// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *  Copyright 2006 Michael Ellerman, IBM Corporation
 */

#include <linux/kernel.h>
#include <linux/interrupt.h>

#include <asm/setup.h>
#include <asm/page.h>
#include <asm/firmware.h>
#include <asm/kexec.h>
#include <asm/xics.h>
#include <asm/xive.h>
#include <asm/smp.h>
#include <asm/plpar_wrappers.h>

#include "pseries.h"

void pseries_kexec_cpu_down(int crash_shutdown, int secondary)
{
        /*
         * Ensure vpa/slb_shadow/dtl cleanup even while we are crashing.
         * Why? The hypervisor is not crashing so at least attempt unregister to
         * avoid the hypervisor stepping on our memory. If hypervisor or kexec
         * kernel steps on the old memory allocated to these areas before the
         * new kexec-kernel happens to allocate and register new areas,
         * the hypervisor will see invalid content which may cause
         * unexpected behavior.
         */
        if (firmware_has_feature(FW_FEATURE_SPLPAR)) {
                int ret;
                int cpu = smp_processor_id();
                int hwcpu = hard_smp_processor_id();

                if (get_lppaca()->dtl_enable_mask) {
                        ret = unregister_dtl(hwcpu);
                        if (ret) {
                                pr_err("WARNING: DTL deregistration for cpu "
                                       "%d (hw %d) failed with %d\n",
                                       cpu, hwcpu, ret);
                        }
                }

                ret = unregister_slb_shadow(hwcpu);
                if (ret) {
                        pr_err("WARNING: SLB shadow buffer deregistration "
                               "for cpu %d (hw %d) failed with %d\n",
                               cpu, hwcpu, ret);
                }

                ret = unregister_vpa(hwcpu);
                if (ret) {
                        pr_err("WARNING: VPA deregistration for cpu %d "
                               "(hw %d) failed with %d\n", cpu, hwcpu, ret);
                }
        }

        if (xive_enabled()) {
                xive_teardown_cpu();

                if (!secondary)
                        xive_shutdown();
        } else
                xics_kexec_teardown_cpu(secondary);
}