xref: /linux-6.15/include/linux/seq_buf.h (revision 3a161d99)
1 #ifndef _LINUX_SEQ_BUF_H
2 #define _LINUX_SEQ_BUF_H
3 
4 #include <linux/fs.h>
5 
6 /*
7  * Trace sequences are used to allow a function to call several other functions
8  * to create a string of data to use.
9  */
10 
11 /**
12  * seq_buf - seq buffer structure
13  * @buffer:	pointer to the buffer
14  * @size:	size of the buffer
15  * @len:	the amount of data inside the buffer
16  * @readpos:	The next position to read in the buffer.
17  */
18 struct seq_buf {
19 	unsigned char		*buffer;
20 	unsigned int		size;
21 	unsigned int		len;
22 	unsigned int		readpos;
23 };
24 
25 static inline void
26 seq_buf_init(struct seq_buf *s, unsigned char *buf, unsigned int size)
27 {
28 	s->buffer = buf;
29 	s->size = size;
30 	s->len = 0;
31 	s->readpos = 0;
32 }
33 
34 /*
35  * seq_buf have a buffer that might overflow. When this happens
36  * the len and size are set to be equal.
37  */
38 static inline bool
39 seq_buf_has_overflowed(struct seq_buf *s)
40 {
41 	return s->len == s->size;
42 }
43 
44 static inline void
45 seq_buf_set_overflow(struct seq_buf *s)
46 {
47 	s->len = s->size;
48 }
49 
50 /*
51  * How much buffer is left on the seq_buf?
52  */
53 static inline unsigned int
54 seq_buf_buffer_left(struct seq_buf *s)
55 {
56 	if (seq_buf_has_overflowed(s))
57 		return 0;
58 
59 	return (s->size - 1) - s->len;
60 }
61 
62 extern __printf(2, 3)
63 int seq_buf_printf(struct seq_buf *s, const char *fmt, ...);
64 extern __printf(2, 0)
65 int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args);
66 extern int
67 seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary);
68 extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s);
69 extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf,
70 			   int cnt);
71 extern int seq_buf_puts(struct seq_buf *s, const char *str);
72 extern int seq_buf_putc(struct seq_buf *s, unsigned char c);
73 extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len);
74 extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem,
75 			      unsigned int len);
76 extern int seq_buf_path(struct seq_buf *s, const struct path *path);
77 
78 extern int seq_buf_bitmask(struct seq_buf *s, const unsigned long *maskp,
79 			   int nmaskbits);
80 
81 #endif /* _LINUX_SEQ_BUF_H */
82