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 */
16 unsigned 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
26 unsigned 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
36 extern 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 */
47 static inline unsigned short
ip_fast_csum(unsigned char * iph,unsigned int ihl)48 ip_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
csum_fold(unsigned int sum)72 static 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
90 static inline unsigned int
csum_tcpudp_nofold(unsigned long saddr,unsigned long daddr,unsigned short len,unsigned short proto,unsigned int sum)91 csum_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
105 static inline unsigned short int
csum_tcpudp_magic(unsigned long saddr,unsigned long daddr,unsigned short len,unsigned short proto,unsigned int sum)106 csum_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
117 static inline unsigned short
ip_compute_csum(unsigned char * buff,int len)118 ip_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
124 static __inline__ unsigned short int
csum_ipv6_magic(struct in6_addr * saddr,struct in6_addr * daddr,__u32 len,unsigned short proto,unsigned int sum)125 csum_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