1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/mm/memory_hotplug.c 4 * 5 * Copyright (C) 6 */ 7 8 #include <linux/stddef.h> 9 #include <linux/mm.h> 10 #include <linux/sched/signal.h> 11 #include <linux/swap.h> 12 #include <linux/interrupt.h> 13 #include <linux/pagemap.h> 14 #include <linux/compiler.h> 15 #include <linux/export.h> 16 #include <linux/pagevec.h> 17 #include <linux/writeback.h> 18 #include <linux/slab.h> 19 #include <linux/sysctl.h> 20 #include <linux/cpu.h> 21 #include <linux/memory.h> 22 #include <linux/memremap.h> 23 #include <linux/memory_hotplug.h> 24 #include <linux/highmem.h> 25 #include <linux/vmalloc.h> 26 #include <linux/ioport.h> 27 #include <linux/delay.h> 28 #include <linux/migrate.h> 29 #include <linux/page-isolation.h> 30 #include <linux/pfn.h> 31 #include <linux/suspend.h> 32 #include <linux/mm_inline.h> 33 #include <linux/firmware-map.h> 34 #include <linux/stop_machine.h> 35 #include <linux/hugetlb.h> 36 #include <linux/memblock.h> 37 #include <linux/compaction.h> 38 #include <linux/rmap.h> 39 40 #include <asm/tlbflush.h> 41 42 #include "internal.h" 43 #include "shuffle.h" 44 45 /* 46 * online_page_callback contains pointer to current page onlining function. 47 * Initially it is generic_online_page(). If it is required it could be 48 * changed by calling set_online_page_callback() for callback registration 49 * and restore_online_page_callback() for generic callback restore. 50 */ 51 52 static online_page_callback_t online_page_callback = generic_online_page; 53 static DEFINE_MUTEX(online_page_callback_lock); 54 55 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); 56 57 void get_online_mems(void) 58 { 59 percpu_down_read(&mem_hotplug_lock); 60 } 61 62 void put_online_mems(void) 63 { 64 percpu_up_read(&mem_hotplug_lock); 65 } 66 67 bool movable_node_enabled = false; 68 69 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE 70 bool memhp_auto_online; 71 #else 72 bool memhp_auto_online = true; 73 #endif 74 EXPORT_SYMBOL_GPL(memhp_auto_online); 75 76 static int __init setup_memhp_default_state(char *str) 77 { 78 if (!strcmp(str, "online")) 79 memhp_auto_online = true; 80 else if (!strcmp(str, "offline")) 81 memhp_auto_online = false; 82 83 return 1; 84 } 85 __setup("memhp_default_state=", setup_memhp_default_state); 86 87 void mem_hotplug_begin(void) 88 { 89 cpus_read_lock(); 90 percpu_down_write(&mem_hotplug_lock); 91 } 92 93 void mem_hotplug_done(void) 94 { 95 percpu_up_write(&mem_hotplug_lock); 96 cpus_read_unlock(); 97 } 98 99 u64 max_mem_size = U64_MAX; 100 101 /* add this memory to iomem resource */ 102 static struct resource *register_memory_resource(u64 start, u64 size) 103 { 104 struct resource *res; 105 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 106 char *resource_name = "System RAM"; 107 108 if (start + size > max_mem_size) 109 return ERR_PTR(-E2BIG); 110 111 /* 112 * Request ownership of the new memory range. This might be 113 * a child of an existing resource that was present but 114 * not marked as busy. 115 */ 116 res = __request_region(&iomem_resource, start, size, 117 resource_name, flags); 118 119 if (!res) { 120 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", 121 start, start + size); 122 return ERR_PTR(-EEXIST); 123 } 124 return res; 125 } 126 127 static void release_memory_resource(struct resource *res) 128 { 129 if (!res) 130 return; 131 release_resource(res); 132 kfree(res); 133 } 134 135 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 136 void get_page_bootmem(unsigned long info, struct page *page, 137 unsigned long type) 138 { 139 page->freelist = (void *)type; 140 SetPagePrivate(page); 141 set_page_private(page, info); 142 page_ref_inc(page); 143 } 144 145 void put_page_bootmem(struct page *page) 146 { 147 unsigned long type; 148 149 type = (unsigned long) page->freelist; 150 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || 151 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); 152 153 if (page_ref_dec_return(page) == 1) { 154 page->freelist = NULL; 155 ClearPagePrivate(page); 156 set_page_private(page, 0); 157 INIT_LIST_HEAD(&page->lru); 158 free_reserved_page(page); 159 } 160 } 161 162 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE 163 #ifndef CONFIG_SPARSEMEM_VMEMMAP 164 static void register_page_bootmem_info_section(unsigned long start_pfn) 165 { 166 unsigned long mapsize, section_nr, i; 167 struct mem_section *ms; 168 struct page *page, *memmap; 169 struct mem_section_usage *usage; 170 171 section_nr = pfn_to_section_nr(start_pfn); 172 ms = __nr_to_section(section_nr); 173 174 /* Get section's memmap address */ 175 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 176 177 /* 178 * Get page for the memmap's phys address 179 * XXX: need more consideration for sparse_vmemmap... 180 */ 181 page = virt_to_page(memmap); 182 mapsize = sizeof(struct page) * PAGES_PER_SECTION; 183 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; 184 185 /* remember memmap's page */ 186 for (i = 0; i < mapsize; i++, page++) 187 get_page_bootmem(section_nr, page, SECTION_INFO); 188 189 usage = ms->usage; 190 page = virt_to_page(usage); 191 192 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 193 194 for (i = 0; i < mapsize; i++, page++) 195 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 196 197 } 198 #else /* CONFIG_SPARSEMEM_VMEMMAP */ 199 static void register_page_bootmem_info_section(unsigned long start_pfn) 200 { 201 unsigned long mapsize, section_nr, i; 202 struct mem_section *ms; 203 struct page *page, *memmap; 204 struct mem_section_usage *usage; 205 206 section_nr = pfn_to_section_nr(start_pfn); 207 ms = __nr_to_section(section_nr); 208 209 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 210 211 register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); 212 213 usage = ms->usage; 214 page = virt_to_page(usage); 215 216 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 217 218 for (i = 0; i < mapsize; i++, page++) 219 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 220 } 221 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 222 223 void __init register_page_bootmem_info_node(struct pglist_data *pgdat) 224 { 225 unsigned long i, pfn, end_pfn, nr_pages; 226 int node = pgdat->node_id; 227 struct page *page; 228 229 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; 230 page = virt_to_page(pgdat); 231 232 for (i = 0; i < nr_pages; i++, page++) 233 get_page_bootmem(node, page, NODE_INFO); 234 235 pfn = pgdat->node_start_pfn; 236 end_pfn = pgdat_end_pfn(pgdat); 237 238 /* register section info */ 239 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 240 /* 241 * Some platforms can assign the same pfn to multiple nodes - on 242 * node0 as well as nodeN. To avoid registering a pfn against 243 * multiple nodes we check that this pfn does not already 244 * reside in some other nodes. 