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         if (likely(pte_get_bits(pte, _PAGE_RW)))
 201                 pte_clear_bits(pte, _PAGE_RW);
 202         else
 203                 return pte;
 204         return(pte_mknewprot(pte));
 205 }
 206
 207 static inline pte_t pte_mkread(pte_t pte)
 208 {
 209         if (unlikely(pte_get_bits(pte, _PAGE_USER)))
 210                 return pte;
 211         pte_set_bits(pte, _PAGE_USER);
 212         return(pte_mknewprot(pte));
 213 }
 214
 215 static inline pte_t pte_mkdirty(pte_t pte)
 216 {
 217         pte_set_bits(pte, _PAGE_DIRTY);
 218         return(pte);
 219 }
 220
 221 static inline pte_t pte_mkyoung(pte_t pte)
 222 {
 223         pte_set_bits(pte, _PAGE_ACCESSED);
 224         return(pte);
 225 }
 226
 227 static inline pte_t pte_mkwrite(pte_t pte)
 228 {
 229         if (unlikely(pte_get_bits(pte,  _PAGE_RW)))
 230                 return pte;
 231         pte_set_bits(pte, _PAGE_RW);
 232         return(pte_mknewprot(pte));
 233 }
 234
 235 static inline pte_t pte_mkuptodate(pte_t pte)
 236 {
 237         pte_clear_bits(pte, _PAGE_NEWPAGE);
 238         if(pte_present(pte))
 239                 pte_clear_bits(pte, _PAGE_NEWPROT);
 240         return(pte);
 241 }
 242
 243 static inline pte_t pte_mknewpage(pte_t pte)
 244 {
 245         pte_set_bits(pte, _PAGE_NEWPAGE);
 246         return(pte);
 247 }
 248
 249 static inline pte_t pte_mkspecial(pte_t pte)
 250 {
 251         return(pte);
 252 }
 253
 254 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 255 {
 256         pte_copy(*pteptr, pteval);
 257
 258         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 259          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 260          * mapped pages.
 261          */
 262
 263         *pteptr = pte_mknewpage(*pteptr);
 264         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 265 }
 266 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 267
 268 #define __HAVE_ARCH_PTE_SAME
 269 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 270 {
 271         return !((pte_val(pte_a) ^ pte_val(pte_b)) & ~_PAGE_NEWPAGE);
 272 }
 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(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 >> 5) & 0x1f)
 350 #define __swp_offset(x)                 ((x).val >> 11)
 351
 352 #define __swp_entry(type, offset) \
 353         ((swp_entry_t) { ((type) << 5) | ((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