1 /* SPDX-License-Identifier: GPL-2.0 */ 2 #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H 3 #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H 4 5 #include <asm-generic/pgtable-nopmd.h> 6 7 /* 8 * The "classic" 32-bit implementation of the PowerPC MMU uses a hash 9 * table containing PTEs, together with a set of 16 segment registers, 10 * to define the virtual to physical address mapping. 11 * 12 * We use the hash table as an extended TLB, i.e. a cache of currently 13 * active mappings. We maintain a two-level page table tree, much 14 * like that used by the i386, for the sake of the Linux memory 15 * management code. Low-level assembler code in hash_low_32.S 16 * (procedure hash_page) is responsible for extracting ptes from the 17 * tree and putting them into the hash table when necessary, and 18 * updating the accessed and modified bits in the page table tree. 19 */ 20 21 #define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ 22 #define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ 23 #define _PAGE_USER 0x004 /* usermode access allowed */ 24 #define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ 25 #define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ 26 #define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ 27 #define _PAGE_WRITETHRU 0x040 /* W: cache write-through */ 28 #define _PAGE_DIRTY 0x080 /* C: page changed */ 29 #define _PAGE_ACCESSED 0x100 /* R: page referenced */ 30 #define _PAGE_EXEC 0x200 /* software: exec allowed */ 31 #define _PAGE_RW 0x400 /* software: user write access allowed */ 32 #define _PAGE_SPECIAL 0x800 /* software: Special page */ 33 34 #ifdef CONFIG_PTE_64BIT 35 /* We never clear the high word of the pte */ 36 #define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE) 37 #else 38 #define _PTE_NONE_MASK _PAGE_HASHPTE 39 #endif 40 41 #define _PMD_PRESENT 0 42 #define _PMD_PRESENT_MASK (PAGE_MASK) 43 #define _PMD_BAD (~PAGE_MASK) 44 45 /* We borrow the _PAGE_USER bit to store the exclusive marker in swap PTEs. */ 46 #define _PAGE_SWP_EXCLUSIVE _PAGE_USER 47 48 /* And here we include common definitions */ 49 50 #define _PAGE_KERNEL_RO 0 51 #define _PAGE_KERNEL_ROX (_PAGE_EXEC) 52 #define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW) 53 #define _PAGE_KERNEL_RWX (_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC) 54 55 #define _PAGE_HPTEFLAGS _PAGE_HASHPTE 56 57 #ifndef __ASSEMBLY__ 58 59 static inline bool pte_user(pte_t pte) 60 { 61 return pte_val(pte) & _PAGE_USER; 62 } 63 #endif /* __ASSEMBLY__ */ 64 65 /* 66 * Location of the PFN in the PTE. Most 32-bit platforms use the same 67 * as _PAGE_SHIFT here (ie, naturally aligned). 68 * Platform who don't just pre-define the value so we don't override it here. 69 */ 70 #define PTE_RPN_SHIFT (PAGE_SHIFT) 71 72 /* 73 * The mask covered by the RPN must be a ULL on 32-bit platforms with 74 * 64-bit PTEs. 75 */ 76 #ifdef CONFIG_PTE_64BIT 77 #define PTE_RPN_MASK (~((1ULL << PTE_RPN_SHIFT) - 1)) 78 #define MAX_POSSIBLE_PHYSMEM_BITS 36 79 #else 80 #define PTE_RPN_MASK (~((1UL << PTE_RPN_SHIFT) - 1)) 81 #define MAX_POSSIBLE_PHYSMEM_BITS 32 82 #endif 83 84 /* 85 * _PAGE_CHG_MASK masks of bits that are to be preserved across 86 * pgprot changes. 87 */ 88 #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HASHPTE | _PAGE_DIRTY | \ 89 _PAGE_ACCESSED | _PAGE_SPECIAL) 90 91 /* 92 * We define 2 sets of base prot bits, one for basic pages (ie, 93 * cacheable kernel and user pages) and one for non cacheable 94 * pages. We always set _PAGE_COHERENT when SMP is enabled or 95 * the processor might need it for DMA coherency. 