// SPDX-License-Identifier: GPL-2.0
/*
 *    Copyright IBM Corp. 2016
 */
#include <linux/kernel.h>
#include <asm/processor.h>
#include <asm/facility.h>
#include <asm/lowcore.h>
#include <asm/sclp.h>
#include "boot.h"

static unsigned long als[] = { FACILITIES_ALS };

static void u16_to_decimal(char *str, u16 val)
{
        int div = 1;

        while (div * 10 <= val)
                div *= 10;
        while (div) {
                *str++ = '0' + val / div;
                val %= div;
                div /= 10;
        }
        *str = '\0';
}

void print_missing_facilities(void)
{
        static char als_str[80] = "Missing facilities: ";
        unsigned long val;
        char val_str[6];
        int i, j, first;

        first = 1;
        for (i = 0; i < ARRAY_SIZE(als); i++) {
                val = ~stfle_fac_list[i] & als[i];
                for (j = 0; j < BITS_PER_LONG; j++) {
                        if (!(val & (1UL << (BITS_PER_LONG - 1 - j))))
                                continue;
                        if (!first)
                                strcat(als_str, ",");
                        /*
                         * Make sure we stay within one line. Consider that
                         * each facility bit adds up to five characters and
                         * z/VM adds a four character prefix.
                         */
                        if (strlen(als_str) > 70) {
                                boot_emerg("%s\n", als_str);
                                *als_str = '\0';
                        }
                        u16_to_decimal(val_str, i * BITS_PER_LONG + j);
                        strcat(als_str, val_str);
                        first = 0;
                }
        }
        boot_emerg("%s\n", als_str);
}

static void facility_mismatch(void)
{
        struct cpuid id;

        get_cpu_id(&id);
        boot_emerg("The Linux kernel requires more recent processor hardware\n");
        boot_emerg("Detected machine-type number: %4x\n", id.machine);
        print_missing_facilities();
        boot_emerg("See z/Architecture Principles of Operation - Facility Indications\n");
        disabled_wait();
}

void verify_facilities(void)
{
        int i;

        __stfle(stfle_fac_list, ARRAY_SIZE(stfle_fac_list));
        for (i = 0; i < ARRAY_SIZE(als); i++) {
                if ((stfle_fac_list[i] & als[i]) != als[i])
                        facility_mismatch();
        }
}