LCOV - code coverage report
Current view: top level - include/linux - mmzone.h (source / functions) Hit Total Coverage
Test: Real Lines: 26 29 89.7 %
Date: 2020-10-17 15:46:16 Functions: 0 5 0.0 %
Legend: Neither, QEMU, Real, Both Branches: 0 0 -

           Branch data     Line data    Source code
       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                 :          0 :         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                 :          3 :         list_add(&page->lru, &area->free_list[migratetype]);
     108                 :          3 :         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                 :          3 :         list_add_tail(&page->lru, &area->free_list[migratetype]);
     116                 :          3 :         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                 :          3 :         list_move(&page->lru, &area->free_list[migratetype]);
     136                 :            : }
     137                 :            : 
     138                 :          3 : static inline struct page *get_page_from_free_area(struct free_area *area,
     139                 :            :                                             int migratetype)
     140                 :            : {
     141                 :          3 :         return list_first_entry_or_null(&area->free_list[migratetype],
     142                 :            :                                         struct page, lru);
     143                 :            : }
     144                 :            : 
     145                 :          3 : 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                 :          3 :         set_page_private(page, 0);
     151                 :          3 :         area->nr_free--;
     152                 :          3 : }
     153                 :            : 
     154                 :            : static inline bool free_area_empty(struct free_area *area, int migratetype)
     155                 :            : {
     156                 :          3 :         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,
     219                 :            :         NR_SLAB_UNRECLAIMABLE,
     220                 :            :         NR_ISOLATED_ANON,       /* Temporary isolated pages from anon lru */
     221                 :            :         NR_ISOLATED_FILE,       /* Temporary isolated pages from file lru */
     222                 :            :         WORKINGSET_NODES,
     223                 :            :         WORKINGSET_REFAULT,
     224                 :            :         WORKINGSET_ACTIVATE,
     225                 :            :         WORKINGSET_RESTORE,
     226                 :            :         WORKINGSET_NODERECLAIM,
     227                 :            :         NR_ANON_MAPPED, /* Mapped anonymous pages */
     228                 :            :         NR_FILE_MAPPED, /* pagecache pages mapped into pagetables.
     229                 :            :                            only modified from process context */
     230                 :            :         NR_FILE_PAGES,
     231                 :            :         NR_FILE_DIRTY,
     232                 :            :         NR_WRITEBACK,
     233                 :            :         NR_WRITEBACK_TEMP,      /* Writeback using temporary buffers */
     234                 :            :         NR_SHMEM,               /* shmem pages (included tmpfs/GEM pages) */
     235                 :            :         NR_SHMEM_THPS,
     236                 :            :         NR_SHMEM_PMDMAPPED,
     237                 :            :         NR_FILE_THPS,
     238                 :            :         NR_FILE_PMDMAPPED,
     239                 :            :         NR_ANON_THPS,
     240                 :            :         NR_UNSTABLE_NFS,        /* NFS unstable pages */
     241                 :            :         NR_VMSCAN_WRITE,
     242                 :            :         NR_VMSCAN_IMMEDIATE,    /* Prioritise for reclaim when writeback ends */
     243                 :            :         NR_DIRTIED,             /* page dirtyings since bootup */
     244                 :            :         NR_WRITTEN,             /* page writings since bootup */
     245                 :            :         NR_KERNEL_MISC_RECLAIMABLE,     /* reclaimable non-slab kernel pages */
     246                 :            :         NR_VM_NODE_STAT_ITEMS
     247                 :            : };
     248                 :            : 
     249                 :            : /*
     250                 :            :  * We do arithmetic on the LRU lists in various places in the code,
     251                 :            :  * so it is important to keep the active lists LRU_ACTIVE higher in
     252                 :            :  * the array than the corresponding inactive lists, and to keep
     253                 :            :  * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
     254                 :            :  *
     255                 :            :  * This has to be kept in sync with the statistics in zone_stat_item
     256                 :            :  * above and the descriptions in vmstat_text in mm/vmstat.c
     257                 :            :  */
     258                 :            : #define LRU_BASE 0
     259                 :            : #define LRU_ACTIVE 1
     260                 :            : #define LRU_FILE 2
     261                 :            : 
     262                 :            : enum lru_list {
     263                 :            :         LRU_INACTIVE_ANON = LRU_BASE,
     264                 :            :         LRU_ACTIVE_ANON = LRU_BASE + LRU_ACTIVE,
     265                 :            :         LRU_INACTIVE_FILE = LRU_BASE + LRU_FILE,
     266                 :            :         LRU_ACTIVE_FILE = LRU_BASE + LRU_FILE + LRU_ACTIVE,
     267                 :            :         LRU_UNEVICTABLE,
     268                 :            :         NR_LRU_LISTS
     269                 :            : };
     270                 :            : 
     271                 :            : #define for_each_lru(lru) for (lru = 0; lru < NR_LRU_LISTS; lru++)
     272                 :            : 
     273                 :            : #define for_each_evictable_lru(lru) for (lru = 0; lru <= LRU_ACTIVE_FILE; lru++)
     274                 :            : 
     275                 :            : static inline int is_file_lru(enum lru_list lru)
     276                 :            : {
     277                 :          0 :         return (lru == LRU_INACTIVE_FILE || lru == LRU_ACTIVE_FILE);
     278                 :            : }
     279                 :            : 
     280                 :            : static inline int is_active_lru(enum lru_list lru)
     281                 :            : {
     282                 :          0 :         return (lru == LRU_ACTIVE_ANON || lru == LRU_ACTIVE_FILE);
     283                 :            : }
     284                 :            : 
     285                 :            : struct zone_reclaim_stat {
     286                 :            :         /*
     287                 :            :          * The pageout code in vmscan.c keeps track of how many of the
     288                 :            :          * mem/swap backed and file backed pages are referenced.
     289                 :            :          * The higher the rotated/scanned ratio, the more valuable
     290                 :            :          * that cache is.
     291                 :            :          *
     292                 :            :          * The anon LRU stats live in [0], file LRU stats in [1]
     293                 :            :          */
     294                 :            :         unsigned long           recent_rotated[2];
     295                 :            :         unsigned long           recent_scanned[2];
     296                 :            : };
     297                 :            : 
     298                 :            : struct lruvec {
     299                 :            :         struct list_head                lists[NR_LRU_LISTS];
     300                 :            :         struct zone_reclaim_stat        reclaim_stat;
     301                 :            :         /* Evictions & activations on the inactive file list */
     302                 :            :         atomic_long_t                   inactive_age;
     303                 :            :         /* Refaults at the time of last reclaim cycle */
     304                 :            :         unsigned long                   refaults;
     305                 :            : #ifdef CONFIG_MEMCG
     306                 :            :         struct pglist_data *pgdat;
     307                 :            : #endif
     308                 :            : };
     309                 :            : 
     310                 :            : /* Isolate unmapped file */
     311                 :            : #define ISOLATE_UNMAPPED        ((__force isolate_mode_t)0x2)
     312                 :            : /* Isolate for asynchronous migration */
     313                 :            : #define ISOLATE_ASYNC_MIGRATE   ((__force isolate_mode_t)0x4)
     314                 :            : /* Isolate unevictable pages */
     315                 :            : #define ISOLATE_UNEVICTABLE     ((__force isolate_mode_t)0x8)
     316                 :            : 
     317                 :            : /* LRU Isolation modes. */
     318                 :            : typedef unsigned __bitwise isolate_mode_t;
     319                 :            : 
     320                 :            : enum zone_watermarks {
     321                 :            :         WMARK_MIN,
     322                 :            :         WMARK_LOW,
     323                 :            :         WMARK_HIGH,
     324                 :            :         NR_WMARK
     325                 :            : };
     326                 :            : 
     327                 :            : #define min_wmark_pages(z) (z->_watermark[WMARK_MIN] + z->watermark_boost)
     328                 :            : #define low_wmark_pages(z) (z->_watermark[WMARK_LOW] + z->watermark_boost)
     329                 :            : #define high_wmark_pages(z) (z->_watermark[WMARK_HIGH] + z->watermark_boost)
     330                 :            : #define wmark_pages(z, i) (z->_watermark[i] + z->watermark_boost)
     331                 :            : 
     332                 :            : struct per_cpu_pages {
     333                 :            :         int count;              /* number of pages in the list */
     334                 :            :         int high;               /* high watermark, emptying needed */
     335                 :            :         int batch;              /* chunk size for buddy add/remove */
     336                 :            : 
     337                 :            :         /* Lists of pages, one per migrate type stored on the pcp-lists */
     338                 :            :         struct list_head lists[MIGRATE_PCPTYPES];
     339                 :            : };
     340                 :            : 
     341                 :            : struct per_cpu_pageset {
     342                 :            :         struct per_cpu_pages pcp;
     343                 :            : #ifdef CONFIG_NUMA
     344                 :            :         s8 expire;
     345                 :            :         u16 vm_numa_stat_diff[NR_VM_NUMA_STAT_ITEMS];
     346                 :            : #endif
     347                 :            : #ifdef CONFIG_SMP
     348                 :            :         s8 stat_threshold;
     349                 :            :         s8 vm_stat_diff[NR_VM_ZONE_STAT_ITEMS];
     350                 :            : #endif
     351                 :            : };
     352                 :            : 
     353                 :            : struct per_cpu_nodestat {
     354                 :            :         s8 stat_threshold;
     355                 :            :         s8 vm_node_stat_diff[NR_VM_NODE_STAT_ITEMS];
     356                 :            : };
     357                 :            : 
     358                 :            : #endif /* !__GENERATING_BOUNDS.H */
     359                 :            : 
     360                 :            : enum zone_type {
     361                 :            :         /*
     362                 :            :          * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able
     363                 :            :          * to DMA to all of the addressable memory (ZONE_NORMAL).
