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 #include <linux/mm_types.h>
  46 #include <linux/sched.h>
  47
  48 extern void __pte_error(const char *file, int line, unsigned long val);
  49 extern void __pmd_error(const char *file, int line, unsigned long val);
  50 extern void __pud_error(const char *file, int line, unsigned long val);
  51 extern void __pgd_error(const char *file, int line, unsigned long val);
  52
  53 /*
  54  * ZERO_PAGE is a global shared page that is always zero: used
  55  * for zero-mapped memory areas etc..
  56  */
  57 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
  58 #define ZERO_PAGE(vaddr)        phys_to_page(__pa_symbol(empty_zero_page))
  59
  60 #define pte_ERROR(pte)          __pte_error(__FILE__, __LINE__, pte_val(pte))
  61
  62 #define pte_pfn(pte)            ((pte_val(pte) & PHYS_MASK) >> PAGE_SHIFT)
  63
  64 #define pfn_pte(pfn,prot)       (__pte(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
  65
  66 #define pte_none(pte)           (!pte_val(pte))
  67 #define pte_clear(mm,addr,ptep) set_pte(ptep, __pte(0))
  68 #define pte_page(pte)           (pfn_to_page(pte_pfn(pte)))
  69
  70 /*
  71  * The following only work if pte_present(). Undefined behaviour otherwise.
  72  */
  73 #define pte_present(pte)        (!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)))
  74 #define pte_young(pte)          (!!(pte_val(pte) & PTE_AF))
  75 #define pte_special(pte)        (!!(pte_val(pte) & PTE_SPECIAL))
  76 #define pte_write(pte)          (!!(pte_val(pte) & PTE_WRITE))
  77 #define pte_user_exec(pte)      (!(pte_val(pte) & PTE_UXN))
  78 #define pte_cont(pte)           (!!(pte_val(pte) & PTE_CONT))
  79
  80 #define pte_cont_addr_end(addr, end)                                            \
  81 ({      unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK;    \
  82         (__boundary - 1 < (end) - 1) ? __boundary : (end);                      \
  83 })
  84
  85 #define pmd_cont_addr_end(addr, end)                                            \
  86 ({      unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK;    \
  87         (__boundary - 1 < (end) - 1) ? __boundary : (end);                      \
  88 })
  89
  90 #define pte_hw_dirty(pte)       (pte_write(pte) && !(pte_val(pte) & PTE_RDONLY))
  91 #define pte_sw_dirty(pte)       (!!(pte_val(pte) & PTE_DIRTY))
  92 #define pte_dirty(pte)          (pte_sw_dirty(pte) || pte_hw_dirty(pte))
  93
  94 #define pte_valid(pte)          (!!(pte_val(pte) & PTE_VALID))
  95 /*
  96  * Execute-only user mappings do not have the PTE_USER bit set. All valid
  97  * kernel mappings have the PTE_UXN bit set.
  98  */
  99 #define pte_valid_not_user(pte) \
 100         ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN))
 101 #define pte_valid_young(pte) \
 102         ((pte_val(pte) & (PTE_VALID | PTE_AF)) == (PTE_VALID | PTE_AF))
 103 #define pte_valid_user(pte) \
 104         ((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER))
 105
 106 /*
 107  * Could the pte be present in the TLB? We must check mm_tlb_flush_pending
 108  * so that we don't erroneously return false for pages that have been
 109  * remapped as PROT_NONE but are yet to be flushed from the TLB.
 110  */
 111 #define pte_accessible(mm, pte) \
 112         (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid_young(pte))
 113
 114 /*
 115  * p??_access_permitted() is true for valid user mappings (subject to the
 116  * write permission check) other than user execute-only which do not have the
 117  * PTE_USER bit set. PROT_NONE mappings do not have the PTE_VALID bit set.