245 */ 246 if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) 247 register_page_bootmem_info_section(pfn); 248 } 249 } 250 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ 251 252 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, 253 const char *reason) 254 { 255 /* 256 * Disallow all operations smaller than a sub-section and only 257 * allow operations smaller than a section for 258 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() 259 * enforces a larger memory_block_size_bytes() granularity for 260 * memory that will be marked online, so this check should only 261 * fire for direct arch_{add,remove}_memory() users outside of 262 * add_memory_resource(). 263 */ 264 unsigned long min_align; 265 266 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) 267 min_align = PAGES_PER_SUBSECTION; 268 else 269 min_align = PAGES_PER_SECTION; 270 if (!IS_ALIGNED(pfn, min_align) 271 || !IS_ALIGNED(nr_pages, min_align)) { 272 WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", 273 reason, pfn, pfn + nr_pages - 1); 274 return -EINVAL; 275 } 276 return 0; 277 } 278 279 static int check_hotplug_memory_addressable(unsigned long pfn, 280 unsigned long nr_pages) 281 { 282 const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; 283 284 if (max_addr >> MAX_PHYSMEM_BITS) { 285 const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1; 286 WARN(1, 287 "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n", 288 (u64)PFN_PHYS(pfn), max_addr, max_allowed); 289 return -E2BIG; 290 } 291 292 return 0; 293 } 294 295 /* 296 * Reasonably generic function for adding memory. It is 297 * expected that archs that support memory hotplug will 298 * call this function after deciding the zone to which to 299 * add the new pages. 300 */ 301 int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, 302 struct mhp_restrictions *restrictions) 303 { 304 int err; 305 unsigned long nr, start_sec, end_sec; 306 struct vmem_altmap *altmap = restrictions->altmap; 307 308 err = check_hotplug_memory_addressable(pfn, nr_pages); 309 if (err) 310 return err; 311 312 if (altmap) { 313 /* 314 * Validate altmap is within bounds of the total request 315 */ 316 if (altmap->base_pfn != pfn 317 || vmem_altmap_offset(altmap) > nr_pages) { 318 pr_warn_once("memory add fail, invalid altmap\n"); 319 return -EINVAL; 320 } 321 altmap->alloc = 0; 322 } 323 324 err = check_pfn_span(pfn, nr_pages, "add"); 325 if (err) 326 return err; 327 328 start_sec = pfn_to_section_nr(pfn); 329 end_sec = pfn_to_section_nr(pfn + nr_pages - 1); 330 for (nr = start_sec; nr <= end_sec; nr++) { 331 unsigned long pfns; 332 333 pfns = min(nr_pages, PAGES_PER_SECTION 334 - (pfn & ~PAGE_SECTION_MASK)); 335 err = sparse_add_section(nid, pfn, pfns, altmap); 336 if (err) 337 break; 338 pfn += pfns; 339 nr_pages -= pfns; 340 cond_resched(); 341 } 342 vmemmap_populate_print_last(); 343 return err; 344 } 345 346 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 347 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 348 unsigned long start_pfn, 349 unsigned long end_pfn) 350 { 351 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 352 if (unlikely(!pfn_to_online_page(start_pfn))) 353 continue; 354 355 if (unlikely(pfn_to_nid(start_pfn) != nid)) 356 continue; 357 358 if (zone != page_zone(pfn_to_page(start_pfn))) 359 continue; 360 361 return start_pfn; 362 } 363 364 return 0; 365 } 366 367 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 368 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 369 unsigned long start_pfn, 370 unsigned long end_pfn) 371 { 372 unsigned long pfn; 373 374 /* pfn is the end pfn of a memory section. */ 375 pfn = end_pfn - 1; 376 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 377 if (unlikely(!pfn_to_online_page(pfn))) 378 continue; 379 380 if (unlikely(pfn_to_nid(pfn) != nid)) 381 continue; 382 383 if (zone != page_zone(pfn_to_page(pfn))) 384 continue; 385 386 return pfn; 387 } 388 389 return 0; 390 } 391 392 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 393 unsigned long end_pfn) 394 { 395 unsigned long zone_start_pfn = zone->zone_start_pfn; 396 unsigned long z = zone_end_pfn(zone); /* zone_end_pfn namespace clash */ 397 unsigned long zone_end_pfn = z; 398 unsigned long pfn; 399 int nid = zone_to_nid(zone); 400 401 zone_span_writelock(zone); 402 if (zone_start_pfn == start_pfn) { 403 /* 404 * If the section is smallest section in the zone, it need 405 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 406 * In this case, we find second smallest valid mem_section 407 * for shrinking zone. 408 */ 409 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 410 zone_end_pfn); 411 if (pfn) { 412 zone->zone_start_pfn = pfn; 413 zone->spanned_pages = zone_end_pfn - pfn; 414 } 415 } else if (zone_end_pfn == end_pfn) { 416 /* 417 * If the section is biggest section in the zone, it need 418 * shrink zone->spanned_pages. 419 * In this case, we find second biggest valid mem_section for 420 * shrinking zone. 421 */ 422 pfn = find_biggest_section_pfn(nid, zone, zone_start_pfn, 423 start_pfn); 424 if (pfn) 425 zone->spanned_pages = pfn - zone_start_pfn + 1; 426 } 427 428 /* 429 * The section is not biggest or smallest mem_section in the zone, it 430 * only creates a hole in the zone. So in this case, we need not 431 * change the zone. But perhaps, the zone has only hole data. Thus 432 * it check the zone has only hole or not. 433 */ 434 pfn = zone_start_pfn; 435 for (; pfn < zone_end_pfn; pfn += PAGES_PER_SUBSECTION) { 436 if (unlikely(!pfn_to_online_page(pfn))) 437 continue; 438 439 if (page_zone(pfn_to_page(pfn)) != zone) 440 continue; 441 442 /* Skip range to be removed */ 443 if (pfn >= start_pfn && pfn < end_pfn) 444 continue; 445 446 /* If we find valid section, we have nothing to do */ 447 zone_span_writeunlock(zone); 448 return; 449 } 450 451 /* The zone has no valid section */ 452 zone->zone_start_pfn = 0; 453 zone->spanned_pages = 0; 454 zone_span_writeunlock(zone); 455 } 456 457 static void update_pgdat_span(struct pglist_data *pgdat) 458 { 459 unsigned long node_start_pfn = 0, node_end_pfn = 0; 460 struct zone *zone; 461 462 for (zone = pgdat->node_zones; 463 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 464 unsigned long zone_end_pfn = zone->zone_start_pfn + 465 zone->spanned_pages; 466 467 /* No need to lock the zones, they can't change. */ 468 if (!zone->spanned_pages) 469 continue; 470 if (!node_end_pfn) { 471 node_start_pfn = zone->zone_start_pfn; 472 node_end_pfn = zone_end_pfn; 473 continue; 474 } 475 476 if (zone_end_pfn > node_end_pfn) 477 node_end_pfn = zone_end_pfn; 478 if (zone->zone_start_pfn < node_start_pfn) 479 node_start_pfn = zone->zone_start_pfn; 480 } 481 482 pgdat->node_start_pfn = node_start_pfn; 483 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 484 } 485 486 void __ref remove_pfn_range_from_zone(struct zone *zone, 487 unsigned long start_pfn, 488 unsigned long nr_pages) 489 { 490 struct pglist_data *pgdat = zone->zone_pgdat; 491 unsigned long flags; 492 493 /* Poison struct pages because they are now uninitialized again. */ 494 page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); 495 496 #ifdef CONFIG_ZONE_DEVICE 497 /* 498 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 499 * we will not try to shrink the zones - which is okay as 500 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 501 */ 502 if (zone_idx(zone) == ZONE_DEVICE) 503 return; 504 #endif 505 506 clear_zone_contiguous(zone); 507 508 pgdat_resize_lock(zone->zone_pgdat, &flags); 509 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 510 update_pgdat_span(pgdat); 511 pgdat_resize_unlock(zone->zone_pgdat, &flags); 512 513 set_zone_contiguous(zone); 514 } 515 516 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 517 unsigned long map_offset, 518 struct vmem_altmap *altmap) 519 { 520 struct mem_section *ms = __nr_to_section(pfn_to_section_nr(pfn)); 521 522 if (WARN_ON_ONCE(!valid_section(ms))) 523 return; 524 525 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 526 } 527 528 /** 529 * __remove_pages() - remove sections of pages 530 * @pfn: starting pageframe (must be aligned to start of a section) 531 * @nr_pages: number of pages to remove (must be multiple of section size) 532 * @altmap: alternative device page map or %NULL if default memmap is used 533 * 534 * Generic helper function to remove section mappings and sysfs entries 535 * for the section of the memory we are removing. Caller needs to make 536 * sure that pages are marked reserved and zones are adjust properly by 537 * calling offline_pages(). 538 */ 539 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 540 struct vmem_altmap *altmap) 541 { 542 unsigned long map_offset = 0; 543 unsigned long nr, start_sec, end_sec; 544 545 map_offset = vmem_altmap_offset(altmap); 546 547 if (check_pfn_span(pfn, nr_pages, "remove")) 548 return; 549 550 start_sec = pfn_to_section_nr(pfn); 551 end_sec = pfn_to_section_nr(pfn + nr_pages - 1); 552 for (nr = start_sec; nr <= end_sec; nr++) { 553 unsigned long pfns; 554 555 cond_resched(); 556 pfns = min(nr_pages, PAGES_PER_SECTION 557 - (pfn & ~PAGE_SECTION_MASK)); 558 __remove_section(pfn, pfns, map_offset, altmap); 559 pfn += pfns; 560 nr_pages -= pfns; 561 map_offset = 0; 562 } 563 } 564 565 int set_online_page_callback(online_page_callback_t callback) 566 { 567 int rc = -EINVAL; 568 569 get_online_mems(); 570 mutex_lock(&online_page_callback_lock); 571 572 if (online_page_callback == generic_online_page) { 573 online_page_callback = callback; 574 rc = 0; 575 } 576 577 mutex_unlock(&online_page_callback_lock); 578 put_online_mems(); 579 580 return rc; 581 } 582 EXPORT_SYMBOL_GPL(set_online_page_callback); 583 584 int restore_online_page_callback(online_page_callback_t callback) 585 { 586 int rc = -EINVAL; 587 588 get_online_mems(); 589 mutex_lock(&online_page_callback_lock); 590 591 if (online_page_callback == callback) { 592 online_page_callback = generic_online_page; 593 rc = 0; 594 } 595 596 mutex_unlock(&online_page_callback_lock); 597 put_online_mems(); 598 599 return rc; 600 } 601 EXPORT_SYMBOL_GPL(restore_online_page_callback); 602 603 void generic_online_page(struct page *page, unsigned int order) 604 { 605 kernel_map_pages(page, 1 << order, 1); 606 __free_pages_core(page, order); 607 totalram_pages_add(1UL << order); 608 #ifdef CONFIG_HIGHMEM 609 if (PageHighMem(page)) 610 totalhigh_pages_add(1UL << order); 611 #endif 612 } 613 EXPORT_SYMBOL_GPL(generic_online_page); 614 615 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, 616 void *arg) 617 { 618 const unsigned long end_pfn = start_pfn + nr_pages; 619 unsigned long pfn; 620 int order; 621 622 /* 623 * Online the pages. The callback might decide to keep some pages 624 * PG_reserved (to add them to the buddy later), but we still account 625 * them as being online/belonging to this zone ("present"). 626 */ 627 for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { 628 order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); 629 /* __free_pages_core() wants pfns to be aligned to the order */ 630 if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) 631 order = 0; 632 (*online_page_callback)(pfn_to_page(pfn), order); 633 } 634 635 /* mark all involved sections as online */ 636 online_mem_sections(start_pfn, end_pfn); 637 638 *(unsigned long *)arg += nr_pages; 639 return 0; 640 } 641 642 /* check which state of node_states will be changed when online memory */ 643 static void node_states_check_changes_online(unsigned long nr_pages, 644 struct zone *zone, struct memory_notify *arg) 645 { 646 int nid = zone_to_nid(zone); 647 648 arg->status_change_nid = NUMA_NO_NODE; 649 arg->status_change_nid_normal = NUMA_NO_NODE; 650 arg->status_change_nid_high = NUMA_NO_NODE; 651 652 if (!node_state(nid, N_MEMORY)) 653 arg->status_change_nid = nid; 654 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 655 arg->status_change_nid_normal = nid; 656 #ifdef CONFIG_HIGHMEM 657 if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) 658 arg->status_change_nid_high = nid; 659 #endif 660 } 661 662 static void node_states_set_node(int node, struct memory_notify *arg) 663 { 664 if (arg->status_change_nid_normal >= 0) 665 node_set_state(node, N_NORMAL_MEMORY); 666 667 if (arg->status_change_nid_high >= 0) 668 node_set_state(node, N_HIGH_MEMORY); 669 670 if (arg->status_change_nid >= 0) 671 node_set_state(node, N_MEMORY); 672 } 673 674 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 675 unsigned long nr_pages) 676 { 677 unsigned long old_end_pfn = zone_end_pfn(zone); 678 679 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 680 zone->zone_start_pfn = start_pfn; 681 682 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 683 } 684 685 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 686 unsigned long nr_pages) 687 { 688 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 689 690 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 691 pgdat->node_start_pfn = start_pfn; 692 693 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 694 695 } 696 /* 697 * Associate the pfn range with the given zone, initializing the memmaps 698 * and resizing the pgdat/zone data to span the added pages. After this 699 * call, all affected pages are PG_reserved. 