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 static int memmap_on_memory_set(const char *val, const struct kernel_param *kp) 47 { 48 if (hugetlb_optimize_vmemmap_enabled()) 49 return 0; 50 return param_set_bool(val, kp); 51 } 52 53 static const struct kernel_param_ops memmap_on_memory_ops = { 54 .flags = KERNEL_PARAM_OPS_FL_NOARG, 55 .set = memmap_on_memory_set, 56 .get = param_get_bool, 57 }; 58 59 /* 60 * memory_hotplug.memmap_on_memory parameter 61 */ 62 static bool memmap_on_memory __ro_after_init; 63 module_param_cb(memmap_on_memory, &memmap_on_memory_ops, &memmap_on_memory, 0444); 64 MODULE_PARM_DESC(memmap_on_memory, "Enable memmap on memory for memory hotplug"); 65 66 bool mhp_memmap_on_memory(void) 67 { 68 return memmap_on_memory; 69 } 70 #endif 71 72 enum { 73 ONLINE_POLICY_CONTIG_ZONES = 0, 74 ONLINE_POLICY_AUTO_MOVABLE, 75 }; 76 77 static const char * const online_policy_to_str[] = { 78 [ONLINE_POLICY_CONTIG_ZONES] = "contig-zones", 79 [ONLINE_POLICY_AUTO_MOVABLE] = "auto-movable", 80 }; 81 82 static int set_online_policy(const char *val, const struct kernel_param *kp) 83 { 84 int ret = sysfs_match_string(online_policy_to_str, val); 85 86 if (ret < 0) 87 return ret; 88 *((int *)kp->arg) = ret; 89 return 0; 90 } 91 92 static int get_online_policy(char *buffer, const struct kernel_param *kp) 93 { 94 return sprintf(buffer, "%s\n", online_policy_to_str[*((int *)kp->arg)]); 95 } 96 97 /* 98 * memory_hotplug.online_policy: configure online behavior when onlining without 99 * specifying a zone (MMOP_ONLINE) 100 * 101 * "contig-zones": keep zone contiguous 102 * "auto-movable": online memory to ZONE_MOVABLE if the configuration 103 * (auto_movable_ratio, auto_movable_numa_aware) allows for it 104 */ 105 static int online_policy __read_mostly = ONLINE_POLICY_CONTIG_ZONES; 106 static const struct kernel_param_ops online_policy_ops = { 107 .set = set_online_policy, 108 .get = get_online_policy, 109 }; 110 module_param_cb(online_policy, &online_policy_ops, &online_policy, 0644); 111 MODULE_PARM_DESC(online_policy, 112 "Set the online policy (\"contig-zones\", \"auto-movable\") " 113 "Default: \"contig-zones\""); 114 115 /* 116 * memory_hotplug.auto_movable_ratio: specify maximum MOVABLE:KERNEL ratio 117 * 118 * The ratio represent an upper limit and the kernel might decide to not 119 * online some memory to ZONE_MOVABLE -- e.g., because hotplugged KERNEL memory 120 * doesn't allow for more MOVABLE memory. 121 */ 122 static unsigned int auto_movable_ratio __read_mostly = 301; 123 module_param(auto_movable_ratio, uint, 0644); 124 MODULE_PARM_DESC(auto_movable_ratio, 125 "Set the maximum ratio of MOVABLE:KERNEL memory in the system " 126 "in percent for \"auto-movable\" online policy. Default: 301"); 127 128 /* 129 * memory_hotplug.auto_movable_numa_aware: consider numa node stats 130 */ 131 #ifdef CONFIG_NUMA 132 static bool auto_movable_numa_aware __read_mostly = true; 133 module_param(auto_movable_numa_aware, bool, 0644); 134 MODULE_PARM_DESC(auto_movable_numa_aware, 135 "Consider numa node stats in addition to global stats in " 136 "\"auto-movable\" online policy. Default: true"); 137 #endif /* CONFIG_NUMA */ 138 139 /* 140 * online_page_callback contains pointer to current page onlining function. 141 * Initially it is generic_online_page(). If it is required it could be 142 * changed by calling set_online_page_callback() for callback registration 143 * and restore_online_page_callback() for generic callback restore. 144 */ 145 146 static online_page_callback_t online_page_callback = generic_online_page; 147 static DEFINE_MUTEX(online_page_callback_lock); 148 149 DEFINE_STATIC_PERCPU_RWSEM(mem_hotplug_lock); 150 151 void get_online_mems(void) 152 { 153 percpu_down_read(&mem_hotplug_lock); 154 } 155 156 void put_online_mems(void) 157 { 158 percpu_up_read(&mem_hotplug_lock); 159 } 160 161 bool movable_node_enabled = false; 162 163 #ifndef CONFIG_MEMORY_HOTPLUG_DEFAULT_ONLINE 164 int mhp_default_online_type = MMOP_OFFLINE; 165 #else 166 int mhp_default_online_type = MMOP_ONLINE; 167 #endif 168 169 static int __init setup_memhp_default_state(char *str) 170 { 171 const int online_type = mhp_online_type_from_str(str); 172 173 if (online_type >= 0) 174 mhp_default_online_type = online_type; 175 176 return 1; 177 } 178 __setup("memhp_default_state=", setup_memhp_default_state); 179 180 void mem_hotplug_begin(void) 181 { 182 cpus_read_lock(); 183 percpu_down_write(&mem_hotplug_lock); 184 } 185 186 void mem_hotplug_done(void) 187 { 188 percpu_up_write(&mem_hotplug_lock); 189 cpus_read_unlock(); 190 } 191 192 u64 max_mem_size = U64_MAX; 193 194 /* add this memory to iomem resource */ 195 static struct resource *register_memory_resource(u64 start, u64 size, 196 const char *resource_name) 197 { 198 struct resource *res; 199 unsigned long flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 200 201 if (strcmp(resource_name, "System RAM")) 202 flags |= IORESOURCE_SYSRAM_DRIVER_MANAGED; 203 204 if (!mhp_range_allowed(start, size, true)) 205 return ERR_PTR(-E2BIG); 206 207 /* 208 * Make sure value parsed from 'mem=' only restricts memory adding 209 * while booting, so that memory hotplug won't be impacted. Please 210 * refer to document of 'mem=' in kernel-parameters.txt for more 211 * details. 212 */ 213 if (start + size > max_mem_size && system_state < SYSTEM_RUNNING) 214 return ERR_PTR(-E2BIG); 215 216 /* 217 * Request ownership of the new memory range. This might be 218 * a child of an existing resource that was present but 219 * not marked as busy. 220 */ 221 res = __request_region(&iomem_resource, start, size, 222 resource_name, flags); 223 224 if (!res) { 225 pr_debug("Unable to reserve System RAM region: %016llx->%016llx\n", 226 start, start + size); 227 return ERR_PTR(-EEXIST); 228 } 229 return res; 230 } 231 232 static void release_memory_resource(struct resource *res) 233 { 234 if (!res) 235 return; 236 release_resource(res); 237 kfree(res); 238 } 239 240 static int check_pfn_span(unsigned long pfn, unsigned long nr_pages, 241 const char *reason) 242 { 243 /* 244 * Disallow all operations smaller than a sub-section and only 245 * allow operations smaller than a section for 246 * SPARSEMEM_VMEMMAP. Note that check_hotplug_memory_range() 247 * enforces a larger memory_block_size_bytes() granularity for 248 * memory that will be marked online, so this check should only 249 * fire for direct arch_{add,remove}_memory() users outside of 250 * add_memory_resource(). 251 */ 252 unsigned long min_align; 253 254 if (IS_ENABLED(CONFIG_SPARSEMEM_VMEMMAP)) 255 min_align = PAGES_PER_SUBSECTION; 256 else 257 min_align = PAGES_PER_SECTION; 258 if (!IS_ALIGNED(pfn, min_align) 259 || !IS_ALIGNED(nr_pages, min_align)) { 260 WARN(1, "Misaligned __%s_pages start: %#lx end: #%lx\n", 261 reason, pfn, pfn + nr_pages - 1); 262 return -EINVAL; 263 } 264 return 0; 265 } 266 267 /* 268 * Return page for the valid pfn only if the page is online. All pfn 269 * walkers which rely on the fully initialized page->flags and others 270 * should use this rather than pfn_valid && pfn_to_page 271 */ 272 struct page *pfn_to_online_page(unsigned long pfn) 273 { 274 unsigned long nr = pfn_to_section_nr(pfn); 275 struct dev_pagemap *pgmap; 276 struct mem_section *ms; 277 278 if (nr >= NR_MEM_SECTIONS) 279 return NULL; 280 281 ms = __nr_to_section(nr); 282 if (!online_section(ms)) 283 return NULL; 284 285 /* 286 * Save some code text when online_section() + 287 * pfn_section_valid() are sufficient. 288 */ 289 if (IS_ENABLED(CONFIG_HAVE_ARCH_PFN_VALID) && !pfn_valid(pfn)) 290 return NULL; 291 292 if (!pfn_section_valid(ms, pfn)) 293 return NULL; 294 295 if (!online_device_section(ms)) 296 return pfn_to_page(pfn); 297 298 /* 299 * Slowpath: when ZONE_DEVICE collides with 300 * ZONE_{NORMAL,MOVABLE} within the same section some pfns in 301 * the section may be 'offline' but 'valid'. Only 302 * get_dev_pagemap() can determine sub-section online status. 