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/bootmem.h>
  15 #include <linux/pagemap.h>
  16 #include <linux/nodemask.h>
  17
  18 #include <asm/page.h>
  19 #include <asm/mmu_context.h>
  20 #include <asm/tlb.h>
  21 #include <asm/io.h>
  22 #include <asm/dma.h>
  23 #include <asm/setup.h>
  24 #include <asm/sections.h>
  25
  26 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  27
  28 pgd_t swapper_pg_dir[PTRS_PER_PGD];
  29
  30 struct page *empty_zero_page;
  31
  32 /*
  33  * Cache of MMU context last used.
  34  */
  35 unsigned long mmu_context_cache = NO_CONTEXT;
  36
  37 void show_mem(void)
  38 {
  39         int total = 0, reserved = 0, cached = 0;
  40         int slab = 0, free = 0, shared = 0;
  41         pg_data_t *pgdat;
  42
  43         printk("Mem-info:\n");
  44         show_free_areas();
  45
  46         for_each_online_pgdat(pgdat) {
  47                 struct page *page, *end;
  48
  49                 page = pgdat->node_mem_map;
  50                 end = page + pgdat->node_spanned_pages;
  51
  52                 do {
  53                         total++;
  54                         if (PageReserved(page))
  55                                 reserved++;
  56                         else if (PageSwapCache(page))
  57                                 cached++;
  58                         else if (PageSlab(page))
  59                                 slab++;
  60                         else if (!page_count(page))
  61                                 free++;
  62                         else
  63                                 shared += page_count(page) - 1;
  64                         page++;
  65                 } while (page < end);
  66         }
  67
  68         printk ("%d pages of RAM\n", total);
  69         printk ("%d free pages\n", free);
  70         printk ("%d reserved pages\n", reserved);
  71         printk ("%d slab pages\n", slab);
  72         printk ("%d pages shared\n", shared);
  73         printk ("%d pages swap cached\n", cached);
  74 }
  75
  76 /*
  77  * paging_init() sets up the page tables
  78  *
  79  * This routine also unmaps the page at virtual kernel address 0, so
  80  * that we can trap those pesky NULL-reference errors in the kernel.
  81  */
  82 void __init paging_init(void)
  83 {
  84         extern unsigned long _evba;
  85         void *zero_page;
  86         int nid;
  87
  88         /*
  89          * Make sure we can handle exceptions before enabling
  90          * paging. Not that we should ever _get_ any exceptions this
  91          * early, but you never know...
  92          */
  93         printk("Exception vectors start at %p\n", &_evba);
  94         sysreg_write(EVBA, (unsigned long)&_evba);
  95
  96         /*
  97          * Since we are ready to handle exceptions now, we should let
  98          * the CPU generate them...
  99          */
 100         __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
 101
 102         /*
 103          * Allocate the zero page. The allocator will panic if it
 104          * can't satisfy the request, so no need to check.
 105          */
 106         zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
 107                                                  PAGE_SIZE);
 108
 109         {
 110                 pgd_t *pg_dir;
 111                 int i;
 112
 113                 pg_dir = swapper_pg_dir;
 114                 sysreg_write(PTBR, (unsigned long)pg_dir);
 115
 116                 for (i = 0; i < PTRS_PER_PGD; i++)
 117                         pgd_val(pg_dir[i]) = 0;
 118
 119                 enable_mmu();
 120                 printk ("CPU: Paging enabled\n");
 121         }
 122
 123         for_each_online_node(nid) {
 124                 pg_data_t *pgdat = NODE_DATA(nid);
 125                 unsigned long zones_size[MAX_NR_ZONES];
 126                 unsigned long low, start_pfn;
 127
 128                 start_pfn = pgdat->bdata->node_boot_start;
 129                 start_pfn >>= PAGE_SHIFT;
 130                 low = pgdat->bdata->node_low_pfn;
 131
 132                 memset(zones_size, 0, sizeof(zones_size));
 133                 zones_size[ZONE_NORMAL] = low - start_pfn;
 134
 135                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 136                        nid, start_pfn, low);
 137
 138                 free_area_init_node(nid, pgdat, zones_size, start_pfn, NULL);
 139
 140                 printk("Node %u: mem_map starts at %p\n",
 141                        pgdat->node_id, pgdat->node_mem_map);
 142         }
 143
 144         mem_map = NODE_DATA(0)->node_mem_map;
 145
 146         memset(zero_page, 0, PAGE_SIZE);
 147         empty_zero_page = virt_to_page(zero_page);
 148         flush_dcache_page(empty_zero_page);
 149 }
 150
 151 void __init mem_init(void)
 152 {
 153         int codesize, reservedpages, datasize, initsize;
 154         int nid, i;
 155
 156         reservedpages = 0;
 157         high_memory = NULL;
 158
 159         /* this will put all low memory onto the freelists */
 160         for_each_online_node(nid) {
 161                 pg_data_t *pgdat = NODE_DATA(nid);
 162                 unsigned long node_pages = 0;
 163                 void *node_high_memory;
 164
 165                 num_physpages += pgdat->node_present_pages;
 166
 167                 if (pgdat->node_spanned_pages != 0)
 168                         node_pages = free_all_bootmem_node(pgdat);
 169
 170                 totalram_pages += node_pages;
 171
 172                 for (i = 0; i < node_pages; i++)
 173                         if (PageReserved(pgdat->node_mem_map + i))
 174                                 reservedpages++;
 175
 176                 node_high_memory = (void *)((pgdat->node_start_pfn
 177                                              + pgdat->node_spanned_pages)
 178                                             << PAGE_SHIFT);
 179                 if (node_high_memory > high_memory)
 180                         high_memory = node_high_memory;
 181         }
 182
 183         max_mapnr = MAP_NR(high_memory);
 184
 185         codesize = (unsigned long)_etext - (unsigned long)_text;
 186         datasize = (unsigned long)_edata - (unsigned long)_data;
 187         initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 188
 189         printk ("Memory: %luk/%luk available (%dk kernel code, "
 190                 "%dk reserved, %dk data, %dk init)\n",
 191                 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
 192                 totalram_pages << (PAGE_SHIFT - 10),
 193                 codesize >> 10,
 194                 reservedpages << (PAGE_SHIFT - 10),
 195                 datasize >> 10,
 196                 initsize >> 10);
 197 }
 198
 199 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 200 {
 201         unsigned int size = (end - addr) >> 10;
 202
 203         for (; addr < end; addr += PAGE_SIZE) {
 204                 struct page *page = virt_to_page(addr);
 205                 ClearPageReserved(page);
 206                 init_page_count(page);
 207                 free_page(addr);
 208                 totalram_pages++;
 209         }
 210
 211         if (size && s)
 212                 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
 213                        s, size, end - (size << 10), end);
 214 }
 215
 216 void free_initmem(void)
 217 {
 218         free_area((unsigned long)__init_begin, (unsigned long)__init_end,
 219                   "init");
 220 }
 221
 222 #ifdef CONFIG_BLK_DEV_INITRD
 223
 224 void free_initrd_mem(unsigned long start, unsigned long end)
 225 {
 226         free_area(start, end, "initrd");
 227 }
 228
 229 #endif