// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
 *  Chen Liqin <liqin.chen@sunplusct.com>
 *  Lennox Wu <lennox.wu@sunplusct.com>
 * Copyright (C) 2012 Regents of the University of California
 * Copyright (C) 2020 FORTH-ICS/CARV
 *  Nick Kossifidis <mick@ics.forth.gr>
 */

#include <linux/acpi.h>
#include <linux/cpu.h>
#include <linux/init.h>
#include <linux/mm.h>
#include <linux/memblock.h>
#include <linux/sched.h>
#include <linux/console.h>
#include <linux/of_fdt.h>
#include <linux/sched/task.h>
#include <linux/smp.h>
#include <linux/efi.h>
#include <linux/crash_dump.h>
#include <linux/panic_notifier.h>
#include <linux/jump_label.h>
#include <linux/gcd.h>

#include <asm/acpi.h>
#include <asm/alternative.h>
#include <asm/cacheflush.h>
#include <asm/cpufeature.h>
#include <asm/early_ioremap.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/set_memory.h>
#include <asm/sections.h>
#include <asm/sbi.h>
#include <asm/tlbflush.h>
#include <asm/thread_info.h>
#include <asm/kasan.h>
#include <asm/efi.h>

#include "head.h"

/*
 * The lucky hart to first increment this variable will boot the other cores.
 * This is used before the kernel initializes the BSS so it can't be in the
 * BSS.
 */
atomic_t hart_lottery __section(".sdata")
#ifdef CONFIG_XIP_KERNEL
= ATOMIC_INIT(0xC001BEEF)
#endif
;
unsigned long boot_cpu_hartid;
EXPORT_SYMBOL_GPL(boot_cpu_hartid);

/*
 * Place kernel memory regions on the resource tree so that
 * kexec-tools can retrieve them from /proc/iomem. While there
 * also add "System RAM" regions for compatibility with other
 * archs, and the rest of the known regions for completeness.
 */
static struct resource kimage_res = { .name = "Kernel image", };
static struct resource code_res = { .name = "Kernel code", };
static struct resource data_res = { .name = "Kernel data", };
static struct resource rodata_res = { .name = "Kernel rodata", };
static struct resource bss_res = { .name = "Kernel bss", };
#ifdef CONFIG_CRASH_DUMP
static struct resource elfcorehdr_res = { .name = "ELF Core hdr", };
#endif

static int num_standard_resources;
static struct resource *standard_resources;

static int __init add_resource(struct resource *parent,
                                struct resource *res)
{
        int ret = 0;

        ret = insert_resource(parent, res);
        if (ret < 0) {
                pr_err("Failed to add a %s resource at %llx\n",
                        res->name, (unsigned long long) res->start);
                return ret;
        }

        return 1;
}

static int __init add_kernel_resources(void)
{
        int ret = 0;

        /*
         * The memory region of the kernel image is continuous and
         * was reserved on setup_bootmem, register it here as a
         * resource, with the various segments of the image as
         * child nodes.
         */

        code_res.start = __pa_symbol(_text);
        code_res.end = __pa_symbol(_etext) - 1;
        code_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

        rodata_res.start = __pa_symbol(__start_rodata);
        rodata_res.end = __pa_symbol(__end_rodata) - 1;
        rodata_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

        data_res.start = __pa_symbol(_data);
        data_res.end = __pa_symbol(_edata) - 1;
        data_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

        bss_res.start = __pa_symbol(__bss_start);
        bss_res.end = __pa_symbol(__bss_stop) - 1;
        bss_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

        kimage_res.start = code_res.start;
        kimage_res.end = bss_res.end;
        kimage_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;

        ret = add_resource(&iomem_resource, &kimage_res);
        if (ret < 0)
                return ret;

        ret = add_resource(&kimage_res, &code_res);
        if (ret < 0)
                return ret;

        ret = add_resource(&kimage_res, &rodata_res);
        if (ret < 0)
                return ret;

        ret = add_resource(&kimage_res, &data_res);
        if (ret < 0)
                return ret;

        ret = add_resource(&kimage_res, &bss_res);

        return ret;
}

static void __init init_resources(void)
{
        struct memblock_region *region = NULL;
        struct resource *res = NULL;
        struct resource *mem_res = NULL;
        size_t mem_res_sz = 0;
        int num_resources = 0, res_idx = 0, non_resv_res = 0;
        int ret = 0;

        /* + 1 as memblock_alloc() might increase memblock.reserved.cnt */
        num_resources = memblock.memory.cnt + memblock.reserved.cnt + 1;
        res_idx = num_resources - 1;

        mem_res_sz = num_resources * sizeof(*mem_res);
        mem_res = memblock_alloc_or_panic(mem_res_sz, SMP_CACHE_BYTES);

        /*
         * Start by adding the reserved regions, if they overlap
         * with /memory regions, insert_resource later on will take
         * care of it.
         */
        ret = add_kernel_resources();
        if (ret < 0)
                goto error;

#ifdef CONFIG_CRASH_DUMP
        if (elfcorehdr_size > 0) {
                elfcorehdr_res.start = elfcorehdr_addr;
                elfcorehdr_res.end = elfcorehdr_addr + elfcorehdr_size - 1;
                elfcorehdr_res.flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
                add_resource(&iomem_resource, &elfcorehdr_res);
        }
#endif

        for_each_reserved_mem_region(region) {
                res = &mem_res[res_idx--];

                res->name = "Reserved";
                res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
                res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
                res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;