303 */ 304 pgmap = get_dev_pagemap(pfn, NULL); 305 put_dev_pagemap(pgmap); 306 307 /* The presence of a pgmap indicates ZONE_DEVICE offline pfn */ 308 if (pgmap) 309 return NULL; 310 311 return pfn_to_page(pfn); 312 } 313 EXPORT_SYMBOL_GPL(pfn_to_online_page); 314 315 int __ref __add_pages(int nid, unsigned long pfn, unsigned long nr_pages, 316 struct mhp_params *params) 317 { 318 const unsigned long end_pfn = pfn + nr_pages; 319 unsigned long cur_nr_pages; 320 int err; 321 struct vmem_altmap *altmap = params->altmap; 322 323 if (WARN_ON_ONCE(!pgprot_val(params->pgprot))) 324 return -EINVAL; 325 326 VM_BUG_ON(!mhp_range_allowed(PFN_PHYS(pfn), nr_pages * PAGE_SIZE, false)); 327 328 if (altmap) { 329 /* 330 * Validate altmap is within bounds of the total request 331 */ 332 if (altmap->base_pfn != pfn 333 || vmem_altmap_offset(altmap) > nr_pages) { 334 pr_warn_once("memory add fail, invalid altmap\n"); 335 return -EINVAL; 336 } 337 altmap->alloc = 0; 338 } 339 340 err = check_pfn_span(pfn, nr_pages, "add"); 341 if (err) 342 return err; 343 344 for (; pfn < end_pfn; pfn += cur_nr_pages) { 345 /* Select all remaining pages up to the next section boundary */ 346 cur_nr_pages = min(end_pfn - pfn, 347 SECTION_ALIGN_UP(pfn + 1) - pfn); 348 err = sparse_add_section(nid, pfn, cur_nr_pages, altmap, 349 params->pgmap); 350 if (err) 351 break; 352 cond_resched(); 353 } 354 vmemmap_populate_print_last(); 355 return err; 356 } 357 358 /* find the smallest valid pfn in the range [start_pfn, end_pfn) */ 359 static unsigned long find_smallest_section_pfn(int nid, struct zone *zone, 360 unsigned long start_pfn, 361 unsigned long end_pfn) 362 { 363 for (; start_pfn < end_pfn; start_pfn += PAGES_PER_SUBSECTION) { 364 if (unlikely(!pfn_to_online_page(start_pfn))) 365 continue; 366 367 if (unlikely(pfn_to_nid(start_pfn) != nid)) 368 continue; 369 370 if (zone != page_zone(pfn_to_page(start_pfn))) 371 continue; 372 373 return start_pfn; 374 } 375 376 return 0; 377 } 378 379 /* find the biggest valid pfn in the range [start_pfn, end_pfn). */ 380 static unsigned long find_biggest_section_pfn(int nid, struct zone *zone, 381 unsigned long start_pfn, 382 unsigned long end_pfn) 383 { 384 unsigned long pfn; 385 386 /* pfn is the end pfn of a memory section. */ 387 pfn = end_pfn - 1; 388 for (; pfn >= start_pfn; pfn -= PAGES_PER_SUBSECTION) { 389 if (unlikely(!pfn_to_online_page(pfn))) 390 continue; 391 392 if (unlikely(pfn_to_nid(pfn) != nid)) 393 continue; 394 395 if (zone != page_zone(pfn_to_page(pfn))) 396 continue; 397 398 return pfn; 399 } 400 401 return 0; 402 } 403 404 static void shrink_zone_span(struct zone *zone, unsigned long start_pfn, 405 unsigned long end_pfn) 406 { 407 unsigned long pfn; 408 int nid = zone_to_nid(zone); 409 410 if (zone->zone_start_pfn == start_pfn) { 411 /* 412 * If the section is smallest section in the zone, it need 413 * shrink zone->zone_start_pfn and zone->zone_spanned_pages. 414 * In this case, we find second smallest valid mem_section 415 * for shrinking zone. 416 */ 417 pfn = find_smallest_section_pfn(nid, zone, end_pfn, 418 zone_end_pfn(zone)); 419 if (pfn) { 420 zone->spanned_pages = zone_end_pfn(zone) - pfn; 421 zone->zone_start_pfn = pfn; 422 } else { 423 zone->zone_start_pfn = 0; 424 zone->spanned_pages = 0; 425 } 426 } else if (zone_end_pfn(zone) == end_pfn) { 427 /* 428 * If the section is biggest section in the zone, it need 429 * shrink zone->spanned_pages. 430 * In this case, we find second biggest valid mem_section for 431 * shrinking zone. 432 */ 433 pfn = find_biggest_section_pfn(nid, zone, zone->zone_start_pfn, 434 start_pfn); 435 if (pfn) 436 zone->spanned_pages = pfn - zone->zone_start_pfn + 1; 437 else { 438 zone->zone_start_pfn = 0; 439 zone->spanned_pages = 0; 440 } 441 } 442 } 443 444 static void update_pgdat_span(struct pglist_data *pgdat) 445 { 446 unsigned long node_start_pfn = 0, node_end_pfn = 0; 447 struct zone *zone; 448 449 for (zone = pgdat->node_zones; 450 zone < pgdat->node_zones + MAX_NR_ZONES; zone++) { 451 unsigned long end_pfn = zone_end_pfn(zone); 452 453 /* No need to lock the zones, they can't change. */ 454 if (!zone->spanned_pages) 455 continue; 456 if (!node_end_pfn) { 457 node_start_pfn = zone->zone_start_pfn; 458 node_end_pfn = end_pfn; 459 continue; 460 } 461 462 if (end_pfn > node_end_pfn) 463 node_end_pfn = end_pfn; 464 if (zone->zone_start_pfn < node_start_pfn) 465 node_start_pfn = zone->zone_start_pfn; 466 } 467 468 pgdat->node_start_pfn = node_start_pfn; 469 pgdat->node_spanned_pages = node_end_pfn - node_start_pfn; 470 } 471 472 void __ref remove_pfn_range_from_zone(struct zone *zone, 473 unsigned long start_pfn, 474 unsigned long nr_pages) 475 { 476 const unsigned long end_pfn = start_pfn + nr_pages; 477 struct pglist_data *pgdat = zone->zone_pgdat; 478 unsigned long pfn, cur_nr_pages; 479 480 /* Poison struct pages because they are now uninitialized again. */ 481 for (pfn = start_pfn; pfn < end_pfn; pfn += cur_nr_pages) { 482 cond_resched(); 483 484 /* Select all remaining pages up to the next section boundary */ 485 cur_nr_pages = 486 min(end_pfn - pfn, SECTION_ALIGN_UP(pfn + 1) - pfn); 487 page_init_poison(pfn_to_page(pfn), 488 sizeof(struct page) * cur_nr_pages); 489 } 490 491 /* 492 * Zone shrinking code cannot properly deal with ZONE_DEVICE. So 493 * we will not try to shrink the zones - which is okay as 494 * set_zone_contiguous() cannot deal with ZONE_DEVICE either way. 495 */ 496 if (zone_is_zone_device(zone)) 497 return; 498 499 clear_zone_contiguous(zone); 500 501 shrink_zone_span(zone, start_pfn, start_pfn + nr_pages); 502 update_pgdat_span(pgdat); 503 504 set_zone_contiguous(zone); 505 } 506 507 static void __remove_section(unsigned long pfn, unsigned long nr_pages, 508 unsigned long map_offset, 509 struct vmem_altmap *altmap) 510 { 511 struct mem_section *ms = __pfn_to_section(pfn); 512 513 if (WARN_ON_ONCE(!valid_section(ms))) 514 return; 515 516 sparse_remove_section(ms, pfn, nr_pages, map_offset, altmap); 517 } 518 519 /** 520 * __remove_pages() - remove sections of pages 521 * @pfn: starting pageframe (must be aligned to start of a section) 522 * @nr_pages: number of pages to remove (must be multiple of section size) 523 * @altmap: alternative device page map or %NULL if default memmap is used 524 * 525 * Generic helper function to remove section mappings and sysfs entries 526 * for the section of the memory we are removing. Caller needs to make 527 * sure that pages are marked reserved and zones are adjust properly by 528 * calling offline_pages(). 529 */ 530 void __remove_pages(unsigned long pfn, unsigned long nr_pages, 531 struct vmem_altmap *altmap) 532 { 533 const unsigned long end_pfn = pfn + nr_pages; 534 unsigned long cur_nr_pages; 535 unsigned long map_offset = 0; 536 537 map_offset = vmem_altmap_offset(altmap); 538 539 if (check_pfn_span(pfn, nr_pages, "remove")) 540 return; 541 542 for (; pfn < end_pfn; pfn += cur_nr_pages) { 543 cond_resched(); 544 /* Select all remaining pages up to the next section boundary */ 545 cur_nr_pages = min(end_pfn - pfn, 546 SECTION_ALIGN_UP(pfn + 1) - pfn); 547 __remove_section(pfn, cur_nr_pages, map_offset, altmap); 548 map_offset = 0; 549 } 550 } 551 552 int set_online_page_callback(online_page_callback_t callback) 553 { 554 int rc = -EINVAL; 555 556 get_online_mems(); 557 mutex_lock(&online_page_callback_lock); 558 559 if (online_page_callback == generic_online_page) { 560 online_page_callback = callback; 561 rc = 0; 562 } 563 564 mutex_unlock(&online_page_callback_lock); 565 put_online_mems(); 566 567 return rc; 568 } 569 EXPORT_SYMBOL_GPL(set_online_page_callback); 570 571 int restore_online_page_callback(online_page_callback_t callback) 572 { 573 int rc = -EINVAL; 574 575 get_online_mems(); 576 mutex_lock(&online_page_callback_lock); 577 578 if (online_page_callback == callback) { 579 online_page_callback = generic_online_page; 580 rc = 0; 581 } 582 583 mutex_unlock(&online_page_callback_lock); 584 put_online_mems(); 585 586 return rc; 587 } 588 EXPORT_SYMBOL_GPL(restore_online_page_callback); 589 590 void generic_online_page(struct page *page, unsigned int order) 591 { 592 /* 593 * Freeing the page with debug_pagealloc enabled will try to unmap it, 594 * so we should map it first. This is better than introducing a special 595 * case in page freeing fast path. 596 */ 597 debug_pagealloc_map_pages(page, 1 << order); 598 __free_pages_core(page, order); 599 totalram_pages_add(1UL << order); 600 } 601 EXPORT_SYMBOL_GPL(generic_online_page); 602 603 static void online_pages_range(unsigned long start_pfn, unsigned long nr_pages) 604 { 605 const unsigned long end_pfn = start_pfn + nr_pages; 606 unsigned long pfn; 607 608 /* 609 * Online the pages in MAX_ORDER - 1 aligned chunks. The callback might 610 * decide to not expose all pages to the buddy (e.g., expose them 611 * later). We account all pages as being online and belonging to this 612 * zone ("present"). 613 * When using memmap_on_memory, the range might not be aligned to 614 * MAX_ORDER_NR_PAGES - 1, but pageblock aligned. __ffs() will detect 615 * this and the first chunk to online will be pageblock_nr_pages. 