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_RECLAIMABLE,
41 MIGRATE_MOVABLE,
42 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
43 MIGRATE_RESERVE = 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 #ifdef CONFIG_CMA
67 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
68 #else
69 # define is_migrate_cma(migratetype) false
70 #endif
71
72 #define for_each_migratetype_order(order, type) \
73 for (order = 0; order < MAX_ORDER; order++) \
74 for (type = 0; type < MIGRATE_TYPES; type++)
75
76 extern int page_group_by_mobility_disabled;
77
78 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1)
79 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1)
80
81 #define get_pageblock_migratetype(page) \
82 get_pfnblock_flags_mask(page, page_to_pfn(page), \
83 PB_migrate_end, MIGRATETYPE_MASK)
84
get_pfnblock_migratetype(struct page * page,unsigned long pfn)85 static inline int get_pfnblock_migratetype(struct page *page, unsigned long pfn)
86 {
87 BUILD_BUG_ON(PB_migrate_end - PB_migrate != 2);
88 return get_pfnblock_flags_mask(page, pfn, PB_migrate_end,
89 MIGRATETYPE_MASK);
90 }
91
92 struct free_area {
93 struct list_head free_list[MIGRATE_TYPES];
94 unsigned long nr_free;
95 };
96
97 struct pglist_data;
98
99 /*
100 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.
101 * So add a wild amount of padding here to ensure that they fall into separate
102 * cachelines. There are very few zone structures in the machine, so space
103 * consumption is not a concern here.
104 */
105 #if defined(CONFIG_SMP)
106 struct zone_padding {
107 char x[0];
108 } ____cacheline_internodealigned_in_smp;
109 #define ZONE_PADDING(name) struct zone_padding name;
110 #else
111 #define ZONE_PADDING(name)
112 #endif
113
114 enum zone_stat_item {
115 /* First 128 byte cacheline (assuming 64 bit words) */
116 NR_FREE_PAGES,
117 NR_ALLOC_BATCH,
118 NR_LRU_BASE,
119 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
120 NR_ACTIVE_ANON, /* " " " " " */
121 NR_INACTIVE_FILE, /* " " " " " */
122 NR_ACTIVE_FILE, /* " " " " " */
123 NR_UNEVICTABLE, /* " " " " " */
124 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
125 NR_ANON_PAGES, /* Mapped anonymous pages */
126 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
127 only modified from process context */
128 NR_FILE_PAGES,
129 NR_FILE_DIRTY,
130 NR_WRITEBACK,
131 NR_SLAB_RECLAIMABLE,
132 NR_SLAB_UNRECLAIMABLE,
133 NR_PAGETABLE, /* used for pagetables */
134 NR_KERNEL_STACK,
135 /* Second 128 byte cacheline */
136 NR_UNSTABLE_NFS, /* NFS unstable pages */
137 NR_BOUNCE,
138 NR_VMSCAN_WRITE,
139 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
140 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
141 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
142 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
143 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
144 NR_DIRTIED, /* page dirtyings since bootup */
145 NR_WRITTEN, /* page writings since bootup */
146 NR_PAGES_SCANNED, /* pages scanned since last reclaim */
147 #ifdef CONFIG_NUMA
148 NUMA_HIT, /* allocated in intended node */
149 NUMA_MISS, /* allocated in non intended node */
150 NUMA_FOREIGN, /* was intended here, hit elsewhere */
151 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
152 NUMA_LOCAL, /* allocation from local node */
153 NUMA_OTHER, /* allocation from other node */
154 #endif
155 WORKINGSET_REFAULT,
156 WORKINGSET_ACTIVATE,
157 WORKINGSET_NODERECLAIM,
158 NR_ANON_TRANSPARENT_HUGEPAGES,
159 NR_FREE_CMA_PAGES,
160 NR_VM_ZONE_STAT_ITEMS };
161
162 /*
163 * We do arithmetic on the LRU lists in various places in the code,
164 * so it is important to keep the active lists LRU_ACTIVE higher in
165 * the array than the corresponding inactive lists, and to keep
166 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
167 *
168 * This has to be kept in sync with the statistics in zone_stat_item
169 * above and the descriptions in vmstat_text in mm/vmstat.c
170 */
171 #define LRU_BASE 0
172 #define LRU_ACTIVE 1
173 #define LRU_FILE 2
174
175 enum lru_list {
176 LRU_INACTIVE_ANON = LRU_BASE,
177 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
178 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
179 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
180 LRU_UNEVICTABLE,
181 NR_LRU_LISTS
182 };
183
184 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
185
186 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
187
is_file_lru(enum lru_list lru)188 static inline int is_file_lru(enum lru_list lru)
189 {
190 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
191 }
192
is_active_lru(enum lru_list lru)193 static inline int is_active_lru(enum lru_list lru)
194 {
195 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
196 }
197
is_unevictable_lru(enum lru_list lru)198 static inline int is_unevictable_lru(enum lru_list lru)
199 {
200 return (lru == LRU_UNEVICTABLE);
201 }
202
203 struct zone_reclaim_stat {
204 /*
205 * The pageout code in vmscan.c keeps track of how many of the
206 * mem/swap backed and file backed pages are referenced.
