include/asm-s390/pgtable.h

   1 /*
   2  *  include/asm-s390/pgtable.h
   3  *
   4  *  S390 version
   5  *    Copyright (C) 1999,2000 IBM Deutschland Entwicklung GmbH, IBM Corporation
   6  *    Author(s): Hartmut Penner (hp@de.ibm.com)
   7  *               Ulrich Weigand (weigand@de.ibm.com)
   8  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
   9  *
  10  *  Derived from "include/asm-i386/pgtable.h"
  11  */
  12
  13 #ifndef _ASM_S390_PGTABLE_H
  14 #define _ASM_S390_PGTABLE_H
  15
  16 #include <asm-generic/4level-fixup.h>
  17
  18 /*
  19  * The Linux memory management assumes a three-level page table setup. For
  20  * s390 31 bit we "fold" the mid level into the top-level page table, so
  21  * that we physically have the same two-level page table as the s390 mmu
  22  * expects in 31 bit mode. For s390 64 bit we use three of the five levels
  23  * the hardware provides (region first and region second tables are not
  24  * used).
  25  *
  26  * The "pgd_xxx()" functions are trivial for a folded two-level
  27  * setup: the pgd is never bad, and a pmd always exists (as it's folded
  28  * into the pgd entry)
  29  *
  30  * This file contains the functions and defines necessary to modify and use
  31  * the S390 page table tree.
  32  */
  33 #ifndef __ASSEMBLY__
  34 #include <asm/bug.h>
  35 #include <asm/processor.h>
  36 #include <linux/threads.h>
  37
  38 struct vm_area_struct; /* forward declaration (include/linux/mm.h) */
  39
  40 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
  41 extern void paging_init(void);
  42
  43 /*
  44  * The S390 doesn't have any external MMU info: the kernel page
  45  * tables contain all the necessary information.
  46  */
  47 #define update_mmu_cache(vma, address, pte)     do { } while (0)
  48
  49 /*
  50  * ZERO_PAGE is a global shared page that is always zero: used
  51  * for zero-mapped memory areas etc..
  52  */
  53 extern char empty_zero_page[PAGE_SIZE];
  54 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  55 #endif /* !__ASSEMBLY__ */
  56
  57 /*
  58  * PMD_SHIFT determines the size of the area a second-level page
  59  * table can map
  60  * PGDIR_SHIFT determines what a third-level page table entry can map
  61  */
  62 #ifndef __s390x__
  63 # define PMD_SHIFT      22
  64 # define PGDIR_SHIFT    22
  65 #else /* __s390x__ */
  66 # define PMD_SHIFT      21
  67 # define PGDIR_SHIFT    31
  68 #endif /* __s390x__ */
  69
  70 #define PMD_SIZE        (1UL << PMD_SHIFT)
  71 #define PMD_MASK        (~(PMD_SIZE-1))
  72 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  73 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  74
  75 /*
  76  * entries per page directory level: the S390 is two-level, so
  77  * we don't really have any PMD directory physically.
  78  * for S390 segment-table entries are combined to one PGD
  79  * that leads to 1024 pte per pgd
  80  */
  81 #ifndef __s390x__
  82 # define PTRS_PER_PTE    1024
  83 # define PTRS_PER_PMD    1
  84 # define PTRS_PER_PGD    512
  85 #else /* __s390x__ */
  86 # define PTRS_PER_PTE    512
  87 # define PTRS_PER_PMD    1024
  88 # define PTRS_PER_PGD    2048
  89 #endif /* __s390x__ */
  90
  91 /*
  92  * pgd entries used up by user/kernel:
  93  */
  94 #ifndef __s390x__
  95 # define USER_PTRS_PER_PGD  512
  96 # define USER_PGD_PTRS      512
  97 # define KERNEL_PGD_PTRS    512
  98 #else /* __s390x__ */
  99 # define USER_PTRS_PER_PGD  2048
 100 # define USER_PGD_PTRS      2048
 101 # define KERNEL_PGD_PTRS    2048
 102 #endif /* __s390x__ */
 103
 104 #define FIRST_USER_ADDRESS  0
 105
 106 #define pte_ERROR(e) \
 107         printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
 108 #define pmd_ERROR(e) \
 109         printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
 110 #define pgd_ERROR(e) \
 111         printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
 112
 113 #ifndef __ASSEMBLY__
 114 /*
 115  * Just any arbitrary offset to the start of the vmalloc VM area: the
 116  * current 8MB value just means that there will be a 8MB "hole" after the
 117  * physical memory until the kernel virtual memory starts.  That means that
 118  * any out-of-bounds memory accesses will hopefully be caught.