96 */ 97 #define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED) 98 #define _PAGE_BASE (_PAGE_BASE_NC | _PAGE_COHERENT) 99 100 /* 101 * Permission masks used to generate the __P and __S table. 102 * 103 * Note:__pgprot is defined in arch/powerpc/include/asm/page.h 104 * 105 * Write permissions imply read permissions for now. 106 */ 107 #define PAGE_NONE __pgprot(_PAGE_BASE) 108 #define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW) 109 #define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC) 110 #define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER) 111 #define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) 112 #define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER) 113 #define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) 114 115 /* Permission masks used for kernel mappings */ 116 #define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW) 117 #define PAGE_KERNEL_NC __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE) 118 #define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE | _PAGE_GUARDED) 119 #define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX) 120 #define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO) 121 #define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX) 122 123 #define PTE_INDEX_SIZE PTE_SHIFT 124 #define PMD_INDEX_SIZE 0 125 #define PUD_INDEX_SIZE 0 126 #define PGD_INDEX_SIZE (32 - PGDIR_SHIFT) 127 128 #define PMD_CACHE_INDEX PMD_INDEX_SIZE 129 #define PUD_CACHE_INDEX PUD_INDEX_SIZE 130 131 #ifndef __ASSEMBLY__ 132 #define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_INDEX_SIZE) 133 #define PMD_TABLE_SIZE 0 134 #define PUD_TABLE_SIZE 0 135 #define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE) 136 137 /* Bits to mask out from a PMD to get to the PTE page */ 138 #define PMD_MASKED_BITS (PTE_TABLE_SIZE - 1) 139 #endif /* __ASSEMBLY__ */ 140 141 #define PTRS_PER_PTE (1 << PTE_INDEX_SIZE) 142 #define PTRS_PER_PGD (1 << PGD_INDEX_SIZE) 143 144 /* 145 * The normal case is that PTEs are 32-bits and we have a 1-page 146 * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages. -- paulus 147 * 148 * For any >32-bit physical address platform, we can use the following 149 * two level page table layout where the pgdir is 8KB and the MS 13 bits 150 * are an index to the second level table. The combined pgdir/pmd first 151 * level has 2048 entries and the second level has 512 64-bit PTE entries. 152 * -Matt 153 */ 154 /* PGDIR_SHIFT determines what a top-level page table entry can map */ 155 #define PGDIR_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE) 156 #define PGDIR_SIZE (1UL << PGDIR_SHIFT) 157 #define PGDIR_MASK (~(PGDIR_SIZE-1)) 158 159 #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) 160 161 #ifndef __ASSEMBLY__ 162 163 int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot); 164 void unmap_kernel_page(unsigned long va); 165 166 #endif /* !__ASSEMBLY__ */ 167 168 /* 169 * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary 170 * value (for now) on others, from where we can start layout kernel 171 * virtual space that goes below PKMAP and FIXMAP 172 */ 173 #include <asm/fixmap.h> 174 175 /* 176 * ioremap_bot starts at that address. Early ioremaps move down from there, 177 * until mem_init() at which point this becomes the top of the vmalloc 178 * and ioremap space 179 */ 180 #ifdef CONFIG_HIGHMEM 181 #define IOREMAP_TOP PKMAP_BASE 182 #else 183 #define IOREMAP_TOP FIXADDR_START 184 #endif 185 186 /* PPC32 shares vmalloc area with ioremap */ 187 #define IOREMAP_START VMALLOC_START 188 #define IOREMAP_END VMALLOC_END 189 190 /* 191 * Just any arbitrary offset to the start of the vmalloc VM area: the 192 * current 16MB value just means that there will be a 64MB "hole" after the 193 * physical memory until the kernel virtual memory starts. That means that 194 * any out-of-bounds memory accesses will hopefully be caught. 