1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* 3 * Copyright (C) 2012 ARM Ltd. 4 */ 5 #ifndef __ASM_PGTABLE_H 6 #define __ASM_PGTABLE_H 7 8 #include <asm/bug.h> 9 #include <asm/proc-fns.h> 10 11 #include <asm/memory.h> 12 #include <asm/mte.h> 13 #include <asm/pgtable-hwdef.h> 14 #include <asm/pgtable-prot.h> 15 #include <asm/tlbflush.h> 16 17 /* 18 * VMALLOC range. 19 * 20 * VMALLOC_START: beginning of the kernel vmalloc space 21 * VMALLOC_END: extends to the available space below vmemmap, PCI I/O space 22 * and fixed mappings 23 */ 24 #define VMALLOC_START (MODULES_END) 25 #define VMALLOC_END (VMEMMAP_START - SZ_256M) 26 27 #define vmemmap ((struct page *)VMEMMAP_START - (memstart_addr >> PAGE_SHIFT)) 28 29 #ifndef __ASSEMBLY__ 30 31 #include <asm/cmpxchg.h> 32 #include <asm/fixmap.h> 33 #include <linux/mmdebug.h> 34 #include <linux/mm_types.h> 35 #include <linux/sched.h> 36 #include <linux/page_table_check.h> 37 38 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 39 #define __HAVE_ARCH_FLUSH_PMD_TLB_RANGE 40 41 /* Set stride and tlb_level in flush_*_tlb_range */ 42 #define flush_pmd_tlb_range(vma, addr, end) \ 43 __flush_tlb_range(vma, addr, end, PMD_SIZE, false, 2) 44 #define flush_pud_tlb_range(vma, addr, end) \ 45 __flush_tlb_range(vma, addr, end, PUD_SIZE, false, 1) 46 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 47 48 static inline bool arch_thp_swp_supported(void) 49 { 50 return !system_supports_mte(); 51 } 52 #define arch_thp_swp_supported arch_thp_swp_supported 53 54 /* 55 * Outside of a few very special situations (e.g. hibernation), we always 56 * use broadcast TLB invalidation instructions, therefore a spurious page 57 * fault on one CPU which has been handled concurrently by another CPU 58 * does not need to perform additional invalidation. 59 */ 60 #define flush_tlb_fix_spurious_fault(vma, address, ptep) do { } while (0) 61 62 /* 63 * ZERO_PAGE is a global shared page that is always zero: used 64 * for zero-mapped memory areas etc.. 65 */ 66 extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; 67 #define ZERO_PAGE(vaddr) phys_to_page(__pa_symbol(empty_zero_page)) 68 69 #define pte_ERROR(e) \ 70 pr_err("%s:%d: bad pte %016llx.\n", __FILE__, __LINE__, pte_val(e)) 71 72 /* 73 * Macros to convert between a physical address and its placement in a 74 * page table entry, taking care of 52-bit addresses. 75 */ 76 #ifdef CONFIG_ARM64_PA_BITS_52 77 static inline phys_addr_t __pte_to_phys(pte_t pte) 78 { 79 return (pte_val(pte) & PTE_ADDR_LOW) | 80 ((pte_val(pte) & PTE_ADDR_HIGH) << PTE_ADDR_HIGH_SHIFT); 81 } 82 static inline pteval_t __phys_to_pte_val(phys_addr_t phys) 83 { 84 return (phys | (phys >> PTE_ADDR_HIGH_SHIFT)) & PTE_ADDR_MASK; 85 } 86 #else 87 #define __pte_to_phys(pte) (pte_val(pte) & PTE_ADDR_MASK) 88 #define __phys_to_pte_val(phys) (phys) 89 #endif 90 91 #define pte_pfn(pte) (__pte_to_phys(pte) >> PAGE_SHIFT) 92 #define pfn_pte(pfn,prot) \ 93 __pte(__phys_to_pte_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) 94 95 #define pte_none(pte) (!pte_val(pte)) 96 #define pte_clear(mm,addr,ptep) set_pte(ptep, __pte(0)) 97 #define pte_page(pte) (pfn_to_page(pte_pfn(pte))) 98 99 /* 100 * The following only work if pte_present(). Undefined behaviour otherwise. 101 */ 102 #define pte_present(pte) (!!(pte_val(pte) & (PTE_VALID | PTE_PROT_NONE))) 103 #define pte_young(pte) (!!(pte_val(pte) & PTE_AF)) 104 #define pte_special(pte) (!!(pte_val(pte) & PTE_SPECIAL)) 105 #define pte_write(pte) (!!(pte_val(pte) & PTE_WRITE)) 106 #define pte_rdonly(pte) (!!(pte_val(pte) & PTE_RDONLY)) 107 #define pte_user(pte) (!!(pte_val(pte) & PTE_USER)) 108 #define pte_user_exec(pte) (!(pte_val(pte) & PTE_UXN)) 109 #define pte_cont(pte) (!!(pte_val(pte) & PTE_CONT)) 110 #define pte_devmap(pte) (!!(pte_val(pte) & PTE_DEVMAP)) 111 #define pte_tagged(pte) ((pte_val(pte) & PTE_ATTRINDX_MASK) == \ 112 PTE_ATTRINDX(MT_NORMAL_TAGGED)) 113 114 #define pte_cont_addr_end(addr, end) \ 115 ({ unsigned long __boundary = ((addr) + CONT_PTE_SIZE) & CONT_PTE_MASK; \ 116 (__boundary - 1 < (end) - 1) ? __boundary : (end); \ 117 }) 118 119 #define pmd_cont_addr_end(addr, end) \ 120 ({ unsigned long __boundary = ((addr) + CONT_PMD_SIZE) & CONT_PMD_MASK; \ 121 (__boundary - 1 < (end) - 1) ? __boundary : (end); \ 122 }) 123 124 #define pte_hw_dirty(pte) (pte_write(pte) && !pte_rdonly(pte)) 125 #define pte_sw_dirty(pte) (!!(pte_val(pte) & PTE_DIRTY)) 126 #define pte_dirty(pte) (pte_sw_dirty(pte) || pte_hw_dirty(pte)) 127 128 #define pte_valid(pte) (!!