     364                 :            :          * On architectures where this area covers the whole 32 bit address
     365                 :            :          * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller
     366                 :            :          * DMA addressing constraints. This distinction is important as a 32bit
     367                 :            :          * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit
     368                 :            :          * platforms may need both zones as they support peripherals with
     369                 :            :          * different DMA addressing limitations.
     370                 :            :          *
     371                 :            :          * Some examples:
     372                 :            :          *
     373                 :            :          *  - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the
     374                 :            :          *    rest of the lower 4G.
     375                 :            :          *
     376                 :            :          *  - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on
     377                 :            :          *    the specific device.
     378                 :            :          *
     379                 :            :          *  - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the
     380                 :            :          *    lower 4G.
     381                 :            :          *
     382                 :            :          *  - powerpc only uses ZONE_DMA, the size, up to 2G, may vary
     383                 :            :          *    depending on the specific device.
     384                 :            :          *
     385                 :            :          *  - s390 uses ZONE_DMA fixed to the lower 2G.
     386                 :            :          *
     387                 :            :          *  - ia64 and riscv only use ZONE_DMA32.
     388                 :            :          *
     389                 :            :          *  - parisc uses neither.
     390                 :            :          */
     391                 :            : #ifdef CONFIG_ZONE_DMA
     392                 :            :         ZONE_DMA,
     393                 :            : #endif
     394                 :            : #ifdef CONFIG_ZONE_DMA32
     395                 :            :         ZONE_DMA32,
     396                 :            : #endif
     397                 :            :         /*
     398                 :            :          * Normal addressable memory is in ZONE_NORMAL. DMA operations can be
     399                 :            :          * performed on pages in ZONE_NORMAL if the DMA devices support
     400                 :            :          * transfers to all addressable memory.
     401                 :            :          */
     402                 :            :         ZONE_NORMAL,
     403                 :            : #ifdef CONFIG_HIGHMEM
     404                 :            :         /*
     405                 :            :          * A memory area that is only addressable by the kernel through
     406                 :            :          * mapping portions into its own address space. This is for example
     407                 :            :          * used by i386 to allow the kernel to address the memory beyond
     408                 :            :          * 900MB. The kernel will set up special mappings (page
     409                 :            :          * table entries on i386) for each page that the kernel needs to
     410                 :            :          * access.
     411                 :            :          */
     412                 :            :         ZONE_HIGHMEM,
     413                 :            : #endif
     414                 :            :         ZONE_MOVABLE,
     415                 :            : #ifdef CONFIG_ZONE_DEVICE
     416                 :            :         ZONE_DEVICE,
     417                 :            : #endif
     418                 :            :         __MAX_NR_ZONES
     419                 :            : 
     420                 :            : };
     421                 :            : 
     422                 :            : #ifndef __GENERATING_BOUNDS_H
     423                 :            : 
     424                 :            : struct zone {
     425                 :            :         /* Read-mostly fields */
     426                 :            : 
     427                 :            :         /* zone watermarks, access with *_wmark_pages(zone) macros */
     428                 :            :         unsigned long _watermark[NR_WMARK];
     429                 :            :         unsigned long watermark_boost;
     430                 :            : 
     431                 :            :         unsigned long nr_reserved_highatomic;
     432                 :            : 
     433                 :            :         /*
     434                 :            :          * We don't know if the memory that we're going to allocate will be
     435                 :            :          * freeable or/and it will be released eventually, so to avoid totally
     436                 :            :          * wasting several GB of ram we must reserve some of the lower zone
     437                 :            :          * memory (otherwise we risk to run OOM on the lower zones despite
     438                 :            :          * there being tons of freeable ram on the higher zones).  This array is
     439                 :            :          * recalculated at runtime if the sysctl_lowmem_reserve_ratio sysctl
     440                 :            :          * changes.
     441                 :            :          */
     442                 :            :         long lowmem_reserve[MAX_NR_ZONES];
     443                 :            : 
     444                 :            : #ifdef CONFIG_NUMA
     445                 :            :         int node;
     446                 :            : #endif
     447                 :            :         struct pglist_data      *zone_pgdat;
     448                 :            :         struct per_cpu_pageset __percpu *pageset;
     449                 :            : 
     450                 :            : #ifndef CONFIG_SPARSEMEM
     451                 :            :         /*
     452                 :            :          * Flags for a pageblock_nr_pages block. See pageblock-flags.h.
     453                 :            :          * In SPARSEMEM, this map is stored in struct mem_section
     454                 :            :          */
     455                 :            :         unsigned long           *pageblock_flags;
     456                 :            : #endif /* CONFIG_SPARSEMEM */
     457                 :            : 
     458                 :            :         /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */
     459                 :            :         unsigned long           zone_start_pfn;
     460                 :            : 
     461                 :            :         /*
     462                 :            :          * spanned_pages is the total pages spanned by the zone, including
     463                 :            :          * holes, which is calculated as:
     464                 :            :          *      spanned_pages = zone_end_pfn - zone_start_pfn;
     465                 :            :          *
     466                 :            :          * present_pages is physical pages existing within the zone, which
     467                 :            :          * is calculated as:
     468                 :            :          *      present_pages = spanned_pages - absent_pages(pages in holes);
     469                 :            :          *
     470                 :            :          * managed_pages is present pages managed by the buddy system, which
     471                 :            :          * is calculated as (reserved_pages includes pages allocated by the
     472                 :            :          * bootmem allocator):
     473                 :            :          *      managed_pages = present_pages - reserved_pages;
     474                 :            :          *
     475                 :            :          * So present_pages may be used by memory hotplug or memory power
     476                 :            :          * management logic to figure out unmanaged pages by checking
     477                 :            :          * (present_pages - managed_pages). And managed_pages should be used
     478                 :            :          * by page allocator and vm scanner to calculate all kinds of watermarks
     479                 :            :          * and thresholds.
     480                 :            :          *
     481                 :            :          * Locking rules:
     482                 :            :          *
     483                 :            :          * zone_start_pfn and spanned_pages are protected by span_seqlock.
     484                 :            :          * It is a seqlock because it has to be read outside of zone->lock,
     485                 :            :          * and it is done in the main allocator path.  But, it is written
     486                 :            :          * quite infrequently.
     487                 :            :          *
     488                 :            :          * The span_seq lock is declared along with zone->lock because it is
     489                 :            :          * frequently read in proximity to zone->lock.  It's good to
     490                 :            :          * give them a chance of being in the same cacheline.
     491                 :            :          *
     492                 :            :          * Write access to present_pages at runtime should be protected by
     493                 :            :          * mem_hotplug_begin/end(). Any reader who can't tolerant drift of
     494                 :            :          * present_pages should get_online_mems() to get a stable value.
     495                 :            :          */
     496                 :            :         atomic_long_t           managed_pages;
     497                 :            :         unsigned long           spanned_pages;
     498                 :            :         unsigned long           present_pages;
     499                 :            : 
     500                 :            :         const char              *name;
     501                 :            : 
     502                 :            : #ifdef CONFIG_MEMORY_ISOLATION
     503                 :            :         /*
     504                 :            :          * Number of isolated pageblock. It is used to solve incorrect
     505                 :            :          * freepage counting problem due to racy retrieving migratetype
     506                 :            :          * of pageblock. Protected by zone->lock.
