include/asm-um/pgtable.h

   1 /*
   2  * Copyright (C) 2000, 2001, 2002 Jeff Dike (jdike@karaya.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 "linux/sched.h"
  12 #include "linux/linkage.h"
  13 #include "asm/processor.h"
  14 #include "asm/page.h"
  15 #include "asm/fixmap.h"
  16
  17 #define _PAGE_PRESENT   0x001
  18 #define _PAGE_NEWPAGE   0x002
  19 #define _PAGE_NEWPROT   0x004
  20 #define _PAGE_RW        0x020
  21 #define _PAGE_USER      0x040
  22 #define _PAGE_ACCESSED  0x080
  23 #define _PAGE_DIRTY     0x100
  24 /* If _PAGE_PRESENT is clear, we use these: */
  25 #define _PAGE_FILE      0x008   /* nonlinear file mapping, saved PTE; unset:swap */
  26 #define _PAGE_PROTNONE  0x010   /* if the user mapped it with PROT_NONE;
  27                                    pte_present gives true */
  28
  29 #ifdef CONFIG_3_LEVEL_PGTABLES
  30 #include "asm/pgtable-3level.h"
  31 #else
  32 #include "asm/pgtable-2level.h"
  33 #endif
  34
  35 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  36
  37 extern void *um_virt_to_phys(struct task_struct *task, unsigned long virt,
  38                              pte_t *pte_out);
  39
  40 /* zero page used for uninitialized stuff */
  41 extern unsigned long *empty_zero_page;
  42
  43 #define pgtable_cache_init() do ; while (0)
  44
  45 /*
  46  * pgd entries used up by user/kernel:
  47  */
  48
  49 #define USER_PGD_PTRS (TASK_SIZE >> PGDIR_SHIFT)
  50 #define KERNEL_PGD_PTRS (PTRS_PER_PGD-USER_PGD_PTRS)
  51
  52 #ifndef __ASSEMBLY__
  53 /* Just any arbitrary offset to the start of the vmalloc VM area: the
  54  * current 8MB value just means that there will be a 8MB "hole" after the
  55  * physical memory until the kernel virtual memory starts.  That means that
  56  * any out-of-bounds memory accesses will hopefully be caught.
  57  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
  58  * area for the same reason. ;)
  59  */
  60
  61 extern unsigned long end_iomem;
  62
  63 #define VMALLOC_OFFSET  (__va_space)
  64 #define VMALLOC_START ((end_iomem + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
  65
  66 #ifdef CONFIG_HIGHMEM
  67 # define VMALLOC_END    (PKMAP_BASE-2*PAGE_SIZE)
  68 #else
  69 # define VMALLOC_END    (FIXADDR_START-2*PAGE_SIZE)
  70 #endif
  71
  72 #define REGION_SHIFT    (sizeof(pte_t) * 8 - 4)
  73 #define REGION_MASK     (((unsigned long) 0xf) << REGION_SHIFT)
  74
  75 #define _PAGE_TABLE     (_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED | _PAGE_DIRTY)
  76 #define _KERNPG_TABLE   (_PAGE_PRESENT | _PAGE_RW | _PAGE_ACCESSED | _PAGE_DIRTY)
  77 #define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
  78
  79 #define PAGE_NONE       __pgprot(_PAGE_PROTNONE | _PAGE_ACCESSED)
  80 #define PAGE_SHARED     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER | _PAGE_ACCESSED)
  81 #define PAGE_COPY       __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  82 #define PAGE_READONLY   __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_ACCESSED)
  83 #define PAGE_KERNEL     __pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_DIRTY | _PAGE_ACCESSED)
  84 #define PAGE_KERNEL_RO  __pgprot(_PAGE_PRESENT | _PAGE_DIRTY | _PAGE_ACCESSED)
  85
  86 /*
  87  * The i386 can't do page protection for execute, and considers that the same are read.
  88  * Also, write permissions imply read permissions. This is the closest we can get..
  89  */
  90 #define __P000  PAGE_NONE
  91 #define __P001  PAGE_READONLY
  92 #define __P010  PAGE_COPY
  93 #define __P011  PAGE_COPY
  94 #define __P100  PAGE_READONLY
  95 #define __P101  PAGE_READONLY
  96 #define __P110  PAGE_COPY
  97 #define __P111  PAGE_COPY
  98
  99 #define __S000  PAGE_NONE
 100 #define __S001  PAGE_READONLY
 101 #define __S010  PAGE_SHARED
 102 #define __S011  PAGE_SHARED
 103 #define __S100  PAGE_READONLY
 104 #define __S101  PAGE_READONLY
 105 #define __S110  PAGE_SHARED
 106 #define __S111  PAGE_SHARED
 107
 108 /*
 109  * Define this if things work differently on an i386 and an i486:
 110  * it will (on an i486) warn about kernel memory accesses that are
 111  * done without a 'access_ok(VERIFY_WRITE,..)'
