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 || 1089 !IS_ALIGNED(pfn, pageblock_nr_pages) || 1090 !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) 1091 return -EINVAL; 1092 1093 mem_hotplug_begin(); 1094 1095 /* associate pfn range with the zone */ 1096 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); 1097 1098 arg.start_pfn = pfn; 1099 arg.nr_pages = nr_pages; 1100 node_states_check_changes_online(nr_pages, zone, &arg); 1101 1102 ret = memory_notify(MEM_GOING_ONLINE, &arg); 1103 ret = notifier_to_errno(ret); 1104 if (ret) 1105 goto failed_addition; 1106 1107 /* 1108 * Fixup the number of isolated pageblocks before marking the sections 1109 * onlining, such that undo_isolate_page_range() works correctly. 1110 */ 1111 spin_lock_irqsave(&zone->lock, flags); 1112 zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; 1113 spin_unlock_irqrestore(&zone->lock, flags); 1114 1115 /* 1116 * If this zone is not populated, then it is not in zonelist. 1117 * This means the page allocator ignores this zone. 1118 * So, zonelist must be updated after online. 1119 */ 1120 if (!populated_zone(zone)) { 1121 need_zonelists_rebuild = 1; 1122 setup_zone_pageset(zone); 1123 } 1124 1125 online_pages_range(pfn, nr_pages); 1126 adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); 1127 1128 node_states_set_node(nid, &arg); 1129 if (need_zonelists_rebuild) 1130 build_all_zonelists(NULL); 1131 1132 /* Basic onlining is complete, allow allocation of onlined pages. */ 1133 undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); 1134 1135 /* 1136 * Freshly onlined pages aren't shuffled (e.g., all pages are placed to 1137 * the tail of the freelist when undoing isolation). Shuffle the whole 1138 * zone to make sure the just onlined pages are properly distributed 1139 * across the whole freelist - to create an initial shuffle. 1140 */ 1141 shuffle_zone(zone); 1142 1143 /* reinitialise watermarks and update pcp limits */ 1144 init_per_zone_wmark_min(); 1145 1146 kswapd_run(nid); 1147 kcompactd_run(nid); 1148 1149 writeback_set_ratelimit(); 1150 1151 memory_notify(MEM_ONLINE, &arg); 1152 mem_hotplug_done(); 1153 return 0; 1154 1155 failed_addition: 1156 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 1157 (unsigned long long) pfn << PAGE_SHIFT, 1158 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 1159 memory_notify(MEM_CANCEL_ONLINE, &arg); 1160 remove_pfn_range_from_zone(zone, pfn, nr_pages); 1161 mem_hotplug_done(); 1162 return ret; 1163 } 1164 1165 static void reset_node_present_pages(pg_data_t *pgdat) 1166 { 1167 struct zone *z; 1168 1169 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 1170 z->present_pages = 0; 1171 1172 pgdat->node_present_pages = 0; 1173 } 1174 1175 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 1176 static pg_data_t __ref *hotadd_init_pgdat(int nid) 1177 { 1178 struct pglist_data *pgdat; 1179 1180 /* 1181 * NODE_DATA is preallocated (free_area_init) but its internal 1182 * state is not allocated completely. Add missing pieces. 1183 * Completely offline nodes stay around and they just need 1184 * reintialization. 1185 */ 1186 pgdat = NODE_DATA(nid); 1187 1188 /* init node's zones as empty zones, we don't have any present pages.*/ 1189 free_area_init_core_hotplug(pgdat); 1190 1191 /* 1192 * The node we allocated has no zone fallback lists. For avoiding 1193 * to access not-initialized zonelist, build here. 1194 */ 1195 build_all_zonelists(pgdat); 1196 1197 /* 1198 * When memory is hot-added, all the memory is in offline state. So 1199 * clear all zones' present_pages because they will be updated in 1200 * online_pages() and offline_pages(). 1201 * TODO: should be in free_area_init_core_hotplug? 1202 */ 1203 reset_node_managed_pages(pgdat); 1204 reset_node_present_pages(pgdat); 1205 1206 return pgdat; 1207 } 1208 1209 /* 1210 * __try_online_node - online a node if offlined 1211 * @nid: the node ID 1212 * @set_node_online: Whether we want to online the node 1213 * called by cpu_up() to online a node without onlined memory. 