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