 119  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 120  * area for the same reason. ;)
 121  */
 122 #define VMALLOC_OFFSET  (8*1024*1024)
 123 #define VMALLOC_START   (((unsigned long) high_memory + VMALLOC_OFFSET) \
 124                          & ~(VMALLOC_OFFSET-1))
 125 #ifndef __s390x__
 126 # define VMALLOC_END     (0x7fffffffL)
 127 #else /* __s390x__ */
 128 # define VMALLOC_END     (0x40000000000L)
 129 #endif /* __s390x__ */
 130
 131
 132 /*
 133  * A 31 bit pagetable entry of S390 has following format:
 134  *  |   PFRA          |    |  OS  |
 135  * 0                   0IP0
 136  * 00000000001111111111222222222233
 137  * 01234567890123456789012345678901
 138  *
 139  * I Page-Invalid Bit:    Page is not available for address-translation
 140  * P Page-Protection Bit: Store access not possible for page
 141  *
 142  * A 31 bit segmenttable entry of S390 has following format:
 143  *  |   P-table origin      |  |PTL
 144  * 0                         IC
 145  * 00000000001111111111222222222233
 146  * 01234567890123456789012345678901
 147  *
 148  * I Segment-Invalid Bit:    Segment is not available for address-translation
 149  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
 150  * PTL Page-Table-Length:    Page-table length (PTL+1*16 entries -> up to 256)
 151  *
 152  * The 31 bit segmenttable origin of S390 has following format:
 153  *
 154  *  |S-table origin   |     | STL |
 155  * X                   **GPS
 156  * 00000000001111111111222222222233
 157  * 01234567890123456789012345678901
 158  *
 159  * X Space-Switch event:
 160  * G Segment-Invalid Bit:     *
 161  * P Private-Space Bit:       Segment is not private (PoP 3-30)
 162  * S Storage-Alteration:
 163  * STL Segment-Table-Length:  Segment-table length (STL+1*16 entries -> up to 2048)
 164  *
 165  * A 64 bit pagetable entry of S390 has following format:
 166  * |                     PFRA                         |0IP0|  OS  |
 167  * 0000000000111111111122222222223333333333444444444455555555556666
 168  * 0123456789012345678901234567890123456789012345678901234567890123
 169  *
 170  * I Page-Invalid Bit:    Page is not available for address-translation
 171  * P Page-Protection Bit: Store access not possible for page
 172  *
 173  * A 64 bit segmenttable entry of S390 has following format:
 174  * |        P-table origin                              |      TT
 175  * 0000000000111111111122222222223333333333444444444455555555556666
 176  * 0123456789012345678901234567890123456789012345678901234567890123
 177  *
 178  * I Segment-Invalid Bit:    Segment is not available for address-translation
 179  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
 180  * P Page-Protection Bit: Store access not possible for page
 181  * TT Type 00
 182  *
 183  * A 64 bit region table entry of S390 has following format:
 184  * |        S-table origin                             |   TF  TTTL
 185  * 0000000000111111111122222222223333333333444444444455555555556666
 186  * 0123456789012345678901234567890123456789012345678901234567890123
 187  *
 188  * I Segment-Invalid Bit:    Segment is not available for address-translation
 189  * TT Type 01
 190  * TF
 191  * TL Table lenght
 192  *
 193  * The 64 bit regiontable origin of S390 has following format:
 194  * |      region table origon                          |       DTTL
 195  * 0000000000111111111122222222223333333333444444444455555555556666
 196  * 0123456789012345678901234567890123456789012345678901234567890123
 197  *
 198  * X Space-Switch event:
 199  * G Segment-Invalid Bit:
