LXR linux/arch/avr32/mm/init.c

   1/*
   2 * Copyright (C) 2004-2006 Atmel Corporation
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License version 2 as
   6 * published by the Free Software Foundation.
   7 */
   8
   9#include <linux/kernel.h>
  10#include <linux/gfp.h>
  11#include <linux/mm.h>
  12#include <linux/swap.h>
  13#include <linux/init.h>
  14#include <linux/mmzone.h>
  15#include <linux/module.h>
  16#include <linux/bootmem.h>
  17#include <linux/pagemap.h>
  18#include <linux/nodemask.h>
  19
  20#include <asm/page.h>
  21#include <asm/mmu_context.h>
  22#include <asm/tlb.h>
  23#include <asm/io.h>
  24#include <asm/dma.h>
  25#include <asm/setup.h>
  26#include <asm/sections.h>
  27
  28pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_data;
  29
  30struct page *empty_zero_page;
  31EXPORT_SYMBOL(empty_zero_page);
  32
  33/*
  34 * Cache of MMU context last used.
  35 */
  36unsigned long mmu_context_cache = NO_CONTEXT;
  37
  38/*
  39 * paging_init() sets up the page tables
  40 *
  41 * This routine also unmaps the page at virtual kernel address 0, so
  42 * that we can trap those pesky NULL-reference errors in the kernel.
  43 */
  44void __init paging_init(void)
  45{
  46        extern unsigned long _evba;
  47        void *zero_page;
  48        int nid;
  49
  50        /*
  51         * Make sure we can handle exceptions before enabling
  52         * paging. Not that we should ever _get_ any exceptions this
  53         * early, but you never know...
  54         */
  55        printk("Exception vectors start at %p\n", &_evba);
  56        sysreg_write(EVBA, (unsigned long)&_evba);
  57
  58        /*
  59         * Since we are ready to handle exceptions now, we should let
  60         * the CPU generate them...
  61         */
  62        __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
  63
  64        /*
  65         * Allocate the zero page. The allocator will panic if it
  66         * can't satisfy the request, so no need to check.
  67         */
  68        zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
  69                                                 PAGE_SIZE);
  70
  71        sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
  72        enable_mmu();
  73        printk ("CPU: Paging enabled\n");
  74
  75        for_each_online_node(nid) {
  76                pg_data_t *pgdat = NODE_DATA(nid);
  77                unsigned long zones_size[MAX_NR_ZONES];
  78                unsigned long low, start_pfn;
  79
  80                start_pfn = pgdat->bdata->node_min_pfn;
  81                low = pgdat->bdata->node_low_pfn;
  82
  83                memset(zones_size, 0, sizeof(zones_size));
  84                zones_size[ZONE_NORMAL] = low - start_pfn;
  85
  86                printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
  87                       nid, start_pfn, low);
  88
  89                free_area_init_node(nid, zones_size, start_pfn, NULL);
  90
  91                printk("Node %u: mem_map starts at %p\n",
  92                       pgdat->node_id, pgdat->node_mem_map);
  93        }
  94
  95        mem_map = NODE_DATA(0)->node_mem_map;
  96
  97        empty_zero_page = virt_to_page(zero_page);
  98        flush_dcache_page(empty_zero_page);
  99}
 100
 101void __init mem_init(void)
 102{
 103        pg_data_t *pgdat;
 104
 105        high_memory = NULL;
 106        for_each_online_pgdat(pgdat)
 107                high_memory = max_t(void *, high_memory,
 108                                    __va(pgdat_end_pfn(pgdat) << PAGE_SHIFT));
 109
 110        set_max_mapnr(MAP_NR(high_memory));
 111        free_all_bootmem();
 112        mem_init_print_info(NULL);
 113}
 114
 115void free_initmem(void)
 116{
 117        free_initmem_default(-1);
 118}
 119
 120#ifdef CONFIG_BLK_DEV_INITRD
 121void free_initrd_mem(unsigned long start, unsigned long end)
 122{
 123        free_reserved_area((void *)start, (void *)end, -1, "initrd");
 124}
 125#endif
 126