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 struct mm_struct;
  40
  41 extern pgd_t swapper_pg_dir[] __attribute__ ((aligned (4096)));
  42 extern void paging_init(void);
  43
  44 /*
  45  * The S390 doesn't have any external MMU info: the kernel page
  46  * tables contain all the necessary information.
  47  */
  48 #define update_mmu_cache(vma, address, pte)     do { } while (0)
  49
  50 /*
  51  * ZERO_PAGE is a global shared page that is always zero: used
  52  * for zero-mapped memory areas etc..
  53  */
  54 extern char empty_zero_page[PAGE_SIZE];
  55 #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
  56 #endif /* !__ASSEMBLY__ */
  57
  58 /*
  59  * PMD_SHIFT determines the size of the area a second-level page
  60  * table can map
  61  * PGDIR_SHIFT determines what a third-level page table entry can map
  62  */
  63 #ifndef __s390x__
  64 # define PMD_SHIFT      22
  65 # define PGDIR_SHIFT    22
  66 #else /* __s390x__ */
  67 # define PMD_SHIFT      21
  68 # define PGDIR_SHIFT    31
  69 #endif /* __s390x__ */
  70
  71 #define PMD_SIZE        (1UL << PMD_SHIFT)
  72 #define PMD_MASK        (~(PMD_SIZE-1))
  73 #define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
  74 #define PGDIR_MASK      (~(PGDIR_SIZE-1))
  75
  76 /*
  77  * entries per page directory level: the S390 is two-level, so
  78  * we don't really have any PMD directory physically.
  79  * for S390 segment-table entries are combined to one PGD
  80  * that leads to 1024 pte per pgd
  81  */
  82 #ifndef __s390x__
  83 # define PTRS_PER_PTE    1024
  84 # define PTRS_PER_PMD    1
  85 # define PTRS_PER_PGD    512
  86 #else /* __s390x__ */
  87 # define PTRS_PER_PTE    512
  88 # define PTRS_PER_PMD    1024
  89 # define PTRS_PER_PGD    2048
  90 #endif /* __s390x__ */
  91
  92 /*
  93  * pgd entries used up by user/kernel:
  94  */
  95 #ifndef __s390x__
  96 # define USER_PTRS_PER_PGD  512
  97 # define USER_PGD_PTRS      512
  98 # define KERNEL_PGD_PTRS    512
  99 #else /* __s390x__ */
 100 # define USER_PTRS_PER_PGD  2048
 101 # define USER_PGD_PTRS      2048
 102 # define KERNEL_PGD_PTRS    2048
 103 #endif /* __s390x__ */
 104
 105 #define FIRST_USER_ADDRESS  0
 106
 107 #define pte_ERROR(e) \
 108         printk("%s:%d: bad pte %p.\n", __FILE__, __LINE__, (void *) pte_val(e))
 109 #define pmd_ERROR(e) \
 110         printk("%s:%d: bad pmd %p.\n", __FILE__, __LINE__, (void *) pmd_val(e))
 111 #define pgd_ERROR(e) \
 112         printk("%s:%d: bad pgd %p.\n", __FILE__, __LINE__, (void *) pgd_val(e))
 113
 114 #ifndef __ASSEMBLY__
 115 /*
 116  * Just any arbitrary offset to the start of the vmalloc VM area: the
 117  * current 8MB value just means that there will be a 8MB "hole" after the
 118  * physical memory until the kernel virtual memory starts.  That means that
 119  * any out-of-bounds memory accesses will hopefully be caught.