 200  * P Private-Space Bit:
 201  * S Storage-Alteration:
 202  * R Real space
 203  * TL Table-Length:
 204  *
 205  * A storage key has the following format:
 206  * | ACC |F|R|C|0|
 207  *  0   3 4 5 6 7
 208  * ACC: access key
 209  * F  : fetch protection bit
 210  * R  : referenced bit
 211  * C  : changed bit
 212  */
 213
 214 /* Hardware bits in the page table entry */
 215 #define _PAGE_RO        0x200          /* HW read-only                     */
 216 #define _PAGE_INVALID   0x400          /* HW invalid                       */
 217
 218 /* Mask and four different kinds of invalid pages. */
 219 #define _PAGE_INVALID_MASK      0x601
 220 #define _PAGE_INVALID_EMPTY     0x400
 221 #define _PAGE_INVALID_NONE      0x401
 222 #define _PAGE_INVALID_SWAP      0x600
 223 #define _PAGE_INVALID_FILE      0x601
 224
 225 #ifndef __s390x__
 226
 227 /* Bits in the segment table entry */
 228 #define _PAGE_TABLE_LEN 0xf            /* only full page-tables            */
 229 #define _PAGE_TABLE_COM 0x10           /* common page-table                */
 230 #define _PAGE_TABLE_INV 0x20           /* invalid page-table               */
 231 #define _SEG_PRESENT    0x001          /* Software (overlap with PTL)      */
 232
 233 /* Bits int the storage key */
 234 #define _PAGE_CHANGED    0x02          /* HW changed bit                   */
 235 #define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
 236
 237 #define _USER_SEG_TABLE_LEN    0x7f    /* user-segment-table up to 2 GB    */
 238 #define _KERNEL_SEG_TABLE_LEN  0x7f    /* kernel-segment-table up to 2 GB  */
 239
 240 /*
 241  * User and Kernel pagetables are identical
 242  */
 243 #define _PAGE_TABLE     _PAGE_TABLE_LEN
 244 #define _KERNPG_TABLE   _PAGE_TABLE_LEN
 245
 246 /*
 247  * The Kernel segment-tables includes the User segment-table
 248  */
 249
 250 #define _SEGMENT_TABLE  (_USER_SEG_TABLE_LEN|0x80000000|0x100)
 251 #define _KERNSEG_TABLE  _KERNEL_SEG_TABLE_LEN
 252
 253 #define USER_STD_MASK   0x00000080UL
 254
 255 #else /* __s390x__ */
 256
 257 /* Bits in the segment table entry */
 258 #define _PMD_ENTRY_INV   0x20          /* invalid segment table entry      */
 259 #define _PMD_ENTRY       0x00
 260
 261 /* Bits in the region third table entry */
 262 #define _PGD_ENTRY_INV   0x20          /* invalid region table entry       */
 263 #define _PGD_ENTRY       0x07
 264
 265 /*
 266  * User and kernel page directory
 267  */
 268 #define _REGION_THIRD       0x4
 269 #define _REGION_THIRD_LEN   0x3
 270 #define _REGION_TABLE       (_REGION_THIRD|_REGION_THIRD_LEN|0x40|0x100)
 271 #define _KERN_REGION_TABLE  (_REGION_THIRD|_REGION_THIRD_LEN)
 272
 273 #define USER_STD_MASK           0x0000000000000080UL
 274
 275 /* Bits in the storage key */
 276 #define _PAGE_CHANGED    0x02          /* HW changed bit                   */
 277 #define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
 278
 279 #endif /* __s390x__ */
 280
 281 /*
 282  * No mapping available
 283  */
 284 #define PAGE_NONE_SHARED  __pgprot(_PAGE_INVALID_NONE)
 285 #define PAGE_NONE_PRIVATE __pgprot(_PAGE_INVALID_NONE)
 286 #define PAGE_RO_SHARED    __pgprot(_PAGE_RO)
 287 #define PAGE_RO_PRIVATE   __pgprot(_PAGE_RO)
 288 #define PAGE_COPY         __pgprot(_PAGE_RO)
 289 #define PAGE_SHARED       __pgprot(0)
 290 #define PAGE_KERNEL       __pgprot(0)
 291
 292 /*
 293  * The S390 can't do page protection for execute, and considers that the
 294  * same are read. Also, write permissions imply read permissions. This is
 295  * the closest we can get..
