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1/*
2 * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
3 * Subject to the GNU Public License v.2
4 *
5 * Wrappers of assembly checksum functions for x86-64.
6 */
7#include <asm/checksum.h>
8#include <linux/export.h>
9#include <linux/uaccess.h>
10#include <asm/smap.h>
11
12/**
13 * csum_partial_copy_from_user - Copy and checksum from user space.
14 * @src: source address (user space)
15 * @dst: destination address
16 * @len: number of bytes to be copied.
17 * @isum: initial sum that is added into the result (32bit unfolded)
18 * @errp: set to -EFAULT for an bad source address.
19 *
20 * Returns an 32bit unfolded checksum of the buffer.
21 * src and dst are best aligned to 64bits.
22 */
23__wsum
24csum_partial_copy_from_user(const void __user *src, void *dst,
25 int len, __wsum isum, int *errp)
26{
27 might_sleep();
28 *errp = 0;
29
30 if (!likely(access_ok(VERIFY_READ, src, len)))
31 goto out_err;
32
33 /*
34 * Why 6, not 7? To handle odd addresses aligned we
35 * would need to do considerable complications to fix the
36 * checksum which is defined as an 16bit accumulator. The
37 * fix alignment code is primarily for performance
38 * compatibility with 32bit and that will handle odd
39 * addresses slowly too.
40 */
41 if (unlikely((unsigned long)src & 6)) {
42 while (((unsigned long)src & 6) && len >= 2) {
43 __u16 val16;
44
45 if (__get_user(val16, (const __u16 __user *)src))
46 goto out_err;
47
48 *(__u16 *)dst = val16;
49 isum = (__force __wsum)add32_with_carry(
50 (__force unsigned)isum, val16);
51 src += 2;
52 dst += 2;
53 len -= 2;
54 }
55 }
56 stac();
57 isum = csum_partial_copy_generic((__force const void *)src,
58 dst, len, isum, errp, NULL);
59 clac();
60 if (unlikely(*errp))
61 goto out_err;
62
63 return isum;
64
65out_err:
66 *errp = -EFAULT;
67 memset(dst, 0, len);
68
69 return isum;
70}
71EXPORT_SYMBOL(csum_partial_copy_from_user);
72
73/**
74 * csum_partial_copy_to_user - Copy and checksum to user space.
75 * @src: source address
76 * @dst: destination address (user space)
77 * @len: number of bytes to be copied.
78 * @isum: initial sum that is added into the result (32bit unfolded)
79 * @errp: set to -EFAULT for an bad destination address.
80 *
81 * Returns an 32bit unfolded checksum of the buffer.
82 * src and dst are best aligned to 64bits.
83 */
84__wsum
85csum_partial_copy_to_user(const void *src, void __user *dst,
86 int len, __wsum isum, int *errp)
87{
88 __wsum ret;
89
90 might_sleep();
91
92 if (unlikely(!access_ok(VERIFY_WRITE, dst, len))) {
93 *errp = -EFAULT;
94 return 0;
95 }
96
97 if (unlikely((unsigned long)dst & 6)) {
98 while (((unsigned long)dst & 6) && len >= 2) {
99 __u16 val16 = *(__u16 *)src;
100
101 isum = (__force __wsum)add32_with_carry(
102 (__force unsigned)isum, val16);
103 *errp = __put_user(val16, (__u16 __user *)dst);
104 if (*errp)
105 return isum;
106 src += 2;
107 dst += 2;
108 len -= 2;
109 }
110 }
111
112 *errp = 0;
113 stac();
114 ret = csum_partial_copy_generic(src, (void __force *)dst,
115 len, isum, NULL, errp);
116 clac();
117 return ret;
118}
119EXPORT_SYMBOL(csum_partial_copy_to_user);
120
121/**
122 * csum_partial_copy_nocheck - Copy and checksum.
123 * @src: source address
124 * @dst: destination address
125 * @len: number of bytes to be copied.