(pte_val(pte) & PTE_VALID)) 129 /* 130 * Execute-only user mappings do not have the PTE_USER bit set. All valid 131 * kernel mappings have the PTE_UXN bit set. 132 */ 133 #define pte_valid_not_user(pte) \ 134 ((pte_val(pte) & (PTE_VALID | PTE_USER | PTE_UXN)) == (PTE_VALID | PTE_UXN)) 135 /* 136 * Could the pte be present in the TLB? We must check mm_tlb_flush_pending 137 * so that we don't erroneously return false for pages that have been 138 * remapped as PROT_NONE but are yet to be flushed from the TLB. 139 * Note that we can't make any assumptions based on the state of the access 140 * flag, since ptep_clear_flush_young() elides a DSB when invalidating the 141 * TLB. 142 */ 143 #define pte_accessible(mm, pte) \ 144 (mm_tlb_flush_pending(mm) ? pte_present(pte) : pte_valid(pte)) 145 146 /* 147 * p??_access_permitted() is true for valid user mappings (PTE_USER 148 * bit set, subject to the write permission check). For execute-only 149 * mappings, like PROT_EXEC with EPAN (both PTE_USER and PTE_UXN bits 150 * not set) must return false. PROT_NONE mappings do not have the 151 * PTE_VALID bit set. 152 */ 153 #define pte_access_permitted(pte, write) \ 154 (((pte_val(pte) & (PTE_VALID | PTE_USER)) == (PTE_VALID | PTE_USER)) && (!(write) || pte_write(pte))) 155 #define pmd_access_permitted(pmd, write) \ 156 (pte_access_permitted(pmd_pte(pmd), (write))) 157 #define pud_access_permitted(pud, write) \ 158 (pte_access_permitted(pud_pte(pud), (write))) 159 160 static inline pte_t clear_pte_bit(pte_t pte, pgprot_t prot) 161 { 162 pte_val(pte) &= ~pgprot_val(prot); 163 return pte; 164 } 165 166 static inline pte_t set_pte_bit(pte_t pte, pgprot_t prot) 167 { 168 pte_val(pte) |= pgprot_val(prot); 169 return pte; 170 } 171 172 static inline pmd_t clear_pmd_bit(pmd_t pmd, pgprot_t prot) 173 { 174 pmd_val(pmd) &= ~pgprot_val(prot); 175 return pmd; 176 } 177 178 static inline pmd_t set_pmd_bit(pmd_t pmd, pgprot_t prot) 179 { 180 pmd_val(pmd) |= pgprot_val(prot); 181 return pmd; 182 } 183 184 static inline pte_t pte_mkwrite_novma(pte_t pte) 185 { 186 pte = set_pte_bit(pte, __pgprot(PTE_WRITE)); 187 pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY)); 188 return pte; 189 } 190 191 static inline pte_t pte_mkclean(pte_t pte) 192 { 193 pte = clear_pte_bit(pte, __pgprot(PTE_DIRTY)); 194 pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); 195 196 return pte; 197 } 198 199 static inline pte_t pte_mkdirty(pte_t pte) 200 { 201 pte = set_pte_bit(pte, __pgprot(PTE_DIRTY)); 202 203 if (pte_write(pte)) 204 pte = clear_pte_bit(pte, __pgprot(PTE_RDONLY)); 205 206 return pte; 207 } 208 209 static inline pte_t pte_wrprotect(pte_t pte) 210 { 211 /* 212 * If hardware-dirty (PTE_WRITE/DBM bit set and PTE_RDONLY 213 * clear), set the PTE_DIRTY bit. 214 */ 215 if (pte_hw_dirty(pte)) 216 pte = set_pte_bit(pte, __pgprot(PTE_DIRTY)); 217 218 pte = clear_pte_bit(pte, __pgprot(PTE_WRITE)); 219 pte = set_pte_bit(pte, __pgprot(PTE_RDONLY)); 220 return pte; 221 } 222 223 static inline pte_t pte_mkold(pte_t pte) 224 { 225 return clear_pte_bit(pte, __pgprot(PTE_AF)); 226 } 227 228 static inline pte_t pte_mkyoung(pte_t pte) 229 { 230 return set_pte_bit(pte, __pgprot(PTE_AF)); 231 } 232 233 static inline pte_t pte_mkspecial(pte_t pte) 234 { 235 return set_pte_bit(pte, __pgprot(PTE_SPECIAL)); 236 } 237 238 static inline pte_t pte_mkcont(pte_t pte) 239 { 240 pte = set_pte_bit(pte, __pgprot(PTE_CONT)); 241 return set_pte_bit(pte, __pgprot(PTE_TYPE_PAGE)); 242 } 243 244 static inline pte_t pte_mknoncont(pte_t pte) 245 { 246 return clear_pte_bit(pte, __pgprot(PTE_CONT)); 247 } 248 249 static inline pte_t pte_mkpresent(pte_t pte) 250 { 251 return set_pte_bit(pte, __pgprot(PTE_VALID)); 252 } 253 254 static inline pmd_t pmd_mkcont(pmd_t pmd) 255 { 256 return __pmd(pmd_val(pmd) | PMD_SECT_CONT); 257 } 258 259 static inline pte_t pte_mkdevmap(pte_t pte) 260 { 261 return set_pte_bit(pte, __pgprot(PTE_DEVMAP | PTE_SPECIAL)); 262 } 263 264 static inline void set_pte(pte_t *ptep, pte_t pte) 265 { 266 WRITE_ONCE(*ptep, pte); 267 268 /* 269 * Only if the new pte is valid and kernel, otherwise TLB maintenance 270 * or update_mmu_cache() have the necessary barriers. 