1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _LINUX_MMZONE_H
3 #define _LINUX_MMZONE_H
4
5 #ifndef __ASSEMBLY__
6 #ifndef __GENERATING_BOUNDS_H
7
8 #include <linux/spinlock.h>
9 #include <linux/list.h>
10 #include <linux/wait.h>
11 #include <linux/bitops.h>
12 #include <linux/cache.h>
13 #include <linux/threads.h>
14 #include <linux/numa.h>
15 #include <linux/init.h>
16 #include <linux/seqlock.h>
17 #include <linux/nodemask.h>
18 #include <linux/pageblock-flags.h>
19 #include <linux/page-flags-layout.h>
20 #include <linux/atomic.h>
21 #include <asm/page.h>
22
23 /* Free memory management - zoned buddy allocator. */
24 #ifndef CONFIG_FORCE_MAX_ZONEORDER
25 #define MAX_ORDER 11
26 #else
27 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER
28 #endif
29 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1))
30
31 /*
32 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
33 * costly to service. That is between allocation orders which should
34 * coalesce naturally under reasonable reclaim pressure and those which
35 * will not.
36 */
37 #define PAGE_ALLOC_COSTLY_ORDER 3
38
39 enum migratetype {
40 MIGRATE_UNMOVABLE,
41 MIGRATE_MOVABLE,
42 MIGRATE_RECLAIMABLE,
43 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */
44 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES,
45 #ifdef CONFIG_CMA
46 /*
47 * MIGRATE_CMA migration type is designed to mimic the way
48 * ZONE_MOVABLE works. Only movable pages can be allocated
49 * from MIGRATE_CMA pageblocks and page allocator never
50 * implicitly change migration type of MIGRATE_CMA pageblock.
51 *
52 * The way to use it is to change migratetype of a range of
53 * pageblocks to MIGRATE_CMA which can be done by
54 * __free_pageblock_cma() function. What is important though
55 * is that a range of pageblocks must be aligned to
56 * MAX_ORDER_NR_PAGES should biggest page be bigger then
57 * a single pageblock.
58 */
59 MIGRATE_CMA,
60 #endif
61 #ifdef CONFIG_MEMORY_ISOLATION
62 MIGRATE_ISOLATE, /* can't allocate from here */
63 #endif
64 MIGRATE_TYPES
65 };
66
67 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
68 extern char * const migratetype_names[MIGRATE_TYPES];
69
70 #ifdef CONFIG_CMA
71 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA)
72 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA)
73 #else
74 # define is_migrate_cma(migratetype) false
75 # define is_migrate_cma_page(_page) false
76 #endif
77
is_migrate_movable(int mt)78 static inline bool is_migrate_movable(int mt)
79 {
80 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE;
81 }
82
83 #define for_each_migratetype_order(order, type) \
84 for (order = 0; order < MAX_ORDER; order++) \
85 for (type = 0; type < MIGRATE_TYPES; type++)
86
87 extern int page_group_by_mobility_disabled;
88
89 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1)
90 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1)
91
92 #define get_pageblock_migratetype(page) \
93 get_pfnblock_flags_mask(page, page_to_pfn(page), \
94 PB_migrate_end, MIGRATETYPE_MASK)
95
96 struct free_area {
97 struct list_head free_list[MIGRATE_TYPES];
98 unsigned long nr_free;
99 };
100
101 struct pglist_data;
102
103 /*
104 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel.
105 * So add a wild amount of padding here to ensure that they fall into separate
106 * cachelines. There are very few zone structures in the machine, so space
107 * consumption is not a concern here.
108 */
109 #if defined(CONFIG_SMP)
110 struct zone_padding {
111 char x[0];
112 } ____cacheline_internodealigned_in_smp;
113 #define ZONE_PADDING(name) struct zone_padding name;
114 #else
115 #define ZONE_PADDING(name)
116 #endif
117
118 #ifdef CONFIG_NUMA
119 enum numa_stat_item {
120 NUMA_HIT, /* allocated in intended node */
121 NUMA_MISS, /* allocated in non intended node */
122 NUMA_FOREIGN, /* was intended here, hit elsewhere */
123 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */
124 NUMA_LOCAL, /* allocation from local node */
125 NUMA_OTHER, /* allocation from other node */
126 NR_VM_NUMA_STAT_ITEMS
127 };
128 #else
129 #define NR_VM_NUMA_STAT_ITEMS 0
130 #endif
131
132 enum zone_stat_item {
133 /* First 128 byte cacheline (assuming 64 bit words) */
134 NR_FREE_PAGES,
135 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */
136 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE,
137 NR_ZONE_ACTIVE_ANON,
138 NR_ZONE_INACTIVE_FILE,
139 NR_ZONE_ACTIVE_FILE,
140 NR_ZONE_UNEVICTABLE,
141 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */
142 NR_MLOCK, /* mlock()ed pages found and moved off LRU */
143 NR_PAGETABLE, /* used for pagetables */
144 NR_KERNEL_STACK_KB, /* measured in KiB */
145 /* Second 128 byte cacheline */
146 NR_BOUNCE,
147 #if IS_ENABLED(CONFIG_ZSMALLOC)
148 NR_ZSPAGES, /* allocated in zsmalloc */
149 #endif
150 NR_FREE_CMA_PAGES,
151 NR_VM_ZONE_STAT_ITEMS };
152
153 enum node_stat_item {
154 NR_LRU_BASE,
155 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */
156 NR_ACTIVE_ANON, /* " " " " " */
157 NR_INACTIVE_FILE, /* " " " " " */
158 NR_ACTIVE_FILE, /* " " " " " */
159 NR_UNEVICTABLE, /* " " " " " */
160 NR_SLAB_RECLAIMABLE,
161 NR_SLAB_UNRECLAIMABLE,
162 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */
163 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */
