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_SYSRAM_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 #ifdef CONFIG_NUMA 354 int __weak memory_add_physaddr_to_nid(u64 start) 355 { 356 pr_info_once("Unknown online node for memory at 0x%llx, assuming node 0\n", 357 start); 358 return 0; 359 } 360 EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); 361 362 int __weak phys_to_target_node(u64 start) 363 { 364 pr_info_once("Unknown target node for memory at 0x%llx, assuming node 0\n", 365 start); 366 return 0; 367 } 368 EXPORT_SYMBOL_GPL(phys_to_target_node); 369 #endif 370 371 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 372 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 373 unsigned long start_pfn, 374 unsigned long end_pfn) 375 { 376 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 377 if (unlikely(!pfn_to_online_page(start_pfn))) 378 continue; 379 380 if (unlikely(pfn_to_nid(start_pfn) != nid)) 381 continue; 382 383 if (zone != page_zone(pfn_to_page(start_pfn))) 384 continue; 385 386 return start_pfn; 387 } 388 389 return 0; 390 } 391 392 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 393 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 394 unsigned long start_pfn, 395 unsigned long end_pfn) 396 { 397 unsigned long pfn; 398 399 /* pfn is the end pfn of a memory section. */ 400 pfn = end_pfn - 1; 401 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 402 if (unlikely(!pfn_to_online_page(pfn))) 403 continue; 404 405 if (unlikely(pfn_to_nid(pfn) != nid)) 406 continue; 407 408 if (zone != page_zone(pfn_to_page(pfn))) 409 continue; 410 411 return pfn; 412 } 413 414 return 0; 415 } 416 417 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 418 unsigned long end_pfn) 419 { 420 unsigned long pfn; 421 int nid = zone_to_nid(zone); 422 423 zone_span_writelock(zone); 424 if (zone->zone_start_pfn == start_pfn) { 425 /* 426 * If the section is smallest section in the zone, it need 427 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 428 * In this case, we find second smallest valid mem_section 429 * for shrinking zone. 430 */ 431 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 432 zone_end_pfn(zone)); 433 if (pfn) { 434 zone->spanned_pages = zone_end_pfn(zone) - pfn; 435 zone->zone_start_pfn = pfn; 436 } else { 437 zone->zone_start_pfn = 0; 438 zone->spanned_pages = 0; 439 } 440 } else if (zone_end_pfn(zone) == end_pfn) { 441 /* 442 * If the section is biggest section in the zone, it need 443 * shrink zone->spanned_pages. 444 * In this case, we find second biggest valid mem_section for 445 * shrinking zone. 446 */ 447 pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, 448 start_pfn); 449 if (pfn) 450 zone->spanned_pages = pfn - zone->zone_start_pfn + 1; 451 else { 452 zone->zone_start_pfn = 0; 453 zone->spanned_pages = 0; 454 } 455 } 456 zone_span_writeunlock(zone); 457 } 458 459 static void update_pgdat_span(struct pglist_data *pgdat) 460 { 461 unsigned long node_start_pfn = 0, node_end_pfn = 0; 462 struct zone *zone; 463 464 for (zone = pgdat->node_zones; 465 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 466 unsigned long zone_end_pfn = zone->zone_start_pfn + 467 zone->spanned_pages; 468 469 /* No need to lock the zones, they can't change. */ 470 if (!zone->spanned_pages) 471 continue; 472 if (!node_end_pfn) { 473 node_start_pfn = zone->zone_start_pfn; 474 node_end_pfn = zone_end_pfn; 475 continue; 476 } 477 478 if (zone_end_pfn > node_end_pfn) 479 node_end_pfn = zone_end_pfn; 480 if (zone->zone_start_pfn < node_start_pfn) 481 node_start_pfn = zone->zone_start_pfn; 482 } 483 484 pgdat->node_start_pfn = node_start_pfn; 485 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 486 } 487 488 void __ref remove_pfn_range_from_zone(struct zone *zone, 489 unsigned long start_pfn, 490 unsigned long nr_pages) 491 { 492 const unsigned long end_pfn = start_pfn + nr_pages; 493 struct pglist_data *pgdat = zone->zone_pgdat; 494 unsigned long pfn, cur_nr_pages, flags; 495 496 /* Poison struct pages because they are now uninitialized again. */ 497 for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { 498 cond_resched(); 499 500 /* Select all remaining pages up to the next section boundary */ 501 cur_nr_pages = 502 min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); 503 page_init_poison(pfn_to_page(pfn), 504 sizeof(struct page) * cur_nr_pages); 505 } 506 507 #ifdef CONFIG_ZONE_DEVICE 508 /* 509 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 510 * we will not try to shrink the zones - which is okay as 511 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 512 */ 513 if (zone_idx(zone) == ZONE_DEVICE) 514 return; 515 #endif 516 517 clear_zone_contiguous(zone); 518 519 pgdat_resize_lock(zone->zone_pgdat, &flags); 520 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 521 update_pgdat_span(pgdat); 522 pgdat_resize_unlock(zone->zone_pgdat, &flags); 523 524 set_zone_contiguous(zone); 525 } 526 527 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 528 unsigned long map_offset, 529 struct vmem_altmap *altmap) 530 { 531 struct mem_section *ms = __pfn_to_section(pfn); 532 533 if (WARN_ON_ONCE(!valid_section(ms))) 534 return; 535 536 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 537 } 538 539 /** 540 * __remove_pages() - remove sections of pages 541 * @pfn: starting pageframe (must be aligned to start of a section) 542 * @nr_pages: number of pages to remove (must be multiple of section size) 543 * @altmap: alternative device page map or %NULL if default memmap is used 544 * 545 * Generic helper function to remove section mappings and sysfs entries 546 * for the section of the memory we are removing. Caller needs to make 547 * sure that pages are marked reserved and zones are adjust properly by 548 * calling offline_pages(). 