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1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * S390 fast network checksum routines
4 *
5 * S390 version
6 * Copyright IBM Corp. 1999
7 * Author(s): Ulrich Hild (first version)
8 * Martin Schwidefsky (heavily optimized CKSM version)
9 * D.J. Barrow (third attempt)
10 */
11
12#ifndef _S390_CHECKSUM_H
13#define _S390_CHECKSUM_H
14
15#include <linux/uaccess.h>
16#include <linux/in6.h>
17
18/*
19 * Computes the checksum of a memory block at buff, length len,
20 * and adds in "sum" (32-bit).
21 *
22 * Returns a 32-bit number suitable for feeding into itself
23 * or csum_tcpudp_magic.
24 *
25 * This function must be called with even lengths, except
26 * for the last fragment, which may be odd.
27 *
28 * It's best to have buff aligned on a 32-bit boundary.
29 */
30static inline __wsum csum_partial(const void *buff, int len, __wsum sum)
31{
32 union register_pair rp = {
33 .even = (unsigned long) buff,
34 .odd = (unsigned long) len,
35 };
36
37 asm volatile(
38 "0: cksm %[sum],%[rp]\n"
39 " jo 0b\n"
40 : [sum] "+&d" (sum), [rp] "+&d" (rp.pair) : : "cc", "memory");
41 return sum;
42}
43
44/*
45 * Fold a partial checksum without adding pseudo headers.
46 */
47static inline __sum16 csum_fold(__wsum sum)
48{
49 u32 csum = (__force u32) sum;
50
51 csum += (csum >> 16) | (csum << 16);
52 csum >>= 16;
53 return (__force __sum16) ~csum;
54}
55
56/*
57 * This is a version of ip_compute_csum() optimized for IP headers,
58 * which always checksums on 4 octet boundaries.
59 */
60static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
61{
62 __u64 csum = 0;
63 __u32 *ptr = (u32 *)iph;
64
65 csum += *ptr++;
66 csum += *ptr++;
67 csum += *ptr++;
68 csum += *ptr++;
69 ihl -= 4;
70 while (ihl--)
71 csum += *ptr++;
72 csum += (csum >> 32) | (csum << 32);
73 return csum_fold((__force __wsum)(csum >> 32));
74}
75
76/*
77 * Computes the checksum of the TCP/UDP pseudo-header.
78 * Returns a 32-bit checksum.
79 */
80static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
81 __u8 proto, __wsum sum)
82{
83 __u64 csum = (__force __u64)sum;
84
85 csum += (__force __u32)saddr;
86 csum += (__force __u32)daddr;
87 csum += len;
88 csum += proto;
89 csum += (csum >> 32) | (csum << 32);
90 return (__force __wsum)(csum >> 32);
91}
92
93/*
94 * Computes the checksum of the TCP/UDP pseudo-header.
95 * Returns a 16-bit checksum, already complemented.
96 */
97static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
98 __u8 proto, __wsum sum)
99{
100 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
101}
102
103/*
104 * Used for miscellaneous IP-like checksums, mainly icmp.
105 */
106static inline __sum16 ip_compute_csum(const void *buff, int len)
107{
108 return csum_fold(csum_partial(buff, len, 0));
109}
110
111#define _HAVE_ARCH_IPV6_CSUM
112static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
113 const struct in6_addr *daddr,
114 __u32 len, __u8 proto, __wsum csum)
115{
116 __u64 sum = (__force __u64)csum;
117
118 sum += (__force __u32)saddr->s6_addr32[0];
119 sum += (__force __u32)saddr->s6_addr32[1];
120 sum += (__force __u32)saddr->s6_addr32[2];
121 sum += (__force __u32)saddr->s6_addr32[3];
122 sum += (__force __u32)daddr->s6_addr32[0];
123 sum += (__force __u32)daddr->s6_addr32[1];
124 sum += (__force __u32)daddr->s6_addr32[2];
125 sum += (__force __u32)daddr->s6_addr32[3];
126 sum += len;
127 sum += proto;
128 sum += (sum >> 32) | (sum << 32);
129 return csum_fold((__force __wsum)(sum >> 32));
130}
131
132#endif /* _S390_CHECKSUM_H */
1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * S390 fast network checksum routines
4 *
5 * S390 version
6 * Copyright IBM Corp. 1999
7 * Author(s): Ulrich Hild (first version)
8 * Martin Schwidefsky (heavily optimized CKSM version)
9 * D.J. Barrow (third attempt)
10 */
11
12#ifndef _S390_CHECKSUM_H
13#define _S390_CHECKSUM_H
14
15#include <linux/instrumented.h>
16#include <linux/in6.h>
17
18static inline __wsum cksm(const void *buff, int len, __wsum sum)
19{
20 union register_pair rp = {
21 .even = (unsigned long)buff,
22 .odd = (unsigned long)len,
23 };
24
25 instrument_read(buff, len);
26 asm volatile("\n"
27 "0: cksm %[sum],%[rp]\n"
28 " jo 0b\n"
29 : [sum] "+&d" (sum), [rp] "+&d" (rp.pair) : : "cc", "memory");
30 return sum;
31}
32
33__wsum csum_partial(const void *buff, int len, __wsum sum);
34
35#define _HAVE_ARCH_CSUM_AND_COPY
36__wsum csum_partial_copy_nocheck(const void *src, void *dst, int len);
37
38/*
39 * Fold a partial checksum without adding pseudo headers.
