include/linux/mmzone.h

   1 #ifndef _LINUX_MMZONE_H
   2 #define _LINUX_MMZONE_H
   3
   4 #ifdef __KERNEL__
   5 #ifndef __ASSEMBLY__
   6
   7 #include <linux/config.h>
   8 #include <linux/spinlock.h>
   9 #include <linux/list.h>
  10 #include <linux/wait.h>
  11 #include <linux/cache.h>
  12 #include <linux/threads.h>
  13 #include <linux/numa.h>
  14 #include <linux/init.h>
  15 #include <linux/seqlock.h>
  16 #include <linux/nodemask.h>
  17 #include <asm/atomic.h>
  18
  19 /* Free memory management - zoned buddy allocator.  */
  20 #ifndef CONFIG_FORCE_MAX_ZONEORDER
  21 #define MAX_ORDER 11
  22 #else
  23 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
  24 #endif
  25
  26 struct free_area {
  27         struct list_head        free_list;
  28         unsigned long           nr_free;
  29 };
  30
  31 struct pglist_data;
  32
  33 /*
  34  * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
  35  * So add a wild amount of padding here to ensure that they fall into separate
  36  * cachelines.  There are very few zone structures in the machine, so space
  37  * consumption is not a concern here.
  38  */
  39 #if defined(CONFIG_SMP)
  40 struct zone_padding {
  41         char x[0];
  42 } ____cacheline_internodealigned_in_smp;
  43 #define ZONE_PADDING(name)      struct zone_padding name;
  44 #else
  45 #define ZONE_PADDING(name)
  46 #endif
  47
  48 struct per_cpu_pages {
  49         int count;              /* number of pages in the list */
  50         int high;               /* high watermark, emptying needed */
  51         int batch;              /* chunk size for buddy add/remove */
  52         struct list_head list;  /* the list of pages */
  53 };
  54
  55 struct per_cpu_pageset {
  56         struct per_cpu_pages pcp[2];    /* 0: hot.  1: cold */
  57 #ifdef CONFIG_NUMA
  58         unsigned long numa_hit;         /* allocated in intended node */
  59         unsigned long numa_miss;        /* allocated in non intended node */
  60         unsigned long numa_foreign;     /* was intended here, hit elsewhere */
  61         unsigned long interleave_hit;   /* interleaver prefered this zone */
  62         unsigned long local_node;       /* allocation from local node */
  63         unsigned long other_node;       /* allocation from other node */
  64 #endif
  65 } ____cacheline_aligned_in_smp;
  66
  67 #ifdef CONFIG_NUMA
  68 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
  69 #else
  70 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
  71 #endif
  72
  73 #define ZONE_DMA                0
  74 #define ZONE_DMA32              1
  75 #define ZONE_NORMAL             2
  76 #define ZONE_HIGHMEM            3
  77
  78 #define MAX_NR_ZONES            4       /* Sync this with ZONES_SHIFT */
  79 #define ZONES_SHIFT             2       /* ceil(log2(MAX_NR_ZONES)) */
  80
  81
  82 /*
  83  * When a memory allocation must conform to specific limitations (such
  84  * as being suitable for DMA) the caller will pass in hints to the
  85  * allocator in the gfp_mask, in the zone modifier bits.  These bits
  86  * are used to select a priority ordered list of memory zones which
  87  * match the requested limits.  GFP_ZONEMASK defines which bits within
  88  * the gfp_mask should be considered as zone modifiers.  Each valid
  89  * combination of the zone modifier bits has a corresponding list
  90  * of zones (in node_zonelists).  Thus for two zone modifiers there
  91  * will be a maximum of 4 (2 ** 2) zonelists, for 3 modifiers there will
  92  * be 8 (2 ** 3) zonelists.  GFP_ZONETYPES defines the number of possible
  93  * combinations of zone modifiers in "zone modifier space".
  94  *
  95  * As an optimisation any zone modifier bits which are only valid when
  96  * no other zone modifier bits are set (loners) should be placed in
  97  * the highest order bits of this field.  This allows us to reduce the
  98  * extent of the zonelists thus saving space.  For example in the case
  99  * of three zone modifier bits, we could require up to eight zonelists.
 100  * If the left most zone modifier is a "loner" then the highest valid
 101  * zonelist would be four allowing us to allocate only five zonelists.
 102  * Use the first form for GFP_ZONETYPES when the left most bit is not
 103  * a "loner", otherwise use the second.
