xref: /openbmc/linux/arch/ia64/include/asm/checksum.h (revision f3539c12)
1 #ifndef _ASM_IA64_CHECKSUM_H
2 #define _ASM_IA64_CHECKSUM_H
3 
4 /*
5  * Modified 1998, 1999
6  *	David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
7  */
8 
9 /*
10  * This is a version of ip_compute_csum() optimized for IP headers,
11  * which always checksum on 4 octet boundaries.
12  */
13 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
14 
15 /*
16  * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit
17  * checksum, already complemented
18  */
19 extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
20 				 __u32 len, __u8 proto, __wsum sum);
21 
22 extern __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
23 				 __u32 len, __u8 proto, __wsum sum);
24 
25 /*
26  * Computes the checksum of a memory block at buff, length len,
27  * and adds in "sum" (32-bit)
28  *
29  * returns a 32-bit number suitable for feeding into itself
30  * or csum_tcpudp_magic
31  *
32  * this function must be called with even lengths, except
33  * for the last fragment, which may be odd
34  *
35  * it's best to have buff aligned on a 32-bit boundary
36  */
37 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
38 
39 /*
40  * Same as csum_partial, but copies from src while it checksums.
41  *
42  * Here it is even more important to align src and dst on a 32-bit (or
43  * even better 64-bit) boundary.
44  */
45 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
46 						 int len, __wsum sum,
47 						 int *errp);
48 
49 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
50 					       int len, __wsum sum);
51 
52 /*
53  * This routine is used for miscellaneous IP-like checksums, mainly in
54  * icmp.c
55  */
56 extern __sum16 ip_compute_csum(const void *buff, int len);
57 
58 /*
59  * Fold a partial checksum without adding pseudo headers.
60  */
61 static inline __sum16 csum_fold(__wsum csum)
62 {
63 	u32 sum = (__force u32)csum;
64 	sum = (sum & 0xffff) + (sum >> 16);
65 	sum = (sum & 0xffff) + (sum >> 16);
66 	return (__force __sum16)~sum;
67 }
68 
69 #define _HAVE_ARCH_IPV6_CSUM	1
70 struct in6_addr;
71 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
72 			       const struct in6_addr *daddr,
73 			       __u32 len, __u8 proto, __wsum csum);
74 
75 #endif /* _ASM_IA64_CHECKSUM_H */
76