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_FILE_THPS, 239 NR_FILE_PMDMAPPED, 240 NR_ANON_THPS, 241 NR_UNSTABLE_NFS, /* NFS unstable pages */ 242 NR_VMSCAN_WRITE, 243 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 244 NR_DIRTIED, /* page dirtyings since bootup */ 245 NR_WRITTEN, /* page writings since bootup */ 246 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ 247 NR_VM_NODE_STAT_ITEMS 248 }; 249 250 /* 251 * We do arithmetic on the LRU lists in various places in the code, 252 * so it is important to keep the active lists LRU_ACTIVE higher in 253 * the array than the corresponding inactive lists, and to keep 254 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 255 * 256 * This has to be kept in sync with the statistics in zone_stat_item 257 * above and the descriptions in vmstat_text in mm/vmstat.c 258 */ 259 #define LRU_BASE 0 260 #define LRU_ACTIVE 1 261 #define LRU_FILE 2 262 263 enum lru_list { 264 LRU_INACTIVE_ANON = LRU_BASE, 265 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 266 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 267 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 268 LRU_UNEVICTABLE, 269 NR_LRU_LISTS 270 }; 271 272 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 273 274 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 275 276 static inline int is_file_lru(enum lru_list lru) 277 { 278 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 279 } 280 281 static inline int is_active_lru(enum lru_list lru) 282 { 283 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 284 } 285 286 struct zone_reclaim_stat { 287 /* 288 * The pageout code in vmscan.c keeps track of how many of the 289 * mem/swap backed and file backed pages are referenced. 290 * The higher the rotated/scanned ratio, the more valuable 291 * that cache is. 292 * 293 * The anon LRU stats live in [0], file LRU stats in [1] 294 */ 295 unsigned long recent_rotated[2]; 296 unsigned long recent_scanned[2]; 297 }; 298 299 struct lruvec { 300 struct list_head lists[NR_LRU_LISTS]; 301 struct zone_reclaim_stat reclaim_stat; 302 /* Evictions & activations on the inactive file list */ 303 atomic_long_t inactive_age; 304 /* Refaults at the time of last reclaim cycle */ 305 unsigned long refaults; 306 #ifdef CONFIG_MEMCG 307 struct pglist_data *pgdat; 308 #endif 309 }; 310 311 /* Isolate unmapped file */ 312 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) 313 /* Isolate for asynchronous migration */ 314 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 315 /* Isolate unevictable pages */ 316 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 317 318 /* LRU Isolation modes. */ 319 typedef unsigned __bitwise isolate_mode_t; 320 321 enum zone_watermarks { 322 WMARK_MIN, 323 WMARK_LOW, 324 WMARK_HIGH, 325 NR_WMARK 326 }; 327 328 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost) 329 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost) 330 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost) 331 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost) 332 333 struct per_cpu_pages { 334 int count; /* number of pages in the list */ 335 int high; /* high watermark, emptying needed */ 336 int batch; /* chunk size for buddy add/remove */ 337 338 /* Lists of pages, one per migrate type stored on the pcp-lists */ 339 struct list_head lists[MIGRATE_PCPTYPES]; 340 }; 341 342 struct per_cpu_pageset { 343 struct per_cpu_pages pcp; 344 #ifdef CONFIG_NUMA 345 s8 expire; 346 u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS]; 347 #endif 348 #ifdef CONFIG_SMP 349 s8 stat_threshold; 350 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 351 #endif 352 }; 353 354 struct per_cpu_nodestat { 355 s8 stat_threshold; 356 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 357 }; 358 359 #endif /* !__GENERATING_BOUNDS.H */ 360 361 enum zone_type { 362 /* 363 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able 364 * to DMA to all of the addressable memory (ZONE_NORMAL). 365 * On architectures where this area covers the whole 32 bit address 366 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller 367 * DMA addressing constraints. This distinction is important as a 32bit 368 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit 369 * platforms may need both zones as they support peripherals with 370 * different DMA addressing limitations. 371 * 372 * Some examples: 373 * 374 * - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the 375 * rest of the lower 4G. 376 * 377 * - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on 378 * the specific device. 379 * 380 * - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the 381 * lower 4G. 382 * 383 * - powerpc only uses ZONE_DMA, the size, up to 2G, may vary 384 * depending on the specific device. 385 * 386 * - s390 uses ZONE_DMA fixed to the lower 2G. 387 * 388 * - ia64 and riscv only use ZONE_DMA32. 389 * 390 * - parisc uses neither. 