     507                 :            :          */
     508                 :            :         unsigned long           nr_isolate_pageblock;
     509                 :            : #endif
     510                 :            : 
     511                 :            : #ifdef CONFIG_MEMORY_HOTPLUG
     512                 :            :         /* see spanned/present_pages for more description */
     513                 :            :         seqlock_t               span_seqlock;
     514                 :            : #endif
     515                 :            : 
     516                 :            :         int initialized;
     517                 :            : 
     518                 :            :         /* Write-intensive fields used from the page allocator */
     519                 :            :         ZONE_PADDING(_pad1_)
     520                 :            : 
     521                 :            :         /* free areas of different sizes */
     522                 :            :         struct free_area        free_area[MAX_ORDER];
     523                 :            : 
     524                 :            :         /* zone flags, see below */
     525                 :            :         unsigned long           flags;
     526                 :            : 
     527                 :            :         /* Primarily protects free_area */
     528                 :            :         spinlock_t              lock;
     529                 :            : 
     530                 :            :         /* Write-intensive fields used by compaction and vmstats. */
     531                 :            :         ZONE_PADDING(_pad2_)
     532                 :            : 
     533                 :            :         /*
     534                 :            :          * When free pages are below this point, additional steps are taken
     535                 :            :          * when reading the number of free pages to avoid per-cpu counter
     536                 :            :          * drift allowing watermarks to be breached
     537                 :            :          */
     538                 :            :         unsigned long percpu_drift_mark;
     539                 :            : 
     540                 :            : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
     541                 :            :         /* pfn where compaction free scanner should start */
     542                 :            :         unsigned long           compact_cached_free_pfn;
     543                 :            :         /* pfn where async and sync compaction migration scanner should start */
     544                 :            :         unsigned long           compact_cached_migrate_pfn[2];
     545                 :            :         unsigned long           compact_init_migrate_pfn;
     546                 :            :         unsigned long           compact_init_free_pfn;
     547                 :            : #endif
     548                 :            : 
     549                 :            : #ifdef CONFIG_COMPACTION
     550                 :            :         /*
     551                 :            :          * On compaction failure, 1<<compact_defer_shift compactions
     552                 :            :          * are skipped before trying again. The number attempted since
     553                 :            :          * last failure is tracked with compact_considered.
     554                 :            :          */
     555                 :            :         unsigned int            compact_considered;
     556                 :            :         unsigned int            compact_defer_shift;
     557                 :            :         int                     compact_order_failed;
     558                 :            : #endif
     559                 :            : 
     560                 :            : #if defined CONFIG_COMPACTION || defined CONFIG_CMA
     561                 :            :         /* Set to true when the PG_migrate_skip bits should be cleared */
     562                 :            :         bool                    compact_blockskip_flush;
     563                 :            : #endif
     564                 :            : 
     565                 :            :         bool                    contiguous;
     566                 :            : 
     567                 :            :         ZONE_PADDING(_pad3_)
     568                 :            :         /* Zone statistics */
     569                 :            :         atomic_long_t           vm_stat[NR_VM_ZONE_STAT_ITEMS];
     570                 :            :         atomic_long_t           vm_numa_stat[NR_VM_NUMA_STAT_ITEMS];
     571                 :            : } ____cacheline_internodealigned_in_smp;
     572                 :            : 
     573                 :            : enum pgdat_flags {
     574                 :            :         PGDAT_CONGESTED,                /* pgdat has many dirty pages backed by
     575                 :            :                                          * a congested BDI
     576                 :            :                                          */
     577                 :            :         PGDAT_DIRTY,                    /* reclaim scanning has recently found
     578                 :            :                                          * many dirty file pages at the tail
     579                 :            :                                          * of the LRU.
     580                 :            :                                          */
     581                 :            :         PGDAT_WRITEBACK,                /* reclaim scanning has recently found
     582                 :            :                                          * many pages under writeback
     583                 :            :                                          */
     584                 :            :         PGDAT_RECLAIM_LOCKED,           /* prevents concurrent reclaim */
     585                 :            : };
     586                 :            : 
     587                 :            : enum zone_flags {
     588                 :            :         ZONE_BOOSTED_WATERMARK,         /* zone recently boosted watermarks.
     589                 :            :                                          * Cleared when kswapd is woken.
     590                 :            :                                          */
     591                 :            : };
     592                 :            : 
     593                 :            : static inline unsigned long zone_managed_pages(struct zone *zone)
     594                 :            : {
     595                 :            :         return (unsigned long)atomic_long_read(&zone->managed_pages);
     596                 :            : }
     597                 :            : 
     598                 :            : static inline unsigned long zone_end_pfn(const struct zone *zone)
     599                 :            : {
     600                 :          3 :         return zone->zone_start_pfn + zone->spanned_pages;
     601                 :            : }
     602                 :            : 
     603                 :            : static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
     604                 :            : {
     605                 :          3 :         return zone->zone_start_pfn <= pfn && pfn < zone_end_pfn(zone);
     606                 :            : }
     607                 :            : 
     608                 :            : static inline bool zone_is_initialized(struct zone *zone)
     609                 :            : {
     610                 :            :         return zone->initialized;
     611                 :            : }
     612                 :            : 
     613                 :            : static inline bool zone_is_empty(struct zone *zone)
     614                 :            : {
     615                 :            :         return zone->spanned_pages == 0;
     616                 :            : }
     617                 :            : 
     618                 :            : /*
     619                 :            :  * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
     620                 :            :  * intersection with the given zone
     621                 :            :  */
     622                 :            : static inline bool zone_intersects(struct zone *zone,
     623                 :            :                 unsigned long start_pfn, unsigned long nr_pages)
     624                 :            : {
     625                 :            :         if (zone_is_empty(zone))
     626                 :            :                 return false;
     627                 :            :         if (start_pfn >= zone_end_pfn(zone) ||
     628                 :            :             start_pfn + nr_pages <= zone->zone_start_pfn)
     629                 :            :                 return false;
     630                 :            : 
     631                 :            :         return true;
     632                 :            : }
     633                 :            : 
     634                 :            : /*
     635                 :            :  * The "priority" of VM scanning is how much of the queues we will scan in one
     636                 :            :  * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
     637                 :            :  * queues ("queue_length >> 12") during an aging round.
     638                 :            :  */
     639                 :            : #define DEF_PRIORITY 12
     640                 :            : 
     641                 :            : /* Maximum number of zones on a zonelist */
     642                 :            : #define MAX_ZONES_PER_ZONELIST (MAX_NUMNODES * MAX_NR_ZONES)
     643                 :            : 
     644                 :            : enum {
     645                 :            :         ZONELIST_FALLBACK,      /* zonelist with fallback */
     646                 :            : #ifdef CONFIG_NUMA
     647                 :            :         /*
     648                 :            :          * The NUMA zonelists are doubled because we need zonelists that
     649                 :            :          * restrict the allocations to a single node for __GFP_THISNODE.
     650                 :            :          */
     651                 :            :         ZONELIST_NOFALLBACK,    /* zonelist without fallback (__GFP_THISNODE) */
     652                 :            : #endif
     653                 :            :         MAX_ZONELISTS
     654                 :            : };
     655                 :            : 
     656                 :            : /*
     657                 :            :  * This struct contains information about a zone in a zonelist. It is stored
     658                 :            :  * here to avoid dereferences into large structures and lookups of tables
     659                 :            :  */
     660                 :            : struct zoneref {
     661                 :            :         struct zone *zone;      /* Pointer to actual zone */
     662                 :            :         int zone_idx;           /* zone_idx(zoneref->zone) */
     663                 :            : };
     664                 :            : 
     665                 :            : /*
     666                 :            :  * One allocation request operates on a zonelist. A zonelist
     667                 :            :  * is a list of zones, the first one is the 'goal' of the
     668                 :            :  * allocation, the other zones are fallback zones, in decreasing
     669                 :            :  * priority.
