#ifndef _LINUX_MM_TYPES_H
  #define _LINUX_MM_TYPES_H

  #include <linux/auxvec.h>

  #include <linux/types.h>
  #include <linux/threads.h>
  #include <linux/list.h>
  #include <linux/spinlock.h>

  #include <linux/prio_tree.h>
  #include <linux/rbtree.h>
  #include <linux/rwsem.h>
  #include <linux/completion.h>

  #include <linux/cpumask.h>

  #include <linux/page-debug-flags.h>

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

  #ifndef AT_VECTOR_SIZE_ARCH
  #define AT_VECTOR_SIZE_ARCH 0
  #endif
  #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))

  struct address_space;

  #define USE_SPLIT_PTLOCKS	(NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)

  /*
   * Each physical page in the system has a struct page associated with
   * it to keep track of whatever it is we are using the page for at the
   * moment. Note that we have no way to track which tasks are using
   * a page, though if it is a pagecache page, rmap structures can tell us
   * who is mapping it.

   *
   * The objects in struct page are organized in double word blocks in
   * order to allows us to use atomic double word operations on portions
   * of struct page. That is currently only used by slub but the arrangement
   * allows the use of atomic double word operations on the flags/mapping
   * and lru list pointers also.

   */
  struct page {

  	/* First double word block */

  	unsigned long flags;		/* Atomic flags, some possibly
  					 * updated asynchronously */

  	struct address_space *mapping;	/* If low bit clear, points to
  					 * inode address_space, or NULL.
  					 * If page mapped as anonymous
  					 * memory, low bit is set, and
  					 * it points to anon_vma object:
  					 * see PAGE_MAPPING_ANON below.
  					 */
  	/* Second double word */

  	struct {
  		union {

  			pgoff_t index;		/* Our offset within mapping. */

  			void *freelist;		/* slub first free object */
  		};
  
  		union {
  			/* Used for cmpxchg_double in slub */
  			unsigned long counters;
  
  			struct {
  
  				union {

  					/*
  					 * Count of ptes mapped in
  					 * mms, to show when page is
  					 * mapped & limit reverse map
  					 * searches.
  					 *
  					 * Used also for tail pages
  					 * refcounting instead of
  					 * _count. Tail pages cannot
  					 * be mapped and keeping the
  					 * tail page _count zero at
  					 * all times guarantees
  					 * get_page_unless_zero() will
  					 * never succeed on tail
  					 * pages.
  					 */
  					atomic_t _mapcount;

  					struct {
  						unsigned inuse:16;
  						unsigned objects:15;
  						unsigned frozen:1;
  					};

  				};

  				atomic_t _count;		/* Usage count, see below. */

  			};

  		};

  	};

  
  	/* Third double word block */

  	union {
  		struct list_head lru;	/* Pageout list, eg. active_list

  					 * protected by zone->lru_lock !
  					 */

  		struct {		/* slub per cpu partial pages */
  			struct page *next;	/* Next partial slab */
  #ifdef CONFIG_64BIT
  			int pages;	/* Nr of partial slabs left */
  			int pobjects;	/* Approximate # of objects */
  #else
  			short int pages;
  			short int pobjects;
  #endif
  		};
  	};

  
  	/* Remainder is not double word aligned */

  	union {

  		unsigned long private;		/* Mapping-private opaque data:
  					 	 * usually used for buffer_heads
  						 * if PagePrivate set; used for
  						 * swp_entry_t if PageSwapCache;
  						 * indicates order in the buddy
  						 * system if PG_buddy is set.
  						 */

  #if USE_SPLIT_PTLOCKS

  		spinlock_t ptl;

  #endif

  		struct kmem_cache *slab;	/* SLUB: Pointer to slab */
  		struct page *first_page;	/* Compound tail pages */

  	};

  	/*
  	 * On machines where all RAM is mapped into kernel address space,
  	 * we can simply calculate the virtual address. On machines with
  	 * highmem some memory is mapped into kernel virtual memory
  	 * dynamically, so we need a place to store that address.
  	 * Note that this field could be 16 bits on x86 ... ;)
  	 *
  	 * Architectures with slow multiplication can define
  	 * WANT_PAGE_VIRTUAL in asm/page.h
  	 */
  #if defined(WANT_PAGE_VIRTUAL)
  	void *virtual;			/* Kernel virtual address (NULL if
  					   not kmapped, ie. highmem) */
  #endif /* WANT_PAGE_VIRTUAL */

  #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
  	unsigned long debug_flags;	/* Use atomic bitops on this */
  #endif

  
  #ifdef CONFIG_KMEMCHECK
  	/*
  	 * kmemcheck wants to track the status of each byte in a page; this
  	 * is a pointer to such a status block. NULL if not tracked.
  	 */
  	void *shadow;
  #endif

  }
  /*

   * The struct page can be forced to be double word aligned so that atomic ops
   * on double words work. The SLUB allocator can make use of such a feature.

