1 /* 2 * Copyright IBM Corp. 2007, 2011 3 * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com> 4 */ 5 6 #include <linux/sched.h> 7 #include <linux/kernel.h> 8 #include <linux/errno.h> 9 #include <linux/gfp.h> 10 #include <linux/mm.h> 11 #include <linux/swap.h> 12 #include <linux/smp.h> 13 #include <linux/highmem.h> 14 #include <linux/pagemap.h> 15 #include <linux/spinlock.h> 16 #include <linux/module.h> 17 #include <linux/quicklist.h> 18 #include <linux/rcupdate.h> 19 #include <linux/slab.h> 20 #include <linux/swapops.h> 21 22 #include <asm/pgtable.h> 23 #include <asm/pgalloc.h> 24 #include <asm/tlb.h> 25 #include <asm/tlbflush.h> 26 #include <asm/mmu_context.h> 27 28 #ifndef CONFIG_64BIT 29 #define ALLOC_ORDER 1 30 #define FRAG_MASK 0x0f 31 #else 32 #define ALLOC_ORDER 2 33 #define FRAG_MASK 0x03 34 #endif 35 36 37 unsigned long *crst_table_alloc(struct mm_struct *mm) 38 { 39 struct page *page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); 40 41 if (!page) 42 return NULL; 43 return (unsigned long *) page_to_phys(page); 44 } 45 46 void crst_table_free(struct mm_struct *mm, unsigned long *table) 47 { 48 free_pages((unsigned long) table, ALLOC_ORDER); 49 } 50 51 #ifdef CONFIG_64BIT 52 static void __crst_table_upgrade(void *arg) 53 { 54 struct mm_struct *mm = arg; 55 56 if (current->active_mm == mm) 57 update_user_asce(mm, 1); 58 __tlb_flush_local(); 59 } 60 61 int crst_table_upgrade(struct mm_struct *mm, unsigned long limit) 62 { 63 unsigned long *table, *pgd; 64 unsigned long entry; 65 int flush; 66 67 BUG_ON(limit > (1UL << 53)); 68 flush = 0; 69 repeat: 70 table = crst_table_alloc(mm); 71 if (!table) 72 return -ENOMEM; 73 spin_lock_bh(&mm->page_table_lock); 74 if (mm->context.asce_limit < limit) { 75 pgd = (unsigned long *) mm->pgd; 76 if (mm->context.asce_limit <= (1UL << 31)) { 77 entry = _REGION3_ENTRY_EMPTY; 78 mm->context.asce_limit = 1UL << 42; 79 mm->context.asce_bits = _ASCE_TABLE_LENGTH | 80 _ASCE_USER_BITS | 81 _ASCE_TYPE_REGION3; 82 } else { 83 entry = _REGION2_ENTRY_EMPTY; 84 mm->context.asce_limit = 1UL << 53; 85 mm->context.asce_bits = _ASCE_TABLE_LENGTH | 86 _ASCE_USER_BITS | 87 _ASCE_TYPE_REGION2; 88 } 89 crst_table_init(table, entry); 90 pgd_populate(mm, (pgd_t *) table, (pud_t *) pgd); 91 mm->pgd = (pgd_t *) table; 92 mm->task_size = mm->context.asce_limit; 93 table = NULL; 94 flush = 1; 95 } 96 spin_unlock_bh(&mm->page_table_lock); 97 if (table) 98 crst_table_free(mm, table); 99 if (mm->context.asce_limit < limit) 100 goto repeat; 101 if (flush) 102 on_each_cpu(__crst_table_upgrade, mm, 0); 103 return 0; 104 } 105 106 void crst_table_downgrade(struct mm_struct *mm, unsigned long limit) 107 { 108 pgd_t *pgd; 109 110 if (current->active_mm == mm) { 111 clear_user_asce(mm, 1); 112 __tlb_flush_mm(mm); 113 } 114 while (mm->context.asce_limit > limit) { 115 pgd = mm->pgd; 116 switch (pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) { 117 case _REGION_ENTRY_TYPE_R2: 118 mm->context.asce_limit = 1UL << 42; 119 mm->context.asce_bits = _ASCE_TABLE_LENGTH | 120 _ASCE_USER_BITS | 121 _ASCE_TYPE_REGION3; 122 break; 123 case _REGION_ENTRY_TYPE_R3: 124 mm->context.asce_limit = 1UL << 31; 125 mm->context.asce_bits = _ASCE_TABLE_LENGTH | 126 _ASCE_USER_BITS | 127 _ASCE_TYPE_SEGMENT; 128 break; 129 default: 130 BUG(); 131 } 132 mm->pgd = (pgd_t *) (pgd_val(*pgd) & _REGION_ENTRY_ORIGIN); 133 mm->task_size = mm->context.asce_limit; 134 crst_table_free(mm, (unsigned long *) pgd); 135 } 136 if (current->active_mm == mm) 137 update_user_asce(mm, 1); 138 } 139 #endif 140 141 #ifdef CONFIG_PGSTE 142 143 /** 144 * gmap_alloc - allocate a guest address space 145 * @mm: pointer to the parent mm_struct 146 * 147 * Returns a guest address space structure. 148 */ 149 struct gmap *gmap_alloc(struct mm_struct *mm) 150 { 151 struct gmap *gmap; 152 struct page *page; 153 unsigned long *table; 154 155 gmap = kzalloc(sizeof(struct gmap), GFP_KERNEL); 156 if (!gmap) 157 goto out; 158 INIT_LIST_HEAD(&gmap->crst_list); 159 gmap->mm = mm; 160 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); 161 if (!page) 162 goto out_free; 163 list_add(&page->lru, &gmap->crst_list); 164 table = (unsigned long *) page_to_phys(page); 165 crst_table_init(table, _REGION1_ENTRY_EMPTY); 166 gmap->table = table; 167 gmap->asce = _ASCE_TYPE_REGION1 | _ASCE_TABLE_LENGTH | 168 _ASCE_USER_BITS | __pa(table); 169 list_add(&gmap->list, &mm->context.gmap_list); 170 return gmap; 171 172 out_free: 173 kfree(gmap); 174 out: 175 return NULL; 176 } 177 EXPORT_SYMBOL_GPL(gmap_alloc); 178 179 static int gmap_unlink_segment(struct gmap *gmap, unsigned long *table) 180 { 181 struct gmap_pgtable *mp; 182 struct gmap_rmap *rmap; 183 struct page *page; 184 185 if (*table & _SEGMENT_ENTRY_INVALID) 186 return 0; 187 page = pfn_to_page(*table >> PAGE_SHIFT); 188 mp = (struct gmap_pgtable *) page->index; 189 list_for_each_entry(rmap, &mp->mapper, list) { 190 if (rmap->entry != table) 191 continue; 192 list_del(&rmap->list); 193 kfree(rmap); 194 break; 195 } 196 *table = mp->vmaddr | _SEGMENT_ENTRY_INVALID | _SEGMENT_ENTRY_PROTECT; 197 return 1; 198 } 199 200 static void gmap_flush_tlb(struct gmap *gmap) 201 { 202 if (MACHINE_HAS_IDTE) 203 __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table | 204 _ASCE_TYPE_REGION1); 205 else 206 __tlb_flush_global(); 207 } 208 209 /** 210 * gmap_free - free a guest address space 211 * @gmap: pointer to the guest address space structure 212 */ 213 void gmap_free(struct gmap *gmap) 214 { 215 struct page *page, *next; 216 unsigned long *table; 217 int i; 218 219 220 /* Flush tlb. */ 221 if (MACHINE_HAS_IDTE) 222 __tlb_flush_asce(gmap->mm, (unsigned long) gmap->table | 223 _ASCE_TYPE_REGION1); 224 else 225 __tlb_flush_global(); 226 227 /* Free all segment & region tables. */ 228 down_read(&gmap->mm->mmap_sem); 229 spin_lock(&gmap->mm->page_table_lock); 230 list_for_each_entry_safe(page, next, &gmap->crst_list, lru) { 231 table = (unsigned long *) page_to_phys(page); 232 if ((*table & _REGION_ENTRY_TYPE_MASK) == 0) 233 /* Remove gmap rmap structures for segment table. */ 234 for (i = 0; i < PTRS_PER_PMD; i++, table++) 235 gmap_unlink_segment(gmap, table); 236 __free_pages(page, ALLOC_ORDER); 237 } 238 spin_unlock(&gmap->mm->page_table_lock); 239 up_read(&gmap->mm->mmap_sem); 240 list_del(&gmap->list); 241 kfree(gmap); 242 } 243 EXPORT_SYMBOL_GPL(gmap_free); 244 245 /** 246 * gmap_enable - switch primary space to the guest address space 247 * @gmap: pointer to the guest address space structure 248 */ 249 void gmap_enable(struct gmap *gmap) 250 { 251 S390_lowcore.gmap = (unsigned long) gmap; 252 } 253 EXPORT_SYMBOL_GPL(gmap_enable); 254 255 /** 256 * gmap_disable - switch back to the standard primary address space 257 * @gmap: pointer to the guest address space structure 258 */ 259 void gmap_disable(struct gmap *gmap) 260 { 261 S390_lowcore.gmap = 0UL; 262 } 263 EXPORT_SYMBOL_GPL(gmap_disable); 264 265 /* 266 * gmap_alloc_table is assumed to be called with mmap_sem held 267 */ 268 static int gmap_alloc_table(struct gmap *gmap, 269 unsigned long *table, unsigned long init) 270 __releases(&gmap->mm->page_table_lock) 271 __acquires(&gmap->mm->page_table_lock) 272 { 273 struct page *page; 274 unsigned long *new; 275 276 /* since we dont free the gmap table until gmap_free we can unlock */ 277 spin_unlock(&gmap->mm->page_table_lock); 278 page = alloc_pages(GFP_KERNEL, ALLOC_ORDER); 279 spin_lock(&gmap->mm->page_table_lock); 280 if (!page) 281 return -ENOMEM; 282 new = (unsigned long *) page_to_phys(page); 283 crst_table_init(new, init); 284 if (*table & _REGION_ENTRY_INVALID) { 285 list_add(&page->lru, &gmap->crst_list); 286 *table = (unsigned long) new | _REGION_ENTRY_LENGTH | 287 (*table & _REGION_ENTRY_TYPE_MASK); 288 } else 289 __free_pages(page, ALLOC_ORDER); 290 return 0; 291 } 292 293 /** 294 * gmap_unmap_segment - unmap segment from the guest address space 295 * @gmap: pointer to the guest address space structure 296 * @addr: address in the guest address space 297 * @len: length of the memory area to unmap 298 * 299 * Returns 0 if the unmap succeeded, -EINVAL if not. 300 */ 301 int gmap_unmap_segment(struct gmap *gmap, unsigned long to, unsigned long len) 302 { 303 unsigned long *table; 304 unsigned long off; 305 int flush; 306 307 if ((to | len) & (PMD_SIZE - 1)) 308 return -EINVAL; 309 if (len == 0 || to + len < to) 310 return -EINVAL; 311 312 flush = 0; 313 down_read(&gmap->mm->mmap_sem); 314 spin_lock(&gmap->mm->page_table_lock); 315 for (off = 0; off < len; off += PMD_SIZE) { 316 /* Walk the guest addr space page table */ 317 table = gmap->table + (((to + off) >> 53) & 0x7ff); 318 if (*table & _REGION_ENTRY_INVALID) 319 goto out; 320 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 321 table = table + (((to + off) >> 42) & 0x7ff); 322 if (*table & _REGION_ENTRY_INVALID) 323 goto out; 324 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 325 table = table + (((to + off) >> 31) & 0x7ff); 326 if (*table & _REGION_ENTRY_INVALID) 327 goto out; 328 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 329 table = table + (((to + off) >> 20) & 0x7ff); 330 331 /* Clear segment table entry in guest address space. */ 332 flush |= gmap_unlink_segment(gmap, table); 333 *table = _SEGMENT_ENTRY_INVALID; 334 } 335 out: 336 spin_unlock(&gmap->mm->page_table_lock); 337 up_read(&gmap->mm->mmap_sem); 338 if (flush) 339 gmap_flush_tlb(gmap); 340 return 0; 341 } 342 EXPORT_SYMBOL_GPL(gmap_unmap_segment); 343 344 /** 345 * gmap_mmap_segment - map a segment to the guest address space 346 * @gmap: pointer to the guest address space structure 347 * @from: source address in the parent address space 348 * @to: target address in the guest address space 349 * 350 * Returns 0 if the mmap succeeded, -EINVAL or -ENOMEM if not. 351 */ 352 int gmap_map_segment(struct gmap *gmap, unsigned long from, 353 unsigned long to, unsigned long len) 354 { 355 unsigned long *table; 356 unsigned long off; 357 int flush; 358 359 if ((from | to | len) & (PMD_SIZE - 1)) 360 return -EINVAL; 361 if (len == 0 || from + len > TASK_MAX_SIZE || 362 from + len < from || to + len < to) 363 return -EINVAL; 364 365 flush = 0; 366 down_read(&gmap->mm->mmap_sem); 367 spin_lock(&gmap->mm->page_table_lock); 368 for (off = 0; off < len; off += PMD_SIZE) { 369 /* Walk the gmap address space page table */ 370 table = gmap->table + (((to + off) >> 53) & 0x7ff); 371 if ((*table & _REGION_ENTRY_INVALID) && 372 gmap_alloc_table(gmap, table, _REGION2_ENTRY_EMPTY)) 373 goto out_unmap; 374 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 375 table = table + (((to + off) >> 42) & 0x7ff); 376 if ((*table & _REGION_ENTRY_INVALID) && 377 gmap_alloc_table(gmap, table, _REGION3_ENTRY_EMPTY)) 378 goto out_unmap; 379 