linux/include/linux/mmzone.h

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MMZONE_H
#define _LINUX_MMZONE_H

#ifndef __ASSEMBLY__
#ifndef __GENERATING_BOUNDS_H

#include <linux/spinlock.h>
#include <linux/list.h>
#include <linux/list_nulls.h>
#include <linux/wait.h>
#include <linux/bitops.h>
#include <linux/cache.h>
#include <linux/threads.h>
#include <linux/numa.h>
#include <linux/init.h>
#include <linux/seqlock.h>
#include <linux/nodemask.h>
#include <linux/pageblock-flags.h>
#include <linux/page-flags-layout.h>
#include <linux/atomic.h>
#include <linux/mm_types.h>
#include <linux/page-flags.h>
#include <linux/local_lock.h>
#include <linux/zswap.h>
#include <asm/page.h>

/* Free memory management - zoned buddy allocator.  */
#ifndef CONFIG_ARCH_FORCE_MAX_ORDER
#define MAX_PAGE_ORDER
#else
#define MAX_PAGE_ORDER
#endif
#define MAX_ORDER_NR_PAGES

#define IS_MAX_ORDER_ALIGNED(pfn)

#define NR_PAGE_ORDERS

/*
 * PAGE_ALLOC_COSTLY_ORDER is the order at which allocations are deemed
 * costly to service.  That is between allocation orders which should
 * coalesce naturally under reasonable reclaim pressure and those which
 * will not.
 */
#define PAGE_ALLOC_COSTLY_ORDER

enum migratetype {};

/* In mm/page_alloc.c; keep in sync also with show_migration_types() there */
extern const char * const migratetype_names[MIGRATE_TYPES];

#ifdef CONFIG_CMA
#define is_migrate_cma(migratetype)
#define is_migrate_cma_page(_page)
#define is_migrate_cma_folio(folio, pfn)
#else
#define is_migrate_cma
#define is_migrate_cma_page
#define is_migrate_cma_folio
#endif

static inline bool is_migrate_movable(int mt)
{}

/*
 * Check whether a migratetype can be merged with another migratetype.
 *
 * It is only mergeable when it can fall back to other migratetypes for
 * allocation. See fallbacks[MIGRATE_TYPES][3] in page_alloc.c.
 */
static inline bool migratetype_is_mergeable(int mt)
{}

#define for_each_migratetype_order(order, type)

extern int page_group_by_mobility_disabled;

#define MIGRATETYPE_MASK

#define get_pageblock_migratetype(page)

#define folio_migratetype(folio)
struct free_area {};

struct pglist_data;

#ifdef CONFIG_NUMA
enum numa_stat_item {};
#else
#define NR_VM_NUMA_EVENT_ITEMS
#endif

enum zone_stat_item {};

enum node_stat_item {};

/*
 * Returns true if the item should be printed in THPs (/proc/vmstat
 * currently prints number of anon, file and shmem THPs. But the item
 * is charged in pages).
 */
static __always_inline bool vmstat_item_print_in_thp(enum node_stat_item item)
{}

/*
 * Returns true if the value is measured in bytes (most vmstat values are
 * measured in pages). This defines the API part, the internal representation
 * might be different.
 */
static __always_inline bool vmstat_item_in_bytes(int idx)
{}

/*
 * We do arithmetic on the LRU lists in various places in the code,
 * so it is important to keep the active lists LRU_ACTIVE higher in
 * the array than the corresponding inactive lists, and to keep
 * the *_FILE lists LRU_FILE higher than the corresponding _ANON lists.
 *
 * This has to be kept in sync with the statistics in zone_stat_item
 * above and the descriptions in vmstat_text in mm/vmstat.c
 */
#define LRU_BASE
#define LRU_ACTIVE
#define LRU_FILE

enum lru_list {};

enum vmscan_throttle_state {};

#define for_each_lru(lru)

#define for_each_evictable_lru(lru)

static inline bool is_file_lru(enum lru_list lru)
{}

static inline bool is_active_lru(enum lru_list lru)
{}

#define WORKINGSET_ANON
#define WORKINGSET_FILE
#define ANON_AND_FILE

enum lruvec_flags {};

