1 #ifndef _LINUX_MMZONE_H
2 #define _LINUX_MMZONE_H
3
4 #ifndef __ASSEMBLY__
5 #ifndef __GENERATING_BOUNDS_H
6
7 #include <linux/spinlock.h>
8 #include <linux/list.h>
9 #include <linux/wait.h>
10 #include <linux/bitops.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 <linux/pageblock-flags.h>
18 #include <linux/page-flags-layout.h>
19 #include <linux/atomic.h>
20 #include <asm/page.h>
21
22 /* Free memory management - zoned buddy allocator. */
23 #ifndef CONFIG_FORCE_MAX_ZONEORDER
24 #define MAX_ORDER 11
25 #else
26 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
27 #endif
28 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
29
30 /*
31 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
32 * costly to service. That is between allocation orders which should
33 * coalesce naturally under reasonable reclaim pressure and those which
34 * will not.
35 */
36 #define PAGE_ALLOC_COSTLY_ORDER 3
37
38 enum {
39 MIGRATE_UNMOVABLE,
40 MIGRATE_MOVABLE,
41 MIGRATE_RECLAIMABLE,
42 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
43 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
44 #ifdef CONFIG_CMA
45 /*
46 * MIGRATE_CMA migration type is designed to mimic the way
47 * ZONE_MOVABLE works. Only movable pages can be allocated
48 * from MIGRATE_CMA pageblocks and page allocator never
49 * implicitly change migration type of MIGRATE_CMA pageblock.
50 *
51 * The way to use it is to change migratetype of a range of
52 * pageblocks to MIGRATE_CMA which can be done by
53 * __free_pageblock_cma() function. What is important though
54 * is that a range of pageblocks must be aligned to
55 * MAX_ORDER_NR_PAGES should biggest page be bigger then
56 * a single pageblock.
57 */
58 MIGRATE_CMA,
59 #endif
60 #ifdef CONFIG_MEMORY_ISOLATION
61 MIGRATE_ISOLATE, /* can't allocate from here */
62 #endif
63 MIGRATE_TYPES
64 };
65
66 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
67 extern char * const migratetype_names[MIGRATE_TYPES];
68
69 #ifdef CONFIG_CMA
70 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
71 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
72 #else
73 # define is_migrate_cma(migratetype) false
74 # define is_migrate_cma_page(_page) false
75 #endif
76
77 #define for_each_migratetype_order(order, type) \
78 for (order = 0; order < MAX_ORDER; order++) \
79 for (type = 0; type < MIGRATE_TYPES; type++)
80
81 extern int page_group_by_mobility_disabled;
82
83 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1)
84 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1)
85
86 #define get_pageblock_migratetype(page) \
87 get_pfnblock_flags_mask(page, page_to_pfn(page), \
88 PB_migrate_end, MIGRATETYPE_MASK)
89
90 struct free_area {
91 struct list_head free_list[MIGRATE_TYPES];
92 unsigned long nr_free;
93 };
94
95 struct pglist_data;
96
97 /*
98 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel.
99 * So add a wild amount of padding here to ensure that they fall into separate
100 * cachelines. There are very few zone structures in the machine, so space
101 * consumption is not a concern here.
102 */
103 #if defined(CONFIG_SMP)
104 struct zone_padding {
105 char x[0];
106 } ____cacheline_internodealigned_in_smp;
107 #define ZONE_PADDING(name) struct zone_padding name;
108 #else
109 #define ZONE_PADDING(name)
110 #endif
111
112 enum zone_stat_item {
113 /* First 128 byte cacheline (assuming 64 bit words) */
114 NR_FREE_PAGES,
115 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
116 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
117 NR_ZONE_ACTIVE_ANON,
118 NR_ZONE_INACTIVE_FILE,
119 NR_ZONE_ACTIVE_FILE,
120 NR_ZONE_UNEVICTABLE,
121 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
122 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
123 NR_SLAB_RECLAIMABLE,
124 NR_SLAB_UNRECLAIMABLE,
125 NR_PAGETABLE, /* used for pagetables */
126 NR_KERNEL_STACK_KB, /* measured in KiB */
127 NR_KAISERTABLE,
128 NR_BOUNCE,
129 /* Second 128 byte cacheline */
130 #if IS_ENABLED(CONFIG_ZSMALLOC)
131 NR_ZSPAGES, /* allocated in zsmalloc */
132 #endif
133 #ifdef CONFIG_NUMA
134 NUMA_HIT, /* allocated in intended node */
135 NUMA_MISS, /* allocated in non intended node */
136 NUMA_FOREIGN, /* was intended here, hit elsewhere */
137 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
138 NUMA_LOCAL, /* allocation from local node */
139 NUMA_OTHER, /* allocation from other node */
140 #endif
141 NR_FREE_CMA_PAGES,
142 NR_VM_ZONE_STAT_ITEMS };
143
144 enum node_stat_item {
145 NR_LRU_BASE,
146 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
147 NR_ACTIVE_ANON, /* " " " " " */
148 NR_INACTIVE_FILE, /* " " " " " */
149 NR_ACTIVE_FILE, /* " " " " " */
150 NR_UNEVICTABLE, /* " " " " " */
151 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
152 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
153 NR_PAGES_SCANNED, /* pages scanned since last reclaim */
154 WORKINGSET_REFAULT,
155 WORKINGSET_ACTIVATE,
156 WORKINGSET_NODERECLAIM,
157 NR_ANON_MAPPED, /* Mapped anonymous pages */