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 380 table = table + (((to + off) >> 31) & 0x7ff); 381 if ((*table & _REGION_ENTRY_INVALID) && 382 gmap_alloc_table(gmap, table, _SEGMENT_ENTRY_EMPTY)) 383 goto out_unmap; 384 table = (unsigned long *) (*table & _REGION_ENTRY_ORIGIN); 385 table = table + (((to + off) >> 20) & 0x7ff); 386 387 /* Store 'from' address in an invalid segment table entry. */ 388 flush |= gmap_unlink_segment(gmap, table); 389 *table = (from + off) | (_SEGMENT_ENTRY_INVALID | 390 _SEGMENT_ENTRY_PROTECT); 391 } 392 spin_unlock(&gmap->mm->page_table_lock); 393 up_read(&gmap->mm->mmap_sem); 394 if (flush) 395 gmap_flush_tlb(gmap); 396 return 0; 397 398 out_unmap: 399 spin_unlock(&gmap->mm->page_table_lock); 400 up_read(&gmap->mm->mmap_sem); 401 gmap_unmap_segment(gmap, to, len); 402 return -ENOMEM; 403 } 404 EXPORT_SYMBOL_GPL(gmap_map_segment); 405 406 static unsigned long *gmap_table_walk(unsigned long address, struct gmap *gmap) 407 { 408 unsigned long *table; 409 410 table = gmap->table + ((address >> 53) & 0x7ff); 411 if (unlikely(*table & _REGION_ENTRY_INVALID)) 412 return ERR_PTR(-EFAULT); 413 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 414 table = table + ((address >> 42) & 0x7ff); 415 if (unlikely(*table & _REGION_ENTRY_INVALID)) 416 return ERR_PTR(-EFAULT); 417 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 418 table = table + ((address >> 31) & 0x7ff); 419 if (unlikely(*table & _REGION_ENTRY_INVALID)) 420 return ERR_PTR(-EFAULT); 421 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 422 table = table + ((address >> 20) & 0x7ff); 423 return table; 424 } 425 426 /** 427 * __gmap_translate - translate a guest address to a user space address 428 * @address: guest address 429 * @gmap: pointer to guest mapping meta data structure 430 * 431 * Returns user space address which corresponds to the guest address or 432 * -EFAULT if no such mapping exists. 433 * This function does not establish potentially missing page table entries. 434 * The mmap_sem of the mm that belongs to the address space must be held 435 * when this function gets called. 436 */ 437 unsigned long __gmap_translate(unsigned long address, struct gmap *gmap) 438 { 439 unsigned long *segment_ptr, vmaddr, segment; 440 struct gmap_pgtable *mp; 441 struct page *page; 442 443 current->thread.gmap_addr = address; 444 segment_ptr = gmap_table_walk(address, gmap); 445 if (IS_ERR(segment_ptr)) 446 return PTR_ERR(segment_ptr); 447 /* Convert the gmap address to an mm address. */ 448 segment = *segment_ptr; 449 if (!(segment & _SEGMENT_ENTRY_INVALID)) { 450 page = pfn_to_page(segment >> PAGE_SHIFT); 451 mp = (struct gmap_pgtable *) page->index; 452 return mp->vmaddr | (address & ~PMD_MASK); 453 } else if (segment & _SEGMENT_ENTRY_PROTECT) { 454 vmaddr = segment & _SEGMENT_ENTRY_ORIGIN; 455 return vmaddr | (address & ~PMD_MASK); 456 } 457 return -EFAULT; 458 } 459 EXPORT_SYMBOL_GPL(__gmap_translate); 460 461 /** 462 * gmap_translate - translate a guest address to a user space address 463 * @address: guest address 464 * @gmap: pointer to guest mapping meta data structure 465 * 466 * Returns user space address which corresponds to the guest address or 467 * -EFAULT if no such mapping exists. 468 * This function does not establish potentially missing page table entries. 469 */ 470 unsigned long gmap_translate(unsigned long address, struct gmap *gmap) 471 { 472 unsigned long rc; 473 474 down_read(&gmap->mm->mmap_sem); 475 rc = __gmap_translate(address, gmap); 476 up_read(&gmap->mm->mmap_sem); 477 return rc; 478 } 479 EXPORT_SYMBOL_GPL(gmap_translate); 480 481 static int gmap_connect_pgtable(unsigned long address, unsigned long segment, 482 unsigned long *segment_ptr, struct gmap *gmap) 483 { 484 unsigned long vmaddr; 485 struct vm_area_struct *vma; 486 struct gmap_pgtable *mp; 487 struct gmap_rmap *rmap; 488 struct mm_struct *mm; 489 struct page *page; 490 pgd_t *pgd; 491 pud_t *pud; 492 pmd_t *pmd; 493 494 mm = gmap->mm; 495 vmaddr = segment & _SEGMENT_ENTRY_ORIGIN; 496 vma = find_vma(mm, vmaddr); 497 if (!vma || vma->vm_start > vmaddr) 498 return -EFAULT; 499 /* Walk the parent mm page table */ 500 pgd = pgd_offset(mm, vmaddr); 501 pud = pud_alloc(mm, pgd, vmaddr); 502 if (!pud) 503 return -ENOMEM; 504 pmd = pmd_alloc(mm, pud, vmaddr); 505 if (!pmd) 506 return -ENOMEM; 507 if (!pmd_present(*pmd) && 508 __pte_alloc(mm, vma, pmd, vmaddr)) 509 return -ENOMEM; 510 /* large pmds cannot yet be handled */ 511 if (pmd_large(*pmd)) 512 return -EFAULT; 513 /* pmd now points to a valid segment table entry. */ 514 rmap = kmalloc(sizeof(*rmap), GFP_KERNEL|__GFP_REPEAT); 515 if (!rmap) 516 return -ENOMEM; 517 /* Link gmap segment table entry location to page table. */ 518 page = pmd_page(*pmd); 519 mp = (struct gmap_pgtable *) page->index; 520 rmap->gmap = gmap; 521 rmap->entry = segment_ptr; 522 rmap->vmaddr = address & PMD_MASK; 523 spin_lock(&mm->page_table_lock); 524 if (*segment_ptr == segment) { 525 list_add(&rmap->list, &mp->mapper); 526 /* Set gmap segment table entry to page table. */ 527 *segment_ptr = pmd_val(*pmd) & PAGE_MASK; 528 rmap = NULL; 529 } 530 spin_unlock(&mm->page_table_lock); 531 kfree(rmap); 532 return 0; 533 } 534 535 static void gmap_disconnect_pgtable(struct mm_struct *mm, unsigned long *table) 536 { 537 struct gmap_rmap *rmap, *next; 538 struct gmap_pgtable *mp; 539 struct page *page; 540 int