target/linux/ar7-2.6/files/arch/mips/ar7/memory.c

   1 /*
   2  * $Id$
   3  *
   4  * Copyright (C) 2007 OpenWrt.org
   5  *
   6  * Based on arch/mips/mm/init.c
   7  * Copyright (C) 1994 - 2000 Ralf Baechle
   8  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
   9  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
  10  * Copyright (C) 2000 MIPS Technologies, Inc.  All rights reserved.
  11  *
  12  * This program is free software; you can redistribute it and/or modify
  13  * it under the terms of the GNU General Public License as published by
  14  * the Free Software Foundation; either version 2 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20  * GNU General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with this program; if not, write to the Free Software
  24  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  25  */
  26 #include <linux/bootmem.h>
  27 #include <linux/init.h>
  28 #include <linux/mm.h>
  29 #include <linux/module.h>
  30 #include <linux/pfn.h>
  31 #include <linux/proc_fs.h>
  32 #include <linux/string.h>
  33 #include <linux/swap.h>
  34
  35 #include <asm/bootinfo.h>
  36 #include <asm/page.h>
  37 #include <asm/sections.h>
  38
  39 #include <asm/mips-boards/prom.h>
  40
  41 static int __init memsize(void)
  42 {
  43         u32 size = (64 << 20);
  44         volatile u32 *addr = (u32 *)KSEG1ADDR(0x14000000 + size - 4);
  45         u32 *kernel_end = (u32 *)KSEG1ADDR(CPHYSADDR((u32)&_end));
  46
  47         while (addr > kernel_end) {
  48                 *addr = (u32)addr;
  49                 size >>= 1;
  50                 addr -= size >> 2;
  51         }
  52
  53         do {
  54                 addr += size >> 2;
  55                 if (*addr != (u32)addr)
  56                         break;
  57                 size <<= 1;
  58         } while (size < (64 << 20));
  59
  60         return size;
  61 }
  62
  63 void __init prom_meminit(void)
  64 {
  65         unsigned long pages;
  66
  67         pages = memsize() >> PAGE_SHIFT;
  68         add_memory_region(ARCH_PFN_OFFSET << PAGE_SHIFT, pages <<
  69                           PAGE_SHIFT, BOOT_MEM_RAM);
  70 }
  71
  72 void __init prom_free_prom_memory(void)
  73 {
  74         return;
  75 }