391 */ 392 #ifdef CONFIG_ZONE_DMA 393 ZONE_DMA, 394 #endif 395 #ifdef CONFIG_ZONE_DMA32 396 ZONE_DMA32, 397 #endif 398 /* 399 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 400 * performed on pages in ZONE_NORMAL if the DMA devices support 401 * transfers to all addressable memory. 402 */ 403 ZONE_NORMAL, 404 #ifdef CONFIG_HIGHMEM 405 /* 406 * A memory area that is only addressable by the kernel through 407 * mapping portions into its own address space. This is for example 408 * used by i386 to allow the kernel to address the memory beyond 409 * 900MB. The kernel will set up special mappings (page 410 * table entries on i386) for each page that the kernel needs to 411 * access. 412 */ 413 ZONE_HIGHMEM, 414 #endif 415 ZONE_MOVABLE, 416 #ifdef CONFIG_ZONE_DEVICE 417 ZONE_DEVICE, 418 #endif 419 __MAX_NR_ZONES 420 421 }; 422 423 #ifndef __GENERATING_BOUNDS_H 424 425 struct zone { 426 /* Read-mostly fields */ 427 428 /* zone watermarks, access with *_wmark_pages(zone) macros */ 429 unsigned long _watermark[NR_WMARK]; 430 unsigned long watermark_boost; 431 432 unsigned long nr_reserved_highatomic; 433 434 /* 435 * We don't know if the memory that we're going to allocate will be 436 * freeable or/and it will be released eventually, so to avoid totally 437 * wasting several GB of ram we must reserve some of the lower zone 438 * memory (otherwise we risk to run OOM on the lower zones despite 439 * there being tons of freeable ram on the higher zones). This array is 440 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 441 * changes. 442 */ 443 long lowmem_reserve[MAX_NR_ZONES]; 444 445 #ifdef CONFIG_NUMA 446 int node; 447 #endif 448 struct pglist_data *zone_pgdat; 449 struct per_cpu_pageset __percpu *pageset; 450 451 #ifndef CONFIG_SPARSEMEM 452 /* 453 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 454 * In SPARSEMEM, this map is stored in struct mem_section 455 */ 456 unsigned long *pageblock_flags; 457 #endif /* CONFIG_SPARSEMEM */ 458 459 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 460 unsigned long zone_start_pfn; 461 462 /* 463 * spanned_pages is the total pages spanned by the zone, including 464 * holes, which is calculated as: 465 * spanned_pages = zone_end_pfn - zone_start_pfn; 466 * 467 * present_pages is physical pages existing within the zone, which 468 * is calculated as: 469 * present_pages = spanned_pages - absent_pages(pages in holes); 470 * 471 * managed_pages is present pages managed by the buddy system, which 472 * is calculated as (reserved_pages includes pages allocated by the 473 * bootmem allocator): 474 * managed_pages = present_pages - reserved_pages; 475 * 476 * So present_pages may be used by memory hotplug or memory power 477 * management logic to figure out unmanaged pages by checking 478 * (present_pages - managed_pages). And managed_pages should be used 479 * by page allocator and vm scanner to calculate all kinds of watermarks 480 * and thresholds. 481 * 482 * Locking rules: 483 * 484 * zone_start_pfn and spanned_pages are protected by span_seqlock. 485 * It is a seqlock because it has to be read outside of zone->lock, 486 * and it is done in the main allocator path. But, it is written 487 * quite infrequently. 488 * 489 * The span_seq lock is declared along with zone->lock because it is 490 * frequently read in proximity to zone->lock. It's good to 491 * give them a chance of being in the same cacheline. 492 * 493 * Write access to present_pages at runtime should be protected by 494 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 495 * present_pages should get_online_mems() to get a stable value. 496 */ 497 atomic_long_t managed_pages; 498 unsigned long spanned_pages; 499 unsigned long present_pages; 500 501 const char *name; 502 503 #ifdef CONFIG_MEMORY_ISOLATION 504 /* 505 * Number of isolated pageblock. It is used to solve incorrect 506 * freepage counting problem due to racy retrieving migratetype 507 * of pageblock. Protected by zone->lock. 508 */ 509 unsigned long nr_isolate_pageblock; 510 #endif 511 512 #ifdef CONFIG_MEMORY_HOTPLUG 513 /* see spanned/present_pages for more description */ 514 seqlock_t span_seqlock; 515 #endif 516 517 int initialized; 518 519 /* Write-intensive fields used from the page allocator */ 520 ZONE_PADDING(_pad1_) 521 522 /* free areas of different sizes */ 523 struct free_area free_area[MAX_ORDER]; 524 525 /* zone flags, see below */ 526 unsigned long flags; 527 528 /* Primarily protects free_area */ 529 spinlock_t lock; 530 531 /* Write-intensive fields used by compaction and vmstats. */ 532 ZONE_PADDING(_pad2_) 533 534 /* 535 * When free pages are below this point, additional steps are taken 536 * when reading the number of free pages to avoid per-cpu counter 537 * drift allowing watermarks to be breached 538 */ 539 unsigned long percpu_drift_mark; 540 541 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 542 /* pfn where compaction free scanner should start */ 543 unsigned long compact_cached_free_pfn; 544 /* pfn where async and sync compaction migration scanner should start */ 545 unsigned long compact_cached_migrate_pfn[2]; 546 unsigned long compact_init_migrate_pfn; 547 unsigned long compact_init_free_pfn; 548 #endif 549 550 #ifdef CONFIG_COMPACTION 551 /* 552 * On compaction failure, 1<<compact_defer_shift compactions 553 * are skipped before trying again. The number attempted since 554 * last failure is tracked with compact_considered. 