// SPDX-License-Identifier: GPL-2.0-only
/*
 * linux/arch/sh/mm/init.c
 *
 *  Copyright (C) 1999  Niibe Yutaka
 *  Copyright (C) 2002 - 2011  Paul Mundt
 *
 *  Based on linux/arch/i386/mm/init.c:
 *   Copyright (C) 1995  Linus Torvalds
 */
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/proc_fs.h>
#include <linux/pagemap.h>
#include <linux/percpu.h>
#include <linux/io.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <asm/mmu_context.h>
#include <asm/mmzone.h>
#include <asm/kexec.h>
#include <asm/tlb.h>
#include <asm/cacheflush.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/cache.h>
#include <asm/pgalloc.h>
#include <linux/sizes.h>
#include "ioremap.h"

pgd_t swapper_pg_dir[PTRS_PER_PGD];

void __init generic_mem_init(void)
{
        memblock_add(__MEMORY_START, __MEMORY_SIZE);
}

void __init __weak plat_mem_setup(void)
{
        /* Nothing to see here, move along. */
}

#ifdef CONFIG_MMU
static pte_t *__get_pte_phys(unsigned long addr)
{
        pgd_t *pgd;
        p4d_t *p4d;
        pud_t *pud;
        pmd_t *pmd;

        pgd = pgd_offset_k(addr);
        if (pgd_none(*pgd)) {
                pgd_ERROR(*pgd);
                return NULL;
        }

        p4d = p4d_alloc(NULL, pgd, addr);
        if (unlikely(!p4d)) {
                p4d_ERROR(*p4d);
                return NULL;
        }

        pud = pud_alloc(NULL, p4d, addr);
        if (unlikely(!pud)) {
                pud_ERROR(*pud);
                return NULL;
        }

        pmd = pmd_alloc(NULL, pud, addr);
        if (unlikely(!pmd)) {
                pmd_ERROR(*pmd);
                return NULL;
        }

        return pte_offset_kernel(pmd, addr);
}

static void set_pte_phys(unsigned long addr, unsigned long phys, pgprot_t prot)
{
        pte_t *pte;

        pte = __get_pte_phys(addr);
        if (!pte_none(*pte)) {
                pte_ERROR(*pte);
                return;
        }

        set_pte(pte, pfn_pte(phys >> PAGE_SHIFT, prot));
        local_flush_tlb_one(get_asid(), addr);

        if (pgprot_val(prot) & _PAGE_WIRED)
                tlb_wire_entry(NULL, addr, *pte);
}

static void clear_pte_phys(unsigned long addr, pgprot_t prot)
{
        pte_t *pte;

        pte = __get_pte_phys(addr);

        if (pgprot_val(prot) & _PAGE_WIRED)
                tlb_unwire_entry();

        set_pte(pte, pfn_pte(0, __pgprot(0)));
        local_flush_tlb_one(get_asid(), addr);
}

void __set_fixmap(enum fixed_addresses idx, unsigned long phys, pgprot_t prot)
{
        unsigned long address = __fix_to_virt(idx);

        if (idx >= __end_of_fixed_addresses) {
                BUG();
                return;
        }

        set_pte_phys(address, phys, prot);
}

void __clear_fixmap(enum fixed_addresses idx, pgprot_t prot)
{
        unsigned long address = __fix_to_virt(idx);

        if (idx >= __end_of_fixed_addresses) {
                BUG();
                return;
        }

        clear_pte_phys(address, prot);
}

static pmd_t * __init one_md_table_init(pud_t *pud)
{
        if (pud_none(*pud)) {
                pmd_t *pmd;

                pmd = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
                pud_populate(&init_mm, pud, pmd);
                BUG_ON(pmd != pmd_offset(pud, 0));
        }

        return pmd_offset(pud, 0);
}

static pte_t * __init one_page_table_init(pmd_t *pmd)
{
        if (pmd_none(*pmd)) {
                pte_t *pte;

                pte = memblock_alloc_or_panic(PAGE_SIZE, PAGE_SIZE);
                pmd_populate_kernel(&init_mm, pmd, pte);
                BUG_ON(pte != pte_offset_kernel(pmd, 0));
        }

        return pte_offset_kernel(pmd, 0);
}

static pte_t * __init page_table_kmap_check(pte_t *pte, pmd_t *pmd,
                                            unsigned long vaddr, pte_t *lastpte)
{
        return pte;
}

void __init page_table_range_init(unsigned long start, unsigned long end,
                                         pgd_t *pgd_base)
{
        pgd_t *pgd;
        pud_t *pud;
        pmd_t *pmd;
        pte_t *pte = NULL;
        int i, j, k;
        unsigned long vaddr;

        vaddr = start;
        i = pgd_index(vaddr);
        j = pud_index(vaddr);
        k = pmd_index(vaddr);
        pgd = pgd_base + i;

        for ( ; (i < PTRS_PER_PGD) && (vaddr != end); pgd++, i++) {
                pud = (pud_t *)pgd;
                for ( ; (j < PTRS_PER_PUD) && (vaddr != end); pud++, j++) {
                        pmd = one_md_table_init(pud);
#ifndef __PAGETABLE_PMD_FOLDED
                        pmd += k;
#endif
                        for (; (k < PTRS_PER_PMD) && (vaddr != end); pmd++, k++) {
                                pte = page_table_kmap_check(one_page_table_init(pmd),
                                                            pmd, vaddr, pte);
                                vaddr += PMD_SIZE;
                        }
                        k = 0;
                }
                j = 0;
        }
}
#endif  /* CONFIG_MMU */

void __init allocate_pgdat(unsigned int nid)
{
        unsigned long start_pfn, end_pfn;

        get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);

