// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
 *
 * Derived from MIPS:
 * Copyright (C) 1995 Linus Torvalds
 * Copyright (C) 1995 Waldorf Electronics
 * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03  Ralf Baechle
 * Copyright (C) 1996 Stoned Elipot
 * Copyright (C) 1999 Silicon Graphics, Inc.
 * Copyright (C) 2000, 2001, 2002, 2007  Maciej W. Rozycki
 */
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/ioport.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <linux/root_dev.h>
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/libfdt.h>
#include <linux/of_fdt.h>
#include <linux/of_address.h>
#include <linux/suspend.h>
#include <linux/swiotlb.h>

#include <asm/addrspace.h>
#include <asm/alternative.h>
#include <asm/bootinfo.h>
#include <asm/cache.h>
#include <asm/cpu.h>
#include <asm/dma.h>
#include <asm/efi.h>
#include <asm/loongson.h>
#include <asm/numa.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/time.h>
#include <asm/unwind.h>

#define SMBIOS_BIOSSIZE_OFFSET          0x09
#define SMBIOS_BIOSEXTERN_OFFSET        0x13
#define SMBIOS_FREQLOW_OFFSET           0x16
#define SMBIOS_FREQHIGH_OFFSET          0x17
#define SMBIOS_FREQLOW_MASK             0xFF
#define SMBIOS_CORE_PACKAGE_OFFSET      0x23
#define SMBIOS_THREAD_PACKAGE_OFFSET    0x25
#define SMBIOS_THREAD_PACKAGE_2_OFFSET  0x2E
#define LOONGSON_EFI_ENABLE             (1 << 3)

unsigned long fw_arg0, fw_arg1, fw_arg2;
DEFINE_PER_CPU(unsigned long, kernelsp);
struct cpuinfo_loongarch cpu_data[NR_CPUS] __read_mostly;

EXPORT_SYMBOL(cpu_data);

struct loongson_board_info b_info;
static const char dmi_empty_string[] = "        ";

/*
 * Setup information
 *
 * These are initialized so they are in the .data section
 */
char init_command_line[COMMAND_LINE_SIZE] __initdata;

static int num_standard_resources;
static struct resource *standard_resources;

static struct resource code_resource = { .name = "Kernel code", };
static struct resource data_resource = { .name = "Kernel data", };
static struct resource bss_resource  = { .name = "Kernel bss", };

const char *get_system_type(void)
{
        return "generic-loongson-machine";
}

void __init arch_cpu_finalize_init(void)
{
        alternative_instructions();
}

static const char *dmi_string_parse(const struct dmi_header *dm, u8 s)
{
        const u8 *bp = ((u8 *) dm) + dm->length;

        if (s) {
                s--;
                while (s > 0 && *bp) {
                        bp += strlen(bp) + 1;
                        s--;
                }

                if (*bp != 0) {
                        size_t len = strlen(bp)+1;
                        size_t cmp_len = len > 8 ? 8 : len;

                        if (!memcmp(bp, dmi_empty_string, cmp_len))
                                return dmi_empty_string;

                        return bp;
                }
        }

        return "";
}

static void __init parse_cpu_table(const struct dmi_header *dm)
{
        long freq_temp = 0;
        char *dmi_data = (char *)dm;

        freq_temp = ((*(dmi_data + SMBIOS_FREQHIGH_OFFSET) << 8) +
                        ((*(dmi_data + SMBIOS_FREQLOW_OFFSET)) & SMBIOS_FREQLOW_MASK));
        cpu_clock_freq = freq_temp * 1000000;

        loongson_sysconf.cpuname = (void *)dmi_string_parse(dm, dmi_data[16]);
        loongson_sysconf.cores_per_package = *(u8 *)(dmi_data + SMBIOS_THREAD_PACKAGE_OFFSET);
        if (dm->length >= 0x30 && loongson_sysconf.cores_per_package == 0xff) {
                /* SMBIOS 3.0+ has ThreadCount2 for more than 255 threads */
                loongson_sysconf.cores_per_package =
                                          *(u16 *)(dmi_data + SMBIOS_THREAD_PACKAGE_2_OFFSET);
        }

        pr_info("CpuClock = %llu\n", cpu_clock_freq);
}

static void __init parse_bios_table(const struct dmi_header *dm)
{
        char *dmi_data = (char *)dm;

