mm/sparse.c

   1 /*
   2  * sparse memory mappings.
   3  */
   4 #include <linux/mm.h>
   5 #include <linux/slab.h>
   6 #include <linux/mmzone.h>
   7 #include <linux/bootmem.h>
   8 #include <linux/highmem.h>
   9 #include <linux/export.h>
  10 #include <linux/spinlock.h>
  11 #include <linux/vmalloc.h>
  12 #include "internal.h"
  13 #include <asm/dma.h>
  14 #include <asm/pgalloc.h>
  15 #include <asm/pgtable.h>
  16
  17 /*
  18  * Permanent SPARSEMEM data:
  19  *
  20  * 1) mem_section       - memory sections, mem_map's for valid memory
  21  */
  22 #ifdef CONFIG_SPARSEMEM_EXTREME
  23 struct mem_section *mem_section[NR_SECTION_ROOTS]
  24         ____cacheline_internodealigned_in_smp;
  25 #else
  26 struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
  27         ____cacheline_internodealigned_in_smp;
  28 #endif
  29 EXPORT_SYMBOL(mem_section);
  30
  31 #ifdef NODE_NOT_IN_PAGE_FLAGS
  32 /*
  33  * If we did not store the node number in the page then we have to
  34  * do a lookup in the section_to_node_table in order to find which
  35  * node the page belongs to.
  36  */
  37 #if MAX_NUMNODES <= 256
  38 static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  39 #else
  40 static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  41 #endif
  42
  43 int page_to_nid(const struct page *page)
  44 {
  45         return section_to_node_table[page_to_section(page)];
  46 }
  47 EXPORT_SYMBOL(page_to_nid);
  48
  49 static void set_section_nid(unsigned long section_nr, int nid)
  50 {
  51         section_to_node_table[section_nr] = nid;
  52 }
  53 #else /* !NODE_NOT_IN_PAGE_FLAGS */
  54 static inline void set_section_nid(unsigned long section_nr, int nid)
  55 {
  56 }
  57 #endif
  58
  59 #ifdef CONFIG_SPARSEMEM_EXTREME
  60 static struct mem_section noinline __init_refok *sparse_index_alloc(int nid)
  61 {
  62         struct mem_section *section = NULL;
  63         unsigned long array_size = SECTIONS_PER_ROOT *
  64                                    sizeof(struct mem_section);
  65
  66         if (slab_is_available()) {
  67                 if (node_state(nid, N_HIGH_MEMORY))
  68                         section = kzalloc_node(array_size, GFP_KERNEL, nid);
  69                 else
  70                         section = kzalloc(array_size, GFP_KERNEL);
  71         } else {
  72                 section = alloc_bootmem_node(NODE_DATA(nid), array_size);
  73         }
  74
  75         return section;
  76 }
  77
  78 static int __meminit sparse_index_init(unsigned long section_nr, int nid)
  79 {
  80         unsigned long root = SECTION_NR_TO_ROOT(section_nr);
  81         struct mem_section *section;
  82
  83         if (mem_section[root])
  84                 return -EEXIST;
  85
  86         section = sparse_index_alloc(nid);
  87         if (!section)
  88                 return -ENOMEM;
  89
  90         mem_section[root] = section;
  91
  92         return 0;
  93 }
  94 #else /* !SPARSEMEM_EXTREME */
  95 static inline int sparse_index_init(unsigned long section_nr, int nid)
  96 {
  97         return 0;
  98 }
  99 #endif
 100
 101 /*
 102  * Although written for the SPARSEMEM_EXTREME case, this happens
 103  * to also work for the flat array case because
 104  * NR_SECTION_ROOTS==NR_MEM_SECTIONS.
