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b2441318 | 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
3a161d99 SRRH |
2 | #ifndef _LINUX_SEQ_BUF_H |
3 | #define _LINUX_SEQ_BUF_H | |
4 | ||
8a566f94 AS |
5 | #include <linux/bug.h> |
6 | #include <linux/minmax.h> | |
7 | #include <linux/seq_file.h> | |
8 | #include <linux/types.h> | |
3a161d99 SRRH |
9 | |
10 | /* | |
11 | * Trace sequences are used to allow a function to call several other functions | |
12 | * to create a string of data to use. | |
13 | */ | |
14 | ||
15 | /** | |
6efe4d18 | 16 | * struct seq_buf - seq buffer structure |
3a161d99 SRRH |
17 | * @buffer: pointer to the buffer |
18 | * @size: size of the buffer | |
19 | * @len: the amount of data inside the buffer | |
3a161d99 SRRH |
20 | */ |
21 | struct seq_buf { | |
9a777793 SRRH |
22 | char *buffer; |
23 | size_t size; | |
24 | size_t len; | |
3a161d99 SRRH |
25 | }; |
26 | ||
dcc4e572 | 27 | #define DECLARE_SEQ_BUF(NAME, SIZE) \ |
dcc4e572 | 28 | struct seq_buf NAME = { \ |
7a8e9cdf | 29 | .buffer = (char[SIZE]) { 0 }, \ |
dcc4e572 KC |
30 | .size = SIZE, \ |
31 | } | |
32 | ||
0736c033 SRRH |
33 | static inline void seq_buf_clear(struct seq_buf *s) |
34 | { | |
35 | s->len = 0; | |
dcc4e572 KC |
36 | if (s->size) |
37 | s->buffer[0] = '\0'; | |
0736c033 SRRH |
38 | } |
39 | ||
3a161d99 | 40 | static inline void |
d9a9280a | 41 | seq_buf_init(struct seq_buf *s, char *buf, unsigned int size) |
3a161d99 SRRH |
42 | { |
43 | s->buffer = buf; | |
44 | s->size = size; | |
0736c033 | 45 | seq_buf_clear(s); |
3a161d99 SRRH |
46 | } |
47 | ||
48 | /* | |
49 | * seq_buf have a buffer that might overflow. When this happens | |
845e31e1 | 50 | * len is set to be greater than size. |
3a161d99 SRRH |
51 | */ |
52 | static inline bool | |
53 | seq_buf_has_overflowed(struct seq_buf *s) | |
54 | { | |
8cd709ae | 55 | return s->len > s->size; |
3a161d99 SRRH |
56 | } |
57 | ||
58 | static inline void | |
59 | seq_buf_set_overflow(struct seq_buf *s) | |
60 | { | |
8cd709ae | 61 | s->len = s->size + 1; |
3a161d99 SRRH |
62 | } |
63 | ||
64 | /* | |
65 | * How much buffer is left on the seq_buf? | |
66 | */ | |
67 | static inline unsigned int | |
68 | seq_buf_buffer_left(struct seq_buf *s) | |
69 | { | |
70 | if (seq_buf_has_overflowed(s)) | |
71 | return 0; | |
72 | ||
8cd709ae | 73 | return s->size - s->len; |
3a161d99 SRRH |
74 | } |
75 | ||
eeab9815 SRRH |
76 | /* How much buffer was written? */ |
77 | static inline unsigned int seq_buf_used(struct seq_buf *s) | |
78 | { | |
79 | return min(s->len, s->size); | |
80 | } | |
81 | ||
f2616c77 | 82 | /** |
6efe4d18 | 83 | * seq_buf_str - get NUL-terminated C string from seq_buf |
dcc4e572 | 84 | * @s: the seq_buf handle |
f2616c77 | 85 | * |
6efe4d18 | 86 | * This makes sure that the buffer in @s is NUL-terminated and |
f2616c77 SRV |
87 | * safe to read as a string. |
88 | * | |
89 | * Note, if this is called when the buffer has overflowed, then | |
90 | * the last byte of the buffer is zeroed, and the len will still | |
91 | * point passed it. | |
92 | * | |
93 | * After this function is called, s->buffer is safe to use | |
94 | * in string operations. | |
dcc4e572 | 95 | * |
6efe4d18 | 96 | * Returns: @s->buf after making sure it is terminated. |
