include/linux/swap.h - LeafOS-Devices/android_kernel_samsung_exynos9820 - Gitiles

 #ifndef _LINUX_SWAP_H
 #define _LINUX_SWAP_H

 #include <linux/config.h>
 #include <linux/spinlock.h>
 #include <linux/linkage.h>
 #include <linux/mmzone.h>
 #include <linux/list.h>
 #include <linux/sched.h>

 #include <asm/atomic.h>
 #include <asm/page.h>

 #define SWAP_FLAG_PREFER	0x8000	/* set if swap priority specified */
 #define SWAP_FLAG_PRIO_MASK	0x7fff
 #define SWAP_FLAG_PRIO_SHIFT	0

 static inline int current_is_kswapd(void)
 {
 	return current->flags & PF_KSWAPD;
 }

 /*
  * MAX_SWAPFILES defines the maximum number of swaptypes: things which can
  * be swapped to.  The swap type and the offset into that swap type are
  * encoded into pte's and into pgoff_t's in the swapcache.  Using five bits
  * for the type means that the maximum number of swapcache pages is 27 bits
  * on 32-bit-pgoff_t architectures.  And that assumes that the architecture packs
  * the type/offset into the pte as 5/27 as well.
  */
 #define MAX_SWAPFILES_SHIFT	5
 #define MAX_SWAPFILES		(1 << MAX_SWAPFILES_SHIFT)

 /*
  * Magic header for a swap area. The first part of the union is
  * what the swap magic looks like for the old (limited to 128MB)
  * swap area format, the second part of the union adds - in the
  * old reserved area - some extra information. Note that the first
  * kilobyte is reserved for boot loader or disk label stuff...
  *
  * Having the magic at the end of the PAGE_SIZE makes detecting swap
  * areas somewhat tricky on machines that support multiple page sizes.
  * For 2.5 we'll probably want to move the magic to just beyond the
  * bootbits...
  */
 union swap_header {
 	struct {
 		char reserved[PAGE_SIZE - 10];
 		char magic[10];			/* SWAP-SPACE or SWAPSPACE2 */
 	} magic;
 	struct {
 		char	     bootbits[1024];	/* Space for disklabel etc. */
 		unsigned int version;
 		unsigned int last_page;
 		unsigned int nr_badpages;
 		unsigned int padding[125];
 		unsigned int badpages[1];
 	} info;
 };

  /* A swap entry has to fit into a "unsigned long", as
   * the entry is hidden in the "index" field of the
   * swapper address space.
   */
 typedef struct {
 	unsigned long val;
 } swp_entry_t;

 /*
  * current->reclaim_state points to one of these when a task is running
  * memory reclaim
  */
 struct reclaim_state {
 	unsigned long reclaimed_slab;
 };

 #ifdef __KERNEL__

 struct address_space;
 struct sysinfo;
 struct writeback_control;
 struct zone;

 /*
  * A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
  * disk blocks.  A list of swap extents maps the entire swapfile.  (Where the
  * term `swapfile' refers to either a blockdevice or an IS_REG file.  Apart
  * from setup, they're handled identically.
  *
  * We always assume that blocks are of size PAGE_SIZE.
  */
 struct swap_extent {
 	struct list_head list;
 	pgoff_t start_page;
 	pgoff_t nr_pages;
 	sector_t start_block;
 };

 /*
  * Max bad pages in the new format..
  */
 #define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
 #define MAX_SWAP_BADPAGES \
 	((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))

 enum {
 	SWP_USED	= (1 << 0),	/* is slot in swap_info[] used? */
 	SWP_WRITEOK	= (1 << 1),	/* ok to write to this swap?	*/
 	SWP_ACTIVE	= (SWP_USED | SWP_WRITEOK),
 					/* add others here before... */
 	SWP_SCANNING	= (1 << 8),	/* refcount in scan_swap_map */
 };

