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/vmalloc.h> 25 #include <linux/ioport.h> 26 #include <linux/delay.h> 27 #include <linux/migrate.h> 28 #include <linux/page-isolation.h> 29 #include <linux/pfn.h> 30 #include <linux/suspend.h> 31 #include <linux/mm_inline.h> 32 #include <linux/firmware-map.h> 33 #include <linux/stop_machine.h> 34 #include <linux/hugetlb.h> 35 #include <linux/memblock.h> 36 #include <linux/compaction.h> 37 #include <linux/rmap.h> 38 #include <linux/module.h> 39 40 #include <asm/tlbflush.h> 41 42 #include "internal.h" 43 #include "shuffle.h" 44 45 #ifdef CONFIG_MHP_MEMMAP_ON_MEMORY 46 /* 47 * memory_hotplug.memmap_on_memory parameter 48 */ 49 static bool memmap_on_memory __ro_after_init; 50 module_param(memmap_on_memory, bool, 0444); 51 MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug"); 52 53 static inline bool mhp_memmap_on_memory(void) 54 { 55 return memmap_on_memory; 56 } 57 #else 58 static inline bool mhp_memmap_on_memory(void) 59 { 60 return false; 61 } 62 #endif 63 64 enum { 65 ONLINE_POLICY_CONTIG_ZONES = 0, 66 ONLINE_POLICY_AUTO_MOVABLE, 67 }; 68 69 static const char * const online_policy_to_str[] = { 70 [ONLINE_POLICY_CONTIG_ZONES] = "contig-zones", 71 [ONLINE_POLICY_AUTO_MOVABLE] = "auto-movable", 72 }; 73 74 static int set_online_policy(const char *val, const struct kernel_param *kp) 75 { 76 int ret = sysfs_match_string(online_policy_to_str, val); 77 78 if (ret < 0) 79 return ret; 80 *((int *)kp->arg) = ret; 81 return 0; 82 } 83 84 static int get_online_policy(char *buffer, const struct kernel_param *kp) 85 { 86 return sprintf(buffer, "%s\n", online_policy_to_str[*((int *)kp->arg)]); 87 } 88 89 /* 90 * memory_hotplug.online_policy: configure online behavior when onlining without 91 * specifying a zone (MMOP_ONLINE) 92 * 93 * "contig-zones": keep zone contiguous 94 * "auto-movable": online memory to ZONE_MOVABLE if the configuration 95 * (auto_movable_ratio, auto_movable_numa_aware) allows for it 96 */ 97 static int online_policy __read_mostly = ONLINE_POLICY_CONTIG_ZONES; 98 static const struct kernel_param_ops online_policy_ops = { 99 .set = set_online_policy, 100 .get = get_online_policy, 101 }; 102 module_param_cb(online_policy, &online_policy_ops, &online_policy, 0644); 103 MODULE_PARM_DESC(online_policy, 104 "Set the online policy (\"contig-zones\", \"auto-movable\") " 105 "Default: \"contig-zones\""); 106 107 /* 108 * memory_hotplug.auto_movable_ratio: specify maximum MOVABLE:KERNEL ratio 109 * 110 * The ratio represent an upper limit and the kernel might decide to not 111 * online some memory to ZONE_MOVABLE -- e.g., because hotplugged KERNEL memory 112 * doesn't allow for more MOVABLE memory. 113 */ 114 static unsigned int auto_movable_ratio __read_mostly = 301; 115 module_param(auto_movable_ratio, uint, 0644); 116 MODULE_PARM_DESC(auto_movable_ratio, 117 "Set the maximum ratio of MOVABLE:KERNEL memory in the system " 118 "in percent for \"auto-movable\" online policy. Default: 301"); 119 120 /* 121 * memory_hotplug.auto_movable_numa_aware: consider numa node stats 122 */ 123 #ifdef CONFIG_NUMA 124 static bool auto_movable_numa_aware __read_mostly = true; 125 module_param(auto_movable_numa_aware, bool, 0644); 126 MODULE_PARM_DESC(auto_movable_numa_aware, 127 "Consider numa node stats in addition to global stats in " 128 "\"auto-movable\" online policy. Default: true"); 129 #endif /* CONFIG_NUMA */ 130 131 /* 132 * online_page_callback contains pointer to current page onlining function. 133 * Initially it is generic_online_page(). If it is required it could be 134 * changed by calling set_online_page_callback() for callback registration 135 * and restore_online_page_callback() for generic callback restore. 136 */ 137 138 static online_page_callback_t online_page_callback = generic_online_page; 139 static DEFINE_MUTEX(online_page_callback_lock); 140 141 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); 142 143 void get_online_mems(void) 144 { 145 percpu_down_read(&mem_hotplug_lock); 146 } 147 148 void put_online_mems(void) 149 { 150 percpu_up_read(&mem_hotplug_lock); 151 } 152 153 bool movable_node_enabled = false; 154 155 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE 156 int mhp_default_online_type = MMOP_OFFLINE; 157 #else 158 int mhp_default_online_type = MMOP_ONLINE; 159 #endif 160 161 static int __init setup_memhp_default_state(char *str) 162 { 163 const int online_type = mhp_online_type_from_str(str); 164 165 if (online_type >= 0) 166 mhp_default_online_type = online_type; 167 168 return 1; 169 } 170 __setup("memhp_default_state=", setup_memhp_default_state); 171 172 void mem_hotplug_begin(void) 173 { 174 cpus_read_lock(); 175 percpu_down_write(&mem_hotplug_lock); 176 } 177 178 void mem_hotplug_done(void) 179 { 180 percpu_up_write(&mem_hotplug_lock); 181 cpus_read_unlock(); 182 } 183 184 u64 max_mem_size = U64_MAX; 185 186 /* add this memory to iomem resource */ 187 static struct resource *register_memory_resource(u64 start, u64 size, 188 const char *resource_name) 189 { 190 struct resource *res; 191 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 192 193 if (strcmp(resource_name, "System RAM")) 194 flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; 195 196 if (!mhp_range_allowed(start, size, true)) 197 return ERR_PTR(-E2BIG); 198 199 /* 200 * Make sure value parsed from 'mem=' only restricts memory adding 201 * while booting, so that memory hotplug won't be impacted. Please 202 * refer to document of 'mem=' in kernel-parameters.txt for more 203 * details. 204 */ 205 if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) 206 return ERR_PTR(-E2BIG); 207 208 /* 209 * Request ownership of the new memory range. This might be 210 * a child of an existing resource that was present but 211 * not marked as busy. 212 */ 213 res = __request_region(&iomem_resource, start, size, 214 resource_name, flags); 215 216 if (!res) { 217 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", 218 start, start + size); 219 return ERR_PTR(-EEXIST); 220 } 221 return res; 222 } 223 224 static void release_memory_resource(struct resource *res) 225 { 226 if (!res) 227 return; 228 release_resource(res); 229 kfree(res); 230 } 231 232 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages) 233 { 234 /* 235 * Disallow all operations smaller than a sub-section and only 236 * allow operations smaller than a section for 237 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() 238 * enforces a larger memory_block_size_bytes() granularity for 239 * memory that will be marked online, so this check should only 240 * fire for direct arch_{add,remove}_memory() users outside of 241 * add_memory_resource(). 242 */ 243 unsigned long min_align; 244 245 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) 246 min_align = PAGES_PER_SUBSECTION; 247 else 248 min_align = PAGES_PER_SECTION; 249 if (!IS_ALIGNED(pfn | nr_pages, min_align)) 250 return -EINVAL; 251 return 0; 252 } 253 254 /* 255 * Return page for the valid pfn only if the page is online. All pfn 256 * walkers which rely on the fully initialized page->flags and others 257 * should use this rather than pfn_valid && pfn_to_page 258 */ 259 struct page *pfn_to_online_page(unsigned long pfn) 260 { 261 unsigned long nr = pfn_to_section_nr(pfn); 262 struct dev_pagemap *pgmap; 263 struct mem_section *ms; 264 265 if (nr >= NR_MEM_SECTIONS) 266 return NULL; 267 268 ms = __nr_to_section(nr); 269 if (!online_section(ms)) 270 return NULL; 271 272 /* 273 * Save some code text when online_section() + 274 * pfn_section_valid() are sufficient. 275 */ 276 if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) 277 return NULL; 278 279 if (!pfn_section_valid(ms, pfn)) 280 return NULL; 281 282 if (!online_device_section(ms)) 283 return pfn_to_page(pfn); 284 285 /* 286 * Slowpath: when ZONE_DEVICE collides with 287 * ZONE_{NORMAL,MOVABLE} within the same section some pfns in 288 * the section may be 'offline' but 'valid'. Only 289 * get_dev_pagemap() can determine sub-section online status. 