700 */ 701 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 702 unsigned long nr_pages, struct vmem_altmap *altmap) 703 { 704 struct pglist_data *pgdat = zone->zone_pgdat; 705 int nid = pgdat->node_id; 706 unsigned long flags; 707 708 clear_zone_contiguous(zone); 709 710 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ 711 pgdat_resize_lock(pgdat, &flags); 712 zone_span_writelock(zone); 713 if (zone_is_empty(zone)) 714 init_currently_empty_zone(zone, start_pfn, nr_pages); 715 resize_zone_range(zone, start_pfn, nr_pages); 716 zone_span_writeunlock(zone); 717 resize_pgdat_range(pgdat, start_pfn, nr_pages); 718 pgdat_resize_unlock(pgdat, &flags); 719 720 /* 721 * TODO now we have a visible range of pages which are not associated 722 * with their zone properly. Not nice but set_pfnblock_flags_mask 723 * expects the zone spans the pfn range. All the pages in the range 724 * are reserved so nobody should be touching them so we should be safe 725 */ 726 memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, 727 MEMMAP_HOTPLUG, altmap); 728 729 set_zone_contiguous(zone); 730 } 731 732 /* 733 * Returns a default kernel memory zone for the given pfn range. 734 * If no kernel zone covers this pfn range it will automatically go 735 * to the ZONE_NORMAL. 736 */ 737 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 738 unsigned long nr_pages) 739 { 740 struct pglist_data *pgdat = NODE_DATA(nid); 741 int zid; 742 743 for (zid = 0; zid <= ZONE_NORMAL; zid++) { 744 struct zone *zone = &pgdat->node_zones[zid]; 745 746 if (zone_intersects(zone, start_pfn, nr_pages)) 747 return zone; 748 } 749 750 return &pgdat->node_zones[ZONE_NORMAL]; 751 } 752 753 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 754 unsigned long nr_pages) 755 { 756 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 757 nr_pages); 758 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 759 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 760 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 761 762 /* 763 * We inherit the existing zone in a simple case where zones do not 764 * overlap in the given range 765 */ 766 if (in_kernel ^ in_movable) 767 return (in_kernel) ? kernel_zone : movable_zone; 768 769 /* 770 * If the range doesn't belong to any zone or two zones overlap in the 771 * given range then we use movable zone only if movable_node is 772 * enabled because we always online to a kernel zone by default. 773 */ 774 return movable_node_enabled ? movable_zone : kernel_zone; 775 } 776 777 struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, 778 unsigned long nr_pages) 779 { 780 if (online_type == MMOP_ONLINE_KERNEL) 781 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 782 783 if (online_type == MMOP_ONLINE_MOVABLE) 784 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 785 786 return default_zone_for_pfn(nid, start_pfn, nr_pages); 787 } 788 789 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 790 int online_type, int nid) 791 { 792 unsigned long flags; 793 unsigned long onlined_pages = 0; 794 struct zone *zone; 795 int need_zonelists_rebuild = 0; 796 int ret; 797 struct memory_notify arg; 798 799 mem_hotplug_begin(); 800 801 /* associate pfn range with the zone */ 802 zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); 803 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); 804 805 arg.start_pfn = pfn; 806 arg.nr_pages = nr_pages; 807 node_states_check_changes_online(nr_pages, zone, &arg); 808 809 ret = memory_notify(MEM_GOING_ONLINE, &arg); 810 ret = notifier_to_errno(ret); 811 if (ret) 812 goto failed_addition; 813 814 /* 815 * If this zone is not populated, then it is not in zonelist. 816 * This means the page allocator ignores this zone. 817 * So, zonelist must be updated after online. 818 */ 819 if (!populated_zone(zone)) { 820 need_zonelists_rebuild = 1; 821 setup_zone_pageset(zone); 822 } 823 824 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, 825 online_pages_range); 826 if (ret) { 827 /* not a single memory resource was applicable */ 828 if (need_zonelists_rebuild) 829 zone_pcp_reset(zone); 830 goto failed_addition; 831 } 832 833 zone->present_pages += onlined_pages; 834 835 pgdat_resize_lock(zone->zone_pgdat, &flags); 836 zone->zone_pgdat->node_present_pages += onlined_pages; 837 pgdat_resize_unlock(zone->zone_pgdat, &flags); 838 839 shuffle_zone(zone); 840 841 node_states_set_node(nid, &arg); 842 if (need_zonelists_rebuild) 843 build_all_zonelists(NULL); 844 else 845 zone_pcp_update(zone); 846 847 init_per_zone_wmark_min(); 848 849 kswapd_run(nid); 850 kcompactd_run(nid); 851 852 vm_total_pages = nr_free_pagecache_pages(); 853 854 writeback_set_ratelimit(); 855 856 memory_notify(MEM_ONLINE, &arg); 857 mem_hotplug_done(); 858 return 0; 859 860 failed_addition: 861 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 862 (unsigned long long) pfn << PAGE_SHIFT, 863 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 864 memory_notify(MEM_CANCEL_ONLINE, &arg); 865 remove_pfn_range_from_zone(zone, pfn, nr_pages); 866 mem_hotplug_done(); 867 return ret; 868 } 869 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 870 871 static void reset_node_present_pages(pg_data_t *pgdat) 872 { 873 struct zone *z; 874 875 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 876 z->present_pages = 0; 877 878 pgdat->node_present_pages = 0; 879 } 880 881 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 882 static pg_data_t __ref *hotadd_new_pgdat(int nid, u64 start) 883 { 884 struct pglist_data *pgdat; 885 unsigned long start_pfn = PFN_DOWN(start); 886 887 pgdat = NODE_DATA(nid); 888 if (!pgdat) { 889 pgdat = arch_alloc_nodedata(nid); 890 if (!pgdat) 891 return NULL; 892 893 pgdat->per_cpu_nodestats = 894 alloc_percpu(struct per_cpu_nodestat); 895 arch_refresh_nodedata(nid, pgdat); 896 } else { 897 int cpu; 898 /* 899 * Reset the nr_zones, order and classzone_idx before reuse. 900 * Note that kswapd will init kswapd_classzone_idx properly 901 * when it starts in the near future. 902 */ 903 pgdat->nr_zones = 0; 904 pgdat->kswapd_order = 0; 905 pgdat->kswapd_classzone_idx = 0; 906 for_each_online_cpu(cpu) { 907 struct per_cpu_nodestat *p; 908 909 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); 910 memset(p, 0, sizeof(*p)); 911 } 912 } 913 914 /* we can use NODE_DATA(nid) from here */ 915 916 pgdat->node_id = nid; 917 pgdat->node_start_pfn = start_pfn; 918 919 /* init node's zones as empty zones, we don't have any present pages.