release/src-rt-6.x.4708/linux/linux-2.6.36/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 /* Use a slab cache for the pte pages (see also sparc64 implementation) */
  42
  43 extern struct kmem_cache *pgtable_cache;
  44
  45 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
  46                                          unsigned long address)
  47 {
  48         return kmem_cache_alloc(pgtable_cache, GFP_KERNEL|__GFP_REPEAT);
  49 }
  50
  51 static inline pgtable_t pte_alloc_one(struct mm_struct *mm,
  52                                         unsigned long addr)
  53 {
  54         struct page *page;
  55
  56         page = virt_to_page(pte_alloc_one_kernel(mm, addr));
  57         pgtable_page_ctor(page);
  58         return page;
  59 }
  60
  61 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  62 {
  63         kmem_cache_free(pgtable_cache, pte);
  64 }
  65
  66 static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
  67 {
  68         pgtable_page_dtor(pte);
  69         kmem_cache_free(pgtable_cache, page_address(pte));
  70 }
  71 #define pmd_pgtable(pmd) pmd_page(pmd)
  72
  73 #endif /* __KERNEL__ */
  74 #endif /* _XTENSA_PGALLOC_H */