#endif /* !__GENERATING_BOUNDS_H */

/*
 * Evictable pages are divided into multiple generations. The youngest and the
 * oldest generation numbers, max_seq and min_seq, are monotonically increasing.
 * They form a sliding window of a variable size [MIN_NR_GENS, MAX_NR_GENS]. An
 * offset within MAX_NR_GENS, i.e., gen, indexes the LRU list of the
 * corresponding generation. The gen counter in folio->flags stores gen+1 while
 * a page is on one of lrugen->folios[]. Otherwise it stores 0.
 *
 * A page is added to the youngest generation on faulting. The aging needs to
 * check the accessed bit at least twice before handing this page over to the
 * eviction. The first check takes care of the accessed bit set on the initial
 * fault; the second check makes sure this page hasn't been used since then.
 * This process, AKA second chance, requires a minimum of two generations,
 * hence MIN_NR_GENS. And to maintain ABI compatibility with the active/inactive
 * LRU, e.g., /proc/vmstat, these two generations are considered active; the
 * rest of generations, if they exist, are considered inactive. See
 * lru_gen_is_active().
 *
 * PG_active is always cleared while a page is on one of lrugen->folios[] so
 * that the aging needs not to worry about it. And it's set again when a page
 * considered active is isolated for non-reclaiming purposes, e.g., migration.
 * See lru_gen_add_folio() and lru_gen_del_folio().
 *
 * MAX_NR_GENS is set to 4 so that the multi-gen LRU can support twice the
 * number of categories of the active/inactive LRU when keeping track of
 * accesses through page tables. This requires order_base_2(MAX_NR_GENS+1) bits
 * in folio->flags.
 */
#define MIN_NR_GENS
#define MAX_NR_GENS

/*
 * Each generation is divided into multiple tiers. A page accessed N times
 * through file descriptors is in tier order_base_2(N). A page in the first tier
 * (N=0,1) is marked by PG_referenced unless it was faulted in through page
 * tables or read ahead. A page in any other tier (N>1) is marked by
 * PG_referenced and PG_workingset. This implies a minimum of two tiers is
 * supported without using additional bits in folio->flags.
 *
 * In contrast to moving across generations which requires the LRU lock, moving
 * across tiers only involves atomic operations on folio->flags and therefore
 * has a negligible cost in the buffered access path. In the eviction path,
 * comparisons of refaulted/(evicted+protected) from the first tier and the
 * rest infer whether pages accessed multiple times through file descriptors
 * are statistically hot and thus worth protecting.
 *
 * MAX_NR_TIERS is set to 4 so that the multi-gen LRU can support twice the
 * number of categories of the active/inactive LRU when keeping track of
 * accesses through file descriptors. This uses MAX_NR_TIERS-2 spare bits in
 * folio->flags.
 */
#define MAX_NR_TIERS

#ifndef __GENERATING_BOUNDS_H

struct lruvec;
struct page_vma_mapped_walk;

#define LRU_GEN_MASK
#define LRU_REFS_MASK

#ifdef CONFIG_LRU_GEN

enum {};

enum {};

#define MIN_LRU_BATCH
#define MAX_LRU_BATCH

/* whether to keep historical stats from evicted generations */
#ifdef CONFIG_LRU_GEN_STATS
#define NR_HIST_GENS
#else
#define NR_HIST_GENS
#endif

/*
 * The youngest generation number is stored in max_seq for both anon and file
 * types as they are aged on an equal footing. The oldest generation numbers are
 * stored in min_seq[] separately for anon and file types as clean file pages
 * can be evicted regardless of swap constraints.
 *
 * Normally anon and file min_seq are in sync. But if swapping is constrained,
 * e.g., out of swap space, file min_seq is allowed to advance and leave anon
 * min_seq behind.
 *
 * The number of pages in each generation is eventually consistent and therefore
 * can be transiently negative when reset_batch_size() is pending.
 */
struct lru_gen_folio {};

enum {};

/* double-buffering Bloom filters */
#define NR_BLOOM_FILTERS

struct lru_gen_mm_state {};

struct lru_gen_mm_walk {};

