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 {
 426         struct page *map;
 427         unsigned long size;
 428
 429         map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
 430         if (map)
 431                 return map;
 432
 433         size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 434         map = memblock_virt_alloc_try_nid(size,
 435                                           PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
 436                                           BOOTMEM_ALLOC_ACCESSIBLE, nid);
 437         return map;
 438 }
 439 void __init sparse_mem_maps_populate_node(struct page **map_map,
 440                                           unsigned long pnum_begin,
 441                                           unsigned long pnum_end,
 442                                           unsigned long map_count, int nodeid)
 443 {
 444         void *map;
 445         unsigned long pnum;
 446         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
 447
 448         map = alloc_remap(nodeid, size * map_count);
 449         if (map) {
 450                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 451                         if (!present_section_nr(pnum))
 452                                 continue;
 453                         map_map[pnum] = map;
 454                         map += size;
 455                 }
 456                 return;
 457         }
 458
 459         size = PAGE_ALIGN(size);
 460         map = memblock_virt_alloc_try_nid_raw(size * map_count,
 461                                               PAGE_SIZE, __pa(MAX_DMA_ADDRESS),
 462                                               BOOTMEM_ALLOC_ACCESSIBLE, nodeid);
 463         if (map) {
 464                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 465                         if (!present_section_nr(pnum))
 466                                 continue;
 467                         map_map[pnum] = map;
 468                         map += size;
 469                 }
 470                 return;
 471         }
 472
 473         /* fallback */
 474         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 475                 struct mem_section *ms;
 476
 477                 if (!present_section_nr(pnum))
 478                         continue;
 479                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
 480                 if (map_map[pnum])
 481                         continue;
 482                 ms = __nr_to_section(pnum);
 483                 pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 484                        __func__);
 485                 ms->section_mem_map = 0;
 486         }
 487 }
 488 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 489
 490 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 491 static void __init sparse_early_mem_maps_alloc_node(void *data,
 492                                  unsigned long pnum_begin,
 493                                  unsigned long pnum_end,
 494                                  unsigned long map_count, int nodeid)
 495 {
 496         struct page **map_map = (struct page **)data;
 497         sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
 498                                          map_count, nodeid);
 499 }
 500 #else
 501 static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
 502 {
 503         struct page *map;
 504         struct mem_section *ms = __nr_to_section(pnum);
 505         int nid = sparse_early_nid(ms);
 506
 507         map = sparse_mem_map_populate(pnum, nid);
 508         if (map)
 509                 return map;
 510
 511         pr_err("%s: sparsemem memory map backing failed some memory will not be available\n",
 512                __func__);
 513         ms->section_mem_map = 0;
 514         return NULL;
 515 }
 516 #endif
 517
 518 void __weak __meminit vmemmap_populate_print_last(void)
 519 {
 520 }
 521
 522 /**
 523  *  alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
 524  *  @map: usemap_map for pageblock flags or mmap_map for vmemmap
 525  */
 526 static void __init alloc_usemap_and_memmap(void (*alloc_func)
 527                                         (void *, unsigned long, unsigned long,
 528                                         unsigned long, int), void *data)
 529 {
 530         unsigned long pnum;
 531         unsigned long map_count;
 532         int nodeid_begin = 0;
 533         unsigned long pnum_begin = 0;
 534
 535         for_each_present_section_nr(0, pnum) {
 536                 struct mem_section *ms;
 537
 538                 ms = __nr_to_section(pnum);
 539                 nodeid_begin = sparse_early_nid(ms);
 540                 pnum_begin = pnum;
 541                 break;
 542         }
 543         map_count = 1;
 544         for_each_present_section_nr(pnum_begin + 1, pnum) {
 545                 struct mem_section *ms;
 546                 int nodeid;
 547
 548                 ms = __nr_to_section(pnum);
 549                 nodeid = sparse_early_nid(ms);
 550                 if (nodeid == nodeid_begin) {
 551                         map_count++;
 552                         continue;
 553                 }
 554                 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
 555                 alloc_func(data, pnum_begin, pnum,
 556                                                 map_count, nodeid_begin);
 557                 /* new start, update count etc*/
 558                 nodeid_begin = nodeid;
 559                 pnum_begin = pnum;
 560                 map_count = 1;
 561         }
 562         /* ok, last chunk */
 563         alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
 564                                                 map_count, nodeid_begin);
 565 }
 566
 567 /*
 568  * Allocate the accumulated non-linear sections, allocate a mem_map
 569  * for each and record the physical to section mapping.
 570  */
 571 void __init sparse_init(void)
 572 {
 573         unsigned long pnum;
 574         struct page *map;
 575         unsigned long *usemap;
 576         unsigned long **usemap_map;
 577         int size;
 578 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 579         int size2;
 580         struct page **map_map;
 581 #endif
 582
 583         /* see include/linux/mmzone.h 'struct mem_section' definition */
 584         BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
 585
 586         /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 587         set_pageblock_order();
 588
 589         /*
 590          * map is using big page (aka 2M in x86 64 bit)
 591          * usemap is less one page (aka 24 bytes)
 592          * so alloc 2M (with 2M align) and 24 bytes in turn will
 593          * make next 2M slip to one more 2M later.