 120  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
 121  * area for the same reason. ;)
 122  */
 123 #define VMALLOC_OFFSET  (8*1024*1024)
 124 #define VMALLOC_START   (((unsigned long) high_memory + VMALLOC_OFFSET) \
 125                          & ~(VMALLOC_OFFSET-1))
 126 #ifndef __s390x__
 127 # define VMALLOC_END     (0x7fffffffL)
 128 #else /* __s390x__ */
 129 # define VMALLOC_END     (0x40000000000L)
 130 #endif /* __s390x__ */
 131
 132
 133 /*
 134  * A 31 bit pagetable entry of S390 has following format:
 135  *  |   PFRA          |    |  OS  |
 136  * 0                   0IP0
 137  * 00000000001111111111222222222233
 138  * 01234567890123456789012345678901
 139  *
 140  * I Page-Invalid Bit:    Page is not available for address-translation
 141  * P Page-Protection Bit: Store access not possible for page
 142  *
 143  * A 31 bit segmenttable entry of S390 has following format:
 144  *  |   P-table origin      |  |PTL
 145  * 0                         IC
 146  * 00000000001111111111222222222233
 147  * 01234567890123456789012345678901
 148  *
 149  * I Segment-Invalid Bit:    Segment is not available for address-translation
 150  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
 151  * PTL Page-Table-Length:    Page-table length (PTL+1*16 entries -> up to 256)
 152  *
 153  * The 31 bit segmenttable origin of S390 has following format:
 154  *
 155  *  |S-table origin   |     | STL |
 156  * X                   **GPS
 157  * 00000000001111111111222222222233
 158  * 01234567890123456789012345678901
 159  *
 160  * X Space-Switch event:
 161  * G Segment-Invalid Bit:     *
 162  * P Private-Space Bit:       Segment is not private (PoP 3-30)
 163  * S Storage-Alteration:
 164  * STL Segment-Table-Length:  Segment-table length (STL+1*16 entries -> up to 2048)
 165  *
 166  * A 64 bit pagetable entry of S390 has following format:
 167  * |                     PFRA                         |0IP0|  OS  |
 168  * 0000000000111111111122222222223333333333444444444455555555556666
 169  * 0123456789012345678901234567890123456789012345678901234567890123
 170  *
 171  * I Page-Invalid Bit:    Page is not available for address-translation
 172  * P Page-Protection Bit: Store access not possible for page
 173  *
 174  * A 64 bit segmenttable entry of S390 has following format:
 175  * |        P-table origin                              |      TT
 176  * 0000000000111111111122222222223333333333444444444455555555556666
 177  * 0123456789012345678901234567890123456789012345678901234567890123
 178  *
 179  * I Segment-Invalid Bit:    Segment is not available for address-translation
 180  * C Common-Segment Bit:     Segment is not private (PoP 3-30)
 181  * P Page-Protection Bit: Store access not possible for page
 182  * TT Type 00
 183  *
 184  * A 64 bit region table entry of S390 has following format:
 185  * |        S-table origin                             |   TF  TTTL
 186  * 0000000000111111111122222222223333333333444444444455555555556666
 187  * 0123456789012345678901234567890123456789012345678901234567890123
 188  *
 189  * I Segment-Invalid Bit:    Segment is not available for address-translation
 190  * TT Type 01
 191  * TF
 192  * TL Table lenght
 193  *
 194  * The 64 bit regiontable origin of S390 has following format:
 195  * |      region table origon                          |       DTTL
 196  * 0000000000111111111122222222223333333333444444444455555555556666
 197  * 0123456789012345678901234567890123456789012345678901234567890123
 198  *
 199  * X Space-Switch event:
 200  * G Segment-Invalid Bit:
