1*4882a593Smuzhiyun // SPDX-License-Identifier: GPL-2.0-only
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright 2002, 2003 Andi Kleen, SuSE Labs.
4*4882a593Smuzhiyun *
5*4882a593Smuzhiyun * Wrappers of assembly checksum functions for x86-64.
6*4882a593Smuzhiyun */
7*4882a593Smuzhiyun #include <asm/checksum.h>
8*4882a593Smuzhiyun #include <linux/export.h>
9*4882a593Smuzhiyun #include <linux/uaccess.h>
10*4882a593Smuzhiyun #include <asm/smap.h>
11*4882a593Smuzhiyun
12*4882a593Smuzhiyun /**
13*4882a593Smuzhiyun * csum_and_copy_from_user - Copy and checksum from user space.
14*4882a593Smuzhiyun * @src: source address (user space)
15*4882a593Smuzhiyun * @dst: destination address
16*4882a593Smuzhiyun * @len: number of bytes to be copied.
17*4882a593Smuzhiyun * @isum: initial sum that is added into the result (32bit unfolded)
18*4882a593Smuzhiyun * @errp: set to -EFAULT for an bad source address.
19*4882a593Smuzhiyun *
20*4882a593Smuzhiyun * Returns an 32bit unfolded checksum of the buffer.
21*4882a593Smuzhiyun * src and dst are best aligned to 64bits.
22*4882a593Smuzhiyun */
23*4882a593Smuzhiyun __wsum
csum_and_copy_from_user(const void __user * src,void * dst,int len)24*4882a593Smuzhiyun csum_and_copy_from_user(const void __user *src, void *dst, int len)
25*4882a593Smuzhiyun {
26*4882a593Smuzhiyun __wsum sum;
27*4882a593Smuzhiyun
28*4882a593Smuzhiyun might_sleep();
29*4882a593Smuzhiyun if (!user_access_begin(src, len))
30*4882a593Smuzhiyun return 0;
31*4882a593Smuzhiyun sum = csum_partial_copy_generic((__force const void *)src, dst, len);
32*4882a593Smuzhiyun user_access_end();
33*4882a593Smuzhiyun return sum;
34*4882a593Smuzhiyun }
35*4882a593Smuzhiyun EXPORT_SYMBOL(csum_and_copy_from_user);
36*4882a593Smuzhiyun
37*4882a593Smuzhiyun /**
38*4882a593Smuzhiyun * csum_and_copy_to_user - Copy and checksum to user space.
39*4882a593Smuzhiyun * @src: source address
40*4882a593Smuzhiyun * @dst: destination address (user space)
41*4882a593Smuzhiyun * @len: number of bytes to be copied.
42*4882a593Smuzhiyun * @isum: initial sum that is added into the result (32bit unfolded)
43*4882a593Smuzhiyun * @errp: set to -EFAULT for an bad destination address.
44*4882a593Smuzhiyun *
45*4882a593Smuzhiyun * Returns an 32bit unfolded checksum of the buffer.
46*4882a593Smuzhiyun * src and dst are best aligned to 64bits.
47*4882a593Smuzhiyun */
48*4882a593Smuzhiyun __wsum
csum_and_copy_to_user(const void * src,void __user * dst,int len)49*4882a593Smuzhiyun csum_and_copy_to_user(const void *src, void __user *dst, int len)
50*4882a593Smuzhiyun {
51*4882a593Smuzhiyun __wsum sum;
52*4882a593Smuzhiyun
53*4882a593Smuzhiyun might_sleep();
54*4882a593Smuzhiyun if (!user_access_begin(dst, len))
55*4882a593Smuzhiyun return 0;
56*4882a593Smuzhiyun sum = csum_partial_copy_generic(src, (void __force *)dst, len);
57*4882a593Smuzhiyun user_access_end();
58*4882a593Smuzhiyun return sum;
59*4882a593Smuzhiyun }
60*4882a593Smuzhiyun EXPORT_SYMBOL(csum_and_copy_to_user);
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun /**
63*4882a593Smuzhiyun * csum_partial_copy_nocheck - Copy and checksum.
64*4882a593Smuzhiyun * @src: source address
65*4882a593Smuzhiyun * @dst: destination address
66*4882a593Smuzhiyun * @len: number of bytes to be copied.
67*4882a593Smuzhiyun * @sum: initial sum that is added into the result (32bit unfolded)
68*4882a593Smuzhiyun *
69*4882a593Smuzhiyun * Returns an 32bit unfolded checksum of the buffer.
70*4882a593Smuzhiyun */
71*4882a593Smuzhiyun __wsum
csum_partial_copy_nocheck(const void * src,void * dst,int len)72*4882a593Smuzhiyun csum_partial_copy_nocheck(const void *src, void *dst, int len)
73*4882a593Smuzhiyun {
74*4882a593Smuzhiyun return csum_partial_copy_generic(src, dst, len);
75*4882a593Smuzhiyun }
76*4882a593Smuzhiyun EXPORT_SYMBOL(csum_partial_copy_nocheck);
77*4882a593Smuzhiyun
csum_ipv6_magic(const struct in6_addr * saddr,const struct in6_addr * daddr,__u32 len,__u8 proto,__wsum sum)78*4882a593Smuzhiyun __sum16 csum_ipv6_magic(const struct in6_addr *saddr,
79*4882a593Smuzhiyun const struct in6_addr *daddr,
80*4882a593Smuzhiyun __u32 len, __u8 proto, __wsum sum)
81*4882a593Smuzhiyun {
82*4882a593Smuzhiyun __u64 rest, sum64;
83*4882a593Smuzhiyun
84*4882a593Smuzhiyun rest = (__force __u64)htonl(len) + (__force __u64)htons(proto) +
85*4882a593Smuzhiyun (__force __u64)sum;
86*4882a593Smuzhiyun
87*4882a593Smuzhiyun asm(" addq (%[saddr]),%[sum]\n"
88*4882a593Smuzhiyun " adcq 8(%[saddr]),%[sum]\n"
89*4882a593Smuzhiyun " adcq (%[daddr]),%[sum]\n"
90*4882a593Smuzhiyun " adcq 8(%[daddr]),%[sum]\n"
91*4882a593Smuzhiyun " adcq $0,%[sum]\n"
92*4882a593Smuzhiyun
93*4882a593Smuzhiyun : [sum] "=r" (sum64)
94*4882a593Smuzhiyun : "[sum]" (rest), [saddr] "r" (saddr), [daddr] "r" (daddr));
95*4882a593Smuzhiyun
96*4882a593Smuzhiyun return csum_fold(
97*4882a593Smuzhiyun (__force __wsum)add32_with_carry(sum64 & 0xffffffff, sum64>>32));
98*4882a593Smuzhiyun }
99*4882a593Smuzhiyun EXPORT_SYMBOL(csum_ipv6_magic);
100