| /* 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 */ |