1214 * 1215 * Returns: 1216 * 1 -> a new node has been allocated 1217 * 0 -> the node is already online 1218 * -ENOMEM -> the node could not be allocated 1219 */ 1220 static int __try_online_node(int nid, bool set_node_online) 1221 { 1222 pg_data_t *pgdat; 1223 int ret = 1; 1224 1225 if (node_online(nid)) 1226 return 0; 1227 1228 pgdat = hotadd_init_pgdat(nid); 1229 if (!pgdat) { 1230 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 1231 ret = -ENOMEM; 1232 goto out; 1233 } 1234 1235 if (set_node_online) { 1236 node_set_online(nid); 1237 ret = register_one_node(nid); 1238 BUG_ON(ret); 1239 } 1240 out: 1241 return ret; 1242 } 1243 1244 /* 1245 * Users of this function always want to online/register the node 1246 */ 1247 int try_online_node(int nid) 1248 { 1249 int ret; 1250 1251 mem_hotplug_begin(); 1252 ret = __try_online_node(nid, true); 1253 mem_hotplug_done(); 1254 return ret; 1255 } 1256 1257 static int check_hotplug_memory_range(u64 start, u64 size) 1258 { 1259 /* memory range must be block size aligned */ 1260 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1261 !IS_ALIGNED(size, memory_block_size_bytes())) { 1262 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1263 memory_block_size_bytes(), start, size); 1264 return -EINVAL; 1265 } 1266 1267 return 0; 1268 } 1269 1270 static int online_memory_block(struct memory_block *mem, void *arg) 1271 { 1272 mem->online_type = mhp_default_online_type; 1273 return device_online(&mem->dev); 1274 } 1275 1276 bool mhp_supports_memmap_on_memory(unsigned long size) 1277 { 1278 unsigned long nr_vmemmap_pages = size / PAGE_SIZE; 1279 unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); 1280 unsigned long remaining_size = size - vmemmap_size; 1281 1282 /* 1283 * Besides having arch support and the feature enabled at runtime, we 1284 * need a few more assumptions to hold true: 1285 * 1286 * a) We span a single memory block: memory onlining/offlinin;g happens 1287 * in memory block granularity. We don't want the vmemmap of online 1288 * memory blocks to reside on offline memory blocks. In the future, 1289 * we might want to support variable-sized memory blocks to make the 1290 * feature more versatile. 1291 * 1292 * b) The vmemmap pages span complete PMDs: We don't want vmemmap code 1293 * to populate memory from the altmap for unrelated parts (i.e., 1294 * other memory blocks) 1295 * 1296 * c) The vmemmap pages (and thereby the pages that will be exposed to 1297 * the buddy) have to cover full pageblocks: memory onlining/offlining 1298 * code requires applicable ranges to be page-aligned, for example, to 1299 * set the migratetypes properly. 1300 * 1301 * TODO: Although we have a check here to make sure that vmemmap pages 1302 * fully populate a PMD, it is not the right place to check for 1303 * this. A much better solution involves improving vmemmap code 1304 * to fallback to base pages when trying to populate vmemmap using 1305 * altmap as an alternative source of memory, and we do not exactly 1306 * populate a single PMD. 1307 */ 1308 return mhp_memmap_on_memory() && 1309 size == memory_block_size_bytes() && 1310 IS_ALIGNED(vmemmap_size, PMD_SIZE) && 1311 IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); 1312 } 1313 1314 /* 1315 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1316 * and online/offline operations (triggered e.g. by sysfs). 1317 * 1318 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1319 */ 1320 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) 1321 { 1322 struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; 1323 enum memblock_flags memblock_flags = MEMBLOCK_NONE; 1324 struct vmem_altmap mhp_altmap = {}; 1325 struct memory_group *group = NULL; 1326 u64 start, size; 1327 bool new_node = false; 1328 int ret; 1329 1330 start = res->start; 1331 size = resource_size(res); 1332 1333 ret = check_hotplug_memory_range(start, size); 1334 if (ret) 1335 return ret; 1336 1337 if (mhp_flags & MHP_NID_IS_MGID) { 1338 group = memory_group_find_by_id(nid); 1339 if (!group) 1340 return -EINVAL; 1341 nid = group->nid; 1342 } 1343 1344 if (!node_possible(nid)) { 1345 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1346 return -EINVAL; 1347 } 1348 1349 mem_hotplug_begin(); 1350 1351 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 1352 if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) 1353 memblock_flags = MEMBLOCK_DRIVER_MANAGED; 1354 ret = memblock_add_node(start, size, nid, memblock_flags); 1355 if (ret) 1356 goto error_mem_hotplug_end; 1357 } 1358 1359 ret = __try_online_node(nid, false); 1360 if (ret < 0) 1361 goto error; 1362 new_node = ret; 1363 1364 /* 1365 * Self hosted memmap array 1366 */ 1367 if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { 1368 if (!mhp_supports_memmap_on_memory(size)) { 1369 ret = -EINVAL; 1370 goto error; 1371 } 1372 mhp_altmap.free = PHYS_PFN(size); 1373 mhp_altmap.base_pfn = PHYS_PFN(start); 1374 params.altmap = &mhp_altmap; 1375 } 1376 1377 /* call arch's memory hotadd */ 1378 ret = arch_add_memory(nid, start, size, ¶ms); 1379 if (ret < 0) 1380 goto error; 1381 1382 /* create memory block devices after memory was added */ 1383 ret = create_memory_block_devices(start, size, mhp_altmap.alloc, 1384 group); 1385 if (ret) { 1386 arch_remove_memory(start, size, NULL); 1387 goto error; 1388 } 1389 1390 if (new_node) { 1391 /* If sysfs file of new node can't be created, cpu on the node 1392 * can't be hot-added. There is no rollback way now. 1393 * So, check by BUG_ON() to catch it reluctantly.. 