1\n\t"
78		"addxw %1, %0"
79		: "=&d" (sum), "=&d" (tmp)
80		: "0" (sum), "1" (sum));
81	return ~sum;
82}
83
84
85/*
86 * computes the checksum of the TCP/UDP pseudo-header
87 * returns a 16-bit checksum, already complemented
88 */
89
90static inline unsigned int
91csum_tcpudp_nofold(unsigned long saddr, unsigned long daddr, unsigned short len,
92		  unsigned short proto, unsigned int sum)
93{
94	__asm__ ("addl  %1,%0\n\t"
95		 "addxl %4,%0\n\t"
96		 "addxl %5,%0\n\t"
97		 "clrl %1\n\t"
98		 "addxl %1,%0"
99		 : "=&d" (sum), "=&d" (saddr)
100		 : "0" (daddr), "1" (saddr), "d" (len + proto),
101		   "d"(sum));
102	return sum;
103}
104
105static inline unsigned short int
106csum_tcpudp_magic(unsigned long saddr, unsigned long daddr, unsigned short len,
107		  unsigned short proto, unsigned int sum)
108{
109	return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
110}
111
112/*
113 * this routine is used for miscellaneous IP-like checksums, mainly
114 * in icmp.c
115 */
116
117static inline unsigned short
118ip_compute_csum(unsigned char * buff, int len)
119{
120	return csum_fold (csum_partial(buff, len, 0));
121}
122
123#define _HAVE_ARCH_IPV6_CSUM
124static __inline__ unsigned short int
125csum_ipv6_magic(struct in6_addr *saddr, struct in6_addr *daddr,
126		__u32 len, unsigned short proto, unsigned int sum)
127{
128	register unsigned long tmp;
129	__asm__("addl %2@,%0\n\t"
130		"movel %2@(4),%1\n\t"
131		"addxl %1,%0\n\t"
132		"movel %2@(8),%1\n\t"
133		"addxl %1,%0\n\t"
134		"movel %2@(12),%1\n\t"
135		"addxl %1,%0\n\t"
136		"movel %3@,%1\n\t"
137		"addxl %1,%0\n\t"
138		"movel %3@(4),%1\n\t"
139		"addxl %1,%0\n\t"
140		"movel %3@(8),%1\n\t"
141		"addxl %1,%0\n\t"
142		"movel %3@(12),%1\n\t"
143		"addxl %1,%0\n\t"
144		"addxl %4,%0\n\t"
145		"clrl %1\n\t"
146		"addxl %1,%0"
147		: "=&d" (sum), "=&d" (tmp)
148		: "a" (saddr), "a" (daddr), "d" (len + proto),
149		  "0" (sum));
150
151	return csum_fold(sum);
152}
153
154#endif /* _M68K_CHECKSUM_H */
155