 118  */
 119 #define pte_access_permitted(pte, write) \
 120         (pte_valid_user(pte) && (!(write) || pte_write(pte)))
 121 #define pmd_access_permitted(pmd, write) \
 122         (pte_access_permitted(pmd_pte(pmd), (write)))
 123 #define pud_access_permitted(pud, write) \
 124         (pte_access_permitted(pud_pte(pud), (write)))
 125
 126 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot)
 127 {
 128         pte_val(pte) &= ~pgprot_val(prot);
 129         return pte;
 130 }
 131
 132 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot)
 133 {
 134         pte_val(pte) |= pgprot_val(prot);
 135         return pte;
 136 }
 137
 138 static inline pte_t pte_wrprotect(pte_t pte)
 139 {
 140         pte = clear_pte_bit(pte, __pgprot(PTE_WRITE));
 141         pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
 142         return pte;
 143 }
 144
 145 static inline pte_t pte_mkwrite(pte_t pte)
 146 {
 147         pte = set_pte_bit(pte, __pgprot(PTE_WRITE));
 148         pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
 149         return pte;
 150 }
 151
 152 static inline pte_t pte_mkclean(pte_t pte)
 153 {
 154         pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY));
 155         pte = set_pte_bit(pte, __pgprot(PTE_RDONLY));
 156
 157         return pte;
 158 }
 159
 160 static inline pte_t pte_mkdirty(pte_t pte)
 161 {
 162         pte = set_pte_bit(pte, __pgprot(PTE_DIRTY));
 163
 164         if (pte_write(pte))
 165                 pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY));
 166
 167         return pte;
 168 }
 169
 170 static inline pte_t pte_mkold(pte_t pte)
 171 {
 172         return clear_pte_bit(pte, __pgprot(PTE_AF));
 173 }
 174
 175 static inline pte_t pte_mkyoung(pte_t pte)
 176 {
 177         return set_pte_bit(pte, __pgprot(PTE_AF));
 178 }
 179
 180 static inline pte_t pte_mkspecial(pte_t pte)
 181 {
 182         return set_pte_bit(pte, __pgprot(PTE_SPECIAL));
 183 }
 184
 185 static inline pte_t pte_mkcont(pte_t pte)
 186 {
 187         pte = set_pte_bit(pte, __pgprot(PTE_CONT));
 188         return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE));
 189 }
 190
 191 static inline pte_t pte_mknoncont(pte_t pte)
 192 {
 193         return clear_pte_bit(pte, __pgprot(PTE_CONT));
 194 }
 195
 196 static inline pte_t pte_mkpresent(pte_t pte)
 197 {
 198         return set_pte_bit(pte, __pgprot(PTE_VALID));
 199 }
 200
 201 static inline pmd_t pmd_mkcont(pmd_t pmd)
 202 {
 203         return __pmd(pmd_val(pmd) | PMD_SECT_CONT);
 204 }
 205
 206 static inline void set_pte(pte_t *ptep, pte_t pte)
 207 {
 208         *ptep = pte;
 209
 210         /*
 211          * Only if the new pte is valid and kernel, otherwise TLB maintenance
 212          * or update_mmu_cache() have the necessary barriers.
 213          */
 214         if (pte_valid_not_user(pte)) {
 215                 dsb(ishst);
 216                 isb();
 217         }
 218 }
 219
 220 extern void __sync_icache_dcache(pte_t pteval, unsigned long addr);
 221
 222 /*
 223  * PTE bits configuration in the presence of hardware Dirty Bit Management
 224  * (PTE_WRITE == PTE_DBM):
 225  *
 226  * Dirty  Writable | PTE_RDONLY  PTE_WRITE  PTE_DIRTY (sw)
 227  *   0      0      |   1           0          0
 228  *   0      1      |   1           1          0
 229  *   1      0      |   1           0          1
 230  *   1      1      |   0           1          x
 231  *
 232  * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via
 233  * the page fault mechanism. Checking the dirty status of a pte becomes:
 234  *
 235  *   PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY)
 236  */
 237 static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
 238                               pte_t *ptep, pte_t pte)
 239 {
 240         if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte))
 241                 __sync_icache_dcache(pte, addr);
 242
 243         /*
 244          * If the existing pte is valid, check for potential race with
 245          * hardware updates of the pte (ptep_set_access_flags safely changes
 246          * valid ptes without going through an invalid entry).