 104  *
 105  * NOTE! Make sure this matches the zones in <linux/gfp.h>
 106  */
 107 #define GFP_ZONEMASK    0x07
 108 /* #define GFP_ZONETYPES       (GFP_ZONEMASK + 1) */           /* Non-loner */
 109 #define GFP_ZONETYPES  ((GFP_ZONEMASK + 1) / 2 + 1)            /* Loner */
 110
 111 /*
 112  * On machines where it is needed (eg PCs) we divide physical memory
 113  * into multiple physical zones. On a 32bit PC we have 4 zones:
 114  *
 115  * ZONE_DMA       < 16 MB       ISA DMA capable memory
 116  * ZONE_DMA32        0 MB       Empty
 117  * ZONE_NORMAL  16-896 MB       direct mapped by the kernel
 118  * ZONE_HIGHMEM  > 896 MB       only page cache and user processes
 119  */
 120
 121 struct zone {
 122         /* Fields commonly accessed by the page allocator */
 123         unsigned long           free_pages;
 124         unsigned long           pages_min, pages_low, pages_high;
 125         /*
 126          * We don't know if the memory that we're going to allocate will be freeable
 127          * or/and it will be released eventually, so to avoid totally wasting several
 128          * GB of ram we must reserve some of the lower zone memory (otherwise we risk
 129          * to run OOM on the lower zones despite there's tons of freeable ram
 130          * on the higher zones). This array is recalculated at runtime if the
 131          * sysctl_lowmem_reserve_ratio sysctl changes.
 132          */
 133         unsigned long           lowmem_reserve[MAX_NR_ZONES];
 134
 135 #ifdef CONFIG_NUMA
 136         struct per_cpu_pageset  *pageset[NR_CPUS];
 137 #else
 138         struct per_cpu_pageset  pageset[NR_CPUS];
 139 #endif
 140         /*
 141          * free areas of different sizes
 142          */
 143         spinlock_t              lock;
 144 #ifdef CONFIG_MEMORY_HOTPLUG
 145         /* see spanned/present_pages for more description */
 146         seqlock_t               span_seqlock;
 147 #endif
 148         struct free_area        free_area[MAX_ORDER];
 149
 150
 151         ZONE_PADDING(_pad1_)
 152
 153         /* Fields commonly accessed by the page reclaim scanner */
 154         spinlock_t              lru_lock;
 155         struct list_head        active_list;
 156         struct list_head        inactive_list;
 157         unsigned long           nr_scan_active;
 158         unsigned long           nr_scan_inactive;
 159         unsigned long           nr_active;
 160         unsigned long           nr_inactive;
 161         unsigned long           pages_scanned;     /* since last reclaim */
 162         int                     all_unreclaimable; /* All pages pinned */
 163
 164         /* A count of how many reclaimers are scanning this zone */
 165         atomic_t                reclaim_in_progress;
 166
 167         /*
 168          * timestamp (in jiffies) of the last zone reclaim that did not
 169          * result in freeing of pages. This is used to avoid repeated scans
 170          * if all memory in the zone is in use.
 171          */
 172         unsigned long           last_unsuccessful_zone_reclaim;
 173
 174         /*
 175          * prev_priority holds the scanning priority for this zone.  It is
 176          * defined as the scanning priority at which we achieved our reclaim
 177          * target at the previous try_to_free_pages() or balance_pgdat()
 178          * invokation.
 179          *
 180          * We use prev_priority as a measure of how much stress page reclaim is
 181          * under - it drives the swappiness decision: whether to unmap mapped
 182          * pages.
 183          *
 184          * temp_priority is used to remember the scanning priority at which
 185          * this zone was successfully refilled to free_pages == pages_high.
 186          *
 187          * Access to both these fields is quite racy even on uniprocessor.  But
 188          * it is expected to average out OK.
 189          */
 190         int temp_priority;
 191         int prev_priority;
 192
 193
 194         ZONE_PADDING(_pad2_)
 195         /* Rarely used or read-mostly fields */
 196
 197         /*
 198          * wait_table           -- the array holding the hash table
 199          * wait_table_size      -- the size of the hash table array
 200          * wait_table_bits      -- wait_table_size == (1 << wait_table_bits)
 201          *
 202          * The purpose of all these is to keep track of the people
 203          * waiting for a page to become available and make them
 204          * runnable again when possible. The trouble is that this
 205          * consumes a lot of space, especially when so few things
 206          * wait on pages at a given time. So instead of using
 207          * per-page waitqueues, we use a waitqueue hash table.
 208          *
 209          * The bucket discipline is to sleep on the same queue when
 210          * colliding and wake all in that wait queue when removing.
 211          * When something wakes, it must check to be sure its page is
 212          * truly available, a la thundering herd. The cost of a
 213          * collision is great, but given the expected load of the
 214          * table, they should be so rare as to be outweighed by the
 215          * benefits from the saved space.
