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        int codesize, reservedpages, datasize, initsize;
 104        int nid, i;
 105
 106        reservedpages = 0;
 107        high_memory = NULL;
 108
 109        /* this will put all low memory onto the freelists */
 110        for_each_online_node(nid) {
 111                pg_data_t *pgdat = NODE_DATA(nid);
 112                unsigned long node_pages = 0;
 113                void *node_high_memory;
 114
 115                num_physpages += pgdat->node_present_pages;
 116
 117                if (pgdat->node_spanned_pages != 0)
 118                        node_pages = free_all_bootmem_node(pgdat);
 119
 120                totalram_pages += node_pages;
 121
 122                for (i = 0; i < node_pages; i++)
 123                        if (PageReserved(pgdat->node_mem_map + i))
 124                                reservedpages++;
 125
 126                node_high_memory = (void *)((pgdat->node_start_pfn
 127                                             + pgdat->node_spanned_pages)
 128                                            << PAGE_SHIFT);
 129                if (node_high_memory > high_memory)
 130                        high_memory = node_high_memory;
 131        }
 132
 133        max_mapnr = MAP_NR(high_memory);
 134
 135        codesize = (unsigned long)_etext - (unsigned long)_text;
 136        datasize = (unsigned long)_edata - (unsigned long)_data;
 137        initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 138
 139        printk ("Memory: %luk/%luk available (%dk kernel code, "
 140                "%dk reserved, %dk data, %dk init)\n",
 141                nr_free_pages() << (PAGE_SHIFT - 10),
 142                totalram_pages << (PAGE_SHIFT - 10),
 143                codesize >> 10,
 144                reservedpages << (PAGE_SHIFT - 10),
 145                datasize >> 10,
 146                initsize >> 10);
 147}
 148
 149void free_initmem(void)
 150{
 151        free_initmem_default(0);
 152}
 153
 154#ifdef CONFIG_BLK_DEV_INITRD
 155void free_initrd_mem(unsigned long start, unsigned long end)
 156{
 157        free_reserved_area(start, end, 0, "initrd");
 158}
 159#endif
 160