290 */ 291 pgmap = get_dev_pagemap(pfn, NULL); 292 put_dev_pagemap(pgmap); 293 294 /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ 295 if (pgmap) 296 return NULL; 297 298 return pfn_to_page(pfn); 299 } 300 EXPORT_SYMBOL_GPL(pfn_to_online_page); 301 302 int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, 303 struct mhp_params *params) 304 { 305 const unsigned long end_pfn = pfn + nr_pages; 306 unsigned long cur_nr_pages; 307 int err; 308 struct vmem_altmap *altmap = params->altmap; 309 310 if (WARN_ON_ONCE(!pgprot_val(params->pgprot))) 311 return -EINVAL; 312 313 VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); 314 315 if (altmap) { 316 /* 317 * Validate altmap is within bounds of the total request 318 */ 319 if (altmap->base_pfn != pfn 320 || vmem_altmap_offset(altmap) > nr_pages) { 321 pr_warn_once("memory add fail, invalid altmap\n"); 322 return -EINVAL; 323 } 324 altmap->alloc = 0; 325 } 326 327 if (check_pfn_span(pfn, nr_pages)) { 328 WARN(1, "Misaligned %s start: %#lx end: #%lx\n", __func__, pfn, pfn + nr_pages - 1); 329 return -EINVAL; 330 } 331 332 for (; pfn < end_pfn; pfn += cur_nr_pages) { 333 /* Select all remaining pages up to the next section boundary */ 334 cur_nr_pages = min(end_pfn - pfn, 335 SECTION_ALIGN_UP(pfn + 1) - pfn); 336 err = sparse_add_section(nid, pfn, cur_nr_pages, altmap, 337 params->pgmap); 338 if (err) 339 break; 340 cond_resched(); 341 } 342 vmemmap_populate_print_last(); 343 return err; 344 } 345 346 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 347 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 348 unsigned long start_pfn, 349 unsigned long end_pfn) 350 { 351 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 352 if (unlikely(!pfn_to_online_page(start_pfn))) 353 continue; 354 355 if (unlikely(pfn_to_nid(start_pfn) != nid)) 356 continue; 357 358 if (zone != page_zone(pfn_to_page(start_pfn))) 359 continue; 360 361 return start_pfn; 362 } 363 364 return 0; 365 } 366 367 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 368 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 369 unsigned long start_pfn, 370 unsigned long end_pfn) 371 { 372 unsigned long pfn; 373 374 /* pfn is the end pfn of a memory section. */ 375 pfn = end_pfn - 1; 376 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 377 if (unlikely(!pfn_to_online_page(pfn))) 378 continue; 379 380 if (unlikely(pfn_to_nid(pfn) != nid)) 381 continue; 382 383 if (zone != page_zone(pfn_to_page(pfn))) 384 continue; 385 386 return pfn; 387 } 388 389 return 0; 390 } 391 392 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 393 unsigned long end_pfn) 394 { 395 unsigned long pfn; 396 int nid = zone_to_nid(zone); 397 398 if (zone->zone_start_pfn == start_pfn) { 399 /* 400 * If the section is smallest section in the zone, it need 401 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 402 * In this case, we find second smallest valid mem_section 403 * for shrinking zone. 404 */ 405 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 406 zone_end_pfn(zone)); 407 if (pfn) { 408 zone->spanned_pages = zone_end_pfn(zone) - pfn; 409 zone->zone_start_pfn = pfn; 410 } else { 411 zone->zone_start_pfn = 0; 412 zone->spanned_pages = 0; 413 } 414 } else if (zone_end_pfn(zone) == end_pfn) { 415 /* 416 * If the section is biggest section in the zone, it need 417 * shrink zone->spanned_pages. 418 * In this case, we find second biggest valid mem_section for 419 * shrinking zone. 420 */ 421 pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, 422 start_pfn); 423 if (pfn) 424 zone->spanned_pages = pfn - zone->zone_start_pfn + 1; 425 else { 426 zone->zone_start_pfn = 0; 427 zone->spanned_pages = 0; 428 } 429 } 430 } 431 432 static void update_pgdat_span(struct pglist_data *pgdat) 433 { 434 unsigned long node_start_pfn = 0, node_end_pfn = 0; 435 struct zone *zone; 436 437 for (zone = pgdat->node_zones; 438 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 439 unsigned long end_pfn = zone_end_pfn(zone); 440 441 /* No need to lock the zones, they can't change. */ 442 if (!zone->spanned_pages) 443 continue; 444 if (!node_end_pfn) { 445 node_start_pfn = zone->zone_start_pfn; 446 node_end_pfn = end_pfn; 447 continue; 448 } 449 450 if (end_pfn > node_end_pfn) 451 node_end_pfn = end_pfn; 452 if (zone->zone_start_pfn < node_start_pfn) 453 node_start_pfn = zone->zone_start_pfn; 454 } 455 456 pgdat->node_start_pfn = node_start_pfn; 457 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 458 } 459 460 void __ref remove_pfn_range_from_zone(struct zone *zone, 461 unsigned long start_pfn, 462 unsigned long nr_pages) 463 { 464 const unsigned long end_pfn = start_pfn + nr_pages; 465 struct pglist_data *pgdat = zone->zone_pgdat; 466 unsigned long pfn, cur_nr_pages; 467 468 /* Poison struct pages because they are now uninitialized again. */ 469 for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { 470 cond_resched(); 471 472 /* Select all remaining pages up to the next section boundary */ 473 cur_nr_pages = 474 min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); 475 page_init_poison(pfn_to_page(pfn), 476 sizeof(struct page) * cur_nr_pages); 477 } 478 479 /* 480 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 481 * we will not try to shrink the zones - which is okay as 482 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 483 */ 484 if (zone_is_zone_device(zone)) 485 return; 486 487 clear_zone_contiguous(zone); 488 489 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 490 update_pgdat_span(pgdat); 491 492 set_zone_contiguous(zone); 493 } 494 495 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 496 unsigned long map_offset, 497 struct vmem_altmap *altmap) 498 { 499 struct mem_section *ms = __pfn_to_section(pfn); 500 501 if (WARN_ON_ONCE(!valid_section(ms))) 502 return; 503 504 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 505 } 506 507 /** 508 * __remove_pages() - remove sections of pages 509 * @pfn: starting pageframe (must be aligned to start of a section) 510 * @nr_pages: number of pages to remove (must be multiple of section size) 511 * @altmap: alternative device page map or %NULL if default memmap is used 512 * 513 * Generic helper function to remove section mappings and sysfs entries 514 * for the section of the memory we are removing. Caller needs to make 515 * sure that pages are marked reserved and zones are adjust properly by 516 * calling offline_pages(). 517 */ 518 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 519 struct vmem_altmap *altmap) 520 { 521 const unsigned long end_pfn = pfn + nr_pages; 522 unsigned long cur_nr_pages; 523 unsigned long map_offset = 0; 524 525 map_offset = vmem_altmap_offset(altmap); 526 527 if (check_pfn_span(pfn, nr_pages)) { 528 WARN(1, "Misaligned %s start: %#lx end: #%lx\n", __func__, pfn, pfn + nr_pages - 1); 529 return; 530 } 531 532 for (; pfn < end_pfn; pfn += cur_nr_pages) { 533 cond_resched(); 534 /* Select all remaining pages up to the next section boundary */ 535 cur_nr_pages = min(end_pfn - pfn, 536 SECTION_ALIGN_UP(pfn + 1) - pfn); 537 __remove_section(pfn, cur_nr_pages, map_offset, altmap); 538 map_offset = 0; 539 } 540 } 541 542 int set_online_page_callback(online_page_callback_t callback) 543 { 544 int rc = -EINVAL; 545 546 get_online_mems(); 547 mutex_lock(&online_page_callback_lock); 548 549 if (online_page_callback == generic_online_page) { 550 online_page_callback = callback; 551 rc = 0; 552 } 553 554 mutex_unlock(&online_page_callback_lock); 555 put_online_mems(); 556 557 return rc; 558 } 559 EXPORT_SYMBOL_GPL(set_online_page_callback); 560 561 int restore_online_page_callback(online_page_callback_t callback) 562 { 563 int rc = -EINVAL; 564 565 get_online_mems(); 566 mutex_lock(&online_page_callback_lock); 567 568 if (online_page_callback == callback) { 569 online_page_callback = generic_online_page; 570 rc = 0; 571 } 572 573 mutex_unlock(&online_page_callback_lock); 574 put_online_mems(); 575 576 return rc; 577 } 578 EXPORT_SYMBOL_GPL(restore_online_page_callback); 579 580 void generic_online_page(struct page *page, unsigned int order) 581 { 582 /* 583 * Freeing the page with debug_pagealloc enabled will try to unmap it, 584 * so we should map it first. This is better than introducing a special 585 * case in page freeing fast path. 586 */ 587 debug_pagealloc_map_pages(page, 1 << order); 588 __free_pages_core(page, order); 589 totalram_pages_add(1UL << order); 590 } 591 EXPORT_SYMBOL_GPL(generic_online_page); 592 593 static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) 594 { 595 const unsigned long end_pfn = start_pfn + nr_pages; 596 unsigned long pfn; 597 598 /* 599 * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might 600 * decide to not expose all pages to the buddy (e.g., expose them 601 * later). We account all pages as being online and belonging to this 602 * zone ("present"). 603 * When using memmap_on_memory, the range might not be aligned to 604 * MAX_ORDER_NR_PAGES - 1, but pageblock aligned. __ffs() will detect 605 * this and the first chunk to online will be pageblock_nr_pages. 