549 */ 550 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 551 struct vmem_altmap *altmap) 552 { 553 const unsigned long end_pfn = pfn + nr_pages; 554 unsigned long cur_nr_pages; 555 unsigned long map_offset = 0; 556 557 map_offset = vmem_altmap_offset(altmap); 558 559 if (check_pfn_span(pfn, nr_pages, "remove")) 560 return; 561 562 for (; pfn < end_pfn; pfn += cur_nr_pages) { 563 cond_resched(); 564 /* Select all remaining pages up to the next section boundary */ 565 cur_nr_pages = min(end_pfn - pfn, 566 SECTION_ALIGN_UP(pfn + 1) - pfn); 567 __remove_section(pfn, cur_nr_pages, map_offset, altmap); 568 map_offset = 0; 569 } 570 } 571 572 int set_online_page_callback(online_page_callback_t callback) 573 { 574 int rc = -EINVAL; 575 576 get_online_mems(); 577 mutex_lock(&online_page_callback_lock); 578 579 if (online_page_callback == generic_online_page) { 580 online_page_callback = callback; 581 rc = 0; 582 } 583 584 mutex_unlock(&online_page_callback_lock); 585 put_online_mems(); 586 587 return rc; 588 } 589 EXPORT_SYMBOL_GPL(set_online_page_callback); 590 591 int restore_online_page_callback(online_page_callback_t callback) 592 { 593 int rc = -EINVAL; 594 595 get_online_mems(); 596 mutex_lock(&online_page_callback_lock); 597 598 if (online_page_callback == callback) { 599 online_page_callback = generic_online_page; 600 rc = 0; 601 } 602 603 mutex_unlock(&online_page_callback_lock); 604 put_online_mems(); 605 606 return rc; 607 } 608 EXPORT_SYMBOL_GPL(restore_online_page_callback); 609 610 void generic_online_page(struct page *page, unsigned int order) 611 { 612 /* 613 * Freeing the page with debug_pagealloc enabled will try to unmap it, 614 * so we should map it first. This is better than introducing a special 615 * case in page freeing fast path. 616 */ 617 if (debug_pagealloc_enabled_static()) 618 kernel_map_pages(page, 1 << order, 1); 619 __free_pages_core(page, order); 620 totalram_pages_add(1UL << order); 621 #ifdef CONFIG_HIGHMEM 622 if (PageHighMem(page)) 623 totalhigh_pages_add(1UL << order); 624 #endif 625 } 626 EXPORT_SYMBOL_GPL(generic_online_page); 627 628 static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) 629 { 630 const unsigned long end_pfn = start_pfn + nr_pages; 631 unsigned long pfn; 632 633 /* 634 * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might 635 * decide to not expose all pages to the buddy (e.g., expose them 636 * later). We account all pages as being online and belonging to this 637 * zone ("present"). 638 */ 639 for (pfn = start_pfn; pfn < end_pfn; pfn += MAX_ORDER_NR_PAGES) 640 (*online_page_callback)(pfn_to_page(pfn), MAX_ORDER - 1); 641 642 /* mark all involved sections as online */ 643 online_mem_sections(start_pfn, end_pfn); 644 } 645 646 /* check which state of node_states will be changed when online memory */ 647 static void node_states_check_changes_online(unsigned long nr_pages, 648 struct zone *zone, struct memory_notify *arg) 649 { 650 int nid = zone_to_nid(zone); 651 652 arg->status_change_nid = NUMA_NO_NODE; 653 arg->status_change_nid_normal = NUMA_NO_NODE; 654 arg->status_change_nid_high = NUMA_NO_NODE; 655 656 if (!node_state(nid, N_MEMORY)) 657 arg->status_change_nid = nid; 658 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 659 arg->status_change_nid_normal = nid; 660 #ifdef CONFIG_HIGHMEM 661 if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) 662 arg->status_change_nid_high = nid; 663 #endif 664 } 665 666 static void node_states_set_node(int node, struct memory_notify *arg) 667 { 668 if (arg->status_change_nid_normal >= 0) 669 node_set_state(node, N_NORMAL_MEMORY); 670 671 if (arg->status_change_nid_high >= 0) 672 node_set_state(node, N_HIGH_MEMORY); 673 674 if (arg->status_change_nid >= 0) 675 node_set_state(node, N_MEMORY); 676 } 677 678 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 679 unsigned long nr_pages) 680 { 681 unsigned long old_end_pfn = zone_end_pfn(zone); 682 683 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 684 zone->zone_start_pfn = start_pfn; 685 686 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 687 } 688 689 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 690 unsigned long nr_pages) 691 { 692 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 693 694 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 695 pgdat->node_start_pfn = start_pfn; 696 697 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 698 699 } 700 /* 701 * Associate the pfn range with the given zone, initializing the memmaps 702 * and resizing the pgdat/zone data to span the added pages. After this 703 * call, all affected pages are PG_reserved. 704 * 705 * All aligned pageblocks are initialized to the specified migratetype 706 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related 707 * zone stats (e.g., nr_isolate_pageblock) are touched. 708 */ 709 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 710 unsigned long nr_pages, 711 struct vmem_altmap *altmap, int migratetype) 712 { 713 struct pglist_data *pgdat = zone->zone_pgdat; 714 int nid = pgdat->node_id; 715 unsigned long flags; 716 717 clear_zone_contiguous(zone); 718 719 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ 720 pgdat_resize_lock(pgdat, &flags); 721 zone_span_writelock(zone); 722 if (zone_is_empty(zone)) 723 init_currently_empty_zone(zone, start_pfn, nr_pages); 724 resize_zone_range(zone, start_pfn, nr_pages); 725 zone_span_writeunlock(zone); 726 resize_pgdat_range(pgdat, start_pfn, nr_pages); 727 pgdat_resize_unlock(pgdat, &flags); 728 729 /* 730 * TODO now we have a visible range of pages which are not associated 731 * with their zone properly. Not nice but set_pfnblock_flags_mask 732 * expects the zone spans the pfn range. All the pages in the range 733 * are reserved so nobody should be touching them so we should be safe 734 */ 735 memmap_init_zone(nr_pages, nid, zone_idx(zone), start_pfn, 736 MEMINIT_HOTPLUG, altmap, migratetype); 737 738 set_zone_contiguous(zone); 739 } 740 741 /* 742 * Returns a default kernel memory zone for the given pfn range. 