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 MIGRATETYPE_MASK ((1UL << PB_migratetype_bits) - 1) 92 93 #define get_pageblock_migratetype(page) \ 94 get_pfnblock_flags_mask(page, page_to_pfn(page), MIGRATETYPE_MASK) 95 96 struct free_area { 97 struct list_head free_list[MIGRATE_TYPES]; 98 unsigned long nr_free; 99 }; 100 101 static inline struct page *get_page_from_free_area(struct free_area *area, 102 int migratetype) 103 { 104 return list_first_entry_or_null(&area->free_list[migratetype], 105 struct page, lru); 106 } 107 108 static inline bool free_area_empty(struct free_area *area, int migratetype) 109 { 110 return list_empty(&area->free_list[migratetype]); 111 } 112 113 struct pglist_data; 114 115 /* 116 * Add a wild amount of padding here to ensure datas fall into separate 117 * cachelines. There are very few zone structures in the machine, so space 118 * consumption is not a concern here. 119 */ 120 #if defined(CONFIG_SMP) 121 struct zone_padding { 122 char x[0]; 123 } ____cacheline_internodealigned_in_smp; 124 #define ZONE_PADDING(name) struct zone_padding name; 125 #else 126 #define ZONE_PADDING(name) 127 #endif 128 129 #ifdef CONFIG_NUMA 130 enum numa_stat_item { 131 NUMA_HIT, /* allocated in intended node */ 132 NUMA_MISS, /* allocated in non intended node */ 133 NUMA_FOREIGN, /* was intended here, hit elsewhere */ 134 NUMA_INTERLEAVE_HIT, /* interleaver preferred this zone */ 135 NUMA_LOCAL, /* allocation from local node */ 136 NUMA_OTHER, /* allocation from other node */ 137 NR_VM_NUMA_STAT_ITEMS 138 }; 139 #else 140 #define NR_VM_NUMA_STAT_ITEMS 0 141 #endif 142 143 enum zone_stat_item { 144 /* First 128 byte cacheline (assuming 64 bit words) */ 145 NR_FREE_PAGES, 146 NR_ZONE_LRU_BASE, /* Used only for compaction and reclaim retry */ 147 NR_ZONE_INACTIVE_ANON = NR_ZONE_LRU_BASE, 148 NR_ZONE_ACTIVE_ANON, 149 NR_ZONE_INACTIVE_FILE, 150 NR_ZONE_ACTIVE_FILE, 151 NR_ZONE_UNEVICTABLE, 152 NR_ZONE_WRITE_PENDING, /* Count of dirty, writeback and unstable pages */ 153 NR_MLOCK, /* mlock()ed pages found and moved off LRU */ 154 /* Second 128 byte cacheline */ 155 NR_BOUNCE, 156 #if IS_ENABLED(CONFIG_ZSMALLOC) 157 NR_ZSPAGES, /* allocated in zsmalloc */ 158 #endif 159 NR_FREE_CMA_PAGES, 160 NR_VM_ZONE_STAT_ITEMS }; 161 162 enum node_stat_item { 163 NR_LRU_BASE, 164 NR_INACTIVE_ANON = NR_LRU_BASE, /* must match order of LRU_[IN]ACTIVE */ 165 NR_ACTIVE_ANON, /* " " " " " */ 166 NR_INACTIVE_FILE, /* " " " " " */ 167 NR_ACTIVE_FILE, /* " " " " " */ 168 NR_UNEVICTABLE, /* " " " " " */ 169 NR_SLAB_RECLAIMABLE_B, 170 NR_SLAB_UNRECLAIMABLE_B, 171 NR_ISOLATED_ANON, /* Temporary isolated pages from anon lru */ 172 NR_ISOLATED_FILE, /* Temporary isolated pages from file lru */ 173 WORKINGSET_NODES, 174 WORKINGSET_REFAULT_BASE, 175 WORKINGSET_REFAULT_ANON = WORKINGSET_REFAULT_BASE, 176 WORKINGSET_REFAULT_FILE, 177 WORKINGSET_ACTIVATE_BASE, 178 WORKINGSET_ACTIVATE_ANON = WORKINGSET_ACTIVATE_BASE, 179 WORKINGSET_ACTIVATE_FILE, 180 WORKINGSET_RESTORE_BASE, 181 WORKINGSET_RESTORE_ANON = WORKINGSET_RESTORE_BASE, 182 WORKINGSET_RESTORE_FILE, 183 WORKINGSET_NODERECLAIM, 184 NR_ANON_MAPPED, /* Mapped anonymous pages */ 185 NR_FILE_MAPPED, /* pagecache pages mapped into pagetables. 186 only modified from process context */ 187 NR_FILE_PAGES, 188 NR_FILE_DIRTY, 189 NR_WRITEBACK, 190 NR_WRITEBACK_TEMP, /* Writeback using temporary buffers */ 191 NR_SHMEM, /* shmem pages (included tmpfs/GEM pages) */ 192 NR_SHMEM_THPS, 193 NR_SHMEM_PMDMAPPED, 194 NR_FILE_THPS, 195 NR_FILE_PMDMAPPED, 196 NR_ANON_THPS, 197 NR_VMSCAN_WRITE, 198 NR_VMSCAN_IMMEDIATE, /* Prioritise for reclaim when writeback ends */ 199 NR_DIRTIED, /* page dirtyings since bootup */ 200 NR_WRITTEN, /* page writings since bootup */ 201 NR_KERNEL_MISC_RECLAIMABLE, /* reclaimable non-slab kernel pages */ 202 NR_FOLL_PIN_ACQUIRED, /* via: pin_user_page(), gup flag: FOLL_PIN */ 203 NR_FOLL_PIN_RELEASED, /* pages returned via unpin_user_page() */ 204 NR_KERNEL_STACK_KB, /* measured in KiB */ 205 #if IS_ENABLED(CONFIG_SHADOW_CALL_STACK) 206 NR_KERNEL_SCS_KB, /* measured in KiB */ 207 #endif 208 NR_PAGETABLE, /* used for pagetables */ 209 #ifdef CONFIG_SWAP 210 NR_SWAPCACHE, 211 #endif 212 NR_VM_NODE_STAT_ITEMS 213 }; 214 215 /* 216 * Returns true if the item should be printed in THPs (/proc/vmstat 217 * currently prints number of anon, file and shmem THPs. But the item 218 * is charged in pages). 219 */ 220 static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item) 221 { 222 if (!IS_ENABLED(CONFIG_TRANSPARENT_HUGEPAGE)) 223 return false; 224 225 return item == NR_ANON_THPS || 226 item == NR_FILE_THPS || 227 item == NR_SHMEM_THPS || 228 item == NR_SHMEM_PMDMAPPED || 229 item == NR_FILE_PMDMAPPED; 230 } 231 232 /* 233 * Returns true if the value is measured in bytes (most vmstat values are 234 * measured in pages). This defines the API part, the internal representation 235 * might be different. 236 */ 237 static __always_inline bool vmstat_item_in_bytes(int idx) 238 { 239 /* 240 * Global and per-node slab counters track slab pages. 241 * It's expected that changes are multiples of PAGE_SIZE. 242 * Internally values are stored in pages. 243 * 244 * Per-memcg and per-lruvec counters track memory, consumed 245 * by individual slab objects. These counters are actually 246 * byte-precise. 