arch/arm64/include/asm/pgtable.h

   1 /*
   2  * Copyright (C) 2012 ARM Ltd.
   3  *
   4  * This program is free software; you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License version 2 as
   6  * published by the Free Software Foundation.
   7  *
   8  * This program is distributed in the hope that it will be useful,
   9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11  * GNU General Public License for more details.
  12  *
  13  * You should have received a copy of the GNU General Public License
  14  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  15  */
  16 #ifndef __ASM_PGTABLE_H
  17 #define __ASM_PGTABLE_H
  18
  19 #include <asm/bug.h>
  20 #include <asm/proc-fns.h>
  21
  22 #include <asm/memory.h>
  23 #include <asm/pgtable-hwdef.h>
  24 #include <asm/pgtable-prot.h>
  25
  26 /*
  27  * VMALLOC range.
  28  *
  29  * VMALLOC_START: beginning of the kernel vmalloc space
  30  * VMALLOC_END: extends to the available space below vmmemmap, PCI I/O space
  31  *      and fixed mappings
  32  */
  33 #define VMALLOC_START           (MODULES_END)
  34 #define VMALLOC_END             (PAGE_OFFSET - PUD_SIZE - VMEMMAP_SIZE - SZ_64K)
  35
  36 #define vmemmap                 ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT))
  37
  38 #define FIRST_USER_ADDRESS      0UL
  39
  40 #ifndef __ASSEMBLY__
  41
  42 #include <asm/cmpxchg.h>
  43 #include <asm/fixmap.h>
  44 #include <linux/mmdebug.h>
  45
  46 extern void __pte_error(const char *file, int line, unsigned long val);
  47 extern void __pmd_error(const char *file, int line, unsigned long val);
  48 extern void __pud_error(const char *file, int line, unsigned long val);
  49 extern void __pgd_error(const char *file, int line, unsigned long val);
  50
  51 /*
  52  * ZERO_PAGE is a global shared page that is always zero: used
  53  * for zero-mapped memory areas etc..
  54  */
  55 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  56 #define ZERO_PAGE(vaddr)        phys_to_page(__pa_symbol(empty_zero_page))
  57
  58 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  59
  60 #define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
  61
  62 #define pfn_pte(pfn,prot)       (__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
  63
  64 #define pte_none(pte)           (!pte_val(pte))
  65 #define pte_clear(mm,addr,ptep) set_pte(ptep, __pte(0))
  66 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
  67
  68 /*
  69  * The following only work if pte_present(). Undefined behaviour otherwise.
  70  */
  71 #define pte_present(pte)        (!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
  72 #define pte_young(pte)          (!!(pte_val(pte) & PTE_AF))
  73 #define pte_special(pte)        (!!(pte_val(pte) & PTE_SPECIAL))
  74 #define pte_write(pte)          (!!(pte_val(pte) & PTE_WRITE))
  75 #define pte_user_exec(pte)      (!(pte_val(pte) & PTE_UXN))
  76 #define pte_cont(pte)           (!!(pte_val(pte) & PTE_CONT))
  77
  78 #define pte_cont_addr_end(addr, end)                                            \
  79 ({      unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;    \
  80         (__boundary - 1 < (end) - 1) ? __boundary : (end);                      \
  81 })
  82
  83 #define pmd_cont_addr_end(addr, end)                                            \
  84 ({      unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;    \
  85         (__boundary - 1 < (end) - 1) ? __boundary : (end);                      \
  86 })
  87
  88 #define pte_hw_dirty(pte)       (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
  89 #define pte_sw_dirty(pte)       (!!(pte_val(pte) & PTE_DIRTY))
  90 #define pte_dirty(pte)          (pte_sw_dirty(pte) || pte_hw_dirty(pte))
  91
  92 #define pte_valid(pte)          (!!(pte_val(pte) & PTE_VALID))
  93 /*
  94  * Execute-only user mappings do not have the PTE_USER bit set. All valid
  95  * kernel mappings have the PTE_UXN bit set.
  96  */
  97 #define pte_valid_not_user(pte) \
  98         ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
  99 #define pte_valid_young(pte) \
 100         ((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
 101 #define pte_valid_user(pte) \
 102         ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
 103
 104 /*
 105  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
 106  * so that we don't erroneously return false for pages that have been
 107  * remapped as PROT_NONE but are yet to be flushed from the TLB.