        b_info.bios_size = (*(dmi_data + SMBIOS_BIOSSIZE_OFFSET) + 1) << 6;
}

static void __init find_tokens(const struct dmi_header *dm, void *dummy)
{
        switch (dm->type) {
        case 0x0: /* Extern BIOS */
                parse_bios_table(dm);
                break;
        case 0x4: /* Calling interface */
                parse_cpu_table(dm);
                break;
        }
}
static void __init smbios_parse(void)
{
        b_info.bios_vendor = (void *)dmi_get_system_info(DMI_BIOS_VENDOR);
        b_info.bios_version = (void *)dmi_get_system_info(DMI_BIOS_VERSION);
        b_info.bios_release_date = (void *)dmi_get_system_info(DMI_BIOS_DATE);
        b_info.board_vendor = (void *)dmi_get_system_info(DMI_BOARD_VENDOR);
        b_info.board_name = (void *)dmi_get_system_info(DMI_BOARD_NAME);
        dmi_walk(find_tokens, NULL);
}

#ifdef CONFIG_ARCH_WRITECOMBINE
bool wc_enabled = true;
#else
bool wc_enabled = false;
#endif

EXPORT_SYMBOL(wc_enabled);

static int __init setup_writecombine(char *p)
{
        if (!strcmp(p, "on"))
                wc_enabled = true;
        else if (!strcmp(p, "off"))
                wc_enabled = false;
        else
                pr_warn("Unknown writecombine setting \"%s\".\n", p);

        return 0;
}
early_param("writecombine", setup_writecombine);

static int usermem __initdata;

static int __init early_parse_mem(char *p)
{
        phys_addr_t start, size;

        if (!p) {
                pr_err("mem parameter is empty, do nothing\n");
                return -EINVAL;
        }

        start = 0;
        size = memparse(p, &p);
        if (*p == '@')  /* Every mem=... should contain '@' */
                start = memparse(p + 1, &p);
        else {          /* Only one mem=... is allowed if no '@' */
                usermem = 1;
                memblock_enforce_memory_limit(size);
                return 0;
        }

        /*
         * If a user specifies memory size, we
         * blow away any automatically generated
         * size.
         */
        if (usermem == 0) {
                usermem = 1;
                memblock_remove(memblock_start_of_DRAM(),
                        memblock_end_of_DRAM() - memblock_start_of_DRAM());
        }

        if (!IS_ENABLED(CONFIG_NUMA))
                memblock_add(start, size);
        else
                memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);

        return 0;
}
early_param("mem", early_parse_mem);

static void __init arch_reserve_vmcore(void)
{
#ifdef CONFIG_PROC_VMCORE
        u64 i;
        phys_addr_t start, end;

        if (!is_kdump_kernel())
                return;

        if (!elfcorehdr_size) {
                for_each_mem_range(i, &start, &end) {
                        if (elfcorehdr_addr >= start && elfcorehdr_addr < end) {
                                /*
                                 * Reserve from the elf core header to the end of
                                 * the memory segment, that should all be kdump
                                 * reserved memory.
                                 */
                                elfcorehdr_size = end - elfcorehdr_addr;
                                break;
                        }
                }
        }

        if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
                pr_warn("elfcorehdr is overlapped\n");
                return;
        }

        memblock_reserve(elfcorehdr_addr, elfcorehdr_size);

        pr_info("Reserving %llu KiB of memory at 0x%llx for elfcorehdr\n",
                elfcorehdr_size >> 10, elfcorehdr_addr);
#endif
}

static void __init arch_reserve_crashkernel(void)
{
        int ret;
        unsigned long long low_size = 0;
        unsigned long long crash_base, crash_size;
        bool high = false;

        if (!IS_ENABLED(CONFIG_CRASH_RESERVE))
                return;

        ret = parse_crashkernel(boot_command_line, memblock_phys_mem_size(),
                                &crash_size, &crash_base, &low_size, NULL, &high);
        if (ret)
                return;

        reserve_crashkernel_generic(crash_size, crash_base, low_size, high);
}

static void __init fdt_setup(void)
{
#ifdef CONFIG_OF_EARLY_FLATTREE
        void *fdt_pointer;

        /* ACPI-based systems do not require parsing fdt */
        if (acpi_os_get_root_pointer())
                return;

        /* Prefer to use built-in dtb, checking its legality first. */
        if (IS_ENABLED(CONFIG_BUILTIN_DTB) && !fdt_check_header(__dtb_start))
                fdt_pointer = __dtb_start;
        else
                fdt_pointer = efi_fdt_pointer(); /* Fallback to firmware dtb */

        if (!fdt_pointer || fdt_check_header(fdt_pointer))
                return;

        early_init_dt_scan(fdt_pointer, __pa(fdt_pointer));
        early_init_fdt_reserve_self();
#endif
}

static void __init bootcmdline_init(char **cmdline_p)
{
        /*
         * If CONFIG_CMDLINE_FORCE is enabled then initializing the command line
         * is trivial - we simply use the built-in command line unconditionally &
         * unmodified.
         */
        if (IS_ENABLED(CONFIG_CMDLINE_FORCE)) {
                strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
                goto out;
        }

