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 <linux/mm_types.h> 22 #include <linux/page-flags.h> 23 #include <asm/page.h> 24 25 /* Free memory management - zoned buddy allocator. */ 26 #ifndef CONFIG_FORCE_MAX_ZONEORDER 27 #define MAX_ORDER 11 28 #else 29 #define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER 30 #endif 31 #define MAX_ORDER_NR_PAGES (1 << (MAX_ORDER - 1)) 32 33 /* 34 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed 35 * costly to service. That is between allocation orders which should 36 * coalesce naturally under reasonable reclaim pressure and those which 37 * will not. 38 */ 39 #define PAGE_ALLOC_COSTLY_ORDER 3 40 41 enum migratetype { 42 MIGRATE_UNMOVABLE, 43 MIGRATE_MOVABLE, 44 MIGRATE_RECLAIMABLE, 45 MIGRATE_PCPTYPES, /* the number of types on the pcp lists */ 46 MIGRATE_HIGHATOMIC = MIGRATE_PCPTYPES, 47 #ifdef CONFIG_CMA 48 /* 49 * MIGRATE_CMA migration type is designed to mimic the way 50 * ZONE_MOVABLE works. Only movable pages can be allocated 51 * from MIGRATE_CMA pageblocks and page allocator never 52 * implicitly change migration type of MIGRATE_CMA pageblock. 53 * 54 * The way to use it is to change migratetype of a range of 55 * pageblocks to MIGRATE_CMA which can be done by 56 * __free_pageblock_cma() function. What is important though 57 * is that a range of pageblocks must be aligned to 58 * MAX_ORDER_NR_PAGES should biggest page be bigger then 59 * a single pageblock. 60 */ 61 MIGRATE_CMA, 62 #endif 63 #ifdef CONFIG_MEMORY_ISOLATION 64 MIGRATE_ISOLATE, /* can't allocate from here */ 65 #endif 66 MIGRATE_TYPES 67 }; 68 69 /* In mm/page_alloc.c; keep in sync also with show_migration_types() there */ 70 extern const char * const migratetype_names[MIGRATE_TYPES]; 71 72 #ifdef CONFIG_CMA 73 # define is_migrate_cma(migratetype) unlikely((migratetype) == MIGRATE_CMA) 74 # define is_migrate_cma_page(_page) (get_pageblock_migratetype(_page) == MIGRATE_CMA) 75 #else 76 # define is_migrate_cma(migratetype) false 77 # define is_migrate_cma_page(_page) false 78 #endif 79 80 static inline bool is_migrate_movable(int mt) 81 { 82 return is_migrate_cma(mt) || mt == MIGRATE_MOVABLE; 83 } 84 85 #define for_each_migratetype_order(order, type) \ 86 for (order = 0; order < MAX_ORDER; order++) \ 87 for (type = 0; type < MIGRATE_TYPES; type++) 88 89 extern int page_group_by_mobility_disabled; 90 91 #define NR_MIGRATETYPE_BITS (PB_migrate_end - PB_migrate + 1) 92 #define MIGRATETYPE_MASK ((1UL << NR_MIGRATETYPE_BITS) - 1) 93 94 #define get_pageblock_migratetype(page) \ 95 get_pfnblock_flags_mask(page, page_to_pfn(page), \ 96 PB_migrate_end, MIGRATETYPE_MASK) 97 98 struct free_area { 99 struct list_head free_list[MIGRATE_TYPES]; 100 unsigned long nr_free; 101 }; 102 103 /* Used for pages not on another list */ 104 static inline void add_to_free_area(struct page *page, struct free_area *area, 105 int migratetype) 106 { 107 list_add(&page->lru, &area->free_list[migratetype]); 108 area->nr_free++; 109 } 110 111 /* Used for pages not on another list */ 112 static inline void add_to_free_area_tail(struct page *page, struct free_area *area, 113 int migratetype) 114 { 115 list_add_tail(&page->lru, &area->free_list[migratetype]); 116 area->nr_free++; 117 } 118 119 #ifdef CONFIG_SHUFFLE_PAGE_ALLOCATOR 120 /* Used to preserve page allocation order entropy */ 121 void add_to_free_area_random(struct page *page, struct free_area *area, 122 int migratetype); 123 #else 124 static inline void add_to_free_area_random(struct page *page, 125 struct free_area *area, int migratetype) 126 { 127 add_to_free_area(page, area, migratetype); 128 } 129 #endif 130 131 /* Used for pages which are on another list */ 132 static inline void move_to_free_area(struct page *page, struct free_area *area, 133 int migratetype) 134 { 135 list_move(&page->lru, &area->free_list[migratetype]); 136 } 137 138 static inline struct page *get_page_from_free_area(struct free_area *area, 139 int migratetype) 140 { 141 return list_first_entry_or_null(&area->free_list[migratetype], 142 struct page, lru); 143 } 144 145 static inline void del_page_from_free_area(struct page *page, 146 struct free_area *area) 147 { 148 list_del(&page->lru); 149 __ClearPageBuddy(page); 150 set_page_private(page, 0); 151 area->nr_free--; 152 } 153 154 static inline bool free_area_empty(struct free_area *area, int migratetype) 155 { 156 return list_empty(&area->free_list[migratetype]); 157 } 158 159 struct pglist_data; 160 161 /* 162 * zone->lock and the zone lru_lock are two of the hottest locks in the kernel. 163 * So add a wild amount of padding here to ensure that they fall into separate 164 * cachelines. There are very few zone structures in the machine, so space 165 * consumption is not a concern here. 166 */ 167 #if defined(CONFIG_SMP) 168 struct zone_padding { 169 char x[0]; 170 } ____cacheline_internodealigned_in_smp; 171 #define ZONE_PADDING(name) struct zone_padding name; 172 #else 173 #define ZONE_PADDING(name) 174 #endif 175 176 #ifdef CONFIG_NUMA 177 enum numa_stat_item { 178 NUMA_HIT, /* allocated in intended node */ 179 NUMA_MISS, /* allocated in non intended node */ 180 NUMA_FOREIGN, /* was intended here, hit elsewhere */ 181 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ 182 NUMA_LOCAL, /* allocation from local node */ 183 NUMA_OTHER, /* allocation from other node */ 184 NR_VM_NUMA_STAT_ITEMS 185 }; 186 #else 187 #define NR_VM_NUMA_STAT_ITEMS 0 188 #endif 189 190 enum zone_stat_item { 191 /* First 128 byte cacheline (assuming 64 bit words) */ 192 NR_FREE_PAGES, 193 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ 194 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, 195 NR_ZONE_ACTIVE_ANON, 196 NR_ZONE_INACTIVE_FILE, 197 NR_ZONE_ACTIVE_FILE, 198 NR_ZONE_UNEVICTABLE, 199 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ 200 NR_MLOCK, /* mlock()ed pages found and moved off LRU */ 201 NR_PAGETABLE, /* used for pagetables */ 202 NR_KERNEL_STACK_KB, /* measured in KiB */ 203 /* Second 128 byte cacheline */ 204 NR_BOUNCE, 205 #if IS_ENABLED(CONFIG_ZSMALLOC) 206 NR_ZSPAGES, /* allocated in zsmalloc */ 207 #endif 208 NR_FREE_CMA_PAGES, 209 NR_VM_ZONE_STAT_ITEMS }; 210 211 enum node_stat_item { 212 NR_LRU_BASE, 213 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ 214 NR_ACTIVE_ANON, /* " " " " " */ 215 NR_INACTIVE_FILE, /* " " " " " */ 216 NR_ACTIVE_FILE, /* " " " " " */ 217 NR_UNEVICTABLE, /* " " " " " */ 218 NR_SLAB_RECLAIMABLE, /* Please do not reorder this item */ 219 NR_SLAB_UNRECLAIMABLE, /* and this one without looking at 220 * memcg_flush_percpu_vmstats() first. */ 221 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ 222 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ 223 WORKINGSET_NODES, 224 WORKINGSET_REFAULT, 225 WORKINGSET_ACTIVATE, 226 WORKINGSET_RESTORE, 227 WORKINGSET_NODERECLAIM, 228 NR_ANON_MAPPED, /* Mapped anonymous pages */ 229 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. 230 only modified from process context */ 231 NR_FILE_PAGES, 232 NR_FILE_DIRTY, 233 NR_WRITEBACK, 234 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ 235 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ 236 NR_SHMEM_THPS, 237 NR_SHMEM_PMDMAPPED, 238 NR_ANON_THPS, 239 NR_UNSTABLE_NFS, /* NFS unstable pages */ 240 NR_VMSCAN_WRITE, 241 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 242 NR_DIRTIED, /* page dirtyings since bootup */ 243 NR_WRITTEN, /* page writings since bootup */ 244 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ 245 NR_VM_NODE_STAT_ITEMS 246 }; 247 248 /* 249 * We do arithmetic on the LRU lists in various places in the code, 250 * so it is important to keep the active lists LRU_ACTIVE higher in 251 * the array than the corresponding inactive lists, and to keep 252 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 253 * 254 * This has to be kept in sync with the statistics in zone_stat_item 255 * above and the descriptions in vmstat_text in mm/vmstat.c 256 */ 257 #define LRU_BASE 0 258 #define LRU_ACTIVE 1 259 #define LRU_FILE 2 260 261 enum lru_list { 262 LRU_INACTIVE_ANON = LRU_BASE, 263 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 264 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 265 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 266 LRU_UNEVICTABLE, 267 NR_LRU_LISTS 268 }; 269 270 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 271 272 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 273 274 static inline int is_file_lru(enum lru_list lru) 275 { 276 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 277 } 278 279 static inline int is_active_lru(enum lru_list lru) 280 { 281 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 282 } 283 284 struct zone_reclaim_stat { 285 /* 286 * The pageout code in vmscan.c keeps track of how many of the 287 * mem/swap backed and file backed pages are referenced. 288 * The higher the rotated/scanned ratio, the more valuable 289 * that cache is. 290 * 291 * The anon LRU stats live in [0], file LRU stats in [1] 292 */ 293 unsigned long recent_rotated[2]; 294 unsigned long recent_scanned[2]; 295 }; 296 297 struct lruvec { 298 struct list_head lists[NR_LRU_LISTS]; 299 struct zone_reclaim_stat reclaim_stat; 300 /* Evictions & activations on the inactive file list */ 301 atomic_long_t inactive_age; 302 /* Refaults at the time of last reclaim cycle */ 303 unsigned long refaults; 304 #ifdef CONFIG_MEMCG 305 struct pglist_data *pgdat; 306 #endif 307 }; 308 309 /* Isolate unmapped file */ 310 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) 311 /* Isolate for asynchronous migration */ 312 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 313 /* Isolate unevictable pages */ 314 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 315 316 /* LRU Isolation modes. */ 317 typedef unsigned __bitwise isolate_mode_t; 318 319 enum zone_watermarks { 320 WMARK_MIN, 321 WMARK_LOW, 322 WMARK_HIGH, 323 NR_WMARK 324 }; 325 326 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost) 327 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost) 328 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost) 329 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost) 330 331 struct per_cpu_pages { 332 int count; /* number of pages in the list */ 333 int high; /* high watermark, emptying needed */ 334 int batch; /* chunk size for buddy add/remove */ 335 336 /* Lists of pages, one per migrate type stored on the pcp-lists */ 337 struct list_head lists[MIGRATE_PCPTYPES]; 338 }; 339 340 struct per_cpu_pageset { 341 struct per_cpu_pages pcp; 342 #ifdef CONFIG_NUMA 343 s8 expire; 344 u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS]; 345 #endif 346 #ifdef CONFIG_SMP 347 s8 stat_threshold; 348 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 349 #endif 350 }; 351 352 struct per_cpu_nodestat { 353 s8 stat_threshold; 354 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 355 }; 356 357 #endif /* !__GENERATING_BOUNDS.H */ 358 359 enum zone_type { 360 #ifdef CONFIG_ZONE_DMA 361 /* 362 * ZONE_DMA is used when there are devices that are not able 363 * to do DMA to all of addressable memory (ZONE_NORMAL). Then we 364 * carve out the portion of memory that is needed for these devices. 365 * The range is arch specific. 366 * 367 * Some examples 368 * 369 * Architecture Limit 370 * --------------------------- 371 * parisc, ia64, sparc <4G 372 * s390, powerpc <2G 373 * arm Various 374 * alpha Unlimited or 0-16MB. 375 * 376 * i386, x86_64 and multiple other arches 377 * <16M. 378 */ 379 ZONE_DMA, 380 #endif 381 #ifdef CONFIG_ZONE_DMA32 382 /* 383 * x86_64 needs two ZONE_DMAs because it supports devices that are 384 * only able to do DMA to the lower 16M but also 32 bit devices that 385 * can only do DMA areas below 4G. 386 */ 387 ZONE_DMA32, 388 #endif 389 /* 390 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 391 * performed on pages in ZONE_NORMAL if the DMA devices support 392 * transfers to all addressable memory. 