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