flush; 541 542 flush = 0; 543 spin_lock(&mm->page_table_lock); 544 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 545 mp = (struct gmap_pgtable *) page->index; 546 list_for_each_entry_safe(rmap, next, &mp->mapper, list) { 547 *rmap->entry = mp->vmaddr | (_SEGMENT_ENTRY_INVALID | 548 _SEGMENT_ENTRY_PROTECT); 549 list_del(&rmap->list); 550 kfree(rmap); 551 flush = 1; 552 } 553 spin_unlock(&mm->page_table_lock); 554 if (flush) 555 __tlb_flush_global(); 556 } 557 558 /* 559 * this function is assumed to be called with mmap_sem held 560 */ 561 unsigned long __gmap_fault(unsigned long address, struct gmap *gmap) 562 { 563 unsigned long *segment_ptr, segment; 564 struct gmap_pgtable *mp; 565 struct page *page; 566 int rc; 567 568 current->thread.gmap_addr = address; 569 segment_ptr = gmap_table_walk(address, gmap); 570 if (IS_ERR(segment_ptr)) 571 return -EFAULT; 572 /* Convert the gmap address to an mm address. */ 573 while (1) { 574 segment = *segment_ptr; 575 if (!(segment & _SEGMENT_ENTRY_INVALID)) { 576 /* Page table is present */ 577 page = pfn_to_page(segment >> PAGE_SHIFT); 578 mp = (struct gmap_pgtable *) page->index; 579 return mp->vmaddr | (address & ~PMD_MASK); 580 } 581 if (!(segment & _SEGMENT_ENTRY_PROTECT)) 582 /* Nothing mapped in the gmap address space. */ 583 break; 584 rc = gmap_connect_pgtable(address, segment, segment_ptr, gmap); 585 if (rc) 586 return rc; 587 } 588 return -EFAULT; 589 } 590 591 unsigned long gmap_fault(unsigned long address, struct gmap *gmap) 592 { 593 unsigned long rc; 594 595 down_read(&gmap->mm->mmap_sem); 596 rc = __gmap_fault(address, gmap); 597 up_read(&gmap->mm->mmap_sem); 598 599 return rc; 600 } 601 EXPORT_SYMBOL_GPL(gmap_fault); 602 603 static void gmap_zap_swap_entry(swp_entry_t entry, struct mm_struct *mm) 604 { 605 if (!non_swap_entry(entry)) 606 dec_mm_counter(mm, MM_SWAPENTS); 607 else if (is_migration_entry(entry)) { 608 struct page *page = migration_entry_to_page(entry); 609 610 if (PageAnon(page)) 611 dec_mm_counter(mm, MM_ANONPAGES); 612 else 613 dec_mm_counter(mm, MM_FILEPAGES); 614 } 615 free_swap_and_cache(entry); 616 } 617 618 /** 619 * The mm->mmap_sem lock must be held 620 */ 621 static void gmap_zap_unused(struct mm_struct *mm, unsigned long address) 622 { 623 unsigned long ptev, pgstev; 624 spinlock_t *ptl; 625 pgste_t pgste; 626 pte_t *ptep, pte; 627 628 ptep = get_locked_pte(mm, address, &ptl); 629 if (unlikely(!ptep)) 630 return; 631 pte = *ptep; 632 if (!pte_swap(pte)) 633 goto out_pte; 634 /* Zap unused and logically-zero pages */ 635 pgste = pgste_get_lock(ptep); 636 pgstev = pgste_val(pgste); 637 ptev = pte_val(pte); 638 if (((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) || 639 ((pgstev & _PGSTE_GPS_ZERO) && (ptev & _PAGE_INVALID))) { 640 gmap_zap_swap_entry(pte_to_swp_entry(pte), mm); 641 pte_clear(mm, address, ptep); 642 } 643 pgste_set_unlock(ptep, pgste); 644 out_pte: 645 pte_unmap_unlock(*ptep, ptl); 646 } 647 648 /* 649 * this function is assumed to be called with mmap_sem held 650 */ 651 void __gmap_zap(unsigned long address, struct gmap *gmap) 652 { 653 unsigned long *table, *segment_ptr; 654 unsigned long segment, pgstev, ptev; 655 struct gmap_pgtable *mp; 656 struct page *page; 657 658 segment_ptr = gmap_table_walk(address, gmap); 659 if (IS_ERR(segment_ptr)) 660 return; 661 segment = *segment_ptr; 662 if (segment & _SEGMENT_ENTRY_INVALID) 663 return; 664 page = pfn_to_page(segment >> PAGE_SHIFT); 665 mp = (struct gmap_pgtable *) page->index; 666 address = mp->vmaddr | (address & ~PMD_MASK); 667 /* Page table is present */ 668 table = (unsigned long *)(segment & _SEGMENT_ENTRY_ORIGIN); 669 table = table + ((address >> 12) & 0xff); 670 pgstev = table[PTRS_PER_PTE]; 671 ptev = table[0]; 672 /* quick check, checked again with locks held */ 673 if (((pgstev & _PGSTE_GPS_USAGE_MASK) == _PGSTE_GPS_USAGE_UNUSED) || 674 ((pgstev & _PGSTE_GPS_ZERO) && (ptev & _PAGE_INVALID))) 675 gmap_zap_unused(gmap->mm, address); 676 } 677 EXPORT_SYMBOL_GPL(__gmap_zap); 678 679 void gmap_discard(unsigned long from, unsigned long to, struct gmap *gmap) 680 { 681 682 unsigned long *table, address, size; 683 struct vm_area_struct *vma; 684 struct gmap_pgtable *mp; 685 struct page *page; 686 687 down_read(&gmap->mm->mmap_sem); 688 address = from; 689 while (address < to) { 690 /* Walk the gmap address space page table */ 691 table = gmap->table + ((address >> 53) & 0x7ff); 692 if (unlikely(*table & _REGION_ENTRY_INVALID)) { 693 address = (address + PMD_SIZE) & PMD_MASK; 694 continue; 695 } 696 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 697 table = table + ((address >> 42) & 0x7ff); 698 if (unlikely(*table & _REGION_ENTRY_INVALID)) { 699 address = (address + PMD_SIZE) & PMD_MASK; 700 continue; 701 } 702 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 703 table = table + ((address >> 31) & 0x7ff); 704 if (unlikely(*table & _REGION_ENTRY_INVALID)) { 705 address = (address + PMD_SIZE) & PMD_MASK; 706 continue; 707 } 708 table = (unsigned long *)(*table & _REGION_ENTRY_ORIGIN); 709 table = table + ((address >> 20) & 0x7ff); 710 if (unlikely(*table & _SEGMENT_ENTRY_INVALID)) { 711 address = (address + PMD_SIZE) & PMD_MASK; 712 continue; 713 } 714 page = pfn_to_page(*table >> PAGE_SHIFT); 715 mp = (struct gmap_pgtable *) page->index; 716 vma = find_vma(gmap->mm, mp->vmaddr); 717 size = min(to - address, PMD_SIZE - (address & ~PMD_MASK)); 718 zap_page_range(vma, mp->vmaddr | (address & ~PMD_MASK), 719 size, NULL); 720 address = (address + PMD_SIZE) & PMD_MASK; 721 } 722 up_read(&gmap->mm->mmap_sem); 723 } 724 EXPORT_SYMBOL_GPL(gmap_discard); 725 726 static LIST_HEAD(gmap_notifier_list); 727 static DEFINE_SPINLOCK(gmap_notifier_lock); 728 729 /** 730 * gmap_register_ipte_notifier - register a pte invalidation callback 731 * @nb: pointer to the gmap notifier block 732 */ 733 void gmap_register_ipte_notifier(struct gmap_notifier *nb) 734 { 735 spin_lock(&gmap_notifier_lock); 736 list_add(&nb->list, &gmap_notifier_list); 737 spin_unlock(&gmap_notifier_lock); 738 } 739 EXPORT_SYMBOL_GPL(gmap_register_ipte_notifier); 740 741 /** 742 * gmap_unregister_ipte_notifier - remove a pte invalidation callback 743 * @nb: pointer to the gmap notifier block 744 */ 745 void gmap_unregister_ipte_notifier(struct gmap_notifier *nb) 746 { 747 spin_lock(&gmap_notifier_lock); 748 list_del_init(&nb->list); 749 spin_unlock(&gmap_notifier_lock); 750 } 751 EXPORT_SYMBOL_GPL(gmap_unregister_ipte_notifier); 752 753 /** 754 * gmap_ipte_notify - mark a range of ptes for invalidation notification 755 * @gmap: pointer to guest mapping meta data structure 756 * @start: virtual address in the guest address space 757 * @len: size of area 758 * 759 * Returns 0 if for each page in the given range a gmap mapping exists and 760 * the invalidation notification could be set. If the gmap mapping is missing 761 * for one or more pages -EFAULT is returned. If no memory could be allocated 762 * -ENOMEM is returned. This function establishes missing page table entries. 763 */ 764 int gmap_ipte_notify(struct gmap *gmap, unsigned long start, unsigned long len) 765 { 766 unsigned long addr; 767 spinlock_t *ptl; 768 pte_t *ptep, entry; 769 pgste_t pgste; 770 int rc = 0; 771 772 if ((start & ~PAGE_MASK) || (len & ~PAGE_MASK)) 773 return -EINVAL; 774 down_read(&gmap->mm->mmap_sem); 775 while (len) { 776 /* Convert gmap address and connect the page tables */ 777 addr = __gmap_fault(start, gmap); 778 if (IS_ERR_VALUE(addr)) { 779 rc = addr; 780 break; 781 } 782 /* Get the page mapped */ 783 if (fixup_user_fault(current, gmap->mm, addr, FAULT_FLAG_WRITE)) { 784 rc = -EFAULT; 785 break; 786 } 787 /* Walk the process page table, lock and get pte pointer */ 788 ptep = get_locked_pte(gmap->mm, addr, &ptl); 789 if (unlikely(!ptep)) 790 continue; 791 /* Set notification bit in the pgste of the pte */ 792 entry = *ptep; 793 if ((pte_val(entry) & (_PAGE_INVALID | _PAGE_PROTECT)) == 0) { 794 pgste = pgste_get_lock(ptep); 795 pgste_val(pgste) |= PGSTE_IN_BIT; 796 pgste_set_unlock(ptep, pgste); 797 start += PAGE_SIZE; 798 len -= PAGE_SIZE; 799 } 800 spin_unlock(ptl); 801 } 802 up_read(&gmap->mm->mmap_sem); 803 return rc; 804 } 805 EXPORT_SYMBOL_GPL(gmap_ipte_notify); 806 807 /** 808 * gmap_do_ipte_notify - call all invalidation callbacks for a specific pte. 809 * @mm: pointer to the process mm_struct 810 * @pte: pointer to the page table entry 811 * 812 * This function is assumed to be called with the page table lock held 813 * for the pte to notify. 814 */ 815 void gmap_do_ipte_notify(struct mm_struct *mm, pte_t *pte) 816 { 817 unsigned long segment_offset; 818 struct gmap_notifier *nb; 819 struct gmap_pgtable *mp; 820 struct gmap_rmap *rmap; 821 struct page *page; 822 823 segment_offset = ((unsigned long) pte) & (255 * sizeof(pte_t)); 824 segment_offset = segment_offset * (4096 / sizeof(pte_t)); 825 page = pfn_to_page(__pa(pte) >> PAGE_SHIFT); 826 mp = (struct gmap_pgtable *) page->index; 827 spin_lock(&gmap_notifier_lock); 828 list_for_each_entry(rmap, &mp->mapper, list) { 829 list_for_each_entry(nb, &gmap_notifier_list, list) 830 nb->notifier_call(rmap->gmap, 831 rmap->vmaddr + segment_offset); 832 } 833 spin_unlock(&gmap_notifier_lock); 834 } 835 836 static inline int page_table_with_pgste(struct page *page) 837 { 838 return atomic_read(&page->_mapcount) == 0; 839 } 840 841 static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, 842 unsigned long vmaddr) 843 { 844 struct page *page; 845 unsigned long *table; 846 struct gmap_pgtable *mp; 847 848 page = alloc_page(GFP_KERNEL|__GFP_REPEAT); 849 if (!page) 850 return NULL; 851 mp = kmalloc(sizeof(*mp), GFP_KERNEL|__GFP_REPEAT); 852 if (!mp) { 853 __free_page(page); 854 return NULL; 855 } 856 if (!pgtable_page_ctor(page)) { 857 kfree(mp); 858 __free_page(page); 859 return NULL; 860 } 861 mp->vmaddr = vmaddr & PMD_MASK; 862 INIT_LIST_HEAD(&mp->mapper); 863 page->index = (unsigned long) mp; 864 atomic_set(&page->_mapcount, 0); 865 table = (unsigned long *) page_to_phys(page); 866 clear_table(table, _PAGE_INVALID, PAGE_SIZE/2); 867 clear_table(table + PTRS_PER_PTE, PGSTE_HR_BIT | PGSTE_HC_BIT, 868 PAGE_SIZE/2); 869 return table; 870 } 871 872 static inline void page_table_free_pgste(unsigned long *table) 873 { 874 struct page *page; 875 struct gmap_pgtable *mp; 876 877 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 878 mp = (struct gmap_pgtable *) page->index; 879 BUG_ON(!list_empty(&mp->mapper)); 880 pgtable_page_dtor(page); 881 atomic_set(&page->_mapcount, -1); 882 kfree(mp); 883 __free_page(page); 884 } 885 886 static inline unsigned long page_table_reset_pte(struct mm_struct *mm, 887 pmd_t *pmd, unsigned long addr, unsigned long end) 888 { 889 pte_t *start_pte, *pte; 890 spinlock_t *ptl; 891 pgste_t