arch/um/include/asm/pgtable.h

   1 /*
   2  * Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
   3  * Copyright 2003 PathScale, Inc.
   4  * Derived from include/asm-i386/pgtable.h
   5  * Licensed under the GPL
   6  */
   7
   8 #ifndef __UM_PGTABLE_H
   9 #define __UM_PGTABLE_H
  10
  11 #include <asm/fixmap.h>
  12
  13 #define _PAGE_PRESENT   0x001
  14 #define _PAGE_NEWPAGE   0x002
  15 #define _PAGE_NEWPROT   0x004
  16 #define _PAGE_RW        0x020
  17 #define _PAGE_USER      0x040
  18 #define _PAGE_ACCESSED  0x080
  19 #define _PAGE_DIRTY     0x100
  20 /* If _PAGE_PRESENT is clear, we use these: */
  21 #define _PAGE_FILE      0x008   /* nonlinear file mapping, saved PTE; unset:swap */
  22 #define _PAGE_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
  23                                    pte_present gives true */
  24
  25 #ifdef CONFIG_3_LEVEL_PGTABLES
  26 #include "asm/pgtable-3level.h"
  27 #else
  28 #include "asm/pgtable-2level.h"
  29 #endif
  30
  31 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  32
  33 /* zero page used for uninitialized stuff */
  34 extern unsigned long *empty_zero_page;
  35
  36 #define pgtable_cache_init() do ; while (0)
  37
  38 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  39  * current 8MB value just means that there will be a 8MB "hole" after the
  40  * physical memory until the kernel virtual memory starts.  That means that
  41  * any out-of-bounds memory accesses will hopefully be caught.
  42  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  43  * area for the same reason. ;)
  44  */
  45
  46 extern unsigned long end_iomem;
  47
  48 #define VMALLOC_OFFSET  (__va_space)
  49 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  50 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
  51 #ifdef CONFIG_HIGHMEM
  52 # define VMALLOC_END    (PKMAP_BASE-2*PAGE_SIZE)
  53 #else
  54 # define VMALLOC_END    (FIXADDR_START-2*PAGE_SIZE)
  55 #endif
  56 #define MODULES_VADDR   VMALLOC_START
  57 #define MODULES_END     VMALLOC_END
  58 #define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  59
  60 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  61 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  62 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  63 #define __PAGE_KERNEL_EXEC                                              \
  64          (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  65 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  66 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  67 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  68 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  69 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  70 #define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
  71
  72 /*
  73  * The i386 can't do page protection for execute, and considers that the same
  74  * are read.
  75  * Also, write permissions imply read permissions. This is the closest we can
  76  * get..
  77  */
  78 #define __P000  PAGE_NONE
  79 #define __P001  PAGE_READONLY
  80 #define __P010  PAGE_COPY
  81 #define __P011  PAGE_COPY
  82 #define __P100  PAGE_READONLY
  83 #define __P101  PAGE_READONLY
  84 #define __P110  PAGE_COPY
  85 #define __P111  PAGE_COPY
  86
  87 #define __S000  PAGE_NONE
  88 #define __S001  PAGE_READONLY
  89 #define __S010  PAGE_SHARED
  90 #define __S011  PAGE_SHARED
  91 #define __S100  PAGE_READONLY
  92 #define __S101  PAGE_READONLY
  93 #define __S110  PAGE_SHARED
  94 #define __S111  PAGE_SHARED
  95
  96 /*
  97  * ZERO_PAGE is a global shared page that is always zero: used
  98  * for zero-mapped memory areas etc..
  99  */
 100 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
 101
 102 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
 103
 104 #define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
 105 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 106
 107 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 108 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 109
 110 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 111 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 112
 113 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 114 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 115
 116 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 117
 118 #define pte_page(x) pfn_to_page(pte_pfn(x))
 119
 120 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 121
 122 /*
 123  * =================================
 124  * Flags checking section.
 125  * =================================
 126  */
 127
 128 static inline int pte_none(pte_t pte)
 129 {
 130         return pte_is_zero(pte);
 131 }
 132
 133 /*
 134  * The following only work if pte_present() is true.
 135  * Undefined behaviour if not..
 136  */
 137 static inline int pte_read(pte_t pte)
 138 {
 139         return((pte_get_bits(pte, _PAGE_USER)) &&
 140                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 141 }
 142
 143 static inline int pte_exec(pte_t pte){
 144         return((pte_get_bits(pte, _PAGE_USER)) &&
 145                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 146 }
 147
 148 static inline int pte_write(pte_t pte)
 149 {
 150         return((pte_get_bits(pte, _PAGE_RW)) &&
 151                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 152 }
 153
 154 /*
 155  * The following only works if pte_present() is not true.
 156  */
 157 static inline int pte_file(pte_t pte)
 158 {
 159         return pte_get_bits(pte, _PAGE_FILE);
 160 }
 161
 162 static inline int pte_dirty(pte_t pte)
 163 {
 164         return pte_get_bits(pte, _PAGE_DIRTY);
 165 }
 166
 167 static inline int pte_young(pte_t pte)
 168 {
 169         return pte_get_bits(pte, _PAGE_ACCESSED);
 170 }
 171
 172 static inline int pte_newpage(pte_t pte)
 173 {
 174         return pte_get_bits(pte, _PAGE_NEWPAGE);
 175 }
 176
 177 static inline int pte_newprot(pte_t pte)
 178 {
 179         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 180 }
 181
 182 static inline int pte_special(pte_t pte)
 183 {
 184         return 0;
 185 }
 186
 187 /*
 188  * =================================
 189  * Flags setting section.
