1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * sparse memory mappings. 4 */ 5 #include <linux/mm.h> 6 #include <linux/slab.h> 7 #include <linux/mmzone.h> 8 #include <linux/memblock.h> 9 #include <linux/compiler.h> 10 #include <linux/highmem.h> 11 #include <linux/export.h> 12 #include <linux/spinlock.h> 13 #include <linux/vmalloc.h> 14 #include <linux/swap.h> 15 #include <linux/swapops.h> 16 17 #include "internal.h" 18 #include <asm/dma.h> 19 #include <asm/pgalloc.h> 20 #include <asm/pgtable.h> 21 22 /* 23 * Permanent SPARSEMEM data: 24 * 25 * 1) mem_section - memory sections, mem_map's for valid memory 26 */ 27 #ifdef CONFIG_SPARSEMEM_EXTREME 28 struct mem_section **mem_section; 29 #else 30 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT] 31 ____cacheline_internodealigned_in_smp; 32 #endif 33 EXPORT_SYMBOL(mem_section); 34 35 #ifdef NODE_NOT_IN_PAGE_FLAGS 36 /* 37 * If we did not store the node number in the page then we have to 38 * do a lookup in the section_to_node_table in order to find which 39 * node the page belongs to. 40 */ 41 #if MAX_NUMNODES <= 256 42 static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 43 #else 44 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned; 45 #endif 46 47 int page_to_nid(const struct page *page) 48 { 49 return section_to_node_table[page_to_section(page)]; 50 } 51 EXPORT_SYMBOL(page_to_nid); 52 53 static void set_section_nid(unsigned long section_nr, int nid) 54 { 55 section_to_node_table[section_nr] = nid; 56 } 57 #else /* !NODE_NOT_IN_PAGE_FLAGS */ 58 static inline void set_section_nid(unsigned long section_nr, int nid) 59 { 60 } 61 #endif 62 63 #ifdef CONFIG_SPARSEMEM_EXTREME 64 static noinline struct mem_section __ref *sparse_index_alloc(int nid) 65 { 66 struct mem_section *section = NULL; 67 unsigned long array_size = SECTIONS_PER_ROOT * 68 sizeof(struct mem_section); 69 70 if (slab_is_available()) { 71 section = kzalloc_node(array_size, GFP_KERNEL, nid); 72 } else { 73 section = memblock_alloc_node(array_size, SMP_CACHE_BYTES, 74 nid); 75 if (!section) 76 panic("%s: Failed to allocate %lu bytes nid=%d\n", 77 __func__, array_size, nid); 78 } 79 80 return section; 81 } 82 83 static int __meminit sparse_index_init(unsigned long section_nr, int nid) 84 { 85 unsigned long root = SECTION_NR_TO_ROOT(section_nr); 86 struct mem_section *section; 87 88 /* 89 * An existing section is possible in the sub-section hotplug 90 * case. First hot-add instantiates, follow-on hot-add reuses 91 * the existing section. 92 * 93 * The mem_hotplug_lock resolves the apparent race below. 94 */ 95 if (mem_section[root]) 96 return 0; 97 98 section = sparse_index_alloc(nid); 99 if (!section) 100 return -ENOMEM; 101 102 mem_section[root] = section; 103 104 return 0; 105 } 106 #else /* !SPARSEMEM_EXTREME */ 107 static inline int sparse_index_init(unsigned long section_nr, int nid) 108 { 109 return 0; 110 } 111 #endif 112 113 #ifdef CONFIG_SPARSEMEM_EXTREME 114 unsigned long __section_nr(struct mem_section *ms) 115 { 116 unsigned long root_nr; 117 struct mem_section *root = NULL; 118 119 for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) { 120 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT); 121 if (!root) 122 continue; 123 124 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT))) 125 break; 126 } 127 128 VM_BUG_ON(!root); 129 130 return (root_nr * SECTIONS_PER_ROOT) + (ms - root); 131 } 132 #else 133 unsigned long __section_nr(struct mem_section *ms) 134 { 135 return (unsigned