 201  * P Private-Space Bit:
 202  * S Storage-Alteration:
 203  * R Real space
 204  * TL Table-Length:
 205  *
 206  * A storage key has the following format:
 207  * | ACC |F|R|C|0|
 208  *  0   3 4 5 6 7
 209  * ACC: access key
 210  * F  : fetch protection bit
 211  * R  : referenced bit
 212  * C  : changed bit
 213  */
 214
 215 /* Hardware bits in the page table entry */
 216 #define _PAGE_RO        0x200          /* HW read-only                     */
 217 #define _PAGE_INVALID   0x400          /* HW invalid                       */
 218
 219 /* Mask and four different kinds of invalid pages. */
 220 #define _PAGE_INVALID_MASK      0x601
 221 #define _PAGE_INVALID_EMPTY     0x400
 222 #define _PAGE_INVALID_NONE      0x401
 223 #define _PAGE_INVALID_SWAP      0x600
 224 #define _PAGE_INVALID_FILE      0x601
 225
 226 #ifndef __s390x__
 227
 228 /* Bits in the segment table entry */
 229 #define _PAGE_TABLE_LEN 0xf            /* only full page-tables            */
 230 #define _PAGE_TABLE_COM 0x10           /* common page-table                */
 231 #define _PAGE_TABLE_INV 0x20           /* invalid page-table               */
 232 #define _SEG_PRESENT    0x001          /* Software (overlap with PTL)      */
 233
 234 /* Bits int the storage key */
 235 #define _PAGE_CHANGED    0x02          /* HW changed bit                   */
 236 #define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
 237
 238 #define _USER_SEG_TABLE_LEN    0x7f    /* user-segment-table up to 2 GB    */
 239 #define _KERNEL_SEG_TABLE_LEN  0x7f    /* kernel-segment-table up to 2 GB  */
 240
 241 /*
 242  * User and Kernel pagetables are identical
 243  */
 244 #define _PAGE_TABLE     _PAGE_TABLE_LEN
 245 #define _KERNPG_TABLE   _PAGE_TABLE_LEN
 246
 247 /*
 248  * The Kernel segment-tables includes the User segment-table
 249  */
 250
 251 #define _SEGMENT_TABLE  (_USER_SEG_TABLE_LEN|0x80000000|0x100)
 252 #define _KERNSEG_TABLE  _KERNEL_SEG_TABLE_LEN
 253
 254 #define USER_STD_MASK   0x00000080UL
 255
 256 #else /* __s390x__ */
 257
 258 /* Bits in the segment table entry */
 259 #define _PMD_ENTRY_INV   0x20          /* invalid segment table entry      */
 260 #define _PMD_ENTRY       0x00
 261
 262 /* Bits in the region third table entry */
 263 #define _PGD_ENTRY_INV   0x20          /* invalid region table entry       */
 264 #define _PGD_ENTRY       0x07
 265
 266 /*
 267  * User and kernel page directory
 268  */
 269 #define _REGION_THIRD       0x4
 270 #define _REGION_THIRD_LEN   0x3
 271 #define _REGION_TABLE       (_REGION_THIRD|_REGION_THIRD_LEN|0x40|0x100)
 272 #define _KERN_REGION_TABLE  (_REGION_THIRD|_REGION_THIRD_LEN)
 273
 274 #define USER_STD_MASK           0x0000000000000080UL
 275
 276 /* Bits in the storage key */
 277 #define _PAGE_CHANGED    0x02          /* HW changed bit                   */
 278 #define _PAGE_REFERENCED 0x04          /* HW referenced bit                */
 279
 280 #endif /* __s390x__ */
 281
 282 /*
 283  * No mapping available
 284  */
 285 #define PAGE_NONE_SHARED  __pgprot(_PAGE_INVALID_NONE)
 286 #define PAGE_NONE_PRIVATE __pgprot(_PAGE_INVALID_NONE)
 287 #define PAGE_RO_SHARED    __pgprot(_PAGE_RO)
 288 #define PAGE_RO_PRIVATE   __pgprot(_PAGE_RO)
 289 #define PAGE_COPY         __pgprot(_PAGE_RO)
 290 #define PAGE_SHARED       __pgprot(0)
 291 #define PAGE_KERNEL       __pgprot(0)
 292
 293 /*
 294  * The S390 can't do page protection for execute, and considers that the
 295  * same are read. Also, write permissions imply read permissions. This is
 296  * the closest we can get..