     670                 :            :  *
     671                 :            :  * To speed the reading of the zonelist, the zonerefs contain the zone index
     672                 :            :  * of the entry being read. Helper functions to access information given
     673                 :            :  * a struct zoneref are
     674                 :            :  *
     675                 :            :  * zonelist_zone()      - Return the struct zone * for an entry in _zonerefs
     676                 :            :  * zonelist_zone_idx()  - Return the index of the zone for an entry
     677                 :            :  * zonelist_node_idx()  - Return the index of the node for an entry
     678                 :            :  */
     679                 :            : struct zonelist {
     680                 :            :         struct zoneref _zonerefs[MAX_ZONES_PER_ZONELIST + 1];
     681                 :            : };
     682                 :            : 
     683                 :            : #ifndef CONFIG_DISCONTIGMEM
     684                 :            : /* The array of struct pages - for discontigmem use pgdat->lmem_map */
     685                 :            : extern struct page *mem_map;
     686                 :            : #endif
     687                 :            : 
     688                 :            : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     689                 :            : struct deferred_split {
     690                 :            :         spinlock_t split_queue_lock;
     691                 :            :         struct list_head split_queue;
     692                 :            :         unsigned long split_queue_len;
     693                 :            : };
     694                 :            : #endif
     695                 :            : 
     696                 :            : /*
     697                 :            :  * On NUMA machines, each NUMA node would have a pg_data_t to describe
     698                 :            :  * it's memory layout. On UMA machines there is a single pglist_data which
     699                 :            :  * describes the whole memory.
     700                 :            :  *
     701                 :            :  * Memory statistics and page replacement data structures are maintained on a
     702                 :            :  * per-zone basis.
     703                 :            :  */
     704                 :            : struct bootmem_data;
     705                 :            : typedef struct pglist_data {
     706                 :            :         struct zone node_zones[MAX_NR_ZONES];
     707                 :            :         struct zonelist node_zonelists[MAX_ZONELISTS];
     708                 :            :         int nr_zones;
     709                 :            : #ifdef CONFIG_FLAT_NODE_MEM_MAP /* means !SPARSEMEM */
     710                 :            :         struct page *node_mem_map;
     711                 :            : #ifdef CONFIG_PAGE_EXTENSION
     712                 :            :         struct page_ext *node_page_ext;
     713                 :            : #endif
     714                 :            : #endif
     715                 :            : #if defined(CONFIG_MEMORY_HOTPLUG) || defined(CONFIG_DEFERRED_STRUCT_PAGE_INIT)
     716                 :            :         /*
     717                 :            :          * Must be held any time you expect node_start_pfn,
     718                 :            :          * node_present_pages, node_spanned_pages or nr_zones to stay constant.
     719                 :            :          * Also synchronizes pgdat->first_deferred_pfn during deferred page
     720                 :            :          * init.
     721                 :            :          *
     722                 :            :          * pgdat_resize_lock() and pgdat_resize_unlock() are provided to
     723                 :            :          * manipulate node_size_lock without checking for CONFIG_MEMORY_HOTPLUG
     724                 :            :          * or CONFIG_DEFERRED_STRUCT_PAGE_INIT.
     725                 :            :          *
     726                 :            :          * Nests above zone->lock and zone->span_seqlock
     727                 :            :          */
     728                 :            :         spinlock_t node_size_lock;
     729                 :            : #endif
     730                 :            :         unsigned long node_start_pfn;
     731                 :            :         unsigned long node_present_pages; /* total number of physical pages */
     732                 :            :         unsigned long node_spanned_pages; /* total size of physical page
     733                 :            :                                              range, including holes */
     734                 :            :         int node_id;
     735                 :            :         wait_queue_head_t kswapd_wait;
     736                 :            :         wait_queue_head_t pfmemalloc_wait;
     737                 :            :         struct task_struct *kswapd;     /* Protected by
     738                 :            :                                            mem_hotplug_begin/end() */
     739                 :            :         int kswapd_order;
     740                 :            :         enum zone_type kswapd_classzone_idx;
     741                 :            : 
     742                 :            :         int kswapd_failures;            /* Number of 'reclaimed == 0' runs */
     743                 :            : 
     744                 :            : #ifdef CONFIG_COMPACTION
     745                 :            :         int kcompactd_max_order;
     746                 :            :         enum zone_type kcompactd_classzone_idx;
     747                 :            :         wait_queue_head_t kcompactd_wait;
     748                 :            :         struct task_struct *kcompactd;
     749                 :            : #endif
     750                 :            :         /*
     751                 :            :          * This is a per-node reserve of pages that are not available
     752                 :            :          * to userspace allocations.
     753                 :            :          */
     754                 :            :         unsigned long           totalreserve_pages;
     755                 :            : 
     756                 :            : #ifdef CONFIG_NUMA
     757                 :            :         /*
     758                 :            :          * zone reclaim becomes active if more unmapped pages exist.
     759                 :            :          */
     760                 :            :         unsigned long           min_unmapped_pages;
     761                 :            :         unsigned long           min_slab_pages;
     762                 :            : #endif /* CONFIG_NUMA */
     763                 :            : 
     764                 :            :         /* Write-intensive fields used by page reclaim */
     765                 :            :         ZONE_PADDING(_pad1_)
     766                 :            :         spinlock_t              lru_lock;
     767                 :            : 
     768                 :            : #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
     769                 :            :         /*
     770                 :            :          * If memory initialisation on large machines is deferred then this
     771                 :            :          * is the first PFN that needs to be initialised.
     772                 :            :          */
     773                 :            :         unsigned long first_deferred_pfn;
     774                 :            : #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
     775                 :            : 
     776                 :            : #ifdef CONFIG_TRANSPARENT_HUGEPAGE
     777                 :            :         struct deferred_split deferred_split_queue;
     778                 :            : #endif
     779                 :            : 
     780                 :            :         /* Fields commonly accessed by the page reclaim scanner */
     781                 :            :         struct lruvec           lruvec;
     782                 :            : 
     783                 :            :         unsigned long           flags;
     784                 :            : 
     785                 :            :         ZONE_PADDING(_pad2_)
     786                 :            : 
     787                 :            :         /* Per-node vmstats */
     788                 :            :         struct per_cpu_nodestat __percpu *per_cpu_nodestats;
     789                 :            :         atomic_long_t           vm_stat[NR_VM_NODE_STAT_ITEMS];
     790                 :            : } pg_data_t;
     791                 :            : 
     792                 :            : #define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)
     793                 :            : #define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)
     794                 :            : #ifdef CONFIG_FLAT_NODE_MEM_MAP
     795                 :            : #define pgdat_page_nr(pgdat, pagenr)    ((pgdat)->node_mem_map + (pagenr))
     796                 :            : #else
     797                 :            : #define pgdat_page_nr(pgdat, pagenr)    pfn_to_page((pgdat)->node_start_pfn + (pagenr))
     798                 :            : #endif
     799                 :            : #define nid_page_nr(nid, pagenr)        pgdat_page_nr(NODE_DATA(nid),(pagenr))
     800                 :            : 
     801                 :            : #define node_start_pfn(nid)     (NODE_DATA(nid)->node_start_pfn)
     802                 :            : #define node_end_pfn(nid) pgdat_end_pfn(NODE_DATA(nid))
     803                 :            : 
     804                 :            : static inline struct lruvec *node_lruvec(struct pglist_data *pgdat)
     805                 :            : {
     806                 :          3 :         return &pgdat->lruvec;
     807                 :            : }
     808                 :            : 
     809                 :            : static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
     810                 :            : {
     811                 :          3 :         return pgdat->node_start_pfn + pgdat->node_spanned_pages;
     812                 :            : }
     813                 :            : 
     814                 :            : static inline bool pgdat_is_empty(pg_data_t *pgdat)
     815                 :            : {
     816                 :            :         return !pgdat->node_start_pfn && !pgdat->node_spanned_pages;
     817                 :            : }
     818                 :            : 
     819                 :            : #include <linux/memory_hotplug.h>
     820                 :            : 
     821                 :            : void build_all_zonelists(pg_data_t *pgdat);
     822                 :            : void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
     823                 :            :                    enum zone_type classzone_idx);
     824                 :            : bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
     825                 :            :                          int classzone_idx, unsigned int alloc_flags,
     826                 :            :                          long free_pages);
     827                 :            : bool zone_watermark_ok(struct zone *z, unsigned int order,
     828                 :            :                 unsigned long mark, int classzone_idx,
     829                 :            :                 unsigned int alloc_flags);
     830                 :            : bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
     831                 :            :                 unsigned long mark, int classzone_idx);
     832                 :            : enum memmap_context {
     833                 :            :         MEMMAP_EARLY,
     834                 :            :         MEMMAP_HOTPLUG,
     835                 :            : };
     836                 :            : extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
     837                 :            :                                      unsigned long size);
     838                 :            : 
     839                 :            : extern void lruvec_init(struct lruvec *lruvec);
     840                 :            : 
     841                 :          3 : static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
     842                 :            : {
     843                 :            : #ifdef CONFIG_MEMCG
     844                 :          3 :         return lruvec->pgdat;
     845                 :            : #else
     846                 :            :         return container_of(lruvec, struct pglist_data, lruvec);
     847                 :            : #endif
     848                 :            : }
     849                 :            : 
     850                 :            : extern unsigned long lruvec_lru_size(struct lruvec *lruvec, enum lru_list lru, int zone_idx);
     851                 :            : 
     852                 :            : #ifdef CONFIG_HAVE_MEMORY_PRESENT
     853                 :            : void memory_present(int nid, unsigned long start, unsigned long end);
     854                 :            : #else
     855                 :            : static inline void memory_present(int nid, unsigned long start, unsigned long end) {}
     856                 :            : #endif
     857                 :            : 
     858                 :            : #if defined(CONFIG_SPARSEMEM)
     859                 :            : void memblocks_present(void);
     860                 :            : #else
     861                 :            : static inline void memblocks_present(void) {}
     862                 :            : #endif
     863                 :            : 
     864                 :            : #ifdef CONFIG_HAVE_MEMORYLESS_NODES
     865                 :            : int local_memory_node(int node_id);
     866                 :            : #else
     867                 :            : static inline int local_memory_node(int node_id) { return node_id; };
     868                 :            : #endif
     869                 :            : 
     870                 :            : /*
     871                 :            :  * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
     872                 :            :  */
     873                 :            : #define zone_idx(zone)          ((zone) - (zone)->zone_pgdat->node_zones)
     874                 :            : 
     875                 :            : /*
     876                 :            :  * Returns true if a zone has pages managed by the buddy allocator.