 296  */
 297          /*xwr*/
 298 #define __P000  PAGE_NONE_PRIVATE
 299 #define __P001  PAGE_RO_PRIVATE
 300 #define __P010  PAGE_COPY
 301 #define __P011  PAGE_COPY
 302 #define __P100  PAGE_RO_PRIVATE
 303 #define __P101  PAGE_RO_PRIVATE
 304 #define __P110  PAGE_COPY
 305 #define __P111  PAGE_COPY
 306
 307 #define __S000  PAGE_NONE_SHARED
 308 #define __S001  PAGE_RO_SHARED
 309 #define __S010  PAGE_SHARED
 310 #define __S011  PAGE_SHARED
 311 #define __S100  PAGE_RO_SHARED
 312 #define __S101  PAGE_RO_SHARED
 313 #define __S110  PAGE_SHARED
 314 #define __S111  PAGE_SHARED
 315
 316 /*
 317  * Certain architectures need to do special things when PTEs
 318  * within a page table are directly modified.  Thus, the following
 319  * hook is made available.
 320  */
 321 extern inline void set_pte(pte_t *pteptr, pte_t pteval)
 322 {
 323         *pteptr = pteval;
 324 }
 325 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 326
 327 /*
 328  * pgd/pmd/pte query functions
 329  */
 330 #ifndef __s390x__
 331
 332 extern inline int pgd_present(pgd_t pgd) { return 1; }
 333 extern inline int pgd_none(pgd_t pgd)    { return 0; }
 334 extern inline int pgd_bad(pgd_t pgd)     { return 0; }
 335
 336 extern inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _SEG_PRESENT; }
 337 extern inline int pmd_none(pmd_t pmd)    { return pmd_val(pmd) & _PAGE_TABLE_INV; }
 338 extern inline int pmd_bad(pmd_t pmd)
 339 {
 340         return (pmd_val(pmd) & (~PAGE_MASK & ~_PAGE_TABLE_INV)) != _PAGE_TABLE;
 341 }
 342
 343 #else /* __s390x__ */
 344
 345 extern inline int pgd_present(pgd_t pgd)
 346 {
 347         return (pgd_val(pgd) & ~PAGE_MASK) == _PGD_ENTRY;
 348 }
 349
 350 extern inline int pgd_none(pgd_t pgd)
 351 {
 352         return pgd_val(pgd) & _PGD_ENTRY_INV;
 353 }
 354
 355 extern inline int pgd_bad(pgd_t pgd)
 356 {
 357         return (pgd_val(pgd) & (~PAGE_MASK & ~_PGD_ENTRY_INV)) != _PGD_ENTRY;
 358 }
 359
 360 extern inline int pmd_present(pmd_t pmd)
 361 {
 362         return (pmd_val(pmd) & ~PAGE_MASK) == _PMD_ENTRY;
 363 }
 364
 365 extern inline int pmd_none(pmd_t pmd)
 366 {
 367         return pmd_val(pmd) & _PMD_ENTRY_INV;
 368 }
 369
 370 extern inline int pmd_bad(pmd_t pmd)
 371 {
 372         return (pmd_val(pmd) & (~PAGE_MASK & ~_PMD_ENTRY_INV)) != _PMD_ENTRY;
 373 }
 374
 375 #endif /* __s390x__ */
 376
 377 extern inline int pte_none(pte_t pte)
 378 {
 379         return (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_EMPTY;
 380 }
 381
 382 extern inline int pte_present(pte_t pte)
 383 {
 384         return !(pte_val(pte) & _PAGE_INVALID) ||
 385                 (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_NONE;
 386 }
 387
 388 extern inline int pte_file(pte_t pte)
 389 {
 390         return (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_FILE;
 391 }
 392
 393 #define pte_same(a,b)   (pte_val(a) == pte_val(b))
 394
 395 /*
 396  * query functions pte_write/pte_dirty/pte_young only work if
 397  * pte_present() is true. Undefined behaviour if not..
