/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * 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/ioport.h>
#include <linux/export.h>
#include <linux/screen_info.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/root_dev.h>
#include <linux/highmem.h>
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/debugfs.h>
#include <linux/kexec.h>
#include <linux/sizes.h>
#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/decompress/generic.h>
#include <linux/of_fdt.h>
#include <linux/dmi.h>
#include <linux/crash_dump.h>

#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/bugs.h>
#include <asm/cache.h>
#include <asm/cdmm.h>
#include <asm/cpu.h>
#include <asm/debug.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/smp-ops.h>
#include <asm/prom.h>

#ifdef CONFIG_MIPS_ELF_APPENDED_DTB
char __section(".appended_dtb") __appended_dtb[0x100000];
#endif /* CONFIG_MIPS_ELF_APPENDED_DTB */

struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly;

EXPORT_SYMBOL(cpu_data);

#ifdef CONFIG_VT
struct screen_info screen_info;
#endif

/*
 * Setup information
 *
 * These are initialized so they are in the .data section
 */
unsigned long mips_machtype __read_mostly = MACH_UNKNOWN;

EXPORT_SYMBOL(mips_machtype);

static char __initdata command_line[COMMAND_LINE_SIZE];
char __initdata arcs_cmdline[COMMAND_LINE_SIZE];

#ifdef CONFIG_CMDLINE_BOOL
static const char builtin_cmdline[] __initconst = CONFIG_CMDLINE;
#else
static const char builtin_cmdline[] __initconst = "";
#endif

/*
 * mips_io_port_base is the begin of the address space to which x86 style
 * I/O ports are mapped.
 */
unsigned long mips_io_port_base = -1;
EXPORT_SYMBOL(mips_io_port_base);

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

unsigned long __kaslr_offset __ro_after_init;
EXPORT_SYMBOL(__kaslr_offset);

static void *detect_magic __initdata = detect_memory_region;

#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
unsigned long ARCH_PFN_OFFSET;
EXPORT_SYMBOL(ARCH_PFN_OFFSET);
#endif

void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max)
{
        void *dm = &detect_magic;
        phys_addr_t size;

        for (size = sz_min; size < sz_max; size <<= 1) {
                if (!memcmp(dm, dm + size, sizeof(detect_magic)))
                        break;
        }

        pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n",
                ((unsigned long long) size) / SZ_1M,
                (unsigned long long) start,
                ((unsigned long long) sz_min) / SZ_1M,
                ((unsigned long long) sz_max) / SZ_1M);

        memblock_add(start, size);
}

/*
 * Manage initrd
 */
#ifdef CONFIG_BLK_DEV_INITRD

static int __init rd_start_early(char *p)
{
        unsigned long start = memparse(p, &p);

#ifdef CONFIG_64BIT
        /* Guess if the sign extension was forgotten by bootloader */
        if (start < XKPHYS)
                start = (int)start;
#endif
        initrd_start = start;
        initrd_end += start;
        return 0;
}
early_param("rd_start", rd_start_early);

static int __init rd_size_early(char *p)
{
        initrd_end += memparse(p, &p);
        return 0;
}
early_param("rd_size", rd_size_early);

/* it returns the next free pfn after initrd */
static unsigned long __init init_initrd(void)
{
        unsigned long end;

        /*
         * Board specific code or command line parser should have
         * already set up initrd_start and initrd_end. In these cases
         * perfom sanity checks and use them if all looks good.
         */
        if (!initrd_start || initrd_end <= initrd_start)
                goto disable;

        if (initrd_start & ~PAGE_MASK) {
                pr_err("initrd start must be page aligned\n");
                goto disable;
        }
        if (initrd_start < PAGE_OFFSET) {
                pr_err("initrd start < PAGE_OFFSET\n");
                goto disable;
        }

        /*
         * Sanitize initrd addresses. For example firmware
         * can't guess if they need to pass them through
         * 64-bits values if the kernel has been built in pure
         * 32-bit. We need also to switch from KSEG0 to XKPHYS
         * addresses now, so the code can now safely use __pa().
         */
        end = __pa(initrd_end);
        initrd_end = (unsigned long)__va(end);
        initrd_start = (unsigned long)__va(__pa(initrd_start));