 108  */
 109 #define pte_accessible(mm, pte) \
 110         (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
 111
 112 /*
 113  * p??_access_permitted() is true for valid user mappings (subject to the
 114  * write permission check) other than user execute-only which do not have the
 115  * PTE_USER bit set. PROT_NONE mappings do not have the PTE_VALID bit set.
 116  */
 117 #define pte_access_permitted(pte, write) \
 118         (pte_valid_user(pte) && (!(write) || pte_write(pte)))
 119 #define pmd_access_permitted(pmd, write) \
 120         (pte_access_permitted(pmd_pte(pmd), (write)))
 121 #define pud_access_permitted(pud, write) \
 122         (pte_access_permitted(pud_pte(pud), (write)))
 123
 124 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
 125 {
 126         pte_val(pte) &= ~pgprot_val(prot);
 127         return pte;
 128 }
 129
 130 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
 131 {
 132         pte_val(pte) |= pgprot_val(prot);
 133         return pte;
 134 }
 135
 136 static inline pte_t pte_wrprotect(pte_t pte)
 137 {
 138         pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
 139         pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
 140         return pte;
 141 }
 142
 143 static inline pte_t pte_mkwrite(pte_t pte)
 144 {
 145         pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
 146         pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
 147         return pte;
 148 }
 149
 150 static inline pte_t pte_mkclean(pte_t pte)
 151 {
 152         return clear_pte_bit(pte, __pgprot(PTE_DIRTY));
 153 }
 154
 155 static inline pte_t pte_mkdirty(pte_t pte)
 156 {
 157         return set_pte_bit(pte, __pgprot(PTE_DIRTY));
 158 }
 159
 160 static inline pte_t pte_mkold(pte_t pte)
 161 {
 162         return clear_pte_bit(pte, __pgprot(PTE_AF));
 163 }
 164
 165 static inline pte_t pte_mkyoung(pte_t pte)
 166 {
 167         return set_pte_bit(pte, __pgprot(PTE_AF));
 168 }
 169
 170 static inline pte_t pte_mkspecial(pte_t pte)
 171 {
 172         return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
 173 }
 174
 175 static inline pte_t pte_mkcont(pte_t pte)
 176 {
 177         pte = set_pte_bit(pte, __pgprot(PTE_CONT));
 178         return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
 179 }
 180
 181 static inline pte_t pte_mknoncont(pte_t pte)
 182 {
 183         return clear_pte_bit(pte, __pgprot(PTE_CONT));
 184 }
 185
 186 static inline pte_t pte_mkpresent(pte_t pte)
 187 {
 188         return set_pte_bit(pte, __pgprot(PTE_VALID));
 189 }
 190
 191 static inline pmd_t pmd_mkcont(pmd_t pmd)
 192 {
 193         return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
 194 }
 195
 196 static inline void set_pte(pte_t *ptep, pte_t pte)
 197 {
 198         *ptep = pte;
 199
 200         /*
 201          * Only if the new pte is valid and kernel, otherwise TLB maintenance
 202          * or update_mmu_cache() have the necessary barriers.
 203          */
 204         if (pte_valid_not_user(pte)) {
 205                 dsb(ishst);
 206                 isb();
 207         }
 208 }
 209
 210 struct mm_struct;
 211 struct vm_area_struct;
 212
 213 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
 214
 215 /*
 216  * PTE bits configuration in the presence of hardware Dirty Bit Management
 217  * (PTE_WRITE == PTE_DBM):
 218  *
 219  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
 220  *   0      0      |   1           0          0
 221  *   0      1      |   1           1          0
 222  *   1      0      |   1           0          1
 223  *   1      1      |   0           1          x
 224  *
 225  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
 226  * the page fault mechanism. Checking the dirty status of a pte becomes:
 227  *
 228  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
 229  */
 230 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 231                               pte_t *ptep, pte_t pte)
 232 {
 233         if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
 234                 __sync_icache_dcache(pte, addr);
 235
 236         /*
 237          * If the existing pte is valid, check for potential race with
 238          * hardware updates of the pte (ptep_set_access_flags safely changes
 239          * valid ptes without going through an invalid entry).
