include/asm-arm/pgalloc.h

   1 /*
   2  *  linux/include/asm-arm/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 <asm/domain.h>
  14 #include <asm/pgtable-hwdef.h>
  15 #include <asm/processor.h>
  16 #include <asm/cacheflush.h>
  17 #include <asm/tlbflush.h>
  18
  19 #define check_pgt_cache()               do { } while (0)
  20
  21 #ifdef CONFIG_MMU
  22
  23 #define _PAGE_USER_TABLE        (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_USER))
  24 #define _PAGE_KERNEL_TABLE      (PMD_TYPE_TABLE | PMD_BIT4 | PMD_DOMAIN(DOMAIN_KERNEL))
  25
  26 /*
  27  * Since we have only two-level page tables, these are trivial
  28  */
  29 #define pmd_alloc_one(mm,addr)          ({ BUG(); ((pmd_t *)2); })
  30 #define pmd_free(mm, pmd)               do { } while (0)
  31 #define pgd_populate(mm,pmd,pte)        BUG()
  32
  33 extern pgd_t *get_pgd_slow(struct mm_struct *mm);
  34 extern void free_pgd_slow(struct mm_struct *mm, pgd_t *pgd);
  35
  36 #define pgd_alloc(mm)                   get_pgd_slow(mm)
  37 #define pgd_free(mm, pgd)               free_pgd_slow(mm, pgd)
  38
  39 /*
  40  * Allocate one PTE table.
  41  *
  42  * This actually allocates two hardware PTE tables, but we wrap this up
  43  * into one table thus:
  44  *
  45  *  +------------+
  46  *  |  h/w pt 0  |
  47  *  +------------+
  48  *  |  h/w pt 1  |
  49  *  +------------+
  50  *  | Linux pt 0 |
  51  *  +------------+
  52  *  | Linux pt 1 |
  53  *  +------------+
  54  */
  55 static inline pte_t *
  56 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
  57 {
  58         pte_t *pte;
  59
  60         pte = (pte_t *)__get_free_page(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO);
  61         if (pte) {
  62                 clean_dcache_area(pte, sizeof(pte_t) * PTRS_PER_PTE);
  63                 pte += PTRS_PER_PTE;
  64         }
  65
  66         return pte;
  67 }
  68
  69 static inline pgtable_t
  70 pte_alloc_one(struct mm_struct *mm, unsigned long addr)
  71 {
  72         struct page *pte;
  73
  74         pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT|__GFP_ZERO, 0);
  75         if (pte) {
  76                 void *page = page_address(pte);
  77                 clean_dcache_area(page, sizeof(pte_t) * PTRS_PER_PTE);
  78                 pgtable_page_ctor(pte);
  79         }
  80
  81         return pte;
  82 }
  83
  84 /*
  85  * Free one PTE table.
  86  */
  87 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  88 {
  89         if (pte) {
  90                 pte -= PTRS_PER_PTE;
  91                 free_page((unsigned long)pte);
  92         }
  93 }
  94
  95 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
  96 {
  97         pgtable_page_dtor(pte);
  98         __free_page(pte);
  99 }
 100
 101 static inline void __pmd_populate(pmd_t *pmdp, unsigned long pmdval)
 102 {
 103         pmdp[0] = __pmd(pmdval);
 104         pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 105         flush_pmd_entry(pmdp);
 106 }
 107
 108 /*
 109  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 110  * of the mm address space.
 111  *
 112  * Ensure that we always set both PMD entries.
 113  */
 114 static inline void
 115 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 116 {
 117         unsigned long pte_ptr = (unsigned long)ptep;
 118
 119         /*
 120          * The pmd must be loaded with the physical
 121          * address of the PTE table
 122          */
 123         pte_ptr -= PTRS_PER_PTE * sizeof(void *);
 124         __pmd_populate(pmdp, __pa(pte_ptr) | _PAGE_KERNEL_TABLE);
 125 }
 126
 127 static inline void
 128 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 129 {
 130         __pmd_populate(pmdp, page_to_pfn(ptep) << PAGE_SHIFT | _PAGE_USER_TABLE);
 131 }
 132 #define pmd_pgtable(pmd) pmd_page(pmd)
 133
 134 #endif /* CONFIG_MMU */
 135
 136 #endif