271 */ 272 if (pte_valid_not_user(pte)) { 273 dsb(ishst); 274 isb(); 275 } 276 } 277 278 extern void __sync_icache_dcache(pte_t pteval); 279 bool pgattr_change_is_safe(u64 old, u64 new); 280 281 /* 282 * PTE bits configuration in the presence of hardware Dirty Bit Management 283 * (PTE_WRITE == PTE_DBM): 284 * 285 * Dirty Writable | PTE_RDONLY PTE_WRITE PTE_DIRTY (sw) 286 * 0 0 | 1 0 0 287 * 0 1 | 1 1 0 288 * 1 0 | 1 0 1 289 * 1 1 | 0 1 x 290 * 291 * When hardware DBM is not present, the sofware PTE_DIRTY bit is updated via 292 * the page fault mechanism. Checking the dirty status of a pte becomes: 293 * 294 * PTE_DIRTY || (PTE_WRITE && !PTE_RDONLY) 295 */ 296 297 static inline void __check_safe_pte_update(struct mm_struct *mm, pte_t *ptep, 298 pte_t pte) 299 { 300 pte_t old_pte; 301 302 if (!IS_ENABLED(CONFIG_DEBUG_VM)) 303 return; 304 305 old_pte = READ_ONCE(*ptep); 306 307 if (!pte_valid(old_pte) || !pte_valid(pte)) 308 return; 309 if (mm != current->active_mm && atomic_read(&mm->mm_users) <= 1) 310 return; 311 312 /* 313 * Check for potential race with hardware updates of the pte 314 * (ptep_set_access_flags safely changes valid ptes without going 315 * through an invalid entry). 316 */ 317 VM_WARN_ONCE(!pte_young(pte), 318 "%s: racy access flag clearing: 0x%016llx -> 0x%016llx", 319 __func__, pte_val(old_pte), pte_val(pte)); 320 VM_WARN_ONCE(pte_write(old_pte) && !pte_dirty(pte), 321 "%s: racy dirty state clearing: 0x%016llx -> 0x%016llx", 322 __func__, pte_val(old_pte), pte_val(pte)); 323 VM_WARN_ONCE(!pgattr_change_is_safe(pte_val(old_pte), pte_val(pte)), 324 "%s: unsafe attribute change: 0x%016llx -> 0x%016llx", 325 __func__, pte_val(old_pte), pte_val(pte)); 326 } 327 328 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, 329 pte_t *ptep, pte_t pte) 330 { 331 if (pte_present(pte) && pte_user_exec(pte) && !pte_special(pte)) 332 __sync_icache_dcache(pte); 333 334 /* 335 * If the PTE would provide user space access to the tags associated 336 * with it then ensure that the MTE tags are synchronised. Although 337 * pte_access_permitted() returns false for exec only mappings, they 338 * don't expose tags (instruction fetches don't check tags). 339 */ 340 if (system_supports_mte() && pte_access_permitted(pte, false) && 341 !pte_special(pte) && pte_tagged(pte)) 342 mte_sync_tags(pte); 343 344 __check_safe_pte_update(mm, ptep, pte); 345 346 set_pte(ptep, pte); 347 } 348 349 static inline void set_ptes(struct mm_struct *mm, unsigned long addr, 350 pte_t *ptep, pte_t pte, unsigned int nr) 351 { 352 page_table_check_ptes_set(mm, ptep, pte, nr); 353 354 for (;;) { 355 __set_pte_at(mm, addr, ptep, pte); 356 if (--nr == 0) 357 break; 358 ptep++; 359 addr += PAGE_SIZE; 360 pte_val(pte) += PAGE_SIZE; 361 } 362 } 363 #define set_ptes set_ptes 364 365 /* 366 * Huge pte definitions. 367 */ 368 #define pte_mkhuge(pte) (__pte(pte_val(pte) & ~PTE_TABLE_BIT)) 369 370 /* 371 * Hugetlb definitions. 372 */ 373 #define HUGE_MAX_HSTATE 4 374 #define HPAGE_SHIFT PMD_SHIFT 375 #define HPAGE_SIZE (_AC(1, UL) << HPAGE_SHIFT) 376 #define HPAGE_MASK (~(HPAGE_SIZE - 1)) 377 #define HUGETLB_PAGE_ORDER (HPAGE_SHIFT - PAGE_SHIFT) 378 379 static inline pte_t pgd_pte(pgd_t pgd) 380 { 381 return __pte(pgd_val(pgd)); 382 } 383 384 static inline pte_t p4d_pte(p4d_t p4d) 385 { 386 return __pte(p4d_val(p4d)); 387 } 388 389 static inline pte_t pud_pte(pud_t pud) 390 { 391 return __pte(pud_val(pud)); 392 } 393 394 static inline pud_t pte_pud(pte_t pte) 395 { 396 return __pud(pte_val(pte)); 397 } 398 399 static inline pmd_t pud_pmd(pud_t pud) 400 { 401 return __pmd(pud_val(pud)); 402 } 403 404 static inline pte_t pmd_pte(pmd_t pmd) 405 { 406 return __pte(pmd_val(pmd)); 407 } 408 409 static inline pmd_t pte_pmd(pte_t pte) 410 { 411 return __pmd(pte_val(pte)); 412 } 413 414 static inline pgprot_t mk_pud_sect_prot(pgprot_t prot) 415 { 416 return __pgprot((pgprot_val(prot) & ~PUD_TABLE_BIT) | PUD_TYPE_SECT); 417 } 418 419 static inline pgprot_t mk_pmd_sect_prot(pgprot_t prot) 420 { 421 return __pgprot((pgprot_val(prot) & ~PMD_TABLE_BIT) | PMD_TYPE_SECT); 422 } 423 424 static inline pte_t pte_swp_mkexclusive(pte_t pte) 425 { 426 return set_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE)); 427 } 428 429 static inline int pte_swp_exclusive(pte_t pte) 430 { 431 return pte_val(pte) & PTE_SWP_EXCLUSIVE; 432 } 433 434 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 435 { 436 return clear_pte_bit(pte, __pgprot(PTE_SWP_EXCLUSIVE)); 437 } 438 439 /* 440 * Select all bits except the pfn 441 */ 442 static inline pgprot_t pte_pgprot(pte_t pte) 443 { 444 unsigned long pfn = pte_pfn(pte); 445 446 return __pgprot(pte_val(pfn_pte(pfn, __pgprot(0))) ^ pte_val(pte)); 447 } 448 449 #ifdef CONFIG_NUMA_BALANCING 450 /* 451 * See the comment in include/linux/pgtable.h 452 */ 453 static inline int pte_protnone(pte_t pte) 454 { 455 return (pte_val(pte) & (PTE_VALID | PTE_PROT_NONE)) == PTE_PROT_NONE; 456 } 457 458 static inline int pmd_protnone(pmd_t pmd) 459 { 460 return pte_protnone(pmd_pte(pmd)); 461 } 462 #endif 463 464 #define pmd_present_invalid(pmd) (!!