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#ifndef _LINUX_MMZONE_H

#define _LINUX_MMZONE_H

#ifdef __KERNEL__

#ifndef __ASSEMBLY__

#include <linux/config.h>

#include <linux/spinlock.h>

#include <linux/list.h>

#include <linux/wait.h>

#include <linux/cache.h>

#include <linux/threads.h>

#include <linux/numa.h>

#include <asm/atomic.h>

/* Free memory management - zoned buddy allocator.  */

#ifndef CONFIG_FORCE_MAX_ZONEORDER

#define MAX_ORDER 11

#else

#define MAX_ORDER CONFIG_FORCE_MAX_ZONEORDER

#endif

struct free_area {

        struct list_head        free_list;

        unsigned long           *map;

};

struct pglist_data;

/*

 * zone->lock and zone->lru_lock are two of the hottest locks in the kernel.

 * So add a wild amount of padding here to ensure that they fall into separate

 * cachelines.  There are very few zone structures in the machine, so space

 * consumption is not a concern here.

 */

#if defined(CONFIG_SMP)

struct zone_padding {

        int x;

} ____cacheline_maxaligned_in_smp;

#define ZONE_PADDING(name)      struct zone_padding name;

#else

#define ZONE_PADDING(name)

#endif

struct per_cpu_pages {

        int count;              /* number of pages in the list */

        int low;                /* low watermark, refill needed */

        int high;               /* high watermark, emptying needed */

        int batch;              /* chunk size for buddy add/remove */

        struct list_head list;  /* the list of pages */

};

struct per_cpu_pageset {

        struct per_cpu_pages pcp[2];    /* 0: hot.  1: cold */

} ____cacheline_aligned_in_smp;

/*

 * On machines where it is needed (eg PCs) we divide physical memory

 * into multiple physical zones. On a PC we have 3 zones:

 *

 * ZONE_DMA       < 16 MB       ISA DMA capable memory

 * ZONE_NORMAL  16-896 MB       direct mapped by the kernel

 * ZONE_HIGHMEM  > 896 MB       only page cache and user processes

 */

struct zone {

        /*

         * Commonly accessed fields:

         */

        spinlock_t              lock;

        unsigned long           free_pages;

        unsigned long           pages_min, pages_low, pages_high;

        ZONE_PADDING(_pad1_)

        spinlock_t              lru_lock;      

        struct list_head        active_list;

        struct list_head        inactive_list;

        atomic_t                refill_counter;

        unsigned long           nr_active;

        unsigned long           nr_inactive;

        int                     all_unreclaimable; /* All pages pinned */

        unsigned long           pages_scanned;     /* since last reclaim */

        ZONE_PADDING(_pad2_)

        /*

         * prev_priority holds the scanning priority for this zone.  It is

         * defined as the scanning priority at which we achieved our reclaim

         * target at the previous try_to_free_pages() or balance_pgdat()

         * invokation.

         *

         * We use prev_priority as a measure of how much stress page reclaim is

         * under - it drives the swappiness decision: whether to unmap mapped

         * pages.

         *

         * temp_priority is used to remember the scanning priority at which

         * this zone was successfully refilled to free_pages == pages_high.

         *

         * Access to both these fields is quite racy even on uniprocessor.  But

         * it is expected to average out OK.

         */

        int temp_priority;

        int prev_priority;

        /*

         * free areas of different sizes

         */

        struct free_area        free_area[MAX_ORDER];

        /*

         * wait_table           -- the array holding the hash table

         * wait_table_size      -- the size of the hash table array

         * wait_table_bits      -- wait_table_size == (1 << wait_table_bits)

         *

         * The purpose of all these is to keep track of the people

         * waiting for a page to become available and make them

         * runnable again when possible. The trouble is that this

         * consumes a lot of space, especially when so few things

         * wait on pages at a given time. So instead of using

         * per-page waitqueues, we use a waitqueue hash table.

         *

         * The bucket discipline is to sleep on the same queue when

         * colliding and wake all in that wait queue when removing.

         * When something wakes, it must check to be sure its page is

         * truly available, a la thundering herd. The cost of a

         * collision is great, but given the expected load of the

         * table, they should be so rare as to be outweighed by the

         * benefits from the saved space.