555 */ 556 unsigned int compact_considered; 557 unsigned int compact_defer_shift; 558 int compact_order_failed; 559 #endif 560 561 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 562 /* Set to true when the PG_migrate_skip bits should be cleared */ 563 bool compact_blockskip_flush; 564 #endif 565 566 bool contiguous; 567 568 ZONE_PADDING(_pad3_) 569 /* Zone statistics */ 570 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 571 atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS]; 572 } ____cacheline_internodealigned_in_smp; 573 574 enum pgdat_flags { 575 PGDAT_CONGESTED, /* pgdat has many dirty pages backed by 576 * a congested BDI 577 */ 578 PGDAT_DIRTY, /* reclaim scanning has recently found 579 * many dirty file pages at the tail 580 * of the LRU. 581 */ 582 PGDAT_WRITEBACK, /* reclaim scanning has recently found 583 * many pages under writeback 584 */ 585 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 586 }; 587 588 enum zone_flags { 589 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. 590 * Cleared when kswapd is woken. 591 */ 592 }; 593 594 static inline unsigned long zone_managed_pages(struct zone *zone) 595 { 596 return (unsigned long)atomic_long_read(&zone->managed_pages); 597 } 598 599 static inline unsigned long zone_end_pfn(const struct zone *zone) 600 { 601 return zone->zone_start_pfn + zone->spanned_pages; 602 } 603 604 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 605 { 606 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 607 } 608 609 static inline bool zone_is_initialized(struct zone *zone) 610 { 611 return zone->initialized; 612 } 613 614 static inline bool zone_is_empty(struct zone *zone) 615 { 616 return zone->spanned_pages == 0; 617 } 618 619 /* 620 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty 621 * intersection with the given zone 622 */ 623 static inline bool zone_intersects(struct zone *zone, 624 unsigned long start_pfn, unsigned long nr_pages) 625 { 626 if (zone_is_empty(zone)) 627 return false; 628 if (start_pfn >= zone_end_pfn(zone) || 629 start_pfn + nr_pages <= zone->zone_start_pfn) 630 return false; 631 632 return true; 633 } 634 635 /* 636 * The "priority" of VM scanning is how much of the queues we will scan in one 637 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 638 * queues ("queue_length >> 12") during an aging round. 639 */ 640 #define DEF_PRIORITY 12 641 642 /* Maximum number of zones on a zonelist */ 643 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 644 645 enum { 646 ZONELIST_FALLBACK, /* zonelist with fallback */ 647 #ifdef CONFIG_NUMA 648 /* 649 * The NUMA zonelists are doubled because we need zonelists that 650 * restrict the allocations to a single node for __GFP_THISNODE. 651 */ 652 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 653 #endif 654 MAX_ZONELISTS 655 }; 656 657 /* 658 * This struct contains information about a zone in a zonelist. It is stored 659 * here to avoid dereferences into large structures and lookups of tables 660 */ 661 struct zoneref { 662 struct zone *zone; /* Pointer to actual zone */ 663 int zone_idx; /* zone_idx(zoneref->zone) */ 664 }; 665 666 /* 667 * One allocation request operates on a zonelist. A zonelist 668 * is a list of zones, the first one is the 'goal' of the 669 * allocation, the other zones are fallback zones, in decreasing 670 * priority. 671 * 672 * To speed the reading of the zonelist, the zonerefs contain the zone index 673 * of the entry being read. Helper functions to access information given 674 * a struct zoneref are 675 * 676 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 677 * zonelist_zone_idx() - Return the index of the zone for an entry 678 * zonelist_node_idx() - Return the index of the node for an entry 679 */ 680 struct zonelist { 681 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 682 }; 683 684 #ifndef CONFIG_DISCONTIGMEM 685 /* The array of struct pages - for discontigmem use pgdat->lmem_map */ 686 extern struct page *mem_map; 687 #endif 688 689 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 690 struct deferred_split { 691 spinlock_t split_queue_lock; 692 struct list_head split_queue; 693 unsigned long split_queue_len; 694 }; 695 #endif 696 697 /* 698 * On NUMA machines, each NUMA node would have a pg_data_t to describe 699 * it's memory layout. On UMA machines there is a single pglist_data which 700 * describes the whole memory. 701 * 702 * Memory statistics and page replacement data structures are maintained on a 703 * per-zone basis. 