207 * The higher the rotated/scanned ratio, the more valuable
208 * that cache is.
209 *
210 * The anon LRU stats live in [0], file LRU stats in [1]
211 */
212 unsigned long recent_rotated[2];
213 unsigned long recent_scanned[2];
214 };
215
216 struct lruvec {
217 struct list_head lists[NR_LRU_LISTS];
218 struct zone_reclaim_stat reclaim_stat;
219 #ifdef CONFIG_MEMCG
220 struct zone *zone;
221 #endif
222 };
223
224 /* Mask used at gathering information at once (see memcontrol.c) */
225 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
226 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
227 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
228
229 /* Isolate clean file */
230 #define ISOLATE_CLEAN ((__force isolate_mode_t)0x1)
231 /* Isolate unmapped file */
232 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
233 /* Isolate for asynchronous migration */
234 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
235 /* Isolate unevictable pages */
236 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
237
238 /* LRU Isolation modes. */
239 typedef unsigned __bitwise__ isolate_mode_t;
240
241 enum zone_watermarks {
242 WMARK_MIN,
243 WMARK_LOW,
244 WMARK_HIGH,
245 NR_WMARK
246 };
247
248 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
249 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
250 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
251
252 struct per_cpu_pages {
253 int count; /* number of pages in the list */
254 int high; /* high watermark, emptying needed */
255 int batch; /* chunk size for buddy add/remove */
256
257 /* Lists of pages, one per migrate type stored on the pcp-lists */
258 struct list_head lists[MIGRATE_PCPTYPES];
259 };
260
261 struct per_cpu_pageset {
262 struct per_cpu_pages pcp;
263 #ifdef CONFIG_NUMA
264 s8 expire;
265 #endif
266 #ifdef CONFIG_SMP
267 s8 stat_threshold;
268 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
269 #endif
270 };
271
272 #endif /* !__GENERATING_BOUNDS.H */
273
274 enum zone_type {
275 #ifdef CONFIG_ZONE_DMA
276 /*
277 * ZONE_DMA is used when there are devices that are not able
278 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
279 * carve out the portion of memory that is needed for these devices.
280 * The range is arch specific.
281 *
282 * Some examples
283 *
284 * Architecture Limit
285 * ---------------------------
286 * parisc, ia64, sparc <4G
287 * s390 <2G
288 * arm Various
289 * alpha Unlimited or 0-16MB.
290 *
291 * i386, x86_64 and multiple other arches
292 * <16M.
293 */
294 ZONE_DMA,
295 #endif
296 #ifdef CONFIG_ZONE_DMA32
297 /*
298 * x86_64 needs two ZONE_DMAs because it supports devices that are
299 * only able to do DMA to the lower 16M but also 32 bit devices that
300 * can only do DMA areas below 4G.
301 */
302 ZONE_DMA32,
303 #endif
304 /*
305 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
306 * performed on pages in ZONE_NORMAL if the DMA devices support
307 * transfers to all addressable memory.
308 */
309 ZONE_NORMAL,
310 #ifdef CONFIG_HIGHMEM
311 /*
312 * A memory area that is only addressable by the kernel through
313 * mapping portions into its own address space. This is for example
314 * used by i386 to allow the kernel to address the memory beyond
315 * 900MB. The kernel will set up special mappings (page
316 * table entries on i386) for each page that the kernel needs to
317 * access.