long)(ms - mem_section[0]); 136 } 137 #endif 138 139 /* 140 * During early boot, before section_mem_map is used for an actual 141 * mem_map, we use section_mem_map to store the section's NUMA 142 * node. This keeps us from having to use another data structure. The 143 * node information is cleared just before we store the real mem_map. 144 */ 145 static inline unsigned long sparse_encode_early_nid(int nid) 146 { 147 return (nid << SECTION_NID_SHIFT); 148 } 149 150 static inline int sparse_early_nid(struct mem_section *section) 151 { 152 return (section->section_mem_map >> SECTION_NID_SHIFT); 153 } 154 155 /* Validate the physical addressing limitations of the model */ 156 void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn, 157 unsigned long *end_pfn) 158 { 159 unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT); 160 161 /* 162 * Sanity checks - do not allow an architecture to pass 163 * in larger pfns than the maximum scope of sparsemem: 164 */ 165 if (*start_pfn > max_sparsemem_pfn) { 166 mminit_dprintk(MMINIT_WARNING, "pfnvalidation", 167 "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n", 168 *start_pfn, *end_pfn, max_sparsemem_pfn); 169 WARN_ON_ONCE(1); 170 *start_pfn = max_sparsemem_pfn; 171 *end_pfn = max_sparsemem_pfn; 172 } else if (*end_pfn > max_sparsemem_pfn) { 173 mminit_dprintk(MMINIT_WARNING, "pfnvalidation", 174 "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n", 175 *start_pfn, *end_pfn, max_sparsemem_pfn); 176 WARN_ON_ONCE(1); 177 *end_pfn = max_sparsemem_pfn; 178 } 179 } 180 181 /* 182 * There are a number of times that we loop over NR_MEM_SECTIONS, 183 * looking for section_present() on each. But, when we have very 184 * large physical address spaces, NR_MEM_SECTIONS can also be 185 * very large which makes the loops quite long. 186 * 187 * Keeping track of this gives us an easy way to break out of 188 * those loops early. 189 */ 190 unsigned long __highest_present_section_nr; 191 static void section_mark_present(struct mem_section *ms) 192 { 193 unsigned long section_nr = __section_nr(ms); 194 195 if (section_nr > __highest_present_section_nr) 196 __highest_present_section_nr = section_nr; 197 198 ms->section_mem_map |= SECTION_MARKED_PRESENT; 199 } 200 201 static inline unsigned long next_present_section_nr(unsigned long section_nr) 202 { 203 do { 204 section_nr++; 205 if (present_section_nr(section_nr)) 206 return section_nr; 207 } while ((section_nr <= __highest_present_section_nr)); 208 209 return -1; 210 } 211 #define for_each_present_section_nr(start, section_nr) \ 212 for (section_nr = next_present_section_nr(start-1); \ 213 ((section_nr != -1) && \ 214 (section_nr <= __highest_present_section_nr)); \ 215 section_nr = next_present_section_nr(section_nr)) 216 217 static inline unsigned long first_present_section_nr(void) 218 { 219 return next_present_section_nr(-1); 220 } 221 222 static void subsection_mask_set(unsigned long *map, unsigned long pfn, 223 unsigned long nr_pages) 224 { 225 int idx = subsection_map_index(pfn); 226 int end = subsection_map_index(pfn + nr_pages - 1); 227 228 bitmap_set(map, idx, end - idx + 1); 229 } 230 231 void __init subsection_map_init(unsigned long pfn, unsigned long nr_pages) 232 { 233 int end_sec = pfn_to_section_nr(pfn + nr_pages - 1); 234 unsigned long nr, start_sec = pfn_to_section_nr(pfn); 235 236 if (!nr_pages) 237 return; 238 239 for (nr = start_sec; nr <= end_sec; nr++) { 240 struct mem_section *ms; 241 unsigned long pfns; 242 243 pfns = min(nr_pages, PAGES_PER_SECTION 244 - (pfn & ~PAGE_SECTION_MASK)); 245 ms = __nr_to_section(nr); 246 subsection_mask_set(ms->usage->subsection_map, pfn, pfns); 247 248 pr_debug("%s: sec: %lu pfns: %lu set(%d, %d)\n", __func__, nr, 249 pfns, subsection_map_index(pfn), 250 subsection_map_index(pfn + pfns - 1)); 251 252 pfn += pfns; 253 nr_pages -= pfns; 254 } 255 } 256 257 /* Record a memory area against a node. */ 258 void __init memory_present(int nid, unsigned long start, unsigned long end) 259 { 260 unsigned long pfn; 261 262 #ifdef CONFIG_SPARSEMEM_EXTREME 263 if (unlikely(!mem_section)) { 264 unsigned long size, align; 265 266 size = sizeof(struct mem_section*) * NR_SECTION_ROOTS; 267 align = 1 << (INTERNODE_CACHE_SHIFT); 268 mem_section = memblock_alloc(size, align); 269 if (!mem_section) 270 panic("%s: Failed to allocate %lu bytes align=0x%lx\n", 271 __func__, size, align); 272 } 273 #endif 274 275 start &= PAGE_SECTION_MASK; 276 mminit_validate_memmodel_limits(&start, &end); 277 for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) { 278 unsigned long section = pfn_to_section_nr(pfn); 279 struct mem_section *ms; 280 281 sparse_index_init(section, nid); 282 set_section_nid(section, nid); 283 284 ms = __nr_to_section(section); 285 if (!ms->section_mem_map) { 286 ms->section_mem_map = sparse_encode_early_nid(nid) | 287 SECTION_IS_ONLINE; 288 section_mark_present(ms); 289 } 290 } 291 } 292 293 /* 294 * Mark all memblocks as present using memory_present(). This is a 295 * convienence function that is useful for a number of arches 296 * to mark all of the systems memory as present during initialization. 297 */ 298 void __init memblocks_present(void) 299 { 300 struct memblock_region *reg; 301 302 for_each_memblock(memory, reg) { 303 memory_present(memblock_get_region_node(reg), 304 memblock_region_memory_base_pfn(reg), 305 memblock_region_memory_end_pfn(reg)); 306 } 307 } 308 309 /* 310 * Subtle, we encode the real pfn into the mem_map such that 311 * the identity pfn - section_mem_map will return the actual 312 * physical page frame number. 313 */ 314 static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum) 315 { 316 unsigned long coded_mem_map = 317 (unsigned long)(mem_map - (section_nr_to_pfn(pnum))); 318 BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT)); 319 BUG_ON(coded_mem_map & ~SECTION_MAP_MASK); 320 return coded_mem_map; 321 } 322 323 /* 324 * Decode mem_map from the coded memmap 325 */ 326 struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) 327 { 328 /* mask off the extra low bits of information */ 329 coded_mem_map &= SECTION_MAP_MASK; 330 return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); 331 } 332 333 static void __meminit sparse_init_one_section(struct mem_section *ms, 334 unsigned long pnum, struct page *mem_map, 335 struct mem_section_usage *usage, unsigned long flags) 336 { 337 ms->section_mem_map &= ~SECTION_MAP_MASK; 338 ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) 339 | SECTION_HAS_MEM_MAP | flags; 340 ms->usage = usage; 341 } 342 343 static unsigned long usemap_size(void) 344 { 345 return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long); 346 } 347 348 size_t mem_section_usage_size(void) 349 { 350 return sizeof(struct mem_section_usage) + usemap_size(); 351 } 352 353 #ifdef CONFIG_MEMORY_HOTREMOVE 354 static struct mem_section_usage * __init 355 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, 356 unsigned long size) 357 { 358 struct mem_section_usage *usage; 359 unsigned long goal, limit; 360 int nid; 361 /* 362 * A page may contain usemaps for other sections preventing the 363 * page being freed and making a section unremovable while 364 * other sections referencing the usemap remain active. Similarly, 365 * a pgdat can prevent a section being removed. If section A 366 * contains a pgdat and section B contains the usemap, both 367 * sections become inter-dependent. This allocates usemaps 368 * from the same section as the pgdat where possible to avoid 369 * this problem. 370 */ 371 goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT); 372 limit = goal + (1UL << PA_SECTION_SHIFT); 373 nid = early_pfn_to_nid(goal >> PAGE_SHIFT); 374 again: 375 usage = memblock_alloc_try_nid(size, SMP_CACHE_BYTES, goal, limit, nid); 376 if (!usage && limit) { 377 limit = 0; 378 goto again; 379 } 380 return usage; 381 } 382 383 static void __init check_usemap_section_nr(int nid, 384 struct mem_section_usage *usage) 385 { 386 unsigned long usemap_snr, pgdat_snr; 387 static unsigned long old_usemap_snr; 388 static unsigned long old_pgdat_snr; 389 struct pglist_data *pgdat = NODE_DATA(nid); 390 int usemap_nid; 391 392 /* First call */ 393 if (!old_usemap_snr) { 394 old_usemap_snr = NR_MEM_SECTIONS; 395 old_pgdat_snr = NR_MEM_SECTIONS; 396 } 397 398 usemap_snr = pfn_to_section_nr(__pa(usage) >> PAGE_SHIFT); 399 pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT); 400 if (usemap_snr == pgdat_snr) 401 return; 402 403 if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr) 404 /* skip redundant message */ 405 return; 406 407 old_usemap_snr = usemap_snr; 408 old_pgdat_snr = pgdat_snr; 409 410 usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr)); 411 if (usemap_nid != nid) { 412 pr_info("node %d must be removed before remove section %ld\n", 413 nid, usemap_snr); 414 return; 415 } 416 /* 417 * There is a circular dependency. 418 * Some platforms allow un-removable section because they will just 419 * gather other removable sections for dynamic partitioning. 420 * Just notify un-removable section's number here. 421 */ 422 pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n", 423 usemap_snr, pgdat_snr, nid); 424 } 425 #else 426 static struct mem_section_usage * __init 427 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat, 428 unsigned long size) 429 { 430 return memblock_alloc_node(size, SMP_CACHE_BYTES, pgdat->node_id); 431 } 432 433 static void __init check_usemap_section_nr(int nid, 434 struct mem_section_usage *usage) 435 { 436 } 437 #endif /* CONFIG_MEMORY_HOTREMOVE */ 438 439 #ifdef CONFIG_SPARSEMEM_VMEMMAP 440 static unsigned long __init section_map_size(void) 441 { 442 return ALIGN(sizeof(struct page) * PAGES_PER_SECTION, PMD_SIZE); 443 } 444 445 #else 446 static unsigned long __init section_map_size(void) 447 { 448 return PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION); 449 } 450 451 struct page __init *__populate_section_memmap(unsigned long pfn, 452 unsigned long nr_pages, int nid, struct vmem_altmap *altmap) 453 { 454 unsigned long size = section_map_size(); 455 struct page *map = sparse_buffer_alloc(size); 456 phys_addr_t addr = __pa(MAX_DMA_ADDRESS); 457 458 if (map) 459 return map; 460 461 map = memblock_alloc_try_nid(size, 462 PAGE_SIZE, addr, 463 MEMBLOCK_ALLOC_ACCESSIBLE, nid); 464 if (!map) 465 panic("%s: Failed to allocate %lu bytes align=0x%lx nid=%d from=%pa\n", 466 __func__, size, PAGE_SIZE, nid, &addr); 467 468 return map; 469 } 470 