158 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
159 only modified from process context */
160 NR_FILE_PAGES,
161 NR_FILE_DIRTY,
162 NR_WRITEBACK,
163 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
164 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
165 NR_SHMEM_THPS,
166 NR_SHMEM_PMDMAPPED,
167 NR_ANON_THPS,
168 NR_UNSTABLE_NFS, /* NFS unstable pages */
169 NR_VMSCAN_WRITE,
170 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
171 NR_DIRTIED, /* page dirtyings since bootup */
172 NR_WRITTEN, /* page writings since bootup */
173 NR_VM_NODE_STAT_ITEMS
174 };
175
176 /*
177 * We do arithmetic on the LRU lists in various places in the code,
178 * so it is important to keep the active lists LRU_ACTIVE higher in
179 * the array than the corresponding inactive lists, and to keep
180 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
181 *
182 * This has to be kept in sync with the statistics in zone_stat_item
183 * above and the descriptions in vmstat_text in mm/vmstat.c
184 */
185 #define LRU_BASE 0
186 #define LRU_ACTIVE 1
187 #define LRU_FILE 2
188
189 enum lru_list {
190 LRU_INACTIVE_ANON = LRU_BASE,
191 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
192 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
193 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
194 LRU_UNEVICTABLE,
195 NR_LRU_LISTS
196 };
197
198 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
199
200 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
201
is_file_lru(enum lru_list lru)202 static inline int is_file_lru(enum lru_list lru)
203 {
204 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
205 }
206
is_active_lru(enum lru_list lru)207 static inline int is_active_lru(enum lru_list lru)
208 {
209 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
210 }
211
212 struct zone_reclaim_stat {
213 /*
214 * The pageout code in vmscan.c keeps track of how many of the
215 * mem/swap backed and file backed pages are referenced.
216 * The higher the rotated/scanned ratio, the more valuable
217 * that cache is.
218 *
219 * The anon LRU stats live in [0], file LRU stats in [1]
220 */
221 unsigned long recent_rotated[2];
222 unsigned long recent_scanned[2];
223 };
224
225 struct lruvec {
226 struct list_head lists[NR_LRU_LISTS];
227 struct zone_reclaim_stat reclaim_stat;
228 /* Evictions & activations on the inactive file list */
229 atomic_long_t inactive_age;
230 #ifdef CONFIG_MEMCG
231 struct pglist_data *pgdat;
232 #endif
233 };
234
235 /* Mask used at gathering information at once (see memcontrol.c) */
236 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
237 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
238 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
239
240 /* Isolate clean file */
241 #define ISOLATE_CLEAN ((__force isolate_mode_t)0x1)
242 /* Isolate unmapped file */
243 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
244 /* Isolate for asynchronous migration */
245 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
246 /* Isolate unevictable pages */
247 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
248
249 /* LRU Isolation modes. */
250 typedef unsigned __bitwise__ isolate_mode_t;
251
252 enum zone_watermarks {
253 WMARK_MIN,
254 WMARK_LOW,
255 WMARK_HIGH,
256 NR_WMARK
257 };
258
259 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
260 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
261 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
262
263 struct per_cpu_pages {
264 int count; /* number of pages in the list */
265 int high; /* high watermark, emptying needed */
266 int batch; /* chunk size for buddy add/remove */
267
268 /* Lists of pages, one per migrate type stored on the pcp-lists */
269 struct list_head lists[MIGRATE_PCPTYPES];
270 };
271
272 struct per_cpu_pageset {
273 struct per_cpu_pages pcp;
274 #ifdef CONFIG_NUMA
275 s8 expire;
276 #endif
277 #ifdef CONFIG_SMP
278 s8 stat_threshold;
279 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
280 #endif
281 };
282
283 struct per_cpu_nodestat {
284 s8 stat_threshold;
285 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
286 };
287
288 #endif /* !__GENERATING_BOUNDS.H */
289
290 enum zone_type {
291 #ifdef CONFIG_ZONE_DMA
292 /*
293 * ZONE_DMA is used when there are devices that are not able
294 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
295 * carve out the portion of memory that is needed for these devices.
296 * The range is arch specific.
297 *
298 * Some examples
299 *
300 * Architecture Limit
301 * ---------------------------
302 * parisc, ia64, sparc <4G
303 * s390 <2G
304 * arm Various
305 * alpha Unlimited or 0-16MB.
306 *
307 * i386, x86_64 and multiple other arches
308 * <16M.
309 */
310 ZONE_DMA,
311 #endif
312 #ifdef CONFIG_ZONE_DMA32
313 /*
314 * x86_64 needs two ZONE_DMAs because it supports devices that are
315 * only able to do DMA to the lower 16M but also 32 bit devices that
316 * can only do DMA areas below 4G.