616 */ 617 for (pfn = start_pfn; pfn < end_pfn;) { 618 int order = min(MAX_ORDER - 1UL, __ffs(pfn)); 619 620 (*online_page_callback)(pfn_to_page(pfn), order); 621 pfn += (1UL << order); 622 } 623 624 /* mark all involved sections as online */ 625 online_mem_sections(start_pfn, end_pfn); 626 } 627 628 /* check which state of node_states will be changed when online memory */ 629 static void node_states_check_changes_online(unsigned long nr_pages, 630 struct zone *zone, struct memory_notify *arg) 631 { 632 int nid = zone_to_nid(zone); 633 634 arg->status_change_nid = NUMA_NO_NODE; 635 arg->status_change_nid_normal = NUMA_NO_NODE; 636 637 if (!node_state(nid, N_MEMORY)) 638 arg->status_change_nid = nid; 639 if (zone_idx(zone) <= ZONE_NORMAL && !node_state(nid, N_NORMAL_MEMORY)) 640 arg->status_change_nid_normal = nid; 641 } 642 643 static void node_states_set_node(int node, struct memory_notify *arg) 644 { 645 if (arg->status_change_nid_normal >= 0) 646 node_set_state(node, N_NORMAL_MEMORY); 647 648 if (arg->status_change_nid >= 0) 649 node_set_state(node, N_MEMORY); 650 } 651 652 static void __meminit resize_zone_range(struct zone *zone, unsigned long start_pfn, 653 unsigned long nr_pages) 654 { 655 unsigned long old_end_pfn = zone_end_pfn(zone); 656 657 if (zone_is_empty(zone) || start_pfn < zone->zone_start_pfn) 658 zone->zone_start_pfn = start_pfn; 659 660 zone->spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - zone->zone_start_pfn; 661 } 662 663 static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned long start_pfn, 664 unsigned long nr_pages) 665 { 666 unsigned long old_end_pfn = pgdat_end_pfn(pgdat); 667 668 if (!pgdat->node_spanned_pages || start_pfn < pgdat->node_start_pfn) 669 pgdat->node_start_pfn = start_pfn; 670 671 pgdat->node_spanned_pages = max(start_pfn + nr_pages, old_end_pfn) - pgdat->node_start_pfn; 672 673 } 674 675 static void section_taint_zone_device(unsigned long pfn) 676 { 677 struct mem_section *ms = __pfn_to_section(pfn); 678 679 ms->section_mem_map |= SECTION_TAINT_ZONE_DEVICE; 680 } 681 682 /* 683 * Associate the pfn range with the given zone, initializing the memmaps 684 * and resizing the pgdat/zone data to span the added pages. After this 685 * call, all affected pages are PG_reserved. 686 * 687 * All aligned pageblocks are initialized to the specified migratetype 688 * (usually MIGRATE_MOVABLE). Besides setting the migratetype, no related 689 * zone stats (e.g., nr_isolate_pageblock) are touched. 690 */ 691 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn, 692 unsigned long nr_pages, 693 struct vmem_altmap *altmap, int migratetype) 694 { 695 struct pglist_data *pgdat = zone->zone_pgdat; 696 int nid = pgdat->node_id; 697 698 clear_zone_contiguous(zone); 699 700 if (zone_is_empty(zone)) 701 init_currently_empty_zone(zone, start_pfn, nr_pages); 702 resize_zone_range(zone, start_pfn, nr_pages); 703 resize_pgdat_range(pgdat, start_pfn, nr_pages); 704 705 /* 706 * Subsection population requires care in pfn_to_online_page(). 707 * Set the taint to enable the slow path detection of 708 * ZONE_DEVICE pages in an otherwise ZONE_{NORMAL,MOVABLE} 709 * section. 710 */ 711 if (zone_is_zone_device(zone)) { 712 if (!IS_ALIGNED(start_pfn, PAGES_PER_SECTION)) 713 section_taint_zone_device(start_pfn); 714 if (!IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION)) 715 section_taint_zone_device(start_pfn + nr_pages); 716 } 717 718 /* 719 * TODO now we have a visible range of pages which are not associated 720 * with their zone properly. Not nice but set_pfnblock_flags_mask 721 * expects the zone spans the pfn range. All the pages in the range 722 * are reserved so nobody should be touching them so we should be safe 723 */ 724 memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0, 725 MEMINIT_HOTPLUG, altmap, migratetype); 726 727 set_zone_contiguous(zone); 728 } 729 730 struct auto_movable_stats { 731 unsigned long kernel_early_pages; 732 unsigned long movable_pages; 733 }; 734 735 static void auto_movable_stats_account_zone(struct auto_movable_stats *stats, 736 struct zone *zone) 737 { 738 if (zone_idx(zone) == ZONE_MOVABLE) { 739 stats->movable_pages += zone->present_pages; 740 } else { 741 stats->kernel_early_pages += zone->present_early_pages; 742 #ifdef CONFIG_CMA 743 /* 744 * CMA pages (never on hotplugged memory) behave like 745 * ZONE_MOVABLE. 746 */ 747 stats->movable_pages += zone->cma_pages; 748 stats->kernel_early_pages -= zone->cma_pages; 749 #endif /* CONFIG_CMA */ 750 } 751 } 752 struct auto_movable_group_stats { 753 unsigned long movable_pages; 754 unsigned long req_kernel_early_pages; 755 }; 756 757 static int auto_movable_stats_account_group(struct memory_group *group, 758 void *arg) 759 { 760 const int ratio = READ_ONCE(auto_movable_ratio); 761 struct auto_movable_group_stats *stats = arg; 762 long pages; 763 764 /* 765 * We don't support modifying the config while the auto-movable online 766 * policy is already enabled. Just avoid the division by zero below. 767 */ 768 if (!ratio) 769 return 0; 770 771 /* 772 * Calculate how many early kernel pages this group requires to 773 * satisfy the configured zone ratio. 774 */ 775 pages = group->present_movable_pages * 100 / ratio; 776 pages -= group->present_kernel_pages; 777 778 if (pages > 0) 779 stats->req_kernel_early_pages += pages; 780 stats->movable_pages += group->present_movable_pages; 781 return 0; 782 } 783 784 static bool auto_movable_can_online_movable(int nid, struct memory_group *group, 785 unsigned long nr_pages) 786 { 787 unsigned long kernel_early_pages, movable_pages; 788 struct auto_movable_group_stats group_stats = {}; 789 struct auto_movable_stats stats = {}; 790 pg_data_t *pgdat = NODE_DATA(nid); 791 struct zone *zone; 792 int i; 793 794 /* Walk all relevant zones and collect MOVABLE vs. KERNEL stats. */ 795 if (nid == NUMA_NO_NODE) { 796 /* TODO: cache values */ 797 for_each_populated_zone(zone) 798 auto_movable_stats_account_zone(&stats, zone); 799 } else { 800 for (i = 0; i < MAX_NR_ZONES; i++) { 801 zone = pgdat->node_zones + i; 802 if (populated_zone(zone)) 803 auto_movable_stats_account_zone(&stats, zone); 804 } 805 } 806 807 kernel_early_pages = stats.kernel_early_pages; 808 movable_pages = stats.movable_pages; 809 810 /* 811 * Kernel memory inside dynamic memory group allows for more MOVABLE 812 * memory within the same group. Remove the effect of all but the 813 * current group from the stats. 814 */ 815 walk_dynamic_memory_groups(nid, auto_movable_stats_account_group, 816 group, &group_stats); 817 if (kernel_early_pages <= group_stats.req_kernel_early_pages) 818 return false; 819 kernel_early_pages -= group_stats.req_kernel_early_pages; 820 movable_pages -= group_stats.movable_pages; 821 822 if (group && group->is_dynamic) 823 kernel_early_pages += group->present_kernel_pages; 824 825 /* 826 * Test if we could online the given number of pages to ZONE_MOVABLE 827 * and still stay in the configured ratio. 828 */ 829 movable_pages += nr_pages; 830 return movable_pages <= (auto_movable_ratio * kernel_early_pages) / 100; 831 } 832 833 /* 834 * Returns a default kernel memory zone for the given pfn range. 835 * If no kernel zone covers this pfn range it will automatically go 836 * to the ZONE_NORMAL. 837 */ 838 static struct zone *default_kernel_zone_for_pfn(int nid, unsigned long start_pfn, 839 unsigned long nr_pages) 840 { 841 struct pglist_data *pgdat = NODE_DATA(nid); 842 int zid; 843 844 for (zid = 0; zid < ZONE_NORMAL; zid++) { 845 struct zone *zone = &pgdat->node_zones[zid]; 846 847 if (zone_intersects(zone, start_pfn, nr_pages)) 848 return zone; 849 } 850 851 return &pgdat->node_zones[ZONE_NORMAL]; 852 } 853 854 /* 855 * Determine to which zone to online memory dynamically based on user 856 * configuration and system stats. We care about the following ratio: 857 * 858 * MOVABLE : KERNEL 859 * 860 * Whereby MOVABLE is memory in ZONE_MOVABLE and KERNEL is memory in 861 * one of the kernel zones. CMA pages inside one of the kernel zones really 862 * behaves like ZONE_MOVABLE, so we treat them accordingly. 863 * 864 * We don't allow for hotplugged memory in a KERNEL zone to increase the 865 * amount of MOVABLE memory we can have, so we end up with: 866 * 867 * MOVABLE : KERNEL_EARLY 868 * 869 * Whereby KERNEL_EARLY is memory in one of the kernel zones, available sinze 870 * boot. We base our calculation on KERNEL_EARLY internally, because: 871 * 872 * a) Hotplugged memory in one of the kernel zones can sometimes still get 873 * hotunplugged, especially when hot(un)plugging individual memory blocks. 874 * There is no coordination across memory devices, therefore "automatic" 875 * hotunplugging, as implemented in hypervisors, could result in zone 876 * imbalances. 877 * b) Early/boot memory in one of the kernel zones can usually not get 878 * hotunplugged again (e.g., no firmware interface to unplug, fragmented 879 * with unmovable allocations). While there are corner cases where it might 880 * still work, it is barely relevant in practice. 881 * 882 * Exceptions are dynamic memory groups, which allow for more MOVABLE 883 * memory within the same memory group -- because in that case, there is 884 * coordination within the single memory device managed by a single driver. 885 * 886 * We rely on "present pages" instead of "managed pages", as the latter is 887 * highly unreliable and dynamic in virtualized environments, and does not 888 * consider boot time allocations. For example, memory ballooning adjusts the 889 * managed pages when inflating/deflating the balloon, and balloon compaction 890 * can even migrate inflated pages between zones. 