include/asm-mips/pgtable-32.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
   7  * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
   8  */
   9 #ifndef _ASM_PGTABLE_32_H
  10 #define _ASM_PGTABLE_32_H
  11
  12 #include <linux/config.h>
  13 #include <asm/addrspace.h>
  14 #include <asm/page.h>
  15
  16 #include <linux/linkage.h>
  17 #include <asm/cachectl.h>
  18 #include <asm/fixmap.h>
  19
  20 /*
  21  * - add_wired_entry() add a fixed TLB entry, and move wired register
  22  */
  23 extern void add_wired_entry(unsigned long entrylo0, unsigned long entrylo1,
  24                                unsigned long entryhi, unsigned long pagemask);
  25
  26 /*
  27  * - add_temporary_entry() add a temporary TLB entry. We use TLB entries
  28  *      starting at the top and working down. This is for populating the
  29  *      TLB before trap_init() puts the TLB miss handler in place. It
  30  *      should be used only for entries matching the actual page tables,
  31  *      to prevent inconsistencies.
  32  */
  33 extern int add_temporary_entry(unsigned long entrylo0, unsigned long entrylo1,
  34                                unsigned long entryhi, unsigned long pagemask);
  35
  36
  37 /* Basically we have the same two-level (which is the logical three level
  38  * Linux page table layout folded) page tables as the i386.  Some day
  39  * when we have proper page coloring support we can have a 1% quicker
  40  * tlb refill handling mechanism, but for now it is a bit slower but
  41  * works even with the cache aliasing problem the R4k and above have.
  42  */
  43
  44 /* PMD_SHIFT determines the size of the area a second-level page table can map */
  45 #ifdef CONFIG_64BIT_PHYS_ADDR
  46 #define PMD_SHIFT       21
  47 #else
  48 #define PMD_SHIFT       22
  49 #endif
  50 #define PMD_SIZE        (1UL << PMD_SHIFT)
  51 #define PMD_MASK        (~(PMD_SIZE-1))
  52
  53 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  54 #define PGDIR_SHIFT     PMD_SHIFT
  55 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  56 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  57
  58 /*
  59  * Entries per page directory level: we use two-level, so
  60  * we don't really have any PMD directory physically.
  61  */
  62 #ifdef CONFIG_64BIT_PHYS_ADDR
  63 #define PGD_ORDER       1
  64 #define PMD_ORDER       0
  65 #define PTE_ORDER       0
  66 #else
  67 #define PGD_ORDER       0
  68 #define PMD_ORDER       0
  69 #define PTE_ORDER       0
  70 #endif
  71
  72 #define PTRS_PER_PGD    ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
  73 #define PTRS_PER_PMD    1
  74 #define PTRS_PER_PTE    ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
  75
  76 #define USER_PTRS_PER_PGD       (0x80000000UL/PGDIR_SIZE)
  77 #define FIRST_USER_PGD_NR       0
  78
  79 #define VMALLOC_START     KSEG2
  80
  81 #ifdef CONFIG_HIGHMEM
  82 # define VMALLOC_END    (PKMAP_BASE-2*PAGE_SIZE)
  83 #else
  84 # define VMALLOC_END    (FIXADDR_START-2*PAGE_SIZE)
  85 #endif
  86
  87 #ifdef CONFIG_64BIT_PHYS_ADDR
  88 #define pte_ERROR(e) \
  89         printk("%s:%d: bad pte %016Lx.\n", __FILE__, __LINE__, pte_val(e))
  90 #else
  91 #define pte_ERROR(e) \
  92         printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
  93 #endif
  94 #define pmd_ERROR(e) \
  95         printk("%s:%d: bad pmd %08lx.\n", __FILE__, __LINE__, pmd_val(e))
  96 #define pgd_ERROR(e) \
  97         printk("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e))
  98
  99 extern void load_pgd(unsigned long pg_dir);
 100
 101 extern pmd_t invalid_pte_table[PAGE_SIZE/sizeof(pmd_t)];
 102
 103 /*
 104  * Empty pgd/pmd entries point to the invalid_pte_table.