743 * If no kernel zone covers this pfn range it will automatically go 744 * to the ZONE_NORMAL. 745 */ 746 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 747 unsigned long nr_pages) 748 { 749 struct pglist_data *pgdat = NODE_DATA(nid); 750 int zid; 751 752 for (zid = 0; zid <= ZONE_NORMAL; zid++) { 753 struct zone *zone = &pgdat->node_zones[zid]; 754 755 if (zone_intersects(zone, start_pfn, nr_pages)) 756 return zone; 757 } 758 759 return &pgdat->node_zones[ZONE_NORMAL]; 760 } 761 762 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 763 unsigned long nr_pages) 764 { 765 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 766 nr_pages); 767 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 768 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 769 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 770 771 /* 772 * We inherit the existing zone in a simple case where zones do not 773 * overlap in the given range 774 */ 775 if (in_kernel ^ in_movable) 776 return (in_kernel) ? kernel_zone : movable_zone; 777 778 /* 779 * If the range doesn't belong to any zone or two zones overlap in the 780 * given range then we use movable zone only if movable_node is 781 * enabled because we always online to a kernel zone by default. 782 */ 783 return movable_node_enabled ? movable_zone : kernel_zone; 784 } 785 786 struct zone * zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, 787 unsigned long nr_pages) 788 { 789 if (online_type == MMOP_ONLINE_KERNEL) 790 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 791 792 if (online_type == MMOP_ONLINE_MOVABLE) 793 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 794 795 return default_zone_for_pfn(nid, start_pfn, nr_pages); 796 } 797 798 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 799 int online_type, int nid) 800 { 801 unsigned long flags; 802 struct zone *zone; 803 int need_zonelists_rebuild = 0; 804 int ret; 805 struct memory_notify arg; 806 807 /* We can only online full sections (e.g., SECTION_IS_ONLINE) */ 808 if (WARN_ON_ONCE(!nr_pages || 809 !IS_ALIGNED(pfn | nr_pages, PAGES_PER_SECTION))) 810 return -EINVAL; 811 812 mem_hotplug_begin(); 813 814 /* associate pfn range with the zone */ 815 zone = zone_for_pfn_range(online_type, nid, pfn, nr_pages); 816 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); 817 818 arg.start_pfn = pfn; 819 arg.nr_pages = nr_pages; 820 node_states_check_changes_online(nr_pages, zone, &arg); 821 822 ret = memory_notify(MEM_GOING_ONLINE, &arg); 823 ret = notifier_to_errno(ret); 824 if (ret) 825 goto failed_addition; 826 827 /* 828 * Fixup the number of isolated pageblocks before marking the sections 829 * onlining, such that undo_isolate_page_range() works correctly. 830 */ 831 spin_lock_irqsave(&zone->lock, flags); 832 zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; 833 spin_unlock_irqrestore(&zone->lock, flags); 834 835 /* 836 * If this zone is not populated, then it is not in zonelist. 837 * This means the page allocator ignores this zone. 838 * So, zonelist must be updated after online. 839 */ 840 if (!populated_zone(zone)) { 841 need_zonelists_rebuild = 1; 842 setup_zone_pageset(zone); 843 } 844 845 online_pages_range(pfn, nr_pages); 846 zone->present_pages += nr_pages; 847 848 pgdat_resize_lock(zone->zone_pgdat, &flags); 849 zone->zone_pgdat->node_present_pages += nr_pages; 850 pgdat_resize_unlock(zone->zone_pgdat, &flags); 851 852 node_states_set_node(nid, &arg); 853 if (need_zonelists_rebuild) 854 build_all_zonelists(NULL); 855 zone_pcp_update(zone); 856 857 /* Basic onlining is complete, allow allocation of onlined pages. */ 858 undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); 859 860 /* 861 * When exposing larger, physically contiguous memory areas to the 862 * buddy, shuffling in the buddy (when freeing onlined pages, putting 863 * them either to the head or the tail of the freelist) is only helpful 864 * for maintaining the shuffle, but not for creating the initial 865 * shuffle. Shuffle the whole zone to make sure the just onlined pages 866 * are properly distributed across the whole freelist. Make sure to 867 * shuffle once pageblocks are no longer isolated. 868 */ 869 shuffle_zone(zone); 870 871 init_per_zone_wmark_min(); 872 873 kswapd_run(nid); 874 kcompactd_run(nid); 875 876 writeback_set_ratelimit(); 877 878 memory_notify(MEM_ONLINE, &arg); 879 mem_hotplug_done(); 880 return 0; 881 882 failed_addition: 883 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 884 (unsigned long long) pfn << PAGE_SHIFT, 885 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 886 memory_notify(MEM_CANCEL_ONLINE, &arg); 887 remove_pfn_range_from_zone(zone, pfn, nr_pages); 888 mem_hotplug_done(); 889 return ret; 890 } 891 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 892 893 static void reset_node_present_pages(pg_data_t *pgdat) 894 { 895 struct zone *z; 896 897 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 898 z->present_pages = 0; 899 900 pgdat->node_present_pages = 0; 901 } 902 903 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 904 static pg_data_t __ref *hotadd_new_pgdat(int nid) 905 { 906 struct pglist_data *pgdat; 907 908 pgdat = NODE_DATA(nid); 909 if (!pgdat) { 910 pgdat = arch_alloc_nodedata(nid); 911 if (!pgdat) 912 return NULL; 913 914 pgdat->per_cpu_nodestats = 915 alloc_percpu(struct per_cpu_nodestat); 916 arch_refresh_nodedata(nid, pgdat); 917 } else { 918 int cpu; 919 /* 920 * Reset the nr_zones, order and highest_zoneidx before reuse. 