247 */ 248 return (idx == NR_SLAB_RECLAIMABLE_B || 249 idx == NR_SLAB_UNRECLAIMABLE_B); 250 } 251 252 /* 253 * We do arithmetic on the LRU lists in various places in the code, 254 * so it is important to keep the active lists LRU_ACTIVE higher in 255 * the array than the corresponding inactive lists, and to keep 256 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists. 257 * 258 * This has to be kept in sync with the statistics in zone_stat_item 259 * above and the descriptions in vmstat_text in mm/vmstat.c 260 */ 261 #define LRU_BASE 0 262 #define LRU_ACTIVE 1 263 #define LRU_FILE 2 264 265 enum lru_list { 266 LRU_INACTIVE_ANON = LRU_BASE, 267 LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE, 268 LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE, 269 LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE, 270 LRU_UNEVICTABLE, 271 NR_LRU_LISTS 272 }; 273 274 #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++) 275 276 #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++) 277 278 static inline bool is_file_lru(enum lru_list lru) 279 { 280 return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE); 281 } 282 283 static inline bool is_active_lru(enum lru_list lru) 284 { 285 return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE); 286 } 287 288 #define ANON_AND_FILE 2 289 290 enum lruvec_flags { 291 LRUVEC_CONGESTED, /* lruvec has many dirty pages 292 * backed by a congested BDI 293 */ 294 }; 295 296 struct lruvec { 297 struct list_head lists[NR_LRU_LISTS]; 298 /* per lruvec lru_lock for memcg */ 299 spinlock_t lru_lock; 300 /* 301 * These track the cost of reclaiming one LRU - file or anon - 302 * over the other. As the observed cost of reclaiming one LRU 303 * increases, the reclaim scan balance tips toward the other. 304 */ 305 unsigned long anon_cost; 306 unsigned long file_cost; 307 /* Non-resident age, driven by LRU movement */ 308 atomic_long_t nonresident_age; 309 /* Refaults at the time of last reclaim cycle */ 310 unsigned long refaults[ANON_AND_FILE]; 311 /* Various lruvec state flags (enum lruvec_flags) */ 312 unsigned long flags; 313 #ifdef CONFIG_MEMCG 314 struct pglist_data *pgdat; 315 #endif 316 }; 317 318 /* Isolate unmapped pages */ 319 #define ISOLATE_UNMAPPED ((__force isolate_mode_t)0x2) 320 /* Isolate for asynchronous migration */ 321 #define ISOLATE_ASYNC_MIGRATE ((__force isolate_mode_t)0x4) 322 /* Isolate unevictable pages */ 323 #define ISOLATE_UNEVICTABLE ((__force isolate_mode_t)0x8) 324 325 /* LRU Isolation modes. */ 326 typedef unsigned __bitwise isolate_mode_t; 327 328 enum zone_watermarks { 329 WMARK_MIN, 330 WMARK_LOW, 331 WMARK_HIGH, 332 NR_WMARK 333 }; 334 335 #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost) 336 #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost) 337 #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost) 338 #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost) 339 340 struct per_cpu_pages { 341 int count; /* number of pages in the list */ 342 int high; /* high watermark, emptying needed */ 343 int batch; /* chunk size for buddy add/remove */ 344 345 /* Lists of pages, one per migrate type stored on the pcp-lists */ 346 struct list_head lists[MIGRATE_PCPTYPES]; 347 }; 348 349 struct per_cpu_pageset { 350 struct per_cpu_pages pcp; 351 #ifdef CONFIG_NUMA 352 s8 expire; 353 u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS]; 354 #endif 355 #ifdef CONFIG_SMP 356 s8 stat_threshold; 357 s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS]; 358 #endif 359 }; 360 361 struct per_cpu_nodestat { 362 s8 stat_threshold; 363 s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS]; 364 }; 365 366 #endif /* !__GENERATING_BOUNDS.H */ 367 368 enum zone_type { 369 /* 370 * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able 371 * to DMA to all of the addressable memory (ZONE_NORMAL). 372 * On architectures where this area covers the whole 32 bit address 373 * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller 374 * DMA addressing constraints. This distinction is important as a 32bit 375 * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit 376 * platforms may need both zones as they support peripherals with 377 * different DMA addressing limitations. 378 */ 379 #ifdef CONFIG_ZONE_DMA 380 ZONE_DMA, 381 #endif 382 #ifdef CONFIG_ZONE_DMA32 383 ZONE_DMA32, 384 #endif 385 /* 386 * Normal addressable memory is in ZONE_NORMAL. DMA operations can be 387 * performed on pages in ZONE_NORMAL if the DMA devices support 388 * transfers to all addressable memory. 389 */ 390 ZONE_NORMAL, 391 #ifdef CONFIG_HIGHMEM 392 /* 393 * A memory area that is only addressable by the kernel through 394 * mapping portions into its own address space. This is for example 395 * used by i386 to allow the kernel to address the memory beyond 396 * 900MB. The kernel will set up special mappings (page 397 * table entries on i386) for each page that the kernel needs to 398 * access. 399 */ 400 ZONE_HIGHMEM, 401 #endif 402 /* 403 * ZONE_MOVABLE is similar to ZONE_NORMAL, except that it contains 404 * movable pages with few exceptional cases described below. Main use 405 * cases for ZONE_MOVABLE are to make memory offlining/unplug more 406 * likely to succeed, and to locally limit unmovable allocations - e.g., 407 * to increase the number of THP/huge pages. Notable special cases are: 408 * 409 * 1. Pinned pages: (long-term) pinning of movable pages might 410 * essentially turn such pages unmovable. Memory offlining might 411 * retry a long time. 412 * 2. memblock allocations: kernelcore/movablecore setups might create 413 * situations where ZONE_MOVABLE contains unmovable allocations 414 * after boot. Memory offlining and allocations fail early. 415 * 3. Memory holes: kernelcore/movablecore setups might create very rare 416 * situations where ZONE_MOVABLE contains memory holes after boot, 417 * for example, if we have sections that are only partially 418 * populated. Memory offlining and allocations fail early. 419 * 4. PG_hwpoison pages: while poisoned pages can be skipped during 420 * memory offlining, such pages cannot be allocated. 