/*
 * For each node, memcgs are divided into two generations: the old and the
 * young. For each generation, memcgs are randomly sharded into multiple bins
 * to improve scalability. For each bin, the hlist_nulls is virtually divided
 * into three segments: the head, the tail and the default.
 *
 * An onlining memcg is added to the tail of a random bin in the old generation.
 * The eviction starts at the head of a random bin in the old generation. The
 * per-node memcg generation counter, whose reminder (mod MEMCG_NR_GENS) indexes
 * the old generation, is incremented when all its bins become empty.
 *
 * There are four operations:
 * 1. MEMCG_LRU_HEAD, which moves a memcg to the head of a random bin in its
 *    current generation (old or young) and updates its "seg" to "head";
 * 2. MEMCG_LRU_TAIL, which moves a memcg to the tail of a random bin in its
 *    current generation (old or young) and updates its "seg" to "tail";
 * 3. MEMCG_LRU_OLD, which moves a memcg to the head of a random bin in the old
 *    generation, updates its "gen" to "old" and resets its "seg" to "default";
 * 4. MEMCG_LRU_YOUNG, which moves a memcg to the tail of a random bin in the
 *    young generation, updates its "gen" to "young" and resets its "seg" to
 *    "default".
 *
 * The events that trigger the above operations are:
 * 1. Exceeding the soft limit, which triggers MEMCG_LRU_HEAD;
 * 2. The first attempt to reclaim a memcg below low, which triggers
 *    MEMCG_LRU_TAIL;
 * 3. The first attempt to reclaim a memcg offlined or below reclaimable size
 *    threshold, which triggers MEMCG_LRU_TAIL;
 * 4. The second attempt to reclaim a memcg offlined or below reclaimable size
 *    threshold, which triggers MEMCG_LRU_YOUNG;
 * 5. Attempting to reclaim a memcg below min, which triggers MEMCG_LRU_YOUNG;
 * 6. Finishing the aging on the eviction path, which triggers MEMCG_LRU_YOUNG;
 * 7. Offlining a memcg, which triggers MEMCG_LRU_OLD.
 *
 * Notes:
 * 1. Memcg LRU only applies to global reclaim, and the round-robin incrementing
 *    of their max_seq counters ensures the eventual fairness to all eligible
 *    memcgs. For memcg reclaim, it still relies on mem_cgroup_iter().
 * 2. There are only two valid generations: old (seq) and young (seq+1).
 *    MEMCG_NR_GENS is set to three so that when reading the generation counter
 *    locklessly, a stale value (seq-1) does not wraparound to young.
 */
#define MEMCG_NR_GENS
#define MEMCG_NR_BINS

struct lru_gen_memcg {};

void lru_gen_init_pgdat(struct pglist_data *pgdat);
void lru_gen_init_lruvec(struct lruvec *lruvec);
bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw);

void lru_gen_init_memcg(struct mem_cgroup *memcg);
void lru_gen_exit_memcg(struct mem_cgroup *memcg);
void lru_gen_online_memcg(struct mem_cgroup *memcg);
void lru_gen_offline_memcg(struct mem_cgroup *memcg);
void lru_gen_release_memcg(struct mem_cgroup *memcg);
void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid);

#else /* !CONFIG_LRU_GEN */

static inline void lru_gen_init_pgdat(struct pglist_data *pgdat)
{
}

static inline void lru_gen_init_lruvec(struct lruvec *lruvec)
{
}

static inline bool lru_gen_look_around(struct page_vma_mapped_walk *pvmw)
{
	return false;
}

static inline void lru_gen_init_memcg(struct mem_cgroup *memcg)
{
}

static inline void lru_gen_exit_memcg(struct mem_cgroup *memcg)
{
}

static inline void lru_gen_online_memcg(struct mem_cgroup *memcg)
{
}

static inline void lru_gen_offline_memcg(struct mem_cgroup *memcg)
{
}

static inline void lru_gen_release_memcg(struct mem_cgroup *memcg)
{
}

static inline void lru_gen_soft_reclaim(struct mem_cgroup *memcg, int nid)
{
}

#endif /* CONFIG_LRU_GEN */

struct lruvec {};

/* Isolate for asynchronous migration */
#define ISOLATE_ASYNC_MIGRATE
/* Isolate unevictable pages */
#define ISOLATE_UNEVICTABLE

