linuxdebug/arch/s390/kernel/cpufeature.c

47 lines
1009 B
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2022
*/
#include <linux/cpufeature.h>
#include <linux/bug.h>
#include <asm/elf.h>
enum {
TYPE_HWCAP,
TYPE_FACILITY,
};
struct s390_cpu_feature {
unsigned int type : 4;
unsigned int num : 28;
};
static struct s390_cpu_feature s390_cpu_features[MAX_CPU_FEATURES] = {
[S390_CPU_FEATURE_MSA] = {.type = TYPE_HWCAP, .num = HWCAP_NR_MSA},
[S390_CPU_FEATURE_VXRS] = {.type = TYPE_HWCAP, .num = HWCAP_NR_VXRS},
[S390_CPU_FEATURE_UV] = {.type = TYPE_FACILITY, .num = 158},
};
/*
* cpu_have_feature - Test CPU features on module initialization
*/
int cpu_have_feature(unsigned int num)
{
struct s390_cpu_feature *feature;
if (WARN_ON_ONCE(num >= MAX_CPU_FEATURES))
return 0;
feature = &s390_cpu_features[num];
switch (feature->type) {
case TYPE_HWCAP:
return !!(elf_hwcap & BIT(feature->num));
case TYPE_FACILITY:
return test_facility(feature->num);
default:
WARN_ON_ONCE(1);
return 0;
}
}
EXPORT_SYMBOL(cpu_have_feature);