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 int memhp_default_online_type = MMOP_OFFLINE; 71 #else 72 int memhp_default_online_type = MMOP_ONLINE; 73 #endif 74 75 static int __init setup_memhp_default_state(char *str) 76 { 77 const int online_type = memhp_online_type_from_str(str); 78 79 if (online_type >= 0) 80 memhp_default_online_type = online_type; 81 82 return 1; 83 } 84 __setup("memhp_default_state=", setup_memhp_default_state); 85 86 void mem_hotplug_begin(void) 87 { 88 cpus_read_lock(); 89 percpu_down_write(&mem_hotplug_lock); 90 } 91 92 void mem_hotplug_done(void) 93 { 94 percpu_up_write(&mem_hotplug_lock); 95 cpus_read_unlock(); 96 } 97 98 u64 max_mem_size = U64_MAX; 99 100 /* add this memory to iomem resource */ 101 static struct resource *register_memory_resource(u64 start, u64 size, 102 const char *resource_name) 103 { 104 struct resource *res; 105 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 106 107 if (strcmp(resource_name, "System RAM")) 108 flags |= IORESOURCE_MEM_DRIVER_MANAGED; 109 110 /* 111 * Make sure value parsed from 'mem=' only restricts memory adding 112 * while booting, so that memory hotplug won't be impacted. Please 113 * refer to document of 'mem=' in kernel-parameters.txt for more 114 * details. 115 */ 116 if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) 117 return ERR_PTR(-E2BIG); 118 119 /* 120 * Request ownership of the new memory range. This might be 121 * a child of an existing resource that was present but 122 * not marked as busy. 123 */ 124 res = __request_region(&iomem_resource, start, size, 125 resource_name, flags); 126 127 if (!res) { 128 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", 129 start, start + size); 130 return ERR_PTR(-EEXIST); 131 } 132 return res; 133 } 134 135 static void release_memory_resource(struct resource *res) 136 { 137 if (!res) 138 return; 139 release_resource(res); 140 kfree(res); 141 } 142 143 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 144 void get_page_bootmem(unsigned long info, struct page *page, 145 unsigned long type) 146 { 147 page->freelist = (void *)type; 148 SetPagePrivate(page); 149 set_page_private(page, info); 150 page_ref_inc(page); 151 } 152 153 void put_page_bootmem(struct page *page) 154 { 155 unsigned long type; 156 157 type = (unsigned long) page->freelist; 158 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || 159 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); 160 161 if (page_ref_dec_return(page) == 1) { 162 page->freelist = NULL; 163 ClearPagePrivate(page); 164 set_page_private(page, 0); 165 INIT_LIST_HEAD(&page->lru); 166 free_reserved_page(page); 167 } 168 } 169 170 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE 171 #ifndef CONFIG_SPARSEMEM_VMEMMAP 172 static void register_page_bootmem_info_section(unsigned long start_pfn) 173 { 174 unsigned long mapsize, section_nr, i; 175 struct mem_section *ms; 176 struct page *page, *memmap; 177 struct mem_section_usage *usage; 178 179 section_nr = pfn_to_section_nr(start_pfn); 180 ms = __nr_to_section(section_nr); 181 182 /* Get section's memmap address */ 183 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 184 185 /* 186 * Get page for the memmap's phys address 187 * XXX: need more consideration for sparse_vmemmap... 188 */ 189 page = virt_to_page(memmap); 190 mapsize = sizeof(struct page) * PAGES_PER_SECTION; 191 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; 192 193 /* remember memmap's page */ 194 for (i = 0; i < mapsize; i++, page++) 195 get_page_bootmem(section_nr, page, SECTION_INFO); 196 197 usage = ms->usage; 198 page = virt_to_page(usage); 199 200 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 201 202 for (i = 0; i < mapsize; i++, page++) 203 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 204 205 } 206 #else /* CONFIG_SPARSEMEM_VMEMMAP */ 207 static void register_page_bootmem_info_section(unsigned long start_pfn) 208 { 209 unsigned long mapsize, section_nr, i; 210 struct mem_section *ms; 211 struct page *page, *memmap; 212 struct mem_section_usage *usage; 213 214 section_nr = pfn_to_section_nr(start_pfn); 215 ms = __nr_to_section(section_nr); 216 217 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 218 219 register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); 220 221 usage = ms->usage; 222 page = virt_to_page(usage); 223 224 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 225 226 for (i = 0; i < mapsize; i++, page++) 227 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 228 } 229 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 230 231 void __init register_page_bootmem_info_node(struct pglist_data *pgdat) 232 { 233 unsigned long i, pfn, end_pfn, nr_pages; 234 int node = pgdat->node_id; 235 struct page *page; 236 237 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; 238 page = virt_to_page(pgdat); 239 240 for (i = 0; i < nr_pages; i++, page++) 241 get_page_bootmem(node, page, NODE_INFO); 242 243 pfn = pgdat->node_start_pfn; 244 end_pfn = pgdat_end_pfn(pgdat); 245 246 /* register section info */ 247 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 248 /* 249 * Some platforms can assign the same pfn to multiple nodes - on 250 * node0 as well as nodeN. To avoid registering a pfn against 251 * multiple nodes we check that this pfn does not already 252 * reside in some other nodes. 253 */ 254 if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) 255 register_page_bootmem_info_section(pfn); 256 } 257 } 258 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ 259 260 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, 261 const char *reason) 262 { 263 /* 264 * Disallow all operations smaller than a sub-section and only 265 * allow operations smaller than a section for 266 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() 267 * enforces a larger memory_block_size_bytes() granularity for 268 * memory that will be marked online, so this check should only 269 * fire for direct arch_{add,remove}_memory() users outside of 270 * add_memory_resource(). 