1 // SPDX-License-Identifier: GPL-2.0-only
2 // Copyright (C) 2019-2020 Arm Ltd.
5 #include <linux/kasan-checks.h>
10 /* Looks dumb, but generates nice-ish code */
14 	return tmp + (tmp >> 64);  in accumulate()
18  * We over-read the buffer and this makes KASAN unhappy. Instead, disable
34 	 * should absolutely not be pointing to anything read-sensitive. We do,  in do_csum()
37 	 * compensate with an explicit check up-front.  in do_csum()
40 	ptr = (u64 *)(buff - offset);  in do_csum()
41 	len = len + offset - 8;  in do_csum()
62 	while (unlikely(len > 64)) {  in do_csum()
70 		len -= 64;  in do_csum()
74 		tmp1 += (tmp1 >> 64) | (tmp1 << 64);  in do_csum()
75 		tmp2 += (tmp2 >> 64) | (tmp2 << 64);  in do_csum()
76 		tmp3 += (tmp3 >> 64) | (tmp3 << 64);  in do_csum()
77 		tmp4 += (tmp4 >> 64) | (tmp4 << 64);  in do_csum()
78 		tmp1 = ((tmp1 >> 64) << 64) | (tmp2 >> 64);  in do_csum()
79 		tmp1 += (tmp1 >> 64) | (tmp1 << 64);  in do_csum()
80 		tmp3 = ((tmp3 >> 64) << 64) | (tmp4 >> 64);  in do_csum()
81 		tmp3 += (tmp3 >> 64) | (tmp3 << 64);  in do_csum()
82 		tmp1 = ((tmp1 >> 64) << 64) | (tmp3 >> 64);  in do_csum()
83 		tmp1 += (tmp1 >> 64) | (tmp1 << 64);  in do_csum()
84 		tmp1 = ((tmp1 >> 64) << 64) | sum64;  in do_csum()
85 		tmp1 += (tmp1 >> 64) | (tmp1 << 64);  in do_csum()
86 		sum64 = tmp1 >> 64;  in do_csum()
94 		len -= 16;  in do_csum()
98 		data = tmp >> 64;  in do_csum()
102 		sum64 = accumulate(sum64, tmp >> 64);  in do_csum()
108 		len -= 8;  in do_csum()
111 	 * Tail: zero any over-read bytes similarly to the head, again  in do_csum()
114 	shift = len * -8;  in do_csum()
139 	src = *(const __uint128_t *)saddr->s6_addr;  in csum_ipv6_magic()
140 	dst = *(const __uint128_t *)daddr->s6_addr;  in csum_ipv6_magic()
148 	src += (src >> 64) | (src << 64);  in csum_ipv6_magic()
149 	dst += (dst >> 64) | (dst << 64);  in csum_ipv6_magic()
151 	sum = accumulate(sum, src >> 64);  in csum_ipv6_magic()
152 	sum = accumulate(sum, dst >> 64);  in csum_ipv6_magic()