     877                 :            :  * All the reclaim decisions have to use this function rather than
     878                 :            :  * populated_zone(). If the whole zone is reserved then we can easily
     879                 :            :  * end up with populated_zone() && !managed_zone().
     880                 :            :  */
     881                 :            : static inline bool managed_zone(struct zone *zone)
     882                 :            : {
     883                 :            :         return zone_managed_pages(zone);
     884                 :            : }
     885                 :            : 
     886                 :            : /* Returns true if a zone has memory */
     887                 :            : static inline bool populated_zone(struct zone *zone)
     888                 :            : {
     889                 :          3 :         return zone->present_pages;
     890                 :            : }
     891                 :            : 
     892                 :            : #ifdef CONFIG_NUMA
     893                 :            : static inline int zone_to_nid(struct zone *zone)
     894                 :            : {
     895                 :            :         return zone->node;
     896                 :            : }
     897                 :            : 
     898                 :            : static inline void zone_set_nid(struct zone *zone, int nid)
     899                 :            : {
     900                 :            :         zone->node = nid;
     901                 :            : }
     902                 :            : #else
     903                 :            : static inline int zone_to_nid(struct zone *zone)
     904                 :            : {
     905                 :            :         return 0;
     906                 :            : }
     907                 :            : 
     908                 :            : static inline void zone_set_nid(struct zone *zone, int nid) {}
     909                 :            : #endif
     910                 :            : 
     911                 :            : extern int movable_zone;
     912                 :            : 
     913                 :            : #ifdef CONFIG_HIGHMEM
     914                 :            : static inline int zone_movable_is_highmem(void)
     915                 :            : {
     916                 :            : #ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
     917                 :            :         return movable_zone == ZONE_HIGHMEM;
     918                 :            : #else
     919                 :            :         return (ZONE_MOVABLE - 1) == ZONE_HIGHMEM;
     920                 :            : #endif
     921                 :            : }
     922                 :            : #endif
     923                 :            : 
     924                 :            : static inline int is_highmem_idx(enum zone_type idx)
     925                 :            : {
     926                 :            : #ifdef CONFIG_HIGHMEM
     927                 :            :         return (idx == ZONE_HIGHMEM ||
     928                 :            :                 (idx == ZONE_MOVABLE && zone_movable_is_highmem()));
     929                 :            : #else
     930                 :            :         return 0;
     931                 :            : #endif
     932                 :            : }
     933                 :            : 
     934                 :            : /**
     935                 :            :  * is_highmem - helper function to quickly check if a struct zone is a
     936                 :            :  *              highmem zone or not.  This is an attempt to keep references
     937                 :            :  *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
     938                 :            :  * @zone - pointer to struct zone variable
     939                 :            :  */
     940                 :            : static inline int is_highmem(struct zone *zone)
     941                 :            : {
     942                 :            : #ifdef CONFIG_HIGHMEM
     943                 :            :         return is_highmem_idx(zone_idx(zone));
     944                 :            : #else
     945                 :            :         return 0;
     946                 :            : #endif
     947                 :            : }
     948                 :            : 
     949                 :            : /* These two functions are used to setup the per zone pages min values */
     950                 :            : struct ctl_table;
     951                 :            : int min_free_kbytes_sysctl_handler(struct ctl_table *, int,
     952                 :            :                                         void __user *, size_t *, loff_t *);
     953                 :            : int watermark_boost_factor_sysctl_handler(struct ctl_table *, int,
     954                 :            :                                         void __user *, size_t *, loff_t *);
     955                 :            : int watermark_scale_factor_sysctl_handler(struct ctl_table *, int,
     956                 :            :                                         void __user *, size_t *, loff_t *);
     957                 :            : extern int sysctl_lowmem_reserve_ratio[MAX_NR_ZONES];
     958                 :            : int lowmem_reserve_ratio_sysctl_handler(struct ctl_table *, int,
     959                 :            :                                         void __user *, size_t *, loff_t *);
     960                 :            : int percpu_pagelist_fraction_sysctl_handler(struct ctl_table *, int,
     961                 :            :                                         void __user *, size_t *, loff_t *);
     962                 :            : int sysctl_min_unmapped_ratio_sysctl_handler(struct ctl_table *, int,
     963                 :            :                         void __user *, size_t *, loff_t *);
     964                 :            : int sysctl_min_slab_ratio_sysctl_handler(struct ctl_table *, int,
     965                 :            :                         void __user *, size_t *, loff_t *);
     966                 :            : 
     967                 :            : extern int numa_zonelist_order_handler(struct ctl_table *, int,
     968                 :            :                         void __user *, size_t *, loff_t *);
     969                 :            : extern char numa_zonelist_order[];
     970                 :            : #define NUMA_ZONELIST_ORDER_LEN 16
     971                 :            : 
     972                 :            : #ifndef CONFIG_NEED_MULTIPLE_NODES
     973                 :            : 
     974                 :            : extern struct pglist_data contig_page_data;
     975                 :            : #define NODE_DATA(nid)          (&contig_page_data)
     976                 :            : #define NODE_MEM_MAP(nid)       mem_map
     977                 :            : 
     978                 :            : #else /* CONFIG_NEED_MULTIPLE_NODES */
     979                 :            : 
     980                 :            : #include <asm/mmzone.h>
     981                 :            : 
     982                 :            : #endif /* !CONFIG_NEED_MULTIPLE_NODES */
     983                 :            : 
     984                 :            : extern struct pglist_data *first_online_pgdat(void);
     985                 :            : extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
     986                 :            : extern struct zone *next_zone(struct zone *zone);
     987                 :            : 
     988                 :            : /**
     989                 :            :  * for_each_online_pgdat - helper macro to iterate over all online nodes
     990                 :            :  * @pgdat - pointer to a pg_data_t variable
     991                 :            :  */
     992                 :            : #define for_each_online_pgdat(pgdat)                    \
     993                 :            :         for (pgdat = first_online_pgdat();              \
     994                 :            :              pgdat;                                     \
     995                 :            :              pgdat = next_online_pgdat(pgdat))
     996                 :            : /**
     997                 :            :  * for_each_zone - helper macro to iterate over all memory zones
     998                 :            :  * @zone - pointer to struct zone variable
     999                 :            :  *
    1000                 :            :  * The user only needs to declare the zone variable, for_each_zone
    1001                 :            :  * fills it in.
