release/src-rt-6.x/linux/linux-2.6/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(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(pgd_t *pgd);
  35
  36 #define pgd_alloc(mm)                   get_pgd_slow(mm)
  37 #define pgd_free(pgd)                   free_pgd_slow(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 struct page *
  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         }
  79
  80         return pte;
  81 }
  82
  83 /*
  84  * Free one PTE table.
  85  */
  86 static inline void pte_free_kernel(pte_t *pte)
  87 {
  88         if (pte) {
  89                 pte -= PTRS_PER_PTE;
  90                 free_page((unsigned long)pte);
  91         }
  92 }
  93
  94 static inline void pte_free(struct page *pte)
  95 {
  96         __free_page(pte);
  97 }
  98
  99 static inline void __pmd_populate(pmd_t *pmdp, unsigned long pmdval)
 100 {
 101         pmdp[0] = __pmd(pmdval);
 102         pmdp[1] = __pmd(pmdval + 256 * sizeof(pte_t));
 103         flush_pmd_entry(pmdp);
 104 }
 105
 106 /*
 107  * Populate the pmdp entry with a pointer to the pte.  This pmd is part
 108  * of the mm address space.
 109  *
 110  * Ensure that we always set both PMD entries.
 111  */
 112 static inline void
 113 pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmdp, pte_t *ptep)
 114 {
 115         unsigned long pte_ptr = (unsigned long)ptep;
 116
 117         /*
 118          * The pmd must be loaded with the physical
 119          * address of the PTE table
 120          */
 121         pte_ptr -= PTRS_PER_PTE * sizeof(void *);
 122         __pmd_populate(pmdp, __pa(pte_ptr) | _PAGE_KERNEL_TABLE);
 123 }
 124
 125 static inline void
 126 pmd_populate(struct mm_struct *mm, pmd_t *pmdp, struct page *ptep)
 127 {
 128         __pmd_populate(pmdp, page_to_pfn(ptep) << PAGE_SHIFT | _PAGE_USER_TABLE);
 129 }
 130
 131 #endif /* CONFIG_MMU */
 132
 133 #endif