 216          *
 217          * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
 218          * primary users of these fields, and in mm/page_alloc.c
 219          * free_area_init_core() performs the initialization of them.
 220          */
 221         wait_queue_head_t       * wait_table;
 222         unsigned long           wait_table_size;
 223         unsigned long           wait_table_bits;
 224
 225         /*
 226          * Discontig memory support fields.
 227          */
 228         struct pglist_data      *zone_pgdat;
 229         /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
 230         unsigned long           zone_start_pfn;
 231
 232         /*
 233          * zone_start_pfn, spanned_pages and present_pages are all
 234          * protected by span_seqlock.  It is a seqlock because it has
 235          * to be read outside of zone->lock, and it is done in the main
 236          * allocator path.  But, it is written quite infrequently.
 237          *
 238          * The lock is declared along with zone->lock because it is
 239          * frequently read in proximity to zone->lock.  It's good to
 240          * give them a chance of being in the same cacheline.
 241          */
 242         unsigned long           spanned_pages;  /* total size, including holes */
 243         unsigned long           present_pages;  /* amount of memory (excluding holes) */
 244
 245         /*
 246          * rarely used fields:
 247          */
 248         char                    *name;
 249 } ____cacheline_internodealigned_in_smp;
 250
 251
 252 /*
 253  * The "priority" of VM scanning is how much of the queues we will scan in one
 254  * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
 255  * queues ("queue_length >> 12") during an aging round.
 256  */
 257 #define DEF_PRIORITY 12
 258
 259 /*
 260  * One allocation request operates on a zonelist. A zonelist
 261  * is a list of zones, the first one is the 'goal' of the
 262  * allocation, the other zones are fallback zones, in decreasing
 263  * priority.
 264  *
 265  * Right now a zonelist takes up less than a cacheline. We never
 266  * modify it apart from boot-up, and only a few indices are used,
 267  * so despite the zonelist table being relatively big, the cache
 268  * footprint of this construct is very small.
 269  */
 270 struct zonelist {
 271         struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited
 272 };
 273
 274
 275 /*
 276  * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
 277  * (mostly NUMA machines?) to denote a higher-level memory zone than the
 278  * zone denotes.
 279  *
 280  * On NUMA machines, each NUMA node would have a pg_data_t to describe
 281  * it's memory layout.
 282  *
 283  * Memory statistics and page replacement data structures are maintained on a
 284  * per-zone basis.
 285  */
 286 struct bootmem_data;
 287 typedef struct pglist_data {
 288         struct zone node_zones[MAX_NR_ZONES];
 289         struct zonelist node_zonelists[GFP_ZONETYPES];
 290         int nr_zones;
 291 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 292         struct page *node_mem_map;
 293 #endif
 294         struct bootmem_data *bdata;
 295 #ifdef CONFIG_MEMORY_HOTPLUG
 296         /*
 297          * Must be held any time you expect node_start_pfn, node_present_pages
 298          * or node_spanned_pages stay constant.  Holding this will also
 299          * guarantee that any pfn_valid() stays that way.
 300          *
 301          * Nests above zone->lock and zone->size_seqlock.
 302          */
 303         spinlock_t node_size_lock;
 304 #endif
 305         unsigned long node_start_pfn;
 306         unsigned long node_present_pages; /* total number of physical pages */
 307         unsigned long node_spanned_pages; /* total size of physical page
 308                                              range, including holes */
 309         int node_id;
 310         wait_queue_head_t kswapd_wait;
 311         struct task_struct *kswapd;
 312         int kswapd_max_order;
 313 } pg_data_t;
 314
 315 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
 316 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
 317 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 318 #define pgdat_page_nr(pgdat, pagenr)    ((pgdat)->node_mem_map + (pagenr))
 319 #else
 320 #define pgdat_page_nr(pgdat, pagenr)    pfn_to_page((pgdat)->node_start_pfn + (pagenr))
 321 #endif
 322 #define nid_page_nr(nid, pagenr)        pgdat_page_nr(NODE_DATA(nid),(pagenr))
 323
 324 #include <linux/memory_hotplug.h>
 325
 326 void __get_zone_counts(unsigned long *active, unsigned long *inactive,
