linux/mm/sparse.c
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   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
  23struct mem_section *mem_section[NR_SECTION_ROOTS]
  24        ____cacheline_internodealigned_in_smp;
  25#else
  26struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]
  27        ____cacheline_internodealigned_in_smp;
  28#endif
  29EXPORT_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
  38static u8 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  39#else
  40static u16 section_to_node_table[NR_MEM_SECTIONS] __cacheline_aligned;
  41#endif
  42
  43int page_to_nid(const struct page *page)
  44{
  45        return section_to_node_table[page_to_section(page)];
  46}
  47EXPORT_SYMBOL(page_to_nid);
  48
  49static 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 */
  54static inline void set_section_nid(unsigned long section_nr, int nid)
  55{
  56}
  57#endif
  58
  59#ifdef CONFIG_SPARSEMEM_EXTREME
  60static 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
  78static 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 */
  95static 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 */
 106int __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 */
 131static inline unsigned long sparse_encode_early_nid(int nid)
 132{
 133        return (nid << SECTION_NID_SHIFT);
 134}
 135
 136static 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 */
 142void __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. */
 168void __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 */
 192unsigned 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 */
 215static 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 */
 223struct 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
 230static 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
 245unsigned 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
 254static 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
 261static unsigned long * __init
 262sparse_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);
 281again:
 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
 291static 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
 330static unsigned long * __init
 331sparse_early_usemaps_alloc_pgdat_section(struct pglist_data *pgdat,
 332                                         unsigned long size)
 333{
 334        return alloc_bootmem_node_nopanic(pgdat, size);
 335}
 336
 337static void __init check_usemap_section_nr(int nid, unsigned long *usemap)
 338{
 339}
 340#endif /* CONFIG_MEMORY_HOTREMOVE */
 341
 342static void __init sparse_early_usemaps_alloc_node(void *data,
 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        unsigned long **usemap_map = (unsigned long **)data;
 350        int size = usemap_size();
 351
 352        usemap = sparse_early_usemaps_alloc_pgdat_section(NODE_DATA(nodeid),
 353                                                          size * usemap_count);
 354        if (!usemap) {
 355                printk(KERN_WARNING "%s: allocation failed\n", __func__);
 356                return;
 357        }
 358
 359        for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 360                if (!present_section_nr(pnum))
 361                        continue;
 362                usemap_map[pnum] = usemap;
 363                usemap += size;
 364                check_usemap_section_nr(nodeid, usemap_map[pnum]);
 365        }
 366}
 367
 368#ifndef CONFIG_SPARSEMEM_VMEMMAP
 369struct page __init *sparse_mem_map_populate(unsigned long pnum, int nid)
 370{
 371        struct page *map;
 372        unsigned long size;
 373
 374        map = alloc_remap(nid, sizeof(struct page) * PAGES_PER_SECTION);
 375        if (map)
 376                return map;
 377
 378        size = PAGE_ALIGN(sizeof(struct page) * PAGES_PER_SECTION);
 379        map = __alloc_bootmem_node_high(NODE_DATA(nid), size,
 380                                         PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 381        return map;
 382}
 383void __init sparse_mem_maps_populate_node(struct page **map_map,
 384                                          unsigned long pnum_begin,
 385                                          unsigned long pnum_end,
 386                                          unsigned long map_count, int nodeid)
 387{
 388        void *map;
 389        unsigned long pnum;
 390        unsigned long size = sizeof(struct page) * PAGES_PER_SECTION;
 391
 392        map = alloc_remap(nodeid, size * map_count);
 393        if (map) {
 394                for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 395                        if (!present_section_nr(pnum))
 396                                continue;
 397                        map_map[pnum] = map;
 398                        map += size;
 399                }
 400                return;
 401        }
 402
 403        size = PAGE_ALIGN(size);
 404        map = __alloc_bootmem_node_high(NODE_DATA(nodeid), size * map_count,
 405                                         PAGE_SIZE, __pa(MAX_DMA_ADDRESS));
 406        if (map) {
 407                for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 408                        if (!present_section_nr(pnum))
 409                                continue;
 410                        map_map[pnum] = map;
