facility.c

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