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/spinlock.h>
   8 #include <linux/list.h>
   9 #include <linux/wait.h>
  10 #include <linux/cache.h>
  11 #include <linux/threads.h>
  12 #include <linux/numa.h>
  13 #include <linux/init.h>
  14 #include <linux/seqlock.h>
  15 #include <linux/nodemask.h>
  16 #include <asm/atomic.h>
  17 #include <asm/page.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 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
  26
  27 struct free_area {
  28         struct list_head        free_list;
  29         unsigned long           nr_free;
  30 };
  31
  32 struct pglist_data;
  33
  34 /*
  35  * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
  36  * So add a wild amount of padding here to ensure that they fall into separate
  37  * cachelines.  There are very few zone structures in the machine, so space
  38  * consumption is not a concern here.
  39  */
  40 #if defined(CONFIG_SMP)
  41 struct zone_padding {
  42         char x[0];
  43 } ____cacheline_internodealigned_in_smp;
  44 #define ZONE_PADDING(name)      struct zone_padding name;
  45 #else
  46 #define ZONE_PADDING(name)
  47 #endif
  48
  49 enum zone_stat_item {
  50         NR_VM_ZONE_STAT_ITEMS };
  51
  52 struct per_cpu_pages {
  53         int count;              /* number of pages in the list */
  54         int high;               /* high watermark, emptying needed */
  55         int batch;              /* chunk size for buddy add/remove */
  56         struct list_head list;  /* the list of pages */
  57 };
  58
  59 struct per_cpu_pageset {
  60         struct per_cpu_pages pcp[2];    /* 0: hot.  1: cold */
  61 #ifdef CONFIG_SMP
  62         s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
  63 #endif
  64
  65 #ifdef CONFIG_NUMA
  66         unsigned long numa_hit;         /* allocated in intended node */
  67         unsigned long numa_miss;        /* allocated in non intended node */
  68         unsigned long numa_foreign;     /* was intended here, hit elsewhere */
  69         unsigned long interleave_hit;   /* interleaver prefered this zone */
  70         unsigned long local_node;       /* allocation from local node */
  71         unsigned long other_node;       /* allocation from other node */
  72 #endif
  73 } ____cacheline_aligned_in_smp;
  74
  75 #ifdef CONFIG_NUMA
  76 #define zone_pcp(__z, __cpu) ((__z)->pageset[(__cpu)])
  77 #else
  78 #define zone_pcp(__z, __cpu) (&(__z)->pageset[(__cpu)])
  79 #endif
  80
  81 #define ZONE_DMA                0
  82 #define ZONE_DMA32              1
  83 #define ZONE_NORMAL             2
  84 #define ZONE_HIGHMEM            3
  85
  86 #define MAX_NR_ZONES            4       /* Sync this with ZONES_SHIFT */
  87 #define ZONES_SHIFT             2       /* ceil(log2(MAX_NR_ZONES)) */
  88
  89
  90 /*
  91  * When a memory allocation must conform to specific limitations (such
  92  * as being suitable for DMA) the caller will pass in hints to the
  93  * allocator in the gfp_mask, in the zone modifier bits.  These bits
  94  * are used to select a priority ordered list of memory zones which
  95  * match the requested limits.  GFP_ZONEMASK defines which bits within
  96  * the gfp_mask should be considered as zone modifiers.  Each valid
  97  * combination of the zone modifier bits has a corresponding list
  98  * of zones (in node_zonelists).  Thus for two zone modifiers there
  99  * will be a maximum of 4 (2 ** 2) zonelists, for 3 modifiers there will
 100  * be 8 (2 ** 3) zonelists.  GFP_ZONETYPES defines the number of possible
 101  * combinations of zone modifiers in "zone modifier space".
 102  *
 103  * As an optimisation any zone modifier bits which are only valid when
 104  * no other zone modifier bits are set (loners) should be placed in
 105  * the highest order bits of this field.  This allows us to reduce the
 106  * extent of the zonelists thus saving space.  For example in the case
 107  * of three zone modifier bits, we could require up to eight zonelists.
