LXR linux/arch/arc/include/asm/pgtable-levels.h

   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright (C) 2020 Synopsys, Inc. (www.synopsys.com)
   4 */
   5
   6/*
   7 * Helpers for implemenintg paging levels
   8 */
   9
  10#ifndef _ASM_ARC_PGTABLE_LEVELS_H
  11#define _ASM_ARC_PGTABLE_LEVELS_H
  12
  13#if CONFIG_PGTABLE_LEVELS == 2
  14
  15/*
  16 * 2 level paging setup for software walked MMUv3 (ARC700) and MMUv4 (HS)
  17 *
  18 * [31]            32 bit virtual address              [0]
  19 * -------------------------------------------------------
  20 * |               | <---------- PGDIR_SHIFT ----------> |
  21 * |               |                | <-- PAGE_SHIFT --> |
  22 * -------------------------------------------------------
  23 *       |                  |                |
  24 *       |                  |                --> off in page frame
  25 *       |                  ---> index into Page Table
  26 *       ----> index into Page Directory
  27 *
  28 * Given software walk, the vaddr split is arbitrary set to 11:8:13
  29 * However enabling of super page in a 2 level regime pegs PGDIR_SHIFT to
  30 * super page size.
  31 */
  32
  33#if defined(CONFIG_ARC_HUGEPAGE_16M)
  34#define PGDIR_SHIFT             24
  35#elif defined(CONFIG_ARC_HUGEPAGE_2M)
  36#define PGDIR_SHIFT             21
  37#else
  38/*
  39 * No Super page case
  40 * Default value provides 11:8:13 (8K), 10:10:12 (4K)
  41 * Limits imposed by pgtable_t only PAGE_SIZE long
  42 * (so 4K page can only have 1K entries: or 10 bits)
  43 */
  44#ifdef CONFIG_ARC_PAGE_SIZE_4K
  45#define PGDIR_SHIFT             22
  46#else
  47#define PGDIR_SHIFT             21
  48#endif
  49
  50#endif
  51
  52#else /* CONFIG_PGTABLE_LEVELS != 2 */
  53
  54/*
  55 * A default 3 level paging testing setup in software walked MMU
  56 *   MMUv4 (8K page): <4> : <7> : <8> : <13>
  57 * A default 4 level paging testing setup in software walked MMU
  58 *   MMUv4 (8K page): <4> : <3> : <4> : <8> : <13>
  59 */
  60#define PGDIR_SHIFT             28
  61#if CONFIG_PGTABLE_LEVELS > 3
  62#define PUD_SHIFT               25
  63#endif
  64#if CONFIG_PGTABLE_LEVELS > 2
  65#define PMD_SHIFT               21
  66#endif
  67
  68#endif /* CONFIG_PGTABLE_LEVELS */
  69
  70#define PGDIR_SIZE              BIT(PGDIR_SHIFT)
  71#define PGDIR_MASK              (~(PGDIR_SIZE - 1))
  72#define PTRS_PER_PGD            BIT(32 - PGDIR_SHIFT)
  73
  74#if CONFIG_PGTABLE_LEVELS > 3
  75#define PUD_SIZE                BIT(PUD_SHIFT)
  76#define PUD_MASK                (~(PUD_SIZE - 1))
  77#define PTRS_PER_PUD            BIT(PGDIR_SHIFT - PUD_SHIFT)
  78#endif
  79
  80#if CONFIG_PGTABLE_LEVELS > 2
  81#define PMD_SIZE                BIT(PMD_SHIFT)
  82#define PMD_MASK                (~(PMD_SIZE - 1))
  83#define PTRS_PER_PMD            BIT(PUD_SHIFT - PMD_SHIFT)
  84#endif
  85
  86#define PTRS_PER_PTE            BIT(PMD_SHIFT - PAGE_SHIFT)
  87
  88#ifndef __ASSEMBLY__
  89
  90#if CONFIG_PGTABLE_LEVELS > 3
  91#include <asm-generic/pgtable-nop4d.h>
  92#elif CONFIG_PGTABLE_LEVELS > 2
  93#include <asm-generic/pgtable-nopud.h>
  94#else
  95#include <asm-generic/pgtable-nopmd.h>
  96#endif
  97
  98/*
  99 * 1st level paging: pgd
 100 */
 101#define pgd_index(addr)         ((addr) >> PGDIR_SHIFT)
 102#define pgd_offset(mm, addr)    (((mm)->pgd) + pgd_index(addr))
 103#define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 104#define pgd_ERROR(e) \