/* LRU Isolation modes. */
isolate_mode_t;

enum zone_watermarks {};

/*
 * One per migratetype for each PAGE_ALLOC_COSTLY_ORDER. Two additional lists
 * are added for THP. One PCP list is used by GPF_MOVABLE, and the other PCP list
 * is used by GFP_UNMOVABLE and GFP_RECLAIMABLE.
 */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
#define NR_PCP_THP
#else
#define NR_PCP_THP
#endif
#define NR_LOWORDER_PCP_LISTS
#define NR_PCP_LISTS

/*
 * Flags used in pcp->flags field.
 *
 * PCPF_PREV_FREE_HIGH_ORDER: a high-order page is freed in the
 * previous page freeing.  To avoid to drain PCP for an accident
 * high-order page freeing.
 *
 * PCPF_FREE_HIGH_BATCH: preserve "pcp->batch" pages in PCP before
 * draining PCP for consecutive high-order pages freeing without
 * allocation if data cache slice of CPU is large enough.  To reduce
 * zone lock contention and keep cache-hot pages reusing.
 */
#define PCPF_PREV_FREE_HIGH_ORDER
#define PCPF_FREE_HIGH_BATCH

struct per_cpu_pages {} ____cacheline_aligned_in_smp;

struct per_cpu_zonestat {};

struct per_cpu_nodestat {};

#endif /* !__GENERATING_BOUNDS.H */

enum zone_type {};

#ifndef __GENERATING_BOUNDS_H

#define ASYNC_AND_SYNC

struct zone {} ____cacheline_internodealigned_in_smp;

enum pgdat_flags {};

enum zone_flags {};

static inline unsigned long wmark_pages(const struct zone *z,
					enum zone_watermarks w)
{}

static inline unsigned long min_wmark_pages(const struct zone *z)
{}

static inline unsigned long low_wmark_pages(const struct zone *z)
{}

static inline unsigned long high_wmark_pages(const struct zone *z)
{}

static inline unsigned long promo_wmark_pages(const struct zone *z)
{}

static inline unsigned long zone_managed_pages(struct zone *zone)
{}

static inline unsigned long zone_cma_pages(struct zone *zone)
{}

static inline unsigned long zone_end_pfn(const struct zone *zone)
{}

static inline bool zone_spans_pfn(const struct zone *zone, unsigned long pfn)
{}

static inline bool zone_is_initialized(struct zone *zone)
{}

static inline bool zone_is_empty(struct zone *zone)
{}

#ifndef BUILD_VDSO32_64
/*
 * The zone field is never updated after free_area_init_core()
 * sets it, so none of the operations on it need to be atomic.
 */

/* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
#define SECTIONS_PGOFF
#define NODES_PGOFF
#define ZONES_PGOFF
#define LAST_CPUPID_PGOFF
#define KASAN_TAG_PGOFF
#define LRU_GEN_PGOFF
#define LRU_REFS_PGOFF

/*
 * Define the bit shifts to access each section.  For non-existent
 * sections we define the shift as 0; that plus a 0 mask ensures
 * the compiler will optimise away reference to them.
 */
#define SECTIONS_PGSHIFT
#define NODES_PGSHIFT
#define ZONES_PGSHIFT
#define LAST_CPUPID_PGSHIFT
#define KASAN_TAG_PGSHIFT

/* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
#ifdef NODE_NOT_IN_PAGE_FLAGS
#define ZONEID_SHIFT
#define ZONEID_PGOFF
#else
#define ZONEID_SHIFT
#define ZONEID_PGOFF
#endif

#define ZONEID_PGSHIFT

#define ZONES_MASK
#define NODES_MASK
#define SECTIONS_MASK
#define LAST_CPUPID_MASK
#define KASAN_TAG_MASK
#define ZONEID_MASK

static inline enum zone_type page_zonenum(const struct page *page)
{}

static inline enum zone_type folio_zonenum(const struct folio *folio)
{}

#ifdef CONFIG_ZONE_DEVICE
static inline bool is_zone_device_page(const struct page *page)
{}

