LXR linux/arch/mn10300/mm/init.c

   1/* MN10300 Memory management initialisation
   2 *
   3 * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
   4 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5 * Modified by David Howells (dhowells@redhat.com)
   6 *
   7 * This program is free software; you can redistribute it and/or
   8 * modify it under the terms of the GNU General Public Licence
   9 * as published by the Free Software Foundation; either version
  10 * 2 of the Licence, or (at your option) any later version.
  11 */
  12#include <linux/signal.h>
  13#include <linux/sched.h>
  14#include <linux/kernel.h>
  15#include <linux/errno.h>
  16#include <linux/string.h>
  17#include <linux/types.h>
  18#include <linux/ptrace.h>
  19#include <linux/mman.h>
  20#include <linux/fs.h>
  21#include <linux/mm.h>
  22#include <linux/swap.h>
  23#include <linux/smp.h>
  24#include <linux/init.h>
  25#include <linux/initrd.h>
  26#include <linux/highmem.h>
  27#include <linux/pagemap.h>
  28#include <linux/bootmem.h>
  29#include <linux/gfp.h>
  30
  31#include <asm/processor.h>
  32#include <asm/uaccess.h>
  33#include <asm/pgtable.h>
  34#include <asm/pgalloc.h>
  35#include <asm/dma.h>
  36#include <asm/tlb.h>
  37#include <asm/sections.h>
  38
  39unsigned long highstart_pfn, highend_pfn;
  40
  41#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  42static struct vm_struct user_iomap_vm;
  43#endif
  44
  45/*
  46 * set up paging
  47 */
  48void __init paging_init(void)
  49{
  50        unsigned long zones_size[MAX_NR_ZONES] = {0,};
  51        pte_t *ppte;
  52        int loop;
  53
  54        /* main kernel space -> RAM mapping is handled as 1:1 transparent by
  55         * the MMU */
  56        memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  57        memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
  58
  59        /* load the VMALLOC area PTE table addresses into the kernel PGD */
  60        ppte = kernel_vmalloc_ptes;
  61        for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
  62             loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
  63             loop++
  64             ) {
  65                set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
  66                ppte += PAGE_SIZE / sizeof(pte_t);
  67        }
  68
  69        /* declare the sizes of the RAM zones (only use the normal zone) */
  70        zones_size[ZONE_NORMAL] =
  71                contig_page_data.bdata->node_low_pfn -
  72                contig_page_data.bdata->node_min_pfn;
  73
  74        /* pass the memory from the bootmem allocator to the main allocator */
  75        free_area_init(zones_size);
  76
  77#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  78        /* The Atomic Operation Unit registers need to be mapped to userspace
  79         * for all processes.  The following uses vm_area_register_early() to
  80         * reserve the first page of the vmalloc area and sets the pte for that
  81         * page.
  82         *
  83         * glibc hardcodes this virtual mapping, so we're pretty much stuck with
  84         * it from now on.
  85         */
  86        user_iomap_vm.flags = VM_USERMAP;
  87        user_iomap_vm.size = 1 << PAGE_SHIFT;
  88        vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
  89        ppte = kernel_vmalloc_ptes;
  90        set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
  91                              PAGE_USERIO));
  92#endif
  93
  94        local_flush_tlb_all();
  95}
  96
  97/*
  98 * transfer all the memory from the bootmem allocator to the runtime allocator
  99 */
 100void __init mem_init(void)
 101{
 102        BUG_ON(!mem_map);
 103
 104#define START_PFN       (contig_page_data.bdata->node_min_pfn)
 105#define MAX_LOW_PFN     (contig_page_data.bdata->node_low_pfn)
 106
 107        max_mapnr = MAX_LOW_PFN - START_PFN;
 108        high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
 109
 110        /* clear the zero-page */
 111        memset(empty_zero_page, 0, PAGE_SIZE);
 112
 113        /* this will put all low memory onto the freelists */
 114        free_all_bootmem();
 115
 116        mem_init_print_info(NULL);
 117}
 118
 119/*
 120 * recycle memory containing stuff only required for initialisation
 121 */
 122void free_initmem(void)
 123{
 124        free_initmem_default(POISON_FREE_INITMEM);
 125}
 126
 127/*
 128 * dispose of the memory on which the initial ramdisk resided
 129 */
 130#ifdef CONFIG_BLK_DEV_INITRD
 131void free_initrd_mem(unsigned long start, unsigned long end)
 132{
 133        free_reserved_area((void *)start, (void *)end, POISON_FREE_INITMEM,
 134                           "initrd");
 135}
 136#endif
 137