393 */ 394 ZONE_NORMAL, 395 #ifdef CONFIG_HIGHMEM 396 /* 397 * A memory area that is only addressable by the kernel through 398 * mapping portions into its own address space. This is for example 399 * used by i386 to allow the kernel to address the memory beyond 400 * 900MB. The kernel will set up special mappings (page 401 * table entries on i386) for each page that the kernel needs to 402 * access. 403 */ 404 ZONE_HIGHMEM, 405 #endif 406 ZONE_MOVABLE, 407 #ifdef CONFIG_ZONE_DEVICE 408 ZONE_DEVICE, 409 #endif 410 __MAX_NR_ZONES 411 412 }; 413 414 #ifndef __GENERATING_BOUNDS_H 415 416 struct zone { 417 /* Read-mostly fields */ 418 419 /* zone watermarks, access with *_wmark_pages(zone) macros */ 420 unsigned long _watermark[NR_WMARK]; 421 unsigned long watermark_boost; 422 423 unsigned long nr_reserved_highatomic; 424 425 /* 426 * We don't know if the memory that we're going to allocate will be 427 * freeable or/and it will be released eventually, so to avoid totally 428 * wasting several GB of ram we must reserve some of the lower zone 429 * memory (otherwise we risk to run OOM on the lower zones despite 430 * there being tons of freeable ram on the higher zones). This array is 431 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 432 * changes. 433 */ 434 long lowmem_reserve[MAX_NR_ZONES]; 435 436 #ifdef CONFIG_NUMA 437 int node; 438 #endif 439 struct pglist_data *zone_pgdat; 440 struct per_cpu_pageset __percpu *pageset; 441 442 #ifndef CONFIG_SPARSEMEM 443 /* 444 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 445 * In SPARSEMEM, this map is stored in struct mem_section 446 */ 447 unsigned long *pageblock_flags; 448 #endif /* CONFIG_SPARSEMEM */ 449 450 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 451 unsigned long zone_start_pfn; 452 453 /* 454 * spanned_pages is the total pages spanned by the zone, including 455 * holes, which is calculated as: 456 * spanned_pages = zone_end_pfn - zone_start_pfn; 457 * 458 * present_pages is physical pages existing within the zone, which 459 * is calculated as: 460 * present_pages = spanned_pages - absent_pages(pages in holes); 461 * 462 * managed_pages is present pages managed by the buddy system, which 463 * is calculated as (reserved_pages includes pages allocated by the 464 * bootmem allocator): 465 * managed_pages = present_pages - reserved_pages; 466 * 467 * So present_pages may be used by memory hotplug or memory power 468 * management logic to figure out unmanaged pages by checking 469 * (present_pages - managed_pages). And managed_pages should be used 470 * by page allocator and vm scanner to calculate all kinds of watermarks 471 * and thresholds. 472 * 473 * Locking rules: 474 * 475 * zone_start_pfn and spanned_pages are protected by span_seqlock. 476 * It is a seqlock because it has to be read outside of zone->lock, 477 * and it is done in the main allocator path. But, it is written 478 * quite infrequently. 479 * 480 * The span_seq lock is declared along with zone->lock because it is 481 * frequently read in proximity to zone->lock. It's good to 482 * give them a chance of being in the same cacheline. 483 * 484 * Write access to present_pages at runtime should be protected by 485 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 486 * present_pages should get_online_mems() to get a stable value. 487 */ 488 atomic_long_t managed_pages; 489 unsigned long spanned_pages; 490 unsigned long present_pages; 491 492 const char *name; 493 494 #ifdef CONFIG_MEMORY_ISOLATION 495 /* 496 * Number of isolated pageblock. It is used to solve incorrect 497 * freepage counting problem due to racy retrieving migratetype 498 * of pageblock. Protected by zone->lock. 499 */ 500 unsigned long nr_isolate_pageblock; 501 #endif 502 503 #ifdef CONFIG_MEMORY_HOTPLUG 504 /* see spanned/present_pages for more description */ 505 seqlock_t span_seqlock; 506 #endif 507 508 int initialized; 509 510 /* Write-intensive fields used from the page allocator */ 511 ZONE_PADDING(_pad1_) 512 513 /* free areas of different sizes */ 514 struct free_area free_area[MAX_ORDER]; 515 516 /* zone flags, see below */ 517 unsigned long flags; 518 519 /* Primarily protects free_area */ 520 spinlock_t lock; 521 522 /* Write-intensive fields used by compaction and vmstats. */ 523 ZONE_PADDING(_pad2_) 524 525 /* 526 * When free pages are below this point, additional steps are taken 527 * when reading the number of free pages to avoid per-cpu counter 528 * drift allowing watermarks to be breached 529 */ 530 unsigned long percpu_drift_mark; 531 532 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 533 /* pfn where compaction free scanner should start */ 534 unsigned long compact_cached_free_pfn; 535 /* pfn where async and sync compaction migration scanner should start */ 536 unsigned long compact_cached_migrate_pfn[2]; 537 unsigned long compact_init_migrate_pfn; 538 unsigned long compact_init_free_pfn; 539 #endif 540 541 #ifdef CONFIG_COMPACTION 542 /* 543 * On compaction failure, 1<<compact_defer_shift compactions 544 * are skipped before trying again. The number attempted since 545 * last failure is tracked with compact_considered. 