arch/mips/include/asm/pgtable-64.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_64_H
  10 #define _ASM_PGTABLE_64_H
  11
  12 #include <linux/compiler.h>
  13 #include <linux/linkage.h>
  14
  15 #include <asm/addrspace.h>
  16 #include <asm/page.h>
  17 #include <asm/cachectl.h>
  18 #include <asm/fixmap.h>
  19
  20 #define __ARCH_USE_5LEVEL_HACK
  21 #if defined(CONFIG_PAGE_SIZE_64KB) && !defined(CONFIG_MIPS_VA_BITS_48)
  22 #include <asm-generic/pgtable-nopmd.h>
  23 #else
  24 #include <asm-generic/pgtable-nopud.h>
  25 #endif
  26
  27 /*
  28  * Each address space has 2 4K pages as its page directory, giving 1024
  29  * (== PTRS_PER_PGD) 8 byte pointers to pmd tables. Each pmd table is a
  30  * single 4K page, giving 512 (== PTRS_PER_PMD) 8 byte pointers to page
  31  * tables. Each page table is also a single 4K page, giving 512 (==
  32  * PTRS_PER_PTE) 8 byte ptes. Each pud entry is initialized to point to
  33  * invalid_pmd_table, each pmd entry is initialized to point to
  34  * invalid_pte_table, each pte is initialized to 0. When memory is low,
  35  * and a pmd table or a page table allocation fails, empty_bad_pmd_table
  36  * and empty_bad_page_table is returned back to higher layer code, so
  37  * that the failure is recognized later on. Linux does not seem to
  38  * handle these failures very well though. The empty_bad_page_table has
  39  * invalid pte entries in it, to force page faults.
  40  *
  41  * Kernel mappings: kernel mappings are held in the swapper_pg_table.
  42  * The layout is identical to userspace except it's indexed with the
  43  * fault address - VMALLOC_START.
  44  */
  45
  46
  47 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  48 #ifdef __PAGETABLE_PMD_FOLDED
  49 #define PGDIR_SHIFT     (PAGE_SHIFT + PAGE_SHIFT + PTE_ORDER - 3)
  50 #else
  51
  52 /* PMD_SHIFT determines the size of the area a second-level page table can map */
  53 #define PMD_SHIFT       (PAGE_SHIFT + (PAGE_SHIFT + PTE_ORDER - 3))
  54 #define PMD_SIZE        (1UL << PMD_SHIFT)
  55 #define PMD_MASK        (~(PMD_SIZE-1))
  56
  57
  58 #define PGDIR_SHIFT     (PMD_SHIFT + (PAGE_SHIFT + PMD_ORDER - 3))
  59 #endif
  60 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  61 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  62
  63 /*
  64  * For 4kB page size we use a 3 level page tree and an 8kB pud, which
  65  * permits us mapping 40 bits of virtual address space.
  66  *
  67  * We used to implement 41 bits by having an order 1 pmd level but that seemed
  68  * rather pointless.
  69  *
  70  * For 8kB page size we use a 3 level page tree which permits a total of
  71  * 8TB of address space.  Alternatively a 33-bit / 8GB organization using
  72  * two levels would be easy to implement.
  73  *
  74  * For 16kB page size we use a 2 level page tree which permits a total of
  75  * 36 bits of virtual address space.  We could add a third level but it seems
  76  * like at the moment there's no need for this.
  77  *
  78  * For 64kB page size we use a 2 level page table tree for a total of 42 bits
  79  * of virtual address space.