f2616c77 | 97 | */ |
dcc4e572 | 98 | static inline const char *seq_buf_str(struct seq_buf *s) |
f2616c77 SRV |
99 | { |
100 | if (WARN_ON(s->size == 0)) | |
dcc4e572 | 101 | return ""; |
f2616c77 SRV |
102 | |
103 | if (seq_buf_buffer_left(s)) | |
104 | s->buffer[s->len] = 0; | |
105 | else | |
106 | s->buffer[s->size - 1] = 0; | |
dcc4e572 KC |
107 | |
108 | return s->buffer; | |
f2616c77 SRV |
109 | } |
110 | ||
01cb06a4 SRRH |
111 | /** |
112 | * seq_buf_get_buf - get buffer to write arbitrary data to | |
113 | * @s: the seq_buf handle | |
114 | * @bufp: the beginning of the buffer is stored here | |
115 | * | |
6efe4d18 | 116 | * Returns: the number of bytes available in the buffer, or zero if |
01cb06a4 SRRH |
117 | * there's no space. |
118 | */ | |
119 | static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp) | |
120 | { | |
121 | WARN_ON(s->len > s->size + 1); | |
122 | ||
123 | if (s->len < s->size) { | |
124 | *bufp = s->buffer + s->len; | |
125 | return s->size - s->len; | |
126 | } | |
127 | ||
128 | *bufp = NULL; | |
129 | return 0; | |
130 | } | |
131 | ||
132 | /** | |
133 | * seq_buf_commit - commit data to the buffer | |
134 | * @s: the seq_buf handle | |
135 | * @num: the number of bytes to commit | |
136 | * | |
137 | * Commit @num bytes of data written to a buffer previously acquired | |
6efe4d18 | 138 | * by seq_buf_get_buf(). To signal an error condition, or that the data |
01cb06a4 SRRH |
139 | * didn't fit in the available space, pass a negative @num value. |
140 | */ | |
141 | static inline void seq_buf_commit(struct seq_buf *s, int num) | |
142 | { | |
143 | if (num < 0) { | |
144 | seq_buf_set_overflow(s); | |
145 | } else { | |
146 | /* num must be negative on overflow */ | |
147 | BUG_ON(s->len + num > s->size); | |
148 | s->len += num; | |
149 | } | |
150 | } | |
151 | ||
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152 | extern __printf(2, 3) |
153 | int seq_buf_printf(struct seq_buf *s, const char *fmt, ...); | |
154 | extern __printf(2, 0) | |
155 | int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args); | |
3a161d99 SRRH |
156 | extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s); |
157 | extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, | |
d0ed46b6 | 158 | size_t start, int cnt); |
3a161d99 SRRH |
159 | extern int seq_buf_puts(struct seq_buf *s, const char *str); |
160 | extern int seq_buf_putc(struct seq_buf *s, unsigned char c); | |
161 | extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len); | |
162 | extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, | |
163 | unsigned int len); | |
dd23180a | 164 | extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc); |
353cade3 PM |
165 | extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, |
166 | int prefix_type, int rowsize, int groupsize, | |
167 | const void *buf, size_t len, bool ascii); | |
3a161d99 | 168 | |
2448913e SRRH |
169 | #ifdef CONFIG_BINARY_PRINTF |
170 | extern int | |
171 | seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary); | |
172 | #endif | |
173 | ||
96928d90 SS |
174 | void seq_buf_do_printk(struct seq_buf *s, const char *lvl); |
175 | ||
3a161d99 | 176 | #endif /* _LINUX_SEQ_BUF_H */ |