pgste; 892 893 start_pte = pte_offset_map_lock(mm, pmd, addr, &ptl); 894 pte = start_pte; 895 do { 896 pgste = pgste_get_lock(pte); 897 pgste_val(pgste) &= ~_PGSTE_GPS_USAGE_MASK; 898 pgste_set_unlock(pte, pgste); 899 } while (pte++, addr += PAGE_SIZE, addr != end); 900 pte_unmap_unlock(start_pte, ptl); 901 902 return addr; 903 } 904 905 static inline unsigned long page_table_reset_pmd(struct mm_struct *mm, 906 pud_t *pud, unsigned long addr, unsigned long end) 907 { 908 unsigned long next; 909 pmd_t *pmd; 910 911 pmd = pmd_offset(pud, addr); 912 do { 913 next = pmd_addr_end(addr, end); 914 if (pmd_none_or_clear_bad(pmd)) 915 continue; 916 next = page_table_reset_pte(mm, pmd, addr, next); 917 } while (pmd++, addr = next, addr != end); 918 919 return addr; 920 } 921 922 static inline unsigned long page_table_reset_pud(struct mm_struct *mm, 923 pgd_t *pgd, unsigned long addr, unsigned long end) 924 { 925 unsigned long next; 926 pud_t *pud; 927 928 pud = pud_offset(pgd, addr); 929 do { 930 next = pud_addr_end(addr, end); 931 if (pud_none_or_clear_bad(pud)) 932 continue; 933 next = page_table_reset_pmd(mm, pud, addr, next); 934 } while (pud++, addr = next, addr != end); 935 936 return addr; 937 } 938 939 void page_table_reset_pgste(struct mm_struct *mm, 940 unsigned long start, unsigned long end) 941 { 942 unsigned long addr, next; 943 pgd_t *pgd; 944 945 addr = start; 946 down_read(&mm->mmap_sem); 947 pgd = pgd_offset(mm, addr); 948 do { 949 next = pgd_addr_end(addr, end); 950 if (pgd_none_or_clear_bad(pgd)) 951 continue; 952 next = page_table_reset_pud(mm, pgd, addr, next); 953 } while (pgd++, addr = next, addr != end); 954 up_read(&mm->mmap_sem); 955 } 956 EXPORT_SYMBOL(page_table_reset_pgste); 957 958 int set_guest_storage_key(struct mm_struct *mm, unsigned long addr, 959 unsigned long key, bool nq) 960 { 961 spinlock_t *ptl; 962 pgste_t old, new; 963 pte_t *ptep; 964 965 down_read(&mm->mmap_sem); 966 ptep = get_locked_pte(current->mm, addr, &ptl); 967 if (unlikely(!ptep)) { 968 up_read(&mm->mmap_sem); 969 return -EFAULT; 970 } 971 972 new = old = pgste_get_lock(ptep); 973 pgste_val(new) &= ~(PGSTE_GR_BIT | PGSTE_GC_BIT | 974 PGSTE_ACC_BITS | PGSTE_FP_BIT); 975 pgste_val(new) |= (key & (_PAGE_CHANGED | _PAGE_REFERENCED)) << 48; 976 pgste_val(new) |= (key & (_PAGE_ACC_BITS | _PAGE_FP_BIT)) << 56; 977 if (!(pte_val(*ptep) & _PAGE_INVALID)) { 978 unsigned long address, bits, skey; 979 980 address = pte_val(*ptep) & PAGE_MASK; 981 skey = (unsigned long) page_get_storage_key(address); 982 bits = skey & (_PAGE_CHANGED | _PAGE_REFERENCED); 983 skey = key & (_PAGE_ACC_BITS | _PAGE_FP_BIT); 984 /* Set storage key ACC and FP */ 985 page_set_storage_key(address, skey, !nq); 986 /* Merge host changed & referenced into pgste */ 987 pgste_val(new) |= bits << 52; 988 } 989 /* changing the guest storage key is considered a change of the page */ 990 if ((pgste_val(new) ^ pgste_val(old)) & 991 (PGSTE_ACC_BITS | PGSTE_FP_BIT | PGSTE_GR_BIT | PGSTE_GC_BIT)) 992 pgste_val(new) |= PGSTE_HC_BIT; 993 994 pgste_set_unlock(ptep, new); 995 pte_unmap_unlock(*ptep, ptl); 996 up_read(&mm->mmap_sem); 997 return 0; 998 } 999 EXPORT_SYMBOL(set_guest_storage_key); 1000 1001 #else /* CONFIG_PGSTE */ 1002 1003 static inline int page_table_with_pgste(struct page *page) 1004 { 1005 return 0; 1006 } 1007 1008 static inline unsigned long *page_table_alloc_pgste(struct mm_struct *mm, 1009 unsigned long vmaddr) 1010 { 1011 return NULL; 1012 } 1013 1014 static inline void page_table_free_pgste(unsigned long *table) 1015 { 1016 } 1017 1018 static inline void gmap_disconnect_pgtable(struct mm_struct *mm, 1019 unsigned long *table) 1020 { 1021 } 1022 1023 #endif /* CONFIG_PGSTE */ 1024 1025 static inline unsigned int atomic_xor_bits(atomic_t *v, unsigned int bits) 1026 { 1027 unsigned int old, new; 1028 1029 do { 1030 old = atomic_read(v); 1031 new = old ^ bits; 1032 } while (atomic_cmpxchg(v, old, new) != old); 1033 return new; 1034 } 1035 1036 /* 1037 * page table entry allocation/free routines. 1038 */ 1039 unsigned long *page_table_alloc(struct mm_struct *mm, unsigned long vmaddr) 1040 { 1041 unsigned long *uninitialized_var(table); 1042 struct page *uninitialized_var(page); 1043 unsigned int mask, bit; 1044 1045 if (mm_has_pgste(mm)) 1046 return page_table_alloc_pgste(mm, vmaddr); 1047 /* Allocate fragments of a 4K page as 1K/2K page table */ 1048 spin_lock_bh(&mm->context.list_lock); 1049 mask = FRAG_MASK; 1050 if (!list_empty(&mm->context.pgtable_list)) { 1051 page = list_first_entry(&mm->context.pgtable_list, 1052 struct page, lru); 1053 table = (unsigned long *) page_to_phys(page); 1054 mask = atomic_read(&page->_mapcount); 1055 mask = mask | (mask >> 4); 1056 } 1057 if ((mask & FRAG_MASK) == FRAG_MASK) { 1058 spin_unlock_bh(&mm->context.list_lock); 1059 page = alloc_page(GFP_KERNEL|__GFP_REPEAT); 1060 if (!page) 1061 return NULL; 1062 if (!pgtable_page_ctor(page)) { 1063 __free_page(page); 1064 return NULL; 1065 } 1066 atomic_set(&page->_mapcount, 1); 1067 table = (unsigned long *) page_to_phys(page); 1068 clear_table(table, _PAGE_INVALID, PAGE_SIZE); 1069 spin_lock_bh(&mm->context.list_lock); 1070 list_add(&page->lru, &mm->context.pgtable_list); 1071 } else { 1072 for (bit = 1; mask & bit; bit <<= 1) 1073 table += PTRS_PER_PTE; 1074 mask = atomic_xor_bits(&page->_mapcount, bit); 1075 if ((mask & FRAG_MASK) == FRAG_MASK) 1076 