 105  */
 106 static inline int pmd_none(pmd_t pmd)
 107 {
 108         return pmd_val(pmd) == (unsigned long) invalid_pte_table;
 109 }
 110
 111 #define pmd_bad(pmd)            (pmd_val(pmd) & ~PAGE_MASK)
 112
 113 static inline int pmd_present(pmd_t pmd)
 114 {
 115         return pmd_val(pmd) != (unsigned long) invalid_pte_table;
 116 }
 117
 118 static inline void pmd_clear(pmd_t *pmdp)
 119 {
 120         pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
 121 }
 122
 123 /*
 124  * The "pgd_xxx()" functions here are trivial for a folded two-level
 125  * setup: the pgd is never bad, and a pmd always exists (as it's folded
 126  * into the pgd entry)
 127  */
 128 static inline int pgd_none(pgd_t pgd)           { return 0; }
 129 static inline int pgd_bad(pgd_t pgd)            { return 0; }
 130 static inline int pgd_present(pgd_t pgd)        { return 1; }
 131 static inline void pgd_clear(pgd_t *pgdp)       { }
 132
 133 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 134
 135
 136 #ifdef CONFIG_CPU_VR41XX
 137 #define pte_pfn(x)              ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
 138 #define pfn_pte(pfn, prot)      __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
 139 #else
 140 #define pte_pfn(x)              ((unsigned long)((x).pte >> PAGE_SHIFT))
 141 #define pfn_pte(pfn, prot)      __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
 142 #endif
 143
 144 #define __pgd_offset(address)   pgd_index(address)
 145 #define __pmd_offset(address)   (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 146
 147 /* to find an entry in a kernel page-table-directory */
 148 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 149
 150 #define pgd_index(address)      ((address) >> PGDIR_SHIFT)
 151
 152 /* to find an entry in a page-table-directory */
 153 #define pgd_offset(mm,addr)     ((mm)->pgd + pgd_index(addr))
 154
 155 /* Find an entry in the second-level page table.. */
 156 static inline pmd_t *pmd_offset(pgd_t *dir, unsigned long address)
 157 {
 158         return (pmd_t *) dir;
 159 }
 160
 161 /* Find an entry in the third-level page table.. */
 162 #define __pte_offset(address)                                           \
 163         (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 164 #define pte_offset(dir, address)                                        \
 165         ((pte_t *) (pmd_page_kernel(*dir)) + __pte_offset(address))
 166 #define pte_offset_kernel(dir, address) \
 167         ((pte_t *) pmd_page_kernel(*(dir)) +  __pte_offset(address))
 168
 169 #define pte_offset_map(dir, address)                                    \
 170         ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
 171 #define pte_offset_map_nested(dir, address)                             \
 172         ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
 173 #define pte_unmap(pte) ((void)(pte))
 174 #define pte_unmap_nested(pte) ((void)(pte))
 175
 176 #if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
 177
 178 /* Swap entries must have VALID bit cleared. */
 179 #define __swp_type(x)           (((x).val >> 10) & 0x1f)
 180 #define __swp_offset(x)         ((x).val >> 15)
 181 #define __swp_entry(type,offset)        \
 182         ((swp_entry_t) { ((type) << 10) | ((offset) << 15) })
 183
 184 /*
 185  * Bits 0, 1, 2, 9 and 10 are taken, split up the 27 bits of offset
 186  * into this range:
 187  */
 188 #define PTE_FILE_MAX_BITS       27
 189
 190 #define pte_to_pgoff(_pte) \
 191         ((((_pte).pte >> 3) & 0x3f ) + (((_pte).pte >> 11) << 8 ))
 192
 193 #define pgoff_to_pte(off) \
 194         ((pte_t) { (((off) & 0x3f) << 3) + (((off) >> 8) << 11) + _PAGE_FILE })
 195
 196 #else
 197
 198 /* Swap entries must have VALID and GLOBAL bits cleared. */
 199 #define __swp_type(x)           (((x).val >> 8) & 0x1f)
 200 #define __swp_offset(x)         ((x).val >> 13)
 201 #define __swp_entry(type,offset)        \
 202                 ((swp_entry_t) { ((type) << 8) | ((offset) << 13) })
 203
 204 /*
 205  * Bits 0, 1, 2, 7 and 8 are taken, split up the 27 bits of offset
 206  * into this range:
 207  */
 208 #define PTE_FILE_MAX_BITS       27
 209
 210 #define pte_to_pgoff(_pte) \
 211         ((((_pte).pte >> 3) & 0x1f ) + (((_pte).pte >> 9) << 6 ))
 212
 213 #define pgoff_to_pte(off) \
 214         ((pte_t) { (((off) & 0x1f) << 3) + (((off) >> 6) << 9) + _PAGE_FILE })
 215
 216 #endif
 217
 218 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 219 #define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
 220
 221 #endif /* _ASM_PGTABLE_32_H */