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/fs.h>
  21 #include <linux/mm.h>
  22 #include <linux/swap.h>
  23 #include <linux/smp.h>
  24 #include <linux/init.h>
  25 #include <linux/initrd.h>
  26 #include <linux/highmem.h>
  27 #include <linux/pagemap.h>
  28 #include <linux/bootmem.h>
  29 #include <linux/gfp.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 unsigned long highstart_pfn, highend_pfn;
  41
  42 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  43 static struct vm_struct user_iomap_vm;
  44 #endif
  45
  46 /*
  47  * set up paging
  48  */
  49 void __init paging_init(void)
  50 {
  51         unsigned long zones_size[MAX_NR_ZONES] = {0,};
  52         pte_t *ppte;
  53         int loop;
  54
  55         /* main kernel space -> RAM mapping is handled as 1:1 transparent by
  56          * the MMU */
  57         memset(swapper_pg_dir, 0, sizeof(swapper_pg_dir));
  58         memset(kernel_vmalloc_ptes, 0, sizeof(kernel_vmalloc_ptes));
  59
  60         /* load the VMALLOC area PTE table addresses into the kernel PGD */
  61         ppte = kernel_vmalloc_ptes;
  62         for (loop = VMALLOC_START / (PAGE_SIZE * PTRS_PER_PTE);
  63              loop < VMALLOC_END / (PAGE_SIZE * PTRS_PER_PTE);
  64              loop++
  65              ) {
  66                 set_pgd(swapper_pg_dir + loop, __pgd(__pa(ppte) | _PAGE_TABLE));
  67                 ppte += PAGE_SIZE / sizeof(pte_t);
  68         }
  69
  70         /* declare the sizes of the RAM zones (only use the normal zone) */
  71         zones_size[ZONE_NORMAL] =
  72                 contig_page_data.bdata->node_low_pfn -
  73                 contig_page_data.bdata->node_min_pfn;
  74
  75         /* pass the memory from the bootmem allocator to the main allocator */
  76         free_area_init(zones_size);
  77
  78 #ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT
  79         /* The Atomic Operation Unit registers need to be mapped to userspace
  80          * for all processes.  The following uses vm_area_register_early() to
  81          * reserve the first page of the vmalloc area and sets the pte for that
  82          * page.
  83          *
  84          * glibc hardcodes this virtual mapping, so we're pretty much stuck with
  85          * it from now on.
  86          */
  87         user_iomap_vm.flags = VM_USERMAP;
  88         user_iomap_vm.size = 1 << PAGE_SHIFT;
  89         vm_area_register_early(&user_iomap_vm, PAGE_SIZE);
  90         ppte = kernel_vmalloc_ptes;
  91         set_pte(ppte, pfn_pte(USER_ATOMIC_OPS_PAGE_ADDR >> PAGE_SHIFT,
  92                               PAGE_USERIO));
  93 #endif
  94
  95         local_flush_tlb_all();
  96 }
  97
  98 /*
  99  * transfer all the memory from the bootmem allocator to the runtime allocator
 100  */
 101 void __init mem_init(void)
 102 {
 103         int codesize, reservedpages, datasize, initsize;
 104         int tmp;
 105
 106         BUG_ON(!mem_map);
 107
 108 #define START_PFN       (contig_page_data.bdata->node_min_pfn)
 109 #define MAX_LOW_PFN     (contig_page_data.bdata->node_low_pfn)
 110
 111         max_mapnr = num_physpages = MAX_LOW_PFN - START_PFN;
 112         high_memory = (void *) __va(MAX_LOW_PFN * PAGE_SIZE);
 113
 114         /* clear the zero-page */
 115         memset(empty_zero_page, 0, PAGE_SIZE);
 116
 117         /* this will put all low memory onto the freelists */
 118         totalram_pages += free_all_bootmem();
 119
 120         reservedpages = 0;
 121         for (tmp = 0; tmp < num_physpages; tmp++)
 122                 if (PageReserved(&mem_map[tmp]))
 123                         reservedpages++;
 124
 125         codesize =  (unsigned long) &_etext - (unsigned long) &_stext;
 126         datasize =  (unsigned long) &_edata - (unsigned long) &_etext;
 127         initsize =  (unsigned long) &__init_end - (unsigned long) &__init_begin;
 128
 129         printk(KERN_INFO
 130                "Memory: %luk/%luk available"
 131                " (%dk kernel code, %dk reserved, %dk data, %dk init,"
 132                " %ldk highmem)\n",
 133                nr_free_pages() << (PAGE_SHIFT - 10),
 134                max_mapnr << (PAGE_SHIFT - 10),
 135                codesize >> 10,
 136                reservedpages << (PAGE_SHIFT - 10),
 137                datasize >> 10,
 138                initsize >> 10,
 139                totalhigh_pages << (PAGE_SHIFT - 10));
 140 }
 141
 142 /*
 143  *
 144  */
 145 void free_init_pages(char *what, unsigned long begin, unsigned long end)
 146 {
 147         unsigned long addr;
 148
 149         for (addr = begin; addr < end; addr += PAGE_SIZE) {
 150                 ClearPageReserved(virt_to_page(addr));
 151                 init_page_count(virt_to_page(addr));
 152                 memset((void *) addr, 0xcc, PAGE_SIZE);
 153                 free_page(addr);
 154                 totalram_pages++;
 155         }
 156         printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 157 }
 158
 159 /*
 160  * recycle memory containing stuff only required for initialisation
 161  */
 162 void free_initmem(void)
 163 {
 164         free_init_pages("unused kernel memory",
 165                         (unsigned long) &__init_begin,
 166                         (unsigned long) &__init_end);
 167 }
 168
 169 /*
 170  * dispose of the memory on which the initial ramdisk resided
 171  */
 172 #ifdef CONFIG_BLK_DEV_INITRD
 173 void free_initrd_mem(unsigned long start, unsigned long end)
 174 {
 175         free_init_pages("initrd memory", start, end);
 176 }
 177 #endif