    1002                 :            :  */
    1003                 :            : #define for_each_zone(zone)                             \
    1004                 :            :         for (zone = (first_online_pgdat())->node_zones; \
    1005                 :            :              zone;                                      \
    1006                 :            :              zone = next_zone(zone))
    1007                 :            : 
    1008                 :            : #define for_each_populated_zone(zone)                   \
    1009                 :            :         for (zone = (first_online_pgdat())->node_zones; \
    1010                 :            :              zone;                                      \
    1011                 :            :              zone = next_zone(zone))                    \
    1012                 :            :                 if (!populated_zone(zone))              \
    1013                 :            :                         ; /* do nothing */              \
    1014                 :            :                 else
    1015                 :            : 
    1016                 :            : static inline struct zone *zonelist_zone(struct zoneref *zoneref)
    1017                 :            : {
    1018                 :          3 :         return zoneref->zone;
    1019                 :            : }
    1020                 :            : 
    1021                 :          3 : static inline int zonelist_zone_idx(struct zoneref *zoneref)
    1022                 :            : {
    1023                 :          3 :         return zoneref->zone_idx;
    1024                 :            : }
    1025                 :            : 
    1026                 :            : static inline int zonelist_node_idx(struct zoneref *zoneref)
    1027                 :            : {
    1028                 :            :         return zone_to_nid(zoneref->zone);
    1029                 :            : }
    1030                 :            : 
    1031                 :            : struct zoneref *__next_zones_zonelist(struct zoneref *z,
    1032                 :            :                                         enum zone_type highest_zoneidx,
    1033                 :            :                                         nodemask_t *nodes);
    1034                 :            : 
    1035                 :            : /**
    1036                 :            :  * 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
    1037                 :            :  * @z - The cursor used as a starting point for the search
    1038                 :            :  * @highest_zoneidx - The zone index of the highest zone to return
    1039                 :            :  * @nodes - An optional nodemask to filter the zonelist with
    1040                 :            :  *
    1041                 :            :  * This function returns the next zone at or below a given zone index that is
    1042                 :            :  * within the allowed nodemask using a cursor as the starting point for the
    1043                 :            :  * search. The zoneref returned is a cursor that represents the current zone
    1044                 :            :  * being examined. It should be advanced by one before calling
    1045                 :            :  * next_zones_zonelist again.
    1046                 :            :  */
    1047                 :            : static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
    1048                 :            :                                         enum zone_type highest_zoneidx,
    1049                 :            :                                         nodemask_t *nodes)
    1050                 :            : {
    1051                 :          3 :         if (likely(!nodes && zonelist_zone_idx(z) <= highest_zoneidx))
    1052                 :            :                 return z;
    1053                 :          3 :         return __next_zones_zonelist(z, highest_zoneidx, nodes);
    1054                 :            : }
    1055                 :            : 
    1056                 :            : /**
    1057                 :            :  * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
    1058                 :            :  * @zonelist - The zonelist to search for a suitable zone
    1059                 :            :  * @highest_zoneidx - The zone index of the highest zone to return
    1060                 :            :  * @nodes - An optional nodemask to filter the zonelist with
    1061                 :            :  * @return - Zoneref pointer for the first suitable zone found (see below)
    1062                 :            :  *
    1063                 :            :  * This function returns the first zone at or below a given zone index that is
    1064                 :            :  * within the allowed nodemask. The zoneref returned is a cursor that can be
    1065                 :            :  * used to iterate the zonelist with next_zones_zonelist by advancing it by
    1066                 :            :  * one before calling.
    1067                 :            :  *
    1068                 :            :  * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
    1069                 :            :  * never NULL). This may happen either genuinely, or due to concurrent nodemask
    1070                 :            :  * update due to cpuset modification.
    1071                 :            :  */
    1072                 :          3 : static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
    1073                 :            :                                         enum zone_type highest_zoneidx,
    1074                 :            :                                         nodemask_t *nodes)
    1075                 :            : {
    1076                 :          3 :         return next_zones_zonelist(zonelist->_zonerefs,
    1077                 :            :                                                         highest_zoneidx, nodes);
    1078                 :            : }
    1079                 :            : 
    1080                 :            : /**
    1081                 :            :  * 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
    1082                 :            :  * @zone - The current zone in the iterator
    1083                 :            :  * @z - The current pointer within zonelist->zones being iterated
    1084                 :            :  * @zlist - The zonelist being iterated
    1085                 :            :  * @highidx - The zone index of the highest zone to return
    1086                 :            :  * @nodemask - Nodemask allowed by the allocator
    1087                 :            :  *
    1088                 :            :  * This iterator iterates though all zones at or below a given zone index and
    1089                 :            :  * within a given nodemask
    1090                 :            :  */
    1091                 :            : #define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
    1092                 :            :         for (z = first_zones_zonelist(zlist, highidx, nodemask), zone = zonelist_zone(z);       \
    1093                 :            :                 zone;                                                   \
    1094                 :            :                 z = next_zones_zonelist(++z, highidx, nodemask),        \
    1095                 :            :                         zone = zonelist_zone(z))
    1096                 :            : 
    1097                 :            : #define for_next_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask) \
    1098                 :            :         for (zone = z->zone; \
    1099                 :            :                 zone;                                                   \
    1100                 :            :                 z = next_zones_zonelist(++z, highidx, nodemask),        \
    1101                 :            :                         zone = zonelist_zone(z))
    1102                 :            : 
    1103                 :            : 
    1104                 :            : /**
    1105                 :            :  * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
    1106                 :            :  * @zone - The current zone in the iterator
    1107                 :            :  * @z - The current pointer within zonelist->zones being iterated
    1108                 :            :  * @zlist - The zonelist being iterated
    1109                 :            :  * @highidx - The zone index of the highest zone to return
    1110                 :            :  *
    1111                 :            :  * This iterator iterates though all zones at or below a given zone index.
    1112                 :            :  */
    1113                 :            : #define for_each_zone_zonelist(zone, z, zlist, highidx) \
    1114                 :            :         for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, NULL)
    1115                 :            : 
    1116                 :            : #ifdef CONFIG_SPARSEMEM
    1117                 :            : #include <asm/sparsemem.h>
    1118                 :            : #endif
    1119                 :            : 
    1120                 :            : #if !defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) && \
    1121                 :            :         !defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
    1122                 :            : static inline unsigned long early_pfn_to_nid(unsigned long pfn)
    1123                 :            : {
    1124                 :            :         BUILD_BUG_ON(IS_ENABLED(CONFIG_NUMA));
    1125                 :            :         return 0;
    1126                 :            : }
    1127                 :            : #endif
    1128                 :            : 
    1129                 :            : #ifdef CONFIG_FLATMEM
    1130                 :            : #define pfn_to_nid(pfn)         (0)
    1131                 :            : #endif
    1132                 :            : 
    1133                 :            : #ifdef CONFIG_SPARSEMEM
    1134                 :            : 
    1135                 :            : /*
    1136                 :            :  * SECTION_SHIFT                #bits space required to store a section #
    1137                 :            :  *
    1138                 :            :  * PA_SECTION_SHIFT             physical address to/from section number
    1139                 :            :  * PFN_SECTION_SHIFT            pfn to/from section number
    1140                 :            :  */
    1141                 :            : #define PA_SECTION_SHIFT        (SECTION_SIZE_BITS)
    1142                 :            : #define PFN_SECTION_SHIFT       (SECTION_SIZE_BITS - PAGE_SHIFT)
    1143                 :            : 
    1144                 :            : #define NR_MEM_SECTIONS         (1UL << SECTIONS_SHIFT)
    1145                 :            : 
    1146                 :            : #define PAGES_PER_SECTION       (1UL << PFN_SECTION_SHIFT)
    1147                 :            : #define PAGE_SECTION_MASK       (~(PAGES_PER_SECTION-1))
    1148                 :            : 
    1149                 :            : #define SECTION_BLOCKFLAGS_BITS \
    1150                 :            :         ((1UL << (PFN_SECTION_SHIFT - pageblock_order)) * NR_PAGEBLOCK_BITS)
    1151                 :            : 
    1152                 :            : #if (MAX_ORDER - 1 + PAGE_SHIFT) > SECTION_SIZE_BITS
    1153                 :            : #error Allocator MAX_ORDER exceeds SECTION_SIZE
    1154                 :            : #endif
    1155                 :            : 
    1156                 :            : static inline unsigned long pfn_to_section_nr(unsigned long pfn)
    1157                 :            : {
    1158                 :            :         return pfn >> PFN_SECTION_SHIFT;
    1159                 :            : }
    1160                 :            : static inline unsigned long section_nr_to_pfn(unsigned long sec)
    1161                 :            : {
    1162                 :            :         return sec << PFN_SECTION_SHIFT;
    1163                 :            : }
    1164                 :            : 
    1165                 :            : #define SECTION_ALIGN_UP(pfn)   (((pfn) + PAGES_PER_SECTION - 1) & PAGE_SECTION_MASK)
    1166                 :            : #define SECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SECTION_MASK)
    1167                 :            : 
    1168                 :            : #define SUBSECTION_SHIFT 21
    1169                 :            : 
    1170                 :            : #define PFN_SUBSECTION_SHIFT (SUBSECTION_SHIFT - PAGE_SHIFT)
    1171                 :            : #define PAGES_PER_SUBSECTION (1UL << PFN_SUBSECTION_SHIFT)
    1172                 :            : #define PAGE_SUBSECTION_MASK (~(PAGES_PER_SUBSECTION-1))
    1173                 :            : 
    1174                 :            : #if SUBSECTION_SHIFT > SECTION_SIZE_BITS
    1175                 :            : #error Subsection size exceeds section size
    1176                 :            : #else
    1177                 :            : #define SUBSECTIONS_PER_SECTION (1UL << (SECTION_SIZE_BITS - SUBSECTION_SHIFT))
    1178                 :            : #endif
    1179                 :            : 
    1180                 :            : #define SUBSECTION_ALIGN_UP(pfn) ALIGN((pfn), PAGES_PER_SUBSECTION)
    1181                 :            : #define SUBSECTION_ALIGN_DOWN(pfn) ((pfn) & PAGE_SUBSECTION_MASK)
    1182                 :            : 
    1183                 :            : struct mem_section_usage {
    1184                 :            :         DECLARE_BITMAP(subsection_map, SUBSECTIONS_PER_SECTION);
    1185                 :            :         /* See declaration of similar field in struct zone */
    1186                 :            :         unsigned long pageblock_flags[0];
    1187                 :            : };
    1188                 :            : 
    1189                 :            : void subsection_map_init(unsigned long pfn, unsigned long nr_pages);
    1190                 :            : 
    1191                 :            : struct page;
    1192                 :            : struct page_ext;
    1193                 :            : struct mem_section {
    1194                 :            :         /*
    1195                 :            :          * This is, logically, a pointer to an array of struct
    1196                 :            :          * pages.  However, it is stored with some other magic.
