#ifndef _LINUX_VMALLOC_H
  #define _LINUX_VMALLOC_H
  
  #include <linux/spinlock.h>

  #include <linux/init.h>

  #include <asm/page.h>		/* pgprot_t */

  struct vm_area_struct;		/* vma defining user mapping in mm_types.h */

  extern bool vmap_lazy_unmap;

  /* bits in flags of vmalloc's vm_struct below */

  #define VM_IOREMAP	0x00000001	/* ioremap() and friends */
  #define VM_ALLOC	0x00000002	/* vmalloc() */
  #define VM_MAP		0x00000004	/* vmap()ed pages */

  #define VM_USERMAP	0x00000008	/* suitable for remap_vmalloc_range */

  #define VM_VPAGES	0x00000010	/* buffer for pages was vmalloc'ed */

  /* bits [20..32] reserved for arch specific ioremap internals */

  /*
   * Maximum alignment for ioremap() regions.
   * Can be overriden by arch-specific value.
   */
  #ifndef IOREMAP_MAX_ORDER
  #define IOREMAP_MAX_ORDER	(7 + PAGE_SHIFT)	/* 128 pages */
  #endif

  struct vm_struct {

  	struct vm_struct	*next;

  	void			*addr;
  	unsigned long		size;
  	unsigned long		flags;
  	struct page		**pages;
  	unsigned int		nr_pages;

  	phys_addr_t		phys_addr;

  	void			*caller;

  };
  
  /*
   *	Highlevel APIs for driver use
   */

  extern void vm_unmap_ram(const void *mem, unsigned int count);
  extern void *vm_map_ram(struct page **pages, unsigned int count,
  				int node, pgprot_t prot);
  extern void vm_unmap_aliases(void);
  
  #ifdef CONFIG_MMU
  extern void __init vmalloc_init(void);
  #else
  static inline void vmalloc_init(void)
  {
  }
  #endif

  extern void *vmalloc(unsigned long size);

  extern void *vmalloc_user(unsigned long size);

  extern void *vmalloc_node(unsigned long size, int node);

  extern void *vmalloc_exec(unsigned long size);
  extern void *vmalloc_32(unsigned long size);

  extern void *vmalloc_32_user(unsigned long size);

  extern void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot);

  extern void *__vmalloc_area(struct vm_struct *area, gfp_t gfp_mask,
  				pgprot_t prot);

  extern void vfree(const void *addr);

  
  extern void *vmap(struct page **pages, unsigned int count,
  			unsigned long flags, pgprot_t prot);

  extern void vunmap(const void *addr);

  
  extern int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
  							unsigned long pgoff);

  void vmalloc_sync_all(void);

   
  /*
   *	Lowlevel-APIs (not for driver use!)
   */

  
  static inline size_t get_vm_area_size(const struct vm_struct *area)
  {
  	/* return actual size without guard page */
  	return area->size - PAGE_SIZE;
  }

  extern struct vm_struct *get_vm_area(unsigned long size, unsigned long flags);

  extern struct vm_struct *get_vm_area_caller(unsigned long size,
  					unsigned long flags, void *caller);

  extern struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
  					unsigned long start, unsigned long end);

  extern struct vm_struct *__get_vm_area_caller(unsigned long size,
  					unsigned long flags,
  					unsigned long start, unsigned long end,
  					void *caller);

  extern struct vm_struct *get_vm_area_node(unsigned long size,

  					  unsigned long flags, int node,
  					  gfp_t gfp_mask);

  extern struct vm_struct *remove_vm_area(const void *addr);

  extern int map_vm_area(struct vm_struct *area, pgprot_t prot,
  			struct page ***pages);

  extern int map_kernel_range_noflush(unsigned long start, unsigned long size,
  				    pgprot_t prot, struct page **pages);
  extern void unmap_kernel_range_noflush(unsigned long addr, unsigned long size);

  extern void unmap_kernel_range(unsigned long addr, unsigned long size);

  /* Allocate/destroy a 'vmalloc' VM area. */
  extern struct vm_struct *alloc_vm_area(size_t size);
  extern void free_vm_area(struct vm_struct *area);

  /* for /dev/kmem */
  extern long vread(char *buf, char *addr, unsigned long count);
  extern long vwrite(char *buf, char *addr, unsigned long count);

  /*
   *	Internals.  Dont't use..
   */
  extern rwlock_t vmlist_lock;
  extern struct vm_struct *vmlist;

  extern __init void vm_area_register_early(struct vm_struct *vm, size_t align);

  struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
  				     const size_t *sizes, int nr_vms,
  				     size_t align, gfp_t gfp_mask);
  
  void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);

  #endif /* _LINUX_VMALLOC_H */