 327                         unsigned long *free, struct pglist_data *pgdat);
 328 void get_zone_counts(unsigned long *active, unsigned long *inactive,
 329                         unsigned long *free);
 330 void build_all_zonelists(void);
 331 void wakeup_kswapd(struct zone *zone, int order);
 332 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 333                 int classzone_idx, int alloc_flags);
 334
 335 #ifdef CONFIG_HAVE_MEMORY_PRESENT
 336 void memory_present(int nid, unsigned long start, unsigned long end);
 337 #else
 338 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
 339 #endif
 340
 341 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
 342 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 343 #endif
 344
 345 /*
 346  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
 347  */
 348 #define zone_idx(zone)          ((zone) - (zone)->zone_pgdat->node_zones)
 349
 350 static inline int populated_zone(struct zone *zone)
 351 {
 352         return (!!zone->present_pages);
 353 }
 354
 355 static inline int is_highmem_idx(int idx)
 356 {
 357         return (idx == ZONE_HIGHMEM);
 358 }
 359
 360 static inline int is_normal_idx(int idx)
 361 {
 362         return (idx == ZONE_NORMAL);
 363 }
 364
 365 /**
 366  * is_highmem - helper function to quickly check if a struct zone is a
 367  *              highmem zone or not.  This is an attempt to keep references
 368  *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
 369  * @zone - pointer to struct zone variable
 370  */
 371 static inline int is_highmem(struct zone *zone)
 372 {
 373         return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM;
 374 }
 375
 376 static inline int is_normal(struct zone *zone)
 377 {
 378         return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
 379 }
 380
 381 static inline int is_dma32(struct zone *zone)
 382 {
 383         return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
 384 }
 385
 386 static inline int is_dma(struct zone *zone)
 387 {
 388         return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
 389 }
 390
 391 /* These two functions are used to setup the per zone pages min values */
 392 struct ctl_table;
 393 struct file;
 394 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
 395                                         void __user *, size_t *, loff_t *);
 396 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
 397 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
 398                                         void __user *, size_t *, loff_t *);
 399 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
 400                                         void __user *, size_t *, loff_t *);
 401
 402 #include <linux/topology.h>
 403 /* Returns the number of the current Node. */
 404 #ifndef numa_node_id
 405 #define numa_node_id()          (cpu_to_node(raw_smp_processor_id()))
 406 #endif
 407
 408 #ifndef CONFIG_NEED_MULTIPLE_NODES
 409
 410 extern struct pglist_data contig_page_data;
 411 #define NODE_DATA(nid)          (&contig_page_data)
 412 #define NODE_MEM_MAP(nid)       mem_map
 413 #define MAX_NODES_SHIFT         1
 414
 415 #else /* CONFIG_NEED_MULTIPLE_NODES */
 416
 417 #include <asm/mmzone.h>
 418
 419 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 420
 421 extern struct pglist_data *first_online_pgdat(void);
 422 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
 423 extern struct zone *next_zone(struct zone *zone);
 424
 425 /**
 426  * for_each_pgdat - helper macro to iterate over all nodes
 427  * @pgdat - pointer to a pg_data_t variable
 428  */
 429 #define for_each_online_pgdat(pgdat)                    \
 430         for (pgdat = first_online_pgdat();              \
 431              pgdat;                                     \
 432              pgdat = next_online_pgdat(pgdat))
 433 /**
 434  * for_each_zone - helper macro to iterate over all memory zones
 435  * @zone - pointer to struct zone variable
 436  *
 437  * The user only needs to declare the zone variable, for_each_zone
 438  * fills it in.
 439  */
 440 #define for_each_zone(zone)                             \
 441         for (zone = (first_online_pgdat())->node_zones; \
 442              zone;                                      \
 443              zone = next_zone(zone))
 444
 445 #ifdef CONFIG_SPARSEMEM
 446 #include <asm/sparsemem.h>
 447 #endif
 448
 449 #if BITS_PER_LONG == 32
 450 /*
 451  * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
 452  * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
 453  */
 454 #define FLAGS_RESERVED          9
 455
 456 #elif BITS_PER_LONG == 64
 457 /*
 458  * with 64 bit flags field, there's plenty of room.
