arch/hexagon/include/asm/vm_mmu.h

   1 /*
   2  * Hexagon VM page table entry definitions
   3  *
   4  * Copyright (c) 2010-2011,2013 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_VM_MMU_H
  22 #define _ASM_VM_MMU_H
  23
  24 /*
  25  * Shift, mask, and other constants for the Hexagon Virtual Machine
  26  * page tables.
  27  *
  28  * Virtual machine MMU allows first-level entries to either be
  29  * single-level lookup PTEs for very large pages, or PDEs pointing
  30  * to second-level PTEs for smaller pages. If PTE is single-level,
  31  * the least significant bits cannot be used as software bits to encode
  32  * virtual memory subsystem information about the page, and that state
  33  * must be maintained in some parallel data structure.
  34  */
  35
  36 /* S or Page Size field in PDE */
  37 #define __HVM_PDE_S             (0x7 << 0)
  38 #define __HVM_PDE_S_4KB         0
  39 #define __HVM_PDE_S_16KB        1
  40 #define __HVM_PDE_S_64KB        2
  41 #define __HVM_PDE_S_256KB       3
  42 #define __HVM_PDE_S_1MB         4
  43 #define __HVM_PDE_S_4MB         5
  44 #define __HVM_PDE_S_16MB        6
  45 #define __HVM_PDE_S_INVALID     7
  46
  47 /* Masks for L2 page table pointer, as function of page size */
  48 #define __HVM_PDE_PTMASK_4KB    0xfffff000
  49 #define __HVM_PDE_PTMASK_16KB   0xfffffc00
  50 #define __HVM_PDE_PTMASK_64KB   0xffffff00
  51 #define __HVM_PDE_PTMASK_256KB  0xffffffc0
  52 #define __HVM_PDE_PTMASK_1MB    0xfffffff0
  53
  54 /*
  55  * Virtual Machine PTE Bits/Fields
  56  */
  57 #define __HVM_PTE_T             (1<<4)
  58 #define __HVM_PTE_U             (1<<5)
  59 #define __HVM_PTE_C             (0x7<<6)
  60 #define __HVM_PTE_CVAL(pte)     (((pte) & __HVM_PTE_C) >> 6)
  61 #define __HVM_PTE_R             (1<<9)
  62 #define __HVM_PTE_W             (1<<10)
  63 #define __HVM_PTE_X             (1<<11)
  64
  65 /*
  66  * Cache Attributes, to be shifted as necessary for virtual/physical PTEs
  67  */
  68
  69 #define __HEXAGON_C_WB          0x0     /* Write-back, no L2 */
  70 #define __HEXAGON_C_WT          0x1     /* Write-through, no L2 */
  71 #define __HEXAGON_C_UNC         0x6     /* Uncached memory */
  72 #if CONFIG_HEXAGON_ARCH_VERSION >= 2
  73 #define __HEXAGON_C_DEV         0x4     /* Device register space */
  74 #else
  75 #define __HEXAGON_C_DEV         __HEXAGON_C_UNC
  76 #endif
  77 #define __HEXAGON_C_WT_L2       0x5     /* Write-through, with L2 */
  78 #define __HEXAGON_C_WB_L2       0x7     /* Write-back, with L2 */
  79
  80 /*
  81  * This can be overriden, but we're defaulting to the most aggressive
  82  * cache policy, the better to find bugs sooner.
  83  */
  84
  85 #define CACHE_DEFAULT   __HEXAGON_C_WB_L2
  86
  87 /* Masks for physical page address, as a function of page size */
  88
  89 #define __HVM_PTE_PGMASK_4KB    0xfffff000
  90 #define __HVM_PTE_PGMASK_16KB   0xffffc000
  91 #define __HVM_PTE_PGMASK_64KB   0xffff0000
  92 #define __HVM_PTE_PGMASK_256KB  0xfffc0000
  93 #define __HVM_PTE_PGMASK_1MB    0xfff00000
  94
  95 /* Masks for single-level large page lookups */
  96
  97 #define __HVM_PTE_PGMASK_4MB    0xffc00000
  98 #define __HVM_PTE_PGMASK_16MB   0xff000000
  99
 100 /*
 101  * "Big kernel page mappings" (see vm_init_segtable.S)
 102  * are currently 16MB
 103  */
 104
 105 #define BIG_KERNEL_PAGE_SHIFT 24
 106 #define BIG_KERNEL_PAGE_SIZE (1 << BIG_KERNEL_PAGE_SHIFT)
 107
 108
 109
 110 #endif /* _ASM_VM_MMU_H */