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
  23 #define PGDIR_ORDER     0
  24
  25 /*
  26  * This is handled very differently on MicroBlaze since out page tables
  27  * are all 0's and I want to be able to use these zero'd pages elsewhere
  28  * as well - it gives us quite a speedup.
  29  * -- Cort
  30  */
  31 extern struct pgtable_cache_struct {
  32         unsigned long *pgd_cache;
  33         unsigned long *pte_cache;
  34         unsigned long pgtable_cache_sz;
  35 } quicklists;
  36
  37 #define pgd_quicklist           (quicklists.pgd_cache)
  38 #define pmd_quicklist           ((unsigned long *)0)
  39 #define pte_quicklist           (quicklists.pte_cache)
  40 #define pgtable_cache_size      (quicklists.pgtable_cache_sz)
  41
  42 extern unsigned long *zero_cache; /* head linked list of pre-zero'd pages */
  43 extern atomic_t zero_sz; /* # currently pre-zero'd pages */
  44 extern atomic_t zeropage_hits; /* # zero'd pages request that we've done */
  45 extern atomic_t zeropage_calls; /* # zero'd pages request that've been made */
  46 extern atomic_t zerototal; /* # pages zero'd over time */
  47
  48 #define zero_quicklist          (zero_cache)
  49 #define zero_cache_sz           (zero_sz)
  50 #define zero_cache_calls        (zeropage_calls)
  51 #define zero_cache_hits         (zeropage_hits)
  52 #define zero_cache_total        (zerototal)
  53
  54 /*
  55  * return a pre-zero'd page from the list,
  56  * return NULL if none available -- Cort
  57  */
  58 extern unsigned long get_zero_page_fast(void);
  59
  60 extern void __bad_pte(pmd_t *pmd);
  61
  62 extern inline pgd_t *get_pgd_slow(void)
  63 {
  64         pgd_t *ret;
  65
  66         ret = (pgd_t *)__get_free_pages(GFP_KERNEL, PGDIR_ORDER);
  67         if (ret != NULL)
  68                 clear_page(ret);
  69         return ret;
  70 }
  71
  72 extern inline pgd_t *get_pgd_fast(void)
  73 {
  74         unsigned long *ret;
  75
  76         ret = pgd_quicklist;
  77         if (ret != NULL) {
  78                 pgd_quicklist = (unsigned long *)(*ret);
  79                 ret[0] = 0;
  80                 pgtable_cache_size--;
  81         } else
  82                 ret = (unsigned long *)get_pgd_slow();
  83         return (pgd_t *)ret;
  84 }
  85
  86 extern inline void free_pgd_fast(pgd_t *pgd)
  87 {
  88         *(unsigned long **)pgd = pgd_quicklist;
  89         pgd_quicklist = (unsigned long *) pgd;
  90         pgtable_cache_size++;
  91 }
  92
  93 extern inline void free_pgd_slow(pgd_t *pgd)
  94 {
  95         free_page((unsigned long)pgd);
  96 }
  97
  98 #define pgd_free(mm, pgd)        free_pgd_fast(pgd)
  99 #define pgd_alloc(mm)           get_pgd_fast()
 100
 101 #define pmd_pgtable(pmd)        pmd_page(pmd)
 102
 103 /*
 104  * We don't have any real pmd's, and this code never triggers because
 105  * the pgd will always be present..
 106  */
 107 #define pmd_alloc_one_fast(mm, address) ({ BUG(); ((pmd_t *)1); })
 108 #define pmd_alloc_one(mm, address)      ({ BUG(); ((pmd_t *)2); })
 109 /* FIXME two definition - look below */
 110 #define pmd_free(mm, x)                 do { } while (0)
 111 #define pgd_populate(mm, pmd, pte)      BUG()
 112
 113 static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
 114                 unsigned long address)
 115 {
 116         pte_t *pte;
 117         extern int mem_init_done;
 118         extern void *early_get_page(void);
 119         if (mem_init_done) {
 120                 pte = (pte_t *)__get_free_page(GFP_KERNEL |
 121                                         __GFP_REPEAT | __GFP_ZERO);
 122         } else {
 123                 pte = (pte_t *)early_get_page();
 124                 if (pte)
 125                         clear_page(pte);
 126         }
 127         return pte;
 128 }
 129
 130 static inline struct page *pte_alloc_one(struct mm_struct *mm,
 131                 unsigned long address)
 132 {
 133         struct page *ptepage;
 134
 135 #ifdef CONFIG_HIGHPTE
 136         int flags = GFP_KERNEL | __GFP_HIGHMEM | __GFP_REPEAT;
 137 #else
 138         int flags = GFP_KERNEL | __GFP_REPEAT;
 139 #endif
 140
 141         ptepage = alloc_pages(flags, 0);
 142         if (ptepage)
 143                 clear_highpage(ptepage);
 144         return ptepage;
 145 }
 146
 147 static inline pte_t *pte_alloc_one_fast(struct mm_struct *mm,
 148                 unsigned long address)
 149 {
 150         unsigned long *ret;
 151
 152         ret = pte_quicklist;
 153         if (ret != NULL) {
 154                 pte_quicklist = (unsigned long *)(*ret);
 155                 ret[0] = 0;
 156                 pgtable_cache_size--;
 157         }
 158         return (pte_t *)ret;
 159 }
 160
 161 extern inline void pte_free_fast(pte_t *pte)
 162 {
 163         *(unsigned long **)pte = pte_quicklist;
 164         pte_quicklist = (unsigned long *) pte;
 165         pgtable_cache_size++;
 166 }
 167
 168 extern inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
 169 {
 170         free_page((unsigned long)pte);
 171 }
 172
 173 extern inline void pte_free_slow(struct page *ptepage)
 174 {
 175         __free_page(ptepage);
 176 }
 177
 178 extern inline void pte_free(struct mm_struct *mm, struct page *ptepage)
 179 {
 180         __free_page(ptepage);
 181 }
 182
 183 #define __pte_free_tlb(tlb, pte, addr)  pte_free((tlb)->mm, (pte))
 184
 185 #define pmd_populate(mm, pmd, pte)      (pmd_val(*(pmd)) = page_address(pte))
 186
 187 #define pmd_populate_kernel(mm, pmd, pte) \
 188                 (pmd_val(*(pmd)) = (unsigned long) (pte))
 189
 190 /*
 191  * We don't have any real pmd's, and this code never triggers because
 192  * the pgd will always be present..
 193  */
 194 #define pmd_alloc_one(mm, address)      ({ BUG(); ((pmd_t *)2); })
 195 /*#define pmd_free(mm, x)                       do { } while (0)*/
 196 #define __pmd_free_tlb(tlb, x, addr)    do { } while (0)
 197 #define pgd_populate(mm, pmd, pte)      BUG()
 198
 199 extern int do_check_pgt_cache(int, int);
 200
 201 #endif /* CONFIG_MMU */
 202
 203 #define check_pgt_cache()       do {} while (0)
 204
 205 #endif /* _ASM_MICROBLAZE_PGALLOC_H */