117 	size_t read_tail;  member
136 	return ldata->read_head - ldata->read_tail;  in read_cnt()
224 	return head - ldata->read_tail;  in chars_in_buffer()
249 	if (ldata->icanon && ldata->canon_head == ldata->read_tail)  in n_tty_check_throttle()
325 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;  in reset_buffer_flags()
1713 		size_t tail = smp_load_acquire(&ldata->read_tail);  in n_tty_receive_buf_common()
1801 		ldata->line_start = ldata->read_tail;  in n_tty_set_termios()
1803 			ldata->canon_head = ldata->read_tail;  in n_tty_set_termios()
1935 		return ldata->canon_head != ldata->read_tail;  in input_available_p()
1937 		return ldata->commit_head - ldata->read_tail >= amt;  in input_available_p()
1966 	size_t tail = MASK(ldata->read_tail);  in copy_from_read_buf()
1968 	n = min(head - ldata->read_tail, N_TTY_BUF_SIZE - tail);  in copy_from_read_buf()
1976 		smp_store_release(&ldata->read_tail, ldata->read_tail + n);  in copy_from_read_buf()
1979 		    (head == ldata->read_tail))  in copy_from_read_buf()
1985 		return head != ldata->read_tail;  in copy_from_read_buf()
2026 	n = min(*nr, canon_head - ldata->read_tail);  in canon_copy_from_read_buf()
2028 	tail = MASK(ldata->read_tail);  in canon_copy_from_read_buf()
2060 	smp_store_release(&ldata->read_tail, ldata->read_tail + c);  in canon_copy_from_read_buf()
2064 			ldata->line_start = ldata->read_tail;  in canon_copy_from_read_buf()
2072 	return ldata->read_tail != canon_head;  in canon_copy_from_read_buf()
2085 	tail = ldata->read_tail;  in canon_skip_eof()
2100 	smp_store_release(&ldata->read_tail, ldata->read_tail + 1);  in canon_skip_eof()
2225 	old_tail = ldata->read_tail;  in n_tty_read()
2314 	if (old_tail != ldata->read_tail) {  in n_tty_read()
2483 	if (ldata->canon_head == ldata->read_tail)  in inq_canon()
2486 	tail = ldata->read_tail;  in inq_canon()