421 * 5. Unmovable PG_offline pages: in paravirtualized environments, 422 * hotplugged memory blocks might only partially be managed by the 423 * buddy (e.g., via XEN-balloon, Hyper-V balloon, virtio-mem). The 424 * parts not manged by the buddy are unmovable PG_offline pages. In 425 * some cases (virtio-mem), such pages can be skipped during 426 * memory offlining, however, cannot be moved/allocated. These 427 * techniques might use alloc_contig_range() to hide previously 428 * exposed pages from the buddy again (e.g., to implement some sort 429 * of memory unplug in virtio-mem). 430 * 431 * In general, no unmovable allocations that degrade memory offlining 432 * should end up in ZONE_MOVABLE. Allocators (like alloc_contig_range()) 433 * have to expect that migrating pages in ZONE_MOVABLE can fail (even 434 * if has_unmovable_pages() states that there are no unmovable pages, 435 * there can be false negatives). 436 */ 437 ZONE_MOVABLE, 438 #ifdef CONFIG_ZONE_DEVICE 439 ZONE_DEVICE, 440 #endif 441 __MAX_NR_ZONES 442 443 }; 444 445 #ifndef __GENERATING_BOUNDS_H 446 447 #define ASYNC_AND_SYNC 2 448 449 struct zone { 450 /* Read-mostly fields */ 451 452 /* zone watermarks, access with *_wmark_pages(zone) macros */ 453 unsigned long _watermark[NR_WMARK]; 454 unsigned long watermark_boost; 455 456 unsigned long nr_reserved_highatomic; 457 458 /* 459 * We don't know if the memory that we're going to allocate will be 460 * freeable or/and it will be released eventually, so to avoid totally 461 * wasting several GB of ram we must reserve some of the lower zone 462 * memory (otherwise we risk to run OOM on the lower zones despite 463 * there being tons of freeable ram on the higher zones). This array is 464 * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl 465 * changes. 466 */ 467 long lowmem_reserve[MAX_NR_ZONES]; 468 469 #ifdef CONFIG_NUMA 470 int node; 471 #endif 472 struct pglist_data *zone_pgdat; 473 struct per_cpu_pageset __percpu *pageset; 474 /* 475 * the high and batch values are copied to individual pagesets for 476 * faster access 477 */ 478 int pageset_high; 479 int pageset_batch; 480 481 #ifndef CONFIG_SPARSEMEM 482 /* 483 * Flags for a pageblock_nr_pages block. See pageblock-flags.h. 484 * In SPARSEMEM, this map is stored in struct mem_section 485 */ 486 unsigned long *pageblock_flags; 487 #endif /* CONFIG_SPARSEMEM */ 488 489 /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */ 490 unsigned long zone_start_pfn; 491 492 /* 493 * spanned_pages is the total pages spanned by the zone, including 494 * holes, which is calculated as: 495 * spanned_pages = zone_end_pfn - zone_start_pfn; 496 * 497 * present_pages is physical pages existing within the zone, which 498 * is calculated as: 499 * present_pages = spanned_pages - absent_pages(pages in holes); 500 * 501 * managed_pages is present pages managed by the buddy system, which 502 * is calculated as (reserved_pages includes pages allocated by the 503 * bootmem allocator): 504 * managed_pages = present_pages - reserved_pages; 505 * 506 * cma pages is present pages that are assigned for CMA use 507 * (MIGRATE_CMA). 508 * 509 * So present_pages may be used by memory hotplug or memory power 510 * management logic to figure out unmanaged pages by checking 511 * (present_pages - managed_pages). And managed_pages should be used 512 * by page allocator and vm scanner to calculate all kinds of watermarks 513 * and thresholds. 514 * 515 * Locking rules: 516 * 517 * zone_start_pfn and spanned_pages are protected by span_seqlock. 518 * It is a seqlock because it has to be read outside of zone->lock, 519 * and it is done in the main allocator path. But, it is written 520 * quite infrequently. 521 * 522 * The span_seq lock is declared along with zone->lock because it is 523 * frequently read in proximity to zone->lock. It's good to 524 * give them a chance of being in the same cacheline. 525 * 526 * Write access to present_pages at runtime should be protected by 527 * mem_hotplug_begin/end(). Any reader who can't tolerant drift of 528 * present_pages should get_online_mems() to get a stable value. 529 */ 530 atomic_long_t managed_pages; 531 unsigned long spanned_pages; 532 unsigned long present_pages; 533 #ifdef CONFIG_CMA 534 unsigned long cma_pages; 535 #endif 536 537 const char *name; 538 539 #ifdef CONFIG_MEMORY_ISOLATION 540 /* 541 * Number of isolated pageblock. It is used to solve incorrect 542 * freepage counting problem due to racy retrieving migratetype 543 * of pageblock. Protected by zone->lock. 544 */ 545 unsigned long nr_isolate_pageblock; 546 #endif 547 548 #ifdef CONFIG_MEMORY_HOTPLUG 549 /* see spanned/present_pages for more description */ 550 seqlock_t span_seqlock; 551 #endif 552 553 int initialized; 554 555 /* Write-intensive fields used from the page allocator */ 556 ZONE_PADDING(_pad1_) 557 558 /* free areas of different sizes */ 559 struct free_area free_area[MAX_ORDER]; 560 561 /* zone flags, see below */ 562 unsigned long flags; 563 564 /* Primarily protects free_area */ 565 spinlock_t lock; 566 567 /* Write-intensive fields used by compaction and vmstats. */ 568 ZONE_PADDING(_pad2_) 569 570 /* 571 * When free pages are below this point, additional steps are taken 572 * when reading the number of free pages to avoid per-cpu counter 573 * drift allowing watermarks to be breached 574 */ 575 unsigned long percpu_drift_mark; 576 577 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 578 /* pfn where compaction free scanner should start */ 579 unsigned long compact_cached_free_pfn; 580 /* pfn where compaction migration scanner should start */ 581 unsigned long compact_cached_migrate_pfn[ASYNC_AND_SYNC]; 582 unsigned long compact_init_migrate_pfn; 583 unsigned long compact_init_free_pfn; 584 #endif 585 586 #ifdef CONFIG_COMPACTION 587 /* 588 * On compaction failure, 1<<compact_defer_shift compactions 589 * are skipped before trying again. The number attempted since 590 * last failure is tracked with compact_considered. 