 190  * =================================
 191  */
 192
 193 static inline pte_t pte_mknewprot(pte_t pte)
 194 {
 195         pte_set_bits(pte, _PAGE_NEWPROT);
 196         return(pte);
 197 }
 198
 199 static inline pte_t pte_mkclean(pte_t pte)
 200 {
 201         pte_clear_bits(pte, _PAGE_DIRTY);
 202         return(pte);
 203 }
 204
 205 static inline pte_t pte_mkold(pte_t pte)
 206 {
 207         pte_clear_bits(pte, _PAGE_ACCESSED);
 208         return(pte);
 209 }
 210
 211 static inline pte_t pte_wrprotect(pte_t pte)
 212 {
 213         pte_clear_bits(pte, _PAGE_RW);
 214         return(pte_mknewprot(pte));
 215 }
 216
 217 static inline pte_t pte_mkread(pte_t pte)
 218 {
 219         pte_set_bits(pte, _PAGE_USER);
 220         return(pte_mknewprot(pte));
 221 }
 222
 223 static inline pte_t pte_mkdirty(pte_t pte)
 224 {
 225         pte_set_bits(pte, _PAGE_DIRTY);
 226         return(pte);
 227 }
 228
 229 static inline pte_t pte_mkyoung(pte_t pte)
 230 {
 231         pte_set_bits(pte, _PAGE_ACCESSED);
 232         return(pte);
 233 }
 234
 235 static inline pte_t pte_mkwrite(pte_t pte)
 236 {
 237         pte_set_bits(pte, _PAGE_RW);
 238         return(pte_mknewprot(pte));
 239 }
 240
 241 static inline pte_t pte_mkuptodate(pte_t pte)
 242 {
 243         pte_clear_bits(pte, _PAGE_NEWPAGE);
 244         if(pte_present(pte))
 245                 pte_clear_bits(pte, _PAGE_NEWPROT);
 246         return(pte);
 247 }
 248
 249 static inline pte_t pte_mknewpage(pte_t pte)
 250 {
 251         pte_set_bits(pte, _PAGE_NEWPAGE);
 252         return(pte);
 253 }
 254
 255 static inline pte_t pte_mkspecial(pte_t pte)
 256 {
 257         return(pte);
 258 }
 259
 260 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 261 {
 262         pte_copy(*pteptr, pteval);
 263
 264         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 265          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 266          * mapped pages.
 267          */
 268
 269         *pteptr = pte_mknewpage(*pteptr);
 270         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 271 }
 272 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 273
 274 /*
 275  * Conversion functions: convert a page and protection to a page entry,
 276  * and a page entry and page directory to the page they refer to.
 277  */
 278
 279 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 280 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 281 #define page_to_phys(page) pfn_to_phys((pfn_t) page_to_pfn(page))
 282 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 283
 284 #define mk_pte(page, pgprot) \
 285         ({ pte_t pte;                                   \
 286                                                         \
 287         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 288         if (pte_present(pte))                           \
 289                 pte_mknewprot(pte_mknewpage(pte));      \
 290         pte;})
 291
 292 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 293 {
 294         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 295         return pte;
 296 }
 297
 298 /*
 299  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 300  *
 301  * this macro returns the index of the entry in the pgd page which would
 302  * control the given virtual address
 303  */
 304 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 305
 306 /*
 307  * pgd_offset() returns a (pgd_t *)
 308  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 309  */
 310 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 311
 312 /*
 313  * a shortcut which implies the use of the kernel's pgd, instead
 314  * of a process's
 315  */
 316 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 317
 318 /*
 319  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 320  *
 321  * this macro returns the index of the entry in the pmd page which would
 322  * control the given virtual address
 323  */
 324 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 325 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 326
 327 #define pmd_page_vaddr(pmd) \
 328         ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 329
 330 /*
 331  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 332  *
 333  * this macro returns the index of the entry in the pte page which would
 334  * control the given virtual address
 335  */
 336 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 337 #define pte_offset_kernel(dir, address) \
 338         ((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
 339 #define pte_offset_map(dir, address) \
 340         ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 341 #define pte_unmap(pte) do { } while (0)
 342
 343 struct mm_struct;
 344 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 345
 346 #define update_mmu_cache(vma,address,ptep) do ; while (0)
 347
 348 /* Encode and de-code a swap entry */
 349 #define __swp_type(x)                   (((x).val >> 4) & 0x3f)
 350 #define __swp_offset(x)                 ((x).val >> 11)
 351
 352 #define __swp_entry(type, offset) \
 353         ((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
 354 #define __pte_to_swp_entry(pte) \
 355         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 356 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 357
 358 #define kern_addr_valid(addr) (1)
 359
 360 #include <asm-generic/pgtable.h>
 361
 362 /* Clear a kernel PTE and flush it from the TLB */
 363 #define kpte_clear_flush(ptep, vaddr)           \
 364 do {                                            \
 365         pte_clear(&init_mm, (vaddr), (ptep));   \
 366         __flush_tlb_one((vaddr));               \
 367 } while (0)
 368
 369 #endif