// SPDX-License-Identifier: GPL-2.0-only
/*
 * Default generic APIC driver. This handles up to 8 CPUs.
 *
 * Copyright 2003 Andi Kleen, SuSE Labs.
 *
 * Generic x86 APIC driver probe layer.
 */
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/smp.h>

#include <xen/xen.h>

#include <asm/io_apic.h>
#include <asm/apic.h>
#include <asm/acpi.h>

#include "local.h"

static u32 default_get_apic_id(u32 x)
{
        unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));

        if (APIC_XAPIC(ver) || boot_cpu_has(X86_FEATURE_EXTD_APICID))
                return (x >> 24) & 0xFF;
        else
                return (x >> 24) & 0x0F;
}

/* should be called last. */
static int probe_default(void)
{
        return 1;
}

static struct apic apic_default __ro_after_init = {

        .name                           = "default",
        .probe                          = probe_default,

        .dest_mode_logical              = true,

        .disable_esr                    = 0,

        .init_apic_ldr                  = default_init_apic_ldr,
        .cpu_present_to_apicid          = default_cpu_present_to_apicid,

        .max_apic_id                    = 0xFE,
        .get_apic_id                    = default_get_apic_id,

        .calc_dest_apicid               = apic_flat_calc_apicid,

        .send_IPI                       = default_send_IPI_single,
        .send_IPI_mask                  = default_send_IPI_mask_logical,
        .send_IPI_mask_allbutself       = default_send_IPI_mask_allbutself_logical,
        .send_IPI_allbutself            = default_send_IPI_allbutself,
        .send_IPI_all                   = default_send_IPI_all,
        .send_IPI_self                  = default_send_IPI_self,

        .read                           = native_apic_mem_read,
        .write                          = native_apic_mem_write,
        .eoi                            = native_apic_mem_eoi,
        .icr_read                       = native_apic_icr_read,
        .icr_write                      = native_apic_icr_write,
        .wait_icr_idle                  = apic_mem_wait_icr_idle,
        .safe_wait_icr_idle             = apic_mem_wait_icr_idle_timeout,
};

apic_driver(apic_default);

struct apic *apic __ro_after_init = &apic_default;
EXPORT_SYMBOL_GPL(apic);

static int cmdline_apic __initdata;
static int __init parse_apic(char *arg)
{
        struct apic **drv;

        if (!arg)
                return -EINVAL;

        for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
                if (!strcmp((*drv)->name, arg)) {
                        apic_install_driver(*drv);
                        cmdline_apic = 1;
                        return 0;
                }
        }

        /* Parsed again by __setup for debug/verbose */
        return 0;
}
early_param("apic", parse_apic);

void __init x86_32_probe_apic(void)
{
        if (!cmdline_apic) {
                struct apic **drv;

                for (drv = __apicdrivers; drv < __apicdrivers_end; drv++) {
                        if ((*drv)->probe()) {
                                apic_install_driver(*drv);
                                break;
                        }
                }
                /* Not visible without early console */
                if (drv == __apicdrivers_end)
                        panic("Didn't find an APIC driver");
        }
}