        ROOT_DEV = Root_RAM0;
        return PFN_UP(end);
disable:
        initrd_start = 0;
        initrd_end = 0;
        return 0;
}

/* In some conditions (e.g. big endian bootloader with a little endian
   kernel), the initrd might appear byte swapped.  Try to detect this and
   byte swap it if needed.  */
static void __init maybe_bswap_initrd(void)
{
#if defined(CONFIG_CPU_CAVIUM_OCTEON)
        u64 buf;

        /* Check for CPIO signature */
        if (!memcmp((void *)initrd_start, "070701", 6))
                return;

        /* Check for compressed initrd */
        if (decompress_method((unsigned char *)initrd_start, 8, NULL))
                return;

        /* Try again with a byte swapped header */
        buf = swab64p((u64 *)initrd_start);
        if (!memcmp(&buf, "070701", 6) ||
            decompress_method((unsigned char *)(&buf), 8, NULL)) {
                unsigned long i;

                pr_info("Byteswapped initrd detected\n");
                for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8)
                        swab64s((u64 *)i);
        }
#endif
}

static void __init finalize_initrd(void)
{
        unsigned long size = initrd_end - initrd_start;

        if (size == 0) {
                printk(KERN_INFO "Initrd not found or empty");
                goto disable;
        }
        if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) {
                printk(KERN_ERR "Initrd extends beyond end of memory");
                goto disable;
        }

        maybe_bswap_initrd();

        memblock_reserve(__pa(initrd_start), size);
        initrd_below_start_ok = 1;

        pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n",
                initrd_start, size);
        return;
disable:
        printk(KERN_CONT " - disabling initrd\n");
        initrd_start = 0;
        initrd_end = 0;
}

#else  /* !CONFIG_BLK_DEV_INITRD */

static unsigned long __init init_initrd(void)
{
        return 0;
}

#define finalize_initrd()       do {} while (0)

#endif

/*
 * Initialize the bootmem allocator. It also setup initrd related data
 * if needed.
 */
#if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON64) && defined(CONFIG_NUMA))

static void __init bootmem_init(void)
{
        init_initrd();
        finalize_initrd();
}

#else  /* !CONFIG_SGI_IP27 */

static void __init bootmem_init(void)
{
        phys_addr_t ramstart, ramend;
        unsigned long start, end;
        int i;

        ramstart = memblock_start_of_DRAM();
        ramend = memblock_end_of_DRAM();

        /*
         * Sanity check any INITRD first. We don't take it into account
         * for bootmem setup initially, rely on the end-of-kernel-code
         * as our memory range starting point. Once bootmem is inited we
         * will reserve the area used for the initrd.
         */
        init_initrd();

        /* Reserve memory occupied by kernel. */
        memblock_reserve(__pa_symbol(&_text),
                        __pa_symbol(&_end) - __pa_symbol(&_text));

        /* max_low_pfn is not a number of pages but the end pfn of low mem */

#ifdef CONFIG_MIPS_AUTO_PFN_OFFSET
        ARCH_PFN_OFFSET = PFN_UP(ramstart);
#else
        /*
         * Reserve any memory between the start of RAM and PHYS_OFFSET
         */
        if (ramstart > PHYS_OFFSET)
                memblock_reserve(PHYS_OFFSET, ramstart - PHYS_OFFSET);

        if (PFN_UP(ramstart) > ARCH_PFN_OFFSET) {
                pr_info("Wasting %lu bytes for tracking %lu unused pages\n",
                        (unsigned long)((PFN_UP(ramstart) - ARCH_PFN_OFFSET) * sizeof(struct page)),
                        (unsigned long)(PFN_UP(ramstart) - ARCH_PFN_OFFSET));
        }
#endif