 108  * If the left most zone modifier is a "loner" then the highest valid
 109  * zonelist would be four allowing us to allocate only five zonelists.
 110  * Use the first form for GFP_ZONETYPES when the left most bit is not
 111  * a "loner", otherwise use the second.
 112  *
 113  * NOTE! Make sure this matches the zones in <linux/gfp.h>
 114  */
 115 #define GFP_ZONEMASK    0x07
 116 /* #define GFP_ZONETYPES       (GFP_ZONEMASK + 1) */           /* Non-loner */
 117 #define GFP_ZONETYPES  ((GFP_ZONEMASK + 1) / 2 + 1)            /* Loner */
 118
 119 /*
 120  * On machines where it is needed (eg PCs) we divide physical memory
 121  * into multiple physical zones. On a 32bit PC we have 4 zones:
 122  *
 123  * ZONE_DMA       < 16 MB       ISA DMA capable memory
 124  * ZONE_DMA32        0 MB       Empty
 125  * ZONE_NORMAL  16-896 MB       direct mapped by the kernel
 126  * ZONE_HIGHMEM  > 896 MB       only page cache and user processes
 127  */
 128
 129 struct zone {
 130         /* Fields commonly accessed by the page allocator */
 131         unsigned long           free_pages;
 132         unsigned long           pages_min, pages_low, pages_high;
 133         /*
 134          * We don't know if the memory that we're going to allocate will be freeable
 135          * or/and it will be released eventually, so to avoid totally wasting several
 136          * GB of ram we must reserve some of the lower zone memory (otherwise we risk
 137          * to run OOM on the lower zones despite there's tons of freeable ram
 138          * on the higher zones). This array is recalculated at runtime if the
 139          * sysctl_lowmem_reserve_ratio sysctl changes.
 140          */
 141         unsigned long           lowmem_reserve[MAX_NR_ZONES];
 142
 143 #ifdef CONFIG_NUMA
 144         struct per_cpu_pageset  *pageset[NR_CPUS];
 145 #else
 146         struct per_cpu_pageset  pageset[NR_CPUS];
 147 #endif
 148         /*
 149          * free areas of different sizes
 150          */
 151         spinlock_t              lock;
 152 #ifdef CONFIG_MEMORY_HOTPLUG
 153         /* see spanned/present_pages for more description */
 154         seqlock_t               span_seqlock;
 155 #endif
 156         struct free_area        free_area[MAX_ORDER];
 157
 158
 159         ZONE_PADDING(_pad1_)
 160
 161         /* Fields commonly accessed by the page reclaim scanner */
 162         spinlock_t              lru_lock;
 163         struct list_head        active_list;
 164         struct list_head        inactive_list;
 165         unsigned long           nr_scan_active;
 166         unsigned long           nr_scan_inactive;
 167         unsigned long           nr_active;
 168         unsigned long           nr_inactive;
 169         unsigned long           pages_scanned;     /* since last reclaim */
 170         int                     all_unreclaimable; /* All pages pinned */
 171
 172         /* A count of how many reclaimers are scanning this zone */
 173         atomic_t                reclaim_in_progress;
 174
 175         /* Zone statistics */
 176         atomic_long_t           vm_stat[NR_VM_ZONE_STAT_ITEMS];
 177         /*
 178          * timestamp (in jiffies) of the last zone reclaim that did not
 179          * result in freeing of pages. This is used to avoid repeated scans
 180          * if all memory in the zone is in use.
 181          */
 182         unsigned long           last_unsuccessful_zone_reclaim;
 183
 184         /*
 185          * prev_priority holds the scanning priority for this zone.  It is
 186          * defined as the scanning priority at which we achieved our reclaim
 187          * target at the previous try_to_free_pages() or balance_pgdat()
 188          * invokation.
 189          *
 190          * We use prev_priority as a measure of how much stress page reclaim is
 191          * under - it drives the swappiness decision: whether to unmap mapped
 192          * pages.