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */ 471 472 static void *sparsemap_buf __meminitdata; 473 static void *sparsemap_buf_end __meminitdata; 474 475 static inline void __meminit sparse_buffer_free(unsigned long size) 476 { 477 WARN_ON(!sparsemap_buf || size == 0); 478 memblock_free_early(__pa(sparsemap_buf), size); 479 } 480 481 static void __init sparse_buffer_init(unsigned long size, int nid) 482 { 483 phys_addr_t addr = __pa(MAX_DMA_ADDRESS); 484 WARN_ON(sparsemap_buf); /* forgot to call sparse_buffer_fini()? */ 485 sparsemap_buf = 486 memblock_alloc_try_nid_raw(size, PAGE_SIZE, 487 addr, 488 MEMBLOCK_ALLOC_ACCESSIBLE, nid); 489 sparsemap_buf_end = sparsemap_buf + size; 490 } 491 492 static void __init sparse_buffer_fini(void) 493 { 494 unsigned long size = sparsemap_buf_end - sparsemap_buf; 495 496 if (sparsemap_buf && size > 0) 497 sparse_buffer_free(size); 498 sparsemap_buf = NULL; 499 } 500 501 void * __meminit sparse_buffer_alloc(unsigned long size) 502 { 503 void *ptr = NULL; 504 505 if (sparsemap_buf) { 506 ptr = (void *) roundup((unsigned long)sparsemap_buf, size); 507 if (ptr + size > sparsemap_buf_end) 508 ptr = NULL; 509 else { 510 /* Free redundant aligned space */ 511 if ((unsigned long)(ptr - sparsemap_buf) > 0) 512 sparse_buffer_free((unsigned long)(ptr - sparsemap_buf)); 513 sparsemap_buf = ptr + size; 514 } 515 } 516 return ptr; 517 } 518 519 void __weak __meminit vmemmap_populate_print_last(void) 520 { 521 } 522 523 /* 524 * Initialize sparse on a specific node. The node spans [pnum_begin, pnum_end) 525 * And number of present sections in this node is map_count. 526 */ 527 static void __init sparse_init_nid(int nid, unsigned long pnum_begin, 528 unsigned long pnum_end, 529 unsigned long map_count) 530 { 531 struct mem_section_usage *usage; 532 unsigned long pnum; 533 struct page *map; 534 535 usage = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nid), 536 mem_section_usage_size() * map_count); 537 if (!usage) { 538 pr_err("%s: node[%d] usemap allocation failed", __func__, nid); 539 goto failed; 540 } 541 sparse_buffer_init(map_count * section_map_size(), nid); 542 for_each_present_section_nr(pnum_begin, pnum) { 543 unsigned long pfn = section_nr_to_pfn(pnum); 544 545 if (pnum >= pnum_end) 546 break; 547 548 map = __populate_section_memmap(pfn, PAGES_PER_SECTION, 549 nid, NULL); 550 if (!map) { 551 pr_err("%s: node[%d] memory map backing failed. Some memory will not be available.", 552 __func__, nid); 553 pnum_begin = pnum; 554 goto failed; 555 } 556 check_usemap_section_nr(nid, usage); 557 sparse_init_one_section(__nr_to_section(pnum), pnum, map, usage, 558 SECTION_IS_EARLY); 559 usage = (void *) usage + mem_section_usage_size(); 560 } 561 sparse_buffer_fini(); 562 return; 563 failed: 564 /* We failed to allocate, mark all the following pnums as not present */ 565 for_each_present_section_nr(pnum_begin, pnum) { 566 struct mem_section *ms; 567 568 if (pnum >= pnum_end) 569 break; 570 ms = __nr_to_section(pnum); 571 ms->section_mem_map = 0; 572 } 573 } 574 575 /* 576 * Allocate the accumulated non-linear sections, allocate a mem_map 577 * for each and record the physical to section mapping. 