318 */
319 ZONE_HIGHMEM,
320 #endif
321 ZONE_MOVABLE,
322 __MAX_NR_ZONES
323 };
324
325 #ifndef __GENERATING_BOUNDS_H
326
327 struct zone {
328 /* Read-mostly fields */
329
330 /* zone watermarks, access with *_wmark_pages(zone) macros */
331 unsigned long watermark[NR_WMARK];
332
333 /*
334 * We don't know if the memory that we're going to allocate will be freeable
335 * or/and it will be released eventually, so to avoid totally wasting several
336 * GB of ram we must reserve some of the lower zone memory (otherwise we risk
337 * to run OOM on the lower zones despite there's tons of freeable ram
338 * on the higher zones). This array is recalculated at runtime if the
339 * sysctl_lowmem_reserve_ratio sysctl changes.
340 */
341 long lowmem_reserve[MAX_NR_ZONES];
342
343 #ifdef CONFIG_NUMA
344 int node;
345 #endif
346
347 /*
348 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
349 * this zone's LRU. Maintained by the pageout code.
350 */
351 unsigned int inactive_ratio;
352
353 struct pglist_data *zone_pgdat;
354 struct per_cpu_pageset __percpu *pageset;
355
356 /*
357 * This is a per-zone reserve of pages that should not be
358 * considered dirtyable memory.
359 */
360 unsigned long dirty_balance_reserve;
361
362 #ifndef CONFIG_SPARSEMEM
363 /*
364 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
365 * In SPARSEMEM, this map is stored in struct mem_section
366 */
367 unsigned long *pageblock_flags;
368 #endif /* CONFIG_SPARSEMEM */
369
370 #ifdef CONFIG_NUMA
371 /*
372 * zone reclaim becomes active if more unmapped pages exist.
373 */
374 unsigned long min_unmapped_pages;
375 unsigned long min_slab_pages;
376 #endif /* CONFIG_NUMA */
377
378 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
379 unsigned long zone_start_pfn;
380
381 /*
382 * spanned_pages is the total pages spanned by the zone, including
383 * holes, which is calculated as:
384 * spanned_pages = zone_end_pfn - zone_start_pfn;
385 *
386 * present_pages is physical pages existing within the zone, which
387 * is calculated as:
388 * present_pages = spanned_pages - absent_pages(pages in holes);
389 *
390 * managed_pages is present pages managed by the buddy system, which
391 * is calculated as (reserved_pages includes pages allocated by the
392 * bootmem allocator):
393 * managed_pages = present_pages - reserved_pages;
394 *
395 * So present_pages may be used by memory hotplug or memory power
396 * management logic to figure out unmanaged pages by checking
397 * (present_pages - managed_pages). And managed_pages should be used
398 * by page allocator and vm scanner to calculate all kinds of watermarks
399 * and thresholds.
400 *
401 * Locking rules:
402 *
403 * zone_start_pfn and spanned_pages are protected by span_seqlock.
404 * It is a seqlock because it has to be read outside of zone->lock,
405 * and it is done in the main allocator path. But, it is written
406 * quite infrequently.
407 *
408 * The span_seq lock is declared along with zone->lock because it is
409 * frequently read in proximity to zone->lock. It's good to
410 * give them a chance of being in the same cacheline.
411 *
412 * Write access to present_pages at runtime should be protected by
413 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
414 * present_pages should get_online_mems() to get a stable value.
415 *
416 * Read access to managed_pages should be safe because it's unsigned
417 * long. Write access to zone->managed_pages and totalram_pages are
418 * protected by managed_page_count_lock at runtime. Idealy only
419 * adjust_managed_page_count() should be used instead of directly
420 * touching zone->managed_pages and totalram_pages.
421 */
422 unsigned long managed_pages;
423 unsigned long spanned_pages;
424 unsigned long present_pages;
425
426 const char *name;
427
428 /*
429 * Number of MIGRATE_RESERVE page block. To maintain for just
430 * optimization. Protected by zone->lock.
431 */
432 int nr_migrate_reserve_block;
433
434 #ifdef CONFIG_MEMORY_ISOLATION
435 /*
436 * Number of isolated pageblock. It is used to solve incorrect
437 * freepage counting problem due to racy retrieving migratetype
438 * of pageblock. Protected by zone->lock.
439 */
440 unsigned long nr_isolate_pageblock;
441 #endif
442
443 #ifdef CONFIG_MEMORY_HOTPLUG
444 /* see spanned/present_pages for more description */
445 seqlock_t span_seqlock;
446 #endif
447
448 /*
449 * wait_table -- the array holding the hash table
450 * wait_table_hash_nr_entries -- the size of the hash table array
451 * wait_table_bits -- wait_table_size == (1 << wait_table_bits)
452 *
453 * The purpose of all these is to keep track of the people
454 * waiting for a page to become available and make them
455 * runnable again when possible. The trouble is that this
456 * consumes a lot of space, especially when so few things
457 * wait on pages at a given time. So instead of using
458 * per-page waitqueues, we use a waitqueue hash table.
