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
10 enum {
11 TYPE_HWCAP,
12 TYPE_FACILITY,
13 };
14
15 struct s390_cpu_feature {
16 unsigned int type : 4;
17 unsigned int num : 28;
18 };
19
20 static 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 */
29 int 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 }
46 EXPORT_SYMBOL(cpu_have_feature);
47
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.