578 */ 579 void __init sparse_init(void) 580 { 581 unsigned long pnum_begin = first_present_section_nr(); 582 int nid_begin = sparse_early_nid(__nr_to_section(pnum_begin)); 583 unsigned long pnum_end, map_count = 1; 584 585 /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */ 586 set_pageblock_order(); 587 588 for_each_present_section_nr(pnum_begin + 1, pnum_end) { 589 int nid = sparse_early_nid(__nr_to_section(pnum_end)); 590 591 if (nid == nid_begin) { 592 map_count++; 593 continue; 594 } 595 /* Init node with sections in range [pnum_begin, pnum_end) */ 596 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count); 597 nid_begin = nid; 598 pnum_begin = pnum_end; 599 map_count = 1; 600 } 601 /* cover the last node */ 602 sparse_init_nid(nid_begin, pnum_begin, pnum_end, map_count); 603 vmemmap_populate_print_last(); 604 } 605 606 #ifdef CONFIG_MEMORY_HOTPLUG 607 608 /* Mark all memory sections within the pfn range as online */ 609 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn) 610 { 611 unsigned long pfn; 612 613 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 614 unsigned long section_nr = pfn_to_section_nr(pfn); 615 struct mem_section *ms; 616 617 /* onlining code should never touch invalid ranges */ 618 if (WARN_ON(!valid_section_nr(section_nr))) 619 continue; 620 621 ms = __nr_to_section(section_nr); 622 ms->section_mem_map |= SECTION_IS_ONLINE; 623 } 624 } 625 626 #ifdef CONFIG_MEMORY_HOTREMOVE 627 /* Mark all memory sections within the pfn range as offline */ 628 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn) 629 { 630 unsigned long pfn; 631 632 for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { 633 unsigned long section_nr = pfn_to_section_nr(pfn); 634 struct mem_section *ms; 635 636 /* 637 * TODO this needs some double checking. Offlining code makes 638 * sure to check pfn_valid but those checks might be just bogus 639 */ 640 if (WARN_ON(!valid_section_nr(section_nr))) 641 continue; 642 643 ms = __nr_to_section(section_nr); 644 ms->section_mem_map &= ~SECTION_IS_ONLINE; 645 } 646 } 647 #endif 648 649 #ifdef CONFIG_SPARSEMEM_VMEMMAP 650 static struct page *populate_section_memmap(unsigned long pfn, 651 unsigned long nr_pages, int nid, struct vmem_altmap *altmap) 652 { 653 return __populate_section_memmap(pfn, nr_pages, nid, altmap); 654 } 655 656 static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, 657 struct vmem_altmap *altmap) 658 { 659 unsigned long start = (unsigned long) pfn_to_page(pfn); 660 unsigned long end = start + nr_pages * sizeof(struct page); 661 662 vmemmap_free(start, end, altmap); 663 } 664 static void free_map_bootmem(struct page *memmap) 665 { 666 unsigned long start = (unsigned long)memmap; 667 unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION); 668 669 vmemmap_free(start, end, NULL); 670 } 671 #else 672 struct page *populate_section_memmap(unsigned long pfn, 673 unsigned long nr_pages, int nid, struct vmem_altmap *altmap) 674 { 675 struct page *page, *ret; 676 unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION; 677 678 page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size)); 679 if (page) 680 goto got_map_page; 681 682 ret = vmalloc(memmap_size); 683 if (ret) 684 goto got_map_ptr; 685 686 return NULL; 687 got_map_page: 688 ret = (struct page *)pfn_to_kaddr(page_to_pfn(page)); 689 got_map_ptr: 690 691 return ret; 692 } 693 694 static void depopulate_section_memmap(unsigned long pfn, unsigned long nr_pages, 695 struct vmem_altmap *altmap) 696 { 697 struct page *memmap = pfn_to_page(pfn); 698 699 if (is_vmalloc_addr(memmap)) 700 vfree(memmap); 701 else 702 free_pages((unsigned long)memmap, 703 get_order(sizeof(struct page) * PAGES_PER_SECTION)); 704 } 705 706 static void free_map_bootmem(struct page *memmap) 707 { 708 unsigned long maps_section_nr, removing_section_nr, i; 