init.c

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/*
 *  linux/arch/unicore32/mm/init.c
 *
 *  Copyright (C) 2010 GUAN Xue-tao
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/swap.h>
#include <linux/init.h>
#include <linux/bootmem.h>
#include <linux/mman.h>
#include <linux/nodemask.h>
#include <linux/initrd.h>
#include <linux/highmem.h>
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/sort.h>
#include <linux/dma-mapping.h>
#include <linux/export.h>

#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/sizes.h>
#include <asm/tlb.h>
#include <asm/memblock.h>
#include <mach/map.h>

#include "mm.h"

static unsigned long phys_initrd_start __initdata = 0x01000000;
static unsigned long phys_initrd_size __initdata = SZ_8M;

static int __init early_initrd(char *p)
{
    unsigned long start, size;
    char *endp;

    start = memparse(p, &endp);
    if (*endp == ',') {
        size = memparse(endp + 1, NULL);

        phys_initrd_start = start;
        phys_initrd_size = size;
    }
    return 0;
}
early_param("initrd", early_initrd);

/*
 * This keeps memory configuration data used by a couple memory
 * initialization functions, as well as show_mem() for the skipping
 * of holes in the memory map.  It is populated by uc32_add_memory().
 */
struct meminfo meminfo;

void show_mem(unsigned int filter)
{
    int free = 0, total = 0, reserved = 0;
    int shared = 0, cached = 0, slab = 0, i;
    struct meminfo *mi = &meminfo;

    printk(KERN_DEFAULT "Mem-info:\n");
    show_free_areas(filter);

    for_each_bank(i, mi) {
        struct membank *bank = &mi->bank[i];
        unsigned int pfn1, pfn2;
        struct page *page, *end;

        pfn1 = bank_pfn_start(bank);
        pfn2 = bank_pfn_end(bank);

        page = pfn_to_page(pfn1);
        end  = pfn_to_page(pfn2 - 1) + 1;

        do {
            total++;
            if (PageReserved(page))
                reserved++;
            else if (PageSwapCache(page))
                cached++;
            else if (PageSlab(page))
                slab++;
            else if (!page_count(page))
                free++;
            else
                shared += page_count(page) - 1;
            page++;
        } while (page < end);
    }

    printk(KERN_DEFAULT "%d pages of RAM\n", total);
    printk(KERN_DEFAULT "%d free pages\n", free);
    printk(KERN_DEFAULT "%d reserved pages\n", reserved);
    printk(KERN_DEFAULT "%d slab pages\n", slab);
    printk(KERN_DEFAULT "%d pages shared\n", shared);
    printk(KERN_DEFAULT "%d pages swap cached\n", cached);
}

static void __init find_limits(unsigned long *min, unsigned long *max_low,
    unsigned long *max_high)
{
    struct meminfo *mi = &meminfo;
    int i;

    *min = -1UL;
    *max_low = *max_high = 0;

    for_each_bank(i, mi) {
        struct membank *bank = &mi->bank[i];
        unsigned long start, end;

        start = bank_pfn_start(bank);
        end = bank_pfn_end(bank);

        if (*min > start)
            *min = start;
        if (*max_high < end)
            *max_high = end;
        if (bank->highmem)
            continue;
        if (*max_low < end)
            *max_low = end;
    }
}

static void __init uc32_bootmem_init(unsigned long start_pfn,
    unsigned long end_pfn)
{
    struct memblock_region *reg;
    unsigned int boot_pages;
    phys_addr_t bitmap;
    pg_data_t *pgdat;

    /*
     * Allocate the bootmem bitmap page.  This must be in a region
     * of memory which has already been mapped.
     */
    boot_pages = bootmem_bootmap_pages(end_pfn - start_pfn);
    bitmap = memblock_alloc_base(boot_pages << PAGE_SHIFT, L1_CACHE_BYTES,
                __pfn_to_phys(end_pfn));

    /*
     * Initialise the bootmem allocator, handing the
     * memory banks over to bootmem.
     */
    node_set_online(0);
    pgdat = NODE_DATA(0);
    init_bootmem_node(pgdat, __phys_to_pfn(bitmap), start_pfn, end_pfn);