1394 * We online node here. We can't roll back from here. 1395 */ 1396 node_set_online(nid); 1397 ret = __register_one_node(nid); 1398 BUG_ON(ret); 1399 } 1400 1401 register_memory_blocks_under_node(nid, PFN_DOWN(start), 1402 PFN_UP(start + size - 1), 1403 MEMINIT_HOTPLUG); 1404 1405 /* create new memmap entry */ 1406 if (!strcmp(res->name, "System RAM")) 1407 firmware_map_add_hotplug(start, start + size, "System RAM"); 1408 1409 /* device_online() will take the lock when calling online_pages() */ 1410 mem_hotplug_done(); 1411 1412 /* 1413 * In case we're allowed to merge the resource, flag it and trigger 1414 * merging now that adding succeeded. 1415 */ 1416 if (mhp_flags & MHP_MERGE_RESOURCE) 1417 merge_system_ram_resource(res); 1418 1419 /* online pages if requested */ 1420 if (mhp_default_online_type != MMOP_OFFLINE) 1421 walk_memory_blocks(start, size, NULL, online_memory_block); 1422 1423 return ret; 1424 error: 1425 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1426 memblock_remove(start, size); 1427 error_mem_hotplug_end: 1428 mem_hotplug_done(); 1429 return ret; 1430 } 1431 1432 /* requires device_hotplug_lock, see add_memory_resource() */ 1433 int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1434 { 1435 struct resource *res; 1436 int ret; 1437 1438 res = register_memory_resource(start, size, "System RAM"); 1439 if (IS_ERR(res)) 1440 return PTR_ERR(res); 1441 1442 ret = add_memory_resource(nid, res, mhp_flags); 1443 if (ret < 0) 1444 release_memory_resource(res); 1445 return ret; 1446 } 1447 1448 int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1449 { 1450 int rc; 1451 1452 lock_device_hotplug(); 1453 rc = __add_memory(nid, start, size, mhp_flags); 1454 unlock_device_hotplug(); 1455 1456 return rc; 1457 } 1458 EXPORT_SYMBOL_GPL(add_memory); 1459 1460 /* 1461 * Add special, driver-managed memory to the system as system RAM. Such 1462 * memory is not exposed via the raw firmware-provided memmap as system 1463 * RAM, instead, it is detected and added by a driver - during cold boot, 1464 * after a reboot, and after kexec. 1465 * 1466 * Reasons why this memory should not be used for the initial memmap of a 1467 * kexec kernel or for placing kexec images: 1468 * - The booting kernel is in charge of determining how this memory will be 1469 * used (e.g., use persistent memory as system RAM) 1470 * - Coordination with a hypervisor is required before this memory 1471 * can be used (e.g., inaccessible parts). 1472 * 1473 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1474 * memory map") are created. Also, the created memory resource is flagged 1475 * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case 1476 * this memory as well (esp., not place kexec images onto it). 1477 * 1478 * The resource_name (visible via /proc/iomem) has to have the format 1479 * "System RAM ($DRIVER)". 1480 */ 1481 int add_memory_driver_managed(int nid, u64 start, u64 size, 1482 const char *resource_name, mhp_t mhp_flags) 1483 { 1484 struct resource *res; 1485 int rc; 1486 1487 if (!resource_name || 1488 strstr(resource_name, "System RAM (") != resource_name || 1489 resource_name[strlen(resource_name) - 1] != ')') 1490 return -EINVAL; 1491 1492 lock_device_hotplug(); 1493 1494 res = register_memory_resource(start, size, resource_name); 1495 if (IS_ERR(res)) { 1496 rc = PTR_ERR(res); 1497 goto out_unlock; 1498 } 1499 1500 rc = add_memory_resource(nid, res, mhp_flags); 1501 if (rc < 0) 1502 release_memory_resource(res); 1503 1504 out_unlock: 1505 unlock_device_hotplug(); 1506 return rc; 1507 } 1508 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1509 1510 /* 1511 * Platforms should define arch_get_mappable_range() that provides 1512 * maximum possible addressable physical memory range for which the 1513 * linear mapping could be created. The platform returned address 1514 * range must adhere to these following semantics. 1515 * 1516 * - range.start <= range.end 1517 * - Range includes both end points [range.start..range.end] 1518 * 1519 * There is also a fallback definition provided here, allowing the 1520 * entire possible physical address range in case any platform does 1521 * not define arch_get_mappable_range(). 