xref: /openbmc/linux/arch/arm/boot/compressed/string.c (revision 407e7517)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/arm/boot/compressed/string.c
4  *
5  * Small subset of simple string routines
6  */
7 
8 #include <linux/string.h>
9 
10 void *memcpy(void *__dest, __const void *__src, size_t __n)
11 {
12 	int i = 0;
13 	unsigned char *d = (unsigned char *)__dest, *s = (unsigned char *)__src;
14 
15 	for (i = __n >> 3; i > 0; i--) {
16 		*d++ = *s++;
17 		*d++ = *s++;
18 		*d++ = *s++;
19 		*d++ = *s++;
20 		*d++ = *s++;
21 		*d++ = *s++;
22 		*d++ = *s++;
23 		*d++ = *s++;
24 	}
25 
26 	if (__n & 1 << 2) {
27 		*d++ = *s++;
28 		*d++ = *s++;
29 		*d++ = *s++;
30 		*d++ = *s++;
31 	}
32 
33 	if (__n & 1 << 1) {
34 		*d++ = *s++;
35 		*d++ = *s++;
36 	}
37 
38 	if (__n & 1)
39 		*d++ = *s++;
40 
41 	return __dest;
42 }
43 
44 void *memmove(void *__dest, __const void *__src, size_t count)
45 {
46 	unsigned char *d = __dest;
47 	const unsigned char *s = __src;
48 
49 	if (__dest == __src)
50 		return __dest;
51 
52 	if (__dest < __src)
53 		return memcpy(__dest, __src, count);
54 
55 	while (count--)
56 		d[count] = s[count];
57 	return __dest;
58 }
59 
60 size_t strlen(const char *s)
61 {
62 	const char *sc = s;
63 
64 	while (*sc != '\0')
65 		sc++;
66 	return sc - s;
67 }
68 
69 size_t strnlen(const char *s, size_t count)
70 {
71 	const char *sc;
72 
73 	for (sc = s; count-- && *sc != '\0'; ++sc)
74 		/* nothing */;
75 	return sc - s;
76 }
77 
78 int memcmp(const void *cs, const void *ct, size_t count)
79 {
80 	const unsigned char *su1 = cs, *su2 = ct, *end = su1 + count;
81 	int res = 0;
82 
83 	while (su1 < end) {
84 		res = *su1++ - *su2++;
85 		if (res)
86 			break;
87 	}
88 	return res;
89 }
90 
91 int strcmp(const char *cs, const char *ct)
92 {
93 	unsigned char c1, c2;
94 	int res = 0;
95 
96 	do {
97 		c1 = *cs++;
98 		c2 = *ct++;
99 		res = c1 - c2;
100 		if (res)
101 			break;
102 	} while (c1);
103 	return res;
104 }
105 
106 void *memchr(const void *s, int c, size_t count)
107 {
108 	const unsigned char *p = s;
109 
110 	while (count--)
111 		if ((unsigned char)c == *p++)
112 			return (void *)(p - 1);
113 	return NULL;
114 }
115 
116 char *strchr(const char *s, int c)
117 {
118 	while (*s != (char)c)
119 		if (*s++ == '\0')
120 			return NULL;
121 	return (char *)s;
122 }
123 
124 #undef memset
125 
126 void *memset(void *s, int c, size_t count)
127 {
128 	char *xs = s;
129 	while (count--)
130 		*xs++ = c;
131 	return s;
132 }
133