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
  57 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  58 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  59 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  60
  61 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  62 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  63 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  64 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  65 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  66
  67 /*
  68  * The i386 can't do page protection for execute, and considers that the same
  69  * are read.
  70  * Also, write permissions imply read permissions. This is the closest we can
  71  * get..
  72  */
  73 #define __P000  PAGE_NONE
  74 #define __P001  PAGE_READONLY
  75 #define __P010  PAGE_COPY
  76 #define __P011  PAGE_COPY
  77 #define __P100  PAGE_READONLY
  78 #define __P101  PAGE_READONLY
  79 #define __P110  PAGE_COPY
  80 #define __P111  PAGE_COPY
  81
  82 #define __S000  PAGE_NONE
  83 #define __S001  PAGE_READONLY
  84 #define __S010  PAGE_SHARED
  85 #define __S011  PAGE_SHARED
  86 #define __S100  PAGE_READONLY
  87 #define __S101  PAGE_READONLY
  88 #define __S110  PAGE_SHARED
  89 #define __S111  PAGE_SHARED
  90
  91 /*
  92  * ZERO_PAGE is a global shared page that is always zero: used
  93  * for zero-mapped memory areas etc..
  94  */
  95 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
  96
  97 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
  98
  99 #define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
 100 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 101
 102 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 103 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 104
 105 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 106 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 107
 108 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 109 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 110
 111 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 112
 113 #define pte_page(x) pfn_to_page(pte_pfn(x))
 114
 115 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 116
 117 /*
 118  * =================================
 119  * Flags checking section.
 120  * =================================
 121  */
 122
 123 static inline int pte_none(pte_t pte)
 124 {
 125         return pte_is_zero(pte);
 126 }
 127
 128 /*
 129  * The following only work if pte_present() is true.
 130  * Undefined behaviour if not..
 131  */
 132 static inline int pte_read(pte_t pte)
 133 {
 134         return((pte_get_bits(pte, _PAGE_USER)) &&
 135                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 136 }
 137
 138 static inline int pte_exec(pte_t pte){
 139         return((pte_get_bits(pte, _PAGE_USER)) &&
 140                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 141 }
 142
 143 static inline int pte_write(pte_t pte)
 144 {
 145         return((pte_get_bits(pte, _PAGE_RW)) &&
 146                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 147 }
 148
 149 /*
 150  * The following only works if pte_present() is not true.
 151  */
 152 static inline int pte_file(pte_t pte)
 153 {
 154         return pte_get_bits(pte, _PAGE_FILE);
 155 }
 156
 157 static inline int pte_dirty(pte_t pte)
 158 {
 159         return pte_get_bits(pte, _PAGE_DIRTY);
 160 }
 161
 162 static inline int pte_young(pte_t pte)
 163 {
 164         return pte_get_bits(pte, _PAGE_ACCESSED);
 165 }
 166
 167 static inline int pte_newpage(pte_t pte)
 168 {
 169         return pte_get_bits(pte, _PAGE_NEWPAGE);
 170 }
 171
 172 static inline int pte_newprot(pte_t pte)
 173 {
 174         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 175 }
 176
 177 static inline int pte_special(pte_t pte)
 178 {
 179         return 0;
 180 }
 181
 182 /*
 183  * =================================
 184  * Flags setting section.
