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 /* 47 * memory_hotplug.memmap_on_memory parameter 48 */ 49 static bool memmap_on_memory __ro_after_init; 50 #ifdef CONFIG_MHP_MEMMAP_ON_MEMORY 51 module_param(memmap_on_memory, bool, 0444); 52 MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug"); 53 #endif 54 55 /* 56 * online_page_callback contains pointer to current page onlining function. 57 * Initially it is generic_online_page(). If it is required it could be 58 * changed by calling set_online_page_callback() for callback registration 59 * and restore_online_page_callback() for generic callback restore. 60 */ 61 62 static online_page_callback_t online_page_callback = generic_online_page; 63 static DEFINE_MUTEX(online_page_callback_lock); 64 65 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); 66 67 void get_online_mems(void) 68 { 69 percpu_down_read(&mem_hotplug_lock); 70 } 71 72 void put_online_mems(void) 73 { 74 percpu_up_read(&mem_hotplug_lock); 75 } 76 77 bool movable_node_enabled = false; 78 79 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE 80 int mhp_default_online_type = MMOP_OFFLINE; 81 #else 82 int mhp_default_online_type = MMOP_ONLINE; 83 #endif 84 85 static int __init setup_memhp_default_state(char *str) 86 { 87 const int online_type = mhp_online_type_from_str(str); 88 89 if (online_type >= 0) 90 mhp_default_online_type = online_type; 91 92 return 1; 93 } 94 __setup("memhp_default_state=", setup_memhp_default_state); 95 96 void mem_hotplug_begin(void) 97 { 98 cpus_read_lock(); 99 percpu_down_write(&mem_hotplug_lock); 100 } 101 102 void mem_hotplug_done(void) 103 { 104 percpu_up_write(&mem_hotplug_lock); 105 cpus_read_unlock(); 106 } 107 108 u64 max_mem_size = U64_MAX; 109 110 /* add this memory to iomem resource */ 111 static struct resource *register_memory_resource(u64 start, u64 size, 112 const char *resource_name) 113 { 114 struct resource *res; 115 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 116 117 if (strcmp(resource_name, "System RAM")) 118 flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; 119 120 if (!mhp_range_allowed(start, size, true)) 121 return ERR_PTR(-E2BIG); 122 123 /* 124 * Make sure value parsed from 'mem=' only restricts memory adding 125 * while booting, so that memory hotplug won't be impacted. Please 126 * refer to document of 'mem=' in kernel-parameters.txt for more 127 * details. 128 */ 129 if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) 130 return ERR_PTR(-E2BIG); 131 132 /* 133 * Request ownership of the new memory range. This might be 134 * a child of an existing resource that was present but 135 * not marked as busy. 136 */ 137 res = __request_region(&iomem_resource, start, size, 138 resource_name, flags); 139 140 if (!res) { 141 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", 142 start, start + size); 143 return ERR_PTR(-EEXIST); 144 } 145 return res; 146 } 147 148 static void release_memory_resource(struct resource *res) 149 { 150 if (!res) 151 return; 152 release_resource(res); 153 kfree(res); 154 } 155 156 #ifdef CONFIG_MEMORY_HOTPLUG_SPARSE 157 void get_page_bootmem(unsigned long info, struct page *page, 158 unsigned long type) 159 { 160 page->freelist = (void *)type; 161 SetPagePrivate(page); 162 set_page_private(page, info); 163 page_ref_inc(page); 164 } 165 166 void put_page_bootmem(struct page *page) 167 { 168 unsigned long type; 169 170 type = (unsigned long) page->freelist; 171 BUG_ON(type < MEMORY_HOTPLUG_MIN_BOOTMEM_TYPE || 172 type > MEMORY_HOTPLUG_MAX_BOOTMEM_TYPE); 173 174 if (page_ref_dec_return(page) == 1) { 175 page->freelist = NULL; 176 ClearPagePrivate(page); 177 set_page_private(page, 0); 178 INIT_LIST_HEAD(&page->lru); 179 free_reserved_page(page); 180 } 181 } 182 183 #ifdef CONFIG_HAVE_BOOTMEM_INFO_NODE 184 #ifndef CONFIG_SPARSEMEM_VMEMMAP 185 static void register_page_bootmem_info_section(unsigned long start_pfn) 186 { 187 unsigned long mapsize, section_nr, i; 188 struct mem_section *ms; 189 struct page *page, *memmap; 190 struct mem_section_usage *usage; 191 192 section_nr = pfn_to_section_nr(start_pfn); 193 ms = __nr_to_section(section_nr); 194 195 /* Get section's memmap address */ 196 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 197 198 /* 199 * Get page for the memmap's phys address 200 * XXX: need more consideration for sparse_vmemmap... 201 */ 202 page = virt_to_page(memmap); 203 mapsize = sizeof(struct page) * PAGES_PER_SECTION; 204 mapsize = PAGE_ALIGN(mapsize) >> PAGE_SHIFT; 205 206 /* remember memmap's page */ 207 for (i = 0; i < mapsize; i++, page++) 208 get_page_bootmem(section_nr, page, SECTION_INFO); 209 210 usage = ms->usage; 211 page = virt_to_page(usage); 212 213 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 214 215 for (i = 0; i < mapsize; i++, page++) 216 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 217 218 } 219 #else /* CONFIG_SPARSEMEM_VMEMMAP */ 220 static void register_page_bootmem_info_section(unsigned long start_pfn) 221 { 222 unsigned long mapsize, section_nr, i; 223 struct mem_section *ms; 224 struct page *page, *memmap; 225 struct mem_section_usage *usage; 226 227 section_nr = pfn_to_section_nr(start_pfn); 228 ms = __nr_to_section(section_nr); 229 230 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 231 232 register_page_bootmem_memmap(section_nr, memmap, PAGES_PER_SECTION); 233 234 usage = ms->usage; 235 page = virt_to_page(usage); 236 237 mapsize = PAGE_ALIGN(mem_section_usage_size()) >> PAGE_SHIFT; 238 239 for (i = 0; i < mapsize; i++, page++) 240 get_page_bootmem(section_nr, page, MIX_SECTION_INFO); 241 } 242 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 243 244 void __init register_page_bootmem_info_node(struct pglist_data *pgdat) 245 { 246 unsigned long i, pfn, end_pfn, nr_pages; 247 int node = pgdat->node_id; 248 struct page *page; 249 250 nr_pages = PAGE_ALIGN(sizeof(struct pglist_data)) >> PAGE_SHIFT; 251 page = virt_to_page(pgdat); 252 253 for (i = 0; i < nr_pages; i++, page++) 254 get_page_bootmem(node, page, NODE_INFO); 255 256 pfn = pgdat->node_start_pfn; 257 end_pfn = pgdat_end_pfn(pgdat); 258 259 /* register section info */ 260 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 261 /* 262 * Some platforms can assign the same pfn to multiple nodes - on 263 * node0 as well as nodeN. To avoid registering a pfn against 264 * multiple nodes we check that this pfn does not already 265 * reside in some other nodes. 266 */ 267 if (pfn_valid(pfn) && (early_pfn_to_nid(pfn) == node)) 268 register_page_bootmem_info_section(pfn); 269 } 270 } 271 #endif /* CONFIG_HAVE_BOOTMEM_INFO_NODE */ 272 273 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, 274 const char *reason) 275 { 276 /* 277 * Disallow all operations smaller than a sub-section and only 278 * allow operations smaller than a section for 279 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() 280 * enforces a larger memory_block_size_bytes() granularity for 281 * memory that will be marked online, so this check should only 282 * fire for direct arch_{add,remove}_memory() users outside of 283 * add_memory_resource(). 284 */ 285 unsigned long min_align; 286 287 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) 288 min_align = PAGES_PER_SUBSECTION; 289 else 290 min_align = PAGES_PER_SECTION; 291 if (!IS_ALIGNED(pfn, min_align) 292 || !IS_ALIGNED(nr_pages, min_align)) { 293 WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", 294 reason, pfn, pfn + nr_pages - 1); 295 return -EINVAL; 296 } 297 return 0; 298 } 299 300 /* 301 * Return page for the valid pfn only if the page is online. All pfn 302 * walkers which rely on the fully initialized page->flags and others 303 * should use this rather than pfn_valid && pfn_to_page 304 */ 305 struct page *pfn_to_online_page(unsigned long pfn) 306 { 307 unsigned long nr = pfn_to_section_nr(pfn); 308 struct dev_pagemap *pgmap; 309 struct mem_section *ms; 310 311 if (nr >= NR_MEM_SECTIONS) 312 return NULL; 313 314 ms = __nr_to_section(nr); 315 if (!online_section(ms)) 316 return NULL; 317 318 /* 319 * Save some code text when online_section() + 320 * pfn_section_valid() are sufficient. 