459 *
460 * The bucket discipline is to sleep on the same queue when
461 * colliding and wake all in that wait queue when removing.
462 * When something wakes, it must check to be sure its page is
463 * truly available, a la thundering herd. The cost of a
464 * collision is great, but given the expected load of the
465 * table, they should be so rare as to be outweighed by the
466 * benefits from the saved space.
467 *
468 * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the
469 * primary users of these fields, and in mm/page_alloc.c
470 * free_area_init_core() performs the initialization of them.
471 */
472 wait_queue_head_t *wait_table;
473 unsigned long wait_table_hash_nr_entries;
474 unsigned long wait_table_bits;
475
476 ZONE_PADDING(_pad1_)
477 /* free areas of different sizes */
478 struct free_area free_area[MAX_ORDER];
479
480 /* zone flags, see below */
481 unsigned long flags;
482
483 /* Write-intensive fields used from the page allocator */
484 spinlock_t lock;
485
486 ZONE_PADDING(_pad2_)
487
488 /* Write-intensive fields used by page reclaim */
489
490 /* Fields commonly accessed by the page reclaim scanner */
491 spinlock_t lru_lock;
492 struct lruvec lruvec;
493
494 /* Evictions & activations on the inactive file list */
495 atomic_long_t inactive_age;
496
497 /*
498 * When free pages are below this point, additional steps are taken
499 * when reading the number of free pages to avoid per-cpu counter
500 * drift allowing watermarks to be breached
501 */
502 unsigned long percpu_drift_mark;
503
504 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
505 /* pfn where compaction free scanner should start */
506 unsigned long compact_cached_free_pfn;
507 /* pfn where async and sync compaction migration scanner should start */
508 unsigned long compact_cached_migrate_pfn[2];
509 #endif
510
511 #ifdef CONFIG_COMPACTION
512 /*
513 * On compaction failure, 1<<compact_defer_shift compactions
514 * are skipped before trying again. The number attempted since
515 * last failure is tracked with compact_considered.
516 */
517 unsigned int compact_considered;
518 unsigned int compact_defer_shift;
519 int compact_order_failed;
520 #endif
521
522 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
523 /* Set to true when the PG_migrate_skip bits should be cleared */
524 bool compact_blockskip_flush;
525 #endif
526
527 ZONE_PADDING(_pad3_)
528 /* Zone statistics */
529 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
530 } ____cacheline_internodealigned_in_smp;
531
532 enum zone_flags {
533 ZONE_RECLAIM_LOCKED, /* prevents concurrent reclaim */
534 ZONE_OOM_LOCKED, /* zone is in OOM killer zonelist */
535 ZONE_CONGESTED, /* zone has many dirty pages backed by
536 * a congested BDI
537 */
538 ZONE_DIRTY, /* reclaim scanning has recently found
539 * many dirty file pages at the tail
540 * of the LRU.
541 */
542 ZONE_WRITEBACK, /* reclaim scanning has recently found
543 * many pages under writeback
544 */
545 ZONE_FAIR_DEPLETED, /* fair zone policy batch depleted */
546 };
547
zone_end_pfn(const struct zone * zone)548 static inline unsigned long zone_end_pfn(const struct zone *zone)
549 {
550 return zone->zone_start_pfn + zone->spanned_pages;
551 }
552
zone_spans_pfn(const struct zone * zone,unsigned long pfn)553 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
554 {
555 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
556 }
557
zone_is_initialized(struct zone * zone)558 static inline bool zone_is_initialized(struct zone *zone)
559 {
560 return !!zone->wait_table;
561 }
562
zone_is_empty(struct zone * zone)563 static inline bool zone_is_empty(struct zone *zone)
564 {
565 return zone->spanned_pages == 0;
566 }
567
568 /*
569 * The "priority" of VM scanning is how much of the queues we will scan in one
570 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
571 * queues ("queue_length >> 12") during an aging round.
572 */
573 #define DEF_PRIORITY 12
574
575 /* Maximum number of zones on a zonelist */
576 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
577
578 #ifdef CONFIG_NUMA
579
580 /*
581 * The NUMA zonelists are doubled because we need zonelists that restrict the
582 * allocations to a single node for __GFP_THISNODE.