606 */ 607 for (pfn = start_pfn; pfn < end_pfn;) { 608 int order = min(MAX_ORDER - 1UL, __ffs(pfn)); 609 610 (*online_page_callback)(pfn_to_page(pfn), order); 611 pfn += (1UL << order); 612 } 613 614 /* mark all involved sections as online */ 615 online_mem_sections(start_pfn, end_pfn); 616 } 617 618 /* check which state of node_states will be changed when online memory */ 619 static void node_states_check_changes_online(unsigned long nr_pages, 620 struct zone *zone, struct memory_notify *arg) 621 { 622 int nid = zone_to_nid(zone); 623 624 arg->status_change_nid = NUMA_NO_NODE; 625 arg->status_change_nid_normal = NUMA_NO_NODE; 626 627 if (!node_state(nid, N_MEMORY)) 628 arg->status_change_nid = nid; 629 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 630 arg->status_change_nid_normal = nid; 631 } 632 633 static void node_states_set_node(int node, struct memory_notify *arg) 634 { 635 if (arg->status_change_nid_normal >= 0) 636 node_set_state(node, N_NORMAL_MEMORY); 637 638 if (arg->status_change_nid >= 0) 639 node_set_state(node, N_MEMORY); 640 } 641 642 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 643 unsigned long nr_pages) 644 { 645 unsigned long old_end_pfn = zone_end_pfn(zone); 646 647 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 648 zone->zone_start_pfn = start_pfn; 649 650 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 651 } 652 653 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 654 unsigned long nr_pages) 655 { 656 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 657 658 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 659 pgdat->node_start_pfn = start_pfn; 660 661 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 662 663 } 664 665 #ifdef CONFIG_ZONE_DEVICE 666 static void section_taint_zone_device(unsigned long pfn) 667 { 668 struct mem_section *ms = __pfn_to_section(pfn); 669 670 ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; 671 } 672 #else 673 static inline void section_taint_zone_device(unsigned long pfn) 674 { 675 } 676 #endif 677 678 /* 679 * Associate the pfn range with the given zone, initializing the memmaps 680 * and resizing the pgdat/zone data to span the added pages. After this 681 * call, all affected pages are PG_reserved. 682 * 683 * All aligned pageblocks are initialized to the specified migratetype 684 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related 685 * zone stats (e.g., nr_isolate_pageblock) are touched. 686 */ 687 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 688 unsigned long nr_pages, 689 struct vmem_altmap *altmap, int migratetype) 690 { 691 struct pglist_data *pgdat = zone->zone_pgdat; 692 int nid = pgdat->node_id; 693 694 clear_zone_contiguous(zone); 695 696 if (zone_is_empty(zone)) 697 init_currently_empty_zone(zone, start_pfn, nr_pages); 698 resize_zone_range(zone, start_pfn, nr_pages); 699 resize_pgdat_range(pgdat, start_pfn, nr_pages); 700 701 /* 702 * Subsection population requires care in pfn_to_online_page(). 703 * Set the taint to enable the slow path detection of 704 * ZONE_DEVICE pages in an otherwise ZONE_{NORMAL,MOVABLE} 705 * section. 706 */ 707 if (zone_is_zone_device(zone)) { 708 if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) 709 section_taint_zone_device(start_pfn); 710 if (!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)) 711 section_taint_zone_device(start_pfn + nr_pages); 712 } 713 714 /* 715 * TODO now we have a visible range of pages which are not associated 716 * with their zone properly. Not nice but set_pfnblock_flags_mask 717 * expects the zone spans the pfn range. All the pages in the range 718 * are reserved so nobody should be touching them so we should be safe 719 */ 720 memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, 721 MEMINIT_HOTPLUG, altmap, migratetype); 722 723 set_zone_contiguous(zone); 724 } 725 726 struct auto_movable_stats { 727 unsigned long kernel_early_pages; 728 unsigned long movable_pages; 729 }; 730 731 static void auto_movable_stats_account_zone(struct auto_movable_stats *stats, 732 struct zone *zone) 733 { 734 if (zone_idx(zone) == ZONE_MOVABLE) { 735 stats->movable_pages += zone->present_pages; 736 } else { 737 stats->kernel_early_pages += zone->present_early_pages; 738 #ifdef CONFIG_CMA 739 /* 740 * CMA pages (never on hotplugged memory) behave like 741 * ZONE_MOVABLE. 742 */ 743 stats->movable_pages += zone->cma_pages; 744 stats->kernel_early_pages -= zone->cma_pages; 745 #endif /* CONFIG_CMA */ 746 } 747 } 748 struct auto_movable_group_stats { 749 unsigned long movable_pages; 750 unsigned long req_kernel_early_pages; 751 }; 752 753 static int auto_movable_stats_account_group(struct memory_group *group, 754 void *arg) 755 { 756 const int ratio = READ_ONCE(auto_movable_ratio); 757 struct auto_movable_group_stats *stats = arg; 758 long pages; 759 760 /* 761 * We don't support modifying the config while the auto-movable online 762 * policy is already enabled. Just avoid the division by zero below. 763 */ 764 if (!ratio) 765 return 0; 766 767 /* 768 * Calculate how many early kernel pages this group requires to 769 * satisfy the configured zone ratio. 770 */ 771 pages = group->present_movable_pages * 100 / ratio; 772 pages -= group->present_kernel_pages; 773 774 if (pages > 0) 775 stats->req_kernel_early_pages += pages; 776 stats->movable_pages += group->present_movable_pages; 777 return 0; 778 } 779 780 static bool auto_movable_can_online_movable(int nid, struct memory_group *group, 781 unsigned long nr_pages) 782 { 783 unsigned long kernel_early_pages, movable_pages; 784 struct auto_movable_group_stats group_stats = {}; 785 struct auto_movable_stats stats = {}; 786 pg_data_t *pgdat = NODE_DATA(nid); 787 struct zone *zone; 788 int i; 789 790 /* Walk all relevant zones and collect MOVABLE vs. KERNEL stats. */ 791 if (nid == NUMA_NO_NODE) { 792 /* TODO: cache values */ 793 for_each_populated_zone(zone) 794 auto_movable_stats_account_zone(&stats, zone); 795 } else { 796 for (i = 0; i < MAX_NR_ZONES; i++) { 797 zone = pgdat->node_zones + i; 798 if (populated_zone(zone)) 799 auto_movable_stats_account_zone(&stats, zone); 800 } 801 } 802 803 kernel_early_pages = stats.kernel_early_pages; 804 movable_pages = stats.movable_pages; 805 806 /* 807 * Kernel memory inside dynamic memory group allows for more MOVABLE 808 * memory within the same group. Remove the effect of all but the 809 * current group from the stats. 810 */ 811 walk_dynamic_memory_groups(nid, auto_movable_stats_account_group, 812 group, &group_stats); 813 if (kernel_early_pages <= group_stats.req_kernel_early_pages) 814 return false; 815 kernel_early_pages -= group_stats.req_kernel_early_pages; 816 movable_pages -= group_stats.movable_pages; 817 818 if (group && group->is_dynamic) 819 kernel_early_pages += group->present_kernel_pages; 820 821 /* 822 * Test if we could online the given number of pages to ZONE_MOVABLE 823 * and still stay in the configured ratio. 824 */ 825 movable_pages += nr_pages; 826 return movable_pages <= (auto_movable_ratio * kernel_early_pages) / 100; 827 } 828 829 /* 830 * Returns a default kernel memory zone for the given pfn range. 831 * If no kernel zone covers this pfn range it will automatically go 832 * to the ZONE_NORMAL. 833 */ 834 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 835 unsigned long nr_pages) 836 { 837 struct pglist_data *pgdat = NODE_DATA(nid); 838 int zid; 839 840 for (zid = 0; zid < ZONE_NORMAL; zid++) { 841 struct zone *zone = &pgdat->node_zones[zid]; 842 843 if (zone_intersects(zone, start_pfn, nr_pages)) 844 return zone; 845 } 846 847 return &pgdat->node_zones[ZONE_NORMAL]; 848 } 849 850 /* 851 * Determine to which zone to online memory dynamically based on user 852 * configuration and system stats. We care about the following ratio: 853 * 854 * MOVABLE : KERNEL 855 * 856 * Whereby MOVABLE is memory in ZONE_MOVABLE and KERNEL is memory in 857 * one of the kernel zones. CMA pages inside one of the kernel zones really 858 * behaves like ZONE_MOVABLE, so we treat them accordingly. 859 * 860 * We don't allow for hotplugged memory in a KERNEL zone to increase the 861 * amount of MOVABLE memory we can have, so we end up with: 862 * 863 * MOVABLE : KERNEL_EARLY 864 * 865 * Whereby KERNEL_EARLY is memory in one of the kernel zones, available sinze 866 * boot. We base our calculation on KERNEL_EARLY internally, because: 867 * 868 * a) Hotplugged memory in one of the kernel zones can sometimes still get 869 * hotunplugged, especially when hot(un)plugging individual memory blocks. 870 * There is no coordination across memory devices, therefore "automatic" 871 * hotunplugging, as implemented in hypervisors, could result in zone 872 * imbalances. 873 * b) Early/boot memory in one of the kernel zones can usually not get 874 * hotunplugged again (e.g., no firmware interface to unplug, fragmented 875 * with unmovable allocations). While there are corner cases where it might 876 * still work, it is barely relevant in practice. 877 * 878 * Exceptions are dynamic memory groups, which allow for more MOVABLE 879 * memory within the same memory group -- because in that case, there is 880 * coordination within the single memory device managed by a single driver. 