 247          */
 248         if (IS_ENABLED(CONFIG_DEBUG_VM) && pte_valid(*ptep) && pte_valid(pte) &&
 249            (mm == current->active_mm || atomic_read(&mm->mm_users) > 1)) {
 250                 VM_WARN_ONCE(!pte_young(pte),
 251                              "%s: racy access flag clearing: 0x%016llx -> 0x%016llx",
 252                              __func__, pte_val(*ptep), pte_val(pte));
 253                 VM_WARN_ONCE(pte_write(*ptep) && !pte_dirty(pte),
 254                              "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx",
 255                              __func__, pte_val(*ptep), pte_val(pte));
 256         }
 257
 258         set_pte(ptep, pte);
 259 }
 260
 261 #define __HAVE_ARCH_PTE_SAME
 262 static inline int pte_same(pte_t pte_a, pte_t pte_b)
 263 {
 264         pteval_t lhs, rhs;
 265
 266         lhs = pte_val(pte_a);
 267         rhs = pte_val(pte_b);
 268
 269         if (pte_present(pte_a))
 270                 lhs &= ~PTE_RDONLY;
 271
 272         if (pte_present(pte_b))
 273                 rhs &= ~PTE_RDONLY;
 274
 275         return (lhs == rhs);
 276 }
 277
 278 /*
 279  * Huge pte definitions.
 280  */
 281 #define pte_huge(pte)           (!(pte_val(pte) & PTE_TABLE_BIT))
 282 #define pte_mkhuge(pte)         (__pte(pte_val(pte) & ~PTE_TABLE_BIT))
 283
 284 /*
 285  * Hugetlb definitions.
 286  */
 287 #define HUGE_MAX_HSTATE         4
 288 #define HPAGE_SHIFT             PMD_SHIFT
 289 #define HPAGE_SIZE              (_AC(1, UL) << HPAGE_SHIFT)
 290 #define HPAGE_MASK              (~(HPAGE_SIZE - 1))
 291 #define HUGETLB_PAGE_ORDER      (HPAGE_SHIFT - PAGE_SHIFT)
 292
 293 #define __HAVE_ARCH_PTE_SPECIAL
 294
 295 static inline pte_t pud_pte(pud_t pud)
 296 {
 297         return __pte(pud_val(pud));
 298 }
 299
 300 static inline pmd_t pud_pmd(pud_t pud)
 301 {
 302         return __pmd(pud_val(pud));
 303 }
 304
 305 static inline pte_t pmd_pte(pmd_t pmd)
 306 {
 307         return __pte(pmd_val(pmd));
 308 }
 309
 310 static inline pmd_t pte_pmd(pte_t pte)
 311 {
 312         return __pmd(pte_val(pte));
 313 }
 314
 315 static inline pgprot_t mk_sect_prot(pgprot_t prot)
 316 {
 317         return __pgprot(pgprot_val(prot) & ~PTE_TABLE_BIT);
 318 }
 319
 320 #ifdef CONFIG_NUMA_BALANCING
 321 /*
 322  * See the comment in include/asm-generic/pgtable.h
 323  */
 324 static inline int pte_protnone(pte_t pte)
 325 {
 326         return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE;
 327 }
 328
 329 static inline int pmd_protnone(pmd_t pmd)
 330 {
 331         return pte_protnone(pmd_pte(pmd));
 332 }
 333 #endif
 334
 335 /*
 336  * THP definitions.