921 * Note that kswapd will init kswapd_highest_zoneidx properly 922 * when it starts in the near future. 923 */ 924 pgdat->nr_zones = 0; 925 pgdat->kswapd_order = 0; 926 pgdat->kswapd_highest_zoneidx = 0; 927 for_each_online_cpu(cpu) { 928 struct per_cpu_nodestat *p; 929 930 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); 931 memset(p, 0, sizeof(*p)); 932 } 933 } 934 935 /* we can use NODE_DATA(nid) from here */ 936 pgdat->node_id = nid; 937 pgdat->node_start_pfn = 0; 938 939 /* init node's zones as empty zones, we don't have any present pages.*/ 940 free_area_init_core_hotplug(nid); 941 942 /* 943 * The node we allocated has no zone fallback lists. For avoiding 944 * to access not-initialized zonelist, build here. 945 */ 946 build_all_zonelists(pgdat); 947 948 /* 949 * When memory is hot-added, all the memory is in offline state. So 950 * clear all zones' present_pages because they will be updated in 951 * online_pages() and offline_pages(). 952 */ 953 reset_node_managed_pages(pgdat); 954 reset_node_present_pages(pgdat); 955 956 return pgdat; 957 } 958 959 static void rollback_node_hotadd(int nid) 960 { 961 pg_data_t *pgdat = NODE_DATA(nid); 962 963 arch_refresh_nodedata(nid, NULL); 964 free_percpu(pgdat->per_cpu_nodestats); 965 arch_free_nodedata(pgdat); 966 } 967 968 969 /** 970 * try_online_node - online a node if offlined 971 * @nid: the node ID 972 * @set_node_online: Whether we want to online the node 973 * called by cpu_up() to online a node without onlined memory. 974 * 975 * Returns: 976 * 1 -> a new node has been allocated 977 * 0 -> the node is already online 978 * -ENOMEM -> the node could not be allocated 979 */ 980 static int __try_online_node(int nid, bool set_node_online) 981 { 982 pg_data_t *pgdat; 983 int ret = 1; 984 985 if (node_online(nid)) 986 return 0; 987 988 pgdat = hotadd_new_pgdat(nid); 989 if (!pgdat) { 990 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 991 ret = -ENOMEM; 992 goto out; 993 } 994 995 if (set_node_online) { 996 node_set_online(nid); 997 ret = register_one_node(nid); 998 BUG_ON(ret); 999 } 1000 out: 1001 return ret; 1002 } 1003 1004 /* 1005 * Users of this function always want to online/register the node 1006 */ 1007 int try_online_node(int nid) 1008 { 1009 int ret; 1010 1011 mem_hotplug_begin(); 1012 ret = __try_online_node(nid, true); 1013 mem_hotplug_done(); 1014 return ret; 1015 } 1016 1017 static int check_hotplug_memory_range(u64 start, u64 size) 1018 { 1019 /* memory range must be block size aligned */ 1020 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1021 !IS_ALIGNED(size, memory_block_size_bytes())) { 1022 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1023 memory_block_size_bytes(), start, size); 1024 return -EINVAL; 1025 } 1026 1027 return 0; 1028 } 1029 1030 static int online_memory_block(struct memory_block *mem, void *arg) 1031 { 1032 mem->online_type = memhp_default_online_type; 1033 return device_online(&mem->dev); 1034 } 1035 1036 /* 1037 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1038 * and online/offline operations (triggered e.g. by sysfs). 1039 * 1040 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1041 */ 1042 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) 1043 { 1044 struct mhp_params params = { .pgprot = PAGE_KERNEL }; 1045 u64 start, size; 1046 bool new_node = false; 1047 int ret; 1048 1049 start = res->start; 1050 size = resource_size(res); 1051 1052 ret = check_hotplug_memory_range(start, size); 1053 if (ret) 1054 return ret; 1055 1056 if (!node_possible(nid)) { 1057 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1058 return -EINVAL; 1059 } 1060 1061 mem_hotplug_begin(); 1062 1063 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1064 memblock_add_node(start, size, nid); 1065 1066 ret = __try_online_node(nid, false); 1067 if (ret < 0) 1068 goto error; 1069 new_node = ret; 1070 1071 /* call arch's memory hotadd */ 1072 ret = arch_add_memory(nid, start, size, ¶ms); 1073 if (ret < 0) 1074 goto error; 1075 1076 /* create memory block devices after memory was added */ 1077 ret = create_memory_block_devices(start, size); 1078 if (ret) { 1079 arch_remove_memory(nid, start, size, NULL); 1080 goto error; 1081 } 1082 1083 if (new_node) { 1084 /* If sysfs file of new node can't be created, cpu on the node 1085 * can't be hot-added. There is no rollback way now. 1086 * So, check by BUG_ON() to catch it reluctantly.. 1087 * We online node here. We can't roll back from here. 1088 */ 1089 node_set_online(nid); 1090 ret = __register_one_node(nid); 1091 BUG_ON(ret); 1092 } 1093 1094 /* link memory sections under this node.*/ 1095 ret = link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1), 1096 MEMINIT_HOTPLUG); 1097 BUG_ON(ret); 1098 1099 /* create new memmap entry */ 1100 if (!strcmp(res->name, "System RAM")) 1101 firmware_map_add_hotplug(start, start + size, "System RAM"); 1102 1103 /* device_online() will take the lock when calling online_pages() */ 1104 mem_hotplug_done(); 1105 1106 /* 1107 * In case we're allowed to merge the resource, flag it and trigger 1108 * merging now that adding succeeded. 