         *

         * __wait_on_page_locked() and unlock_page() in mm/filemap.c, are the

         * primary users of these fields, and in mm/page_alloc.c

         * free_area_init_core() performs the initialization of them.

         */

        wait_queue_head_t       * wait_table;

        unsigned long           wait_table_size;

        unsigned long           wait_table_bits;

        ZONE_PADDING(_pad3_)

        struct per_cpu_pageset  pageset[NR_CPUS];

        /*

         * Discontig memory support fields.

         */

        struct pglist_data      *zone_pgdat;

        struct page             *zone_mem_map;

        /* zone_start_pfn == zone_start_paddr >> PAGE_SHIFT */

        unsigned long           zone_start_pfn;

        /*

         * rarely used fields:

         */

        char                    *name;

        unsigned long           spanned_pages;  /* total size, including holes */

        unsigned long           present_pages;  /* amount of memory (excluding holes) */

} ____cacheline_maxaligned_in_smp;

#define ZONE_DMA                0

#define ZONE_NORMAL             1

#define ZONE_HIGHMEM            2

#define MAX_NR_ZONES            3

#define GFP_ZONEMASK    0x03

/*

 * 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.

 *

 * Right now a zonelist takes up less than a cacheline. We never

 * modify it apart from boot-up, and only a few indices are used,

 * so despite the zonelist table being relatively big, the cache

 * footprint of this construct is very small.

 */

struct zonelist {

        struct zone *zones[MAX_NUMNODES * MAX_NR_ZONES + 1]; // NULL delimited

};

/*

 * The pg_data_t structure is used in machines with CONFIG_DISCONTIGMEM

 * (mostly NUMA machines?) to denote a higher-level memory zone than the

 * zone denotes.

 *

 * On NUMA machines, each NUMA node would have a pg_data_t to describe

 * it's memory layout.

 *

 * Memory statistics and page replacement data structures are maintained on a

 * per-zone basis.

 */

struct bootmem_data;

typedef struct pglist_data {

        struct zone node_zones[MAX_NR_ZONES];

        struct zonelist node_zonelists[MAX_NR_ZONES];

        int nr_zones;

        struct page *node_mem_map;

        unsigned long *valid_addr_bitmap;

        struct bootmem_data *bdata;

        unsigned long node_start_pfn;

        unsigned long node_present_pages; /* total number of physical pages */

        unsigned long node_spanned_pages; /* total size of physical page

                                             range, including holes */

        int node_id;

        struct pglist_data *pgdat_next;

        wait_queue_head_t       kswapd_wait;

} pg_data_t;

#define node_present_pages(nid) (NODE_DATA(nid)->node_present_pages)

#define node_spanned_pages(nid) (NODE_DATA(nid)->node_spanned_pages)

extern int numnodes;

extern struct pglist_data *pgdat_list;

void get_zone_counts(unsigned long *active, unsigned long *inactive,

                        unsigned long *free);

void build_all_zonelists(void);

void wakeup_kswapd(struct zone *zone);

/**

 * for_each_pgdat - helper macro to iterate over all nodes

 * @pgdat - pointer to a pg_data_t variable

 *

 * Meant to help with common loops of the form

 * pgdat = pgdat_list;

 * while(pgdat) {

 *      ...

 *      pgdat = pgdat->pgdat_next;

 * }

 */

#define for_each_pgdat(pgdat) \

        for (pgdat = pgdat_list; pgdat; pgdat = pgdat->pgdat_next)

/*

 * next_zone - helper magic for for_each_zone()

 * Thanks to William Lee Irwin III for this piece of ingenuity.

 */

static inline struct zone *next_zone(struct zone *zone)

{

        pg_data_t *pgdat = zone->zone_pgdat;

        if (zone - pgdat->node_zones < MAX_NR_ZONES - 1)

                zone++;

        else if (pgdat->pgdat_next) {

                pgdat = pgdat->pgdat_next;

                zone = pgdat->node_zones;

        } else

                zone = NULL;

        return zone;

}

/**

 * 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. This basically means for_each_zone() is an

 * easier to read version of this piece of code:

 *

 * for (pgdat = pgdat_list; pgdat; pgdat = pgdat->node_next)

 *      for (i = 0; i < MAX_NR_ZONES; ++i) {

 *              struct zone * z = pgdat->node_zones + i;

 *              ...