704 */ 705 struct bootmem_data; 706 typedef struct pglist_data { 707 struct zone node_zones[MAX_NR_ZONES]; 708 struct zonelist node_zonelists[MAX_ZONELISTS]; 709 int nr_zones; 710 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ 711 struct page *node_mem_map; 712 #ifdef CONFIG_PAGE_EXTENSION 713 struct page_ext *node_page_ext; 714 #endif 715 #endif 716 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) 717 /* 718 * Must be held any time you expect node_start_pfn, 719 * node_present_pages, node_spanned_pages or nr_zones to stay constant. 720 * 721 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 722 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG 723 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. 724 * 725 * Nests above zone->lock and zone->span_seqlock 726 */ 727 spinlock_t node_size_lock; 728 #endif 729 unsigned long node_start_pfn; 730 unsigned long node_present_pages; /* total number of physical pages */ 731 unsigned long node_spanned_pages; /* total size of physical page 732 range, including holes */ 733 int node_id; 734 wait_queue_head_t kswapd_wait; 735 wait_queue_head_t pfmemalloc_wait; 736 struct task_struct *kswapd; /* Protected by 737 mem_hotplug_begin/end() */ 738 int kswapd_order; 739 enum zone_type kswapd_classzone_idx; 740 741 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 742 743 #ifdef CONFIG_COMPACTION 744 int kcompactd_max_order; 745 enum zone_type kcompactd_classzone_idx; 746 wait_queue_head_t kcompactd_wait; 747 struct task_struct *kcompactd; 748 #endif 749 /* 750 * This is a per-node reserve of pages that are not available 751 * to userspace allocations. 752 */ 753 unsigned long totalreserve_pages; 754 755 #ifdef CONFIG_NUMA 756 /* 757 * zone reclaim becomes active if more unmapped pages exist. 758 */ 759 unsigned long min_unmapped_pages; 760 unsigned long min_slab_pages; 761 #endif /* CONFIG_NUMA */ 762 763 /* Write-intensive fields used by page reclaim */ 764 ZONE_PADDING(_pad1_) 765 spinlock_t lru_lock; 766 767 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 768 /* 769 * If memory initialisation on large machines is deferred then this 770 * is the first PFN that needs to be initialised. 771 */ 772 unsigned long first_deferred_pfn; 773 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 774 775 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 776 struct deferred_split deferred_split_queue; 777 #endif 778 779 /* Fields commonly accessed by the page reclaim scanner */ 780 struct lruvec lruvec; 781 782 unsigned long flags; 783 784 ZONE_PADDING(_pad2_) 785 786 /* Per-node vmstats */ 787 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 788 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 789 } pg_data_t; 790 791 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 792 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 793 #ifdef CONFIG_FLAT_NODE_MEM_MAP 794 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) 795 #else 796 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) 797 #endif 798 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 799 800 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 801 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 802 803 static inline struct lruvec *node_lruvec(struct pglist_data *pgdat) 804 { 805 return &pgdat->lruvec; 806 } 807 808 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 809 { 810 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 811 } 812 813 static inline bool pgdat_is_empty(pg_data_t *pgdat) 814 { 815 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 816 } 817 818 #include <linux/memory_hotplug.h> 819 820 void build_all_zonelists(pg_data_t *pgdat); 821 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, 822 enum zone_type classzone_idx); 823 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 824 int classzone_idx, unsigned int alloc_flags, 825 long free_pages); 826 bool zone_watermark_ok(struct zone *z, unsigned int order, 827 unsigned long mark, int classzone_idx, 828 unsigned int alloc_flags); 829 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 830 unsigned long mark, int classzone_idx); 831 enum memmap_context { 832 MEMMAP_EARLY, 833 MEMMAP_HOTPLUG, 834 }; 835 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 836 unsigned long size); 837 838 extern void lruvec_init(struct lruvec *lruvec); 839 840 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 841 { 842 #ifdef CONFIG_MEMCG 843 return lruvec->pgdat; 844 #else 845 return container_of(lruvec, struct pglist_data, lruvec); 846 #endif 847 } 848 849 extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx); 850 851 #ifdef CONFIG_HAVE_MEMORY_PRESENT 852 void memory_present(int nid, unsigned long start, unsigned long end); 853 #else 854 static inline void memory_present(int nid, unsigned long start, unsigned long end) {} 855 #endif 856 857 #if defined(CONFIG_SPARSEMEM) 858 void memblocks_present(void); 859 #else 860 static inline void memblocks_present(void) {} 861 #endif 862 863 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 864 int local_memory_node(int node_id); 865 #else 866 static inline int local_memory_node(int node_id) { return node_id; }; 867 #endif 868 869 /* 870 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 871 */ 872 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 873 874 /* 875 * Returns true if a zone has pages managed by the buddy allocator. 