 459  */
 460 #define FLAGS_RESERVED          32
 461
 462 #else
 463
 464 #error BITS_PER_LONG not defined
 465
 466 #endif
 467
 468 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
 469 #define early_pfn_to_nid(nid)  (0UL)
 470 #endif
 471
 472 #ifdef CONFIG_FLATMEM
 473 #define pfn_to_nid(pfn)         (0)
 474 #endif
 475
 476 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
 477 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
 478
 479 #ifdef CONFIG_SPARSEMEM
 480
 481 /*
 482  * SECTION_SHIFT                #bits space required to store a section #
 483  *
 484  * PA_SECTION_SHIFT             physical address to/from section number
 485  * PFN_SECTION_SHIFT            pfn to/from section number
 486  */
 487 #define SECTIONS_SHIFT          (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
 488
 489 #define PA_SECTION_SHIFT        (SECTION_SIZE_BITS)
 490 #define PFN_SECTION_SHIFT       (SECTION_SIZE_BITS - PAGE_SHIFT)
 491
 492 #define NR_MEM_SECTIONS         (1UL << SECTIONS_SHIFT)
 493
 494 #define PAGES_PER_SECTION       (1UL << PFN_SECTION_SHIFT)
 495 #define PAGE_SECTION_MASK       (~(PAGES_PER_SECTION-1))
 496
 497 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
 498 #error Allocator MAX_ORDER exceeds SECTION_SIZE
 499 #endif
 500
 501 struct page;
 502 struct mem_section {
 503         /*
 504          * This is, logically, a pointer to an array of struct
 505          * pages.  However, it is stored with some other magic.
 506          * (see sparse.c::sparse_init_one_section())
 507          *
 508          * Making it a UL at least makes someone do a cast
 509          * before using it wrong.
 510          */
 511         unsigned long section_mem_map;
 512 };
 513
 514 #ifdef CONFIG_SPARSEMEM_EXTREME
 515 #define SECTIONS_PER_ROOT       (PAGE_SIZE / sizeof (struct mem_section))
 516 #else
 517 #define SECTIONS_PER_ROOT       1
 518 #endif
 519
 520 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
 521 #define NR_SECTION_ROOTS        (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
 522 #define SECTION_ROOT_MASK       (SECTIONS_PER_ROOT - 1)
 523
 524 #ifdef CONFIG_SPARSEMEM_EXTREME
 525 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
 526 #else
 527 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
 528 #endif
 529
 530 static inline struct mem_section *__nr_to_section(unsigned long nr)
 531 {
 532         if (!mem_section[SECTION_NR_TO_ROOT(nr)])
 533                 return NULL;
 534         return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 535 }
 536 extern int __section_nr(struct mem_section* ms);
 537
 538 /*
 539  * We use the lower bits of the mem_map pointer to store
 540  * a little bit of information.  There should be at least
 541  * 3 bits here due to 32-bit alignment.
 542  */
 543 #define SECTION_MARKED_PRESENT  (1UL<<0)
 544 #define SECTION_HAS_MEM_MAP     (1UL<<1)
 545 #define SECTION_MAP_LAST_BIT    (1UL<<2)
 546 #define SECTION_MAP_MASK        (~(SECTION_MAP_LAST_BIT-1))
 547
 548 static inline struct page *__section_mem_map_addr(struct mem_section *section)
 549 {
 550         unsigned long map = section->section_mem_map;
 551         map &= SECTION_MAP_MASK;
 552         return (struct page *)map;
 553 }
 554
 555 static inline int valid_section(struct mem_section *section)
 556 {
 557         return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
 558 }
 559
 560 static inline int section_has_mem_map(struct mem_section *section)
 561 {
 562         return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 563 }
 564
 565 static inline int valid_section_nr(unsigned long nr)
 566 {
 567         return valid_section(__nr_to_section(nr));
 568 }
 569
 570 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
 571 {
 572         return __nr_to_section(pfn_to_section_nr(pfn));
 573 }
 574
 575 static inline int pfn_valid(unsigned long pfn)
 576 {
 577         if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
 578                 return 0;
 579         return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
 580 }
 581
 582 /*
 583  * These are _only_ used during initialisation, therefore they
 584  * can use __initdata ...  They could have names to indicate
 585  * this restriction.
 586  */
 587 #ifdef CONFIG_NUMA
 588 #define pfn_to_nid(pfn)                                                 \
 589 ({                                                                      \
 590         unsigned long __pfn_to_nid_pfn = (pfn);                         \
 591         page_to_nid(pfn_to_page(__pfn_to_nid_pfn));                     \
 592 })
 593 #else
 594 #define pfn_to_nid(pfn)         (0)
 595 #endif
 596
 597 #define early_pfn_valid(pfn)    pfn_valid(pfn)
 598 void sparse_init(void);
 599 #else
 600 #define sparse_init()   do {} while (0)
 601 #define sparse_index_init(_sec, _nid)  do {} while (0)
 602 #endif /* CONFIG_SPARSEMEM */
 603
 604 #ifndef early_pfn_valid
 605 #define early_pfn_valid(pfn)    (1)
 606 #endif
 607
 608 void memory_present(int nid, unsigned long start, unsigned long end);
 609 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 610
 611 #endif /* !__ASSEMBLY__ */
 612 #endif /* __KERNEL__ */
 613 #endif /* _LINUX_MMZONE_H */