// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright IBM Corp. 2022
 */

#include <linux/cpufeature.h>
#include <linux/export.h>
#include <linux/bug.h>
#include <asm/machine.h>
#include <asm/elf.h>

enum {
        TYPE_HWCAP,
        TYPE_FACILITY,
        TYPE_MACHINE,
};

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},
        [S390_CPU_FEATURE_D288] = {.type = TYPE_MACHINE, .num = MFEATURE_DIAG288},
};

/*
 * 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);
        case TYPE_MACHINE:
                return test_machine_feature(feature->num);
        default:
                WARN_ON_ONCE(1);
                return 0;
        }
}
EXPORT_SYMBOL(cpu_have_feature);