 411                        map += size;
 412                }
 413                return;
 414        }
 415
 416        /* fallback */
 417        for (pnum = pnum_begin; pnum < pnum_end; pnum++) {
 418                struct mem_section *ms;
 419
 420                if (!present_section_nr(pnum))
 421                        continue;
 422                map_map[pnum] = sparse_mem_map_populate(pnum, nodeid);
 423                if (map_map[pnum])
 424                        continue;
 425                ms = __nr_to_section(pnum);
 426                printk(KERN_ERR "%s: sparsemem memory map backing failed "
 427                        "some memory will not be available.\n", __func__);
 428                ms->section_mem_map = 0;
 429        }
 430}
 431#endif /* !CONFIG_SPARSEMEM_VMEMMAP */
 432
 433#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 434static void __init sparse_early_mem_maps_alloc_node(void *data,
 435                                 unsigned long pnum_begin,
 436                                 unsigned long pnum_end,
 437                                 unsigned long map_count, int nodeid)
 438{
 439        struct page **map_map = (struct page **)data;
 440        sparse_mem_maps_populate_node(map_map, pnum_begin, pnum_end,
 441                                         map_count, nodeid);
 442}
 443#else
 444static struct page __init *sparse_early_mem_map_alloc(unsigned long pnum)
 445{
 446        struct page *map;
 447        struct mem_section *ms = __nr_to_section(pnum);
 448        int nid = sparse_early_nid(ms);
 449
 450        map = sparse_mem_map_populate(pnum, nid);
 451        if (map)
 452                return map;
 453
 454        printk(KERN_ERR "%s: sparsemem memory map backing failed "
 455                        "some memory will not be available.\n", __func__);
 456        ms->section_mem_map = 0;
 457        return NULL;
 458}
 459#endif
 460
 461void __attribute__((weak)) __meminit vmemmap_populate_print_last(void)
 462{
 463}
 464
 465/**
 466 *  alloc_usemap_and_memmap - memory alloction for pageblock flags and vmemmap
 467 *  @map: usemap_map for pageblock flags or mmap_map for vmemmap
 468 */
 469static void __init alloc_usemap_and_memmap(void (*alloc_func)
 470                                        (void *, unsigned long, unsigned long,
 471                                        unsigned long, int), void *data)
 472{
 473        unsigned long pnum;
 474        unsigned long map_count;
 475        int nodeid_begin = 0;
 476        unsigned long pnum_begin = 0;
 477
 478        for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
 479                struct mem_section *ms;
 480
 481                if (!present_section_nr(pnum))
 482                        continue;
 483                ms = __nr_to_section(pnum);
 484                nodeid_begin = sparse_early_nid(ms);
 485                pnum_begin = pnum;
 486                break;
 487        }
 488        map_count = 1;
 489        for (pnum = pnum_begin + 1; pnum < NR_MEM_SECTIONS; pnum++) {
 490                struct mem_section *ms;
 491                int nodeid;
 492
 493                if (!present_section_nr(pnum))
 494                        continue;
 495                ms = __nr_to_section(pnum);
 496                nodeid = sparse_early_nid(ms);
 497                if (nodeid == nodeid_begin) {
 498                        map_count++;
 499                        continue;
 500                }
 501                /* ok, we need to take cake of from pnum_begin to pnum - 1*/
 502                alloc_func(data, pnum_begin, pnum,
 503                                                map_count, nodeid_begin);
 504                /* new start, update count etc*/
 505                nodeid_begin = nodeid;
 506                pnum_begin = pnum;
 507                map_count = 1;
 508        }
 509        /* ok, last chunk */
 510        alloc_func(data, pnum_begin, NR_MEM_SECTIONS,
 511                                                map_count, nodeid_begin);
 512}
 513
 514/*
 515 * Allocate the accumulated non-linear sections, allocate a mem_map
 516 * for each and record the physical to section mapping.
 517 */
 518void __init sparse_init(void)
 519{
 520        unsigned long pnum;
 521        struct page *map;
 522        unsigned long *usemap;
 523        unsigned long **usemap_map;
 524        int size;
 525#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 526        int size2;
 527        struct page **map_map;
 528#endif
 529
 530        /* see include/linux/mmzone.h 'struct mem_section' definition */
 531        BUILD_BUG_ON(!is_power_of_2(sizeof(struct mem_section)));
 532
 533        /* Setup pageblock_order for HUGETLB_PAGE_SIZE_VARIABLE */
 534        set_pageblock_order();
 535
 536        /*
 537         * map is using big page (aka 2M in x86 64 bit)
 538         * usemap is less one page (aka 24 bytes)
 539         * so alloc 2M (with 2M align) and 24 bytes in turn will
 540         * make next 2M slip to one more 2M later.
 541         * then in big system, the memory will have a lot of holes...
 542         * here try to allocate 2M pages continuously.
 543         *
 544         * powerpc need to call sparse_init_one_section right after each
 545         * sparse_early_mem_map_alloc, so allocate usemap_map at first.