876 * All the reclaim decisions have to use this function rather than 877 * populated_zone(). If the whole zone is reserved then we can easily 878 * end up with populated_zone() && !managed_zone(). 879 */ 880 static inline bool managed_zone(struct zone *zone) 881 { 882 return zone_managed_pages(zone); 883 } 884 885 /* Returns true if a zone has memory */ 886 static inline bool populated_zone(struct zone *zone) 887 { 888 return zone->present_pages; 889 } 890 891 #ifdef CONFIG_NUMA 892 static inline int zone_to_nid(struct zone *zone) 893 { 894 return zone->node; 895 } 896 897 static inline void zone_set_nid(struct zone *zone, int nid) 898 { 899 zone->node = nid; 900 } 901 #else 902 static inline int zone_to_nid(struct zone *zone) 903 { 904 return 0; 905 } 906 907 static inline void zone_set_nid(struct zone *zone, int nid) {} 908 #endif 909 910 extern int movable_zone; 911 912 #ifdef CONFIG_HIGHMEM 913 static inline int zone_movable_is_highmem(void) 914 { 915 #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP 916 return movable_zone == ZONE_HIGHMEM; 917 #else 918 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; 919 #endif 920 } 921 #endif 922 923 static inline int is_highmem_idx(enum zone_type idx) 924 { 925 #ifdef CONFIG_HIGHMEM 926 return (idx == ZONE_HIGHMEM || 927 (idx == ZONE_MOVABLE && zone_movable_is_highmem())); 928 #else 929 return 0; 930 #endif 931 } 932 933 /** 934 * is_highmem - helper function to quickly check if a struct zone is a 935 * highmem zone or not. This is an attempt to keep references 936 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 937 * @zone - pointer to struct zone variable 938 */ 939 static inline int is_highmem(struct zone *zone) 940 { 941 #ifdef CONFIG_HIGHMEM 942 return is_highmem_idx(zone_idx(zone)); 943 #else 944 return 0; 945 #endif 946 } 947 948 /* These two functions are used to setup the per zone pages min values */ 949 struct ctl_table; 950 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, 951 void __user *, size_t *, loff_t *); 952 int watermark_boost_factor_sysctl_handler(struct ctl_table *, int, 953 void __user *, size_t *, loff_t *); 954 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, 955 void __user *, size_t *, loff_t *); 956 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; 957 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, 958 void __user *, size_t *, loff_t *); 959 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, 960 void __user *, size_t *, loff_t *); 961 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 962 void __user *, size_t *, loff_t *); 963 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 964 void __user *, size_t *, loff_t *); 965 966 extern int numa_zonelist_order_handler(struct ctl_table *, int, 967 void __user *, size_t *, loff_t *); 968 extern char numa_zonelist_order[]; 969 #define NUMA_ZONELIST_ORDER_LEN 16 970 971 #ifndef CONFIG_NEED_MULTIPLE_NODES 972 973 extern struct pglist_data contig_page_data; 974 #define NODE_DATA(nid) (&contig_page_data) 975 #define NODE_MEM_MAP(nid) mem_map 976 977 #else /* CONFIG_NEED_MULTIPLE_NODES */ 978 979 #include <asm/mmzone.h> 980 981 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 982 983 extern struct pglist_data *first_online_pgdat(void); 984 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 985 extern struct zone *next_zone(struct zone *zone); 986 987 /** 988 * for_each_online_pgdat - helper macro to iterate over all online nodes 989 * @pgdat - pointer to a pg_data_t variable 990 */ 991 #define for_each_online_pgdat(pgdat) \ 992 for (pgdat = first_online_pgdat(); \ 993 pgdat; \ 994 pgdat = next_online_pgdat(pgdat)) 995 /** 996 * for_each_zone - helper macro to iterate over all memory zones 997 * @zone - pointer to struct zone variable 998 * 999 * The user only needs to declare the zone variable, for_each_zone 1000 * fills it in. 1001 */ 1002 #define for_each_zone(zone) \ 1003 for (zone = (first_online_pgdat())->node_zones; \ 1004 zone; \ 1005 zone = next_zone(zone)) 1006 1007 #define for_each_populated_zone(zone) \ 1008 for (zone = (first_online_pgdat())->node_zones; \ 1009 zone; \ 1010 zone = next_zone(zone)) \ 1011 if (!populated_zone(zone)) \ 1012 ; /* do nothing */ \ 1013 else 1014 1015 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 1016 { 1017 return zoneref->zone; 1018 } 1019 1020 static inline int zonelist_zone_idx(struct zoneref *zoneref) 1021 { 1022 return zoneref->zone_idx; 1023 } 1024 1025 static inline int zonelist_node_idx(struct zoneref *zoneref) 1026 { 1027 return zone_to_nid(zoneref->zone); 1028 } 1029 1030 struct zoneref *__next_zones_zonelist(struct zoneref *z, 1031 enum zone_type highest_zoneidx, 1032 nodemask_t *nodes); 1033 1034 /** 1035 * 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 1036 * @z - The cursor used as a starting point for the search 1037 * @highest_zoneidx - The zone index of the highest zone to return 1038 * @nodes - An optional nodemask to filter the zonelist with 1039 * 1040 * This function returns the next zone at or below a given zone index that is 1041 * within the allowed nodemask using a cursor as the starting point for the 1042 * search. The zoneref returned is a cursor that represents the current zone 1043 * being examined. It should be advanced by one before calling 1044 * next_zones_zonelist again. 