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 /*
  42  * paging_init() sets up the page tables
  43  *
  44  * This routine also unmaps the page at virtual kernel address 0, so
  45  * that we can trap those pesky NULL-reference errors in the kernel.
  46  */
  47 void __init paging_init(void)
  48 {
  49         extern unsigned long _evba;
  50         void *zero_page;
  51         int nid;
  52
  53         /*
  54          * Make sure we can handle exceptions before enabling
  55          * paging. Not that we should ever _get_ any exceptions this
  56          * early, but you never know...
  57          */
  58         printk("Exception vectors start at %p\n", &_evba);
  59         sysreg_write(EVBA, (unsigned long)&_evba);
  60
  61         /*
  62          * Since we are ready to handle exceptions now, we should let
  63          * the CPU generate them...
  64          */
  65         __asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
  66
  67         /*
  68          * Allocate the zero page. The allocator will panic if it
  69          * can't satisfy the request, so no need to check.
  70          */
  71         zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
  72                                                  PAGE_SIZE);
  73
  74         sysreg_write(PTBR, (unsigned long)swapper_pg_dir);
  75         enable_mmu();
  76         printk ("CPU: Paging enabled\n");
  77
  78         for_each_online_node(nid) {
  79                 pg_data_t *pgdat = NODE_DATA(nid);
  80                 unsigned long zones_size[MAX_NR_ZONES];
  81                 unsigned long low, start_pfn;
  82
  83                 start_pfn = pgdat->bdata->node_min_pfn;
  84                 low = pgdat->bdata->node_low_pfn;
  85
  86                 memset(zones_size, 0, sizeof(zones_size));
  87                 zones_size[ZONE_NORMAL] = low - start_pfn;
  88
  89                 printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
  90                        nid, start_pfn, low);
  91
  92                 free_area_init_node(nid, zones_size, start_pfn, NULL);
  93
  94                 printk("Node %u: mem_map starts at %p\n",
  95                        pgdat->node_id, pgdat->node_mem_map);
  96         }
  97
  98         mem_map = NODE_DATA(0)->node_mem_map;
  99
 100         memset(zero_page, 0, PAGE_SIZE);
 101         empty_zero_page = virt_to_page(zero_page);
 102         flush_dcache_page(empty_zero_page);
 103 }
 104
 105 void __init mem_init(void)
 106 {
 107         int codesize, reservedpages, datasize, initsize;
 108         int nid, i;
 109
 110         reservedpages = 0;
 111         high_memory = NULL;
 112
 113         /* this will put all low memory onto the freelists */
 114         for_each_online_node(nid) {
 115                 pg_data_t *pgdat = NODE_DATA(nid);
 116                 unsigned long node_pages = 0;
 117                 void *node_high_memory;
 118
 119                 num_physpages += pgdat->node_present_pages;
 120
 121                 if (pgdat->node_spanned_pages != 0)
 122                         node_pages = free_all_bootmem_node(pgdat);
 123
 124                 totalram_pages += node_pages;
 125
 126                 for (i = 0; i < node_pages; i++)
 127                         if (PageReserved(pgdat->node_mem_map + i))
 128                                 reservedpages++;
 129
 130                 node_high_memory = (void *)((pgdat->node_start_pfn
 131                                              + pgdat->node_spanned_pages)
 132                                             << PAGE_SHIFT);
 133                 if (node_high_memory > high_memory)
 134                         high_memory = node_high_memory;
 135         }
 136
 137         max_mapnr = MAP_NR(high_memory);
 138
 139         codesize = (unsigned long)_etext - (unsigned long)_text;
 140         datasize = (unsigned long)_edata - (unsigned long)_data;
 141         initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
 142
 143         printk ("Memory: %luk/%luk available (%dk kernel code, "
 144                 "%dk reserved, %dk data, %dk init)\n",
 145                 (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
 146                 totalram_pages << (PAGE_SHIFT - 10),
 147                 codesize >> 10,
 148                 reservedpages << (PAGE_SHIFT - 10),
 149                 datasize >> 10,
 150                 initsize >> 10);
 151 }
 152
 153 static inline void free_area(unsigned long addr, unsigned long end, char *s)
 154 {
 155         unsigned int size = (end - addr) >> 10;
 156
 157         for (; addr < end; addr += PAGE_SIZE) {
 158                 struct page *page = virt_to_page(addr);
 159                 ClearPageReserved(page);
 160                 init_page_count(page);
 161                 free_page(addr);
 162                 totalram_pages++;
 163         }
 164
 165         if (size && s)
 166                 printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
 167                        s, size, end - (size << 10), end);
 168 }
 169
 170 void free_initmem(void)
 171 {
 172         free_area((unsigned long)__init_begin, (unsigned long)__init_end,
 173                   "init");
 174 }
 175
 176 #ifdef CONFIG_BLK_DEV_INITRD
 177
 178 void free_initrd_mem(unsigned long start, unsigned long end)
 179 {
 180         free_area(start, end, "initrd");
 181 }
 182
 183 #endif