1109 */ 1110 if (mhp_flags & MEMHP_MERGE_RESOURCE) 1111 merge_system_ram_resource(res); 1112 1113 /* online pages if requested */ 1114 if (memhp_default_online_type != MMOP_OFFLINE) 1115 walk_memory_blocks(start, size, NULL, online_memory_block); 1116 1117 return ret; 1118 error: 1119 /* rollback pgdat allocation and others */ 1120 if (new_node) 1121 rollback_node_hotadd(nid); 1122 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1123 memblock_remove(start, size); 1124 mem_hotplug_done(); 1125 return ret; 1126 } 1127 1128 /* requires device_hotplug_lock, see add_memory_resource() */ 1129 int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1130 { 1131 struct resource *res; 1132 int ret; 1133 1134 res = register_memory_resource(start, size, "System RAM"); 1135 if (IS_ERR(res)) 1136 return PTR_ERR(res); 1137 1138 ret = add_memory_resource(nid, res, mhp_flags); 1139 if (ret < 0) 1140 release_memory_resource(res); 1141 return ret; 1142 } 1143 1144 int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1145 { 1146 int rc; 1147 1148 lock_device_hotplug(); 1149 rc = __add_memory(nid, start, size, mhp_flags); 1150 unlock_device_hotplug(); 1151 1152 return rc; 1153 } 1154 EXPORT_SYMBOL_GPL(add_memory); 1155 1156 /* 1157 * Add special, driver-managed memory to the system as system RAM. Such 1158 * memory is not exposed via the raw firmware-provided memmap as system 1159 * RAM, instead, it is detected and added by a driver - during cold boot, 1160 * after a reboot, and after kexec. 1161 * 1162 * Reasons why this memory should not be used for the initial memmap of a 1163 * kexec kernel or for placing kexec images: 1164 * - The booting kernel is in charge of determining how this memory will be 1165 * used (e.g., use persistent memory as system RAM) 1166 * - Coordination with a hypervisor is required before this memory 1167 * can be used (e.g., inaccessible parts). 1168 * 1169 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1170 * memory map") are created. Also, the created memory resource is flagged 1171 * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case 1172 * this memory as well (esp., not place kexec images onto it). 1173 * 1174 * The resource_name (visible via /proc/iomem) has to have the format 1175 * "System RAM ($DRIVER)". 1176 */ 1177 int add_memory_driver_managed(int nid, u64 start, u64 size, 1178 const char *resource_name, mhp_t mhp_flags) 1179 { 1180 struct resource *res; 1181 int rc; 1182 1183 if (!resource_name || 1184 strstr(resource_name, "System RAM (") != resource_name || 1185 resource_name[strlen(resource_name) - 1] != ')') 1186 return -EINVAL; 1187 1188 lock_device_hotplug(); 1189 1190 res = register_memory_resource(start, size, resource_name); 1191 if (IS_ERR(res)) { 1192 rc = PTR_ERR(res); 1193 goto out_unlock; 1194 } 1195 1196 rc = add_memory_resource(nid, res, mhp_flags); 1197 if (rc < 0) 1198 release_memory_resource(res); 1199 1200 out_unlock: 1201 unlock_device_hotplug(); 1202 return rc; 1203 } 1204 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1205 1206 #ifdef CONFIG_MEMORY_HOTREMOVE 1207 /* 1208 * Confirm all pages in a range [start, end) belong to the same zone (skipping 1209 * memory holes). When true, return the zone. 1210 */ 1211 struct zone *test_pages_in_a_zone(unsigned long start_pfn, 1212 unsigned long end_pfn) 1213 { 1214 unsigned long pfn, sec_end_pfn; 1215 struct zone *zone = NULL; 1216 struct page *page; 1217 int i; 1218 for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); 1219 pfn < end_pfn; 1220 pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { 1221 /* Make sure the memory section is present first */ 1222 if (!present_section_nr(pfn_to_section_nr(pfn))) 1223 continue; 1224 for (; pfn < sec_end_pfn && pfn < end_pfn; 1225 pfn += MAX_ORDER_NR_PAGES) { 1226 i = 0; 1227 /* This is just a CONFIG_HOLES_IN_ZONE check.*/ 1228 while ((i < MAX_ORDER_NR_PAGES) && 1229 !pfn_valid_within(pfn + i)) 1230 i++; 1231 if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) 1232 continue; 1233 /* Check if we got outside of the zone */ 1234 if (zone && !zone_spans_pfn(zone, pfn + i)) 1235 return NULL; 1236 page = pfn_to_page(pfn + i); 1237 if (zone && page_zone(page) != zone) 1238 return NULL; 1239 zone = page_zone(page); 1240 } 1241 } 1242 1243 return zone; 1244 } 1245 1246 /* 1247 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1248 * non-lru movable pages and hugepages). Will skip over most unmovable 1249 * pages (esp., pages that can be skipped when offlining), but bail out on 1250 * definitely unmovable pages. 1251 * 1252 * Returns: 1253 * 0 in case a movable page is found and movable_pfn was updated. 1254 * -ENOENT in case no movable page was found. 1255 * -EBUSY in case a definitely unmovable page was found. 1256 */ 1257 static int scan_movable_pages(unsigned long start, unsigned long end, 1258 unsigned long *movable_pfn) 1259 { 1260 unsigned long pfn; 1261 1262 for (pfn = start; pfn < end; pfn++) { 1263 struct page *page, *head; 1264 unsigned long skip; 1265 1266 if (!pfn_valid(pfn)) 1267 continue; 1268 page = pfn_to_page(pfn); 1269 if (PageLRU(page)) 1270 goto found; 1271 if (__PageMovable(page)) 1272 goto found; 1273 1274 /* 1275 * PageOffline() pages that are not marked __PageMovable() and 1276 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1277 * definitely unmovable. If their reference count would be 0, 1278 * they could at least be skipped when offlining memory. 