 297  */
 298          /*xwr*/
 299 #define __P000  PAGE_NONE_PRIVATE
 300 #define __P001  PAGE_RO_PRIVATE
 301 #define __P010  PAGE_COPY
 302 #define __P011  PAGE_COPY
 303 #define __P100  PAGE_RO_PRIVATE
 304 #define __P101  PAGE_RO_PRIVATE
 305 #define __P110  PAGE_COPY
 306 #define __P111  PAGE_COPY
 307
 308 #define __S000  PAGE_NONE_SHARED
 309 #define __S001  PAGE_RO_SHARED
 310 #define __S010  PAGE_SHARED
 311 #define __S011  PAGE_SHARED
 312 #define __S100  PAGE_RO_SHARED
 313 #define __S101  PAGE_RO_SHARED
 314 #define __S110  PAGE_SHARED
 315 #define __S111  PAGE_SHARED
 316
 317 /*
 318  * Certain architectures need to do special things when PTEs
 319  * within a page table are directly modified.  Thus, the following
 320  * hook is made available.
 321  */
 322 static inline void set_pte(pte_t *pteptr, pte_t pteval)
 323 {
 324         *pteptr = pteval;
 325 }
 326 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
 327
 328 /*
 329  * pgd/pmd/pte query functions
 330  */
 331 #ifndef __s390x__
 332
 333 static inline int pgd_present(pgd_t pgd) { return 1; }
 334 static inline int pgd_none(pgd_t pgd)    { return 0; }
 335 static inline int pgd_bad(pgd_t pgd)     { return 0; }
 336
 337 static inline int pmd_present(pmd_t pmd) { return pmd_val(pmd) & _SEG_PRESENT; }
 338 static inline int pmd_none(pmd_t pmd)    { return pmd_val(pmd) & _PAGE_TABLE_INV; }
 339 static inline int pmd_bad(pmd_t pmd)
 340 {
 341         return (pmd_val(pmd) & (~PAGE_MASK & ~_PAGE_TABLE_INV)) != _PAGE_TABLE;
 342 }
 343
 344 #else /* __s390x__ */
 345
 346 static inline int pgd_present(pgd_t pgd)
 347 {
 348         return (pgd_val(pgd) & ~PAGE_MASK) == _PGD_ENTRY;
 349 }
 350
 351 static inline int pgd_none(pgd_t pgd)
 352 {
 353         return pgd_val(pgd) & _PGD_ENTRY_INV;
 354 }
 355
 356 static inline int pgd_bad(pgd_t pgd)
 357 {
 358         return (pgd_val(pgd) & (~PAGE_MASK & ~_PGD_ENTRY_INV)) != _PGD_ENTRY;
 359 }
 360
 361 static inline int pmd_present(pmd_t pmd)
 362 {
 363         return (pmd_val(pmd) & ~PAGE_MASK) == _PMD_ENTRY;
 364 }
 365
 366 static inline int pmd_none(pmd_t pmd)
 367 {
 368         return pmd_val(pmd) & _PMD_ENTRY_INV;
 369 }
 370
 371 static inline int pmd_bad(pmd_t pmd)
 372 {
 373         return (pmd_val(pmd) & (~PAGE_MASK & ~_PMD_ENTRY_INV)) != _PMD_ENTRY;
 374 }
 375
 376 #endif /* __s390x__ */
 377
 378 static inline int pte_none(pte_t pte)
 379 {
 380         return (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_EMPTY;
 381 }
 382
 383 static inline int pte_present(pte_t pte)
 384 {
 385         return !(pte_val(pte) & _PAGE_INVALID) ||
 386                 (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_NONE;
 387 }
 388
 389 static inline int pte_file(pte_t pte)
 390 {
 391         return (pte_val(pte) & _PAGE_INVALID_MASK) == _PAGE_INVALID_FILE;
 392 }
 393
 394 #define pte_same(a,b)   (pte_val(a) == pte_val(b))
 395
 396 /*
 397  * query functions pte_write/pte_dirty/pte_young only work if
 398  * pte_present() is true. Undefined behaviour if not..
 399  */
 400 static inline int pte_write(pte_t pte)
 401 {
 402         return (pte_val(pte) & _PAGE_RO) == 0;
 403 }
 404
 405 static inline int pte_dirty(pte_t pte)
 406 {
 407         /* A pte is neither clean nor dirty on s/390. The dirty bit
 408          * is in the storage key. See page_test_and_clear_dirty for
 409          * details.