 398  */
 399 extern inline int pte_write(pte_t pte)
 400 {
 401         return (pte_val(pte) & _PAGE_RO) == 0;
 402 }
 403
 404 extern inline int pte_dirty(pte_t pte)
 405 {
 406         /* A pte is neither clean nor dirty on s/390. The dirty bit
 407          * is in the storage key. See page_test_and_clear_dirty for
 408          * details.
 409          */
 410         return 0;
 411 }
 412
 413 extern inline int pte_young(pte_t pte)
 414 {
 415         /* A pte is neither young nor old on s/390. The young bit
 416          * is in the storage key. See page_test_and_clear_young for
 417          * details.
 418          */
 419         return 0;
 420 }
 421
 422 extern inline int pte_read(pte_t pte)
 423 {
 424         /* All pages are readable since we don't use the fetch
 425          * protection bit in the storage key.
 426          */
 427         return 1;
 428 }
 429
 430 /*
 431  * pgd/pmd/pte modification functions
 432  */
 433
 434 #ifndef __s390x__
 435
 436 extern inline void pgd_clear(pgd_t * pgdp)      { }
 437
 438 extern inline void pmd_clear(pmd_t * pmdp)
 439 {
 440         pmd_val(pmdp[0]) = _PAGE_TABLE_INV;
 441         pmd_val(pmdp[1]) = _PAGE_TABLE_INV;
 442         pmd_val(pmdp[2]) = _PAGE_TABLE_INV;
 443         pmd_val(pmdp[3]) = _PAGE_TABLE_INV;
 444 }
 445
 446 #else /* __s390x__ */
 447
 448 extern inline void pgd_clear(pgd_t * pgdp)
 449 {
 450         pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
 451 }
 452
 453 extern inline void pmd_clear(pmd_t * pmdp)
 454 {
 455         pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
 456         pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
 457 }
 458
 459 #endif /* __s390x__ */
 460
 461 extern inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 462 {
 463         pte_val(*ptep) = _PAGE_INVALID_EMPTY;
 464 }
 465
 466 /*
 467  * The following pte modification functions only work if
 468  * pte_present() is true. Undefined behaviour if not..
 469  */
 470 extern inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 471 {
 472         pte_val(pte) &= PAGE_MASK;
 473         pte_val(pte) |= pgprot_val(newprot);
 474         return pte;
 475 }
 476
 477 extern inline pte_t pte_wrprotect(pte_t pte)
 478 {
 479         /* Do not clobber _PAGE_INVALID_NONE pages!  */
 480         if (!(pte_val(pte) & _PAGE_INVALID))
 481                 pte_val(pte) |= _PAGE_RO;
 482         return pte;
 483 }
 484
 485 extern inline pte_t pte_mkwrite(pte_t pte)
 486 {
 487         pte_val(pte) &= ~_PAGE_RO;
 488         return pte;
 489 }
 490
 491 extern inline pte_t pte_mkclean(pte_t pte)
 492 {
 493         /* The only user of pte_mkclean is the fork() code.
