111 	size_t read_tail;  member
130 	return ldata->read_head - ldata->read_tail;  in read_cnt()
218 	return head - ldata->read_tail;  in chars_in_buffer()
243 	if (ldata->icanon && ldata->canon_head == ldata->read_tail)  in n_tty_check_throttle()
314 	ldata->read_head = ldata->canon_head = ldata->read_tail = 0;  in reset_buffer_flags()
1694 		size_t tail = smp_load_acquire(&ldata->read_tail);  in n_tty_receive_buf_common()
1780 		ldata->line_start = ldata->read_tail;  in n_tty_set_termios()
1782 			ldata->canon_head = ldata->read_tail;  in n_tty_set_termios()
1913 		return ldata->canon_head != ldata->read_tail;  in input_available_p()
1915 		return ldata->commit_head - ldata->read_tail >= amt;  in input_available_p()
1944 	size_t tail = MASK(ldata->read_tail);  in copy_from_read_buf()
1946 	n = min3(head - ldata->read_tail, N_TTY_BUF_SIZE - tail, *nr);  in copy_from_read_buf()
1955 	smp_store_release(&ldata->read_tail, ldata->read_tail + n);  in copy_from_read_buf()
1959 	    head == ldata->read_tail)  in copy_from_read_buf()
1966 	return head != ldata->read_tail;  in copy_from_read_buf()
2005 	n = min(*nr, canon_head - ldata->read_tail);  in canon_copy_from_read_buf()
2007 	tail = MASK(ldata->read_tail);  in canon_copy_from_read_buf()
2033 	smp_store_release(&ldata->read_tail, ldata->read_tail + c);  in canon_copy_from_read_buf()
2037 			ldata->line_start = ldata->read_tail;  in canon_copy_from_read_buf()
2045 	return ldata->read_tail != canon_head;  in canon_copy_from_read_buf()
2058 	tail = ldata->read_tail;  in canon_skip_eof()
2073 	smp_store_release(&ldata->read_tail, ldata->read_tail + 1);  in canon_skip_eof()
2230 	old_tail = ldata->read_tail;  in n_tty_read()
2284 	if (old_tail != ldata->read_tail) {  in n_tty_read()
2464 	if (ldata->canon_head == ldata->read_tail)  in inq_canon()
2467 	tail = ldata->read_tail;  in inq_canon()