317 */
318 ZONE_DMA32,
319 #endif
320 /*
321 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
322 * performed on pages in ZONE_NORMAL if the DMA devices support
323 * transfers to all addressable memory.
324 */
325 ZONE_NORMAL,
326 #ifdef CONFIG_HIGHMEM
327 /*
328 * A memory area that is only addressable by the kernel through
329 * mapping portions into its own address space. This is for example
330 * used by i386 to allow the kernel to address the memory beyond
331 * 900MB. The kernel will set up special mappings (page
332 * table entries on i386) for each page that the kernel needs to
333 * access.
334 */
335 ZONE_HIGHMEM,
336 #endif
337 ZONE_MOVABLE,
338 #ifdef CONFIG_ZONE_DEVICE
339 ZONE_DEVICE,
340 #endif
341 __MAX_NR_ZONES
342
343 };
344
345 #ifndef __GENERATING_BOUNDS_H
346
347 struct zone {
348 /* Read-mostly fields */
349
350 /* zone watermarks, access with *_wmark_pages(zone) macros */
351 unsigned long watermark[NR_WMARK];
352
353 unsigned long nr_reserved_highatomic;
354
355 /*
356 * We don't know if the memory that we're going to allocate will be
357 * freeable or/and it will be released eventually, so to avoid totally
358 * wasting several GB of ram we must reserve some of the lower zone
359 * memory (otherwise we risk to run OOM on the lower zones despite
360 * there being tons of freeable ram on the higher zones). This array is
361 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
362 * changes.
363 */
364 long lowmem_reserve[MAX_NR_ZONES];
365
366 #ifdef CONFIG_NUMA
367 int node;
368 #endif
369 struct pglist_data *zone_pgdat;
370 struct per_cpu_pageset __percpu *pageset;
371
372 #ifndef CONFIG_SPARSEMEM
373 /*
374 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
375 * In SPARSEMEM, this map is stored in struct mem_section
376 */
377 unsigned long *pageblock_flags;
378 #endif /* CONFIG_SPARSEMEM */
379
380 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
381 unsigned long zone_start_pfn;
382
383 /*
384 * spanned_pages is the total pages spanned by the zone, including
385 * holes, which is calculated as:
386 * spanned_pages = zone_end_pfn - zone_start_pfn;
387 *
388 * present_pages is physical pages existing within the zone, which
389 * is calculated as:
390 * present_pages = spanned_pages - absent_pages(pages in holes);
391 *
392 * managed_pages is present pages managed by the buddy system, which
393 * is calculated as (reserved_pages includes pages allocated by the
394 * bootmem allocator):
395 * managed_pages = present_pages - reserved_pages;
396 *
397 * So present_pages may be used by memory hotplug or memory power
398 * management logic to figure out unmanaged pages by checking
399 * (present_pages - managed_pages). And managed_pages should be used
400 * by page allocator and vm scanner to calculate all kinds of watermarks
401 * and thresholds.
402 *
403 * Locking rules:
404 *
405 * zone_start_pfn and spanned_pages are protected by span_seqlock.
406 * It is a seqlock because it has to be read outside of zone->lock,
407 * and it is done in the main allocator path. But, it is written
408 * quite infrequently.
409 *
410 * The span_seq lock is declared along with zone->lock because it is
411 * frequently read in proximity to zone->lock. It's good to
412 * give them a chance of being in the same cacheline.
413 *
414 * Write access to present_pages at runtime should be protected by
415 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
416 * present_pages should get_online_mems() to get a stable value.
417 *
418 * Read access to managed_pages should be safe because it's unsigned
419 * long. Write access to zone->managed_pages and totalram_pages are
420 * protected by managed_page_count_lock at runtime. Idealy only
421 * adjust_managed_page_count() should be used instead of directly
422 * touching zone->managed_pages and totalram_pages.
423 */
424 unsigned long managed_pages;
425 unsigned long spanned_pages;
426 unsigned long present_pages;
427
428 const char *name;
429
430 #ifdef CONFIG_MEMORY_ISOLATION
431 /*
432 * Number of isolated pageblock. It is used to solve incorrect
433 * freepage counting problem due to racy retrieving migratetype
434 * of pageblock. Protected by zone->lock.
435 */
436 unsigned long nr_isolate_pageblock;
437 #endif
438
439 #ifdef CONFIG_MEMORY_HOTPLUG
440 /* see spanned/present_pages for more description */
441 seqlock_t span_seqlock;
442 #endif
443
444 int initialized;
445
446 /* Write-intensive fields used from the page allocator */
447 ZONE_PADDING(_pad1_)
448
449 /* free areas of different sizes */
450 struct free_area free_area[MAX_ORDER];
451
452 /* zone flags, see below */
453 unsigned long flags;
454
455 /* Primarily protects free_area */
456 spinlock_t lock;
457
458 /* Write-intensive fields used by compaction and vmstats. */
459 ZONE_PADDING(_pad2_)
460
461 /*
462 * When free pages are below this point, additional steps are taken
463 * when reading the number of free pages to avoid per-cpu counter
464 * drift allowing watermarks to be breached
465 */
466 unsigned long percpu_drift_mark;
467
468 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
469 /* pfn where compaction free scanner should start */
470 unsigned long compact_cached_free_pfn;
471 /* pfn where async and sync compaction migration scanner should start */
472 unsigned long compact_cached_migrate_pfn[2];
473 #endif
474
475 #ifdef CONFIG_COMPACTION
476 /*
477 * On compaction failure, 1<<compact_defer_shift compactions
478 * are skipped before trying again. The number attempted since
479 * last failure is tracked with compact_considered.
