mm/sparse.c

   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/bootmem.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
  15 #include "internal.h"
  16 #include <asm/dma.h>
  17 #include <asm/pgalloc.h>
  18 #include <asm/pgtable.h>
  19
  20 /*
  21  * Permanent SPARSEMEM data:
  22  *
  23  * 1) mem_section       - memory sections, mem_map's for valid memory
  24  */
  25 #ifdef CONFIG_SPARSEMEM_EXTREME
  26 struct mem_section **mem_section;
  27 #else
  28 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
  29         ____cacheline_internodealigned_in_smp;
  30 #endif
  31 EXPORT_SYMBOL(mem_section);
  32
  33 #ifdef NODE_NOT_IN_PAGE_FLAGS
  34 /*
  35  * If we did not store the node number in the page then we have to
  36  * do a lookup in the section_to_node_table in order to find which
  37  * node the page belongs to.
  38  */
  39 #if MAX_NUMNODES <= 256
  40 static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  41 #else
  42 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  43 #endif
  44
  45 int page_to_nid(const struct page *page)
  46 {
  47         return section_to_node_table[page_to_section(page)];
  48 }
  49 EXPORT_SYMBOL(page_to_nid);
  50
  51 static void set_section_nid(unsigned long section_nr, int nid)
  52 {
  53         section_to_node_table[section_nr] = nid;
  54 }
  55 #else /* !NODE_NOT_IN_PAGE_FLAGS */
  56 static inline void set_section_nid(unsigned long section_nr, int nid)
  57 {
  58 }
  59 #endif
  60
  61 #ifdef CONFIG_SPARSEMEM_EXTREME
  62 static noinline struct mem_section __ref *sparse_index_alloc(int nid)
  63 {
  64         struct mem_section *section = NULL;
  65         unsigned long array_size = SECTIONS_PER_ROOT *
  66                                    sizeof(struct mem_section);
  67
  68         if (slab_is_available())
  69                 section = kzalloc_node(array_size, GFP_KERNEL, nid);
  70         else
  71                 section = memblock_virt_alloc_node(array_size, nid);
  72
  73         return section;
  74 }
  75
  76 static int __meminit sparse_index_init(unsigned long section_nr, int nid)
  77 {
  78         unsigned long root = SECTION_NR_TO_ROOT(section_nr);
  79         struct mem_section *section;
  80
  81         if (mem_section[root])
  82                 return -EEXIST;
  83
  84         section = sparse_index_alloc(nid);
  85         if (!section)
  86                 return -ENOMEM;
  87
  88         mem_section[root] = section;
  89
  90         return 0;
  91 }
  92 #else /* !SPARSEMEM_EXTREME */
  93 static inline int sparse_index_init(unsigned long section_nr, int nid)
  94 {
  95         return 0;
  96 }
  97 #endif
  98
  99 #ifdef CONFIG_SPARSEMEM_EXTREME
 100 int __section_nr(struct mem_section* ms)
 101 {
 102         unsigned long root_nr;
 103         struct mem_section *root = NULL;
 104
 105         for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
 106                 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
 107                 if (!root)
 108                         continue;
 109
 110                 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
 111                      break;
 112         }
 113
 114         VM_BUG_ON(!root);
 115
 116         return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
 117 }
 118 #else
 119 int __section_nr(struct mem_section* ms)
 120 {
 121         return (int)(ms - mem_section[0]);
 122 }
 123 #endif
 124
 125 /*
 126  * During early boot, before section_mem_map is used for an actual
 127  * mem_map, we use section_mem_map to store the section's NUMA
 128  * node.  This keeps us from having to use another data structure.  The
 129  * node information is cleared just before we store the real mem_map.