 #define SWAP_CLUSTER_MAX 32

 #define SWAP_MAP_MAX	0x7fff
 #define SWAP_MAP_BAD	0x8000

 /*
  * The in-memory structure used to track swap areas.
  */
 struct swap_info_struct {
 	unsigned int flags;
 	int prio;			/* swap priority */
 	struct file *swap_file;
 	struct block_device *bdev;
 	struct list_head extent_list;
 	struct swap_extent *curr_swap_extent;
 	unsigned old_block_size;
 	unsigned short * swap_map;
 	unsigned int lowest_bit;
 	unsigned int highest_bit;
 	unsigned int cluster_next;
 	unsigned int cluster_nr;
 	unsigned int pages;
 	unsigned int max;
 	unsigned int inuse_pages;
 	int next;			/* next entry on swap list */
 };

 struct swap_list_t {
 	int head;	/* head of priority-ordered swapfile list */
 	int next;	/* swapfile to be used next */
 };

 /* Swap 50% full? Release swapcache more aggressively.. */
 #define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)

 /* linux/mm/oom_kill.c */
 extern void out_of_memory(gfp_t gfp_mask, int order);

 /* linux/mm/memory.c */
 extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *);

 /* linux/mm/page_alloc.c */
 extern unsigned long totalram_pages;
 extern unsigned long totalhigh_pages;
 extern long nr_swap_pages;
 extern unsigned int nr_free_pages(void);
 extern unsigned int nr_free_pages_pgdat(pg_data_t *pgdat);
 extern unsigned int nr_free_buffer_pages(void);
 extern unsigned int nr_free_pagecache_pages(void);

 /* linux/mm/swap.c */
 extern void FASTCALL(lru_cache_add(struct page *));
 extern void FASTCALL(lru_cache_add_active(struct page *));
 extern void FASTCALL(activate_page(struct page *));
 extern void FASTCALL(mark_page_accessed(struct page *));
 extern void lru_add_drain(void);
 extern int lru_add_drain_all(void);
 extern int rotate_reclaimable_page(struct page *page);
 extern void swap_setup(void);

 /* linux/mm/vmscan.c */
 extern int try_to_free_pages(struct zone **, gfp_t);
 extern int shrink_all_memory(int);
 extern int vm_swappiness;

 #ifdef CONFIG_NUMA
 extern int zone_reclaim_mode;
 extern int zone_reclaim_interval;
 extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
 #else
 #define zone_reclaim_mode 0
 static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
 {
 	return 0;
 }
 #endif

 #ifdef CONFIG_MIGRATION
 extern int isolate_lru_page(struct page *p);
 extern int putback_lru_pages(struct list_head *l);
 extern int migrate_page(struct page *, struct page *);
 extern void migrate_page_copy(struct page *, struct page *);
 extern int migrate_page_remove_references(struct page *, struct page *, int);
 extern int migrate_pages(struct list_head *l, struct list_head *t,
 		struct list_head *moved, struct list_head *failed);
 extern int fail_migrate_page(struct page *, struct page *);
 #else
 static inline int isolate_lru_page(struct page *p) { return -ENOSYS; }
 static inline int putback_lru_pages(struct list_head *l) { return 0; }
 static inline int migrate_pages(struct list_head *l, struct list_head *t,
 	struct list_head *moved, struct list_head *failed) { return -ENOSYS; }
 /* Possible settings for the migrate_page() method in address_operations */
 #define migrate_page NULL
 #define fail_migrate_page NULL
 #endif

 #ifdef CONFIG_MMU
 /* linux/mm/shmem.c */
 extern int shmem_unuse(swp_entry_t entry, struct page *page);
 #endif /* CONFIG_MMU */

 extern void swap_unplug_io_fn(struct backing_dev_info *, struct page *);

 #ifdef CONFIG_SWAP
 /* linux/mm/page_io.c */
 extern int swap_readpage(struct file *, struct page *);
 extern int swap_writepage(struct page *page, struct writeback_control *wbc);
 extern int rw_swap_page_sync(int, swp_entry_t, struct page *);