583 *
584 * [0] : Zonelist with fallback
585 * [1] : No fallback (__GFP_THISNODE)
586 */
587 #define MAX_ZONELISTS 2
588
589
590 /*
591 * We cache key information from each zonelist for smaller cache
592 * footprint when scanning for free pages in get_page_from_freelist().
593 *
594 * 1) The BITMAP fullzones tracks which zones in a zonelist have come
595 * up short of free memory since the last time (last_fullzone_zap)
596 * we zero'd fullzones.
597 * 2) The array z_to_n[] maps each zone in the zonelist to its node
598 * id, so that we can efficiently evaluate whether that node is
599 * set in the current tasks mems_allowed.
600 *
601 * Both fullzones and z_to_n[] are one-to-one with the zonelist,
602 * indexed by a zones offset in the zonelist zones[] array.
603 *
604 * The get_page_from_freelist() routine does two scans. During the
605 * first scan, we skip zones whose corresponding bit in 'fullzones'
606 * is set or whose corresponding node in current->mems_allowed (which
607 * comes from cpusets) is not set. During the second scan, we bypass
608 * this zonelist_cache, to ensure we look methodically at each zone.
609 *
610 * Once per second, we zero out (zap) fullzones, forcing us to
611 * reconsider nodes that might have regained more free memory.
612 * The field last_full_zap is the time we last zapped fullzones.
613 *
614 * This mechanism reduces the amount of time we waste repeatedly
615 * reexaming zones for free memory when they just came up low on
616 * memory momentarilly ago.
617 *
618 * The zonelist_cache struct members logically belong in struct
619 * zonelist. However, the mempolicy zonelists constructed for
620 * MPOL_BIND are intentionally variable length (and usually much
621 * shorter). A general purpose mechanism for handling structs with
622 * multiple variable length members is more mechanism than we want
623 * here. We resort to some special case hackery instead.
624 *
625 * The MPOL_BIND zonelists don't need this zonelist_cache (in good
626 * part because they are shorter), so we put the fixed length stuff
627 * at the front of the zonelist struct, ending in a variable length
628 * zones[], as is needed by MPOL_BIND.
629 *
630 * Then we put the optional zonelist cache on the end of the zonelist
631 * struct. This optional stuff is found by a 'zlcache_ptr' pointer in
632 * the fixed length portion at the front of the struct. This pointer
633 * both enables us to find the zonelist cache, and in the case of
634 * MPOL_BIND zonelists, (which will just set the zlcache_ptr to NULL)
635 * to know that the zonelist cache is not there.
636 *
637 * The end result is that struct zonelists come in two flavors:
638 * 1) The full, fixed length version, shown below, and
639 * 2) The custom zonelists for MPOL_BIND.
640 * The custom MPOL_BIND zonelists have a NULL zlcache_ptr and no zlcache.
641 *
642 * Even though there may be multiple CPU cores on a node modifying
643 * fullzones or last_full_zap in the same zonelist_cache at the same
644 * time, we don't lock it. This is just hint data - if it is wrong now
645 * and then, the allocator will still function, perhaps a bit slower.
646 */
647
648
649 struct zonelist_cache {
650 unsigned short z_to_n[MAX_ZONES_PER_ZONELIST]; /* zone->nid */
651 DECLARE_BITMAP(fullzones, MAX_ZONES_PER_ZONELIST); /* zone full? */
652 unsigned long last_full_zap; /* when last zap'd (jiffies) */
653 };
654 #else
655 #define MAX_ZONELISTS 1
656 struct zonelist_cache;
657 #endif
658
659 /*
660 * This struct contains information about a zone in a zonelist. It is stored
661 * here to avoid dereferences into large structures and lookups of tables
662 */
663 struct zoneref {
664 struct zone *zone; /* Pointer to actual zone */
665 int zone_idx; /* zone_idx(zoneref->zone) */
666 };
667
668 /*
669 * One allocation request operates on a zonelist. A zonelist
670 * is a list of zones, the first one is the 'goal' of the
671 * allocation, the other zones are fallback zones, in decreasing
672 * priority.
673 *
674 * If zlcache_ptr is not NULL, then it is just the address of zlcache,
675 * as explained above. If zlcache_ptr is NULL, there is no zlcache.
