/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_SEQ_BUF_H #define _LINUX_SEQ_BUF_H #include <linux/fs.h> /* * Trace sequences are used to allow a function to call several other functions * to create a string of data to use. */ /** * seq_buf - seq buffer structure * @buffer: pointer to the buffer * @size: size of the buffer * @len: the amount of data inside the buffer * @readpos: The next position to read in the buffer. */ struct seq_buf { char *buffer; size_t size; size_t len; loff_t readpos; }; static inline void seq_buf_clear(struct seq_buf *s) { s->len = 0; s->readpos = 0; } static inline void seq_buf_init(struct seq_buf *s, char *buf, unsigned int size) { s->buffer = buf; s->size = size; seq_buf_clear(s); } /* * seq_buf have a buffer that might overflow. When this happens * the len and size are set to be equal. */ static inline bool seq_buf_has_overflowed(struct seq_buf *s) { return s->len > s->size; } static inline void seq_buf_set_overflow(struct seq_buf *s) { s->len = s->size + 1; } /* * How much buffer is left on the seq_buf? */ static inline unsigned int seq_buf_buffer_left(struct seq_buf *s) { if (seq_buf_has_overflowed(s)) return 0; return s->size - s->len; } /* How much buffer was written? */ static inline unsigned int seq_buf_used(struct seq_buf *s) { return min(s->len, s->size); } /** * seq_buf_get_buf - get buffer to write arbitrary data to * @s: the seq_buf handle * @bufp: the beginning of the buffer is stored here * * Return the number of bytes available in the buffer, or zero if * there's no space. */ static inline size_t seq_buf_get_buf(struct seq_buf *s, char **bufp) { WARN_ON(s->len > s->size + 1); if (s->len < s->size) { *bufp = s->buffer + s->len; return s->size - s->len; } *bufp = NULL; return 0; } /** * seq_buf_commit - commit data to the buffer * @s: the seq_buf handle * @num: the number of bytes to commit * * Commit @num bytes of data written to a buffer previously acquired * by seq_buf_get. To signal an error condition, or that the data * didn't fit in the available space, pass a negative @num value. */ static inline void seq_buf_commit(struct seq_buf *s, int num) { if (num < 0) { seq_buf_set_overflow(s); } else { /* num must be negative on overflow */ BUG_ON(s->len + num > s->size); s->len += num; } } extern __printf(2, 3) int seq_buf_printf(struct seq_buf *s, const char *fmt, ...); extern __printf(2, 0) int seq_buf_vprintf(struct seq_buf *s, const char *fmt, va_list args); extern int seq_buf_print_seq(struct seq_file *m, struct seq_buf *s); extern int seq_buf_to_user(struct seq_buf *s, char __user *ubuf, int cnt); extern int seq_buf_puts(struct seq_buf *s, const char *str); extern int seq_buf_putc(struct seq_buf *s, unsigned char c); extern int seq_buf_putmem(struct seq_buf *s, const void *mem, unsigned int len); extern int seq_buf_putmem_hex(struct seq_buf *s, const void *mem, unsigned int len); extern int seq_buf_path(struct seq_buf *s, const struct path *path, const char *esc); extern int seq_buf_hex_dump(struct seq_buf *s, const char *prefix_str, int prefix_type, int rowsize, int groupsize, const void *buf, size_t len, bool ascii); #ifdef CONFIG_BINARY_PRINTF extern int seq_buf_bprintf(struct seq_buf *s, const char *fmt, const u32 *binary); #endif #endif /* _LINUX_SEQ_BUF_H */