546 */ 547 unsigned int compact_considered; 548 unsigned int compact_defer_shift; 549 int compact_order_failed; 550 #endif 551 552 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 553 /* Set to true when the PG_migrate_skip bits should be cleared */ 554 bool compact_blockskip_flush; 555 #endif 556 557 bool contiguous; 558 559 ZONE_PADDING(_pad3_) 560 /* Zone statistics */ 561 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 562 atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS]; 563 } ____cacheline_internodealigned_in_smp; 564 565 enum pgdat_flags { 566 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by 567 * a congested BDI 568 */ 569 PGDAT_DIRTY, /* reclaim scanning has recently found 570 * many dirty file pages at the tail 571 * of the LRU. 572 */ 573 PGDAT_WRITEBACK, /* reclaim scanning has recently found 574 * many pages under writeback 575 */ 576 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 577 }; 578 579 enum zone_flags { 580 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. 581 * Cleared when kswapd is woken. 582 */ 583 }; 584 585 static inline unsigned long zone_managed_pages(struct zone *zone) 586 { 587 return (unsigned long)atomic_long_read(&zone->managed_pages); 588 } 589 590 static inline unsigned long zone_end_pfn(const struct zone *zone) 591 { 592 return zone->zone_start_pfn + zone->spanned_pages; 593 } 594 595 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 596 { 597 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 598 } 599 600 static inline bool zone_is_initialized(struct zone *zone) 601 { 602 return zone->initialized; 603 } 604 605 static inline bool zone_is_empty(struct zone *zone) 606 { 607 return zone->spanned_pages == 0; 608 } 609 610 /* 611 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty 612 * intersection with the given zone 613 */ 614 static inline bool zone_intersects(struct zone *zone, 615 unsigned long start_pfn, unsigned long nr_pages) 616 { 617 if (zone_is_empty(zone)) 618 return false; 619 if (start_pfn >= zone_end_pfn(zone) || 620 start_pfn + nr_pages <= zone->zone_start_pfn) 621 return false; 622 623 return true; 624 } 625 626 /* 627 * The "priority" of VM scanning is how much of the queues we will scan in one 628 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 629 * queues ("queue_length >> 12") during an aging round. 630 */ 631 #define DEF_PRIORITY 12 632 633 /* Maximum number of zones on a zonelist */ 634 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 635 636 enum { 637 ZONELIST_FALLBACK, /* zonelist with fallback */ 638 #ifdef CONFIG_NUMA 639 /* 640 * The NUMA zonelists are doubled because we need zonelists that 641 * restrict the allocations to a single node for __GFP_THISNODE. 642 */ 643 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 644 #endif 645 MAX_ZONELISTS 646 }; 647 648 /* 649 * This struct contains information about a zone in a zonelist. It is stored 650 * here to avoid dereferences into large structures and lookups of tables 651 */ 652 struct zoneref { 653 struct zone *zone; /* Pointer to actual zone */ 654 int zone_idx; /* zone_idx(zoneref->zone) */ 655 }; 656 657 /* 658 * One allocation request operates on a zonelist. A zonelist 659 * is a list of zones, the first one is the 'goal' of the 660 * allocation, the other zones are fallback zones, in decreasing 661 * priority. 662 * 663 * To speed the reading of the zonelist, the zonerefs contain the zone index 664 * of the entry being read. Helper functions to access information given 665 * a struct zoneref are 666 * 667 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 668 * zonelist_zone_idx() - Return the index of the zone for an entry 669 * zonelist_node_idx() - Return the index of the node for an entry 670 */ 671 struct zonelist { 672 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 673 }; 674 675 #ifndef CONFIG_DISCONTIGMEM 676 /* The array of struct pages - for discontigmem use pgdat->lmem_map */ 677 extern struct page *mem_map; 678 #endif 679 680 /* 681 * On NUMA machines, each NUMA node would have a pg_data_t to describe 682 * it's memory layout. On UMA machines there is a single pglist_data which 683 * describes the whole memory. 684 * 685 * Memory statistics and page replacement data structures are maintained on a 686 * per-zone basis. 687 */ 688 struct bootmem_data; 689 typedef struct pglist_data { 690 struct zone node_zones[MAX_NR_ZONES]; 691 struct zonelist node_zonelists[MAX_ZONELISTS]; 692 int nr_zones; 693 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ 694 struct page *node_mem_map; 695 #ifdef CONFIG_PAGE_EXTENSION 696 struct page_ext *node_page_ext; 697 #endif 698 #endif 699 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) 700 /* 701 * Must be held any time you expect node_start_pfn, 702 * node_present_pages, node_spanned_pages or nr_zones to stay constant. 703 * 704 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 705 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG 706 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. 707 * 708 * Nests above zone->lock and zone->span_seqlock 709 */ 710 spinlock_t node_size_lock; 711 #endif 712 unsigned long node_start_pfn; 713 unsigned long node_present_pages; /* total number of physical pages */ 714 unsigned long node_spanned_pages; /* total size of physical page 715 range, including holes */ 716 int node_id; 717 wait_queue_head_t kswapd_wait; 718 wait_queue_head_t pfmemalloc_wait; 719 struct task_struct *kswapd; /* Protected by 720 mem_hotplug_begin/end() */ 721 int kswapd_order; 722 enum zone_type kswapd_classzone_idx; 723 724 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 725 726 #ifdef CONFIG_COMPACTION 727 int kcompactd_max_order; 728 enum zone_type kcompactd_classzone_idx; 729 wait_queue_head_t kcompactd_wait; 730 struct task_struct *kcompactd; 731 #endif 732 /* 733 * This is a per-node reserve of pages that are not available 734 * to userspace allocations. 735 */ 736 unsigned long totalreserve_pages; 737 738 #ifdef CONFIG_NUMA 739 /* 740 * zone reclaim becomes active if more unmapped pages exist. 