164 WORKINGSET_REFAULT,
165 WORKINGSET_ACTIVATE,
166 WORKINGSET_RESTORE,
167 WORKINGSET_NODERECLAIM,
168 NR_ANON_MAPPED, /* Mapped anonymous pages */
169 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
170 only modified from process context */
171 NR_FILE_PAGES,
172 NR_FILE_DIRTY,
173 NR_WRITEBACK,
174 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */
175 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */
176 NR_SHMEM_THPS,
177 NR_SHMEM_PMDMAPPED,
178 NR_ANON_THPS,
179 NR_UNSTABLE_NFS, /* NFS unstable pages */
180 NR_VMSCAN_WRITE,
181 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */
182 NR_DIRTIED, /* page dirtyings since bootup */
183 NR_WRITTEN, /* page writings since bootup */
184 NR_INDIRECTLY_RECLAIMABLE_BYTES, /* measured in bytes */
185 NR_VM_NODE_STAT_ITEMS
186 };
187
188 /*
189 * We do arithmetic on the LRU lists in various places in the code,
190 * so it is important to keep the active lists LRU_ACTIVE higher in
191 * the array than the corresponding inactive lists, and to keep
192 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
193 *
194 * This has to be kept in sync with the statistics in zone_stat_item
195 * above and the descriptions in vmstat_text in mm/vmstat.c
196 */
197 #define LRU_BASE 0
198 #define LRU_ACTIVE 1
199 #define LRU_FILE 2
200
201 enum lru_list {
202 LRU_INACTIVE_ANON = LRU_BASE,
203 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
204 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
205 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
206 LRU_UNEVICTABLE,
207 NR_LRU_LISTS
208 };
209
210 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
211
212 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
213
is_file_lru(enum lru_list lru)214 static inline int is_file_lru(enum lru_list lru)
215 {
216 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
217 }
218
is_active_lru(enum lru_list lru)219 static inline int is_active_lru(enum lru_list lru)
220 {
221 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
222 }
223
224 struct zone_reclaim_stat {
225 /*
226 * The pageout code in vmscan.c keeps track of how many of the
227 * mem/swap backed and file backed pages are referenced.
228 * The higher the rotated/scanned ratio, the more valuable
229 * that cache is.
230 *
231 * The anon LRU stats live in [0], file LRU stats in [1]
232 */
233 unsigned long recent_rotated[2];
234 unsigned long recent_scanned[2];
235 };
236
237 struct lruvec {
238 struct list_head lists[NR_LRU_LISTS];
239 struct zone_reclaim_stat reclaim_stat;
240 /* Evictions & activations on the inactive file list */
241 atomic_long_t inactive_age;
242 /* Refaults at the time of last reclaim cycle */
243 unsigned long refaults;
244 #ifdef CONFIG_MEMCG
245 struct pglist_data *pgdat;
246 #endif
247 };
248
249 /* Mask used at gathering information at once (see memcontrol.c) */
250 #define LRU_ALL_FILE (BIT(LRU_INACTIVE_FILE) | BIT(LRU_ACTIVE_FILE))
251 #define LRU_ALL_ANON (BIT(LRU_INACTIVE_ANON) | BIT(LRU_ACTIVE_ANON))
252 #define LRU_ALL ((1 << NR_LRU_LISTS) - 1)
253
254 /* Isolate unmapped file */
255 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2)
256 /* Isolate for asynchronous migration */
257 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4)
258 /* Isolate unevictable pages */
259 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8)
260
261 /* LRU Isolation modes. */
262 typedef unsigned __bitwise isolate_mode_t;
263
264 enum zone_watermarks {
265 WMARK_MIN,
266 WMARK_LOW,
267 WMARK_HIGH,
268 NR_WMARK
269 };
270
271 #define min_wmark_pages(z) (z->watermark[WMARK_MIN])
272 #define low_wmark_pages(z) (z->watermark[WMARK_LOW])
273 #define high_wmark_pages(z) (z->watermark[WMARK_HIGH])
274
275 struct per_cpu_pages {
276 int count; /* number of pages in the list */
277 int high; /* high watermark, emptying needed */
278 int batch; /* chunk size for buddy add/remove */
279
280 /* Lists of pages, one per migrate type stored on the pcp-lists */
281 struct list_head lists[MIGRATE_PCPTYPES];
282 };
283
284 struct per_cpu_pageset {
285 struct per_cpu_pages pcp;
286 #ifdef CONFIG_NUMA
287 s8 expire;
288 u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS];
289 #endif
290 #ifdef CONFIG_SMP
291 s8 stat_threshold;
292 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
293 #endif
294 };
295
296 struct per_cpu_nodestat {
297 s8 stat_threshold;
298 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
299 };
300
301 #endif /* !__GENERATING_BOUNDS.H */
302
303 enum zone_type {
304 #ifdef CONFIG_ZONE_DMA
305 /*
306 * ZONE_DMA is used when there are devices that are not able
307 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we
308 * carve out the portion of memory that is needed for these devices.
309 * The range is arch specific.
310 *
311 * Some examples
312 *
313 * Architecture Limit
314 * ---------------------------
315 * parisc, ia64, sparc <4G
316 * s390 <2G
317 * arm Various
318 * alpha Unlimited or 0-16MB.
319 *
320 * i386, x86_64 and multiple other arches
321 * <16M.
322 */
323 ZONE_DMA,
324 #endif
325 #ifdef CONFIG_ZONE_DMA32
326 /*
327 * x86_64 needs two ZONE_DMAs because it supports devices that are
328 * only able to do DMA to the lower 16M but also 32 bit devices that
329 * can only do DMA areas below 4G.
