/*
   * NUMA memory policies for Linux.
   * Copyright 2003,2004 Andi Kleen SuSE Labs
   */
  #ifndef _LINUX_MEMPOLICY_H
  #define _LINUX_MEMPOLICY_H 1
  
  
  #include <linux/mmzone.h>
  #include <linux/slab.h>
  #include <linux/rbtree.h>
  #include <linux/spinlock.h>
  #include <linux/nodemask.h>
  #include <linux/pagemap.h>
  #include <uapi/linux/mempolicy.h>
  
  struct mm_struct;
  
  #ifdef CONFIG_NUMA
  
  /*
   * Describe a memory policy.
   *
   * A mempolicy can be either associated with a process or with a VMA.
   * For VMA related allocations the VMA policy is preferred, otherwise
   * the process policy is used. Interrupts ignore the memory policy
   * of the current process.
   *
   * Locking policy for interlave:
   * In process context there is no locking because only the process accesses
   * its own state. All vma manipulation is somewhat protected by a down_read on
   * mmap_sem.
   *
   * Freeing policy:
   * Mempolicy objects are reference counted.  A mempolicy will be freed when
   * mpol_put() decrements the reference count to zero.
   *
   * Duplicating policy objects:
   * mpol_dup() allocates a new mempolicy and copies the specified mempolicy
   * to the new storage.  The reference count of the new object is initialized
   * to 1, representing the caller of mpol_dup().
   */
  struct mempolicy {
  	atomic_t refcnt;
  	unsigned short mode; 	/* See MPOL_* above */
  	unsigned short flags;	/* See set_mempolicy() MPOL_F_* above */
  	union {
  		short 		 preferred_node; /* preferred */
  		nodemask_t	 nodes;		/* interleave/bind */
  		/* undefined for default */
  	} v;
  	union {
  		nodemask_t cpuset_mems_allowed;	/* relative to these nodes */
  		nodemask_t user_nodemask;	/* nodemask passed by user */
  	} w;
  };
  
  /*
   * Support for managing mempolicy data objects (clone, copy, destroy)
   * The default fast path of a NULL MPOL_DEFAULT policy is always inlined.
   */
  
  extern void __mpol_put(struct mempolicy *pol);
  static inline void mpol_put(struct mempolicy *pol)
  {
  	if (pol)
  		__mpol_put(pol);
  }
  
  /*
   * Does mempolicy pol need explicit unref after use?
   * Currently only needed for shared policies.
   */
  static inline int mpol_needs_cond_ref(struct mempolicy *pol)
  {
  	return (pol && (pol->flags & MPOL_F_SHARED));
  }
  
  static inline void mpol_cond_put(struct mempolicy *pol)
  {
  	if (mpol_needs_cond_ref(pol))
  		__mpol_put(pol);
  }
  
  extern struct mempolicy *__mpol_dup(struct mempolicy *pol);
  static inline struct mempolicy *mpol_dup(struct mempolicy *pol)
  {
  	if (pol)
  		pol = __mpol_dup(pol);
  	return pol;
  }
  
  #define vma_policy(vma) ((vma)->vm_policy)
  
  static inline void mpol_get(struct mempolicy *pol)
  {
  	if (pol)
  		atomic_inc(&pol->refcnt);
  }
  
  extern bool __mpol_equal(struct mempolicy *a, struct mempolicy *b);
  static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
  {
  	if (a == b)
  		return true;
  	return __mpol_equal(a, b);
  }
  
  /*
   * Tree of shared policies for a shared memory region.
   * Maintain the policies in a pseudo mm that contains vmas. The vmas
   * carry the policy. As a special twist the pseudo mm is indexed in pages, not
   * bytes, so that we can work with shared memory segments bigger than
   * unsigned long.
   */
  
  struct sp_node {
  	struct rb_node nd;
  	unsigned long start, end;
  	struct mempolicy *policy;
  };
  
  struct shared_policy {
  	struct rb_root root;
  	spinlock_t lock;
  };
  
  int vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst);
  void mpol_shared_policy_init(struct shared_policy *sp, struct mempolicy *mpol);
  int mpol_set_shared_policy(struct shared_policy *info,
  				struct vm_area_struct *vma,
  				struct mempolicy *new);
  void mpol_free_shared_policy(struct shared_policy *p);
  struct mempolicy *mpol_shared_policy_lookup(struct shared_policy *sp,
  					    unsigned long idx);
  
  struct mempolicy *get_vma_policy(struct task_struct *tsk,
  		struct vm_area_struct *vma, unsigned long addr);
  bool vma_policy_mof(struct task_struct *task, struct vm_area_struct *vma);
  