741 */ 742 unsigned long min_unmapped_pages; 743 unsigned long min_slab_pages; 744 #endif /* CONFIG_NUMA */ 745 746 /* Write-intensive fields used by page reclaim */ 747 ZONE_PADDING(_pad1_) 748 spinlock_t lru_lock; 749 750 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 751 /* 752 * If memory initialisation on large machines is deferred then this 753 * is the first PFN that needs to be initialised. 754 */ 755 unsigned long first_deferred_pfn; 756 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 757 758 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 759 spinlock_t split_queue_lock; 760 struct list_head split_queue; 761 unsigned long split_queue_len; 762 #endif 763 764 /* Fields commonly accessed by the page reclaim scanner */ 765 struct lruvec lruvec; 766 767 unsigned long flags; 768 769 ZONE_PADDING(_pad2_) 770 771 /* Per-node vmstats */ 772 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 773 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 774 } pg_data_t; 775 776 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 777 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 778 #ifdef CONFIG_FLAT_NODE_MEM_MAP 779 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) 780 #else 781 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) 782 #endif 783 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 784 785 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 786 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 787 788 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat) 789 { 790 return &pgdat->lruvec; 791 } 792 793 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 794 { 795 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 796 } 797 798 static inline bool pgdat_is_empty(pg_data_t *pgdat) 799 { 800 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 801 } 802 803 #include <linux/memory_hotplug.h> 804 805 void build_all_zonelists(pg_data_t *pgdat); 806 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, 807 enum zone_type classzone_idx); 808 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 809 int classzone_idx, unsigned int alloc_flags, 810 long free_pages); 811 bool zone_watermark_ok(struct zone *z, unsigned int order, 812 unsigned long mark, int classzone_idx, 813 unsigned int alloc_flags); 814 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 815 unsigned long mark, int classzone_idx); 816 enum memmap_context { 817 MEMMAP_EARLY, 818 MEMMAP_HOTPLUG, 819 }; 820 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 821 unsigned long size); 822 823 extern void lruvec_init(struct lruvec *lruvec); 824 825 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 826 { 827 #ifdef CONFIG_MEMCG 828 return lruvec->pgdat; 829 #else 830 return container_of(lruvec, struct pglist_data, lruvec); 831 #endif 832 } 833 834 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx); 835 836 #ifdef CONFIG_HAVE_MEMORY_PRESENT 837 void memory_present(int nid, unsigned long start, unsigned long end); 838 #else 839 static inline void memory_present(int nid, unsigned long start, unsigned long end) {} 840 #endif 841 842 #if defined(CONFIG_SPARSEMEM) 843 void memblocks_present(void); 844 #else 845 static inline void memblocks_present(void) {} 846 #endif 847 848 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 849 int local_memory_node(int node_id); 850 #else 851 static inline int local_memory_node(int node_id) { return node_id; }; 852 #endif 853 854 /* 855 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 856 */ 857 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 858 859 /* 860 * Returns true if a zone has pages managed by the buddy allocator. 861 * All the reclaim decisions have to use this function rather than 862 * populated_zone(). If the whole zone is reserved then we can easily 863 * end up with populated_zone() && !managed_zone(). 864 */ 865 static inline bool managed_zone(struct zone *zone) 866 { 867 return zone_managed_pages(zone); 868 } 869 870 /* Returns true if a zone has memory */ 871 static inline bool populated_zone(struct zone *zone) 872 { 873 return zone->present_pages; 874 } 875 876 #ifdef CONFIG_NUMA 877 static inline int zone_to_nid(struct zone *zone) 878 { 879 return zone->node; 880 } 881 882 static inline void zone_set_nid(struct zone *zone, int nid) 883 { 884 zone->node = nid; 885 } 886 #else 887 static inline int zone_to_nid(struct zone *zone) 888 { 889 return 0; 890 } 891 892 static inline void zone_set_nid(struct zone *zone, int nid) {} 893 #endif 894 895 extern int movable_zone; 896 897 #ifdef CONFIG_HIGHMEM 898 static inline int zone_movable_is_highmem(void) 899 { 900 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 901 return movable_zone == ZONE_HIGHMEM; 902 #else 903 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; 904 #endif 905 } 906 #endif 907 908 static inline int is_highmem_idx(enum zone_type idx) 909 { 910 #ifdef CONFIG_HIGHMEM 911 return (idx == ZONE_HIGHMEM || 912 (idx == ZONE_MOVABLE && zone_movable_is_highmem())); 913 #else 914 return 0; 915 #endif 916 } 917 918 /** 919 * is_highmem - helper function to quickly check if a struct zone is a 920 * highmem zone or not. This is an attempt to keep references 921 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 922 * @zone - pointer to struct zone variable 923 */ 924 static inline int is_highmem(struct zone *zone) 925 { 926 #ifdef CONFIG_HIGHMEM 927 return is_highmem_idx(zone_idx(zone)); 928 #else 929 return 0; 930 #endif 931 } 932 933 /* These two functions are used to setup the per zone pages min values */ 934 struct ctl_table; 935 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, 936 void __user *, size_t *, loff_t *); 937 int watermark_boost_factor_sysctl_handler(struct ctl_table *, int, 938 void __user *, size_t *, loff_t *); 939 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, 940 