include/asm-arm/arch-clps711x/memory.h

   1 /*
   2  *  linux/include/asm-arm/arch-clps711x/memory.h
   3  *
   4  *  Copyright (C) 1999 ARM Limited
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  19  */
  20 #ifndef __ASM_ARCH_MEMORY_H
  21 #define __ASM_ARCH_MEMORY_H
  22
  23
  24 /*
  25  * Physical DRAM offset.
  26  */
  27 #define PHYS_OFFSET     UL(0xc0000000)
  28
  29 /*
  30  * Virtual view <-> DMA view memory address translations
  31  * virt_to_bus: Used to translate the virtual address to an
  32  *              address suitable to be passed to set_dma_addr
  33  * bus_to_virt: Used to convert an address for DMA operations
  34  *              to an address that the kernel can use.
  35  */
  36
  37 #if defined(CONFIG_ARCH_CDB89712)
  38
  39 #define __virt_to_bus(x)        (x)
  40 #define __bus_to_virt(x)        (x)
  41
  42 #elif defined (CONFIG_ARCH_AUTCPU12)
  43
  44 #define __virt_to_bus(x)        (x)
  45 #define __bus_to_virt(x)        (x)
  46
  47 #else
  48
  49 #define __virt_to_bus(x)        ((x) - PAGE_OFFSET)
  50 #define __bus_to_virt(x)        ((x) + PAGE_OFFSET)
  51
  52 #endif
  53
  54
  55 /*
  56  * Like the SA1100, the EDB7211 has a large gap between physical RAM
  57  * banks.  In 2.2, the Psion (CL-PS7110) port added custom support for
  58  * discontiguous physical memory.  In 2.4, we can use the standard
  59  * Linux NUMA support.
  60  *
  61  * This is not necessary for EP7211 implementations with only one used
  62  * memory bank.  For those systems, simply undefine CONFIG_DISCONTIGMEM.
  63  */
  64
  65 /*
  66  * The PS7211 allows up to 256MB max per DRAM bank, but the EDB7211
  67  * uses only one of the two banks (bank #1).  However, even within
  68  * bank #1, memory is discontiguous.
  69  *
  70  * The EDB7211 has two 8MB DRAM areas with 8MB of empty space between
  71  * them, so we use 24 for the node max shift to get 16MB node sizes.
  72  */
  73
  74 /*
  75  * Because of the wide memory address space between physical RAM banks on the
  76  * SA1100, it's much more convenient to use Linux's NUMA support to implement
  77  * our memory map representation.  Assuming all memory nodes have equal access
  78  * characteristics, we then have generic discontiguous memory support.
  79  *
  80  * Of course, all this isn't mandatory for SA1100 implementations with only
  81  * one used memory bank.  For those, simply undefine CONFIG_DISCONTIGMEM.
  82  *
  83  * The nodes are matched with the physical memory bank addresses which are
  84  * incidentally the same as virtual addresses.
  85  *
  86  *      node 0:  0xc0000000 - 0xc7ffffff
  87  *      node 1:  0xc8000000 - 0xcfffffff
  88  *      node 2:  0xd0000000 - 0xd7ffffff
  89  *      node 3:  0xd8000000 - 0xdfffffff
  90  */
  91 #define NODE_MEM_SIZE_BITS      24
  92
  93 #endif
  94