480 */
481 unsigned int compact_considered;
482 unsigned int compact_defer_shift;
483 int compact_order_failed;
484 #endif
485
486 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
487 /* Set to true when the PG_migrate_skip bits should be cleared */
488 bool compact_blockskip_flush;
489 #endif
490
491 bool contiguous;
492
493 ZONE_PADDING(_pad3_)
494 /* Zone statistics */
495 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
496 } ____cacheline_internodealigned_in_smp;
497
498 enum pgdat_flags {
499 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by
500 * a congested BDI
501 */
502 PGDAT_DIRTY, /* reclaim scanning has recently found
503 * many dirty file pages at the tail
504 * of the LRU.
505 */
506 PGDAT_WRITEBACK, /* reclaim scanning has recently found
507 * many pages under writeback
508 */
509 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
510 };
511
zone_end_pfn(const struct zone * zone)512 static inline unsigned long zone_end_pfn(const struct zone *zone)
513 {
514 return zone->zone_start_pfn + zone->spanned_pages;
515 }
516
zone_spans_pfn(const struct zone * zone,unsigned long pfn)517 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
518 {
519 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
520 }
521
zone_is_initialized(struct zone * zone)522 static inline bool zone_is_initialized(struct zone *zone)
523 {
524 return zone->initialized;
525 }
526
zone_is_empty(struct zone * zone)527 static inline bool zone_is_empty(struct zone *zone)
528 {
529 return zone->spanned_pages == 0;
530 }
531
532 /*
533 * The "priority" of VM scanning is how much of the queues we will scan in one
534 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
535 * queues ("queue_length >> 12") during an aging round.
536 */
537 #define DEF_PRIORITY 12
538
539 /* Maximum number of zones on a zonelist */
540 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
541
542 enum {
543 ZONELIST_FALLBACK, /* zonelist with fallback */
544 #ifdef CONFIG_NUMA
545 /*
546 * The NUMA zonelists are doubled because we need zonelists that
547 * restrict the allocations to a single node for __GFP_THISNODE.
548 */
549 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
550 #endif
551 MAX_ZONELISTS
552 };
553
554 /*
555 * This struct contains information about a zone in a zonelist. It is stored
556 * here to avoid dereferences into large structures and lookups of tables
557 */
558 struct zoneref {
559 struct zone *zone; /* Pointer to actual zone */
560 int zone_idx; /* zone_idx(zoneref->zone) */
561 };
562
563 /*
564 * One allocation request operates on a zonelist. A zonelist
565 * is a list of zones, the first one is the 'goal' of the
566 * allocation, the other zones are fallback zones, in decreasing
567 * priority.
568 *
569 * To speed the reading of the zonelist, the zonerefs contain the zone index
570 * of the entry being read. Helper functions to access information given
571 * a struct zoneref are
572 *
573 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
574 * zonelist_zone_idx() - Return the index of the zone for an entry
575 * zonelist_node_idx() - Return the index of the node for an entry
576 */
577 struct zonelist {
578 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
579 };
580
581 #ifndef CONFIG_DISCONTIGMEM
582 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
583 extern struct page *mem_map;
584 #endif
585
586 /*
587 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
588 * (mostly NUMA machines?) to denote a higher-level memory zone than the
589 * zone denotes.
590 *
591 * On NUMA machines, each NUMA node would have a pg_data_t to describe
592 * it's memory layout.
593 *
594 * Memory statistics and page replacement data structures are maintained on a
595 * per-zone basis.
596 */
597 struct bootmem_data;
598 typedef struct pglist_data {
599 struct zone node_zones[MAX_NR_ZONES];
600 struct zonelist node_zonelists[MAX_ZONELISTS];
601 int nr_zones;
602 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
603 struct page *node_mem_map;
604 #ifdef CONFIG_PAGE_EXTENSION
605 struct page_ext *node_page_ext;
606 #endif
607 #endif
608 #ifndef CONFIG_NO_BOOTMEM
609 struct bootmem_data *bdata;
610 #endif
611 #ifdef CONFIG_MEMORY_HOTPLUG
612 /*
613 * Must be held any time you expect node_start_pfn, node_present_pages
614 * or node_spanned_pages stay constant. Holding this will also
615 * guarantee that any pfn_valid() stays that way.
616 *
617 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
618 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG.