591 * compact_order_failed is the minimum compaction failed order. 592 */ 593 unsigned int compact_considered; 594 unsigned int compact_defer_shift; 595 int compact_order_failed; 596 #endif 597 598 #if defined CONFIG_COMPACTION || defined CONFIG_CMA 599 /* Set to true when the PG_migrate_skip bits should be cleared */ 600 bool compact_blockskip_flush; 601 #endif 602 603 bool contiguous; 604 605 ZONE_PADDING(_pad3_) 606 /* Zone statistics */ 607 atomic_long_t vm_stat[NR_VM_ZONE_STAT_ITEMS]; 608 atomic_long_t vm_numa_stat[NR_VM_NUMA_STAT_ITEMS]; 609 } ____cacheline_internodealigned_in_smp; 610 611 enum pgdat_flags { 612 PGDAT_DIRTY, /* reclaim scanning has recently found 613 * many dirty file pages at the tail 614 * of the LRU. 615 */ 616 PGDAT_WRITEBACK, /* reclaim scanning has recently found 617 * many pages under writeback 618 */ 619 PGDAT_RECLAIM_LOCKED, /* prevents concurrent reclaim */ 620 }; 621 622 enum zone_flags { 623 ZONE_BOOSTED_WATERMARK, /* zone recently boosted watermarks. 624 * Cleared when kswapd is woken. 625 */ 626 }; 627 628 static inline unsigned long zone_managed_pages(struct zone *zone) 629 { 630 return (unsigned long)atomic_long_read(&zone->managed_pages); 631 } 632 633 static inline unsigned long zone_cma_pages(struct zone *zone) 634 { 635 #ifdef CONFIG_CMA 636 return zone->cma_pages; 637 #else 638 return 0; 639 #endif 640 } 641 642 static inline unsigned long zone_end_pfn(const struct zone *zone) 643 { 644 return zone->zone_start_pfn + zone->spanned_pages; 645 } 646 647 static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn) 648 { 649 return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone); 650 } 651 652 static inline bool zone_is_initialized(struct zone *zone) 653 { 654 return zone->initialized; 655 } 656 657 static inline bool zone_is_empty(struct zone *zone) 658 { 659 return zone->spanned_pages == 0; 660 } 661 662 /* 663 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty 664 * intersection with the given zone 665 */ 666 static inline bool zone_intersects(struct zone *zone, 667 unsigned long start_pfn, unsigned long nr_pages) 668 { 669 if (zone_is_empty(zone)) 670 return false; 671 if (start_pfn >= zone_end_pfn(zone) || 672 start_pfn + nr_pages <= zone->zone_start_pfn) 673 return false; 674 675 return true; 676 } 677 678 /* 679 * The "priority" of VM scanning is how much of the queues we will scan in one 680 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the 681 * queues ("queue_length >> 12") during an aging round. 682 */ 683 #define DEF_PRIORITY 12 684 685 /* Maximum number of zones on a zonelist */ 686 #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES) 687 688 enum { 689 ZONELIST_FALLBACK, /* zonelist with fallback */ 690 #ifdef CONFIG_NUMA 691 /* 692 * The NUMA zonelists are doubled because we need zonelists that 693 * restrict the allocations to a single node for __GFP_THISNODE. 694 */ 695 ZONELIST_NOFALLBACK, /* zonelist without fallback (__GFP_THISNODE) */ 696 #endif 697 MAX_ZONELISTS 698 }; 699 700 /* 701 * This struct contains information about a zone in a zonelist. It is stored 702 * here to avoid dereferences into large structures and lookups of tables 703 */ 704 struct zoneref { 705 struct zone *zone; /* Pointer to actual zone */ 706 int zone_idx; /* zone_idx(zoneref->zone) */ 707 }; 708 709 /* 710 * One allocation request operates on a zonelist. A zonelist 711 * is a list of zones, the first one is the 'goal' of the 712 * allocation, the other zones are fallback zones, in decreasing 713 * priority. 714 * 715 * To speed the reading of the zonelist, the zonerefs contain the zone index 716 * of the entry being read. Helper functions to access information given 717 * a struct zoneref are 718 * 719 * zonelist_zone() - Return the struct zone * for an entry in _zonerefs 720 * zonelist_zone_idx() - Return the index of the zone for an entry 721 * zonelist_node_idx() - Return the index of the node for an entry 722 */ 723 struct zonelist { 724 struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1]; 725 }; 726 727 #ifndef CONFIG_DISCONTIGMEM 728 /* The array of struct pages - for discontigmem use pgdat->lmem_map */ 729 extern struct page *mem_map; 730 #endif 731 732 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 733 struct deferred_split { 734 spinlock_t split_queue_lock; 735 struct list_head split_queue; 736 unsigned long split_queue_len; 737 }; 738 #endif 739 740 /* 741 * On NUMA machines, each NUMA node would have a pg_data_t to describe 742 * it's memory layout. On UMA machines there is a single pglist_data which 743 * describes the whole memory. 744 * 745 * Memory statistics and page replacement data structures are maintained on a 746 * per-zone basis. 747 */ 748 typedef struct pglist_data { 749 /* 750 * node_zones contains just the zones for THIS node. Not all of the 751 * zones may be populated, but it is the full list. It is referenced by 752 * this node's node_zonelists as well as other node's node_zonelists. 753 */ 754 struct zone node_zones[MAX_NR_ZONES]; 755 756 /* 757 * node_zonelists contains references to all zones in all nodes. 758 * Generally the first zones will be references to this node's 759 * node_zones. 760 */ 761 struct zonelist node_zonelists[MAX_ZONELISTS]; 762 763 int nr_zones; /* number of populated zones in this node */ 764 #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */ 765 struct page *node_mem_map; 766 #ifdef CONFIG_PAGE_EXTENSION 767 struct page_ext *node_page_ext; 768 #endif 769 #endif 770 #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT) 771 /* 772 * Must be held any time you expect node_start_pfn, 773 * node_present_pages, node_spanned_pages or nr_zones to stay constant. 