321 */ 322 if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) 323 return NULL; 324 325 if (!pfn_section_valid(ms, pfn)) 326 return NULL; 327 328 if (!online_device_section(ms)) 329 return pfn_to_page(pfn); 330 331 /* 332 * Slowpath: when ZONE_DEVICE collides with 333 * ZONE_{NORMAL,MOVABLE} within the same section some pfns in 334 * the section may be 'offline' but 'valid'. Only 335 * get_dev_pagemap() can determine sub-section online status. 336 */ 337 pgmap = get_dev_pagemap(pfn, NULL); 338 put_dev_pagemap(pgmap); 339 340 /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ 341 if (pgmap) 342 return NULL; 343 344 return pfn_to_page(pfn); 345 } 346 EXPORT_SYMBOL_GPL(pfn_to_online_page); 347 348 /* 349 * Reasonably generic function for adding memory. It is 350 * expected that archs that support memory hotplug will 351 * call this function after deciding the zone to which to 352 * add the new pages. 353 */ 354 int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, 355 struct mhp_params *params) 356 { 357 const unsigned long end_pfn = pfn + nr_pages; 358 unsigned long cur_nr_pages; 359 int err; 360 struct vmem_altmap *altmap = params->altmap; 361 362 if (WARN_ON_ONCE(!params->pgprot.pgprot)) 363 return -EINVAL; 364 365 VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); 366 367 if (altmap) { 368 /* 369 * Validate altmap is within bounds of the total request 370 */ 371 if (altmap->base_pfn != pfn 372 || vmem_altmap_offset(altmap) > nr_pages) { 373 pr_warn_once("memory add fail, invalid altmap\n"); 374 return -EINVAL; 375 } 376 altmap->alloc = 0; 377 } 378 379 err = check_pfn_span(pfn, nr_pages, "add"); 380 if (err) 381 return err; 382 383 for (; pfn < end_pfn; pfn += cur_nr_pages) { 384 /* Select all remaining pages up to the next section boundary */ 385 cur_nr_pages = min(end_pfn - pfn, 386 SECTION_ALIGN_UP(pfn + 1) - pfn); 387 err = sparse_add_section(nid, pfn, cur_nr_pages, altmap); 388 if (err) 389 break; 390 cond_resched(); 391 } 392 vmemmap_populate_print_last(); 393 return err; 394 } 395 396 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 397 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 398 unsigned long start_pfn, 399 unsigned long end_pfn) 400 { 401 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 402 if (unlikely(!pfn_to_online_page(start_pfn))) 403 continue; 404 405 if (unlikely(pfn_to_nid(start_pfn) != nid)) 406 continue; 407 408 if (zone != page_zone(pfn_to_page(start_pfn))) 409 continue; 410 411 return start_pfn; 412 } 413 414 return 0; 415 } 416 417 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 418 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 419 unsigned long start_pfn, 420 unsigned long end_pfn) 421 { 422 unsigned long pfn; 423 424 /* pfn is the end pfn of a memory section. */ 425 pfn = end_pfn - 1; 426 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 427 if (unlikely(!pfn_to_online_page(pfn))) 428 continue; 429 430 if (unlikely(pfn_to_nid(pfn) != nid)) 431 continue; 432 433 if (zone != page_zone(pfn_to_page(pfn))) 434 continue; 435 436 return pfn; 437 } 438 439 return 0; 440 } 441 442 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 443 unsigned long end_pfn) 444 { 445 unsigned long pfn; 446 int nid = zone_to_nid(zone); 447 448 zone_span_writelock(zone); 449 if (zone->zone_start_pfn == start_pfn) { 450 /* 451 * If the section is smallest section in the zone, it need 452 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 453 * In this case, we find second smallest valid mem_section 454 * for shrinking zone. 455 */ 456 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 457 zone_end_pfn(zone)); 458 if (pfn) { 459 zone->spanned_pages = zone_end_pfn(zone) - pfn; 460 zone->zone_start_pfn = pfn; 461 } else { 462 zone->zone_start_pfn = 0; 463 zone->spanned_pages = 0; 464 } 465 } else if (zone_end_pfn(zone) == end_pfn) { 466 /* 467 * If the section is biggest section in the zone, it need 468 * shrink zone->spanned_pages. 469 * In this case, we find second biggest valid mem_section for 470 * shrinking zone. 471 */ 472 pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, 473 start_pfn); 474 if (pfn) 475 zone->spanned_pages = pfn - zone->zone_start_pfn + 1; 476 else { 477 zone->zone_start_pfn = 0; 478 zone->spanned_pages = 0; 479 } 480 } 481 zone_span_writeunlock(zone); 482 } 483 484 static void update_pgdat_span(struct pglist_data *pgdat) 485 { 486 unsigned long node_start_pfn = 0, node_end_pfn = 0; 487 struct zone *zone; 488 489 for (zone = pgdat->node_zones; 490 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 491 unsigned long end_pfn = zone_end_pfn(zone); 492 493 /* No need to lock the zones, they can't change. */ 494 if (!zone->spanned_pages) 495 continue; 496 if (!node_end_pfn) { 497 node_start_pfn = zone->zone_start_pfn; 498 node_end_pfn = end_pfn; 499 continue; 500 } 501 502 if (end_pfn > node_end_pfn) 503 node_end_pfn = end_pfn; 504 if (zone->zone_start_pfn < node_start_pfn) 505 node_start_pfn = zone->zone_start_pfn; 506 } 507 508 pgdat->node_start_pfn = node_start_pfn; 509 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 510 } 511 512 void __ref remove_pfn_range_from_zone(struct zone *zone, 513 unsigned long start_pfn, 514 unsigned long nr_pages) 515 { 516 const unsigned long end_pfn = start_pfn + nr_pages; 517 struct pglist_data *pgdat = zone->zone_pgdat; 518 unsigned long pfn, cur_nr_pages, flags; 519 520 /* Poison struct pages because they are now uninitialized again. */ 521 for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { 522 cond_resched(); 523 524 /* Select all remaining pages up to the next section boundary */ 525 cur_nr_pages = 526 min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); 527 page_init_poison(pfn_to_page(pfn), 528 sizeof(struct page) * cur_nr_pages); 529 } 530 531 #ifdef CONFIG_ZONE_DEVICE 532 /* 533 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 534 * we will not try to shrink the zones - which is okay as 535 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 536 */ 537 if (zone_idx(zone) == ZONE_DEVICE) 538 return; 539 #endif 540 541 clear_zone_contiguous(zone); 542 543 pgdat_resize_lock(zone->zone_pgdat, &flags); 544 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 545 update_pgdat_span(pgdat); 546 pgdat_resize_unlock(zone->zone_pgdat, &flags); 547 548 set_zone_contiguous(zone); 549 } 550 551 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 552 unsigned long map_offset, 553 struct vmem_altmap *altmap) 554 { 555 struct mem_section *ms = __pfn_to_section(pfn); 556 557 if (WARN_ON_ONCE(!valid_section(ms))) 558 return; 559 560 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 561 } 562 563 /** 564 * __remove_pages() - remove sections of pages 565 * @pfn: starting pageframe (must be aligned to start of a section) 566 * @nr_pages: number of pages to remove (must be multiple of section size) 567 * @altmap: alternative device page map or %NULL if default memmap is used 568 * 569 * Generic helper function to remove section mappings and sysfs entries 570 * for the section of the memory we are removing. Caller needs to make 571 * sure that pages are marked reserved and zones are adjust properly by 572 * calling offline_pages(). 