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