1/* SPDX-License-Identifier: GPL-2.0 */
2#ifndef _ASM_X86_STRING_64_H
3#define _ASM_X86_STRING_64_H
4
5#ifdef __KERNEL__
6#include <linux/jump_label.h>
7
8/* Written 2002 by Andi Kleen */
9
10/* Even with __builtin_ the compiler may decide to use the out of line
11 function. */
12
13#if defined(__SANITIZE_MEMORY__) && defined(__NO_FORTIFY)
14#include <linux/kmsan_string.h>
15#endif
16
17#define __HAVE_ARCH_MEMCPY 1
18extern void *memcpy(void *to, const void *from, size_t len);
19extern void *__memcpy(void *to, const void *from, size_t len);
20
21#define __HAVE_ARCH_MEMSET
22void *memset(void *s, int c, size_t n);
23void *__memset(void *s, int c, size_t n);
24KCFI_REFERENCE(__memset);
25
26/*
27 * KMSAN needs to instrument as much code as possible. Use C versions of
28 * memsetXX() from lib/string.c under KMSAN.
29 */
30#if !defined(CONFIG_KMSAN)
31#define __HAVE_ARCH_MEMSET16
32static inline void *memset16(uint16_t *s, uint16_t v, size_t n)
33{
34 const __auto_type s0 = s;
35 asm volatile (
36 "rep stosw"
37 : "+D" (s), "+c" (n)
38 : "a" (v)
39 : "memory"
40 );
41 return s0;
42}
43
44#define __HAVE_ARCH_MEMSET32
45static inline void *memset32(uint32_t *s, uint32_t v, size_t n)
46{
47 const __auto_type s0 = s;
48 asm volatile (
49 "rep stosl"
50 : "+D" (s), "+c" (n)
51 : "a" (v)
52 : "memory"
53 );
54 return s0;
55}
56
57#define __HAVE_ARCH_MEMSET64
58static inline void *memset64(uint64_t *s, uint64_t v, size_t n)
59{
60 const __auto_type s0 = s;
61 asm volatile (
62 "rep stosq"
63 : "+D" (s), "+c" (n)
64 : "a" (v)
65 : "memory"
66 );
67 return s0;
68}
69#endif
70
71#define __HAVE_ARCH_MEMMOVE
72void *memmove(void *dest, const void *src, size_t count);
73void *__memmove(void *dest, const void *src, size_t count);
74KCFI_REFERENCE(__memmove);
75
76int memcmp(const void *cs, const void *ct, size_t count);
77size_t strlen(const char *s);
78char *strcpy(char *dest, const char *src);
79char *strcat(char *dest, const char *src);
80int strcmp(const char *cs, const char *ct);
81
82#ifdef CONFIG_ARCH_HAS_UACCESS_FLUSHCACHE
83#define __HAVE_ARCH_MEMCPY_FLUSHCACHE 1
84void __memcpy_flushcache(void *dst, const void *src, size_t cnt);
85static __always_inline void memcpy_flushcache(void *dst, const void *src, size_t cnt)
86{
87 if (__builtin_constant_p(cnt)) {
88 switch (cnt) {
89 case 4:
90 asm ("movntil %1, %0" : "=m"(*(u32 *)dst) : "r"(*(u32 *)src));
91 return;
92 case 8:
93 asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
94 return;
95 case 16:
96 asm ("movntiq %1, %0" : "=m"(*(u64 *)dst) : "r"(*(u64 *)src));
97 asm ("movntiq %1, %0" : "=m"(*(u64 *)(dst + 8)) : "r"(*(u64 *)(src + 8)));
98 return;
99 }
100 }
101 __memcpy_flushcache(dst, src, cnt);
102}
103#endif
104
105#endif /* __KERNEL__ */
106
107#endif /* _ASM_X86_STRING_64_H */
108

source code of linux/arch/x86/include/asm/string_64.h