arch/openrisc/include/asm/pgalloc.h

   1 /*
   2  * OpenRISC Linux
   3  *
   4  * Linux architectural port borrowing liberally from similar works of
   5  * others.  All original copyrights apply as per the original source
   6  * declaration.
   7  *
   8  * OpenRISC implementation:
   9  * Copyright (C) 2003 Matjaz Breskvar <phoenix@bsemi.com>
  10  * Copyright (C) 2010-2011 Jonas Bonn <jonas@southpole.se>
  11  * et al.
  12  *
  13  * This program is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  */
  18
  19 #ifndef __ASM_OPENRISC_PGALLOC_H
  20 #define __ASM_OPENRISC_PGALLOC_H
  21
  22 #include <asm/page.h>
  23 #include <linux/threads.h>
  24 #include <linux/mm.h>
  25 #include <linux/memblock.h>
  26 #include <linux/bootmem.h>
  27
  28 extern int mem_init_done;
  29
  30 #define pmd_populate_kernel(mm, pmd, pte) \
  31         set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte)))
  32
  33 static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
  34                                 struct page *pte)
  35 {
  36         set_pmd(pmd, __pmd(_KERNPG_TABLE +
  37                      ((unsigned long)page_to_pfn(pte) <<
  38                      (unsigned long) PAGE_SHIFT)));
  39 }
  40
  41 /*
  42  * Allocate and free page tables.
  43  */
  44 static inline pgd_t *pgd_alloc(struct mm_struct *mm)
  45 {
  46         pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL);
  47
  48         if (ret) {
  49                 memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
  50                 memcpy(ret + USER_PTRS_PER_PGD,
  51                        swapper_pg_dir + USER_PTRS_PER_PGD,
  52                        (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
  53
  54         }
  55         return ret;
  56 }
  57
  58 #if 0
  59 /* FIXME: This seems to be the preferred style, but we are using
  60  * current_pgd (from mm->pgd) to load kernel pages so we need it
  61  * initialized.  This needs to be looked into.
  62  */
  63 extern inline pgd_t *pgd_alloc(struct mm_struct *mm)
  64 {
  65         return (pgd_t *)get_zeroed_page(GFP_KERNEL);
  66 }
  67 #endif
  68
  69 static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
  70 {
  71         free_page((unsigned long)pgd);
  72 }
  73
  74 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address);
  75
  76 static inline struct page *pte_alloc_one(struct mm_struct *mm,
  77                                          unsigned long address)
  78 {
  79         struct page *pte;
  80         pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0);
  81         if (pte)
  82                 clear_page(page_address(pte));
  83         return pte;
  84 }
  85
  86 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
  87 {
  88         free_page((unsigned long)pte);
  89 }
  90
  91 static inline void pte_free(struct mm_struct *mm, struct page *pte)
  92 {
  93         __free_page(pte);
  94 }
  95
  96
  97 #define __pte_free_tlb(tlb, pte, addr) tlb_remove_page((tlb), (pte))
  98 #define pmd_pgtable(pmd) pmd_page(pmd)
  99
 100 #define check_pgt_cache()          do { } while (0)
 101
 102 #endif