881 * 882 * We rely on "present pages" instead of "managed pages", as the latter is 883 * highly unreliable and dynamic in virtualized environments, and does not 884 * consider boot time allocations. For example, memory ballooning adjusts the 885 * managed pages when inflating/deflating the balloon, and balloon compaction 886 * can even migrate inflated pages between zones. 887 * 888 * Using "present pages" is better but some things to keep in mind are: 889 * 890 * a) Some memblock allocations, such as for the crashkernel area, are 891 * effectively unused by the kernel, yet they account to "present pages". 892 * Fortunately, these allocations are comparatively small in relevant setups 893 * (e.g., fraction of system memory). 894 * b) Some hotplugged memory blocks in virtualized environments, esecially 895 * hotplugged by virtio-mem, look like they are completely present, however, 896 * only parts of the memory block are actually currently usable. 897 * "present pages" is an upper limit that can get reached at runtime. As 898 * we base our calculations on KERNEL_EARLY, this is not an issue. 899 */ 900 static struct zone *auto_movable_zone_for_pfn(int nid, 901 struct memory_group *group, 902 unsigned long pfn, 903 unsigned long nr_pages) 904 { 905 unsigned long online_pages = 0, max_pages, end_pfn; 906 struct page *page; 907 908 if (!auto_movable_ratio) 909 goto kernel_zone; 910 911 if (group && !group->is_dynamic) { 912 max_pages = group->s.max_pages; 913 online_pages = group->present_movable_pages; 914 915 /* If anything is !MOVABLE online the rest !MOVABLE. */ 916 if (group->present_kernel_pages) 917 goto kernel_zone; 918 } else if (!group || group->d.unit_pages == nr_pages) { 919 max_pages = nr_pages; 920 } else { 921 max_pages = group->d.unit_pages; 922 /* 923 * Take a look at all online sections in the current unit. 924 * We can safely assume that all pages within a section belong 925 * to the same zone, because dynamic memory groups only deal 926 * with hotplugged memory. 927 */ 928 pfn = ALIGN_DOWN(pfn, group->d.unit_pages); 929 end_pfn = pfn + group->d.unit_pages; 930 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 931 page = pfn_to_online_page(pfn); 932 if (!page) 933 continue; 934 /* If anything is !MOVABLE online the rest !MOVABLE. */ 935 if (!is_zone_movable_page(page)) 936 goto kernel_zone; 937 online_pages += PAGES_PER_SECTION; 938 } 939 } 940 941 /* 942 * Online MOVABLE if we could *currently* online all remaining parts 943 * MOVABLE. We expect to (add+) online them immediately next, so if 944 * nobody interferes, all will be MOVABLE if possible. 945 */ 946 nr_pages = max_pages - online_pages; 947 if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) 948 goto kernel_zone; 949 950 #ifdef CONFIG_NUMA 951 if (auto_movable_numa_aware && 952 !auto_movable_can_online_movable(nid, group, nr_pages)) 953 goto kernel_zone; 954 #endif /* CONFIG_NUMA */ 955 956 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 957 kernel_zone: 958 return default_kernel_zone_for_pfn(nid, pfn, nr_pages); 959 } 960 961 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 962 unsigned long nr_pages) 963 { 964 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 965 nr_pages); 966 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 967 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 968 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 969 970 /* 971 * We inherit the existing zone in a simple case where zones do not 972 * overlap in the given range 973 */ 974 if (in_kernel ^ in_movable) 975 return (in_kernel) ? kernel_zone : movable_zone; 976 977 /* 978 * If the range doesn't belong to any zone or two zones overlap in the 979 * given range then we use movable zone only if movable_node is 980 * enabled because we always online to a kernel zone by default. 981 */ 982 return movable_node_enabled ? movable_zone : kernel_zone; 983 } 984 985 struct zone *zone_for_pfn_range(int online_type, int nid, 986 struct memory_group *group, unsigned long start_pfn, 987 unsigned long nr_pages) 988 { 989 if (online_type == MMOP_ONLINE_KERNEL) 990 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 991 992 if (online_type == MMOP_ONLINE_MOVABLE) 993 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 994 995 if (online_policy == ONLINE_POLICY_AUTO_MOVABLE) 996 return auto_movable_zone_for_pfn(nid, group, start_pfn, nr_pages); 997 998 return default_zone_for_pfn(nid, start_pfn, nr_pages); 999 } 1000 1001 /* 1002 * This function should only be called by memory_block_{online,offline}, 1003 * and {online,offline}_pages. 1004 */ 1005 void adjust_present_page_count(struct page *page, struct memory_group *group, 1006 long nr_pages) 1007 { 1008 struct zone *zone = page_zone(page); 1009 const bool movable = zone_idx(zone) == ZONE_MOVABLE; 1010 1011 /* 1012 * We only support onlining/offlining/adding/removing of complete 1013 * memory blocks; therefore, either all is either early or hotplugged. 1014 */ 1015 if (early_section(__pfn_to_section(page_to_pfn(page)))) 1016 zone->present_early_pages += nr_pages; 1017 zone->present_pages += nr_pages; 1018 zone->zone_pgdat->node_present_pages += nr_pages; 1019 1020 if (group && movable) 1021 group->present_movable_pages += nr_pages; 1022 else if (group && !movable) 1023 group->present_kernel_pages += nr_pages; 1024 } 1025 1026 int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, 1027 struct zone *zone) 1028 { 1029 unsigned long end_pfn = pfn + nr_pages; 1030 int ret, i; 1031 1032 ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 1033 if (ret) 1034 return ret; 1035 1036 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); 1037 1038 for (i = 0; i < nr_pages; i++) 1039 SetPageVmemmapSelfHosted(pfn_to_page(pfn + i)); 1040 1041 /* 1042 * It might be that the vmemmap_pages fully span sections. If that is 1043 * the case, mark those sections online here as otherwise they will be 1044 * left offline. 1045 */ 1046 if (nr_pages >= PAGES_PER_SECTION) 1047 online_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 1048 1049 return ret; 1050 } 1051 1052 void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages) 1053 { 1054 unsigned long end_pfn = pfn + nr_pages; 1055 1056 /* 1057 * It might be that the vmemmap_pages fully span sections. If that is 1058 * the case, mark those sections offline here as otherwise they will be 1059 * left online. 1060 */ 1061 if (nr_pages >= PAGES_PER_SECTION) 1062 offline_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 1063 1064 /* 1065 * The pages associated with this vmemmap have been offlined, so 1066 * we can reset its state here. 1067 */ 1068 remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, nr_pages); 1069 kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 1070 } 1071 1072 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 1073 struct zone *zone, struct memory_group *group) 1074 { 1075 unsigned long flags; 1076 int need_zonelists_rebuild = 0; 1077 const int nid = zone_to_nid(zone); 1078 int ret; 1079 struct memory_notify arg; 1080 1081 /* 1082 * {on,off}lining is constrained to full memory sections (or more 1083 * precisely to memory blocks from the user space POV). 1084 * memmap_on_memory is an exception because it reserves initial part 1085 * of the physical memory space for vmemmaps. That space is pageblock 1086 * aligned. 1087 */ 1088 if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(pfn) || 1089 !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) 1090 return -EINVAL; 1091 1092 mem_hotplug_begin(); 1093 1094 /* associate pfn range with the zone */ 1095 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); 1096 1097 arg.start_pfn = pfn; 1098 arg.nr_pages = nr_pages; 1099 node_states_check_changes_online(nr_pages, zone, &arg); 1100 1101 ret = memory_notify(MEM_GOING_ONLINE, &arg); 1102 ret = notifier_to_errno(ret); 1103 if (ret) 1104 goto failed_addition; 1105 1106 /* 1107 * Fixup the number of isolated pageblocks before marking the sections 1108 * onlining, such that undo_isolate_page_range() works correctly. 1109 */ 1110 spin_lock_irqsave(&zone->lock, flags); 1111 zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; 1112 spin_unlock_irqrestore(&zone->lock, flags); 1113 1114 /* 1115 * If this zone is not populated, then it is not in zonelist. 1116 * This means the page allocator ignores this zone. 1117 * So, zonelist must be updated after online. 1118 */ 1119 if (!populated_zone(zone)) { 1120 need_zonelists_rebuild = 1; 1121 setup_zone_pageset(zone); 1122 } 1123 1124 online_pages_range(pfn, nr_pages); 1125 adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); 1126 1127 node_states_set_node(nid, &arg); 1128 if (need_zonelists_rebuild) 1129 build_all_zonelists(NULL); 1130 1131 /* Basic onlining is complete, allow allocation of onlined pages. */ 1132 undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); 1133 1134 /* 1135 * Freshly onlined pages aren't shuffled (e.g., all pages are placed to 1136 * the tail of the freelist when undoing isolation). Shuffle the whole 1137 * zone to make sure the just onlined pages are properly distributed 1138 * across the whole freelist - to create an initial shuffle. 