arch/blackfin/mm/init.c

   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  */
  50 static unsigned long empty_bad_page_table;
  51
  52 static unsigned long empty_bad_page;
  53
  54 unsigned 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  */
  62 void __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
 101 void __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
 142 static 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 }
 161 pure_initcall(sram_init);
 162
 163 static 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
 177 void __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
 185 void __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 }