271 */ 272 unsigned long min_align; 273 274 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) 275 min_align = PAGES_PER_SUBSECTION; 276 else 277 min_align = PAGES_PER_SECTION; 278 if (!IS_ALIGNED(pfn, min_align) 279 || !IS_ALIGNED(nr_pages, min_align)) { 280 WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", 281 reason, pfn, pfn + nr_pages - 1); 282 return -EINVAL; 283 } 284 return 0; 285 } 286 287 static int check_hotplug_memory_addressable(unsigned long pfn, 288 unsigned long nr_pages) 289 { 290 const u64 max_addr = PFN_PHYS(pfn + nr_pages) - 1; 291 292 if (max_addr >> MAX_PHYSMEM_BITS) { 293 const u64 max_allowed = (1ull << (MAX_PHYSMEM_BITS + 1)) - 1; 294 WARN(1, 295 "Hotplugged memory exceeds maximum addressable address, range=%#llx-%#llx, maximum=%#llx\n", 296 (u64)PFN_PHYS(pfn), max_addr, max_allowed); 297 return -E2BIG; 298 } 299 300 return 0; 301 } 302 303 /* 304 * Reasonably generic function for adding memory. It is 305 * expected that archs that support memory hotplug will 306 * call this function after deciding the zone to which to 307 * add the new pages. 308 */ 309 int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, 310 struct mhp_params *params) 311 { 312 const unsigned long end_pfn = pfn + nr_pages; 313 unsigned long cur_nr_pages; 314 int err; 315 struct vmem_altmap *altmap = params->altmap; 316 317 if (WARN_ON_ONCE(!params->pgprot.pgprot)) 318 return -EINVAL; 319 320 err = check_hotplug_memory_addressable(pfn, nr_pages); 321 if (err) 322 return err; 323 324 if (altmap) { 325 /* 326 * Validate altmap is within bounds of the total request 327 */ 328 if (altmap->base_pfn != pfn 329 || vmem_altmap_offset(altmap) > nr_pages) { 330 pr_warn_once("memory add fail, invalid altmap\n"); 331 return -EINVAL; 332 } 333 altmap->alloc = 0; 334 } 335 336 err = check_pfn_span(pfn, nr_pages, "add"); 337 if (err) 338 return err; 339 340 for (; pfn < end_pfn; pfn += cur_nr_pages) { 341 /* Select all remaining pages up to the next section boundary */ 342 cur_nr_pages = min(end_pfn - pfn, 343 SECTION_ALIGN_UP(pfn + 1) - pfn); 344 err = sparse_add_section(nid, pfn, cur_nr_pages, altmap); 345 if (err) 346 break; 347 cond_resched(); 348 } 349 vmemmap_populate_print_last(); 350 return err; 351 } 352 353 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 354 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 355 unsigned long start_pfn, 356 unsigned long end_pfn) 357 { 358 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 359 if (unlikely(!pfn_to_online_page(start_pfn))) 360 continue; 361 362 if (unlikely(pfn_to_nid(start_pfn) != nid)) 363 continue; 364 365 if (zone != page_zone(pfn_to_page(start_pfn))) 366 continue; 367 368 return start_pfn; 369 } 370 371 return 0; 372 } 373 374 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 375 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 376 unsigned long start_pfn, 377 unsigned long end_pfn) 378 { 379 unsigned long pfn; 380 381 /* pfn is the end pfn of a memory section. */ 382 pfn = end_pfn - 1; 383 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 384 if (unlikely(!pfn_to_online_page(pfn))) 385 continue; 386 387 if (unlikely(pfn_to_nid(pfn) != nid)) 388 continue; 389 390 if (zone != page_zone(pfn_to_page(pfn))) 391 continue; 392 393 return pfn; 394 } 395 396 return 0; 397 } 398 399 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 400 unsigned long end_pfn) 401 { 402 unsigned long pfn; 403 int nid = zone_to_nid(zone); 404 405 zone_span_writelock(zone); 406 if (zone->zone_start_pfn == start_pfn) { 407 /* 408 * If the section is smallest section in the zone, it need 409 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 410 * In this case, we find second smallest valid mem_section 411 * for shrinking zone. 412 */ 413 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 414 zone_end_pfn(zone)); 415 if (pfn) { 416 zone->spanned_pages = zone_end_pfn(zone) - pfn; 417 zone->zone_start_pfn = pfn; 418 } else { 419 zone->zone_start_pfn = 0; 420 zone->spanned_pages = 0; 421 } 422 } else if (zone_end_pfn(zone) == end_pfn) { 423 /* 424 * If the section is biggest section in the zone, it need 425 * shrink zone->spanned_pages. 426 * In this case, we find second biggest valid mem_section for 427 * shrinking zone. 428 */ 429 pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, 430 start_pfn); 431 if (pfn) 432 zone->spanned_pages = pfn - zone->zone_start_pfn + 1; 433 else { 434 zone->zone_start_pfn = 0; 435 zone->spanned_pages = 0; 436 } 437 } 438 zone_span_writeunlock(zone); 439 } 440 441 static void update_pgdat_span(struct pglist_data *pgdat) 442 { 443 unsigned long node_start_pfn = 0, node_end_pfn = 0; 444 struct zone *zone; 445 446 for (zone = pgdat->node_zones; 447 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 448 unsigned long zone_end_pfn = zone->zone_start_pfn + 449 zone->spanned_pages; 450 451 /* No need to lock the zones, they can't change. */ 452 if (!zone->spanned_pages) 453 continue; 454 if (!node_end_pfn) { 455 node_start_pfn = zone->zone_start_pfn; 456 node_end_pfn = zone_end_pfn; 457 continue; 458 } 459 460 if (zone_end_pfn > node_end_pfn) 461 node_end_pfn = zone_end_pfn; 462 if (zone->zone_start_pfn < node_start_pfn) 463 node_start_pfn = zone->zone_start_pfn; 464 } 465 466 pgdat->node_start_pfn = node_start_pfn; 467 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 468 } 469 470 void __ref remove_pfn_range_from_zone(struct zone *zone, 471 unsigned long start_pfn, 472 unsigned long nr_pages) 473 { 474 struct pglist_data *pgdat = zone->zone_pgdat; 475 unsigned long flags; 476 477 /* Poison struct pages because they are now uninitialized again. */ 478 page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); 479 480 #ifdef CONFIG_ZONE_DEVICE 481 /* 482 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 483 * we will not try to shrink the zones - which is okay as 484 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 485 */ 486 if (zone_idx(zone) == ZONE_DEVICE) 487 return; 488 #endif 489 490 clear_zone_contiguous(zone); 491 492 pgdat_resize_lock(zone->zone_pgdat, &flags); 493 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 494 update_pgdat_span(pgdat); 495 pgdat_resize_unlock(zone->zone_pgdat, &flags); 496 497 set_zone_contiguous(zone); 498 } 499 500 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 501 unsigned long map_offset, 502 struct vmem_altmap *altmap) 503 { 504 struct mem_section *ms = __pfn_to_section(pfn); 505 506 if (WARN_ON_ONCE(!valid_section(ms))) 507 return; 508 509 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 510 } 511 512 /** 513 * __remove_pages() - remove sections of pages 514 * @pfn: starting pageframe (must be aligned to start of a section) 515 * @nr_pages: number of pages to remove (must be multiple of section size) 516 * @altmap: alternative device page map or %NULL if default memmap is used 517 * 518 * Generic helper function to remove section mappings and sysfs entries 519 * for the section of the memory we are removing. Caller needs to make 520 * sure that pages are marked reserved and zones are adjust properly by 521 * calling offline_pages(). 