1139 */ 1140 shuffle_zone(zone); 1141 1142 /* reinitialise watermarks and update pcp limits */ 1143 init_per_zone_wmark_min(); 1144 1145 kswapd_run(nid); 1146 kcompactd_run(nid); 1147 1148 writeback_set_ratelimit(); 1149 1150 memory_notify(MEM_ONLINE, &arg); 1151 mem_hotplug_done(); 1152 return 0; 1153 1154 failed_addition: 1155 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 1156 (unsigned long long) pfn << PAGE_SHIFT, 1157 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 1158 memory_notify(MEM_CANCEL_ONLINE, &arg); 1159 remove_pfn_range_from_zone(zone, pfn, nr_pages); 1160 mem_hotplug_done(); 1161 return ret; 1162 } 1163 1164 static void reset_node_present_pages(pg_data_t *pgdat) 1165 { 1166 struct zone *z; 1167 1168 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 1169 z->present_pages = 0; 1170 1171 pgdat->node_present_pages = 0; 1172 } 1173 1174 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 1175 static pg_data_t __ref *hotadd_init_pgdat(int nid) 1176 { 1177 struct pglist_data *pgdat; 1178 1179 /* 1180 * NODE_DATA is preallocated (free_area_init) but its internal 1181 * state is not allocated completely. Add missing pieces. 1182 * Completely offline nodes stay around and they just need 1183 * reintialization. 1184 */ 1185 pgdat = NODE_DATA(nid); 1186 1187 /* init node's zones as empty zones, we don't have any present pages.*/ 1188 free_area_init_core_hotplug(pgdat); 1189 1190 /* 1191 * The node we allocated has no zone fallback lists. For avoiding 1192 * to access not-initialized zonelist, build here. 1193 */ 1194 build_all_zonelists(pgdat); 1195 1196 /* 1197 * When memory is hot-added, all the memory is in offline state. So 1198 * clear all zones' present_pages because they will be updated in 1199 * online_pages() and offline_pages(). 1200 * TODO: should be in free_area_init_core_hotplug? 1201 */ 1202 reset_node_managed_pages(pgdat); 1203 reset_node_present_pages(pgdat); 1204 1205 return pgdat; 1206 } 1207 1208 /* 1209 * __try_online_node - online a node if offlined 1210 * @nid: the node ID 1211 * @set_node_online: Whether we want to online the node 1212 * called by cpu_up() to online a node without onlined memory. 1213 * 1214 * Returns: 1215 * 1 -> a new node has been allocated 1216 * 0 -> the node is already online 1217 * -ENOMEM -> the node could not be allocated 1218 */ 1219 static int __try_online_node(int nid, bool set_node_online) 1220 { 1221 pg_data_t *pgdat; 1222 int ret = 1; 1223 1224 if (node_online(nid)) 1225 return 0; 1226 1227 pgdat = hotadd_init_pgdat(nid); 1228 if (!pgdat) { 1229 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 1230 ret = -ENOMEM; 1231 goto out; 1232 } 1233 1234 if (set_node_online) { 1235 node_set_online(nid); 1236 ret = register_one_node(nid); 1237 BUG_ON(ret); 1238 } 1239 out: 1240 return ret; 1241 } 1242 1243 /* 1244 * Users of this function always want to online/register the node 1245 */ 1246 int try_online_node(int nid) 1247 { 1248 int ret; 1249 1250 mem_hotplug_begin(); 1251 ret = __try_online_node(nid, true); 1252 mem_hotplug_done(); 1253 return ret; 1254 } 1255 1256 static int check_hotplug_memory_range(u64 start, u64 size) 1257 { 1258 /* memory range must be block size aligned */ 1259 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1260 !IS_ALIGNED(size, memory_block_size_bytes())) { 1261 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1262 memory_block_size_bytes(), start, size); 1263 return -EINVAL; 1264 } 1265 1266 return 0; 1267 } 1268 1269 static int online_memory_block(struct memory_block *mem, void *arg) 1270 { 1271 mem->online_type = mhp_default_online_type; 1272 return device_online(&mem->dev); 1273 } 1274 1275 bool mhp_supports_memmap_on_memory(unsigned long size) 1276 { 1277 unsigned long nr_vmemmap_pages = size / PAGE_SIZE; 1278 unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); 1279 unsigned long remaining_size = size - vmemmap_size; 1280 1281 /* 1282 * Besides having arch support and the feature enabled at runtime, we 1283 * need a few more assumptions to hold true: 1284 * 1285 * a) We span a single memory block: memory onlining/offlinin;g happens 1286 * in memory block granularity. We don't want the vmemmap of online 1287 * memory blocks to reside on offline memory blocks. In the future, 1288 * we might want to support variable-sized memory blocks to make the 1289 * feature more versatile. 1290 * 1291 * b) The vmemmap pages span complete PMDs: We don't want vmemmap code 1292 * to populate memory from the altmap for unrelated parts (i.e., 1293 * other memory blocks) 1294 * 1295 * c) The vmemmap pages (and thereby the pages that will be exposed to 1296 * the buddy) have to cover full pageblocks: memory onlining/offlining 1297 * code requires applicable ranges to be page-aligned, for example, to 1298 * set the migratetypes properly. 1299 * 1300 * TODO: Although we have a check here to make sure that vmemmap pages 1301 * fully populate a PMD, it is not the right place to check for 1302 * this. A much better solution involves improving vmemmap code 1303 * to fallback to base pages when trying to populate vmemmap using 1304 * altmap as an alternative source of memory, and we do not exactly 1305 * populate a single PMD. 1306 */ 1307 return mhp_memmap_on_memory() && 1308 size == memory_block_size_bytes() && 1309 IS_ALIGNED(vmemmap_size, PMD_SIZE) && 1310 IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); 1311 } 1312 1313 /* 1314 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1315 * and online/offline operations (triggered e.g. by sysfs). 1316 * 1317 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1318 */ 1319 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) 1320 { 1321 struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; 1322 enum memblock_flags memblock_flags = MEMBLOCK_NONE; 1323 struct vmem_altmap mhp_altmap = {}; 1324 struct memory_group *group = NULL; 1325 u64 start, size; 1326 bool new_node = false; 1327 int ret; 1328 1329 start = res->start; 1330 size = resource_size(res); 1331 1332 ret = check_hotplug_memory_range(start, size); 1333 if (ret) 1334 return ret; 1335 1336 if (mhp_flags & MHP_NID_IS_MGID) { 1337 group = memory_group_find_by_id(nid); 1338 if (!group) 1339 return -EINVAL; 1340 nid = group->nid; 1341 } 1342 1343 if (!node_possible(nid)) { 1344 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1345 return -EINVAL; 1346 } 1347 1348 mem_hotplug_begin(); 1349 1350 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 1351 if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) 1352 memblock_flags = MEMBLOCK_DRIVER_MANAGED; 1353 ret = memblock_add_node(start, size, nid, memblock_flags); 1354 if (ret) 1355 goto error_mem_hotplug_end; 1356 } 1357 1358 ret = __try_online_node(nid, false); 1359 if (ret < 0) 1360 goto error; 1361 new_node = ret; 1362 1363 /* 1364 * Self hosted memmap array 1365 */ 1366 if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { 1367 if (!mhp_supports_memmap_on_memory(size)) { 1368 ret = -EINVAL; 1369 goto error; 1370 } 1371 mhp_altmap.free = PHYS_PFN(size); 1372 mhp_altmap.base_pfn = PHYS_PFN(start); 1373 params.altmap = &mhp_altmap; 1374 } 1375 1376 /* call arch's memory hotadd */ 1377 ret = arch_add_memory(nid, start, size, ¶ms); 1378 if (ret < 0) 1379 goto error; 1380 1381 /* create memory block devices after memory was added */ 1382 ret = create_memory_block_devices(start, size, mhp_altmap.alloc, 1383 group); 1384 if (ret) { 1385 arch_remove_memory(start, size, NULL); 1386 goto error; 1387 } 1388 1389 if (new_node) { 1390 /* If sysfs file of new node can't be created, cpu on the node 1391 * can't be hot-added. There is no rollback way now. 1392 * So, check by BUG_ON() to catch it reluctantly.. 1393 * We online node here. We can't roll back from here. 1394 */ 1395 node_set_online(nid); 1396 ret = __register_one_node(nid); 1397 BUG_ON(ret); 1398 } 1399 1400 register_memory_blocks_under_node(nid, PFN_DOWN(start), 1401 PFN_UP(start + size - 1), 1402 MEMINIT_HOTPLUG); 1403 1404 /* create new memmap entry */ 1405 if (!strcmp(res->name, "System RAM")) 1406 firmware_map_add_hotplug(start, start + size, "System RAM"); 1407 1408 /* device_online() will take the lock when calling online_pages() */ 1409 mem_hotplug_done(); 1410 1411 /* 1412 * In case we're allowed to merge the resource, flag it and trigger 1413 * merging now that adding succeeded. 