 410          */
 411         return 0;
 412 }
 413
 414 static inline int pte_young(pte_t pte)
 415 {
 416         /* A pte is neither young nor old on s/390. The young bit
 417          * is in the storage key. See page_test_and_clear_young for
 418          * details.
 419          */
 420         return 0;
 421 }
 422
 423 static inline int pte_read(pte_t pte)
 424 {
 425         /* All pages are readable since we don't use the fetch
 426          * protection bit in the storage key.
 427          */
 428         return 1;
 429 }
 430
 431 /*
 432  * pgd/pmd/pte modification functions
 433  */
 434
 435 #ifndef __s390x__
 436
 437 static inline void pgd_clear(pgd_t * pgdp)      { }
 438
 439 static inline void pmd_clear(pmd_t * pmdp)
 440 {
 441         pmd_val(pmdp[0]) = _PAGE_TABLE_INV;
 442         pmd_val(pmdp[1]) = _PAGE_TABLE_INV;
 443         pmd_val(pmdp[2]) = _PAGE_TABLE_INV;
 444         pmd_val(pmdp[3]) = _PAGE_TABLE_INV;
 445 }
 446
 447 #else /* __s390x__ */
 448
 449 static inline void pgd_clear(pgd_t * pgdp)
 450 {
 451         pgd_val(*pgdp) = _PGD_ENTRY_INV | _PGD_ENTRY;
 452 }
 453
 454 static inline void pmd_clear(pmd_t * pmdp)
 455 {
 456         pmd_val(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
 457         pmd_val1(*pmdp) = _PMD_ENTRY_INV | _PMD_ENTRY;
 458 }
 459
 460 #endif /* __s390x__ */
 461
 462 static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 463 {
 464         pte_val(*ptep) = _PAGE_INVALID_EMPTY;
 465 }
 466
 467 /*
 468  * The following pte modification functions only work if
 469  * pte_present() is true. Undefined behaviour if not..
 470  */
 471 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 472 {
 473         pte_val(pte) &= PAGE_MASK;
 474         pte_val(pte) |= pgprot_val(newprot);
 475         return pte;
 476 }
 477
 478 static inline pte_t pte_wrprotect(pte_t pte)
 479 {
 480         /* Do not clobber _PAGE_INVALID_NONE pages!  */
 481         if (!(pte_val(pte) & _PAGE_INVALID))
 482                 pte_val(pte) |= _PAGE_RO;
 483         return pte;
 484 }
 485
 486 static inline pte_t pte_mkwrite(pte_t pte)
 487 {
 488         pte_val(pte) &= ~_PAGE_RO;
 489         return pte;
 490 }
 491
 492 static inline pte_t pte_mkclean(pte_t pte)
 493 {
 494         /* The only user of pte_mkclean is the fork() code.
 495            We must *not* clear the *physical* page dirty bit
 496            just because fork() wants to clear the dirty bit in
 497            *one* of the page's mappings.  So we just do nothing. */
 498         return pte;
 499 }
 500
 501 static inline pte_t pte_mkdirty(pte_t pte)
 502 {
 503         /* We do not explicitly set the dirty bit because the
 504          * sske instruction is slow. It is faster to let the
 505          * next instruction set the dirty bit.
 506          */
 507         return pte;
 508 }
 509
 510 static inline pte_t pte_mkold(pte_t pte)
 511 {
 512         /* S/390 doesn't keep its dirty/referenced bit in the pte.
 513          * There is no point in clearing the real referenced bit.
 514          */
 515         return pte;
 516 }
 517
 518 static inline pte_t pte_mkyoung(pte_t pte)
 519 {
 520         /* S/390 doesn't keep its dirty/referenced bit in the pte.
 521          * There is no point in setting the real referenced bit.