  80  */
  81 #ifdef CONFIG_PAGE_SIZE_4KB
  82 #define PGD_ORDER               1
  83 #define PUD_ORDER               aieeee_attempt_to_allocate_pud
  84 #define PMD_ORDER               0
  85 #define PTE_ORDER               0
  86 #endif
  87 #ifdef CONFIG_PAGE_SIZE_8KB
  88 #define PGD_ORDER               0
  89 #define PUD_ORDER               aieeee_attempt_to_allocate_pud
  90 #define PMD_ORDER               0
  91 #define PTE_ORDER               0
  92 #endif
  93 #ifdef CONFIG_PAGE_SIZE_16KB
  94 #ifdef CONFIG_MIPS_VA_BITS_48
  95 #define PGD_ORDER               1
  96 #else
  97 #define PGD_ORDER               0
  98 #endif
  99 #define PUD_ORDER               aieeee_attempt_to_allocate_pud
 100 #define PMD_ORDER               0
 101 #define PTE_ORDER               0
 102 #endif
 103 #ifdef CONFIG_PAGE_SIZE_32KB
 104 #define PGD_ORDER               0
 105 #define PUD_ORDER               aieeee_attempt_to_allocate_pud
 106 #define PMD_ORDER               0
 107 #define PTE_ORDER               0
 108 #endif
 109 #ifdef CONFIG_PAGE_SIZE_64KB
 110 #define PGD_ORDER               0
 111 #define PUD_ORDER               aieeee_attempt_to_allocate_pud
 112 #ifdef CONFIG_MIPS_VA_BITS_48
 113 #define PMD_ORDER               0
 114 #else
 115 #define PMD_ORDER               aieeee_attempt_to_allocate_pmd
 116 #endif
 117 #define PTE_ORDER               0
 118 #endif
 119
 120 #define PTRS_PER_PGD    ((PAGE_SIZE << PGD_ORDER) / sizeof(pgd_t))
 121 #ifndef __PAGETABLE_PMD_FOLDED
 122 #define PTRS_PER_PMD    ((PAGE_SIZE << PMD_ORDER) / sizeof(pmd_t))
 123 #endif
 124 #define PTRS_PER_PTE    ((PAGE_SIZE << PTE_ORDER) / sizeof(pte_t))
 125
 126 #define USER_PTRS_PER_PGD       ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1)
 127 #define FIRST_USER_ADDRESS      0UL
 128
 129 /*
 130  * TLB refill handlers also map the vmalloc area into xuseg.  Avoid
 131  * the first couple of pages so NULL pointer dereferences will still
 132  * reliably trap.
 133  */
 134 #define VMALLOC_START           (MAP_BASE + (2 * PAGE_SIZE))
 135 #define VMALLOC_END     \
 136         (MAP_BASE + \
 137          min(PTRS_PER_PGD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, \
 138              (1UL << cpu_vmbits)) - (1UL << 32))
 139
 140 #if defined(CONFIG_MODULES) && defined(KBUILD_64BIT_SYM32) && \
 141         VMALLOC_START != CKSSEG
 142 /* Load modules into 32bit-compatible segment. */
 143 #define MODULE_START    CKSSEG
 144 #define MODULE_END      (FIXADDR_START-2*PAGE_SIZE)
 145 #endif
 146
 147 #define pte_ERROR(e) \
 148         printk("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
 149 #ifndef __PAGETABLE_PMD_FOLDED
 150 #define pmd_ERROR(e) \
 151         printk("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
 152 #endif
 153 #define pgd_ERROR(e) \
 154         printk("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
 155
 156 extern pte_t invalid_pte_table[PTRS_PER_PTE];
 157 extern pte_t empty_bad_page_table[PTRS_PER_PTE];
 158
 159
 160 #ifndef __PAGETABLE_PMD_FOLDED
 161 /*
 162  * For 3-level pagetables we defines these ourselves, for 2-level the
 163  * definitions are supplied by <asm-generic/pgtable-nopmd.h>.
 164  */
 165 typedef struct { unsigned long pmd; } pmd_t;
 166 #define pmd_val(x)      ((x).pmd)
 167 #define __pmd(x)        ((pmd_t) { (x) } )
 168
 169
 170 extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
 171 #endif
 172
 173 /*
 174  * Empty pgd/pmd entries point to the invalid_pte_table.
 175  */
 176 static inline int pmd_none(pmd_t pmd)
 177 {
 178         return pmd_val(pmd) == (unsigned long) invalid_pte_table;
 179 }
 180
 181 static inline int pmd_bad(pmd_t pmd)
 182 {
 183 #ifdef CONFIG_MIPS_HUGE_TLB_SUPPORT
 184         /* pmd_huge(pmd) but inline */
 185         if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
 186                 return 0;
 187 #endif
 188
 189         if (unlikely(pmd_val(pmd) & ~PAGE_MASK))
 190                 return 1;
 191
 192         return 0;
 193 }
 194
 195 static inline int pmd_present(pmd_t pmd)
 196 {
 197         return pmd_val(pmd) != (unsigned long) invalid_pte_table;
 198 }
 199
 200 static inline void pmd_clear(pmd_t *pmdp)
 201 {
 202         pmd_val(*pmdp) = ((unsigned long) invalid_pte_table);
 203 }
 204 #ifndef __PAGETABLE_PMD_FOLDED
 205
 206 /*
 207  * Empty pud entries point to the invalid_pmd_table.