1414 */ 1415 if (mhp_flags & MHP_MERGE_RESOURCE) 1416 merge_system_ram_resource(res); 1417 1418 /* online pages if requested */ 1419 if (mhp_default_online_type != MMOP_OFFLINE) 1420 walk_memory_blocks(start, size, NULL, online_memory_block); 1421 1422 return ret; 1423 error: 1424 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1425 memblock_remove(start, size); 1426 error_mem_hotplug_end: 1427 mem_hotplug_done(); 1428 return ret; 1429 } 1430 1431 /* requires device_hotplug_lock, see add_memory_resource() */ 1432 int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1433 { 1434 struct resource *res; 1435 int ret; 1436 1437 res = register_memory_resource(start, size, "System RAM"); 1438 if (IS_ERR(res)) 1439 return PTR_ERR(res); 1440 1441 ret = add_memory_resource(nid, res, mhp_flags); 1442 if (ret < 0) 1443 release_memory_resource(res); 1444 return ret; 1445 } 1446 1447 int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1448 { 1449 int rc; 1450 1451 lock_device_hotplug(); 1452 rc = __add_memory(nid, start, size, mhp_flags); 1453 unlock_device_hotplug(); 1454 1455 return rc; 1456 } 1457 EXPORT_SYMBOL_GPL(add_memory); 1458 1459 /* 1460 * Add special, driver-managed memory to the system as system RAM. Such 1461 * memory is not exposed via the raw firmware-provided memmap as system 1462 * RAM, instead, it is detected and added by a driver - during cold boot, 1463 * after a reboot, and after kexec. 1464 * 1465 * Reasons why this memory should not be used for the initial memmap of a 1466 * kexec kernel or for placing kexec images: 1467 * - The booting kernel is in charge of determining how this memory will be 1468 * used (e.g., use persistent memory as system RAM) 1469 * - Coordination with a hypervisor is required before this memory 1470 * can be used (e.g., inaccessible parts). 1471 * 1472 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1473 * memory map") are created. Also, the created memory resource is flagged 1474 * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case 1475 * this memory as well (esp., not place kexec images onto it). 1476 * 1477 * The resource_name (visible via /proc/iomem) has to have the format 1478 * "System RAM ($DRIVER)". 1479 */ 1480 int add_memory_driver_managed(int nid, u64 start, u64 size, 1481 const char *resource_name, mhp_t mhp_flags) 1482 { 1483 struct resource *res; 1484 int rc; 1485 1486 if (!resource_name || 1487 strstr(resource_name, "System RAM (") != resource_name || 1488 resource_name[strlen(resource_name) - 1] != ')') 1489 return -EINVAL; 1490 1491 lock_device_hotplug(); 1492 1493 res = register_memory_resource(start, size, resource_name); 1494 if (IS_ERR(res)) { 1495 rc = PTR_ERR(res); 1496 goto out_unlock; 1497 } 1498 1499 rc = add_memory_resource(nid, res, mhp_flags); 1500 if (rc < 0) 1501 release_memory_resource(res); 1502 1503 out_unlock: 1504 unlock_device_hotplug(); 1505 return rc; 1506 } 1507 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1508 1509 /* 1510 * Platforms should define arch_get_mappable_range() that provides 1511 * maximum possible addressable physical memory range for which the 1512 * linear mapping could be created. The platform returned address 1513 * range must adhere to these following semantics. 1514 * 1515 * - range.start <= range.end 1516 * - Range includes both end points [range.start..range.end] 1517 * 1518 * There is also a fallback definition provided here, allowing the 1519 * entire possible physical address range in case any platform does 1520 * not define arch_get_mappable_range(). 1521 */ 1522 struct range __weak arch_get_mappable_range(void) 1523 { 1524 struct range mhp_range = { 1525 .start = 0UL, 1526 .end = -1ULL, 1527 }; 1528 return mhp_range; 1529 } 1530 1531 struct range mhp_get_pluggable_range(bool need_mapping) 1532 { 1533 const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; 1534 struct range mhp_range; 1535 1536 if (need_mapping) { 1537 mhp_range = arch_get_mappable_range(); 1538 if (mhp_range.start > max_phys) { 1539 mhp_range.start = 0; 1540 mhp_range.end = 0; 1541 } 1542 mhp_range.end = min_t(u64, mhp_range.end, max_phys); 1543 } else { 1544 mhp_range.start = 0; 1545 mhp_range.end = max_phys; 1546 } 1547 return mhp_range; 1548 } 1549 EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); 1550 1551 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) 1552 { 1553 struct range mhp_range = mhp_get_pluggable_range(need_mapping); 1554 u64 end = start + size; 1555 1556 if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) 1557 return true; 1558 1559 pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", 1560 start, end, mhp_range.start, mhp_range.end); 1561 return false; 1562 } 1563 1564 #ifdef CONFIG_MEMORY_HOTREMOVE 1565 /* 1566 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1567 * non-lru movable pages and hugepages). Will skip over most unmovable 1568 * pages (esp., pages that can be skipped when offlining), but bail out on 1569 * definitely unmovable pages. 1570 * 1571 * Returns: 1572 * 0 in case a movable page is found and movable_pfn was updated. 1573 * -ENOENT in case no movable page was found. 1574 * -EBUSY in case a definitely unmovable page was found. 1575 */ 1576 static int scan_movable_pages(unsigned long start, unsigned long end, 1577 unsigned long *movable_pfn) 1578 { 1579 unsigned long pfn; 1580 1581 for (pfn = start; pfn < end; pfn++) { 1582 struct page *page, *head; 1583 unsigned long skip; 1584 1585 if (!pfn_valid(pfn)) 1586 continue; 1587 page = pfn_to_page(pfn); 1588 if (PageLRU(page)) 1589 goto found; 1590 if (__PageMovable(page)) 1591 goto found; 1592 1593 /* 1594 * PageOffline() pages that are not marked __PageMovable() and 1595 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1596 * definitely unmovable. If their reference count would be 0, 1597 * they could at least be skipped when offlining memory. 1598 */ 1599 if (PageOffline(page) && page_count(page)) 1600 return -EBUSY; 1601 1602 if (!PageHuge(page)) 1603 continue; 1604 head = compound_head(page); 1605 /* 1606 * This test is racy as we hold no reference or lock. The 1607 * hugetlb page could have been free'ed and head is no longer 1608 * a hugetlb page before the following check. In such unlikely 1609 * cases false positives and negatives are possible. Calling 1610 * code must deal with these scenarios. 1611 */ 1612 if (HPageMigratable(head)) 1613 goto found; 1614 skip = compound_nr(head) - (page - head); 1615 pfn += skip - 1; 1616 } 1617 return -ENOENT; 1618 found: 1619 *movable_pfn = pfn; 1620 return 0; 1621 } 1622 1623 static void do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1624 { 1625 unsigned long pfn; 1626 struct page *page, *head; 1627 LIST_HEAD(source); 1628 static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, 1629 DEFAULT_RATELIMIT_BURST); 1630 1631 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1632 struct folio *folio; 1633 bool isolated; 1634 1635 if (!pfn_valid(pfn)) 1636 continue; 1637 page = pfn_to_page(pfn); 1638 folio = page_folio(page); 1639 head = &folio->page; 1640 1641 if (PageHuge(page)) { 1642 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1643 isolate_hugetlb(folio, &source); 1644 continue; 1645 } else if (PageTransHuge(page)) 1646 pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; 1647 1648 /* 1649 * HWPoison pages have elevated reference counts so the migration would 1650 * fail on them. It also doesn't make any sense to migrate them in the 1651 * first place. Still try to unmap such a page in case it is still mapped 1652 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1653 * the unmap as the catch all safety net). 1654 */ 1655 if (PageHWPoison(page)) { 1656 if (WARN_ON(folio_test_lru(folio))) 1657 folio_isolate_lru(folio); 1658 if (folio_mapped(folio)) 1659 try_to_unmap(folio, TTU_IGNORE_MLOCK); 1660 continue; 1661 } 1662 1663 if (!get_page_unless_zero(page)) 1664 continue; 1665 /* 1666 * We can skip free pages. And we can deal with pages on 1667 * LRU and non-lru movable pages. 1668 */ 1669 if (PageLRU(page)) 1670 isolated = isolate_lru_page(page); 1671 else 1672 isolated = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1673 if (isolated) { 1674 list_add_tail(&page->lru, &source); 1675 if (!__PageMovable(page)) 1676 inc_node_page_state(page, NR_ISOLATED_ANON + 1677 page_is_file_lru(page)); 1678 1679 } else { 1680 if (__ratelimit(&migrate_rs)) { 1681 pr_warn("failed to isolate pfn %lx\n", pfn); 1682 dump_page(page, "isolation failed"); 1683 } 1684 } 1685 put_page(page); 1686 } 1687 if (!list_empty(&source)) { 1688 nodemask_t nmask = node_states[N_MEMORY]; 1689 struct migration_target_control mtc = { 1690 .nmask = &nmask, 1691 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, 1692 }; 1693 int ret; 1694 1695 /* 1696 * We have checked that migration range is on a single zone so 1697 * we can use the nid of the first page to all the others. 