330 */
331 ZONE_DMA32,
332 #endif
333 /*
334 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
335 * performed on pages in ZONE_NORMAL if the DMA devices support
336 * transfers to all addressable memory.
337 */
338 ZONE_NORMAL,
339 #ifdef CONFIG_HIGHMEM
340 /*
341 * A memory area that is only addressable by the kernel through
342 * mapping portions into its own address space. This is for example
343 * used by i386 to allow the kernel to address the memory beyond
344 * 900MB. The kernel will set up special mappings (page
345 * table entries on i386) for each page that the kernel needs to
346 * access.
347 */
348 ZONE_HIGHMEM,
349 #endif
350 ZONE_MOVABLE,
351 #ifdef CONFIG_ZONE_DEVICE
352 ZONE_DEVICE,
353 #endif
354 __MAX_NR_ZONES
355
356 };
357
358 #ifndef __GENERATING_BOUNDS_H
359
360 struct zone {
361 /* Read-mostly fields */
362
363 /* zone watermarks, access with *_wmark_pages(zone) macros */
364 unsigned long watermark[NR_WMARK];
365
366 unsigned long nr_reserved_highatomic;
367
368 /*
369 * We don't know if the memory that we're going to allocate will be
370 * freeable or/and it will be released eventually, so to avoid totally
371 * wasting several GB of ram we must reserve some of the lower zone
372 * memory (otherwise we risk to run OOM on the lower zones despite
373 * there being tons of freeable ram on the higher zones). This array is
374 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
375 * changes.
376 */
377 long lowmem_reserve[MAX_NR_ZONES];
378
379 #ifdef CONFIG_NUMA
380 int node;
381 #endif
382 struct pglist_data *zone_pgdat;
383 struct per_cpu_pageset __percpu *pageset;
384
385 #ifndef CONFIG_SPARSEMEM
386 /*
387 * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
388 * In SPARSEMEM, this map is stored in struct mem_section
389 */
390 unsigned long *pageblock_flags;
391 #endif /* CONFIG_SPARSEMEM */
392
393 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
394 unsigned long zone_start_pfn;
395
396 /*
397 * spanned_pages is the total pages spanned by the zone, including
398 * holes, which is calculated as:
399 * spanned_pages = zone_end_pfn - zone_start_pfn;
400 *
401 * present_pages is physical pages existing within the zone, which
402 * is calculated as:
403 * present_pages = spanned_pages - absent_pages(pages in holes);
404 *
405 * managed_pages is present pages managed by the buddy system, which
406 * is calculated as (reserved_pages includes pages allocated by the
407 * bootmem allocator):
408 * managed_pages = present_pages - reserved_pages;
409 *
410 * So present_pages may be used by memory hotplug or memory power
411 * management logic to figure out unmanaged pages by checking
412 * (present_pages - managed_pages). And managed_pages should be used
413 * by page allocator and vm scanner to calculate all kinds of watermarks
414 * and thresholds.
415 *
416 * Locking rules:
417 *
418 * zone_start_pfn and spanned_pages are protected by span_seqlock.
419 * It is a seqlock because it has to be read outside of zone->lock,
420 * and it is done in the main allocator path. But, it is written
421 * quite infrequently.
422 *
423 * The span_seq lock is declared along with zone->lock because it is
424 * frequently read in proximity to zone->lock. It's good to
425 * give them a chance of being in the same cacheline.
426 *
427 * Write access to present_pages at runtime should be protected by
428 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
429 * present_pages should get_online_mems() to get a stable value.
430 *
431 * Read access to managed_pages should be safe because it's unsigned
432 * long. Write access to zone->managed_pages and totalram_pages are
433 * protected by managed_page_count_lock at runtime. Idealy only
434 * adjust_managed_page_count() should be used instead of directly
435 * touching zone->managed_pages and totalram_pages.
436 */
437 unsigned long managed_pages;
438 unsigned long spanned_pages;
439 unsigned long present_pages;
440
441 const char *name;
442
443 #ifdef CONFIG_MEMORY_ISOLATION
444 /*
445 * Number of isolated pageblock. It is used to solve incorrect
446 * freepage counting problem due to racy retrieving migratetype
447 * of pageblock. Protected by zone->lock.
448 */
449 unsigned long nr_isolate_pageblock;
450 #endif
451
452 #ifdef CONFIG_MEMORY_HOTPLUG
453 /* see spanned/present_pages for more description */
454 seqlock_t span_seqlock;
455 #endif
456
457 int initialized;
458
459 /* Write-intensive fields used from the page allocator */
460 ZONE_PADDING(_pad1_)
461
462 /* free areas of different sizes */
463 struct free_area free_area[MAX_ORDER];
464
465 /* zone flags, see below */
466 unsigned long flags;
467
468 /* Primarily protects free_area */
469 spinlock_t lock;
470
471 /* Write-intensive fields used by compaction and vmstats. */
472 ZONE_PADDING(_pad2_)
473
474 /*
475 * When free pages are below this point, additional steps are taken
476 * when reading the number of free pages to avoid per-cpu counter
477 * drift allowing watermarks to be breached
478 */
479 unsigned long percpu_drift_mark;
480
481 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
482 /* pfn where compaction free scanner should start */
483 unsigned long compact_cached_free_pfn;
484 /* pfn where async and sync compaction migration scanner should start */
485 unsigned long compact_cached_migrate_pfn[2];
486 #endif
487
488 #ifdef CONFIG_COMPACTION
489 /*
490 * On compaction failure, 1<<compact_defer_shift compactions
491 * are skipped before trying again. The number attempted since
492 * last failure is tracked with compact_considered.