774 * Also synchronizes pgdat->first_deferred_pfn during deferred page 775 * init. 776 * 777 * pgdat_resize_lock() and pgdat_resize_unlock() are provided to 778 * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG 779 * or CONFIG_DEFERRED_STRUCT_PAGE_INIT. 780 * 781 * Nests above zone->lock and zone->span_seqlock 782 */ 783 spinlock_t node_size_lock; 784 #endif 785 unsigned long node_start_pfn; 786 unsigned long node_present_pages; /* total number of physical pages */ 787 unsigned long node_spanned_pages; /* total size of physical page 788 range, including holes */ 789 int node_id; 790 wait_queue_head_t kswapd_wait; 791 wait_queue_head_t pfmemalloc_wait; 792 struct task_struct *kswapd; /* Protected by 793 mem_hotplug_begin/end() */ 794 int kswapd_order; 795 enum zone_type kswapd_highest_zoneidx; 796 797 int kswapd_failures; /* Number of 'reclaimed == 0' runs */ 798 799 #ifdef CONFIG_COMPACTION 800 int kcompactd_max_order; 801 enum zone_type kcompactd_highest_zoneidx; 802 wait_queue_head_t kcompactd_wait; 803 struct task_struct *kcompactd; 804 #endif 805 /* 806 * This is a per-node reserve of pages that are not available 807 * to userspace allocations. 808 */ 809 unsigned long totalreserve_pages; 810 811 #ifdef CONFIG_NUMA 812 /* 813 * node reclaim becomes active if more unmapped pages exist. 814 */ 815 unsigned long min_unmapped_pages; 816 unsigned long min_slab_pages; 817 #endif /* CONFIG_NUMA */ 818 819 /* Write-intensive fields used by page reclaim */ 820 ZONE_PADDING(_pad1_) 821 822 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT 823 /* 824 * If memory initialisation on large machines is deferred then this 825 * is the first PFN that needs to be initialised. 826 */ 827 unsigned long first_deferred_pfn; 828 #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */ 829 830 #ifdef CONFIG_TRANSPARENT_HUGEPAGE 831 struct deferred_split deferred_split_queue; 832 #endif 833 834 /* Fields commonly accessed by the page reclaim scanner */ 835 836 /* 837 * NOTE: THIS IS UNUSED IF MEMCG IS ENABLED. 838 * 839 * Use mem_cgroup_lruvec() to look up lruvecs. 840 */ 841 struct lruvec __lruvec; 842 843 unsigned long flags; 844 845 ZONE_PADDING(_pad2_) 846 847 /* Per-node vmstats */ 848 struct per_cpu_nodestat __percpu *per_cpu_nodestats; 849 atomic_long_t vm_stat[NR_VM_NODE_STAT_ITEMS]; 850 } pg_data_t; 851 852 #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages) 853 #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages) 854 #ifdef CONFIG_FLAT_NODE_MEM_MAP 855 #define pgdat_page_nr(pgdat, pagenr) ((pgdat)->node_mem_map + (pagenr)) 856 #else 857 #define pgdat_page_nr(pgdat, pagenr) pfn_to_page((pgdat)->node_start_pfn + (pagenr)) 858 #endif 859 #define nid_page_nr(nid, pagenr) pgdat_page_nr(NODE_DATA(nid),(pagenr)) 860 861 #define node_start_pfn(nid) (NODE_DATA(nid)->node_start_pfn) 862 #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid)) 863 864 static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat) 865 { 866 return pgdat->node_start_pfn + pgdat->node_spanned_pages; 867 } 868 869 static inline bool pgdat_is_empty(pg_data_t *pgdat) 870 { 871 return !pgdat->node_start_pfn && !pgdat->node_spanned_pages; 872 } 873 874 #include <linux/memory_hotplug.h> 875 876 void build_all_zonelists(pg_data_t *pgdat); 877 void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order, 878 enum zone_type highest_zoneidx); 879 bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark, 880 int highest_zoneidx, unsigned int alloc_flags, 881 long free_pages); 882 bool zone_watermark_ok(struct zone *z, unsigned int order, 883 unsigned long mark, int highest_zoneidx, 884 unsigned int alloc_flags); 885 bool zone_watermark_ok_safe(struct zone *z, unsigned int order, 886 unsigned long mark, int highest_zoneidx); 887 /* 888 * Memory initialization context, use to differentiate memory added by 889 * the platform statically or via memory hotplug interface. 890 */ 891 enum meminit_context { 892 MEMINIT_EARLY, 893 MEMINIT_HOTPLUG, 894 }; 895 896 extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn, 897 unsigned long size); 898 899 extern void lruvec_init(struct lruvec *lruvec); 900 901 static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec) 902 { 903 #ifdef CONFIG_MEMCG 904 return lruvec->pgdat; 905 #else 906 return container_of(lruvec, struct pglist_data, __lruvec); 907 #endif 908 } 909 910 #ifdef CONFIG_HAVE_MEMORYLESS_NODES 911 int local_memory_node(int node_id); 912 #else 913 static inline int local_memory_node(int node_id) { return node_id; }; 914 #endif 915 916 /* 917 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc. 918 */ 919 #define zone_idx(zone) ((zone) - (zone)->zone_pgdat->node_zones) 920 921 #ifdef CONFIG_ZONE_DEVICE 922 static inline bool zone_is_zone_device(struct zone *zone) 923 { 924 return zone_idx(zone) == ZONE_DEVICE; 925 } 926 #else 927 static inline bool zone_is_zone_device(struct zone *zone) 928 { 929 return false; 930 } 931 #endif 932 933 /* 934 * Returns true if a zone has pages managed by the buddy allocator. 935 * All the reclaim decisions have to use this function rather than 936 * populated_zone(). If the whole zone is reserved then we can easily 937 * end up with populated_zone() && !managed_zone(). 