573 */ 574 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 575 struct vmem_altmap *altmap) 576 { 577 const unsigned long end_pfn = pfn + nr_pages; 578 unsigned long cur_nr_pages; 579 unsigned long map_offset = 0; 580 581 map_offset = vmem_altmap_offset(altmap); 582 583 if (check_pfn_span(pfn, nr_pages, "remove")) 584 return; 585 586 for (; pfn < end_pfn; pfn += cur_nr_pages) { 587 cond_resched(); 588 /* Select all remaining pages up to the next section boundary */ 589 cur_nr_pages = min(end_pfn - pfn, 590 SECTION_ALIGN_UP(pfn + 1) - pfn); 591 __remove_section(pfn, cur_nr_pages, map_offset, altmap); 592 map_offset = 0; 593 } 594 } 595 596 int set_online_page_callback(online_page_callback_t callback) 597 { 598 int rc = -EINVAL; 599 600 get_online_mems(); 601 mutex_lock(&online_page_callback_lock); 602 603 if (online_page_callback == generic_online_page) { 604 online_page_callback = callback; 605 rc = 0; 606 } 607 608 mutex_unlock(&online_page_callback_lock); 609 put_online_mems(); 610 611 return rc; 612 } 613 EXPORT_SYMBOL_GPL(set_online_page_callback); 614 615 int restore_online_page_callback(online_page_callback_t callback) 616 { 617 int rc = -EINVAL; 618 619 get_online_mems(); 620 mutex_lock(&online_page_callback_lock); 621 622 if (online_page_callback == callback) { 623 online_page_callback = generic_online_page; 624 rc = 0; 625 } 626 627 mutex_unlock(&online_page_callback_lock); 628 put_online_mems(); 629 630 return rc; 631 } 632 EXPORT_SYMBOL_GPL(restore_online_page_callback); 633 634 void generic_online_page(struct page *page, unsigned int order) 635 { 636 /* 637 * Freeing the page with debug_pagealloc enabled will try to unmap it, 638 * so we should map it first. This is better than introducing a special 639 * case in page freeing fast path. 640 */ 641 debug_pagealloc_map_pages(page, 1 << order); 642 __free_pages_core(page, order); 643 totalram_pages_add(1UL << order); 644 #ifdef CONFIG_HIGHMEM 645 if (PageHighMem(page)) 646 totalhigh_pages_add(1UL << order); 647 #endif 648 } 649 EXPORT_SYMBOL_GPL(generic_online_page); 650 651 static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) 652 { 653 const unsigned long end_pfn = start_pfn + nr_pages; 654 unsigned long pfn; 655 656 /* 657 * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might 658 * decide to not expose all pages to the buddy (e.g., expose them 659 * later). We account all pages as being online and belonging to this 660 * zone ("present"). 661 * When using memmap_on_memory, the range might not be aligned to 662 * MAX_ORDER_NR_PAGES - 1, but pageblock aligned. __ffs() will detect 663 * this and the first chunk to online will be pageblock_nr_pages. 664 */ 665 for (pfn = start_pfn; pfn < end_pfn;) { 666 int order = min(MAX_ORDER - 1UL, __ffs(pfn)); 667 668 (*online_page_callback)(pfn_to_page(pfn), order); 669 pfn += (1UL << order); 670 } 671 672 /* mark all involved sections as online */ 673 online_mem_sections(start_pfn, end_pfn); 674 } 675 676 /* check which state of node_states will be changed when online memory */ 677 static void node_states_check_changes_online(unsigned long nr_pages, 678 struct zone *zone, struct memory_notify *arg) 679 { 680 int nid = zone_to_nid(zone); 681 682 arg->status_change_nid = NUMA_NO_NODE; 683 arg->status_change_nid_normal = NUMA_NO_NODE; 684 arg->status_change_nid_high = NUMA_NO_NODE; 685 686 if (!node_state(nid, N_MEMORY)) 687 arg->status_change_nid = nid; 688 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 689 arg->status_change_nid_normal = nid; 690 #ifdef CONFIG_HIGHMEM 691 if (zone_idx(zone) <= ZONE_HIGHMEM && !node_state(nid, N_HIGH_MEMORY)) 692 arg->status_change_nid_high = nid; 693 #endif 694 } 695 696 static void node_states_set_node(int node, struct memory_notify *arg) 697 { 698 if (arg->status_change_nid_normal >= 0) 699 node_set_state(node, N_NORMAL_MEMORY); 700 701 if (arg->status_change_nid_high >= 0) 702 node_set_state(node, N_HIGH_MEMORY); 703 704 if (arg->status_change_nid >= 0) 705 node_set_state(node, N_MEMORY); 706 } 707 708 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 709 unsigned long nr_pages) 710 { 711 unsigned long old_end_pfn = zone_end_pfn(zone); 712 713 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 714 zone->zone_start_pfn = start_pfn; 715 716 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 717 } 718 719 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 720 unsigned long nr_pages) 721 { 722 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 723 724 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 725 pgdat->node_start_pfn = start_pfn; 726 727 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 728 729 } 730 731 static void section_taint_zone_device(unsigned long pfn) 732 { 733 struct mem_section *ms = __pfn_to_section(pfn); 734 735 ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; 736 } 737 738 /* 739 * Associate the pfn range with the given zone, initializing the memmaps 740 * and resizing the pgdat/zone data to span the added pages. After this 741 * call, all affected pages are PG_reserved. 742 * 743 * All aligned pageblocks are initialized to the specified migratetype 744 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related 745 * zone stats (e.g., nr_isolate_pageblock) are touched. 746 */ 747 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 748 unsigned long nr_pages, 749 struct vmem_altmap *altmap, int migratetype) 750 { 751 struct pglist_data *pgdat = zone->zone_pgdat; 752 int nid = pgdat->node_id; 753 unsigned long flags; 754 755 clear_zone_contiguous(zone); 756 757 /* TODO Huh pgdat is irqsave while zone is not. It used to be like that before */ 758 pgdat_resize_lock(pgdat, &flags); 759 zone_span_writelock(zone); 760 if (zone_is_empty(zone)) 761 init_currently_empty_zone(zone, start_pfn, nr_pages); 762 resize_zone_range(zone, start_pfn, nr_pages); 763 zone_span_writeunlock(zone); 764 resize_pgdat_range(pgdat, start_pfn, nr_pages); 765 pgdat_resize_unlock(pgdat, &flags); 766 767 /* 768 * Subsection population requires care in pfn_to_online_page(). 769 * Set the taint to enable the slow path detection of 770 * ZONE_DEVICE pages in an otherwise ZONE_{NORMAL,MOVABLE} 771 * section. 772 */ 773 if (zone_is_zone_device(zone)) { 774 if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) 775 section_taint_zone_device(start_pfn); 776 if (!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)) 777 section_taint_zone_device(start_pfn + nr_pages); 778 } 779 780 /* 781 * TODO now we have a visible range of pages which are not associated 782 * with their zone properly. Not nice but set_pfnblock_flags_mask 783 * expects the zone spans the pfn range. All the pages in the range 784 * are reserved so nobody should be touching them so we should be safe 785 */ 786 memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, 787 MEMINIT_HOTPLUG, altmap, migratetype); 788 789 set_zone_contiguous(zone); 790 } 791 792 /* 793 * Returns a default kernel memory zone for the given pfn range. 794 * If no kernel zone covers this pfn range it will automatically go 795 * to the ZONE_NORMAL. 796 */ 797 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 798 unsigned long nr_pages) 799 { 800 struct pglist_data *pgdat = NODE_DATA(nid); 801 int zid; 802 803 for (zid = 0; zid <= ZONE_NORMAL; zid++) { 804 struct zone *zone = &pgdat->node_zones[zid]; 805 806 if (zone_intersects(zone, start_pfn, nr_pages)) 807 return zone; 808 } 809 810 return &pgdat->node_zones[ZONE_NORMAL]; 811 } 812 813 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 814 unsigned long nr_pages) 815 { 816 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 817 nr_pages); 818 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 819 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 820 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 821 822 /* 823 * We inherit the existing zone in a simple case where zones do not 824 * overlap in the given range 825 */ 826 if (in_kernel ^ in_movable) 827 return (in_kernel) ? kernel_zone : movable_zone; 828 829 /* 830 * If the range doesn't belong to any zone or two zones overlap in the 831 * given range then we use movable zone only if movable_node is 832 * enabled because we always online to a kernel zone by default. 833 */ 834 return movable_node_enabled ? movable_zone : kernel_zone; 835 } 836 837 struct zone *zone_for_pfn_range(int online_type, int nid, unsigned start_pfn, 838 unsigned long nr_pages) 839 { 840 if (online_type == MMOP_ONLINE_KERNEL) 841 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 842 843 if (online_type == MMOP_ONLINE_MOVABLE) 844 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 845 846 return default_zone_for_pfn(nid, start_pfn, nr_pages); 847 } 848 849 /* 850 * This function should only be called by memory_block_{online,offline}, 851 * and {online,offline}_pages. 