list_del(&page->lru); 1077 } 1078 spin_unlock_bh(&mm->context.list_lock); 1079 return table; 1080 } 1081 1082 void page_table_free(struct mm_struct *mm, unsigned long *table) 1083 { 1084 struct page *page; 1085 unsigned int bit, mask; 1086 1087 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 1088 if (page_table_with_pgste(page)) { 1089 gmap_disconnect_pgtable(mm, table); 1090 return page_table_free_pgste(table); 1091 } 1092 /* Free 1K/2K page table fragment of a 4K page */ 1093 bit = 1 << ((__pa(table) & ~PAGE_MASK)/(PTRS_PER_PTE*sizeof(pte_t))); 1094 spin_lock_bh(&mm->context.list_lock); 1095 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK) 1096 list_del(&page->lru); 1097 mask = atomic_xor_bits(&page->_mapcount, bit); 1098 if (mask & FRAG_MASK) 1099 list_add(&page->lru, &mm->context.pgtable_list); 1100 spin_unlock_bh(&mm->context.list_lock); 1101 if (mask == 0) { 1102 pgtable_page_dtor(page); 1103 atomic_set(&page->_mapcount, -1); 1104 __free_page(page); 1105 } 1106 } 1107 1108 static void __page_table_free_rcu(void *table, unsigned bit) 1109 { 1110 struct page *page; 1111 1112 if (bit == FRAG_MASK) 1113 return page_table_free_pgste(table); 1114 /* Free 1K/2K page table fragment of a 4K page */ 1115 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 1116 if (atomic_xor_bits(&page->_mapcount, bit) == 0) { 1117 pgtable_page_dtor(page); 1118 atomic_set(&page->_mapcount, -1); 1119 __free_page(page); 1120 } 1121 } 1122 1123 void page_table_free_rcu(struct mmu_gather *tlb, unsigned long *table) 1124 { 1125 struct mm_struct *mm; 1126 struct page *page; 1127 unsigned int bit, mask; 1128 1129 mm = tlb->mm; 1130 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 1131 if (page_table_with_pgste(page)) { 1132 gmap_disconnect_pgtable(mm, table); 1133 table = (unsigned long *) (__pa(table) | FRAG_MASK); 1134 tlb_remove_table(tlb, table); 1135 return; 1136 } 1137 bit = 1 << ((__pa(table) & ~PAGE_MASK) / (PTRS_PER_PTE*sizeof(pte_t))); 1138 spin_lock_bh(&mm->context.list_lock); 1139 if ((atomic_read(&page->_mapcount) & FRAG_MASK) != FRAG_MASK) 1140 list_del(&page->lru); 1141 mask = atomic_xor_bits(&page->_mapcount, bit | (bit << 4)); 1142 if (mask & FRAG_MASK) 1143 list_add_tail(&page->lru, &mm->context.pgtable_list); 1144 spin_unlock_bh(&mm->context.list_lock); 1145 table = (unsigned long *) (__pa(table) | (bit << 4)); 1146 tlb_remove_table(tlb, table); 1147 } 1148 1149 static void __tlb_remove_table(void *_table) 1150 { 1151 const unsigned long mask = (FRAG_MASK << 4) | FRAG_MASK; 1152 void *table = (void *)((unsigned long) _table & ~mask); 1153 unsigned type = (unsigned long) _table & mask; 1154 1155 if (type) 1156 __page_table_free_rcu(table, type); 1157 else 1158 free_pages((unsigned long) table, ALLOC_ORDER); 1159 } 1160 1161 static void tlb_remove_table_smp_sync(void *arg) 1162 { 1163 /* Simply deliver the interrupt */ 1164 } 1165 1166 static void tlb_remove_table_one(void *table) 1167 { 1168 /* 1169 * This isn't an RCU grace period and hence the page-tables cannot be 1170 * assumed to be actually RCU-freed. 1171 * 1172 * It is however sufficient for software page-table walkers that rely 1173 * on IRQ disabling. See the comment near struct mmu_table_batch. 1174 */ 1175 smp_call_function(tlb_remove_table_smp_sync, NULL, 1); 1176 __tlb_remove_table(table); 1177 } 1178 1179 static void tlb_remove_table_rcu(struct rcu_head *head) 1180 { 1181 struct mmu_table_batch *batch; 1182 int i; 1183 1184 batch = container_of(head, struct mmu_table_batch, rcu); 1185 1186 for (i = 0; i < batch->nr; i++) 1187 __tlb_remove_table(batch->tables[i]); 1188 1189 free_page((unsigned long)batch); 1190 } 1191 1192 void tlb_table_flush(struct mmu_gather *tlb) 1193 { 1194 struct mmu_table_batch **batch = &tlb->batch; 1195 1196 if (*batch) { 1197 call_rcu_sched(&(*batch)->rcu, tlb_remove_table_rcu); 1198 *batch = NULL; 1199 } 1200 } 1201 1202 void tlb_remove_table(struct mmu_gather *tlb, void *table) 1203 { 1204 struct mmu_table_batch **batch = &tlb->batch; 1205 1206 tlb->mm->context.flush_mm = 1; 1207 if (*batch == NULL) { 1208 *batch = (struct mmu_table_batch *) 1209 __get_free_page(GFP_NOWAIT | __GFP_NOWARN); 1210 if (*batch == NULL) { 1211 __tlb_flush_mm_lazy(tlb->mm); 1212 tlb_remove_table_one(table); 1213 return; 1214 } 1215 (*batch)->nr = 0; 1216 } 1217 (*batch)->tables[(*batch)->nr++] = table; 1218 if ((*batch)->nr == MAX_TABLE_BATCH) 1219 tlb_flush_mmu(tlb); 1220 } 1221 1222 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1223 static inline void thp_split_vma(struct vm_area_struct *vma) 1224 { 1225 unsigned long addr; 1226 1227 for (addr = vma->vm_start; addr < vma->vm_end; addr += PAGE_SIZE) 1228 follow_page(vma, addr, FOLL_SPLIT); 1229 } 1230 1231 static inline void thp_split_mm(struct mm_struct *mm) 1232 { 1233 struct vm_area_struct *vma; 1234 1235 for (vma = mm->mmap; vma != NULL; vma = vma->vm_next) { 1236 thp_split_vma(vma); 1237 vma->vm_flags &= ~VM_HUGEPAGE; 1238 vma->vm_flags |= VM_NOHUGEPAGE; 1239 } 1240 mm->def_flags |= VM_NOHUGEPAGE; 1241 } 1242 #else 1243 static inline void thp_split_mm(struct mm_struct *mm) 1244 { 1245 } 1246 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1247 1248 static unsigned long page_table_realloc_pmd(struct mmu_gather *tlb, 1249 struct mm_struct *mm, pud_t *pud, 1250 unsigned long addr, unsigned long end) 1251 { 1252 unsigned long next, *table, *new; 