493 */
494 unsigned int compact_considered;
495 unsigned int compact_defer_shift;
496 int compact_order_failed;
497 #endif
498
499 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
500 /* Set to true when the PG_migrate_skip bits should be cleared */
501 bool compact_blockskip_flush;
502 #endif
503
504 bool contiguous;
505
506 ZONE_PADDING(_pad3_)
507 /* Zone statistics */
508 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS];
509 atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS];
510 } ____cacheline_internodealigned_in_smp;
511
512 enum pgdat_flags {
513 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by
514 * a congested BDI
515 */
516 PGDAT_DIRTY, /* reclaim scanning has recently found
517 * many dirty file pages at the tail
518 * of the LRU.
519 */
520 PGDAT_WRITEBACK, /* reclaim scanning has recently found
521 * many pages under writeback
522 */
523 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */
524 };
525
zone_end_pfn(const struct zone * zone)526 static inline unsigned long zone_end_pfn(const struct zone *zone)
527 {
528 return zone->zone_start_pfn + zone->spanned_pages;
529 }
530
zone_spans_pfn(const struct zone * zone,unsigned long pfn)531 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
532 {
533 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
534 }
535
zone_is_initialized(struct zone * zone)536 static inline bool zone_is_initialized(struct zone *zone)
537 {
538 return zone->initialized;
539 }
540
zone_is_empty(struct zone * zone)541 static inline bool zone_is_empty(struct zone *zone)
542 {
543 return zone->spanned_pages == 0;
544 }
545
546 /*
547 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
548 * intersection with the given zone
549 */
zone_intersects(struct zone * zone,unsigned long start_pfn,unsigned long nr_pages)550 static inline bool zone_intersects(struct zone *zone,
551 unsigned long start_pfn, unsigned long nr_pages)
552 {
553 if (zone_is_empty(zone))
554 return false;
555 if (start_pfn >= zone_end_pfn(zone) ||
556 start_pfn + nr_pages <= zone->zone_start_pfn)
557 return false;
558
559 return true;
560 }
561
562 /*
563 * The "priority" of VM scanning is how much of the queues we will scan in one
564 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
565 * queues ("queue_length >> 12") during an aging round.
566 */
567 #define DEF_PRIORITY 12
568
569 /* Maximum number of zones on a zonelist */
570 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
571
572 enum {
573 ZONELIST_FALLBACK, /* zonelist with fallback */
574 #ifdef CONFIG_NUMA
575 /*
576 * The NUMA zonelists are doubled because we need zonelists that
577 * restrict the allocations to a single node for __GFP_THISNODE.
578 */
579 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */
580 #endif
581 MAX_ZONELISTS
582 };
583
584 /*
585 * This struct contains information about a zone in a zonelist. It is stored
586 * here to avoid dereferences into large structures and lookups of tables
587 */
588 struct zoneref {
589 struct zone *zone; /* Pointer to actual zone */
590 int zone_idx; /* zone_idx(zoneref->zone) */
591 };
592
593 /*
594 * One allocation request operates on a zonelist. A zonelist
595 * is a list of zones, the first one is the 'goal' of the
596 * allocation, the other zones are fallback zones, in decreasing
597 * priority.
598 *
599 * To speed the reading of the zonelist, the zonerefs contain the zone index
600 * of the entry being read. Helper functions to access information given
601 * a struct zoneref are
602 *
603 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs
604 * zonelist_zone_idx() - Return the index of the zone for an entry
605 * zonelist_node_idx() - Return the index of the node for an entry
606 */
607 struct zonelist {
608 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
609 };
610
611 #ifndef CONFIG_DISCONTIGMEM
612 /* The array of struct pages - for discontigmem use pgdat->lmem_map */
613 extern struct page *mem_map;
614 #endif
615
616 /*
617 * On NUMA machines, each NUMA node would have a pg_data_t to describe
618 * it's memory layout. On UMA machines there is a single pglist_data which
619 * describes the whole memory.
620 *
621 * Memory statistics and page replacement data structures are maintained on a
622 * per-zone basis.
623 */
624 struct bootmem_data;
625 typedef struct pglist_data {
626 struct zone node_zones[MAX_NR_ZONES];
627 struct zonelist node_zonelists[MAX_ZONELISTS];
628 int nr_zones;
629 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
630 struct page *node_mem_map;
631 #ifdef CONFIG_PAGE_EXTENSION
632 struct page_ext *node_page_ext;
633 #endif
634 #endif
635 #ifndef CONFIG_NO_BOOTMEM
636 struct bootmem_data *bdata;
637 #endif
638 #ifdef CONFIG_MEMORY_HOTPLUG
639 /*
640 * Must be held any time you expect node_start_pfn, node_present_pages
641 * or node_spanned_pages stay constant. Holding this will also
642 * guarantee that any pfn_valid() stays that way.
643 *
644 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
645 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG.
646 *
647 * Nests above zone->lock and zone->span_seqlock
648 */
649 spinlock_t node_size_lock;
650 #endif
651 unsigned long node_start_pfn;
652 unsigned long node_present_pages; /* total number of physical pages */
653 unsigned long node_spanned_pages; /* total size of physical page
654 range, including holes */
655 int node_id;
656 wait_queue_head_t kswapd_wait;
657 wait_queue_head_t pfmemalloc_wait;
658 struct task_struct *kswapd; /* Protected by
659 mem_hotplug_begin/end() */
660 int kswapd_order;
661 enum zone_type kswapd_classzone_idx;
662
663 int kswapd_failures; /* Number of 'reclaimed == 0' runs */
664
665 #ifdef CONFIG_COMPACTION
666 int kcompactd_max_order;
667 enum zone_type kcompactd_classzone_idx;
668 wait_queue_head_t kcompactd_wait;
669 struct task_struct *kcompactd;
670 #endif
671 #ifdef CONFIG_NUMA_BALANCING
672 /* Lock serializing the migrate rate limiting window */
673 spinlock_t numabalancing_migrate_lock;
674
675 /* Rate limiting time interval */
676 unsigned long numabalancing_migrate_next_window;
677
678 /* Number of pages migrated during the rate limiting time interval */
679 unsigned long numabalancing_migrate_nr_pages;
680 #endif
681 /*
682 * This is a per-node reserve of pages that are not available
683 * to userspace allocations.