852 */ 853 void adjust_present_page_count(struct zone *zone, long nr_pages) 854 { 855 unsigned long flags; 856 857 zone->present_pages += nr_pages; 858 pgdat_resize_lock(zone->zone_pgdat, &flags); 859 zone->zone_pgdat->node_present_pages += nr_pages; 860 pgdat_resize_unlock(zone->zone_pgdat, &flags); 861 } 862 863 int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, 864 struct zone *zone) 865 { 866 unsigned long end_pfn = pfn + nr_pages; 867 int ret; 868 869 ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 870 if (ret) 871 return ret; 872 873 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); 874 875 /* 876 * It might be that the vmemmap_pages fully span sections. If that is 877 * the case, mark those sections online here as otherwise they will be 878 * left offline. 879 */ 880 if (nr_pages >= PAGES_PER_SECTION) 881 online_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 882 883 return ret; 884 } 885 886 void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages) 887 { 888 unsigned long end_pfn = pfn + nr_pages; 889 890 /* 891 * It might be that the vmemmap_pages fully span sections. If that is 892 * the case, mark those sections offline here as otherwise they will be 893 * left online. 894 */ 895 if (nr_pages >= PAGES_PER_SECTION) 896 offline_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 897 898 /* 899 * The pages associated with this vmemmap have been offlined, so 900 * we can reset its state here. 901 */ 902 remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, nr_pages); 903 kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 904 } 905 906 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, struct zone *zone) 907 { 908 unsigned long flags; 909 int need_zonelists_rebuild = 0; 910 const int nid = zone_to_nid(zone); 911 int ret; 912 struct memory_notify arg; 913 914 /* 915 * {on,off}lining is constrained to full memory sections (or more 916 * precisly to memory blocks from the user space POV). 917 * memmap_on_memory is an exception because it reserves initial part 918 * of the physical memory space for vmemmaps. That space is pageblock 919 * aligned. 920 */ 921 if (WARN_ON_ONCE(!nr_pages || 922 !IS_ALIGNED(pfn, pageblock_nr_pages) || 923 !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) 924 return -EINVAL; 925 926 mem_hotplug_begin(); 927 928 /* associate pfn range with the zone */ 929 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); 930 931 arg.start_pfn = pfn; 932 arg.nr_pages = nr_pages; 933 node_states_check_changes_online(nr_pages, zone, &arg); 934 935 ret = memory_notify(MEM_GOING_ONLINE, &arg); 936 ret = notifier_to_errno(ret); 937 if (ret) 938 goto failed_addition; 939 940 /* 941 * Fixup the number of isolated pageblocks before marking the sections 942 * onlining, such that undo_isolate_page_range() works correctly. 943 */ 944 spin_lock_irqsave(&zone->lock, flags); 945 zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; 946 spin_unlock_irqrestore(&zone->lock, flags); 947 948 /* 949 * If this zone is not populated, then it is not in zonelist. 950 * This means the page allocator ignores this zone. 951 * So, zonelist must be updated after online. 952 */ 953 if (!populated_zone(zone)) { 954 need_zonelists_rebuild = 1; 955 setup_zone_pageset(zone); 956 } 957 958 online_pages_range(pfn, nr_pages); 959 adjust_present_page_count(zone, nr_pages); 960 961 node_states_set_node(nid, &arg); 962 if (need_zonelists_rebuild) 963 build_all_zonelists(NULL); 964 zone_pcp_update(zone); 965 966 /* Basic onlining is complete, allow allocation of onlined pages. */ 967 undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); 968 969 /* 970 * Freshly onlined pages aren't shuffled (e.g., all pages are placed to 971 * the tail of the freelist when undoing isolation). Shuffle the whole 972 * zone to make sure the just onlined pages are properly distributed 973 * across the whole freelist - to create an initial shuffle. 974 */ 975 shuffle_zone(zone); 976 977 init_per_zone_wmark_min(); 978 979 kswapd_run(nid); 980 kcompactd_run(nid); 981 982 writeback_set_ratelimit(); 983 984 memory_notify(MEM_ONLINE, &arg); 985 mem_hotplug_done(); 986 return 0; 987 988 failed_addition: 989 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 990 (unsigned long long) pfn << PAGE_SHIFT, 991 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 992 memory_notify(MEM_CANCEL_ONLINE, &arg); 993 remove_pfn_range_from_zone(zone, pfn, nr_pages); 994 mem_hotplug_done(); 995 return ret; 996 } 997 #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ 998 999 static void reset_node_present_pages(pg_data_t *pgdat) 1000 { 1001 struct zone *z; 1002 1003 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 1004 z->present_pages = 0; 1005 1006 pgdat->node_present_pages = 0; 1007 } 1008 1009 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 1010 static pg_data_t __ref *hotadd_new_pgdat(int nid) 1011 { 1012 struct pglist_data *pgdat; 1013 1014 pgdat = NODE_DATA(nid); 1015 if (!pgdat) { 1016 pgdat = arch_alloc_nodedata(nid); 1017 if (!pgdat) 1018 return NULL; 1019 1020 pgdat->per_cpu_nodestats = 1021 alloc_percpu(struct per_cpu_nodestat); 1022 arch_refresh_nodedata(nid, pgdat); 1023 } else { 1024 int cpu; 1025 /* 1026 * Reset the nr_zones, order and highest_zoneidx before reuse. 1027 * Note that kswapd will init kswapd_highest_zoneidx properly 1028 * when it starts in the near future. 1029 */ 1030 pgdat->nr_zones = 0; 1031 pgdat->kswapd_order = 0; 1032 pgdat->kswapd_highest_zoneidx = 0; 1033 for_each_online_cpu(cpu) { 1034 struct per_cpu_nodestat *p; 1035 1036 p = per_cpu_ptr(pgdat->per_cpu_nodestats, cpu); 1037 memset(p, 0, sizeof(*p)); 1038 } 1039 } 1040 1041 /* we can use NODE_DATA(nid) from here */ 1042 pgdat->node_id = nid; 1043 pgdat->node_start_pfn = 0; 1044 1045 /* init node's zones as empty zones, we don't have any present pages.*/ 1046 free_area_init_core_hotplug(nid); 1047 1048 /* 1049 * The node we allocated has no zone fallback lists. For avoiding 1050 * to access not-initialized zonelist, build here. 1051 */ 1052 build_all_zonelists(pgdat); 1053 1054 /* 1055 * When memory is hot-added, all the memory is in offline state. So 1056 * clear all zones' present_pages because they will be updated in 1057 * online_pages() and offline_pages(). 1058 */ 1059 reset_node_managed_pages(pgdat); 1060 reset_node_present_pages(pgdat); 1061 1062 return pgdat; 1063 } 1064 1065 static void rollback_node_hotadd(int nid) 1066 { 1067 pg_data_t *pgdat = NODE_DATA(nid); 1068 1069 arch_refresh_nodedata(nid, NULL); 1070 free_percpu(pgdat->per_cpu_nodestats); 1071 arch_free_nodedata(pgdat); 1072 } 1073 1074 1075 /** 1076 * try_online_node - online a node if offlined 1077 * @nid: the node ID 1078 * @set_node_online: Whether we want to online the node 1079 * called by cpu_up() to online a node without onlined memory. 1080 * 1081 * Returns: 1082 * 1 -> a new node has been allocated 1083 * 0 -> the node is already online 1084 * -ENOMEM -> the node could not be allocated 1085 */ 1086 static int __try_online_node(int nid, bool set_node_online) 1087 { 1088 pg_data_t *pgdat; 1089 int ret = 1; 1090 1091 if (node_online(nid)) 1092 return 0; 1093 1094 pgdat = hotadd_new_pgdat(nid); 1095 if (!pgdat) { 1096 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 1097 ret = -ENOMEM; 1098 goto out; 1099 } 1100 1101 if (set_node_online) { 1102 node_set_online(nid); 1103 ret = register_one_node(nid); 1104 BUG_ON(ret); 1105 } 1106 out: 1107 return ret; 1108 } 1109 1110 /* 1111 * Users of this function always want to online/register the node 1112 */ 1113 int try_online_node(int nid) 1114 { 1115 int ret; 1116 1117 mem_hotplug_begin(); 1118 ret = __try_online_node(nid, true); 1119 mem_hotplug_done(); 1120 return ret; 1121 } 1122 1123 static int check_hotplug_memory_range(u64 start, u64 size) 1124 { 1125 /* memory range must be block size aligned */ 1126 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1127 !IS_ALIGNED(size, memory_block_size_bytes())) { 1128 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1129 memory_block_size_bytes(), start, size); 1130 return -EINVAL; 1131 } 1132 1133 return 0; 1134 } 1135 1136 static int online_memory_block(struct memory_block *mem, void *arg) 1137 { 1138 mem->online_type = mhp_default_online_type; 1139 return device_online(&mem->dev); 1140 } 1141 1142 bool mhp_supports_memmap_on_memory(unsigned long size) 1143 { 1144 unsigned long nr_vmemmap_pages = size / PAGE_SIZE; 1145 unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); 1146 unsigned long remaining_size = size - vmemmap_size; 1147 1148 /* 1149 * Besides having arch support and the feature enabled at runtime, we 1150 * need a few more assumptions to hold true: 1151 * 1152 * a) We span a single memory block: memory onlining/offlinin;g happens 1153 * in memory block granularity. We don't want the vmemmap of online 1154 * memory blocks to reside on offline memory blocks. In the future, 1155 * we might want to support variable-sized memory blocks to make the 1156 * feature more versatile. 