 546         */
 547        size = sizeof(unsigned long *) * NR_MEM_SECTIONS;
 548        usemap_map = alloc_bootmem(size);
 549        if (!usemap_map)
 550                panic("can not allocate usemap_map\n");
 551        alloc_usemap_and_memmap(sparse_early_usemaps_alloc_node,
 552                                                        (void *)usemap_map);
 553
 554#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 555        size2 = sizeof(struct page *) * NR_MEM_SECTIONS;
 556        map_map = alloc_bootmem(size2);
 557        if (!map_map)
 558                panic("can not allocate map_map\n");
 559        alloc_usemap_and_memmap(sparse_early_mem_maps_alloc_node,
 560                                                        (void *)map_map);
 561#endif
 562
 563        for (pnum = 0; pnum < NR_MEM_SECTIONS; pnum++) {
 564                if (!present_section_nr(pnum))
 565                        continue;
 566
 567                usemap = usemap_map[pnum];
 568                if (!usemap)
 569                        continue;
 570
 571#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 572                map = map_map[pnum];
 573#else
 574                map = sparse_early_mem_map_alloc(pnum);
 575#endif
 576                if (!map)
 577                        continue;
 578
 579                sparse_init_one_section(__nr_to_section(pnum), pnum, map,
 580                                                                usemap);
 581        }
 582
 583        vmemmap_populate_print_last();
 584
 585#ifdef CONFIG_SPARSEMEM_ALLOC_MEM_MAP_TOGETHER
 586        free_bootmem(__pa(map_map), size2);
 587#endif
 588        free_bootmem(__pa(usemap_map), size);
 589}
 590
 591#ifdef CONFIG_MEMORY_HOTPLUG
 592#ifdef CONFIG_SPARSEMEM_VMEMMAP
 593static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 594                                                 unsigned long nr_pages)
 595{
 596        /* This will make the necessary allocations eventually. */
 597        return sparse_mem_map_populate(pnum, nid);
 598}
 599static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
 600{
 601        unsigned long start = (unsigned long)memmap;
 602        unsigned long end = (unsigned long)(memmap + nr_pages);
 603
 604        vmemmap_free(start, end);
 605}
 606#ifdef CONFIG_MEMORY_HOTREMOVE
 607static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
 608{
 609        unsigned long start = (unsigned long)memmap;
 610        unsigned long end = (unsigned long)(memmap + nr_pages);
 611
 612        vmemmap_free(start, end);
 613}
 614#endif /* CONFIG_MEMORY_HOTREMOVE */
 615#else
 616static struct page *__kmalloc_section_memmap(unsigned long nr_pages)
 617{
 618        struct page *page, *ret;
 619        unsigned long memmap_size = sizeof(struct page) * nr_pages;
 620
 621        page = alloc_pages(GFP_KERNEL|__GFP_NOWARN, get_order(memmap_size));
 622        if (page)
 623                goto got_map_page;
 624
 625        ret = vmalloc(memmap_size);
 626        if (ret)
 627                goto got_map_ptr;
 628
 629        return NULL;
 630got_map_page:
 631        ret = (struct page *)pfn_to_kaddr(page_to_pfn(page));
 632got_map_ptr:
 633
 634        return ret;
 635}
 636
 637static inline struct page *kmalloc_section_memmap(unsigned long pnum, int nid,
 638                                                  unsigned long nr_pages)
 639{
 640        return __kmalloc_section_memmap(nr_pages);
 641}
 642
 643static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages)
 644{
 645        if (is_vmalloc_addr(memmap))
 646                vfree(memmap);
 647        else
 648                free_pages((unsigned long)memmap,
 649                           get_order(sizeof(struct page) * nr_pages));
 650}
 651
 652#ifdef CONFIG_MEMORY_HOTREMOVE
 653static void free_map_bootmem(struct page *memmap, unsigned long nr_pages)
 654{
 655        unsigned long maps_section_nr, removing_section_nr, i;
 656        unsigned long magic;
 657        struct page *page = virt_to_page(memmap);
 658
 659        for (i = 0; i < nr_pages; i++, page++) {
 660                magic = (unsigned long) page->lru.next;
 661
 662                BUG_ON(magic == NODE_INFO);
 663
 664                maps_section_nr = pfn_to_section_nr(page_to_pfn(page));
 665                removing_section_nr = page->private;
 666
 667                /*
 668                 * When this function is called, the removing section is
 669                 * logical offlined state. This means all pages are isolated
 670                 * from page allocator. If removing section's memmap is placed
 671                 * on the same section, it must not be freed.
 672                 * If it is freed, page allocator may allocate it which will
 673                 * be removed physically soon.
 674                 */
 675                if (maps_section_nr != removing_section_nr)
 676                        put_page_bootmem(page);
 677        }
 678}
 679#endif /* CONFIG_MEMORY_HOTREMOVE */
 680#endif /* CONFIG_SPARSEMEM_VMEMMAP */
 681
 682/*
 683 * returns the number of sections whose mem_maps were properly
 684 * set.  If this is <=0, then that means that the passed-in
 685 * map was not consumed and must be freed.