195 * The vmalloc() routines leaves a hole of 4kB between each vmalloced 196 * area for the same reason. ;) 197 * 198 * We no longer map larger than phys RAM with the BATs so we don't have 199 * to worry about the VMALLOC_OFFSET causing problems. We do have to worry 200 * about clashes between our early calls to ioremap() that start growing down 201 * from ioremap_base being run into the VM area allocations (growing upwards 202 * from VMALLOC_START). For this reason we have ioremap_bot to check when 203 * we actually run into our mappings setup in the early boot with the VM 204 * system. This really does become a problem for machines with good amounts 205 * of RAM. -- Cort 206 */ 207 #define VMALLOC_OFFSET (0x1000000) /* 16M */ 208 209 #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))) 210 211 #ifdef CONFIG_KASAN_VMALLOC 212 #define VMALLOC_END ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT) 213 #else 214 #define VMALLOC_END ioremap_bot 215 #endif 216 217 #define MODULES_END ALIGN_DOWN(PAGE_OFFSET, SZ_256M) 218 #define MODULES_VADDR (MODULES_END - SZ_256M) 219 220 #ifndef __ASSEMBLY__ 221 #include <linux/sched.h> 222 #include <linux/threads.h> 223 224 /* Bits to mask out from a PGD to get to the PUD page */ 225 #define PGD_MASKED_BITS 0 226 227 #define pte_ERROR(e) \ 228 pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \ 229 (unsigned long long)pte_val(e)) 230 #define pgd_ERROR(e) \ 231 pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) 232 /* 233 * Bits in a linux-style PTE. These match the bits in the 234 * (hardware-defined) PowerPC PTE as closely as possible. 235 */ 236 237 #define pte_clear(mm, addr, ptep) \ 238 do { pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0); } while (0) 239 240 #define pmd_none(pmd) (!pmd_val(pmd)) 241 #define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD) 242 #define pmd_present(pmd) (pmd_val(pmd) & _PMD_PRESENT_MASK) 243 static inline void pmd_clear(pmd_t *pmdp) 244 { 245 *pmdp = __pmd(0); 246 } 247 248 249 /* 250 * When flushing the tlb entry for a page, we also need to flush the hash 251 * table entry. flush_hash_pages is assembler (for speed) in hashtable.S. 252 */ 253 extern int flush_hash_pages(unsigned context, unsigned long va, 254 unsigned long pmdval, int count); 255 256 /* Add an HPTE to the hash table */ 257 extern void add_hash_page(unsigned context, unsigned long va, 258 unsigned long pmdval); 259 260 /* Flush an entry from the TLB/hash table */ 261 static inline void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr) 262 { 263 if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) { 264 unsigned long ptephys = __pa(ptep) & PAGE_MASK; 265 266 flush_hash_pages(mm->context.id, addr, ptephys, 1); 267 } 268 } 269 270 /* 271 * PTE updates. This function is called whenever an existing 272 * valid PTE is updated. This does -not- include set_pte_at() 273 * which nowadays only sets a new PTE. 274 * 275 * Depending on the type of MMU, we may need to use atomic updates 276 * and the PTE may be either 32 or 64 bit wide. In the later case, 277 * when using atomic updates, only the low part of the PTE is 278 * accessed atomically. 