891 * 892 * Using "present pages" is better but some things to keep in mind are: 893 * 894 * a) Some memblock allocations, such as for the crashkernel area, are 895 * effectively unused by the kernel, yet they account to "present pages". 896 * Fortunately, these allocations are comparatively small in relevant setups 897 * (e.g., fraction of system memory). 898 * b) Some hotplugged memory blocks in virtualized environments, esecially 899 * hotplugged by virtio-mem, look like they are completely present, however, 900 * only parts of the memory block are actually currently usable. 901 * "present pages" is an upper limit that can get reached at runtime. As 902 * we base our calculations on KERNEL_EARLY, this is not an issue. 903 */ 904 static struct zone *auto_movable_zone_for_pfn(int nid, 905 struct memory_group *group, 906 unsigned long pfn, 907 unsigned long nr_pages) 908 { 909 unsigned long online_pages = 0, max_pages, end_pfn; 910 struct page *page; 911 912 if (!auto_movable_ratio) 913 goto kernel_zone; 914 915 if (group && !group->is_dynamic) { 916 max_pages = group->s.max_pages; 917 online_pages = group->present_movable_pages; 918 919 /* If anything is !MOVABLE online the rest !MOVABLE. */ 920 if (group->present_kernel_pages) 921 goto kernel_zone; 922 } else if (!group || group->d.unit_pages == nr_pages) { 923 max_pages = nr_pages; 924 } else { 925 max_pages = group->d.unit_pages; 926 /* 927 * Take a look at all online sections in the current unit. 928 * We can safely assume that all pages within a section belong 929 * to the same zone, because dynamic memory groups only deal 930 * with hotplugged memory. 931 */ 932 pfn = ALIGN_DOWN(pfn, group->d.unit_pages); 933 end_pfn = pfn + group->d.unit_pages; 934 for (; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 935 page = pfn_to_online_page(pfn); 936 if (!page) 937 continue; 938 /* If anything is !MOVABLE online the rest !MOVABLE. */ 939 if (page_zonenum(page) != ZONE_MOVABLE) 940 goto kernel_zone; 941 online_pages += PAGES_PER_SECTION; 942 } 943 } 944 945 /* 946 * Online MOVABLE if we could *currently* online all remaining parts 947 * MOVABLE. We expect to (add+) online them immediately next, so if 948 * nobody interferes, all will be MOVABLE if possible. 949 */ 950 nr_pages = max_pages - online_pages; 951 if (!auto_movable_can_online_movable(NUMA_NO_NODE, group, nr_pages)) 952 goto kernel_zone; 953 954 #ifdef CONFIG_NUMA 955 if (auto_movable_numa_aware && 956 !auto_movable_can_online_movable(nid, group, nr_pages)) 957 goto kernel_zone; 958 #endif /* CONFIG_NUMA */ 959 960 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 961 kernel_zone: 962 return default_kernel_zone_for_pfn(nid, pfn, nr_pages); 963 } 964 965 static inline struct zone *default_zone_for_pfn(int nid, unsigned long start_pfn, 966 unsigned long nr_pages) 967 { 968 struct zone *kernel_zone = default_kernel_zone_for_pfn(nid, start_pfn, 969 nr_pages); 970 struct zone *movable_zone = &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 971 bool in_kernel = zone_intersects(kernel_zone, start_pfn, nr_pages); 972 bool in_movable = zone_intersects(movable_zone, start_pfn, nr_pages); 973 974 /* 975 * We inherit the existing zone in a simple case where zones do not 976 * overlap in the given range 977 */ 978 if (in_kernel ^ in_movable) 979 return (in_kernel) ? kernel_zone : movable_zone; 980 981 /* 982 * If the range doesn't belong to any zone or two zones overlap in the 983 * given range then we use movable zone only if movable_node is 984 * enabled because we always online to a kernel zone by default. 985 */ 986 return movable_node_enabled ? movable_zone : kernel_zone; 987 } 988 989 struct zone *zone_for_pfn_range(int online_type, int nid, 990 struct memory_group *group, unsigned long start_pfn, 991 unsigned long nr_pages) 992 { 993 if (online_type == MMOP_ONLINE_KERNEL) 994 return default_kernel_zone_for_pfn(nid, start_pfn, nr_pages); 995 996 if (online_type == MMOP_ONLINE_MOVABLE) 997 return &NODE_DATA(nid)->node_zones[ZONE_MOVABLE]; 998 999 if (online_policy == ONLINE_POLICY_AUTO_MOVABLE) 1000 return auto_movable_zone_for_pfn(nid, group, start_pfn, nr_pages); 1001 1002 return default_zone_for_pfn(nid, start_pfn, nr_pages); 1003 } 1004 1005 /* 1006 * This function should only be called by memory_block_{online,offline}, 1007 * and {online,offline}_pages. 1008 */ 1009 void adjust_present_page_count(struct page *page, struct memory_group *group, 1010 long nr_pages) 1011 { 1012 struct zone *zone = page_zone(page); 1013 const bool movable = zone_idx(zone) == ZONE_MOVABLE; 1014 1015 /* 1016 * We only support onlining/offlining/adding/removing of complete 1017 * memory blocks; therefore, either all is either early or hotplugged. 1018 */ 1019 if (early_section(__pfn_to_section(page_to_pfn(page)))) 1020 zone->present_early_pages += nr_pages; 1021 zone->present_pages += nr_pages; 1022 zone->zone_pgdat->node_present_pages += nr_pages; 1023 1024 if (group && movable) 1025 group->present_movable_pages += nr_pages; 1026 else if (group && !movable) 1027 group->present_kernel_pages += nr_pages; 1028 } 1029 1030 int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages, 1031 struct zone *zone) 1032 { 1033 unsigned long end_pfn = pfn + nr_pages; 1034 int ret; 1035 1036 ret = kasan_add_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 1037 if (ret) 1038 return ret; 1039 1040 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE); 1041 1042 /* 1043 * It might be that the vmemmap_pages fully span sections. If that is 1044 * the case, mark those sections online here as otherwise they will be 1045 * left offline. 1046 */ 1047 if (nr_pages >= PAGES_PER_SECTION) 1048 online_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 1049 1050 return ret; 1051 } 1052 1053 void mhp_deinit_memmap_on_memory(unsigned long pfn, unsigned long nr_pages) 1054 { 1055 unsigned long end_pfn = pfn + nr_pages; 1056 1057 /* 1058 * It might be that the vmemmap_pages fully span sections. If that is 1059 * the case, mark those sections offline here as otherwise they will be 1060 * left online. 1061 */ 1062 if (nr_pages >= PAGES_PER_SECTION) 1063 offline_mem_sections(pfn, ALIGN_DOWN(end_pfn, PAGES_PER_SECTION)); 1064 1065 /* 1066 * The pages associated with this vmemmap have been offlined, so 1067 * we can reset its state here. 1068 */ 1069 remove_pfn_range_from_zone(page_zone(pfn_to_page(pfn)), pfn, nr_pages); 1070 kasan_remove_zero_shadow(__va(PFN_PHYS(pfn)), PFN_PHYS(nr_pages)); 1071 } 1072 1073 int __ref online_pages(unsigned long pfn, unsigned long nr_pages, 1074 struct zone *zone, struct memory_group *group) 1075 { 1076 unsigned long flags; 1077 int need_zonelists_rebuild = 0; 1078 const int nid = zone_to_nid(zone); 1079 int ret; 1080 struct memory_notify arg; 1081 1082 /* 1083 * {on,off}lining is constrained to full memory sections (or more 1084 * precisely to memory blocks from the user space POV). 1085 * memmap_on_memory is an exception because it reserves initial part 1086 * of the physical memory space for vmemmaps. That space is pageblock 1087 * aligned. 1088 */ 1089 if (WARN_ON_ONCE(!nr_pages || 1090 !IS_ALIGNED(pfn, pageblock_nr_pages) || 1091 !IS_ALIGNED(pfn + nr_pages, PAGES_PER_SECTION))) 1092 return -EINVAL; 1093 1094 mem_hotplug_begin(); 1095 1096 /* associate pfn range with the zone */ 1097 move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE); 1098 1099 arg.start_pfn = pfn; 1100 arg.nr_pages = nr_pages; 1101 node_states_check_changes_online(nr_pages, zone, &arg); 1102 1103 ret = memory_notify(MEM_GOING_ONLINE, &arg); 1104 ret = notifier_to_errno(ret); 1105 if (ret) 1106 goto failed_addition; 1107 1108 /* 1109 * Fixup the number of isolated pageblocks before marking the sections 1110 * onlining, such that undo_isolate_page_range() works correctly. 1111 */ 1112 spin_lock_irqsave(&zone->lock, flags); 1113 zone->nr_isolate_pageblock += nr_pages / pageblock_nr_pages; 1114 spin_unlock_irqrestore(&zone->lock, flags); 1115 1116 /* 1117 * If this zone is not populated, then it is not in zonelist. 1118 * This means the page allocator ignores this zone. 1119 * So, zonelist must be updated after online. 1120 */ 1121 if (!populated_zone(zone)) { 1122 need_zonelists_rebuild = 1; 1123 setup_zone_pageset(zone); 1124 } 1125 1126 online_pages_range(pfn, nr_pages); 1127 adjust_present_page_count(pfn_to_page(pfn), group, nr_pages); 1128 1129 node_states_set_node(nid, &arg); 1130 if (need_zonelists_rebuild) 1131 build_all_zonelists(NULL); 1132 1133 /* Basic onlining is complete, allow allocation of onlined pages. */ 1134 undo_isolate_page_range(pfn, pfn + nr_pages, MIGRATE_MOVABLE); 1135 1136 /* 1137 * Freshly onlined pages aren't shuffled (e.g., all pages are placed to 1138 * the tail of the freelist when undoing isolation). Shuffle the whole 1139 * zone to make sure the just onlined pages are properly distributed 1140 * across the whole freelist - to create an initial shuffle. 