arch/frv/mm/init.c

   1 /* init.c: memory initialisation for FRV
   2  *
   3  * Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
   4  * Written by David Howells (dhowells@redhat.com)
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * as published by the Free Software Foundation; either version
   9  * 2 of the License, or (at your option) any later version.
  10  *
  11  * Derived from:
  12  *  - linux/arch/m68knommu/mm/init.c
  13  *    - Copyright (C) 1998  D. Jeff Dionne <jeff@lineo.ca>, Kenneth Albanowski <kjahds@kjahds.com>,
  14  *    - Copyright (C) 2000  Lineo, Inc.  (www.lineo.com)
  15  *  - linux/arch/m68k/mm/init.c
  16  *    - Copyright (C) 1995  Hamish Macdonald
  17  */
  18
  19 #include <linux/signal.h>
  20 #include <linux/sched.h>
  21 #include <linux/sched/task.h>
  22 #include <linux/pagemap.h>
  23 #include <linux/gfp.h>
  24 #include <linux/swap.h>
  25 #include <linux/mm.h>
  26 #include <linux/kernel.h>
  27 #include <linux/string.h>
  28 #include <linux/types.h>
  29 #include <linux/bootmem.h>
  30 #include <linux/highmem.h>
  31 #include <linux/module.h>
  32
  33 #include <asm/setup.h>
  34 #include <asm/segment.h>
  35 #include <asm/page.h>
  36 #include <asm/pgtable.h>
  37 #include <asm/mmu_context.h>
  38 #include <asm/virtconvert.h>
  39 #include <asm/sections.h>
  40 #include <asm/tlb.h>
  41
  42 #undef DEBUG
  43
  44 /*
  45  * ZERO_PAGE is a special page that is used for zero-initialized
  46  * data and COW.
  47  */
  48 unsigned long empty_zero_page;
  49 EXPORT_SYMBOL(empty_zero_page);
  50
  51 /*****************************************************************************/
  52 /*
  53  * paging_init() continues the virtual memory environment setup which
  54  * was begun by the code in arch/head.S.
  55  * The parameters are pointers to where to stick the starting and ending
  56  * addresses  of available kernel virtual memory.
  57  */
  58 void __init paging_init(void)
  59 {
  60         unsigned long zones_size[MAX_NR_ZONES] = {0, };
  61
  62         /* allocate some pages for kernel housekeeping tasks */
  63         empty_zero_page         = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
  64
  65         memset((void *) empty_zero_page, 0, PAGE_SIZE);
  66
  67 #ifdef CONFIG_HIGHMEM
  68         if (get_num_physpages() - num_mappedpages) {
  69                 pgd_t *pge;
  70                 pud_t *pue;
  71                 pmd_t *pme;
  72
  73                 pkmap_page_table = alloc_bootmem_pages(PAGE_SIZE);
  74
  75                 pge = swapper_pg_dir + pgd_index_k(PKMAP_BASE);
  76                 pue = pud_offset(pge, PKMAP_BASE);
  77                 pme = pmd_offset(pue, PKMAP_BASE);
  78                 __set_pmd(pme, virt_to_phys(pkmap_page_table) | _PAGE_TABLE);
  79         }
  80 #endif
  81
  82         /* distribute the allocatable pages across the various zones and pass them to the allocator
  83          */
  84         zones_size[ZONE_NORMAL]  = max_low_pfn - min_low_pfn;
  85 #ifdef CONFIG_HIGHMEM
  86         zones_size[ZONE_HIGHMEM] = get_num_physpages() - num_mappedpages;
  87 #endif
  88
  89         free_area_init(zones_size);
  90
  91 #ifdef CONFIG_MMU
  92         /* initialise init's MMU context */
  93         init_new_context(&init_task, &init_mm);
  94 #endif
  95
  96 } /* end paging_init() */
  97
  98 /*****************************************************************************/
  99 /*
 100  *
 101  */
 102 void __init mem_init(void)
 103 {
 104         unsigned long code_size = _etext - _stext;
 105
 106         /* this will put all low memory onto the freelists */
 107         free_all_bootmem();
 108 #if defined(CONFIG_MMU) && defined(CONFIG_HIGHMEM)
 109         {
 110                 unsigned long pfn;
 111
 112                 for (pfn = get_num_physpages() - 1;
 113                      pfn >= num_mappedpages; pfn--)
 114                         free_highmem_page(&mem_map[pfn]);
 115         }
 116 #endif
 117
 118         mem_init_print_info(NULL);
 119         if (rom_length > 0 && rom_length >= code_size)
 120                 printk("Memory available:  %luKiB/%luKiB ROM\n",
 121                         (rom_length - code_size) >> 10, rom_length >> 10);
 122 } /* end mem_init() */
 123
 124 /*****************************************************************************/
 125 /*
 126  * free the memory that was only required for initialisation
 127  */
 128 void free_initmem(void)
 129 {
 130 #if defined(CONFIG_RAMKERNEL) && !defined(CONFIG_PROTECT_KERNEL)
 131         free_initmem_default(-1);
 132 #endif
 133 } /* end free_initmem() */
 134
 135 /*****************************************************************************/
 136 /*
 137  * free the initial ramdisk memory
 138  */
 139 #ifdef CONFIG_BLK_DEV_INITRD
 140 void __init free_initrd_mem(unsigned long start, unsigned long end)
 141 {
 142         free_reserved_area((void *)start, (void *)end, -1, "initrd");
 143 } /* end free_initrd_mem() */
 144 #endif