        min_low_pfn = ARCH_PFN_OFFSET;
        max_pfn = PFN_DOWN(ramend);
        for_each_mem_pfn_range(i, MAX_NUMNODES, &start, &end, NULL) {
                /*
                 * Skip highmem here so we get an accurate max_low_pfn if low
                 * memory stops short of high memory.
                 * If the region overlaps HIGHMEM_START, end is clipped so
                 * max_pfn excludes the highmem portion.
                 */
                if (start >= PFN_DOWN(HIGHMEM_START))
                        continue;
                if (end > PFN_DOWN(HIGHMEM_START))
                        end = PFN_DOWN(HIGHMEM_START);
                if (end > max_low_pfn)
                        max_low_pfn = end;
        }

        if (min_low_pfn >= max_low_pfn)
                panic("Incorrect memory mapping !!!");

        if (max_pfn > PFN_DOWN(HIGHMEM_START)) {
#ifdef CONFIG_HIGHMEM
                highstart_pfn = PFN_DOWN(HIGHMEM_START);
                highend_pfn = max_pfn;
#else
                max_low_pfn = PFN_DOWN(HIGHMEM_START);
                max_pfn = max_low_pfn;
#endif
        }

        /*
         * Reserve initrd memory if needed.
         */
        finalize_initrd();
}

#endif  /* CONFIG_SGI_IP27 */

static int usermem __initdata;

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

        /*
         * 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());
        }
        start = 0;
        size = memparse(p, &p);
        if (*p == '@')
                start = memparse(p + 1, &p);

        memblock_add(start, size);

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

static int __init early_parse_memmap(char *p)
{
        char *oldp;
        u64 start_at, mem_size;

        if (!p)
                return -EINVAL;

        if (!strncmp(p, "exactmap", 8)) {
                pr_err("\"memmap=exactmap\" invalid on MIPS\n");
                return 0;
        }

        oldp = p;
        mem_size = memparse(p, &p);
        if (p == oldp)
                return -EINVAL;

        if (*p == '@') {
                start_at = memparse(p+1, &p);
                memblock_add(start_at, mem_size);
        } else if (*p == '#') {
                pr_err("\"memmap=nn#ss\" (force ACPI data) invalid on MIPS\n");
                return -EINVAL;
        } else if (*p == '$') {
                start_at = memparse(p+1, &p);
                memblock_add(start_at, mem_size);
                memblock_reserve(start_at, mem_size);
        } else {
                pr_err("\"memmap\" invalid format!\n");
                return -EINVAL;
        }

        if (*p == '\0') {
                usermem = 1;
                return 0;
        } else
                return -EINVAL;
}
early_param("memmap", early_parse_memmap);

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

        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;
                        }
                }
        }

        pr_info("Reserving %ldKB of memory at %ldKB for kdump\n",
                (unsigned long)elfcorehdr_size >> 10, (unsigned long)elfcorehdr_addr >> 10);

        memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
#endif
}

#ifdef CONFIG_KEXEC

/* 64M alignment for crash kernel regions */
#define CRASH_ALIGN     SZ_64M
#define CRASH_ADDR_MAX  SZ_512M

static void __init mips_parse_crashkernel(void)
{
        unsigned long long total_mem;
        unsigned long long crash_size, crash_base;
        int ret;

        total_mem = memblock_phys_mem_size();
        ret = parse_crashkernel(boot_command_line, total_mem,
                                &crash_size, &crash_base);
        if (ret != 0 || crash_size <= 0)
                return;

        if (crash_base <= 0) {
                crash_base = memblock_find_in_range(CRASH_ALIGN, CRASH_ADDR_MAX,
                                                        crash_size, CRASH_ALIGN);
                if (!crash_base) {
                        pr_warn("crashkernel reservation failed - No suitable area found.\n");
                        return;
                }
        } else {
                unsigned long long start;

                start = memblock_find_in_range(crash_base, crash_base + crash_size,
                                                crash_size, 1);
                if (start != crash_base) {
                        pr_warn("Invalid memory region reserved for crash kernel\n");
                        return;
                }
        }

        crashk_res.start = crash_base;
        crashk_res.end   = crash_base + crash_size - 1;
}

static void __init request_crashkernel(struct resource *res)
{
        int ret;

        if (crashk_res.start == crashk_res.end)
                return;

        ret = request_resource(res, &crashk_res);
        if (!ret)
                pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n",
                        (unsigned long)(resource_size(&crashk_res) >> 20),
                        (unsigned long)(crashk_res.start  >> 20));
}
#else /* !defined(CONFIG_KEXEC)         */
static void __init mips_parse_crashkernel(void)
{
}

static void __init request_crashkernel(struct resource *res)
{
}
#endif /* !defined(CONFIG_KEXEC)  */