   */

  #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
  	__aligned(2 * sizeof(unsigned long))

  #endif
  ;

  struct page_frag {
  	struct page *page;
  #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
  	__u32 offset;
  	__u32 size;
  #else
  	__u16 offset;
  	__u16 size;
  #endif
  };

  typedef unsigned long __nocast vm_flags_t;

  /*

   * A region containing a mapping of a non-memory backed file under NOMMU
   * conditions.  These are held in a global tree and are pinned by the VMAs that
   * map parts of them.
   */
  struct vm_region {
  	struct rb_node	vm_rb;		/* link in global region tree */

  	vm_flags_t	vm_flags;	/* VMA vm_flags */

  	unsigned long	vm_start;	/* start address of region */
  	unsigned long	vm_end;		/* region initialised to here */

  	unsigned long	vm_top;		/* region allocated to here */

  	unsigned long	vm_pgoff;	/* the offset in vm_file corresponding to vm_start */
  	struct file	*vm_file;	/* the backing file or NULL */

  	int		vm_usage;	/* region usage count (access under nommu_region_sem) */

  	bool		vm_icache_flushed : 1; /* true if the icache has been flushed for
  						* this region */

  };
  
  /*

   * This struct defines a memory VMM memory area. There is one of these
   * per VM-area/task.  A VM area is any part of the process virtual memory
   * space that has a special rule for the page-fault handlers (ie a shared
   * library, the executable area etc).
   */
  struct vm_area_struct {
  	struct mm_struct * vm_mm;	/* The address space we belong to. */
  	unsigned long vm_start;		/* Our start address within vm_mm. */
  	unsigned long vm_end;		/* The first byte after our end address
  					   within vm_mm. */
  
  	/* linked list of VM areas per task, sorted by address */

  	struct vm_area_struct *vm_next, *vm_prev;

  
  	pgprot_t vm_page_prot;		/* Access permissions of this VMA. */

  	unsigned long vm_flags;		/* Flags, see mm.h. */

  
  	struct rb_node vm_rb;
  
  	/*
  	 * For areas with an address space and backing store,
  	 * linkage into the address_space->i_mmap prio tree, or
  	 * linkage to the list of like vmas hanging off its node, or
  	 * linkage of vma in the address_space->i_mmap_nonlinear list.
  	 */
  	union {
  		struct {
  			struct list_head list;
  			void *parent;	/* aligns with prio_tree_node parent */
  			struct vm_area_struct *head;
  		} vm_set;
  
  		struct raw_prio_tree_node prio_tree_node;
  	} shared;
  
  	/*
  	 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
  	 * list, after a COW of one of the file pages.	A MAP_SHARED vma
  	 * can only be in the i_mmap tree.  An anonymous MAP_PRIVATE, stack
  	 * or brk vma (with NULL file) can only be in an anon_vma list.
  	 */

  	struct list_head anon_vma_chain; /* Serialized by mmap_sem &
  					  * page_table_lock */

  	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
  
  	/* Function pointers to deal with this struct. */

  	const struct vm_operations_struct *vm_ops;

  
  	/* Information about our backing store: */
  	unsigned long vm_pgoff;		/* Offset (within vm_file) in PAGE_SIZE
  					   units, *not* PAGE_CACHE_SIZE */
  	struct file * vm_file;		/* File we map to (can be NULL). */
  	void * vm_private_data;		/* was vm_pte (shared mem) */

  
  #ifndef CONFIG_MMU

  	struct vm_region *vm_region;	/* NOMMU mapping region */

  #endif
  #ifdef CONFIG_NUMA
  	struct mempolicy *vm_policy;	/* NUMA policy for the VMA */
  #endif
  };

  struct core_thread {
  	struct task_struct *task;
  	struct core_thread *next;
  };

  struct core_state {

  	atomic_t nr_threads;

  	struct core_thread dumper;

  	struct completion startup;
  };

  enum {
  	MM_FILEPAGES,
  	MM_ANONPAGES,

  	MM_SWAPENTS,

  	NR_MM_COUNTERS
  };

  #if USE_SPLIT_PTLOCKS && defined(CONFIG_MMU)

  #define SPLIT_RSS_COUNTING

  /* per-thread cached information, */
  struct task_rss_stat {
  	int events;	/* for synchronization threshold */
  	int count[NR_MM_COUNTERS];
  };

  #endif /* USE_SPLIT_PTLOCKS */

  struct mm_rss_stat {

  	atomic_long_t count[NR_MM_COUNTERS];