 *      }

 * }

 */

#define for_each_zone(zone) \

        for (zone = pgdat_list->node_zones; zone; zone = next_zone(zone))

/**

 * 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

 */

static inline int is_highmem(struct zone *zone)

{

        return (zone - zone->zone_pgdat->node_zones == ZONE_HIGHMEM);

}

/* These two functions are used to setup the per zone pages min values */

struct ctl_table;

struct file;

int min_free_kbytes_sysctl_handler(struct ctl_table *, int, struct file *,

                                          void *, size_t *);

extern void setup_per_zone_pages_min(void);

#ifdef CONFIG_NUMA

#define MAX_NR_MEMBLKS  BITS_PER_LONG /* Max number of Memory Blocks */

#else /* !CONFIG_NUMA */

#define MAX_NR_MEMBLKS  1

#endif /* CONFIG_NUMA */

#include <linux/topology.h>

/* Returns the number of the current Node. */

#define numa_node_id()          (cpu_to_node(smp_processor_id()))

#ifndef CONFIG_DISCONTIGMEM

extern struct pglist_data contig_page_data;

#define NODE_DATA(nid)          (&contig_page_data)

#define NODE_MEM_MAP(nid)       mem_map

#define MAX_NODES_SHIFT         0

#else /* CONFIG_DISCONTIGMEM */

#include <asm/mmzone.h>

#if BITS_PER_LONG == 32

/*

 * with 32 bit flags field, page->zone is currently 8 bits.

 * there are 3 zones (2 bits) and this leaves 8-2=6 bits for nodes.

 */

#define MAX_NODES_SHIFT         6

#elif BITS_PER_LONG == 64

/*

 * with 64 bit flags field, there's plenty of room.

 */

#define MAX_NODES_SHIFT         10

#endif

#endif /* !CONFIG_DISCONTIGMEM */

#if NODES_SHIFT > MAX_NODES_SHIFT

#error NODES_SHIFT > MAX_NODES_SHIFT

#endif

extern DECLARE_BITMAP(node_online_map, MAX_NUMNODES);

extern DECLARE_BITMAP(memblk_online_map, MAX_NR_MEMBLKS);

#if defined(CONFIG_DISCONTIGMEM) || defined(CONFIG_NUMA)

#define node_online(node)       test_bit(node, node_online_map)

#define node_set_online(node)   set_bit(node, node_online_map)

#define node_set_offline(node)  clear_bit(node, node_online_map)

static inline unsigned int num_online_nodes(void)

{

        int i, num = 0;

        for(i = 0; i < MAX_NUMNODES; i++){

                if (node_online(i))

                        num++;

        }

        return num;

}

#define memblk_online(memblk)           test_bit(memblk, memblk_online_map)

#define memblk_set_online(memblk)       set_bit(memblk, memblk_online_map)

#define memblk_set_offline(memblk)      clear_bit(memblk, memblk_online_map)

static inline unsigned int num_online_memblks(void)

{

        int i, num = 0;

        for(i = 0; i < MAX_NR_MEMBLKS; i++){

                if (memblk_online(i))

                        num++;

        }

        return num;

}

#else /* !CONFIG_DISCONTIGMEM && !CONFIG_NUMA */

#define node_online(node) \

        ({ BUG_ON((node) != 0); test_bit(node, node_online_map); })

#define node_set_online(node) \

        ({ BUG_ON((node) != 0); set_bit(node, node_online_map); })

#define node_set_offline(node) \

        ({ BUG_ON((node) != 0); clear_bit(node, node_online_map); })

#define num_online_nodes()      1

#define memblk_online(memblk) \

        ({ BUG_ON((memblk) != 0); test_bit(memblk, memblk_online_map); })

#define memblk_set_online(memblk) \

        ({ BUG_ON((memblk) != 0); set_bit(memblk, memblk_online_map); })

#define memblk_set_offline(memblk) \

        ({ BUG_ON((memblk) != 0); clear_bit(memblk, memblk_online_map); })

#define num_online_memblks()            1

#endif /* CONFIG_DISCONTIGMEM || CONFIG_NUMA */

#endif /* !__ASSEMBLY__ */

#endif /* __KERNEL__ */

#endif /* _LINUX_MMZONE_H */