 337  */
 338
 339 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 340 #define pmd_trans_huge(pmd)     (pmd_val(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT))
 341 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 342
 343 #define pmd_present(pmd)        pte_present(pmd_pte(pmd))
 344 #define pmd_dirty(pmd)          pte_dirty(pmd_pte(pmd))
 345 #define pmd_young(pmd)          pte_young(pmd_pte(pmd))
 346 #define pmd_wrprotect(pmd)      pte_pmd(pte_wrprotect(pmd_pte(pmd)))
 347 #define pmd_mkold(pmd)          pte_pmd(pte_mkold(pmd_pte(pmd)))
 348 #define pmd_mkwrite(pmd)        pte_pmd(pte_mkwrite(pmd_pte(pmd)))
 349 #define pmd_mkclean(pmd)        pte_pmd(pte_mkclean(pmd_pte(pmd)))
 350 #define pmd_mkdirty(pmd)        pte_pmd(pte_mkdirty(pmd_pte(pmd)))
 351 #define pmd_mkyoung(pmd)        pte_pmd(pte_mkyoung(pmd_pte(pmd)))
 352 #define pmd_mknotpresent(pmd)   (__pmd(pmd_val(pmd) & ~PMD_SECT_VALID))
 353
 354 #define pmd_thp_or_huge(pmd)    (pmd_huge(pmd) || pmd_trans_huge(pmd))
 355
 356 #define pmd_write(pmd)          pte_write(pmd_pte(pmd))
 357
 358 #define pmd_mkhuge(pmd)         (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT))
 359
 360 #define pmd_pfn(pmd)            (((pmd_val(pmd) & PMD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 361 #define pfn_pmd(pfn,prot)       (__pmd(((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)))
 362 #define mk_pmd(page,prot)       pfn_pmd(page_to_pfn(page),prot)
 363
 364 #define pud_write(pud)          pte_write(pud_pte(pud))
 365 #define pud_pfn(pud)            (((pud_val(pud) & PUD_MASK) & PHYS_MASK) >> PAGE_SHIFT)
 366
 367 #define set_pmd_at(mm, addr, pmdp, pmd) set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd))
 368
 369 #define __pgprot_modify(prot,mask,bits) \
 370         __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
 371
 372 /*
 373  * Mark the prot value as uncacheable and unbufferable.
 374  */
 375 #define pgprot_noncached(prot) \
 376         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN)
 377 #define pgprot_writecombine(prot) \
 378         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN)
 379 #define pgprot_device(prot) \
 380         __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN)
 381 #define __HAVE_PHYS_MEM_ACCESS_PROT
 382 struct file;
 383 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
 384                                      unsigned long size, pgprot_t vma_prot);
 385
 386 #define pmd_none(pmd)           (!pmd_val(pmd))
 387
 388 #define pmd_bad(pmd)            (!(pmd_val(pmd) & PMD_TABLE_BIT))
 389
 390 #define pmd_table(pmd)          ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 391                                  PMD_TYPE_TABLE)
 392 #define pmd_sect(pmd)           ((pmd_val(pmd) & PMD_TYPE_MASK) == \
 393                                  PMD_TYPE_SECT)
 394
 395 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
 396 #define pud_sect(pud)           (0)
 397 #define pud_table(pud)          (1)
 398 #else
 399 #define pud_sect(pud)           ((pud_val(pud) & PUD_TYPE_MASK) == \
 400                                  PUD_TYPE_SECT)
 401 #define pud_table(pud)          ((pud_val(pud) & PUD_TYPE_MASK) == \
 402                                  PUD_TYPE_TABLE)
 403 #endif
 404
 405 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
 406 {
 407         *pmdp = pmd;
 408         dsb(ishst);
 409         isb();
 410 }
 411
 412 static inline void pmd_clear(pmd_t *pmdp)
 413 {
 414         set_pmd(pmdp, __pmd(0));
 415 }
 416
 417 static inline phys_addr_t pmd_page_paddr(pmd_t pmd)
 418 {
 419         return pmd_val(pmd) & PHYS_MASK & (s32)PAGE_MASK;
 420 }
 421
 422 /* Find an entry in the third-level page table. */
 423 #define pte_index(addr)         (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
 424
 425 #define pte_offset_phys(dir,addr)       (pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t))
 426 #define pte_offset_kernel(dir,addr)     ((pte_t *)__va(pte_offset_phys((dir), (addr))))
 427
 428 #define pte_offset_map(dir,addr)        pte_offset_kernel((dir), (addr))
 429 #define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir), (addr))
 430 #define pte_unmap(pte)                  do { } while (0)
 431 #define pte_unmap_nested(pte)           do { } while (0)
 432
 433 #define pte_set_fixmap(addr)            ((pte_t *)set_fixmap_offset(FIX_PTE, addr))
 434 #define pte_set_fixmap_offset(pmd, addr)        pte_set_fixmap(pte_offset_phys(pmd, addr))
 435 #define pte_clear_fixmap()              clear_fixmap(FIX_PTE)
 436
 437 #define pmd_page(pmd)           pfn_to_page(__phys_to_pfn(pmd_val(pmd) & PHYS_MASK))
 438
 439 /* use ONLY for statically allocated translation tables */
 440 #define pte_offset_kimg(dir,addr)       ((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr))))
 441
 442 /*
 443  * Conversion functions: convert a page and protection to a page entry,
 444  * and a page entry and page directory to the page they refer to.