 130  */
 131 static inline unsigned long sparse_encode_early_nid(int nid)
 132 {
 133         return (nid << SECTION_NID_SHIFT);
 134 }
 135
 136 static inline int sparse_early_nid(struct mem_section *section)
 137 {
 138         return (section->section_mem_map >> SECTION_NID_SHIFT);
 139 }
 140
 141 /* Validate the physical addressing limitations of the model */
 142 void __meminit mminit_validate_memmodel_limits(unsigned long *start_pfn,
 143                                                 unsigned long *end_pfn)
 144 {
 145         unsigned long max_sparsemem_pfn = 1UL << (MAX_PHYSMEM_BITS-PAGE_SHIFT);
 146
 147         /*
 148          * Sanity checks - do not allow an architecture to pass
 149          * in larger pfns than the maximum scope of sparsemem:
 150          */
 151         if (*start_pfn > max_sparsemem_pfn) {
 152                 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
 153                         "Start of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
 154                         *start_pfn, *end_pfn, max_sparsemem_pfn);
 155                 WARN_ON_ONCE(1);
 156                 *start_pfn = max_sparsemem_pfn;
 157                 *end_pfn = max_sparsemem_pfn;
 158         } else if (*end_pfn > max_sparsemem_pfn) {
 159                 mminit_dprintk(MMINIT_WARNING, "pfnvalidation",
 160                         "End of range %lu -> %lu exceeds SPARSEMEM max %lu\n",
 161                         *start_pfn, *end_pfn, max_sparsemem_pfn);
 162                 WARN_ON_ONCE(1);
 163                 *end_pfn = max_sparsemem_pfn;
 164         }
 165 }
 166
 167 /*
 168  * There are a number of times that we loop over NR_MEM_SECTIONS,
 169  * looking for section_present() on each.  But, when we have very
 170  * large physical address spaces, NR_MEM_SECTIONS can also be
 171  * very large which makes the loops quite long.
 172  *
 173  * Keeping track of this gives us an easy way to break out of
 174  * those loops early.
 175  */
 176 int __highest_present_section_nr;
 177 static void section_mark_present(struct mem_section *ms)
 178 {
 179         int section_nr = __section_nr(ms);
 180
 181         if (section_nr > __highest_present_section_nr)
 182                 __highest_present_section_nr = section_nr;
 183
 184         ms->section_mem_map |= SECTION_MARKED_PRESENT;
 185 }
 186
 187 static inline int next_present_section_nr(int section_nr)
 188 {
 189         do {
 190                 section_nr++;
 191                 if (present_section_nr(section_nr))
 192                         return section_nr;
 193         } while ((section_nr < NR_MEM_SECTIONS) &&
 194                  (section_nr <= __highest_present_section_nr));
 195
 196         return -1;
 197 }
 198 #define for_each_present_section_nr(start, section_nr)          \
 199         for (section_nr = next_present_section_nr(start-1);     \
 200              ((section_nr >= 0) &&                              \
 201               (section_nr < NR_MEM_SECTIONS) &&                 \
 202               (section_nr <= __highest_present_section_nr));    \
 203              section_nr = next_present_section_nr(section_nr))
 204
 205 /* Record a memory area against a node. */
 206 void __init memory_present(int nid, unsigned long start, unsigned long end)
 207 {
 208         unsigned long pfn;
 209
 210 #ifdef CONFIG_SPARSEMEM_EXTREME
 211         if (unlikely(!mem_section)) {
 212                 unsigned long size, align;
 213
 214                 size = sizeof(struct mem_section*) * NR_SECTION_ROOTS;
 215                 align = 1 << (INTERNODE_CACHE_SHIFT);
 216                 mem_section = memblock_virt_alloc(size, align);
 217         }
 218 #endif
 219
 220         start &= PAGE_SECTION_MASK;
 221         mminit_validate_memmodel_limits(&start, &end);
 222         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
 223                 unsigned long section = pfn_to_section_nr(pfn);
 224                 struct mem_section *ms;
 225
 226                 sparse_index_init(section, nid);
 227                 set_section_nid(section, nid);
 228
 229                 ms = __nr_to_section(section);
 230                 if (!ms->section_mem_map) {
 231                         ms->section_mem_map = sparse_encode_early_nid(nid) |
 232                                                         SECTION_IS_ONLINE;
 233                         section_mark_present(ms);
 234                 }
 235         }
 236 }
 237
 238 /*
 239  * Only used by the i386 NUMA architecures, but relatively
 240  * generic code.