  };

  struct mm_struct {
  	struct vm_area_struct * mmap;		/* list of VMAs */
  	struct rb_root mm_rb;
  	struct vm_area_struct * mmap_cache;	/* last find_vma result */

  #ifdef CONFIG_MMU

  	unsigned long (*get_unmapped_area) (struct file *filp,
  				unsigned long addr, unsigned long len,
  				unsigned long pgoff, unsigned long flags);
  	void (*unmap_area) (struct mm_struct *mm, unsigned long addr);

  #endif

  	unsigned long mmap_base;		/* base of mmap area */
  	unsigned long task_size;		/* size of task vm space */
  	unsigned long cached_hole_size; 	/* if non-zero, the largest hole below free_area_cache */
  	unsigned long free_area_cache;		/* first hole of size cached_hole_size or larger */
  	pgd_t * pgd;
  	atomic_t mm_users;			/* How many users with user space? */
  	atomic_t mm_count;			/* How many references to "struct mm_struct" (users count as 1) */
  	int map_count;				/* number of VMAs */

  	spinlock_t page_table_lock;		/* Protects page tables and some counters */

  	struct rw_semaphore mmap_sem;

  
  	struct list_head mmlist;		/* List of maybe swapped mm's.	These are globally strung
  						 * together off init_mm.mmlist, and are protected
  						 * by mmlist_lock
  						 */

  
  	unsigned long hiwater_rss;	/* High-watermark of RSS usage */
  	unsigned long hiwater_vm;	/* High-water virtual memory usage */

  	unsigned long total_vm;		/* Total pages mapped */
  	unsigned long locked_vm;	/* Pages that have PG_mlocked set */
  	unsigned long pinned_vm;	/* Refcount permanently increased */
  	unsigned long shared_vm;	/* Shared pages (files) */
  	unsigned long exec_vm;		/* VM_EXEC & ~VM_WRITE */
  	unsigned long stack_vm;		/* VM_GROWSUP/DOWN */
  	unsigned long reserved_vm;	/* VM_RESERVED|VM_IO pages */
  	unsigned long def_flags;
  	unsigned long nr_ptes;		/* Page table pages */

  	unsigned long start_code, end_code, start_data, end_data;
  	unsigned long start_brk, brk, start_stack;
  	unsigned long arg_start, arg_end, env_start, env_end;
  
  	unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */

  	/*
  	 * Special counters, in some configurations protected by the
  	 * page_table_lock, in other configurations by being atomic.
  	 */
  	struct mm_rss_stat rss_stat;

  	struct linux_binfmt *binfmt;

  	cpumask_var_t cpu_vm_mask_var;

  	/* Architecture-specific MM context */
  	mm_context_t context;
  
  	/* Swap token stuff */
  	/*
  	 * Last value of global fault stamp as seen by this process.
  	 * In other words, this value gives an indication of how long
  	 * it has been since this task got the token.
  	 * Look at mm/thrash.c
  	 */
  	unsigned int faultstamp;
  	unsigned int token_priority;
  	unsigned int last_interval;
  
  	unsigned long flags; /* Must use atomic bitops to access the bits */

  	struct core_state *core_state; /* coredumping support */

  #ifdef CONFIG_AIO

  	spinlock_t		ioctx_lock;
  	struct hlist_head	ioctx_list;

  #endif

  #ifdef CONFIG_MM_OWNER

  	/*
  	 * "owner" points to a task that is regarded as the canonical
  	 * user/owner of this mm. All of the following must be true in
  	 * order for it to be changed:
  	 *
  	 * current == mm->owner
  	 * current->mm != mm
  	 * new_owner->mm == mm
  	 * new_owner->alloc_lock is held
  	 */

  	struct task_struct __rcu *owner;

  #endif

  	/* store ref to file /proc/<pid>/exe symlink points to */
  	struct file *exe_file;
  	unsigned long num_exe_file_vmas;

  #ifdef CONFIG_MMU_NOTIFIER
  	struct mmu_notifier_mm *mmu_notifier_mm;
  #endif

  #ifdef CONFIG_TRANSPARENT_HUGEPAGE
  	pgtable_t pmd_huge_pte; /* protected by page_table_lock */
  #endif

  #ifdef CONFIG_CPUMASK_OFFSTACK
  	struct cpumask cpumask_allocation;
  #endif

  };

  static inline void mm_init_cpumask(struct mm_struct *mm)
  {
  #ifdef CONFIG_CPUMASK_OFFSTACK
  	mm->cpu_vm_mask_var = &mm->cpumask_allocation;
  #endif
  }

  /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */

  static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
  {
  	return mm->cpu_vm_mask_var;
  }

  #endif /* _LINUX_MM_TYPES_H */