#ifdef CONFIG_NUMA
        alloc_node_data(nid);
#endif

        NODE_DATA(nid)->node_start_pfn = start_pfn;
        NODE_DATA(nid)->node_spanned_pages = end_pfn - start_pfn;
}

static void __init do_init_bootmem(void)
{
        unsigned long start_pfn, end_pfn;
        int i;

        /* Add active regions with valid PFNs. */
        for_each_mem_pfn_range(i, MAX_NUMNODES, &start_pfn, &end_pfn, NULL)
                __add_active_range(0, start_pfn, end_pfn);

        /* All of system RAM sits in node 0 for the non-NUMA case */
        allocate_pgdat(0);
        node_set_online(0);

        plat_mem_setup();
}

static void __init early_reserve_mem(void)
{
        unsigned long start_pfn;
        u32 zero_base = (u32)__MEMORY_START + (u32)PHYSICAL_OFFSET;
        u32 start = zero_base + (u32)CONFIG_ZERO_PAGE_OFFSET;

        /*
         * Partially used pages are not usable - thus
         * we are rounding upwards:
         */
        start_pfn = PFN_UP(__pa(_end));

        /*
         * Reserve the kernel text and Reserve the bootmem bitmap. We do
         * this in two steps (first step was init_bootmem()), because
         * this catches the (definitely buggy) case of us accidentally
         * initializing the bootmem allocator with an invalid RAM area.
         */
        memblock_reserve(start, (PFN_PHYS(start_pfn) + PAGE_SIZE - 1) - start);

        /*
         * Reserve physical pages below CONFIG_ZERO_PAGE_OFFSET.
         */
        if (CONFIG_ZERO_PAGE_OFFSET != 0)
                memblock_reserve(zero_base, CONFIG_ZERO_PAGE_OFFSET);

        /*
         * Handle additional early reservations
         */
        check_for_initrd();
        reserve_crashkernel();
}

void __init arch_zone_limits_init(unsigned long *max_zone_pfns)
{
        max_zone_pfns[ZONE_NORMAL] = max_low_pfn;
}

void __init paging_init(void)
{
        unsigned long vaddr, end;

        sh_mv.mv_mem_init();

        early_reserve_mem();

        /*
         * Once the early reservations are out of the way, give the
         * platforms a chance to kick out some memory.
         */
        if (sh_mv.mv_mem_reserve)
                sh_mv.mv_mem_reserve();

        memblock_enforce_memory_limit(memory_limit);
        memblock_allow_resize();

        memblock_dump_all();

        /*
         * Determine low and high memory ranges:
         */
        max_low_pfn = max_pfn = memblock_end_of_DRAM() >> PAGE_SHIFT;
        min_low_pfn = __MEMORY_START >> PAGE_SHIFT;

        nodes_clear(node_online_map);

        memory_start = (unsigned long)__va(__MEMORY_START);
        memory_end = memory_start + (memory_limit ?: memblock_phys_mem_size());

        uncached_init();
        pmb_init();
        do_init_bootmem();
        ioremap_fixed_init();

        /* We don't need to map the kernel through the TLB, as
         * it is permanatly mapped using P1. So clear the
         * entire pgd. */
        memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));

        /* Set an initial value for the MMU.TTB so we don't have to
         * check for a null value. */
        set_TTB(swapper_pg_dir);

        /*
         * Populate the relevant portions of swapper_pg_dir so that
         * we can use the fixmap entries without calling kmalloc.
         * pte's will be filled in by __set_fixmap().
         */
        vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
        end = (FIXADDR_TOP + PMD_SIZE - 1) & PMD_MASK;
        page_table_range_init(vaddr, end, swapper_pg_dir);

        kmap_coherent_init();
}

unsigned int mem_init_done = 0;

void __init mem_init(void)
{
        /* Set this up early, so we can take care of the zero page */
        cpu_cache_init();

        /* clear the zero-page */
        memset(empty_zero_page, 0, PAGE_SIZE);
        __flush_wback_region(empty_zero_page, PAGE_SIZE);

        vsyscall_init();

        pr_info("virtual kernel memory layout:\n"
                "    fixmap  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
                "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB) (cached)\n"
#ifdef CONFIG_UNCACHED_MAPPING
                "            : 0x%08lx - 0x%08lx   (%4ld MB) (uncached)\n"
#endif
                "      .init : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                "      .data : 0x%08lx - 0x%08lx   (%4ld kB)\n"
                "      .text : 0x%08lx - 0x%08lx   (%4ld kB)\n",
                FIXADDR_START, FIXADDR_TOP,
                (FIXADDR_TOP - FIXADDR_START) >> 10,

                (unsigned long)VMALLOC_START, VMALLOC_END,
                (VMALLOC_END - VMALLOC_START) >> 20,

                (unsigned long)memory_start, (unsigned long)high_memory,
                ((unsigned long)high_memory - (unsigned long)memory_start) >> 20,

#ifdef CONFIG_UNCACHED_MAPPING
                uncached_start, uncached_end, uncached_size >> 20,
#endif

                (unsigned long)&__init_begin, (unsigned long)&__init_end,
                ((unsigned long)&__init_end -
                 (unsigned long)&__init_begin) >> 10,

                (unsigned long)&_etext, (unsigned long)&_edata,
                ((unsigned long)&_edata - (unsigned long)&_etext) >> 10,

                (unsigned long)&_text, (unsigned long)&_etext,
                ((unsigned long)&_etext - (unsigned long)&_text) >> 10);

        mem_init_done = 1;
}