1157 * 1158 * b) The vmemmap pages span complete PMDs: We don't want vmemmap code 1159 * to populate memory from the altmap for unrelated parts (i.e., 1160 * other memory blocks) 1161 * 1162 * c) The vmemmap pages (and thereby the pages that will be exposed to 1163 * the buddy) have to cover full pageblocks: memory onlining/offlining 1164 * code requires applicable ranges to be page-aligned, for example, to 1165 * set the migratetypes properly. 1166 * 1167 * TODO: Although we have a check here to make sure that vmemmap pages 1168 * fully populate a PMD, it is not the right place to check for 1169 * this. A much better solution involves improving vmemmap code 1170 * to fallback to base pages when trying to populate vmemmap using 1171 * altmap as an alternative source of memory, and we do not exactly 1172 * populate a single PMD. 1173 */ 1174 return memmap_on_memory && 1175 IS_ENABLED(CONFIG_MHP_MEMMAP_ON_MEMORY) && 1176 size == memory_block_size_bytes() && 1177 IS_ALIGNED(vmemmap_size, PMD_SIZE) && 1178 IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); 1179 } 1180 1181 /* 1182 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1183 * and online/offline operations (triggered e.g. by sysfs). 1184 * 1185 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1186 */ 1187 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) 1188 { 1189 struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; 1190 struct vmem_altmap mhp_altmap = {}; 1191 u64 start, size; 1192 bool new_node = false; 1193 int ret; 1194 1195 start = res->start; 1196 size = resource_size(res); 1197 1198 ret = check_hotplug_memory_range(start, size); 1199 if (ret) 1200 return ret; 1201 1202 if (!node_possible(nid)) { 1203 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1204 return -EINVAL; 1205 } 1206 1207 mem_hotplug_begin(); 1208 1209 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1210 memblock_add_node(start, size, nid); 1211 1212 ret = __try_online_node(nid, false); 1213 if (ret < 0) 1214 goto error; 1215 new_node = ret; 1216 1217 /* 1218 * Self hosted memmap array 1219 */ 1220 if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { 1221 if (!mhp_supports_memmap_on_memory(size)) { 1222 ret = -EINVAL; 1223 goto error; 1224 } 1225 mhp_altmap.free = PHYS_PFN(size); 1226 mhp_altmap.base_pfn = PHYS_PFN(start); 1227 params.altmap = &mhp_altmap; 1228 } 1229 1230 /* call arch's memory hotadd */ 1231 ret = arch_add_memory(nid, start, size, ¶ms); 1232 if (ret < 0) 1233 goto error; 1234 1235 /* create memory block devices after memory was added */ 1236 ret = create_memory_block_devices(start, size, mhp_altmap.alloc); 1237 if (ret) { 1238 arch_remove_memory(nid, start, size, NULL); 1239 goto error; 1240 } 1241 1242 if (new_node) { 1243 /* If sysfs file of new node can't be created, cpu on the node 1244 * can't be hot-added. There is no rollback way now. 1245 * So, check by BUG_ON() to catch it reluctantly.. 1246 * We online node here. We can't roll back from here. 1247 */ 1248 node_set_online(nid); 1249 ret = __register_one_node(nid); 1250 BUG_ON(ret); 1251 } 1252 1253 /* link memory sections under this node.*/ 1254 link_mem_sections(nid, PFN_DOWN(start), PFN_UP(start + size - 1), 1255 MEMINIT_HOTPLUG); 1256 1257 /* create new memmap entry */ 1258 if (!strcmp(res->name, "System RAM")) 1259 firmware_map_add_hotplug(start, start + size, "System RAM"); 1260 1261 /* device_online() will take the lock when calling online_pages() */ 1262 mem_hotplug_done(); 1263 1264 /* 1265 * In case we're allowed to merge the resource, flag it and trigger 1266 * merging now that adding succeeded. 1267 */ 1268 if (mhp_flags & MHP_MERGE_RESOURCE) 1269 merge_system_ram_resource(res); 1270 1271 /* online pages if requested */ 1272 if (mhp_default_online_type != MMOP_OFFLINE) 1273 walk_memory_blocks(start, size, NULL, online_memory_block); 1274 1275 return ret; 1276 error: 1277 /* rollback pgdat allocation and others */ 1278 if (new_node) 1279 rollback_node_hotadd(nid); 1280 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1281 memblock_remove(start, size); 1282 mem_hotplug_done(); 1283 return ret; 1284 } 1285 1286 /* requires device_hotplug_lock, see add_memory_resource() */ 1287 int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1288 { 1289 struct resource *res; 1290 int ret; 1291 1292 res = register_memory_resource(start, size, "System RAM"); 1293 if (IS_ERR(res)) 1294 return PTR_ERR(res); 1295 1296 ret = add_memory_resource(nid, res, mhp_flags); 1297 if (ret < 0) 1298 release_memory_resource(res); 1299 return ret; 1300 } 1301 1302 int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1303 { 1304 int rc; 1305 1306 lock_device_hotplug(); 1307 rc = __add_memory(nid, start, size, mhp_flags); 1308 unlock_device_hotplug(); 1309 1310 return rc; 1311 } 1312 EXPORT_SYMBOL_GPL(add_memory); 1313 1314 /* 1315 * Add special, driver-managed memory to the system as system RAM. Such 1316 * memory is not exposed via the raw firmware-provided memmap as system 1317 * RAM, instead, it is detected and added by a driver - during cold boot, 1318 * after a reboot, and after kexec. 1319 * 1320 * Reasons why this memory should not be used for the initial memmap of a 1321 * kexec kernel or for placing kexec images: 1322 * - The booting kernel is in charge of determining how this memory will be 1323 * used (e.g., use persistent memory as system RAM) 1324 * - Coordination with a hypervisor is required before this memory 1325 * can be used (e.g., inaccessible parts). 1326 * 1327 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1328 * memory map") are created. Also, the created memory resource is flagged 1329 * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case 1330 * this memory as well (esp., not place kexec images onto it). 1331 * 1332 * The resource_name (visible via /proc/iomem) has to have the format 1333 * "System RAM ($DRIVER)". 1334 */ 1335 int add_memory_driver_managed(int nid, u64 start, u64 size, 1336 const char *resource_name, mhp_t mhp_flags) 1337 { 1338 struct resource *res; 1339 int rc; 1340 1341 if (!resource_name || 1342 strstr(resource_name, "System RAM (") != resource_name || 1343 resource_name[strlen(resource_name) - 1] != ')') 1344 return -EINVAL; 1345 1346 lock_device_hotplug(); 1347 1348 res = register_memory_resource(start, size, resource_name); 1349 if (IS_ERR(res)) { 1350 rc = PTR_ERR(res); 1351 goto out_unlock; 1352 } 1353 1354 rc = add_memory_resource(nid, res, mhp_flags); 1355 if (rc < 0) 1356 release_memory_resource(res); 1357 1358 out_unlock: 1359 unlock_device_hotplug(); 1360 return rc; 1361 } 1362 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1363 1364 /* 1365 * Platforms should define arch_get_mappable_range() that provides 1366 * maximum possible addressable physical memory range for which the 1367 * linear mapping could be created. The platform returned address 1368 * range must adhere to these following semantics. 1369 * 1370 * - range.start <= range.end 1371 * - Range includes both end points [range.start..range.end] 1372 * 1373 * There is also a fallback definition provided here, allowing the 1374 * entire possible physical address range in case any platform does 1375 * not define arch_get_mappable_range(). 