*/ 920 free_area_init_core_hotplug(nid); 921 922 /* 923 * The node we allocated has no zone fallback lists. For avoiding 924 * to access not-initialized zonelist, build here. 925 */ 926 build_all_zonelists(pgdat); 927 928 /* 929 * When memory is hot-added, all the memory is in offline state. So 930 * clear all zones' present_pages because they will be updated in 931 * online_pages() and offline_pages(). 932 */ 933 reset_node_managed_pages(pgdat); 934 reset_node_present_pages(pgdat); 935 936 return pgdat; 937 } 938 939 static void rollback_node_hotadd(int nid) 940 { 941 pg_data_t *pgdat = NODE_DATA(nid); 942 943 arch_refresh_nodedata(nid, NULL); 944 free_percpu(pgdat->per_cpu_nodestats); 945 arch_free_nodedata(pgdat); 946 } 947 948 949 /** 950 * try_online_node - online a node if offlined 951 * @nid: the node ID 952 * @start: start addr of the node 953 * @set_node_online: Whether we want to online the node 954 * called by cpu_up() to online a node without onlined memory. 955 * 956 * Returns: 957 * 1 -> a new node has been allocated 958 * 0 -> the node is already online 959 * -ENOMEM -> the node could not be allocated 960 */ 961 static int __try_online_node(int nid, u64 start, bool set_node_online) 962 { 963 pg_data_t *pgdat; 964 int ret = 1; 965 966 if (node_online(nid)) 967 return 0; 968 969 pgdat = hotadd_new_pgdat(nid, start); 970 if (!pgdat) { 971 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 972 ret = -ENOMEM; 973 goto out; 974 } 975 976 if (set_node_online) { 977 node_set_online(nid); 978 ret = register_one_node(nid); 979 BUG_ON(ret); 980 } 981 out: 982 return ret; 983 } 984 985 /* 986 * Users of this function always want to online/register the node 987 */ 988 int try_online_node(int nid) 989 { 990 int ret; 991 992 mem_hotplug_begin(); 993 ret = __try_online_node(nid, 0, true); 994 mem_hotplug_done(); 995 return ret; 996 } 997 998 static int check_hotplug_memory_range(u64 start, u64 size) 999 { 1000 /* memory range must be block size aligned */ 1001 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1002 !IS_ALIGNED(size, memory_block_size_bytes())) { 1003 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1004 memory_block_size_bytes(), start, size); 1005 return -EINVAL; 1006 } 1007 1008 return 0; 1009 } 1010 1011 static int online_memory_block(struct memory_block *mem, void *arg) 1012 { 1013 return device_online(&mem->dev); 1014 } 1015 1016 /* 1017 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1018 * and online/offline operations (triggered e.g. by sysfs). 1019 * 1020 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1021 */ 1022 int __ref add_memory_resource(int nid, struct resource *res) 1023 { 1024 struct mhp_restrictions restrictions = {}; 1025 u64 start, size; 1026 bool new_node = false; 1027 int ret; 1028 1029 start = res->start; 1030 size = resource_size(res); 1031 1032 ret = check_hotplug_memory_range(start, size); 1033 if (ret) 1034 return ret; 1035 1036 mem_hotplug_begin(); 1037 1038 /* 1039 * Add new range to memblock so that when hotadd_new_pgdat() is called 1040 * to allocate new pgdat, get_pfn_range_for_nid() will be able to find 1041 * this new range and calculate total pages correctly. The range will 1042 * be removed at hot-remove time. 1043 */ 1044 memblock_add_node(start, size, nid); 1045 1046 ret = __try_online_node(nid, start, false); 1047 if (ret < 0) 1048 goto error; 1049 new_node = ret; 1050 1051 /* call arch's memory hotadd */ 1052 ret = arch_add_memory(nid, start, size, &restrictions); 1053 if (ret < 0) 1054 goto error; 1055 1056 /* create memory block devices after memory was added */ 1057 ret = create_memory_block_devices(start, size); 1058 if (ret) { 1059 arch_remove_memory(nid, start, size, NULL); 1060 goto error; 1061 } 1062 1063 if (new_node) { 1064 /* If sysfs file of new node can't be created, cpu on the node 1065 * can't be hot-added. There is no rollback way now. 1066 * So, check by BUG_ON() to catch it reluctantly.. 1067 * We online node here. We can't roll back from here. 1068 */ 1069 node_set_online(nid); 1070 ret = __register_one_node(nid); 1071 BUG_ON(ret); 1072 } 1073 1074 /* link memory sections under this node.*/ 1075 ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); 1076 BUG_ON(ret); 1077 1078 /* create new memmap entry */ 1079 firmware_map_add_hotplug(start, start + size, "System RAM"); 1080 1081 /* device_online() will take the lock when calling online_pages() */ 1082 mem_hotplug_done(); 1083 1084 /* online pages if requested */ 1085 if (memhp_auto_online) 1086 walk_memory_blocks(start, size, NULL, online_memory_block); 1087 1088 return ret; 1089 error: 1090 /* rollback pgdat allocation and others */ 1091 if (new_node) 1092 rollback_node_hotadd(nid); 1093 memblock_remove(start, size); 1094 mem_hotplug_done(); 1095 return ret; 1096 } 1097 1098 /* requires device_hotplug_lock, see add_memory_resource() */ 1099 int __ref __add_memory(int nid, u64 start, u64 size) 1100 { 1101 struct resource *res; 1102 int ret; 1103 1104 res = register_memory_resource(start, size); 1105 if (IS_ERR(res)) 1106 return PTR_ERR(res); 1107 1108 ret = add_memory_resource(nid, res); 1109 if (ret < 0) 1110 release_memory_resource(res); 1111 return ret; 1112 } 1113 1114 int add_memory(int nid, u64 start, u64 size) 1115 { 1116 int rc; 1117 1118 lock_device_hotplug(); 1119 rc = __add_memory(nid, start, size); 1120 unlock_device_hotplug(); 1121 1122 return rc; 1123 } 1124 EXPORT_SYMBOL_GPL(add_memory); 1125 1126 #ifdef CONFIG_MEMORY_HOTREMOVE 1127 /* 1128 * A free page on the buddy free lists (not the per-cpu lists) has PageBuddy 1129 * set and the size of the free page is given by page_order(). Using this, 1130 * the function determines if the pageblock contains only free pages. 1131 * Due to buddy contraints, a free page at least the size of a pageblock will 1132 * be located at the start of the pageblock 1133 */ 1134 static inline int pageblock_free(struct page *page) 1135 { 1136 return PageBuddy(page) && page_order(page) >= pageblock_order; 1137 } 1138 1139 /* Return the pfn of the start of the next active pageblock after a given pfn */ 1140 static unsigned long next_active_pageblock(unsigned long pfn) 1141 { 1142 struct page *page = pfn_to_page(pfn); 1143 1144 /* Ensure the starting page is pageblock-aligned */ 1145 BUG_ON(pfn & (pageblock_nr_pages - 1)); 1146 1147 /* If the entire pageblock is free, move to the end of free page */ 1148 if (pageblock_free(page)) { 1149 int order; 1150 /* be careful. we don't have locks, page_order can be changed.*/ 1151 order = page_order(page); 1152 if ((order < MAX_ORDER) && (order >= pageblock_order)) 1153 return pfn + (1 << order); 1154 } 1155 1156 return pfn + pageblock_nr_pages; 1157 } 1158 1159 static bool is_pageblock_removable_nolock(unsigned long pfn) 1160 { 1161 struct page *page = pfn_to_page(pfn); 1162 struct zone *zone; 1163 1164 /* 1165 * We have to be careful here because we are iterating over memory 1166 * sections which are not zone aware so we might end up outside of 1167 * the zone but still within the section. 