arch/mips/ar7/memory.c

   1 /*
   2  * Copyright (C) 2007 Felix Fietkau <nbd@openwrt.org>
   3  * Copyright (C) 2007 Eugene Konev <ejka@openwrt.org>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License as published by
   7  * the Free Software Foundation; either version 2 of the License, or
   8  * (at your option) any later version.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  18  */
  19 #include <linux/bootmem.h>
  20 #include <linux/init.h>
  21 #include <linux/mm.h>
  22 #include <linux/module.h>
  23 #include <linux/pfn.h>
  24 #include <linux/proc_fs.h>
  25 #include <linux/string.h>
  26 #include <linux/swap.h>
  27
  28 #include <asm/bootinfo.h>
  29 #include <asm/page.h>
  30 #include <asm/sections.h>
  31
  32 #include <asm/mach-ar7/ar7.h>
  33 #include <asm/mips-boards/prom.h>
  34
  35 static int __init memsize(void)
  36 {
  37         u32 size = (64 << 20);
  38         u32 *addr = (u32 *)KSEG1ADDR(AR7_SDRAM_BASE + size - 4);
  39         u32 *kernel_end = (u32 *)KSEG1ADDR(CPHYSADDR((u32)&_end));
  40         u32 *tmpaddr = addr;
  41
  42         while (tmpaddr > kernel_end) {
  43                 *tmpaddr = (u32)tmpaddr;
  44                 size >>= 1;
  45                 tmpaddr -= size >> 2;
  46         }
  47
  48         do {
  49                 tmpaddr += size >> 2;
  50                 if (*tmpaddr != (u32)tmpaddr)
  51                         break;
  52                 size <<= 1;
  53         } while (size < (64 << 20));
  54
  55         writel((u32)tmpaddr, &addr);
  56
  57         return size;
  58 }
  59
  60 void __init prom_meminit(void)
  61 {
  62         unsigned long pages;
  63
  64         pages = memsize() >> PAGE_SHIFT;
  65         add_memory_region(PHYS_OFFSET, pages << PAGE_SHIFT, BOOT_MEM_RAM);
  66 }
  67
  68 void __init prom_free_prom_memory(void)
  69 {
  70         /* Nothing to free */
  71 }