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 #define START_PFN       (NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
  38 #define MAX_LOW_PFN     (NODE_DATA(0)->bdata->node_low_pfn)
  39
  40 void show_mem(void)
  41 {
  42         int total = 0, reserved = 0, cached = 0;
  43         int slab = 0, free = 0, shared = 0;
  44         pg_data_t *pgdat;
  45
  46         printk("Mem-info:\n");
  47         show_free_areas();
  48
  49         for_each_online_pgdat(pgdat) {
  50                 struct page *page, *end;
  51
  52                 page = pgdat->node_mem_map;
  53                 end = page + pgdat->node_spanned_pages;
  54
  55                 do {
  56                         total++;
  57                         if (PageReserved(page))
  58                                 reserved++;
  59                         else if (PageSwapCache(page))
  60                                 cached++;
  61                         else if (PageSlab(page))
  62                                 slab++;
  63                         else if (!page_count(page))
  64                                 free++;
  65                         else
  66                                 shared += page_count(page) - 1;
  67                         page++;
  68                 } while (page < end);
  69         }
  70
  71         printk ("%d pages of RAM\n", total);
  72         printk ("%d free pages\n", free);
  73         printk ("%d reserved pages\n", reserved);
  74         printk ("%d slab pages\n", slab);
  75         printk ("%d pages shared\n", shared);
  76         printk ("%d pages swap cached\n", cached);
  77 }
  78
  79 /*
  80  * paging_init() sets up the page tables
  81  *
  82  * This routine also unmaps the page at virtual kernel address 0, so
  83  * that we can trap those pesky NULL-reference errors in the kernel.
  84  */
  85 void __init paging_init(void)
  86 {
  87         extern unsigned long _evba;
  88         void *zero_page;
  89         int nid;
  90
  91         /*
  92          * Make sure we can handle exceptions before enabling
  93          * paging. Not that we should ever _get_ any exceptions this
  94          * early, but you never know...
  95          */
  96         printk("Exception vectors start at %p\n", &_evba);
  97         sysreg_write(EVBA, (unsigned long)&_evba);
  98
  99         /*
 100          * Since we are ready to handle exceptions now, we should let
 101          * the CPU generate them...
 102          */
 103         __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
 104
 105         /*
 106          * Allocate the zero page. The allocator will panic if it
 107          * can't satisfy the request, so no need to check.
 108          */
 109         zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
 110                                                  PAGE_SIZE);
 111
 112         {
 113                 pgd_t *pg_dir;
 114                 int i;
 115
 116                 pg_dir = swapper_pg_dir;
 117                 sysreg_write(PTBR, (unsigned long)pg_dir);
 118
 119                 for (i = 0; i < PTRS_PER_PGD; i++)
 120                         pgd_val(pg_dir[i]) = 0;
 121
 122                 enable_mmu();
 123                 printk ("CPU: Paging enabled\n");
 124         }
 125
 126         for_each_online_node(nid) {
 127                 pg_data_t *pgdat = NODE_DATA(nid);
 128                 unsigned long zones_size[MAX_NR_ZONES];
 129                 unsigned long low, start_pfn;
 130
 131                 start_pfn = pgdat->bdata->node_boot_start;
 132                 start_pfn >>= PAGE_SHIFT;
 133                 low = pgdat->bdata->node_low_pfn;
 134
 135                 memset(zones_size, 0, sizeof(zones_size));
 136                 zones_size[ZONE_NORMAL] = low - start_pfn;
 137
 138                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 139                        nid, start_pfn, low);
 140
 141                 free_area_init_node(nid, pgdat, zones_size, start_pfn, NULL);
 142
 143                 printk("Node %u: mem_map starts at %p\n",
 144                        pgdat->node_id, pgdat->node_mem_map);
 145         }
 146
 147         mem_map = NODE_DATA(0)->node_mem_map;
 148
 149         memset(zero_page, 0, PAGE_SIZE);
 150         empty_zero_page = virt_to_page(zero_page);
 151         flush_dcache_page(empty_zero_page);
 152 }
 153
 154 void __init mem_init(void)
 155 {
 156         int codesize, reservedpages, datasize, initsize;
 157         int nid, i;
 158
 159         reservedpages = 0;
 160         high_memory = NULL;
 161
 162         /* this will put all low memory onto the freelists */
 163         for_each_online_node(nid) {
 164                 pg_data_t *pgdat = NODE_DATA(nid);
 165                 unsigned long node_pages = 0;
 166                 void *node_high_memory;
 167
 168                 num_physpages += pgdat->node_present_pages;
 169
 170                 if (pgdat->node_spanned_pages != 0)
 171                         node_pages = free_all_bootmem_node(pgdat);
 172
 173                 totalram_pages += node_pages;
 174
 175                 for (i = 0; i < node_pages; i++)
 176                         if (PageReserved(pgdat->node_mem_map + i))
 177                                 reservedpages++;
 178
 179                 node_high_memory = (void *)((pgdat->node_start_pfn
 180                                              + pgdat->node_spanned_pages)
 181                                             << PAGE_SHIFT);
 182                 if (node_high_memory > high_memory)
 183                         high_memory = node_high_memory;
 184         }
 185
 186         max_mapnr = MAP_NR(high_memory);
 187
 188         codesize = (unsigned long)_etext - (unsigned long)_text;
 189         datasize = (unsigned long)_edata - (unsigned long)_data;
 190         initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 191
 192         printk ("Memory: %luk/%luk available (%dk kernel code, "
 193                 "%dk reserved, %dk data, %dk init)\n",
 194                 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
 195                 totalram_pages << (PAGE_SHIFT - 10),
 196                 codesize >> 10,
 197                 reservedpages << (PAGE_SHIFT - 10),
 198                 datasize >> 10,
 199                 initsize >> 10);
 200 }
 201
 202 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 203 {
 204         unsigned int size = (end - addr) >> 10;
 205
 206         for (; addr < end; addr += PAGE_SIZE) {
 207                 struct page *page = virt_to_page(addr);
 208                 ClearPageReserved(page);
 209                 init_page_count(page);
 210                 free_page(addr);
 211                 totalram_pages++;
 212         }
 213
 214         if (size && s)
 215                 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
 216                        s, size, end - (size << 10), end);
 217 }
 218
 219 void free_initmem(void)
 220 {
 221         free_area((unsigned long)__init_begin, (unsigned long)__init_end,
 222                   "init");
 223 }
 224
 225 #ifdef CONFIG_BLK_DEV_INITRD
 226
 227 static int keep_initrd;
 228
 229 void free_initrd_mem(unsigned long start, unsigned long end)
 230 {
 231         if (!keep_initrd)
 232                 free_area(start, end, "initrd");
 233 }
 234
 235 static int __init keepinitrd_setup(char *__unused)
 236 {
 237         keep_initrd = 1;
 238         return 1;
 239 }
 240
 241 __setup("keepinitrd", keepinitrd_setup);
 242 #endif