676 * *
677 * To speed the reading of the zonelist, the zonerefs contain the zone index
678 * of the entry being read. Helper functions to access information given
679 * a struct zoneref are
680 *
681 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
682 * zonelist_zone_idx() - Return the index of the zone for an entry
683 * zonelist_node_idx() - Return the index of the node for an entry
684 */
685 struct zonelist {
686 struct zonelist_cache *zlcache_ptr; // NULL or &zlcache
687 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
688 #ifdef CONFIG_NUMA
689 struct zonelist_cache zlcache; // optional ...
690 #endif
691 };
692
693 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
694 struct node_active_region {
695 unsigned long start_pfn;
696 unsigned long end_pfn;
697 int nid;
698 };
699 #endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
700
701 #ifndef CONFIG_DISCONTIGMEM
702 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
703 extern struct page *mem_map;
704 #endif
705
706 /*
707 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM
708 * (mostly NUMA machines?) to denote a higher-level memory zone than the
709 * zone denotes.
710 *
711 * On NUMA machines, each NUMA node would have a pg_data_t to describe
712 * it's memory layout.
713 *
714 * Memory statistics and page replacement data structures are maintained on a
715 * per-zone basis.
716 */
717 struct bootmem_data;
718 typedef struct pglist_data {
719 struct zone node_zones[MAX_NR_ZONES];
720 struct zonelist node_zonelists[MAX_ZONELISTS];
721 int nr_zones;
722 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
723 struct page *node_mem_map;
724 #ifdef CONFIG_PAGE_EXTENSION
725 struct page_ext *node_page_ext;
726 #endif
727 #endif
728 #ifndef CONFIG_NO_BOOTMEM
729 struct bootmem_data *bdata;
730 #endif
731 #ifdef CONFIG_MEMORY_HOTPLUG
732 /*
733 * Must be held any time you expect node_start_pfn, node_present_pages
734 * or node_spanned_pages stay constant. Holding this will also
735 * guarantee that any pfn_valid() stays that way.
736 *
737 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
738 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG.
739 *
740 * Nests above zone->lock and zone->span_seqlock
741 */
742 spinlock_t node_size_lock;
743 #endif
744 unsigned long node_start_pfn;
745 unsigned long node_present_pages; /* total number of physical pages */
746 unsigned long node_spanned_pages; /* total size of physical page
747 range, including holes */
748 int node_id;
749 wait_queue_head_t kswapd_wait;
750 wait_queue_head_t pfmemalloc_wait;
751 struct task_struct *kswapd; /* Protected by
752 mem_hotplug_begin/end() */
753 int kswapd_max_order;
754 enum zone_type classzone_idx;
755 #ifdef CONFIG_NUMA_BALANCING
756 /* Lock serializing the migrate rate limiting window */
757 spinlock_t numabalancing_migrate_lock;
758
759 /* Rate limiting time interval */
760 unsigned long numabalancing_migrate_next_window;
761
762 /* Number of pages migrated during the rate limiting time interval */
763 unsigned long numabalancing_migrate_nr_pages;
764 #endif
765 } pg_data_t;
766
767 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
768 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
769 #ifdef CONFIG_FLAT_NODE_MEM_MAP
770 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
771 #else
772 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
773 #endif
774 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
775
776 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
777 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
778
pgdat_end_pfn(pg_data_t * pgdat)779 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
780 {
781 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
782 }
783
pgdat_is_empty(pg_data_t * pgdat)784 static inline bool pgdat_is_empty(pg_data_t *pgdat)
785 {
786 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
787 }
788
789 #include <linux/memory_hotplug.h>
790
791 extern struct mutex zonelists_mutex;
792 void build_all_zonelists(pg_data_t *pgdat, struct zone *zone);
793 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
794 bool zone_watermark_ok(struct zone *z, unsigned int order,
795 unsigned long mark, int classzone_idx, int alloc_flags);
796 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
797 unsigned long mark, int classzone_idx, int alloc_flags);
798 enum memmap_context {
799 MEMMAP_EARLY,
800 MEMMAP_HOTPLUG,
801 };
802 extern int init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
803 unsigned long size,
804 enum memmap_context context);
805
806 extern void lruvec_init(struct lruvec *lruvec);
807
lruvec_zone(struct lruvec * lruvec)808 static inline struct zone *lruvec_zone(struct lruvec *lruvec)
809 {
810 #ifdef CONFIG_MEMCG
811 return lruvec->zone;
812 #else
813 return container_of(lruvec, struct zone, lruvec);
814 #endif
815 }
816
817 #ifdef CONFIG_HAVE_MEMORY_PRESENT
818 void memory_present(int nid, unsigned long start, unsigned long end);
819 #else
memory_present(int nid,unsigned long start,unsigned long end)820 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
821 #endif
822
823 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
