arch/xtensa/include/asm/pgalloc.h

   1 /*
   2  * include/asm-xtensa/pgalloc.h
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * Copyright (C) 2001-2007 Tensilica Inc.
   9  */
  10
  11 #ifndef _XTENSA_PGALLOC_H
  12 #define _XTENSA_PGALLOC_H
  13
  14 #ifdef __KERNEL__
  15
  16 #include <linux/highmem.h>
  17 #include <linux/slab.h>
  18
  19 /*
  20  * Allocating and freeing a pmd is trivial: the 1-entry pmd is
  21  * inside the pgd, so has no extra memory associated with it.
  22  */
  23
  24 #define pmd_populate_kernel(mm, pmdp, ptep)                                  \
  25         (pmd_val(*(pmdp)) = ((unsigned long)ptep))
  26 #define pmd_populate(mm, pmdp, page)                                         \
  27         (pmd_val(*(pmdp)) = ((unsigned long)page_to_virt(page)))
  28 #define pmd_pgtable(pmd) pmd_page(pmd)
  29
  30 static inline pgd_t*
  31 pgd_alloc(struct mm_struct *mm)
  32 {
  33         return (pgd_t*) __get_free_pages(GFP_KERNEL | __GFP_ZERO, PGD_ORDER);
  34 }
  35
  36 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  37 {
  38         free_page((unsigned long)pgd);
  39 }
  40
  41 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
  42                                          unsigned long address)
  43 {
  44         pte_t *ptep;
  45         int i;
  46
  47         ptep = (pte_t *)__get_free_page(GFP_KERNEL);
  48         if (!ptep)
  49                 return NULL;
  50         for (i = 0; i < 1024; i++)
  51                 pte_clear(NULL, 0, ptep + i);
  52         return ptep;
  53 }
  54
  55 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
  56                                         unsigned long addr)
  57 {
  58         pte_t *pte;
  59         struct page *page;
  60
  61         pte = pte_alloc_one_kernel(mm, addr);
  62         if (!pte)
  63                 return NULL;
  64         page = virt_to_page(pte);
  65         if (!pgtable_page_ctor(page)) {
  66                 __free_page(page);
  67                 return NULL;
  68         }
  69         return page;
  70 }
  71
  72 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  73 {
  74         free_page((unsigned long)pte);
  75 }
  76
  77 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
  78 {
  79         pgtable_page_dtor(pte);
  80         __free_page(pte);
  81 }
  82 #define pmd_pgtable(pmd) pmd_page(pmd)
  83
  84 #endif /* __KERNEL__ */
  85 #endif /* _XTENSA_PGALLOC_H */