 445  */
 446 #define mk_pte(page,prot)       pfn_pte(page_to_pfn(page),prot)
 447
 448 #if CONFIG_PGTABLE_LEVELS > 2
 449
 450 #define pmd_ERROR(pmd)          __pmd_error(__FILE__, __LINE__, pmd_val(pmd))
 451
 452 #define pud_none(pud)           (!pud_val(pud))
 453 #define pud_bad(pud)            (!(pud_val(pud) & PUD_TABLE_BIT))
 454 #define pud_present(pud)        pte_present(pud_pte(pud))
 455
 456 static inline void set_pud(pud_t *pudp, pud_t pud)
 457 {
 458         *pudp = pud;
 459         dsb(ishst);
 460         isb();
 461 }
 462
 463 static inline void pud_clear(pud_t *pudp)
 464 {
 465         set_pud(pudp, __pud(0));
 466 }
 467
 468 static inline phys_addr_t pud_page_paddr(pud_t pud)
 469 {
 470         return pud_val(pud) & PHYS_MASK & (s32)PAGE_MASK;
 471 }
 472
 473 /* Find an entry in the second-level page table. */
 474 #define pmd_index(addr)         (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
 475
 476 #define pmd_offset_phys(dir, addr)      (pud_page_paddr(*(dir)) + pmd_index(addr) * sizeof(pmd_t))
 477 #define pmd_offset(dir, addr)           ((pmd_t *)__va(pmd_offset_phys((dir), (addr))))
 478
 479 #define pmd_set_fixmap(addr)            ((pmd_t *)set_fixmap_offset(FIX_PMD, addr))
 480 #define pmd_set_fixmap_offset(pud, addr)        pmd_set_fixmap(pmd_offset_phys(pud, addr))
 481 #define pmd_clear_fixmap()              clear_fixmap(FIX_PMD)
 482
 483 #define pud_page(pud)           pfn_to_page(__phys_to_pfn(pud_val(pud) & PHYS_MASK))
 484
 485 /* use ONLY for statically allocated translation tables */
 486 #define pmd_offset_kimg(dir,addr)       ((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr))))
 487
 488 #else
 489
 490 #define pud_page_paddr(pud)     ({ BUILD_BUG(); 0; })
 491
 492 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
 493 #define pmd_set_fixmap(addr)            NULL
 494 #define pmd_set_fixmap_offset(pudp, addr)       ((pmd_t *)pudp)
 495 #define pmd_clear_fixmap()
 496
 497 #define pmd_offset_kimg(dir,addr)       ((pmd_t *)dir)
 498
 499 #endif  /* CONFIG_PGTABLE_LEVELS > 2 */
 500
 501 #if CONFIG_PGTABLE_LEVELS > 3
 502
 503 #define pud_ERROR(pud)          __pud_error(__FILE__, __LINE__, pud_val(pud))
 504
 505 #define pgd_none(pgd)           (!pgd_val(pgd))
 506 #define pgd_bad(pgd)            (!(pgd_val(pgd) & 2))
 507 #define pgd_present(pgd)        (pgd_val(pgd))
 508
 509 static inline void set_pgd(pgd_t *pgdp, pgd_t pgd)
 510 {
 511         *pgdp = pgd;
 512         dsb(ishst);
 513 }
 514
 515 static inline void pgd_clear(pgd_t *pgdp)
 516 {
 517         set_pgd(pgdp, __pgd(0));
 518 }
 519
 520 static inline phys_addr_t pgd_page_paddr(pgd_t pgd)
 521 {
 522         return pgd_val(pgd) & PHYS_MASK & (s32)PAGE_MASK;
 523 }
 524
 525 /* Find an entry in the frst-level page table. */
 526 #define pud_index(addr)         (((addr) >> PUD_SHIFT) & (PTRS_PER_PUD - 1))
 527
 528 #define pud_offset_phys(dir, addr)      (pgd_page_paddr(*(dir)) + pud_index(addr) * sizeof(pud_t))