522 */ 523 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 524 struct vmem_altmap *altmap) 525 { 526 const unsigned long end_pfn = pfn + nr_pages; 527 unsigned long cur_nr_pages; 528 unsigned long map_offset = 0; 529 530 map_offset = vmem_altmap_offset(altmap); 531 532 if (check_pfn_span(pfn, nr_pages, "remove")) 533 return; 534 535 for (; pfn < end_pfn; pfn += cur_nr_pages) { 536 cond_resched(); 537 /* Select all remaining pages up to the next section boundary */ 538 cur_nr_pages = min(end_pfn - pfn, 539 SECTION_ALIGN_UP(pfn + 1) - pfn); 540 __remove_section(pfn, cur_nr_pages, map_offset, altmap); 541 map_offset = 0; 542 } 543 } 544 545 int set_online_page_callback(online_page_callback_t callback) 546 { 547 int rc = -EINVAL; 548 549 get_online_mems(); 550 mutex_lock(&online_page_callback_lock); 551 552 if (online_page_callback == generic_online_page) { 553 online_page_callback = callback; 554 rc = 0; 555 } 556 557 mutex_unlock(&online_page_callback_lock); 558 put_online_mems(); 559 560 return rc; 561 } 562 EXPORT_SYMBOL_GPL(set_online_page_callback); 563 564 int restore_online_page_callback(online_page_callback_t callback) 565 { 566 int rc = -EINVAL; 567 568 get_online_mems(); 569 mutex_lock(&online_page_callback_lock); 570 571 if (online_page_callback == callback) { 572 online_page_callback = generic_online_page; 573 rc = 0; 574 } 575 576 mutex_unlock(&online_page_callback_lock); 577 put_online_mems(); 578 579 return rc; 580 } 581 EXPORT_SYMBOL_GPL(restore_online_page_callback); 582 583 void generic_online_page(struct page *page, unsigned int order) 584 { 585 /* 586 * Freeing the page with debug_pagealloc enabled will try to unmap it, 587 * so we should map it first. This is better than introducing a special 588 * case in page freeing fast path. 589 */ 590 if (debug_pagealloc_enabled_static()) 591 kernel_map_pages(page, 1 << order, 1); 592 __free_pages_core(page, order); 593 totalram_pages_add(1UL << order); 594 #ifdef CONFIG_HIGHMEM 595 if (PageHighMem(page)) 596 totalhigh_pages_add(1UL << order); 597 #endif 598 } 599 EXPORT_SYMBOL_GPL(generic_online_page); 600 601 static int online_pages_range(unsigned long start_pfn, unsigned long nr_pages, 602 void *arg) 603 { 604 const unsigned long end_pfn = start_pfn + nr_pages; 605 unsigned long pfn; 606 int order; 607 608 /* 609 * Online the pages. The callback might decide to keep some pages 610 * PG_reserved (to add them to the buddy later), but we still account 611 * them as being online/belonging to this zone ("present"). 612 */ 613 for (pfn = start_pfn; pfn < end_pfn; pfn += 1ul << order) { 614 order = min(MAX_ORDER - 1, get_order(PFN_PHYS(end_pfn - pfn))); 615 /* __free_pages_core() wants pfns to be aligned to the order */ 616 if (WARN_ON_ONCE(!IS_ALIGNED(pfn, 1ul << order))) 617 order = 0; 618 (*online_page_callback)(pfn_to_page(pfn), order); 619 } 620 621 /* mark all involved sections as online */ 622 online_mem_sections(start_pfn, end_pfn); 623 624 *(unsigned long *)arg += nr_pages; 625 return 0; 626 } 627 628 /* check which state of node_states will be changed when online memory */ 629 static void node_states_check_changes_online(unsigned long nr_pages, 630 struct zone *zone, struct memory_notify *arg) 631 { 632 int nid = zone_to_nid(zone); 633 634 arg->status_change_nid = NUMA_NO_NODE; 635 arg->status_change_nid_normal = NUMA_NO_NODE; 636 arg->status_change_nid_high = NUMA_NO_NODE; 637 638 if (!node_state(nid, N_MEMORY)) 639 arg->status_change_nid = nid; 640 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 641 arg->status_change_nid_normal = nid; 642 #ifdef CONFIG_HIGHMEM 643 if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) 644 arg->status_change_nid_high = nid; 645 #endif 646 } 647 648 static void node_states_set_node(int node, struct memory_notify *arg) 649 { 650 if (arg->status_change_nid_normal >= 0) 651 node_set_state(node, N_NORMAL_MEMORY); 652 653 if (arg->status_change_nid_high >= 0) 654 node_set_state(node, N_HIGH_MEMORY); 655 656 if (arg->status_change_nid >= 0) 657 node_set_state(node, N_MEMORY); 658 } 659 660 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 661 unsigned long nr_pages) 662 { 663 unsigned long old_end_pfn = zone_end_pfn(zone); 664 665 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 666 zone->zone_start_pfn = start_pfn; 667 668 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 669 } 670 671 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 672 unsigned long nr_pages) 673 { 674 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 675 676 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 677 pgdat->node_start_pfn = start_pfn; 678 679 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 680 681 } 682 /* 683 * Associate the pfn range with the given zone, initializing the memmaps 684 * and resizing the pgdat/zone data to span the added pages. After this 685 * call, all affected pages are PG_reserved. 686 */ 687 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 688 unsigned long nr_pages, struct vmem_altmap *altmap) 689 { 690 struct pglist_data *pgdat = zone->zone_pgdat; 691 int nid = pgdat->node_id; 692 unsigned long flags; 693 694 clear_zone_contiguous(zone); 695 696 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ 697 pgdat_resize_lock(pgdat, &flags); 698 zone_span_writelock(zone); 699 if (zone_is_empty(zone)) 700 init_currently_empty_zone(zone, start_pfn, nr_pages); 701 resize_zone_range(zone, start_pfn, nr_pages); 702 zone_span_writeunlock(zone); 703 resize_pgdat_range(pgdat, start_pfn, nr_pages); 704 pgdat_resize_unlock(pgdat, &flags); 705 706 /* 707 * TODO now we have a visible range of pages which are not associated 708 * with their zone properly. Not nice but set_pfnblock_flags_mask 709 * expects the zone spans the pfn range. All the pages in the range 710 * are reserved so nobody should be touching them so we should be safe 711 */ 712 memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, 713 MEMMAP_HOTPLUG, altmap); 714 715 set_zone_contiguous(zone); 716 } 717 718 /* 719 * Returns a default kernel memory zone for the given pfn range. 720 * If no kernel zone covers this pfn range it will automatically go 721 * to the ZONE_NORMAL. 