#ifdef CONFIG_OF_FLATTREE
        /*
         * If CONFIG_CMDLINE_BOOTLOADER is enabled and we are in FDT-based system,
         * the boot_command_line will be overwritten by early_init_dt_scan_chosen().
         * So we need to append init_command_line (the original copy of boot_command_line)
         * to boot_command_line.
         */
        if (initial_boot_params) {
                if (boot_command_line[0])
                        strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);

                if (!strstr(boot_command_line, init_command_line))
                        strlcat(boot_command_line, init_command_line, COMMAND_LINE_SIZE);

                goto out;
        }
#endif

        /*
         * Append built-in command line to the bootloader command line if
         * CONFIG_CMDLINE_EXTEND is enabled.
         */
        if (IS_ENABLED(CONFIG_CMDLINE_EXTEND) && CONFIG_CMDLINE[0]) {
                strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);
                strlcat(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);
        }

        /*
         * Use built-in command line if the bootloader command line is empty.
         */
        if (IS_ENABLED(CONFIG_CMDLINE_BOOTLOADER) && !boot_command_line[0])
                strscpy(boot_command_line, CONFIG_CMDLINE, COMMAND_LINE_SIZE);

out:
        *cmdline_p = boot_command_line;
}

void __init platform_init(void)
{
        arch_reserve_vmcore();
        arch_reserve_crashkernel();

#ifdef CONFIG_ACPI
        acpi_table_upgrade();
        acpi_gbl_use_global_lock = false;
        acpi_gbl_use_default_register_widths = false;
        acpi_boot_table_init();
#endif

        early_init_fdt_scan_reserved_mem();
        unflatten_and_copy_device_tree();

#ifdef CONFIG_NUMA
        init_numa_memory();
#endif
        dmi_setup();
        smbios_parse();
        pr_info("The BIOS Version: %s\n", b_info.bios_version);

        efi_runtime_init();
}

static void __init check_kernel_sections_mem(void)
{
        phys_addr_t start = __pa_symbol(&_text);
        phys_addr_t size = __pa_symbol(&_end) - start;

        if (!memblock_is_region_memory(start, size)) {
                pr_info("Kernel sections are not in the memory maps\n");
                memblock_add(start, size);
        }
}

/*
 * arch_mem_init - initialize memory management subsystem
 */
static void __init arch_mem_init(char **cmdline_p)
{
        /* Recalculate max_low_pfn for "mem=xxx" */
        max_pfn = PFN_DOWN(memblock_end_of_DRAM());
        max_low_pfn = min(PFN_DOWN(HIGHMEM_START), max_pfn);

        if (usermem)
                pr_info("User-defined physical RAM map overwrite\n");

        check_kernel_sections_mem();

        memblock_set_bottom_up(true);

        swiotlb_init(true, SWIOTLB_VERBOSE);

        dma_contiguous_reserve(PFN_PHYS(max_low_pfn));

        /* Reserve for hibernation. */
        register_nosave_region(PFN_DOWN(__pa_symbol(&__nosave_begin)),
                                   PFN_UP(__pa_symbol(&__nosave_end)));

        memblock_dump_all();
        memblock_set_bottom_up(false);

        early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
}

static void __init resource_init(void)
{
        long i = 0;
        size_t res_size;
        struct resource *res;
        struct memblock_region *region;

        code_resource.start = __pa_symbol(&_text);
        code_resource.end = __pa_symbol(&_etext) - 1;
        data_resource.start = __pa_symbol(&_etext);
        data_resource.end = __pa_symbol(&_edata) - 1;
        bss_resource.start = __pa_symbol(&__bss_start);
        bss_resource.end = __pa_symbol(&__bss_stop) - 1;

        num_standard_resources = memblock.memory.cnt;
        res_size = num_standard_resources * sizeof(*standard_resources);
        standard_resources = memblock_alloc_or_panic(res_size, SMP_CACHE_BYTES);

        for_each_mem_region(region) {
                res = &standard_resources[i++];
                if (!memblock_is_nomap(region)) {
                        res->name  = "System RAM";
                        res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
                        res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
                        res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
                } else {
                        res->name  = "Reserved";
                        res->flags = IORESOURCE_MEM;
                        res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
                        res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
                }

                request_resource(&iomem_resource, res);