 240          */
 241         if (pte_valid(*ptep) && pte_valid(pte)) {
 242                 VM_WARN_ONCE(!pte_young(pte),
 243                              "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
 244                              __func__, pte_val(*ptep), pte_val(pte));
 245                 VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
 246                              "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
 247                              __func__, pte_val(*ptep), pte_val(pte));
 248         }
 249
 250         set_pte(ptep, pte);
 251 }
 252
 253 #define __HAVE_ARCH_PTE_SAME
 254 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 255 {
 256         pteval_t lhs, rhs;
 257
 258         lhs = pte_val(pte_a);
 259         rhs = pte_val(pte_b);
 260
 261         if (pte_present(pte_a))
 262                 lhs &= ~PTE_RDONLY;
 263
 264         if (pte_present(pte_b))
 265                 rhs &= ~PTE_RDONLY;
 266
 267         return (lhs == rhs);
 268 }
 269
 270 /*
 271  * Huge pte definitions.
 272  */
 273 #define pte_huge(pte)           (!(pte_val(pte) & PTE_TABLE_BIT))
 274 #define pte_mkhuge(pte)         (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
 275
 276 /*
 277  * Hugetlb definitions.
 278  */
 279 #define HUGE_MAX_HSTATE         4
 280 #define HPAGE_SHIFT             PMD_SHIFT
 281 #define HPAGE_SIZE              (_AC(1, UL) << HPAGE_SHIFT)
 282 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
 283 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 284
 285 #define __HAVE_ARCH_PTE_SPECIAL
 286
 287 static inline pte_t pud_pte(pud_t pud)
 288 {
 289         return __pte(pud_val(pud));
 290 }
 291
 292 static inline pmd_t pud_pmd(pud_t pud)
 293 {
 294         return __pmd(pud_val(pud));
 295 }
 296
 297 static inline pte_t pmd_pte(pmd_t pmd)
 298 {
 299         return __pte(pmd_val(pmd));
 300 }
 301
 302 static inline pmd_t pte_pmd(pte_t pte)
 303 {
 304         return __pmd(pte_val(pte));
 305 }
 306
 307 static inline pgprot_t mk_sect_prot(pgprot_t prot)
 308 {
 309         return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
 310 }
 311
 312 #ifdef CONFIG_NUMA_BALANCING
 313 /*
 314  * See the comment in include/asm-generic/pgtable.h
 315  */
 316 static inline int pte_protnone(pte_t pte)
 317 {
 318         return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
 319 }
 320
 321 static inline int pmd_protnone(pmd_t pmd)
 322 {
 323         return pte_protnone(pmd_pte(pmd));
 324 }
 325 #endif
 326
 327 /*
 328  * THP definitions.
 329  */
 330
 331 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 332 #define pmd_trans_huge(pmd)     (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
 333 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 334
 335 #define pmd_present(pmd)        pte_present(pmd_pte(pmd))
 336 #define pmd_dirty(pmd)          pte_dirty(pmd_pte(pmd))
 337 #define pmd_young(pmd)          pte_young(pmd_pte(pmd))
 338 #define pmd_wrprotect(pmd)      pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 339 #define pmd_mkold(pmd)          pte_pmd(pte_mkold(pmd_pte(pmd)))
 340 #define pmd_mkwrite(pmd)        pte_pmd(pte_mkwrite(pmd_pte(pmd)))
 341 #define pmd_mkclean(pmd)        pte_pmd(pte_mkclean(pmd_pte(pmd)))
 342 #define pmd_mkdirty(pmd)        pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 343 #define pmd_mkyoung(pmd)        pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 344 #define pmd_mknotpresent(pmd)   (__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
 345
 346 #define pmd_thp_or_huge(pmd)    (pmd_huge(pmd) || pmd_trans_huge(pmd))
 347
 348 #define __HAVE_ARCH_PMD_WRITE
 349 #define pmd_write(pmd)          pte_write(pmd_pte(pmd))
 350
 351 #define pmd_mkhuge(pmd)         (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
 352
 353 #define pmd_pfn(pmd)            (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 354 #define pfn_pmd(pfn,prot)       (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
 355 #define mk_pmd(page,prot)       pfn_pmd(page_to_pfn(page),prot)
 356
 357 #define pud_write(pud)          pte_write(pud_pte(pud))
 358 #define pud_pfn(pud)            (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 359
 360 #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
 361
 362 #define __pgprot_modify(prot,mask,bits) \
 363         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
 364
 365 /*
 366  * Mark the prot value as uncacheable and unbufferable.
