linux/arch/avr32/mm/init.c
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   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/mm.h>
  11#include <linux/swap.h>
  12#include <linux/init.h>
  13#include <linux/mmzone.h>
  14#include <linux/module.h>
  15#include <linux/bootmem.h>
  16#include <linux/pagemap.h>
  17#include <linux/nodemask.h>
  18
  19#include <asm/page.h>
  20#include <asm/mmu_context.h>
  21#include <asm/tlb.h>
  22#include <asm/io.h>
  23#include <asm/dma.h>
  24#include <asm/setup.h>
  25#include <asm/sections.h>
  26
  27#define __page_aligned  __attribute__((section(".data.page_aligned")))
  28
  29DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  30
  31pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned;
  32
  33struct page *empty_zero_page;
  34EXPORT_SYMBOL(empty_zero_page);
  35
  36/*
  37 * Cache of MMU context last used.
  38 */
  39unsigned long mmu_context_cache = NO_CONTEXT;
  40
  41/*
  42 * paging_init() sets up the page tables
  43 *
  44 * This routine also unmaps the page at virtual kernel address 0, so
  45 * that we can trap those pesky NULL-reference errors in the kernel.
  46 */
  47void __init paging_init(void)
  48{
  49        extern unsigned long _evba;
  50        void *zero_page;
  51        int nid;
  52
  53        /*
  54         * Make sure we can handle exceptions before enabling
  55         * paging. Not that we should ever _get_ any exceptions this
  56         * early, but you never know...
  57         */
  58        printk("Exception vectors start at %p\n", &_evba);
  59        sysreg_write(EVBA, (unsigned long)&_evba);
  60
  61        /*
  62         * Since we are ready to handle exceptions now, we should let
  63         * the CPU generate them...
  64         */
  65        __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
  66
  67        /*
  68         * Allocate the zero page. The allocator will panic if it
  69         * can't satisfy the request, so no need to check.
  70         */
  71        zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
  72                                                 PAGE_SIZE);
  73
  74        sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
  75        enable_mmu();
  76        printk ("CPU: Paging enabled\n");
  77
  78        for_each_online_node(nid) {
  79                pg_data_t *pgdat = NODE_DATA(nid);
  80                unsigned long zones_size[MAX_NR_ZONES];
  81                unsigned long low, start_pfn;
  82
  83                start_pfn = pgdat->bdata->node_min_pfn;
  84                low = pgdat->bdata->node_low_pfn;
  85
  86                memset(zones_size, 0, sizeof(zones_size));
  87                zones_size[ZONE_NORMAL] = low - start_pfn;
  88
  89                printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
  90                       nid, start_pfn, low);
  91
  92                free_area_init_node(nid, zones_size, start_pfn, NULL);
  93
  94                printk("Node %u: mem_map starts at %p\n",
  95                       pgdat->node_id, pgdat->node_mem_map);
  96        }
  97
  98        mem_map = NODE_DATA(0)->node_mem_map;
  99
 100        memset(zero_page, 0, PAGE_SIZE);
 101        empty_zero_page = virt_to_page(zero_page);
 102        flush_dcache_page(empty_zero_page);
 103}
 104
 105void __init mem_init(void)
 106{
 107        int codesize, reservedpages, datasize, initsize;
 108        int nid, i;
 109
 110        reservedpages = 0;
 111        high_memory = NULL;
 112
 113        /* this will put all low memory onto the freelists */
 114        for_each_online_node(nid) {
 115                pg_data_t *pgdat = NODE_DATA(nid);
 116                unsigned long node_pages = 0;
 117                void *node_high_memory;
 118
 119                num_physpages += pgdat->node_present_pages;
 120
 121                if (pgdat->node_spanned_pages != 0)
 122                        node_pages = free_all_bootmem_node(pgdat);
 123
 124                totalram_pages += node_pages;
 125
 126                for (i = 0; i < node_pages; i++)
 127                        if (PageReserved(pgdat->node_mem_map + i))
 128                                reservedpages++;
 129
 130                node_high_memory = (void *)((pgdat->node_start_pfn
 131                                             + pgdat->node_spanned_pages)
 132                                            << PAGE_SHIFT);
 133                if (node_high_memory > high_memory)
 134                        high_memory = node_high_memory;
 135        }
 136
 137        max_mapnr = MAP_NR(high_memory);
 138
 139        codesize = (unsigned long)_etext - (unsigned long)_text;
 140        datasize = (unsigned long)_edata - (unsigned long)_data;
 141        initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 142
 143        printk ("Memory: %luk/%luk available (%dk kernel code, "
 144                "%dk reserved, %dk data, %dk init)\n",
 145                (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
 146                totalram_pages << (PAGE_SHIFT - 10),
 147                codesize >> 10,
 148                reservedpages << (PAGE_SHIFT - 10),
 149                datasize >> 10,
 150                initsize >> 10);
 151}
 152
 153static inline void free_area(unsigned long addr, unsigned long end, char *s)
 154{
 155        unsigned int size = (end - addr) >> 10;
 156
 157        for (; addr < end; addr += PAGE_SIZE) {
 158                struct page *page = virt_to_page(addr);
 159                ClearPageReserved(page);
 160                init_page_count(page);
 161                free_page(addr);
 162                totalram_pages++;
 163        }
 164
 165        if (size && s)
 166                printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
 167                       s, size, end - (size << 10), end);
 168}
 169
 170void free_initmem(void)
 171{
 172        free_area((unsigned long)__init_begin, (unsigned long)__init_end,
 173                  "init");
 174}
 175
 176#ifdef CONFIG_BLK_DEV_INITRD
 177
 178void free_initrd_mem(unsigned long start, unsigned long end)
 179{
 180        free_area(start, end, "initrd");
 181}
 182
 183#endif
 184