619 *
620 * Nests above zone->lock and zone->span_seqlock
621 */
622 spinlock_t node_size_lock;
623 #endif
624 unsigned long node_start_pfn;
625 unsigned long node_present_pages; /* total number of physical pages */
626 unsigned long node_spanned_pages; /* total size of physical page
627 range, including holes */
628 int node_id;
629 wait_queue_head_t kswapd_wait;
630 wait_queue_head_t pfmemalloc_wait;
631 struct task_struct *kswapd; /* Protected by
632 mem_hotplug_begin/end() */
633 int kswapd_order;
634 enum zone_type kswapd_classzone_idx;
635
636 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
637
638 #ifdef CONFIG_COMPACTION
639 int kcompactd_max_order;
640 enum zone_type kcompactd_classzone_idx;
641 wait_queue_head_t kcompactd_wait;
642 struct task_struct *kcompactd;
643 #endif
644 #ifdef CONFIG_NUMA_BALANCING
645 /* Lock serializing the migrate rate limiting window */
646 spinlock_t numabalancing_migrate_lock;
647
648 /* Rate limiting time interval */
649 unsigned long numabalancing_migrate_next_window;
650
651 /* Number of pages migrated during the rate limiting time interval */
652 unsigned long numabalancing_migrate_nr_pages;
653 #endif
654 /*
655 * This is a per-node reserve of pages that are not available
656 * to userspace allocations.
657 */
658 unsigned long totalreserve_pages;
659
660 #ifdef CONFIG_NUMA
661 /*
662 * zone reclaim becomes active if more unmapped pages exist.
663 */
664 unsigned long min_unmapped_pages;
665 unsigned long min_slab_pages;
666 #endif /* CONFIG_NUMA */
667
668 /* Write-intensive fields used by page reclaim */
669 ZONE_PADDING(_pad1_)
670 spinlock_t lru_lock;
671
672 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
673 /*
674 * If memory initialisation on large machines is deferred then this
675 * is the first PFN that needs to be initialised.
676 */
677 unsigned long first_deferred_pfn;
678 /* Number of non-deferred pages */
679 unsigned long static_init_pgcnt;
680 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
681
682 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
683 spinlock_t split_queue_lock;
684 struct list_head split_queue;
685 unsigned long split_queue_len;
686 #endif
687
688 /* Fields commonly accessed by the page reclaim scanner */
689 struct lruvec lruvec;
690
691 /*
692 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
693 * this node's LRU. Maintained by the pageout code.
694 */
695 unsigned int inactive_ratio;
696
697 unsigned long flags;
698
699 ZONE_PADDING(_pad2_)
700
701 /* Per-node vmstats */
702 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
703 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
704 } pg_data_t;
705
706 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
707 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
708 #ifdef CONFIG_FLAT_NODE_MEM_MAP
709 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
710 #else
711 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
712 #endif
713 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
714
715 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
716 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
zone_lru_lock(struct zone * zone)717 static inline spinlock_t *zone_lru_lock(struct zone *zone)
718 {
719 return &zone->zone_pgdat->lru_lock;
720 }
721
node_lruvec(struct pglist_data * pgdat)722 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
723 {
724 return &pgdat->lruvec;
725 }
726
pgdat_end_pfn(pg_data_t * pgdat)727 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
728 {
729 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
730 }
731
pgdat_is_empty(pg_data_t * pgdat)732 static inline bool pgdat_is_empty(pg_data_t *pgdat)
733 {
734 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
735 }
736
zone_id(const struct zone * zone)737 static inline int zone_id(const struct zone *zone)
738 {
739 struct pglist_data *pgdat = zone->zone_pgdat;
740
741 return zone - pgdat->node_zones;
742 }
743
744 #ifdef CONFIG_ZONE_DEVICE
is_dev_zone(const struct zone * zone)745 static inline bool is_dev_zone(const struct zone *zone)
746 {
747 return zone_id(zone) == ZONE_DEVICE;
748 }
749 #else
is_dev_zone(const struct zone * zone)750 static inline bool is_dev_zone(const struct zone *zone)
751 {
752 return false;
753 }
754 #endif
755
756 #include <linux/memory_hotplug.h>
757
758 extern struct mutex zonelists_mutex;
759 void build_all_zonelists(pg_data_t *pgdat, struct zone *zone);
760 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
761 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
762 int classzone_idx, unsigned int alloc_flags,
763 long free_pages);
764 bool zone_watermark_ok(struct zone *z, unsigned int order,
765 unsigned long mark, int classzone_idx,
766 unsigned int alloc_flags);
767 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
768 unsigned long mark, int classzone_idx);
769 enum memmap_context {
770 MEMMAP_EARLY,
771 MEMMAP_HOTPLUG,
772 };
773 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
774 unsigned long size);
775
776 extern void lruvec_init(struct lruvec *lruvec);
777
lruvec_pgdat(struct lruvec * lruvec)778 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
779 {
780 #ifdef CONFIG_MEMCG
781 return lruvec->pgdat;
782 #else
783 return container_of(lruvec, struct pglist_data, lruvec);
784 #endif
785 }
786
787 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx);
788
789 #ifdef CONFIG_HAVE_MEMORY_PRESENT
790 void memory_present(int nid, unsigned long start, unsigned long end);
791 #else
memory_present(int nid,unsigned long start,unsigned long end)792 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
793 #endif
794
795 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
796 int local_memory_node(int node_id);
797 #else
local_memory_node(int node_id)798 static inline int local_memory_node(int node_id) { return node_id; };
799 #endif
800
801 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
802 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
803 #endif
804
805 /*
806 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
807 */
808 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
809
810 /*
811 * Returns true if a zone has pages managed by the buddy allocator.