1168 * We have to take care about the node as well. If the node is offline 1169 * its NODE_DATA will be NULL - see page_zone. 1170 */ 1171 if (!node_online(page_to_nid(page))) 1172 return false; 1173 1174 zone = page_zone(page); 1175 pfn = page_to_pfn(page); 1176 if (!zone_spans_pfn(zone, pfn)) 1177 return false; 1178 1179 return !has_unmovable_pages(zone, page, MIGRATE_MOVABLE, 1180 MEMORY_OFFLINE); 1181 } 1182 1183 /* Checks if this range of memory is likely to be hot-removable. */ 1184 bool is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) 1185 { 1186 unsigned long end_pfn, pfn; 1187 1188 end_pfn = min(start_pfn + nr_pages, 1189 zone_end_pfn(page_zone(pfn_to_page(start_pfn)))); 1190 1191 /* Check the starting page of each pageblock within the range */ 1192 for (pfn = start_pfn; pfn < end_pfn; pfn = next_active_pageblock(pfn)) { 1193 if (!is_pageblock_removable_nolock(pfn)) 1194 return false; 1195 cond_resched(); 1196 } 1197 1198 /* All pageblocks in the memory block are likely to be hot-removable */ 1199 return true; 1200 } 1201 1202 /* 1203 * Confirm all pages in a range [start, end) belong to the same zone. 1204 * When true, return its valid [start, end). 1205 */ 1206 int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn, 1207 unsigned long *valid_start, unsigned long *valid_end) 1208 { 1209 unsigned long pfn, sec_end_pfn; 1210 unsigned long start, end; 1211 struct zone *zone = NULL; 1212 struct page *page; 1213 int i; 1214 for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); 1215 pfn < end_pfn; 1216 pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { 1217 /* Make sure the memory section is present first */ 1218 if (!present_section_nr(pfn_to_section_nr(pfn))) 1219 continue; 1220 for (; pfn < sec_end_pfn && pfn < end_pfn; 1221 pfn += MAX_ORDER_NR_PAGES) { 1222 i = 0; 1223 /* This is just a CONFIG_HOLES_IN_ZONE check.*/ 1224 while ((i < MAX_ORDER_NR_PAGES) && 1225 !pfn_valid_within(pfn + i)) 1226 i++; 1227 if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) 1228 continue; 1229 /* Check if we got outside of the zone */ 1230 if (zone && !zone_spans_pfn(zone, pfn + i)) 1231 return 0; 1232 page = pfn_to_page(pfn + i); 1233 if (zone && page_zone(page) != zone) 1234 return 0; 1235 if (!zone) 1236 start = pfn + i; 1237 zone = page_zone(page); 1238 end = pfn + MAX_ORDER_NR_PAGES; 1239 } 1240 } 1241 1242 if (zone) { 1243 *valid_start = start; 1244 *valid_end = min(end, end_pfn); 1245 return 1; 1246 } else { 1247 return 0; 1248 } 1249 } 1250 1251 /* 1252 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1253 * non-lru movable pages and hugepages). We scan pfn because it's much 1254 * easier than scanning over linked list. This function returns the pfn 1255 * of the first found movable page if it's found, otherwise 0. 1256 */ 1257 static unsigned long scan_movable_pages(unsigned long start, unsigned long end) 1258 { 1259 unsigned long pfn; 1260 1261 for (pfn = start; pfn < end; pfn++) { 1262 struct page *page, *head; 1263 unsigned long skip; 1264 1265 if (!pfn_valid(pfn)) 1266 continue; 1267 page = pfn_to_page(pfn); 1268 if (PageLRU(page)) 1269 return pfn; 1270 if (__PageMovable(page)) 1271 return pfn; 1272 1273 if (!PageHuge(page)) 1274 continue; 1275 head = compound_head(page); 1276 if (page_huge_active(head)) 1277 return pfn; 1278 skip = compound_nr(head) - (page - head); 1279 pfn += skip - 1; 1280 } 1281 return 0; 1282 } 1283 1284 static struct page *new_node_page(struct page *page, unsigned long private) 1285 { 1286 int nid = page_to_nid(page); 1287 nodemask_t nmask = node_states[N_MEMORY]; 1288 1289 /* 1290 * try to allocate from a different node but reuse this node if there 1291 * are no other online nodes to be used (e.g. we are offlining a part 1292 * of the only existing node) 1293 */ 1294 node_clear(nid, nmask); 1295 if (nodes_empty(nmask)) 1296 node_set(nid, nmask); 1297 1298 return new_page_nodemask(page, nid, &nmask); 1299 } 1300 1301 static int 1302 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1303 { 1304 unsigned long pfn; 1305 struct page *page; 1306 int ret = 0; 1307 LIST_HEAD(source); 1308 1309 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1310 if (!pfn_valid(pfn)) 1311 continue; 1312 page = pfn_to_page(pfn); 1313 1314 if (PageHuge(page)) { 1315 struct page *head = compound_head(page); 1316 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1317 isolate_huge_page(head, &source); 1318 continue; 1319 } else if (PageTransHuge(page)) 1320 pfn = page_to_pfn(compound_head(page)) 1321 + hpage_nr_pages(page) - 1; 1322 1323 /* 1324 * HWPoison pages have elevated reference counts so the migration would 1325 * fail on them. It also doesn't make any sense to migrate them in the 1326 * first place. Still try to unmap such a page in case it is still mapped 1327 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1328 * the unmap as the catch all safety net). 1329 */ 1330 if (PageHWPoison(page)) { 1331 if (WARN_ON(PageLRU(page))) 1332 isolate_lru_page(page); 1333 if (page_mapped(page)) 1334 try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); 1335 continue; 1336 } 1337 1338 if (!get_page_unless_zero(page)) 1339 continue; 1340 /* 1341 * We can skip free pages. And we can deal with pages on 1342 * LRU and non-lru movable pages. 1343 */ 1344 if (PageLRU(page)) 1345 ret = isolate_lru_page(page); 1346 else 1347 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1348 if (!ret) { /* Success */ 1349 list_add_tail(&page->lru, &source); 1350 if (!__PageMovable(page)) 1351 inc_node_page_state(page, NR_ISOLATED_ANON + 1352 page_is_file_cache(page)); 1353 1354 } else { 1355 pr_warn("failed to isolate pfn %lx\n", pfn); 1356 dump_page(page, "isolation failed"); 1357 } 1358 put_page(page); 1359 } 1360 if (!list_empty(&source)) { 1361 /* Allocate a new page from the nearest neighbor node */ 1362 ret = migrate_pages(&source, new_node_page, NULL, 0, 1363 MIGRATE_SYNC, MR_MEMORY_HOTPLUG); 1364 if (ret) { 1365 list_for_each_entry(page, &source, lru) { 1366 pr_warn("migrating pfn %lx failed ret:%d ", 1367 page_to_pfn(page), ret); 1368 dump_page(page, "migration failure"); 1369 } 1370 putback_movable_pages(&source); 1371 } 1372 } 1373 1374 return ret; 1375 } 1376 1377 /* Mark all sections offline and remove all free pages from the buddy. */ 1378 static int 1379 offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, 1380 void *data) 1381 { 1382 unsigned long *offlined_pages = (unsigned long *)data; 1383 1384 *offlined_pages += __offline_isolated_pages(start, start + nr_pages); 1385 return 0; 1386 } 1387 1388 /* 1389 * Check all pages in range, recoreded as memory resource, are isolated. 