1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2023
4 */
5
6#include <asm/facility.h>
7
8unsigned int stfle_size(void)
9{
10 static unsigned int size;
11 unsigned int r;
12 u64 dummy;
13
14 r = READ_ONCE(size);
15 if (!r) {
16 r = __stfle_asm(&dummy, 1) + 1;
17 WRITE_ONCE(size, r);
18 }
19 return r;
20}
21EXPORT_SYMBOL(stfle_size);
22

source code of linux/arch/s390/kernel/facility.c