 /* linux/mm/swap_state.c */
 extern struct address_space swapper_space;
 #define total_swapcache_pages  swapper_space.nrpages
 extern void show_swap_cache_info(void);
 extern int add_to_swap(struct page *, gfp_t);
 extern void __delete_from_swap_cache(struct page *);
 extern void delete_from_swap_cache(struct page *);
 extern int move_to_swap_cache(struct page *, swp_entry_t);
 extern int move_from_swap_cache(struct page *, unsigned long,
 		struct address_space *);
 extern void free_page_and_swap_cache(struct page *);
 extern void free_pages_and_swap_cache(struct page **, int);
 extern struct page * lookup_swap_cache(swp_entry_t);
 extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma,
 					   unsigned long addr);
 /* linux/mm/swapfile.c */
 extern long total_swap_pages;
 extern unsigned int nr_swapfiles;
 extern struct swap_info_struct swap_info[];
 extern void si_swapinfo(struct sysinfo *);
 extern swp_entry_t get_swap_page(void);
 extern swp_entry_t get_swap_page_of_type(int type);
 extern int swap_duplicate(swp_entry_t);
 extern int valid_swaphandles(swp_entry_t, unsigned long *);
 extern void swap_free(swp_entry_t);
 extern void free_swap_and_cache(swp_entry_t);
 extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
 extern struct swap_info_struct *get_swap_info_struct(unsigned);
 extern int can_share_swap_page(struct page *);
 extern int remove_exclusive_swap_page(struct page *);
 struct backing_dev_info;

 extern spinlock_t swap_lock;
 extern int remove_vma_swap(struct vm_area_struct *vma, struct page *page);

 /* linux/mm/thrash.c */
 extern struct mm_struct * swap_token_mm;
 extern unsigned long swap_token_default_timeout;
 extern void grab_swap_token(void);
 extern void __put_swap_token(struct mm_struct *);

 static inline int has_swap_token(struct mm_struct *mm)
 {
 	return (mm == swap_token_mm);
 }

 static inline void put_swap_token(struct mm_struct *mm)
 {
 	if (has_swap_token(mm))
 		__put_swap_token(mm);
 }

 static inline void disable_swap_token(void)
 {
 	put_swap_token(swap_token_mm);
 }

 #else /* CONFIG_SWAP */

 #define total_swap_pages			0
 #define total_swapcache_pages			0UL

 #define si_swapinfo(val) \
 	do { (val)->freeswap = (val)->totalswap = 0; } while (0)
 /* only sparc can not include linux/pagemap.h in this file
  * so leave page_cache_release and release_pages undeclared... */
 #define free_page_and_swap_cache(page) \
 	page_cache_release(page)
 #define free_pages_and_swap_cache(pages, nr) \
 	release_pages((pages), (nr), 0);

 #define show_swap_cache_info()			/*NOTHING*/
 #define free_swap_and_cache(swp)		/*NOTHING*/
 #define swap_duplicate(swp)			/*NOTHING*/
 #define swap_free(swp)				/*NOTHING*/
 #define read_swap_cache_async(swp,vma,addr)	NULL
 #define lookup_swap_cache(swp)			NULL
 #define valid_swaphandles(swp, off)		0
 #define can_share_swap_page(p)			0
 #define move_to_swap_cache(p, swp)		1
 #define move_from_swap_cache(p, i, m)		1
 #define __delete_from_swap_cache(p)		/*NOTHING*/
 #define delete_from_swap_cache(p)		/*NOTHING*/
 #define swap_token_default_timeout		0

 static inline int remove_exclusive_swap_page(struct page *p)
 {
 	return 0;
 }

 static inline swp_entry_t get_swap_page(void)
 {
 	swp_entry_t entry;
 	entry.val = 0;
 	return entry;
 }

 /* linux/mm/thrash.c */
 #define put_swap_token(x) do { } while(0)
 #define grab_swap_token()  do { } while(0)
 #define has_swap_token(x) 0
 #define disable_swap_token() do { } while(0)

 #endif /* CONFIG_SWAP */
 #endif /* __KERNEL__*/
 #endif /* _LINUX_SWAP_H */
	#ifndef _LINUX_SWAP_H
	#define _LINUX_SWAP_H