 241  */
 242 unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
 243                                                      unsigned long end_pfn)
 244 {
 245         unsigned long pfn;
 246         unsigned long nr_pages = 0;
 247
 248         mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
 249         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 250                 if (nid != early_pfn_to_nid(pfn))
 251                         continue;
 252
 253                 if (pfn_present(pfn))
 254                         nr_pages += PAGES_PER_SECTION;
 255         }
 256
 257         return nr_pages * sizeof(struct page);
 258 }
 259
 260 /*
 261  * Subtle, we encode the real pfn into the mem_map such that
 262  * the identity pfn - section_mem_map will return the actual
 263  * physical page frame number.
 264  */
 265 static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
 266 {
 267         unsigned long coded_mem_map =
 268                 (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
 269         BUILD_BUG_ON(SECTION_MAP_LAST_BIT > (1UL<<PFN_SECTION_SHIFT));
 270         BUG_ON(coded_mem_map & ~SECTION_MAP_MASK);
 271         return coded_mem_map;
 272 }
 273
 274 /*
 275  * Decode mem_map from the coded memmap
 276  */
 277 struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
 278 {
 279         /* mask off the extra low bits of information */
 280         coded_mem_map &= SECTION_MAP_MASK;
 281         return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
 282 }
 283
 284 static int __meminit sparse_init_one_section(struct mem_section *ms,
 285                 unsigned long pnum, struct page *mem_map,
 286                 unsigned long *pageblock_bitmap)
 287 {
 288         if (!present_section(ms))
 289                 return -EINVAL;
 290
 291         ms->section_mem_map &= ~SECTION_MAP_MASK;
 292         ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
 293                                                         SECTION_HAS_MEM_MAP;
 294         ms->pageblock_flags = pageblock_bitmap;
 295
 296         return 1;
 297 }
 298
 299 unsigned long usemap_size(void)
 300 {
 301         return BITS_TO_LONGS(SECTION_BLOCKFLAGS_BITS) * sizeof(unsigned long);
 302 }
 303
 304 #ifdef CONFIG_MEMORY_HOTPLUG
 305 static unsigned long *__kmalloc_section_usemap(void)
 306 {
 307         return kmalloc(usemap_size(), GFP_KERNEL);
 308 }
 309 #endif /* CONFIG_MEMORY_HOTPLUG */
 310
 311 #ifdef CONFIG_MEMORY_HOTREMOVE
 312 static unsigned long * __init
 313 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
 314                                          unsigned long size)
 315 {
 316         unsigned long goal, limit;
 317         unsigned long *p;
 318         int nid;
 319         /*
 320          * A page may contain usemaps for other sections preventing the
 321          * page being freed and making a section unremovable while
 322          * other sections referencing the usemap remain active. Similarly,
 323          * a pgdat can prevent a section being removed. If section A
 324          * contains a pgdat and section B contains the usemap, both
 325          * sections become inter-dependent. This allocates usemaps
 326          * from the same section as the pgdat where possible to avoid
 327          * this problem.
 328          */
 329         goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
 330         limit = goal + (1UL << PA_SECTION_SHIFT);
 331         nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
 332 again:
 333         p = memblock_virt_alloc_try_nid_nopanic(size,
 334                                                 SMP_CACHE_BYTES, goal, limit,
 335                                                 nid);
 336         if (!p && limit) {
 337                 limit = 0;
 338                 goto again;
 339         }
 340         return p;
 341 }
 342
 343 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 344 {
 345         unsigned long usemap_snr, pgdat_snr;
 346         static unsigned long old_usemap_snr;
 347         static unsigned long old_pgdat_snr;
 348         struct pglist_data *pgdat = NODE_DATA(nid);
 349         int usemap_nid;
 350
 351         /* First call */
 352         if (!old_usemap_snr) {
 353                 old_usemap_snr = NR_MEM_SECTIONS;
 354                 old_pgdat_snr = NR_MEM_SECTIONS;
 355         }
 356
 357         usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
 358         pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
 359         if (usemap_snr == pgdat_snr)
 360                 return;
 361
 362         if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
 363                 /* skip redundant message */
 364                 return;
 365
 366         old_usemap_snr = usemap_snr;
 367         old_pgdat_snr = pgdat_snr;
 368
 369         usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
 370         if (usemap_nid != nid) {
 371                 pr_info("node %d must be removed before remove section %ld\n",
 372                         nid, usemap_snr);
 373                 return;
 374         }
 375         /*
 376          * There is a circular dependency.
