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