LXR linux/arch/microblaze/include/asm/pgalloc.h

   1/*
   2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
   3 * Copyright (C) 2008-2009 PetaLogix
   4 * Copyright (C) 2006 Atmark Techno, Inc.
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License. See the file "COPYING" in the main directory of this archive
   8 * for more details.
   9 */
  10
  11#ifndef _ASM_MICROBLAZE_PGALLOC_H
  12#define _ASM_MICROBLAZE_PGALLOC_H
  13
  14#ifdef CONFIG_MMU
  15
  16#include <linux/kernel.h>       /* For min/max macros */
  17#include <linux/highmem.h>
  18#include <asm/setup.h>
  19#include <asm/io.h>
  20#include <asm/page.h>
  21#include <asm/cache.h>
  22#include <asm/pgtable.h>
  23
  24#define PGDIR_ORDER     0
  25
  26/*
  27 * This is handled very differently on MicroBlaze since out page tables
  28 * are all 0's and I want to be able to use these zero'd pages elsewhere
  29 * as well - it gives us quite a speedup.
  30 * -- Cort
  31 */
  32extern struct pgtable_cache_struct {
  33        unsigned long *pgd_cache;
  34        unsigned long *pte_cache;
  35        unsigned long pgtable_cache_sz;
  36} quicklists;
  37
  38#define pgd_quicklist           (quicklists.pgd_cache)
  39#define pmd_quicklist           ((unsigned long *)0)
  40#define pte_quicklist           (quicklists.pte_cache)
  41#define pgtable_cache_size      (quicklists.pgtable_cache_sz)
  42
  43extern unsigned long *zero_cache; /* head linked list of pre-zero'd pages */
  44extern atomic_t zero_sz; /* # currently pre-zero'd pages */
  45extern atomic_t zeropage_hits; /* # zero'd pages request that we've done */
  46extern atomic_t zeropage_calls; /* # zero'd pages request that've been made */
  47extern atomic_t zerototal; /* # pages zero'd over time */
  48
  49#define zero_quicklist          (zero_cache)
  50#define zero_cache_sz           (zero_sz)
  51#define zero_cache_calls        (zeropage_calls)
  52#define zero_cache_hits         (zeropage_hits)
  53#define zero_cache_total        (zerototal)
  54
  55/*
  56 * return a pre-zero'd page from the list,
  57 * return NULL if none available -- Cort
  58 */
  59extern unsigned long get_zero_page_fast(void);
  60
  61extern void __bad_pte(pmd_t *pmd);
  62
  63extern inline pgd_t *get_pgd_slow(void)
  64{
  65        pgd_t *ret;
  66
  67        ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGDIR_ORDER);
  68        if (ret != NULL)
  69                clear_page(ret);
  70        return ret;
  71}
  72
  73extern inline pgd_t *get_pgd_fast(void)
  74{
  75        unsigned long *ret;
  76
  77        ret = pgd_quicklist;
  78        if (ret != NULL) {
  79                pgd_quicklist = (unsigned long *)(*ret);
  80                ret[0] = 0;
  81                pgtable_cache_size--;
  82        } else
  83                ret = (unsigned long *)get_pgd_slow();
  84        return (pgd_t *)ret;
  85}
  86
  87extern inline void free_pgd_fast(pgd_t *pgd)
  88{
  89        *(unsigned long **)pgd = pgd_quicklist;
  90        pgd_quicklist = (unsigned long *) pgd;
  91        pgtable_cache_size++;
  92}
  93
  94extern inline void free_pgd_slow(pgd_t *pgd)
  95{
  96        free_page((unsigned long)pgd);
  97}
  98
  99#define pgd_free(mm, pgd)        free_pgd_fast(pgd)
 100#define pgd_alloc(mm)           get_pgd_fast()
 101
 102#define pmd_pgtable(pmd)        pmd_page(pmd)
 103
 104/*
 105 * We don't have any real pmd's, and this code never triggers because
 106 * the pgd will always be present..
 107 */
 108#define pmd_alloc_one_fast(mm, address) ({ BUG(); ((pmd_t *)1); })
 109#define pmd_alloc_one(mm, address)      ({ BUG(); ((pmd_t *)2); })
 110
 111extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
 112
 113static inline struct page *pte_alloc_one(struct mm_struct *mm,
 114                unsigned long address)
 115{
 116        struct page *ptepage;
 117
 118#ifdef CONFIG_HIGHPTE
 119        int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
 120#else
 121        int flags = GFP_KERNEL | __GFP_REPEAT;
 122#endif
 123
 124        ptepage = alloc_pages(flags, 0);
 125        if (ptepage)
 126                clear_highpage(ptepage);
 127        return ptepage;
 128}
 129
 130static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm,
 131                unsigned long address)
 132{
 133        unsigned long *ret;
 134
 135        ret = pte_quicklist;
 136        if (ret != NULL) {
 137                pte_quicklist = (unsigned long *)(*ret);
 138                ret[0] = 0;
 139                pgtable_cache_size--;
 140        }
 141        return (pte_t *)ret;
 142}
 143
 144extern inline void pte_free_fast(pte_t *pte)
 145{
 146        *(unsigned long **)pte = pte_quicklist;
 147        pte_quicklist = (unsigned long *) pte;
 148        pgtable_cache_size++;
 149}
 150
 151extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 152{
 153        free_page((unsigned long)pte);
 154}
 155
 156extern inline void pte_free_slow(struct page *ptepage)
 157{
 158        __free_page(ptepage);
 159}
 160
 161extern inline void pte_free(struct mm_struct *mm, struct page *ptepage)
 162{
 163        __free_page(ptepage);
 164}
 165
 166#define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, (pte))
 167
 168#define pmd_populate(mm, pmd, pte) \
 169                        (pmd_val(*(pmd)) = (unsigned long)page_address(pte))
 170
 171#define pmd_populate_kernel(mm, pmd, pte) \
 172                (pmd_val(*(pmd)) = (unsigned long) (pte))
 173
 174/*
 175 * We don't have any real pmd's, and this code never triggers because
 176 * the pgd will always be present..
 177 */
 178#define pmd_alloc_one(mm, address)      ({ BUG(); ((pmd_t *)2); })
 179#define pmd_free(mm, x)                 do { } while (0)
 180#define __pmd_free_tlb(tlb, x, addr)    pmd_free((tlb)->mm, x)
 181#define pgd_populate(mm, pmd, pte)      BUG()
 182
 183extern int do_check_pgt_cache(int, int);
 184
 185#endif /* CONFIG_MMU */
 186
 187#define check_pgt_cache()               do { } while (0)
 188
 189#endif /* _ASM_MICROBLAZE_PGALLOC_H */
 190