// SPDX-License-Identifier: GPL-2.0
/*
 * EFI initialization
 *
 * Author: Jianmin Lv <lvjianmin@loongson.cn>
 *         Huacai Chen <chenhuacai@loongson.cn>
 *
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 */

#include <linux/acpi.h>
#include <linux/efi.h>
#include <linux/efi-bgrt.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/io.h>
#include <linux/kobject.h>
#include <linux/memblock.h>
#include <linux/reboot.h>
#include <linux/sysfb.h>
#include <linux/uaccess.h>

#include <asm/early_ioremap.h>
#include <asm/efi.h>
#include <asm/loongson.h>

static unsigned long efi_nr_tables;
static unsigned long efi_config_table;

static unsigned long __initdata boot_memmap = EFI_INVALID_TABLE_ADDR;
static unsigned long __initdata fdt_pointer = EFI_INVALID_TABLE_ADDR;

static efi_system_table_t *efi_systab;
static efi_config_table_type_t arch_tables[] __initdata = {
        {LINUX_EFI_BOOT_MEMMAP_GUID,    &boot_memmap,   "MEMMAP" },
        {DEVICE_TREE_GUID,              &fdt_pointer,   "FDTPTR" },
        {},
};

void __init *efi_fdt_pointer(void)
{
        if (!efi_systab)
                return NULL;

        if (fdt_pointer == EFI_INVALID_TABLE_ADDR)
                return NULL;

        return early_memremap_ro(fdt_pointer, SZ_64K);
}

void __init efi_runtime_init(void)
{
        if (!efi_enabled(EFI_BOOT) || !efi_systab->runtime)
                return;

        if (efi_runtime_disabled()) {
                pr_info("EFI runtime services will be disabled.\n");
                return;
        }

        efi.runtime = (efi_runtime_services_t *)efi_systab->runtime;
        efi.runtime_version = (unsigned int)efi.runtime->hdr.revision;

        efi_native_runtime_setup();
        set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
}

bool efi_poweroff_required(void)
{
        return efi_enabled(EFI_RUNTIME_SERVICES) &&
                (acpi_gbl_reduced_hardware || acpi_no_s5);
}

unsigned long __initdata primary_display_table = EFI_INVALID_TABLE_ADDR;

#if defined(CONFIG_SYSFB) || defined(CONFIG_EFI_EARLYCON)
struct sysfb_display_info sysfb_primary_display __section(".data");
EXPORT_SYMBOL_GPL(sysfb_primary_display);
#endif

static void __init init_primary_display(void)
{
        struct sysfb_display_info *dpy;

        if (primary_display_table == EFI_INVALID_TABLE_ADDR)
                return;

        dpy = early_memremap(primary_display_table, sizeof(*dpy));
        if (!dpy) {
                pr_err("Could not map primary_display config table\n");
                return;
        }
        sysfb_primary_display = *dpy;
        memset(dpy, 0, sizeof(*dpy));
        early_memunmap(dpy, sizeof(*dpy));

        memblock_reserve(__screen_info_lfb_base(&sysfb_primary_display.screen),
                         sysfb_primary_display.screen.lfb_size);
}

void __init efi_init(void)
{
        int size;
        void *config_tables;
        struct efi_boot_memmap *tbl;

        if (!efi_system_table)
                return;

        efi_systab = (efi_system_table_t *)early_memremap_ro(efi_system_table, sizeof(*efi_systab));
        if (!efi_systab) {
                pr_err("Can't find EFI system table.\n");
                return;
        }

        efi_systab_report_header(&efi_systab->hdr, efi_systab->fw_vendor);

        if (IS_ENABLED(CONFIG_64BIT))
                set_bit(EFI_64BIT, &efi.flags);

        efi_nr_tables    = efi_systab->nr_tables;
        efi_config_table = (unsigned long)efi_systab->tables;

        size = sizeof(efi_config_table_t);
        config_tables = early_memremap(efi_config_table, efi_nr_tables * size);
        efi_config_parse_tables(config_tables, efi_systab->nr_tables, arch_tables);
        early_memunmap(config_tables, efi_nr_tables * size);

        set_bit(EFI_CONFIG_TABLES, &efi.flags);

        if (IS_ENABLED(CONFIG_EFI_EARLYCON) || IS_ENABLED(CONFIG_SYSFB))
                init_primary_display();

        if (boot_memmap == EFI_INVALID_TABLE_ADDR)
                return;

        tbl = early_memremap_ro(boot_memmap, sizeof(*tbl));
        if (tbl) {
                struct efi_memory_map_data data;

                data.phys_map           = boot_memmap + sizeof(*tbl);
                data.size               = tbl->map_size;
                data.desc_size          = tbl->desc_size;
                data.desc_version       = tbl->desc_ver;

                if (efi_memmap_init_early(&data) < 0)
                        panic("Unable to map EFI memory map.\n");

                /*
                 * Reserve the physical memory region occupied by the EFI
                 * memory map table (header + descriptors). This is crucial
                 * for kdump, as the kdump kernel relies on this original
                 * memmap passed by the bootloader. Without reservation,
                 * this region could be overwritten by the primary kernel.
                 * Also, set the EFI_PRESERVE_BS_REGIONS flag to indicate that
                 * critical boot services code/data regions like this are preserved.
                 */
                memblock_reserve((phys_addr_t)boot_memmap, sizeof(*tbl) + data.size);
                set_bit(EFI_PRESERVE_BS_REGIONS, &efi.flags);

                early_memunmap(tbl, sizeof(*tbl));
        }

        efi_esrt_init();
}