	#include <linux/config.h>
	#include <linux/spinlock.h>
	#include <linux/linkage.h>
	#include <linux/mmzone.h>
	#include <linux/list.h>
	#include <linux/sched.h>

	#include <asm/atomic.h>
	#include <asm/page.h>

	#define SWAP_FLAG_PREFER 0x8000 /* set if swap priority specified */
	#define SWAP_FLAG_PRIO_MASK 0x7fff
	#define SWAP_FLAG_PRIO_SHIFT 0

	static inline int current_is_kswapd(void)
	{
	return current->flags & PF_KSWAPD;
	}

	/*
	* MAX_SWAPFILES defines the maximum number of swaptypes: things which can
	* be swapped to. The swap type and the offset into that swap type are
	* encoded into pte's and into pgoff_t's in the swapcache. Using five bits
	* for the type means that the maximum number of swapcache pages is 27 bits
	* on 32-bit-pgoff_t architectures. And that assumes that the architecture packs
	* the type/offset into the pte as 5/27 as well.
	*/
	#define MAX_SWAPFILES_SHIFT 5
	#define MAX_SWAPFILES (1 << MAX_SWAPFILES_SHIFT)

	/*
	* Magic header for a swap area. The first part of the union is
	* what the swap magic looks like for the old (limited to 128MB)
	* swap area format, the second part of the union adds - in the
	* old reserved area - some extra information. Note that the first
	* kilobyte is reserved for boot loader or disk label stuff...
	*
	* Having the magic at the end of the PAGE_SIZE makes detecting swap
	* areas somewhat tricky on machines that support multiple page sizes.
	* For 2.5 we'll probably want to move the magic to just beyond the
	* bootbits...
	*/
	union swap_header {
	struct {
	char reserved[PAGE_SIZE - 10];
	char magic[10]; /* SWAP-SPACE or SWAPSPACE2 */
	} magic;
	struct {
	char bootbits[1024]; /* Space for disklabel etc. */
	unsigned int version;
	unsigned int last_page;
	unsigned int nr_badpages;
	unsigned int padding[125];
	unsigned int badpages[1];
	} info;
	};

	/* A swap entry has to fit into a "unsigned long", as
	* the entry is hidden in the "index" field of the
	* swapper address space.
	*/
	typedef struct {
	unsigned long val;
	} swp_entry_t;

	/*
	* current->reclaim_state points to one of these when a task is running
	* memory reclaim
	*/
	struct reclaim_state {
	unsigned long reclaimed_slab;
	};

	#ifdef __KERNEL__

	struct address_space;
	struct sysinfo;
	struct writeback_control;
	struct zone;

	/*
	* A swap extent maps a range of a swapfile's PAGE_SIZE pages onto a range of
	* disk blocks. A list of swap extents maps the entire swapfile. (Where the
	* term `swapfile' refers to either a blockdevice or an IS_REG file. Apart
	* from setup, they're handled identically.
	*
	* We always assume that blocks are of size PAGE_SIZE.
	*/
	struct swap_extent {
	struct list_head list;
	pgoff_t start_page;
	pgoff_t nr_pages;
	sector_t start_block;
	};

	/*
	* Max bad pages in the new format..
	*/
	#define __swapoffset(x) ((unsigned long)&((union swap_header *)0)->x)
	#define MAX_SWAP_BADPAGES \
	((__swapoffset(magic.magic) - __swapoffset(info.badpages)) / sizeof(int))

	enum {
	SWP_USED = (1 << 0), /* is slot in swap_info[] used? */
	SWP_WRITEOK = (1 << 1), /* ok to write to this swap? */
	SWP_ACTIVE = (SWP_USED \| SWP_WRITEOK),
	/* add others here before... */
	SWP_SCANNING = (1 << 8), /* refcount in scan_swap_map */
	};