 367  */
 368 #define pgprot_noncached(prot) \
 369         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
 370 #define pgprot_writecombine(prot) \
 371         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
 372 #define pgprot_device(prot) \
 373         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
 374 #define __HAVE_PHYS_MEM_ACCESS_PROT
 375 struct file;
 376 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 377                                      unsigned long size, pgprot_t vma_prot);
 378
 379 #define pmd_none(pmd)           (!pmd_val(pmd))
 380
 381 #define pmd_bad(pmd)            (!(pmd_val(pmd) & PMD_TABLE_BIT))
 382
 383 #define pmd_table(pmd)          ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 384                                  PMD_TYPE_TABLE)
 385 #define pmd_sect(pmd)           ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 386                                  PMD_TYPE_SECT)
 387
 388 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
 389 #define pud_sect(pud)           (0)
 390 #define pud_table(pud)          (1)
 391 #else
 392 #define pud_sect(pud)           ((pud_val(pud) & PUD_TYPE_MASK) == \
 393                                  PUD_TYPE_SECT)
 394 #define pud_table(pud)          ((pud_val(pud) & PUD_TYPE_MASK) == \
 395                                  PUD_TYPE_TABLE)
 396 #endif
 397
 398 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 399 {
 400         *pmdp = pmd;
 401         dsb(ishst);
 402         isb();
 403 }
 404
 405 static inline void pmd_clear(pmd_t *pmdp)
 406 {
 407         set_pmd(pmdp, __pmd(0));
 408 }
 409
 410 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 411 {
 412         return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
 413 }
 414
 415 /* Find an entry in the third-level page table. */
 416 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 417
 418 #define pte_offset_phys(dir,addr)       (pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
 419 #define pte_offset_kernel(dir,addr)     ((pte_t *)__va(pte_offset_phys((dir), (addr))))
 420
 421 #define pte_offset_map(dir,addr)        pte_offset_kernel((dir), (addr))
 422 #define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
 423 #define pte_unmap(pte)                  do { } while (0)
 424 #define pte_unmap_nested(pte)           do { } while (0)
 425
 426 #define pte_set_fixmap(addr)            ((pte_t *)set_fixmap_offset(FIX_PTE, addr))
 427 #define pte_set_fixmap_offset(pmd, addr)        pte_set_fixmap(pte_offset_phys(pmd, addr))
 428 #define pte_clear_fixmap()              clear_fixmap(FIX_PTE)
 429
 430 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 431
 432 /* use ONLY for statically allocated translation tables */
 433 #define pte_offset_kimg(dir,addr)       ((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
 434
 435 /*
 436  * Conversion functions: convert a page and protection to a page entry,
 437  * and a page entry and page directory to the page they refer to.
 438  */
 439 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page),prot)
 440
 441 #if CONFIG_PGTABLE_LEVELS > 2
 442
 443 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
 444
 445 #define pud_none(pud)           (!pud_val(pud))
 446 #define pud_bad(pud)            (!(pud_val(pud) & PUD_TABLE_BIT))
 447 #define pud_present(pud)        pte_present(pud_pte(pud))
 448
 449 static inline void set_pud(pud_t *pudp, pud_t pud)
 450 {
 451         *pudp = pud;
 452         dsb(ishst);
 453         isb();
 454 }
 455
 456 static inline void pud_clear(pud_t *pudp)
 457 {
 458         set_pud(pudp, __pud(0));
 459 }
 460
 461 static inline phys_addr_t pud_page_paddr(pud_t pud)
 462 {
 463         return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
 464 }
 465
 466 /* Find an entry in the second-level page table. */
 467 #define pmd_index(addr)         (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 468
 469 #define pmd_offset_phys(dir, addr)      (pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
 470 #define pmd_offset(dir, addr)           ((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
 471
 472 #define pmd_set_fixmap(addr)            ((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
 473 #define pmd_set_fixmap_offset(pud, addr)        pmd_set_fixmap(pmd_offset_phys(pud, addr))
 474 #define pmd_clear_fixmap()              clear_fixmap(FIX_PMD)
 475
 476 #define pud_page(pud)           pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
 477
