1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright IBM Corp. 2022
4 */
5
6#include <linux/cpufeature.h>
7#include <linux/bug.h>
8#include <asm/elf.h>
9
10enum {
11	TYPE_HWCAP,
12	TYPE_FACILITY,
13};
14
15struct s390_cpu_feature {
16	unsigned int type	: 4;
17	unsigned int num	: 28;
18};
19
20static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
21	[S390_CPU_FEATURE_MSA]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
22	[S390_CPU_FEATURE_VXRS]	= {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
23	[S390_CPU_FEATURE_UV]	= {.type = TYPE_FACILITY, .num = 158},
24};
25
26/*
27 * cpu_have_feature - Test CPU features on module initialization
28 */
29int cpu_have_feature(unsigned int num)
30{
31	struct s390_cpu_feature *feature;
32
33	if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES))
34		return 0;
35	feature = &s390_cpu_features[num];
36	switch (feature->type) {
37	case TYPE_HWCAP:
38		return !!(elf_hwcap & BIT(feature->num));
39	case TYPE_FACILITY:
40		return test_facility(feature->num);
41	default:
42		WARN_ON_ONCE(1);
43		return 0;
44	}
45}
46EXPORT_SYMBOL(cpu_have_feature);
47