722 */ 723 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 724 unsigned long nr_pages) 725 { 726 struct pglist_data *pgdat = NODE_DATA(nid); 727 int zid; 728 729 for (zid = 0; zid <= ZONE_NORMAL; zid++) { 730 struct zone *zone = &pgdat->node_zones[zid]; 731 732 if (zone_intersects(zone, start_pfn, nr_pages)) 733 return zone; 734 } 735 736 return &pgdat->node_zones[ZONE_NORMAL]; 737 } 738 739 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 740 unsigned long nr_pages) 741 { 742 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 743 nr_pages); 744 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 745 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 746 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 747 748 /* 749 * We inherit the existing zone in a simple case where zones do not 750 * overlap in the given range 751 */ 752 if (in_kernel ^ in_movable) 753 return (in_kernel) ? kernel_zone : movable_zone; 754 755 /* 756 * If the range doesn't belong to any zone or two zones overlap in the 757 * given range then we use movable zone only if movable_node is 758 * enabled because we always online to a kernel zone by default. 759 */ 760 return movable_node_enabled ? movable_zone : kernel_zone; 761 } 762 763 struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, 764 unsigned long nr_pages) 765 { 766 if (online_type == MMOP_ONLINE_KERNEL) 767 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 768 769 if (online_type == MMOP_ONLINE_MOVABLE) 770 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 771 772 return default_zone_for_pfn(nid, start_pfn, nr_pages); 773 } 774 775 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 776 int online_type, int nid) 777 { 778 unsigned long flags; 779 unsigned long onlined_pages = 0; 780 struct zone *zone; 781 int need_zonelists_rebuild = 0; 782 int ret; 783 struct memory_notify arg; 784 785 mem_hotplug_begin(); 786 787 /* associate pfn range with the zone */ 788 zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); 789 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL); 790 791 arg.start_pfn = pfn; 792 arg.nr_pages = nr_pages; 793 node_states_check_changes_online(nr_pages, zone, &arg); 794 795 ret = memory_notify(MEM_GOING_ONLINE, &arg); 796 ret = notifier_to_errno(ret); 797 if (ret) 798 goto failed_addition; 799 800 /* 801 * If this zone is not populated, then it is not in zonelist. 802 * This means the page allocator ignores this zone. 803 * So, zonelist must be updated after online. 804 */ 805 if (!populated_zone(zone)) { 806 need_zonelists_rebuild = 1; 807 setup_zone_pageset(zone); 808 } 809 810 ret = walk_system_ram_range(pfn, nr_pages, &onlined_pages, 811 online_pages_range); 812 if (ret) { 813 /* not a single memory resource was applicable */ 814 if (need_zonelists_rebuild) 815 zone_pcp_reset(zone); 816 goto failed_addition; 817 } 818 819 zone->present_pages += onlined_pages; 820 821 pgdat_resize_lock(zone->zone_pgdat, &flags); 822 zone->zone_pgdat->node_present_pages += onlined_pages; 823 pgdat_resize_unlock(zone->zone_pgdat, &flags); 824 825 shuffle_zone(zone); 826 827 node_states_set_node(nid, &arg); 828 if (need_zonelists_rebuild) 829 build_all_zonelists(NULL); 830 else 831 zone_pcp_update(zone); 832 833 init_per_zone_wmark_min(); 834 835 kswapd_run(nid); 836 kcompactd_run(nid); 837 838 vm_total_pages = nr_free_pagecache_pages(); 839 840 writeback_set_ratelimit(); 841 842 memory_notify(MEM_ONLINE, &arg); 843 mem_hotplug_done(); 844 return 0; 845 846 failed_addition: 847 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 848 (unsigned long long) pfn << PAGE_SHIFT, 849 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 850 memory_notify(MEM_CANCEL_ONLINE, &arg); 851 remove_pfn_range_from_zone(zone, pfn, nr_pages); 852 mem_hotplug_done(); 853 return ret; 854 } 855 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 856 857 static void reset_node_present_pages(pg_data_t *pgdat) 858 { 859 struct zone *z; 860 861 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 862 z->present_pages = 0; 863 864 pgdat->node_present_pages = 0; 865 } 866 867 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 868 static pg_data_t __ref *hotadd_new_pgdat(int nid) 869 { 870 struct pglist_data *pgdat; 871 872 pgdat = NODE_DATA(nid); 873 if (!pgdat) { 874 pgdat = arch_alloc_nodedata(nid); 875 if (!pgdat) 876 return NULL; 877 878 pgdat->per_cpu_nodestats = 879 alloc_percpu(struct per_cpu_nodestat); 880 arch_refresh_nodedata(nid, pgdat); 881 } else { 882 int cpu; 883 /* 884 * Reset the nr_zones, order and highest_zoneidx before reuse. 885 * Note that kswapd will init kswapd_highest_zoneidx properly 886 * when it starts in the near future. 887 */ 888 pgdat->nr_zones = 0; 889 pgdat->kswapd_order = 0; 890 pgdat->kswapd_highest_zoneidx = 0; 891 for_each_online_cpu(cpu) { 892 struct per_cpu_nodestat *p; 893 894 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); 895 memset(p, 0, sizeof(*p)); 896 } 897 } 898 899 /* we can use NODE_DATA(nid) from here */ 900 pgdat->node_id = nid; 901 pgdat->node_start_pfn = 0; 902 903 /* init node's zones as empty zones, we don't have any present pages.*/ 904 free_area_init_core_hotplug(nid); 905 906 /* 907 * The node we allocated has no zone fallback lists. For avoiding 908 * to access not-initialized zonelist, build here. 909 */ 910 build_all_zonelists(pgdat); 911 912 /* 913 * When memory is hot-added, all the memory is in offline state. So 914 * clear all zones' present_pages because they will be updated in 915 * online_pages() and offline_pages(). 916 */ 917 reset_node_managed_pages(pgdat); 918 reset_node_present_pages(pgdat); 919 920 return pgdat; 921 } 922 923 static void rollback_node_hotadd(int nid) 924 { 925 pg_data_t *pgdat = NODE_DATA(nid); 926 927 arch_refresh_nodedata(nid, NULL); 928 free_percpu(pgdat->per_cpu_nodestats); 929 arch_free_nodedata(pgdat); 930 } 931 932 933 /** 934 * try_online_node - online a node if offlined 935 * @nid: the node ID 936 * @set_node_online: Whether we want to online the node 937 * called by cpu_up() to online a node without onlined memory. 