/*
 * Consecutive zone device pages should not be merged into the same sgl
 * or bvec segment with other types of pages or if they belong to different
 * pgmaps. Otherwise getting the pgmap of a given segment is not possible
 * without scanning the entire segment. This helper returns true either if
 * both pages are not zone device pages or both pages are zone device pages
 * with the same pgmap.
 */
static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
						     const struct page *b)
{}

extern void memmap_init_zone_device(struct zone *, unsigned long,
				    unsigned long, struct dev_pagemap *);
#else
static inline bool is_zone_device_page(const struct page *page)
{
	return false;
}
static inline bool zone_device_pages_have_same_pgmap(const struct page *a,
						     const struct page *b)
{
	return true;
}
#endif

static inline bool folio_is_zone_device(const struct folio *folio)
{}

static inline bool is_zone_movable_page(const struct page *page)
{}

static inline bool folio_is_zone_movable(const struct folio *folio)
{}
#endif

/*
 * Return true if [start_pfn, start_pfn + nr_pages) range has a non-empty
 * intersection with the given zone
 */
static inline bool zone_intersects(struct zone *zone,
		unsigned long start_pfn, unsigned long nr_pages)
{}

/*
 * The "priority" of VM scanning is how much of the queues we will scan in one
 * go. A value of 12 for DEF_PRIORITY implies that we will scan 1/4096th of the
 * queues ("queue_length >> 12") during an aging round.
 */
#define DEF_PRIORITY

/* Maximum number of zones on a zonelist */
#define MAX_ZONES_PER_ZONELIST

enum {};

/*
 * This struct contains information about a zone in a zonelist. It is stored
 * here to avoid dereferences into large structures and lookups of tables
 */
struct zoneref {};

/*
 * One allocation request operates on a zonelist. A zonelist
 * is a list of zones, the first one is the 'goal' of the
 * allocation, the other zones are fallback zones, in decreasing
 * priority.
 *
 * To speed the reading of the zonelist, the zonerefs contain the zone index
 * of the entry being read. Helper functions to access information given
 * a struct zoneref are
 *
 * zonelist_zone()	- Return the struct zone * for an entry in _zonerefs
 * zonelist_zone_idx()	- Return the index of the zone for an entry
 * zonelist_node_idx()	- Return the index of the node for an entry
 */
struct zonelist {};

/*
 * The array of struct pages for flatmem.
 * It must be declared for SPARSEMEM as well because there are configurations
 * that rely on that.
 */
extern struct page *mem_map;

#ifdef CONFIG_TRANSPARENT_HUGEPAGE
struct deferred_split {};
#endif

#ifdef CONFIG_MEMORY_FAILURE
/*
 * Per NUMA node memory failure handling statistics.
 */
struct memory_failure_stats {};
#endif

/*
 * On NUMA machines, each NUMA node would have a pg_data_t to describe
 * it's memory layout. On UMA machines there is a single pglist_data which
 * describes the whole memory.
 *
 * Memory statistics and page replacement data structures are maintained on a
 * per-zone basis.
 */
pg_data_t;

#define node_present_pages(nid)
#define node_spanned_pages(nid)

#define node_start_pfn(nid)
#define node_end_pfn(nid)

static inline unsigned long pgdat_end_pfn(pg_data_t *pgdat)
{}

#include <linux/memory_hotplug.h>

void build_all_zonelists(pg_data_t *pgdat);
void wakeup_kswapd(struct zone *zone, gfp_t gfp_mask, int order,
		   enum zone_type highest_zoneidx);
bool __zone_watermark_ok(struct zone *z, unsigned int order, unsigned long mark,
			 int highest_zoneidx, unsigned int alloc_flags,
			 long free_pages);
bool zone_watermark_ok(struct zone *z, unsigned int order,
		unsigned long mark, int highest_zoneidx,
		unsigned int alloc_flags);
bool zone_watermark_ok_safe(struct zone *z, unsigned int order,
		unsigned long mark, int highest_zoneidx);
/*
 * Memory initialization context, use to differentiate memory added by
 * the platform statically or via memory hotplug interface.
 */
enum meminit_context {};

extern void init_currently_empty_zone(struct zone *zone, unsigned long start_pfn,
				     unsigned long size);

extern void lruvec_init(struct lruvec *lruvec);

static inline struct pglist_data *lruvec_pgdat(struct lruvec *lruvec)
{}

#ifdef CONFIG_HAVE_MEMORYLESS_NODES
int local_memory_node(int node_id);
#else
static inline int local_memory_node(int node_id) { return node_id; };
#endif