1522 */ 1523 struct range __weak arch_get_mappable_range(void) 1524 { 1525 struct range mhp_range = { 1526 .start = 0UL, 1527 .end = -1ULL, 1528 }; 1529 return mhp_range; 1530 } 1531 1532 struct range mhp_get_pluggable_range(bool need_mapping) 1533 { 1534 const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; 1535 struct range mhp_range; 1536 1537 if (need_mapping) { 1538 mhp_range = arch_get_mappable_range(); 1539 if (mhp_range.start > max_phys) { 1540 mhp_range.start = 0; 1541 mhp_range.end = 0; 1542 } 1543 mhp_range.end = min_t(u64, mhp_range.end, max_phys); 1544 } else { 1545 mhp_range.start = 0; 1546 mhp_range.end = max_phys; 1547 } 1548 return mhp_range; 1549 } 1550 EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); 1551 1552 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) 1553 { 1554 struct range mhp_range = mhp_get_pluggable_range(need_mapping); 1555 u64 end = start + size; 1556 1557 if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) 1558 return true; 1559 1560 pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", 1561 start, end, mhp_range.start, mhp_range.end); 1562 return false; 1563 } 1564 1565 #ifdef CONFIG_MEMORY_HOTREMOVE 1566 /* 1567 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1568 * non-lru movable pages and hugepages). Will skip over most unmovable 1569 * pages (esp., pages that can be skipped when offlining), but bail out on 1570 * definitely unmovable pages. 1571 * 1572 * Returns: 1573 * 0 in case a movable page is found and movable_pfn was updated. 1574 * -ENOENT in case no movable page was found. 1575 * -EBUSY in case a definitely unmovable page was found. 1576 */ 1577 static int scan_movable_pages(unsigned long start, unsigned long end, 1578 unsigned long *movable_pfn) 1579 { 1580 unsigned long pfn; 1581 1582 for (pfn = start; pfn < end; pfn++) { 1583 struct page *page, *head; 1584 unsigned long skip; 1585 1586 if (!pfn_valid(pfn)) 1587 continue; 1588 page = pfn_to_page(pfn); 1589 if (PageLRU(page)) 1590 goto found; 1591 if (__PageMovable(page)) 1592 goto found; 1593 1594 /* 1595 * PageOffline() pages that are not marked __PageMovable() and 1596 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1597 * definitely unmovable. If their reference count would be 0, 1598 * they could at least be skipped when offlining memory. 1599 */ 1600 if (PageOffline(page) && page_count(page)) 1601 return -EBUSY; 1602 1603 if (!PageHuge(page)) 1604 continue; 1605 head = compound_head(page); 1606 /* 1607 * This test is racy as we hold no reference or lock. The 1608 * hugetlb page could have been free'ed and head is no longer 1609 * a hugetlb page before the following check. In such unlikely 1610 * cases false positives and negatives are possible. Calling 1611 * code must deal with these scenarios. 1612 */ 1613 if (HPageMigratable(head)) 1614 goto found; 1615 skip = compound_nr(head) - (page - head); 1616 pfn += skip - 1; 1617 } 1618 return -ENOENT; 1619 found: 1620 *movable_pfn = pfn; 1621 return 0; 1622 } 1623 1624 static int 1625 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1626 { 1627 unsigned long pfn; 1628 struct page *page, *head; 1629 int ret = 0; 1630 LIST_HEAD(source); 1631 static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, 1632 DEFAULT_RATELIMIT_BURST); 1633 1634 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1635 struct folio *folio; 1636 1637 if (!pfn_valid(pfn)) 1638 continue; 1639 page = pfn_to_page(pfn); 1640 folio = page_folio(page); 1641 head = &folio->page; 1642 1643 if (PageHuge(page)) { 1644 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1645 isolate_hugetlb(head, &source); 1646 continue; 1647 } else if (PageTransHuge(page)) 1648 pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; 1649 1650 /* 1651 * HWPoison pages have elevated reference counts so the migration would 1652 * fail on them. It also doesn't make any sense to migrate them in the 1653 * first place. Still try to unmap such a page in case it is still mapped 1654 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1655 * the unmap as the catch all safety net). 1656 */ 1657 if (PageHWPoison(page)) { 1658 if (WARN_ON(folio_test_lru(folio))) 1659 folio_isolate_lru(folio); 1660 if (folio_mapped(folio)) 1661 try_to_unmap(folio, TTU_IGNORE_MLOCK); 1662 continue; 1663 } 1664 1665 if (!get_page_unless_zero(page)) 1666 continue; 1667 /* 1668 * We can skip free pages. And we can deal with pages on 1669 * LRU and non-lru movable pages. 1670 */ 1671 if (PageLRU(page)) 1672 ret = isolate_lru_page(page); 1673 else 1674 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1675 if (!ret) { /* Success */ 1676 list_add_tail(&page->lru, &source); 1677 if (!