(pmd_val(pmd) & PMD_PRESENT_INVALID)) 465 466 static inline int pmd_present(pmd_t pmd) 467 { 468 return pte_present(pmd_pte(pmd)) || pmd_present_invalid(pmd); 469 } 470 471 /* 472 * THP definitions. 473 */ 474 475 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 476 static inline int pmd_trans_huge(pmd_t pmd) 477 { 478 return pmd_val(pmd) && pmd_present(pmd) && !(pmd_val(pmd) & PMD_TABLE_BIT); 479 } 480 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 481 482 #define pmd_dirty(pmd) pte_dirty(pmd_pte(pmd)) 483 #define pmd_young(pmd) pte_young(pmd_pte(pmd)) 484 #define pmd_valid(pmd) pte_valid(pmd_pte(pmd)) 485 #define pmd_user(pmd) pte_user(pmd_pte(pmd)) 486 #define pmd_user_exec(pmd) pte_user_exec(pmd_pte(pmd)) 487 #define pmd_cont(pmd) pte_cont(pmd_pte(pmd)) 488 #define pmd_wrprotect(pmd) pte_pmd(pte_wrprotect(pmd_pte(pmd))) 489 #define pmd_mkold(pmd) pte_pmd(pte_mkold(pmd_pte(pmd))) 490 #define pmd_mkwrite_novma(pmd) pte_pmd(pte_mkwrite_novma(pmd_pte(pmd))) 491 #define pmd_mkclean(pmd) pte_pmd(pte_mkclean(pmd_pte(pmd))) 492 #define pmd_mkdirty(pmd) pte_pmd(pte_mkdirty(pmd_pte(pmd))) 493 #define pmd_mkyoung(pmd) pte_pmd(pte_mkyoung(pmd_pte(pmd))) 494 495 static inline pmd_t pmd_mkinvalid(pmd_t pmd) 496 { 497 pmd = set_pmd_bit(pmd, __pgprot(PMD_PRESENT_INVALID)); 498 pmd = clear_pmd_bit(pmd, __pgprot(PMD_SECT_VALID)); 499 500 return pmd; 501 } 502 503 #define pmd_thp_or_huge(pmd) (pmd_huge(pmd) || pmd_trans_huge(pmd)) 504 505 #define pmd_write(pmd) pte_write(pmd_pte(pmd)) 506 507 #define pmd_mkhuge(pmd) (__pmd(pmd_val(pmd) & ~PMD_TABLE_BIT)) 508 509 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 510 #define pmd_devmap(pmd) pte_devmap(pmd_pte(pmd)) 511 #endif 512 static inline pmd_t pmd_mkdevmap(pmd_t pmd) 513 { 514 return pte_pmd(set_pte_bit(pmd_pte(pmd), __pgprot(PTE_DEVMAP))); 515 } 516 517 #define __pmd_to_phys(pmd) __pte_to_phys(pmd_pte(pmd)) 518 #define __phys_to_pmd_val(phys) __phys_to_pte_val(phys) 519 #define pmd_pfn(pmd) ((__pmd_to_phys(pmd) & PMD_MASK) >> PAGE_SHIFT) 520 #define pfn_pmd(pfn,prot) __pmd(__phys_to_pmd_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) 521 #define mk_pmd(page,prot) pfn_pmd(page_to_pfn(page),prot) 522 523 #define pud_young(pud) pte_young(pud_pte(pud)) 524 #define pud_mkyoung(pud) pte_pud(pte_mkyoung(pud_pte(pud))) 525 #define pud_write(pud) pte_write(pud_pte(pud)) 526 527 #define pud_mkhuge(pud) (__pud(pud_val(pud) & ~PUD_TABLE_BIT)) 528 529 #define __pud_to_phys(pud) __pte_to_phys(pud_pte(pud)) 530 #define __phys_to_pud_val(phys) __phys_to_pte_val(phys) 531 #define pud_pfn(pud) ((__pud_to_phys(pud) & PUD_MASK) >> PAGE_SHIFT) 532 #define pfn_pud(pfn,prot) __pud(__phys_to_pud_val((phys_addr_t)(pfn) << PAGE_SHIFT) | pgprot_val(prot)) 533 534 static inline void set_pmd_at(struct mm_struct *mm, unsigned long addr, 535 pmd_t *pmdp, pmd_t pmd) 536 { 537 page_table_check_pmd_set(mm, pmdp, pmd); 538 return __set_pte_at(mm, addr, (pte_t *)pmdp, pmd_pte(pmd)); 539 } 540 541 static inline void set_pud_at(struct mm_struct *mm, unsigned long addr, 542 pud_t *pudp, pud_t pud) 543 { 544 page_table_check_pud_set(mm, pudp, pud); 545 return __set_pte_at(mm, addr, (pte_t *)pudp, pud_pte(pud)); 546 } 547 548 #define __p4d_to_phys(p4d) __pte_to_phys(p4d_pte(p4d)) 549 #define __phys_to_p4d_val(phys) __phys_to_pte_val(phys) 550 551 #define __pgd_to_phys(pgd) __pte_to_phys(pgd_pte(pgd)) 552 #define __phys_to_pgd_val(phys) __phys_to_pte_val(phys) 553 554 #define __pgprot_modify(prot,mask,bits) \ 555 __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) 556 557 #define pgprot_nx(prot) \ 558 __pgprot_modify(prot, PTE_MAYBE_GP, PTE_PXN) 559 560 /* 561 * Mark the prot value as uncacheable and unbufferable. 