1390 */ 1391 static int 1392 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, 1393 void *data) 1394 { 1395 return test_pages_isolated(start_pfn, start_pfn + nr_pages, 1396 MEMORY_OFFLINE); 1397 } 1398 1399 static int __init cmdline_parse_movable_node(char *p) 1400 { 1401 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 1402 movable_node_enabled = true; 1403 #else 1404 pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n"); 1405 #endif 1406 return 0; 1407 } 1408 early_param("movable_node", cmdline_parse_movable_node); 1409 1410 /* check which state of node_states will be changed when offline memory */ 1411 static void node_states_check_changes_offline(unsigned long nr_pages, 1412 struct zone *zone, struct memory_notify *arg) 1413 { 1414 struct pglist_data *pgdat = zone->zone_pgdat; 1415 unsigned long present_pages = 0; 1416 enum zone_type zt; 1417 1418 arg->status_change_nid = NUMA_NO_NODE; 1419 arg->status_change_nid_normal = NUMA_NO_NODE; 1420 arg->status_change_nid_high = NUMA_NO_NODE; 1421 1422 /* 1423 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1424 * If the memory to be offline is within the range 1425 * [0..ZONE_NORMAL], and it is the last present memory there, 1426 * the zones in that range will become empty after the offlining, 1427 * thus we can determine that we need to clear the node from 1428 * node_states[N_NORMAL_MEMORY]. 1429 */ 1430 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1431 present_pages += pgdat->node_zones[zt].present_pages; 1432 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1433 arg->status_change_nid_normal = zone_to_nid(zone); 1434 1435 #ifdef CONFIG_HIGHMEM 1436 /* 1437 * node_states[N_HIGH_MEMORY] contains nodes which 1438 * have normal memory or high memory. 1439 * Here we add the present_pages belonging to ZONE_HIGHMEM. 1440 * If the zone is within the range of [0..ZONE_HIGHMEM), and 1441 * we determine that the zones in that range become empty, 1442 * we need to clear the node for N_HIGH_MEMORY. 1443 */ 1444 present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1445 if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) 1446 arg->status_change_nid_high = zone_to_nid(zone); 1447 #endif 1448 1449 /* 1450 * We have accounted the pages from [0..ZONE_NORMAL), and 1451 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM 1452 * as well. 1453 * Here we count the possible pages from ZONE_MOVABLE. 1454 * If after having accounted all the pages, we see that the nr_pages 1455 * to be offlined is over or equal to the accounted pages, 1456 * we know that the node will become empty, and so, we can clear 1457 * it for N_MEMORY as well. 1458 */ 1459 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1460 1461 if (nr_pages >= present_pages) 1462 arg->status_change_nid = zone_to_nid(zone); 1463 } 1464 1465 static void node_states_clear_node(int node, struct memory_notify *arg) 1466 { 1467 if (arg->status_change_nid_normal >= 0) 1468 node_clear_state(node, N_NORMAL_MEMORY); 1469 1470 if (arg->status_change_nid_high >= 0) 1471 node_clear_state(node, N_HIGH_MEMORY); 1472 1473 if (arg->status_change_nid >= 0) 1474 node_clear_state(node, N_MEMORY); 1475 } 1476 1477 static int count_system_ram_pages_cb(unsigned long start_pfn, 1478 unsigned long nr_pages, void *data) 1479 { 1480 unsigned long *nr_system_ram_pages = data; 1481 1482 *nr_system_ram_pages += nr_pages; 1483 return 0; 1484 } 1485 1486 static int __ref __offline_pages(unsigned long start_pfn, 1487 unsigned long end_pfn) 1488 { 1489 unsigned long pfn, nr_pages = 0; 1490 unsigned long offlined_pages = 0; 1491 int ret, node, nr_isolate_pageblock; 1492 unsigned long flags; 1493 unsigned long valid_start, valid_end; 1494 struct zone *zone; 1495 struct memory_notify arg; 1496 char *reason; 1497 1498 mem_hotplug_begin(); 1499 1500 /* 1501 * Don't allow to offline memory blocks that contain holes. 1502 * Consequently, memory blocks with holes can never get onlined 1503 * via the hotplug path - online_pages() - as hotplugged memory has 1504 * no holes. This way, we e.g., don't have to worry about marking 1505 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1506 * avoid using walk_system_ram_range() later. 1507 */ 1508 walk_system_ram_range(start_pfn, end_pfn - start_pfn, &nr_pages, 1509 count_system_ram_pages_cb); 1510 if (nr_pages != end_pfn - start_pfn) { 1511 ret = -EINVAL; 1512 reason = "memory holes"; 1513 goto failed_removal; 1514 } 1515 1516 /* This makes hotplug much easier...and readable. 1517 we assume this for now. .*/ 1518 if (!test_pages_in_a_zone(start_pfn, end_pfn, &valid_start, 1519 &valid_end)) { 1520 ret = -EINVAL; 1521 reason = "multizone range"; 1522 goto failed_removal; 1523 } 1524 1525 zone = page_zone(pfn_to_page(valid_start)); 1526 node = zone_to_nid(zone); 1527 1528 /* set above range as isolated */ 1529 ret = start_isolate_page_range(start_pfn, end_pfn, 1530 MIGRATE_MOVABLE, 1531 MEMORY_OFFLINE | REPORT_FAILURE); 1532 if (ret < 0) { 1533 reason = "failure to isolate range"; 1534 goto failed_removal; 1535 } 1536 nr_isolate_pageblock = ret; 1537 1538 arg.start_pfn = start_pfn; 1539 arg.nr_pages = nr_pages; 1540 node_states_check_changes_offline(nr_pages, zone, &arg); 1541 1542 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1543 ret = notifier_to_errno(ret); 1544 if (ret) { 1545 reason = "notifier failure"; 1546 goto failed_removal_isolated; 1547 } 1548 1549 do { 1550 for (pfn = start_pfn; pfn;) { 1551 if (signal_pending(current)) { 1552 ret = -EINTR; 1553 reason = "signal backoff"; 1554 goto failed_removal_isolated; 1555 } 1556 1557 cond_resched(); 1558 lru_add_drain_all(); 1559 1560 pfn = scan_movable_pages(pfn, end_pfn); 1561 if (pfn) { 1562 /* 1563 * TODO: fatal migration failures should bail 1564 * out 1565 */ 1566 do_migrate_range(pfn, end_pfn); 1567 } 1568 } 1569 1570 /* 1571 * Dissolve free hugepages in the memory block before doing 1572 * offlining actually in order to make hugetlbfs's object 1573 * counting consistent. 1574 */ 1575 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1576 if (ret) { 1577 reason = "failure to dissolve huge pages"; 1578 goto failed_removal_isolated; 1579 } 1580 /* check again */ 1581 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, 1582 NULL, check_pages_isolated_cb); 1583 } while (ret); 1584 1585 /* Ok, all of our target is isolated. 