__PageMovable(page)) 1678 inc_node_page_state(page, NR_ISOLATED_ANON + 1679 page_is_file_lru(page)); 1680 1681 } else { 1682 if (__ratelimit(&migrate_rs)) { 1683 pr_warn("failed to isolate pfn %lx\n", pfn); 1684 dump_page(page, "isolation failed"); 1685 } 1686 } 1687 put_page(page); 1688 } 1689 if (!list_empty(&source)) { 1690 nodemask_t nmask = node_states[N_MEMORY]; 1691 struct migration_target_control mtc = { 1692 .nmask = &nmask, 1693 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, 1694 }; 1695 1696 /* 1697 * We have checked that migration range is on a single zone so 1698 * we can use the nid of the first page to all the others. 1699 */ 1700 mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); 1701 1702 /* 1703 * try to allocate from a different node but reuse this node 1704 * if there are no other online nodes to be used (e.g. we are 1705 * offlining a part of the only existing node) 1706 */ 1707 node_clear(mtc.nid, nmask); 1708 if (nodes_empty(nmask)) 1709 node_set(mtc.nid, nmask); 1710 ret = migrate_pages(&source, alloc_migration_target, NULL, 1711 (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL); 1712 if (ret) { 1713 list_for_each_entry(page, &source, lru) { 1714 if (__ratelimit(&migrate_rs)) { 1715 pr_warn("migrating pfn %lx failed ret:%d\n", 1716 page_to_pfn(page), ret); 1717 dump_page(page, "migration failure"); 1718 } 1719 } 1720 putback_movable_pages(&source); 1721 } 1722 } 1723 1724 return ret; 1725 } 1726 1727 static int __init cmdline_parse_movable_node(char *p) 1728 { 1729 movable_node_enabled = true; 1730 return 0; 1731 } 1732 early_param("movable_node", cmdline_parse_movable_node); 1733 1734 /* check which state of node_states will be changed when offline memory */ 1735 static void node_states_check_changes_offline(unsigned long nr_pages, 1736 struct zone *zone, struct memory_notify *arg) 1737 { 1738 struct pglist_data *pgdat = zone->zone_pgdat; 1739 unsigned long present_pages = 0; 1740 enum zone_type zt; 1741 1742 arg->status_change_nid = NUMA_NO_NODE; 1743 arg->status_change_nid_normal = NUMA_NO_NODE; 1744 1745 /* 1746 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1747 * If the memory to be offline is within the range 1748 * [0..ZONE_NORMAL], and it is the last present memory there, 1749 * the zones in that range will become empty after the offlining, 1750 * thus we can determine that we need to clear the node from 1751 * node_states[N_NORMAL_MEMORY]. 1752 */ 1753 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1754 present_pages += pgdat->node_zones[zt].present_pages; 1755 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1756 arg->status_change_nid_normal = zone_to_nid(zone); 1757 1758 /* 1759 * We have accounted the pages from [0..ZONE_NORMAL); ZONE_HIGHMEM 1760 * does not apply as we don't support 32bit. 1761 * Here we count the possible pages from ZONE_MOVABLE. 1762 * If after having accounted all the pages, we see that the nr_pages 1763 * to be offlined is over or equal to the accounted pages, 1764 * we know that the node will become empty, and so, we can clear 1765 * it for N_MEMORY as well. 1766 */ 1767 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1768 1769 if (nr_pages >= present_pages) 1770 arg->status_change_nid = zone_to_nid(zone); 1771 } 1772 1773 static void node_states_clear_node(int node, struct memory_notify *arg) 1774 { 1775 if (arg->status_change_nid_normal >= 0) 1776 node_clear_state(node, N_NORMAL_MEMORY); 1777 1778 if (arg->status_change_nid >= 0) 1779 node_clear_state(node, N_MEMORY); 1780 } 1781 1782 static int count_system_ram_pages_cb(unsigned long start_pfn, 1783 unsigned long nr_pages, void *data) 1784 { 1785 unsigned long *nr_system_ram_pages = data; 1786 1787 *nr_system_ram_pages += nr_pages; 1788 return 0; 1789 } 1790 1791 int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, 1792 struct zone *zone, struct memory_group *group) 1793 { 1794 const unsigned long end_pfn = start_pfn + nr_pages; 1795 unsigned long pfn, system_ram_pages = 0; 1796 const int node = zone_to_nid(zone); 1797 unsigned long flags; 1798 struct memory_notify arg; 1799 char *reason; 1800 int ret; 1801 1802 /* 1803 * {on,off}lining is constrained to full memory sections (or more 1804 * precisely to memory blocks from the user space POV). 1805 * memmap_on_memory is an exception because it reserves initial part 1806 * of the physical memory space for vmemmaps. That space is pageblock 1807 * aligned. 1808 */ 1809 if (WARN_ON_ONCE(!nr_pages || 1810 !IS_ALIGNED(start_pfn, pageblock_nr_pages) || 1811 !