 105        pr_crit("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
 106
 107#if CONFIG_PGTABLE_LEVELS > 3
 108
 109/* In 4 level paging, p4d_* macros work on pgd */
 110#define p4d_none(x)             (!p4d_val(x))
 111#define p4d_bad(x)              ((p4d_val(x) & ~PAGE_MASK))
 112#define p4d_present(x)          (p4d_val(x))
 113#define p4d_clear(xp)           do { p4d_val(*(xp)) = 0; } while (0)
 114#define p4d_pgtable(p4d)        ((pud_t *)(p4d_val(p4d) & PAGE_MASK))
 115#define p4d_page(p4d)           virt_to_page(p4d_pgtable(p4d))
 116#define set_p4d(p4dp, p4d)      (*(p4dp) = p4d)
 117
 118/*
 119 * 2nd level paging: pud
 120 */
 121#define pud_ERROR(e) \
 122        pr_crit("%s:%d: bad pud %08lx.\n", __FILE__, __LINE__, pud_val(e))
 123
 124#endif
 125
 126#if CONFIG_PGTABLE_LEVELS > 2
 127
 128/*
 129 * In 3 level paging, pud_* macros work on pgd
 130 * In 4 level paging, pud_* macros work on pud
 131 */
 132#define pud_none(x)             (!pud_val(x))
 133#define pud_bad(x)              ((pud_val(x) & ~PAGE_MASK))
 134#define pud_present(x)          (pud_val(x))
 135#define pud_clear(xp)           do { pud_val(*(xp)) = 0; } while (0)
 136#define pud_pgtable(pud)        ((pmd_t *)(pud_val(pud) & PAGE_MASK))
 137#define pud_page(pud)           virt_to_page(pud_pgtable(pud))
 138#define set_pud(pudp, pud)      (*(pudp) = pud)
 139
 140/*
 141 * 3rd level paging: pmd
 142 */
 143#define pmd_ERROR(e) \
 144        pr_crit("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
 145
 146#define pmd_pfn(pmd)            ((pmd_val(pmd) & PMD_MASK) >> PAGE_SHIFT)
 147#define pfn_pmd(pfn,prot)       __pmd(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 148#define mk_pmd(page,prot)       pfn_pmd(page_to_pfn(page),prot)
 149
 150#endif
 151
 152/*
 153 * Due to the strange way generic pgtable level folding works, the pmd_* macros
 154 *  - are valid even for 2 levels (which supposedly only has pgd - pte)
 155 *  - behave differently for 2 vs. 3
 156 * In 2  level paging        (pgd -> pte), pmd_* macros work on pgd
 157 * In 3+ level paging (pgd -> pmd -> pte), pmd_* macros work on pmd
 158 */
 159#define pmd_none(x)             (!pmd_val(x))
 160#define pmd_bad(x)              ((pmd_val(x) & ~PAGE_MASK))
 161#define pmd_present(x)          (pmd_val(x))
 162#define pmd_clear(xp)           do { pmd_val(*(xp)) = 0; } while (0)
 163#define pmd_page_vaddr(pmd)     (pmd_val(pmd) & PAGE_MASK)
 164#define pmd_page(pmd)           virt_to_page(pmd_page_vaddr(pmd))
 165#define set_pmd(pmdp, pmd)      (*(pmdp) = pmd)
 166#define pmd_pgtable(pmd)        ((pgtable_t) pmd_page_vaddr(pmd))
 167
 168/*
 169 * 4th level paging: pte
 170 */
 171#define pte_ERROR(e) \
 172        pr_crit("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
 173
 174#define pte_none(x)             (!pte_val(x))
 175#define pte_present(x)          (pte_val(x) & _PAGE_PRESENT)
 176#define pte_clear(mm,addr,ptep) set_pte_at(mm, addr, ptep, __pte(0))
 177#define pte_page(pte)           pfn_to_page(pte_pfn(pte))
 178#define set_pte(ptep, pte)      ((*(ptep)) = (pte))
 179#define pte_pfn(pte)            (pte_val(pte) >> PAGE_SHIFT)
 180#define pfn_pte(pfn, prot)      __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
 181#define mk_pte(page, prot)      pfn_pte(page_to_pfn(page), prot)
 182
 183#ifdef CONFIG_ISA_ARCV2
 184#define pmd_leaf(x)             (pmd_val(x) & _PAGE_HW_SZ)
 185#endif
 186
 187#endif  /* !__ASSEMBLY__ */
 188
 189#endif
 190