1376 */ 1377 struct range __weak arch_get_mappable_range(void) 1378 { 1379 struct range mhp_range = { 1380 .start = 0UL, 1381 .end = -1ULL, 1382 }; 1383 return mhp_range; 1384 } 1385 1386 struct range mhp_get_pluggable_range(bool need_mapping) 1387 { 1388 const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; 1389 struct range mhp_range; 1390 1391 if (need_mapping) { 1392 mhp_range = arch_get_mappable_range(); 1393 if (mhp_range.start > max_phys) { 1394 mhp_range.start = 0; 1395 mhp_range.end = 0; 1396 } 1397 mhp_range.end = min_t(u64, mhp_range.end, max_phys); 1398 } else { 1399 mhp_range.start = 0; 1400 mhp_range.end = max_phys; 1401 } 1402 return mhp_range; 1403 } 1404 EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); 1405 1406 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) 1407 { 1408 struct range mhp_range = mhp_get_pluggable_range(need_mapping); 1409 u64 end = start + size; 1410 1411 if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) 1412 return true; 1413 1414 pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", 1415 start, end, mhp_range.start, mhp_range.end); 1416 return false; 1417 } 1418 1419 #ifdef CONFIG_MEMORY_HOTREMOVE 1420 /* 1421 * Confirm all pages in a range [start, end) belong to the same zone (skipping 1422 * memory holes). When true, return the zone. 1423 */ 1424 struct zone *test_pages_in_a_zone(unsigned long start_pfn, 1425 unsigned long end_pfn) 1426 { 1427 unsigned long pfn, sec_end_pfn; 1428 struct zone *zone = NULL; 1429 struct page *page; 1430 int i; 1431 for (pfn = start_pfn, sec_end_pfn = SECTION_ALIGN_UP(start_pfn + 1); 1432 pfn < end_pfn; 1433 pfn = sec_end_pfn, sec_end_pfn += PAGES_PER_SECTION) { 1434 /* Make sure the memory section is present first */ 1435 if (!present_section_nr(pfn_to_section_nr(pfn))) 1436 continue; 1437 for (; pfn < sec_end_pfn && pfn < end_pfn; 1438 pfn += MAX_ORDER_NR_PAGES) { 1439 i = 0; 1440 /* This is just a CONFIG_HOLES_IN_ZONE check.*/ 1441 while ((i < MAX_ORDER_NR_PAGES) && 1442 !pfn_valid_within(pfn + i)) 1443 i++; 1444 if (i == MAX_ORDER_NR_PAGES || pfn + i >= end_pfn) 1445 continue; 1446 /* Check if we got outside of the zone */ 1447 if (zone && !zone_spans_pfn(zone, pfn + i)) 1448 return NULL; 1449 page = pfn_to_page(pfn + i); 1450 if (zone && page_zone(page) != zone) 1451 return NULL; 1452 zone = page_zone(page); 1453 } 1454 } 1455 1456 return zone; 1457 } 1458 1459 /* 1460 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1461 * non-lru movable pages and hugepages). Will skip over most unmovable 1462 * pages (esp., pages that can be skipped when offlining), but bail out on 1463 * definitely unmovable pages. 1464 * 1465 * Returns: 1466 * 0 in case a movable page is found and movable_pfn was updated. 1467 * -ENOENT in case no movable page was found. 1468 * -EBUSY in case a definitely unmovable page was found. 1469 */ 1470 static int scan_movable_pages(unsigned long start, unsigned long end, 1471 unsigned long *movable_pfn) 1472 { 1473 unsigned long pfn; 1474 1475 for (pfn = start; pfn < end; pfn++) { 1476 struct page *page, *head; 1477 unsigned long skip; 1478 1479 if (!pfn_valid(pfn)) 1480 continue; 1481 page = pfn_to_page(pfn); 1482 if (PageLRU(page)) 1483 goto found; 1484 if (__PageMovable(page)) 1485 goto found; 1486 1487 /* 1488 * PageOffline() pages that are not marked __PageMovable() and 1489 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1490 * definitely unmovable. If their reference count would be 0, 1491 * they could at least be skipped when offlining memory. 1492 */ 1493 if (PageOffline(page) && page_count(page)) 1494 return -EBUSY; 1495 1496 if (!PageHuge(page)) 1497 continue; 1498 head = compound_head(page); 1499 /* 1500 * This test is racy as we hold no reference or lock. The 1501 * hugetlb page could have been free'ed and head is no longer 1502 * a hugetlb page before the following check. In such unlikely 1503 * cases false positives and negatives are possible. Calling 1504 * code must deal with these scenarios. 1505 */ 1506 if (HPageMigratable(head)) 1507 goto found; 1508 skip = compound_nr(head) - (page - head); 1509 pfn += skip - 1; 1510 } 1511 return -ENOENT; 1512 found: 1513 *movable_pfn = pfn; 1514 return 0; 1515 } 1516 1517 static int 1518 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1519 { 1520 unsigned long pfn; 1521 struct page *page, *head; 1522 int ret = 0; 1523 LIST_HEAD(source); 1524 1525 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1526 if (!pfn_valid(pfn)) 1527 continue; 1528 page = pfn_to_page(pfn); 1529 head = compound_head(page); 1530 1531 if (PageHuge(page)) { 1532 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1533 isolate_huge_page(head, &source); 1534 continue; 1535 } else if (PageTransHuge(page)) 1536 pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; 1537 1538 /* 1539 * HWPoison pages have elevated reference counts so the migration would 1540 * fail on them. It also doesn't make any sense to migrate them in the 1541 * first place. Still try to unmap such a page in case it is still mapped 1542 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1543 * the unmap as the catch all safety net). 1544 */ 1545 if (PageHWPoison(page)) { 1546 if (WARN_ON(PageLRU(page))) 1547 isolate_lru_page(page); 1548 if (page_mapped(page)) 1549 try_to_unmap(page, TTU_IGNORE_MLOCK); 1550 continue; 1551 } 1552 1553 if (!get_page_unless_zero(page)) 1554 continue; 1555 /* 1556 * We can skip free pages. And we can deal with pages on 1557 * LRU and non-lru movable pages. 1558 */ 1559 if (PageLRU(page)) 1560 ret = isolate_lru_page(page); 1561 else 1562 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1563 if (!ret) { /* Success */ 1564 list_add_tail(&page->lru, &source); 1565 if (!__PageMovable(page)) 1566 inc_node_page_state(page, NR_ISOLATED_ANON + 1567 page_is_file_lru(page)); 1568 1569 } else { 1570 pr_warn("failed to isolate pfn %lx\n", pfn); 1571 dump_page(page, "isolation failed"); 1572 } 1573 put_page(page); 1574 } 1575 if (!list_empty(&source)) { 1576 nodemask_t nmask = node_states[N_MEMORY]; 1577 struct migration_target_control mtc = { 1578 .nmask = &nmask, 1579 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, 1580 }; 1581 1582 /* 1583 * We have checked that migration range is on a single zone so 1584 * we can use the nid of the first page to all the others. 1585 */ 1586 mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); 1587 1588 /* 1589 * try to allocate from a different node but reuse this node 1590 * if there are no other online nodes to be used (e.g. we are 1591 * offlining a part of the only existing node) 1592 */ 1593 node_clear(mtc.nid, nmask); 1594 if (nodes_empty(nmask)) 1595 node_set(mtc.nid, nmask); 1596 ret = migrate_pages(&source, alloc_migration_target, NULL, 1597 (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG); 1598 if (ret) { 1599 list_for_each_entry(page, &source, lru) { 1600 pr_warn("migrating pfn %lx failed ret:%d ", 1601 page_to_pfn(page), ret); 1602 dump_page(page, "migration failure"); 1603 } 1604 putback_movable_pages(&source); 1605 } 1606 } 1607 1608 return ret; 1609 } 1610 1611 static int __init cmdline_parse_movable_node(char *p) 1612 { 1613 movable_node_enabled = true; 1614 return 0; 1615 } 1616 early_param("movable_node", cmdline_parse_movable_node); 1617 1618 /* check which state of node_states will be changed when offline memory */ 1619 static void node_states_check_changes_offline(unsigned long nr_pages, 1620 struct zone *zone, struct memory_notify *arg) 1621 { 1622 struct pglist_data *pgdat = zone->zone_pgdat; 1623 unsigned long present_pages = 0; 1624 enum zone_type zt; 1625 1626 arg->status_change_nid = NUMA_NO_NODE; 1627 arg->status_change_nid_normal = NUMA_NO_NODE; 1628 arg->status_change_nid_high = NUMA_NO_NODE; 1629 1630 /* 1631 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1632 * If the memory to be offline is within the range 1633 * [0..ZONE_NORMAL], and it is the last present memory there, 1634 * the zones in that range will become empty after the offlining, 1635 * thus we can determine that we need to clear the node from 1636 * node_states[N_NORMAL_MEMORY]. 