	#define SWAP_CLUSTER_MAX 32

	#define SWAP_MAP_MAX 0x7fff
	#define SWAP_MAP_BAD 0x8000

	/*
	* The in-memory structure used to track swap areas.
	*/
	struct swap_info_struct {
	unsigned int flags;
	int prio; /* swap priority */
	struct file *swap_file;
	struct block_device *bdev;
	struct list_head extent_list;
	struct swap_extent *curr_swap_extent;
	unsigned old_block_size;
	unsigned short * swap_map;
	unsigned int lowest_bit;
	unsigned int highest_bit;
	unsigned int cluster_next;
	unsigned int cluster_nr;
	unsigned int pages;
	unsigned int max;
	unsigned int inuse_pages;
	int next; /* next entry on swap list */
	};

	struct swap_list_t {
	int head; /* head of priority-ordered swapfile list */
	int next; /* swapfile to be used next */
	};

	/* Swap 50% full? Release swapcache more aggressively.. */
	#define vm_swap_full() (nr_swap_pages*2 < total_swap_pages)

	/* linux/mm/oom_kill.c */
	extern void out_of_memory(gfp_t gfp_mask, int order);

	/* linux/mm/memory.c */
	extern void swapin_readahead(swp_entry_t, unsigned long, struct vm_area_struct *);

	/* linux/mm/page_alloc.c */
	extern unsigned long totalram_pages;
	extern unsigned long totalhigh_pages;
	extern long nr_swap_pages;
	extern unsigned int nr_free_pages(void);
	extern unsigned int nr_free_pages_pgdat(pg_data_t *pgdat);
	extern unsigned int nr_free_buffer_pages(void);
	extern unsigned int nr_free_pagecache_pages(void);

	/* linux/mm/swap.c */
	extern void FASTCALL(lru_cache_add(struct page *));
	extern void FASTCALL(lru_cache_add_active(struct page *));
	extern void FASTCALL(activate_page(struct page *));
	extern void FASTCALL(mark_page_accessed(struct page *));
	extern void lru_add_drain(void);
	extern int lru_add_drain_all(void);
	extern int rotate_reclaimable_page(struct page *page);
	extern void swap_setup(void);

	/* linux/mm/vmscan.c */
	extern int try_to_free_pages(struct zone **, gfp_t);
	extern int shrink_all_memory(int);
	extern int vm_swappiness;

	#ifdef CONFIG_NUMA
	extern int zone_reclaim_mode;
	extern int zone_reclaim_interval;
	extern int zone_reclaim(struct zone *, gfp_t, unsigned int);
	#else
	#define zone_reclaim_mode 0
	static inline int zone_reclaim(struct zone *z, gfp_t mask, unsigned int order)
	{
	return 0;
	}
	#endif

	#ifdef CONFIG_MIGRATION
	extern int isolate_lru_page(struct page *p);
	extern int putback_lru_pages(struct list_head *l);
	extern int migrate_page(struct page , struct page );
	extern void migrate_page_copy(struct page , struct page );
	extern int migrate_page_remove_references(struct page , struct page , int);
	extern int migrate_pages(struct list_head l, struct list_head t,
	struct list_head moved, struct list_head failed);
	extern int fail_migrate_page(struct page , struct page );
	#else
	static inline int isolate_lru_page(struct page *p) { return -ENOSYS; }
	static inline int putback_lru_pages(struct list_head *l) { return 0; }
	static inline int migrate_pages(struct list_head l, struct list_head t,
	struct list_head moved, struct list_head failed) { return -ENOSYS; }
	/* Possible settings for the migrate_page() method in address_operations */
	#define migrate_page NULL
	#define fail_migrate_page NULL
	#endif

	#ifdef CONFIG_MMU
	/* linux/mm/shmem.c */
	extern int shmem_unuse(swp_entry_t entry, struct page *page);
	#endif /* CONFIG_MMU */

	extern void swap_unplug_io_fn(struct backing_dev_info , struct page );

	#ifdef CONFIG_SWAP
	/* linux/mm/page_io.c */
	extern int swap_readpage(struct file , struct page );
	extern int swap_writepage(struct page page, struct writeback_control wbc);
	extern int rw_swap_page_sync(int, swp_entry_t, struct page *);

