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 /*
  29  * Since we have only two-level page tables, these are trivial
  30  */
  31 #define pmd_alloc_one(mm,addr)          ({ BUG(); ((pmd_t *)2); })
  32 #define pmd_free(mm, pmd)               do { } while (0)
  33 #define pgd_populate(mm,pmd,pte)        BUG()
  34
  35 extern pgd_t *pgd_alloc(struct mm_struct *mm);
  36 extern void pgd_free(struct mm_struct *mm, pgd_t *pgd);
  37
  38 #define PGALLOC_GFP     (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
  39
  40 static inline void clean_pte_table(pte_t *pte)
  41 {
  42         clean_dcache_area(pte + PTE_HWTABLE_PTRS, PTE_HWTABLE_SIZE);
  43 }
  44
  45 /*
  46  * Allocate one PTE table.
  47  *
  48  * This actually allocates two hardware PTE tables, but we wrap this up
  49  * into one table thus:
  50  *
  51  *  +------------+
  52  *  | Linux pt 0 |
  53  *  +------------+
  54  *  | Linux pt 1 |
  55  *  +------------+
  56  *  |  h/w pt 0  |
  57  *  +------------+
  58  *  |  h/w pt 1  |
  59  *  +------------+
  60  */
  61 static inline pte_t *
  62 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
  63 {
  64         pte_t *pte;
  65
  66         pte = (pte_t *)__get_free_page(PGALLOC_GFP);
  67         if (pte)
  68                 clean_pte_table(pte);
  69
  70         return pte;
  71 }
  72
  73 static inline pgtable_t
  74 pte_alloc_one(struct mm_struct *mm, unsigned long addr)
  75 {
  76         struct page *pte;
  77
  78 #ifdef CONFIG_HIGHPTE
  79         pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
  80 #else
  81         pte = alloc_pages(PGALLOC_GFP, 0);
  82 #endif
  83         if (pte) {
  84                 if (!PageHighMem(pte))
  85                         clean_pte_table(page_address(pte));
  86                 pgtable_page_ctor(pte);
  87         }
  88
  89         return pte;
  90 }
  91
  92 /*
  93  * Free one PTE table.
  94  */
  95 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  96 {
  97         if (pte)
  98                 free_page((unsigned long)pte);
  99 }
 100
 101 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
 102 {
 103         pgtable_page_dtor(pte);
 104         __free_page(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         pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 113         flush_pmd_entry(pmdp);
 114 }
 115
 116 /*
 117  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 118  * of the mm address space.
 119  *
 120  * Ensure that we always set both PMD entries.
 121  */
 122 static inline void
 123 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 124 {
 125         /*
 126          * The pmd must be loaded with the physical address of the PTE table
 127          */
 128         __pmd_populate(pmdp, __pa(ptep), _PAGE_KERNEL_TABLE);
 129 }
 130
 131 static inline void
 132 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 133 {
 134         __pmd_populate(pmdp, page_to_phys(ptep), _PAGE_USER_TABLE);
 135 }
 136 #define pmd_pgtable(pmd) pmd_page(pmd)
 137
 138 #endif /* CONFIG_MMU */
 139
 140 #endif