    /* Free the lowmem regions from memblock into bootmem. */
    for_each_memblock(memory, reg) {
        unsigned long start = memblock_region_memory_base_pfn(reg);
        unsigned long end = memblock_region_memory_end_pfn(reg);

        if (end >= end_pfn)
            end = end_pfn;
        if (start >= end)
            break;

        free_bootmem(__pfn_to_phys(start), (end - start) << PAGE_SHIFT);
    }

    /* Reserve the lowmem memblock reserved regions in bootmem. */
    for_each_memblock(reserved, reg) {
        unsigned long start = memblock_region_reserved_base_pfn(reg);
        unsigned long end = memblock_region_reserved_end_pfn(reg);

        if (end >= end_pfn)
            end = end_pfn;
        if (start >= end)
            break;

        reserve_bootmem(__pfn_to_phys(start),
            (end - start) << PAGE_SHIFT, BOOTMEM_DEFAULT);
    }
}

static void __init uc32_bootmem_free(unsigned long min, unsigned long max_low,
    unsigned long max_high)
{
    unsigned long zone_size[MAX_NR_ZONES], zhole_size[MAX_NR_ZONES];
    struct memblock_region *reg;

    /*
     * initialise the zones.
     */
    memset(zone_size, 0, sizeof(zone_size));

    /*
     * The memory size has already been determined.  If we need
     * to do anything fancy with the allocation of this memory
     * to the zones, now is the time to do it.
     */
    zone_size[0] = max_low - min;

    /*
     * Calculate the size of the holes.
     *  holes = node_size - sum(bank_sizes)
     */
    memcpy(zhole_size, zone_size, sizeof(zhole_size));
    for_each_memblock(memory, reg) {
        unsigned long start = memblock_region_memory_base_pfn(reg);
        unsigned long end = memblock_region_memory_end_pfn(reg);

        if (start < max_low) {
            unsigned long low_end = min(end, max_low);
            zhole_size[0] -= low_end - start;
        }
    }

    /*
     * Adjust the sizes according to any special requirements for
     * this machine type.
     */
    arch_adjust_zones(zone_size, zhole_size);

    free_area_init_node(0, zone_size, min, zhole_size);
}

int pfn_valid(unsigned long pfn)
{
    return memblock_is_memory(pfn << PAGE_SHIFT);
}
EXPORT_SYMBOL(pfn_valid);

static void uc32_memory_present(void)
{
}

static int __init meminfo_cmp(const void *_a, const void *_b)
{
    const struct membank *a = _a, *b = _b;
    long cmp = bank_pfn_start(a) - bank_pfn_start(b);
    return cmp < 0 ? -1 : cmp > 0 ? 1 : 0;
}

void __init uc32_memblock_init(struct meminfo *mi)
{
    int i;

    sort(&meminfo.bank, meminfo.nr_banks, sizeof(meminfo.bank[0]),
        meminfo_cmp, NULL);

    for (i = 0; i < mi->nr_banks; i++)
        memblock_add(mi->bank[i].start, mi->bank[i].size);

    /* Register the kernel text, kernel data and initrd with memblock. */
    memblock_reserve(__pa(_text), _end - _text);

#ifdef CONFIG_BLK_DEV_INITRD
    if (phys_initrd_size) {
        memblock_reserve(phys_initrd_start, phys_initrd_size);

        /* Now convert initrd to virtual addresses */
        initrd_start = __phys_to_virt(phys_initrd_start);
        initrd_end = initrd_start + phys_initrd_size;
    }
#endif

    uc32_mm_memblock_reserve();

    memblock_allow_resize();
    memblock_dump_all();
}

void __init bootmem_init(void)
{
    unsigned long min, max_low, max_high;

    max_low = max_high = 0;

    find_limits(&min, &max_low, &max_high);

    uc32_bootmem_init(min, max_low);