1141 */ 1142 shuffle_zone(zone); 1143 1144 /* reinitialise watermarks and update pcp limits */ 1145 init_per_zone_wmark_min(); 1146 1147 kswapd_run(nid); 1148 kcompactd_run(nid); 1149 1150 writeback_set_ratelimit(); 1151 1152 memory_notify(MEM_ONLINE, &arg); 1153 mem_hotplug_done(); 1154 return 0; 1155 1156 failed_addition: 1157 pr_debug("online_pages [mem %#010llx-%#010llx] failed\n", 1158 (unsigned long long) pfn << PAGE_SHIFT, 1159 (((unsigned long long) pfn + nr_pages) << PAGE_SHIFT) - 1); 1160 memory_notify(MEM_CANCEL_ONLINE, &arg); 1161 remove_pfn_range_from_zone(zone, pfn, nr_pages); 1162 mem_hotplug_done(); 1163 return ret; 1164 } 1165 1166 static void reset_node_present_pages(pg_data_t *pgdat) 1167 { 1168 struct zone *z; 1169 1170 for (z = pgdat->node_zones; z < pgdat->node_zones + MAX_NR_ZONES; z++) 1171 z->present_pages = 0; 1172 1173 pgdat->node_present_pages = 0; 1174 } 1175 1176 /* we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG */ 1177 static pg_data_t __ref *hotadd_init_pgdat(int nid) 1178 { 1179 struct pglist_data *pgdat; 1180 1181 /* 1182 * NODE_DATA is preallocated (free_area_init) but its internal 1183 * state is not allocated completely. Add missing pieces. 1184 * Completely offline nodes stay around and they just need 1185 * reintialization. 1186 */ 1187 pgdat = NODE_DATA(nid); 1188 1189 /* init node's zones as empty zones, we don't have any present pages.*/ 1190 free_area_init_core_hotplug(pgdat); 1191 1192 /* 1193 * The node we allocated has no zone fallback lists. For avoiding 1194 * to access not-initialized zonelist, build here. 1195 */ 1196 build_all_zonelists(pgdat); 1197 1198 /* 1199 * When memory is hot-added, all the memory is in offline state. So 1200 * clear all zones' present_pages because they will be updated in 1201 * online_pages() and offline_pages(). 1202 * TODO: should be in free_area_init_core_hotplug? 1203 */ 1204 reset_node_managed_pages(pgdat); 1205 reset_node_present_pages(pgdat); 1206 1207 return pgdat; 1208 } 1209 1210 /* 1211 * __try_online_node - online a node if offlined 1212 * @nid: the node ID 1213 * @set_node_online: Whether we want to online the node 1214 * called by cpu_up() to online a node without onlined memory. 1215 * 1216 * Returns: 1217 * 1 -> a new node has been allocated 1218 * 0 -> the node is already online 1219 * -ENOMEM -> the node could not be allocated 1220 */ 1221 static int __try_online_node(int nid, bool set_node_online) 1222 { 1223 pg_data_t *pgdat; 1224 int ret = 1; 1225 1226 if (node_online(nid)) 1227 return 0; 1228 1229 pgdat = hotadd_init_pgdat(nid); 1230 if (!pgdat) { 1231 pr_err("Cannot online node %d due to NULL pgdat\n", nid); 1232 ret = -ENOMEM; 1233 goto out; 1234 } 1235 1236 if (set_node_online) { 1237 node_set_online(nid); 1238 ret = register_one_node(nid); 1239 BUG_ON(ret); 1240 } 1241 out: 1242 return ret; 1243 } 1244 1245 /* 1246 * Users of this function always want to online/register the node 1247 */ 1248 int try_online_node(int nid) 1249 { 1250 int ret; 1251 1252 mem_hotplug_begin(); 1253 ret = __try_online_node(nid, true); 1254 mem_hotplug_done(); 1255 return ret; 1256 } 1257 1258 static int check_hotplug_memory_range(u64 start, u64 size) 1259 { 1260 /* memory range must be block size aligned */ 1261 if (!size || !IS_ALIGNED(start, memory_block_size_bytes()) || 1262 !IS_ALIGNED(size, memory_block_size_bytes())) { 1263 pr_err("Block size [%#lx] unaligned hotplug range: start %#llx, size %#llx", 1264 memory_block_size_bytes(), start, size); 1265 return -EINVAL; 1266 } 1267 1268 return 0; 1269 } 1270 1271 static int online_memory_block(struct memory_block *mem, void *arg) 1272 { 1273 mem->online_type = mhp_default_online_type; 1274 return device_online(&mem->dev); 1275 } 1276 1277 bool mhp_supports_memmap_on_memory(unsigned long size) 1278 { 1279 unsigned long nr_vmemmap_pages = size / PAGE_SIZE; 1280 unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); 1281 unsigned long remaining_size = size - vmemmap_size; 1282 1283 /* 1284 * Besides having arch support and the feature enabled at runtime, we 1285 * need a few more assumptions to hold true: 1286 * 1287 * a) We span a single memory block: memory onlining/offlinin;g happens 1288 * in memory block granularity. We don't want the vmemmap of online 1289 * memory blocks to reside on offline memory blocks. In the future, 1290 * we might want to support variable-sized memory blocks to make the 1291 * feature more versatile. 1292 * 1293 * b) The vmemmap pages span complete PMDs: We don't want vmemmap code 1294 * to populate memory from the altmap for unrelated parts (i.e., 1295 * other memory blocks) 1296 * 1297 * c) The vmemmap pages (and thereby the pages that will be exposed to 1298 * the buddy) have to cover full pageblocks: memory onlining/offlining 1299 * code requires applicable ranges to be page-aligned, for example, to 1300 * set the migratetypes properly. 1301 * 1302 * TODO: Although we have a check here to make sure that vmemmap pages 1303 * fully populate a PMD, it is not the right place to check for 1304 * this. A much better solution involves improving vmemmap code 1305 * to fallback to base pages when trying to populate vmemmap using 1306 * altmap as an alternative source of memory, and we do not exactly 1307 * populate a single PMD. 1308 */ 1309 return mhp_memmap_on_memory() && 1310 size == memory_block_size_bytes() && 1311 IS_ALIGNED(vmemmap_size, PMD_SIZE) && 1312 IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); 1313 } 1314 1315 /* 1316 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 1317 * and online/offline operations (triggered e.g. by sysfs). 1318 * 1319 * we are OK calling __meminit stuff here - we have CONFIG_MEMORY_HOTPLUG 1320 */ 1321 int __ref add_memory_resource(int nid, struct resource *res, mhp_t mhp_flags) 1322 { 1323 struct mhp_params params = { .pgprot = pgprot_mhp(PAGE_KERNEL) }; 1324 enum memblock_flags memblock_flags = MEMBLOCK_NONE; 1325 struct vmem_altmap mhp_altmap = {}; 1326 struct memory_group *group = NULL; 1327 u64 start, size; 1328 bool new_node = false; 1329 int ret; 1330 1331 start = res->start; 1332 size = resource_size(res); 1333 1334 ret = check_hotplug_memory_range(start, size); 1335 if (ret) 1336 return ret; 1337 1338 if (mhp_flags & MHP_NID_IS_MGID) { 1339 group = memory_group_find_by_id(nid); 1340 if (!group) 1341 return -EINVAL; 1342 nid = group->nid; 1343 } 1344 1345 if (!node_possible(nid)) { 1346 WARN(1, "node %d was absent from the node_possible_map\n", nid); 1347 return -EINVAL; 1348 } 1349 1350 mem_hotplug_begin(); 1351 1352 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 1353 if (res->flags & IORESOURCE_SYSRAM_DRIVER_MANAGED) 1354 memblock_flags = MEMBLOCK_DRIVER_MANAGED; 1355 ret = memblock_add_node(start, size, nid, memblock_flags); 1356 if (ret) 1357 goto error_mem_hotplug_end; 1358 } 1359 1360 ret = __try_online_node(nid, false); 1361 if (ret < 0) 1362 goto error; 1363 new_node = ret; 1364 1365 /* 1366 * Self hosted memmap array 1367 */ 1368 if (mhp_flags & MHP_MEMMAP_ON_MEMORY) { 1369 if (!mhp_supports_memmap_on_memory(size)) { 1370 ret = -EINVAL; 1371 goto error; 1372 } 1373 mhp_altmap.free = PHYS_PFN(size); 1374 mhp_altmap.base_pfn = PHYS_PFN(start); 1375 params.altmap = &mhp_altmap; 1376 } 1377 1378 /* call arch's memory hotadd */ 1379 ret = arch_add_memory(nid, start, size, ¶ms); 1380 if (ret < 0) 1381 goto error; 1382 1383 /* create memory block devices after memory was added */ 1384 ret = create_memory_block_devices(start, size, mhp_altmap.alloc, 1385 group); 1386 if (ret) { 1387 arch_remove_memory(start, size, NULL); 1388 goto error; 1389 } 1390 1391 if (new_node) { 1392 /* If sysfs file of new node can't be created, cpu on the node 1393 * can't be hot-added. There is no rollback way now. 1394 * So, check by BUG_ON() to catch it reluctantly.. 1395 * We online node here. We can't roll back from here. 1396 */ 1397 node_set_online(nid); 1398 ret = __register_one_node(nid); 1399 BUG_ON(ret); 1400 } 1401 1402 register_memory_blocks_under_node(nid, PFN_DOWN(start), 1403 PFN_UP(start + size - 1), 1404 MEMINIT_HOTPLUG); 1405 1406 /* create new memmap entry */ 1407 if (!strcmp(res->name, "System RAM")) 1408 firmware_map_add_hotplug(start, start + size, "System RAM"); 1409 1410 /* device_online() will take the lock when calling online_pages() */ 1411 mem_hotplug_done(); 1412 1413 /* 1414 * In case we're allowed to merge the resource, flag it and trigger 1415 * merging now that adding succeeded. 