// SPDX-License-Identifier: GPL-2.0-only
/* -*- linux-c -*- ------------------------------------------------------- *
 *
 *   Copyright (C) 1991, 1992 Linus Torvalds
 *   Copyright 2007-2008 rPath, Inc. - All Rights Reserved
 *
 * ----------------------------------------------------------------------- */

/*
 * arch/x86/boot/cpu.c
 *
 * Check for obligatory CPU features and abort if the features are not
 * present.
 */

#include "boot.h"
#include "cpustr.h"

static char *cpu_name(int level)
{
        static char buf[6];

        if (level == 64) {
                return "x86-64";
        } else {
                if (level == 15)
                        level = 6;
                sprintf(buf, "i%d86", level);
                return buf;
        }
}

static void show_cap_strs(u32 *err_flags)
{
        int i, j;
        const unsigned char *msg_strs = (const unsigned char *)x86_cap_strs;
        for (i = 0; i < NCAPINTS; i++) {
                u32 e = err_flags[i];
                for (j = 0; j < 32; j++) {
                        if (msg_strs[0] < i ||
                            (msg_strs[0] == i && msg_strs[1] < j)) {
                                /* Skip to the next string */
                                msg_strs += 2;
                                while (*msg_strs++)
                                        ;
                        }
                        if (e & 1) {
                                if (msg_strs[0] == i &&
                                    msg_strs[1] == j &&
                                    msg_strs[2])
                                        printf("%s ", msg_strs+2);
                                else
                                        printf("%d:%d ", i, j);
                        }
                        e >>= 1;
                }
        }
}

int validate_cpu(void)
{
        u32 *err_flags;
        int cpu_level, req_level;

        check_cpu(&cpu_level, &req_level, &err_flags);

        if (cpu_level < req_level) {
                printf("This kernel requires an %s CPU, ",
                       cpu_name(req_level));
                printf("but only detected an %s CPU.\n",
                       cpu_name(cpu_level));
                return -1;
        }

        if (err_flags) {
                puts("This kernel requires the following features "
                     "not present on the CPU:\n");
                show_cap_strs(err_flags);
                putchar('\n');
                return -1;
        } else if (check_knl_erratum()) {
                return -1;
        } else {
                return 0;
        }
}