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) 1812 return -EINVAL; 1813 1814 mem_hotplug_begin(); 1815 1816 /* 1817 * Don't allow to offline memory blocks that contain holes. 1818 * Consequently, memory blocks with holes can never get onlined 1819 * via the hotplug path - online_pages() - as hotplugged memory has 1820 * no holes. This way, we e.g., don't have to worry about marking 1821 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1822 * avoid using walk_system_ram_range() later. 1823 */ 1824 walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, 1825 count_system_ram_pages_cb); 1826 if (system_ram_pages != nr_pages) { 1827 ret = -EINVAL; 1828 reason = "memory holes"; 1829 goto failed_removal; 1830 } 1831 1832 /* 1833 * We only support offlining of memory blocks managed by a single zone, 1834 * checked by calling code. This is just a sanity check that we might 1835 * want to remove in the future. 1836 */ 1837 if (WARN_ON_ONCE(page_zone(pfn_to_page(start_pfn)) != zone || 1838 page_zone(pfn_to_page(end_pfn - 1)) != zone)) { 1839 ret = -EINVAL; 1840 reason = "multizone range"; 1841 goto failed_removal; 1842 } 1843 1844 /* 1845 * Disable pcplists so that page isolation cannot race with freeing 1846 * in a way that pages from isolated pageblock are left on pcplists. 1847 */ 1848 zone_pcp_disable(zone); 1849 lru_cache_disable(); 1850 1851 /* set above range as isolated */ 1852 ret = start_isolate_page_range(start_pfn, end_pfn, 1853 MIGRATE_MOVABLE, 1854 MEMORY_OFFLINE | REPORT_FAILURE, 1855 GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL); 1856 if (ret) { 1857 reason = "failure to isolate range"; 1858 goto failed_removal_pcplists_disabled; 1859 } 1860 1861 arg.start_pfn = start_pfn; 1862 arg.nr_pages = nr_pages; 1863 node_states_check_changes_offline(nr_pages, zone, &arg); 1864 1865 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1866 ret = notifier_to_errno(ret); 1867 if (ret) { 1868 reason = "notifier failure"; 1869 goto failed_removal_isolated; 1870 } 1871 1872 do { 1873 pfn = start_pfn; 1874 do { 1875 if (signal_pending(current)) { 1876 ret = -EINTR; 1877 reason = "signal backoff"; 1878 goto failed_removal_isolated; 1879 } 1880 1881 cond_resched(); 1882 1883 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1884 if (!ret) { 1885 /* 1886 * TODO: fatal migration failures should bail 1887 * out 1888 */ 1889 do_migrate_range(pfn, end_pfn); 1890 } 1891 } while (!ret); 1892 1893 if (ret != -ENOENT) { 1894 reason = "unmovable page"; 1895 goto failed_removal_isolated; 1896 } 1897 1898 /* 1899 * Dissolve free hugepages in the memory block before doing 1900 * offlining actually in order to make hugetlbfs's object 1901 * counting consistent. 1902 */ 1903 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1904 if (ret) { 1905 reason = "failure to dissolve huge pages"; 1906 goto failed_removal_isolated; 1907 } 1908 1909 ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); 1910 1911 } while (ret); 1912 1913 /* Mark all sections offline and remove free pages from the buddy. */ 1914 __offline_isolated_pages(start_pfn, end_pfn); 1915 pr_debug("Offlined Pages %ld\n", nr_pages); 1916 1917 /* 1918 * The memory sections are marked offline, and the pageblock flags 1919 * effectively stale; nobody should be touching them. Fixup the number 1920 * of isolated pageblocks, memory onlining will properly revert this. 1921 */ 1922 spin_lock_irqsave(&zone->lock, flags); 1923 zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; 1924 spin_unlock_irqrestore(&zone->lock, flags); 1925 1926 lru_cache_enable(); 1927 zone_pcp_enable(zone); 1928 1929 /* removal success */ 1930 adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); 1931 adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages); 1932 1933 /* reinitialise watermarks and update pcp limits */ 1934 init_per_zone_wmark_min(); 1935 1936 if (!populated_zone(zone)) { 1937 zone_pcp_reset(zone); 1938 build_all_zonelists(NULL); 1939 } 1940 1941 node_states_clear_node(node, &arg); 1942 if (arg.status_change_nid >= 0) { 1943 kswapd_stop(node); 1944 kcompactd_stop(node); 1945 } 1946 1947 writeback_set_ratelimit(); 1948 1949 memory_notify(MEM_OFFLINE, &arg); 1950 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1951 mem_hotplug_done(); 1952 return 0; 1953 1954 failed_removal_isolated: 1955 /* pushback to free area */ 1956 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1957 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1958 failed_removal_pcplists_disabled: 1959 lru_cache_enable(); 1960 zone_pcp_enable(zone); 1961 failed_removal: 1962 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1963 (unsigned long long) start_pfn << PAGE_SHIFT, 1964 