1253 struct page *page; 1254 pmd_t *pmd; 1255 1256 pmd = pmd_offset(pud, addr); 1257 do { 1258 next = pmd_addr_end(addr, end); 1259 again: 1260 if (pmd_none_or_clear_bad(pmd)) 1261 continue; 1262 table = (unsigned long *) pmd_deref(*pmd); 1263 page = pfn_to_page(__pa(table) >> PAGE_SHIFT); 1264 if (page_table_with_pgste(page)) 1265 continue; 1266 /* Allocate new page table with pgstes */ 1267 new = page_table_alloc_pgste(mm, addr); 1268 if (!new) 1269 return -ENOMEM; 1270 1271 spin_lock(&mm->page_table_lock); 1272 if (likely((unsigned long *) pmd_deref(*pmd) == table)) { 1273 /* Nuke pmd entry pointing to the "short" page table */ 1274 pmdp_flush_lazy(mm, addr, pmd); 1275 pmd_clear(pmd); 1276 /* Copy ptes from old table to new table */ 1277 memcpy(new, table, PAGE_SIZE/2); 1278 clear_table(table, _PAGE_INVALID, PAGE_SIZE/2); 1279 /* Establish new table */ 1280 pmd_populate(mm, pmd, (pte_t *) new); 1281 /* Free old table with rcu, there might be a walker! */ 1282 page_table_free_rcu(tlb, table); 1283 new = NULL; 1284 } 1285 spin_unlock(&mm->page_table_lock); 1286 if (new) { 1287 page_table_free_pgste(new); 1288 goto again; 1289 } 1290 } while (pmd++, addr = next, addr != end); 1291 1292 return addr; 1293 } 1294 1295 static unsigned long page_table_realloc_pud(struct mmu_gather *tlb, 1296 struct mm_struct *mm, pgd_t *pgd, 1297 unsigned long addr, unsigned long end) 1298 { 1299 unsigned long next; 1300 pud_t *pud; 1301 1302 pud = pud_offset(pgd, addr); 1303 do { 1304 next = pud_addr_end(addr, end); 1305 if (pud_none_or_clear_bad(pud)) 1306 continue; 1307 next = page_table_realloc_pmd(tlb, mm, pud, addr, next); 1308 if (unlikely(IS_ERR_VALUE(next))) 1309 return next; 1310 } while (pud++, addr = next, addr != end); 1311 1312 return addr; 1313 } 1314 1315 static unsigned long page_table_realloc(struct mmu_gather *tlb, struct mm_struct *mm, 1316 unsigned long addr, unsigned long end) 1317 { 1318 unsigned long next; 1319 pgd_t *pgd; 1320 1321 pgd = pgd_offset(mm, addr); 1322 do { 1323 next = pgd_addr_end(addr, end); 1324 if (pgd_none_or_clear_bad(pgd)) 1325 continue; 1326 next = page_table_realloc_pud(tlb, mm, pgd, addr, next); 1327 if (unlikely(IS_ERR_VALUE(next))) 1328 return next; 1329 } while (pgd++, addr = next, addr != end); 1330 1331 return 0; 1332 } 1333 1334 /* 1335 * switch on pgstes for its userspace process (for kvm) 1336 */ 1337 int s390_enable_sie(void) 1338 { 1339 struct task_struct *tsk = current; 1340 struct mm_struct *mm = tsk->mm; 1341 struct mmu_gather tlb; 1342 1343 /* Do we have pgstes? if yes, we are done */ 1344 if (mm_has_pgste(tsk->mm)) 1345 return 0; 1346 1347 down_write(&mm->mmap_sem); 1348 /* split thp mappings and disable thp for future mappings */ 1349 thp_split_mm(mm); 1350 /* Reallocate the page tables with pgstes */ 1351 tlb_gather_mmu(&tlb, mm, 0, TASK_SIZE); 1352 if (!page_table_realloc(&tlb, mm, 0, TASK_SIZE)) 1353 mm->context.has_pgste = 1; 1354 tlb_finish_mmu(&tlb, 0, TASK_SIZE); 1355 up_write(&mm->mmap_sem); 1356 return mm->context.has_pgste ? 0 : -ENOMEM; 1357 } 1358 EXPORT_SYMBOL_GPL(s390_enable_sie); 1359 1360 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 1361 int pmdp_clear_flush_young(struct vm_area_struct *vma, unsigned long address, 1362 pmd_t *pmdp) 1363 { 1364 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 1365 /* No need to flush TLB 1366 * On s390 reference bits are in storage key and never in TLB */ 1367 return pmdp_test_and_clear_young(vma, address, pmdp); 1368 } 1369 1370 int pmdp_set_access_flags(struct vm_area_struct *vma, 1371 unsigned long address, pmd_t *pmdp, 1372 pmd_t entry, int dirty) 1373 { 1374 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 1375 1376 if (pmd_same(*pmdp, entry)) 1377 return 0; 1378 pmdp_invalidate(vma, address, pmdp); 1379 set_pmd_at(vma->vm_mm, address, pmdp, entry); 1380 return 1; 1381 } 1382 1383 static void pmdp_splitting_flush_sync(void *arg) 1384 { 1385 /* Simply deliver the interrupt */ 1386 } 1387 1388 void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, 1389 pmd_t *pmdp) 1390 { 1391 VM_BUG_ON(address & ~HPAGE_PMD_MASK); 1392 if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT, 1393 (unsigned long *) pmdp)) { 1394 /* need to serialize against gup-fast (IRQ disabled) */ 1395 smp_call_function(pmdp_splitting_flush_sync, NULL, 1); 1396 } 1397 } 1398 1399 void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, 1400 pgtable_t pgtable) 1401 { 1402 struct list_head *lh = (struct list_head *) pgtable; 1403 1404 assert_spin_locked(pmd_lockptr(mm, pmdp)); 1405 1406 /* FIFO */ 1407 if (!pmd_huge_pte(mm, pmdp)) 1408 INIT_LIST_HEAD(lh); 1409 else 1410 list_add(lh, (struct list_head *) pmd_huge_pte(mm, pmdp)); 1411 pmd_huge_pte(mm, pmdp) = pgtable; 1412 } 1413 1414 pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp) 1415 { 1416 struct list_head *lh; 1417 pgtable_t pgtable; 1418 pte_t *ptep; 1419 1420 assert_spin_locked(pmd_lockptr(mm, pmdp)); 1421 1422 /* FIFO */ 1423 pgtable = pmd_huge_pte(mm, pmdp); 1424 lh = (struct list_head *) pgtable; 1425 if (list_empty(lh)) 1426 pmd_huge_pte(mm, pmdp) = NULL; 1427 else { 1428 pmd_huge_pte(mm, pmdp) = (pgtable_t) lh->next; 1429 list_del(lh); 1430 } 1431 ptep = (pte_t *) pgtable; 1432 pte_val(*ptep) = _PAGE_INVALID; 1433 ptep++; 1434 pte_val(*ptep) = _PAGE_INVALID; 1435 return pgtable; 1436 } 1437 #endif /* CONFIG_TRANSPARENT_HUGEPAGE */ 1438