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