// SPDX-License-Identifier: GPL-2.0-only
/*
 * PPC32 code to handle Linux booting another kernel.
 *
 * Copyright (C) 2002-2003 Eric Biederman  <ebiederm@xmission.com>
 * GameCube/ppc32 port Copyright (C) 2004 Albert Herranz
 * Copyright (C) 2005 IBM Corporation.
 */

#include <linux/irq.h>
#include <linux/kexec.h>
#include <linux/mm.h>
#include <linux/string.h>
#include <asm/cacheflush.h>
#include <asm/hw_irq.h>
#include <asm/io.h>

typedef void (*relocate_new_kernel_t)(
                                unsigned long indirection_page,
                                unsigned long reboot_code_buffer,
                                unsigned long start_address) __noreturn;

/*
 * This is a generic machine_kexec function suitable at least for
 * non-OpenFirmware embedded platforms.
 * It merely copies the image relocation code to the control page and
 * jumps to it.
 * A platform specific function may just call this one.
 */
void default_machine_kexec(struct kimage *image)
{
        extern const unsigned int relocate_new_kernel_size;
        unsigned long page_list;
        unsigned long reboot_code_buffer, reboot_code_buffer_phys;
        relocate_new_kernel_t rnk;

        /* Interrupts aren't acceptable while we reboot */
        local_irq_disable();

        /* mask each interrupt so we are in a more sane state for the
         * kexec kernel */
        machine_kexec_mask_interrupts();

        page_list = image->head;

        /* we need both effective and real address here */
        reboot_code_buffer =
                        (unsigned long)page_address(image->control_code_page);
        reboot_code_buffer_phys = virt_to_phys((void *)reboot_code_buffer);

        /* copy our kernel relocation code to the control code page */
        memcpy((void *)reboot_code_buffer, relocate_new_kernel,
                                                relocate_new_kernel_size);

        flush_icache_range(reboot_code_buffer,
                                reboot_code_buffer + KEXEC_CONTROL_PAGE_SIZE);
        printk(KERN_INFO "Bye!\n");

        if (!IS_ENABLED(CONFIG_PPC_85xx) && !IS_ENABLED(CONFIG_44x))
                relocate_new_kernel(page_list, reboot_code_buffer_phys, image->start);

        /* now call it */
        rnk = (relocate_new_kernel_t) reboot_code_buffer;
        (*rnk)(page_list, reboot_code_buffer_phys, image->start);
}

int machine_kexec_prepare(struct kimage *image)
{
        return 0;
}