1045 */ 1046 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 1047 enum zone_type highest_zoneidx, 1048 nodemask_t *nodes) 1049 { 1050 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 1051 return z; 1052 return __next_zones_zonelist(z, highest_zoneidx, nodes); 1053 } 1054 1055 /** 1056 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 1057 * @zonelist - The zonelist to search for a suitable zone 1058 * @highest_zoneidx - The zone index of the highest zone to return 1059 * @nodes - An optional nodemask to filter the zonelist with 1060 * @return - Zoneref pointer for the first suitable zone found (see below) 1061 * 1062 * This function returns the first zone at or below a given zone index that is 1063 * within the allowed nodemask. The zoneref returned is a cursor that can be 1064 * used to iterate the zonelist with next_zones_zonelist by advancing it by 1065 * one before calling. 1066 * 1067 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 1068 * never NULL). This may happen either genuinely, or due to concurrent nodemask 1069 * update due to cpuset modification. 1070 */ 1071 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 1072 enum zone_type highest_zoneidx, 1073 nodemask_t *nodes) 1074 { 1075 return next_zones_zonelist(zonelist->_zonerefs, 1076 highest_zoneidx, nodes); 1077 } 1078 1079 /** 1080 * 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 1081 * @zone - The current zone in the iterator 1082 * @z - The current pointer within zonelist->zones being iterated 1083 * @zlist - The zonelist being iterated 1084 * @highidx - The zone index of the highest zone to return 1085 * @nodemask - Nodemask allowed by the allocator 1086 * 1087 * This iterator iterates though all zones at or below a given zone index and 1088 * within a given nodemask 1089 */ 1090 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1091 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1092 zone; \ 1093 z = next_zones_zonelist(++z, highidx, nodemask), \ 1094 zone = zonelist_zone(z)) 1095 1096 #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1097 for (zone = z->zone; \ 1098 zone; \ 1099 z = next_zones_zonelist(++z, highidx, nodemask), \ 1100 zone = zonelist_zone(z)) 1101 1102 1103 /** 1104 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1105 * @zone - The current zone in the iterator 1106 * @z - The current pointer within zonelist->zones being iterated 1107 * @zlist - The zonelist being iterated 1108 * @highidx - The zone index of the highest zone to return 1109 * 1110 * This iterator iterates though all zones at or below a given zone index. 1111 */ 1112 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1113 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1114 1115 #ifdef CONFIG_SPARSEMEM 1116 #include <asm/sparsemem.h> 1117 #endif 1118 1119 #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \ 1120 !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) 1121 static inline unsigned long early_pfn_to_nid(unsigned long pfn) 1122 { 1123 BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA)); 1124 return 0; 1125 } 1126 #endif 1127 1128 #ifdef CONFIG_FLATMEM 1129 #define pfn_to_nid(pfn) (0) 1130 #endif 1131 1132 #ifdef CONFIG_SPARSEMEM 1133 1134 /* 1135 * SECTION_SHIFT #bits space required to store a section # 1136 * 1137 * PA_SECTION_SHIFT physical address to/from section number 1138 * PFN_SECTION_SHIFT pfn to/from section number 1139 */ 1140 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1141 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1142 1143 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1144 1145 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1146 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1147 1148 #define SECTION_BLOCKFLAGS_BITS \ 1149 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1150 1151 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1152 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1153 #endif 1154 1155 static inline unsigned long pfn_to_section_nr(unsigned long pfn) 1156 { 1157 return pfn >> PFN_SECTION_SHIFT; 1158 } 1159 static inline unsigned long section_nr_to_pfn(unsigned long sec) 1160 { 1161 return sec << PFN_SECTION_SHIFT; 1162 } 1163 1164 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1165 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1166 1167 #define SUBSECTION_SHIFT 