562 */ 563 #define pgprot_noncached(prot) \ 564 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRnE) | PTE_PXN | PTE_UXN) 565 #define pgprot_writecombine(prot) \ 566 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) 567 #define pgprot_device(prot) \ 568 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_DEVICE_nGnRE) | PTE_PXN | PTE_UXN) 569 #define pgprot_tagged(prot) \ 570 __pgprot_modify(prot, PTE_ATTRINDX_MASK, PTE_ATTRINDX(MT_NORMAL_TAGGED)) 571 #define pgprot_mhp pgprot_tagged 572 /* 573 * DMA allocations for non-coherent devices use what the Arm architecture calls 574 * "Normal non-cacheable" memory, which permits speculation, unaligned accesses 575 * and merging of writes. This is different from "Device-nGnR[nE]" memory which 576 * is intended for MMIO and thus forbids speculation, preserves access size, 577 * requires strict alignment and can also force write responses to come from the 578 * endpoint. 579 */ 580 #define pgprot_dmacoherent(prot) \ 581 __pgprot_modify(prot, PTE_ATTRINDX_MASK, \ 582 PTE_ATTRINDX(MT_NORMAL_NC) | PTE_PXN | PTE_UXN) 583 584 #define __HAVE_PHYS_MEM_ACCESS_PROT 585 struct file; 586 extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, 587 unsigned long size, pgprot_t vma_prot); 588 589 #define pmd_none(pmd) (!pmd_val(pmd)) 590 591 #define pmd_table(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ 592 PMD_TYPE_TABLE) 593 #define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \ 594 PMD_TYPE_SECT) 595 #define pmd_leaf(pmd) (pmd_present(pmd) && !pmd_table(pmd)) 596 #define pmd_bad(pmd) (!pmd_table(pmd)) 597 598 #define pmd_leaf_size(pmd) (pmd_cont(pmd) ? CONT_PMD_SIZE : PMD_SIZE) 599 #define pte_leaf_size(pte) (pte_cont(pte) ? CONT_PTE_SIZE : PAGE_SIZE) 600 601 #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3 602 static inline bool pud_sect(pud_t pud) { return false; } 603 static inline bool pud_table(pud_t pud) { return true; } 604 #else 605 #define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \ 606 PUD_TYPE_SECT) 607 #define pud_table(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \ 608 PUD_TYPE_TABLE) 609 #endif 610 611 extern pgd_t init_pg_dir[PTRS_PER_PGD]; 612 extern pgd_t init_pg_end[]; 613 extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; 614 extern pgd_t idmap_pg_dir[PTRS_PER_PGD]; 615 extern pgd_t tramp_pg_dir[PTRS_PER_PGD]; 616 extern pgd_t reserved_pg_dir[PTRS_PER_PGD]; 617 618 extern void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd); 619 620 static inline bool in_swapper_pgdir(void *addr) 621 { 622 return ((unsigned long)addr & PAGE_MASK) == 623 ((unsigned long)swapper_pg_dir & PAGE_MASK); 624 } 625 626 static inline void set_pmd(pmd_t *pmdp, pmd_t pmd) 627 { 628 #ifdef __PAGETABLE_PMD_FOLDED 629 if (in_swapper_pgdir(pmdp)) { 630 set_swapper_pgd((pgd_t *)pmdp, __pgd(pmd_val(pmd))); 631 return; 632 } 633 #endif /* __PAGETABLE_PMD_FOLDED */ 634 635 WRITE_ONCE(*pmdp, pmd); 636 637 if (pmd_valid(pmd)) { 638 dsb(ishst); 639 isb(); 640 } 641 } 642 643 static inline void pmd_clear(pmd_t *pmdp) 644 { 645 set_pmd(pmdp, __pmd(0)); 646 } 647 648 static inline phys_addr_t pmd_page_paddr(pmd_t pmd) 649 { 650 return __pmd_to_phys(pmd); 651 } 652 653 static inline unsigned long pmd_page_vaddr(pmd_t pmd) 654 { 655 return (unsigned long)__va(pmd_page_paddr(pmd)); 656 } 657 658 /* Find an entry in the third-level page table. */ 659 #define pte_offset_phys(dir,addr) (pmd_page_paddr(READ_ONCE(*(dir))) + pte_index(addr) * sizeof(pte_t)) 660 661 #define pte_set_fixmap(addr) ((pte_t *)set_fixmap_offset(FIX_PTE, addr)) 662 #define pte_set_fixmap_offset(pmd, addr) pte_set_fixmap(pte_offset_phys(pmd, addr)) 663 #define pte_clear_fixmap() clear_fixmap(FIX_PTE) 664 665 #define pmd_page(pmd) phys_to_page(__pmd_to_phys(pmd)) 666 667 /* use ONLY for statically allocated translation tables */ 668 #define pte_offset_kimg(dir,addr) ((pte_t *)__phys_to_kimg(pte_offset_phys((dir), (addr)))) 669 670 /* 671 * Conversion functions: convert a page and protection to a page entry, 672 * and a page entry and page directory to the page they refer to. 673 */ 674 #define mk_pte(page,prot) pfn_pte(page_to_pfn(page),prot) 675 676 #if CONFIG_PGTABLE_LEVELS > 2 677 678 #define pmd_ERROR(e) \ 679 pr_err("%s:%d: bad pmd %016llx.