126 * @sum: initial sum that is added into the result (32bit unfolded)
127 *
128 * Returns an 32bit unfolded checksum of the buffer.
129 */
130__wsum
131csum_partial_copy_nocheck(const void *src, void *dst, int len, __wsum sum)
132{
133 return csum_partial_copy_generic(src, dst, len, sum, NULL, NULL);
134}
135EXPORT_SYMBOL(csum_partial_copy_nocheck);
136
137__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
138 const struct in6_addr *daddr,
139 __u32 len, __u8 proto, __wsum sum)
140{
141 __u64 rest, sum64;
142
143 rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
144 (__force __u64)sum;
145
146 asm(" addq (%[saddr]),%[sum]\n"
147 " adcq 8(%[saddr]),%[sum]\n"
148 " adcq (%[daddr]),%[sum]\n"
149 " adcq 8(%[daddr]),%[sum]\n"
150 " adcq $0,%[sum]\n"
151
152 : [sum] "=r" (sum64)
153 : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
154
155 return csum_fold(
156 (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
157}
158EXPORT_SYMBOL(csum_ipv6_magic);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
4 *
5 * Wrappers of assembly checksum functions for x86-64.
6 */
7#include <asm/checksum.h>
8#include <linux/export.h>
9#include <linux/uaccess.h>
10#include <asm/smap.h>
11
12/**
13 * csum_and_copy_from_user - Copy and checksum from user space.
14 * @src: source address (user space)
15 * @dst: destination address
16 * @len: number of bytes to be copied.
17 *
18 * Returns an 32bit unfolded checksum of the buffer.
19 * src and dst are best aligned to 64bits.
20 */
21__wsum
22csum_and_copy_from_user(const void __user *src, void *dst, int len)
23{
24 __wsum sum;
25
26 might_sleep();
27 if (!user_access_begin(src, len))
28 return 0;
29 sum = csum_partial_copy_generic((__force const void *)src, dst, len);
30 user_access_end();
31 return sum;
32}
33
34/**
35 * csum_and_copy_to_user - Copy and checksum to user space.
36 * @src: source address
37 * @dst: destination address (user space)
38 * @len: number of bytes to be copied.
39 *
40 * Returns an 32bit unfolded checksum of the buffer.
41 * src and dst are best aligned to 64bits.
42 */
43__wsum
44csum_and_copy_to_user(const void *src, void __user *dst, int len)
45{
46 __wsum sum;
47
48 might_sleep();
49 if (!user_access_begin(dst, len))
50 return 0;
51 sum = csum_partial_copy_generic(src, (void __force *)dst, len);
52 user_access_end();
53 return sum;
54}
55
56/**
57 * csum_partial_copy_nocheck - Copy and checksum.
58 * @src: source address
59 * @dst: destination address
60 * @len: number of bytes to be copied.
61 *
62 * Returns an 32bit unfolded checksum of the buffer.
63 */
64__wsum
65csum_partial_copy_nocheck(const void *src, void *dst, int len)
66{
67 return csum_partial_copy_generic(src, dst, len);
68}
69EXPORT_SYMBOL(csum_partial_copy_nocheck);
70
71__sum16 csum_ipv6_magic(const struct in6_addr *saddr,
72 const struct in6_addr *daddr,
73 __u32 len, __u8 proto, __wsum sum)
74{
75 __u64 rest, sum64;
76
77 rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
78 (__force __u64)sum;
79
80 asm(" addq (%[saddr]),%[sum]\n"
81 " adcq 8(%[saddr]),%[sum]\n"
82 " adcq (%[daddr]),%[sum]\n"
83 " adcq 8(%[daddr]),%[sum]\n"
84 " adcq $0,%[sum]\n"
85
86 : [sum] "=r" (sum64)
87 : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
88
89 return csum_fold(
90 (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
91}
92EXPORT_SYMBOL(csum_ipv6_magic);