    1197                 :            :          * (see sparse.c::sparse_init_one_section())
    1198                 :            :          *
    1199                 :            :          * Additionally during early boot we encode node id of
    1200                 :            :          * the location of the section here to guide allocation.
    1201                 :            :          * (see sparse.c::memory_present())
    1202                 :            :          *
    1203                 :            :          * Making it a UL at least makes someone do a cast
    1204                 :            :          * before using it wrong.
    1205                 :            :          */
    1206                 :            :         unsigned long section_mem_map;
    1207                 :            : 
    1208                 :            :         struct mem_section_usage *usage;
    1209                 :            : #ifdef CONFIG_PAGE_EXTENSION
    1210                 :            :         /*
    1211                 :            :          * If SPARSEMEM, pgdat doesn't have page_ext pointer. We use
    1212                 :            :          * section. (see page_ext.h about this.)
    1213                 :            :          */
    1214                 :            :         struct page_ext *page_ext;
    1215                 :            :         unsigned long pad;
    1216                 :            : #endif
    1217                 :            :         /*
    1218                 :            :          * WARNING: mem_section must be a power-of-2 in size for the
    1219                 :            :          * calculation and use of SECTION_ROOT_MASK to make sense.
    1220                 :            :          */
    1221                 :            : };
    1222                 :            : 
    1223                 :            : #ifdef CONFIG_SPARSEMEM_EXTREME
    1224                 :            : #define SECTIONS_PER_ROOT       (PAGE_SIZE / sizeof (struct mem_section))
    1225                 :            : #else
    1226                 :            : #define SECTIONS_PER_ROOT       1
    1227                 :            : #endif
    1228                 :            : 
    1229                 :            : #define SECTION_NR_TO_ROOT(sec) ((sec) / SECTIONS_PER_ROOT)
    1230                 :            : #define NR_SECTION_ROOTS        DIV_ROUND_UP(NR_MEM_SECTIONS, SECTIONS_PER_ROOT)
    1231                 :            : #define SECTION_ROOT_MASK       (SECTIONS_PER_ROOT - 1)
    1232                 :            : 
    1233                 :            : #ifdef CONFIG_SPARSEMEM_EXTREME
    1234                 :            : extern struct mem_section **mem_section;
    1235                 :            : #else
    1236                 :            : extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
    1237                 :            : #endif
    1238                 :            : 
    1239                 :            : static inline unsigned long *section_to_usemap(struct mem_section *ms)
    1240                 :            : {
    1241                 :            :         return ms->usage->pageblock_flags;
    1242                 :            : }
    1243                 :            : 
    1244                 :            : static inline struct mem_section *__nr_to_section(unsigned long nr)
    1245                 :            : {
    1246                 :            : #ifdef CONFIG_SPARSEMEM_EXTREME
    1247                 :            :         if (!mem_section)
    1248                 :            :                 return NULL;
    1249                 :            : #endif
    1250                 :            :         if (!mem_section[SECTION_NR_TO_ROOT(nr)])
    1251                 :            :                 return NULL;
    1252                 :            :         return &mem_section[SECTION_NR_TO_ROOT(nr)][nr & SECTION_ROOT_MASK];
    1253                 :            : }
    1254                 :            : extern unsigned long __section_nr(struct mem_section *ms);
    1255                 :            : extern size_t mem_section_usage_size(void);
    1256                 :            : 
    1257                 :            : /*
    1258                 :            :  * We use the lower bits of the mem_map pointer to store
    1259                 :            :  * a little bit of information.  The pointer is calculated
    1260                 :            :  * as mem_map - section_nr_to_pfn(pnum).  The result is
    1261                 :            :  * aligned to the minimum alignment of the two values:
    1262                 :            :  *   1. All mem_map arrays are page-aligned.
    1263                 :            :  *   2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
    1264                 :            :  *      lowest bits.  PFN_SECTION_SHIFT is arch-specific
    1265                 :            :  *      (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
    1266                 :            :  *      worst combination is powerpc with 256k pages,
    1267                 :            :  *      which results in PFN_SECTION_SHIFT equal 6.
    1268                 :            :  * To sum it up, at least 6 bits are available.
