arch/mn10300/mm/init.c

   1 /* MN10300 Memory management initialisation
   2  *
   3  * Copyright (C) 2007 Matsushita Electric Industrial Co., Ltd.
   4  * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
   5  * Modified by David Howells (dhowells@redhat.com)
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public Licence
   9  * as published by the Free Software Foundation; either version
  10  * 2 of the Licence, or (at your option) any later version.
  11  */
  12 #include <linux/signal.h>
  13 #include <linux/sched.h>
  14 #include <linux/kernel.h>
  15 #include <linux/errno.h>
  16 #include <linux/string.h>
  17 #include <linux/types.h>
  18 #include <linux/ptrace.h>
  19 #include <linux/mman.h>
  20 #include <linux/slab.h>
  21 #include <linux/fs.h>
  22 #include <linux/mm.h>
  23 #include <linux/swap.h>
  24 #include <linux/smp.h>
  25 #include <linux/init.h>
  26 #include <linux/initrd.h>
  27 #include <linux/highmem.h>
  28 #include <linux/pagemap.h>
  29 #include <linux/bootmem.h>
  30
  31 #include <asm/processor.h>
  32 #include <asm/system.h>
  33 #include <asm/uaccess.h>
  34 #include <asm/pgtable.h>
  35 #include <asm/pgalloc.h>
  36 #include <asm/dma.h>
  37 #include <asm/tlb.h>
  38 #include <asm/sections.h>
  39
  40 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
  41
  42 unsigned long highstart_pfn, highend_pfn;
  43
  44 /*
  45  * set up paging
  46  */
  47 void __init paging_init(void)
  48 {
  49         unsigned long zones_size[MAX_NR_ZONES] = {0,};
  50         pte_t *ppte;
  51         int loop;
  52
  53         /* main kernel space -> RAM mapping is handled as 1:1 transparent by
  54          * the MMU */
  55         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  56         memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
  57
  58         /* load the VMALLOC area PTE table addresses into the kernel PGD */
  59         ppte = kernel_vmalloc_ptes;
  60         for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
  61              loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
  62              loop++
  63              ) {
  64                 set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
  65                 ppte += PAGE_SIZE / sizeof(pte_t);
  66         }
  67
  68         /* declare the sizes of the RAM zones (only use the normal zone) */
  69         zones_size[ZONE_NORMAL] =
  70                 contig_page_data.bdata->node_low_pfn -
  71                 contig_page_data.bdata->node_min_pfn;
  72
  73         /* pass the memory from the bootmem allocator to the main allocator */
  74         free_area_init(zones_size);
  75
  76         __flush_tlb_all();
  77 }
  78
  79 /*
  80  * transfer all the memory from the bootmem allocator to the runtime allocator
  81  */
  82 void __init mem_init(void)
  83 {
  84         int codesize, reservedpages, datasize, initsize;
  85         int tmp;
  86
  87         if (!mem_map)
  88                 BUG();
  89
  90 #define START_PFN       (contig_page_data.bdata->node_min_pfn)
  91 #define MAX_LOW_PFN     (contig_page_data.bdata->node_low_pfn)
  92
  93         max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
  94         high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
  95
  96         /* clear the zero-page */
  97         memset(empty_zero_page, 0, PAGE_SIZE);
  98
  99         /* this will put all low memory onto the freelists */
 100         totalram_pages += free_all_bootmem();
 101
 102         reservedpages = 0;
 103         for (tmp = 0; tmp < num_physpages; tmp++)
 104                 if (PageReserved(&mem_map[tmp]))
 105                         reservedpages++;
 106
 107         codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
 108         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 109         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 110
 111         printk(KERN_INFO
 112                "Memory: %luk/%luk available"
 113                " (%dk kernel code, %dk reserved, %dk data, %dk init,"
 114                " %ldk highmem)\n",
 115                nr_free_pages() << (PAGE_SHIFT - 10),
 116                max_mapnr << (PAGE_SHIFT - 10),
 117                codesize >> 10,
 118                reservedpages << (PAGE_SHIFT - 10),
 119                datasize >> 10,
 120                initsize >> 10,
 121                (unsigned long) (totalhigh_pages << (PAGE_SHIFT - 10))
 122                );
 123 }
 124
 125 /*
 126  *
 127  */
 128 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 129 {
 130         unsigned long addr;
 131
 132         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 133                 ClearPageReserved(virt_to_page(addr));
 134                 init_page_count(virt_to_page(addr));
 135                 memset((void *) addr, 0xcc, PAGE_SIZE);
 136                 free_page(addr);
 137                 totalram_pages++;
 138         }
 139         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 140 }
 141
 142 /*
 143  * recycle memory containing stuff only required for initialisation
 144  */
 145 void free_initmem(void)
 146 {
 147         free_init_pages("unused kernel memory",
 148                         (unsigned long) &__init_begin,
 149                         (unsigned long) &__init_end);
 150 }
 151
 152 /*
 153  * dispose of the memory on which the initial ramdisk resided
 154  */
 155 #ifdef CONFIG_BLK_DEV_INITRD
 156 void free_initrd_mem(unsigned long start, unsigned long end)
 157 {
 158         free_init_pages("initrd memory", start, end);
 159 }
 160 #endif