Loading...
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#ifndef _S390_CHECKSUM_H
2#define _S390_CHECKSUM_H
3
4/*
5 * include/asm-s390/checksum.h
6 * S390 fast network checksum routines
7 * see also arch/S390/lib/checksum.c
8 *
9 * S390 version
10 * Copyright (C) 1999 IBM Deutschland Entwicklung GmbH, IBM Corporation
11 * Author(s): Ulrich Hild (first version)
12 * Martin Schwidefsky (heavily optimized CKSM version)
13 * D.J. Barrow (third attempt)
14 */
15
16#include <asm/uaccess.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
31csum_partial(const void *buff, int len, __wsum sum)
32{
33 register unsigned long reg2 asm("2") = (unsigned long) buff;
34 register unsigned long reg3 asm("3") = (unsigned long) len;
35
36 asm volatile(
37 "0: cksm %0,%1\n" /* do checksum on longs */
38 " jo 0b\n"
39 : "+d" (sum), "+d" (reg2), "+d" (reg3) : : "cc", "memory");
40 return sum;
41}
42
43/*
44 * the same as csum_partial_copy, but copies from user space.
45 *
46 * here even more important to align src and dst on a 32-bit (or even
47 * better 64-bit) boundary
48 *
49 * Copy from userspace and compute checksum. If we catch an exception
50 * then zero the rest of the buffer.
51 */
52static inline __wsum
53csum_partial_copy_from_user(const void __user *src, void *dst,
54 int len, __wsum sum,
55 int *err_ptr)
56{
57 int missing;
58
59 missing = copy_from_user(dst, src, len);
60 if (missing) {
61 memset(dst + len - missing, 0, missing);
62 *err_ptr = -EFAULT;
63 }
64
65 return csum_partial(dst, len, sum);
66}
67
68
69static inline __wsum
70csum_partial_copy_nocheck (const void *src, void *dst, int len, __wsum sum)
71{
72 memcpy(dst,src,len);
73 return csum_partial(dst, len, sum);
74}
75
76/*
77 * Fold a partial checksum without adding pseudo headers
78 */
79static inline __sum16 csum_fold(__wsum sum)
80{
81 u32 csum = (__force u32) sum;
82
83 csum += (csum >> 16) + (csum << 16);
84 csum >>= 16;
85 return (__force __sum16) ~csum;
86}
87
88/*
89 * This is a version of ip_compute_csum() optimized for IP headers,
90 * which always checksum on 4 octet boundaries.
91 *
92 */
93static inline __sum16 ip_fast_csum(const void *iph, unsigned int ihl)
94{
95 return csum_fold(csum_partial(iph, ihl*4, 0));
96}
97
98/*
99 * computes the checksum of the TCP/UDP pseudo-header
100 * returns a 32-bit checksum
101 */
102static inline __wsum
103csum_tcpudp_nofold(__be32 saddr, __be32 daddr,
104 unsigned short len, unsigned short proto,
105 __wsum sum)
106{
107 __u32 csum = (__force __u32)sum;
108
109 csum += (__force __u32)saddr;
110 if (csum < (__force __u32)saddr)
111 csum++;
112
113 csum += (__force __u32)daddr;
114 if (csum < (__force __u32)daddr)
115 csum++;
116
117 csum += len + proto;
118 if (csum < len + proto)
119 csum++;
120
121 return (__force __wsum)csum;
122}
123
124/*
125 * computes the checksum of the TCP/UDP pseudo-header
126 * returns a 16-bit checksum, already complemented
127 */
128
129static inline __sum16
130csum_tcpudp_magic(__be32 saddr, __be32 daddr,
131 unsigned short len, unsigned short proto,
132 __wsum sum)
133{
134 return csum_fold(csum_tcpudp_nofold(saddr,daddr,len,proto,sum));
135}
136
137/*
138 * this routine is used for miscellaneous IP-like checksums, mainly
139 * in icmp.c
140 */
141
142static inline __sum16 ip_compute_csum(const void *buff, int len)
143{
144 return csum_fold(csum_partial(buff, len, 0));
145}
146
147#endif /* _S390_CHECKSUM_H */
148
149