1698 */ 1699 mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); 1700 1701 /* 1702 * try to allocate from a different node but reuse this node 1703 * if there are no other online nodes to be used (e.g. we are 1704 * offlining a part of the only existing node) 1705 */ 1706 node_clear(mtc.nid, nmask); 1707 if (nodes_empty(nmask)) 1708 node_set(mtc.nid, nmask); 1709 ret = migrate_pages(&source, alloc_migration_target, NULL, 1710 (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL); 1711 if (ret) { 1712 list_for_each_entry(page, &source, lru) { 1713 if (__ratelimit(&migrate_rs)) { 1714 pr_warn("migrating pfn %lx failed ret:%d\n", 1715 page_to_pfn(page), ret); 1716 dump_page(page, "migration failure"); 1717 } 1718 } 1719 putback_movable_pages(&source); 1720 } 1721 } 1722 } 1723 1724 static int __init cmdline_parse_movable_node(char *p) 1725 { 1726 movable_node_enabled = true; 1727 return 0; 1728 } 1729 early_param("movable_node", cmdline_parse_movable_node); 1730 1731 /* check which state of node_states will be changed when offline memory */ 1732 static void node_states_check_changes_offline(unsigned long nr_pages, 1733 struct zone *zone, struct memory_notify *arg) 1734 { 1735 struct pglist_data *pgdat = zone->zone_pgdat; 1736 unsigned long present_pages = 0; 1737 enum zone_type zt; 1738 1739 arg->status_change_nid = NUMA_NO_NODE; 1740 arg->status_change_nid_normal = NUMA_NO_NODE; 1741 1742 /* 1743 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1744 * If the memory to be offline is within the range 1745 * [0..ZONE_NORMAL], and it is the last present memory there, 1746 * the zones in that range will become empty after the offlining, 1747 * thus we can determine that we need to clear the node from 1748 * node_states[N_NORMAL_MEMORY]. 1749 */ 1750 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1751 present_pages += pgdat->node_zones[zt].present_pages; 1752 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1753 arg->status_change_nid_normal = zone_to_nid(zone); 1754 1755 /* 1756 * We have accounted the pages from [0..ZONE_NORMAL); ZONE_HIGHMEM 1757 * does not apply as we don't support 32bit. 1758 * Here we count the possible pages from ZONE_MOVABLE. 1759 * If after having accounted all the pages, we see that the nr_pages 1760 * to be offlined is over or equal to the accounted pages, 1761 * we know that the node will become empty, and so, we can clear 1762 * it for N_MEMORY as well. 1763 */ 1764 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1765 1766 if (nr_pages >= present_pages) 1767 arg->status_change_nid = zone_to_nid(zone); 1768 } 1769 1770 static void node_states_clear_node(int node, struct memory_notify *arg) 1771 { 1772 if (arg->status_change_nid_normal >= 0) 1773 node_clear_state(node, N_NORMAL_MEMORY); 1774 1775 if (arg->status_change_nid >= 0) 1776 node_clear_state(node, N_MEMORY); 1777 } 1778 1779 static int count_system_ram_pages_cb(unsigned long start_pfn, 1780 unsigned long nr_pages, void *data) 1781 { 1782 unsigned long *nr_system_ram_pages = data; 1783 1784 *nr_system_ram_pages += nr_pages; 1785 return 0; 1786 } 1787 1788 int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, 1789 struct zone *zone, struct memory_group *group) 1790 { 1791 const unsigned long end_pfn = start_pfn + nr_pages; 1792 unsigned long pfn, system_ram_pages = 0; 1793 const int node = zone_to_nid(zone); 1794 unsigned long flags; 1795 struct memory_notify arg; 1796 char *reason; 1797 int ret; 1798 1799 /* 1800 * {on,off}lining is constrained to full memory sections (or more 1801 * precisely to memory blocks from the user space POV). 1802 * memmap_on_memory is an exception because it reserves initial part 1803 * of the physical memory space for vmemmaps. That space is pageblock 1804 * aligned. 1805 */ 1806 if (WARN_ON_ONCE(!nr_pages || !pageblock_aligned(start_pfn) || 1807 !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) 1808 return -EINVAL; 1809 1810 mem_hotplug_begin(); 1811 1812 /* 1813 * Don't allow to offline memory blocks that contain holes. 1814 * Consequently, memory blocks with holes can never get onlined 1815 * via the hotplug path - online_pages() - as hotplugged memory has 1816 * no holes. This way, we e.g., don't have to worry about marking 1817 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1818 * avoid using walk_system_ram_range() later. 1819 */ 1820 walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, 1821 count_system_ram_pages_cb); 1822 if (system_ram_pages != nr_pages) { 1823 ret = -EINVAL; 1824 reason = "memory holes"; 1825 goto failed_removal; 1826 } 1827 1828 /* 1829 * We only support offlining of memory blocks managed by a single zone, 1830 * checked by calling code. This is just a sanity check that we might 1831 * want to remove in the future. 1832 */ 1833 if (WARN_ON_ONCE(page_zone(pfn_to_page(start_pfn)) != zone || 1834 page_zone(pfn_to_page(end_pfn - 1)) != zone)) { 1835 ret = -EINVAL; 1836 reason = "multizone range"; 1837 goto failed_removal; 1838 } 1839 1840 /* 1841 * Disable pcplists so that page isolation cannot race with freeing 1842 * in a way that pages from isolated pageblock are left on pcplists. 1843 */ 1844 zone_pcp_disable(zone); 1845 lru_cache_disable(); 1846 1847 /* set above range as isolated */ 1848 ret = start_isolate_page_range(start_pfn, end_pfn, 1849 MIGRATE_MOVABLE, 1850 MEMORY_OFFLINE | REPORT_FAILURE, 1851 GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL); 1852 if (ret) { 1853 reason = "failure to isolate range"; 1854 goto failed_removal_pcplists_disabled; 1855 } 1856 1857 arg.start_pfn = start_pfn; 1858 arg.nr_pages = nr_pages; 1859 node_states_check_changes_offline(nr_pages, zone, &arg); 1860 1861 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1862 ret = notifier_to_errno(ret); 1863 if (ret) { 1864 reason = "notifier failure"; 1865 goto failed_removal_isolated; 1866 } 1867 1868 do { 1869 pfn = start_pfn; 1870 do { 1871 if (signal_pending(current)) { 1872 ret = -EINTR; 1873 reason = "signal backoff"; 1874 goto failed_removal_isolated; 1875 } 1876 1877 cond_resched(); 1878 1879 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1880 if (!ret) { 1881 /* 1882 * TODO: fatal migration failures should bail 1883 * out 1884 */ 1885 do_migrate_range(pfn, end_pfn); 1886 } 1887 } while (!ret); 1888 1889 if (ret != -ENOENT) { 1890 reason = "unmovable page"; 1891 goto failed_removal_isolated; 1892 } 1893 1894 /* 1895 * Dissolve free hugepages in the memory block before doing 1896 * offlining actually in order to make hugetlbfs's object 1897 * counting consistent. 1898 */ 1899 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1900 if (ret) { 1901 reason = "failure to dissolve huge pages"; 1902 goto failed_removal_isolated; 1903 } 1904 1905 ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); 1906 1907 } while (ret); 1908 1909 /* Mark all sections offline and remove free pages from the buddy. */ 1910 __offline_isolated_pages(start_pfn, end_pfn); 1911 pr_debug("Offlined Pages %ld\n", nr_pages); 1912 1913 /* 1914 * The memory sections are marked offline, and the pageblock flags 1915 * effectively stale; nobody should be touching them. Fixup the number 1916 * of isolated pageblocks, memory onlining will properly revert this. 1917 */ 1918 spin_lock_irqsave(&zone->lock, flags); 1919 zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; 1920 spin_unlock_irqrestore(&zone->lock, flags); 1921 1922 lru_cache_enable(); 1923 zone_pcp_enable(zone); 1924 1925 /* removal success */ 1926 adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); 1927 adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages); 1928 1929 /* reinitialise watermarks and update pcp limits */ 1930 init_per_zone_wmark_min(); 1931 1932 if (!populated_zone(zone)) { 1933 zone_pcp_reset(zone); 1934 build_all_zonelists(NULL); 1935 } 1936 1937 node_states_clear_node(node, &arg); 1938 if (arg.status_change_nid >= 0) { 1939 kcompactd_stop(node); 1940 kswapd_stop(node); 1941 } 1942 1943 writeback_set_ratelimit(); 1944 1945 memory_notify(MEM_OFFLINE, &arg); 1946 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1947 mem_hotplug_done(); 1948 return 0; 1949 1950 failed_removal_isolated: 1951 /* pushback to free area */ 1952 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1953 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1954 failed_removal_pcplists_disabled: 1955 lru_cache_enable(); 1956 zone_pcp_enable(zone); 1957 failed_removal: 1958 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1959 (unsigned long long) start_pfn << PAGE_SHIFT, 1960 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1961 reason); 1962 mem_hotplug_done(); 1963 return ret; 1964 } 1965 1966 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1967 { 1968 int *nid = arg; 1969 1970 *nid = mem->nid; 1971 if (unlikely(mem->state != MEM_OFFLINE)) { 1972 phys_addr_t beginpa, endpa; 1973 1974 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1975 endpa = beginpa + memory_block_size_bytes() - 1; 1976 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1977 &beginpa, &endpa); 1978 1979 return -EBUSY; 1980 } 1981 return 0; 1982 } 1983 1984 static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg) 1985 { 1986 /* 1987 * If not set, continue with the next block. 