 112  */
 113 #undef TEST_VERIFY_AREA
 114
 115 /* page table for 0-4MB for everybody */
 116 extern unsigned long pg0[1024];
 117
 118 /*
 119  * ZERO_PAGE is a global shared page that is always zero: used
 120  * for zero-mapped memory areas etc..
 121  */
 122
 123 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
 124
 125 /* number of bits that fit into a memory pointer */
 126 #define BITS_PER_PTR                    (8*sizeof(unsigned long))
 127
 128 /* to align the pointer to a pointer address */
 129 #define PTR_MASK                        (~(sizeof(void*)-1))
 130
 131 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 132 /* 64-bit machines, beware!  SRB. */
 133 #define SIZEOF_PTR_LOG2                 3
 134
 135 /* to find an entry in a page-table */
 136 #define PAGE_PTR(address) \
 137 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
 138
 139 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
 140
 141 #define pmd_none(x)     (!((unsigned long)pmd_val(x) & ~_PAGE_NEWPAGE))
 142 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 143 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 144 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 145
 146 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 147 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 148
 149 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 150 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 151
 152 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
 153
 154 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 155
 156 #define pte_page(x) pfn_to_page(pte_pfn(x))
 157 #define pte_address(x) (__va(pte_val(x) & PAGE_MASK))
 158 #define mk_phys(a, r) ((a) + (((unsigned long) r) << REGION_SHIFT))
 159 #define phys_addr(p) ((p) & ~REGION_MASK)
 160
 161 #define pte_present(x)  pte_get_bits(x, (_PAGE_PRESENT | _PAGE_PROTNONE))
 162
 163 /*
 164  * =================================
 165  * Flags checking section.
 166  * =================================
 167  */
 168
 169 static inline int pte_none(pte_t pte)
 170 {
 171         return pte_is_zero(pte);
 172 }
 173
 174 /*
 175  * The following only work if pte_present() is true.
 176  * Undefined behaviour if not..
 177  */
 178 static inline int pte_read(pte_t pte)
 179 {
 180         return((pte_get_bits(pte, _PAGE_USER)) &&
 181                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 182 }
 183
 184 static inline int pte_exec(pte_t pte){
 185         return((pte_get_bits(pte, _PAGE_USER)) &&
 186                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 187 }
 188
 189 static inline int pte_write(pte_t pte)
 190 {
 191         return((pte_get_bits(pte, _PAGE_RW)) &&
 192                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 193 }
 194
 195 /*
 196  * The following only works if pte_present() is not true.
 197  */
 198 static inline int pte_file(pte_t pte)
 199 {
 200         return pte_get_bits(pte, _PAGE_FILE);
 201 }
 202
 203 static inline int pte_dirty(pte_t pte)
 204 {
 205         return pte_get_bits(pte, _PAGE_DIRTY);
 206 }
 207
 208 static inline int pte_young(pte_t pte)
 209 {
 210         return pte_get_bits(pte, _PAGE_ACCESSED);
 211 }
 212
 213 static inline int pte_newpage(pte_t pte)
 214 {
 215         return pte_get_bits(pte, _PAGE_NEWPAGE);
 216 }
 217
 218 static inline int pte_newprot(pte_t pte)
 219 {
 220         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 221 }
 222
 223 /*
 224  * =================================
 225  * Flags setting section.
 226  * =================================
 227  */
 228
 229 static inline pte_t pte_mknewprot(pte_t pte)
 230 {
 231         pte_set_bits(pte, _PAGE_NEWPROT);
 232         return(pte);
 233 }
 234
 235 static inline pte_t pte_mkclean(pte_t pte)
 236 {
 237         pte_clear_bits(pte, _PAGE_DIRTY);
 238         return(pte);
 239 }
 240
 241 static inline pte_t pte_mkold(pte_t pte)
 242 {
 243         pte_clear_bits(pte, _PAGE_ACCESSED);
 244         return(pte);
 245 }
 246
 247 static inline pte_t pte_wrprotect(pte_t pte)
 248 {
 249         pte_clear_bits(pte, _PAGE_RW);
 250         return(pte_mknewprot(pte));
 251 }
 252
 253 static inline pte_t pte_mkread(pte_t pte)
 254 {
 255         pte_set_bits(pte, _PAGE_USER);
 256         return(pte_mknewprot(pte));
 257 }
 258
 259 static inline pte_t pte_mkdirty(pte_t pte)
 260 {
 261         pte_set_bits(pte, _PAGE_DIRTY);
 262         return(pte);
 263 }
 264
 265 static inline pte_t pte_mkyoung(pte_t pte)
 266 {
 267         pte_set_bits(pte, _PAGE_ACCESSED);
 268         return(pte);
 269 }
 270
 271 static inline pte_t pte_mkwrite(pte_t pte)
 272 {
 273         pte_set_bits(pte, _PAGE_RW);
 274         return(pte_mknewprot(pte));
 275 }
 276
 277 static inline pte_t pte_mkuptodate(pte_t pte)
 278 {
 279         pte_clear_bits(pte, _PAGE_NEWPAGE);
 280         if(pte_present(pte))
 281                 pte_clear_bits(pte, _PAGE_NEWPROT);
 282         return(pte);
 283 }
 284
 285 static inline pte_t pte_mknewpage(pte_t pte)
 286 {
 287         pte_set_bits(pte, _PAGE_NEWPAGE);
 288         return(pte);
 289 }
 290
 291 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 292 {
 293         pte_copy(*pteptr, pteval);
 294
 295         /* If it's a swap entry, it needs to be marked _PAGE_NEWPAGE so
 296          * fix_range knows to unmap it.  _PAGE_NEWPROT is specific to
 297          * mapped pages.