void __user *, size_t *, loff_t *); 941 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; 942 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, 943 void __user *, size_t *, loff_t *); 944 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, 945 void __user *, size_t *, loff_t *); 946 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 947 void __user *, size_t *, loff_t *); 948 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 949 void __user *, size_t *, loff_t *); 950 951 extern int numa_zonelist_order_handler(struct ctl_table *, int, 952 void __user *, size_t *, loff_t *); 953 extern char numa_zonelist_order[]; 954 #define NUMA_ZONELIST_ORDER_LEN 16 955 956 #ifndef CONFIG_NEED_MULTIPLE_NODES 957 958 extern struct pglist_data contig_page_data; 959 #define NODE_DATA(nid) (&contig_page_data) 960 #define NODE_MEM_MAP(nid) mem_map 961 962 #else /* CONFIG_NEED_MULTIPLE_NODES */ 963 964 #include <asm/mmzone.h> 965 966 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 967 968 extern struct pglist_data *first_online_pgdat(void); 969 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 970 extern struct zone *next_zone(struct zone *zone); 971 972 /** 973 * for_each_online_pgdat - helper macro to iterate over all online nodes 974 * @pgdat - pointer to a pg_data_t variable 975 */ 976 #define for_each_online_pgdat(pgdat) \ 977 for (pgdat = first_online_pgdat(); \ 978 pgdat; \ 979 pgdat = next_online_pgdat(pgdat)) 980 /** 981 * for_each_zone - helper macro to iterate over all memory zones 982 * @zone - pointer to struct zone variable 983 * 984 * The user only needs to declare the zone variable, for_each_zone 985 * fills it in. 986 */ 987 #define for_each_zone(zone) \ 988 for (zone = (first_online_pgdat())->node_zones; \ 989 zone; \ 990 zone = next_zone(zone)) 991 992 #define for_each_populated_zone(zone) \ 993 for (zone = (first_online_pgdat())->node_zones; \ 994 zone; \ 995 zone = next_zone(zone)) \ 996 if (!populated_zone(zone)) \ 997 ; /* do nothing */ \ 998 else 999 1000 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 1001 { 1002 return zoneref->zone; 1003 } 1004 1005 static inline int zonelist_zone_idx(struct zoneref *zoneref) 1006 { 1007 return zoneref->zone_idx; 1008 } 1009 1010 static inline int zonelist_node_idx(struct zoneref *zoneref) 1011 { 1012 return zone_to_nid(zoneref->zone); 1013 } 1014 1015 struct zoneref *__next_zones_zonelist(struct zoneref *z, 1016 enum zone_type highest_zoneidx, 1017 nodemask_t *nodes); 1018 1019 /** 1020 * 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 1021 * @z - The cursor used as a starting point for the search 1022 * @highest_zoneidx - The zone index of the highest zone to return 1023 * @nodes - An optional nodemask to filter the zonelist with 1024 * 1025 * This function returns the next zone at or below a given zone index that is 1026 * within the allowed nodemask using a cursor as the starting point for the 1027 * search. The zoneref returned is a cursor that represents the current zone 1028 * being examined. It should be advanced by one before calling 1029 * next_zones_zonelist again. 1030 */ 1031 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 1032 enum zone_type highest_zoneidx, 1033 nodemask_t *nodes) 1034 { 1035 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 1036 return z; 1037 return __next_zones_zonelist(z, highest_zoneidx, nodes); 1038 } 1039 1040 /** 1041 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 1042 * @zonelist - The zonelist to search for a suitable zone 1043 * @highest_zoneidx - The zone index of the highest zone to return 1044 * @nodes - An optional nodemask to filter the zonelist with 1045 * @return - Zoneref pointer for the first suitable zone found (see below) 1046 * 1047 * This function returns the first zone at or below a given zone index that is 1048 * within the allowed nodemask. The zoneref returned is a cursor that can be 1049 * used to iterate the zonelist with next_zones_zonelist by advancing it by 1050 * one before calling. 1051 * 1052 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 1053 * never NULL). This may happen either genuinely, or due to concurrent nodemask 1054 * update due to cpuset modification. 1055 */ 1056 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 1057 enum zone_type highest_zoneidx, 1058 nodemask_t *nodes) 1059 { 1060 return next_zones_zonelist(zonelist->_zonerefs, 1061 highest_zoneidx, nodes); 1062 } 1063 1064 /** 1065 * 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 1066 * @zone - The current zone in the iterator 1067 * @z - The current pointer within zonelist->zones being iterated 1068 * @zlist - The zonelist being iterated 1069 * @highidx - The zone index of the highest zone to return 1070 * @nodemask - Nodemask allowed by the allocator 1071 * 1072 * This iterator iterates though all zones at or below a given zone index and 1073 * within a given nodemask 1074 */ 1075 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1076 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1077 zone; \ 1078 z = next_zones_zonelist(++z, highidx, nodemask), \ 1079 zone = zonelist_zone(z)) 1080 1081 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1082 for (zone = z->zone; \ 1083 zone; \ 1084 z = next_zones_zonelist(++z, highidx, nodemask), \ 1085 zone = zonelist_zone(z)) 1086 1087 1088 /** 1089 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1090 * @zone - The current zone in the iterator 1091 * @z - The current pointer within zonelist->zones being iterated 1092 * @zlist - The zonelist being iterated 1093 * @highidx - The zone index of the highest zone to return 1094 * 1095 * This iterator iterates though all zones at or below a given zone index. 