 193          *
 194          * temp_priority is used to remember the scanning priority at which
 195          * this zone was successfully refilled to free_pages == pages_high.
 196          *
 197          * Access to both these fields is quite racy even on uniprocessor.  But
 198          * it is expected to average out OK.
 199          */
 200         int temp_priority;
 201         int prev_priority;
 202
 203
 204         ZONE_PADDING(_pad2_)
 205         /* Rarely used or read-mostly fields */
 206
 207         /*
 208          * wait_table           -- the array holding the hash table
 209          * wait_table_hash_nr_entries   -- the size of the hash table array
 210          * wait_table_bits      -- wait_table_size == (1 << wait_table_bits)
 211          *
 212          * The purpose of all these is to keep track of the people
 213          * waiting for a page to become available and make them
 214          * runnable again when possible. The trouble is that this
 215          * consumes a lot of space, especially when so few things
 216          * wait on pages at a given time. So instead of using
 217          * per-page waitqueues, we use a waitqueue hash table.
 218          *
 219          * The bucket discipline is to sleep on the same queue when
 220          * colliding and wake all in that wait queue when removing.
 221          * When something wakes, it must check to be sure its page is
 222          * truly available, a la thundering herd. The cost of a
 223          * collision is great, but given the expected load of the
 224          * table, they should be so rare as to be outweighed by the
 225          * benefits from the saved space.
 226          *
 227          * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
 228          * primary users of these fields, and in mm/page_alloc.c
 229          * free_area_init_core() performs the initialization of them.
 230          */
 231         wait_queue_head_t       * wait_table;
 232         unsigned long           wait_table_hash_nr_entries;
 233         unsigned long           wait_table_bits;
 234
 235         /*
 236          * Discontig memory support fields.
 237          */
 238         struct pglist_data      *zone_pgdat;
 239         /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
 240         unsigned long           zone_start_pfn;
 241
 242         /*
 243          * zone_start_pfn, spanned_pages and present_pages are all
 244          * protected by span_seqlock.  It is a seqlock because it has
 245          * to be read outside of zone->lock, and it is done in the main
 246          * allocator path.  But, it is written quite infrequently.
 247          *
 248          * The lock is declared along with zone->lock because it is
 249          * frequently read in proximity to zone->lock.  It's good to
 250          * give them a chance of being in the same cacheline.
 251          */
 252         unsigned long           spanned_pages;  /* total size, including holes */
 253         unsigned long           present_pages;  /* amount of memory (excluding holes) */
 254
 255         /*
 256          * rarely used fields:
 257          */
 258         char                    *name;
 259 } ____cacheline_internodealigned_in_smp;
 260
 261
 262 /*
 263  * The "priority" of VM scanning is how much of the queues we will scan in one
 264  * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
 265  * queues ("queue_length >> 12") during an aging round.
 266  */
 267 #define DEF_PRIORITY 12
 268
 269 /*
 270  * One allocation request operates on a zonelist. A zonelist
 271  * is a list of zones, the first one is the 'goal' of the
 272  * allocation, the other zones are fallback zones, in decreasing
 273  * priority.
 274  *
 275  * Right now a zonelist takes up less than a cacheline. We never
 276  * modify it apart from boot-up, and only a few indices are used,
 277  * so despite the zonelist table being relatively big, the cache
 278  * footprint of this construct is very small.
 279  */
 280 struct zonelist {
 281         struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited
 282 };
 283
 284
 285 /*
 286  * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
 287  * (mostly NUMA machines?) to denote a higher-level memory zone than the
 288  * zone denotes.
 289  *
 290  * On NUMA machines, each NUMA node would have a pg_data_t to describe
 291  * it's memory layout.
 292  *
 293  * Memory statistics and page replacement data structures are maintained on a
 294  * per-zone basis.