#ifdef CONFIG_SWIOTLB
    swiotlb_init(1);
#endif
    /*
     * Sparsemem tries to allocate bootmem in memory_present(),
     * so must be done after the fixed reservations
     */
    uc32_memory_present();

    /*
     * sparse_init() needs the bootmem allocator up and running.
     */
    sparse_init();

    /*
     * Now free the memory - free_area_init_node needs
     * the sparse mem_map arrays initialized by sparse_init()
     * for memmap_init_zone(), otherwise all PFNs are invalid.
     */
    uc32_bootmem_free(min, max_low, max_high);

    high_memory = __va((max_low << PAGE_SHIFT) - 1) + 1;

    /*
     * This doesn't seem to be used by the Linux memory manager any
     * more, but is used by ll_rw_block.  If we can get rid of it, we
     * also get rid of some of the stuff above as well.
     *
     * Note: max_low_pfn and max_pfn reflect the number of _pages_ in
     * the system, not the maximum PFN.
     */
    max_low_pfn = max_low - PHYS_PFN_OFFSET;
    max_pfn = max_high - PHYS_PFN_OFFSET;
}

static inline int free_area(unsigned long pfn, unsigned long end, char *s)
{
    unsigned int pages = 0, size = (end - pfn) << (PAGE_SHIFT - 10);

    for (; pfn < end; pfn++) {
        struct page *page = pfn_to_page(pfn);
        ClearPageReserved(page);
        init_page_count(page);
        __free_page(page);
        pages++;
    }

    if (size && s)
        printk(KERN_INFO "Freeing %s memory: %dK\n", s, size);

    return pages;
}

static inline void
free_memmap(unsigned long start_pfn, unsigned long end_pfn)
{
    struct page *start_pg, *end_pg;
    unsigned long pg, pgend;

    /*
     * Convert start_pfn/end_pfn to a struct page pointer.
     */
    start_pg = pfn_to_page(start_pfn - 1) + 1;
    end_pg = pfn_to_page(end_pfn);

    /*
     * Convert to physical addresses, and
     * round start upwards and end downwards.
     */
    pg = PAGE_ALIGN(__pa(start_pg));
    pgend = __pa(end_pg) & PAGE_MASK;

    /*
     * If there are free pages between these,
     * free the section of the memmap array.
     */
    if (pg < pgend)
        free_bootmem(pg, pgend - pg);
}

/*
 * The mem_map array can get very big.  Free the unused area of the memory map.
 */
static void __init free_unused_memmap(struct meminfo *mi)
{
    unsigned long bank_start, prev_bank_end = 0;
    unsigned int i;

    /*
     * This relies on each bank being in address order.
     * The banks are sorted previously in bootmem_init().
     */
    for_each_bank(i, mi) {
        struct membank *bank = &mi->bank[i];

        bank_start = bank_pfn_start(bank);

        /*
         * If we had a previous bank, and there is a space
         * between the current bank and the previous, free it.
         */
        if (prev_bank_end && prev_bank_end < bank_start)
            free_memmap(prev_bank_end, bank_start);

        /*
         * Align up here since the VM subsystem insists that the
         * memmap entries are valid from the bank end aligned to
         * MAX_ORDER_NR_PAGES.
         */
        prev_bank_end = ALIGN(bank_pfn_end(bank), MAX_ORDER_NR_PAGES);
    }
}

/*
 * mem_init() marks the free areas in the mem_map and tells us how much
 * memory is free.  This is done after various parts of the system have
 * claimed their memory after the kernel image.
 */
void __init mem_init(void)
{
    unsigned long reserved_pages, free_pages;
    struct memblock_region *reg;
    int i;

    max_mapnr   = pfn_to_page(max_pfn + PHYS_PFN_OFFSET) - mem_map;

