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