 295  */
 296 struct bootmem_data;
 297 typedef struct pglist_data {
 298         struct zone node_zones[MAX_NR_ZONES];
 299         struct zonelist node_zonelists[GFP_ZONETYPES];
 300         int nr_zones;
 301 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 302         struct page *node_mem_map;
 303 #endif
 304         struct bootmem_data *bdata;
 305 #ifdef CONFIG_MEMORY_HOTPLUG
 306         /*
 307          * Must be held any time you expect node_start_pfn, node_present_pages
 308          * or node_spanned_pages stay constant.  Holding this will also
 309          * guarantee that any pfn_valid() stays that way.
 310          *
 311          * Nests above zone->lock and zone->size_seqlock.
 312          */
 313         spinlock_t node_size_lock;
 314 #endif
 315         unsigned long node_start_pfn;
 316         unsigned long node_present_pages; /* total number of physical pages */
 317         unsigned long node_spanned_pages; /* total size of physical page
 318                                              range, including holes */
 319         int node_id;
 320         wait_queue_head_t kswapd_wait;
 321         struct task_struct *kswapd;
 322         int kswapd_max_order;
 323 } pg_data_t;
 324
 325 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
 326 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
 327 #ifdef CONFIG_FLAT_NODE_MEM_MAP
 328 #define pgdat_page_nr(pgdat, pagenr)    ((pgdat)->node_mem_map + (pagenr))
 329 #else
 330 #define pgdat_page_nr(pgdat, pagenr)    pfn_to_page((pgdat)->node_start_pfn + (pagenr))
 331 #endif
 332 #define nid_page_nr(nid, pagenr)        pgdat_page_nr(NODE_DATA(nid),(pagenr))
 333
 334 #include <linux/memory_hotplug.h>
 335
 336 void __get_zone_counts(unsigned long *active, unsigned long *inactive,
 337                         unsigned long *free, struct pglist_data *pgdat);
 338 void get_zone_counts(unsigned long *active, unsigned long *inactive,
 339                         unsigned long *free);
 340 void build_all_zonelists(void);
 341 void wakeup_kswapd(struct zone *zone, int order);
 342 int zone_watermark_ok(struct zone *z, int order, unsigned long mark,
 343                 int classzone_idx, int alloc_flags);
 344
 345 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
 346                                      unsigned long size);
 347
 348 #ifdef CONFIG_HAVE_MEMORY_PRESENT
 349 void memory_present(int nid, unsigned long start, unsigned long end);
 350 #else
 351 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
 352 #endif
 353
 354 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
 355 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 356 #endif
 357
 358 /*
 359  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
 360  */
 361 #define zone_idx(zone)          ((zone) - (zone)->zone_pgdat->node_zones)
 362
 363 static inline int populated_zone(struct zone *zone)
 364 {
 365         return (!!zone->present_pages);
 366 }
 367
 368 static inline int is_highmem_idx(int idx)
 369 {
 370         return (idx == ZONE_HIGHMEM);
 371 }
 372
 373 static inline int is_normal_idx(int idx)
 374 {
 375         return (idx == ZONE_NORMAL);
 376 }
 377
 378 /**
 379  * is_highmem - helper function to quickly check if a struct zone is a
 380  *              highmem zone or not.  This is an attempt to keep references
 381  *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
 382  * @zone - pointer to struct zone variable
 383  */
 384 static inline int is_highmem(struct zone *zone)
 385 {
 386         return zone == zone->zone_pgdat->node_zones + ZONE_HIGHMEM;
 387 }
 388
 389 static inline int is_normal(struct zone *zone)
 390 {
 391         return zone == zone->zone_pgdat->node_zones + ZONE_NORMAL;
 392 }
 393
 394 static inline int is_dma32(struct zone *zone)
 395 {
 396         return zone == zone->zone_pgdat->node_zones + ZONE_DMA32;
 397 }
 398
 399 static inline int is_dma(struct zone *zone)
 400 {
 401         return zone == zone->zone_pgdat->node_zones + ZONE_DMA;
 402 }
 403
 404 /* These two functions are used to setup the per zone pages min values */