684 */
685 unsigned long totalreserve_pages;
686
687 #ifdef CONFIG_NUMA
688 /*
689 * zone reclaim becomes active if more unmapped pages exist.
690 */
691 unsigned long min_unmapped_pages;
692 unsigned long min_slab_pages;
693 #endif /* CONFIG_NUMA */
694
695 /* Write-intensive fields used by page reclaim */
696 ZONE_PADDING(_pad1_)
697 spinlock_t lru_lock;
698
699 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
700 /*
701 * If memory initialisation on large machines is deferred then this
702 * is the first PFN that needs to be initialised.
703 */
704 unsigned long first_deferred_pfn;
705 /* Number of non-deferred pages */
706 unsigned long static_init_pgcnt;
707 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
708
709 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
710 spinlock_t split_queue_lock;
711 struct list_head split_queue;
712 unsigned long split_queue_len;
713 #endif
714
715 /* Fields commonly accessed by the page reclaim scanner */
716 struct lruvec lruvec;
717
718 /*
719 * The target ratio of ACTIVE_ANON to INACTIVE_ANON pages on
720 * this node's LRU. Maintained by the pageout code.
721 */
722 unsigned int inactive_ratio;
723
724 unsigned long flags;
725
726 ZONE_PADDING(_pad2_)
727
728 /* Per-node vmstats */
729 struct per_cpu_nodestat __percpu *per_cpu_nodestats;
730 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS];
731 } pg_data_t;
732
733 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
734 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
735 #ifdef CONFIG_FLAT_NODE_MEM_MAP
736 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr))
737 #else
738 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr))
739 #endif
740 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr))
741
742 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn)
743 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
zone_lru_lock(struct zone * zone)744 static inline spinlock_t *zone_lru_lock(struct zone *zone)
745 {
746 return &zone->zone_pgdat->lru_lock;
747 }
748
node_lruvec(struct pglist_data * pgdat)749 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
750 {
751 return &pgdat->lruvec;
752 }
753
pgdat_end_pfn(pg_data_t * pgdat)754 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
755 {
756 return pgdat->node_start_pfn + pgdat->node_spanned_pages;
757 }
758
pgdat_is_empty(pg_data_t * pgdat)759 static inline bool pgdat_is_empty(pg_data_t *pgdat)
760 {
761 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
762 }
763
zone_id(const struct zone * zone)764 static inline int zone_id(const struct zone *zone)
765 {
766 struct pglist_data *pgdat = zone->zone_pgdat;
767
768 return zone - pgdat->node_zones;
769 }
770
771 #ifdef CONFIG_ZONE_DEVICE
is_dev_zone(const struct zone * zone)772 static inline bool is_dev_zone(const struct zone *zone)
773 {
774 return zone_id(zone) == ZONE_DEVICE;
775 }
776 #else
is_dev_zone(const struct zone * zone)777 static inline bool is_dev_zone(const struct zone *zone)
778 {
779 return false;
780 }
781 #endif
782
783 #include <linux/memory_hotplug.h>
784
785 void build_all_zonelists(pg_data_t *pgdat);
786 void wakeup_kswapd(struct zone *zone, int order, enum zone_type classzone_idx);
787 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
788 int classzone_idx, unsigned int alloc_flags,
789 long free_pages);
790 bool zone_watermark_ok(struct zone *z, unsigned int order,
791 unsigned long mark, int classzone_idx,
792 unsigned int alloc_flags);
793 bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
794 unsigned long mark, int classzone_idx);
795 enum memmap_context {
796 MEMMAP_EARLY,
797 MEMMAP_HOTPLUG,
798 };
799 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
800 unsigned long size);
801
802 extern void lruvec_init(struct lruvec *lruvec);
803
lruvec_pgdat(struct lruvec * lruvec)804 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
805 {
806 #ifdef CONFIG_MEMCG
807 return lruvec->pgdat;
808 #else
809 return container_of(lruvec, struct pglist_data, lruvec);
810 #endif
811 }
812
813 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx);
814
815 #ifdef CONFIG_HAVE_MEMORY_PRESENT
816 void memory_present(int nid, unsigned long start, unsigned long end);
817 #else
memory_present(int nid,unsigned long start,unsigned long end)818 static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
819 #endif
820
821 #ifdef CONFIG_HAVE_MEMORYLESS_NODES
822 int local_memory_node(int node_id);
823 #else
local_memory_node(int node_id)824 static inline int local_memory_node(int node_id) { return node_id; };
825 #endif
826
827 #ifdef CONFIG_NEED_NODE_MEMMAP_SIZE
828 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
829 #endif
830
831 /*
832 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
833 */
834 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones)
835
836 /*
837 * Returns true if a zone has pages managed by the buddy allocator.
838 * All the reclaim decisions have to use this function rather than
839 * populated_zone(). If the whole zone is reserved then we can easily
840 * end up with populated_zone() && !managed_zone().