21 1168 1169 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) 1170 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) 1171 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) 1172 1173 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS 1174 #error Subsection size exceeds section size 1175 #else 1176 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) 1177 #endif 1178 1179 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) 1180 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) 1181 1182 struct mem_section_usage { 1183 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); 1184 /* See declaration of similar field in struct zone */ 1185 unsigned long pageblock_flags[0]; 1186 }; 1187 1188 void subsection_map_init(unsigned long pfn, unsigned long nr_pages); 1189 1190 struct page; 1191 struct page_ext; 1192 struct mem_section { 1193 /* 1194 * This is, logically, a pointer to an array of struct 1195 * pages. However, it is stored with some other magic. 1196 * (see sparse.c::sparse_init_one_section()) 1197 * 1198 * Additionally during early boot we encode node id of 1199 * the location of the section here to guide allocation. 1200 * (see sparse.c::memory_present()) 1201 * 1202 * Making it a UL at least makes someone do a cast 1203 * before using it wrong. 1204 */ 1205 unsigned long section_mem_map; 1206 1207 struct mem_section_usage *usage; 1208 #ifdef CONFIG_PAGE_EXTENSION 1209 /* 1210 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1211 * section. (see page_ext.h about this.) 1212 */ 1213 struct page_ext *page_ext; 1214 unsigned long pad; 1215 #endif 1216 /* 1217 * WARNING: mem_section must be a power-of-2 in size for the 1218 * calculation and use of SECTION_ROOT_MASK to make sense. 1219 */ 1220 }; 1221 1222 #ifdef CONFIG_SPARSEMEM_EXTREME 1223 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1224 #else 1225 #define SECTIONS_PER_ROOT 1 1226 #endif 1227 1228 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1229 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1230 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1231 1232 #ifdef CONFIG_SPARSEMEM_EXTREME 1233 extern struct mem_section **mem_section; 1234 #else 1235 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1236 #endif 1237 1238 static inline unsigned long *section_to_usemap(struct mem_section *ms) 1239 { 1240 return ms->usage->pageblock_flags; 1241 } 1242 1243 static inline struct mem_section *__nr_to_section(unsigned long nr) 1244 { 1245 #ifdef CONFIG_SPARSEMEM_EXTREME 1246 if (!mem_section) 1247 return NULL; 1248 #endif 1249 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) 1250 return NULL; 1251 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; 1252 } 1253 extern unsigned long __section_nr(struct mem_section *ms); 1254 extern size_t mem_section_usage_size(void); 1255 1256 /* 1257 * We use the lower bits of the mem_map pointer to store 1258 * a little bit of information. The pointer is calculated 1259 * as mem_map - section_nr_to_pfn(pnum). The result is 1260 * aligned to the minimum alignment of the two values: 1261 * 1. All mem_map arrays are page-aligned. 1262 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT 1263 * lowest bits. PFN_SECTION_SHIFT is arch-specific 1264 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the 1265 * worst combination is powerpc with 256k pages, 1266 * which results in PFN_SECTION_SHIFT equal 6. 1267 * To sum it up, at least 6 bits are available. 1268 */ 1269 #define SECTION_MARKED_PRESENT (1UL<<0) 1270 #define SECTION_HAS_MEM_MAP (1UL<<1) 1271 #define SECTION_IS_ONLINE (1UL<<2) 1272 #define SECTION_IS_EARLY (1UL<<3) 1273 #define SECTION_MAP_LAST_BIT (1UL<<4) 1274 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1275 #define SECTION_NID_SHIFT 3 1276 1277 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1278 { 1279 unsigned long map = section->section_mem_map; 1280 map &= SECTION_MAP_MASK; 1281 return (struct page *)map; 1282 } 1283 1284 static inline int present_section(struct mem_section *section) 1285 { 1286 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1287 } 1288 1289 static inline int present_section_nr(unsigned long nr) 1290 { 1291 return present_section(__nr_to_section(nr)); 1292 } 1293 1294 static inline int valid_section(struct mem_section *section) 1295 { 1296 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1297 } 1298 1299 static inline int early_section(struct mem_section *section) 1300 { 1301 return (section && (section->section_mem_map & SECTION_IS_EARLY)); 1302 } 1303 1304 static inline int valid_section_nr(unsigned long nr) 1305 { 1306 return valid_section(__nr_to_section(nr)); 1307 } 1308 1309 static inline int online_section(struct mem_section *section) 1310 { 1311 return (section && (section->section_mem_map & SECTION_IS_ONLINE)); 1312 } 1313 1314 static inline int online_section_nr(unsigned long nr) 1315 { 1316 return online_section(__nr_to_section(nr)); 1317 } 1318 1319 #ifdef CONFIG_MEMORY_HOTPLUG 1320 