279 */ 280 static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p, 281 unsigned long clr, unsigned long set, int huge) 282 { 283 pte_basic_t old; 284 285 if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) { 286 unsigned long tmp; 287 288 asm volatile( 289 #ifndef CONFIG_PTE_64BIT 290 "1: lwarx %0, 0, %3\n" 291 " andc %1, %0, %4\n" 292 #else 293 "1: lwarx %L0, 0, %3\n" 294 " lwz %0, -4(%3)\n" 295 " andc %1, %L0, %4\n" 296 #endif 297 " or %1, %1, %5\n" 298 " stwcx. %1, 0, %3\n" 299 " bne- 1b" 300 : "=&r" (old), "=&r" (tmp), "=m" (*p) 301 #ifndef CONFIG_PTE_64BIT 302 : "r" (p), 303 #else 304 : "b" ((unsigned long)(p) + 4), 305 #endif 306 "r" (clr), "r" (set), "m" (*p) 307 : "cc" ); 308 } else { 309 old = pte_val(*p); 310 311 *p = __pte((old & ~(pte_basic_t)clr) | set); 312 } 313 314 return old; 315 } 316 317 /* 318 * 2.6 calls this without flushing the TLB entry; this is wrong 319 * for our hash-based implementation, we fix that up here. 320 */ 321 #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG 322 static inline int __ptep_test_and_clear_young(struct mm_struct *mm, 323 unsigned long addr, pte_t *ptep) 324 { 325 unsigned long old; 326 old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0); 327 if (old & _PAGE_HASHPTE) 328 flush_hash_entry(mm, ptep, addr); 329 330 return (old & _PAGE_ACCESSED) != 0; 331 } 332 #define ptep_test_and_clear_young(__vma, __addr, __ptep) \ 333 __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep) 334 335 #define __HAVE_ARCH_PTEP_GET_AND_CLEAR 336 static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, 337 pte_t *ptep) 338 { 339 return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0)); 340 } 341 342 #define __HAVE_ARCH_PTEP_SET_WRPROTECT 343 static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, 344 pte_t *ptep) 345 { 346 pte_update(mm, addr, ptep, _PAGE_RW, 0, 0); 347 } 348 349 static inline void __ptep_set_access_flags(struct vm_area_struct *vma, 350 pte_t *ptep, pte_t entry, 351 unsigned long address, 352 int psize) 353 { 354 unsigned long set = pte_val(entry) & 355 (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); 356 357 pte_update(vma->vm_mm, address, ptep, 0, set, 0); 358 359 flush_tlb_page(vma, address); 360 } 361 362 #define __HAVE_ARCH_PTE_SAME 363 #define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0) 364 365 #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT) 366 #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd)) 367 368 /* 369 * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that 370 * are !pte_none() && !pte_present(). 371 * 372 * Format of swap PTEs (32bit PTEs): 373 * 374 * 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 375 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 376 * <----------------- offset --------------------> < type -> E H P 377 * 378 * E is the exclusive marker that is not stored in swap entries. 379 * _PAGE_PRESENT (P) and __PAGE_HASHPTE (H) must be 0. 380 * 381 * For 64bit PTEs, the offset is extended by 32bit. 382 */ 383 #define __swp_type(entry) ((entry).val & 0x1f) 384 #define __swp_offset(entry) ((entry).val >> 5) 385 #define __swp_entry(type, offset) ((swp_entry_t) { ((type) & 0x1f) | ((offset) << 5) }) 386 #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 3 }) 387 #define __swp_entry_to_pte(x) ((pte_t) { (x).val << 3 }) 388 389 static inline int pte_swp_exclusive(pte_t pte) 390 { 391 return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; 392 } 393 394 static inline pte_t pte_swp_mkexclusive(pte_t pte) 395 { 396 return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE); 397 } 398 399 static inline pte_t pte_swp_clear_exclusive(pte_t pte) 400 { 401 return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE); 402 } 403 404 /* Generic accessors to PTE bits */ 405 static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_RW);} 406 static inline int pte_read(pte_t pte) { return 1; } 407 static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) & _PAGE_DIRTY); } 408 static inline int pte_young(pte_t pte) { return !!