linux/arch/blackfin/mm/init.c
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   1/*
   2 * File:         arch/blackfin/mm/init.c
   3 * Based on:
   4 * Author:
   5 *
   6 * Created:
   7 * Description:
   8 *
   9 * Modified:
  10 *               Copyright 2004-2007 Analog Devices Inc.
  11 *
  12 * Bugs:         Enter bugs at http://blackfin.uclinux.org/
  13 *
  14 * This program is free software; you can redistribute it and/or modify
  15 * it under the terms of the GNU General Public License as published by
  16 * the Free Software Foundation; either version 2 of the License, or
  17 * (at your option) any later version.
  18 *
  19 * This program is distributed in the hope that it will be useful,
  20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22 * GNU General Public License for more details.
  23 *
  24 * You should have received a copy of the GNU General Public License
  25 * along with this program; if not, see the file COPYING, or write
  26 * to the Free Software Foundation, Inc.,
  27 * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  28 */
  29
  30#include <linux/swap.h>
  31#include <linux/bootmem.h>
  32#include <linux/uaccess.h>
  33#include <asm/bfin-global.h>
  34#include <asm/l1layout.h>
  35#include "blackfin_sram.h"
  36
  37/*
  38 * BAD_PAGE is the page that is used for page faults when linux
  39 * is out-of-memory. Older versions of linux just did a
  40 * do_exit(), but using this instead means there is less risk
  41 * for a process dying in kernel mode, possibly leaving a inode
  42 * unused etc..
  43 *
  44 * BAD_PAGETABLE is the accompanying page-table: it is initialized
  45 * to point to BAD_PAGE entries.
  46 *
  47 * ZERO_PAGE is a special page that is used for zero-initialized
  48 * data and COW.
  49 */
  50static unsigned long empty_bad_page_table;
  51
  52static unsigned long empty_bad_page;
  53
  54unsigned long empty_zero_page;
  55
  56/*
  57 * paging_init() continues the virtual memory environment setup which
  58 * was begun by the code in arch/head.S.
  59 * The parameters are pointers to where to stick the starting and ending
  60 * addresses  of available kernel virtual memory.
  61 */
  62void __init paging_init(void)
  63{
  64        /*
  65         * make sure start_mem is page aligned,  otherwise bootmem and
  66         * page_alloc get different views og the world
  67         */
  68        unsigned long end_mem = memory_end & PAGE_MASK;
  69
  70        pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
  71
  72        /*
  73         * initialize the bad page table and bad page to point
  74         * to a couple of allocated pages
  75         */
  76        empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  77        empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  78        empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
  79        memset((void *)empty_zero_page, 0, PAGE_SIZE);
  80
  81        /*
  82         * Set up SFC/DFC registers (user data space)
  83         */
  84        set_fs(KERNEL_DS);
  85
  86        pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
  87                PAGE_ALIGN(memory_start), end_mem);
  88
  89        {
  90                unsigned long zones_size[MAX_NR_ZONES] = { 0, };
  91
  92                zones_size[ZONE_DMA] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
  93                zones_size[ZONE_NORMAL] = 0;
  94#ifdef CONFIG_HIGHMEM
  95                zones_size[ZONE_HIGHMEM] = 0;
  96#endif
  97                free_area_init(zones_size);
  98        }
  99}
 100
 101void __init mem_init(void)
 102{
 103        unsigned int codek = 0, datak = 0, initk = 0;
 104        unsigned int reservedpages = 0, freepages = 0;
 105        unsigned long tmp;
 106        unsigned long start_mem = memory_start;
 107        unsigned long end_mem = memory_end;
 108
 109        end_mem &= PAGE_MASK;
 110        high_memory = (void *)end_mem;
 111
 112        start_mem = PAGE_ALIGN(start_mem);
 113        max_mapnr = num_physpages = MAP_NR(high_memory);
 114        printk(KERN_DEBUG "Kernel managed physical pages: %lu\n", num_physpages);
 115
 116        /* This will put all memory onto the freelists. */
 117        totalram_pages = free_all_bootmem();
 118
 119        reservedpages = 0;
 120        for (tmp = 0; tmp < max_mapnr; tmp++)
 121                if (PageReserved(pfn_to_page(tmp)))
 122                        reservedpages++;
 123        freepages =  max_mapnr - reservedpages;
 124
 125        /* do not count in kernel image between _rambase and _ramstart */
 126        reservedpages -= (_ramstart - _rambase) >> PAGE_SHIFT;
 127#if (defined(CONFIG_BFIN_ICACHE) && ANOMALY_05000263)
 128        reservedpages += (_ramend - memory_end - DMA_UNCACHED_REGION) >> PAGE_SHIFT;
 129#endif
 130
 131        codek = (_etext - _stext) >> 10;
 132        initk = (__init_end - __init_begin) >> 10;
 133        datak = ((_ramstart - _rambase) >> 10) - codek - initk;
 134
 135        printk(KERN_INFO
 136             "Memory available: %luk/%luk RAM, "
 137                "(%uk init code, %uk kernel code, %uk data, %uk dma, %uk reserved)\n",
 138                (unsigned long) freepages << (PAGE_SHIFT-10), _ramend >> 10,
 139                initk, codek, datak, DMA_UNCACHED_REGION >> 10, (reservedpages << (PAGE_SHIFT-10)));
 140}
 141
 142static int __init sram_init(void)
 143{
 144        unsigned long tmp;
 145
 146        /* Initialize the blackfin L1 Memory. */
 147        bfin_sram_init();
 148
 149        /* Allocate this once; never free it.  We assume this gives us a
 150           pointer to the start of L1 scratchpad memory; panic if it
 151           doesn't.  */
 152        tmp = (unsigned long)l1sram_alloc(sizeof(struct l1_scratch_task_info));
 153        if (tmp != (unsigned long)L1_SCRATCH_TASK_INFO) {
 154                printk(KERN_EMERG "mem_init(): Did not get the right address from l1sram_alloc: %08lx != %08lx\n",
 155                        tmp, (unsigned long)L1_SCRATCH_TASK_INFO);
 156                panic("No L1, time to give up\n");
 157        }
 158
 159        return 0;
 160}
 161pure_initcall(sram_init);
 162
 163static void __init free_init_pages(const char *what, unsigned long begin, unsigned long end)
 164{
 165        unsigned long addr;
 166        /* next to check that the page we free is not a partial page */
 167        for (addr = begin; addr + PAGE_SIZE <= end; addr += PAGE_SIZE) {
 168                ClearPageReserved(virt_to_page(addr));
 169                init_page_count(virt_to_page(addr));
 170                free_page(addr);
 171                totalram_pages++;
 172        }
 173        printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
 174}
 175
 176#ifdef CONFIG_BLK_DEV_INITRD
 177void __init free_initrd_mem(unsigned long start, unsigned long end)
 178{
 179#ifndef CONFIG_MPU
 180        free_init_pages("initrd memory", start, end);
 181#endif
 182}
 183#endif
 184
 185void __init_refok free_initmem(void)
 186{
 187#if defined CONFIG_RAMKERNEL && !defined CONFIG_MPU
 188        free_init_pages("unused kernel memory",
 189                        (unsigned long)(&__init_begin),
 190                        (unsigned long)(&__init_end));
 191#endif
 192}
 193