824 int local_memory_node(int node_id);
825 #else
local_memory_node(int node_id)826 static inline int local_memory_node(int node_id) { return node_id; };
827 #endif
828
829 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
830 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
831 #endif
832
833 /*
834 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
835 */
836 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
837
populated_zone(struct zone * zone)838 static inline int populated_zone(struct zone *zone)
839 {
840 return (!!zone->present_pages);
841 }
842
843 extern int movable_zone;
844
845 #ifdef CONFIG_HIGHMEM
zone_movable_is_highmem(void)846 static inline int zone_movable_is_highmem(void)
847 {
848 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
849 return movable_zone == ZONE_HIGHMEM;
850 #else
851 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
852 #endif
853 }
854 #endif
855
is_highmem_idx(enum zone_type idx)856 static inline int is_highmem_idx(enum zone_type idx)
857 {
858 #ifdef CONFIG_HIGHMEM
859 return (idx == ZONE_HIGHMEM ||
860 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
861 #else
862 return 0;
863 #endif
864 }
865
866 /**
867 * is_highmem - helper function to quickly check if a struct zone is a
868 * highmem zone or not. This is an attempt to keep references
869 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
870 * @zone - pointer to struct zone variable
871 */
is_highmem(struct zone * zone)872 static inline int is_highmem(struct zone *zone)
873 {
874 #ifdef CONFIG_HIGHMEM
875 int zone_off = (char *)zone - (char *)zone->zone_pgdat->node_zones;
876 return zone_off == ZONE_HIGHMEM * sizeof(*zone) ||
877 (zone_off == ZONE_MOVABLE * sizeof(*zone) &&
878 zone_movable_is_highmem());
879 #else
880 return 0;
881 #endif
882 }
883
884 /* These two functions are used to setup the per zone pages min values */
885 struct ctl_table;
886 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
887 void __user *, size_t *, loff_t *);
888 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
889 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
890 void __user *, size_t *, loff_t *);
891 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
892 void __user *, size_t *, loff_t *);
893 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
894 void __user *, size_t *, loff_t *);
895 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
896 void __user *, size_t *, loff_t *);
897
898 extern int numa_zonelist_order_handler(struct ctl_table *, int,
899 void __user *, size_t *, loff_t *);
900 extern char numa_zonelist_order[];
901 #define NUMA_ZONELIST_ORDER_LEN 16 /* string buffer size */
902
903 #ifndef CONFIG_NEED_MULTIPLE_NODES
904
905 extern struct pglist_data contig_page_data;
906 #define NODE_DATA(nid) (&contig_page_data)
907 #define NODE_MEM_MAP(nid) mem_map
908
909 #else /* CONFIG_NEED_MULTIPLE_NODES */
910
911 #include <asm/mmzone.h>
912
913 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
914
915 extern struct pglist_data *first_online_pgdat(void);
916 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
917 extern struct zone *next_zone(struct zone *zone);
918
919 /**
920 * for_each_online_pgdat - helper macro to iterate over all online nodes
921 * @pgdat - pointer to a pg_data_t variable
922 */
923 #define for_each_online_pgdat(pgdat) \
924 for (pgdat = first_online_pgdat(); \
925 pgdat; \
926 pgdat = next_online_pgdat(pgdat))
927 /**
928 * for_each_zone - helper macro to iterate over all memory zones
929 * @zone - pointer to struct zone variable
930 *
931 * The user only needs to declare the zone variable, for_each_zone
932 * fills it in.
933 */
934 #define for_each_zone(zone) \
935 for (zone = (first_online_pgdat())->node_zones; \
936 zone; \
937 zone = next_zone(zone))
938
939 #define for_each_populated_zone(zone) \
940 for (zone = (first_online_pgdat())->node_zones; \
941 zone; \
942 zone = next_zone(zone)) \
943 if (!populated_zone(zone)) \
944 ; /* do nothing */ \
945 else
946
zonelist_zone(struct zoneref * zoneref)947 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
948 {
949 return zoneref->zone;
950 }
951
zonelist_zone_idx(struct zoneref * zoneref)952 static inline int zonelist_zone_idx(struct zoneref *zoneref)
953 {
954 return zoneref->zone_idx;
955 }
956
zonelist_node_idx(struct zoneref * zoneref)957 static inline int zonelist_node_idx(struct zoneref *zoneref)
958 {
959 #ifdef CONFIG_NUMA
960 /* zone_to_nid not available in this context */
961 return zoneref->zone->node;
962 #else
963 return 0;
964 #endif /* CONFIG_NUMA */
965 }
966
967 /**
968 * 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
969 * @z - The cursor used as a starting point for the search
970 * @highest_zoneidx - The zone index of the highest zone to return
971 * @nodes - An optional nodemask to filter the zonelist with
972 *
973 * This function returns the next zone at or below a given zone index that is
974 * within the allowed nodemask using a cursor as the starting point for the
975 * search. The zoneref returned is a cursor that represents the current zone
976 * being examined. It should be advanced by one before calling
977 * next_zones_zonelist again.