1416 */ 1417 if (mhp_flags & MHP_MERGE_RESOURCE) 1418 merge_system_ram_resource(res); 1419 1420 /* online pages if requested */ 1421 if (mhp_default_online_type != MMOP_OFFLINE) 1422 walk_memory_blocks(start, size, NULL, online_memory_block); 1423 1424 return ret; 1425 error: 1426 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) 1427 memblock_remove(start, size); 1428 error_mem_hotplug_end: 1429 mem_hotplug_done(); 1430 return ret; 1431 } 1432 1433 /* requires device_hotplug_lock, see add_memory_resource() */ 1434 int __ref __add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1435 { 1436 struct resource *res; 1437 int ret; 1438 1439 res = register_memory_resource(start, size, "System RAM"); 1440 if (IS_ERR(res)) 1441 return PTR_ERR(res); 1442 1443 ret = add_memory_resource(nid, res, mhp_flags); 1444 if (ret < 0) 1445 release_memory_resource(res); 1446 return ret; 1447 } 1448 1449 int add_memory(int nid, u64 start, u64 size, mhp_t mhp_flags) 1450 { 1451 int rc; 1452 1453 lock_device_hotplug(); 1454 rc = __add_memory(nid, start, size, mhp_flags); 1455 unlock_device_hotplug(); 1456 1457 return rc; 1458 } 1459 EXPORT_SYMBOL_GPL(add_memory); 1460 1461 /* 1462 * Add special, driver-managed memory to the system as system RAM. Such 1463 * memory is not exposed via the raw firmware-provided memmap as system 1464 * RAM, instead, it is detected and added by a driver - during cold boot, 1465 * after a reboot, and after kexec. 1466 * 1467 * Reasons why this memory should not be used for the initial memmap of a 1468 * kexec kernel or for placing kexec images: 1469 * - The booting kernel is in charge of determining how this memory will be 1470 * used (e.g., use persistent memory as system RAM) 1471 * - Coordination with a hypervisor is required before this memory 1472 * can be used (e.g., inaccessible parts). 1473 * 1474 * For this memory, no entries in /sys/firmware/memmap ("raw firmware-provided 1475 * memory map") are created. Also, the created memory resource is flagged 1476 * with IORESOURCE_SYSRAM_DRIVER_MANAGED, so in-kernel users can special-case 1477 * this memory as well (esp., not place kexec images onto it). 1478 * 1479 * The resource_name (visible via /proc/iomem) has to have the format 1480 * "System RAM ($DRIVER)". 1481 */ 1482 int add_memory_driver_managed(int nid, u64 start, u64 size, 1483 const char *resource_name, mhp_t mhp_flags) 1484 { 1485 struct resource *res; 1486 int rc; 1487 1488 if (!resource_name || 1489 strstr(resource_name, "System RAM (") != resource_name || 1490 resource_name[strlen(resource_name) - 1] != ')') 1491 return -EINVAL; 1492 1493 lock_device_hotplug(); 1494 1495 res = register_memory_resource(start, size, resource_name); 1496 if (IS_ERR(res)) { 1497 rc = PTR_ERR(res); 1498 goto out_unlock; 1499 } 1500 1501 rc = add_memory_resource(nid, res, mhp_flags); 1502 if (rc < 0) 1503 release_memory_resource(res); 1504 1505 out_unlock: 1506 unlock_device_hotplug(); 1507 return rc; 1508 } 1509 EXPORT_SYMBOL_GPL(add_memory_driver_managed); 1510 1511 /* 1512 * Platforms should define arch_get_mappable_range() that provides 1513 * maximum possible addressable physical memory range for which the 1514 * linear mapping could be created. The platform returned address 1515 * range must adhere to these following semantics. 1516 * 1517 * - range.start <= range.end 1518 * - Range includes both end points [range.start..range.end] 1519 * 1520 * There is also a fallback definition provided here, allowing the 1521 * entire possible physical address range in case any platform does 1522 * not define arch_get_mappable_range(). 1523 */ 1524 struct range __weak arch_get_mappable_range(void) 1525 { 1526 struct range mhp_range = { 1527 .start = 0UL, 1528 .end = -1ULL, 1529 }; 1530 return mhp_range; 1531 } 1532 1533 struct range mhp_get_pluggable_range(bool need_mapping) 1534 { 1535 const u64 max_phys = (1ULL << MAX_PHYSMEM_BITS) - 1; 1536 struct range mhp_range; 1537 1538 if (need_mapping) { 1539 mhp_range = arch_get_mappable_range(); 1540 if (mhp_range.start > max_phys) { 1541 mhp_range.start = 0; 1542 mhp_range.end = 0; 1543 } 1544 mhp_range.end = min_t(u64, mhp_range.end, max_phys); 1545 } else { 1546 mhp_range.start = 0; 1547 mhp_range.end = max_phys; 1548 } 1549 return mhp_range; 1550 } 1551 EXPORT_SYMBOL_GPL(mhp_get_pluggable_range); 1552 1553 bool mhp_range_allowed(u64 start, u64 size, bool need_mapping) 1554 { 1555 struct range mhp_range = mhp_get_pluggable_range(need_mapping); 1556 u64 end = start + size; 1557 1558 if (start < end && start >= mhp_range.start && (end - 1) <= mhp_range.end) 1559 return true; 1560 1561 pr_warn("Hotplug memory [%#llx-%#llx] exceeds maximum addressable range [%#llx-%#llx]\n", 1562 start, end, mhp_range.start, mhp_range.end); 1563 return false; 1564 } 1565 1566 #ifdef CONFIG_MEMORY_HOTREMOVE 1567 /* 1568 * Scan pfn range [start,end) to find movable/migratable pages (LRU pages, 1569 * non-lru movable pages and hugepages). Will skip over most unmovable 1570 * pages (esp., pages that can be skipped when offlining), but bail out on 1571 * definitely unmovable pages. 1572 * 1573 * Returns: 1574 * 0 in case a movable page is found and movable_pfn was updated. 1575 * -ENOENT in case no movable page was found. 1576 * -EBUSY in case a definitely unmovable page was found. 1577 */ 1578 static int scan_movable_pages(unsigned long start, unsigned long end, 1579 unsigned long *movable_pfn) 1580 { 1581 unsigned long pfn; 1582 1583 for (pfn = start; pfn < end; pfn++) { 1584 struct page *page, *head; 1585 unsigned long skip; 1586 1587 if (!pfn_valid(pfn)) 1588 continue; 1589 page = pfn_to_page(pfn); 1590 if (PageLRU(page)) 1591 goto found; 1592 if (__PageMovable(page)) 1593 goto found; 1594 1595 /* 1596 * PageOffline() pages that are not marked __PageMovable() and 1597 * have a reference count > 0 (after MEM_GOING_OFFLINE) are 1598 * definitely unmovable. If their reference count would be 0, 1599 * they could at least be skipped when offlining memory. 1600 */ 1601 if (PageOffline(page) && page_count(page)) 1602 return -EBUSY; 1603 1604 if (!PageHuge(page)) 1605 continue; 1606 head = compound_head(page); 1607 /* 1608 * This test is racy as we hold no reference or lock. The 1609 * hugetlb page could have been free'ed and head is no longer 1610 * a hugetlb page before the following check. In such unlikely 1611 * cases false positives and negatives are possible. Calling 1612 * code must deal with these scenarios. 1613 */ 1614 if (HPageMigratable(head)) 1615 goto found; 1616 skip = compound_nr(head) - (page - head); 1617 pfn += skip - 1; 1618 } 1619 return -ENOENT; 1620 found: 1621 *movable_pfn = pfn; 1622 return 0; 1623 } 1624 1625 static int 1626 do_migrate_range(unsigned long start_pfn, unsigned long end_pfn) 1627 { 1628 unsigned long pfn; 1629 struct page *page, *head; 1630 int ret = 0; 1631 LIST_HEAD(source); 1632 static DEFINE_RATELIMIT_STATE(migrate_rs, DEFAULT_RATELIMIT_INTERVAL, 1633 DEFAULT_RATELIMIT_BURST); 1634 1635 for (pfn = start_pfn; pfn < end_pfn; pfn++) { 1636 struct folio *folio; 1637 1638 if (!pfn_valid(pfn)) 1639 continue; 1640 page = pfn_to_page(pfn); 1641 folio = page_folio(page); 1642 head = &folio->page; 1643 1644 if (PageHuge(page)) { 1645 pfn = page_to_pfn(head) + compound_nr(head) - 1; 1646 isolate_huge_page(head, &source); 1647 continue; 1648 } else if (PageTransHuge(page)) 1649 pfn = page_to_pfn(head) + thp_nr_pages(page) - 1; 1650 1651 /* 1652 * HWPoison pages have elevated reference counts so the migration would 1653 * fail on them. It also doesn't make any sense to migrate them in the 1654 * first place. Still try to unmap such a page in case it is still mapped 1655 * (e.g. current hwpoison implementation doesn't unmap KSM pages but keep 1656 * the unmap as the catch all safety net). 1657 */ 1658 if (PageHWPoison(page)) { 1659 if (WARN_ON(folio_test_lru(folio))) 1660 folio_isolate_lru(folio); 1661 if (folio_mapped(folio)) 1662 try_to_unmap(folio, TTU_IGNORE_MLOCK); 1663 continue; 1664 } 1665 1666 if (!get_page_unless_zero(page)) 1667 continue; 1668 /* 1669 * We can skip free pages. And we can deal with pages on 1670 * LRU and non-lru movable pages. 1671 */ 1672 if (PageLRU(page)) 1673 ret = isolate_lru_page(page); 1674 else 1675 ret = isolate_movable_page(page, ISOLATE_UNEVICTABLE); 1676 if (!ret) { /* Success */ 1677 list_add_tail(&page->lru, &source); 1678 if (!__PageMovable(page)) 1679 inc_node_page_state(page, NR_ISOLATED_ANON + 1680 page_is_file_lru(page)); 1681 1682 } else { 1683 if (__ratelimit(&migrate_rs)) { 1684 pr_warn("failed to isolate pfn %lx\n", pfn); 1685 dump_page(page, "isolation failed"); 1686 } 1687 } 1688 put_page(page); 1689 } 1690 if (!list_empty(&source)) { 1691 nodemask_t nmask = node_states[N_MEMORY]; 1692 struct migration_target_control mtc = { 1693 .nmask = &nmask, 1694 .gfp_mask = GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL, 1695 }; 1696 1697 /* 1698 * We have checked that migration range is on a single zone so 1699 * we can use the nid of the first page to all the others. 