 594          * then in big system, the memory will have a lot of holes...
 595          * here try to allocate 2M pages continuously.
 596          *
 597          * powerpc need to call sparse_init_one_section right after each
 598          * sparse_early_mem_map_alloc, so allocate usemap_map at first.
 599          */
 600         size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
 601         usemap_map = memblock_virt_alloc(size, 0);
 602         if (!usemap_map)
 603                 panic("can not allocate usemap_map\n");
 604         alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
 605                                                         (void *)usemap_map);
 606
 607 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 608         size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
 609         map_map = memblock_virt_alloc(size2, 0);
 610         if (!map_map)
 611                 panic("can not allocate map_map\n");
 612         alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
 613                                                         (void *)map_map);
 614 #endif
 615
 616         for_each_present_section_nr(0, pnum) {
 617                 usemap = usemap_map[pnum];
 618                 if (!usemap)
 619                         continue;
 620
 621 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 622                 map = map_map[pnum];
 623 #else
 624                 map = sparse_early_mem_map_alloc(pnum);
 625 #endif
 626                 if (!map)
 627                         continue;
 628
 629                 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
 630                                                                 usemap);
 631         }
 632
 633         vmemmap_populate_print_last();
 634
 635 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 636         memblock_free_early(__pa(map_map), size2);
 637 #endif
 638         memblock_free_early(__pa(usemap_map), size);
 639 }
 640
 641 #ifdef CONFIG_MEMORY_HOTPLUG
 642
 643 /* Mark all memory sections within the pfn range as online */
 644 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
 645 {
 646         unsigned long pfn;
 647
 648         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 649                 unsigned long section_nr = pfn_to_section_nr(pfn);
 650                 struct mem_section *ms;
 651
 652                 /* onlining code should never touch invalid ranges */
 653                 if (WARN_ON(!valid_section_nr(section_nr)))
 654                         continue;
 655
 656                 ms = __nr_to_section(section_nr);
 657                 ms->section_mem_map |= SECTION_IS_ONLINE;
 658         }
 659 }
 660
 661 #ifdef CONFIG_MEMORY_HOTREMOVE
 662 /* Mark all memory sections within the pfn range as online */
 663 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn)
 664 {
 665         unsigned long pfn;
 666
 667         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 668                 unsigned long section_nr = pfn_to_section_nr(start_pfn);
 669                 struct mem_section *ms;
 670
 671                 /*
 672                  * TODO this needs some double checking. Offlining code makes
 673                  * sure to check pfn_valid but those checks might be just bogus
 674                  */
 675                 if (WARN_ON(!valid_section_nr(section_nr)))
 676                         continue;
 677
 678                 ms = __nr_to_section(section_nr);
 679                 ms->section_mem_map &= ~SECTION_IS_ONLINE;
 680         }
 681 }
 682 #endif
 683
 684 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 685 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
 686 {
 687         /* This will make the necessary allocations eventually. */
 688         return sparse_mem_map_populate(pnum, nid);
 689 }
 690 static void __kfree_section_memmap(struct page *memmap)
 691 {
 692         unsigned long start = (unsigned long)memmap;
 693         unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 694
 695         vmemmap_free(start, end);
 696 }
 697 #ifdef CONFIG_MEMORY_HOTREMOVE
 698 static void free_map_bootmem(struct page *memmap)
 699 {
 700         unsigned long start = (unsigned long)memmap;
 701         unsigned long end = (unsigned long)(memmap + PAGES_PER_SECTION);
 702
 703         vmemmap_free(start, end);
 704 }
 705 #endif /* CONFIG_MEMORY_HOTREMOVE */
 706 #else
 707 static struct page *__kmalloc_section_memmap(void)
 708 {
 709         struct page *page, *ret;
 710         unsigned long memmap_size = sizeof(struct page) * PAGES_PER_SECTION;
 711
 712         page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
 713         if (page)
 714                 goto got_map_page;
 715
 716         ret = vmalloc(memmap_size);
 717         if (ret)
 718                 goto got_map_ptr;
 719
 720         return NULL;
 721 got_map_page:
 722         ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
 723 got_map_ptr:
 724
 725         return ret;
 726 }
 727
 728 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid)
 729 {
 730         return __kmalloc_section_memmap();
 731 }
 732
 733 static void __kfree_section_memmap(struct page *memmap)
 734 {
 735         if (is_vmalloc_addr(memmap))
 736                 vfree(memmap);
 737         else
 738                 free_pages((unsigned long)memmap,
 739                            get_order(sizeof(struct page) * PAGES_PER_SECTION));
 740 }
 741
 742 #ifdef CONFIG_MEMORY_HOTREMOVE
 743 static void free_map_bootmem(struct page *memmap)
 744 {
 745         unsigned long maps_section_nr, removing_section_nr, i;
 746         unsigned long magic, nr_pages;
 747         struct page *page = virt_to_page(memmap);
 748
 749         nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
 750                 >> PAGE_SHIFT;
 751
 752         for (i = 0; i < nr_pages; i++, page++) {
 753                 magic = (unsigned long) page->freelist;
 754
 755                 BUG_ON(magic == NODE_INFO);
 756
 757                 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
 758                 removing_section_nr = page_private(page);
 759
 760                 /*
 761                  * When this function is called, the removing section is
 762                  * logical offlined state. This means all pages are isolated
 763                  * from page allocator. If removing section's memmap is placed
 764                  * on the same section, it must not be freed.