\n", __FILE__, __LINE__, pmd_val(e)) 680 681 #define pud_none(pud) (!pud_val(pud)) 682 #define pud_bad(pud) (!pud_table(pud)) 683 #define pud_present(pud) pte_present(pud_pte(pud)) 684 #define pud_leaf(pud) (pud_present(pud) && !pud_table(pud)) 685 #define pud_valid(pud) pte_valid(pud_pte(pud)) 686 #define pud_user(pud) pte_user(pud_pte(pud)) 687 #define pud_user_exec(pud) pte_user_exec(pud_pte(pud)) 688 689 static inline void set_pud(pud_t *pudp, pud_t pud) 690 { 691 #ifdef __PAGETABLE_PUD_FOLDED 692 if (in_swapper_pgdir(pudp)) { 693 set_swapper_pgd((pgd_t *)pudp, __pgd(pud_val(pud))); 694 return; 695 } 696 #endif /* __PAGETABLE_PUD_FOLDED */ 697 698 WRITE_ONCE(*pudp, pud); 699 700 if (pud_valid(pud)) { 701 dsb(ishst); 702 isb(); 703 } 704 } 705 706 static inline void pud_clear(pud_t *pudp) 707 { 708 set_pud(pudp, __pud(0)); 709 } 710 711 static inline phys_addr_t pud_page_paddr(pud_t pud) 712 { 713 return __pud_to_phys(pud); 714 } 715 716 static inline pmd_t *pud_pgtable(pud_t pud) 717 { 718 return (pmd_t *)__va(pud_page_paddr(pud)); 719 } 720 721 /* Find an entry in the second-level page table. */ 722 #define pmd_offset_phys(dir, addr) (pud_page_paddr(READ_ONCE(*(dir))) + pmd_index(addr) * sizeof(pmd_t)) 723 724 #define pmd_set_fixmap(addr) ((pmd_t *)set_fixmap_offset(FIX_PMD, addr)) 725 #define pmd_set_fixmap_offset(pud, addr) pmd_set_fixmap(pmd_offset_phys(pud, addr)) 726 #define pmd_clear_fixmap() clear_fixmap(FIX_PMD) 727 728 #define pud_page(pud) phys_to_page(__pud_to_phys(pud)) 729 730 /* use ONLY for statically allocated translation tables */ 731 #define pmd_offset_kimg(dir,addr) ((pmd_t *)__phys_to_kimg(pmd_offset_phys((dir), (addr)))) 732 733 #else 734 735 #define pud_page_paddr(pud) ({ BUILD_BUG(); 0; }) 736 #define pud_user_exec(pud) pud_user(pud) /* Always 0 with folding */ 737 738 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */ 739 #define pmd_set_fixmap(addr) NULL 740 #define pmd_set_fixmap_offset(pudp, addr) ((pmd_t *)pudp) 741 #define pmd_clear_fixmap() 742 743 #define pmd_offset_kimg(dir,addr) ((pmd_t *)dir) 744 745 #endif /* CONFIG_PGTABLE_LEVELS > 2 */ 746 747 #if CONFIG_PGTABLE_LEVELS > 3 748 749 #define pud_ERROR(e) \ 750 pr_err("%s:%d: bad pud %016llx.\n", __FILE__, __LINE__, pud_val(e)) 751 752 #define p4d_none(p4d) (!p4d_val(p4d)) 753 #define p4d_bad(p4d) (!(p4d_val(p4d) & 2)) 754 #define p4d_present(p4d) (p4d_val(p4d)) 755 756 static inline void set_p4d(p4d_t *p4dp, p4d_t p4d) 757 { 758 if (in_swapper_pgdir(p4dp)) { 759 set_swapper_pgd((pgd_t *)p4dp, __pgd(p4d_val(p4d))); 760 return; 761 } 762 763 WRITE_ONCE(*p4dp, p4d); 764 dsb(ishst); 765 isb(); 766 } 767 768 static inline void p4d_clear(p4d_t *p4dp) 769 { 770 set_p4d(p4dp, __p4d(0)); 771 } 772 773 static inline phys_addr_t p4d_page_paddr(p4d_t p4d) 774 { 775 return __p4d_to_phys(p4d); 776 } 777 778 static inline pud_t *p4d_pgtable(p4d_t p4d) 779 { 780 return (pud_t *)__va(p4d_page_paddr(p4d)); 781 } 782 783 /* Find an entry in the first-level page table. */ 784 #define pud_offset_phys(dir, addr) (p4d_page_paddr(READ_ONCE(*(dir))) + pud_index(addr) * sizeof(pud_t)) 785 786 #define pud_set_fixmap(addr) ((pud_t *)set_fixmap_offset(FIX_PUD, addr)) 787 #define pud_set_fixmap_offset(p4d, addr) pud_set_fixmap(pud_offset_phys(p4d, addr)) 788 #define pud_clear_fixmap() clear_fixmap(FIX_PUD) 789 790 #define p4d_page(p4d) pfn_to_page(__phys_to_pfn(__p4d_to_phys(p4d))) 791 792 /* use ONLY for statically allocated translation tables */ 793 #define pud_offset_kimg(dir,addr) ((pud_t *)__phys_to_kimg(pud_offset_phys((dir), (addr)))) 794 795 #else 796 797 #define p4d_page_paddr(p4d) ({ BUILD_BUG(); 0;}) 798 #define pgd_page_paddr(pgd) ({ BUILD_BUG(); 0;}) 799 800 /* Match pud_offset folding in <asm/generic/pgtable-nopud.h> */ 801 #define pud_set_fixmap(addr) NULL 802 #define pud_set_fixmap_offset(pgdp, addr) ((pud_t *)pgdp) 803 #define pud_clear_fixmap() 804 805 #define pud_offset_kimg(dir,addr) ((pud_t *)dir) 806 807 #endif /* CONFIG_PGTABLE_LEVELS > 3 */ 808 809 #define pgd_ERROR(e) \ 810 pr_err("%s:%d: bad pgd %016llx.\n", __FILE__, __LINE__, pgd_val(e)) 811 812 #define pgd_set_fixmap(addr) ((pgd_t *)set_fixmap_offset(FIX_PGD, addr)) 813 #define pgd_clear_fixmap() clear_fixmap(FIX_PGD) 814 815 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 816 { 817 /* 818 * Normal and Normal-Tagged are two different memory types and indices 819 * in MAIR_EL1. The mask below has to include PTE_ATTRINDX_MASK. 820 */ 821 const pteval_t mask = PTE_USER | PTE_PXN | PTE_UXN | PTE_RDONLY | 822 PTE_PROT_NONE | PTE_VALID | PTE_WRITE | PTE_GP | 823 PTE_ATTRINDX_MASK; 824 /* preserve the hardware dirty information */ 825 if (pte_hw_dirty(pte)) 826 pte = set_pte_bit(pte, __pgprot(PTE_DIRTY)); 827 828 pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask); 829 /* 830 * If we end up clearing hw dirtiness for a sw-dirty PTE, set hardware 831 * dirtiness again. 