 377          * Some platforms allow un-removable section because they will just
 378          * gather other removable sections for dynamic partitioning.
 379          * Just notify un-removable section's number here.
 380          */
 381         pr_info("Section %ld and %ld (node %d) have a circular dependency on usemap and pgdat allocations\n",
 382                 usemap_snr, pgdat_snr, nid);
 383 }
 384 #else
 385 static unsigned long * __init
 386 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
 387                                          unsigned long size)
 388 {
 389         return memblock_virt_alloc_node_nopanic(size, pgdat->node_id);
 390 }
 391
 392 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 393 {
 394 }
 395 #endif /* CONFIG_MEMORY_HOTREMOVE */
 396
 397 static void __init sparse_early_usemaps_alloc_node(void *data,
 398                                  unsigned long pnum_begin,
 399                                  unsigned long pnum_end,
 400                                  unsigned long usemap_count, int nodeid)
 401 {
 402         void *usemap;
 403         unsigned long pnum;
 404         unsigned long **usemap_map = (unsigned long **)data;
 405         int size = usemap_size();
 406
 407         usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
 408                                                           size * usemap_count);
 409         if (!usemap) {
 410                 pr_warn("%s: allocation failed\n", __func__);
 411                 return;
 412         }
 413
 414         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 415                 if (!present_section_nr(pnum))
 416                         continue;
 417                 usemap_map[pnum] = usemap;
 418                 usemap += size;
 419                 check_usemap_section_nr(nodeid, usemap_map[pnum]);
 420         }
 421 }
 422
 423 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 424 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid,
 425                 struct vmem_altmap *altmap)
 426 {
 427         struct page *map;
 428         unsigned long size;
 429
 430         map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
 431         if (map)
 432                 return map;
 433
 434         size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 435         map = memblock_virt_alloc_try_nid(size,
 436                                           PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
 437                                           BOOTMEM_ALLOC_ACCESSIBLE, nid);
 438         return map;
 439 }
 440 void __init sparse_mem_maps_populate_node(struct page **map_map,
 441                                           unsigned long pnum_begin,
 442                                           unsigned long pnum_end,
 443                                           unsigned long map_count, int nodeid)
 444 {
 445         void *map;
 446         unsigned long pnum;
 447         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
 448
 449         map = alloc_remap(nodeid, size * map_count);
 450         if (map) {
 451                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 452                         if (!present_section_nr(pnum))
 453                                 continue;
 454                         map_map[pnum] = map;
 455                         map += size;
 456                 }
 457                 return;
 458         }
 459
 460         size = PAGE_ALIGN(size);
 461         map = memblock_virt_alloc_try_nid_raw(size * map_count,
 462                                               PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
 463                                               BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
 464         if (map) {
 465                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 466                         if (!present_section_nr(pnum))
 467                                 continue;
 468                         map_map[pnum] = map;
 469                         map += size;
 470                 }
 471                 return;
 472         }
 473
 474         /* fallback */
 475         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 476                 struct mem_section *ms;
 477
 478                 if (!present_section_nr(pnum))
 479                         continue;
 480                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid, NULL);
 481                 if (map_map[pnum])
 482                         continue;
 483                 ms = __nr_to_section(pnum);
 484                 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 485                        __func__);
 486                 ms->section_mem_map = 0;
 487         }
 488 }
 489 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 490
 491 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 492 static void __init sparse_early_mem_maps_alloc_node(void *data,
 493                                  unsigned long pnum_begin,
 494                                  unsigned long pnum_end,
 495                                  unsigned long map_count, int nodeid)
 496 {
 497         struct page **map_map = (struct page **)data;
 498         sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
 499                                          map_count, nodeid);
 500 }
 501 #else
