LXR linux/arch/arm/include/asm/pgalloc.h

   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
  25static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
  26{
  27        return (pmd_t *)get_zeroed_page(GFP_KERNEL);
  28}
  29
  30static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
  31{
  32        BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
  33        free_page((unsigned long)pmd);
  34}
  35
  36static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
  37{
  38        set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
  39}
  40
  41#else   /* !CONFIG_ARM_LPAE */
  42
  43/*
  44 * Since we have only two-level page tables, these are trivial
  45 */
  46#define pmd_alloc_one(mm,addr)          ({ BUG(); ((pmd_t *)2); })
  47#define pmd_free(mm, pmd)               do { } while (0)
  48#define pud_populate(mm,pmd,pte)        BUG()
  49
  50#endif  /* CONFIG_ARM_LPAE */
  51
  52extern pgd_t *pgd_alloc(struct mm_struct *mm);
  53extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  54
  55static inline void clean_pte_table(pte_t *pte)
  56{
  57        clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
  58}
  59
  60/*
  61 * Allocate one PTE table.
  62 *
  63 * This actually allocates two hardware PTE tables, but we wrap this up
  64 * into one table thus:
  65 *
  66 *  +------------+
  67 *  | Linux pt 0 |
  68 *  +------------+
  69 *  | Linux pt 1 |
  70 *  +------------+
  71 *  |  h/w pt 0  |
  72 *  +------------+
  73 *  |  h/w pt 1  |
  74 *  +------------+
  75 */
  76
  77#define __HAVE_ARCH_PTE_ALLOC_ONE_KERNEL
  78#define __HAVE_ARCH_PTE_ALLOC_ONE
  79#include <asm-generic/pgalloc.h>
  80
  81static inline pte_t *
  82pte_alloc_one_kernel(struct mm_struct *mm)
  83{
  84        pte_t *pte = __pte_alloc_one_kernel(mm);
  85
  86        if (pte)
  87                clean_pte_table(pte);
  88
  89        return pte;
  90}
  91
  92#ifdef CONFIG_HIGHPTE
  93#define PGTABLE_HIGHMEM __GFP_HIGHMEM
  94#else
  95#define PGTABLE_HIGHMEM 0
  96#endif
  97
  98static inline pgtable_t
  99pte_alloc_one(struct mm_struct *mm)
 100{
 101        struct page *pte;
 102
 103        pte = __pte_alloc_one(mm, GFP_PGTABLE_USER | PGTABLE_HIGHMEM);
 104        if (!pte)
 105                return NULL;
 106        if (!PageHighMem(pte))
 107                clean_pte_table(page_address(pte));
 108        return pte;
 109}
 110
 111static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
 112                                  pmdval_t prot)
 113{
 114        pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
 115        pmdp[0] = __pmd(pmdval);
 116#ifndef CONFIG_ARM_LPAE
 117        pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 118#endif
 119        flush_pmd_entry(pmdp);
 120}
 121
 122/*
 123 * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 124 * of the mm address space.
 125 *
 126 * Ensure that we always set both PMD entries.
 127 */
 128static inline void
 129pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 130{
 131        /*
 132         * The pmd must be loaded with the physical address of the PTE table
 133         */
 134        __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
 135}
 136
 137static inline void
 138pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 139{
 140        extern pmdval_t user_pmd_table;
 141        pmdval_t prot;
 142
 143        if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
 144                prot = user_pmd_table;
 145        else
 146                prot = _PAGE_USER_TABLE;
 147
 148        __pmd_populate(pmdp, page_to_phys(ptep), prot);
 149}
 150#define pmd_pgtable(pmd) pmd_page(pmd)
 151
 152#endif /* CONFIG_MMU */
 153
 154#endif
 155