841 */
managed_zone(struct zone * zone)842 static inline bool managed_zone(struct zone *zone)
843 {
844 return zone->managed_pages;
845 }
846
847 /* Returns true if a zone has memory */
populated_zone(struct zone * zone)848 static inline bool populated_zone(struct zone *zone)
849 {
850 return zone->present_pages;
851 }
852
853 extern int movable_zone;
854
855 #ifdef CONFIG_HIGHMEM
zone_movable_is_highmem(void)856 static inline int zone_movable_is_highmem(void)
857 {
858 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
859 return movable_zone == ZONE_HIGHMEM;
860 #else
861 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
862 #endif
863 }
864 #endif
865
is_highmem_idx(enum zone_type idx)866 static inline int is_highmem_idx(enum zone_type idx)
867 {
868 #ifdef CONFIG_HIGHMEM
869 return (idx == ZONE_HIGHMEM ||
870 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
871 #else
872 return 0;
873 #endif
874 }
875
876 /**
877 * is_highmem - helper function to quickly check if a struct zone is a
878 * highmem zone or not. This is an attempt to keep references
879 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
880 * @zone - pointer to struct zone variable
881 */
is_highmem(struct zone * zone)882 static inline int is_highmem(struct zone *zone)
883 {
884 #ifdef CONFIG_HIGHMEM
885 return is_highmem_idx(zone_idx(zone));
886 #else
887 return 0;
888 #endif
889 }
890
891 /* These two functions are used to setup the per zone pages min values */
892 struct ctl_table;
893 int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
894 void __user *, size_t *, loff_t *);
895 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
896 void __user *, size_t *, loff_t *);
897 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES-1];
898 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
899 void __user *, size_t *, loff_t *);
900 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
901 void __user *, size_t *, loff_t *);
902 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
903 void __user *, size_t *, loff_t *);
904 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
905 void __user *, size_t *, loff_t *);
906
907 extern int numa_zonelist_order_handler(struct ctl_table *, int,
908 void __user *, size_t *, loff_t *);
909 extern char numa_zonelist_order[];
910 #define NUMA_ZONELIST_ORDER_LEN 16
911
912 #ifndef CONFIG_NEED_MULTIPLE_NODES
913
914 extern struct pglist_data contig_page_data;
915 #define NODE_DATA(nid) (&contig_page_data)
916 #define NODE_MEM_MAP(nid) mem_map
917
918 #else /* CONFIG_NEED_MULTIPLE_NODES */
919
920 #include <asm/mmzone.h>
921
922 #endif /* !CONFIG_NEED_MULTIPLE_NODES */
923
924 extern struct pglist_data *first_online_pgdat(void);
925 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
926 extern struct zone *next_zone(struct zone *zone);
927
928 /**
929 * for_each_online_pgdat - helper macro to iterate over all online nodes
930 * @pgdat - pointer to a pg_data_t variable
931 */
932 #define for_each_online_pgdat(pgdat) \
933 for (pgdat = first_online_pgdat(); \
934 pgdat; \
935 pgdat = next_online_pgdat(pgdat))
936 /**
937 * for_each_zone - helper macro to iterate over all memory zones
938 * @zone - pointer to struct zone variable
939 *
940 * The user only needs to declare the zone variable, for_each_zone
941 * fills it in.
942 */
943 #define for_each_zone(zone) \
944 for (zone = (first_online_pgdat())->node_zones; \
945 zone; \
946 zone = next_zone(zone))
947
948 #define for_each_populated_zone(zone) \
949 for (zone = (first_online_pgdat())->node_zones; \
950 zone; \
951 zone = next_zone(zone)) \
952 if (!populated_zone(zone)) \
953 ; /* do nothing */ \
954 else
955
zonelist_zone(struct zoneref * zoneref)956 static inline struct zone *zonelist_zone(struct zoneref *zoneref)
957 {
958 return zoneref->zone;
959 }
960
zonelist_zone_idx(struct zoneref * zoneref)961 static inline int zonelist_zone_idx(struct zoneref *zoneref)
962 {
963 return zoneref->zone_idx;
964 }
965
zonelist_node_idx(struct zoneref * zoneref)966 static inline int zonelist_node_idx(struct zoneref *zoneref)
967 {
968 #ifdef CONFIG_NUMA
969 /* zone_to_nid not available in this context */
970 return zoneref->zone->node;
971 #else
972 return 0;
973 #endif /* CONFIG_NUMA */
974 }
975
976 struct zoneref *__next_zones_zonelist(struct zoneref *z,
977 enum zone_type highest_zoneidx,
978 nodemask_t *nodes);
979
980 /**
981 * 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
982 * @z - The cursor used as a starting point for the search
983 * @highest_zoneidx - The zone index of the highest zone to return
984 * @nodes - An optional nodemask to filter the zonelist with
985 *
986 * This function returns the next zone at or below a given zone index that is
987 * within the allowed nodemask using a cursor as the starting point for the
988 * search. The zoneref returned is a cursor that represents the current zone
989 * being examined. It should be advanced by one before calling
990 * next_zones_zonelist again.
991 */
next_zones_zonelist(struct zoneref * z,enum zone_type highest_zoneidx,nodemask_t * nodes)992 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
993 enum zone_type highest_zoneidx,
994 nodemask_t *nodes)
995 {
996 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
997 return z;
998 return __next_zones_zonelist(z, highest_zoneidx, nodes);
999 }
1000
1001 /**
1002 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
1003 * @zonelist - The zonelist to search for a suitable zone
1004 * @highest_zoneidx - The zone index of the highest zone to return
1005 * @nodes - An optional nodemask to filter the zonelist with
1006 * @return - Zoneref pointer for the first suitable zone found (see below)
1007 *
1008 * This function returns the first zone at or below a given zone index that is
1009 * within the allowed nodemask. The zoneref returned is a cursor that can be
1010 * used to iterate the zonelist with next_zones_zonelist by advancing it by
1011 * one before calling.
1012 *
1013 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
1014 * never NULL). This may happen either genuinely, or due to concurrent nodemask
1015 * update due to cpuset modification.