                /*
                 * Ignore any other reserved regions within
                 * system memory.
                 */
                if (memblock_is_memory(res->start)) {
                        /* Re-use this pre-allocated resource */
                        res_idx++;
                        continue;
                }

                ret = add_resource(&iomem_resource, res);
                if (ret < 0)
                        goto error;
        }

        /* Add /memory regions to the resource tree */
        for_each_mem_region(region) {
                res = &mem_res[res_idx--];
                non_resv_res++;

                if (unlikely(memblock_is_nomap(region))) {
                        res->name = "Reserved";
                        res->flags = IORESOURCE_MEM | IORESOURCE_EXCLUSIVE;
                } else {
                        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;

                ret = add_resource(&iomem_resource, res);
                if (ret < 0)
                        goto error;
        }

        num_standard_resources = non_resv_res;
        standard_resources = &mem_res[res_idx + 1];

        /* Clean-up any unused pre-allocated resources */
        if (res_idx >= 0)
                memblock_free(mem_res, (res_idx + 1) * sizeof(*mem_res));
        return;

 error:
        /* Better an empty resource tree than an inconsistent one */
        release_child_resources(&iomem_resource);
        memblock_free(mem_res, mem_res_sz);
}

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);

static void __init parse_dtb(void)
{
        /* Early scan of device tree from init memory */
        if (early_init_dt_scan(dtb_early_va, dtb_early_pa)) {
                const char *name = of_flat_dt_get_machine_name();

                if (name) {
                        pr_info("Machine model: %s\n", name);
                        dump_stack_set_arch_desc("%s (DT)", name);
                }
        } else {
                pr_err("No DTB passed to the kernel\n");
        }
}

#if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
DEFINE_STATIC_KEY_TRUE(qspinlock_key);
EXPORT_SYMBOL(qspinlock_key);
#endif

static void __init riscv_spinlock_init(void)
{
        char *using_ext = NULL;

        if (IS_ENABLED(CONFIG_RISCV_TICKET_SPINLOCKS)) {
                pr_info("Ticket spinlock: enabled\n");
                return;
        }

        if (IS_ENABLED(CONFIG_RISCV_ISA_ZABHA) &&
            IS_ENABLED(CONFIG_RISCV_ISA_ZACAS) &&
            IS_ENABLED(CONFIG_TOOLCHAIN_HAS_ZACAS) &&
            riscv_isa_extension_available(NULL, ZABHA) &&
            riscv_isa_extension_available(NULL, ZACAS)) {
                using_ext = "using Zabha";
        } else if (riscv_isa_extension_available(NULL, ZICCRSE)) {
                using_ext = "using Ziccrse";
        }
#if defined(CONFIG_RISCV_COMBO_SPINLOCKS)
        else {
                static_branch_disable(&qspinlock_key);
                pr_info("Ticket spinlock: enabled\n");
                return;
        }
#endif

        if (!using_ext)
                pr_err("Queued spinlock without Zabha or Ziccrse");
        else
                pr_info("Queued spinlock %s: enabled\n", using_ext);
}

extern void __init init_rt_signal_env(void);

void __init setup_arch(char **cmdline_p)
{
        parse_dtb();
        setup_initial_init_mm(_stext, _etext, _edata, _end);

        *cmdline_p = boot_command_line;

        early_ioremap_setup();
        sbi_init();
        jump_label_init();
        parse_early_param();

        efi_init();
        paging_init();

        /* Parse the ACPI tables for possible boot-time configuration */
        acpi_boot_table_init();

        if (acpi_disabled) {
#if IS_ENABLED(CONFIG_BUILTIN_DTB)
                unflatten_and_copy_device_tree();
#else
                unflatten_device_tree();
#endif
        }

        misc_mem_init();

        init_resources();

#ifdef CONFIG_KASAN
        kasan_init();
#endif

#ifdef CONFIG_SMP
        setup_smp();
#endif

        if (!acpi_disabled) {
                acpi_init_rintc_map();
                acpi_map_cpus_to_nodes();
        }

        riscv_init_cbo_blocksizes();
        riscv_fill_hwcap();
        apply_boot_alternatives();
        init_rt_signal_env();

        if (IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM) &&
            riscv_isa_extension_available(NULL, ZICBOM))
                riscv_noncoherent_supported();
        riscv_set_dma_cache_alignment();

        riscv_user_isa_enable();
        riscv_spinlock_init();

        if (!IS_ENABLED(CONFIG_RISCV_ISA_ZBB) || !riscv_isa_extension_available(NULL, ZBB))
                static_branch_disable(&efficient_ffs_key);
}

bool arch_cpu_is_hotpluggable(int cpu)
{
        return cpu_has_hotplug(cpu);
}

void free_initmem(void)
{
        if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
                set_kernel_memory(lm_alias(__init_begin), lm_alias(__init_end), set_memory_rw_nx);
                if (IS_ENABLED(CONFIG_64BIT))
                        set_kernel_memory(__init_begin, __init_end, set_memory_nx);
        }

        free_initmem_default(POISON_FREE_INITMEM);
}

static int dump_kernel_offset(struct notifier_block *self,
                              unsigned long v, void *p)
{
        pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
                 kernel_map.virt_offset,
                 KERNEL_LINK_ADDR);

        return 0;
}

static struct notifier_block kernel_offset_notifier = {
        .notifier_call = dump_kernel_offset
};

static int __init register_kernel_offset_dumper(void)
{
        if (IS_ENABLED(CONFIG_RANDOMIZE_BASE))
                atomic_notifier_chain_register(&panic_notifier_list,
                                               &kernel_offset_notifier);

        return 0;
}
device_initcall(register_kernel_offset_dumper);