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  */
  32 extern 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
  43 extern unsigned long *zero_cache; /* head linked list of pre-zero'd pages */
  44 extern atomic_t zero_sz; /* # currently pre-zero'd pages */
  45 extern atomic_t zeropage_hits; /* # zero'd pages request that we've done */
  46 extern atomic_t zeropage_calls; /* # zero'd pages request that've been made */
  47 extern 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  */
  59 extern unsigned long get_zero_page_fast(void);
  60
  61 extern void __bad_pte(pmd_t *pmd);
  62
  63 static 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
  73 static 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
  87 static 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
  94 static 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
 111 extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long addr);
 112
 113 static 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                 return NULL;
 127         clear_highpage(ptepage);
 128         if (!pgtable_page_ctor(ptepage)) {
 129                 __free_page(ptepage);
 130                 return NULL;
 131         }
 132         return ptepage;
 133 }
 134
 135 static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm,
 136                 unsigned long address)
 137 {
 138         unsigned long *ret;
 139
 140         ret = pte_quicklist;
 141         if (ret != NULL) {
 142                 pte_quicklist = (unsigned long *)(*ret);
 143                 ret[0] = 0;
 144                 pgtable_cache_size--;
 145         }
 146         return (pte_t *)ret;
 147 }
 148
 149 static inline void pte_free_fast(pte_t *pte)
 150 {
 151         *(unsigned long **)pte = pte_quicklist;
 152         pte_quicklist = (unsigned long *) pte;
 153         pgtable_cache_size++;
 154 }
 155
 156 static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 157 {
 158         free_page((unsigned long)pte);
 159 }
 160
 161 static inline void pte_free_slow(struct page *ptepage)
 162 {
 163         __free_page(ptepage);
 164 }
 165
 166 static inline void pte_free(struct mm_struct *mm, struct page *ptepage)
 167 {
 168         pgtable_page_dtor(ptepage);
 169         __free_page(ptepage);
 170 }
 171
 172 #define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, (pte))
 173
 174 #define pmd_populate(mm, pmd, pte) \
 175                         (pmd_val(*(pmd)) = (unsigned long)page_address(pte))
 176
 177 #define pmd_populate_kernel(mm, pmd, pte) \
 178                 (pmd_val(*(pmd)) = (unsigned long) (pte))
 179
 180 /*
 181  * We don't have any real pmd's, and this code never triggers because
 182  * the pgd will always be present..
 183  */
 184 #define pmd_alloc_one(mm, address)      ({ BUG(); ((pmd_t *)2); })
 185 #define pmd_free(mm, x)                 do { } while (0)
 186 #define __pmd_free_tlb(tlb, x, addr)    pmd_free((tlb)->mm, x)
 187 #define pgd_populate(mm, pmd, pte)      BUG()
 188
 189 extern int do_check_pgt_cache(int, int);
 190
 191 #endif /* CONFIG_MMU */
 192
 193 #define check_pgt_cache()               do { } while (0)
 194
 195 #endif /* _ASM_MICROBLAZE_PGALLOC_H */