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