40 */
41static inline __sum16 csum_fold(__wsum sum)
42{
43 u32 csum = (__force u32) sum;
44
45 csum += (csum >> 16) | (csum << 16);
46 csum >>= 16;
47 return (__force __sum16) ~csum;
48}
49
50/*
51 * This is a version of ip_compute_csum() optimized for IP headers,
52 * which always checksums on 4 octet boundaries.
53 */
54static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
55{
56 __u64 csum = 0;
57 __u32 *ptr = (u32 *)iph;
58
59 csum += *ptr++;
60 csum += *ptr++;
61 csum += *ptr++;
62 csum += *ptr++;
63 ihl -= 4;
64 while (ihl--)
65 csum += *ptr++;
66 csum += (csum >> 32) | (csum << 32);
67 return csum_fold((__force __wsum)(csum >> 32));
68}
69
70/*
71 * Computes the checksum of the TCP/UDP pseudo-header.
72 * Returns a 32-bit checksum.
73 */
74static inline __wsum csum_tcpudp_nofold(__be32 saddr, __be32 daddr, __u32 len,
75 __u8 proto, __wsum sum)
76{
77 __u64 csum = (__force __u64)sum;
78
79 csum += (__force __u32)saddr;
80 csum += (__force __u32)daddr;
81 csum += len;
82 csum += proto;
83 csum += (csum >> 32) | (csum << 32);
84 return (__force __wsum)(csum >> 32);
85}
86
87/*
88 * Computes the checksum of the TCP/UDP pseudo-header.
89 * Returns a 16-bit checksum, already complemented.
90 */
91static inline __sum16 csum_tcpudp_magic(__be32 saddr, __be32 daddr, __u32 len,
92 __u8 proto, __wsum sum)
93{
94 return csum_fold(csum_tcpudp_nofold(saddr, daddr, len, proto, sum));
95}
96
97/*
98 * Used for miscellaneous IP-like checksums, mainly icmp.
99 */
100static inline __sum16 ip_compute_csum(const void *buff, int len)
101{
102 return csum_fold(csum_partial(buff, len, 0));
103}
104
105#define _HAVE_ARCH_IPV6_CSUM
106static inline __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
107 const struct in6_addr *daddr,
108 __u32 len, __u8 proto, __wsum csum)
109{
110 __u64 sum = (__force __u64)csum;
111
112 sum += (__force __u32)saddr->s6_addr32[0];
113 sum += (__force __u32)saddr->s6_addr32[1];
114 sum += (__force __u32)saddr->s6_addr32[2];
115 sum += (__force __u32)saddr->s6_addr32[3];
116 sum += (__force __u32)daddr->s6_addr32[0];
117 sum += (__force __u32)daddr->s6_addr32[1];
118 sum += (__force __u32)daddr->s6_addr32[2];
119 sum += (__force __u32)daddr->s6_addr32[3];
120 sum += len;
121 sum += proto;
122 sum += (sum >> 32) | (sum << 32);
123 return csum_fold((__force __wsum)(sum >> 32));
124}
125
126#endif /* _S390_CHECKSUM_H */