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_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
  22                                    pte_present gives true */
  23
  24 #ifdef CONFIG_3_LEVEL_PGTABLES
  25 #include <asm/pgtable-3level.h>
  26 #else
  27 #include <asm/pgtable-2level.h>
  28 #endif
  29
  30 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  31
  32 /* zero page used for uninitialized stuff */
  33 extern unsigned long *empty_zero_page;
  34
  35 #define pgtable_cache_init() do ; while (0)
  36
  37 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  38  * current 8MB value just means that there will be a 8MB "hole" after the
  39  * physical memory until the kernel virtual memory starts.  That means that
  40  * any out-of-bounds memory accesses will hopefully be caught.
  41  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  42  * area for the same reason. ;)
  43  */
  44
  45 extern unsigned long end_iomem;
  46
  47 #define VMALLOC_OFFSET  (__va_space)
  48 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  49 #define PKMAP_BASE ((FIXADDR_START - LAST_PKMAP * PAGE_SIZE) & PMD_MASK)
  50 #define VMALLOC_END     (FIXADDR_START-2*PAGE_SIZE)
  51 #define MODULES_VADDR   VMALLOC_START
  52 #define MODULES_END     VMALLOC_END
  53 #define MODULES_LEN     (MODULES_VADDR - MODULES_END)
  54
  55 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  56 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  57 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  58 #define __PAGE_KERNEL_EXEC                                              \
  59          (_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  60 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  61 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  62 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  63 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  64 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  65 #define PAGE_KERNEL_EXEC        __pgprot(__PAGE_KERNEL_EXEC)
  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 static inline int pte_dirty(pte_t pte)
 150 {
 151         return pte_get_bits(pte, _PAGE_DIRTY);
 152 }
 153
 154 static inline int pte_young(pte_t pte)
 155 {
 156         return pte_get_bits(pte, _PAGE_ACCESSED);
 157 }
 158
 159 static inline int pte_newpage(pte_t pte)
 160 {
 161         return pte_get_bits(pte, _PAGE_NEWPAGE);
 162 }
 163
 164 static inline int pte_newprot(pte_t pte)
 165 {
 166         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 167 }
 168
 169 static inline int pte_special(pte_t pte)
 170 {
 171         return 0;
 172 }
 173
 174 /*
 175  * =================================
 176  * Flags setting section.
 177  * =================================
 178  */
 179
 180 static inline pte_t pte_mknewprot(pte_t pte)
 181 {
 182         pte_set_bits(pte, _PAGE_NEWPROT);
 183         return(pte);
 184 }
 185
 186 static inline pte_t pte_mkclean(pte_t pte)
 187 {
 188         pte_clear_bits(pte, _PAGE_DIRTY);
 189         return(pte);
 190 }
 191
 192 static inline pte_t pte_mkold(pte_t pte)
 193 {
 194         pte_clear_bits(pte, _PAGE_ACCESSED);
 195         return(pte);
 196 }
 197
 198 static inline pte_t pte_wrprotect(pte_t pte)
 199 {
 200         pte_clear_bits(pte, _PAGE_RW);
 201         return(pte_mknewprot(pte));
 202 }
 203
 204 static inline pte_t pte_mkread(pte_t pte)
 205 {
 206         pte_set_bits(pte, _PAGE_USER);
 207         return(pte_mknewprot(pte));
 208 }
 209
 210 static inline pte_t pte_mkdirty(pte_t pte)
 211 {
 212         pte_set_bits(pte, _PAGE_DIRTY);
 213         return(pte);
 214 }
 215
 216 static inline pte_t pte_mkyoung(pte_t pte)
 217 {
 218         pte_set_bits(pte, _PAGE_ACCESSED);
 219         return(pte);
 220 }
 221
 222 static inline pte_t pte_mkwrite(pte_t pte)
 223 {
 224         pte_set_bits(pte, _PAGE_RW);
 225         return(pte_mknewprot(pte));
 226 }
 227
 228 static inline pte_t pte_mkuptodate(pte_t pte)
 229 {
 230         pte_clear_bits(pte, _PAGE_NEWPAGE);
 231         if(pte_present(pte))
 232                 pte_clear_bits(pte, _PAGE_NEWPROT);
 233         return(pte);
 234 }
 235
 236 static inline pte_t pte_mknewpage(pte_t pte)
 237 {
 238         pte_set_bits(pte, _PAGE_NEWPAGE);
 239         return(pte);
 240 }
 241
 242 static inline pte_t pte_mkspecial(pte_t pte)
 243 {
 244         return(pte);
 245 }
 246
 247 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 248 {
 249         pte_copy(*pteptr, pteval);
 250
 251         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 252          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 253          * mapped pages.
 254          */
 255
 256         *pteptr = pte_mknewpage(*pteptr);
 257         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 258 }
 259 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 260
 261 #define __HAVE_ARCH_PTE_SAME
 262 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 263 {
 264         return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
 265 }
 266
 267 /*
 268  * Conversion functions: convert a page and protection to a page entry,
 269  * and a page entry and page directory to the page they refer to.
 270  */
 271
 272 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 273 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 274 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
 275 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 276
 277 #define mk_pte(page, pgprot) \
 278         ({ pte_t pte;                                   \
 279                                                         \
 280         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 281         if (pte_present(pte))                           \
 282                 pte_mknewprot(pte_mknewpage(pte));      \
 283         pte;})
 284
 285 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 286 {
 287         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 288         return pte;
 289 }
 290
 291 /*
 292  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 293  *
 294  * this macro returns the index of the entry in the pgd page which would
 295  * control the given virtual address
 296  */
 297 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 298
 299 /*
 300  * pgd_offset() returns a (pgd_t *)
 301  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 302  */
 303 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 304
 305 /*
 306  * a shortcut which implies the use of the kernel's pgd, instead
 307  * of a process's
 308  */
 309 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 310
 311 /*
 312  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 313  *
 314  * this macro returns the index of the entry in the pmd page which would
 315  * control the given virtual address
 316  */
 317 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 318 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 319
 320 #define pmd_page_vaddr(pmd) \
 321         ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 322
 323 /*
 324  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 325  *
 326  * this macro returns the index of the entry in the pte page which would
 327  * control the given virtual address
 328  */
 329 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 330 #define pte_offset_kernel(dir, address) \
 331         ((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
 332 #define pte_offset_map(dir, address) \
 333         ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 334 #define pte_unmap(pte) do { } while (0)
 335
 336 struct mm_struct;
 337 extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
 338
 339 #define update_mmu_cache(vma,address,ptep) do ; while (0)
 340
 341 /* Encode and de-code a swap entry */
 342 #define __swp_type(x)                   (((x).val >> 5) & 0x1f)
 343 #define __swp_offset(x)                 ((x).val >> 11)
 344
 345 #define __swp_entry(type, offset) \
 346         ((swp_entry_t) { ((type) << 5) | ((offset) << 11) })
 347 #define __pte_to_swp_entry(pte) \
 348         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 349 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 350
 351 #define kern_addr_valid(addr) (1)
 352
 353 #include <asm-generic/pgtable.h>
 354
 355 /* Clear a kernel PTE and flush it from the TLB */
 356 #define kpte_clear_flush(ptep, vaddr)           \
 357 do {                                            \
 358         pte_clear(&init_mm, (vaddr), (ptep));   \
 359         __flush_tlb_one((vaddr));               \
 360 } while (0)
 361
 362 #endif