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

   1/*
   2 * Copyright 2011 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_64_H
  17#define _ASM_TILE_PGTABLE_64_H
  18
  19/* The level-0 page table breaks the address space into 32-bit chunks. */
  20#define PGDIR_SHIFT     HV_LOG2_L1_SPAN
  21#define PGDIR_SIZE      HV_L1_SPAN
  22#define PGDIR_MASK      (~(PGDIR_SIZE-1))
  23#define PTRS_PER_PGD    HV_L0_ENTRIES
  24#define PGD_INDEX(va)   HV_L0_INDEX(va)
  25#define SIZEOF_PGD      HV_L0_SIZE
  26
  27/*
  28 * The level-1 index is defined by the huge page size.  A PMD is composed
  29 * of PTRS_PER_PMD pgd_t's and is the middle level of the page table.
  30 */
  31#define PMD_SHIFT       HPAGE_SHIFT
  32#define PMD_SIZE        HPAGE_SIZE
  33#define PMD_MASK        (~(PMD_SIZE-1))
  34#define PTRS_PER_PMD    _HV_L1_ENTRIES(HPAGE_SHIFT)
  35#define PMD_INDEX(va)   _HV_L1_INDEX(va, HPAGE_SHIFT)
  36#define SIZEOF_PMD      _HV_L1_SIZE(HPAGE_SHIFT)
  37
  38/*
  39 * The level-2 index is defined by the difference between the huge
  40 * page size and the normal page size.  A PTE is composed of
  41 * PTRS_PER_PTE pte_t's and is the bottom level of the page table.
  42 * Note that the hypervisor docs use PTE for what we call pte_t, so
  43 * this nomenclature is somewhat confusing.
  44 */
  45#define PTRS_PER_PTE    _HV_L2_ENTRIES(HPAGE_SHIFT, PAGE_SHIFT)
  46#define PTE_INDEX(va)   _HV_L2_INDEX(va, HPAGE_SHIFT, PAGE_SHIFT)
  47#define SIZEOF_PTE      _HV_L2_SIZE(HPAGE_SHIFT, PAGE_SHIFT)
  48
  49/*
  50 * Align the vmalloc area to an L2 page table.  Omit guard pages at
  51 * the beginning and end for simplicity (particularly in the per-cpu
  52 * memory allocation code).  The vmalloc code puts in an internal
  53 * guard page between each allocation.
  54 */
  55#define _VMALLOC_END    MEM_SV_START
  56#define VMALLOC_END     _VMALLOC_END
  57#define VMALLOC_START   _VMALLOC_START
  58
  59#ifndef __ASSEMBLY__
  60
  61/* We have no pud since we are a three-level page table. */
  62#include <asm-generic/pgtable-nopud.h>
  63
  64/*
  65 * pmds are the same as pgds and ptes, so converting is a no-op.
  66 */
  67#define pmd_pte(pmd) (pmd)
  68#define pmdp_ptep(pmdp) (pmdp)
  69#define pte_pmd(pte) (pte)
  70
  71#define pud_pte(pud) ((pud).pgd)
  72
  73static inline int pud_none(pud_t pud)
  74{
  75        return pud_val(pud) == 0;
  76}
  77
  78static inline int pud_present(pud_t pud)
  79{
  80        return pud_val(pud) & _PAGE_PRESENT;
  81}
  82
  83static inline int pud_huge_page(pud_t pud)
  84{
  85        return pud_val(pud) & _PAGE_HUGE_PAGE;
  86}
  87
  88#define pmd_ERROR(e) \
  89        pr_err("%s:%d: bad pmd 0x%016llx\n", __FILE__, __LINE__, pmd_val(e))
  90
  91static inline void pud_clear(pud_t *pudp)
  92{
  93        __pte_clear(&pudp->pgd);
  94}
  95
  96static inline int pud_bad(pud_t pud)
  97{
  98        return ((pud_val(pud) & _PAGE_ALL) != _PAGE_TABLE);
  99}
 100
 101/* Return the page-table frame number (ptfn) that a pud_t points at. */
 102#define pud_ptfn(pud) hv_pte_get_ptfn((pud).pgd)
 103
 104/* Return the page frame number (pfn) that a pud_t points at. */
 105#define pud_pfn(pud) pte_pfn(pud_pte(pud))
 106
 107/*
 108 * A given kernel pud_t maps to a kernel pmd_t table at a specific
 109 * virtual address.  Since kernel pmd_t tables can be aligned at
 110 * sub-page granularity, this macro can return non-page-aligned
 111 * pointers, despite its name.
 112 */
 113#define pud_page_vaddr(pud) \
 114        (__va((phys_addr_t)pud_ptfn(pud) << HV_LOG2_PAGE_TABLE_ALIGN))
 115
 116/*
 117 * A pud_t points to a pmd_t array.  Since we can have multiple per
 118 * page, we don't have a one-to-one mapping of pud_t's to pages.
 119 */
 120#define pud_page(pud) pfn_to_page(PFN_DOWN(HV_PTFN_TO_CPA(pud_ptfn(pud))))
 121
 122static inline unsigned long pud_index(unsigned long address)
 123{
 124        return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
 125}
 126
 127#define pmd_offset(pud, address) \
 128        ((pmd_t *)pud_page_vaddr(*(pud)) + pmd_index(address))
 129
 130/* Normalize an address to having the correct high bits set. */
 131#define pgd_addr_normalize pgd_addr_normalize
 132static inline unsigned long pgd_addr_normalize(unsigned long addr)
 133{
 134        return ((long)addr << (CHIP_WORD_SIZE() - CHIP_VA_WIDTH())) >>
 135                (CHIP_WORD_SIZE() - CHIP_VA_WIDTH());
 136}
 137
 138/* We don't define any pgds for these addresses. */
 139static inline int pgd_addr_invalid(unsigned long addr)
 140{
 141        return addr >= KERNEL_HIGH_VADDR || addr != pgd_addr_normalize(addr);
 142}
 143
 144/*
 145 * Use atomic instructions to provide atomicity against the hypervisor.
 146 */
 147#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 148static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 149                                            unsigned long addr, pte_t *ptep)
 150{
 151        return (__insn_fetchand(&ptep->val, ~HV_PTE_ACCESSED) >>
 152                HV_PTE_INDEX_ACCESSED) & 0x1;
 153}
 154
 155#define __HAVE_ARCH_PTEP_SET_WRPROTECT
 156static inline void ptep_set_wrprotect(struct mm_struct *mm,
 157                                      unsigned long addr, pte_t *ptep)
 158{
 159        __insn_fetchand(&ptep->val, ~HV_PTE_WRITABLE);
 160}
 161
 162#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 163static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 164                                       unsigned long addr, pte_t *ptep)
 165{
 166        return hv_pte(__insn_exch(&ptep->val, 0UL));
 167}
 168
 169#endif /* __ASSEMBLY__ */
 170
 171#endif /* _ASM_TILE_PGTABLE_64_H */
 172