	/* linux/mm/swap_state.c */
	extern struct address_space swapper_space;
	#define total_swapcache_pages swapper_space.nrpages
	extern void show_swap_cache_info(void);
	extern int add_to_swap(struct page *, gfp_t);
	extern void __delete_from_swap_cache(struct page *);
	extern void delete_from_swap_cache(struct page *);
	extern int move_to_swap_cache(struct page *, swp_entry_t);
	extern int move_from_swap_cache(struct page *, unsigned long,
	struct address_space *);
	extern void free_page_and_swap_cache(struct page *);
	extern void free_pages_and_swap_cache(struct page **, int);
	extern struct page * lookup_swap_cache(swp_entry_t);
	extern struct page * read_swap_cache_async(swp_entry_t, struct vm_area_struct *vma,
	unsigned long addr);
	/* linux/mm/swapfile.c */
	extern long total_swap_pages;
	extern unsigned int nr_swapfiles;
	extern struct swap_info_struct swap_info[];
	extern void si_swapinfo(struct sysinfo *);
	extern swp_entry_t get_swap_page(void);
	extern swp_entry_t get_swap_page_of_type(int type);
	extern int swap_duplicate(swp_entry_t);
	extern int valid_swaphandles(swp_entry_t, unsigned long *);
	extern void swap_free(swp_entry_t);
	extern void free_swap_and_cache(swp_entry_t);
	extern sector_t map_swap_page(struct swap_info_struct *, pgoff_t);
	extern struct swap_info_struct *get_swap_info_struct(unsigned);
	extern int can_share_swap_page(struct page *);
	extern int remove_exclusive_swap_page(struct page *);
	struct backing_dev_info;

	extern spinlock_t swap_lock;
	extern int remove_vma_swap(struct vm_area_struct vma, struct page page);

	/* linux/mm/thrash.c */
	extern struct mm_struct * swap_token_mm;
	extern unsigned long swap_token_default_timeout;
	extern void grab_swap_token(void);
	extern void __put_swap_token(struct mm_struct *);

	static inline int has_swap_token(struct mm_struct *mm)
	{
	return (mm == swap_token_mm);
	}

	static inline void put_swap_token(struct mm_struct *mm)
	{
	if (has_swap_token(mm))
	__put_swap_token(mm);
	}

	static inline void disable_swap_token(void)
	{
	put_swap_token(swap_token_mm);
	}

	#else /* CONFIG_SWAP */

	#define total_swap_pages 0
	#define total_swapcache_pages 0UL

	#define si_swapinfo(val) \
	do { (val)->freeswap = (val)->totalswap = 0; } while (0)
	/* only sparc can not include linux/pagemap.h in this file
	* so leave page_cache_release and release_pages undeclared... */
	#define free_page_and_swap_cache(page) \
	page_cache_release(page)
	#define free_pages_and_swap_cache(pages, nr) \
	release_pages((pages), (nr), 0);

	#define show_swap_cache_info() /NOTHING/
	#define free_swap_and_cache(swp) /NOTHING/
	#define swap_duplicate(swp) /NOTHING/
	#define swap_free(swp) /NOTHING/
	#define read_swap_cache_async(swp,vma,addr) NULL
	#define lookup_swap_cache(swp) NULL
	#define valid_swaphandles(swp, off) 0
	#define can_share_swap_page(p) 0
	#define move_to_swap_cache(p, swp) 1
	#define move_from_swap_cache(p, i, m) 1
	#define __delete_from_swap_cache(p) /NOTHING/
	#define delete_from_swap_cache(p) /NOTHING/
	#define swap_token_default_timeout 0

	static inline int remove_exclusive_swap_page(struct page *p)
	{
	return 0;
	}

	static inline swp_entry_t get_swap_page(void)
	{
	swp_entry_t entry;
	entry.val = 0;
	return entry;
	}

	/* linux/mm/thrash.c */
	#define put_swap_token(x) do { } while(0)
	#define grab_swap_token() do { } while(0)
	#define has_swap_token(x) 0
	#define disable_swap_token() do { } while(0)

	#endif /* CONFIG_SWAP */
	#endif /* __KERNEL__*/
	#endif /* _LINUX_SWAP_H */