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