 185  * =================================
 186  */
 187
 188 static inline pte_t pte_mknewprot(pte_t pte)
 189 {
 190         pte_set_bits(pte, _PAGE_NEWPROT);
 191         return(pte);
 192 }
 193
 194 static inline pte_t pte_mkclean(pte_t pte)
 195 {
 196         pte_clear_bits(pte, _PAGE_DIRTY);
 197         return(pte);
 198 }
 199
 200 static inline pte_t pte_mkold(pte_t pte)
 201 {
 202         pte_clear_bits(pte, _PAGE_ACCESSED);
 203         return(pte);
 204 }
 205
 206 static inline pte_t pte_wrprotect(pte_t pte)
 207 {
 208         pte_clear_bits(pte, _PAGE_RW);
 209         return(pte_mknewprot(pte));
 210 }
 211
 212 static inline pte_t pte_mkread(pte_t pte)
 213 {
 214         pte_set_bits(pte, _PAGE_USER);
 215         return(pte_mknewprot(pte));
 216 }
 217
 218 static inline pte_t pte_mkdirty(pte_t pte)
 219 {
 220         pte_set_bits(pte, _PAGE_DIRTY);
 221         return(pte);
 222 }
 223
 224 static inline pte_t pte_mkyoung(pte_t pte)
 225 {
 226         pte_set_bits(pte, _PAGE_ACCESSED);
 227         return(pte);
 228 }
 229
 230 static inline pte_t pte_mkwrite(pte_t pte)
 231 {
 232         pte_set_bits(pte, _PAGE_RW);
 233         return(pte_mknewprot(pte));
 234 }
 235
 236 static inline pte_t pte_mkuptodate(pte_t pte)
 237 {
 238         pte_clear_bits(pte, _PAGE_NEWPAGE);
 239         if(pte_present(pte))
 240                 pte_clear_bits(pte, _PAGE_NEWPROT);
 241         return(pte);
 242 }
 243
 244 static inline pte_t pte_mknewpage(pte_t pte)
 245 {
 246         pte_set_bits(pte, _PAGE_NEWPAGE);
 247         return(pte);
 248 }
 249
 250 static inline pte_t pte_mkspecial(pte_t pte)
 251 {
 252         return(pte);
 253 }
 254
 255 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 256 {
 257         pte_copy(*pteptr, pteval);
 258
 259         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 260          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 261          * mapped pages.
 262          */
 263
 264         *pteptr = pte_mknewpage(*pteptr);
 265         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 266 }
 267 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 268
 269 /*
 270  * Conversion functions: convert a page and protection to a page entry,
 271  * and a page entry and page directory to the page they refer to.
 272  */
 273
 274 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 275 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 276 #define page_to_phys(page) pfn_to_phys((pfn_t) page_to_pfn(page))
 277 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 278
 279 #define mk_pte(page, pgprot) \
 280         ({ pte_t pte;                                   \
 281                                                         \
 282         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 283         if (pte_present(pte))                           \
 284                 pte_mknewprot(pte_mknewpage(pte));      \
 285         pte;})
 286
 287 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 288 {
 289         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 290         return pte;
 291 }
 292
 293 /*
 294  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 295  *
 296  * this macro returns the index of the entry in the pgd page which would
 297  * control the given virtual address
 298  */
 299 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 300
 301 /*
 302  * pgd_offset() returns a (pgd_t *)
 303  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 304  */
 305 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 306
 307 /*
 308  * a shortcut which implies the use of the kernel's pgd, instead
 309  * of a process's
 310  */
 311 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 312
 313 /*
 314  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 315  *
 316  * this macro returns the index of the entry in the pmd page which would
 317  * control the given virtual address
 318  */
 319 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 320 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 321
 322 #define pmd_page_vaddr(pmd) \
 323         ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 324
 325 /*
 326  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 327  *
 328  * this macro returns the index of the entry in the pte page which would
 329  * control the given virtual address
 330  */
 331 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 332 #define pte_offset_kernel(dir, address) \
 333         ((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
 334 #define pte_offset_map(dir, address) \
 335         ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 336 #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
 337 #define pte_unmap(pte) do { } while (0)
 338 #define pte_unmap_nested(pte) do { } while (0)
 339
 340 struct mm_struct;
 341 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 342
 343 #define update_mmu_cache(vma,address,pte) do ; while (0)
 344
 345 /* Encode and de-code a swap entry */
 346 #define __swp_type(x)                   (((x).val >> 4) & 0x3f)
 347 #define __swp_offset(x)                 ((x).val >> 11)
 348
 349 #define __swp_entry(type, offset) \
 350         ((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
 351 #define __pte_to_swp_entry(pte) \
 352         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 353 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 354
 355 #define kern_addr_valid(addr) (1)
 356
 357 #include <asm-generic/pgtable.h>
 358
 359 /* Clear a kernel PTE and flush it from the TLB */
 360 #define kpte_clear_flush(ptep, vaddr)           \
 361 do {                                            \
 362         pte_clear(&init_mm, (vaddr), (ptep));   \
 363         __flush_tlb_one((vaddr));               \
 364 } while (0)
 365
 366 #endif