938 */ 939 static inline bool managed_zone(struct zone *zone) 940 { 941 return zone_managed_pages(zone); 942 } 943 944 /* Returns true if a zone has memory */ 945 static inline bool populated_zone(struct zone *zone) 946 { 947 return zone->present_pages; 948 } 949 950 #ifdef CONFIG_NUMA 951 static inline int zone_to_nid(struct zone *zone) 952 { 953 return zone->node; 954 } 955 956 static inline void zone_set_nid(struct zone *zone, int nid) 957 { 958 zone->node = nid; 959 } 960 #else 961 static inline int zone_to_nid(struct zone *zone) 962 { 963 return 0; 964 } 965 966 static inline void zone_set_nid(struct zone *zone, int nid) {} 967 #endif 968 969 extern int movable_zone; 970 971 #ifdef CONFIG_HIGHMEM 972 static inline int zone_movable_is_highmem(void) 973 { 974 #ifdef CONFIG_NEED_MULTIPLE_NODES 975 return movable_zone == ZONE_HIGHMEM; 976 #else 977 return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM; 978 #endif 979 } 980 #endif 981 982 static inline int is_highmem_idx(enum zone_type idx) 983 { 984 #ifdef CONFIG_HIGHMEM 985 return (idx == ZONE_HIGHMEM || 986 (idx == ZONE_MOVABLE && zone_movable_is_highmem())); 987 #else 988 return 0; 989 #endif 990 } 991 992 /** 993 * is_highmem - helper function to quickly check if a struct zone is a 994 * highmem zone or not. This is an attempt to keep references 995 * to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum. 996 * @zone - pointer to struct zone variable 997 */ 998 static inline int is_highmem(struct zone *zone) 999 { 1000 #ifdef CONFIG_HIGHMEM 1001 return is_highmem_idx(zone_idx(zone)); 1002 #else 1003 return 0; 1004 #endif 1005 } 1006 1007 /* These two functions are used to setup the per zone pages min values */ 1008 struct ctl_table; 1009 1010 int min_free_kbytes_sysctl_handler(struct ctl_table *, int, void *, size_t *, 1011 loff_t *); 1012 int watermark_scale_factor_sysctl_handler(struct ctl_table *, int, void *, 1013 size_t *, loff_t *); 1014 extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES]; 1015 int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int, void *, 1016 size_t *, loff_t *); 1017 int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int, 1018 void *, size_t *, loff_t *); 1019 int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int, 1020 void *, size_t *, loff_t *); 1021 int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int, 1022 void *, size_t *, loff_t *); 1023 int numa_zonelist_order_handler(struct ctl_table *, int, 1024 void *, size_t *, loff_t *); 1025 extern int percpu_pagelist_fraction; 1026 extern char numa_zonelist_order[]; 1027 #define NUMA_ZONELIST_ORDER_LEN 16 1028 1029 #ifndef CONFIG_NEED_MULTIPLE_NODES 1030 1031 extern struct pglist_data contig_page_data; 1032 #define NODE_DATA(nid) (&contig_page_data) 1033 #define NODE_MEM_MAP(nid) mem_map 1034 1035 #else /* CONFIG_NEED_MULTIPLE_NODES */ 1036 1037 #include <asm/mmzone.h> 1038 1039 #endif /* !CONFIG_NEED_MULTIPLE_NODES */ 1040 1041 extern struct pglist_data *first_online_pgdat(void); 1042 extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat); 1043 extern struct zone *next_zone(struct zone *zone); 1044 1045 /** 1046 * for_each_online_pgdat - helper macro to iterate over all online nodes 1047 * @pgdat - pointer to a pg_data_t variable 1048 */ 1049 #define for_each_online_pgdat(pgdat) \ 1050 for (pgdat = first_online_pgdat(); \ 1051 pgdat; \ 1052 pgdat = next_online_pgdat(pgdat)) 1053 /** 1054 * for_each_zone - helper macro to iterate over all memory zones 1055 * @zone - pointer to struct zone variable 1056 * 1057 * The user only needs to declare the zone variable, for_each_zone 1058 * fills it in. 1059 */ 1060 #define for_each_zone(zone) \ 1061 for (zone = (first_online_pgdat())->node_zones; \ 1062 zone; \ 1063 zone = next_zone(zone)) 1064 1065 #define for_each_populated_zone(zone) \ 1066 for (zone = (first_online_pgdat())->node_zones; \ 1067 zone; \ 1068 zone = next_zone(zone)) \ 1069 if (!populated_zone(zone)) \ 1070 ; /* do nothing */ \ 1071 else 1072 1073 static inline struct zone *zonelist_zone(struct zoneref *zoneref) 1074 { 1075 return zoneref->zone; 1076 } 1077 1078 static inline int zonelist_zone_idx(struct zoneref *zoneref) 1079 { 1080 return zoneref->zone_idx; 1081 } 1082 1083 static inline int zonelist_node_idx(struct zoneref *zoneref) 1084 { 1085 return zone_to_nid(zoneref->zone); 1086 } 1087 1088 struct zoneref *__next_zones_zonelist(struct zoneref *z, 1089 enum zone_type highest_zoneidx, 1090 nodemask_t *nodes); 1091 1092 /** 1093 * 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 1094 * @z - The cursor used as a starting point for the search 1095 * @highest_zoneidx - The zone index of the highest zone to return 1096 * @nodes - An optional nodemask to filter the zonelist with 1097 * 1098 * This function returns the next zone at or below a given zone index that is 1099 * within the allowed nodemask using a cursor as the starting point for the 1100 * search. The zoneref returned is a cursor that represents the current zone 1101 * being examined. It should be advanced by one before calling 1102 * next_zones_zonelist again. 1103 */ 1104 static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z, 1105 enum zone_type highest_zoneidx, 1106 nodemask_t *nodes) 1107 { 1108 if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx)) 1109 return z; 1110 return __next_zones_zonelist(z, highest_zoneidx, nodes); 1111 } 1112 1113 /** 1114 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist 1115 * @zonelist - The zonelist to search for a suitable zone 1116 * @highest_zoneidx - The zone index of the highest zone to return 1117 * @nodes - An optional nodemask to filter the zonelist with 1118 * @return - Zoneref pointer for the first suitable zone found (see below) 1119 * 1120 * This function returns the first zone at or below a given zone index that is 1121 * within the allowed nodemask. The zoneref returned is a cursor that can be 1122 * used to iterate the zonelist with next_zones_zonelist by advancing it by 1123 * one before calling. 1124 * 1125 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is 1126 * never NULL). This may happen either genuinely, or due to concurrent nodemask 1127 * update due to cpuset modification. 