1096 */ 1097 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1098 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1099 1100 #ifdef CONFIG_SPARSEMEM 1101 #include <asm/sparsemem.h> 1102 #endif 1103 1104 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ 1105 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) 1106 static inline unsigned long early_pfn_to_nid(unsigned long pfn) 1107 { 1108 BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA)); 1109 return 0; 1110 } 1111 #endif 1112 1113 #ifdef CONFIG_FLATMEM 1114 #define pfn_to_nid(pfn) (0) 1115 #endif 1116 1117 #ifdef CONFIG_SPARSEMEM 1118 1119 /* 1120 * SECTION_SHIFT #bits space required to store a section # 1121 * 1122 * PA_SECTION_SHIFT physical address to/from section number 1123 * PFN_SECTION_SHIFT pfn to/from section number 1124 */ 1125 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1126 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1127 1128 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1129 1130 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1131 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1132 1133 #define SECTION_BLOCKFLAGS_BITS \ 1134 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1135 1136 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1137 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1138 #endif 1139 1140 static inline unsigned long pfn_to_section_nr(unsigned long pfn) 1141 { 1142 return pfn >> PFN_SECTION_SHIFT; 1143 } 1144 static inline unsigned long section_nr_to_pfn(unsigned long sec) 1145 { 1146 return sec << PFN_SECTION_SHIFT; 1147 } 1148 1149 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1150 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1151 1152 #define SUBSECTION_SHIFT 21 1153 1154 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) 1155 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) 1156 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) 1157 1158 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS 1159 #error Subsection size exceeds section size 1160 #else 1161 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) 1162 #endif 1163 1164 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) 1165 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) 1166 1167 struct mem_section_usage { 1168 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); 1169 /* See declaration of similar field in struct zone */ 1170 unsigned long pageblock_flags[0]; 1171 }; 1172 1173 void subsection_map_init(unsigned long pfn, unsigned long nr_pages); 1174 1175 struct page; 1176 struct page_ext; 1177 struct mem_section { 1178 /* 1179 * This is, logically, a pointer to an array of struct 1180 * pages. However, it is stored with some other magic. 1181 * (see sparse.c::sparse_init_one_section()) 1182 * 1183 * Additionally during early boot we encode node id of 1184 * the location of the section here to guide allocation. 1185 * (see sparse.c::memory_present()) 1186 * 1187 * Making it a UL at least makes someone do a cast 1188 * before using it wrong. 1189 */ 1190 unsigned long section_mem_map; 1191 1192 struct mem_section_usage *usage; 1193 #ifdef CONFIG_PAGE_EXTENSION 1194 /* 1195 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1196 * section. (see page_ext.h about this.) 1197 */ 1198 struct page_ext *page_ext; 1199 unsigned long pad; 1200 #endif 1201 /* 1202 * WARNING: mem_section must be a power-of-2 in size for the 1203 * calculation and use of SECTION_ROOT_MASK to make sense. 1204 */ 1205 }; 1206 1207 #ifdef CONFIG_SPARSEMEM_EXTREME 1208 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1209 #else 1210 #define SECTIONS_PER_ROOT 1 1211 #endif 1212 1213 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1214 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1215 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1216 1217 #ifdef CONFIG_SPARSEMEM_EXTREME 1218 extern struct mem_section **mem_section; 1219 #else 1220 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1221 #endif 1222 1223 static inline unsigned long *section_to_usemap(struct mem_section *ms) 1224 { 1225 return ms->usage->pageblock_flags; 1226 } 1227 1228 static inline struct mem_section *__nr_to_section(unsigned long nr) 1229 { 1230 #ifdef CONFIG_SPARSEMEM_EXTREME 1231 if (!mem_section) 1232 return NULL; 1233 #endif 1234 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) 1235 return NULL; 1236 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; 1237 } 1238 extern unsigned long __section_nr(struct mem_section *ms); 1239 extern size_t mem_section_usage_size(void); 1240 1241 /* 1242 * We use the lower bits of the mem_map pointer to store 1243 * a little bit of information. The pointer is calculated 1244 * as mem_map - section_nr_to_pfn(pnum). The result is 1245 * aligned to the minimum alignment of the two values: 1246 * 1. All mem_map arrays are page-aligned. 1247 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT 1248 * lowest bits. PFN_SECTION_SHIFT is arch-specific 1249 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the 1250 * worst combination is powerpc with 256k pages, 1251 * which results in PFN_SECTION_SHIFT equal 6. 1252 * To sum it up, at least 6 bits are available. 