  extern void numa_default_policy(void);
  extern void numa_policy_init(void);
  extern void mpol_rebind_task(struct task_struct *tsk, const nodemask_t *new,
  				enum mpol_rebind_step step);
  extern void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new);
  extern void mpol_fix_fork_child_flag(struct task_struct *p);
  
  extern struct zonelist *huge_zonelist(struct vm_area_struct *vma,
  				unsigned long addr, gfp_t gfp_flags,
  				struct mempolicy **mpol, nodemask_t **nodemask);
  extern bool init_nodemask_of_mempolicy(nodemask_t *mask);
  extern bool mempolicy_nodemask_intersects(struct task_struct *tsk,
  				const nodemask_t *mask);
  extern unsigned slab_node(void);
  
  extern enum zone_type policy_zone;
  
  static inline void check_highest_zone(enum zone_type k)
  {
  	if (k > policy_zone && k != ZONE_MOVABLE)
  		policy_zone = k;
  }
  
  int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
  		     const nodemask_t *to, int flags);
  
  
  #ifdef CONFIG_TMPFS
  extern int mpol_parse_str(char *str, struct mempolicy **mpol);
  #endif
  
  extern void mpol_to_str(char *buffer, int maxlen, struct mempolicy *pol);
  
  /* Check if a vma is migratable */
  static inline int vma_migratable(struct vm_area_struct *vma)
  {
  	if (vma->vm_flags & (VM_IO | VM_PFNMAP))
  		return 0;
  
  #ifndef CONFIG_ARCH_ENABLE_HUGEPAGE_MIGRATION
  	if (vma->vm_flags & VM_HUGETLB)
  		return 0;
  #endif
  
  	/*
  	 * Migration allocates pages in the highest zone. If we cannot
  	 * do so then migration (at least from node to node) is not
  	 * possible.
  	 */
  	if (vma->vm_file &&
  		gfp_zone(mapping_gfp_mask(vma->vm_file->f_mapping))
  								< policy_zone)
  			return 0;
  	return 1;
  }
  
  extern int mpol_misplaced(struct page *, struct vm_area_struct *, unsigned long);
  
  #else
  
  struct mempolicy {};
  
  static inline bool mpol_equal(struct mempolicy *a, struct mempolicy *b)
  {
  	return true;
  }
  
  static inline void mpol_put(struct mempolicy *p)
  {
  }
  
  static inline void mpol_cond_put(struct mempolicy *pol)
  {
  }
  
  static inline void mpol_get(struct mempolicy *pol)
  {
  }
  
  struct shared_policy {};
  
  static inline void mpol_shared_policy_init(struct shared_policy *sp,
  						struct mempolicy *mpol)
  {
  }
  
  static inline void mpol_free_shared_policy(struct shared_policy *p)
  {
  }
  
  #define vma_policy(vma) NULL
  
  static inline int
  vma_dup_policy(struct vm_area_struct *src, struct vm_area_struct *dst)
  {
  	return 0;
  }
  
  static inline void numa_policy_init(void)
  {
  }
  
  static inline void numa_default_policy(void)
  {
  }
  
  static inline void mpol_rebind_task(struct task_struct *tsk,
  				const nodemask_t *new,
  				enum mpol_rebind_step step)
  {
  }
  
  static inline void mpol_rebind_mm(struct mm_struct *mm, nodemask_t *new)
  {
  }
  
  static inline struct zonelist *huge_zonelist(struct vm_area_struct *vma,
  				unsigned long addr, gfp_t gfp_flags,
  				struct mempolicy **mpol, nodemask_t **nodemask)
  {
  	*mpol = NULL;
  	*nodemask = NULL;
  	return node_zonelist(0, gfp_flags);
  }
  
  static inline bool init_nodemask_of_mempolicy(nodemask_t *m)
  {
  	return false;
  }
  
  static inline int do_migrate_pages(struct mm_struct *mm, const nodemask_t *from,
  				   const nodemask_t *to, int flags)
  {
  	return 0;
  }
  
  static inline void check_highest_zone(int k)
  {
  }
  
  #ifdef CONFIG_TMPFS
  static inline int mpol_parse_str(char *str, struct mempolicy **mpol)
  {
  	return 1;	/* error */
  }
  #endif
  
  static inline int mpol_misplaced(struct page *page, struct vm_area_struct *vma,
  				 unsigned long address)
  {
  	return -1; /* no node preference */
  }
  
  #endif /* CONFIG_NUMA */
  #endif