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1321 #ifdef CONFIG_MEMORY_HOTREMOVE 1322 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1323 #endif 1324 #endif 1325 1326 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1327 { 1328 return __nr_to_section(pfn_to_section_nr(pfn)); 1329 } 1330 1331 extern unsigned long __highest_present_section_nr; 1332 1333 static inline int subsection_map_index(unsigned long pfn) 1334 { 1335 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; 1336 } 1337 1338 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1339 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1340 { 1341 int idx = subsection_map_index(pfn); 1342 1343 return test_bit(idx, ms->usage->subsection_map); 1344 } 1345 #else 1346 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1347 { 1348 return 1; 1349 } 1350 #endif 1351 1352 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1353 static inline int pfn_valid(unsigned long pfn) 1354 { 1355 struct mem_section *ms; 1356 1357 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1358 return 0; 1359 ms = __nr_to_section(pfn_to_section_nr(pfn)); 1360 if (!valid_section(ms)) 1361 return 0; 1362 /* 1363 * Traditionally early sections always returned pfn_valid() for 1364 * the entire section-sized span. 1365 */ 1366 return early_section(ms) || pfn_section_valid(ms, pfn); 1367 } 1368 #endif 1369 1370 static inline int pfn_present(unsigned long pfn) 1371 { 1372 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1373 return 0; 1374 return present_section(__nr_to_section(pfn_to_section_nr(pfn))); 1375 } 1376 1377 /* 1378 * These are _only_ used during initialisation, therefore they 1379 * can use __initdata ... They could have names to indicate 1380 * this restriction. 1381 */ 1382 #ifdef CONFIG_NUMA 1383 #define pfn_to_nid(pfn) \ 1384 ({ \ 1385 unsigned long __pfn_to_nid_pfn = (pfn); \ 1386 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1387 }) 1388 #else 1389 #define pfn_to_nid(pfn) (0) 1390 #endif 1391 1392 #define early_pfn_valid(pfn) pfn_valid(pfn) 1393 void sparse_init(void); 1394 #else 1395 #define sparse_init() do {} while (0) 1396 #define sparse_index_init(_sec, _nid) do {} while (0) 1397 #define pfn_present pfn_valid 1398 #define subsection_map_init(_pfn, _nr_pages) do {} while (0) 1399 #endif /* CONFIG_SPARSEMEM */ 1400 1401 /* 1402 * During memory init memblocks map pfns to nids. The search is expensive and 1403 * this caches recent lookups. The implementation of __early_pfn_to_nid 1404 * may treat start/end as pfns or sections. 1405 */ 1406 struct mminit_pfnnid_cache { 1407 unsigned long last_start; 1408 unsigned long last_end; 1409 int last_nid; 1410 }; 1411 1412 #ifndef early_pfn_valid 1413 #define early_pfn_valid(pfn) (1) 1414 #endif 1415 1416 void memory_present(int nid, unsigned long start, unsigned long end); 1417 1418 /* 1419 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we 1420 * need to check pfn validity within that MAX_ORDER_NR_PAGES block. 1421 * pfn_valid_within() should be used in this case; we optimise this away 1422 * when we have no holes within a MAX_ORDER_NR_PAGES block. 1423 */ 1424 #ifdef CONFIG_HOLES_IN_ZONE 1425 #define pfn_valid_within(pfn) pfn_valid(pfn) 1426 #else 1427 #define pfn_valid_within(pfn) (1) 1428 #endif 1429 1430 #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL 1431 /* 1432 * pfn_valid() is meant to be able to tell if a given PFN has valid memmap 1433 * associated with it or not. This means that a struct page exists for this 1434 * pfn. The caller cannot assume the page is fully initialized in general. 1435 * Hotplugable pages might not have been onlined yet. pfn_to_online_page() 1436 * will ensure the struct page is fully online and initialized. Special pages 1437 * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly. 1438 * 1439 * In FLATMEM, it is expected that holes always have valid memmap as long as 1440 * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed 1441 * that a valid section has a memmap for the entire section. 1442 * 1443 * However, an ARM, and maybe other embedded architectures in the future 1444 * free memmap backing holes to save memory on the assumption the memmap is 1445 * never used. The page_zone linkages are then broken even though pfn_valid() 1446 * returns true. A walker of the full memmap must then do this additional 1447 * check to ensure the memmap they are looking at is sane by making sure 1448 * the zone and PFN linkages are still valid. This is expensive, but walkers 1449 * of the full memmap are extremely rare. 1450 */ 1451 bool memmap_valid_within(unsigned long pfn, 1452 struct page *page, struct zone *zone); 1453 #else 1454 static inline bool memmap_valid_within(unsigned long pfn, 1455 struct page *page, struct zone *zone) 1456 { 1457 return true; 1458 } 1459 #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */ 1460 1461 #endif /* !__GENERATING_BOUNDS.H */ 1462 #endif /* !__ASSEMBLY__ */ 1463 #endif /* _LINUX_MMZONE_H */ 1464