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);
        }
}

static void __init bootcmdline_append(const char *s, size_t max)
{
        if (!s[0] || !max)
                return;

        if (boot_command_line[0])
                strlcat(boot_command_line, " ", COMMAND_LINE_SIZE);

        strlcat(boot_command_line, s, max);
}

#ifdef CONFIG_OF_EARLY_FLATTREE

static int __init bootcmdline_scan_chosen(unsigned long node, const char *uname,
                                          int depth, void *data)
{
        bool *dt_bootargs = data;
        const char *p;
        int l;

        if (depth != 1 || !data ||
            (strcmp(uname, "chosen") != 0 && strcmp(uname, "chosen@0") != 0))
                return 0;

        p = of_get_flat_dt_prop(node, "bootargs", &l);
        if (p != NULL && l > 0) {
                bootcmdline_append(p, min(l, COMMAND_LINE_SIZE));
                *dt_bootargs = true;
        }

        return 1;
}

#endif /* CONFIG_OF_EARLY_FLATTREE */

static void __init bootcmdline_init(void)
{
        bool dt_bootargs = false;

        /*
         * If CMDLINE_OVERRIDE is enabled then initializing the command line is
         * trivial - we simply use the built-in command line unconditionally &
         * unmodified.
         */
        if (IS_ENABLED(CONFIG_CMDLINE_OVERRIDE)) {
                strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
                return;
        }

        /*
         * If the user specified a built-in command line &
         * MIPS_CMDLINE_BUILTIN_EXTEND, then the built-in command line is
         * prepended to arguments from the bootloader or DT so we'll copy them
         * to the start of boot_command_line here. Otherwise, empty
         * boot_command_line to undo anything early_init_dt_scan_chosen() did.
         */
        if (IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
                strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE);
        else
                boot_command_line[0] = 0;

#ifdef CONFIG_OF_EARLY_FLATTREE
        /*
         * If we're configured to take boot arguments from DT, look for those
         * now.
         */
        if (IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) ||
            IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND))
                of_scan_flat_dt(bootcmdline_scan_chosen, &dt_bootargs);
#endif

        /*
         * If we didn't get any arguments from DT (regardless of whether that's
         * because we weren't configured to look for them, or because we looked
         * & found none) then we'll take arguments from the bootloader.
         * plat_mem_setup() should have filled arcs_cmdline with arguments from
         * the bootloader.
         */
        if (IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) || !dt_bootargs)
                bootcmdline_append(arcs_cmdline, COMMAND_LINE_SIZE);

        /*
         * If the user specified a built-in command line & we didn't already
         * prepend it, we append it to boot_command_line here.
         */
        if (IS_ENABLED(CONFIG_CMDLINE_BOOL) &&
            !IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND))
                bootcmdline_append(builtin_cmdline, COMMAND_LINE_SIZE);
}

/*
 * arch_mem_init - initialize memory management subsystem
 *
 *  o plat_mem_setup() detects the memory configuration and will record detected
 *    memory areas using memblock_add.
 *
 * At this stage the memory configuration of the system is known to the
 * kernel but generic memory management system is still entirely uninitialized.
 *
 *  o bootmem_init()
 *  o sparse_init()
 *  o paging_init()
 *  o dma_contiguous_reserve()
 *
 * At this stage the bootmem allocator is ready to use.
 *
 * NOTE: historically plat_mem_setup did the entire platform initialization.
 *       This was rather impractical because it meant plat_mem_setup had to
 * get away without any kind of memory allocator.  To keep old code from
 * breaking plat_setup was just renamed to plat_mem_setup and a second platform
 * initialization hook for anything else was introduced.
 */
static void __init arch_mem_init(char **cmdline_p)
{
        /* call board setup routine */
        plat_mem_setup();
        memblock_set_bottom_up(true);

        bootcmdline_init();
        strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
        *cmdline_p = command_line;

        parse_early_param();

