release/src-rt-6.x.4708/linux/linux-2.6.36/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 <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 #define PGALLOC_GFP     (GFP_KERNEL | __GFP_NOTRACK | __GFP_REPEAT | __GFP_ZERO)
  40
  41 /*
  42  * Allocate one PTE table.
  43  *
  44  * This actually allocates two hardware PTE tables, but we wrap this up
  45  * into one table thus:
  46  *
  47  *  +------------+
  48  *  |  h/w pt 0  |
  49  *  +------------+
  50  *  |  h/w pt 1  |
  51  *  +------------+
  52  *  | Linux pt 0 |
  53  *  +------------+
  54  *  | Linux pt 1 |
  55  *  +------------+
  56  */
  57 static inline pte_t *
  58 pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr)
  59 {
  60         pte_t *pte;
  61
  62         pte = (pte_t *)__get_free_page(PGALLOC_GFP);
  63         if (pte) {
  64                 clean_dcache_area(pte, sizeof(pte_t) * PTRS_PER_PTE);
  65                 pte += PTRS_PER_PTE;
  66         }
  67
  68         return pte;
  69 }
  70
  71 static inline pgtable_t
  72 pte_alloc_one(struct mm_struct *mm, unsigned long addr)
  73 {
  74         struct page *pte;
  75
  76 #ifdef CONFIG_HIGHPTE
  77         pte = alloc_pages(PGALLOC_GFP | __GFP_HIGHMEM, 0);
  78 #else
  79         pte = alloc_pages(PGALLOC_GFP, 0);
  80 #endif
  81         if (pte) {
  82                 if (!PageHighMem(pte)) {
  83                         void *page = page_address(pte);
  84                         clean_dcache_area(page, sizeof(pte_t) * PTRS_PER_PTE);
  85                 }
  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                 pte -= PTRS_PER_PTE;
  99                 free_page((unsigned long)pte);
 100         }
 101 }
 102
 103 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
 104 {
 105         pgtable_page_dtor(pte);
 106         __free_page(pte);
 107 }
 108
 109 static inline void __pmd_populate(pmd_t *pmdp, unsigned long pmdval)
 110 {
 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         unsigned long pte_ptr = (unsigned long)ptep;
 126
 127         /*
 128          * The pmd must be loaded with the physical
 129          * address of the PTE table
 130          */
 131         pte_ptr -= PTRS_PER_PTE * sizeof(void *);
 132         __pmd_populate(pmdp, __pa(pte_ptr) | _PAGE_KERNEL_TABLE);
 133 }
 134
 135 static inline void
 136 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, pgtable_t ptep)
 137 {
 138         __pmd_populate(pmdp, page_to_pfn(ptep) << PAGE_SHIFT | _PAGE_USER_TABLE);
 139 }
 140 #define pmd_pgtable(pmd) pmd_page(pmd)
 141
 142 #endif /* CONFIG_MMU */
 143
 144 #endif