 208  */
 209 static inline int pud_none(pud_t pud)
 210 {
 211         return pud_val(pud) == (unsigned long) invalid_pmd_table;
 212 }
 213
 214 static inline int pud_bad(pud_t pud)
 215 {
 216         return pud_val(pud) & ~PAGE_MASK;
 217 }
 218
 219 static inline int pud_present(pud_t pud)
 220 {
 221         return pud_val(pud) != (unsigned long) invalid_pmd_table;
 222 }
 223
 224 static inline void pud_clear(pud_t *pudp)
 225 {
 226         pud_val(*pudp) = ((unsigned long) invalid_pmd_table);
 227 }
 228 #endif
 229
 230 #define pte_page(x)             pfn_to_page(pte_pfn(x))
 231
 232 #ifdef CONFIG_CPU_VR41XX
 233 #define pte_pfn(x)              ((unsigned long)((x).pte >> (PAGE_SHIFT + 2)))
 234 #define pfn_pte(pfn, prot)      __pte(((pfn) << (PAGE_SHIFT + 2)) | pgprot_val(prot))
 235 #else
 236 #define pte_pfn(x)              ((unsigned long)((x).pte >> _PFN_SHIFT))
 237 #define pfn_pte(pfn, prot)      __pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
 238 #define pfn_pmd(pfn, prot)      __pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
 239 #endif
 240
 241 #define __pgd_offset(address)   pgd_index(address)
 242 #define __pud_offset(address)   (((address) >> PUD_SHIFT) & (PTRS_PER_PUD-1))
 243 #define __pmd_offset(address)   pmd_index(address)
 244
 245 /* to find an entry in a kernel page-table-directory */
 246 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 247
 248 #define pgd_index(address)      (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 249 #define pmd_index(address)      (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 250
 251 /* to find an entry in a page-table-directory */
 252 #define pgd_offset(mm, addr)    ((mm)->pgd + pgd_index(addr))
 253
 254 #ifndef __PAGETABLE_PMD_FOLDED
 255 static inline unsigned long pud_page_vaddr(pud_t pud)
 256 {
 257         return pud_val(pud);
 258 }
 259 #define pud_phys(pud)           virt_to_phys((void *)pud_val(pud))
 260 #define pud_page(pud)           (pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
 261
 262 /* Find an entry in the second-level page table.. */
 263 static inline pmd_t *pmd_offset(pud_t * pud, unsigned long address)
 264 {
 265         return (pmd_t *) pud_page_vaddr(*pud) + pmd_index(address);
 266 }
 267 #endif
 268
 269 /* Find an entry in the third-level page table.. */
 270 #define __pte_offset(address)                                           \
 271         (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 272 #define pte_offset(dir, address)                                        \
 273         ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
 274 #define pte_offset_kernel(dir, address)                                 \
 275         ((pte_t *) pmd_page_vaddr(*(dir)) + __pte_offset(address))
 276 #define pte_offset_map(dir, address)                                    \
 277         ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address))
 278 #define pte_unmap(pte) ((void)(pte))
 279
 280 /*
 281  * Initialize a new pgd / pmd table with invalid pointers.
 282  */
 283 extern void pgd_init(unsigned long page);
 284 extern void pmd_init(unsigned long page, unsigned long pagetable);
 285
 286 /*
 287  * Non-present pages:  high 40 bits are offset, next 8 bits type,
 288  * low 16 bits zero.
 289  */
 290 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 291 { pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; }
 292
 293 #define __swp_type(x)           (((x).val >> 16) & 0xff)
 294 #define __swp_offset(x)         ((x).val >> 24)
 295 #define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
 296 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 297 #define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
 298
 299 #endif /* _ASM_PGTABLE_64_H */