 494            We must *not* clear the *physical* page dirty bit
 495            just because fork() wants to clear the dirty bit in
 496            *one* of the page's mappings.  So we just do nothing. */
 497         return pte;
 498 }
 499
 500 extern inline pte_t pte_mkdirty(pte_t pte)
 501 {
 502         /* We do not explicitly set the dirty bit because the
 503          * sske instruction is slow. It is faster to let the
 504          * next instruction set the dirty bit.
 505          */
 506         return pte;
 507 }
 508
 509 extern inline pte_t pte_mkold(pte_t pte)
 510 {
 511         /* S/390 doesn't keep its dirty/referenced bit in the pte.
 512          * There is no point in clearing the real referenced bit.
 513          */
 514         return pte;
 515 }
 516
 517 extern inline pte_t pte_mkyoung(pte_t pte)
 518 {
 519         /* S/390 doesn't keep its dirty/referenced bit in the pte.
 520          * There is no point in setting the real referenced bit.
 521          */
 522         return pte;
 523 }
 524
 525 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 526 {
 527         return 0;
 528 }
 529
 530 static inline int
 531 ptep_clear_flush_young(struct vm_area_struct *vma,
 532                         unsigned long address, pte_t *ptep)
 533 {
 534         /* No need to flush TLB; bits are in storage key */
 535         return ptep_test_and_clear_young(vma, address, ptep);
 536 }
 537
 538 static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 539 {
 540         return 0;
 541 }
 542
 543 static inline int
 544 ptep_clear_flush_dirty(struct vm_area_struct *vma,
 545                         unsigned long address, pte_t *ptep)
 546 {
 547         /* No need to flush TLB; bits are in storage key */
 548         return ptep_test_and_clear_dirty(vma, address, ptep);
 549 }
 550
 551 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 552 {
 553         pte_t pte = *ptep;
 554         pte_clear(mm, addr, ptep);
 555         return pte;
 556 }
 557
 558 static inline pte_t
 559 ptep_clear_flush(struct vm_area_struct *vma,
 560                  unsigned long address, pte_t *ptep)
 561 {
 562         pte_t pte = *ptep;
 563 #ifndef __s390x__
 564         if (!(pte_val(pte) & _PAGE_INVALID)) {
 565                 /* S390 has 1mb segments, we are emulating 4MB segments */
 566                 pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
 567                 __asm__ __volatile__ ("ipte %2,%3"
 568                                       : "=m" (*ptep) : "m" (*ptep),
 569                                         "a" (pto), "a" (address) );
 570         }
 571 #else /* __s390x__ */
 572         if (!(pte_val(pte) & _PAGE_INVALID))
 573                 __asm__ __volatile__ ("ipte %2,%3"
 574                                       : "=m" (*ptep) : "m" (*ptep),
 575                                         "a" (ptep), "a" (address) );
 576 #endif /* __s390x__ */
 577         pte_val(*ptep) = _PAGE_INVALID_EMPTY;
 578         return pte;
 579 }
 580
 581 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 582 {
 583         pte_t old_pte = *ptep;
 584         set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
 585 }
 586
 587 static inline void
 588 ptep_establish(struct vm_area_struct *vma,
 589                unsigned long address, pte_t *ptep,
 590                pte_t entry)
 591 {
 592         ptep_clear_flush(vma, address, ptep);
 593         set_pte(ptep, entry);
 594 }
 595
 596 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
 597         ptep_establish(__vma, __address, __ptep, __entry)
 598
 599 /*
 600  * Test and clear dirty bit in storage key.
 601  * We can't clear the changed bit atomically. This is a potential
 602  * race against modification of the referenced bit. This function
 603  * should therefore only be called if it is not mapped in any
 604  * address space.