832 */ 833 if (pte_sw_dirty(pte)) 834 pte = pte_mkdirty(pte); 835 return pte; 836 } 837 838 static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot) 839 { 840 return pte_pmd(pte_modify(pmd_pte(pmd), newprot)); 841 } 842 843 #define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS 844 extern int ptep_set_access_flags(struct vm_area_struct *vma, 845 unsigned long address, pte_t *ptep, 846 pte_t entry, int dirty); 847 848 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 849 #define __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS 850 static inline int pmdp_set_access_flags(struct vm_area_struct *vma, 851 unsigned long address, pmd_t *pmdp, 852 pmd_t entry, int dirty) 853 { 854 return ptep_set_access_flags(vma, address, (pte_t *)pmdp, pmd_pte(entry), dirty); 855 } 856 857 static inline int pud_devmap(pud_t pud) 858 { 859 return 0; 860 } 861 862 static inline int pgd_devmap(pgd_t pgd) 863 { 864 return 0; 865 } 866 #endif 867 868 #ifdef CONFIG_PAGE_TABLE_CHECK 869 static inline bool pte_user_accessible_page(pte_t pte) 870 { 871 return pte_present(pte) && (pte_user(pte) || pte_user_exec(pte)); 872 } 873 874 static inline bool pmd_user_accessible_page(pmd_t pmd) 875 { 876 return pmd_leaf(pmd) && !pmd_present_invalid(pmd) && (pmd_user(pmd) || pmd_user_exec(pmd)); 877 } 878 879 static inline bool pud_user_accessible_page(pud_t pud) 880 { 881 return pud_leaf(pud) && (pud_user(pud) || pud_user_exec(pud)); 882 } 883 #endif 884 885 /* 886 * Atomic pte/pmd modifications. 887 */ 888 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG 889 static inline int __ptep_test_and_clear_young(pte_t *ptep) 890 { 891 pte_t old_pte, pte; 892 893 pte = READ_ONCE(*ptep); 894 do { 895 old_pte = pte; 896 pte = pte_mkold(pte); 897 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), 898 pte_val(old_pte), pte_val(pte)); 899 } while (pte_val(pte) != pte_val(old_pte)); 900 901 return pte_young(pte); 902 } 903 904 static inline int ptep_test_and_clear_young(struct vm_area_struct *vma, 905 unsigned long address, 906 pte_t *ptep) 907 { 908 return __ptep_test_and_clear_young(ptep); 909 } 910 911 #define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH 912 static inline int ptep_clear_flush_young(struct vm_area_struct *vma, 913 unsigned long address, pte_t *ptep) 914 { 915 int young = ptep_test_and_clear_young(vma, address, ptep); 916 917 if (young) { 918 /* 919 * We can elide the trailing DSB here since the worst that can 920 * happen is that a CPU continues to use the young entry in its 921 * TLB and we mistakenly reclaim the associated page. The 922 * window for such an event is bounded by the next 923 * context-switch, which provides a DSB to complete the TLB 924 * invalidation. 925 */ 926 flush_tlb_page_nosync(vma, address); 927 } 928 929 return young; 930 } 931 932 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 933 #define __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG 934 static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma, 935 unsigned long address, 936 pmd_t *pmdp) 937 { 938 return ptep_test_and_clear_young(vma, address, (pte_t *)pmdp); 939 } 940 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 941 942 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR 943 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, 944 unsigned long address, pte_t *ptep) 945 { 946 pte_t pte = __pte(xchg_relaxed(&pte_val(*ptep), 0)); 947 948 page_table_check_pte_clear(mm, pte); 949 950 return pte; 951 } 952 953 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 954 #define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR 955 static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm, 956 unsigned long address, pmd_t *pmdp) 957 { 958 pmd_t pmd = __pmd(xchg_relaxed(&pmd_val(*pmdp), 0)); 959 960 page_table_check_pmd_clear(mm, pmd); 961 962 return pmd; 963 } 964 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 965 966 /* 967 * ptep_set_wrprotect - mark read-only while trasferring potential hardware 968 * dirty status (PTE_DBM && !PTE_RDONLY) to the software PTE_DIRTY bit. 969 */ 970 #define __HAVE_ARCH_PTEP_SET_WRPROTECT 971 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep) 972 { 973 pte_t old_pte, pte; 974 975 pte = READ_ONCE(*ptep); 976 do { 977 old_pte = pte; 978 pte = pte_wrprotect(pte); 979 pte_val(pte) = cmpxchg_relaxed(&pte_val(*ptep), 980 pte_val(old_pte), pte_val(pte)); 981 } while (pte_val(pte) != pte_val(old_pte)); 982 } 983 984 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 985 #define __HAVE_ARCH_PMDP_SET_WRPROTECT 986 static inline void pmdp_set_wrprotect(struct mm_struct *mm, 987 unsigned long address, pmd_t *pmdp) 988 { 989 ptep_set_wrprotect(mm, address, (pte_t *)pmdp); 990 } 991 992 #define