1016 */
first_zones_zonelist(struct zonelist * zonelist,enum zone_type highest_zoneidx,nodemask_t * nodes)1017 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
1018 enum zone_type highest_zoneidx,
1019 nodemask_t *nodes)
1020 {
1021 return next_zones_zonelist(zonelist->_zonerefs,
1022 highest_zoneidx, nodes);
1023 }
1024
1025 /**
1026 * 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
1027 * @zone - The current zone in the iterator
1028 * @z - The current pointer within zonelist->zones being iterated
1029 * @zlist - The zonelist being iterated
1030 * @highidx - The zone index of the highest zone to return
1031 * @nodemask - Nodemask allowed by the allocator
1032 *
1033 * This iterator iterates though all zones at or below a given zone index and
1034 * within a given nodemask
1035 */
1036 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1037 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \
1038 zone; \
1039 z = next_zones_zonelist(++z, highidx, nodemask), \
1040 zone = zonelist_zone(z))
1041
1042 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
1043 for (zone = z->zone; \
1044 zone; \
1045 z = next_zones_zonelist(++z, highidx, nodemask), \
1046 zone = zonelist_zone(z))
1047
1048
1049 /**
1050 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
1051 * @zone - The current zone in the iterator
1052 * @z - The current pointer within zonelist->zones being iterated
1053 * @zlist - The zonelist being iterated
1054 * @highidx - The zone index of the highest zone to return
1055 *
1056 * This iterator iterates though all zones at or below a given zone index.
1057 */
1058 #define for_each_zone_zonelist(zone, z, zlist, highidx) \
1059 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
1060
1061 #ifdef CONFIG_SPARSEMEM
1062 #include <asm/sparsemem.h>
1063 #endif
1064
1065 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
1066 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
early_pfn_to_nid(unsigned long pfn)1067 static inline unsigned long early_pfn_to_nid(unsigned long pfn)
1068 {
1069 BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA));
1070 return 0;
1071 }
1072 #endif
1073
1074 #ifdef CONFIG_FLATMEM
1075 #define pfn_to_nid(pfn) (0)
1076 #endif
1077
1078 #ifdef CONFIG_SPARSEMEM
1079
1080 /*
1081 * SECTION_SHIFT #bits space required to store a section #
1082 *
1083 * PA_SECTION_SHIFT physical address to/from section number
1084 * PFN_SECTION_SHIFT pfn to/from section number
1085 */
1086 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS)
1087 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT)
1088
1089 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT)
1090
1091 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT)
1092 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1))
1093
1094 #define SECTION_BLOCKFLAGS_BITS \
1095 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
1096
1097 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
1098 #error Allocator MAX_ORDER exceeds SECTION_SIZE
1099 #endif
1100
pfn_to_section_nr(unsigned long pfn)1101 static inline unsigned long pfn_to_section_nr(unsigned long pfn)
1102 {
1103 return pfn >> PFN_SECTION_SHIFT;
1104 }
section_nr_to_pfn(unsigned long sec)1105 static inline unsigned long section_nr_to_pfn(unsigned long sec)
1106 {
1107 return sec << PFN_SECTION_SHIFT;
1108 }
1109
1110 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
1111 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
1112
1113 struct page;
1114 struct page_ext;
1115 struct mem_section {
1116 /*
1117 * This is, logically, a pointer to an array of struct
1118 * pages. However, it is stored with some other magic.
1119 * (see sparse.c::sparse_init_one_section())
1120 *
1121 * Additionally during early boot we encode node id of
1122 * the location of the section here to guide allocation.
1123 * (see sparse.c::memory_present())
1124 *
1125 * Making it a UL at least makes someone do a cast
1126 * before using it wrong.
1127 */
1128 unsigned long section_mem_map;
1129
1130 /* See declaration of similar field in struct zone */
1131 unsigned long *pageblock_flags;
1132 #ifdef CONFIG_PAGE_EXTENSION
1133 /*
1134 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
1135 * section. (see page_ext.h about this.)
1136 */
1137 struct page_ext *page_ext;
1138 unsigned long pad;
1139 #endif
1140 /*
1141 * WARNING: mem_section must be a power-of-2 in size for the
1142 * calculation and use of SECTION_ROOT_MASK to make sense.
1143 */
1144 };
1145
1146 #ifdef CONFIG_SPARSEMEM_EXTREME
1147 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section))
1148 #else
1149 #define SECTIONS_PER_ROOT 1
1150 #endif
1151
1152 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
1153 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
1154 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1)
1155
1156 #ifdef CONFIG_SPARSEMEM_EXTREME
1157 extern struct mem_section **mem_section;
1158 #else
1159 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
1160 #endif
1161
__nr_to_section(unsigned long nr)1162 static inline struct mem_section *__nr_to_section(unsigned long nr)
1163 {
1164 #ifdef CONFIG_SPARSEMEM_EXTREME
1165 if (!mem_section)
1166 return NULL;
1167 #endif
1168 if (!mem_section[SECTION_NR_TO_ROOT(nr)])
1169 return NULL;
1170 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
1171 }
1172 extern int __section_nr(struct mem_section* ms);
1173 extern unsigned long usemap_size(void);
1174
1175 /*
1176 * We use the lower bits of the mem_map pointer to store
1177 * a little bit of information. There should be at least
1178 * 3 bits here due to 32-bit alignment.