 105  */
 106 int __section_nr(struct mem_section* ms)
 107 {
 108         unsigned long root_nr;
 109         struct mem_section* root;
 110
 111         for (root_nr = 0; root_nr < NR_SECTION_ROOTS; root_nr++) {
 112                 root = __nr_to_section(root_nr * SECTIONS_PER_ROOT);
 113                 if (!root)
 114                         continue;
 115
 116                 if ((ms >= root) && (ms < (root + SECTIONS_PER_ROOT)))
 117                      break;
 118         }
 119
 120         VM_BUG_ON(root_nr == NR_SECTION_ROOTS);
 121
 122         return (root_nr * SECTIONS_PER_ROOT) + (ms - root);
 123 }
 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 /* Record a memory area against a node. */
 168 void __init memory_present(int nid, unsigned long start, unsigned long end)
 169 {
 170         unsigned long pfn;
 171
 172         start &= PAGE_SECTION_MASK;
 173         mminit_validate_memmodel_limits(&start, &end);
 174         for (pfn = start; pfn < end; pfn += PAGES_PER_SECTION) {
 175                 unsigned long section = pfn_to_section_nr(pfn);
 176                 struct mem_section *ms;
 177
 178                 sparse_index_init(section, nid);
 179                 set_section_nid(section, nid);
 180
 181                 ms = __nr_to_section(section);
 182                 if (!ms->section_mem_map)
 183                         ms->section_mem_map = sparse_encode_early_nid(nid) |
 184                                                         SECTION_MARKED_PRESENT;
 185         }
 186 }
 187
 188 /*
 189  * Only used by the i386 NUMA architecures, but relatively
 190  * generic code.
 191  */
 192 unsigned long __init node_memmap_size_bytes(int nid, unsigned long start_pfn,
 193                                                      unsigned long end_pfn)
 194 {
 195         unsigned long pfn;
 196         unsigned long nr_pages = 0;
 197
 198         mminit_validate_memmodel_limits(&start_pfn, &end_pfn);
 199         for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) {
 200                 if (nid != early_pfn_to_nid(pfn))
 201                         continue;
 202
 203                 if (pfn_present(pfn))
 204                         nr_pages += PAGES_PER_SECTION;
 205         }
 206
 207         return nr_pages * sizeof(struct page);
 208 }
 209
 210 /*
 211  * Subtle, we encode the real pfn into the mem_map such that
 212  * the identity pfn - section_mem_map will return the actual
 213  * physical page frame number.
 214  */
 215 static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long pnum)
 216 {
 217         return (unsigned long)(mem_map - (section_nr_to_pfn(pnum)));
 218 }
 219
 220 /*
 221  * Decode mem_map from the coded memmap
 222  */
 223 struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum)
 224 {
 225         /* mask off the extra low bits of information */
 226         coded_mem_map &= SECTION_MAP_MASK;
 227         return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum);
 228 }
 229
 230 static int __meminit sparse_init_one_section(struct mem_section *ms,
 231                 unsigned long pnum, struct page *mem_map,
 232                 unsigned long *pageblock_bitmap)
 233 {
 234         if (!present_section(ms))
 235                 return -EINVAL;
 236
 237         ms->section_mem_map &= ~SECTION_MAP_MASK;
 238         ms->section_mem_map |= sparse_encode_mem_map(mem_map, pnum) |
 239                                                         SECTION_HAS_MEM_MAP;
 240         ms->pageblock_flags = pageblock_bitmap;
 241
 242         return 1;
 243 }
 244
 245 unsigned long usemap_size(void)
 246 {
 247         unsigned long size_bytes;
 248         size_bytes = roundup(SECTION_BLOCKFLAGS_BITS, 8) / 8;
 249         size_bytes = roundup(size_bytes, sizeof(unsigned long));
 250         return size_bytes;
 251 }
 252
 253 #ifdef CONFIG_MEMORY_HOTPLUG
 254 static unsigned long *__kmalloc_section_usemap(void)
 255 {
 256         return kmalloc(usemap_size(), GFP_KERNEL);
 257 }
 258 #endif /* CONFIG_MEMORY_HOTPLUG */
 259
 260 #ifdef CONFIG_MEMORY_HOTREMOVE
 261 static unsigned long * __init
 262 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
 263                                          unsigned long size)
 264 {
 265         unsigned long goal, limit;
 266         unsigned long *p;
 267         int nid;
 268         /*
 269          * A page may contain usemaps for other sections preventing the
 270          * page being freed and making a section unremovable while
 271          * other sections referencing the usemap retmain active. Similarly,
 272          * a pgdat can prevent a section being removed. If section A
 273          * contains a pgdat and section B contains the usemap, both
 274          * sections become inter-dependent. This allocates usemaps
 275          * from the same section as the pgdat where possible to avoid
 276          * this problem.