 502 static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
 503 {
 504         struct page *map;
 505         struct mem_section *ms = __nr_to_section(pnum);
 506         int nid = sparse_early_nid(ms);
 507
 508         map = sparse_mem_map_populate(pnum, nid, NULL);
 509         if (map)
 510                 return map;
 511
 512         pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 513                __func__);
 514         ms->section_mem_map = 0;
 515         return NULL;
 516 }
 517 #endif
 518
 519 void __weak __meminit vmemmap_populate_print_last(void)
 520 {
 521 }
 522
 523 /**
 524  *  alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
 525  *  @map: usemap_map for pageblock flags or mmap_map for vmemmap
 526  */
 527 static void __init alloc_usemap_and_memmap(void (*alloc_func)
 528                                         (void *, unsigned long, unsigned long,
 529                                         unsigned long, int), void *data)
 530 {
 531         unsigned long pnum;
 532         unsigned long map_count;
 533         int nodeid_begin = 0;
 534         unsigned long pnum_begin = 0;
 535
 536         for_each_present_section_nr(0, pnum) {
 537                 struct mem_section *ms;
 538
 539                 ms = __nr_to_section(pnum);
 540                 nodeid_begin = sparse_early_nid(ms);
 541                 pnum_begin = pnum;
 542                 break;
 543         }
 544         map_count = 1;
 545         for_each_present_section_nr(pnum_begin + 1, pnum) {
 546                 struct mem_section *ms;
 547                 int nodeid;
 548
 549                 ms = __nr_to_section(pnum);
 550                 nodeid = sparse_early_nid(ms);
 551                 if (nodeid == nodeid_begin) {
 552                         map_count++;
 553                         continue;
 554                 }
 555                 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
 556                 alloc_func(data, pnum_begin, pnum,
 557                                                 map_count, nodeid_begin);
 558                 /* new start, update count etc*/
 559                 nodeid_begin = nodeid;
 560                 pnum_begin = pnum;
 561                 map_count = 1;
 562         }
 563         /* ok, last chunk */
 564         alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
 565                                                 map_count, nodeid_begin);
 566 }
 567
 568 /*
 569  * Allocate the accumulated non-linear sections, allocate a mem_map
 570  * for each and record the physical to section mapping.
 571  */
 572 void __init sparse_init(void)
 573 {
 574         unsigned long pnum;
 575         struct page *map;
 576         unsigned long *usemap;
 577         unsigned long **usemap_map;
 578         int size;
 579 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 580         int size2;
 581         struct page **map_map;
 582 #endif
 583
 584         /* see include/linux/mmzone.h 'struct mem_section' definition */
 585         BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
 586
 587         /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 588         set_pageblock_order();
 589
 590         /*
 591          * map is using big page (aka 2M in x86 64 bit)
 592          * usemap is less one page (aka 24 bytes)
 593          * so alloc 2M (with 2M align) and 24 bytes in turn will
 594          * make next 2M slip to one more 2M later.
 595          * then in big system, the memory will have a lot of holes...
 596          * here try to allocate 2M pages continuously.
 597          *
 598          * powerpc need to call sparse_init_one_section right after each
 599          * sparse_early_mem_map_alloc, so allocate usemap_map at first.
 600          */
 601         size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
 602         usemap_map = memblock_virt_alloc(size, 0);
 603         if (!usemap_map)
 604                 panic("can not allocate usemap_map\n");
 605         alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
 606                                                         (void *)usemap_map);
 607
 608 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 609         size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
 610         map_map = memblock_virt_alloc(size2, 0);
 611         if (!map_map)
 612                 panic("can not allocate map_map\n");
 613         alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
 614                                                         (void *)map_map);
 615 #endif
 616
 617         for_each_present_section_nr(0, pnum) {
 618                 usemap = usemap_map[pnum];
 619                 if (!usemap)
 620                         continue;
 621
 622 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 623                 map = map_map[pnum];
 624 #else
 625                 map = sparse_early_mem_map_alloc(pnum);
 626 #endif
 627                 if (!map)
 628                         continue;
 629
 630                 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
 631                                                                 usemap);
 632         }
 633
 634         vmemmap_populate_print_last();
 635
 636 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 637         memblock_free_early(__pa(map_map), size2);
 638 #endif