1637 */ 1638 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1639 present_pages += pgdat->node_zones[zt].present_pages; 1640 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1641 arg->status_change_nid_normal = zone_to_nid(zone); 1642 1643 #ifdef CONFIG_HIGHMEM 1644 /* 1645 * node_states[N_HIGH_MEMORY] contains nodes which 1646 * have normal memory or high memory. 1647 * Here we add the present_pages belonging to ZONE_HIGHMEM. 1648 * If the zone is within the range of [0..ZONE_HIGHMEM), and 1649 * we determine that the zones in that range become empty, 1650 * we need to clear the node for N_HIGH_MEMORY. 1651 */ 1652 present_pages += pgdat->node_zones[ZONE_HIGHMEM].present_pages; 1653 if (zone_idx(zone) <= ZONE_HIGHMEM && nr_pages >= present_pages) 1654 arg->status_change_nid_high = zone_to_nid(zone); 1655 #endif 1656 1657 /* 1658 * We have accounted the pages from [0..ZONE_NORMAL), and 1659 * in case of CONFIG_HIGHMEM the pages from ZONE_HIGHMEM 1660 * as well. 1661 * Here we count the possible pages from ZONE_MOVABLE. 1662 * If after having accounted all the pages, we see that the nr_pages 1663 * to be offlined is over or equal to the accounted pages, 1664 * we know that the node will become empty, and so, we can clear 1665 * it for N_MEMORY as well. 1666 */ 1667 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1668 1669 if (nr_pages >= present_pages) 1670 arg->status_change_nid = zone_to_nid(zone); 1671 } 1672 1673 static void node_states_clear_node(int node, struct memory_notify *arg) 1674 { 1675 if (arg->status_change_nid_normal >= 0) 1676 node_clear_state(node, N_NORMAL_MEMORY); 1677 1678 if (arg->status_change_nid_high >= 0) 1679 node_clear_state(node, N_HIGH_MEMORY); 1680 1681 if (arg->status_change_nid >= 0) 1682 node_clear_state(node, N_MEMORY); 1683 } 1684 1685 static int count_system_ram_pages_cb(unsigned long start_pfn, 1686 unsigned long nr_pages, void *data) 1687 { 1688 unsigned long *nr_system_ram_pages = data; 1689 1690 *nr_system_ram_pages += nr_pages; 1691 return 0; 1692 } 1693 1694 int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages) 1695 { 1696 const unsigned long end_pfn = start_pfn + nr_pages; 1697 unsigned long pfn, system_ram_pages = 0; 1698 unsigned long flags; 1699 struct zone *zone; 1700 struct memory_notify arg; 1701 int ret, node; 1702 char *reason; 1703 1704 /* 1705 * {on,off}lining is constrained to full memory sections (or more 1706 * precisly to memory blocks from the user space POV). 1707 * memmap_on_memory is an exception because it reserves initial part 1708 * of the physical memory space for vmemmaps. That space is pageblock 1709 * aligned. 1710 */ 1711 if (WARN_ON_ONCE(!nr_pages || 1712 !IS_ALIGNED(start_pfn, pageblock_nr_pages) || 1713 !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) 1714 return -EINVAL; 1715 1716 mem_hotplug_begin(); 1717 1718 /* 1719 * Don't allow to offline memory blocks that contain holes. 1720 * Consequently, memory blocks with holes can never get onlined 1721 * via the hotplug path - online_pages() - as hotplugged memory has 1722 * no holes. This way, we e.g., don't have to worry about marking 1723 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1724 * avoid using walk_system_ram_range() later. 1725 */ 1726 walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, 1727 count_system_ram_pages_cb); 1728 if (system_ram_pages != nr_pages) { 1729 ret = -EINVAL; 1730 reason = "memory holes"; 1731 goto failed_removal; 1732 } 1733 1734 /* This makes hotplug much easier...and readable. 1735 we assume this for now. .*/ 1736 zone = test_pages_in_a_zone(start_pfn, end_pfn); 1737 if (!zone) { 1738 ret = -EINVAL; 1739 reason = "multizone range"; 1740 goto failed_removal; 1741 } 1742 node = zone_to_nid(zone); 1743 1744 /* 1745 * Disable pcplists so that page isolation cannot race with freeing 1746 * in a way that pages from isolated pageblock are left on pcplists. 1747 */ 1748 zone_pcp_disable(zone); 1749 lru_cache_disable(); 1750 1751 /* set above range as isolated */ 1752 ret = start_isolate_page_range(start_pfn, end_pfn, 1753 MIGRATE_MOVABLE, 1754 MEMORY_OFFLINE | REPORT_FAILURE); 1755 if (ret) { 1756 reason = "failure to isolate range"; 1757 goto failed_removal_pcplists_disabled; 1758 } 1759 1760 arg.start_pfn = start_pfn; 1761 arg.nr_pages = nr_pages; 1762 node_states_check_changes_offline(nr_pages, zone, &arg); 1763 1764 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1765 ret = notifier_to_errno(ret); 1766 if (ret) { 1767 reason = "notifier failure"; 1768 goto failed_removal_isolated; 1769 } 1770 1771 do { 1772 pfn = start_pfn; 1773 do { 1774 if (signal_pending(current)) { 1775 ret = -EINTR; 1776 reason = "signal backoff"; 1777 goto failed_removal_isolated; 1778 } 1779 1780 cond_resched(); 1781 1782 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1783 if (!ret) { 1784 /* 1785 * TODO: fatal migration failures should bail 1786 * out 1787 */ 1788 do_migrate_range(pfn, end_pfn); 1789 } 1790 } while (!ret); 1791 1792 if (ret != -ENOENT) { 1793 reason = "unmovable page"; 1794 goto failed_removal_isolated; 1795 } 1796 1797 /* 1798 * Dissolve free hugepages in the memory block before doing 1799 * offlining actually in order to make hugetlbfs's object 1800 * counting consistent. 1801 */ 1802 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1803 if (ret) { 1804 reason = "failure to dissolve huge pages"; 1805 goto failed_removal_isolated; 1806 } 1807 1808 ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); 1809 1810 } while (ret); 1811 1812 /* Mark all sections offline and remove free pages from the buddy. */ 1813 __offline_isolated_pages(start_pfn, end_pfn); 1814 pr_debug("Offlined Pages %ld\n", nr_pages); 1815 1816 /* 1817 * The memory sections are marked offline, and the pageblock flags 1818 * effectively stale; nobody should be touching them. Fixup the number 1819 * of isolated pageblocks, memory onlining will properly revert this. 1820 */ 1821 spin_lock_irqsave(&zone->lock, flags); 1822 zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; 1823 spin_unlock_irqrestore(&zone->lock, flags); 1824 1825 lru_cache_enable(); 1826 zone_pcp_enable(zone); 1827 1828 /* removal success */ 1829 adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); 1830 adjust_present_page_count(zone, -nr_pages); 1831 1832 init_per_zone_wmark_min(); 1833 1834 if (!populated_zone(zone)) { 1835 zone_pcp_reset(zone); 1836 build_all_zonelists(NULL); 1837 } else 1838 zone_pcp_update(zone); 1839 1840 node_states_clear_node(node, &arg); 1841 if (arg.status_change_nid >= 0) { 1842 kswapd_stop(node); 1843 kcompactd_stop(node); 1844 } 1845 1846 writeback_set_ratelimit(); 1847 1848 memory_notify(MEM_OFFLINE, &arg); 1849 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1850 mem_hotplug_done(); 1851 return 0; 1852 1853 failed_removal_isolated: 1854 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1855 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1856 failed_removal_pcplists_disabled: 1857 zone_pcp_enable(zone); 1858 failed_removal: 1859 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1860 (unsigned long long) start_pfn << PAGE_SHIFT, 1861 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1862 reason); 1863 /* pushback to free area */ 1864 mem_hotplug_done(); 1865 return ret; 1866 } 1867 1868 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1869 { 1870 int ret = !is_memblock_offlined(mem); 1871 1872 if (unlikely(ret)) { 1873 phys_addr_t beginpa, endpa; 1874 1875 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1876 endpa = beginpa + memory_block_size_bytes() - 1; 1877 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1878 &beginpa, &endpa); 1879 1880 return -EBUSY; 1881 } 1882 return 0; 1883 } 1884 1885 static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg) 1886 { 1887 /* 1888 * If not set, continue with the next block. 