978 */
979 struct zoneref *next_zones_zonelist(struct zoneref *z,
980 enum zone_type highest_zoneidx,
981 nodemask_t *nodes);
982
983 /**
984 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
985 * @zonelist - The zonelist to search for a suitable zone
986 * @highest_zoneidx - The zone index of the highest zone to return
987 * @nodes - An optional nodemask to filter the zonelist with
988 * @zone - The first suitable zone found is returned via this parameter
989 *
990 * This function returns the first zone at or below a given zone index that is
991 * within the allowed nodemask. The zoneref returned is a cursor that can be
992 * used to iterate the zonelist with next_zones_zonelist by advancing it by
993 * one before calling.
994 */
first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes,struct zone ** zone)995 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
996 enum zone_type highest_zoneidx,
997 nodemask_t *nodes,
998 struct zone **zone)
999 {
1000 struct zoneref *z = next_zones_zonelist(zonelist->_zonerefs,
1001 highest_zoneidx, nodes);
1002 *zone = zonelist_zone(z);
1003 return z;
1004 }
1005
1006 /**
1007 * 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
1008 * @zone - The current zone in the iterator
1009 * @z - The current pointer within zonelist->zones being iterated
1010 * @zlist - The zonelist being iterated
1011 * @highidx - The zone index of the highest zone to return
1012 * @nodemask - Nodemask allowed by the allocator
1013 *
1014 * This iterator iterates though all zones at or below a given zone index and
1015 * within a given nodemask
1016 */
1017 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1018 for (z = first_zones_zonelist(zlist, highidx, nodemask, &zone); \
1019 zone; \
1020 z = next_zones_zonelist(++z, highidx, nodemask), \
1021 zone = zonelist_zone(z)) \
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 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
1220 bool early_pfn_in_nid(unsigned long pfn, int nid);
1221 #else
1222 #define early_pfn_in_nid(pfn, nid) (1)
1223 #endif
1224
1225 #ifndef early_pfn_valid
1226 #define early_pfn_valid(pfn) (1)
1227 #endif
1228
1229 void memory_present(int nid, unsigned long start, unsigned long end);
1230 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1231
1232 /*
1233 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1234 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1235 * pfn_valid_within() should be used in this case; we optimise this away
1236 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1237 */
1238 #ifdef CONFIG_HOLES_IN_ZONE
1239 #define pfn_valid_within(pfn) pfn_valid(pfn)
1240 #else
1241 #define pfn_valid_within(pfn) (1)
1242 #endif
1243
1244 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1245 /*
1246 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1247 * associated with it or not. In FLATMEM, it is expected that holes always
1248 * have valid memmap as long as there is valid PFNs either side of the hole.
1249 * In SPARSEMEM, it is assumed that a valid section has a memmap for the
1250 * entire section.
1251 *
1252 * However, an ARM, and maybe other embedded architectures in the future
1253 * free memmap backing holes to save memory on the assumption the memmap is
1254 * never used. The page_zone linkages are then broken even though pfn_valid()
1255 * returns true. A walker of the full memmap must then do this additional
1256 * check to ensure the memmap they are looking at is sane by making sure
1257 * the zone and PFN linkages are still valid. This is expensive, but walkers
1258 * of the full memmap are extremely rare.
1259 */
1260 int memmap_valid_within(unsigned long pfn,
1261 struct page *page, struct zone *zone);
1262 #else
memmap_valid_within(unsigned long pfn,struct page * page,struct zone * zone)1263 static inline int memmap_valid_within(unsigned long pfn,
1264 struct page *page, struct zone *zone)
1265 {
1266 return 1;
1267 }
1268 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1269
1270 #endif /* !__GENERATING_BOUNDS.H */
1271 #endif /* !__ASSEMBLY__ */
1272 #endif /* _LINUX_MMZONE_H */
1273