 639         memblock_free_early(__pa(usemap_map), size);
 640 }
 641
 642 #ifdef CONFIG_MEMORY_HOTPLUG
 643
 644 /* Mark all memory sections within the pfn range as online */
 645 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
 646 {
 647         unsigned long pfn;
 648
 649         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 650                 unsigned long section_nr = pfn_to_section_nr(pfn);
 651                 struct mem_section *ms;
 652
 653                 /* onlining code should never touch invalid ranges */
 654                 if (WARN_ON(!valid_section_nr(section_nr)))
 655                         continue;
 656
 657                 ms = __nr_to_section(section_nr);
 658                 ms->section_mem_map |= SECTION_IS_ONLINE;
 659         }
 660 }
 661
 662 #ifdef CONFIG_MEMORY_HOTREMOVE
 663 /* Mark all memory sections within the pfn range as online */
 664 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
 665 {
 666         unsigned long pfn;
 667
 668         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 669                 unsigned long section_nr = pfn_to_section_nr(start_pfn);
 670                 struct mem_section *ms;
 671
 672                 /*
 673                  * TODO this needs some double checking. Offlining code makes
 674                  * sure to check pfn_valid but those checks might be just bogus
 675                  */
 676                 if (WARN_ON(!valid_section_nr(section_nr)))
 677                         continue;
 678
 679                 ms = __nr_to_section(section_nr);
 680                 ms->section_mem_map &= ~SECTION_IS_ONLINE;
 681         }
 682 }
 683 #endif
 684
 685 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 686 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 687                 struct vmem_altmap *altmap)
 688 {
 689         /* This will make the necessary allocations eventually. */
 690         return sparse_mem_map_populate(pnum, nid, altmap);
 691 }
 692 static void __kfree_section_memmap(struct page *memmap,
 693                 struct vmem_altmap *altmap)
 694 {
 695         unsigned long start = (unsigned long)memmap;
 696         unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 697
 698         vmemmap_free(start, end, altmap);
 699 }
 700 #ifdef CONFIG_MEMORY_HOTREMOVE
 701 static void free_map_bootmem(struct page *memmap)
 702 {
 703         unsigned long start = (unsigned long)memmap;
 704         unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 705
 706         vmemmap_free(start, end, NULL);
 707 }
 708 #endif /* CONFIG_MEMORY_HOTREMOVE */
 709 #else
 710 static struct page *__kmalloc_section_memmap(void)
 711 {
 712         struct page *page, *ret;
 713         unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
 714
 715         page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
 716         if (page)
 717                 goto got_map_page;
 718
 719         ret = vmalloc(memmap_size);
 720         if (ret)
 721                 goto got_map_ptr;
 722
 723         return NULL;
 724 got_map_page:
 725         ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
 726 got_map_ptr:
 727
 728         return ret;
 729 }
 730
 731 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 732                 struct vmem_altmap *altmap)
 733 {
 734         return __kmalloc_section_memmap();
 735 }
 736
 737 static void __kfree_section_memmap(struct page *memmap,
 738                 struct vmem_altmap *altmap)
 739 {
 740         if (is_vmalloc_addr(memmap))
 741                 vfree(memmap);
 742         else
 743                 free_pages((unsigned long)memmap,
 744                            get_order(sizeof(struct page) * PAGES_PER_SECTION));
 745 }
 746
 747 #ifdef CONFIG_MEMORY_HOTREMOVE
 748 static void free_map_bootmem(struct page *memmap)
 749 {
 750         unsigned long maps_section_nr, removing_section_nr, i;
 751         unsigned long magic, nr_pages;
 752         struct page *page = virt_to_page(memmap);
 753
 754         nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
 755                 >> PAGE_SHIFT;
 756
 757         for (i = 0; i < nr_pages; i++, page++) {
 758                 magic = (unsigned long) page->freelist;
 759
 760                 BUG_ON(magic == NODE_INFO);
 761
 762                 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
 763                 removing_section_nr = page_private(page);
 764
 765                 /*
 766                  * When this function is called, the removing section is
 767                  * logical offlined state. This means all pages are isolated
 768                  * from page allocator. If removing section's memmap is placed
 769                  * on the same section, it must not be freed.
 770                  * If it is freed, page allocator may allocate it which will
 771                  * be removed physically soon.
 772                  */
 773                 if (maps_section_nr != removing_section_nr)
 774                         put_page_bootmem(page);
 775         }
 776 }
 777 #endif /* CONFIG_MEMORY_HOTREMOVE */
 778 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 779
 780 /*
 781  * returns the number of sections whose mem_maps were properly
 782  * set.  If this is <=0, then that means that the passed-in
 783  * map was not consumed and must be freed.