 478 /* use ONLY for statically allocated translation tables */
 479 #define pmd_offset_kimg(dir,addr)       ((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
 480
 481 #else
 482
 483 #define pud_page_paddr(pud)     ({ BUILD_BUG(); 0; })
 484
 485 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
 486 #define pmd_set_fixmap(addr)            NULL
 487 #define pmd_set_fixmap_offset(pudp, addr)       ((pmd_t *)pudp)
 488 #define pmd_clear_fixmap()
 489
 490 #define pmd_offset_kimg(dir,addr)       ((pmd_t *)dir)
 491
 492 #endif  /* CONFIG_PGTABLE_LEVELS > 2 */
 493
 494 #if CONFIG_PGTABLE_LEVELS > 3
 495
 496 #define pud_ERROR(pud)          __pud_error(__FILE__, __LINE__, pud_val(pud))
 497
 498 #define pgd_none(pgd)           (!pgd_val(pgd))
 499 #define pgd_bad(pgd)            (!(pgd_val(pgd) & 2))
 500 #define pgd_present(pgd)        (pgd_val(pgd))
 501
 502 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
 503 {
 504         *pgdp = pgd;
 505         dsb(ishst);
 506 }
 507
 508 static inline void pgd_clear(pgd_t *pgdp)
 509 {
 510         set_pgd(pgdp, __pgd(0));
 511 }
 512
 513 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
 514 {
 515         return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
 516 }
 517
 518 /* Find an entry in the frst-level page table. */
 519 #define pud_index(addr)         (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
 520
 521 #define pud_offset_phys(dir, addr)      (pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
 522 #define pud_offset(dir, addr)           ((pud_t *)__va(pud_offset_phys((dir), (addr))))
 523
 524 #define pud_set_fixmap(addr)            ((pud_t *)set_fixmap_offset(FIX_PUD, addr))
 525 #define pud_set_fixmap_offset(pgd, addr)        pud_set_fixmap(pud_offset_phys(pgd, addr))
 526 #define pud_clear_fixmap()              clear_fixmap(FIX_PUD)
 527
 528 #define pgd_page(pgd)           pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
 529
 530 /* use ONLY for statically allocated translation tables */
 531 #define pud_offset_kimg(dir,addr)       ((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
 532
 533 #else
 534
 535 #define pgd_page_paddr(pgd)     ({ BUILD_BUG(); 0;})
 536
 537 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
 538 #define pud_set_fixmap(addr)            NULL
 539 #define pud_set_fixmap_offset(pgdp, addr)       ((pud_t *)pgdp)
 540 #define pud_clear_fixmap()
 541
 542 #define pud_offset_kimg(dir,addr)       ((pud_t *)dir)
 543
 544 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
 545
 546 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 547
 548 /* to find an entry in a page-table-directory */
 549 #define pgd_index(addr)         (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 550
 551 #define pgd_offset_raw(pgd, addr)       ((pgd) + pgd_index(addr))
 552
 553 #define pgd_offset(mm, addr)    (pgd_offset_raw((mm)->pgd, (addr)))
 554
 555 /* to find an entry in a kernel page-table-directory */
 556 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 557
 558 #define pgd_set_fixmap(addr)    ((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
 559 #define pgd_clear_fixmap()      clear_fixmap(FIX_PGD)
 560
 561 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 562 {
 563         const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
 564                               PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
 565         /* preserve the hardware dirty information */
 566         if (pte_hw_dirty(pte))
 567                 pte = pte_mkdirty(pte);
 568         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 569         return pte;
 570 }
 571
 572 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 573 {
 574         return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
 575 }
 576
 577 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 578 extern int ptep_set_access_flags(struct vm_area_struct *vma,
 579                                  unsigned long address, pte_t *ptep,
 580                                  pte_t entry, int dirty);
 581
 582 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 583 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
 584 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 585                                         unsigned long address, pmd_t *pmdp,
 586                                         pmd_t entry, int dirty)
 587 {
 588         return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
 589 }
 590 #endif
 591
 592 /*
 593  * Atomic pte/pmd modifications.