812 * All the reclaim decisions have to use this function rather than
813 * populated_zone(). If the whole zone is reserved then we can easily
814 * end up with populated_zone() && !managed_zone().
815 */
managed_zone(struct zone * zone)816 static inline bool managed_zone(struct zone *zone)
817 {
818 return zone->managed_pages;
819 }
820
821 /* Returns true if a zone has memory */
populated_zone(struct zone * zone)822 static inline bool populated_zone(struct zone *zone)
823 {
824 return zone->present_pages;
825 }
826
827 extern int movable_zone;
828
829 #ifdef CONFIG_HIGHMEM
zone_movable_is_highmem(void)830 static inline int zone_movable_is_highmem(void)
831 {
832 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
833 return movable_zone == ZONE_HIGHMEM;
834 #else
835 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
836 #endif
837 }
838 #endif
839
is_highmem_idx(enum zone_type idx)840 static inline int is_highmem_idx(enum zone_type idx)
841 {
842 #ifdef CONFIG_HIGHMEM
843 return (idx == ZONE_HIGHMEM ||
844 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
845 #else
846 return 0;
847 #endif
848 }
849
850 /**
851 * is_highmem - helper function to quickly check if a struct zone is a
852 * highmem zone or not. This is an attempt to keep references
853 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
854 * @zone - pointer to struct zone variable
855 */
is_highmem(struct zone * zone)856 static inline int is_highmem(struct zone *zone)
857 {
858 #ifdef CONFIG_HIGHMEM
859 return is_highmem_idx(zone_idx(zone));
860 #else
861 return 0;
862 #endif
863 }
864
865 /* These two functions are used to setup the per zone pages min values */
866 struct ctl_table;
867 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
868 void __user *, size_t *, loff_t *);
869 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
870 void __user *, size_t *, loff_t *);
871 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
872 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
873 void __user *, size_t *, loff_t *);
874 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
875 void __user *, size_t *, loff_t *);
876 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
877 void __user *, size_t *, loff_t *);
878 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
879 void __user *, size_t *, loff_t *);
880
881 extern int numa_zonelist_order_handler(struct ctl_table *, int,
882 void __user *, size_t *, loff_t *);
883 extern char numa_zonelist_order[];
884 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
885
886 #ifndef CONFIG_NEED_MULTIPLE_NODES
887
888 extern struct pglist_data contig_page_data;
889 #define NODE_DATA(nid) (&contig_page_data)
890 #define NODE_MEM_MAP(nid) mem_map
891
892 #else /* CONFIG_NEED_MULTIPLE_NODES */
893
894 #include <asm/mmzone.h>
895
896 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
897
898 extern struct pglist_data *first_online_pgdat(void);
899 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
900 extern struct zone *next_zone(struct zone *zone);
901
902 /**
903 * for_each_online_pgdat - helper macro to iterate over all online nodes
904 * @pgdat - pointer to a pg_data_t variable
905 */
906 #define for_each_online_pgdat(pgdat) \
907 for (pgdat = first_online_pgdat(); \
908 pgdat; \
909 pgdat = next_online_pgdat(pgdat))
910 /**
911 * for_each_zone - helper macro to iterate over all memory zones
912 * @zone - pointer to struct zone variable
913 *
914 * The user only needs to declare the zone variable, for_each_zone
915 * fills it in.
916 */
917 #define for_each_zone(zone) \
918 for (zone = (first_online_pgdat())->node_zones; \
919 zone; \
920 zone = next_zone(zone))
921
922 #define for_each_populated_zone(zone) \
923 for (zone = (first_online_pgdat())->node_zones; \
924 zone; \
925 zone = next_zone(zone)) \
926 if (!populated_zone(zone)) \
927 ; /* do nothing */ \
928 else
929
zonelist_zone(struct zoneref * zoneref)930 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
931 {
932 return zoneref->zone;
933 }
934
zonelist_zone_idx(struct zoneref * zoneref)935 static inline int zonelist_zone_idx(struct zoneref *zoneref)
936 {
937 return zoneref->zone_idx;
938 }
939
zonelist_node_idx(struct zoneref * zoneref)940 static inline int zonelist_node_idx(struct zoneref *zoneref)
941 {
942 #ifdef CONFIG_NUMA
943 /* zone_to_nid not available in this context */
944 return zoneref->zone->node;
945 #else
946 return 0;
947 #endif /* CONFIG_NUMA */
948 }
949
950 struct zoneref *__next_zones_zonelist(struct zoneref *z,
951 enum zone_type highest_zoneidx,
952 nodemask_t *nodes);
953
954 /**
955 * next_zones_zonelist - Returns the next zone at or below highest_zoneidx within the allowed nodemask using a cursor within a zonelist as a starting point
956 * @z - The cursor used as a starting point for the search
957 * @highest_zoneidx - The zone index of the highest zone to return
958 * @nodes - An optional nodemask to filter the zonelist with
959 *
960 * This function returns the next zone at or below a given zone index that is
961 * within the allowed nodemask using a cursor as the starting point for the
962 * search. The zoneref returned is a cursor that represents the current zone
963 * being examined. It should be advanced by one before calling
964 * next_zones_zonelist again.
