linux/arch/arm/include/asm/pgalloc.h
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   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 *  arch/arm/include/asm/pgalloc.h
   4 *
   5 *  Copyright (C) 2000-2001 Russell King
   6 */
   7#ifndef _ASMARM_PGALLOC_H
   8#define _ASMARM_PGALLOC_H
   9
  10#include <linux/pagemap.h>
  11
  12#include <asm/domain.h>
  13#include <asm/pgtable-hwdef.h>
  14#include <asm/processor.h>
  15#include <asm/cacheflush.h>
  16#include <asm/tlbflush.h>
  17
  18#ifdef CONFIG_MMU
  19
  20#define _PAGE_USER_TABLE        (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
  21#define _PAGE_KERNEL_TABLE      (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
  22
  23#ifdef CONFIG_ARM_LPAE
  24#define PGD_SIZE                (PTRS_PER_PGD * sizeof(pgd_t))
  25
  26static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
  27{
  28        set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
  29}
  30
  31#else   /* !CONFIG_ARM_LPAE */
  32#define PGD_SIZE                (PAGE_SIZE << 2)
  33
  34/*
  35 * Since we have only two-level page tables, these are trivial
  36 */
  37#define pmd_alloc_one(mm,addr)          ({ BUG(); ((pmd_t *)2); })
  38#define pmd_free(mm, pmd)               do { } while (0)
  39#ifdef CONFIG_KASAN
  40/* The KASan core unconditionally calls pud_populate() on all architectures */
  41#define pud_populate(mm,pmd,pte)        do { } while (0)
  42#else
  43#define pud_populate(mm,pmd,pte)        BUG()
  44#endif
  45#endif  /* CONFIG_ARM_LPAE */
  46
  47extern pgd_t *pgd_alloc(struct mm_struct *mm);
  48extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  49
  50static inline void clean_pte_table(pte_t *pte)
  51{
  52        clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
  53}
  54
  55/*
  56 * Allocate one PTE table.
  57 *
  58 * This actually allocates two hardware PTE tables, but we wrap this up
  59 * into one table thus:
  60 *
  61 *  +------------+
  62 *  | Linux pt 0 |
  63 *  +------------+
  64 *  | Linux pt 1 |
  65 *  +------------+
  66 *  |  h/w pt 0  |
  67 *  +------------+
  68 *  |  h/w pt 1  |
  69 *  +------------+
  70 */
  71
  72#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
  73#define __HAVE_ARCH_PTE_ALLOC_ONE
  74#define __HAVE_ARCH_PGD_FREE
  75#include <asm-generic/pgalloc.h>
  76
  77static inline pte_t *
  78pte_alloc_one_kernel(struct mm_struct *mm)
  79{
  80        pte_t *pte = __pte_alloc_one_kernel(mm);
  81
  82        if (pte)
  83                clean_pte_table(pte);
  84
  85        return pte;
  86}
  87
  88#ifdef CONFIG_HIGHPTE
  89#define PGTABLE_HIGHMEM __GFP_HIGHMEM
  90#else
  91#define PGTABLE_HIGHMEM 0
  92#endif
  93
  94static inline pgtable_t
  95pte_alloc_one(struct mm_struct *mm)
  96{
  97        struct page *pte;
  98
  99        pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM);
 100        if (!pte)
 101                return NULL;
 102        if (!PageHighMem(pte))
 103                clean_pte_table(page_address(pte));
 104        return pte;
 105}
 106
 107static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
 108                                  pmdval_t prot)
 109{
 110        pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
 111        pmdp[0] = __pmd(pmdval);
 112#ifndef CONFIG_ARM_LPAE
 113        pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 114#endif
 115        flush_pmd_entry(pmdp);
 116}
 117
 118/*
 119 * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 120 * of the mm address space.
 121 *
 122 * Ensure that we always set both PMD entries.
 123 */
 124static inline void
 125pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 126{
 127        /*
 128         * The pmd must be loaded with the physical address of the PTE table
 129         */
 130        __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
 131}
 132
 133static inline void
 134pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 135{
 136        extern pmdval_t user_pmd_table;
 137        pmdval_t prot;
 138
 139        if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
 140                prot = user_pmd_table;
 141        else
 142                prot = _PAGE_USER_TABLE;
 143
 144        __pmd_populate(pmdp, page_to_phys(ptep), prot);
 145}
 146
 147#endif /* CONFIG_MMU */
 148
 149#endif
 150