/*
 * zone_idx() returns 0 for the ZONE_DMA zone, 1 for the ZONE_NORMAL zone, etc.
 */
#define zone_idx(zone)

#ifdef CONFIG_ZONE_DEVICE
static inline bool zone_is_zone_device(struct zone *zone)
{}
#else
static inline bool zone_is_zone_device(struct zone *zone)
{
	return false;
}
#endif

/*
 * Returns true if a zone has pages managed by the buddy allocator.
 * All the reclaim decisions have to use this function rather than
 * populated_zone(). If the whole zone is reserved then we can easily
 * end up with populated_zone() && !managed_zone().
 */
static inline bool managed_zone(struct zone *zone)
{}

/* Returns true if a zone has memory */
static inline bool populated_zone(struct zone *zone)
{}

#ifdef CONFIG_NUMA
static inline int zone_to_nid(struct zone *zone)
{}

static inline void zone_set_nid(struct zone *zone, int nid)
{}
#else
static inline int zone_to_nid(struct zone *zone)
{
	return 0;
}

static inline void zone_set_nid(struct zone *zone, int nid) {}
#endif

extern int movable_zone;

static inline int is_highmem_idx(enum zone_type idx)
{}

/**
 * is_highmem - helper function to quickly check if a struct zone is a
 *              highmem zone or not.  This is an attempt to keep references
 *              to ZONE_{DMA/NORMAL/HIGHMEM/etc} in general code to a minimum.
 * @zone: pointer to struct zone variable
 * Return: 1 for a highmem zone, 0 otherwise
 */
static inline int is_highmem(struct zone *zone)
{}

#ifdef CONFIG_ZONE_DMA
bool has_managed_dma(void);
#else
static inline bool has_managed_dma(void)
{
	return false;
}
#endif


#ifndef CONFIG_NUMA

extern struct pglist_data contig_page_data;
static inline struct pglist_data *NODE_DATA(int nid)
{
	return &contig_page_data;
}

#else /* CONFIG_NUMA */

#include <asm/mmzone.h>

#endif /* !CONFIG_NUMA */

extern struct pglist_data *first_online_pgdat(void);
extern struct pglist_data *next_online_pgdat(struct pglist_data *pgdat);
extern struct zone *next_zone(struct zone *zone);

/**
 * for_each_online_pgdat - helper macro to iterate over all online nodes
 * @pgdat: pointer to a pg_data_t variable
 */
#define for_each_online_pgdat(pgdat)
/**
 * for_each_zone - helper macro to iterate over all memory zones
 * @zone: pointer to struct zone variable
 *
 * The user only needs to declare the zone variable, for_each_zone
 * fills it in.
 */
#define for_each_zone(zone)

#define for_each_populated_zone(zone)

static inline struct zone *zonelist_zone(struct zoneref *zoneref)
{}

static inline int zonelist_zone_idx(struct zoneref *zoneref)
{}

static inline int zonelist_node_idx(struct zoneref *zoneref)
{}

struct zoneref *__next_zones_zonelist(struct zoneref *z,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes);

/**
 * 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
 * @z: The cursor used as a starting point for the search
 * @highest_zoneidx: The zone index of the highest zone to return
 * @nodes: An optional nodemask to filter the zonelist with
 *
 * This function returns the next zone at or below a given zone index that is
 * within the allowed nodemask using a cursor as the starting point for the
 * search. The zoneref returned is a cursor that represents the current zone
 * being examined. It should be advanced by one before calling
 * next_zones_zonelist again.
 *
 * Return: the next zone at or below highest_zoneidx within the allowed
 * nodemask using a cursor within a zonelist as a starting point
 */
static __always_inline struct zoneref *next_zones_zonelist(struct zoneref *z,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes)
{}

