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
  33 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
  34
  35 extern 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 */
  39 extern 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
  59 extern 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 'access_ok(VERIFY_WRITE,..)'
 110  */
 111 #undef TEST_VERIFY_AREA
 112
 113 /* page table for 0-4MB for everybody */
 114 extern unsigned long pg0[1024];
 115
 116 /*
 117  * ZERO_PAGE is a global shared page that is always zero: used
 118  * for zero-mapped memory areas etc..
 119  */
 120
 121 #define ZERO_PAGE(vaddr) virt_to_page(empty_zero_page)
 122
 123 /* number of bits that fit into a memory pointer */
 124 #define BITS_PER_PTR                    (8*sizeof(unsigned long))
 125
 126 /* to align the pointer to a pointer address */
 127 #define PTR_MASK                        (~(sizeof(void*)-1))
 128
 129 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
 130 /* 64-bit machines, beware!  SRB. */
 131 #define SIZEOF_PTR_LOG2                 3
 132
 133 /* to find an entry in a page-table */
 134 #define PAGE_PTR(address) \
 135 ((unsigned long)(address)>>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK)
 136
 137 #define pte_clear(mm,addr,xp) pte_set_val(*(xp), (phys_t) 0, __pgprot(_PAGE_NEWPAGE))
 138
 139 #define pmd_none(x)     (!(pmd_val(x) & ~_PAGE_NEWPAGE))
 140 #define pmd_bad(x)      ((pmd_val(x) & (~PAGE_MASK & ~_PAGE_USER)) != _KERNPG_TABLE)
 141 #define pmd_present(x)  (pmd_val(x) & _PAGE_PRESENT)
 142 #define pmd_clear(xp)   do { pmd_val(*(xp)) = _PAGE_NEWPAGE; } while (0)
 143
 144 #define pmd_newpage(x)  (pmd_val(x) & _PAGE_NEWPAGE)
 145 #define pmd_mkuptodate(x) (pmd_val(x) &= ~_PAGE_NEWPAGE)
 146
 147 #define pud_newpage(x)  (pud_val(x) & _PAGE_NEWPAGE)
 148 #define pud_mkuptodate(x) (pud_val(x) &= ~_PAGE_NEWPAGE)
 149
 150 #define pages_to_mb(x) ((x) >> (20-PAGE_SHIFT))
 151
 152 #define pmd_page(pmd) phys_to_page(pmd_val(pmd) & PAGE_MASK)
 153
 154 #define pte_address(x) (__va(pte_val(x) & PAGE_MASK))
 155 #define mk_phys(a, r) ((a) + (((unsigned long) r) << REGION_SHIFT))
 156 #define phys_addr(p) ((p) & ~REGION_MASK)
 157
 158 /*
 159  * The following only work if pte_present() is true.
 160  * Undefined behaviour if not..
 161  */
 162 static inline int pte_user(pte_t pte)
 163 {
 164         return((pte_get_bits(pte, _PAGE_USER)) &&
 165                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 166 }
 167
 168 static inline int pte_read(pte_t pte)
 169 {
 170         return((pte_get_bits(pte, _PAGE_USER)) &&
 171                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 172 }
 173
 174 static inline int pte_exec(pte_t pte){
 175         return((pte_get_bits(pte, _PAGE_USER)) &&
 176                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 177 }
 178
 179 static inline int pte_write(pte_t pte)
 180 {
 181         return((pte_get_bits(pte, _PAGE_RW)) &&
 182                !(pte_get_bits(pte, _PAGE_PROTNONE)));
 183 }
 184
 185 /*
 186  * The following only works if pte_present() is not true.
 187  */
 188 static inline int pte_file(pte_t pte)
 189 {
 190         return pte_get_bits(pte, _PAGE_FILE);
 191 }
 192
 193 static inline int pte_dirty(pte_t pte)
 194 {
 195         return pte_get_bits(pte, _PAGE_DIRTY);
 196 }
 197
 198 static inline int pte_young(pte_t pte)
 199 {
 200         return pte_get_bits(pte, _PAGE_ACCESSED);
 201 }
 202
 203 static inline int pte_newpage(pte_t pte)
 204 {
 205         return pte_get_bits(pte, _PAGE_NEWPAGE);
 206 }
 207
 208 static inline int pte_newprot(pte_t pte)
 209 {
 210         return(pte_present(pte) && (pte_get_bits(pte, _PAGE_NEWPROT)));
 211 }
 212
 213 static inline pte_t pte_rdprotect(pte_t pte)
 214 {
 215         pte_clear_bits(pte, _PAGE_USER);
 216         return(pte_mknewprot(pte));
 217 }
 218
 219 static inline pte_t pte_exprotect(pte_t pte)
 220 {
 221         pte_clear_bits(pte, _PAGE_USER);
 222         return(pte_mknewprot(pte));
 223 }
 224
 225 static inline pte_t pte_mkclean(pte_t pte)
 226 {
 227         pte_clear_bits(pte, _PAGE_DIRTY);
 228         return(pte);
 229 }
 230
 231 static inline pte_t pte_mkold(pte_t pte)
 232 {
 233         pte_clear_bits(pte, _PAGE_ACCESSED);
 234         return(pte);
 235 }
 236
 237 static inline pte_t pte_wrprotect(pte_t pte)
 238 {
 239         pte_clear_bits(pte, _PAGE_RW);
 240         return(pte_mknewprot(pte));
 241 }
 242
 243 static inline pte_t pte_mkread(pte_t pte)
 244 {