1179 */
1180 #define SECTION_MARKED_PRESENT (1UL<<0)
1181 #define SECTION_HAS_MEM_MAP (1UL<<1)
1182 #define SECTION_IS_ONLINE (1UL<<2)
1183 #define SECTION_MAP_LAST_BIT (1UL<<3)
1184 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1))
1185 #define SECTION_NID_SHIFT 3
1186
__section_mem_map_addr(struct mem_section * section)1187 static inline struct page *__section_mem_map_addr(struct mem_section *section)
1188 {
1189 unsigned long map = section->section_mem_map;
1190 map &= SECTION_MAP_MASK;
1191 return (struct page *)map;
1192 }
1193
present_section(struct mem_section * section)1194 static inline int present_section(struct mem_section *section)
1195 {
1196 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
1197 }
1198
present_section_nr(unsigned long nr)1199 static inline int present_section_nr(unsigned long nr)
1200 {
1201 return present_section(__nr_to_section(nr));
1202 }
1203
valid_section(struct mem_section * section)1204 static inline int valid_section(struct mem_section *section)
1205 {
1206 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
1207 }
1208
valid_section_nr(unsigned long nr)1209 static inline int valid_section_nr(unsigned long nr)
1210 {
1211 return valid_section(__nr_to_section(nr));
1212 }
1213
online_section(struct mem_section * section)1214 static inline int online_section(struct mem_section *section)
1215 {
1216 return (section && (section->section_mem_map & SECTION_IS_ONLINE));
1217 }
1218
online_section_nr(unsigned long nr)1219 static inline int online_section_nr(unsigned long nr)
1220 {
1221 return online_section(__nr_to_section(nr));
1222 }
1223
1224 #ifdef CONFIG_MEMORY_HOTPLUG
1225 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1226 #ifdef CONFIG_MEMORY_HOTREMOVE
1227 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
1228 #endif
1229 #endif
1230
__pfn_to_section(unsigned long pfn)1231 static inline struct mem_section *__pfn_to_section(unsigned long pfn)
1232 {
1233 return __nr_to_section(pfn_to_section_nr(pfn));
1234 }
1235
1236 extern int __highest_present_section_nr;
1237
1238 #ifndef CONFIG_HAVE_ARCH_PFN_VALID
pfn_valid(unsigned long pfn)1239 static inline int pfn_valid(unsigned long pfn)
1240 {
1241 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1242 return 0;
1243 return valid_section(__nr_to_section(pfn_to_section_nr(pfn)));
1244 }
1245 #endif
1246
pfn_present(unsigned long pfn)1247 static inline int pfn_present(unsigned long pfn)
1248 {
1249 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
1250 return 0;
1251 return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
1252 }
1253
1254 /*
1255 * These are _only_ used during initialisation, therefore they
1256 * can use __initdata ... They could have names to indicate
1257 * this restriction.
1258 */
1259 #ifdef CONFIG_NUMA
1260 #define pfn_to_nid(pfn) \
1261 ({ \
1262 unsigned long __pfn_to_nid_pfn = (pfn); \
1263 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \
1264 })
1265 #else
1266 #define pfn_to_nid(pfn) (0)
1267 #endif
1268
1269 #define early_pfn_valid(pfn) pfn_valid(pfn)
1270 void sparse_init(void);
1271 #else
1272 #define sparse_init() do {} while (0)
1273 #define sparse_index_init(_sec, _nid) do {} while (0)
1274 #endif /* CONFIG_SPARSEMEM */
1275
1276 /*
1277 * During memory init memblocks map pfns to nids. The search is expensive and
1278 * this caches recent lookups. The implementation of __early_pfn_to_nid
1279 * may treat start/end as pfns or sections.
1280 */
1281 struct mminit_pfnnid_cache {
1282 unsigned long last_start;
1283 unsigned long last_end;
1284 int last_nid;
1285 };
1286
1287 #ifndef early_pfn_valid
1288 #define early_pfn_valid(pfn) (1)
1289 #endif
1290
1291 void memory_present(int nid, unsigned long start, unsigned long end);
1292 unsigned long __init node_memmap_size_bytes(int, unsigned long, unsigned long);
1293
1294 /*
1295 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
1296 * need to check pfn validility within that MAX_ORDER_NR_PAGES block.
1297 * pfn_valid_within() should be used in this case; we optimise this away
1298 * when we have no holes within a MAX_ORDER_NR_PAGES block.
1299 */
1300 #ifdef CONFIG_HOLES_IN_ZONE
1301 #define pfn_valid_within(pfn) pfn_valid(pfn)
1302 #else
1303 #define pfn_valid_within(pfn) (1)
1304 #endif
1305
1306 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
1307 /*
1308 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
1309 * associated with it or not. This means that a struct page exists for this
1310 * pfn. The caller cannot assume the page is fully initialized in general.
1311 * Hotplugable pages might not have been onlined yet. pfn_to_online_page()
1312 * will ensure the struct page is fully online and initialized. Special pages
1313 * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly.
1314 *
1315 * In FLATMEM, it is expected that holes always have valid memmap as long as
1316 * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed
1317 * that a valid section has a memmap for the entire section.
1318 *
1319 * However, an ARM, and maybe other embedded architectures in the future
1320 * free memmap backing holes to save memory on the assumption the memmap is
1321 * never used. The page_zone linkages are then broken even though pfn_valid()
1322 * returns true. A walker of the full memmap must then do this additional
1323 * check to ensure the memmap they are looking at is sane by making sure
1324 * the zone and PFN linkages are still valid. This is expensive, but walkers
1325 * of the full memmap are extremely rare.
1326 */
1327 bool memmap_valid_within(unsigned long pfn,
1328 struct page *page, struct zone *zone);
1329 #else
memmap_valid_within(unsigned long pfn,struct page * page,struct zone * zone)1330 static inline bool memmap_valid_within(unsigned long pfn,
1331 struct page *page, struct zone *zone)
1332 {
1333 return true;
1334 }
1335 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
1336
1337 #endif /* !__GENERATING_BOUNDS.H */
1338 #endif /* !__ASSEMBLY__ */
1339 #endif /* _LINUX_MMZONE_H */
1340