 522          */
 523         return pte;
 524 }
 525
 526 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 527 {
 528         return 0;
 529 }
 530
 531 static inline int
 532 ptep_clear_flush_young(struct vm_area_struct *vma,
 533                         unsigned long address, pte_t *ptep)
 534 {
 535         /* No need to flush TLB; bits are in storage key */
 536         return ptep_test_and_clear_young(vma, address, ptep);
 537 }
 538
 539 static inline int ptep_test_and_clear_dirty(struct vm_area_struct *vma, unsigned long addr, pte_t *ptep)
 540 {
 541         return 0;
 542 }
 543
 544 static inline int
 545 ptep_clear_flush_dirty(struct vm_area_struct *vma,
 546                         unsigned long address, pte_t *ptep)
 547 {
 548         /* No need to flush TLB; bits are in storage key */
 549         return ptep_test_and_clear_dirty(vma, address, ptep);
 550 }
 551
 552 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 553 {
 554         pte_t pte = *ptep;
 555         pte_clear(mm, addr, ptep);
 556         return pte;
 557 }
 558
 559 static inline pte_t
 560 ptep_clear_flush(struct vm_area_struct *vma,
 561                  unsigned long address, pte_t *ptep)
 562 {
 563         pte_t pte = *ptep;
 564 #ifndef __s390x__
 565         if (!(pte_val(pte) & _PAGE_INVALID)) {
 566                 /* S390 has 1mb segments, we are emulating 4MB segments */
 567                 pte_t *pto = (pte_t *) (((unsigned long) ptep) & 0x7ffffc00);
 568                 __asm__ __volatile__ ("ipte %2,%3"
 569                                       : "=m" (*ptep) : "m" (*ptep),
 570                                         "a" (pto), "a" (address) );
 571         }
 572 #else /* __s390x__ */
 573         if (!(pte_val(pte) & _PAGE_INVALID))
 574                 __asm__ __volatile__ ("ipte %2,%3"
 575                                       : "=m" (*ptep) : "m" (*ptep),
 576                                         "a" (ptep), "a" (address) );
 577 #endif /* __s390x__ */
 578         pte_val(*ptep) = _PAGE_INVALID_EMPTY;
 579         return pte;
 580 }
 581
 582 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
 583 {
 584         pte_t old_pte = *ptep;
 585         set_pte_at(mm, addr, ptep, pte_wrprotect(old_pte));
 586 }
 587
 588 static inline void
 589 ptep_establish(struct vm_area_struct *vma,
 590                unsigned long address, pte_t *ptep,
 591                pte_t entry)
 592 {
 593         ptep_clear_flush(vma, address, ptep);
 594         set_pte(ptep, entry);
 595 }
 596
 597 #define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \
 598         ptep_establish(__vma, __address, __ptep, __entry)
 599
 600 /*
 601  * Test and clear dirty bit in storage key.
 602  * We can't clear the changed bit atomically. This is a potential
 603  * race against modification of the referenced bit. This function
 604  * should therefore only be called if it is not mapped in any
 605  * address space.
 606  */
 607 #define page_test_and_clear_dirty(_page)                                  \
 608 ({                                                                        \
 609         struct page *__page = (_page);                                    \
 610         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 611         int __skey = page_get_storage_key(__physpage);                    \
 612         if (__skey & _PAGE_CHANGED)                                       \
 613                 page_set_storage_key(__physpage, __skey & ~_PAGE_CHANGED);\
 614         (__skey & _PAGE_CHANGED);                                         \
 615 })
 616
 617 /*
 618  * Test and clear referenced bit in storage key.
 619  */
 620 #define page_test_and_clear_young(page)                                   \
 621 ({                                                                        \
 622         struct page *__page = (page);                                     \
 623         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 624         int __ccode;                                                      \
 625         asm volatile ("rrbe 0,%1\n\t"                                     \
 626                       "ipm  %0\n\t"                                       \
 627                       "srl  %0,28\n\t"                                    \
 628                       : "=d" (__ccode) : "a" (__physpage) : "cc" );       \
 629         (__ccode & 2);                                                    \
 630 })
 631
 632 /*
 633  * Conversion functions: convert a page and protection to a page entry,
 634  * and a page entry and page directory to the page they refer to.