 277          */
 278         goal = __pa(pgdat) & (PAGE_SECTION_MASK << PAGE_SHIFT);
 279         limit = goal + (1UL << PA_SECTION_SHIFT);
 280         nid = early_pfn_to_nid(goal >> PAGE_SHIFT);
 281 again:
 282         p = ___alloc_bootmem_node_nopanic(NODE_DATA(nid), size,
 283                                           SMP_CACHE_BYTES, goal, limit);
 284         if (!p && limit) {
 285                 limit = 0;
 286                 goto again;
 287         }
 288         return p;
 289 }
 290
 291 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 292 {
 293         unsigned long usemap_snr, pgdat_snr;
 294         static unsigned long old_usemap_snr = NR_MEM_SECTIONS;
 295         static unsigned long old_pgdat_snr = NR_MEM_SECTIONS;
 296         struct pglist_data *pgdat = NODE_DATA(nid);
 297         int usemap_nid;
 298
 299         usemap_snr = pfn_to_section_nr(__pa(usemap) >> PAGE_SHIFT);
 300         pgdat_snr = pfn_to_section_nr(__pa(pgdat) >> PAGE_SHIFT);
 301         if (usemap_snr == pgdat_snr)
 302                 return;
 303
 304         if (old_usemap_snr == usemap_snr && old_pgdat_snr == pgdat_snr)
 305                 /* skip redundant message */
 306                 return;
 307
 308         old_usemap_snr = usemap_snr;
 309         old_pgdat_snr = pgdat_snr;
 310
 311         usemap_nid = sparse_early_nid(__nr_to_section(usemap_snr));
 312         if (usemap_nid != nid) {
 313                 printk(KERN_INFO
 314                        "node %d must be removed before remove section %ld\n",
 315                        nid, usemap_snr);
 316                 return;
 317         }
 318         /*
 319          * There is a circular dependency.
 320          * Some platforms allow un-removable section because they will just
 321          * gather other removable sections for dynamic partitioning.
 322          * Just notify un-removable section's number here.
 323          */
 324         printk(KERN_INFO "Section %ld and %ld (node %d)", usemap_snr,
 325                pgdat_snr, nid);
 326         printk(KERN_CONT
 327                " have a circular dependency on usemap and pgdat allocations\n");
 328 }
 329 #else
 330 static unsigned long * __init
 331 sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
 332                                          unsigned long size)
 333 {
 334         return alloc_bootmem_node_nopanic(pgdat, size);
 335 }
 336
 337 static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 338 {
 339 }
 340 #endif /* CONFIG_MEMORY_HOTREMOVE */
 341
 342 static void __init sparse_early_usemaps_alloc_node(unsigned long**usemap_map,
 343                                  unsigned long pnum_begin,
 344                                  unsigned long pnum_end,
 345                                  unsigned long usemap_count, int nodeid)
 346 {
 347         void *usemap;
 348         unsigned long pnum;
 349         int size = usemap_size();
 350
 351         usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
 352                                                           size * usemap_count);
 353         if (!usemap) {
 354                 printk(KERN_WARNING "%s: allocation failed\n", __func__);
 355                 return;
 356         }
 357
 358         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 359                 if (!present_section_nr(pnum))
 360                         continue;
 361                 usemap_map[pnum] = usemap;
 362                 usemap += size;
 363                 check_usemap_section_nr(nodeid, usemap_map[pnum]);
 364         }
 365 }
 366
 367 #ifndef CONFIG_SPARSEMEM_VMEMMAP
 368 struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
 369 {
 370         struct page *map;
 371         unsigned long size;
 372
 373         map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
 374         if (map)
 375                 return map;
 376
 377         size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 378         map = __alloc_bootmem_node_high(NODE_DATA(nid), size,
 379                                          PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 380         return map;
 381 }
 382 void __init sparse_mem_maps_populate_node(struct page **map_map,
 383                                           unsigned long pnum_begin,
 384                                           unsigned long pnum_end,
 385                                           unsigned long map_count, int nodeid)
 386 {
 387         void *map;
 388         unsigned long pnum;
 389         unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
 390
 391         map = alloc_remap(nodeid, size * map_count);
 392         if (map) {
 393                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 394                         if (!present_section_nr(pnum))
 395                                 continue;
 396                         map_map[pnum] = map;
 397                         map += size;
 398                 }
 399                 return;
 400         }
 401
 402         size = PAGE_ALIGN(size);
 403         map = __alloc_bootmem_node_high(NODE_DATA(nodeid), size * map_count,
 404                                          PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 405         if (map) {
 406                 for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 407                         if (!present_section_nr(pnum))
 408                                 continue;
 409                         map_map[pnum] = map;
 410                         map += size;
 411                 }