1889 */ 1890 return mem->nr_vmemmap_pages; 1891 } 1892 1893 static int check_cpu_on_node(pg_data_t *pgdat) 1894 { 1895 int cpu; 1896 1897 for_each_present_cpu(cpu) { 1898 if (cpu_to_node(cpu) == pgdat->node_id) 1899 /* 1900 * the cpu on this node isn't removed, and we can't 1901 * offline this node. 1902 */ 1903 return -EBUSY; 1904 } 1905 1906 return 0; 1907 } 1908 1909 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 1910 { 1911 int nid = *(int *)arg; 1912 1913 /* 1914 * If a memory block belongs to multiple nodes, the stored nid is not 1915 * reliable. However, such blocks are always online (e.g., cannot get 1916 * offlined) and, therefore, are still spanned by the node. 1917 */ 1918 return mem->nid == nid ? -EEXIST : 0; 1919 } 1920 1921 /** 1922 * try_offline_node 1923 * @nid: the node ID 1924 * 1925 * Offline a node if all memory sections and cpus of the node are removed. 1926 * 1927 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1928 * and online/offline operations before this call. 1929 */ 1930 void try_offline_node(int nid) 1931 { 1932 pg_data_t *pgdat = NODE_DATA(nid); 1933 int rc; 1934 1935 /* 1936 * If the node still spans pages (especially ZONE_DEVICE), don't 1937 * offline it. A node spans memory after move_pfn_range_to_zone(), 1938 * e.g., after the memory block was onlined. 1939 */ 1940 if (pgdat->node_spanned_pages) 1941 return; 1942 1943 /* 1944 * Especially offline memory blocks might not be spanned by the 1945 * node. They will get spanned by the node once they get onlined. 1946 * However, they link to the node in sysfs and can get onlined later. 1947 */ 1948 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 1949 if (rc) 1950 return; 1951 1952 if (check_cpu_on_node(pgdat)) 1953 return; 1954 1955 /* 1956 * all memory/cpu of this node are removed, we can offline this 1957 * node now. 1958 */ 1959 node_set_offline(nid); 1960 unregister_one_node(nid); 1961 } 1962 EXPORT_SYMBOL(try_offline_node); 1963 1964 static int __ref try_remove_memory(int nid, u64 start, u64 size) 1965 { 1966 int rc = 0; 1967 struct vmem_altmap mhp_altmap = {}; 1968 struct vmem_altmap *altmap = NULL; 1969 unsigned long nr_vmemmap_pages; 1970 1971 BUG_ON(check_hotplug_memory_range(start, size)); 1972 1973 /* 1974 * All memory blocks must be offlined before removing memory. Check 1975 * whether all memory blocks in question are offline and return error 1976 * if this is not the case. 1977 */ 1978 rc = walk_memory_blocks(start, size, NULL, check_memblock_offlined_cb); 1979 if (rc) 1980 return rc; 1981 1982 /* 1983 * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in 1984 * the same granularity it was added - a single memory block. 1985 */ 1986 if (memmap_on_memory) { 1987 nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, 1988 get_nr_vmemmap_pages_cb); 1989 if (nr_vmemmap_pages) { 1990 if (size != memory_block_size_bytes()) { 1991 pr_warn("Refuse to remove %#llx - %#llx," 1992 "wrong granularity\n", 1993 start, start + size); 1994 return -EINVAL; 1995 } 1996 1997 /* 1998 * Let remove_pmd_table->free_hugepage_table do the 1999 * right thing if we used vmem_altmap when hot-adding 2000 * the range. 2001 */ 2002 mhp_altmap.alloc = nr_vmemmap_pages; 2003 altmap = &mhp_altmap; 2004 } 2005 } 2006 2007 /* remove memmap entry */ 2008 firmware_map_remove(start, start + size, "System RAM"); 2009 2010 /* 2011 * Memory block device removal under the device_hotplug_lock is 2012 * a barrier against racing online attempts. 2013 */ 2014 remove_memory_block_devices(start, size); 2015 2016 mem_hotplug_begin(); 2017 2018 arch_remove_memory(nid, start, size, altmap); 2019 2020 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 2021 memblock_free(start, size); 2022 memblock_remove(start, size); 2023 } 2024 2025 release_mem_region_adjustable(start, size); 2026 2027 try_offline_node(nid); 2028 2029 mem_hotplug_done(); 2030 return 0; 2031 } 2032 2033 /** 2034 * remove_memory 2035 * @nid: the node ID 2036 * @start: physical address of the region to remove 2037 * @size: size of the region to remove 2038 * 2039 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2040 * and online/offline operations before this call, as required by 2041 * try_offline_node(). 2042 */ 2043 void __remove_memory(int nid, u64 start, u64 size) 2044 { 2045 2046 /* 2047 * trigger BUG() if some memory is not offlined prior to calling this 2048 * function 2049 */ 2050 if (try_remove_memory(nid, start, size)) 2051 BUG(); 2052 } 2053 2054 /* 2055 * Remove memory if every memory block is offline, otherwise return -EBUSY is 2056 * some memory is not offline 2057 */ 2058 int remove_memory(int nid, u64 start, u64 size) 2059 { 2060 int rc; 2061 2062 lock_device_hotplug(); 2063 rc = try_remove_memory(nid, start, size); 2064 unlock_device_hotplug(); 2065 2066 return rc; 2067 } 2068 EXPORT_SYMBOL_GPL(remove_memory); 2069 2070 static int try_offline_memory_block(struct memory_block *mem, void *arg) 2071 { 2072 uint8_t online_type = MMOP_ONLINE_KERNEL; 2073 uint8_t **online_types = arg; 2074 struct page *page; 2075 int rc; 2076 2077 /* 2078 * Sense the online_type via the zone of the memory block. Offlining 2079 * with multiple zones within one memory block will be rejected 2080 * by offlining code ... so we don't care about that. 2081 */ 2082 page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); 2083 if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) 2084 online_type = MMOP_ONLINE_MOVABLE; 2085 2086 rc = device_offline(&mem->dev); 2087 /* 2088 * Default is MMOP_OFFLINE - change it only if offlining succeeded, 2089 * so try_reonline_memory_block() can do the right thing. 2090 */ 2091 if (!rc) 2092 **online_types = online_type; 2093 2094 (*online_types)++; 2095 /* Ignore if already offline. */ 2096 return rc < 0 ? rc : 0; 2097 } 2098 2099 static int try_reonline_memory_block(struct memory_block *mem, void *arg) 2100 { 2101 uint8_t **online_types = arg; 2102 int rc; 2103 2104 if (**online_types != MMOP_OFFLINE) { 2105 mem->online_type = **online_types; 2106 rc = device_online(&mem->dev); 2107 if (rc < 0) 2108 pr_warn("%s: Failed to re-online memory: %d", 2109 __func__, rc); 2110 } 2111 2112 /* Continue processing all remaining memory blocks. */ 2113 (*online_types)++; 2114 return 0; 2115 } 2116 2117 /* 2118 * Try to offline and remove memory. Might take a long time to finish in case 2119 * memory is still in use. Primarily useful for memory devices that logically 2120 * unplugged all memory (so it's no longer in use) and want to offline + remove 2121 * that memory. 2122 */ 2123 int offline_and_remove_memory(int nid, u64 start, u64 size) 2124 { 2125 const unsigned long mb_count = size / memory_block_size_bytes(); 2126 uint8_t *online_types, *tmp; 2127 int rc; 2128 2129 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 2130 !IS_ALIGNED(size, memory_block_size_bytes()) || !size) 2131 return -EINVAL; 2132 2133 /* 2134 * We'll remember the old online type of each memory block, so we can 2135 * try to revert whatever we did when offlining one memory block fails 2136 * after offlining some others succeeded. 2137 */ 2138 online_types = kmalloc_array(mb_count, sizeof(*online_types), 2139 GFP_KERNEL); 2140 if (!online_types) 2141 return -ENOMEM; 2142 /* 2143 * Initialize all states to MMOP_OFFLINE, so when we abort processing in 2144 * try_offline_memory_block(), we'll skip all unprocessed blocks in 2145 * try_reonline_memory_block(). 2146 */ 2147 memset(online_types, MMOP_OFFLINE, mb_count); 2148 2149 lock_device_hotplug(); 2150 2151 tmp = online_types; 2152 rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); 2153 2154 /* 2155 * In case we succeeded to offline all memory, remove it. 2156 * This cannot fail as it cannot get onlined in the meantime. 2157 */ 2158 if (!rc) { 2159 rc = try_remove_memory(nid, start, size); 2160 if (rc) 2161 pr_err("%s: Failed to remove memory: %d", __func__, rc); 2162 } 2163 2164 /* 2165 * Rollback what we did. While memory onlining might theoretically fail 2166 * (nacked by a notifier), it barely ever happens. 2167 */ 2168 if (rc) { 2169 tmp = online_types; 2170 walk_memory_blocks(start, size, &tmp, 2171 try_reonline_memory_block); 2172 } 2173 unlock_device_hotplug(); 2174 2175 kfree(online_types); 2176 return rc; 2177 } 2178 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 2179 #endif /* CONFIG_MEMORY_HOTREMOVE */ 2180