pmdp_establish pmdp_establish 993 static inline pmd_t pmdp_establish(struct vm_area_struct *vma, 994 unsigned long address, pmd_t *pmdp, pmd_t pmd) 995 { 996 page_table_check_pmd_set(vma->vm_mm, pmdp, pmd); 997 return __pmd(xchg_relaxed(&pmd_val(*pmdp), pmd_val(pmd))); 998 } 999 #endif 1000 1001 /* 1002 * Encode and decode a swap entry: 1003 * bits 0-1: present (must be zero) 1004 * bits 2: remember PG_anon_exclusive 1005 * bits 3-7: swap type 1006 * bits 8-57: swap offset 1007 * bit 58: PTE_PROT_NONE (must be zero) 1008 */ 1009 #define __SWP_TYPE_SHIFT 3 1010 #define __SWP_TYPE_BITS 5 1011 #define __SWP_OFFSET_BITS 50 1012 #define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1) 1013 #define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT) 1014 #define __SWP_OFFSET_MASK ((1UL << __SWP_OFFSET_BITS) - 1) 1015 1016 #define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK) 1017 #define __swp_offset(x) (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK) 1018 #define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) }) 1019 1020 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) 1021 #define __swp_entry_to_pte(swp) ((pte_t) { (swp).val }) 1022 1023 #ifdef CONFIG_ARCH_ENABLE_THP_MIGRATION 1024 #define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) }) 1025 #define __swp_entry_to_pmd(swp) __pmd((swp).val) 1026 #endif /* CONFIG_ARCH_ENABLE_THP_MIGRATION */ 1027 1028 /* 1029 * Ensure that there are not more swap files than can be encoded in the kernel 1030 * PTEs. 1031 */ 1032 #define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS) 1033 1034 #ifdef CONFIG_ARM64_MTE 1035 1036 #define __HAVE_ARCH_PREPARE_TO_SWAP 1037 static inline int arch_prepare_to_swap(struct page *page) 1038 { 1039 if (system_supports_mte()) 1040 return mte_save_tags(page); 1041 return 0; 1042 } 1043 1044 #define __HAVE_ARCH_SWAP_INVALIDATE 1045 static inline void arch_swap_invalidate_page(int type, pgoff_t offset) 1046 { 1047 if (system_supports_mte()) 1048 mte_invalidate_tags(type, offset); 1049 } 1050 1051 static inline void arch_swap_invalidate_area(int type) 1052 { 1053 if (system_supports_mte()) 1054 mte_invalidate_tags_area(type); 1055 } 1056 1057 #define __HAVE_ARCH_SWAP_RESTORE 1058 static inline void arch_swap_restore(swp_entry_t entry, struct folio *folio) 1059 { 1060 if (system_supports_mte()) 1061 mte_restore_tags(entry, &folio->page); 1062 } 1063 1064 #endif /* CONFIG_ARM64_MTE */ 1065 1066 /* 1067 * On AArch64, the cache coherency is handled via the set_pte_at() function. 1068 */ 1069 static inline void update_mmu_cache_range(struct vm_fault *vmf, 1070 struct vm_area_struct *vma, unsigned long addr, pte_t *ptep, 1071 unsigned int nr) 1072 { 1073 /* 1074 * We don't do anything here, so there's a very small chance of 1075 * us retaking a user fault which we just fixed up. The alternative 1076 * is doing a dsb(ishst), but that penalises the fastpath. 1077 */ 1078 } 1079 1080 #define update_mmu_cache(vma, addr, ptep) \ 1081 update_mmu_cache_range(NULL, vma, addr, ptep, 1) 1082 #define update_mmu_cache_pmd(vma, address, pmd) do { } while (0) 1083 1084 #ifdef CONFIG_ARM64_PA_BITS_52 1085 #define phys_to_ttbr(addr) (((addr) | ((addr) >> 46)) & TTBR_BADDR_MASK_52) 1086 #else 1087 #define phys_to_ttbr(addr) (addr) 1088 #endif 1089 1090 /* 1091 * On arm64 without hardware Access Flag, copying from user will fail because 1092 * the pte is old and cannot be marked young. So we always end up with zeroed 1093 * page after fork() + CoW for pfn mappings. We don't always have a 1094 * hardware-managed access flag on arm64. 1095 */ 1096 #define arch_has_hw_pte_young cpu_has_hw_af 1097 1098 /* 1099 * Experimentally, it's cheap to set the access flag in hardware and we 1100 * benefit from prefaulting mappings as 'old' to start with. 1101 */ 1102 #define arch_wants_old_prefaulted_pte cpu_has_hw_af 1103 1104 static inline bool pud_sect_supported(void) 1105 { 1106 return PAGE_SIZE == SZ_4K; 1107 } 1108 1109 1110 #define __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION 1111 #define ptep_modify_prot_start ptep_modify_prot_start 1112 extern pte_t ptep_modify_prot_start(struct vm_area_struct *vma, 1113 unsigned long addr, pte_t *ptep); 1114 1115 #define ptep_modify_prot_commit ptep_modify_prot_commit 1116 extern void ptep_modify_prot_commit(struct vm_area_struct *vma, 1117 unsigned long addr, pte_t *ptep, 1118 pte_t old_pte, pte_t new_pte); 1119 #endif /* !__ASSEMBLY__ */ 1120 1121 #endif /* __ASM_PGTABLE_H */ 1122