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     HV_LOG2_PAGE_SIZE_LARGE
  24#define PGDIR_SIZE      HV_PAGE_SIZE_LARGE
  25#define PGDIR_MASK      (~(PGDIR_SIZE-1))
  26#define PTRS_PER_PGD    (1 << (32 - PGDIR_SHIFT))
  27#define SIZEOF_PGD      (PTRS_PER_PGD * sizeof(pgd_t))
  28
  29/*
  30 * The level-2 index is defined by the difference between the huge
  31 * page size and the normal page size.  A PTE is composed of
  32 * PTRS_PER_PTE pte_t's and is the bottom level of the page table.
  33 * Note that the hypervisor docs use PTE for what we call pte_t, so
  34 * this nomenclature is somewhat confusing.
  35 */
  36#define PTRS_PER_PTE (1 << (HV_LOG2_PAGE_SIZE_LARGE - HV_LOG2_PAGE_SIZE_SMALL))
  37#define SIZEOF_PTE      (PTRS_PER_PTE * sizeof(pte_t))
  38
  39#ifndef __ASSEMBLY__
  40
  41/*
  42 * Right now we initialize only a single pte table. It can be extended
  43 * easily, subsequent pte tables have to be allocated in one physical
  44 * chunk of RAM.
  45 *
  46 * HOWEVER, if we are using an allocation scheme with slop after the
  47 * end of the page table (e.g. where our L2 page tables are 2KB but
  48 * our pages are 64KB and we are allocating via the page allocator)
  49 * we can't extend it easily.
  50 */
  51#define LAST_PKMAP PTRS_PER_PTE
  52
  53#define PKMAP_BASE   ((FIXADDR_BOOT_START - PAGE_SIZE*LAST_PKMAP) & PGDIR_MASK)
  54
  55#ifdef CONFIG_HIGHMEM
  56# define __VMAPPING_END (PKMAP_BASE & ~(HPAGE_SIZE-1))
  57#else
  58# define __VMAPPING_END (FIXADDR_START & ~(HPAGE_SIZE-1))
  59#endif
  60
  61#ifdef CONFIG_HUGEVMAP
  62#define HUGE_VMAP_END   __VMAPPING_END
  63#define HUGE_VMAP_BASE  (HUGE_VMAP_END - CONFIG_NR_HUGE_VMAPS * HPAGE_SIZE)
  64#define _VMALLOC_END    HUGE_VMAP_BASE
  65#else
  66#define _VMALLOC_END    __VMAPPING_END
  67#endif
  68
  69/*
  70 * Align the vmalloc area to an L2 page table, and leave a guard page
  71 * at the beginning and end.  The vmalloc code also puts in an internal
  72 * guard page between each allocation.
  73 */
  74#define VMALLOC_END     (_VMALLOC_END - PAGE_SIZE)
  75extern unsigned long VMALLOC_RESERVE /* = CONFIG_VMALLOC_RESERVE */;
  76#define _VMALLOC_START  (_VMALLOC_END - VMALLOC_RESERVE)
  77#define VMALLOC_START   (_VMALLOC_START + PAGE_SIZE)
  78
  79/* This is the maximum possible amount of lowmem. */
  80#define MAXMEM          (_VMALLOC_START - PAGE_OFFSET)
  81
  82/* We have no pmd or pud since we are strictly a two-level page table */
  83#include <asm-generic/pgtable-nopmd.h>
  84
  85/* We don't define any pgds for these addresses. */
  86static inline int pgd_addr_invalid(unsigned long addr)
  87{
  88        return addr >= MEM_HV_INTRPT;
  89}
  90
  91/*
  92 * Provide versions of these routines that can be used safely when
  93 * the hypervisor may be asynchronously modifying dirty/accessed bits.
  94 * ptep_get_and_clear() matches the generic one but we provide it to
  95 * be parallel with the 64-bit code.
  96 */
  97#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
  98#define __HAVE_ARCH_PTEP_SET_WRPROTECT
  99
 100extern int ptep_test_and_clear_young(struct vm_area_struct *,
 101                                     unsigned long addr, pte_t *);
 102extern void ptep_set_wrprotect(struct mm_struct *,
 103                               unsigned long addr, pte_t *);
 104
 105#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 106static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 107                                       unsigned long addr, pte_t *ptep)
 108{
 109        pte_t pte = *ptep;
 110        pte_clear(_mm, addr, ptep);
 111        return pte;
 112}
 113
 114static inline void __set_pmd(pmd_t *pmdp, pmd_t pmdval)
 115{
 116        set_pte(&pmdp->pud.pgd, pmdval.pud.pgd);
 117}
 118
 119/* Create a pmd from a PTFN. */
 120static inline pmd_t ptfn_pmd(unsigned long ptfn, pgprot_t prot)
 121{
 122        return (pmd_t){ { hv_pte_set_ptfn(prot, ptfn) } };
 123}
 124
 125/* Return the page-table frame number (ptfn) that a pmd_t points at. */
 126#define pmd_ptfn(pmd) hv_pte_get_ptfn((pmd).pud.pgd)
 127
 128static inline void pmd_clear(pmd_t *pmdp)
 129{
 130        __pte_clear(&pmdp->pud.pgd);
 131}
 132
 133#endif /* __ASSEMBLY__ */
 134
 135#endif /* _ASM_TILE_PGTABLE_32_H */
 136