938 * 939 * Returns: 940 * 1 -> a new node has been allocated 941 * 0 -> the node is already online 942 * -ENOMEM -> the node could not be allocated 943 */ 944 static int __try_online_node(int nid, bool set_node_online) 945 { 946 pg_data_t *pgdat; 947 int ret = 1; 948 949 if (node_online(nid)) 950 return 0; 951 952 pgdat = hotadd_new_pgdat(nid); 953 if (!pgdat) { 954 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 955 ret = -ENOMEM; 956 goto out; 957 } 958 959 if (set_node_online) { 960 node_set_online(nid); 961 ret = register_one_node(nid); 962 BUG_ON(ret); 963 } 964 out: 965 return ret; 966 } 967 968 /* 969 * Users of this function always want to online/register the node 970 */ 971 int try_online_node(int nid) 972 { 973 int ret; 974 975 mem_hotplug_begin(); 976 ret = __try_online_node(nid, true); 977 mem_hotplug_done(); 978 return ret; 979 } 980 981 static int check_hotplug_memory_range(u64 start, u64 size) 982 { 983 /* memory range must be block size aligned */ 984 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 985 !IS_ALIGNED(size, memory_block_size_bytes())) { 986 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 987 memory_block_size_bytes(), start, size); 988 return -EINVAL; 989 } 990 991 return 0; 992 } 993 994 static int online_memory_block(struct memory_block *mem, void *arg) 995 { 996 mem->online_type = memhp_default_online_type; 997 return device_online(&mem->dev); 998 } 999 1000 /* 1001 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1002 * and online/offline operations (triggered e.g. by sysfs). 1003 * 1004 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1005 */ 1006 int __ref add_memory_resource(int nid, struct resource *res) 1007 { 1008 struct mhp_params params = { .pgprot = PAGE_KERNEL }; 1009 u64 start, size; 1010 bool new_node = false; 1011 int ret; 1012 1013 start = res->start; 1014 size = resource_size(res); 1015 1016 ret = check_hotplug_memory_range(start, size); 1017 if (ret) 1018 return ret; 1019 1020 if (!node_possible(nid)) { 1021 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1022 return -EINVAL; 1023 } 1024 1025 mem_hotplug_begin(); 1026 1027 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1028 memblock_add_node(start, size, nid); 1029 1030 ret = __try_online_node(nid, false); 1031 if (ret < 0) 1032 goto error; 1033 new_node = ret; 1034 1035 /* call arch's memory hotadd */ 1036 ret = arch_add_memory(nid, start, size, ¶ms); 1037 if (ret < 0) 1038 goto error; 1039 1040 /* create memory block devices after memory was added */ 1041 ret = create_memory_block_devices(start, size); 1042 if (ret) { 1043 arch_remove_memory(nid, start, size, NULL); 1044 goto error; 1045 } 1046 1047 if (new_node) { 1048 /* If sysfs file of new node can't be created, cpu on the node 1049 * can't be hot-added. There is no rollback way now. 1050 * So, check by BUG_ON() to catch it reluctantly.. 1051 * We online node here. We can't roll back from here. 1052 */ 1053 node_set_online(nid); 1054 ret = __register_one_node(nid); 1055 BUG_ON(ret); 1056 } 1057 1058 /* link memory sections under this node.*/ 1059 ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1)); 1060 BUG_ON(ret); 1061 1062 /* create new memmap entry */ 1063 if (!strcmp(res->name, "System RAM")) 1064 firmware_map_add_hotplug(start, start + size, "System RAM"); 1065 1066 /* device_online() will take the lock when calling online_pages() */ 1067 mem_hotplug_done(); 1068 1069 /* online pages if requested */ 1070 if (memhp_default_online_type != MMOP_OFFLINE) 1071 walk_memory_blocks(start, size, NULL, online_memory_block); 1072 1073 return ret; 1074 error: 1075 /* rollback pgdat allocation and others */ 1076 if (new_node) 1077 rollback_node_hotadd(nid); 1078 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1079 memblock_remove(start, size); 1080 mem_hotplug_done(); 1081 return ret; 1082 } 1083 1084 /* requires device_hotplug_lock, see add_memory_resource() */ 1085 int __ref __add_memory(int nid, u64 start, u64 size) 1086 { 1087 struct resource *res; 1088 int ret; 1089 1090 res = register_memory_resource(start, size, "System RAM"); 1091 if (IS_ERR(res)) 1092 return PTR_ERR(res); 1093 1094 ret = add_memory_resource(nid, res); 1095 if (ret < 0) 1096 release_memory_resource(res); 1097 return ret; 1098 } 1099 1100 int add_memory(int nid, u64 start, u64 size) 1101 { 1102 int rc; 1103 1104 lock_device_hotplug(); 1105 rc = __add_memory(nid, start, size); 1106 unlock_device_hotplug(); 1107 1108 return rc; 1109 } 1110 EXPORT_SYMBOL_GPL(add_memory); 1111 1112 /* 1113 * Add special, driver-managed memory to the system as system RAM. Such 1114 * memory is not exposed via the raw firmware-provided memmap as system 1115 * RAM, instead, it is detected and added by a driver - during cold boot, 1116 * after a reboot, and after kexec. 1117 * 1118 * Reasons why this memory should not be used for the initial memmap of a 1119 * kexec kernel or for placing kexec images: 1120 * - The booting kernel is in charge of determining how this memory will be 1121 * used (e.g., use persistent memory as system RAM) 1122 * - Coordination with a hypervisor is required before this memory 1123 * can be used (e.g., inaccessible parts). 1124 * 1125 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1126 * memory map") are created. Also, the created memory resource is flagged 1127 * with IORESOURCE_MEM_DRIVER_MANAGED, so in-kernel users can special-case 1128 * this memory as well (esp., not place kexec images onto it). 1129 * 1130 * The resource_name (visible via /proc/iomem) has to have the format 1131 * "System RAM ($DRIVER)". 1132 */ 1133 int add_memory_driver_managed(int nid, u64 start, u64 size, 1134 const char *resource_name) 1135 { 1136 struct resource *res; 1137 int rc; 1138 1139 if (!resource_name || 1140 strstr(resource_name, "System RAM (") != resource_name || 1141 resource_name[strlen(resource_name) - 1] != ')') 1142 return -EINVAL; 1143 1144 lock_device_hotplug(); 1145 1146 res = register_memory_resource(start, size, resource_name); 1147 if (IS_ERR(res)) { 1148 rc = PTR_ERR(res); 1149 goto out_unlock; 1150 } 1151 1152 rc = add_memory_resource(nid, res); 1153 if (rc < 0) 1154 release_memory_resource(res); 1155 1156 out_unlock: 1157 unlock_device_hotplug(); 1158 return rc; 1159 } 1160 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1161 1162 #ifdef CONFIG_MEMORY_HOTREMOVE 1163 /* 1164 * Confirm all pages in a range [start, end) belong to the same zone (skipping 1165 * memory holes). When true, return the zone. 1166 */ 1167 struct zone *test_pages_in_a_zone(unsigned long start_pfn, 1168 unsigned long end_pfn) 1169 { 1170 unsigned long pfn, sec_end_pfn; 1171 struct zone *zone = NULL; 1172 struct page *page; 1173 int i; 1174 for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); 1175 pfn < end_pfn; 1176 pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { 1177 /* Make sure the memory section is present first */ 1178 if (!present_section_nr(pfn_to_section_nr(pfn))) 1179 continue; 1180 for (; pfn < sec_end_pfn && pfn < end_pfn; 1181 pfn += MAX_ORDER_NR_PAGES) { 1182 i = 0; 1183 /* This is just a CONFIG_HOLES_IN_ZONE check.