    /* this will put all unused low memory onto the freelists */
    free_unused_memmap(&meminfo);

    totalram_pages += free_all_bootmem();

    reserved_pages = free_pages = 0;

    for_each_bank(i, &meminfo) {
        struct membank *bank = &meminfo.bank[i];
        unsigned int pfn1, pfn2;
        struct page *page, *end;

        pfn1 = bank_pfn_start(bank);
        pfn2 = bank_pfn_end(bank);

        page = pfn_to_page(pfn1);
        end  = pfn_to_page(pfn2 - 1) + 1;

        do {
            if (PageReserved(page))
                reserved_pages++;
            else if (!page_count(page))
                free_pages++;
            page++;
        } while (page < end);
    }

    /*
     * Since our memory may not be contiguous, calculate the
     * real number of pages we have in this system
     */
    printk(KERN_INFO "Memory:");
    num_physpages = 0;
    for_each_memblock(memory, reg) {
        unsigned long pages = memblock_region_memory_end_pfn(reg) -
            memblock_region_memory_base_pfn(reg);
        num_physpages += pages;
        printk(" %ldMB", pages >> (20 - PAGE_SHIFT));
    }
    printk(" = %luMB total\n", num_physpages >> (20 - PAGE_SHIFT));

    printk(KERN_NOTICE "Memory: %luk/%luk available, %luk reserved, %luK highmem\n",
        nr_free_pages() << (PAGE_SHIFT-10),
        free_pages << (PAGE_SHIFT-10),
        reserved_pages << (PAGE_SHIFT-10),
        totalhigh_pages << (PAGE_SHIFT-10));

    printk(KERN_NOTICE "Virtual kernel memory layout:\n"
        "    vector  : 0x%08lx - 0x%08lx   (%4ld kB)\n"
        "    vmalloc : 0x%08lx - 0x%08lx   (%4ld MB)\n"
        "    lowmem  : 0x%08lx - 0x%08lx   (%4ld MB)\n"
        "    modules : 0x%08lx - 0x%08lx   (%4ld MB)\n"
        "      .init : 0x%p" " - 0x%p" "   (%4d kB)\n"
        "      .text : 0x%p" " - 0x%p" "   (%4d kB)\n"
        "      .data : 0x%p" " - 0x%p" "   (%4d kB)\n",

        VECTORS_BASE, VECTORS_BASE + PAGE_SIZE,
        DIV_ROUND_UP(PAGE_SIZE, SZ_1K),
        VMALLOC_START, VMALLOC_END,
        DIV_ROUND_UP((VMALLOC_END - VMALLOC_START), SZ_1M),
        PAGE_OFFSET, (unsigned long)high_memory,
        DIV_ROUND_UP(((unsigned long)high_memory - PAGE_OFFSET), SZ_1M),
        MODULES_VADDR, MODULES_END,
        DIV_ROUND_UP((MODULES_END - MODULES_VADDR), SZ_1M),

        __init_begin, __init_end,
        DIV_ROUND_UP((__init_end - __init_begin), SZ_1K),
        _stext, _etext,
        DIV_ROUND_UP((_etext - _stext), SZ_1K),
        _sdata, _edata,
        DIV_ROUND_UP((_edata - _sdata), SZ_1K));

    BUILD_BUG_ON(TASK_SIZE              > MODULES_VADDR);
    BUG_ON(TASK_SIZE                > MODULES_VADDR);

    if (PAGE_SIZE >= 16384 && num_physpages <= 128) {
        /*
         * On a machine this small we won't get
         * anywhere without overcommit, so turn
         * it on by default.
         */
        sysctl_overcommit_memory = OVERCOMMIT_ALWAYS;
    }
}

void free_initmem(void)
{
    totalram_pages += free_area(__phys_to_pfn(__pa(__init_begin)),
                    __phys_to_pfn(__pa(__init_end)),
                    "init");
}

#ifdef CONFIG_BLK_DEV_INITRD

static int keep_initrd;

void free_initrd_mem(unsigned long start, unsigned long end)
{
    if (!keep_initrd)
        totalram_pages += free_area(__phys_to_pfn(__pa(start)),
                        __phys_to_pfn(__pa(end)),
                        "initrd");
}

static int __init keepinitrd_setup(char *__unused)
{
    keep_initrd = 1;
    return 1;
}

__setup("keepinitrd", keepinitrd_setup);
#endif