    1269                 :            :  */
    1270                 :            : #define SECTION_MARKED_PRESENT  (1UL<<0)
    1271                 :            : #define SECTION_HAS_MEM_MAP     (1UL<<1)
    1272                 :            : #define SECTION_IS_ONLINE       (1UL<<2)
    1273                 :            : #define SECTION_IS_EARLY        (1UL<<3)
    1274                 :            : #define SECTION_MAP_LAST_BIT    (1UL<<4)
    1275                 :            : #define SECTION_MAP_MASK        (~(SECTION_MAP_LAST_BIT-1))
    1276                 :            : #define SECTION_NID_SHIFT       3
    1277                 :            : 
    1278                 :            : static inline struct page *__section_mem_map_addr(struct mem_section *section)
    1279                 :            : {
    1280                 :            :         unsigned long map = section->section_mem_map;
    1281                 :            :         map &= SECTION_MAP_MASK;
    1282                 :            :         return (struct page *)map;
    1283                 :            : }
    1284                 :            : 
    1285                 :            : static inline int present_section(struct mem_section *section)
    1286                 :            : {
    1287                 :            :         return (section && (section->section_mem_map & SECTION_MARKED_PRESENT));
    1288                 :            : }
    1289                 :            : 
    1290                 :            : static inline int present_section_nr(unsigned long nr)
    1291                 :            : {
    1292                 :            :         return present_section(__nr_to_section(nr));
    1293                 :            : }
    1294                 :            : 
    1295                 :            : static inline int valid_section(struct mem_section *section)
    1296                 :            : {
    1297                 :            :         return (section && (section->section_mem_map & SECTION_HAS_MEM_MAP));
    1298                 :            : }
    1299                 :            : 
    1300                 :            : static inline int early_section(struct mem_section *section)
    1301                 :            : {
    1302                 :            :         return (section && (section->section_mem_map & SECTION_IS_EARLY));
    1303                 :            : }
    1304                 :            : 
    1305                 :            : static inline int valid_section_nr(unsigned long nr)
    1306                 :            : {
    1307                 :            :         return valid_section(__nr_to_section(nr));
    1308                 :            : }
    1309                 :            : 
    1310                 :            : static inline int online_section(struct mem_section *section)
    1311                 :            : {
    1312                 :            :         return (section && (section->section_mem_map & SECTION_IS_ONLINE));
    1313                 :            : }
    1314                 :            : 
    1315                 :            : static inline int online_section_nr(unsigned long nr)
    1316                 :            : {
    1317                 :            :         return online_section(__nr_to_section(nr));
    1318                 :            : }
    1319                 :            : 
    1320                 :            : #ifdef CONFIG_MEMORY_HOTPLUG
    1321                 :            : void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
    1322                 :            : #ifdef CONFIG_MEMORY_HOTREMOVE
    1323                 :            : void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
    1324                 :            : #endif
    1325                 :            : #endif
    1326                 :            : 
    1327                 :            : static inline struct mem_section *__pfn_to_section(unsigned long pfn)
    1328                 :            : {
    1329                 :            :         return __nr_to_section(pfn_to_section_nr(pfn));
    1330                 :            : }
    1331                 :            : 
    1332                 :            : extern unsigned long __highest_present_section_nr;
    1333                 :            : 
    1334                 :            : static inline int subsection_map_index(unsigned long pfn)
    1335                 :            : {
    1336                 :            :         return (pfn & ~(PAGE_SECTION_MASK)) / PAGES_PER_SUBSECTION;
    1337                 :            : }
    1338                 :            : 
    1339                 :            : #ifdef CONFIG_SPARSEMEM_VMEMMAP
    1340                 :            : static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
    1341                 :            : {
    1342                 :            :         int idx = subsection_map_index(pfn);
    1343                 :            : 
    1344                 :            :         return test_bit(idx, ms->usage->subsection_map);
    1345                 :            : }
    1346                 :            : #else
    1347                 :            : static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
    1348                 :            : {
    1349                 :            :         return 1;
    1350                 :            : }
    1351                 :            : #endif
    1352                 :            : 
    1353                 :            : #ifndef CONFIG_HAVE_ARCH_PFN_VALID
    1354                 :            : static inline int pfn_valid(unsigned long pfn)
    1355                 :            : {
    1356                 :            :         struct mem_section *ms;
    1357                 :            : 
    1358                 :            :         if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
    1359                 :            :                 return 0;
    1360                 :            :         ms = __nr_to_section(pfn_to_section_nr(pfn));
    1361                 :            :         if (!valid_section(ms))
    1362                 :            :                 return 0;
    1363                 :            :         /*
    1364                 :            :          * Traditionally early sections always returned pfn_valid() for
    1365                 :            :          * the entire section-sized span.
    1366                 :            :          */
    1367                 :            :         return early_section(ms) || pfn_section_valid(ms, pfn);
    1368                 :            : }
    1369                 :            : #endif
    1370                 :            : 
    1371                 :            : static inline int pfn_present(unsigned long pfn)
    1372                 :            : {
    1373                 :            :         if (pfn_to_section_nr(pfn) >= NR_MEM_SECTIONS)
    1374                 :            :                 return 0;
    1375                 :            :         return present_section(__nr_to_section(pfn_to_section_nr(pfn)));
    1376                 :            : }
    1377                 :            : 
    1378                 :            : /*
    1379                 :            :  * These are _only_ used during initialisation, therefore they
    1380                 :            :  * can use __initdata ...  They could have names to indicate
    1381                 :            :  * this restriction.
    1382                 :            :  */
    1383                 :            : #ifdef CONFIG_NUMA
    1384                 :            : #define pfn_to_nid(pfn)                                                 \
    1385                 :            : ({                                                                      \
    1386                 :            :         unsigned long __pfn_to_nid_pfn = (pfn);                         \
    1387                 :            :         page_to_nid(pfn_to_page(__pfn_to_nid_pfn));                     \
    1388                 :            : })
    1389                 :            : #else
    1390                 :            : #define pfn_to_nid(pfn)         (0)
    1391                 :            : #endif
    1392                 :            : 
    1393                 :            : #define early_pfn_valid(pfn)    pfn_valid(pfn)
    1394                 :            : void sparse_init(void);
    1395                 :            : #else
    1396                 :            : #define sparse_init()   do {} while (0)
    1397                 :            : #define sparse_index_init(_sec, _nid)  do {} while (0)
    1398                 :            : #define pfn_present pfn_valid
    1399                 :            : #define subsection_map_init(_pfn, _nr_pages) do {} while (0)
    1400                 :            : #endif /* CONFIG_SPARSEMEM */
    1401                 :            : 
    1402                 :            : /*
    1403                 :            :  * During memory init memblocks map pfns to nids. The search is expensive and
    1404                 :            :  * this caches recent lookups. The implementation of __early_pfn_to_nid
    1405                 :            :  * may treat start/end as pfns or sections.
    1406                 :            :  */
    1407                 :            : struct mminit_pfnnid_cache {
    1408                 :            :         unsigned long last_start;
    1409                 :            :         unsigned long last_end;
    1410                 :            :         int last_nid;
    1411                 :            : };
    1412                 :            : 
    1413                 :            : #ifndef early_pfn_valid
    1414                 :            : #define early_pfn_valid(pfn)    (1)
    1415                 :            : #endif
    1416                 :            : 
    1417                 :            : void memory_present(int nid, unsigned long start, unsigned long end);
    1418                 :            : 
    1419                 :            : /*
    1420                 :            :  * If it is possible to have holes within a MAX_ORDER_NR_PAGES, then we
    1421                 :            :  * need to check pfn validity within that MAX_ORDER_NR_PAGES block.
    1422                 :            :  * pfn_valid_within() should be used in this case; we optimise this away
    1423                 :            :  * when we have no holes within a MAX_ORDER_NR_PAGES block.
    1424                 :            :  */
    1425                 :            : #ifdef CONFIG_HOLES_IN_ZONE
    1426                 :            : #define pfn_valid_within(pfn) pfn_valid(pfn)
    1427                 :            : #else
    1428                 :            : #define pfn_valid_within(pfn) (1)
    1429                 :            : #endif
    1430                 :            : 
    1431                 :            : #ifdef CONFIG_ARCH_HAS_HOLES_MEMORYMODEL
    1432                 :            : /*
    1433                 :            :  * pfn_valid() is meant to be able to tell if a given PFN has valid memmap
    1434                 :            :  * associated with it or not. This means that a struct page exists for this
    1435                 :            :  * pfn. The caller cannot assume the page is fully initialized in general.
    1436                 :            :  * Hotplugable pages might not have been onlined yet. pfn_to_online_page()
    1437                 :            :  * will ensure the struct page is fully online and initialized. Special pages
    1438                 :            :  * (e.g. ZONE_DEVICE) are never onlined and should be treated accordingly.
    1439                 :            :  *
    1440                 :            :  * In FLATMEM, it is expected that holes always have valid memmap as long as
    1441                 :            :  * there is valid PFNs either side of the hole. In SPARSEMEM, it is assumed
    1442                 :            :  * that a valid section has a memmap for the entire section.
    1443                 :            :  *
    1444                 :            :  * However, an ARM, and maybe other embedded architectures in the future
    1445                 :            :  * free memmap backing holes to save memory on the assumption the memmap is
    1446                 :            :  * never used. The page_zone linkages are then broken even though pfn_valid()
    1447                 :            :  * returns true. A walker of the full memmap must then do this additional
    1448                 :            :  * check to ensure the memmap they are looking at is sane by making sure
    1449                 :            :  * the zone and PFN linkages are still valid. This is expensive, but walkers
    1450                 :            :  * of the full memmap are extremely rare.
    1451                 :            :  */
    1452                 :            : bool memmap_valid_within(unsigned long pfn,
    1453                 :            :                                         struct page *page, struct zone *zone);
    1454                 :            : #else
    1455                 :            : static inline bool memmap_valid_within(unsigned long pfn,
    1456                 :            :                                         struct page *page, struct zone *zone)
    1457                 :            : {
    1458                 :            :         return true;
    1459                 :            : }
    1460                 :            : #endif /* CONFIG_ARCH_HAS_HOLES_MEMORYMODEL */
    1461                 :            : 
    1462                 :            : #endif /* !__GENERATING_BOUNDS.H */
    1463                 :            : #endif /* !__ASSEMBLY__ */
    1464                 :            : #endif /* _LINUX_MMZONE_H */
    

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