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 #define PGD_SIZE                (PTRS_PER_PGD * sizeof(pgd_t))
  25
  26 static 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
  47 extern pgd_t *pgd_alloc(struct mm_struct *mm);
  48 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  49
  50 static 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
  77 static inline pte_t *
  78 pte_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
  94 static inline pgtable_t
  95 pte_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
 107 static 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  */
 124 static inline void
 125 pmd_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
 133 static inline void
 134 pmd_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 #define pmd_pgtable(pmd) pmd_page(pmd)
 147
 148 #endif /* CONFIG_MMU */
 149
 150 #endif