init.c

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/* MN10300 Memory management initialisation
 *
 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Modified by David Howells ([email protected])
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public Licence
 * as published by the Free Software Foundation; either version
 * 2 of the Licence, or (at your option) any later version.
 */
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <linux/types.h>
#include <linux/ptrace.h>
#include <linux/mman.h>
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/smp.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/highmem.h>
#include <linux/pagemap.h>
#include <linux/bootmem.h>
#include <linux/gfp.h>

#include <asm/processor.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/dma.h>
#include <asm/tlb.h>
#include <asm/sections.h>

unsigned long highstart_pfn, highend_pfn;

#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
static struct vm_struct user_iomap_vm;
#endif

/*
 * set up paging
 */
void __init paging_init(void)
{
    unsigned long zones_size[MAX_NR_ZONES] = {0,};
    pte_t *ppte;
    int loop;

    /* main kernel space -> RAM mapping is handled as 1:1 transparent by
     * the MMU */
    memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
    memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));

    /* load the VMALLOC area PTE table addresses into the kernel PGD */
    ppte = kernel_vmalloc_ptes;
    for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
         loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
         loop++
         ) {
        set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
        ppte += PAGE_SIZE / sizeof(pte_t);
    }

    /* declare the sizes of the RAM zones (only use the normal zone) */
    zones_size[ZONE_NORMAL] =
        contig_page_data.bdata->node_low_pfn -
        contig_page_data.bdata->node_min_pfn;

    /* pass the memory from the bootmem allocator to the main allocator */
    free_area_init(zones_size);

#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
    /* The Atomic Operation Unit registers need to be mapped to userspace
     * for all processes.  The following uses vm_area_register_early() to
     * reserve the first page of the vmalloc area and sets the pte for that
     * page.
     *
     * glibc hardcodes this virtual mapping, so we're pretty much stuck with
     * it from now on.
     */
    user_iomap_vm.flags = VM_USERMAP;
    user_iomap_vm.size = 1 << PAGE_SHIFT;
    vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
    ppte = kernel_vmalloc_ptes;
    set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
                  PAGE_USERIO));
#endif

    local_flush_tlb_all();
}

/*
 * transfer all the memory from the bootmem allocator to the runtime allocator
 */
void __init mem_init(void)
{
    int codesize, reservedpages, datasize, initsize;
    int tmp;

    BUG_ON(!mem_map);

#define START_PFN   (contig_page_data.bdata->node_min_pfn)
#define MAX_LOW_PFN (contig_page_data.bdata->node_low_pfn)

    max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
    high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);

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

    /* this will put all low memory onto the freelists */
    totalram_pages += free_all_bootmem();

    reservedpages = 0;
    for (tmp = 0; tmp < num_physpages; tmp++)
        if (PageReserved(&mem_map[tmp]))
            reservedpages++;

    codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
    datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
    initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;

    printk(KERN_INFO
           "Memory: %luk/%luk available"
           " (%dk kernel code, %dk reserved, %dk data, %dk init,"
           " %ldk highmem)\n",
           nr_free_pages() << (PAGE_SHIFT - 10),
           max_mapnr << (PAGE_SHIFT - 10),
           codesize >> 10,
           reservedpages << (PAGE_SHIFT - 10),
           datasize >> 10,
           initsize >> 10,
           totalhigh_pages << (PAGE_SHIFT - 10));
}

/*
 *
 */
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
    unsigned long addr;

    for (addr = begin; addr < end; addr += PAGE_SIZE) {
        ClearPageReserved(virt_to_page(addr));
        init_page_count(virt_to_page(addr));
        memset((void *) addr, 0xcc, PAGE_SIZE);
        free_page(addr);
        totalram_pages++;
    }
    printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}

/*
 * recycle memory containing stuff only required for initialisation
 */
void free_initmem(void)
{
    free_init_pages("unused kernel memory",
            (unsigned long) &__init_begin,
            (unsigned long) &__init_end);
}

/*
 * dispose of the memory on which the initial ramdisk resided
 */
#ifdef CONFIG_BLK_DEV_INITRD
void free_initrd_mem(unsigned long start, unsigned long end)
{
    free_init_pages("initrd memory", start, end);
}
#endif