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init.c

/* 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 (dhowells@redhat.com)
 *
 * 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/slab.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 <asm/processor.h>
#include <asm/system.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>

DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);

unsigned long highstart_pfn, highend_pfn;

/*
 * 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);

      __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;

      if (!mem_map)
            BUG();

#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",
             (unsigned long) nr_free_pages() << (PAGE_SHIFT - 10),
             max_mapnr << (PAGE_SHIFT - 10),
             codesize >> 10,
             reservedpages << (PAGE_SHIFT - 10),
             datasize >> 10,
             initsize >> 10,
             (unsigned long) (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

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