1586 We cannot do rollback at this point. */ 1587 walk_system_ram_range(start_pfn, end_pfn - start_pfn, 1588 &offlined_pages, offline_isolated_pages_cb); 1589 pr_info("Offlined Pages %ld\n", offlined_pages); 1590 /* 1591 * Onlining will reset pagetype flags and makes migrate type 1592 * MOVABLE, so just need to decrease the number of isolated 1593 * pageblocks zone counter here. 1594 */ 1595 spin_lock_irqsave(&zone->lock, flags); 1596 zone->nr_isolate_pageblock -= nr_isolate_pageblock; 1597 spin_unlock_irqrestore(&zone->lock, flags); 1598 1599 /* removal success */ 1600 adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); 1601 zone->present_pages -= offlined_pages; 1602 1603 pgdat_resize_lock(zone->zone_pgdat, &flags); 1604 zone->zone_pgdat->node_present_pages -= offlined_pages; 1605 pgdat_resize_unlock(zone->zone_pgdat, &flags); 1606 1607 init_per_zone_wmark_min(); 1608 1609 if (!populated_zone(zone)) { 1610 zone_pcp_reset(zone); 1611 build_all_zonelists(NULL); 1612 } else 1613 zone_pcp_update(zone); 1614 1615 node_states_clear_node(node, &arg); 1616 if (arg.status_change_nid >= 0) { 1617 kswapd_stop(node); 1618 kcompactd_stop(node); 1619 } 1620 1621 vm_total_pages = nr_free_pagecache_pages(); 1622 writeback_set_ratelimit(); 1623 1624 memory_notify(MEM_OFFLINE, &arg); 1625 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1626 mem_hotplug_done(); 1627 return 0; 1628 1629 failed_removal_isolated: 1630 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1631 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1632 failed_removal: 1633 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1634 (unsigned long long) start_pfn << PAGE_SHIFT, 1635 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1636 reason); 1637 /* pushback to free area */ 1638 mem_hotplug_done(); 1639 return ret; 1640 } 1641 1642 int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 1643 { 1644 return __offline_pages(start_pfn, start_pfn + nr_pages); 1645 } 1646 1647 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1648 { 1649 int ret = !is_memblock_offlined(mem); 1650 1651 if (unlikely(ret)) { 1652 phys_addr_t beginpa, endpa; 1653 1654 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1655 endpa = beginpa + memory_block_size_bytes() - 1; 1656 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1657 &beginpa, &endpa); 1658 1659 return -EBUSY; 1660 } 1661 return 0; 1662 } 1663 1664 static int check_cpu_on_node(pg_data_t *pgdat) 1665 { 1666 int cpu; 1667 1668 for_each_present_cpu(cpu) { 1669 if (cpu_to_node(cpu) == pgdat->node_id) 1670 /* 1671 * the cpu on this node isn't removed, and we can't 1672 * offline this node. 1673 */ 1674 return -EBUSY; 1675 } 1676 1677 return 0; 1678 } 1679 1680 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 1681 { 1682 int nid = *(int *)arg; 1683 1684 /* 1685 * If a memory block belongs to multiple nodes, the stored nid is not 1686 * reliable. However, such blocks are always online (e.g., cannot get 1687 * offlined) and, therefore, are still spanned by the node. 1688 */ 1689 return mem->nid == nid ? -EEXIST : 0; 1690 } 1691 1692 /** 1693 * try_offline_node 1694 * @nid: the node ID 1695 * 1696 * Offline a node if all memory sections and cpus of the node are removed. 1697 * 1698 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1699 * and online/offline operations before this call. 1700 */ 1701 void try_offline_node(int nid) 1702 { 1703 pg_data_t *pgdat = NODE_DATA(nid); 1704 int rc; 1705 1706 /* 1707 * If the node still spans pages (especially ZONE_DEVICE), don't 1708 * offline it. A node spans memory after move_pfn_range_to_zone(), 1709 * e.g., after the memory block was onlined. 1710 */ 1711 if (pgdat->node_spanned_pages) 1712 return; 1713 1714 /* 1715 * Especially offline memory blocks might not be spanned by the 1716 * node. They will get spanned by the node once they get onlined. 1717 * However, they link to the node in sysfs and can get onlined later. 1718 */ 1719 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 1720 if (rc) 1721 return; 1722 1723 if (check_cpu_on_node(pgdat)) 1724 return; 1725 1726 /* 1727 * all memory/cpu of this node are removed, we can offline this 1728 * node now. 1729 */ 1730 node_set_offline(nid); 1731 unregister_one_node(nid); 1732 } 1733 EXPORT_SYMBOL(try_offline_node); 1734 1735 static void __release_memory_resource(resource_size_t start, 1736 resource_size_t size) 1737 { 1738 int ret; 1739 1740 /* 1741 * When removing memory in the same granularity as it was added, 1742 * this function never fails. It might only fail if resources 1743 * have to be adjusted or split. We'll ignore the error, as 1744 * removing of memory cannot fail. 1745 */ 1746 ret = release_mem_region_adjustable(&iomem_resource, start, size); 1747 if (ret) { 1748 resource_size_t endres = start + size - 1; 1749 1750 pr_warn("Unable to release resource <%pa-%pa> (%d)\n", 1751 &start, &endres, ret); 1752 } 1753 } 1754 1755 static int __ref try_remove_memory(int nid, u64 start, u64 size) 1756 { 1757 int rc = 0; 1758 1759 BUG_ON(check_hotplug_memory_range(start, size)); 1760 1761 /* 1762 * All memory blocks must be offlined before removing memory. Check 1763 * whether all memory blocks in question are offline and return error 1764 * if this is not the case. 1765 */ 1766 rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); 1767 if (rc) 1768 goto done; 1769 1770 /* remove memmap entry */ 1771 firmware_map_remove(start, start + size, "System RAM"); 1772 1773 /* 1774 * Memory block device removal under the device_hotplug_lock is 1775 * a barrier against racing online attempts. 1776 */ 1777 remove_memory_block_devices(start, size); 1778 1779 mem_hotplug_begin(); 1780 1781 arch_remove_memory(nid, start, size, NULL); 1782 memblock_free(start, size); 1783 memblock_remove(start, size); 1784 __release_memory_resource(start, size); 1785 1786 try_offline_node(nid); 1787 1788 done: 1789 mem_hotplug_done(); 1790 return rc; 1791 } 1792 1793 /** 1794 * remove_memory 1795 * @nid: the node ID 1796 * @start: physical address of the region to remove 1797 * @size: size of the region to remove 1798 * 1799 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1800 * and online/offline operations before this call, as required by 1801 * try_offline_node(). 1802 */ 1803 void __remove_memory(int nid, u64 start, u64 size) 1804 { 1805 1806 /* 1807 * trigger BUG() if some memory is not offlined prior to calling this 1808 * function 1809 */ 1810 if (try_remove_memory(nid, start, size)) 1811 BUG(); 1812 } 1813 1814 /* 1815 * Remove memory if every memory block is offline, otherwise return -EBUSY is 1816 * some memory is not offline 1817 */ 1818 int remove_memory(int nid, u64 start, u64 size) 1819 { 1820 int rc; 1821 1822 lock_device_hotplug(); 1823 rc = try_remove_memory(nid, start, size); 1824 unlock_device_hotplug(); 1825 1826 return rc; 1827 } 1828 EXPORT_SYMBOL_GPL(remove_memory); 1829 #endif /* CONFIG_MEMORY_HOTREMOVE */ 1830