/**
 * first_zones_zonelist - Returns the first zone at or below highest_zoneidx within the allowed nodemask in a zonelist
 * @zonelist: The zonelist to search for a suitable zone
 * @highest_zoneidx: The zone index of the highest zone to return
 * @nodes: An optional nodemask to filter the zonelist with
 *
 * This function returns the first zone at or below a given zone index that is
 * within the allowed nodemask. The zoneref returned is a cursor that can be
 * used to iterate the zonelist with next_zones_zonelist by advancing it by
 * one before calling.
 *
 * When no eligible zone is found, zoneref->zone is NULL (zoneref itself is
 * never NULL). This may happen either genuinely, or due to concurrent nodemask
 * update due to cpuset modification.
 *
 * Return: Zoneref pointer for the first suitable zone found
 */
static inline struct zoneref *first_zones_zonelist(struct zonelist *zonelist,
					enum zone_type highest_zoneidx,
					nodemask_t *nodes)
{}

/**
 * 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
 * @zone: The current zone in the iterator
 * @z: The current pointer within zonelist->_zonerefs being iterated
 * @zlist: The zonelist being iterated
 * @highidx: The zone index of the highest zone to return
 * @nodemask: Nodemask allowed by the allocator
 *
 * This iterator iterates though all zones at or below a given zone index and
 * within a given nodemask
 */
#define for_each_zone_zonelist_nodemask(zone, z, zlist, highidx, nodemask)

#define for_next_zone_zonelist_nodemask(zone, z, highidx, nodemask)


/**
 * for_each_zone_zonelist - helper macro to iterate over valid zones in a zonelist at or below a given zone index
 * @zone: The current zone in the iterator
 * @z: The current pointer within zonelist->zones being iterated
 * @zlist: The zonelist being iterated
 * @highidx: The zone index of the highest zone to return
 *
 * This iterator iterates though all zones at or below a given zone index.
 */
#define for_each_zone_zonelist(zone, z, zlist, highidx)

/* Whether the 'nodes' are all movable nodes */
static inline bool movable_only_nodes(nodemask_t *nodes)
{}


#ifdef CONFIG_SPARSEMEM
#include <asm/sparsemem.h>
#endif

#ifdef CONFIG_FLATMEM
#define pfn_to_nid
#endif

#ifdef CONFIG_SPARSEMEM

/*
 * PA_SECTION_SHIFT		physical address to/from section number
 * PFN_SECTION_SHIFT		pfn to/from section number
 */
#define PA_SECTION_SHIFT
#define PFN_SECTION_SHIFT

#define NR_MEM_SECTIONS

#define PAGES_PER_SECTION
#define PAGE_SECTION_MASK

#define SECTION_BLOCKFLAGS_BITS

#if (MAX_PAGE_ORDER + PAGE_SHIFT) > SECTION_SIZE_BITS
#error Allocator MAX_PAGE_ORDER exceeds SECTION_SIZE
#endif

static inline unsigned long pfn_to_section_nr(unsigned long pfn)
{}
static inline unsigned long section_nr_to_pfn(unsigned long sec)
{}

#define SECTION_ALIGN_UP(pfn)
#define SECTION_ALIGN_DOWN(pfn)

#define SUBSECTION_SHIFT
#define SUBSECTION_SIZE

#define PFN_SUBSECTION_SHIFT
#define PAGES_PER_SUBSECTION
#define PAGE_SUBSECTION_MASK

#if SUBSECTION_SHIFT > SECTION_SIZE_BITS
#error Subsection size exceeds section size
#else
#define SUBSECTIONS_PER_SECTION
#endif

#define SUBSECTION_ALIGN_UP(pfn)
#define SUBSECTION_ALIGN_DOWN(pfn)

struct mem_section_usage {};

void subsection_map_init(unsigned long pfn, unsigned long nr_pages);

struct page;
struct page_ext;
struct mem_section {};

#ifdef CONFIG_SPARSEMEM_EXTREME
#define SECTIONS_PER_ROOT
#else
#define SECTIONS_PER_ROOT
#endif

#define SECTION_NR_TO_ROOT(sec)
#define NR_SECTION_ROOTS
#define SECTION_ROOT_MASK