 529 #define pud_offset(dir, addr)           ((pud_t *)__va(pud_offset_phys((dir), (addr))))
 530
 531 #define pud_set_fixmap(addr)            ((pud_t *)set_fixmap_offset(FIX_PUD, addr))
 532 #define pud_set_fixmap_offset(pgd, addr)        pud_set_fixmap(pud_offset_phys(pgd, addr))
 533 #define pud_clear_fixmap()              clear_fixmap(FIX_PUD)
 534
 535 #define pgd_page(pgd)           pfn_to_page(__phys_to_pfn(pgd_val(pgd) & PHYS_MASK))
 536
 537 /* use ONLY for statically allocated translation tables */
 538 #define pud_offset_kimg(dir,addr)       ((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr))))
 539
 540 #else
 541
 542 #define pgd_page_paddr(pgd)     ({ BUILD_BUG(); 0;})
 543
 544 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */
 545 #define pud_set_fixmap(addr)            NULL
 546 #define pud_set_fixmap_offset(pgdp, addr)       ((pud_t *)pgdp)
 547 #define pud_clear_fixmap()
 548
 549 #define pud_offset_kimg(dir,addr)       ((pud_t *)dir)
 550
 551 #endif  /* CONFIG_PGTABLE_LEVELS > 3 */
 552
 553 #define pgd_ERROR(pgd)          __pgd_error(__FILE__, __LINE__, pgd_val(pgd))
 554
 555 /* to find an entry in a page-table-directory */
 556 #define pgd_index(addr)         (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
 557
 558 #define pgd_offset_raw(pgd, addr)       ((pgd) + pgd_index(addr))
 559
 560 #define pgd_offset(mm, addr)    (pgd_offset_raw((mm)->pgd, (addr)))
 561
 562 /* to find an entry in a kernel page-table-directory */
 563 #define pgd_offset_k(addr)      pgd_offset(&init_mm, addr)
 564
 565 #define pgd_set_fixmap(addr)    ((pgd_t *)set_fixmap_offset(FIX_PGD, addr))
 566 #define pgd_clear_fixmap()      clear_fixmap(FIX_PGD)
 567
 568 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
 569 {
 570         const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY |
 571                               PTE_PROT_NONE | PTE_VALID | PTE_WRITE;
 572         /* preserve the hardware dirty information */
 573         if (pte_hw_dirty(pte))
 574                 pte = pte_mkdirty(pte);
 575         pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
 576         return pte;
 577 }
 578
 579 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
 580 {
 581         return pte_pmd(pte_modify(pmd_pte(pmd), newprot));
 582 }
 583
 584 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
 585 extern int ptep_set_access_flags(struct vm_area_struct *vma,
 586                                  unsigned long address, pte_t *ptep,
 587                                  pte_t entry, int dirty);
 588
 589 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 590 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
 591 static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
 592                                         unsigned long address, pmd_t *pmdp,
 593                                         pmd_t entry, int dirty)
 594 {
 595         return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty);
 596 }
 597 #endif
 598
 599 /*
 600  * Atomic pte/pmd modifications.