1700 */ 1701 mtc.nid = page_to_nid(list_first_entry(&source, struct page, lru)); 1702 1703 /* 1704 * try to allocate from a different node but reuse this node 1705 * if there are no other online nodes to be used (e.g. we are 1706 * offlining a part of the only existing node) 1707 */ 1708 node_clear(mtc.nid, nmask); 1709 if (nodes_empty(nmask)) 1710 node_set(mtc.nid, nmask); 1711 ret = migrate_pages(&source, alloc_migration_target, NULL, 1712 (unsigned long)&mtc, MIGRATE_SYNC, MR_MEMORY_HOTPLUG, NULL); 1713 if (ret) { 1714 list_for_each_entry(page, &source, lru) { 1715 if (__ratelimit(&migrate_rs)) { 1716 pr_warn("migrating pfn %lx failed ret:%d\n", 1717 page_to_pfn(page), ret); 1718 dump_page(page, "migration failure"); 1719 } 1720 } 1721 putback_movable_pages(&source); 1722 } 1723 } 1724 1725 return ret; 1726 } 1727 1728 static int __init cmdline_parse_movable_node(char *p) 1729 { 1730 movable_node_enabled = true; 1731 return 0; 1732 } 1733 early_param("movable_node", cmdline_parse_movable_node); 1734 1735 /* check which state of node_states will be changed when offline memory */ 1736 static void node_states_check_changes_offline(unsigned long nr_pages, 1737 struct zone *zone, struct memory_notify *arg) 1738 { 1739 struct pglist_data *pgdat = zone->zone_pgdat; 1740 unsigned long present_pages = 0; 1741 enum zone_type zt; 1742 1743 arg->status_change_nid = NUMA_NO_NODE; 1744 arg->status_change_nid_normal = NUMA_NO_NODE; 1745 1746 /* 1747 * Check whether node_states[N_NORMAL_MEMORY] will be changed. 1748 * If the memory to be offline is within the range 1749 * [0..ZONE_NORMAL], and it is the last present memory there, 1750 * the zones in that range will become empty after the offlining, 1751 * thus we can determine that we need to clear the node from 1752 * node_states[N_NORMAL_MEMORY]. 1753 */ 1754 for (zt = 0; zt <= ZONE_NORMAL; zt++) 1755 present_pages += pgdat->node_zones[zt].present_pages; 1756 if (zone_idx(zone) <= ZONE_NORMAL && nr_pages >= present_pages) 1757 arg->status_change_nid_normal = zone_to_nid(zone); 1758 1759 /* 1760 * We have accounted the pages from [0..ZONE_NORMAL); ZONE_HIGHMEM 1761 * does not apply as we don't support 32bit. 1762 * Here we count the possible pages from ZONE_MOVABLE. 1763 * If after having accounted all the pages, we see that the nr_pages 1764 * to be offlined is over or equal to the accounted pages, 1765 * we know that the node will become empty, and so, we can clear 1766 * it for N_MEMORY as well. 1767 */ 1768 present_pages += pgdat->node_zones[ZONE_MOVABLE].present_pages; 1769 1770 if (nr_pages >= present_pages) 1771 arg->status_change_nid = zone_to_nid(zone); 1772 } 1773 1774 static void node_states_clear_node(int node, struct memory_notify *arg) 1775 { 1776 if (arg->status_change_nid_normal >= 0) 1777 node_clear_state(node, N_NORMAL_MEMORY); 1778 1779 if (arg->status_change_nid >= 0) 1780 node_clear_state(node, N_MEMORY); 1781 } 1782 1783 static int count_system_ram_pages_cb(unsigned long start_pfn, 1784 unsigned long nr_pages, void *data) 1785 { 1786 unsigned long *nr_system_ram_pages = data; 1787 1788 *nr_system_ram_pages += nr_pages; 1789 return 0; 1790 } 1791 1792 int __ref offline_pages(unsigned long start_pfn, unsigned long nr_pages, 1793 struct zone *zone, struct memory_group *group) 1794 { 1795 const unsigned long end_pfn = start_pfn + nr_pages; 1796 unsigned long pfn, system_ram_pages = 0; 1797 const int node = zone_to_nid(zone); 1798 unsigned long flags; 1799 struct memory_notify arg; 1800 char *reason; 1801 int ret; 1802 1803 /* 1804 * {on,off}lining is constrained to full memory sections (or more 1805 * precisely to memory blocks from the user space POV). 1806 * memmap_on_memory is an exception because it reserves initial part 1807 * of the physical memory space for vmemmaps. That space is pageblock 1808 * aligned. 1809 */ 1810 if (WARN_ON_ONCE(!nr_pages || 1811 !IS_ALIGNED(start_pfn, pageblock_nr_pages) || 1812 !IS_ALIGNED(start_pfn + nr_pages, PAGES_PER_SECTION))) 1813 return -EINVAL; 1814 1815 mem_hotplug_begin(); 1816 1817 /* 1818 * Don't allow to offline memory blocks that contain holes. 1819 * Consequently, memory blocks with holes can never get onlined 1820 * via the hotplug path - online_pages() - as hotplugged memory has 1821 * no holes. This way, we e.g., don't have to worry about marking 1822 * memory holes PG_reserved, don't need pfn_valid() checks, and can 1823 * avoid using walk_system_ram_range() later. 1824 */ 1825 walk_system_ram_range(start_pfn, nr_pages, &system_ram_pages, 1826 count_system_ram_pages_cb); 1827 if (system_ram_pages != nr_pages) { 1828 ret = -EINVAL; 1829 reason = "memory holes"; 1830 goto failed_removal; 1831 } 1832 1833 /* 1834 * We only support offlining of memory blocks managed by a single zone, 1835 * checked by calling code. This is just a sanity check that we might 1836 * want to remove in the future. 1837 */ 1838 if (WARN_ON_ONCE(page_zone(pfn_to_page(start_pfn)) != zone || 1839 page_zone(pfn_to_page(end_pfn - 1)) != zone)) { 1840 ret = -EINVAL; 1841 reason = "multizone range"; 1842 goto failed_removal; 1843 } 1844 1845 /* 1846 * Disable pcplists so that page isolation cannot race with freeing 1847 * in a way that pages from isolated pageblock are left on pcplists. 1848 */ 1849 zone_pcp_disable(zone); 1850 lru_cache_disable(); 1851 1852 /* set above range as isolated */ 1853 ret = start_isolate_page_range(start_pfn, end_pfn, 1854 MIGRATE_MOVABLE, 1855 MEMORY_OFFLINE | REPORT_FAILURE, 1856 GFP_USER | __GFP_MOVABLE | __GFP_RETRY_MAYFAIL); 1857 if (ret) { 1858 reason = "failure to isolate range"; 1859 goto failed_removal_pcplists_disabled; 1860 } 1861 1862 arg.start_pfn = start_pfn; 1863 arg.nr_pages = nr_pages; 1864 node_states_check_changes_offline(nr_pages, zone, &arg); 1865 1866 ret = memory_notify(MEM_GOING_OFFLINE, &arg); 1867 ret = notifier_to_errno(ret); 1868 if (ret) { 1869 reason = "notifier failure"; 1870 goto failed_removal_isolated; 1871 } 1872 1873 do { 1874 pfn = start_pfn; 1875 do { 1876 if (signal_pending(current)) { 1877 ret = -EINTR; 1878 reason = "signal backoff"; 1879 goto failed_removal_isolated; 1880 } 1881 1882 cond_resched(); 1883 1884 ret = scan_movable_pages(pfn, end_pfn, &pfn); 1885 if (!ret) { 1886 /* 1887 * TODO: fatal migration failures should bail 1888 * out 1889 */ 1890 do_migrate_range(pfn, end_pfn); 1891 } 1892 } while (!ret); 1893 1894 if (ret != -ENOENT) { 1895 reason = "unmovable page"; 1896 goto failed_removal_isolated; 1897 } 1898 1899 /* 1900 * Dissolve free hugepages in the memory block before doing 1901 * offlining actually in order to make hugetlbfs's object 1902 * counting consistent. 1903 */ 1904 ret = dissolve_free_huge_pages(start_pfn, end_pfn); 1905 if (ret) { 1906 reason = "failure to dissolve huge pages"; 1907 goto failed_removal_isolated; 1908 } 1909 1910 ret = test_pages_isolated(start_pfn, end_pfn, MEMORY_OFFLINE); 1911 1912 } while (ret); 1913 1914 /* Mark all sections offline and remove free pages from the buddy. */ 1915 __offline_isolated_pages(start_pfn, end_pfn); 1916 pr_debug("Offlined Pages %ld\n", nr_pages); 1917 1918 /* 1919 * The memory sections are marked offline, and the pageblock flags 1920 * effectively stale; nobody should be touching them. Fixup the number 1921 * of isolated pageblocks, memory onlining will properly revert this. 1922 */ 1923 spin_lock_irqsave(&zone->lock, flags); 1924 zone->nr_isolate_pageblock -= nr_pages / pageblock_nr_pages; 1925 spin_unlock_irqrestore(&zone->lock, flags); 1926 1927 lru_cache_enable(); 1928 zone_pcp_enable(zone); 1929 1930 /* removal success */ 1931 adjust_managed_page_count(pfn_to_page(start_pfn), -nr_pages); 1932 adjust_present_page_count(pfn_to_page(start_pfn), group, -nr_pages); 1933 1934 /* reinitialise watermarks and update pcp limits */ 1935 init_per_zone_wmark_min(); 1936 1937 if (!populated_zone(zone)) { 1938 zone_pcp_reset(zone); 1939 build_all_zonelists(NULL); 1940 } 1941 1942 node_states_clear_node(node, &arg); 1943 if (arg.status_change_nid >= 0) { 1944 kswapd_stop(node); 1945 kcompactd_stop(node); 1946 } 1947 1948 writeback_set_ratelimit(); 1949 1950 memory_notify(MEM_OFFLINE, &arg); 1951 remove_pfn_range_from_zone(zone, start_pfn, nr_pages); 1952 mem_hotplug_done(); 1953 return 0; 1954 1955 failed_removal_isolated: 1956 /* pushback to free area */ 1957 undo_isolate_page_range(start_pfn, end_pfn, MIGRATE_MOVABLE); 1958 memory_notify(MEM_CANCEL_OFFLINE, &arg); 1959 failed_removal_pcplists_disabled: 1960 lru_cache_enable(); 1961 zone_pcp_enable(zone); 1962 failed_removal: 1963 pr_debug("memory offlining [mem %#010llx-%#010llx] failed due to %s\n", 1964 (unsigned long long) start_pfn << PAGE_SHIFT, 1965 ((unsigned long long) end_pfn << PAGE_SHIFT) - 1, 1966 reason); 1967 mem_hotplug_done(); 1968 return ret; 1969 } 1970 1971 static int check_memblock_offlined_cb(struct memory_block *mem, void *arg) 1972 { 1973 int ret = !is_memblock_offlined(mem); 1974 int *nid = arg; 1975 1976 *nid = mem->nid; 1977 if (unlikely(ret)) { 1978 phys_addr_t beginpa, endpa; 1979 1980 beginpa = PFN_PHYS(section_nr_to_pfn(mem->start_section_nr)); 1981 endpa = beginpa + memory_block_size_bytes() - 1; 1982 pr_warn("removing memory fails, because memory [%pa-%pa] is onlined\n", 1983 &beginpa, &endpa); 1984 1985 return -EBUSY; 1986 } 1987 return 0; 1988 } 1989 1990 static int get_nr_vmemmap_pages_cb(struct memory_block *mem, void *arg) 1991 { 1992 /* 1993 * If not set, continue with the next block. 