                /*
                 *  We don't know which RAM region contains kernel data,
                 *  so we try it repeatedly and let the resource manager
                 *  test it.
                 */
                request_resource(res, &code_resource);
                request_resource(res, &data_resource);
                request_resource(res, &bss_resource);
        }
}

static int __init add_legacy_isa_io(struct fwnode_handle *fwnode,
                                resource_size_t hw_start, resource_size_t size)
{
        int ret = 0;
        unsigned long vaddr;
        struct logic_pio_hwaddr *range;

        range = kzalloc_obj(*range, GFP_ATOMIC);
        if (!range)
                return -ENOMEM;

        range->fwnode = fwnode;
        range->size = size = round_up(size, PAGE_SIZE);
        range->hw_start = hw_start;
        range->flags = LOGIC_PIO_CPU_MMIO;

        ret = logic_pio_register_range(range);
        if (ret) {
                kfree(range);
                return ret;
        }

        /* Legacy ISA must placed at the start of PCI_IOBASE */
        if (range->io_start != 0) {
                logic_pio_unregister_range(range);
                kfree(range);
                return -EINVAL;
        }

        vaddr = (unsigned long)(PCI_IOBASE + range->io_start);
        vmap_page_range(vaddr, vaddr + size, hw_start, pgprot_device(PAGE_KERNEL));

        return 0;
}

static __init int arch_reserve_pio_range(void)
{
        struct device_node *np;

        for_each_node_by_name(np, "isa") {
                struct of_range range;
                struct of_range_parser parser;

                pr_info("ISA Bridge: %pOF\n", np);

                if (of_range_parser_init(&parser, np)) {
                        pr_info("Failed to parse resources.\n");
                        of_node_put(np);
                        break;
                }

                for_each_of_range(&parser, &range) {
                        switch (range.flags & IORESOURCE_TYPE_BITS) {
                        case IORESOURCE_IO:
                                pr_info(" IO 0x%016llx..0x%016llx  ->  0x%016llx\n",
                                        range.cpu_addr,
                                        range.cpu_addr + range.size - 1,
                                        range.bus_addr);
                                if (add_legacy_isa_io(&np->fwnode, range.cpu_addr, range.size))
                                        pr_warn("Failed to reserve legacy IO in Logic PIO\n");
                                break;
                        case IORESOURCE_MEM:
                                pr_info(" MEM 0x%016llx..0x%016llx  ->  0x%016llx\n",
                                        range.cpu_addr,
                                        range.cpu_addr + range.size - 1,
                                        range.bus_addr);
                                break;
                        }
                }
        }

        return 0;
}
arch_initcall(arch_reserve_pio_range);

static int __init reserve_memblock_reserved_regions(void)
{
        u64 i, j;

        for (i = 0; i < num_standard_resources; ++i) {
                struct resource *mem = &standard_resources[i];
                phys_addr_t r_start, r_end, mem_size = resource_size(mem);

                if (!memblock_is_region_reserved(mem->start, mem_size))
                        continue;

                for_each_reserved_mem_range(j, &r_start, &r_end) {
                        resource_size_t start, end;

                        start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
                        end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);

                        if (start > mem->end || end < mem->start)
                                continue;

                        reserve_region_with_split(mem, start, end, "Reserved");
                }
        }

        return 0;
}
arch_initcall(reserve_memblock_reserved_regions);

#ifdef CONFIG_SMP
static void __init prefill_possible_map(void)
{
        int i, possible;

        possible = num_processors + disabled_cpus;
        if (possible > nr_cpu_ids)
                possible = nr_cpu_ids;

        pr_info("SMP: Allowing %d CPUs, %d hotplug CPUs\n",
                        possible, max((possible - num_processors), 0));

        for (i = 0; i < possible; i++)
                set_cpu_possible(i, true);
        for (; i < NR_CPUS; i++) {
                set_cpu_present(i, false);
                set_cpu_possible(i, false);
        }

        set_nr_cpu_ids(possible);
}
#endif

void __init setup_arch(char **cmdline_p)
{
        cpu_probe();
        unwind_init();

        init_environ();
        efi_init();
        fdt_setup();
        memblock_init();
        pagetable_init();
        bootcmdline_init(cmdline_p);
        parse_early_param();
        reserve_initrd_mem();

        platform_init();
        arch_mem_init(cmdline_p);

        resource_init();
        jump_label_init(); /* Initialise the static keys for paravirtualization */

#ifdef CONFIG_SMP
        plat_smp_setup();
        prefill_possible_map();
#endif

#ifdef CONFIG_KASAN
        kasan_init();
#endif
}