 594  */
 595 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 596 static inline int __ptep_test_and_clear_young(pte_t *ptep)
 597 {
 598         pte_t old_pte, pte;
 599
 600         pte = READ_ONCE(*ptep);
 601         do {
 602                 old_pte = pte;
 603                 pte = pte_mkold(pte);
 604                 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
 605                                                pte_val(old_pte), pte_val(pte));
 606         } while (pte_val(pte) != pte_val(old_pte));
 607
 608         return pte_young(pte);
 609 }
 610
 611 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 612                                             unsigned long address,
 613                                             pte_t *ptep)
 614 {
 615         return __ptep_test_and_clear_young(ptep);
 616 }
 617
 618 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 619 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 620 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 621                                             unsigned long address,
 622                                             pmd_t *pmdp)
 623 {
 624         return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
 625 }
 626 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 627
 628 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 629 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 630                                        unsigned long address, pte_t *ptep)
 631 {
 632         return __pte(xchg_relaxed(&pte_val(*ptep), 0));
 633 }
 634
 635 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 636 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 637 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 638                                             unsigned long address, pmd_t *pmdp)
 639 {
 640         return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
 641 }
 642 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 643
 644 /*
 645  * ptep_set_wrprotect - mark read-only while preserving the hardware update of
 646  * the Access Flag.
 647  */
 648 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 649 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 650 {
 651         pte_t old_pte, pte;
 652
 653         /*
 654          * ptep_set_wrprotect() is only called on CoW mappings which are
 655          * private (!VM_SHARED) with the pte either read-only (!PTE_WRITE &&
 656          * PTE_RDONLY) or writable and software-dirty (PTE_WRITE &&
 657          * !PTE_RDONLY && PTE_DIRTY); see is_cow_mapping() and
 658          * protection_map[]. There is no race with the hardware update of the
 659          * dirty state: clearing of PTE_RDONLY when PTE_WRITE (a.k.a. PTE_DBM)
 660          * is set.
 661          */
 662         VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(*ptep),
 663                      "%s: potential race with hardware DBM", __func__);
 664         pte = READ_ONCE(*ptep);
 665         do {
 666                 old_pte = pte;
 667                 pte = pte_wrprotect(pte);
 668                 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
 669                                                pte_val(old_pte), pte_val(pte));
 670         } while (pte_val(pte) != pte_val(old_pte));
 671 }
 672
 673 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 674 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
 675 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 676                                       unsigned long address, pmd_t *pmdp)
 677 {
 678         ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
 679 }
 680 #endif
 681
 682 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 683 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
 684
 685 /*
 686  * Encode and decode a swap entry:
 687  *      bits 0-1:       present (must be zero)
 688  *      bits 2-7:       swap type
 689  *      bits 8-57:      swap offset
 690  *      bit  58:        PTE_PROT_NONE (must be zero)
 691  */
 692 #define __SWP_TYPE_SHIFT        2
 693 #define __SWP_TYPE_BITS         6
 694 #define __SWP_OFFSET_BITS       50
 695 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 696 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 697 #define __SWP_OFFSET_MASK       ((1UL << __SWP_OFFSET_BITS) - 1)
 698
 699 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 700 #define __swp_offset(x)         (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
 701 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 702
 703 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 704 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 705
 706 /*
 707  * Ensure that there are not more swap files than can be encoded in the kernel
 708  * PTEs.
 709  */
 710 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 711
 712 extern int kern_addr_valid(unsigned long addr);
 713
 714 #include <asm-generic/pgtable.h>
 715
 716 void pgd_cache_init(void);
 717 #define pgtable_cache_init      pgd_cache_init
 718
 719 /*
 720  * On AArch64, the cache coherency is handled via the set_pte_at() function.
 721  */
 722 static inline void update_mmu_cache(struct vm_area_struct *vma,
 723                                     unsigned long addr, pte_t *ptep)
 724 {
 725         /*
 726          * We don't do anything here, so there's a very small chance of
 727          * us retaking a user fault which we just fixed up. The alternative
 728          * is doing a dsb(ishst), but that penalises the fastpath.
 729          */
 730 }
 731
 732 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
 733
 734 #define kc_vaddr_to_offset(v)   ((v) & ~VA_START)
 735 #define kc_offset_to_vaddr(o)   ((o) | VA_START)
 736
 737 #endif /* !__ASSEMBLY__ */
 738
 739 #endif /* __ASM_PGTABLE_H */