709 unsigned long magic, nr_pages; 710 struct page *page = virt_to_page(memmap); 711 712 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page)) 713 >> PAGE_SHIFT; 714 715 for (i = 0; i < nr_pages; i++, page++) { 716 magic = (unsigned long) page->freelist; 717 718 BUG_ON(magic == NODE_INFO); 719 720 maps_section_nr = pfn_to_section_nr(page_to_pfn(page)); 721 removing_section_nr = page_private(page); 722 723 /* 724 * When this function is called, the removing section is 725 * logical offlined state. This means all pages are isolated 726 * from page allocator. If removing section's memmap is placed 727 * on the same section, it must not be freed. 728 * If it is freed, page allocator may allocate it which will 729 * be removed physically soon. 730 */ 731 if (maps_section_nr != removing_section_nr) 732 put_page_bootmem(page); 733 } 734 } 735 #endif /* CONFIG_SPARSEMEM_VMEMMAP */ 736 737 static void section_deactivate(unsigned long pfn, unsigned long nr_pages, 738 struct vmem_altmap *altmap) 739 { 740 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; 741 DECLARE_BITMAP(tmp, SUBSECTIONS_PER_SECTION) = { 0 }; 742 struct mem_section *ms = __pfn_to_section(pfn); 743 bool section_is_early = early_section(ms); 744 struct page *memmap = NULL; 745 unsigned long *subsection_map = ms->usage 746 ? &ms->usage->subsection_map[0] : NULL; 747 748 subsection_mask_set(map, pfn, nr_pages); 749 if (subsection_map) 750 bitmap_and(tmp, map, subsection_map, SUBSECTIONS_PER_SECTION); 751 752 if (WARN(!subsection_map || !bitmap_equal(tmp, map, SUBSECTIONS_PER_SECTION), 753 "section already deactivated (%#lx + %ld)\n", 754 pfn, nr_pages)) 755 return; 756 757 /* 758 * There are 3 cases to handle across two configurations 759 * (SPARSEMEM_VMEMMAP={y,n}): 760 * 761 * 1/ deactivation of a partial hot-added section (only possible 762 * in the SPARSEMEM_VMEMMAP=y case). 763 * a/ section was present at memory init 764 * b/ section was hot-added post memory init 765 * 2/ deactivation of a complete hot-added section 766 * 3/ deactivation of a complete section from memory init 767 * 768 * For 1/, when subsection_map does not empty we will not be 769 * freeing the usage map, but still need to free the vmemmap 770 * range. 771 * 772 * For 2/ and 3/ the SPARSEMEM_VMEMMAP={y,n} cases are unified 773 */ 774 bitmap_xor(subsection_map, map, subsection_map, SUBSECTIONS_PER_SECTION); 775 if (bitmap_empty(subsection_map, SUBSECTIONS_PER_SECTION)) { 776 unsigned long section_nr = pfn_to_section_nr(pfn); 777 778 if (!section_is_early) { 779 kfree(ms->usage); 780 ms->usage = NULL; 781 } 782 memmap = sparse_decode_mem_map(ms->section_mem_map, section_nr); 783 ms->section_mem_map = sparse_encode_mem_map(NULL, section_nr); 784 } 785 786 if (section_is_early && memmap) 787 free_map_bootmem(memmap); 788 else 789 depopulate_section_memmap(pfn, nr_pages, altmap); 790 } 791 792 static struct page * __meminit section_activate(int nid, unsigned long pfn, 793 unsigned long nr_pages, struct vmem_altmap *altmap) 794 { 795 DECLARE_BITMAP(map, SUBSECTIONS_PER_SECTION) = { 0 }; 796 struct mem_section *ms = __pfn_to_section(pfn); 797 struct mem_section_usage *usage = NULL; 798 unsigned long *subsection_map; 799 struct page *memmap; 800 int rc = 0; 801 802 subsection_mask_set(map, pfn, nr_pages); 803 804 if (!ms->usage) { 805 usage = kzalloc(mem_section_usage_size(), GFP_KERNEL); 806 if (!usage) 807 return ERR_PTR(-ENOMEM); 808 ms->usage = usage; 809 } 810 subsection_map = &ms->usage->subsection_map[0]; 811 812 if (bitmap_empty(map, SUBSECTIONS_PER_SECTION)) 813 rc = -EINVAL; 814 else if (bitmap_intersects(map, subsection_map, SUBSECTIONS_PER_SECTION)) 815 rc = -EEXIST; 816 else 817 bitmap_or(subsection_map, map, subsection_map, 818 SUBSECTIONS_PER_SECTION); 819 820 if (rc) { 821 if (usage) 822 ms->usage = NULL; 823 kfree(usage); 824 return ERR_PTR(rc); 825 } 826 827 /* 828 * The early init code does not consider partially populated 829 * initial sections, it simply assumes that memory will never be 830 * referenced. If we hot-add memory into such a section then we 831 * do not need to populate the memmap and can simply reuse what 832 * is already there. 833 */ 834 if (nr_pages < PAGES_PER_SECTION && early_section(ms)) 835 return pfn_to_page(pfn); 836 837 memmap = populate_section_memmap(pfn, nr_pages, nid, altmap); 838 if (!memmap) { 839 section_deactivate(pfn, nr_pages, altmap); 840 return ERR_PTR(-ENOMEM); 841 } 842 843 return memmap; 844 } 845 846 /** 847 * sparse_add_section - add a memory section, or populate an existing one 848 * @nid: The node to add section on 849 * @start_pfn: start pfn of the memory range 850 * @nr_pages: number of pfns to add in the section 851 * @altmap: device page map 852 * 853 * This is only intended for hotplug. 854 * 855 * Return: 856 * * 0 - On success. 857 * * -EEXIST - Section has been present. 858 * * -ENOMEM - Out of memory. 859 */ 860 int __meminit sparse_add_section(int nid, unsigned long start_pfn, 861 unsigned long nr_pages, struct vmem_altmap *altmap) 862 { 863 unsigned long section_nr = pfn_to_section_nr(start_pfn); 864 struct mem_section *ms; 865 struct page *memmap; 866 int ret; 867 868 ret = sparse_index_init(section_nr, nid); 869 if (ret < 0) 870 return ret; 871 872 memmap = section_activate(nid, start_pfn, nr_pages, altmap); 873 if (IS_ERR(memmap)) 874 return PTR_ERR(memmap); 875 876 /* 877 * Poison uninitialized struct pages in order to catch invalid flags 878 * combinations. 879 */ 880 page_init_poison(pfn_to_page(start_pfn), sizeof(struct page) * nr_pages); 881 882 ms = __nr_to_section(section_nr); 883 set_section_nid(section_nr, nid); 884 section_mark_present(ms); 885 886 /* Align memmap to section boundary in the subsection case */ 887 if (section_nr_to_pfn(section_nr) != start_pfn) 888 memmap = pfn_to_kaddr(section_nr_to_pfn(section_nr)); 889 sparse_init_one_section(ms, section_nr, memmap, ms->usage, 0); 890 891 return 0; 892 } 893 894 #ifdef CONFIG_MEMORY_FAILURE 895 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) 896 { 897 int i; 898 899 /* 900 * A further optimization is to have per section refcounted 901 * num_poisoned_pages. But that would need more space per memmap, so 902 * for now just do a quick global check to speed up this routine in the 903 * absence of bad pages. 904 */ 905 if (atomic_long_read(&num_poisoned_pages) == 0) 906 return; 907 908 for (i = 0; i < nr_pages; i++) { 909 if (PageHWPoison(&memmap[i])) { 910 num_poisoned_pages_dec(); 911 ClearPageHWPoison(&memmap[i]); 912 } 913 } 914 } 915 #else 916 static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages) 917 { 918 } 919 #endif 920 921 void sparse_remove_section(struct mem_section *ms, unsigned long pfn, 922 unsigned long nr_pages, unsigned long map_offset, 923 struct vmem_altmap *altmap) 924 { 925 clear_hwpoisoned_pages(pfn_to_page(pfn) + map_offset, 926 nr_pages - map_offset); 927 section_deactivate(pfn, nr_pages, altmap); 928 } 929 #endif /* CONFIG_MEMORY_HOTPLUG */ 930