 635  */
 636 static inline pte_t mk_pte_phys(unsigned long physpage, pgprot_t pgprot)
 637 {
 638         pte_t __pte;
 639         pte_val(__pte) = physpage + pgprot_val(pgprot);
 640         return __pte;
 641 }
 642
 643 #define mk_pte(pg, pgprot)                                                \
 644 ({                                                                        \
 645         struct page *__page = (pg);                                       \
 646         pgprot_t __pgprot = (pgprot);                                     \
 647         unsigned long __physpage = __pa((__page-mem_map) << PAGE_SHIFT);  \
 648         pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
 649         __pte;                                                            \
 650 })
 651
 652 #define pfn_pte(pfn, pgprot)                                              \
 653 ({                                                                        \
 654         pgprot_t __pgprot = (pgprot);                                     \
 655         unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
 656         pte_t __pte = mk_pte_phys(__physpage, __pgprot);                  \
 657         __pte;                                                            \
 658 })
 659
 660 #define SetPageUptodate(_page) \
 661         do {                                                                  \
 662                 struct page *__page = (_page);                                \
 663                 if (!test_and_set_bit(PG_uptodate, &__page->flags))           \
 664                         page_test_and_clear_dirty(_page);                     \
 665         } while (0)
 666
 667 #ifdef __s390x__
 668
 669 #define pfn_pmd(pfn, pgprot)                                              \
 670 ({                                                                        \
 671         pgprot_t __pgprot = (pgprot);                                     \
 672         unsigned long __physpage = __pa((pfn) << PAGE_SHIFT);             \
 673         pmd_t __pmd = __pmd(__physpage + pgprot_val(__pgprot));           \
 674         __pmd;                                                            \
 675 })
 676
 677 #endif /* __s390x__ */
 678
 679 #define pte_pfn(x) (pte_val(x) >> PAGE_SHIFT)
 680 #define pte_page(x) pfn_to_page(pte_pfn(x))
 681
 682 #define pmd_page_kernel(pmd) (pmd_val(pmd) & PAGE_MASK)
 683
 684 #define pmd_page(pmd) (mem_map+(pmd_val(pmd) >> PAGE_SHIFT))
 685
 686 #define pgd_page_kernel(pgd) (pgd_val(pgd) & PAGE_MASK)
 687
 688 /* to find an entry in a page-table-directory */
 689 #define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
 690 #define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address))
 691
 692 /* to find an entry in a kernel page-table-directory */
 693 #define pgd_offset_k(address) pgd_offset(&init_mm, address)
 694
 695 #ifndef __s390x__
 696
 697 /* Find an entry in the second-level page table.. */
 698 static inline pmd_t * pmd_offset(pgd_t * dir, unsigned long address)
 699 {
 700         return (pmd_t *) dir;
 701 }
 702
 703 #else /* __s390x__ */
 704
 705 /* Find an entry in the second-level page table.. */
 706 #define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1))
 707 #define pmd_offset(dir,addr) \
 708         ((pmd_t *) pgd_page_kernel(*(dir)) + pmd_index(addr))
 709
 710 #endif /* __s390x__ */
 711
 712 /* Find an entry in the third-level page table.. */
 713 #define pte_index(address) (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE-1))
 714 #define pte_offset_kernel(pmd, address) \
 715         ((pte_t *) pmd_page_kernel(*(pmd)) + pte_index(address))
 716 #define pte_offset_map(pmd, address) pte_offset_kernel(pmd, address)
 717 #define pte_offset_map_nested(pmd, address) pte_offset_kernel(pmd, address)
 718 #define pte_unmap(pte) do { } while (0)
 719 #define pte_unmap_nested(pte) do { } while (0)
 720
 721 /*
 722  * 31 bit swap entry format:
 723  * A page-table entry has some bits we have to treat in a special way.
 724  * Bits 0, 20 and bit 23 have to be zero, otherwise an specification
 725  * exception will occur instead of a page translation exception. The
 726  * specifiation exception has the bad habit not to store necessary
 727  * information in the lowcore.
 728  * Bit 21 and bit 22 are the page invalid bit and the page protection
 729  * bit. We set both to indicate a swapped page.
