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