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

        check_kernel_sections_mem();

        early_init_fdt_reserve_self();
        early_init_fdt_scan_reserved_mem();

#ifndef CONFIG_NUMA
        memblock_set_node(0, PHYS_ADDR_MAX, &memblock.memory, 0);
#endif
        bootmem_init();

        /*
         * Prevent memblock from allocating high memory.
         * This cannot be done before max_low_pfn is detected, so up
         * to this point is possible to only reserve physical memory
         * with memblock_reserve; memblock_alloc* can be used
         * only after this point
         */
        memblock_set_current_limit(PFN_PHYS(max_low_pfn));

        mips_reserve_vmcore();

        mips_parse_crashkernel();
#ifdef CONFIG_KEXEC
        if (crashk_res.start != crashk_res.end)
                memblock_reserve(crashk_res.start, resource_size(&crashk_res));
#endif
        device_tree_init();

        /*
         * In order to reduce the possibility of kernel panic when failed to
         * get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
         * low memory as small as possible before plat_swiotlb_setup(), so
         * make sparse_init() using top-down allocation.
         */
        memblock_set_bottom_up(false);
        sparse_init();
        memblock_set_bottom_up(true);

        plat_swiotlb_setup();

        dma_contiguous_reserve(PFN_PHYS(max_low_pfn));

        /* Reserve for hibernation. */
        memblock_reserve(__pa_symbol(&__nosave_begin),
                __pa_symbol(&__nosave_end) - __pa_symbol(&__nosave_begin));

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

static void __init resource_init(void)
{
        phys_addr_t start, end;
        u64 i;

        if (UNCAC_BASE != IO_BASE)
                return;

        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;

        for_each_mem_range(i, &start, &end) {
                struct resource *res;

                res = memblock_alloc(sizeof(struct resource), SMP_CACHE_BYTES);
                if (!res)
                        panic("%s: Failed to allocate %zu bytes\n", __func__,
                              sizeof(struct resource));

                res->start = start;
                /*
                 * In memblock, end points to the first byte after the
                 * range while in resourses, end points to the last byte in
                 * the range.
                 */
                res->end = end - 1;
                res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
                res->name = "System RAM";

                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);
                request_crashkernel(res);
        }
}

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

        if (possible > nr_cpu_ids)
                possible = nr_cpu_ids;

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

        nr_cpu_ids = possible;
}
#else
static inline void prefill_possible_map(void) {}
#endif

void __init setup_arch(char **cmdline_p)
{
        cpu_probe();
        mips_cm_probe();
        prom_init();

        setup_early_fdc_console();
#ifdef CONFIG_EARLY_PRINTK
        setup_early_printk();
#endif
        cpu_report();
        check_bugs_early();

#if defined(CONFIG_VT)
#if defined(CONFIG_VGA_CONSOLE)
        conswitchp = &vga_con;
#endif
#endif

        arch_mem_init(cmdline_p);
        dmi_setup();

        resource_init();
        plat_smp_setup();
        prefill_possible_map();

        cpu_cache_init();
        paging_init();

        memblock_dump_all();
}

unsigned long kernelsp[NR_CPUS];
unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3;

#ifdef CONFIG_DEBUG_FS
struct dentry *mips_debugfs_dir;
static int __init debugfs_mips(void)
{
        mips_debugfs_dir = debugfs_create_dir("mips", NULL);
        return 0;
}
arch_initcall(debugfs_mips);
#endif

#ifdef CONFIG_DMA_NONCOHERENT
static int __init setcoherentio(char *str)
{
        dma_default_coherent = true;
        pr_info("Hardware DMA cache coherency (command line)\n");
        return 0;
}
early_param("coherentio", setcoherentio);

static int __init setnocoherentio(char *str)
{
        dma_default_coherent = true;
        pr_info("Software DMA cache coherency (command line)\n");
        return 0;
}
early_param("nocoherentio", setnocoherentio);
#endif