 245         pte_set_bits(pte, _PAGE_RW);
 246         return(pte_mknewprot(pte));
 247 }
 248
 249 static inline pte_t pte_mkexec(pte_t pte)
 250 {
 251         pte_set_bits(pte, _PAGE_USER);
 252         return(pte_mknewprot(pte));
 253 }
 254
 255 static inline pte_t pte_mkdirty(pte_t pte)
 256 {
 257         pte_set_bits(pte, _PAGE_DIRTY);
 258         return(pte);
 259 }
 260
 261 static inline pte_t pte_mkyoung(pte_t pte)
 262 {
 263         pte_set_bits(pte, _PAGE_ACCESSED);
 264         return(pte);
 265 }
 266
 267 static inline pte_t pte_mkwrite(pte_t pte)
 268 {
 269         pte_set_bits(pte, _PAGE_RW);
 270         return(pte_mknewprot(pte));
 271 }
 272
 273 static inline pte_t pte_mkuptodate(pte_t pte)
 274 {
 275         pte_clear_bits(pte, _PAGE_NEWPAGE);
 276         if(pte_present(pte))
 277                 pte_clear_bits(pte, _PAGE_NEWPROT);
 278         return(pte);
 279 }
 280
 281 extern phys_t page_to_phys(struct page *page);
 282
 283 /*
 284  * Conversion functions: convert a page and protection to a page entry,
 285  * and a page entry and page directory to the page they refer to.
 286  */
 287
 288 extern pte_t mk_pte(struct page *page, pgprot_t pgprot);
 289
 290 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 291 {
 292         pte_set_val(pte, (pte_val(pte) & _PAGE_CHG_MASK), newprot);
 293         if(pte_present(pte)) pte = pte_mknewpage(pte_mknewprot(pte));
 294         return pte;
 295 }
 296
 297 #define pmd_page_kernel(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK))
 298
 299 /*
 300  * the pgd page can be thought of an array like this: pgd_t[PTRS_PER_PGD]
 301  *
 302  * this macro returns the index of the entry in the pgd page which would
 303  * control the given virtual address
 304  */
 305 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 306
 307 #define pgd_index_k(addr) pgd_index(addr)
 308
 309 /*
 310  * pgd_offset() returns a (pgd_t *)
 311  * pgd_index() is used get the offset into the pgd page's array of pgd_t's;
 312  */
 313 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 314
 315 /*
 316  * a shortcut which implies the use of the kernel's pgd, instead
 317  * of a process's
 318  */
 319 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 320
 321 /*
 322  * the pmd page can be thought of an array like this: pmd_t[PTRS_PER_PMD]
 323  *
 324  * this macro returns the index of the entry in the pmd page which would
 325  * control the given virtual address
 326  */
 327 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 328
 329 /*
 330  * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE]
 331  *
 332  * this macro returns the index of the entry in the pte page which would
 333  * control the given virtual address
 334  */
 335 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 336 #define pte_offset_kernel(dir, address) \
 337         ((pte_t *) pmd_page_kernel(*(dir)) +  pte_index(address))
 338 #define pte_offset_map(dir, address) \
 339         ((pte_t *)page_address(pmd_page(*(dir))) + pte_index(address))
 340 #define pte_offset_map_nested(dir, address) pte_offset_map(dir, address)
 341 #define pte_unmap(pte) do { } while (0)
 342 #define pte_unmap_nested(pte) do { } while (0)
 343
 344 #define update_mmu_cache(vma,address,pte) do ; while (0)
 345
 346 /* Encode and de-code a swap entry */
 347 #define __swp_type(x)                   (((x).val >> 4) & 0x3f)
 348 #define __swp_offset(x)                 ((x).val >> 11)
 349
 350 #define __swp_entry(type, offset) \
 351         ((swp_entry_t) { ((type) << 4) | ((offset) << 11) })
 352 #define __pte_to_swp_entry(pte) \
 353         ((swp_entry_t) { pte_val(pte_mkuptodate(pte)) })
 354 #define __swp_entry_to_pte(x)           ((pte_t) { (x).val })
 355
 356 #define kern_addr_valid(addr) (1)
 357
 358 #include <asm-generic/pgtable.h>
 359
 360 #include <asm-generic/pgtable-nopud.h>
 361
 362 #endif
 363 #endif
 364
 365 extern struct page *phys_to_page(const unsigned long phys);
 366 extern struct page *__virt_to_page(const unsigned long virt);
 367 #define virt_to_page(addr) __virt_to_page((const unsigned long) addr)
 368
 369 /*
 370  * Overrides for Emacs so that we follow Linus's tabbing style.
 371  * Emacs will notice this stuff at the end of the file and automatically
 372  * adjust the settings for this buffer only.  This must remain at the end
 373  * of the file.
 374  * ---------------------------------------------------------------------------
 375  * Local variables:
 376  * c-file-style: "linux"
 377  * End:
 378  */