xref: /openbmc/linux/arch/alpha/include/asm/checksum.h (revision 1edd0337)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _ALPHA_CHECKSUM_H
3 #define _ALPHA_CHECKSUM_H
4 
5 #include <linux/in6.h>
6 
7 /*
8  *	This is a version of ip_compute_csum() optimized for IP headers,
9  *	which always checksum on 4 octet boundaries.
10  */
11 extern __sum16 ip_fast_csum(const void *iph, unsigned int ihl);
12 
13 /*
14  * computes the checksum of the TCP/UDP pseudo-header
15  * returns a 16-bit checksum, already complemented
16  */
17 __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr,
18 			  __u32 len, __u8 proto, __wsum sum);
19 
20 __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
21 			  __u32 len, __u8 proto, __wsum sum);
22 
23 /*
24  * computes the checksum of a memory block at buff, length len,
25  * and adds in "sum" (32-bit)
26  *
27  * returns a 32-bit number suitable for feeding into itself
28  * or csum_tcpudp_magic
29  *
30  * this function must be called with even lengths, except
31  * for the last fragment, which may be odd
32  *
33  * it's best to have buff aligned on a 32-bit boundary
34  */
35 extern __wsum csum_partial(const void *buff, int len, __wsum sum);
36 
37 /*
38  * the same as csum_partial, but copies from src while it
39  * checksums
40  *
41  * here even more important to align src and dst on a 32-bit (or even
42  * better 64-bit) boundary
43  */
44 #define _HAVE_ARCH_COPY_AND_CSUM_FROM_USER
45 #define _HAVE_ARCH_CSUM_AND_COPY
46 __wsum csum_and_copy_from_user(const void __user *src, void *dst, int len);
47 
48 __wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
49 
50 
51 /*
52  * this routine is used for miscellaneous IP-like checksums, mainly
53  * in icmp.c
54  */
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 
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
71 extern __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
72 			       const struct in6_addr *daddr,
73 			       __u32 len, __u8 proto, __wsum sum);
74 #endif
75