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