 686 */
 687int __meminit sparse_add_one_section(struct zone *zone, unsigned long start_pfn,
 688                           int nr_pages)
 689{
 690        unsigned long section_nr = pfn_to_section_nr(start_pfn);
 691        struct pglist_data *pgdat = zone->zone_pgdat;
 692        struct mem_section *ms;
 693        struct page *memmap;
 694        unsigned long *usemap;
 695        unsigned long flags;
 696        int ret;
 697
 698        /*
 699         * no locking for this, because it does its own
 700         * plus, it does a kmalloc
 701         */
 702        ret = sparse_index_init(section_nr, pgdat->node_id);
 703        if (ret < 0 && ret != -EEXIST)
 704                return ret;
 705        memmap = kmalloc_section_memmap(section_nr, pgdat->node_id, nr_pages);
 706        if (!memmap)
 707                return -ENOMEM;
 708        usemap = __kmalloc_section_usemap();
 709        if (!usemap) {
 710                __kfree_section_memmap(memmap, nr_pages);
 711                return -ENOMEM;
 712        }
 713
 714        pgdat_resize_lock(pgdat, &flags);
 715
 716        ms = __pfn_to_section(start_pfn);
 717        if (ms->section_mem_map & SECTION_MARKED_PRESENT) {
 718                ret = -EEXIST;
 719                goto out;
 720        }
 721
 722        memset(memmap, 0, sizeof(struct page) * nr_pages);
 723
 724        ms->section_mem_map |= SECTION_MARKED_PRESENT;
 725
 726        ret = sparse_init_one_section(ms, section_nr, memmap, usemap);
 727
 728out:
 729        pgdat_resize_unlock(pgdat, &flags);
 730        if (ret <= 0) {
 731                kfree(usemap);
 732                __kfree_section_memmap(memmap, nr_pages);
 733        }
 734        return ret;
 735}
 736
 737#ifdef CONFIG_MEMORY_HOTREMOVE
 738#ifdef CONFIG_MEMORY_FAILURE
 739static void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 740{
 741        int i;
 742
 743        if (!memmap)
 744                return;
 745
 746        for (i = 0; i < PAGES_PER_SECTION; i++) {
 747                if (PageHWPoison(&memmap[i])) {
 748                        atomic_long_sub(1, &num_poisoned_pages);
 749                        ClearPageHWPoison(&memmap[i]);
 750                }
 751        }
 752}
 753#else
 754static inline void clear_hwpoisoned_pages(struct page *memmap, int nr_pages)
 755{
 756}
 757#endif
 758
 759static void free_section_usemap(struct page *memmap, unsigned long *usemap)
 760{
 761        struct page *usemap_page;
 762        unsigned long nr_pages;
 763
 764        if (!usemap)
 765                return;
 766
 767        usemap_page = virt_to_page(usemap);
 768        /*
 769         * Check to see if allocation came from hot-plug-add
 770         */
 771        if (PageSlab(usemap_page) || PageCompound(usemap_page)) {
 772                kfree(usemap);
 773                if (memmap)
 774                        __kfree_section_memmap(memmap, PAGES_PER_SECTION);
 775                return;
 776        }
 777
 778        /*
 779         * The usemap came from bootmem. This is packed with other usemaps
 780         * on the section which has pgdat at boot time. Just keep it as is now.
 781         */
 782
 783        if (memmap) {
 784                nr_pages = PAGE_ALIGN(PAGES_PER_SECTION * sizeof(struct page))
 785                        >> PAGE_SHIFT;
 786
 787                free_map_bootmem(memmap, nr_pages);
 788        }
 789}
 790
 791void sparse_remove_one_section(struct zone *zone, struct mem_section *ms)
 792{
 793        struct page *memmap = NULL;
 794        unsigned long *usemap = NULL, flags;
 795        struct pglist_data *pgdat = zone->zone_pgdat;
 796
 797        pgdat_resize_lock(pgdat, &flags);
 798        if (ms->section_mem_map) {
 799                usemap = ms->pageblock_flags;
 800                memmap = sparse_decode_mem_map(ms->section_mem_map,
 801                                                __section_nr(ms));
 802                ms->section_mem_map = 0;
 803                ms->pageblock_flags = NULL;
 804        }
 805        pgdat_resize_unlock(pgdat, &flags);
 806
 807        clear_hwpoisoned_pages(memmap, PAGES_PER_SECTION);
 808        free_section_usemap(memmap, usemap);
 809}
 810#endif /* CONFIG_MEMORY_HOTREMOVE */
 811#endif /* CONFIG_MEMORY_HOTPLUG */
 812
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