1128 */ 1129 static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist, 1130 enum zone_type highest_zoneidx, 1131 nodemask_t *nodes) 1132 { 1133 return next_zones_zonelist(zonelist->_zonerefs, 1134 highest_zoneidx, nodes); 1135 } 1136 1137 /** 1138 * 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 1139 * @zone - The current zone in the iterator 1140 * @z - The current pointer within zonelist->_zonerefs being iterated 1141 * @zlist - The zonelist being iterated 1142 * @highidx - The zone index of the highest zone to return 1143 * @nodemask - Nodemask allowed by the allocator 1144 * 1145 * This iterator iterates though all zones at or below a given zone index and 1146 * within a given nodemask 1147 */ 1148 #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \ 1149 for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z); \ 1150 zone; \ 1151 z = next_zones_zonelist(++z, highidx, nodemask), \ 1152 zone = zonelist_zone(z)) 1153 1154 #define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask) \ 1155 for (zone = z->zone; \ 1156 zone; \ 1157 z = next_zones_zonelist(++z, highidx, nodemask), \ 1158 zone = zonelist_zone(z)) 1159 1160 1161 /** 1162 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index 1163 * @zone - The current zone in the iterator 1164 * @z - The current pointer within zonelist->zones being iterated 1165 * @zlist - The zonelist being iterated 1166 * @highidx - The zone index of the highest zone to return 1167 * 1168 * This iterator iterates though all zones at or below a given zone index. 1169 */ 1170 #define for_each_zone_zonelist(zone, z, zlist, highidx) \ 1171 for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL) 1172 1173 #ifdef CONFIG_SPARSEMEM 1174 #include <asm/sparsemem.h> 1175 #endif 1176 1177 #ifdef CONFIG_FLATMEM 1178 #define pfn_to_nid(pfn) (0) 1179 #endif 1180 1181 #ifdef CONFIG_SPARSEMEM 1182 1183 /* 1184 * SECTION_SHIFT #bits space required to store a section # 1185 * 1186 * PA_SECTION_SHIFT physical address to/from section number 1187 * PFN_SECTION_SHIFT pfn to/from section number 1188 */ 1189 #define PA_SECTION_SHIFT (SECTION_SIZE_BITS) 1190 #define PFN_SECTION_SHIFT (SECTION_SIZE_BITS - PAGE_SHIFT) 1191 1192 #define NR_MEM_SECTIONS (1UL << SECTIONS_SHIFT) 1193 1194 #define PAGES_PER_SECTION (1UL << PFN_SECTION_SHIFT) 1195 #define PAGE_SECTION_MASK (~(PAGES_PER_SECTION-1)) 1196 1197 #define SECTION_BLOCKFLAGS_BITS \ 1198 ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS) 1199 1200 #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS 1201 #error Allocator MAX_ORDER exceeds SECTION_SIZE 1202 #endif 1203 1204 static inline unsigned long pfn_to_section_nr(unsigned long pfn) 1205 { 1206 return pfn >> PFN_SECTION_SHIFT; 1207 } 1208 static inline unsigned long section_nr_to_pfn(unsigned long sec) 1209 { 1210 return sec << PFN_SECTION_SHIFT; 1211 } 1212 1213 #define SECTION_ALIGN_UP(pfn) (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK) 1214 #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK) 1215 1216 #define SUBSECTION_SHIFT 21 1217 #define SUBSECTION_SIZE (1UL << SUBSECTION_SHIFT) 1218 1219 #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT) 1220 #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT) 1221 #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1)) 1222 1223 #if SUBSECTION_SHIFT > SECTION_SIZE_BITS 1224 #error Subsection size exceeds section size 1225 #else 1226 #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT)) 1227 #endif 1228 1229 #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION) 1230 #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK) 1231 1232 struct mem_section_usage { 1233 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1234 DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION); 1235 #endif 1236 /* See declaration of similar field in struct zone */ 1237 unsigned long pageblock_flags[0]; 1238 }; 1239 1240 void subsection_map_init(unsigned long pfn, unsigned long nr_pages); 1241 1242 struct page; 1243 struct page_ext; 1244 struct mem_section { 1245 /* 1246 * This is, logically, a pointer to an array of struct 1247 * pages. However, it is stored with some other magic. 1248 * (see sparse.c::sparse_init_one_section()) 1249 * 1250 * Additionally during early boot we encode node id of 1251 * the location of the section here to guide allocation. 1252 * (see sparse.c::memory_present()) 1253 * 1254 * Making it a UL at least makes someone do a cast 1255 * before using it wrong. 1256 */ 1257 unsigned long section_mem_map; 1258 1259 struct mem_section_usage *usage; 1260 #ifdef CONFIG_PAGE_EXTENSION 1261 /* 1262 * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use 1263 * section. (see page_ext.h about this.) 1264 */ 1265 struct page_ext *page_ext; 1266 unsigned long pad; 1267 #endif 1268 /* 1269 * WARNING: mem_section must be a power-of-2 in size for the 1270 * calculation and use of SECTION_ROOT_MASK to make sense. 1271 */ 1272 }; 1273 1274 #ifdef CONFIG_SPARSEMEM_EXTREME 1275 #define SECTIONS_PER_ROOT (PAGE_SIZE / sizeof (struct mem_section)) 1276 #else 1277 #define SECTIONS_PER_ROOT 1 1278 #endif 1279 1280 #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT) 1281 #define NR_SECTION_ROOTS DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT) 1282 #define SECTION_ROOT_MASK (SECTIONS_PER_ROOT - 1) 1283 1284 #ifdef CONFIG_SPARSEMEM_EXTREME 1285 extern struct mem_section **mem_section; 1286 #else 1287 extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT]; 1288 #endif 1289 1290 static inline unsigned long *section_to_usemap(struct mem_section *ms) 1291 { 1292 return ms->usage->pageblock_flags; 1293 } 1294 1295 static inline struct mem_section *__nr_to_section(unsigned long nr) 1296 { 1297 #ifdef CONFIG_SPARSEMEM_EXTREME 1298 if (!mem_section) 1299 return NULL; 1300 #endif 1301 if (!mem_section[SECTION_NR_TO_ROOT(nr)]) 1302 return NULL; 1303 return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK]; 1304 } 1305 extern unsigned long __section_nr(struct mem_section *ms); 1306 extern size_t mem_section_usage_size(void); 1307 1308 /* 1309 * We use the lower bits of the mem_map pointer to store 1310 * a little bit of information. The pointer is calculated 1311 * as mem_map - section_nr_to_pfn(pnum). The result is 1312 * aligned to the minimum alignment of the two values: 1313 * 1. All mem_map arrays are page-aligned. 