 601  */
 602 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
 603 static inline int __ptep_test_and_clear_young(pte_t *ptep)
 604 {
 605         pte_t old_pte, pte;
 606
 607         pte = READ_ONCE(*ptep);
 608         do {
 609                 old_pte = pte;
 610                 pte = pte_mkold(pte);
 611                 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
 612                                                pte_val(old_pte), pte_val(pte));
 613         } while (pte_val(pte) != pte_val(old_pte));
 614
 615         return pte_young(pte);
 616 }
 617
 618 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
 619                                             unsigned long address,
 620                                             pte_t *ptep)
 621 {
 622         return __ptep_test_and_clear_young(ptep);
 623 }
 624
 625 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 626 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
 627 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
 628                                             unsigned long address,
 629                                             pmd_t *pmdp)
 630 {
 631         return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp);
 632 }
 633 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 634
 635 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
 636 static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
 637                                        unsigned long address, pte_t *ptep)
 638 {
 639         return __pte(xchg_relaxed(&pte_val(*ptep), 0));
 640 }
 641
 642 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 643 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
 644 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
 645                                             unsigned long address, pmd_t *pmdp)
 646 {
 647         return pte_pmd(ptep_get_and_clear(mm, address, (pte_t *)pmdp));
 648 }
 649 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */
 650
 651 /*
 652  * ptep_set_wrprotect - mark read-only while trasferring potential hardware
 653  * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit.
 654  */
 655 #define __HAVE_ARCH_PTEP_SET_WRPROTECT
 656 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
 657 {
 658         pte_t old_pte, pte;
 659
 660         pte = READ_ONCE(*ptep);
 661         do {
 662                 old_pte = pte;
 663                 /*
 664                  * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY
 665                  * clear), set the PTE_DIRTY bit.
 666                  */
 667                 if (pte_hw_dirty(pte))
 668                         pte = pte_mkdirty(pte);
 669                 pte = pte_wrprotect(pte);
 670                 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep),
 671                                                pte_val(old_pte), pte_val(pte));
 672         } while (pte_val(pte) != pte_val(old_pte));
 673 }
 674
 675 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
 676 #define __HAVE_ARCH_PMDP_SET_WRPROTECT
 677 static inline void pmdp_set_wrprotect(struct mm_struct *mm,
 678                                       unsigned long address, pmd_t *pmdp)
 679 {
 680         ptep_set_wrprotect(mm, address, (pte_t *)pmdp);
 681 }
 682 #endif
 683
 684 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 685 extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
 686
 687 /*
 688  * Encode and decode a swap entry:
 689  *      bits 0-1:       present (must be zero)
 690  *      bits 2-7:       swap type
 691  *      bits 8-57:      swap offset
 692  *      bit  58:        PTE_PROT_NONE (must be zero)
 693  */
 694 #define __SWP_TYPE_SHIFT        2
 695 #define __SWP_TYPE_BITS         6
 696 #define __SWP_OFFSET_BITS       50
 697 #define __SWP_TYPE_MASK         ((1 << __SWP_TYPE_BITS) - 1)
 698 #define __SWP_OFFSET_SHIFT      (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
 699 #define __SWP_OFFSET_MASK       ((1UL << __SWP_OFFSET_BITS) - 1)
 700
 701 #define __swp_type(x)           (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
 702 #define __swp_offset(x)         (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
 703 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
 704
 705 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
 706 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
 707
 708 /*
 709  * Ensure that there are not more swap files than can be encoded in the kernel
 710  * PTEs.
 711  */
 712 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
 713
 714 extern int kern_addr_valid(unsigned long addr);
 715
 716 #include <asm-generic/pgtable.h>
 717
 718 void pgd_cache_init(void);
 719 #define pgtable_cache_init      pgd_cache_init
 720
 721 /*
 722  * On AArch64, the cache coherency is handled via the set_pte_at() function.
 723  */
 724 static inline void update_mmu_cache(struct vm_area_struct *vma,
 725                                     unsigned long addr, pte_t *ptep)
 726 {
 727         /*
 728          * We don't do anything here, so there's a very small chance of
 729          * us retaking a user fault which we just fixed up. The alternative
 730          * is doing a dsb(ishst), but that penalises the fastpath.
 731          */
 732 }
 733
 734 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0)
 735
 736 #define kc_vaddr_to_offset(v)   ((v) & ~VA_START)
 737 #define kc_offset_to_vaddr(o)   ((o) | VA_START)
 738
 739 #endif /* !__ASSEMBLY__ */
 740
 741 #endif /* __ASM_PGTABLE_H */