arch/hexagon/include/asm/mem-layout.h

   1 /*
   2  * Memory layout definitions for the Hexagon architecture
   3  *
   4  * Copyright (c) 2010-2013, The Linux Foundation. All rights reserved.
   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 version 2 and
   8  * only version 2 as published by the Free Software Foundation.
   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 Street, Fifth Floor, Boston, MA
  18  * 02110-1301, USA.
  19  */
  20
  21 #ifndef _ASM_HEXAGON_MEM_LAYOUT_H
  22 #define _ASM_HEXAGON_MEM_LAYOUT_H
  23
  24 #include <linux/const.h>
  25
  26 /*
  27  * Have to do this for ginormous numbers, else they get printed as
  28  * negative numbers, which the linker no likey when you try to
  29  * assign it to the location counter.
  30  */
  31
  32 #define PAGE_OFFSET                     _AC(0xc0000000, UL)
  33
  34 /*
  35  * Compiling for a platform that needs a crazy physical offset
  36  * (like if the memory starts at 1GB and up) means we need
  37  * an actual PHYS_OFFSET.  Should be set up in head.S.
  38  */
  39
  40 #ifdef CONFIG_HEXAGON_PHYS_OFFSET
  41 #ifndef __ASSEMBLY__
  42 extern unsigned long    __phys_offset;
  43 #endif
  44 #define PHYS_OFFSET     __phys_offset
  45 #endif
  46
  47 #ifndef PHYS_OFFSET
  48 #define PHYS_OFFSET     0
  49 #endif
  50
  51 #define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
  52 #define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
  53
  54 #define TASK_SIZE                       (PAGE_OFFSET)
  55
  56 /*  not sure how these are used yet  */
  57 #define STACK_TOP                       TASK_SIZE
  58 #define STACK_TOP_MAX                   TASK_SIZE
  59
  60 #ifndef __ASSEMBLY__
  61 enum fixed_addresses {
  62         FIX_KMAP_BEGIN,
  63         FIX_KMAP_END,  /*  check for per-cpuism  */
  64         __end_of_fixed_addresses
  65 };
  66
  67 #define MIN_KERNEL_SEG (PAGE_OFFSET >> PGDIR_SHIFT)   /* L1 shift is 22 bits */
  68 extern int max_kernel_seg;
  69
  70 /*
  71  * Start of vmalloc virtual address space for kernel;
  72  * supposed to be based on the amount of physical memory available
  73  */
  74
  75 #define VMALLOC_START ((unsigned long) __va(high_memory + VMALLOC_OFFSET))
  76
  77 /* Gap between physical ram and vmalloc space for guard purposes. */
  78 #define VMALLOC_OFFSET PAGE_SIZE
  79
  80 /*
  81  * Create the space between VMALLOC_START and FIXADDR_TOP backwards
  82  * from the ... "top".
  83  *
  84  * Permanent IO mappings will live at 0xfexx_xxxx
  85  * Hypervisor occupies the last 16MB page at 0xffxxxxxx
  86  */
  87
  88 #define FIXADDR_TOP     0xfe000000
  89 #define FIXADDR_SIZE    (__end_of_fixed_addresses << PAGE_SHIFT)
  90 #define FIXADDR_START   (FIXADDR_TOP - FIXADDR_SIZE)
  91
  92 /*
  93  * "permanent kernel mappings", defined as long-lasting mappings of
  94  * high-memory page frames into the kernel address space.
  95  */
  96
  97 #define LAST_PKMAP      PTRS_PER_PTE
  98 #define LAST_PKMAP_MASK (LAST_PKMAP - 1)
  99 #define PKMAP_NR(virt)  ((virt - PKMAP_BASE) >> PAGE_SHIFT)
 100 #define PKMAP_ADDR(nr)  (PKMAP_BASE + ((nr) << PAGE_SHIFT))
 101
 102 /*
 103  * To the "left" of the fixed map space is the kmap space
 104  *
 105  * "Permanent Kernel Mappings"; fancy (or less fancy) PTE table
 106  * that looks like it's actually walked.
 107  * Need to check the alignment/shift usage; some archs use
 108  * PMD_MASK on this value
 109  */
 110 #define PKMAP_BASE (FIXADDR_START-PAGE_SIZE*LAST_PKMAP)
 111
 112 /*
 113  * 2 pages of guard gap between where vmalloc area ends
 114  * and pkmap_base begins.
 115  */
 116 #define VMALLOC_END (PKMAP_BASE-PAGE_SIZE*2)
 117 #endif /*  !__ASSEMBLY__  */
 118
 119
 120 #endif /* _ASM_HEXAGON_MEM_LAYOUT_H */