965 */
next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,nodemask_t * nodes)966 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
967 enum zone_type highest_zoneidx,
968 nodemask_t *nodes)
969 {
970 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
971 return z;
972 return __next_zones_zonelist(z, highest_zoneidx, nodes);
973 }
974
975 /**
976 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
977 * @zonelist - The zonelist to search for a suitable zone
978 * @highest_zoneidx - The zone index of the highest zone to return
979 * @nodes - An optional nodemask to filter the zonelist with
980 * @return - Zoneref pointer for the first suitable zone found (see below)
981 *
982 * This function returns the first zone at or below a given zone index that is
983 * within the allowed nodemask. The zoneref returned is a cursor that can be
984 * used to iterate the zonelist with next_zones_zonelist by advancing it by
985 * one before calling.
986 *
987 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
988 * never NULL). This may happen either genuinely, or due to concurrent nodemask
989 * update due to cpuset modification.
990 */
first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes)991 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
992 enum zone_type highest_zoneidx,
993 nodemask_t *nodes)
994 {
995 return next_zones_zonelist(zonelist->_zonerefs,
996 highest_zoneidx, nodes);
997 }
998
999 /**
1000 * for_each_zone_zonelist_nodemask - helper macro to iterate over valid zones in a zonelist at or below a given zone index and within a nodemask
1001 * @zone - The current zone in the iterator
1002 * @z - The current pointer within zonelist->zones being iterated
1003 * @zlist - The zonelist being iterated
1004 * @highidx - The zone index of the highest zone to return
1005 * @nodemask - Nodemask allowed by the allocator
1006 *
1007 * This iterator iterates though all zones at or below a given zone index and
1008 * within a given nodemask
1009 */
1010 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1011 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1012 zone; \
1013 z = next_zones_zonelist(++z, highidx, nodemask), \
1014 zone = zonelist_zone(z))
1015
1016 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1017 for (zone = z->zone; \
1018 zone; \
1019 z = next_zones_zonelist(++z, highidx, nodemask), \
1020 zone = zonelist_zone(z))
1021
1022
1023 /**
1024 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1025 * @zone - The current zone in the iterator
1026 * @z - The current pointer within zonelist->zones being iterated
1027 * @zlist - The zonelist being iterated
1028 * @highidx - The zone index of the highest zone to return
1029 *
1030 * This iterator iterates though all zones at or below a given zone index.
1031 */
1032 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1033 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1034
1035 #ifdef CONFIG_SPARSEMEM
1036 #include <asm/sparsemem.h>
1037 #endif
1038
1039 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
1040 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
early_pfn_to_nid(unsigned long pfn)1041 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
1042 {
1043 return 0;
1044 }
1045 #endif
1046
1047 #ifdef CONFIG_FLATMEM
1048 #define pfn_to_nid(pfn) (0)
1049 #endif
1050
1051 #ifdef CONFIG_SPARSEMEM
1052
1053 /*
1054 * SECTION_SHIFT #bits space required to store a section #
1055 *
1056 * PA_SECTION_SHIFT physical address to/from section number
1057 * PFN_SECTION_SHIFT pfn to/from section number
1058 */
1059 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1060 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1061
1062 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1063
1064 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1065 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1066
1067 #define SECTION_BLOCKFLAGS_BITS \
1068 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1069
1070 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1071 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1072 #endif
1073
1074 #define pfn_to_section_nr(pfn) ((pfn) >> PFN_SECTION_SHIFT)
1075 #define section_nr_to_pfn(sec) ((sec) << PFN_SECTION_SHIFT)
1076
1077 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1078 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1079
1080 struct page;
1081 struct page_ext;
1082 struct mem_section {
1083 /*
1084 * This is, logically, a pointer to an array of struct
1085 * pages. However, it is stored with some other magic.
1086 * (see sparse.c::sparse_init_one_section())
1087 *
1088 * Additionally during early boot we encode node id of
1089 * the location of the section here to guide allocation.
1090 * (see sparse.c::memory_present())
1091 *
1092 * Making it a UL at least makes someone do a cast
1093 * before using it wrong.
1094 */
1095 unsigned long section_mem_map;
1096
1097 /* See declaration of similar field in struct zone */
1098 unsigned long *pageblock_flags;
1099 #ifdef CONFIG_PAGE_EXTENSION
1100 /*
1101 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1102 * section. (see page_ext.h about this.)
1103 */
1104 struct page_ext *page_ext;
1105 unsigned long pad;
1106 #endif
1107 /*
1108 * WARNING: mem_section must be a power-of-2 in size for the
1109 * calculation and use of SECTION_ROOT_MASK to make sense.