#ifdef CONFIG_SPARSEMEM_EXTREME
extern struct mem_section **mem_section;
#else
extern struct mem_section mem_section[NR_SECTION_ROOTS][SECTIONS_PER_ROOT];
#endif

static inline unsigned long *section_to_usemap(struct mem_section *ms)
{}

static inline struct mem_section *__nr_to_section(unsigned long nr)
{}
extern size_t mem_section_usage_size(void);

/*
 * We use the lower bits of the mem_map pointer to store
 * a little bit of information.  The pointer is calculated
 * as mem_map - section_nr_to_pfn(pnum).  The result is
 * aligned to the minimum alignment of the two values:
 *   1. All mem_map arrays are page-aligned.
 *   2. section_nr_to_pfn() always clears PFN_SECTION_SHIFT
 *      lowest bits.  PFN_SECTION_SHIFT is arch-specific
 *      (equal SECTION_SIZE_BITS - PAGE_SHIFT), and the
 *      worst combination is powerpc with 256k pages,
 *      which results in PFN_SECTION_SHIFT equal 6.
 * To sum it up, at least 6 bits are available on all architectures.
 * However, we can exceed 6 bits on some other architectures except
 * powerpc (e.g. 15 bits are available on x86_64, 13 bits are available
 * with the worst case of 64K pages on arm64) if we make sure the
 * exceeded bit is not applicable to powerpc.
 */
enum {};

#define SECTION_MARKED_PRESENT
#define SECTION_HAS_MEM_MAP
#define SECTION_IS_ONLINE
#define SECTION_IS_EARLY
#ifdef CONFIG_ZONE_DEVICE
#define SECTION_TAINT_ZONE_DEVICE
#endif
#define SECTION_MAP_MASK
#define SECTION_NID_SHIFT

static inline struct page *__section_mem_map_addr(struct mem_section *section)
{}

static inline int present_section(struct mem_section *section)
{}

static inline int present_section_nr(unsigned long nr)
{}

static inline int valid_section(struct mem_section *section)
{}

static inline int early_section(struct mem_section *section)
{}

static inline int valid_section_nr(unsigned long nr)
{}

static inline int online_section(struct mem_section *section)
{}

#ifdef CONFIG_ZONE_DEVICE
static inline int online_device_section(struct mem_section *section)
{}
#else
static inline int online_device_section(struct mem_section *section)
{
	return 0;
}
#endif

static inline int online_section_nr(unsigned long nr)
{}

#ifdef CONFIG_MEMORY_HOTPLUG
void online_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
void offline_mem_sections(unsigned long start_pfn, unsigned long end_pfn);
#endif

static inline struct mem_section *__pfn_to_section(unsigned long pfn)
{}

extern unsigned long __highest_present_section_nr;

static inline int subsection_map_index(unsigned long pfn)
{}

#ifdef CONFIG_SPARSEMEM_VMEMMAP
static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
{}
#else
static inline int pfn_section_valid(struct mem_section *ms, unsigned long pfn)
{
	return 1;
}
#endif

#ifndef CONFIG_HAVE_ARCH_PFN_VALID
/**
 * pfn_valid - check if there is a valid memory map entry for a PFN
 * @pfn: the page frame number to check
 *
 * Check if there is a valid memory map entry aka struct page for the @pfn.
 * Note, that availability of the memory map entry does not imply that
 * there is actual usable memory at that @pfn. The struct page may
 * represent a hole or an unusable page frame.
 *
 * Return: 1 for PFNs that have memory map entries and 0 otherwise
 */
static inline int pfn_valid(unsigned long pfn)
{}
#endif

static inline int pfn_in_present_section(unsigned long pfn)
{}

static inline unsigned long next_present_section_nr(unsigned long section_nr)
{}

/*
 * These are _only_ used during initialisation, therefore they
 * can use __initdata ...  They could have names to indicate
 * this restriction.
 */
#ifdef CONFIG_NUMA
#define pfn_to_nid(pfn)
#else
#define pfn_to_nid
#endif

void sparse_init(void);
#else
#define sparse_init
#define sparse_index_init
#define pfn_in_present_section
#define subsection_map_init
#endif /* CONFIG_SPARSEMEM */

#endif /* !__GENERATING_BOUNDS.H */
#endif /* !__ASSEMBLY__ */
#endif /* _LINUX_MMZONE_H */