 412                 return;
 413         }
 414
 415         /* fallback */
 416         for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 417                 struct mem_section *ms;
 418
 419                 if (!present_section_nr(pnum))
 420                         continue;
 421                 map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
 422                 if (map_map[pnum])
 423                         continue;
 424                 ms = __nr_to_section(pnum);
 425                 printk(KERN_ERR "%s: sparsemem memory map backing failed "
 426                         "some memory will not be available.\n", __func__);
 427                 ms->section_mem_map = 0;
 428         }
 429 }
 430 #endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 431
 432 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 433 static void __init sparse_early_mem_maps_alloc_node(struct page **map_map,
 434                                  unsigned long pnum_begin,
 435                                  unsigned long pnum_end,
 436                                  unsigned long map_count, int nodeid)
 437 {
 438         sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
 439                                          map_count, nodeid);
 440 }
 441 #else
 442 static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
 443 {
 444         struct page *map;
 445         struct mem_section *ms = __nr_to_section(pnum);
 446         int nid = sparse_early_nid(ms);
 447
 448         map = sparse_mem_map_populate(pnum, nid);
 449         if (map)
 450                 return map;
 451
 452         printk(KERN_ERR "%s: sparsemem memory map backing failed "
 453                         "some memory will not be available.\n", __func__);
 454         ms->section_mem_map = 0;
 455         return NULL;
 456 }
 457 #endif
 458
 459 void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
 460 {
 461 }
 462
 463 /*
 464  * Allocate the accumulated non-linear sections, allocate a mem_map
 465  * for each and record the physical to section mapping.
 466  */
 467 void __init sparse_init(void)
 468 {
 469         unsigned long pnum;
 470         struct page *map;
 471         unsigned long *usemap;
 472         unsigned long **usemap_map;
 473         int size;
 474         int nodeid_begin = 0;
 475         unsigned long pnum_begin = 0;
 476         unsigned long usemap_count;
 477 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 478         unsigned long map_count;
 479         int size2;
 480         struct page **map_map;
 481 #endif
 482
 483         /* see include/linux/mmzone.h 'struct mem_section' definition */
 484         BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
 485
 486         /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 487         set_pageblock_order();
 488
 489         /*
 490          * map is using big page (aka 2M in x86 64 bit)
 491          * usemap is less one page (aka 24 bytes)
 492          * so alloc 2M (with 2M align) and 24 bytes in turn will
 493          * make next 2M slip to one more 2M later.
 494          * then in big system, the memory will have a lot of holes...
 495          * here try to allocate 2M pages continuously.
 496          *
 497          * powerpc need to call sparse_init_one_section right after each
 498          * sparse_early_mem_map_alloc, so allocate usemap_map at first.
 499          */
 500         size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
 501         usemap_map = alloc_bootmem(size);
 502         if (!usemap_map)
 503                 panic("can not allocate usemap_map\n");
 504
 505         for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
 506                 struct mem_section *ms;
 507
 508                 if (!present_section_nr(pnum))
 509                         continue;
 510                 ms = __nr_to_section(pnum);
 511                 nodeid_begin = sparse_early_nid(ms);
 512                 pnum_begin = pnum;
 513                 break;
 514         }
 515         usemap_count = 1;
 516         for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
 517                 struct mem_section *ms;
 518                 int nodeid;
 519
 520                 if (!present_section_nr(pnum))
 521                         continue;
 522                 ms = __nr_to_section(pnum);
 523                 nodeid = sparse_early_nid(ms);
 524                 if (nodeid == nodeid_begin) {
 525                         usemap_count++;
 526                         continue;
 527                 }
 528                 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
 529                 sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, pnum,
 530                                                  usemap_count, nodeid_begin);
 531                 /* new start, update count etc*/
 532                 nodeid_begin = nodeid;
 533                 pnum_begin = pnum;
 534                 usemap_count = 1;
 535         }
 536         /* ok, last chunk */
 537         sparse_early_usemaps_alloc_node(usemap_map, pnum_begin, NR_MEM_SECTIONS,
 538                                          usemap_count, nodeid_begin);
 539
 540 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 541         size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
 542         map_map = alloc_bootmem(size2);
 543         if (!map_map)
 544                 panic("can not allocate map_map\n");
 545
 546         for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