*/ 1184 while ((i < MAX_ORDER_NR_PAGES) && 1185 !pfn_valid_within(pfn + i)) 1186 i++; 1187 if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) 1188 continue; 1189 /* Check if we got outside of the zone */ 1190 if (zone && !zone_spans_pfn(zone, pfn + i)) 1191 return NULL; 1192 page = pfn_to_page(pfn + i); 1193 if (zone && page_zone(page) != zone) 1194 return NULL; 1195 zone = page_zone(page); 1196 } 1197 } 1198 1199 return zone; 1200 } 1201 1202 /* 1203 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1204 * non-lru movable pages and hugepages). Will skip over most unmovable 1205 * pages (esp., pages that can be skipped when offlining), but bail out on 1206 * definitely unmovable pages. 1207 * 1208 * Returns: 1209 * 0 in case a movable page is found and movable_pfn was updated. 1210 * -ENOENT in case no movable page was found. 1211 * -EBUSY in case a definitely unmovable page was found. 1212 */ 1213 static int scan_movable_pages(unsigned long start, unsigned long end, 1214 unsigned long *movable_pfn) 1215 { 1216 unsigned long pfn; 1217 1218 for (pfn = start; pfn < end; pfn++) { 1219 struct page *page, *head; 1220 unsigned long skip; 1221 1222 if (!pfn_valid(pfn)) 1223 continue; 1224 page = pfn_to_page(pfn); 1225 if (PageLRU(page)) 1226 goto found; 1227 if (__PageMovable(page)) 1228 goto found; 1229 1230 /* 1231 * PageOffline() pages that are not marked __PageMovable() and 1232 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1233 * definitely unmovable. If their reference count would be 0, 1234 * they could at least be skipped when offlining memory. 1235 */ 1236 if (PageOffline(page) && page_count(page)) 1237 return -EBUSY; 1238 1239 if (!PageHuge(page)) 1240 continue; 1241 head = compound_head(page); 1242 if (page_huge_active(head)) 1243 goto found; 1244 skip = compound_nr(head) - (page - head); 1245 pfn += skip - 1; 1246 } 1247 return -ENOENT; 1248 found: 1249 *movable_pfn = pfn; 1250 return 0; 1251 } 1252 1253 static struct page *new_node_page(struct page *page, unsigned long private) 1254 { 1255 int nid = page_to_nid(page); 1256 nodemask_t nmask = node_states[N_MEMORY]; 1257 1258 /* 1259 * try to allocate from a different node but reuse this node if there 1260 * are no other online nodes to be used (e.g. we are offlining a part 1261 * of the only existing node) 1262 */ 1263 node_clear(nid, nmask); 1264 if (nodes_empty(nmask)) 1265 node_set(nid, nmask); 1266 1267 return new_page_nodemask(page, nid, &nmask); 1268 } 1269 1270 static int 1271 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1272 { 1273 unsigned long pfn; 1274 struct page *page; 1275 int ret = 0; 1276 LIST_HEAD(source); 1277 1278 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1279 if (!pfn_valid(pfn)) 1280 continue; 1281 page = pfn_to_page(pfn); 1282 1283 if (PageHuge(page)) { 1284 struct page *head = compound_head(page); 1285 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1286 isolate_huge_page(head, &source); 1287 continue; 1288 } else if (PageTransHuge(page)) 1289 pfn = page_to_pfn(compound_head(page)) 1290 + hpage_nr_pages(page) - 1; 1291 1292 /* 1293 * HWPoison pages have elevated reference counts so the migration would 1294 * fail on them. It also doesn't make any sense to migrate them in the 1295 * first place. Still try to unmap such a page in case it is still mapped 1296 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1297 * the unmap as the catch all safety net). 1298 */ 1299 if (PageHWPoison(page)) { 1300 if (WARN_ON(PageLRU(page))) 1301 isolate_lru_page(page); 1302 if (page_mapped(page)) 1303 try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); 1304 continue; 1305 } 1306 1307 if (!get_page_unless_zero(page)) 1308 continue; 1309 /* 1310 * We can skip free pages. And we can deal with pages on 1311 * LRU and non-lru movable pages. 1312 */ 1313 if (PageLRU(page)) 1314 ret = isolate_lru_page(page); 1315 else 1316 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1317 if (!ret) { /* Success */ 1318 list_add_tail(&page->lru, &source); 1319 if (!__PageMovable(page)) 1320 inc_node_page_state(page, NR_ISOLATED_ANON + 1321 page_is_file_lru(page)); 1322 1323 } else { 1324 pr_warn("failed to isolate pfn %lx\n", pfn); 1325 dump_page(page, "isolation failed"); 1326 } 1327 put_page(page); 1328 } 1329 if (!list_empty(&source)) { 1330 /* Allocate a new page from the nearest neighbor node */ 1331 ret = migrate_pages(&source, new_node_page, NULL, 0, 1332 MIGRATE_SYNC, MR_MEMORY_HOTPLUG); 1333 if (ret) { 1334 list_for_each_entry(page, &source, lru) { 1335 pr_warn("migrating pfn %lx failed ret:%d ", 1336 page_to_pfn(page), ret); 1337 dump_page(page, "migration failure"); 1338 } 1339 putback_movable_pages(&source); 1340 } 1341 } 1342 1343 return ret; 1344 } 1345 1346 /* Mark all sections offline and remove all free pages from the buddy. */ 1347 static int 1348 offline_isolated_pages_cb(unsigned long start, unsigned long nr_pages, 1349 void *data) 1350 { 1351 unsigned long *offlined_pages = (unsigned long *)data; 1352 1353 *offlined_pages += __offline_isolated_pages(start, start + nr_pages); 1354 return 0; 1355 } 1356 1357 /* 1358 * Check all pages in range, recorded as memory resource, are isolated. 1359 */ 1360 static int 1361 check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages, 1362 void *data) 1363 { 1364 return test_pages_isolated(start_pfn, start_pfn + nr_pages, 1365 MEMORY_OFFLINE); 1366 } 1367 1368 static int __init cmdline_parse_movable_node(char *p) 1369 { 1370 movable_node_enabled = true; 1371 return 0; 1372 } 1373 early_param("movable_node", cmdline_parse_movable_node); 1374 1375 /* check which state of node_states will be changed when offline memory */ 1376 static void node_states_check_changes_offline(unsigned long nr_pages, 1377 struct zone *zone, struct memory_notify *arg) 1378 { 1379 struct pglist_data *pgdat = zone->zone_pgdat; 1380 unsigned long present_pages = 0; 1381 enum zone_type zt; 1382 1383 arg->status_change_nid = NUMA_NO_NODE; 1384 arg->status_change_nid_normal = NUMA_NO_NODE; 1385 arg->status_change_nid_high = NUMA_NO_NODE; 1386 1387 /* 1388 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1389 * If the memory to be offline is within the range 1390 * [0..ZONE_NORMAL], and it is the last present memory there, 1391 * the zones in that range will become empty after the offlining, 1392 * thus we can determine that we need to clear the node from 1393 * node_states[N_NORMAL_MEMORY]. 