 730  * Bit 30 and 31 are used to distinguish the different page types. For
 731  * a swapped page these bits need to be zero.
 732  * This leaves the bits 1-19 and bits 24-29 to store type and offset.
 733  * We use the 5 bits from 25-29 for the type and the 20 bits from 1-19
 734  * plus 24 for the offset.
 735  * 0|     offset        |0110|o|type |00|
 736  * 0 0000000001111111111 2222 2 22222 33
 737  * 0 1234567890123456789 0123 4 56789 01
 738  *
 739  * 64 bit swap entry format:
 740  * A page-table entry has some bits we have to treat in a special way.
 741  * Bits 52 and bit 55 have to be zero, otherwise an specification
 742  * exception will occur instead of a page translation exception. The
 743  * specifiation exception has the bad habit not to store necessary
 744  * information in the lowcore.
 745  * Bit 53 and bit 54 are the page invalid bit and the page protection
 746  * bit. We set both to indicate a swapped page.
 747  * Bit 62 and 63 are used to distinguish the different page types. For
 748  * a swapped page these bits need to be zero.
 749  * This leaves the bits 0-51 and bits 56-61 to store type and offset.
 750  * We use the 5 bits from 57-61 for the type and the 53 bits from 0-51
 751  * plus 56 for the offset.
 752  * |                      offset                        |0110|o|type |00|
 753  *  0000000000111111111122222222223333333333444444444455 5555 5 55566 66
 754  *  0123456789012345678901234567890123456789012345678901 2345 6 78901 23
 755  */
 756 #ifndef __s390x__
 757 #define __SWP_OFFSET_MASK (~0UL >> 12)
 758 #else
 759 #define __SWP_OFFSET_MASK (~0UL >> 11)
 760 #endif
 761 static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 762 {
 763         pte_t pte;
 764         offset &= __SWP_OFFSET_MASK;
 765         pte_val(pte) = _PAGE_INVALID_SWAP | ((type & 0x1f) << 2) |
 766                 ((offset & 1UL) << 7) | ((offset & ~1UL) << 11);
 767         return pte;
 768 }
 769
 770 #define __swp_type(entry)       (((entry).val >> 2) & 0x1f)
 771 #define __swp_offset(entry)     (((entry).val >> 11) | (((entry).val >> 7) & 1))
 772 #define __swp_entry(type,offset) ((swp_entry_t) { pte_val(mk_swap_pte((type),(offset))) })
 773
 774 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 775 #define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
 776
 777 #ifndef __s390x__
 778 # define PTE_FILE_MAX_BITS      26
 779 #else /* __s390x__ */
 780 # define PTE_FILE_MAX_BITS      59
 781 #endif /* __s390x__ */
 782
 783 #define pte_to_pgoff(__pte) \
 784         ((((__pte).pte >> 12) << 7) + (((__pte).pte >> 1) & 0x7f))
 785
 786 #define pgoff_to_pte(__off) \
 787         ((pte_t) { ((((__off) & 0x7f) << 1) + (((__off) >> 7) << 12)) \
 788                    | _PAGE_INVALID_FILE })
 789
 790 #endif /* !__ASSEMBLY__ */
 791
 792 #define kern_addr_valid(addr)   (1)
 793
 794 /*
 795  * No page table caches to initialise
 796  */
 797 #define pgtable_cache_init()    do { } while (0)
 798
 799 #define __HAVE_ARCH_PTEP_ESTABLISH
 800 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 801 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 802 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
 803 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_DIRTY
 804 #define __HAVE_ARCH_PTEP_CLEAR_DIRTY_FLUSH
 805 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 806 #define __HAVE_ARCH_PTEP_CLEAR_FLUSH
 807 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 808 #define __HAVE_ARCH_PTE_SAME
 809 #define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_DIRTY
 810 #define __HAVE_ARCH_PAGE_TEST_AND_CLEAR_YOUNG
 811 #include <asm-generic/pgtable.h>
 812
 813 #endif /* _S390_PAGE_H */
 814