/* SPDX-License-Identifier: GPL-2.0 */

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

  #include <linux/init.h>

  #include <linux/list.h>

  #include <linux/llist.h>

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

  #include <linux/rbtree.h>

  #include <linux/overflow.h>

  #include <asm/vmalloc.h>

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

  struct notifier_block;		/* in notifier.h */

  /* 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_DMA_COHERENT		0x00000010	/* dma_alloc_coherent */

  #define VM_UNINITIALIZED	0x00000020	/* vm_struct is not fully initialized */

  #define VM_NO_GUARD		0x00000040      /* don't add guard page */

  #define VM_KASAN		0x00000080      /* has allocated kasan shadow memory */

  #define VM_MAP_PUT_PAGES	0x00000100	/* put pages and free array in vfree */

  
  /*
   * VM_KASAN is used slighly differently depending on CONFIG_KASAN_VMALLOC.
   *
   * If IS_ENABLED(CONFIG_KASAN_VMALLOC), VM_KASAN is set on a vm_struct after
   * shadow memory has been mapped. It's used to handle allocation errors so that
   * we don't try to poision shadow on free if it was never allocated.
   *
   * Otherwise, VM_KASAN is set for kasan_module_alloc() allocations and used to
   * determine which allocations need the module shadow freed.
   */

  /*
   * Memory with VM_FLUSH_RESET_PERMS cannot be freed in an interrupt or with
   * vfree_atomic().
   */
  #define VM_FLUSH_RESET_PERMS	0x00000100      /* Reset direct map and flush TLB on unmap */

  /* 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;

  	const void		*caller;

  };

  struct vmap_area {
  	unsigned long va_start;
  	unsigned long va_end;

  	struct rb_node rb_node;         /* address sorted rbtree */
  	struct list_head list;          /* address sorted list */

  
  	/*
  	 * The following three variables can be packed, because
  	 * a vmap_area object is always one of the three states:
  	 *    1) in "free" tree (root is vmap_area_root)
  	 *    2) in "busy" tree (root is free_vmap_area_root)
  	 *    3) in purge list  (head is vmap_purge_list)
  	 */
  	union {
  		unsigned long subtree_max_size; /* in "free" tree */
  		struct vm_struct *vm;           /* in "busy" tree */
  		struct llist_node purge_list;   /* in purge list */
  	};

  };

  /*
   *	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);

  extern void vm_unmap_aliases(void);
  
  #ifdef CONFIG_MMU
  extern void __init vmalloc_init(void);

  extern unsigned long vmalloc_nr_pages(void);

  #else
  static inline void vmalloc_init(void)
  {
  }

  static inline unsigned long vmalloc_nr_pages(void) { return 0; }

  #endif

  extern void *vmalloc(unsigned long size);

  extern void *vzalloc(unsigned long size);

  extern void *vmalloc_user(unsigned long size);

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

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

  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);

  extern void *__vmalloc_node_range(unsigned long size, unsigned long align,
  			unsigned long start, unsigned long end, gfp_t gfp_mask,

  			pgprot_t prot, unsigned long vm_flags, int node,
  			const void *caller);

  void *__vmalloc_node(unsigned long size, unsigned long align, gfp_t gfp_mask,
  		int node, const void *caller);

  extern void vfree(const void *addr);

  extern void vfree_atomic(const void *addr);

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

  void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot);

  extern void vunmap(const void *addr);

  extern int remap_vmalloc_range_partial(struct vm_area_struct *vma,
  				       unsigned long uaddr, void *kaddr,

  				       unsigned long pgoff, unsigned long size);

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

  /*

   * Architectures can set this mask to a combination of PGTBL_P?D_MODIFIED values
   * and let generic vmalloc and ioremap code know when arch_sync_kernel_mappings()
   * needs to be called.
   */
  #ifndef ARCH_PAGE_TABLE_SYNC_MASK
  #define ARCH_PAGE_TABLE_SYNC_MASK 0
  #endif
  
  /*
   * There is no default implementation for arch_sync_kernel_mappings(). It is
   * relied upon the compiler to optimize calls out if ARCH_PAGE_TABLE_SYNC_MASK
   * is 0.
   */
  void arch_sync_kernel_mappings(unsigned long start, unsigned long end);
  
  /*

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

  
  static inline size_t get_vm_area_size(const struct vm_struct *area)
  {

  	if (!(area->flags & VM_NO_GUARD))
  		/* return actual size without guard page */
  		return area->size - PAGE_SIZE;
  	else
  		return area->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, const void *caller);

  extern struct vm_struct *__get_vm_area_caller(unsigned long size,
  					unsigned long flags,
  					unsigned long start, unsigned long end,

  					const void *caller);

  void free_vm_area(struct vm_struct *area);

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

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

  #ifdef CONFIG_MMU

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

  int map_kernel_range(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);

  static inline void set_vm_flush_reset_perms(void *addr)
  {
  	struct vm_struct *vm = find_vm_area(addr);
  
  	if (vm)
  		vm->flags |= VM_FLUSH_RESET_PERMS;
  }

  #else
  static inline int
  map_kernel_range_noflush(unsigned long start, unsigned long size,
  			pgprot_t prot, struct page **pages)
  {
  	return size >> PAGE_SHIFT;
  }

  #define map_kernel_range map_kernel_range_noflush

  static inline void
  unmap_kernel_range_noflush(unsigned long addr, unsigned long size)
  {
  }

  #define unmap_kernel_range unmap_kernel_range_noflush

  static inline void set_vm_flush_reset_perms(void *addr)
  {
  }

  #endif

  /* 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 struct list_head vmap_area_list;

  extern __init void vm_area_add_early(struct vm_struct *vm);

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

  #ifdef CONFIG_SMP

  # ifdef CONFIG_MMU

  struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
  				     const size_t *sizes, int nr_vms,

  				     size_t align);

  
  void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms);

  # else
  static inline struct vm_struct **
  pcpu_get_vm_areas(const unsigned long *offsets,
  		const size_t *sizes, int nr_vms,
  		size_t align)
  {
  	return NULL;
  }
  
  static inline void
  pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
  {
  }
  # endif

  #endif

  #ifdef CONFIG_MMU
  #define VMALLOC_TOTAL (VMALLOC_END - VMALLOC_START)

  #else

  #define VMALLOC_TOTAL 0UL

  #endif

  int register_vmap_purge_notifier(struct notifier_block *nb);
  int unregister_vmap_purge_notifier(struct notifier_block *nb);

  #endif /* _LINUX_VMALLOC_H */