(pte_val(pte) & _PAGE_ACCESSED); } 409 static inline int pte_special(pte_t pte) { return !!(pte_val(pte) & _PAGE_SPECIAL); } 410 static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; } 411 static inline bool pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } 412 413 static inline int pte_present(pte_t pte) 414 { 415 return pte_val(pte) & _PAGE_PRESENT; 416 } 417 418 static inline bool pte_hw_valid(pte_t pte) 419 { 420 return pte_val(pte) & _PAGE_PRESENT; 421 } 422 423 static inline bool pte_hashpte(pte_t pte) 424 { 425 return !!(pte_val(pte) & _PAGE_HASHPTE); 426 } 427 428 static inline bool pte_ci(pte_t pte) 429 { 430 return !!(pte_val(pte) & _PAGE_NO_CACHE); 431 } 432 433 /* 434 * We only find page table entry in the last level 435 * Hence no need for other accessors 436 */ 437 #define pte_access_permitted pte_access_permitted 438 static inline bool pte_access_permitted(pte_t pte, bool write) 439 { 440 /* 441 * A read-only access is controlled by _PAGE_USER bit. 442 * We have _PAGE_READ set for WRITE and EXECUTE 443 */ 444 if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte)) 445 return false; 446 447 if (write && !pte_write(pte)) 448 return false; 449 450 return true; 451 } 452 453 /* Conversion functions: convert a page and protection to a page entry, 454 * and a page entry and page directory to the page they refer to. 455 * 456 * Even if PTEs can be unsigned long long, a PFN is always an unsigned 457 * long for now. 458 */ 459 static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) 460 { 461 return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) | 462 pgprot_val(pgprot)); 463 } 464 465 static inline unsigned long pte_pfn(pte_t pte) 466 { 467 return pte_val(pte) >> PTE_RPN_SHIFT; 468 } 469 470 /* Generic modifiers for PTE bits */ 471 static inline pte_t pte_wrprotect(pte_t pte) 472 { 473 return __pte(pte_val(pte) & ~_PAGE_RW); 474 } 475 476 static inline pte_t pte_exprotect(pte_t pte) 477 { 478 return __pte(pte_val(pte) & ~_PAGE_EXEC); 479 } 480 481 static inline pte_t pte_mkclean(pte_t pte) 482 { 483 return __pte(pte_val(pte) & ~_PAGE_DIRTY); 484 } 485 486 static inline pte_t pte_mkold(pte_t pte) 487 { 488 return __pte(pte_val(pte) & ~_PAGE_ACCESSED); 489 } 490 491 static inline pte_t pte_mkexec(pte_t pte) 492 { 493 return __pte(pte_val(pte) | _PAGE_EXEC); 494 } 495 496 static inline pte_t pte_mkpte(pte_t pte) 497 { 498 return pte; 499 } 500 501 static inline pte_t pte_mkwrite(pte_t pte) 502 { 503 return __pte(pte_val(pte) | _PAGE_RW); 504 } 505 506 static inline pte_t pte_mkdirty(pte_t pte) 507 { 508 return __pte(pte_val(pte) | _PAGE_DIRTY); 509 } 510 511 static inline pte_t pte_mkyoung(pte_t pte) 512 { 513 return __pte(pte_val(pte) | _PAGE_ACCESSED); 514 } 515 516 static inline pte_t pte_mkspecial(pte_t pte) 517 { 518 return __pte(pte_val(pte) | _PAGE_SPECIAL); 519 } 520 521 static inline pte_t pte_mkhuge(pte_t pte) 522 { 523 return pte; 524 } 525 526 static inline pte_t pte_mkprivileged(pte_t pte) 527 { 528 return __pte(pte_val(pte) & ~_PAGE_USER); 529 } 530 531 static inline pte_t pte_mkuser(pte_t pte) 532 { 533 return __pte(pte_val(pte) | _PAGE_USER); 534 } 535 536 static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) 537 { 538 return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); 539 } 540 541 542 543 /* This low level function performs the actual PTE insertion 544 * Setting the PTE depends on the MMU type and other factors. It's 545 * an horrible mess that I'm not going