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1965 reason); 1966 mem_hotplug_done(); 1967 return ret; 1968 } 1969 1970 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1971 { 1972 int ret = !is_memblock_offlined(mem); 1973 int *nid = arg; 1974 1975 *nid = mem->nid; 1976 if (unlikely(ret)) { 1977 phys_addr_t beginpa, endpa; 1978 1979 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1980 endpa = beginpa + memory_block_size_bytes() - 1; 1981 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1982 &beginpa, &endpa); 1983 1984 return -EBUSY; 1985 } 1986 return 0; 1987 } 1988 1989 static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg) 1990 { 1991 /* 1992 * If not set, continue with the next block. 1993 */ 1994 return mem->nr_vmemmap_pages; 1995 } 1996 1997 static int check_cpu_on_node(int nid) 1998 { 1999 int cpu; 2000 2001 for_each_present_cpu(cpu) { 2002 if (cpu_to_node(cpu) == nid) 2003 /* 2004 * the cpu on this node isn't removed, and we can't 2005 * offline this node. 2006 */ 2007 return -EBUSY; 2008 } 2009 2010 return 0; 2011 } 2012 2013 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 2014 { 2015 int nid = *(int *)arg; 2016 2017 /* 2018 * If a memory block belongs to multiple nodes, the stored nid is not 2019 * reliable. However, such blocks are always online (e.g., cannot get 2020 * offlined) and, therefore, are still spanned by the node. 2021 */ 2022 return mem->nid == nid ? -EEXIST : 0; 2023 } 2024 2025 /** 2026 * try_offline_node 2027 * @nid: the node ID 2028 * 2029 * Offline a node if all memory sections and cpus of the node are removed. 2030 * 2031 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2032 * and online/offline operations before this call. 2033 */ 2034 void try_offline_node(int nid) 2035 { 2036 int rc; 2037 2038 /* 2039 * If the node still spans pages (especially ZONE_DEVICE), don't 2040 * offline it. A node spans memory after move_pfn_range_to_zone(), 2041 * e.g., after the memory block was onlined. 2042 */ 2043 if (node_spanned_pages(nid)) 2044 return; 2045 2046 /* 2047 * Especially offline memory blocks might not be spanned by the 2048 * node. They will get spanned by the node once they get onlined. 2049 * However, they link to the node in sysfs and can get onlined later. 2050 */ 2051 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 2052 if (rc) 2053 return; 2054 2055 if (check_cpu_on_node(nid)) 2056 return; 2057 2058 /* 2059 * all memory/cpu of this node are removed, we can offline this 2060 * node now. 2061 */ 2062 node_set_offline(nid); 2063 unregister_one_node(nid); 2064 } 2065 EXPORT_SYMBOL(try_offline_node); 2066 2067 static int __ref try_remove_memory(u64 start, u64 size) 2068 { 2069 struct vmem_altmap mhp_altmap = {}; 2070 struct vmem_altmap *altmap = NULL; 2071 unsigned long nr_vmemmap_pages; 2072 int rc = 0, nid = NUMA_NO_NODE; 2073 2074 BUG_ON(check_hotplug_memory_range(start, size)); 2075 2076 /* 2077 * All memory blocks must be offlined before removing memory. Check 2078 * whether all memory blocks in question are offline and return error 2079 * if this is not the case. 2080 * 2081 * While at it, determine the nid. Note that if we'd have mixed nodes, 2082 * we'd only try to offline the last determined one -- which is good 2083 * enough for the cases we care about. 2084 */ 2085 rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb); 2086 if (rc) 2087 return rc; 2088 2089 /* 2090 * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in 2091 * the same granularity it was added - a single memory block. 2092 */ 2093 if (mhp_memmap_on_memory()) { 2094 nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, 2095 get_nr_vmemmap_pages_cb); 2096 if (nr_vmemmap_pages) { 2097 if (size != memory_block_size_bytes()) { 2098 pr_warn("Refuse to remove %#llx - %#llx," 2099 "wrong granularity\n", 2100 start, start + size); 2101 return -EINVAL; 2102 } 2103 2104 /* 2105 * Let remove_pmd_table->free_hugepage_table do the 2106 * right thing if we used vmem_altmap when hot-adding 2107 * the range. 2108 */ 2109 mhp_altmap.alloc = nr_vmemmap_pages; 2110 altmap = &mhp_altmap; 2111 } 2112 } 2113 2114 /* remove memmap entry */ 2115 firmware_map_remove(start, start + size, "System RAM"); 2116 2117 /* 2118 * Memory block device removal under the device_hotplug_lock is 2119 * a barrier against racing online attempts. 