 605  */
 606 #define page_test_and_clear_dirty(_page)                                  \
 607 ({                                                                        \
 608         struct page *__page = (_page);                                    \
 609         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 610         int __skey = page_get_storage_key(__physpage);                    \
 611         if (__skey & _PAGE_CHANGED)                                       \
 612                 page_set_storage_key(__physpage, __skey & ~_PAGE_CHANGED);\
 613         (__skey & _PAGE_CHANGED);                                         \
 614 })
 615
 616 /*
 617  * Test and clear referenced bit in storage key.
 618  */
 619 #define page_test_and_clear_young(page)                                   \
 620 ({                                                                        \
 621         struct page *__page = (page);                                     \
 622         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 623         int __ccode;                                                      \
 624         asm volatile ("rrbe 0,%1\n\t"                                     \
 625                       "ipm  %0\n\t"                                       \
 626                       "srl  %0,28\n\t"                                    \
 627                       : "=d" (__ccode) : "a" (__physpage) : "cc" );       \
 628         (__ccode & 2);                                                    \
 629 })
 630
 631 /*
 632  * Conversion functions: convert a page and protection to a page entry,
 633  * and a page entry and page directory to the page they refer to.
 634  */
 635 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
 636 {
 637         pte_t __pte;
 638         pte_val(__pte) = physpage + pgprot_val(pgprot);
 639         return __pte;
 640 }
 641
 642 #define mk_pte(pg, pgprot)                                                \
 643 ({                                                                        \
 644         struct page *__page = (pg);                                       \
 645         pgprot_t __pgprot = (pgprot);                                     \
 646         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 647         pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
 648         __pte;                                                            \
 649 })
 650
 651 #define pfn_pte(pfn, pgprot)                                              \
 652 ({                                                                        \
 653         pgprot_t __pgprot = (pgprot);                                     \
 654         unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
 655         pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
 656         __pte;                                                            \
 657 })
 658
 659 #define SetPageUptodate(_page) \
 660         do {                                                                  \
 661                 struct page *__page = (_page);                                \
 662                 if (!test_and_set_bit(PG_uptodate, &__page->flags))           \
 663                         page_test_and_clear_dirty(_page);                     \
 664         } while (0)
 665
 666 #ifdef __s390x__
 667
 668 #define pfn_pmd(pfn, pgprot)                                              \
 669 ({                                                                        \
 670         pgprot_t __pgprot = (pgprot);                                     \
 671         unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
 672         pmd_t __pmd = __pmd(__physpage + pgprot_val(__pgprot));           \
 673         __pmd;                                                            \
 674 })
 675
 676 #endif /* __s390x__ */
 677
 678 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
 679 #define pte_page(x) pfn_to_page(pte_pfn(x))
 680
 681 #define pmd_page_kernel(pmd) (pmd_val(pmd) & PAGE_MASK)
 682
 683 #define pmd_page(pmd) (mem_map+(pmd_val(pmd) >> PAGE_SHIFT))
 684
 685 #define pgd_page_kernel(pgd) (pgd_val(pgd) & PAGE_MASK)
 686
 687 /* to find an entry in a page-table-directory */
 688 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 689 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 690
 691 /* to find an entry in a kernel page-table-directory */
 692 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 693
 694 #ifndef __s390x__
 695
 696 /* Find an entry in the second-level page table.. */
 697 extern inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
 698 {
 699         return (pmd_t *) dir;
 700 }
 701
 702 #else /* __s390x__ */
 703
 704 /* Find an entry in the second-level page table.. */
 705 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 706 #define pmd_offset(dir,addr) \
 707         ((pmd_t *) pgd_page_kernel(*(dir)) + pmd_index(addr))
 708
 709 #endif /* __s390x__ */
 710
 711 /* Find an entry in the third-level page table.. */
 712 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
 713 #define pte_offset_kernel(pmd, address) \
 714         ((pte_t *) pmd_page_kernel(*(pmd)) + pte_index(address))
 715 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
 716 #define pte_offset_map_nested(pmd, address) pte_offset_kernel(pmd, address)
 717 #define pte_unmap(pte) do { } while (0)
 718 #define pte_unmap_nested(pte) do { } while (0)
 719
 720 /*
 721  * 31 bit swap entry format:
 722  * A page-table entry has some bits we have to treat in a special way.