 405 struct ctl_table;
 406 struct file;
 407 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,
 408                                         void __user *, size_t *, loff_t *);
 409 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
 410 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, struct file *,
 411                                         void __user *, size_t *, loff_t *);
 412 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, struct file *,
 413                                         void __user *, size_t *, loff_t *);
 414
 415 #include <linux/topology.h>
 416 /* Returns the number of the current Node. */
 417 #ifndef numa_node_id
 418 #define numa_node_id()          (cpu_to_node(raw_smp_processor_id()))
 419 #endif
 420
 421 #ifndef CONFIG_NEED_MULTIPLE_NODES
 422
 423 extern struct pglist_data contig_page_data;
 424 #define NODE_DATA(nid)          (&contig_page_data)
 425 #define NODE_MEM_MAP(nid)       mem_map
 426 #define MAX_NODES_SHIFT         1
 427
 428 #else /* CONFIG_NEED_MULTIPLE_NODES */
 429
 430 #include <asm/mmzone.h>
 431
 432 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
 433
 434 extern struct pglist_data *first_online_pgdat(void);
 435 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
 436 extern struct zone *next_zone(struct zone *zone);
 437
 438 /**
 439  * for_each_pgdat - helper macro to iterate over all nodes
 440  * @pgdat - pointer to a pg_data_t variable
 441  */
 442 #define for_each_online_pgdat(pgdat)                    \
 443         for (pgdat = first_online_pgdat();              \
 444              pgdat;                                     \
 445              pgdat = next_online_pgdat(pgdat))
 446 /**
 447  * for_each_zone - helper macro to iterate over all memory zones
 448  * @zone - pointer to struct zone variable
 449  *
 450  * The user only needs to declare the zone variable, for_each_zone
 451  * fills it in.
 452  */
 453 #define for_each_zone(zone)                             \
 454         for (zone = (first_online_pgdat())->node_zones; \
 455              zone;                                      \
 456              zone = next_zone(zone))
 457
 458 #ifdef CONFIG_SPARSEMEM
 459 #include <asm/sparsemem.h>
 460 #endif
 461
 462 #if BITS_PER_LONG == 32
 463 /*
 464  * with 32 bit page->flags field, we reserve 9 bits for node/zone info.
 465  * there are 4 zones (3 bits) and this leaves 9-3=6 bits for nodes.
 466  */
 467 #define FLAGS_RESERVED          9
 468
 469 #elif BITS_PER_LONG == 64
 470 /*
 471  * with 64 bit flags field, there's plenty of room.
 472  */
 473 #define FLAGS_RESERVED          32
 474
 475 #else
 476
 477 #error BITS_PER_LONG not defined
 478
 479 #endif
 480
 481 #ifndef CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID
 482 #define early_pfn_to_nid(nid)  (0UL)
 483 #endif
 484
 485 #ifdef CONFIG_FLATMEM
 486 #define pfn_to_nid(pfn)         (0)
 487 #endif
 488
 489 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
 490 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
 491
 492 #ifdef CONFIG_SPARSEMEM
 493
 494 /*
 495  * SECTION_SHIFT                #bits space required to store a section #
 496  *
 497  * PA_SECTION_SHIFT             physical address to/from section number
 498  * PFN_SECTION_SHIFT            pfn to/from section number
 499  */
 500 #define SECTIONS_SHIFT          (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
 501
 502 #define PA_SECTION_SHIFT        (SECTION_SIZE_BITS)
 503 #define PFN_SECTION_SHIFT       (SECTION_SIZE_BITS - PAGE_SHIFT)
 504
 505 #define NR_MEM_SECTIONS         (1UL << SECTIONS_SHIFT)
 506
 507 #define PAGES_PER_SECTION       (1UL << PFN_SECTION_SHIFT)
 508 #define PAGE_SECTION_MASK       (~(PAGES_PER_SECTION-1))
 509
 510 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
 511 #error Allocator MAX_ORDER exceeds SECTION_SIZE
 512 #endif
 513
 514 struct page;
 515 struct mem_section {
 516         /*
 517          * This is, logically, a pointer to an array of struct
 518          * pages.  However, it is stored with some other magic.