 784  */
 785 int __meminit sparse_add_one_section(struct pglist_data *pgdat,
 786                 unsigned long start_pfn, struct vmem_altmap *altmap)
 787 {
 788         unsigned long section_nr = pfn_to_section_nr(start_pfn);
 789         struct mem_section *ms;
 790         struct page *memmap;
 791         unsigned long *usemap;
 792         unsigned long flags;
 793         int ret;
 794
 795         /*
 796          * no locking for this, because it does its own
 797          * plus, it does a kmalloc
 798          */
 799         ret = sparse_index_init(section_nr, pgdat->node_id);
 800         if (ret < 0 && ret != -EEXIST)
 801                 return ret;
 802         memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, altmap);
 803         if (!memmap)
 804                 return -ENOMEM;
 805         usemap = __kmalloc_section_usemap();
 806         if (!usemap) {
 807                 __kfree_section_memmap(memmap, altmap);
 808                 return -ENOMEM;
 809         }
 810
 811         pgdat_resize_lock(pgdat, &flags);
 812
 813         ms = __pfn_to_section(start_pfn);
 814         if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
 815                 ret = -EEXIST;
 816                 goto out;
 817         }
 818
 819         memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION);
 820
 821         section_mark_present(ms);
 822
 823         ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 824
 825 out:
 826         pgdat_resize_unlock(pgdat, &flags);
 827         if (ret <= 0) {
 828                 kfree(usemap);
 829                 __kfree_section_memmap(memmap, altmap);
 830         }
 831         return ret;
 832 }
 833
 834 #ifdef CONFIG_MEMORY_HOTREMOVE
 835 #ifdef CONFIG_MEMORY_FAILURE
 836 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 837 {
 838         int i;
 839
 840         if (!memmap)
 841                 return;
 842
 843         for (i = 0; i < nr_pages; i++) {
 844                 if (PageHWPoison(&memmap[i])) {
 845                         atomic_long_sub(1, &num_poisoned_pages);
 846                         ClearPageHWPoison(&memmap[i]);
 847                 }
 848         }
 849 }
 850 #else
 851 static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 852 {
 853 }
 854 #endif
 855
 856 static void free_section_usemap(struct page *memmap, unsigned long *usemap,
 857                 struct vmem_altmap *altmap)
 858 {
 859         struct page *usemap_page;
 860
 861         if (!usemap)
 862                 return;
 863
 864         usemap_page = virt_to_page(usemap);
 865         /*
 866          * Check to see if allocation came from hot-plug-add
 867          */
 868         if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
 869                 kfree(usemap);
 870                 if (memmap)
 871                         __kfree_section_memmap(memmap, altmap);
 872                 return;
 873         }
 874
 875         /*
 876          * The usemap came from bootmem. This is packed with other usemaps
 877          * on the section which has pgdat at boot time. Just keep it as is now.
 878          */
 879
 880         if (memmap)
 881                 free_map_bootmem(memmap);
 882 }
 883
 884 void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
 885                 unsigned long map_offset, struct vmem_altmap *altmap)
 886 {
 887         struct page *memmap = NULL;
 888         unsigned long *usemap = NULL, flags;
 889         struct pglist_data *pgdat = zone->zone_pgdat;
 890
 891         pgdat_resize_lock(pgdat, &flags);
 892         if (ms->section_mem_map) {
 893                 usemap = ms->pageblock_flags;
 894                 memmap = sparse_decode_mem_map(ms->section_mem_map,
 895                                                 __section_nr(ms));
 896                 ms->section_mem_map = 0;
 897                 ms->pageblock_flags = NULL;
 898         }
 899         pgdat_resize_unlock(pgdat, &flags);
 900
 901         clear_hwpoisoned_pages(memmap + map_offset,
 902                         PAGES_PER_SECTION - map_offset);
 903         free_section_usemap(memmap, usemap, altmap);
 904 }
 905 #endif /* CONFIG_MEMORY_HOTREMOVE */
 906 #endif /* CONFIG_MEMORY_HOTPLUG */