1394 */ 1395 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1396 present_pages += pgdat->node_zones[zt].present_pages; 1397 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1398 arg->status_change_nid_normal = zone_to_nid(zone); 1399 1400 #ifdef CONFIG_HIGHMEM 1401 /* 1402 * node_states[N_HIGH_MEMORY] contains nodes which 1403 * have normal memory or high memory. 1404 * Here we add the present_pages belonging to ZONE_HIGHMEM. 1405 * If the zone is within the range of [0..ZONE_HIGHMEM), and 1406 * we determine that the zones in that range become empty, 1407 * we need to clear the node for N_HIGH_MEMORY. 1408 */ 1409 present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1410 if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) 1411 arg->status_change_nid_high = zone_to_nid(zone); 1412 #endif 1413 1414 /* 1415 * We have accounted the pages from [0..ZONE_NORMAL), and 1416 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM 1417 * as well. 1418 * Here we count the possible pages from ZONE_MOVABLE. 1419 * If after having accounted all the pages, we see that the nr_pages 1420 * to be offlined is over or equal to the accounted pages, 1421 * we know that the node will become empty, and so, we can clear 1422 * it for N_MEMORY as well. 1423 */ 1424 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1425 1426 if (nr_pages >= present_pages) 1427 arg->status_change_nid = zone_to_nid(zone); 1428 } 1429 1430 static void node_states_clear_node(int node, struct memory_notify *arg) 1431 { 1432 if (arg->status_change_nid_normal >= 0) 1433 node_clear_state(node, N_NORMAL_MEMORY); 1434 1435 if (arg->status_change_nid_high >= 0) 1436 node_clear_state(node, N_HIGH_MEMORY); 1437 1438 if (arg->status_change_nid >= 0) 1439 node_clear_state(node, N_MEMORY); 1440 } 1441 1442 static int count_system_ram_pages_cb(unsigned long start_pfn, 1443 unsigned long nr_pages, void *data) 1444 { 1445 unsigned long *nr_system_ram_pages = data; 1446 1447 *nr_system_ram_pages += nr_pages; 1448 return 0; 1449 } 1450 1451 static int __ref __offline_pages(unsigned long start_pfn, 1452 unsigned long end_pfn) 1453 { 1454 unsigned long pfn, nr_pages = 0; 1455 unsigned long offlined_pages = 0; 1456 int ret, node, nr_isolate_pageblock; 1457 unsigned long flags; 1458 struct zone *zone; 1459 struct memory_notify arg; 1460 char *reason; 1461 1462 mem_hotplug_begin(); 1463 1464 /* 1465 * Don't allow to offline memory blocks that contain holes. 1466 * Consequently, memory blocks with holes can never get onlined 1467 * via the hotplug path - online_pages() - as hotplugged memory has 1468 * no holes. This way, we e.g., don't have to worry about marking 1469 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1470 * avoid using walk_system_ram_range() later. 1471 */ 1472 walk_system_ram_range(start_pfn, end_pfn - start_pfn, &nr_pages, 1473 count_system_ram_pages_cb); 1474 if (nr_pages != end_pfn - start_pfn) { 1475 ret = -EINVAL; 1476 reason = "memory holes"; 1477 goto failed_removal; 1478 } 1479 1480 /* This makes hotplug much easier...and readable. 1481 we assume this for now. .*/ 1482 zone = test_pages_in_a_zone(start_pfn, end_pfn); 1483 if (!zone) { 1484 ret = -EINVAL; 1485 reason = "multizone range"; 1486 goto failed_removal; 1487 } 1488 node = zone_to_nid(zone); 1489 1490 /* set above range as isolated */ 1491 ret = start_isolate_page_range(start_pfn, end_pfn, 1492 MIGRATE_MOVABLE, 1493 MEMORY_OFFLINE | REPORT_FAILURE); 1494 if (ret < 0) { 1495 reason = "failure to isolate range"; 1496 goto failed_removal; 1497 } 1498 nr_isolate_pageblock = ret; 1499 1500 arg.start_pfn = start_pfn; 1501 arg.nr_pages = nr_pages; 1502 node_states_check_changes_offline(nr_pages, zone, &arg); 1503 1504 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1505 ret = notifier_to_errno(ret); 1506 if (ret) { 1507 reason = "notifier failure"; 1508 goto failed_removal_isolated; 1509 } 1510 1511 do { 1512 pfn = start_pfn; 1513 do { 1514 if (signal_pending(current)) { 1515 ret = -EINTR; 1516 reason = "signal backoff"; 1517 goto failed_removal_isolated; 1518 } 1519 1520 cond_resched(); 1521 lru_add_drain_all(); 1522 1523 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1524 if (!ret) { 1525 /* 1526 * TODO: fatal migration failures should bail 1527 * out 1528 */ 1529 do_migrate_range(pfn, end_pfn); 1530 } 1531 } while (!ret); 1532 1533 if (ret != -ENOENT) { 1534 reason = "unmovable page"; 1535 goto failed_removal_isolated; 1536 } 1537 1538 /* 1539 * Dissolve free hugepages in the memory block before doing 1540 * offlining actually in order to make hugetlbfs's object 1541 * counting consistent. 1542 */ 1543 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1544 if (ret) { 1545 reason = "failure to dissolve huge pages"; 1546 goto failed_removal_isolated; 1547 } 1548 /* check again */ 1549 ret = walk_system_ram_range(start_pfn, end_pfn - start_pfn, 1550 NULL, check_pages_isolated_cb); 1551 } while (ret); 1552 1553 /* Ok, all of our target is isolated. 1554 We cannot do rollback at this point. */ 1555 walk_system_ram_range(start_pfn, end_pfn - start_pfn, 1556 &offlined_pages, offline_isolated_pages_cb); 1557 pr_info("Offlined Pages %ld\n", offlined_pages); 1558 /* 1559 * Onlining will reset pagetype flags and makes migrate type 1560 * MOVABLE, so just need to decrease the number of isolated 1561 * pageblocks zone counter here. 1562 */ 1563 spin_lock_irqsave(&zone->lock, flags); 1564 zone->nr_isolate_pageblock -= nr_isolate_pageblock; 1565 spin_unlock_irqrestore(&zone->lock, flags); 1566 1567 /* removal success */ 1568 adjust_managed_page_count(pfn_to_page(start_pfn), -offlined_pages); 1569 zone->present_pages -= offlined_pages; 1570 1571 pgdat_resize_lock(zone->zone_pgdat, &flags); 1572 zone->zone_pgdat->node_present_pages -= offlined_pages; 1573 pgdat_resize_unlock(zone->zone_pgdat, &flags); 1574 1575 init_per_zone_wmark_min(); 1576 1577 if (!populated_zone(zone)) { 1578 zone_pcp_reset(zone); 1579 build_all_zonelists(NULL); 1580 } else 1581 zone_pcp_update(zone); 1582 1583 node_states_clear_node(node, &arg); 1584 if (arg.status_change_nid >= 0) { 1585 kswapd_stop(node); 1586 kcompactd_stop(node); 1587 } 1588 1589 vm_total_pages = nr_free_pagecache_pages(); 1590 writeback_set_ratelimit(); 1591 1592 memory_notify(MEM_OFFLINE, &arg); 1593 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1594 mem_hotplug_done(); 1595 return 0; 1596 1597 failed_removal_isolated: 1598 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1599 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1600 failed_removal: 1601 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1602 (unsigned long long) start_pfn << PAGE_SHIFT, 1603 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1604 reason); 1605 /* pushback to free area */ 1606 mem_hotplug_done(); 1607 return ret; 1608 } 1609 1610 int offline_pages(unsigned long start_pfn, unsigned long nr_pages) 1611 { 1612 return __offline_pages(start_pfn, start_pfn + nr_pages); 1613 } 1614 1615 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1616 { 1617 int ret = !is_memblock_offlined(mem); 1618 1619 if (unlikely(ret)) { 1620 phys_addr_t beginpa, endpa; 1621 1622 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1623 endpa = beginpa + memory_block_size_bytes() - 1; 1624 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1625 &beginpa, &endpa); 1626 1627 return -EBUSY; 1628 } 1629 return 0; 1630 } 1631 1632 static int check_cpu_on_node(pg_data_t *pgdat) 1633 { 1634 int cpu; 1635 1636 for_each_present_cpu(cpu) { 1637 if (cpu_to_node(cpu) == pgdat->node_id) 1638 /* 1639 * the cpu on this node isn't removed, and we can't 1640 * offline this node. 1641 */ 1642 return -EBUSY; 1643 } 1644 1645 return 0; 1646 } 1647 1648 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 1649 { 1650 int nid = *(int *)arg; 1651 1652 /* 1653 * If a memory block belongs to multiple nodes, the stored nid is not 1654 * reliable. However, such blocks are always online (e.g., cannot get 1655 * offlined) and, therefore, are still spanned by the node. 1656 */ 1657 return mem->nid == nid ? -EEXIST : 0; 1658 } 1659 1660 /** 1661 * try_offline_node 1662 * @nid: the node ID 1663 * 1664 * Offline a node if all memory sections and cpus of the node are removed. 1665 * 1666 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1667 * and online/offline operations before this call. 1668 */ 1669 void try_offline_node(int nid) 1670 { 1671 pg_data_t *pgdat = NODE_DATA(nid); 1672 int rc; 1673 1674 /* 1675 * If the node still spans pages (especially ZONE_DEVICE), don't 1676 * offline it. A node spans memory after move_pfn_range_to_zone(), 1677 * e.g., after the memory block was onlined. 1678 */ 1679 if (pgdat->node_spanned_pages) 1680 return; 1681 1682 /* 1683 * Especially offline memory blocks might not be spanned by the 1684 * node. They will get spanned by the node once they get onlined. 1685 * However, they link to the node in sysfs and can get onlined later. 1686 */ 1687 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 1688 if (rc) 1689 return; 1690 1691 if (check_cpu_on_node(pgdat)) 1692 return; 1693 1694 /* 1695 * all memory/cpu of this node are removed, we can offline this 1696 * node now. 1697 */ 1698 node_set_offline(nid); 1699 unregister_one_node(nid); 1700 } 1701 EXPORT_SYMBOL(try_offline_node); 1702 1703 static void __release_memory_resource(resource_size_t start, 1704 resource_size_t size) 1705 { 1706 int ret; 1707 1708 /* 1709 * When removing memory in the same granularity as it was added, 1710 * this function never fails. It might only fail if resources 1711 * have to be adjusted or split. We'll ignore the error, as 1712 * removing of memory cannot fail. 1713 */ 1714 ret = release_mem_region_adjustable(&iomem_resource, start, size); 1715 if (ret) { 1716 resource_size_t endres = start + size - 1; 1717 1718 pr_warn("Unable to release resource <%pa-%pa> (%d)\n", 1719 &start, &endres, ret); 1720 } 1721 } 1722 1723 static int __ref try_remove_memory(int nid, u64 start, u64 size) 1724 { 1725 int rc = 0; 1726 1727 BUG_ON(check_hotplug_memory_range(start, size)); 1728 1729 /* 1730 * All memory blocks must be offlined before removing memory. Check 1731 * whether all memory blocks in question are offline and return error 1732 * if this is not the case. 1733 */ 1734 rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); 1735 if (rc) 1736 goto done; 1737 1738 /* remove memmap entry */ 1739 firmware_map_remove(start, start + size, "System RAM"); 1740 1741 /* 1742 * Memory block device removal under the device_hotplug_lock is 1743 * a barrier against racing online attempts. 1744 */ 1745 remove_memory_block_devices(start, size); 1746 1747 mem_hotplug_begin(); 1748 1749 arch_remove_memory(nid, start, size, NULL); 1750 1751 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 1752 memblock_free(start, size); 1753 memblock_remove(start, size); 1754 } 1755 1756 __release_memory_resource(start, size); 1757 1758 try_offline_node(nid); 1759 1760 done: 1761 mem_hotplug_done(); 1762 return rc; 1763 } 1764 1765 /** 1766 * remove_memory 1767 * @nid: the node ID 1768 * @start: physical address of the region to remove 1769 * @size: size of the region to remove 1770 * 1771 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1772 * and online/offline operations before this call, as required by 1773 * try_offline_node(). 1774 */ 1775 void __remove_memory(int nid, u64 start, u64 size) 1776 { 1777 1778 /* 1779 * trigger BUG() if some memory is not offlined prior to calling this 1780 * function 1781 */ 1782 if (try_remove_memory(nid, start, size)) 1783 BUG(); 1784 } 1785 1786 /* 1787 * Remove memory if every memory block is offline, otherwise return -EBUSY is 1788 * some memory is not offline 1789 */ 1790 int remove_memory(int nid, u64 start, u64 size) 1791 { 1792 int rc; 1793 1794 lock_device_hotplug(); 1795 rc = try_remove_memory(nid, start, size); 1796 unlock_device_hotplug(); 1797 1798 return rc; 1799 } 1800 EXPORT_SYMBOL_GPL(remove_memory); 1801 1802 /* 1803 * Try to offline and remove a memory block. Might take a long time to 1804 * finish in case memory is still in use. Primarily useful for memory devices 1805 * that logically unplugged all memory (so it's no longer in use) and want to 1806 * offline + remove the memory block. 1807 */ 1808 int offline_and_remove_memory(int nid, u64 start, u64 size) 1809 { 1810 struct memory_block *mem; 1811 int rc = -EINVAL; 1812 1813 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 1814 size != memory_block_size_bytes()) 1815 return rc; 1816 1817 lock_device_hotplug(); 1818 mem = find_memory_block(__pfn_to_section(PFN_DOWN(start))); 1819 if (mem) 1820 rc = device_offline(&mem->dev); 1821 /* Ignore if the device is already offline. */ 1822 if (rc > 0) 1823 rc = 0; 1824 1825 /* 1826 * In case we succeeded to offline the memory block, remove it. 1827 * This cannot fail as it cannot get onlined in the meantime. 1828 */ 1829 if (!rc) { 1830 rc = try_remove_memory(nid, start, size); 1831 WARN_ON_ONCE(rc); 1832 } 1833 unlock_device_hotplug(); 1834 1835 return rc; 1836 } 1837 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 1838 #endif /* CONFIG_MEMORY_HOTREMOVE */ 1839