 298          */
 299
 300         *pteptr = pte_mknewpage(*pteptr);
 301         if(pte_present(*pteptr)) *pteptr = pte_mknewprot(*pteptr);
 302 }
 303 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 304
 305 /*
 306  * Conversion functions: convert a page and protection to a page entry,
 307  * and a page entry and page directory to the page they refer to.
 308  */
 309
 310 #define phys_to_page(phys) pfn_to_page(phys_to_pfn(phys))
 311 #define __virt_to_page(virt) phys_to_page(__pa(virt))
 312 #define page_to_phys(page) pfn_to_phys(page_to_pfn(page))
 313
 314 #define mk_pte(page, pgprot) \
 315         ({ pte_t pte;                                   \
 316                                                         \
 317         pte_set_val(pte, page_to_phys(page), (pgprot)); \
 318         if (pte_present(pte))                           \
 319                 pte_mknewprot(pte_mknewpage(pte));      \
 320         pte;})
 321
 322 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 323 {
 324         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 325         return pte;
 326 }
 327
 328 #define pmd_page_vaddr(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 329
 330 /*
 331  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 332  *
 333  * this macro returns the index of the entry in the pgd page which would
 334  * control the given virtual address
 335  */
 336 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 337
 338 #define pgd_index_k(addr) pgd_index(addr)
 339
 340 /*
 341  * pgd_offset() returns a (pgd_t *)
 342  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 343  */
 344 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 345
 346 /*
 347  * a shortcut which implies the use of the kernel's pgd, instead
 348  * of a process's
 349  */
 350 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 351
 352 /*
 353  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 354  *
 355  * this macro returns the index of the entry in the pmd page which would
 356  * control the given virtual address
 357  */
 358 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 359
 360 /*
 361  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 362  *
 363  * this macro returns the index of the entry in the pte page which would
 364  * control the given virtual address
 365  */
 366 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 367 #define pte_offset_kernel(dir, address) \
 368         ((pte_t *) pmd_page_vaddr(*(dir)) +  pte_index(address))
 369 #define pte_offset_map(dir, address) \
 370         ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 371 #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
 372 #define pte_unmap(pte) do { } while (0)
 373 #define pte_unmap_nested(pte) do { } while (0)
 374
 375 #define update_mmu_cache(vma,address,pte) do ; while (0)
 376
 377 /* Encode and de-code a swap entry */
 378 #define __swp_type(x)                   (((x).val >> 4) & 0x3f)
 379 #define __swp_offset(x)                 ((x).val >> 11)
 380
 381 #define __swp_entry(type, offset) \
 382         ((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
 383 #define __pte_to_swp_entry(pte) \
 384         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 385 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 386
 387 #define kern_addr_valid(addr) (1)
 388
 389 #include <asm-generic/pgtable.h>
 390
 391 #include <asm-generic/pgtable-nopud.h>
 392
 393 #ifdef CONFIG_HIGHMEM
 394 /* Clear a kernel PTE and flush it from the TLB */
 395 #define kpte_clear_flush(ptep, vaddr)                                   \
 396 do {                                                                    \
 397         pte_clear(&init_mm, vaddr, ptep);                               \
 398         __flush_tlb_one(vaddr);                                         \
 399 } while (0)
 400 #endif
 401
 402 #endif
 403 #endif
 404
 405 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 406
 407 /*
 408  * Overrides for Emacs so that we follow Linus's tabbing style.
 409  * Emacs will notice this stuff at the end of the file and automatically
 410  * adjust the settings for this buffer only.  This must remain at the end
 411  * of the file.
 412  * ---------------------------------------------------------------------------
 413  * Local variables:
 414  * c-file-style: "linux"
 415  * End:
 416  */