LXR linux/arch/tile/include/asm/pgtable

   1/*
   2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
   3 *
   4 *   This program is free software; you can redistribute it and/or
   5 *   modify it under the terms of the GNU General Public License
   6 *   as published by the Free Software Foundation, version 2.
   7 *
   8 *   This program is distributed in the hope that it will be useful, but
   9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
  10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
  11 *   NON INFRINGEMENT.  See the GNU General Public License for
  12 *   more details.
  13 *
  14 */
  15
  16#ifndef _ASM_TILE_PGTABLE_32_H
  17#define _ASM_TILE_PGTABLE_32_H
  18
  19/*
  20 * The level-1 index is defined by the huge page size.  A PGD is composed
  21 * of PTRS_PER_PGD pgd_t's and is the top level of the page table.
  22 */
  23#define PGDIR_SHIFT     HPAGE_SHIFT
  24#define PGDIR_SIZE      HPAGE_SIZE
  25#define PGDIR_MASK      (~(PGDIR_SIZE-1))
  26#define PTRS_PER_PGD    _HV_L1_ENTRIES(HPAGE_SHIFT)
  27#define PGD_INDEX(va)   _HV_L1_INDEX(va, HPAGE_SHIFT)
  28#define SIZEOF_PGD      _HV_L1_SIZE(HPAGE_SHIFT)
  29
  30/*
  31 * The level-2 index is defined by the difference between the huge
  32 * page size and the normal page size.  A PTE is composed of
  33 * PTRS_PER_PTE pte_t's and is the bottom level of the page table.
  34 * Note that the hypervisor docs use PTE for what we call pte_t, so
  35 * this nomenclature is somewhat confusing.
  36 */
  37#define PTRS_PER_PTE    _HV_L2_ENTRIES(HPAGE_SHIFT, PAGE_SHIFT)
  38#define PTE_INDEX(va)   _HV_L2_INDEX(va, HPAGE_SHIFT, PAGE_SHIFT)
  39#define SIZEOF_PTE      _HV_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
  40
  41#ifndef __ASSEMBLY__
  42
  43/*
  44 * Right now we initialize only a single pte table. It can be extended
  45 * easily, subsequent pte tables have to be allocated in one physical
  46 * chunk of RAM.
  47 *
  48 * HOWEVER, if we are using an allocation scheme with slop after the
  49 * end of the page table (e.g. where our L2 page tables are 2KB but
  50 * our pages are 64KB and we are allocating via the page allocator)
  51 * we can't extend it easily.
  52 */
  53#define LAST_PKMAP PTRS_PER_PTE
  54
  55#define PKMAP_BASE   ((FIXADDR_BOOT_START - PAGE_SIZE*LAST_PKMAP) & PGDIR_MASK)
  56
  57#ifdef CONFIG_HIGHMEM
  58# define _VMALLOC_END   (PKMAP_BASE & ~(HPAGE_SIZE-1))
  59#else
  60# define _VMALLOC_END   (FIXADDR_START & ~(HPAGE_SIZE-1))
  61#endif
  62
  63/*
  64 * Align the vmalloc area to an L2 page table, and leave a guard page
  65 * at the beginning and end.  The vmalloc code also puts in an internal
  66 * guard page between each allocation.
  67 */
  68#define VMALLOC_END     (_VMALLOC_END - PAGE_SIZE)
  69extern unsigned long VMALLOC_RESERVE /* = CONFIG_VMALLOC_RESERVE */;
  70#define _VMALLOC_START  (_VMALLOC_END - VMALLOC_RESERVE)
  71#define VMALLOC_START   (_VMALLOC_START + PAGE_SIZE)
  72
  73/* This is the maximum possible amount of lowmem. */
  74#define MAXMEM          (_VMALLOC_START - PAGE_OFFSET)
  75
  76/* We have no pmd or pud since we are strictly a two-level page table */
  77#include <asm-generic/pgtable-nopmd.h>
  78
  79static inline int pud_huge_page(pud_t pud)      { return 0; }
  80
  81/* We don't define any pgds for these addresses. */
  82static inline int pgd_addr_invalid(unsigned long addr)
  83{
  84        return addr >= MEM_HV_START;
  85}
  86
  87/*
  88 * Provide versions of these routines that can be used safely when
  89 * the hypervisor may be asynchronously modifying dirty/accessed bits.
  90 * ptep_get_and_clear() matches the generic one but we provide it to
  91 * be parallel with the 64-bit code.
  92 */
  93#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  94#define __HAVE_ARCH_PTEP_SET_WRPROTECT
  95
  96extern int ptep_test_and_clear_young(struct vm_area_struct *,
  97                                     unsigned long addr, pte_t *);
  98extern void ptep_set_wrprotect(struct mm_struct *,
  99                               unsigned long addr, pte_t *);
 100
 101#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 102static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 103                                       unsigned long addr, pte_t *ptep)
 104{
 105        pte_t pte = *ptep;
 106        pte_clear(_mm, addr, ptep);
 107        return pte;
 108}
 109
 110/*
 111 * pmds are wrappers around pgds, which are the same as ptes.
 112 * It's often convenient to "cast" back and forth and use the pte methods,
 113 * which are the methods supplied by the hypervisor.
 114 */
 115#define pmd_pte(pmd) ((pmd).pud.pgd)
 116#define pmdp_ptep(pmdp) (&(pmdp)->pud.pgd)
 117#define pte_pmd(pte) ((pmd_t){ { (pte) } })
 118
 119#endif /* __ASSEMBLY__ */
 120
 121#endif /* _ASM_TILE_PGTABLE_32_H */
 122