arch/arm/include/asm/pgalloc.h

   1 /*
   2  *  arch/arm/include/asm/pgalloc.h
   3  *
   4  *  Copyright (C) 2000-2001 Russell King
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 as
   8  * published by the Free Software Foundation.
   9  */
  10 #ifndef _ASMARM_PGALLOC_H
  11 #define _ASMARM_PGALLOC_H
  12
  13 #include <linux/pagemap.h>
  14
  15 #include <asm/domain.h>
  16 #include <asm/pgtable-hwdef.h>
  17 #include <asm/processor.h>
  18 #include <asm/cacheflush.h>
  19 #include <asm/tlbflush.h>
  20
  21 #define check_pgt_cache()               do { } while (0)
  22
  23 #ifdef CONFIG_MMU
  24
  25 #define _PAGE_USER_TABLE        (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
  26 #define _PAGE_KERNEL_TABLE      (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
  27
  28 #ifdef CONFIG_ARM_LPAE
  29
  30 static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
  31 {
  32         return (pmd_t *)get_zeroed_page(GFP_KERNEL);
  33 }
  34
  35 static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
  36 {
  37         BUG_ON((unsigned long)pmd & (PAGE_SIZE-1));
  38         free_page((unsigned long)pmd);
  39 }
  40
  41 static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
  42 {
  43         set_pud(pud, __pud(__pa(pmd) | PMD_TYPE_TABLE));
  44 }
  45
  46 #else   /* !CONFIG_ARM_LPAE */
  47
  48 /*
  49  * Since we have only two-level page tables, these are trivial
  50  */
  51 #define pmd_alloc_one(mm,addr)          ({ BUG(); ((pmd_t *)2); })
  52 #define pmd_free(mm, pmd)               do { } while (0)
  53 #define pud_populate(mm,pmd,pte)        BUG()
  54
  55 #endif  /* CONFIG_ARM_LPAE */
  56
  57 extern pgd_t *pgd_alloc(struct mm_struct *mm);
  58 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  59
  60 #define PGALLOC_GFP     (GFP_KERNEL | __GFP_ZERO)
  61
  62 static inline void clean_pte_table(pte_t *pte)
  63 {
  64         clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
  65 }
  66
  67 /*
  68  * Allocate one PTE table.
  69  *
  70  * This actually allocates two hardware PTE tables, but we wrap this up
  71  * into one table thus:
  72  *
  73  *  +------------+
  74  *  | Linux pt 0 |
  75  *  +------------+
  76  *  | Linux pt 1 |
  77  *  +------------+
  78  *  |  h/w pt 0  |
  79  *  +------------+
  80  *  |  h/w pt 1  |
  81  *  +------------+
  82  */
  83 static inline pte_t *
  84 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
  85 {
  86         pte_t *pte;
  87
  88         pte = (pte_t *)__get_free_page(PGALLOC_GFP);
  89         if (pte)
  90                 clean_pte_table(pte);
  91
  92         return pte;
  93 }
  94
  95 static inline pgtable_t
  96 pte_alloc_one(struct mm_struct *mm, unsigned long addr)
  97 {
  98         struct page *pte;
  99
 100 #ifdef CONFIG_HIGHPTE
 101         pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
 102 #else
 103         pte = alloc_pages(PGALLOC_GFP, 0);
 104 #endif
 105         if (!pte)
 106                 return NULL;
 107         if (!PageHighMem(pte))
 108                 clean_pte_table(page_address(pte));
 109         if (!pgtable_page_ctor(pte)) {
 110                 __free_page(pte);
 111                 return NULL;
 112         }
 113         return pte;
 114 }
 115
 116 /*
 117  * Free one PTE table.
 118  */
 119 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 120 {
 121         if (pte)
 122                 free_page((unsigned long)pte);
 123 }
 124
 125 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
 126 {
 127         pgtable_page_dtor(pte);
 128         __free_page(pte);
 129 }
 130
 131 static inline void __pmd_populate(pmd_t *pmdp, phys_addr_t pte,
 132                                   pmdval_t prot)
 133 {
 134         pmdval_t pmdval = (pte + PTE_HWTABLE_OFF) | prot;
 135         pmdp[0] = __pmd(pmdval);
 136 #ifndef CONFIG_ARM_LPAE
 137         pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 138 #endif
 139         flush_pmd_entry(pmdp);
 140 }
 141
 142 /*
 143  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 144  * of the mm address space.
 145  *
 146  * Ensure that we always set both PMD entries.
 147  */
 148 static inline void
 149 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 150 {
 151         /*
 152          * The pmd must be loaded with the physical address of the PTE table
 153          */
 154         __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
 155 }
 156
 157 static inline void
 158 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 159 {
 160         extern pmdval_t user_pmd_table;
 161         pmdval_t prot;
 162
 163         if (__LINUX_ARM_ARCH__ >= 6 && !IS_ENABLED(CONFIG_ARM_LPAE))
 164                 prot = user_pmd_table;
 165         else
 166                 prot = _PAGE_USER_TABLE;
 167
 168         __pmd_populate(pmdp, page_to_phys(ptep), prot);
 169 }
 170 #define pmd_pgtable(pmd) pmd_page(pmd)
 171
 172 #endif /* CONFIG_MMU */
 173
 174 #endif