1279 */ 1280 if (PageOffline(page) && page_count(page)) 1281 return -EBUSY; 1282 1283 if (!PageHuge(page)) 1284 continue; 1285 head = compound_head(page); 1286 if (page_huge_active(head)) 1287 goto found; 1288 skip = compound_nr(head) - (page - head); 1289 pfn += skip - 1; 1290 } 1291 return -ENOENT; 1292 found: 1293 *movable_pfn = pfn; 1294 return 0; 1295 } 1296 1297 static struct page *new_node_page(struct page *page, unsigned long private) 1298 { 1299 nodemask_t nmask = node_states[N_MEMORY]; 1300 struct migration_target_control mtc = { 1301 .nid = page_to_nid(page), 1302 .nmask = &nmask, 1303 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, 1304 }; 1305 1306 /* 1307 * try to allocate from a different node but reuse this node if there 1308 * are no other online nodes to be used (e.g. we are offlining a part 1309 * of the only existing node) 1310 */ 1311 node_clear(mtc.nid, nmask); 1312 if (nodes_empty(nmask)) 1313 node_set(mtc.nid, nmask); 1314 1315 return alloc_migration_target(page, (unsigned long)&mtc); 1316 } 1317 1318 static int 1319 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1320 { 1321 unsigned long pfn; 1322 struct page *page, *head; 1323 int ret = 0; 1324 LIST_HEAD(source); 1325 1326 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1327 if (!pfn_valid(pfn)) 1328 continue; 1329 page = pfn_to_page(pfn); 1330 head = compound_head(page); 1331 1332 if (PageHuge(page)) { 1333 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1334 isolate_huge_page(head, &source); 1335 continue; 1336 } else if (PageTransHuge(page)) 1337 pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; 1338 1339 /* 1340 * HWPoison pages have elevated reference counts so the migration would 1341 * fail on them. It also doesn't make any sense to migrate them in the 1342 * first place. Still try to unmap such a page in case it is still mapped 1343 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1344 * the unmap as the catch all safety net). 1345 */ 1346 if (PageHWPoison(page)) { 1347 if (WARN_ON(PageLRU(page))) 1348 isolate_lru_page(page); 1349 if (page_mapped(page)) 1350 try_to_unmap(page, TTU_IGNORE_MLOCK | TTU_IGNORE_ACCESS); 1351 continue; 1352 } 1353 1354 if (!get_page_unless_zero(page)) 1355 continue; 1356 /* 1357 * We can skip free pages. And we can deal with pages on 1358 * LRU and non-lru movable pages. 1359 */ 1360 if (PageLRU(page)) 1361 ret = isolate_lru_page(page); 1362 else 1363 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1364 if (!ret) { /* Success */ 1365 list_add_tail(&page->lru, &source); 1366 if (!__PageMovable(page)) 1367 inc_node_page_state(page, NR_ISOLATED_ANON + 1368 page_is_file_lru(page)); 1369 1370 } else { 1371 pr_warn("failed to isolate pfn %lx\n", pfn); 1372 dump_page(page, "isolation failed"); 1373 } 1374 put_page(page); 1375 } 1376 if (!list_empty(&source)) { 1377 /* Allocate a new page from the nearest neighbor node */ 1378 ret = migrate_pages(&source, new_node_page, NULL, 0, 1379 MIGRATE_SYNC, MR_MEMORY_HOTPLUG); 1380 if (ret) { 1381 list_for_each_entry(page, &source, lru) { 1382 pr_warn("migrating pfn %lx failed ret:%d ", 1383 page_to_pfn(page), ret); 1384 dump_page(page, "migration failure"); 1385 } 1386 putback_movable_pages(&source); 1387 } 1388 } 1389 1390 return ret; 1391 } 1392 1393 static int __init cmdline_parse_movable_node(char *p) 1394 { 1395 movable_node_enabled = true; 1396 return 0; 1397 } 1398 early_param("movable_node", cmdline_parse_movable_node); 1399 1400 /* check which state of node_states will be changed when offline memory */ 1401 static void node_states_check_changes_offline(unsigned long nr_pages, 1402 struct zone *zone, struct memory_notify *arg) 1403 { 1404 struct pglist_data *pgdat = zone->zone_pgdat; 1405 unsigned long present_pages = 0; 1406 enum zone_type zt; 1407 1408 arg->status_change_nid = NUMA_NO_NODE; 1409 arg->status_change_nid_normal = NUMA_NO_NODE; 1410 arg->status_change_nid_high = NUMA_NO_NODE; 1411 1412 /* 1413 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1414 * If the memory to be offline is within the range 1415 * [0..ZONE_NORMAL], and it is the last present memory there, 1416 * the zones in that range will become empty after the offlining, 1417 * thus we can determine that we need to clear the node from 1418 * node_states[N_NORMAL_MEMORY]. 1419 */ 1420 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1421 present_pages += pgdat->node_zones[zt].present_pages; 1422 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1423 arg->status_change_nid_normal = zone_to_nid(zone); 1424 1425 #ifdef CONFIG_HIGHMEM 1426 /* 1427 * node_states[N_HIGH_MEMORY] contains nodes which 1428 * have normal memory or high memory. 1429 * Here we add the present_pages belonging to ZONE_HIGHMEM. 1430 * If the zone is within the range of [0..ZONE_HIGHMEM), and 1431 * we determine that the zones in that range become empty, 1432 * we need to clear the node for N_HIGH_MEMORY. 1433 */ 1434 present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1435 if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) 1436 arg->status_change_nid_high = zone_to_nid(zone); 1437 #endif 1438 1439 /* 1440 * We have accounted the pages from [0..ZONE_NORMAL), and 1441 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM 1442 * as well. 1443 * Here we count the possible pages from ZONE_MOVABLE. 