1253 */ 1254 #define SECTION_MARKED_PRESENT (1UL<<0) 1255 #define SECTION_HAS_MEM_MAP (1UL<<1) 1256 #define SECTION_IS_ONLINE (1UL<<2) 1257 #define SECTION_IS_EARLY (1UL<<3) 1258 #define SECTION_MAP_LAST_BIT (1UL<<4) 1259 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1260 #define SECTION_NID_SHIFT 3 1261 1262 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1263 { 1264 unsigned long map = section->section_mem_map; 1265 map &= SECTION_MAP_MASK; 1266 return (struct page *)map; 1267 } 1268 1269 static inline int present_section(struct mem_section *section) 1270 { 1271 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1272 } 1273 1274 static inline int present_section_nr(unsigned long nr) 1275 { 1276 return present_section(__nr_to_section(nr)); 1277 } 1278 1279 static inline int valid_section(struct mem_section *section) 1280 { 1281 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1282 } 1283 1284 static inline int early_section(struct mem_section *section) 1285 { 1286 return (section && (section->section_mem_map & SECTION_IS_EARLY)); 1287 } 1288 1289 static inline int valid_section_nr(unsigned long nr) 1290 { 1291 return valid_section(__nr_to_section(nr)); 1292 } 1293 1294 static inline int online_section(struct mem_section *section) 1295 { 1296 return (section && (section->section_mem_map & SECTION_IS_ONLINE)); 1297 } 1298 1299 static inline int online_section_nr(unsigned long nr) 1300 { 1301 return online_section(__nr_to_section(nr)); 1302 } 1303 1304 #ifdef CONFIG_MEMORY_HOTPLUG 1305 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1306 #ifdef CONFIG_MEMORY_HOTREMOVE 1307 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1308 #endif 1309 #endif 1310 1311 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1312 { 1313 return __nr_to_section(pfn_to_section_nr(pfn)); 1314 } 1315 1316 extern unsigned long __highest_present_section_nr; 1317 1318 static inline int subsection_map_index(unsigned long pfn) 1319 { 1320 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; 1321 } 1322 1323 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1324 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1325 { 1326 int idx = subsection_map_index(pfn); 1327 1328 return test_bit(idx, ms->usage->subsection_map); 1329 } 1330 #else 1331 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1332 { 1333 return 1; 1334 } 1335 #endif 1336 1337 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1338 static inline int pfn_valid(unsigned long pfn) 1339 { 1340 struct mem_section *ms; 1341 1342 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1343 return 0; 1344 ms = __nr_to_section(pfn_to_section_nr(pfn)); 1345 if (!valid_section(ms)) 1346 return 0; 1347 /* 1348 * Traditionally early sections always returned pfn_valid() for 1349 * the entire section-sized span. 1350 */ 1351 return early_section(ms) || pfn_section_valid(ms, pfn); 1352 } 1353 #endif 1354 1355 static inline int pfn_present(unsigned long pfn) 1356 { 1357 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1358 return 0; 1359 return present_section(__nr_to_section(pfn_to_section_nr(pfn))); 1360 } 1361 1362 /* 1363 * These are _only_ used during initialisation, therefore they 1364 * can use __initdata ... They could have names to indicate 1365 * this restriction. 1366 */ 1367 #ifdef CONFIG_NUMA 1368 #define pfn_to_nid(pfn) \ 1369 ({ \ 1370 unsigned long __pfn_to_nid_pfn = (pfn); \ 1371 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1372 }) 1373 #else 1374 #define pfn_to_nid(pfn) (0) 1375 #endif 1376 1377 #define early_pfn_valid(pfn) pfn_valid(pfn) 1378 void sparse_init(void); 1379 #else 1380 #define sparse_init() do {} while (0) 1381 #define sparse_index_init(_sec, _nid) do {} while (0) 1382 #define pfn_present pfn_valid 1383 #define subsection_map_init(_pfn, _nr_pages) do {} while (0) 1384 #endif /* CONFIG_SPARSEMEM */ 1385 1386 /* 1387 * During memory init memblocks map pfns to nids. The search is expensive and 1388 * this caches recent lookups. The implementation of __early_pfn_to_nid 1389 * may treat start/end as pfns or sections. 1390 */ 1391 struct mminit_pfnnid_cache { 1392 unsigned long last_start; 1393 unsigned long last_end; 1394 int last_nid; 1395 }; 1396 1397 #ifndef early_pfn_valid 1398 #define early_pfn_valid(pfn) (1) 1399 #endif 1400 1401 void memory_present(int nid, unsigned long start, unsigned long end); 1402 1403 /* 1404 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we 1405 * need to check pfn validity within that MAX_ORDER_NR_PAGES block. 1406 * pfn_valid_within() should be used in this case; we optimise this away 1407 * when we have no holes within a MAX_ORDER_NR_PAGES block. 1408 */ 1409 #ifdef CONFIG_HOLES_IN_ZONE 1410 #define pfn_valid_within(pfn) pfn_valid(pfn) 1411 #else 1412 #define pfn_valid_within(pfn) (1) 1413 #endif 1414 1415 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 1416 /* 1417 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap 1418 * associated with it or not. This means that a struct page exists for this 1419 * pfn. The caller cannot assume the page is fully initialized in general. 1420 * Hotplugable pages might not have been onlined yet. pfn_to_online_page() 1421 * will ensure the struct page is fully online and initialized. Special pages 1422 * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly. 1423 * 1424 * In FLATMEM, it is expected that holes always have valid memmap as long as 1425 * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed 1426 * that a valid section has a memmap for the entire section. 1427 * 1428 * However, an ARM, and maybe other embedded architectures in the future 1429 * free memmap backing holes to save memory on the assumption the memmap is 1430 * never used. The page_zone linkages are then broken even though pfn_valid() 1431 * returns true. A walker of the full memmap must then do this additional 1432 * check to ensure the memmap they are looking at is sane by making sure 1433 * the zone and PFN linkages are still valid. This is expensive, but walkers 1434 * of the full memmap are extremely rare. 1435 */ 1436 bool memmap_valid_within(unsigned long pfn, 1437 struct page *page, struct zone *zone); 1438 #else 1439 static inline bool memmap_valid_within(unsigned long pfn, 1440 struct page *page, struct zone *zone) 1441 { 1442 return true; 1443 } 1444 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ 1445 1446 #endif /* !__GENERATING_BOUNDS.H */ 1447 #endif /* !__ASSEMBLY__ */ 1448 #endif /* _LINUX_MMZONE_H */ 1449