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

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