 765                  * If it is freed, page allocator may allocate it which will
 766                  * be removed physically soon.
 767                  */
 768                 if (maps_section_nr != removing_section_nr)
 769                         put_page_bootmem(page);
 770         }
 771 }
 772 #endif /* CONFIG_MEMORY_HOTREMOVE */
 773 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 774
 775 /*
 776  * returns the number of sections whose mem_maps were properly
 777  * set.  If this is <=0, then that means that the passed-in
 778  * map was not consumed and must be freed.
 779  */
 780 int __meminit sparse_add_one_section(struct pglist_data *pgdat, unsigned long start_pfn)
 781 {
 782         unsigned long section_nr = pfn_to_section_nr(start_pfn);
 783         struct mem_section *ms;
 784         struct page *memmap;
 785         unsigned long *usemap;
 786         unsigned long flags;
 787         int ret;
 788
 789         /*
 790          * no locking for this, because it does its own
 791          * plus, it does a kmalloc
 792          */
 793         ret = sparse_index_init(section_nr, pgdat->node_id);
 794         if (ret < 0 && ret != -EEXIST)
 795                 return ret;
 796         memmap = kmalloc_section_memmap(section_nr, pgdat->node_id);
 797         if (!memmap)
 798                 return -ENOMEM;
 799         usemap = __kmalloc_section_usemap();
 800         if (!usemap) {
 801                 __kfree_section_memmap(memmap);
 802                 return -ENOMEM;
 803         }
 804
 805         pgdat_resize_lock(pgdat, &flags);
 806
 807         ms = __pfn_to_section(start_pfn);
 808         if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
 809                 ret = -EEXIST;
 810                 goto out;
 811         }
 812
 813         memset(memmap, 0, sizeof(struct page) * PAGES_PER_SECTION);
 814
 815         section_mark_present(ms);
 816
 817         ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 818
 819 out:
 820         pgdat_resize_unlock(pgdat, &flags);
 821         if (ret <= 0) {
 822                 kfree(usemap);
 823                 __kfree_section_memmap(memmap);
 824         }
 825         return ret;
 826 }
 827
 828 #ifdef CONFIG_MEMORY_HOTREMOVE
 829 #ifdef CONFIG_MEMORY_FAILURE
 830 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 831 {
 832         int i;
 833
 834         if (!memmap)
 835                 return;
 836
 837         for (i = 0; i < nr_pages; i++) {
 838                 if (PageHWPoison(&memmap[i])) {
 839                         atomic_long_sub(1, &num_poisoned_pages);
 840                         ClearPageHWPoison(&memmap[i]);
 841                 }
 842         }
 843 }
 844 #else
 845 static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 846 {
 847 }
 848 #endif
 849
 850 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 851 {
 852         struct page *usemap_page;
 853
 854         if (!usemap)
 855                 return;
 856
 857         usemap_page = virt_to_page(usemap);
 858         /*
 859          * Check to see if allocation came from hot-plug-add
 860          */
 861         if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
 862                 kfree(usemap);
 863                 if (memmap)
 864                         __kfree_section_memmap(memmap);
 865                 return;
 866         }
 867
 868         /*
 869          * The usemap came from bootmem. This is packed with other usemaps
 870          * on the section which has pgdat at boot time. Just keep it as is now.
 871          */
 872
 873         if (memmap)
 874                 free_map_bootmem(memmap);
 875 }
 876
 877 void sparse_remove_one_section(struct zone *zone, struct mem_section *ms,
 878                 unsigned long map_offset)
 879 {
 880         struct page *memmap = NULL;
 881         unsigned long *usemap = NULL, flags;
 882         struct pglist_data *pgdat = zone->zone_pgdat;
 883
 884         pgdat_resize_lock(pgdat, &flags);
 885         if (ms->section_mem_map) {
 886                 usemap = ms->pageblock_flags;
 887                 memmap = sparse_decode_mem_map(ms->section_mem_map,
 888                                                 __section_nr(ms));
 889                 ms->section_mem_map = 0;
 890                 ms->pageblock_flags = NULL;
 891         }
 892         pgdat_resize_unlock(pgdat, &flags);
 893
 894         clear_hwpoisoned_pages(memmap + map_offset,
 895                         PAGES_PER_SECTION - map_offset);
 896         free_section_usemap(memmap, usemap);
 897 }
 898 #endif /* CONFIG_MEMORY_HOTREMOVE */
 899 #endif /* CONFIG_MEMORY_HOTPLUG */