1994 */ 1995 return mem->nr_vmemmap_pages; 1996 } 1997 1998 static int check_cpu_on_node(int nid) 1999 { 2000 int cpu; 2001 2002 for_each_present_cpu(cpu) { 2003 if (cpu_to_node(cpu) == nid) 2004 /* 2005 * the cpu on this node isn't removed, and we can't 2006 * offline this node. 2007 */ 2008 return -EBUSY; 2009 } 2010 2011 return 0; 2012 } 2013 2014 static int check_no_memblock_for_node_cb(struct memory_block *mem, void *arg) 2015 { 2016 int nid = *(int *)arg; 2017 2018 /* 2019 * If a memory block belongs to multiple nodes, the stored nid is not 2020 * reliable. However, such blocks are always online (e.g., cannot get 2021 * offlined) and, therefore, are still spanned by the node. 2022 */ 2023 return mem->nid == nid ? -EEXIST : 0; 2024 } 2025 2026 /** 2027 * try_offline_node 2028 * @nid: the node ID 2029 * 2030 * Offline a node if all memory sections and cpus of the node are removed. 2031 * 2032 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2033 * and online/offline operations before this call. 2034 */ 2035 void try_offline_node(int nid) 2036 { 2037 int rc; 2038 2039 /* 2040 * If the node still spans pages (especially ZONE_DEVICE), don't 2041 * offline it. A node spans memory after move_pfn_range_to_zone(), 2042 * e.g., after the memory block was onlined. 2043 */ 2044 if (node_spanned_pages(nid)) 2045 return; 2046 2047 /* 2048 * Especially offline memory blocks might not be spanned by the 2049 * node. They will get spanned by the node once they get onlined. 2050 * However, they link to the node in sysfs and can get onlined later. 2051 */ 2052 rc = for_each_memory_block(&nid, check_no_memblock_for_node_cb); 2053 if (rc) 2054 return; 2055 2056 if (check_cpu_on_node(nid)) 2057 return; 2058 2059 /* 2060 * all memory/cpu of this node are removed, we can offline this 2061 * node now. 2062 */ 2063 node_set_offline(nid); 2064 unregister_one_node(nid); 2065 } 2066 EXPORT_SYMBOL(try_offline_node); 2067 2068 static int __ref try_remove_memory(u64 start, u64 size) 2069 { 2070 struct vmem_altmap mhp_altmap = {}; 2071 struct vmem_altmap *altmap = NULL; 2072 unsigned long nr_vmemmap_pages; 2073 int rc = 0, nid = NUMA_NO_NODE; 2074 2075 BUG_ON(check_hotplug_memory_range(start, size)); 2076 2077 /* 2078 * All memory blocks must be offlined before removing memory. Check 2079 * whether all memory blocks in question are offline and return error 2080 * if this is not the case. 2081 * 2082 * While at it, determine the nid. Note that if we'd have mixed nodes, 2083 * we'd only try to offline the last determined one -- which is good 2084 * enough for the cases we care about. 2085 */ 2086 rc = walk_memory_blocks(start, size, &nid, check_memblock_offlined_cb); 2087 if (rc) 2088 return rc; 2089 2090 /* 2091 * We only support removing memory added with MHP_MEMMAP_ON_MEMORY in 2092 * the same granularity it was added - a single memory block. 2093 */ 2094 if (mhp_memmap_on_memory()) { 2095 nr_vmemmap_pages = walk_memory_blocks(start, size, NULL, 2096 get_nr_vmemmap_pages_cb); 2097 if (nr_vmemmap_pages) { 2098 if (size != memory_block_size_bytes()) { 2099 pr_warn("Refuse to remove %#llx - %#llx," 2100 "wrong granularity\n", 2101 start, start + size); 2102 return -EINVAL; 2103 } 2104 2105 /* 2106 * Let remove_pmd_table->free_hugepage_table do the 2107 * right thing if we used vmem_altmap when hot-adding 2108 * the range. 2109 */ 2110 mhp_altmap.alloc = nr_vmemmap_pages; 2111 altmap = &mhp_altmap; 2112 } 2113 } 2114 2115 /* remove memmap entry */ 2116 firmware_map_remove(start, start + size, "System RAM"); 2117 2118 /* 2119 * Memory block device removal under the device_hotplug_lock is 2120 * a barrier against racing online attempts. 2121 */ 2122 remove_memory_block_devices(start, size); 2123 2124 mem_hotplug_begin(); 2125 2126 arch_remove_memory(start, size, altmap); 2127 2128 if (IS_ENABLED(CONFIG_ARCH_KEEP_MEMBLOCK)) { 2129 memblock_phys_free(start, size); 2130 memblock_remove(start, size); 2131 } 2132 2133 release_mem_region_adjustable(start, size); 2134 2135 if (nid != NUMA_NO_NODE) 2136 try_offline_node(nid); 2137 2138 mem_hotplug_done(); 2139 return 0; 2140 } 2141 2142 /** 2143 * __remove_memory - Remove memory if every memory block is offline 2144 * @start: physical address of the region to remove 2145 * @size: size of the region to remove 2146 * 2147 * NOTE: The caller must call lock_device_hotplug() to serialize hotplug 2148 * and online/offline operations before this call, as required by 2149 * try_offline_node(). 2150 */ 2151 void __remove_memory(u64 start, u64 size) 2152 { 2153 2154 /* 2155 * trigger BUG() if some memory is not offlined prior to calling this 2156 * function 2157 */ 2158 if (try_remove_memory(start, size)) 2159 BUG(); 2160 } 2161 2162 /* 2163 * Remove memory if every memory block is offline, otherwise return -EBUSY is 2164 * some memory is not offline 2165 */ 2166 int remove_memory(u64 start, u64 size) 2167 { 2168 int rc; 2169 2170 lock_device_hotplug(); 2171 rc = try_remove_memory(start, size); 2172 unlock_device_hotplug(); 2173 2174 return rc; 2175 } 2176 EXPORT_SYMBOL_GPL(remove_memory); 2177 2178 static int try_offline_memory_block(struct memory_block *mem, void *arg) 2179 { 2180 uint8_t online_type = MMOP_ONLINE_KERNEL; 2181 uint8_t **online_types = arg; 2182 struct page *page; 2183 int rc; 2184 2185 /* 2186 * Sense the online_type via the zone of the memory block. Offlining 2187 * with multiple zones within one memory block will be rejected 2188 * by offlining code ... so we don't care about that. 2189 */ 2190 page = pfn_to_online_page(section_nr_to_pfn(mem->start_section_nr)); 2191 if (page && zone_idx(page_zone(page)) == ZONE_MOVABLE) 2192 online_type = MMOP_ONLINE_MOVABLE; 2193 2194 rc = device_offline(&mem->dev); 2195 /* 2196 * Default is MMOP_OFFLINE - change it only if offlining succeeded, 2197 * so try_reonline_memory_block() can do the right thing. 2198 */ 2199 if (!rc) 2200 **online_types = online_type; 2201 2202 (*online_types)++; 2203 /* Ignore if already offline. */ 2204 return rc < 0 ? rc : 0; 2205 } 2206 2207 static int try_reonline_memory_block(struct memory_block *mem, void *arg) 2208 { 2209 uint8_t **online_types = arg; 2210 int rc; 2211 2212 if (**online_types != MMOP_OFFLINE) { 2213 mem->online_type = **online_types; 2214 rc = device_online(&mem->dev); 2215 if (rc < 0) 2216 pr_warn("%s: Failed to re-online memory: %d", 2217 __func__, rc); 2218 } 2219 2220 /* Continue processing all remaining memory blocks. */ 2221 (*online_types)++; 2222 return 0; 2223 } 2224 2225 /* 2226 * Try to offline and remove memory. Might take a long time to finish in case 2227 * memory is still in use. Primarily useful for memory devices that logically 2228 * unplugged all memory (so it's no longer in use) and want to offline + remove 2229 * that memory. 2230 */ 2231 int offline_and_remove_memory(u64 start, u64 size) 2232 { 2233 const unsigned long mb_count = size / memory_block_size_bytes(); 2234 uint8_t *online_types, *tmp; 2235 int rc; 2236 2237 if (!IS_ALIGNED(start, memory_block_size_bytes()) || 2238 !IS_ALIGNED(size, memory_block_size_bytes()) || !size) 2239 return -EINVAL; 2240 2241 /* 2242 * We'll remember the old online type of each memory block, so we can 2243 * try to revert whatever we did when offlining one memory block fails 2244 * after offlining some others succeeded. 2245 */ 2246 online_types = kmalloc_array(mb_count, sizeof(*online_types), 2247 GFP_KERNEL); 2248 if (!online_types) 2249 return -ENOMEM; 2250 /* 2251 * Initialize all states to MMOP_OFFLINE, so when we abort processing in 2252 * try_offline_memory_block(), we'll skip all unprocessed blocks in 2253 * try_reonline_memory_block(). 2254 */ 2255 memset(online_types, MMOP_OFFLINE, mb_count); 2256 2257 lock_device_hotplug(); 2258 2259 tmp = online_types; 2260 rc = walk_memory_blocks(start, size, &tmp, try_offline_memory_block); 2261 2262 /* 2263 * In case we succeeded to offline all memory, remove it. 2264 * This cannot fail as it cannot get onlined in the meantime. 2265 */ 2266 if (!rc) { 2267 rc = try_remove_memory(start, size); 2268 if (rc) 2269 pr_err("%s: Failed to remove memory: %d", __func__, rc); 2270 } 2271 2272 /* 2273 * Rollback what we did. While memory onlining might theoretically fail 2274 * (nacked by a notifier), it barely ever happens. 2275 */ 2276 if (rc) { 2277 tmp = online_types; 2278 walk_memory_blocks(start, size, &tmp, 2279 try_reonline_memory_block); 2280 } 2281 unlock_device_hotplug(); 2282 2283 kfree(online_types); 2284 return rc; 2285 } 2286 EXPORT_SYMBOL_GPL(offline_and_remove_memory); 2287 #endif /* CONFIG_MEMORY_HOTREMOVE */ 2288