 723  * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
 724  * exception will occur instead of a page translation exception. The
 725  * specifiation exception has the bad habit not to store necessary
 726  * information in the lowcore.
 727  * Bit 21 and bit 22 are the page invalid bit and the page protection
 728  * bit. We set both to indicate a swapped page.
 729  * Bit 30 and 31 are used to distinguish the different page types. For
 730  * a swapped page these bits need to be zero.
 731  * This leaves the bits 1-19 and bits 24-29 to store type and offset.
 732  * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
 733  * plus 24 for the offset.
 734  * 0|     offset        |0110|o|type |00|
 735  * 0 0000000001111111111 2222 2 22222 33
 736  * 0 1234567890123456789 0123 4 56789 01
 737  *
 738  * 64 bit swap entry format:
 739  * A page-table entry has some bits we have to treat in a special way.
 740  * Bits 52 and bit 55 have to be zero, otherwise an specification
 741  * exception will occur instead of a page translation exception. The
 742  * specifiation exception has the bad habit not to store necessary
 743  * information in the lowcore.
 744  * Bit 53 and bit 54 are the page invalid bit and the page protection
 745  * bit. We set both to indicate a swapped page.
 746  * Bit 62 and 63 are used to distinguish the different page types. For
 747  * a swapped page these bits need to be zero.
 748  * This leaves the bits 0-51 and bits 56-61 to store type and offset.
 749  * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
 750  * plus 56 for the offset.
 751  * |                      offset                        |0110|o|type |00|
 752  *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
 753  *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
 754  */
 755 #ifndef __s390x__
 756 #define __SWP_OFFSET_MASK (~0UL >> 12)
 757 #else
 758 #define __SWP_OFFSET_MASK (~0UL >> 11)
 759 #endif
 760 extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 761 {
 762         pte_t pte;
 763         offset &= __SWP_OFFSET_MASK;
 764         pte_val(pte) = _PAGE_INVALID_SWAP | ((type & 0x1f) << 2) |
 765                 ((offset & 1UL) << 7) | ((offset & ~1UL) << 11);
 766         return pte;
 767 }
 768
 769 #define __swp_type(entry)       (((entry).val >> 2) & 0x1f)
 770 #define __swp_offset(entry)     (((entry).val >> 11) | (((entry).val >> 7) & 1))
 771 #define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
 772
 773 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 774 #define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
 775
 776 #ifndef __s390x__
 777 # define PTE_FILE_MAX_BITS      26
 778 #else /* __s390x__ */
 779 # define PTE_FILE_MAX_BITS      59
 780 #endif /* __s390x__ */
 781
 782 #define pte_to_pgoff(__pte) \
 783         ((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))
 784
 785 #define pgoff_to_pte(__off) \
 786         ((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
 787                    | _PAGE_INVALID_FILE })
 788
 789 #endif /* !__ASSEMBLY__ */
 790
 791 #define kern_addr_valid(addr)   (1)
 792
 793 /*
 794  * No page table caches to initialise
 795  */
 796 #define pgtable_cache_init()    do { } while (0)
 797
 798 #define __HAVE_ARCH_PTEP_ESTABLISH
 799 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 800 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 801 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 802 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 803 #define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
 804 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 805 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
 806 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 807 #define __HAVE_ARCH_PTE_SAME
 808 #define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
 809 #define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 810 #include <asm-generic/pgtable.h>
 811
 812 #endif /* _S390_PAGE_H */
 813