 519          * (see sparse.c::sparse_init_one_section())
 520          *
 521          * Additionally during early boot we encode node id of
 522          * the location of the section here to guide allocation.
 523          * (see sparse.c::memory_present())
 524          *
 525          * Making it a UL at least makes someone do a cast
 526          * before using it wrong.
 527          */
 528         unsigned long section_mem_map;
 529 };
 530
 531 #ifdef CONFIG_SPARSEMEM_EXTREME
 532 #define SECTIONS_PER_ROOT       (PAGE_SIZE / sizeof (struct mem_section))
 533 #else
 534 #define SECTIONS_PER_ROOT       1
 535 #endif
 536
 537 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
 538 #define NR_SECTION_ROOTS        (NR_MEM_SECTIONS / SECTIONS_PER_ROOT)
 539 #define SECTION_ROOT_MASK       (SECTIONS_PER_ROOT - 1)
 540
 541 #ifdef CONFIG_SPARSEMEM_EXTREME
 542 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
 543 #else
 544 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
 545 #endif
 546
 547 static inline struct mem_section *__nr_to_section(unsigned long nr)
 548 {
 549         if (!mem_section[SECTION_NR_TO_ROOT(nr)])
 550                 return NULL;
 551         return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
 552 }
 553 extern int __section_nr(struct mem_section* ms);
 554
 555 /*
 556  * We use the lower bits of the mem_map pointer to store
 557  * a little bit of information.  There should be at least
 558  * 3 bits here due to 32-bit alignment.
 559  */
 560 #define SECTION_MARKED_PRESENT  (1UL<<0)
 561 #define SECTION_HAS_MEM_MAP     (1UL<<1)
 562 #define SECTION_MAP_LAST_BIT    (1UL<<2)
 563 #define SECTION_MAP_MASK        (~(SECTION_MAP_LAST_BIT-1))
 564 #define SECTION_NID_SHIFT       2
 565
 566 static inline struct page *__section_mem_map_addr(struct mem_section *section)
 567 {
 568         unsigned long map = section->section_mem_map;
 569         map &= SECTION_MAP_MASK;
 570         return (struct page *)map;
 571 }
 572
 573 static inline int valid_section(struct mem_section *section)
 574 {
 575         return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
 576 }
 577
 578 static inline int section_has_mem_map(struct mem_section *section)
 579 {
 580         return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
 581 }
 582
 583 static inline int valid_section_nr(unsigned long nr)
 584 {
 585         return valid_section(__nr_to_section(nr));
 586 }
 587
 588 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
 589 {
 590         return __nr_to_section(pfn_to_section_nr(pfn));
 591 }
 592
 593 static inline int pfn_valid(unsigned long pfn)
 594 {
 595         if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
 596                 return 0;
 597         return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
 598 }
 599
 600 /*
 601  * These are _only_ used during initialisation, therefore they
 602  * can use __initdata ...  They could have names to indicate
 603  * this restriction.
 604  */
 605 #ifdef CONFIG_NUMA
 606 #define pfn_to_nid(pfn)                                                 \
 607 ({                                                                      \
 608         unsigned long __pfn_to_nid_pfn = (pfn);                         \
 609         page_to_nid(pfn_to_page(__pfn_to_nid_pfn));                     \
 610 })
 611 #else
 612 #define pfn_to_nid(pfn)         (0)
 613 #endif
 614
 615 #define early_pfn_valid(pfn)    pfn_valid(pfn)
 616 void sparse_init(void);
 617 #else
 618 #define sparse_init()   do {} while (0)
 619 #define sparse_index_init(_sec, _nid)  do {} while (0)
 620 #endif /* CONFIG_SPARSEMEM */
 621
 622 #ifndef early_pfn_valid
 623 #define early_pfn_valid(pfn)    (1)
 624 #endif
 625
 626 void memory_present(int nid, unsigned long start, unsigned long end);
 627 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
 628
 629 #endif /* !__ASSEMBLY__ */
 630 #endif /* __KERNEL__ */
 631 #endif /* _LINUX_MMZONE_H */