2120 */ 2121 remove_memory_block_devices(start, size); 2122 2123 mem_hotplug_begin(); 2124 2125 arch_remove_memory(start, size, altmap); 2126 2127 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 2128 memblock_phys_free(start, size); 2129 memblock_remove(start, size); 2130 } 2131 2132 release_mem_region_adjustable(start, size); 2133 2134 if (nid != NUMA_NO_NODE) 2135 try_offline_node(nid); 2136 2137 mem_hotplug_done(); 2138 return 0; 2139 } 2140 2141 /** 2142 * __remove_memory - Remove memory if every memory block is offline 2143 * @start: physical address of the region to remove 2144 * @size: size of the region to remove 2145 * 2146 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2147 * and online/offline operations before this call, as required by 2148 * try_offline_node(). 2149 */ 2150 void __remove_memory(u64 start, u64 size) 2151 { 2152 2153 /* 2154 * trigger BUG() if some memory is not offlined prior to calling this 2155 * function 2156 */ 2157 if (try_remove_memory(start, size)) 2158 BUG(); 2159 } 2160 2161 /* 2162 * Remove memory if every memory block is offline, otherwise return -EBUSY is 2163 * some memory is not offline 2164 */ 2165 int remove_memory(u64 start, u64 size) 2166 { 2167 int rc; 2168 2169 lock_device_hotplug(); 2170 rc = try_remove_memory(start, size); 2171 unlock_device_hotplug(); 2172 2173 return rc; 2174 } 2175 EXPORT_SYMBOL_GPL(remove_memory); 2176 2177 static int try_offline_memory_block(struct memory_block *mem, void *arg) 2178 { 2179 uint8_t online_type = MMOP_ONLINE_KERNEL; 2180 uint8_t **online_types = arg; 2181 struct page *page; 2182 int rc; 2183 2184 /* 2185 * Sense the online_type via the zone of the memory block. Offlining 2186 * with multiple zones within one memory block will be rejected 2187 * by offlining code ... so we don't care about that. 2188 */ 2189 page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); 2190 if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) 2191 online_type = MMOP_ONLINE_MOVABLE; 2192 2193 rc = device_offline(&mem->dev); 2194 /* 2195 * Default is MMOP_OFFLINE - change it only if offlining succeeded, 2196 * so try_reonline_memory_block() can do the right thing. 2197 */ 2198 if (!rc) 2199 **online_types = online_type; 2200 2201 (*online_types)++; 2202 /* Ignore if already offline. */ 2203 return rc < 0 ? rc : 0; 2204 } 2205 2206 static int try_reonline_memory_block(struct memory_block *mem, void *arg) 2207 { 2208 uint8_t **online_types = arg; 2209 int rc; 2210 2211 if (**online_types != MMOP_OFFLINE) { 2212 mem->online_type = **online_types; 2213 rc = device_online(&mem->dev); 2214 if (rc < 0) 2215 pr_warn("%s: Failed to re-online memory: %d", 2216 __func__, rc); 2217 } 2218 2219 /* Continue processing all remaining memory blocks. */ 2220 (*online_types)++; 2221 return 0; 2222 } 2223 2224 /* 2225 * Try to offline and remove memory. Might take a long time to finish in case 2226 * memory is still in use. Primarily useful for memory devices that logically 2227 * unplugged all memory (so it's no longer in use) and want to offline + remove 2228 * that memory. 2229 */ 2230 int offline_and_remove_memory(u64 start, u64 size) 2231 { 2232 const unsigned long mb_count = size / memory_block_size_bytes(); 2233 uint8_t *online_types, *tmp; 2234 int rc; 2235 2236 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 2237 !IS_ALIGNED(size, memory_block_size_bytes()) || !size) 2238 return -EINVAL; 2239 2240 /* 2241 * We'll remember the old online type of each memory block, so we can 2242 * try to revert whatever we did when offlining one memory block fails 2243 * after offlining some others succeeded. 2244 */ 2245 online_types = kmalloc_array(mb_count, sizeof(*online_types), 2246 GFP_KERNEL); 2247 if (!online_types) 2248 return -ENOMEM; 2249 /* 2250 * Initialize all states to MMOP_OFFLINE, so when we abort processing in 2251 * try_offline_memory_block(), we'll skip all unprocessed blocks in 2252 * try_reonline_memory_block(). 2253 */ 2254 memset(online_types, MMOP_OFFLINE, mb_count); 2255 2256 lock_device_hotplug(); 2257 2258 tmp = online_types; 2259 rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); 2260 2261 /* 2262 * In case we succeeded to offline all memory, remove it. 2263 * This cannot fail as it cannot get onlined in the meantime. 2264 */ 2265 if (!rc) { 2266 rc = try_remove_memory(start, size); 2267 if (rc) 2268 pr_err("%s: Failed to remove memory: %d", __func__, rc); 2269 } 2270 2271 /* 2272 * Rollback what we did. While memory onlining might theoretically fail 2273 * (nacked by a notifier), it barely ever happens. 2274 */ 2275 if (rc) { 2276 tmp = online_types; 2277 walk_memory_blocks(start, size, &tmp, 2278 try_reonline_memory_block); 2279 } 2280 unlock_device_hotplug(); 2281 2282 kfree(online_types); 2283 return rc; 2284 } 2285 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 2286 #endif /* CONFIG_MEMORY_HOTREMOVE */ 2287