 547                 struct mem_section *ms;
 548
 549                 if (!present_section_nr(pnum))
 550                         continue;
 551                 ms = __nr_to_section(pnum);
 552                 nodeid_begin = sparse_early_nid(ms);
 553                 pnum_begin = pnum;
 554                 break;
 555         }
 556         map_count = 1;
 557         for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
 558                 struct mem_section *ms;
 559                 int nodeid;
 560
 561                 if (!present_section_nr(pnum))
 562                         continue;
 563                 ms = __nr_to_section(pnum);
 564                 nodeid = sparse_early_nid(ms);
 565                 if (nodeid == nodeid_begin) {
 566                         map_count++;
 567                         continue;
 568                 }
 569                 /* ok, we need to take cake of from pnum_begin to pnum - 1*/
 570                 sparse_early_mem_maps_alloc_node(map_map, pnum_begin, pnum,
 571                                                  map_count, nodeid_begin);
 572                 /* new start, update count etc*/
 573                 nodeid_begin = nodeid;
 574                 pnum_begin = pnum;
 575                 map_count = 1;
 576         }
 577         /* ok, last chunk */
 578         sparse_early_mem_maps_alloc_node(map_map, pnum_begin, NR_MEM_SECTIONS,
 579                                          map_count, nodeid_begin);
 580 #endif
 581
 582         for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
 583                 if (!present_section_nr(pnum))
 584                         continue;
 585
 586                 usemap = usemap_map[pnum];
 587                 if (!usemap)
 588                         continue;
 589
 590 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 591                 map = map_map[pnum];
 592 #else
 593                 map = sparse_early_mem_map_alloc(pnum);
 594 #endif
 595                 if (!map)
 596                         continue;
 597
 598                 sparse_init_one_section(__nr_to_section(pnum), pnum, map,
 599                                                                 usemap);
 600         }
 601
 602         vmemmap_populate_print_last();
 603
 604 #ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 605         free_bootmem(__pa(map_map), size2);
 606 #endif
 607         free_bootmem(__pa(usemap_map), size);
 608 }
 609
 610 #ifdef CONFIG_MEMORY_HOTPLUG
 611 #ifdef CONFIG_SPARSEMEM_VMEMMAP
 612 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 613                                                  unsigned long nr_pages)
 614 {
 615         /* This will make the necessary allocations eventually. */
 616         return sparse_mem_map_populate(pnum, nid);
 617 }
 618 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
 619 {
 620         unsigned long start = (unsigned long)memmap;
 621         unsigned long end = (unsigned long)(memmap + nr_pages);
 622
 623         vmemmap_free(start, end);
 624 }
 625 #ifdef CONFIG_MEMORY_HOTREMOVE
 626 static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
 627 {
 628         unsigned long start = (unsigned long)memmap;
 629         unsigned long end = (unsigned long)(memmap + nr_pages);
 630
 631         vmemmap_free(start, end);
 632 }
 633 #endif /* CONFIG_MEMORY_HOTREMOVE */
 634 #else
 635 static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
 636 {
 637         struct page *page, *ret;
 638         unsigned long memmap_size = sizeof(struct page) * nr_pages;
 639
 640         page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
 641         if (page)
 642                 goto got_map_page;
 643
 644         ret = vmalloc(memmap_size);
 645         if (ret)
 646                 goto got_map_ptr;
 647
 648         return NULL;
 649 got_map_page:
 650         ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
 651 got_map_ptr:
 652
 653         return ret;
 654 }
 655
 656 static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 657                                                   unsigned long nr_pages)
 658 {
 659         return __kmalloc_section_memmap(nr_pages);
 660 }
 661
 662 static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
 663 {
 664         if (is_vmalloc_addr(memmap))
 665                 vfree(memmap);
 666         else
 667                 free_pages((unsigned long)memmap,
 668                            get_order(sizeof(struct page) * nr_pages));
 669 }
 670
 671 #ifdef CONFIG_MEMORY_HOTREMOVE
 672 static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
 673 {
 674         unsigned long maps_section_nr, removing_section_nr, i;
 675         unsigned long magic;
 676         struct page *page = virt_to_page(memmap);
 677
 678         for (i = 0; i < nr_pages; i++, page++) {
 679                 magic = (unsigned long) page->lru.next;
 680
 681                 BUG_ON(magic == NODE_INFO);
 682
 683                 maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
 684                 removing_section_nr = page->private;
 685
 686                 /*
 687                  * When this function is called, the removing section is
 688                  * logical offlined state. This means all pages are isolated
 689                  * from page allocator. If removing section's memmap is placed
 690                  * on the same section, it must not be freed.
 691                  * If it is freed, page allocator may allocate it which will
 692                  * be removed physically soon.