1314 * 2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT 1315 * lowest bits. PFN_SECTION_SHIFT is arch-specific 1316 * (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the 1317 * worst combination is powerpc with 256k pages, 1318 * which results in PFN_SECTION_SHIFT equal 6. 1319 * To sum it up, at least 6 bits are available. 1320 */ 1321 #define SECTION_MARKED_PRESENT (1UL<<0) 1322 #define SECTION_HAS_MEM_MAP (1UL<<1) 1323 #define SECTION_IS_ONLINE (1UL<<2) 1324 #define SECTION_IS_EARLY (1UL<<3) 1325 #define SECTION_TAINT_ZONE_DEVICE (1UL<<4) 1326 #define SECTION_MAP_LAST_BIT (1UL<<5) 1327 #define SECTION_MAP_MASK (~(SECTION_MAP_LAST_BIT-1)) 1328 #define SECTION_NID_SHIFT 3 1329 1330 static inline struct page *__section_mem_map_addr(struct mem_section *section) 1331 { 1332 unsigned long map = section->section_mem_map; 1333 map &= SECTION_MAP_MASK; 1334 return (struct page *)map; 1335 } 1336 1337 static inline int present_section(struct mem_section *section) 1338 { 1339 return (section && (section->section_mem_map & SECTION_MARKED_PRESENT)); 1340 } 1341 1342 static inline int present_section_nr(unsigned long nr) 1343 { 1344 return present_section(__nr_to_section(nr)); 1345 } 1346 1347 static inline int valid_section(struct mem_section *section) 1348 { 1349 return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP)); 1350 } 1351 1352 static inline int early_section(struct mem_section *section) 1353 { 1354 return (section && (section->section_mem_map & SECTION_IS_EARLY)); 1355 } 1356 1357 static inline int valid_section_nr(unsigned long nr) 1358 { 1359 return valid_section(__nr_to_section(nr)); 1360 } 1361 1362 static inline int online_section(struct mem_section *section) 1363 { 1364 return (section && (section->section_mem_map & SECTION_IS_ONLINE)); 1365 } 1366 1367 static inline int online_device_section(struct mem_section *section) 1368 { 1369 unsigned long flags = SECTION_IS_ONLINE | SECTION_TAINT_ZONE_DEVICE; 1370 1371 return section && ((section->section_mem_map & flags) == flags); 1372 } 1373 1374 static inline int online_section_nr(unsigned long nr) 1375 { 1376 return online_section(__nr_to_section(nr)); 1377 } 1378 1379 #ifdef CONFIG_MEMORY_HOTPLUG 1380 void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1381 #ifdef CONFIG_MEMORY_HOTREMOVE 1382 void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn); 1383 #endif 1384 #endif 1385 1386 static inline struct mem_section *__pfn_to_section(unsigned long pfn) 1387 { 1388 return __nr_to_section(pfn_to_section_nr(pfn)); 1389 } 1390 1391 extern unsigned long __highest_present_section_nr; 1392 1393 static inline int subsection_map_index(unsigned long pfn) 1394 { 1395 return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION; 1396 } 1397 1398 #ifdef CONFIG_SPARSEMEM_VMEMMAP 1399 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1400 { 1401 int idx = subsection_map_index(pfn); 1402 1403 return test_bit(idx, ms->usage->subsection_map); 1404 } 1405 #else 1406 static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn) 1407 { 1408 return 1; 1409 } 1410 #endif 1411 1412 #ifndef CONFIG_HAVE_ARCH_PFN_VALID 1413 static inline int pfn_valid(unsigned long pfn) 1414 { 1415 struct mem_section *ms; 1416 1417 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1418 return 0; 1419 ms = __nr_to_section(pfn_to_section_nr(pfn)); 1420 if (!valid_section(ms)) 1421 return 0; 1422 /* 1423 * Traditionally early sections always returned pfn_valid() for 1424 * the entire section-sized span. 1425 */ 1426 return early_section(ms) || pfn_section_valid(ms, pfn); 1427 } 1428 #endif 1429 1430 static inline int pfn_in_present_section(unsigned long pfn) 1431 { 1432 if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS) 1433 return 0; 1434 return present_section(__nr_to_section(pfn_to_section_nr(pfn))); 1435 } 1436 1437 static inline unsigned long next_present_section_nr(unsigned long section_nr) 1438 { 1439 while (++section_nr <= __highest_present_section_nr) { 1440 if (present_section_nr(section_nr)) 1441 return section_nr; 1442 } 1443 1444 return -1; 1445 } 1446 1447 /* 1448 * These are _only_ used during initialisation, therefore they 1449 * can use __initdata ... They could have names to indicate 1450 * this restriction. 1451 */ 1452 #ifdef CONFIG_NUMA 1453 #define pfn_to_nid(pfn) \ 1454 ({ \ 1455 unsigned long __pfn_to_nid_pfn = (pfn); \ 1456 page_to_nid(pfn_to_page(__pfn_to_nid_pfn)); \ 1457 }) 1458 #else 1459 #define pfn_to_nid(pfn) (0) 1460 #endif 1461 1462 void sparse_init(void); 1463 #else 1464 #define sparse_init() do {} while (0) 1465 #define sparse_index_init(_sec, _nid) do {} while (0) 1466 #define pfn_in_present_section pfn_valid 1467 #define subsection_map_init(_pfn, _nr_pages) do {} while (0) 1468 #endif /* CONFIG_SPARSEMEM */ 1469 1470 /* 1471 * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we 1472 * need to check pfn validity within that MAX_ORDER_NR_PAGES block. 1473 * pfn_valid_within() should be used in this case; we optimise this away 1474 * when we have no holes within a MAX_ORDER_NR_PAGES block. 1475 */ 1476 #ifdef CONFIG_HOLES_IN_ZONE 1477 #define pfn_valid_within(pfn) pfn_valid(pfn) 1478 #else 1479 #define pfn_valid_within(pfn) (1) 1480 #endif 1481 1482 #endif /* !__GENERATING_BOUNDS.H */ 1483 #endif /* !__ASSEMBLY__ */ 1484 #endif /* _LINUX_MMZONE_H */ 1485