to try to clean up now but 546 * I'm keeping it in one place rather than spread around 547 */ 548 static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, 549 pte_t *ptep, pte_t pte, int percpu) 550 { 551 #if defined(CONFIG_SMP) && !defined(CONFIG_PTE_64BIT) 552 /* First case is 32-bit Hash MMU in SMP mode with 32-bit PTEs. We use the 553 * helper pte_update() which does an atomic update. We need to do that 554 * because a concurrent invalidation can clear _PAGE_HASHPTE. If it's a 555 * per-CPU PTE such as a kmap_atomic, we do a simple update preserving 556 * the hash bits instead (ie, same as the non-SMP case) 557 */ 558 if (percpu) 559 *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE) 560 | (pte_val(pte) & ~_PAGE_HASHPTE)); 561 else 562 pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, pte_val(pte), 0); 563 564 #elif defined(CONFIG_PTE_64BIT) 565 /* Second case is 32-bit with 64-bit PTE. In this case, we 566 * can just store as long as we do the two halves in the right order 567 * with a barrier in between. This is possible because we take care, 568 * in the hash code, to pre-invalidate if the PTE was already hashed, 569 * which synchronizes us with any concurrent invalidation. 570 * In the percpu case, we also fallback to the simple update preserving 571 * the hash bits 572 */ 573 if (percpu) { 574 *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE) 575 | (pte_val(pte) & ~_PAGE_HASHPTE)); 576 return; 577 } 578 if (pte_val(*ptep) & _PAGE_HASHPTE) 579 flush_hash_entry(mm, ptep, addr); 580 __asm__ __volatile__("\ 581 stw%X0 %2,%0\n\ 582 eieio\n\ 583 stw%X1 %L2,%1" 584 : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4)) 585 : "r" (pte) : "memory"); 586 587 #else 588 /* Third case is 32-bit hash table in UP mode, we need to preserve 589 * the _PAGE_HASHPTE bit since we may not have invalidated the previous 590 * translation in the hash yet (done in a subsequent flush_tlb_xxx()) 591 * and see we need to keep track that this PTE needs invalidating 592 */ 593 *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE) 594 | (pte_val(pte) & ~_PAGE_HASHPTE)); 595 #endif 596 } 597 598 /* 599 * Macro to mark a page protection value as "uncacheable". 600 */ 601 602 #define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \ 603 _PAGE_WRITETHRU) 604 605 #define pgprot_noncached pgprot_noncached 606 static inline pgprot_t pgprot_noncached(pgprot_t prot) 607 { 608 return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | 609 _PAGE_NO_CACHE | _PAGE_GUARDED); 610 } 611 612 #define pgprot_noncached_wc pgprot_noncached_wc 613 static inline pgprot_t pgprot_noncached_wc(pgprot_t prot) 614 { 615 return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | 616 _PAGE_NO_CACHE); 617 } 618 619 #define pgprot_cached pgprot_cached 620 static inline pgprot_t pgprot_cached(pgprot_t prot) 621 { 622 return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | 623 _PAGE_COHERENT); 624 } 625 626 #define pgprot_cached_wthru pgprot_cached_wthru 627 static inline pgprot_t pgprot_cached_wthru(pgprot_t prot) 628 { 629 return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | 630 _PAGE_COHERENT | _PAGE_WRITETHRU); 631 } 632 633 #define pgprot_cached_noncoherent pgprot_cached_noncoherent 634 static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot) 635 { 636 return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL); 637 } 638 639 #define pgprot_writecombine pgprot_writecombine 640 static inline pgprot_t pgprot_writecombine(pgprot_t prot) 641 { 642 return pgprot_noncached_wc(prot); 643 } 644 645 #endif /* !__ASSEMBLY__ */ 646 647 #endif /* _ASM_POWERPC_BOOK3S_32_PGTABLE_H */ 648