1444 * If after having accounted all the pages, we see that the nr_pages 1445 * to be offlined is over or equal to the accounted pages, 1446 * we know that the node will become empty, and so, we can clear 1447 * it for N_MEMORY as well. 1448 */ 1449 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1450 1451 if (nr_pages >= present_pages) 1452 arg->status_change_nid = zone_to_nid(zone); 1453 } 1454 1455 static void node_states_clear_node(int node, struct memory_notify *arg) 1456 { 1457 if (arg->status_change_nid_normal >= 0) 1458 node_clear_state(node, N_NORMAL_MEMORY); 1459 1460 if (arg->status_change_nid_high >= 0) 1461 node_clear_state(node, N_HIGH_MEMORY); 1462 1463 if (arg->status_change_nid >= 0) 1464 node_clear_state(node, N_MEMORY); 1465 } 1466 1467 static int count_system_ram_pages_cb(unsigned long start_pfn, 1468 unsigned long nr_pages, void *data) 1469 { 1470 unsigned long *nr_system_ram_pages = data; 1471 1472 *nr_system_ram_pages += nr_pages; 1473 return 0; 1474 } 1475 1476 int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) 1477 { 1478 const unsigned long end_pfn = start_pfn + nr_pages; 1479 unsigned long pfn, system_ram_pages = 0; 1480 unsigned long flags; 1481 struct zone *zone; 1482 struct memory_notify arg; 1483 int ret, node; 1484 char *reason; 1485 1486 /* We can only offline full sections (e.g., SECTION_IS_ONLINE) */ 1487 if (WARN_ON_ONCE(!nr_pages || 1488 !IS_ALIGNED(start_pfn | nr_pages, PAGES_PER_SECTION))) 1489 return -EINVAL; 1490 1491 mem_hotplug_begin(); 1492 1493 /* 1494 * Don't allow to offline memory blocks that contain holes. 1495 * Consequently, memory blocks with holes can never get onlined 1496 * via the hotplug path - online_pages() - as hotplugged memory has 1497 * no holes. This way, we e.g., don't have to worry about marking 1498 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1499 * avoid using walk_system_ram_range() later. 1500 */ 1501 walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, 1502 count_system_ram_pages_cb); 1503 if (system_ram_pages != nr_pages) { 1504 ret = -EINVAL; 1505 reason = "memory holes"; 1506 goto failed_removal; 1507 } 1508 1509 /* This makes hotplug much easier...and readable. 1510 we assume this for now. .*/ 1511 zone = test_pages_in_a_zone(start_pfn, end_pfn); 1512 if (!zone) { 1513 ret = -EINVAL; 1514 reason = "multizone range"; 1515 goto failed_removal; 1516 } 1517 node = zone_to_nid(zone); 1518 1519 /* set above range as isolated */ 1520 ret = start_isolate_page_range(start_pfn, end_pfn, 1521 MIGRATE_MOVABLE, 1522 MEMORY_OFFLINE | REPORT_FAILURE); 1523 if (ret) { 1524 reason = "failure to isolate range"; 1525 goto failed_removal; 1526 } 1527 1528 arg.start_pfn = start_pfn; 1529 arg.nr_pages = nr_pages; 1530 node_states_check_changes_offline(nr_pages, zone, &arg); 1531 1532 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1533 ret = notifier_to_errno(ret); 1534 if (ret) { 1535 reason = "notifier failure"; 1536 goto failed_removal_isolated; 1537 } 1538 1539 do { 1540 pfn = start_pfn; 1541 do { 1542 if (signal_pending(current)) { 1543 ret = -EINTR; 1544 reason = "signal backoff"; 1545 goto failed_removal_isolated; 1546 } 1547 1548 cond_resched(); 1549 lru_add_drain_all(); 1550 1551 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1552 if (!ret) { 1553 /* 1554 * TODO: fatal migration failures should bail 1555 * out 1556 */ 1557 do_migrate_range(pfn, end_pfn); 1558 } 1559 } while (!ret); 1560 1561 if (ret != -ENOENT) { 1562 reason = "unmovable page"; 1563 goto failed_removal_isolated; 1564 } 1565 1566 /* 1567 * Dissolve free hugepages in the memory block before doing 1568 * offlining actually in order to make hugetlbfs's object 1569 * counting consistent. 1570 */ 1571 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1572 if (ret) { 1573 reason = "failure to dissolve huge pages"; 1574 goto failed_removal_isolated; 1575 } 1576 1577 /* 1578 * per-cpu pages are drained in start_isolate_page_range, but if 1579 * there are still pages that are not free, make sure that we 1580 * drain again, because when we isolated range we might 1581 * have raced with another thread that was adding pages to pcp 1582 * list. 1583 * 1584 * Forward progress should be still guaranteed because 1585 * pages on the pcp list can only belong to MOVABLE_ZONE 1586 * because has_unmovable_pages explicitly checks for 1587 * PageBuddy on freed pages on other zones. 1588 */ 1589 ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); 1590 if (ret) 1591 drain_all_pages(zone); 1592 } while (ret); 1593 1594 /* Mark all sections offline and remove free pages from the buddy. */ 1595 __offline_isolated_pages(start_pfn, end_pfn); 1596 pr_info("Offlined Pages %ld\n", nr_pages); 1597 1598 /* 1599 * The memory sections are marked offline, and the pageblock flags 1600 * effectively stale; nobody should be touching them. Fixup the number 1601 * of isolated pageblocks, memory onlining will properly revert this. 1602 */ 1603 spin_lock_irqsave(&zone->lock, flags); 1604 zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; 1605 spin_unlock_irqrestore(&zone->lock, flags); 1606 1607 /* removal success */ 1608 adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); 1609 zone->present_pages -= nr_pages; 1610 1611 pgdat_resize_lock(zone->zone_pgdat, &flags); 1612 zone->zone_pgdat->node_present_pages -= nr_pages; 1613 pgdat_resize_unlock(zone->zone_pgdat, &flags); 1614 1615 init_per_zone_wmark_min(); 1616 1617 if (!populated_zone(zone)) { 1618 zone_pcp_reset(zone); 1619 build_all_zonelists(NULL); 1620 } else 1621 zone_pcp_update(zone); 1622 1623 node_states_clear_node(node, &arg); 1624 if (arg.status_change_nid >= 0) { 1625 kswapd_stop(node); 1626 kcompactd_stop(node); 1627 } 1628 1629 writeback_set_ratelimit(); 1630 1631 memory_notify(MEM_OFFLINE, &arg); 1632 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1633 mem_hotplug_done(); 1634 return 0; 1635 1636 failed_removal_isolated: 1637 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1638 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1639 failed_removal: 1640 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1641 (unsigned long long) start_pfn << PAGE_SHIFT, 1642 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1643 reason); 1644 /* pushback to free area */ 1645 mem_hotplug_done(); 1646 return ret; 1647 } 1648 1649 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1650 { 1651 int ret = !is_memblock_offlined(mem); 1652 1653 if (unlikely(ret)) { 1654 phys_addr_t beginpa, endpa; 1655 1656 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1657 endpa = beginpa + memory_block_size_bytes() - 1; 1658 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1659 &beginpa, &endpa); 1660 1661 return -EBUSY; 1662 } 1663 return 0; 1664 } 1665 1666 static int check_cpu_on_node(pg_data_t *pgdat) 1667 { 1668 int cpu; 1669 1670 for_each_present_cpu(cpu) { 1671 if (cpu_to_node(cpu) == pgdat->node_id) 1672 /* 1673 * the cpu on this node isn't removed, and we can't 1674 * offline this node. 1675 */ 1676 return -EBUSY; 1677 } 1678 1679 return 0; 1680 } 1681 1682 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 1683 { 1684 int nid = *(int *)arg; 1685 1686 /* 1687 * If a memory block belongs to multiple nodes, the stored nid is not 1688 * reliable. However, such blocks are always online (e.g., cannot get 1689 * offlined) and, therefore, are still spanned by the node. 1690 */ 1691 return mem->nid == nid ? -EEXIST : 0; 1692 } 1693 1694 /** 1695 * try_offline_node 1696 * @nid: the node ID 1697 * 1698 * Offline a node if all memory sections and cpus of the node are removed. 1699 * 1700 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1701 * and online/offline operations before this call. 1702 */ 1703 void try_offline_node(int nid) 1704 { 1705 pg_data_t *pgdat = NODE_DATA(nid); 1706 int rc; 1707 1708 /* 1709 * If the node still spans pages (especially ZONE_DEVICE), don't 1710 * offline it. A node spans memory after move_pfn_range_to_zone(), 1711 * e.g., after the memory block was onlined. 1712 */ 1713 if (pgdat->node_spanned_pages) 1714 return; 1715 1716 /* 1717 * Especially offline memory blocks might not be spanned by the 1718 * node. They will get spanned by the node once they get onlined. 1719 * However, they link to the node in sysfs and can get onlined later. 1720 */ 1721 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 1722 if (rc) 1723 return; 1724 1725 if (check_cpu_on_node(pgdat)) 1726 return; 1727 1728 /* 1729 * all memory/cpu of this node are removed, we can offline this 1730 * node now. 1731 */ 1732 node_set_offline(nid); 1733 unregister_one_node(nid); 1734 } 1735 EXPORT_SYMBOL(try_offline_node); 1736 1737 static int __ref try_remove_memory(int nid, u64 start, u64 size) 1738 { 1739 int rc = 0; 1740 1741 BUG_ON(check_hotplug_memory_range(start, size)); 1742 1743 /* 1744 * All memory blocks must be offlined before removing memory. Check 1745 * whether all memory blocks in question are offline and return error 1746 * if this is not the case. 1747 */ 1748 rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); 1749 if (rc) 1750 return rc; 1751 1752 /* remove memmap entry */ 1753 firmware_map_remove(start, start + size, "System RAM"); 1754 1755 /* 1756 * Memory block device removal under the device_hotplug_lock is 1757 * a barrier against racing online attempts. 1758 */ 1759 remove_memory_block_devices(start, size); 1760 1761 mem_hotplug_begin(); 1762 1763 arch_remove_memory(nid, start, size, NULL); 1764 1765 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 1766 memblock_free(start, size); 1767 memblock_remove(start, size); 1768 } 1769 1770 release_mem_region_adjustable(start, size); 1771 1772 try_offline_node(nid); 1773 1774 mem_hotplug_done(); 1775 return 0; 1776 } 1777 1778 /** 1779 * remove_memory 1780 * @nid: the node ID 1781 * @start: physical address of the region to remove 1782 * @size: size of the region to remove 1783 * 1784 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1785 * and online/offline operations before this call, as required by 1786 * try_offline_node(). 1787 */ 1788 void __remove_memory(int nid, u64 start, u64 size) 1789 { 1790 1791 /* 1792 * trigger BUG() if some memory is not offlined prior to calling this 1793 * function 1794 */ 1795 if (try_remove_memory(nid, start, size)) 1796 BUG(); 1797 } 1798 1799 /* 1800 * Remove memory if every memory block is offline, otherwise return -EBUSY is 1801 * some memory is not offline 1802 */ 1803 int remove_memory(int nid, u64 start, u64 size) 1804 { 1805 int rc; 1806 1807 lock_device_hotplug(); 1808 rc = try_remove_memory(nid, start, size); 1809 unlock_device_hotplug(); 1810 1811 return rc; 1812 } 1813 EXPORT_SYMBOL_GPL(remove_memory); 1814 1815 /* 1816 * Try to offline and remove a memory block. Might take a long time to 1817 * finish in case memory is still in use. Primarily useful for memory devices 1818 * that logically unplugged all memory (so it's no longer in use) and want to 1819 * offline + remove the memory block. 1820 */ 1821 int offline_and_remove_memory(int nid, u64 start, u64 size) 1822 { 1823 struct memory_block *mem; 1824 int rc = -EINVAL; 1825 1826 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 1827 size != memory_block_size_bytes()) 1828 return rc; 1829 1830 lock_device_hotplug(); 1831 mem = find_memory_block(__pfn_to_section(PFN_DOWN(start))); 1832 if (mem) 1833 rc = device_offline(&mem->dev); 1834 /* Ignore if the device is already offline. */ 1835 if (rc > 0) 1836 rc = 0; 1837 1838 /* 1839 * In case we succeeded to offline the memory block, remove it. 1840 * This cannot fail as it cannot get onlined in the meantime. 1841 */ 1842 if (!rc) { 1843 rc = try_remove_memory(nid, start, size); 1844 WARN_ON_ONCE(rc); 1845 } 1846 unlock_device_hotplug(); 1847 1848 return rc; 1849 } 1850 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 1851 #endif /* CONFIG_MEMORY_HOTREMOVE */ 1852