1110 */
1111 };
1112
1113 #ifdef CONFIG_SPARSEMEM_EXTREME
1114 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1115 #else
1116 #define SECTIONS_PER_ROOT 1
1117 #endif
1118
1119 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1120 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1121 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1122
1123 #ifdef CONFIG_SPARSEMEM_EXTREME
1124 extern struct mem_section *mem_section[NR_SECTION_ROOTS];
1125 #else
1126 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1127 #endif
1128
__nr_to_section(unsigned long nr)1129 static inline struct mem_section *__nr_to_section(unsigned long nr)
1130 {
1131 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
1132 return NULL;
1133 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
1134 }
1135 extern int __section_nr(struct mem_section* ms);
1136 extern unsigned long usemap_size(void);
1137
1138 /*
1139 * We use the lower bits of the mem_map pointer to store
1140 * a little bit of information. There should be at least
1141 * 3 bits here due to 32-bit alignment.
1142 */
1143 #define SECTION_MARKED_PRESENT (1UL<<0)
1144 #define SECTION_HAS_MEM_MAP (1UL<<1)
1145 #define SECTION_MAP_LAST_BIT (1UL<<2)
1146 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1147 #define SECTION_NID_SHIFT 2
1148
__section_mem_map_addr(struct mem_section * section)1149 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1150 {
1151 unsigned long map = section->section_mem_map;
1152 map &= SECTION_MAP_MASK;
1153 return (struct page *)map;
1154 }
1155
present_section(struct mem_section * section)1156 static inline int present_section(struct mem_section *section)
1157 {
1158 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1159 }
1160
present_section_nr(unsigned long nr)1161 static inline int present_section_nr(unsigned long nr)
1162 {
1163 return present_section(__nr_to_section(nr));
1164 }
1165
valid_section(struct mem_section * section)1166 static inline int valid_section(struct mem_section *section)
1167 {
1168 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1169 }
1170
valid_section_nr(unsigned long nr)1171 static inline int valid_section_nr(unsigned long nr)
1172 {
1173 return valid_section(__nr_to_section(nr));
1174 }
1175
__pfn_to_section(unsigned long pfn)1176 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1177 {
1178 return __nr_to_section(pfn_to_section_nr(pfn));
1179 }
1180
1181 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
pfn_valid(unsigned long pfn)1182 static inline int pfn_valid(unsigned long pfn)
1183 {
1184 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1185 return 0;
1186 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1187 }
1188 #endif
1189
pfn_present(unsigned long pfn)1190 static inline int pfn_present(unsigned long pfn)
1191 {
1192 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1193 return 0;
1194 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1195 }
1196
1197 /*
1198 * These are _only_ used during initialisation, therefore they
1199 * can use __initdata ... They could have names to indicate
1200 * this restriction.
1201 */
1202 #ifdef CONFIG_NUMA
1203 #define pfn_to_nid(pfn) \
1204 ({ \
1205 unsigned long __pfn_to_nid_pfn = (pfn); \
1206 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1207 })
1208 #else
1209 #define pfn_to_nid(pfn) (0)
1210 #endif
1211
1212 #define early_pfn_valid(pfn) pfn_valid(pfn)
1213 void sparse_init(void);
1214 #else
1215 #define sparse_init() do {} while (0)
1216 #define sparse_index_init(_sec, _nid) do {} while (0)
1217 #endif /* CONFIG_SPARSEMEM */
1218
1219 /*
1220 * During memory init memblocks map pfns to nids. The search is expensive and
1221 * this caches recent lookups. The implementation of __early_pfn_to_nid
1222 * may treat start/end as pfns or sections.
1223 */
1224 struct mminit_pfnnid_cache {
1225 unsigned long last_start;
1226 unsigned long last_end;
1227 int last_nid;
1228 };
1229
1230 #ifndef early_pfn_valid
1231 #define early_pfn_valid(pfn) (1)
1232 #endif
1233
1234 void memory_present(int nid, unsigned long start, unsigned long end);
1235 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1236
1237 /*
1238 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1239 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1240 * pfn_valid_within() should be used in this case; we optimise this away
1241 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1242 */
1243 #ifdef CONFIG_HOLES_IN_ZONE
1244 #define pfn_valid_within(pfn) pfn_valid(pfn)
1245 #else
1246 #define pfn_valid_within(pfn) (1)
1247 #endif
1248
1249 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1250 /*
1251 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1252 * associated with it or not. In FLATMEM, it is expected that holes always
1253 * have valid memmap as long as there is valid PFNs either side of the hole.
1254 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1255 * entire section.
1256 *
1257 * However, an ARM, and maybe other embedded architectures in the future
1258 * free memmap backing holes to save memory on the assumption the memmap is
1259 * never used. The page_zone linkages are then broken even though pfn_valid()
1260 * returns true. A walker of the full memmap must then do this additional
1261 * check to ensure the memmap they are looking at is sane by making sure
1262 * the zone and PFN linkages are still valid. This is expensive, but walkers
1263 * of the full memmap are extremely rare.
1264 */
1265 bool memmap_valid_within(unsigned long pfn,
1266 struct page *page, struct zone *zone);
1267 #else
memmap_valid_within(unsigned long pfn,struct page * page,struct zone * zone)1268 static inline bool memmap_valid_within(unsigned long pfn,
1269 struct page *page, struct zone *zone)
1270 {
1271 return true;
1272 }
1273 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1274
1275 #endif /* !__GENERATING_BOUNDS.H */
1276 #endif /* !__ASSEMBLY__ */
1277 #endif /* _LINUX_MMZONE_H */
1278