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/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_PER_CPU(struct mmu_gather, mmu_gathers);
  28
  29 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  30
  31 struct page *empty_zero_page;
  32 EXPORT_SYMBOL(empty_zero_page);
  33
  34 /*
  35  * Cache of MMU context last used.
  36  */
  37 unsigned long mmu_context_cache = NO_CONTEXT;
  38
  39 void show_mem(void)
  40 {
  41         int total = 0, reserved = 0, cached = 0;
  42         int slab = 0, free = 0, shared = 0;
  43         pg_data_t *pgdat;
  44
  45         printk("Mem-info:\n");
  46         show_free_areas();
  47
  48         for_each_online_pgdat(pgdat) {
  49                 struct page *page, *end;
  50
  51                 page = pgdat->node_mem_map;
  52                 end = page + pgdat->node_spanned_pages;
  53
  54                 do {
  55                         total++;
  56                         if (PageReserved(page))
  57                                 reserved++;
  58                         else if (PageSwapCache(page))
  59                                 cached++;
  60                         else if (PageSlab(page))
  61                                 slab++;
  62                         else if (!page_count(page))
  63                                 free++;
  64                         else
  65                                 shared += page_count(page) - 1;
  66                         page++;
  67                 } while (page < end);
  68         }
  69
  70         printk ("%d pages of RAM\n", total);
  71         printk ("%d free pages\n", free);
  72         printk ("%d reserved pages\n", reserved);
  73         printk ("%d slab pages\n", slab);
  74         printk ("%d pages shared\n", shared);
  75         printk ("%d pages swap cached\n", cached);
  76 }
  77
  78 /*
  79  * paging_init() sets up the page tables
  80  *
  81  * This routine also unmaps the page at virtual kernel address 0, so
  82  * that we can trap those pesky NULL-reference errors in the kernel.
  83  */
  84 void __init paging_init(void)
  85 {
  86         extern unsigned long _evba;
  87         void *zero_page;
  88         int nid;
  89
  90         /*
  91          * Make sure we can handle exceptions before enabling
  92          * paging. Not that we should ever _get_ any exceptions this
  93          * early, but you never know...
  94          */
  95         printk("Exception vectors start at %p\n", &_evba);
  96         sysreg_write(EVBA, (unsigned long)&_evba);
  97
  98         /*
  99          * Since we are ready to handle exceptions now, we should let
 100          * the CPU generate them...
 101          */
 102         __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
 103
 104         /*
 105          * Allocate the zero page. The allocator will panic if it
 106          * can't satisfy the request, so no need to check.
 107          */
 108         zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
 109                                                  PAGE_SIZE);
 110
 111         sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
 112         enable_mmu();
 113         printk ("CPU: Paging enabled\n");
 114
 115         for_each_online_node(nid) {
 116                 pg_data_t *pgdat = NODE_DATA(nid);
 117                 unsigned long zones_size[MAX_NR_ZONES];
 118                 unsigned long low, start_pfn;
 119
 120                 start_pfn = pgdat->bdata->node_boot_start;
 121                 start_pfn >>= PAGE_SHIFT;
 122                 low = pgdat->bdata->node_low_pfn;
 123
 124                 memset(zones_size, 0, sizeof(zones_size));
 125                 zones_size[ZONE_NORMAL] = low - start_pfn;
 126
 127                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 128                        nid, start_pfn, low);
 129
 130                 free_area_init_node(nid, pgdat, zones_size, start_pfn, NULL);
 131
 132                 printk("Node %u: mem_map starts at %p\n",
 133                        pgdat->node_id, pgdat->node_mem_map);
 134         }
 135
 136         mem_map = NODE_DATA(0)->node_mem_map;
 137
 138         memset(zero_page, 0, PAGE_SIZE);
 139         empty_zero_page = virt_to_page(zero_page);
 140         flush_dcache_page(empty_zero_page);
 141 }
 142
 143 void __init mem_init(void)
 144 {
 145         int codesize, reservedpages, datasize, initsize;
 146         int nid, i;
 147
 148         reservedpages = 0;
 149         high_memory = NULL;
 150
 151         /* this will put all low memory onto the freelists */
 152         for_each_online_node(nid) {
 153                 pg_data_t *pgdat = NODE_DATA(nid);
 154                 unsigned long node_pages = 0;
 155                 void *node_high_memory;
 156
 157                 num_physpages += pgdat->node_present_pages;
 158
 159                 if (pgdat->node_spanned_pages != 0)
 160                         node_pages = free_all_bootmem_node(pgdat);
 161
 162                 totalram_pages += node_pages;
 163
 164                 for (i = 0; i < node_pages; i++)
 165                         if (PageReserved(pgdat->node_mem_map + i))
 166                                 reservedpages++;
 167
 168                 node_high_memory = (void *)((pgdat->node_start_pfn
 169                                              + pgdat->node_spanned_pages)
 170                                             << PAGE_SHIFT);
 171                 if (node_high_memory > high_memory)
 172                         high_memory = node_high_memory;
 173         }
 174
 175         max_mapnr = MAP_NR(high_memory);
 176
 177         codesize = (unsigned long)_etext - (unsigned long)_text;
 178         datasize = (unsigned long)_edata - (unsigned long)_data;
 179         initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 180
 181         printk ("Memory: %luk/%luk available (%dk kernel code, "
 182                 "%dk reserved, %dk data, %dk init)\n",
 183                 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
 184                 totalram_pages << (PAGE_SHIFT - 10),
 185                 codesize >> 10,
 186                 reservedpages << (PAGE_SHIFT - 10),
 187                 datasize >> 10,
 188                 initsize >> 10);
 189 }
 190
 191 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 192 {
 193         unsigned int size = (end - addr) >> 10;
 194
 195         for (; addr < end; addr += PAGE_SIZE) {
 196                 struct page *page = virt_to_page(addr);
 197                 ClearPageReserved(page);
 198                 init_page_count(page);
 199                 free_page(addr);
 200                 totalram_pages++;
 201         }
 202
 203         if (size && s)
 204                 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
 205                        s, size, end - (size << 10), end);
 206 }
 207
 208 void free_initmem(void)
 209 {
 210         free_area((unsigned long)__init_begin, (unsigned long)__init_end,
 211                   "init");
 212 }
 213
 214 #ifdef CONFIG_BLK_DEV_INITRD
 215
 216 void free_initrd_mem(unsigned long start, unsigned long end)
 217 {
 218         free_area(start, end, "initrd");
 219 }
 220
 221 #endif