1988 */ 1989 return mem->nr_vmemmap_pages; 1990 } 1991 1992 static int check_cpu_on_node(int nid) 1993 { 1994 int cpu; 1995 1996 for_each_present_cpu(cpu) { 1997 if (cpu_to_node(cpu) == nid) 1998 /* 1999 * the cpu on this node isn't removed, and we can't 2000 * offline this node. 2001 */ 2002 return -EBUSY; 2003 } 2004 2005 return 0; 2006 } 2007 2008 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 2009 { 2010 int nid = *(int *)arg; 2011 2012 /* 2013 * If a memory block belongs to multiple nodes, the stored nid is not 2014 * reliable. However, such blocks are always online (e.g., cannot get 2015 * offlined) and, therefore, are still spanned by the node. 2016 */ 2017 return mem->nid == nid ? -EEXIST : 0; 2018 } 2019 2020 /** 2021 * try_offline_node 2022 * @nid: the node ID 2023 * 2024 * Offline a node if all memory sections and cpus of the node are removed. 2025 * 2026 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2027 * and online/offline operations before this call. 2028 */ 2029 void try_offline_node(int nid) 2030 { 2031 int rc; 2032 2033 /* 2034 * If the node still spans pages (especially ZONE_DEVICE), don't 2035 * offline it. A node spans memory after move_pfn_range_to_zone(), 2036 * e.g., after the memory block was onlined. 2037 */ 2038 if (node_spanned_pages(nid)) 2039 return; 2040 2041 /* 2042 * Especially offline memory blocks might not be spanned by the 2043 * node. They will get spanned by the node once they get onlined. 2044 * However, they link to the node in sysfs and can get onlined later. 2045 */ 2046 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 2047 if (rc) 2048 return; 2049 2050 if (check_cpu_on_node(nid)) 2051 return; 2052 2053 /* 2054 * all memory/cpu of this node are removed, we can offline this 2055 * node now. 2056 */ 2057 node_set_offline(nid); 2058 unregister_one_node(nid); 2059 } 2060 EXPORT_SYMBOL(try_offline_node); 2061 2062 static int __ref try_remove_memory(u64 start, u64 size) 2063 { 2064 struct vmem_altmap mhp_altmap = {}; 2065 struct vmem_altmap *altmap = NULL; 2066 unsigned long nr_vmemmap_pages; 2067 int rc = 0, nid = NUMA_NO_NODE; 2068 2069 BUG_ON(check_hotplug_memory_range(start, size)); 2070 2071 /* 2072 * All memory blocks must be offlined before removing memory. Check 2073 * whether all memory blocks in question are offline and return error 2074 * if this is not the case. 2075 * 2076 * While at it, determine the nid. Note that if we'd have mixed nodes, 2077 * we'd only try to offline the last determined one -- which is good 2078 * enough for the cases we care about. 2079 */ 2080 rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb); 2081 if (rc) 2082 return rc; 2083 2084 /* 2085 * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in 2086 * the same granularity it was added - a single memory block. 2087 */ 2088 if (mhp_memmap_on_memory()) { 2089 nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, 2090 get_nr_vmemmap_pages_cb); 2091 if (nr_vmemmap_pages) { 2092 if (size != memory_block_size_bytes()) { 2093 pr_warn("Refuse to remove %#llx - %#llx," 2094 "wrong granularity\n", 2095 start, start + size); 2096 return -EINVAL; 2097 } 2098 2099 /* 2100 * Let remove_pmd_table->free_hugepage_table do the 2101 * right thing if we used vmem_altmap when hot-adding 2102 * the range. 2103 */ 2104 mhp_altmap.alloc = nr_vmemmap_pages; 2105 altmap = &mhp_altmap; 2106 } 2107 } 2108 2109 /* remove memmap entry */ 2110 firmware_map_remove(start, start + size, "System RAM"); 2111 2112 /* 2113 * Memory block device removal under the device_hotplug_lock is 2114 * a barrier against racing online attempts. 2115 */ 2116 remove_memory_block_devices(start, size); 2117 2118 mem_hotplug_begin(); 2119 2120 arch_remove_memory(start, size, altmap); 2121 2122 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 2123 memblock_phys_free(start, size); 2124 memblock_remove(start, size); 2125 } 2126 2127 release_mem_region_adjustable(start, size); 2128 2129 if (nid != NUMA_NO_NODE) 2130 try_offline_node(nid); 2131 2132 mem_hotplug_done(); 2133 return 0; 2134 } 2135 2136 /** 2137 * __remove_memory - Remove memory if every memory block is offline 2138 * @start: physical address of the region to remove 2139 * @size: size of the region to remove 2140 * 2141 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2142 * and online/offline operations before this call, as required by 2143 * try_offline_node(). 2144 */ 2145 void __remove_memory(u64 start, u64 size) 2146 { 2147 2148 /* 2149 * trigger BUG() if some memory is not offlined prior to calling this 2150 * function 2151 */ 2152 if (try_remove_memory(start, size)) 2153 BUG(); 2154 } 2155 2156 /* 2157 * Remove memory if every memory block is offline, otherwise return -EBUSY is 2158 * some memory is not offline 2159 */ 2160 int remove_memory(u64 start, u64 size) 2161 { 2162 int rc; 2163 2164 lock_device_hotplug(); 2165 rc = try_remove_memory(start, size); 2166 unlock_device_hotplug(); 2167 2168 return rc; 2169 } 2170 EXPORT_SYMBOL_GPL(remove_memory); 2171 2172 static int try_offline_memory_block(struct memory_block *mem, void *arg) 2173 { 2174 uint8_t online_type = MMOP_ONLINE_KERNEL; 2175 uint8_t **online_types = arg; 2176 struct page *page; 2177 int rc; 2178 2179 /* 2180 * Sense the online_type via the zone of the memory block. Offlining 2181 * with multiple zones within one memory block will be rejected 2182 * by offlining code ... so we don't care about that. 2183 */ 2184 page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); 2185 if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) 2186 online_type = MMOP_ONLINE_MOVABLE; 2187 2188 rc = device_offline(&mem->dev); 2189 /* 2190 * Default is MMOP_OFFLINE - change it only if offlining succeeded, 2191 * so try_reonline_memory_block() can do the right thing. 2192 */ 2193 if (!rc) 2194 **online_types = online_type; 2195 2196 (*online_types)++; 2197 /* Ignore if already offline. */ 2198 return rc < 0 ? rc : 0; 2199 } 2200 2201 static int try_reonline_memory_block(struct memory_block *mem, void *arg) 2202 { 2203 uint8_t **online_types = arg; 2204 int rc; 2205 2206 if (**online_types != MMOP_OFFLINE) { 2207 mem->online_type = **online_types; 2208 rc = device_online(&mem->dev); 2209 if (rc < 0) 2210 pr_warn("%s: Failed to re-online memory: %d", 2211 __func__, rc); 2212 } 2213 2214 /* Continue processing all remaining memory blocks. */ 2215 (*online_types)++; 2216 return 0; 2217 } 2218 2219 /* 2220 * Try to offline and remove memory. Might take a long time to finish in case 2221 * memory is still in use. Primarily useful for memory devices that logically 2222 * unplugged all memory (so it's no longer in use) and want to offline + remove 2223 * that memory. 2224 */ 2225 int offline_and_remove_memory(u64 start, u64 size) 2226 { 2227 const unsigned long mb_count = size / memory_block_size_bytes(); 2228 uint8_t *online_types, *tmp; 2229 int rc; 2230 2231 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 2232 !IS_ALIGNED(size, memory_block_size_bytes()) || !size) 2233 return -EINVAL; 2234 2235 /* 2236 * We'll remember the old online type of each memory block, so we can 2237 * try to revert whatever we did when offlining one memory block fails 2238 * after offlining some others succeeded. 2239 */ 2240 online_types = kmalloc_array(mb_count, sizeof(*online_types), 2241 GFP_KERNEL); 2242 if (!online_types) 2243 return -ENOMEM; 2244 /* 2245 * Initialize all states to MMOP_OFFLINE, so when we abort processing in 2246 * try_offline_memory_block(), we'll skip all unprocessed blocks in 2247 * try_reonline_memory_block(). 2248 */ 2249 memset(online_types, MMOP_OFFLINE, mb_count); 2250 2251 lock_device_hotplug(); 2252 2253 tmp = online_types; 2254 rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); 2255 2256 /* 2257 * In case we succeeded to offline all memory, remove it. 2258 * This cannot fail as it cannot get onlined in the meantime. 2259 */ 2260 if (!rc) { 2261 rc = try_remove_memory(start, size); 2262 if (rc) 2263 pr_err("%s: Failed to remove memory: %d", __func__, rc); 2264 } 2265 2266 /* 2267 * Rollback what we did. While memory onlining might theoretically fail 2268 * (nacked by a notifier), it barely ever happens. 2269 */ 2270 if (rc) { 2271 tmp = online_types; 2272 walk_memory_blocks(start, size, &tmp, 2273 try_reonline_memory_block); 2274 } 2275 unlock_device_hotplug(); 2276 2277 kfree(online_types); 2278 return rc; 2279 } 2280 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 2281 #endif /* CONFIG_MEMORY_HOTREMOVE */ 2282