xref: /openbmc/linux/arch/ia64/include/asm/checksum.h (revision a2818ee4)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ASM_IA64_CHECKSUM_H
3 #define _ASM_IA64_CHECKSUM_H
4 
5 /*
6  * Modified 1998, 1999
7  *	David Mosberger-Tang <davidm@hpl.hp.com>, Hewlett-Packard Co
8  */
9 
10 /*
11  * This is a version of ip_compute_csum() optimized for IP headers,
12  * which always checksum on 4 octet boundaries.
13  */
14 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
15 
16 /*
17  * Computes the checksum of the TCP/UDP pseudo-header returns a 16-bit
18  * checksum, already complemented
19  */
20 extern __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
21 				 __u32 len, __u8 proto, __wsum sum);
22 
23 extern __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
24 				 __u32 len, __u8 proto, __wsum sum);
25 
26 /*
27  * Computes the checksum of a memory block at buff, length len,
28  * and adds in "sum" (32-bit)
29  *
30  * returns a 32-bit number suitable for feeding into itself
31  * or csum_tcpudp_magic
32  *
33  * this function must be called with even lengths, except
34  * for the last fragment, which may be odd
35  *
36  * it's best to have buff aligned on a 32-bit boundary
37  */
38 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
39 
40 /*
41  * Same as csum_partial, but copies from src while it checksums.
42  *
43  * Here it is even more important to align src and dst on a 32-bit (or
44  * even better 64-bit) boundary.
45  */
46 extern __wsum csum_partial_copy_from_user(const void __user *src, void *dst,
47 						 int len, __wsum sum,
48 						 int *errp);
49 
50 extern __wsum csum_partial_copy_nocheck(const void *src, void *dst,
51 					       int len, __wsum sum);
52 
53 /*
54  * This routine is used for miscellaneous IP-like checksums, mainly in
55  * icmp.c
56  */
57 extern __sum16 ip_compute_csum(const void *buff, int len);
58 
59 /*
60  * Fold a partial checksum without adding pseudo headers.
61  */
62 static inline __sum16 csum_fold(__wsum csum)
63 {
64 	u32 sum = (__force u32)csum;
65 	sum = (sum & 0xffff) + (sum >> 16);
66 	sum = (sum & 0xffff) + (sum >> 16);
67 	return (__force __sum16)~sum;
68 }
69 
70 #define _HAVE_ARCH_IPV6_CSUM	1
71 struct in6_addr;
72 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
73 			       const struct in6_addr *daddr,
74 			       __u32 len, __u8 proto, __wsum csum);
75 
76 #endif /* _ASM_IA64_CHECKSUM_H */
77