 693                  */
 694                 if (maps_section_nr != removing_section_nr)
 695                         put_page_bootmem(page);
 696         }
 697 }
 698 #endif /* CONFIG_MEMORY_HOTREMOVE */
 699 #endif /* CONFIG_SPARSEMEM_VMEMMAP */
 700
 701 /*
 702  * returns the number of sections whose mem_maps were properly
 703  * set.  If this is <=0, then that means that the passed-in
 704  * map was not consumed and must be freed.
 705  */
 706 int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
 707                            int nr_pages)
 708 {
 709         unsigned long section_nr = pfn_to_section_nr(start_pfn);
 710         struct pglist_data *pgdat = zone->zone_pgdat;
 711         struct mem_section *ms;
 712         struct page *memmap;
 713         unsigned long *usemap;
 714         unsigned long flags;
 715         int ret;
 716
 717         /*
 718          * no locking for this, because it does its own
 719          * plus, it does a kmalloc
 720          */
 721         ret = sparse_index_init(section_nr, pgdat->node_id);
 722         if (ret < 0 && ret != -EEXIST)
 723                 return ret;
 724         memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
 725         if (!memmap)
 726                 return -ENOMEM;
 727         usemap = __kmalloc_section_usemap();
 728         if (!usemap) {
 729                 __kfree_section_memmap(memmap, nr_pages);
 730                 return -ENOMEM;
 731         }
 732
 733         pgdat_resize_lock(pgdat, &flags);
 734
 735         ms = __pfn_to_section(start_pfn);
 736         if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
 737                 ret = -EEXIST;
 738                 goto out;
 739         }
 740
 741         memset(memmap, 0, sizeof(struct page) * nr_pages);
 742
 743         ms->section_mem_map |= SECTION_MARKED_PRESENT;
 744
 745         ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 746
 747 out:
 748         pgdat_resize_unlock(pgdat, &flags);
 749         if (ret <= 0) {
 750                 kfree(usemap);
 751                 __kfree_section_memmap(memmap, nr_pages);
 752         }
 753         return ret;
 754 }
 755
 756 #ifdef CONFIG_MEMORY_FAILURE
 757 static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 758 {
 759         int i;
 760
 761         if (!memmap)
 762                 return;
 763
 764         for (i = 0; i < PAGES_PER_SECTION; i++) {
 765                 if (PageHWPoison(&memmap[i])) {
 766                         atomic_long_sub(1, &num_poisoned_pages);
 767                         ClearPageHWPoison(&memmap[i]);
 768                 }
 769         }
 770 }
 771 #else
 772 static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 773 {
 774 }
 775 #endif
 776
 777 #ifdef CONFIG_MEMORY_HOTREMOVE
 778 static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 779 {
 780         struct page *usemap_page;
 781         unsigned long nr_pages;
 782
 783         if (!usemap)
 784                 return;
 785
 786         usemap_page = virt_to_page(usemap);
 787         /*
 788          * Check to see if allocation came from hot-plug-add
 789          */
 790         if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
 791                 kfree(usemap);
 792                 if (memmap)
 793                         __kfree_section_memmap(memmap, PAGES_PER_SECTION);
 794                 return;
 795         }
 796
 797         /*
 798          * The usemap came from bootmem. This is packed with other usemaps
 799          * on the section which has pgdat at boot time. Just keep it as is now.
 800          */
 801
 802         if (memmap) {
 803                 nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
 804                         >> PAGE_SHIFT;
 805
 806                 free_map_bootmem(memmap, nr_pages);
 807         }
 808 }
 809
 810 void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
 811 {
 812         struct page *memmap = NULL;
 813         unsigned long *usemap = NULL, flags;
 814         struct pglist_data *pgdat = zone->zone_pgdat;
 815
 816         pgdat_resize_lock(pgdat, &flags);
 817         if (ms->section_mem_map) {
 818                 usemap = ms->pageblock_flags;
 819                 memmap = sparse_decode_mem_map(ms->section_mem_map,
 820                                                 __section_nr(ms));
 821                 ms->section_mem_map = 0;
 822                 ms->pageblock_flags = NULL;
 823         }
 824         pgdat_resize_unlock(pgdat, &flags);
 825
 826         clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
 827         free_section_usemap(memmap, usemap);
 828 }
 829 #endif /* CONFIG_MEMORY_HOTREMOVE */
 830 #endif /* CONFIG_MEMORY_HOTPLUG */